U.S. patent application number 17/451398 was filed with the patent office on 2022-04-21 for hand-held grinding machine and method for assembling a hand-held grinding machine.
The applicant listed for this patent is Robert Bosch GmbH. Invention is credited to Florian Esenwein.
Application Number | 20220118581 17/451398 |
Document ID | / |
Family ID | |
Filed Date | 2022-04-21 |
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United States Patent
Application |
20220118581 |
Kind Code |
A1 |
Esenwein; Florian |
April 21, 2022 |
Hand-Held Grinding Machine and Method for Assembling a Hand-Held
Grinding Machine
Abstract
A hand-held grinding machine includes a grinding device for
receiving or forming a grinding means, a drive device, a drive
housing, and an interface device operatively connecting the
grinding device to the drive device. The interface device includes
a connecting housing unit formed separately from the drive housing
and the grinding device for at least partially receiving the
grinding device, and a docking interface arranged on the drive
housing. The connecting housing unit engages around the docking
interface in a fixing plane which is perpendicular to an axis of
rotation of a drive shaft of the drive device. In the fixing plane,
the docking interface includes at least one axial form-fitting
element for forming a form fit with the connecting housing unit
parallel to the axis of rotation. A projection of the axial
form-fitting element along the axis of rotation is at least
substantially inside the drive housing.
Inventors: |
Esenwein; Florian;
(Leinfelden-Echterdingen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Robert Bosch GmbH |
Stuttgart |
|
DE |
|
|
Appl. No.: |
17/451398 |
Filed: |
October 19, 2021 |
International
Class: |
B24B 23/02 20060101
B24B023/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2020 |
DE |
10 2020 213 228.3 |
Claims
1. A hand-held grinding machine comprising: at least one grinding
device configured to receive or form a grinding apparatus; a drive
device configured to drive the grinding device; a drive housing,
which receives the drive device; and an interface device configured
to operatively connect the grinding device to the drive device, the
interface device comprising: at least one connecting housing unit
formed separately from the drive housing and the grinding device,
the at least one connecting housing configured to at least
partially receive the grinding device; and a docking interface
arranged on the drive housing, wherein the connecting housing unit
engages around the docking interface in a fixing plane which is
perpendicular to an axis of rotation of a drive shaft of the drive
device, wherein, in the fixing plane, the docking interface
comprises at least one axial form-fitting element for forming a
form fit with the connecting housing unit parallel to the axis of
rotation, and wherein a projection of the at least one axial
form-fitting element along the axis of rotation is at least
substantially completely inside the drive housing.
2. The hand-held grinding machine according to claim 1, wherein the
axial form-fitting element includes a fixing recess defined in the
docking interface.
3. The hand-held grinding machine according to claim 1, wherein the
connecting housing unit has at least two main shells, at least one
of which comprises a fixing element formed as a sleeve, which is
configured to receive a separately formed fixing element.
4. The hand-held grinding machine according to claim 1, wherein the
at least one axial form-fitting element includes a docking cross
section of the docking interface perpendicular to the axis of
rotation that tapers along the axis of rotation in a direction away
from the grinding device.
5. The hand-held grinding machine according to claim 1, wherein the
at least one axial form-fitting element includes an oblique and/or
curved contact surface of the docking interface that runs
transversely to the fixing plane and has a form which is
complementary to a mating surface of the connecting housing
unit.
6. The hand-held grinding machine according to claim 5, wherein the
oblique and/or curved contact surface has a radius of curvature of
between 5 mm and 15 mm.
7. The hand-held grinding machine according to claim 1, wherein the
docking interface comprises at least 10% to 20% of an overall
height of the drive housing including the docking interface
measured parallel to the axis of rotation.
8. The hand-held grinding machine according to claim 1, wherein the
docking interface engages around a bearing element of the drive
device in the fixing plane.
9. The hand-held grinding machine according to claim 1, wherein the
at least one axial form-fitting element includes a boundary portion
of the docking interface at the drive housing that is at least
substantially perpendicular to the axis of rotation, the boundary
portion having a smaller cross section than the drive housing such
that the connecting housing unit is arrangeable at least
substantially flush with the drive housing on the docking
interface.
10. The hand-held grinding machine according to claim 1, wherein
the connecting housing unit has at least two main shells, which are
aligned against one another in the fixing plane via at least one
tongue and groove connection.
11. The hand-held grinding machine according to claim 1, wherein:
the drive device includes a drive fan, the grinding device includes
a fan, and the drive fan and the fan are arranged along the axis of
rotation on different sides of the axial form-fitting element.
12. A method for assembling a hand-held grinding comprising:
arranging a drive device, which is configured to drive a grinding
device that is configured to receive or form a grinding apparatus,
in a drive housing of the hand-held grinding machine; at least
partially arranging the grinding device in at least one connecting
housing unit, which is formed separately from the drive housing and
the grinding device, of an interface device that is configured to
operatively connect the grinding device to the drive device;
arranging the at least one connecting housing unit so as to engage
around a docking interface of the interface device, which is
arranged on the drive housing, in a fixing plane that is
perpendicular to an axis of rotation of a drive shaft of the drive
device forming a form fit parallel to the axis of rotation between
the connecting housing unit and the docking interface via an axial
form-fitting element, which is arranged in the fixing plane, of the
docking interface, wherein a projection of the at least one axial
form-fitting element along the axis of rotation is at least
substantially completely inside the drive housing.
13. The hand-held grinding machine according to claim 1, wherein
the at least one axial form-fitting element is configured as a
fixing recess and/or an oblique or concave surface.
14. The hand-held grinding machine according to claim 2, wherein
the fixing recess extends at least substantially parallel to the
fixing plane and is configured to receive a fixing element of the
connecting housing unit and/or a separately formed fixing
element.
15. The hand-held grinding machine according to claim 3, wherein an
overall receiving length of the sleeve corresponds essentially to a
length of the separately formed fixing element.
16. The hand-held grinding machine according to claim 8, wherein
the bearing element is configured to rotatably mount a gear
mechanism element of the interface device and/or the drive
shaft.
17. The hand-held grinding machine according to claim 10, wherein
the tongue and groove connection is curved.
18. The method according to claim 12, wherein the at least one
axial form-fitting element is configured as a fixing recess and/or
an oblique or concave surface.
Description
[0001] This application claims priority under 35 U.S.C. .sctn. 119
to application no. DE 10 2020 213 228.3, filed on Oct. 20, 2020 in
Germany, the disclosure of which is incorporated herein by
reference in its entirety.
BACKGROUND
[0002] U.S. Pat. No. 4,624,078 has already proposed a hand-held
grinding machine having at least one grinding device for receiving
or forming a grinding means, having a drive device for driving the
grinding device, having a drive housing, which receives the drive
device, and having an interface device for operatively connecting
the grinding device to the drive device, wherein the interface
device comprises at least one connecting housing unit, which is
formed separately from the drive housing and the grinding device,
for at least partially receiving the grinding device, and a docking
interface arranged on the drive housing, wherein the connecting
housing unit engages around the docking interface in a fixing plane
which is perpendicular to an axis of rotation of a drive shaft of
the drive device.
SUMMARY
[0003] The disclosure proceeds from a hand-held grinding machine
having at least one grinding device for receiving or forming a
grinding means, having a drive device for driving the grinding
device, having a drive housing, which receives the drive device,
and having an interface device for operatively connecting the
grinding device to the drive device, wherein the interface device
comprises at least one connecting housing unit, which is formed
separately from the drive housing and the grinding device, for at
least partially receiving the grinding device, and a docking
interface arranged on the drive housing, wherein the connecting
housing unit engages around the docking interface in a fixing plane
which is perpendicular to an axis of rotation of a drive shaft of
the drive device.
[0004] It is proposed that the docking interface in the fixing
plane comprises at least one axial form-fitting element, which is
in particular in the form of a fixing recess and/or oblique or
concave surface, for forming a form fit with the connecting housing
unit parallel to the axis of rotation, wherein a projection of the
axial form-fitting element along the axis of rotation is at least
substantially completely inside the drive housing. The hand-held
grinding machine can preferably be held by a hand, in particular
without a transporting and/or holding device, and can be guided and
operated in particular with the same hand during a grinding
operation. The hand-held grinding machine may be in the form of an
eccentric grinder, a forcibly driven eccentric grinder, an
oscillating grinder, a triangular grinder, a polisher, or the like.
The grinding means may be in the form for example of abrasive
paper, a grinding sponge pad, a non-open grinding fabric, a
grinding cloth, a polishing sponge pad, a scrubbing wheel, a
buffing wheel, or the like. In particular, the grinding device
comprises at least one grinding pad having a planar basic area,
which is in particular at least substantially parallel to the
fixing plane and is provided for fastening the grinding means.
"Provided" is to be understood to mean in particular specially
configured, specially programmed, specially designed and/or
specially equipped. An object being provided for a particular
function should be understood in particular to mean that the object
fulfils and/or carries out this particular function in at least one
use state and/or operating state. "Substantially parallel" should
be understood here in particular to mean an alignment of a
direction relative to a reference direction, in particular in a
plane, wherein the direction deviates in particular by less than
8.degree., advantageously less than 5.degree. and especially
advantageously less than 2.degree. from the reference
direction.
[0005] The drive device preferably comprises an electric motor, in
particular a brushless DC motor, for driving the drive shaft, in
particular about the axis of rotation common to the electric motor
and the drive shaft. The drive device comprises in particular
control electronics for the open-loop or closed-loop control of the
electric motor. The drive device preferably comprises at least one
electrical power supply interface for supplying energy to the
electric motor. The electrical power supply interface is
particularly preferably designed for receiving a battery which can
be detached nondestructively from the drive device and/or a
rechargeable battery, in particular a rechargeable battery pack,
which can be detached nondestructively. As an alternative or in
addition, the electrical power supply interface comprises a
line-bound, inductive or capacitive charging element for supplying
power to an internal energy store of the drive device.
[0006] The drive housing preferably comprises a longitudinal axis,
which runs at least substantially perpendicular to the axis of
rotation. A maximum longitudinal extent of the drive housing
parallel to, in particular along, the longitudinal axis is
preferably greater than an overall height of the drive housing
parallel to, in particular along, the axis of rotation. Along the
longitudinal axis, the drive housing comprises in particular a
longitudinal-axis portion, in which the electrical power supply
interface is arranged, and a front portion, in which the drive
shaft is arranged. The docking interface is arranged in particular
at the front portion along the axis of rotation. A maximum extent
of a cross section of the longitudinal-axis portion perpendicular
to the longitudinal axis is preferably smaller than the overall
height of the drive housing, in particular such that the
longitudinal-axis portion, the front portion and the docking
interface form an L-shaped structure in an assembly plane. The
assembly plane is spanned in particular by the longitudinal axis
and by the axis of rotation.
[0007] The interface device is preferably provided to make
available a standardized connection for the drive device and the
grinding device, with the result that the drive device and the
grinding device can be configured and/or pre-assembled in
particular independently of one another. For example, a
constructionally identical or analogous interface device in a
further hand-held power tool connects a grinding device which is
constructionally identical to that of the hand-held power tool to a
drive device of a different power class to that of the hand-held
power tool. For example, a constructionally identical or analogous
interface device of an alternative hand-held power tool connects a
different grinding device to that of the hand-held power tool to a
drive device which is constructionally identical to that of the
hand-held power tool. In particular, application-dependent gear
mechanism elements for predefining a path of the grinding pad
and/or application-dependent fastening elements for fastening the
grinding pad relative to the drive housing are formed as part of
the grinding device or the interface device.
[0008] In particular, the connecting housing unit is dependent on a
configuration of the grinding device. The docking interface is
preferably independent of a configuration of the grinding device
and independent of a power class of the drive device. The docking
interface is preferably formed in one piece with the drive housing.
"In one piece" should in particular be understood as meaning shaped
in one piece. This one piece is preferably produced from a single
blank, a mass and/or a casting, particularly preferably in a
pressing process, a die-casting process or an injection-molding
process, in particular a single-component and/or multi-component
injection-molding process. As an alternative, the docking interface
is formed separately from the drive housing and is fastened to the
drive housing. The docking interface preferably engages around the
drive shaft in the fixing plane. The fixing plane preferably
intersects the drive shaft. As an alternative, the drive shaft is
set back along the axis of rotation relative to the docking
interface, and therefore the fixing plane does not intersect the
drive shaft. "For operatively connecting" should be understood in
particular to mean for connecting in a manner that allows a
transfer of mechanical work, for example by means of a coupling, by
means of an eccentric gear mechanism, by means of a screw gear
mechanism, by means of a toothed gear mechanism, and/or by means of
another gear mechanism element. The interface device preferably
comprises at least one gear mechanism element for indirectly or
directly transferring a movement of the drive shaft to the grinding
pad. The gear mechanism element of the interface device is
preferably pressed on the drive shaft and/or latched in place on
the drive shaft. As an alternative, the gear mechanism element of
the interface device is formed in one piece with the drive shaft.
The grinding device is preferably formed separately from the gear
mechanism element and fastened to, in particular screwed on,
pressed on and/or latched in place on, the gear mechanism element.
As an alternative, the gear mechanism element of the interface
device is formed in one piece with a gear mechanism element of the
grinding device.
[0009] The connecting housing unit is provided in particular to
enclose an intermediate space between the docking interface and the
grinding pad, with a gear mechanism of the grinding device, a fan
of the grinding device, or the like, for example, being arranged in
said intermediate space. In particular, the connecting housing unit
on a side facing the grinding pad has a groove for fastening a slip
ring of the grinding device. The connecting housing unit is
arranged on the docking interface by means of the axial
form-fitting element in an immovable manner relative to the drive
housing, in particular apart from a material elasticity of the
connecting housing unit, the docking interface and/or the drive
housing. The docking interface and the axial form-fitting element
are provided in particular for a form-fitting and optionally
force-fitting connection of the connecting housing unit to the
drive housing. The connecting housing unit particularly preferably
comprises at least two main shells, which are arranged against one
another, in particular in the assembly plane. In particular, the
main shells each engage partially around the docking interface in
the fixing plane, in particular each around half of the docking
interface in the fixing plane, from different sides of the docking
interface. The main shells are preferably in the form of
half-shells to be assembled. In particular, the connecting housing
unit is arranged directly on the docking interface, in particular
on an outer side, facing away from the axis of rotation, of the
docking interface. The main shells preferably encapsulate the
docking interface. It is preferably the case that at least a volume
fraction of more than 50%, in particular more than 75%,
particularly preferably more than 95%, of the docking interface is
inside the connecting housing unit. In particular, the connecting
housing unit is arranged in the fixing plane at an angular range
with respect to the axis of rotation of more than 180.degree.,
preferably more than 270.degree., particularly preferably by more
than 355.degree., around the docking interface. The connecting
housing unit optionally comprises further housing elements, which
are formed separately from the main shells. The main shells are
preferably fastened by means of the axial form-fitting element to
the docking interface and optionally to one another. The axial
form-fitting element particularly preferably encloses a partial
region of the connecting housing unit parallel to the axis of
rotation inside a basic body of the docking interface and/or clamps
in a partial region of the connecting housing unit between the
docking interface and the drive housing. As an alternative, the
docking interface comprises a structural element, which projects
into a wall of the connecting housing unit.
[0010] The docking interface preferably comprises at least two, in
particular two differently formed, axial form-fitting elements. The
docking interface preferably has at least one pair of identically
formed axial form-fitting elements, which are arranged in
particular on different sides of a plane which encompasses the axis
of rotation and is in particular perpendicular to the assembly
plane. The entire docking interface is particularly preferably
formed as mirror-symmetrical with respect to the plane which is
perpendicular to the assembly plane and encompasses the axis of
rotation. In particular, the assembly plane intersects the axial
form-fitting element, in particular each of the axial form-fitting
elements. The projections of all the axial form-fitting elements of
the docking interface along the axis of rotation are particularly
preferably at least substantially completely inside the drive
housing. In particular, a projection of the entire docking
interface along the axis of rotation is at least substantially
completely inside the drive housing. "Substantially completely"
should be understood to mean in particular at least up to 60%,
preferably at least up to 80%, particularly preferably at least up
to 95%, with respect to a maximum extent and/or a maximum surface
area of the projection. An outer contour of the axial form-fitting
element, in particular of the entire docking interface, in a
projection along the axis of rotation is particularly preferably
spaced apart, to a minimum extent inside the drive housing, from an
outer contour of the drive housing by at least 3%, preferably more
than 5%, with respect to a maximum extent of the projection.
[0011] The configuration according to the disclosure makes it
possible to produce an advantageously secure connection between the
drive housing and the connecting housing unit. In particular, a
relative movement of the drive housing and the connecting housing
unit can advantageously be kept small. In particular, the
connecting housing unit is advantageously connected to the drive
housing unit in an stable manner even when absorbing a force and/or
a torque, for example caused by a hand or by additional components,
for example a material collection container, arranged on the
connecting housing unit. A transition between the drive housing and
the connecting housing can also advantageously have a narrow
configuration, with the result that a hand placed on the connecting
housing unit can advantageously encompass the transition in a
comfortable manner. In particular, an advantageously high operating
comfort can be achieved.
[0012] It is also proposed that the docking interface, as axial
form-fitting element, has a fixing recess, in particular a fixing
recess which extends at least substantially parallel to the fixing
plane and in particular a fixing recess which is provided to
receive a fixing element of the connecting housing unit and/or a
separately formed fixing element. The fixing element of the
connecting housing unit is preferably integrally formed with one of
the main shells and is in the form in particular of a structural
element projecting from a contact surface of these main shells, for
example a pin, a web, a latching tongue, or the like. The
separately formed fixing element is in the form of a screw, a
rivet, a threaded rod, a bar, or the like, for example. The docking
interface preferably comprises the basic body, which in particular
is solid. The fixing recess preferably extends in a direction at
least substantially perpendicular to the axis of rotation, in
particular to the assembly plane, into the basic body of the
docking interface and particularly preferably through the basic
body of the docking interface. As an alternative, the fixing recess
is in the form of a blind hole, a groove, or the like. The
expression "substantially perpendicular" should define here in
particular an alignment of a direction relative to a reference
direction, wherein the direction and the reference direction, in
particular as viewed in a projection plane, forms an angle of
90.degree. and the angle has a maximum deviation of in particular
less than 8.degree., advantageously less than 5.degree. and
especially advantageously less than 2.degree.. The basic body
preferably completely engages around the fixing recess in the
assembly plane. As an alternative, the basic body engages around
the fixing recess in the assembly plane for example in a U-shape
and forms in particular an assembly slot, which leads to the fixing
recess and runs in particular in the fixing plane. The docking
interface preferably comprises at least two fixing recesses, which
are in particular constructionally identical and are arranged in
the assembly plane on different sides of the axis of rotation. The
configuration according to the disclosure advantageously makes it
possible to easily obtain a form fit in both directions along the
axis of rotation. In particular, the drive housing and the
connecting housing unit are advantageously fixedly connected to one
another. In particular, a number of fixing elements for fixing the
connecting housing unit to an outer side of the connecting housing
unit can advantageously be kept small. In particular, the
connecting housing unit makes it possible to provide an
advantageously large surface on which to place a hand.
[0013] It is also proposed that the connecting housing unit has at
least two main shells, in particular those already mentioned, at
least one of which comprises a fixing element in the form of a
sleeve, in particular a fixing element in the form of a sleeve
which is formed for receiving a separately formed fixing element,
wherein an overall receiving length of the sleeve corresponds
essentially to a length of the separately formed fixing element.
The sleeve is preferably materially bonded to at least one of the
main shells. The sleeve particularly preferably comprises two
separately formed sleeve portions, one of which being arranged on
one of the main shells in each case. In particular, the pair of
sleeve portions is aligned one against the other along a fixing
axis, with the result that the separate fixing element engages
through both sleeve portions at the same time along the fixing
axis. The sleeve is preferably arranged in the fixing recess of the
docking interface. As an alternative, the sleeve is arranged
outside the docking interface. That a parameter "corresponds
substantially to a comparative parameter" should be understood in
particular to mean that the parameter is equal to the comparative
parameter by more than 25%, preferably more than 50%, particularly
preferably more than 75%. The overall receiving length of the
sleeve for receiving the fixing element is preferably shorter than
the length of the fixing element. The sleeve portions are
particularly preferably arranged spaced apart from one another
along the fixing axis. In particular, one of the sleeve portions
forms a blind hole, while the other sleeve portion is tubular. As
an alternative, both sleeve portions are tubular. It is optionally
the case that at least one of the sleeve portions forms a thread
and/or a latching recess and/or comprises a recessed nut or another
counterpiece to the separately formed fixing element. As an
alternative, a counterpiece to the separately formed fixing element
is arranged on an outer side of the docking interface. The
configuration according to the disclosure with main shells
advantageously makes it possible to easily assemble the connecting
housing unit. In particular, the main shells can advantageously be
clamped on the docking interface in addition to an axial form fit,
with the result that an additional form and/or force fit at least
substantially parallel to the axis of rotation can be obtained. A
delimitation of the overall receiving length also makes it possible
to obtain a fastening of the main shells to one another under
tension, such that an advantageously tight contact of the main
shells with the docking interface, an advantageously intense force
fit of the main shells to the docking interface, and an
advantageously small clearance of the main shells relative to the
docking interface can be obtained.
[0014] It is furthermore proposed that the docking interface, as
axial form-fitting element, has a docking cross section, which
tapers along the axis of rotation in a direction away from the
grinding device perpendicular to the axis of rotation. The docking
cross section preferably tapers continuously in the direction of
the axis of rotation over a portion which corresponds at least
substantially to a docking height of the docking interface and
comprises in particular more than 80% of the docking height of the
docking interface. In particular, the docking cross section has the
smallest extent parallel to the fixing plane on a side facing the
drive housing. In particular, the docking cross section has the
largest extent parallel to the fixing plane on a side facing away
from the drive housing. In particular, the axial form-fitting
element is in the form of the contact face, facing the drive
housing and in particular facing away from the axis of rotation, of
the docking interface. The contact surface preferably has an
annular form, wherein a geometric central axis of the contact
surface is aligned in particular coaxially with the axis of
rotation. In particular, an inner wall of the housing connecting
unit is arranged on the contact surface of the docking interface. A
leadthrough in the housing connecting unit for receiving the drive
shaft and/or the gear mechanism element of the interface device
particularly preferably has a maximum opening width parallel to the
fixing plane that is smaller than the maximum extent of the docking
interface parallel to the fixing plane. In particular, the housing
connecting unit is arranged between the drive housing and the
docking interface, in particular the contact surface, on an axis
parallel to the axis of rotation. A maximum extent of the docking
cross section, in particular a largest external diameter of the
docking interface, is preferably at least 10%, preferably more than
25%, particularly preferably more than 33% larger than a minimum
extent, in particular a smallest external diameter, of the docking
cross section parallel to the fixing plane. A smallest imaginary
trapezium, which specifically completely surrounds the docking
cross section of the docking interface, preferably has an acute
inner angle between the base and the leg which is between
20.degree. and 70.degree., preferably between 40.degree. and
50.degree.. The configuration according to the disclosure makes it
possible to obtain an advantageously large contact surface on the
docking interface for the connecting housing unit, which contact
surface can be utilized as a clamping surface in particular in
interaction with the fixing element when the connecting housing
unit is being assembled. In particular, an advantageously large
overlap between the connecting housing unit and the docking
interface can be obtained.
[0015] It is additionally proposed that the docking interface, as
axial form-fitting element, has an oblique and/or curved contact
surface which runs transversely to the fixing plane, in particular
that contact surface already mentioned, and has a form which is
complementary to an in particular oblique and/or curved mating
surface of the connecting housing unit. In particular, the contact
surface, and in particular also the mating surface, intersects the
fixing plane at an acute angle, in particular between 10.degree.
and 80.degree., preferably between 20.degree. and 70.degree.. When
it has a curved configuration, the contact surface preferably has a
concave form with respect to the axis of rotation. In particular, a
radius of curvature which describes the concave contact surface
runs outside the docking interface. As an alternative, the contact
surface has a convex form with respect to the axis of rotation. In
particular, a radius of curvature which describes the convex
contact surface intersects the docking interface. In particular,
the contact surface has at least one contact-surface portion which
is formed in an arcuate manner in a plane, in particular any plane,
containing the axis of rotation. At least one tangential plane of
the contact surface preferably has an angle of less than
20.degree., preferably less than 15.degree., to the axis of
rotation, wherein this tangential plane optionally has an angle of
more than 5.degree., in particular more than 10.degree., to the
axis of rotation. In particular, at least one further tangential
plane of the contact surface has an angle of more than 90.degree.,
preferably more than 100.degree., particularly preferably more than
105%, to the axis of rotation, wherein this tangential plane
optionally has an angle of less than 150.degree., in particular
less than 125.degree., to the axis of rotation. In particular, a
center-point angle of at least 35.degree., preferably at least
45.degree., in particular more than 55.degree., about a curvature
center point which is part of the radius of curvature corresponds
to an extent of the arcuate contact-surface portion. The contact
surface in the direction of the grinding device preferably
terminates with a planar contact portion, which is arranged
tangentially to the curved contact portion of the contact surface.
An arcuate extent of the contact surface is preferably longer, in
particular at least twice as long, preferably more than three times
as long, as the tangential continuation thereof in the planar
contact portion. The configuration according to the disclosure
advantageously makes it possible for the connecting housing unit to
have a compact form. In particular, an advantageously large spacing
of the connecting housing unit from the longitudinal-axis portion
of the drive housing can be obtained, in particular such that it is
possible to encompass the longitudinal-axis portion with a hand
advantageously close to the axis of rotation. It is also
advantageously possible for a hand placed on the connecting housing
unit to advantageously also be placed between the longitudinal-axis
portion and the connecting housing unit. In particular, an
advantageously large number of grip positions is provided by the
connecting housing unit.
[0016] It is additionally proposed that the radius of curvature
amounts to between 5 mm and 15 mm. The radius of curvature is
preferably greater than 7 mm, particularly preferably greater than
9 mm. The radius of curvature is preferably less than 12 mm,
particularly preferably less than 10 mm. A ratio of the radius of
curvature to the docking height of the docking interface parallel
to the axis of rotation is preferably greater than 0.5, preferably
greater than 0.7, and particularly preferably greater than 0.8. It
is preferable for the ratio of the radius of curvature to the
docking height of the docking interface parallel to the axis of
rotation to be less than 1.5, preferably less than 1.2,
particularly preferably less than 0.9. The configuration according
to the disclosure makes it possible to advantageously configure the
contact surface as compact and having a large surface area at the
same time.
[0017] It is also proposed that the docking interface, in
particular the contact surface, comprises at least 10% to 20%, in
particular between 13% and 17%, of an overall height of the drive
housing including the docking interface parallel to the axis of
rotation. In an alternative configuration, the docking interface,
in particular the contact surface, comprises between 5% and 10% or
between 20% and 40% of an overall height of the drive housing
including the docking interface parallel to the axis of rotation.
The configuration according to the disclosure makes it possible to
produce an advantageously stable connection between the drive
housing and the connecting housing unit.
[0018] It is also proposed that the docking interface in the fixing
plane engages around a bearing element of the drive device, in
particular a bearing element of the drive device which is set up to
rotatably mount a gear mechanism element, in particular the gear
mechanism element already mentioned, of the interface device and/or
the drive shaft. The bearing element is preferably in the form of a
ball bearing, alternatively a sliding bearing. The bearing element
is preferably arranged in the fixing plane between the fixing
recesses of the docking interface. In particular, the fixing plane
intersects the connecting housing unit and the bearing element. The
gear mechanism element particularly preferably engages around the
drive shaft in the fixing plane. The gear mechanism element
optionally encompasses, on a side facing the electric motor, a
larger cross section perpendicular to the axis of rotation than in
the fixing plane, in particular a larger cross section than an
opening width of the bearing element, for receiving the bearing
element. The docking interface preferably has a groove, in which
the bearing element is inserted or recessed. As an alternative, the
drive shaft is in direct contact with the bearing element and in
particular protrudes beyond the bearing element in the direction of
the grinding device. The configuration according to the disclosure
advantageously makes it possible for an overall height of the drive
housing, in particular of the entire hand-held grinding machine, to
be kept small. In particular, a fixed point on the axis of rotation
can advantageously be established relative to the drive housing and
relative to the connecting housing unit at the same time.
[0019] It is also proposed that the docking interface at a
boundary, which is at least substantially perpendicular to the axis
of rotation, to the drive housing, as axial form-fitting element,
has a smaller cross section than the drive housing, and therefore
the connecting housing unit can be arranged at least substantially
flush with the drive housing on the docking interface.
"Substantially flush" should be understood in particular to mean
with an offset of less than 1 mm, preferably less than 0.75 mm,
particularly preferably less than 0.5 mm. The drive housing
together with the docking interface preferably forms an offset at
the boundary. In particular, the drive housing at the boundary has
a base surface, which is at least substantially parallel to the
fixing plane and protrudes perpendicularly to the axis of rotation
beyond the docking interface at the boundary in a manner
corresponding to a material thickness of the housing connecting
unit. In particular, the housing connecting unit is arranged on the
offset and in particular continues a contour of the drive housing
without any offset. The configuration according to the disclosure
advantageously makes it possible to obtain a form fit counter to a
direction established by the contact surface. In particular, an
axial position of the connecting housing unit relative to the drive
housing along the axis of rotation can be established with an
advantageously low error tolerance. In particular, the risk of a
compensating movement of the connecting housing unit in the
direction of the drive housing, for example when the fixing element
is being fastened and/or when the hand-held grinding machine is
being pressed against a workpiece, can advantageously be kept
low.
[0020] It is also proposed that the connecting housing unit has at
least two main shells, in particular those already mentioned, which
are aligned one against the other by means of at least one tongue
and groove connection, which is in particular oblique or curved, in
the fixing plane. In particular, one of the main shells has at
least one groove and the other main shell has at least one tongue
in the fixing plane, which groove and tongue are arranged one
against the other in the assembly plane. The main shells preferably
have at least one respective tongue and groove connection in the
fixing plane on different sides of the axis of rotation. In
particular, the tongue and groove connection is arranged in a
curved contact portion of the main shells. The curved contact
portion of the main shells forms in particular the mating surface
which complements the contact surface. The contact portion
preferably has an outer surface which is curved and faces away from
the mating surface. A radius of external curvature is formed as
smaller than the radius of curvature of the contact surface and is
arranged in particular outside the main shell. In particular, the
main shells comprise a tangential portion which has a planar form
and continues the curved contact portion tangentially beyond the
docking interface. The tongue and groove connection is preferably
arranged in a transition region between the tangential portion and
the contact portion of the main shells. It is preferable that a
ratio of a transverse extent of the tongue and groove connection
parallel to a material thickness of the main shells to the material
thickness of the main shells is greater than 0.15, preferably
greater than 0.2, and in particular greater than 0.25. The
transverse extent of the tongue and groove connection is preferably
between 0.5 mm and 1.5 mm, particularly preferably between 0.75 mm
and 1 mm. Optionally, the connecting housing unit between the main
shells comprises an elastic sealing element. The tongue and groove
connection is preferably formed as convex, alternatively concave,
with respect to the axis of rotation. In particular, a connecting
surface of the tongue and groove connection runs at least
substantially parallel to the mating surface of the connecting
housing unit. The configuration according to the disclosure
advantageously makes it possible to obtain an additional, mutual
form fit parallel to the axis of rotation and also a frictional
engagement in the fixing plane of the main shells. In particular,
the main shells can advantageously be arranged against one another
in a simple and precise manner. In particular, the main shells, in
particular by contrast with a stepped rebate, can advantageously be
arranged against one another under tension by means of the fixing
element.
[0021] It is furthermore proposed that a drive fan of the drive
device and a fan of the grinding device are arranged along the axis
of rotation on different sides of the axial form-fitting element.
In particular, the drive fan is in the form of a motor fan. The
drive fan is in particular provided to cool the electric motor. In
particular, the fan is arranged inside the connecting housing unit.
The drive fan is preferably arranged in the drive housing. The
docking interface is preferably arranged between the drive fan and
the fan. The docking interface preferably delimits a receiving
space in the drive housing for the drive fan. The docking interface
preferably delimits a fan receiving region of the connecting
housing unit for the fan. In particular, the drive fan and the fan
are arranged at ends, facing away from one another, of the gear
mechanism element of the interface device. In particular, the gear
mechanism element projects into the receiving space for the drive
fan and into the fan receiving region for the fan. The gear
mechanism element of the interface device is provided in particular
to drive the fan. The gear mechanism element of the interface
device is in particular provided to support an axial position of
the drive fan along the drive shaft. The configuration according to
the disclosure advantageously makes it possible to design the
docking interface and in particular the drive device independently
of the specific grinding device. In particular, the docking
interface can be designed independently of a dimensioning of the
grinding device, in particular the fan. In particular, the docking
interface may be utilized in addition to an aerodynamic separation
of the drive fan and the fan, with the result that the hand-held
grinding machine can advantageously be configured as compact.
[0022] The disclosure additionally proceeds from a method for
assembling a hand-held grinding machine having at least one
grinding device for receiving or forming a grinding means, having a
drive device for driving the grinding device, which drive device in
at least one method step is arranged in a drive housing of the
hand-held grinding machine, and having an interface device for
operatively connecting the grinding device to the drive device,
wherein the interface device comprises at least one connecting
housing unit, which is formed separately from the drive housing and
the grinding device and in which in at least one method step the
grinding device is at least partially arranged, and a docking
interface arranged on the drive housing, wherein in at least one
method step the connecting housing unit is arranged so as to engage
around the docking interface in a fixing plane which is
perpendicular to an axis of rotation of a drive shaft of the drive
device. It is proposed that in at least one method step, in which a
form fit, parallel to the axis of rotation, of the connecting
housing unit to the docking interface is formed by means of an
axial form-fitting element of the docking interface that is
arranged in the fixing plane and in the form in particular of a
fixing recess and/or oblique or concave surface, wherein a
projection of the axial form-fitting element along the axis of
rotation is at least substantially completely inside the drive
housing. In at least one method step, the gear mechanism element of
the interface unit is preferably pressed onto the drive shaft of
the drive device, which in particular is pre-assembled. In at least
one method step, the grinding device, which in particular is
pre-assembled, is preferably fastened, in particular screwed, to
the gear mechanism element. In at least one method step, one of the
main shells is preferably arranged on the docking interface. In
particular, the mating surface is arranged on the contact surface.
In particular, the sleeve portion of the main shell is inserted
into the fixing recess of the docking interface. In at least one
method step, a further one of the main shells is preferably
arranged on the docking interface, in particular the main shells
are arranged against one another in the assembly plane and in
particular aligned against one another by means of the tongue and
groove connection. The mating surface of the further one of the
main shells is in particular arranged on the contact surface.
[0023] The sleeve portion of the further one of the main shells is
inserted into the fixing recess. In particular, in at least one
method step the separately formed fixing element is plugged,
pressed or screwed through one of the main shells, the sleeve and
the docking interface into a further one of the main shells. The
configuration according to the disclosure makes it possible to
advantageously produce the hand-held grinding machine in a modular
manner and to advantageously assemble it in a simple manner. In
particular, it is possible to achieve a high degree of flexibility
in terms of a combination of a drive device, which is in particular
standardized, and one of a variety of grinding devices. In
particular, an advantageously high stability of the hand-held
grinding machine can be achieved despite a modular structure.
[0024] The grinding machine according to the disclosure and/or the
method according to the disclosure are not intended to be limited
to the above-described application and embodiment in this respect.
In particular, the grinding machine according to the disclosure
and/or the method according to the disclosure may have a number of
individual elements, components and units and of method steps which
differs from the number thereof stated herein for the purpose of
satisfying a mode of operation described herein. Moreover, for the
value ranges specified in this disclosure, values that also lie
within the stated limits should also be considered to be disclosed
and usable in any desired way.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Further advantages will become apparent from the following
description of the drawing. Four exemplary embodiments of the
disclosure are illustrated in the drawings. The drawings, the
description and the claims contain numerous features in
combination. A person skilled in the art will expediently also
consider the features individually and combine them to form useful
further combinations.
[0026] In the figures:
[0027] FIG. 1 shows a schematic perspective illustration of a
hand-held grinding machine according to the disclosure,
[0028] FIG. 2 shows a schematic plan view of the hand-held grinding
machine according to the disclosure,
[0029] FIG. 3 shows a schematic longitudinal section of the
hand-held grinding machine according to the disclosure,
[0030] FIG. 4 shows a schematic cross section of the hand-held
grinding machine according to the disclosure,
[0031] FIG. 5 shows a schematic illustration of a fastening of a
connecting housing unit of the hand-held grinding machine according
to the disclosure,
[0032] FIG. 6 shows a schematic cross section of the connecting
housing unit,
[0033] FIG. 7 shows a schematic longitudinal section of a material
collection device of the hand-held grinding machine according to
the disclosure,
[0034] FIG. 8 shows a schematic flow diagram of a method according
to the disclosure for assembling the hand-held grinding machine
according to the disclosure,
[0035] FIG. 9 shows a schematic illustration of an alternative
configuration of a hand-held grinding machine according to the
disclosure with an alternative drive device,
[0036] FIG. 10 shows a schematic longitudinal section of the
alternative configuration,
[0037] FIG. 11 shows a schematic illustration of a further
alternative configuration of a hand-held grinding machine according
to the disclosure with an alternative grinding device,
[0038] FIG. 12 shows a schematic longitudinal section of the
further alternative configuration,
[0039] FIG. 13 shows a schematic illustration of a further
alternative configuration of a hand-held grinding machine according
to the disclosure with a further alternative grinding device,
and
[0040] FIG. 14 shows a schematic longitudinal section of the
additional alternative configuration.
DETAILED DESCRIPTION
[0041] FIG. 1 shows a hand-held power tool 118a in the form of a
hand-held grinding machine 10a. The hand-held grinding machine 10a
is in the form in particular of an eccentric grinder. The hand-held
grinding machine 10a comprises a grinding device 12a for receiving
a grinding means 13a. The grinding device 12a comprises in
particular a grinding pad 132a, which is illustrated here by way of
example with a diameter of 125 mm. As an alternative, the grinding
pad 132a has a diameter of 150 mm or another diameter which is
adapted to a size of the grinding means 13a. The hand-held grinding
machine 10a comprises a drive device 14a for driving the grinding
device 12a (see FIG. 4), which drive device in particular defines
an axis of rotation 24a about which the grinding pad 132a can be
driven, in particular eccentrically. The hand-held grinding machine
10a comprises a drive housing 16a, which receives the drive device
14a.
[0042] The drive housing 16a has a longitudinal axis 92a, which
runs at least substantially perpendicular to the axis of rotation
24a. The drive housing 16a preferably has two drive housing
half-shells, which are arranged against one another in an assembly
plane 50a which is spanned by the longitudinal axis 92a and the
axis of rotation 24a (cf. FIG. 2). The drive housing 16a comprises
a longitudinal-axis portion 90a, which is arranged around the
longitudinal axis 92a. The longitudinal-axis portion 90a is
provided in particular for receiving a rechargeable battery pack
138a, in particular a 12 volt rechargeable battery pack. The drive
housing 16a has a front portion 94a. The front portion 94a
surrounds an intersection point region of the axis of rotation 24a
and the longitudinal axis 92a. The front portion 94a comprises a
dome-shaped grip surface 96a. The grip surface 96a is optionally in
the form of a soft component, which is arranged, in particular
recessed, on a housing basic body of the drive housing 16a. As an
alternative, an outer surface of the housing basic body of the
drive housing 16a forms the grip surface 96a. The hand-held
grinding machine 10a comprises at least one actuating element 88a
for controlling the drive device 14a, in particular for switching
the drive device 14a on and off. The actuating element 88a is
preferably able to be latched in place in an activated state of the
drive device 14a. The actuating element 88a is arranged in the grip
surface 96a. The actuating element 88a is arranged on a side,
facing away from the longitudinal-axis portion 90a, of a plane
which is perpendicular to the longitudinal axis 92a and encompasses
the axis of rotation 24a.
[0043] The hand-held grinding machine 10a comprises an interface
device 18a for operatively connecting, in particular for coupling,
the grinding device 12a to the drive device 14a. The interface
device 18a is arranged in particular along the axis of rotation 24a
on the front portion 94a. The interface device 18a comprises at
least one connecting housing portion 20a for at least partially
receiving the grinding device 12a. The connecting housing unit 20a
is formed separately from the drive housing 16a and the grinding
device 12a. The connecting housing unit 20a has at least two main
shells 46a, 48a. The main shells 46a, 48a are arranged in
particular against one another in the assembly plane 50a. The main
shells 46a, 48a are preferably manufactured from plastic. The main
shells 46a, 48a preferably have a wall thickness of between 1 mm
and 3.5 mm, preferably between 1.5 mm and 2.5 mm, particularly
preferably between 1.9 mm and 2.3 mm. The connecting housing unit
20a comprises an ejection port 76a. The ejection port 76a is
provided in particular for ejecting material that has been worn off
during a grinding process from the connecting housing unit 20a. The
ejection port 76a is preferably arranged on one of the main shells
46a. The hand-held grinding machine 10a comprises a material
collection device 116a. The material collection device 116a
comprises a material collection container 112a, which is preferably
air-impermeable, for collecting material, such as in particular
dust, chips and/or grit, which has been removed during operation of
the hand-grinding machine 10a, and in particular ejected via the
ejection port 76a. In at least one configuration of the material
collection container 112a, a container longitudinal axis 114a of
the material collection container 112a runs at least substantially
parallel to the longitudinal axis 92a of the drive housing 16a. In
particular, the container longitudinal axis 114a is in the form of
a container center axis, which runs in particular through a
geometric center of gravity of the material collection container
122a.
[0044] FIG. 2 shows a view of the hand-held grinding machine 10a
along the axis of rotation 24a. The drive housing 16a has a
protrusion 102a, 104a to either side of a plane which is
perpendicular to the axis of rotation 24a and encompasses the
longitudinal axis 92a. A ratio of a maximum protrusion transverse
extent 107a of the protrusion 102a to that of the protrusion 104a
of the drive housing 16a relative to a largest grip-surface
transverse extent 106a of the front portion 94a is between 0.75 and
0.9, in particular between 0.80 and 0.85. The largest grip-surface
transverse extent 106a is preferably at the same time the largest
transverse extent of the drive housing 16 perpendicular to the axis
of rotation 24a and perpendicular to the longitudinal axis 92a. The
largest grip-surface transverse extent 106a amounts, in relation to
an overall height 54a (cf. FIGS. 3 and 4) of the drive housing 16a,
to preferably between 0.8 and 0.95, in particular between 0.85 and
0.9. The largest grip-surface transverse extent 106a preferably
amounts to between 65 mm and 85 mm, in particular between 70 mm and
80 mm. In particular, the overall height 54a of the drive housing
16a parallel to the axis of rotation 24a is smaller than 95 mm,
preferably smaller than 90 mm, in particular smaller than 85 mm. A
maximum machine height parallel to the axis of rotation 24a of the
hand-held grinding machine 10a is particularly preferably smaller
than 115 mm, in particular smaller than 110 mm.
[0045] The grip surface 96a of the drive housing 16a transitions,
proceeding from the front portion 94a, continuously in the
direction of the longitudinal axis 92a into a tapering region 108a,
delimited by the protrusions 102a, 104a, of the longitudinal-axis
portion 90a. A ratio of a maximum tapering transverse extent 110a
of the tapering region 108a to the largest grip-surface transverse
extent 106a of the front portion 94a is between 0.7 and 0.85, in
particular between 0.75 and 0.8. The grip surface 96a of the drive
housing 16a extends from the front portion 94a to a plane which is
perpendicular to the longitudinal axis 92a and intersects the
protrusions 102a, 104a. The grip surface 96a optionally extends
along the longitudinal axis 92a over the protrusions 102a, 104a. A
plane which is perpendicular to the longitudinal axis 92a and
intersects the protrusions 102a, 104a, subdivides a maximum
longitudinal extent 111a, 113a of the drive housing 16a in a ratio
of between 0.45 and 0.65. In particular, a ratio of a protrusion
position 139a of the plane, intersecting the protrusions 102a,
104a, along the longitudinal axis 92a proceeding from a point of
the front portion 94a that is furthest away from the maximum
longitudinal extent 111a without a rechargeable battery pack 138a
amounts to between 0.55 and 0.60. In particular, a ratio of a
protrusion position 139a of the plane, intersecting the protrusions
102a, 104a, along the longitudinal axis 92a proceeding from a point
of the front portion 94a that is furthest away from the maximum
longitudinal extent 113a including a rechargeable battery pack 138a
amounts to between 0.5 and 0.55. In particular, the maximum
longitudinal extent 111a, 113a parallel to, in particular along,
the longitudinal axis 92a is greater than the overall height 54a of
the drive housing 16a.
[0046] The material collection container 112a is arranged spaced
apart from the grip surface 96a of the drive housing 16a in a plane
which is perpendicular to the axis of rotation 24a. In particular,
the material collection container 112a is arranged only on the
ejector port 76a by means of an assembly unit 124a of the material
collection device 116a, in particular in a suspended manner and in
particular without further support elements. A transition between
the assembly unit 124a and the material collection container 112a
is arranged in a plane which is perpendicular to the longitudinal
axis 92a with the tapering region 108a. A channel longitudinal axis
84a of the ejector port 76a of the connecting housing unit 20a is
aligned at an acute angle, in particular between 40.degree. and
50.degree., preferably between 44.degree. and 46.degree., to the
longitudinal axis 92a in a plane which is perpendicular to the axis
of rotation 24a. The channel longitudinal axis 84a is preferably in
the form of a channel center axis, which runs in particular through
a geometric center of gravity of the ejector port 76a. The
hand-held grinding machine 10a has an operating element 117a, in
particular one which is different from the actuating element 88a,
for controlling the grinding device 12a (cf. FIG. 1), for example
for matching a rotational speed of the grinding pad 132a. For
example, the operating element 117a is in the form of a rotary
controller. The operating element 117a and the material collection
container 112a are arranged on different sides of the assembly
plane 50a spanned by the axis of rotation 24a and the longitudinal
axis 92a. The drive housing 16a has a spacing from the material
collection container 112a which is between 10 mm and 40 mm,
preferably between 15 mm and 35 mm, particularly preferably between
20 mm and 30 mm. The operating element 117a is preferably arranged
in the tapering region 108a. The operating element 117a and the
actuating element 88a are preferably arranged on different sides of
a transverse plane 98a which is perpendicular to the axis of
rotation 24a and in which the front portion 94a has the largest
grip-surface transverse extent 106a.
[0047] FIG. 3 shows a longitudinal section of the hand-held
grinding machine 10a in the assembly plane 50a and FIG. 4 shows a
cross section of the hand-held grinding machine 10a. The grinding
device 12a preferably comprises an eccentric, which is driven by a
drive shaft 26a. The grinding device 12a preferably comprises an
eccentric bearing 158a, which is in particular in the form of a
ball bearing. The eccentric bearing 158a optionally comprises a
plurality of ball bearings, which are in particular stacked one on
top of another along the axis of rotation 24a, or a multi-row, in
particular two-row, ball bearing. The eccentric bearing 158a is
arranged in particular on the eccentric and engages around the
eccentric preferably in a plane which is perpendicular to the axis
of rotation 24a. The eccentric bearing 158a is clamped on an offset
of the eccentric, in particular by means of an assembly plate and a
screw. In particular, a geometric center point of the eccentric
bearing 158a is arranged spaced apart from the axis of rotation
24a. In particular, the grinding device 12a comprises an annular
grinding-pad holder 156a. The grinding-pad holder 156a is arranged
on the eccentric bearing 158a and engages around it preferably in a
plane which is perpendicular to the axis of rotation 24a. The
grinding-pad holder 156a preferably has a groove, in which the
eccentric bearing 158a is arranged. The eccentric bearing is
particularly preferably formed such that it is injection molded
around the grinding-pad holder 156a. In particular, the
grinding-pad holder 156a can be rotated relative to the eccentric.
The grinding pad 132a is preferably fastened to the grinding-pad
holder 156a, in particular screw-connected in a direction parallel
to the axis of rotation 24a. In particular, the grinding device 12a
optionally comprises a fan 66a. In particular, the fan 66a is
operated by the drive shaft 26a. A blading of the fan 66a
preferably surrounds the grinding-pad holder 156a in a plane which
is perpendicular to the axis of rotation 24a, wherein the
grinding-pad holder 156a projects beyond the fan 66a in a direction
of the axis of rotation 24a. The grinding device 12a preferably
comprises a slip ring 154a of an elastic material, which slip ring
is fastened in a rotationally fixed manner to the connecting
housing unit 20a on the connecting housing unit 20a in a groove,
and in particular rests on the grinding pad 132a, in particular in
order to stabilize a rotational movement of the grinding pad
132a.
[0048] The drive device 14a preferably comprises an electric motor
134a. In particular, the electric motor 134a incorporates a rated
voltage of 12 volts. The drive device 14a comprises the drive shaft
26a, which is driven in particular by the electric motor 134a about
the axis of rotation 24a. In particular, the drive device 14a
comprises an electrical power supply interface 136a, in particular
for connecting the rechargeable battery pack 138a. The drive device
14a preferably comprises at least one set of control electronics
140a, in particular for controlling the electric motor 134a. The
electric motor 134a, the control electronics 140a and the
electrical power supply interface 136a are preferably arranged
along the longitudinal axis 92a, in particular in this order. In
particular, the electric motor 134a is arranged in the front
portion 94a. In particular, the control electronics 140a are
arranged in the tapering region 108a. In particular, the electrical
power supply interface 136a is arranged in the longitudinal-axis
portion 90a. The drive shaft 26a preferably protrudes proceeding
from the front portion 94a into the interface device 18a.
[0049] The actuating element 88a is arranged, in particular
recessed, in a partial surface area, arranged obliquely to the
longitudinal axis 92a and to the axis of rotation 24a, of the grip
surface 96a. The partial surface area which receives the actuating
element 88a preferably has an angle of between 40.degree. and
50.degree. to the longitudinal axis 92a. A projection of the
actuating element 88a along the axis of rotation 24a in particular
does not overlap the electric motor 134a. The actuating element 88a
and the grinding device 12a are arranged on different sides of the
transverse plane 98a which is at least substantially perpendicular
to the axis of rotation 24a and in which the front portion 94a has
the largest grip-surface transverse extent 106a. In particular,
more than half, preferably more than 66%, particularly preferably
more than 75%, of a volume of the electric motor 134a is arranged
on that side of the transverse plane 98a which is opposite the
actuating element 88a. Between 40% and 60% of a volume of a
receiving region of the electrical power supply interface 136a for
receiving the rechargeable battery pack 138a is preferably arranged
on that side of the transverse plane 98a which is opposite the
actuating element 88a. In particular, the partial surface area,
surrounding the actuating element 88a, of the grip surface 96a is
flattened, in particular has a planar form in sections, in the
assembly plane 50a. The front portion 94a in the transverse plane
98a preferably has a continuously curved profile. Partial surface
areas of the grip surface 96a, one of which surrounds the actuating
element 88a and which terminate the front portion 94a along the
longitudinal axis 92a, are arranged at a front angle 142a of
between 95.degree. and 110.degree. to one another. The front angle
142a is in particular in the assembly plane 50a. In particular, the
partial surface areas terminating the front portion 94a are
arranged on different sides of the transverse plane 98a which has
the largest grip-surface transverse extent 106a and runs
perpendicular to the axis of rotation 24a.
[0050] A ratio of a maximum grip-surface height 100a, parallel to
the axis of rotation 24a, of the grip surface 96a to the overall
height 54a, parallel to said maximum grip-surface height, of the
drive housing 16a, is between 0.65 and 0.8 and preferably between
0.7 and 0.75. In particular, the grip surface 96a extends in a
direction of the axis of rotation 24a as far as an end of the
electric motor 134a that faces the grinding device 12a. The drive
device 14a preferably comprises a drive fan 64a, in particular for
cooling the electric motor 134a. The drive fan 64a is arranged on
the axis of rotation 24a between the electric motor 134a and the
interface device 18a. The grip surface 96a preferably extends in a
direction of the axis of rotation 24a as far as a fan portion 144a
of the drive housing 16a, in which ventilation openings for sucking
in and/or blowing out air through the drive fan 64a are arranged.
The grip-surface height 100a preferably decreases, in particular
continuously, in a direction of the longitudinal axis 92a (cf. also
FIG. 5). The drive fan 64a and the longitudinal-axis portion 90a
are preferably arranged, in particular completely, on different
sides of a plane which is perpendicular to the axis of rotation
24a. The front portion 94a preferably tapers in a direction of the
axis of rotation 24a to the fan portion 144a. In particular, the
actuating element 88a projects along the longitudinal axis 92a at
least partially beyond the fan portion 144a. A unit composed of the
drive housing 16a and the connecting housing unit 20a preferably
has, on the fan portion 144a, a cross section, perpendicular to the
axis of rotation 24a, between the actuating element 88a and the
grinding device 12a that has the smallest surface area. In
particular, the fan portion 144a has a maximum transverse extent
perpendicular to the axis of rotation 24a of less than 65 mm,
preferably less than 60 mm, particularly preferably less than 55
mm.
[0051] The interface device 18a comprises a docking interface 22a,
which is arranged on the drive housing 16a. The connecting housing
unit 20a engages around the docking interface 22a in a fixing plane
27a perpendicular to the axis of rotation 24a of the drive shaft
26a of the drive device 14a. The docking interface 22a has, in the
fixing plane 27a, at least one axial form-fitting element 28a, 29a,
30a, 32a for forming a form fit, parallel to the axis of rotation
24a, with the connecting housing unit 20a. A projection of the
axial form-fitting element 28a, 29a, 30a, 32a along the axis of
rotation 24a is at least substantially completely inside the drive
housing 16a. In particular, the docking interface 22a comprises a
plurality of axial form-fitting elements 28a, 29a, 30a, 32a, the
projections of which along the axis of rotation 24a are at least
substantially completely inside the drive housing 16a. In
particular, a projection of the entire docking interface 22a is at
least substantially completely inside the drive housing 16a. The
docking interface 22a is preferably arranged along the axis of
rotation 24a on the front portion 94a. In particular, the fan
portion 144a is arranged between the front portion 94a and the
docking interface 22a. The docking interface 22a is preferably
materially bonded to the drive housing 16a. In particular, the
overall height 54a of the drive housing 16a refers to an extent
which is parallel to the axis of rotation 24a and also includes the
docking interface 22a.
[0052] The docking interface 22a, as axial form-fitting element
30a, 32a, comprises a fixing recess 34a, 36a. The fixing recess
34a, 36a preferably extends at least substantially parallel to the
fixing plane 27a. In particular, the fixing recess 34a, 36a is
provided to receive a fixing element 38a, 40a of the connecting
housing unit 20a and a separately formed fixing element 42a, 44a.
The fixing element 38a, 40a of the connecting housing unit 20a is
in the form of a sleeve, particularly preferably a screw boss. The
sleeve is designed to receive the separately formed fixing element
42a, 44a. The separately formed fixing element 42a, 44a is
preferably in the form of a screw. An overall receiving length of
the sleeve corresponds in particular substantially, but in
particular not completely, to a length of the separately formed
fixing element 42a, 44a. In particular, the sleeve comprises two
sleeve portions, one of which is arranged on each of the two main
shells 46a, 48a, with the result that there is an air gap between
the two sleeve portions. In particular, the main shells 46a, 48a
are fastened to the docking interface 22a under tension by
tightening the separately formed fixing element 42a, 44a in the
sleeve. In particular, the separately formed fixing element 42a,
44a engages in, and in particular through, the docking interface
22a. In the fixing plane 27a, the docking interface 22a preferably
comprises at least two, in particular exactly two, copies of the
fixing element 38a, 40a per main shell 46a, 48a and in particular
at least two, in particular exactly two, copies of the separately
formed fixing element 42s, 44a, which are arranged in particular on
different sides of a plane which is perpendicular to the
longitudinal axis 92a and encompasses the axis of rotation 24a. The
connecting housing unit 20a optionally comprises at least one
additional fixing element 150a, 152a, which is provided to fasten
the main shells 46a, 48a to one another at a position spaced apart
from the fixing plane 27a. The connecting housing unit 20a
preferably comprises at least two additional fixing elements 150a,
152a, which are arranged in particular between the fixing plane
27a, in particular between an end of the docking interface 22a
which faces the grinding pad 132a and the grinding pad 132a. In
particular, the additional fixing elements 150a, 152a are in the
form of screws. Additional fixing recesses for the main shells 46a,
48a for receiving the additional fixing elements 150a, 152a are
preferably arranged in a plane which is parallel to the fixing
plane 27a and comprises the greatest transverse extent of the
connecting housing unit 20a in the assembly plane 50a.
[0053] Perpendicular to the axis of rotation 24a, the docking
interface 22a, as axial form-fitting element 28a, encompasses a
docking cross section which tapers along the axis of rotation 24a
in a direction away from the grinding device 12a and in particular
leading toward the fan portion 144a. In particular, the fixing
recess 34a, 36a is arranged between a maximum cross section of the
docking interface 22a perpendicular to the axis of rotation 24a and
a minimum cross section of the docking interface 22a perpendicular
to the axis of rotation 24a. The docking interface 22a preferably
comprises a contact surface 52a, which is formed on a surface of
the docking interface 22a that forms the taper. The contact surface
52a faces away in particular from the grinding device 12a and faces
in particular the drive device 14a. The main shells 46a, 48a have
in particular a mating surface, complementary to the contact
surface 52a, on one of their respective inner walls. The mating
surfaces of the main shells 46a, 48a are arranged in particular on
the contact surface 52a and particularly preferably pressed against
the contact surface 52a over their surface area by means of the
fixing elements 42a. At a boundary, which is at least substantially
perpendicular to the axis of rotation 24a, to the drive housing
16a, in particular to the fan portion 144a, the docking interface
22a, as axial form-fitting element 29a, has a smaller cross section
than the drive housing 16a. In particular, a difference in the
cross sections of the docking interface 22a and of the drive
housing 16a at the boundary corresponds to a wall thickness, in
particular twice the wall thickness, of the connecting housing unit
20a. A portion of the main shells 46a, 48a which forms the mating
surfaces extends preferably along the contact surface to the
boundary. The connecting housing unit 20a is arranged at least
substantially flush with the drive housing 16a on the docking
interface 22a. The docking interface 22a, in particular the contact
surface 52a, encompasses at least 10% to 20% of the overall height
54a of the drive housing 16a including the docking interface 22a
parallel to the axis of rotation 24a. It is preferably the case
that a ratio of a docking height of the docking interface 22a
parallel to the axis of rotation to a maximum transverse extent, in
particular a maximum diameter, of the docking interface 22a
perpendicular to the axis of rotation is between 0.1 and 0.3,
preferably between 0.15 and 0.2. It is preferably the case that a
ratio of the docking height of the docking interface 22a parallel
to the axis of rotation to a minimum transverse extent, in
particular a minimum diameter, of the docking interface 22a
perpendicular to the axis of rotation 24a is between 0.15 and 0.35,
preferably between 0.2 and 0.25. It is preferably the case that a
spacing parallel to the axis of rotation 24a between the maximum
transverse extent and the minimum transverse extent of the docking
interface 22a perpendicular to the axis of rotation 24a corresponds
to at least 60%, preferably more than 75%, of the docking
height.
[0054] The contact surface 52a runs transversely to the fixing
plane 27a and has a curved form. The mating surface has a curvature
which complements the contact surface 52a. The curvature of the
contact surface 52a and in particular of the mating surface
preferably have a concave form with respect to the axis of rotation
24a. A radius of curvature which describes the contact surface 52a
and in particular the mating surface runs outside the docking
interface 22a and in particular through the connecting housing unit
20a. The radius of curvature amounts to between 5 mm and 15 mm,
preferably between 9 mm and 10 mm. A curvature center point which
is part of the radius of curvature preferably lies outside the
connecting housing unit 20a. The wall thickness of the connecting
housing unit 20a optionally decreases along the curvature in the
direction of the drive housing 16a. As an alternative, the wall
thickness of the connecting housing unit 20a is constant along the
curvature. The contact surface 52a preferably encompasses a planar
contact portion, which continues the curvature of the docking
interface 22a tangentially in the direction of the grinding pad
132a. In particular, the planar contact portion of the contact
surface 52a is inclined with respect to the fixing plane 27a at an
angle of between 10.degree. and 20.degree. in the direction of the
grinding pad 132a. A portion of the main shells 46a, 48a that forms
the mating surfaces preferably extends over the planar contact
portion, in particular at the same angle to the fixing plane 27a as
the planar contact portion of the contact surface 52a. This extent
of the main shells 46a, 48a continues in particular as far as one
end of the connecting housing unit 20a in this direction or as far
as the additional fixing recesses or as far as the ejector port
76a. In particular, a top side, facing the drive device 14a, of the
main shells 46a, 48a forms a hand placement surface, which is
inclined in particular relative to the grinding pad 132a and falls
away in particular outward from the axis of rotation 24a, in
particular for supporting natural holding in the hand when thumb
and index finger are arranged on different sides of the axis of
rotation 24a. The main shells 46a, 48a are aligned against one
another by means of a tongue and groove connection 60a, 62a, which
is in particular curved, of the housing unit 20a in the fixing
plane 27a.
[0055] FIG. 5 illustrates the interface device 18a without one of
the main shells 48a. The docking interface 22a has, as basic body,
in particular a rotary body with respect to the axis of rotation
24a. As an alternative, the basic body of the docking interface 22a
extends parallel to the longitudinal axis 92a and has in particular
an elliptical or tapering cross section perpendicular to the axis
of rotation 24a. The docking interface 22a has, recessed in the
basic body, depressions, access shafts, in particular for the
sleeve of the main shells 46a, 48a and the separately formed fixing
element 42a, 44a, and/or ventilation openings.
[0056] It can also be seen from FIGS. 3 and 4 that the interface
device 18a comprises a gear mechanism element 58a. The gear
mechanism element 58a of the interface device 18a is in the form in
particular of an eccentric shank. The gear mechanism element 58a of
the interface device 18a is preferably formed separately from the
drive device 14a and the grinding device 12a. The gear mechanism
element 58a of the interface device 18a is preferably pressed on
the drive shaft 26a along the axis of rotation 24a and in
particular connected to the drive shaft 26a for rotation therewith.
The eccentric, in particular together with the already mentioned
assembly plate, is preferably screwed on the gear mechanism element
58a of the interface device 18a and in particular connected to the
gear mechanism element 58a of the interface device 18a for rotation
therewith. As an alternative, the gear mechanism element 58a is
formed integrally with the drive shaft 26a or with the eccentric of
the grinding device 12a.
[0057] The docking interface 22a engages around a bearing element
56a of the drive device 14a in the fixing plane 27a, which bearing
element is configured for rotatably mounting the gear mechanism
element 58a of the interface device 18a. The drive shaft 26a
preferably extends along the axis of rotation 24a into the bearing
element 56a, in particular through the bearing element 56a. The
gear mechanism element 58a preferably surrounds the drive shaft 26a
in the fixing plane 27a, such that the drive shaft 26a in
particular is not in direct contact with the bearing element 56a.
In particular, the bearing element 56a is in the form of a ball
bearing. The gear mechanism element 58a of the interface device 18a
preferably extends along the axis of rotation 24a through the
bearing element 56a. In particular, the gear mechanism element 58a
of the interface device 18a has a greater maximum transverse extent
perpendicular to the axis of rotation 24a on a side of the fixing
plane 27a which faces the drive device 14a than on a side of the
fixing plane 27a which faces the grinding device 12a, for the
purpose of an axial form fit along the axis of rotation 24a with
the bearing element 56a. The fan 66a of the grinding device 12a is
preferably arranged on the gear mechanism element 58a of the
interface device 18a, in particular for centric rotation about the
axis of rotation 24a. The fan 66a is not illustrated in FIG. 4 in
order to ensure that an inner wall 70a of the main shells 46a, 48a
can be seen. The fan 66a has an asymmetrical form for the purpose
of forming a gear mechanism element of the grinding device 12a. In
particular, the fan 66a forms the eccentric. In particular, the fan
66a has a disk-shaped base plate, which is in particular solid, and
to which the blading of the fan 66a is fastened. The base plate
preferably faces the docking interface 22a and is arranged in
particular in the same plane perpendicular to the axis of rotation
24a as the additional fixing elements 150a, 152a. The blading of
the fan 66a preferably faces the grinding pad 132a. In particular,
as eccentric the fan 66a has a central shank, which is surrounded
by the blading in a plane which is perpendicular to the axis of
rotation 24a. In particular, the central shaft is arranged on the
base plate eccentrically in relation to the base plate. The gear
mechanism element 58a of the interface device 18a preferably
engages in the central shank, forming the eccentric, of the fan 66a
and is connected to it in particular for rotation therewith (cf.
FIG. 6). The fan 66a preferably has at least one fan counterbalance
148a, which is arranged inside the blading. In particular, a shape
of the fan counterbalance 148a is matched to a shape of the
blading. The base plate of the fan 66 preferably has a recess 162a,
which is arranged offset with respect to the rest of the base plate
in the direction of the axis of rotation 24a. The recess 162a is in
the form in particular of a half-ring. The recess 162a and the fan
counterbalance 148a, in particular together with part of the
blading, are preferably arranged on the recess 162a. In a section
of the fan 66a along a plane encompassing the axis of rotation 24a,
the recess 162a and the fan counterbalance 148a are arranged in
particular in a half of the fan 66a which comprises a smaller
volume fraction of the central shank which is in the form of an
eccentric. A height of the blading on the recess 162a parallel to
the axis of rotation 24a is preferably smaller than a height of the
rest of the part of the blading, in particular with the result that
the entire blading of the fan 66a has a common termination plane
which is perpendicular to the axis of rotation 24a. The drive fan
64a of the drive device 14a and the fan 66a of the grinding device
12a are arranged on different sides of the axial form-fitting
element 28a, 29a, 30a, 32a in the direction of the axis of rotation
24a. In particular, at the boundary the docking interface 22a
terminates a receiving space of the drive housing 16a in which the
drive fan 64a is arranged. In particular, an end of the docking
interface 22a along the axis of rotation 24a delimits a fan
receiving region 68a, in which the fan 66a is arranged.
[0058] The grinding device 12a comprises the fan 66a for the
purpose of transporting away material removed during a grinding
operation. The inner wall 70a, which delimits the fan receiving
region 68a, of the connecting housing unit 20a is in the form of a
funnel about the axis of rotation 24a of the drive shaft 26a of the
drive device 14a in order to guide an air stream created by the fan
66a. In particular, the fan receiving region 68a narrows along the
axis of rotation 24a in the direction of the grinding pad 132a
proceeding from the plane which is perpendicular to the axis of
rotation 24a and in which the additional fixing elements 150a, 152a
are arranged. The main shells 46a, 48a of the connecting housing
unit 20a at least partially surround the fan 66a in the assembly
plane 50a, which is parallel to the axis of rotation 24a. In
particular, the main shells 46a, 48a surround the fan 66a, in
particular the blading thereof, in a direction parallel to the axis
of rotation 24a. In particular, the main shells 46a, 48a comprise
at least one base portion 180a, which is arranged between the fan
66a and the grinding pad 132a. The connecting housing unit 20a has
an air inlet 74a. The air inlet 74a is preferably arranged in the
base portion 180a of the main shells 46a, 48a. In particular, the
base portion 180a has a base surface which faces the fan 66a and
runs at least substantially perpendicularly to the axis of rotation
24a. A maximum transverse extent of the base surface perpendicular
to the axis of rotation 24a is in particular smaller than a maximum
transverse extent of the fan 66a perpendicular to the axis of
rotation 24a. The grinding-pad holder 156a projects in particular
through the air inlet 74a, in particular without making contact
with the main shells 46a, 48a. The eccentric bearing 158a, the gear
mechanism element 58a and/or the eccentric are preferably arranged
at least substantially flush with the base portion 180a of the main
shells 46a, 48a or are arranged set back in the direction of the
drive device 14a relative to the base portion 180a.
[0059] The inner wall 70a is segmented in the direction of the axis
of rotation 24a. A mouth opening 78a in the ejector port 76a of the
connecting housing unit 20a and the air inlet 74a of the connecting
housing unit 20a are arranged in different segments of the inner
wall 70a. In particular, the mouth opening 78a is arranged in an
ejector segment 182a of the connecting housing unit 20a. The inner
wall 70a runs in the ejector segment 182a preferably at least
substantially parallel to the axis of rotation 24a. In particular,
the ejector segment 182a is arranged in the plane with the
additional fixing elements 150a, 152a. The connecting housing unit
20a preferably comprises at least one guide segment 184a, which is
arranged in the direction of the axis of rotation 24a between the
ejector segment 182a and the base portion 180a. The inner wall 70a
runs in the guide segment 184a in particular at an acute angle to
the axis of rotation 24a. The connecting housing unit 20a
preferably comprises at least one further guide segment 186a, which
is arranged between the guide segment 184a and the base portion
180a. In particular, the inner wall 70a in a further guide segment
186a has an angle in relation to the axis of rotation 24a which is
larger than the angle of the guide segment 184a in relation to the
axis of rotation 24a. In particular, the portions of the ejector
segment 182a, the guide segment 184, the further guide segment 186a
and the base portion 180a and the portion, forming the mating
surface, of one of the main shells 46a, 48a are formed integrally
with one another.
[0060] The connecting housing unit 20a has a conical spiral track
72a arranged on the inner wall 70a. The spiral track 72a leads in
particular from the air inlet 74a of the connecting housing unit
20a in the direction of the axis of rotation 24a to the ejector
port 76a of the connecting housing unit 20a. In particular, the
conical spiral track 72a is arranged in the guide segment 184a.
FIG. 6 shows a cross section, perpendicular to the axis of rotation
24a, through the ejector segment 182a. The fan receiving region 68a
preferably has an asymmetrical form. On account of the spiral track
72a, in a plane which is perpendicular to the axis of rotation 24a,
the inner wall 70a has in particular a spacing from the axis of
rotation 24a which is dependent on an angular position with respect
to the axis of rotation 24a. The mouth opening 78a of the ejector
port 76a, together with the inner wall 70, in particular forms a
separating edge 82a, which runs at least substantially parallel to
the axis of rotation 24a. The spacing between the inner wall 70a
and the axis of rotation 24a is preferably at its smallest at the
separating edge 82a. The spacing between the inner wall 70a and the
axis of rotation 24a preferably increases continuously or remains
constant in sections. The spacing between the inner wall 70a and
the axis of rotation 24a particularly preferably increases linearly
with an angular difference in relation to an angular position of
the separating edge 82a, illustrated here in particular in the
clockwise direction. The spiral track 72a is optionally formed in
only one of the main shells 48a, while the spacing of the guide
segments 184a is kept constant in sections in the main shell 46a
with the ejector port 76a. The conical spiral track 72a preferably
has a pitch parallel to the axis of rotation 24a which leads in at
most one revolution, preferably a half-revolution, from the further
guide segment 186a to the mouth opening 78a. The guide segment
184a, forming the spiral track 72a, of the inner wall 70a has an
angle of between 25 and 40.degree., preferably between 30.degree.
and 35.degree., in relation to the axis of rotation 24a in a plane
which encompasses the axis of rotation 24.
[0061] The spiral track 72a, in particular the guide segment 184a,
in a projection along the axis of rotation 24a preferably has no
overlap with the fan 66a. More than 50%, in particular more than
75%, preferably more than 90%, of the further guide segment 184a in
a projection along the axis of rotation 24a is arranged inside the
fan 66a. The blading of the fan 66a has a bevel 86a (see FIG. 3).
The bevel 86a is arranged transversely to the axis of rotation 24a
and at least substantially parallel to the further guide segment
186a of the inner wall 70a. The inner wall 70a in the further guide
segment 186a and in particular the bevel 86a preferably has an
angle in relation to the axis of rotation 24a in a plane which
encompasses the axis of rotation 24a of between 50.degree. and
70.degree., in particular between 55.degree. and 65.degree..
[0062] A further separating edge 80a, which is formed by the mouth
opening 78a of the ejector port 76a of the connecting housing unit
20a, runs at least substantially perpendicularly to the axis of
rotation 24a. In particular, the further separating edge 80a
separates the ejector segment 182a from the guide segment 184a. The
further separating edge 80a continues in particular the spiral path
72a in the region of the mouth opening 78a as far as the separating
edge 82a with a constant spacing from the axis of rotation 24a. The
further separating edge 80a is arranged in particular at a height
along the axis of rotation 24a between the base plate of the fan
66a and the termination plane of the blading. The separating edge
82a, which is formed by the mouth opening 78a of the ejector port
76a of the connecting housing unit 20a and runs at least
substantially parallel to the axis of rotation 24a, has a tapering
form and has a radius of curvature of less than 10 mm, preferably
of less than 3 mm, particularly preferably of less than 2 mm. The
radius of curvature of the separating edge 82a is in particular in
a plane which is perpendicular to the axis of rotation 24a. The
radius of curvature of the separating edge 82a, in particular
independently of a precise shaping of the separating edge 82a,
describes a smallest imaginary circle, which rests against both the
inner wall 70a which faces the fan 66a and an inner wall of the
ejector port 76a. Tangents which rest against the inner wall 70a
and the inner wall of the ejector port 76a preferably form an angle
of between 45.degree. and 65.degree., preferably between 55.degree.
and 60.degree., in a plane which is perpendicular to the axis of
rotation 24a.
[0063] The channel longitudinal axis 84a runs centrally through an
ejector port 76a and predefines in particular a main flow direction
of air through the ejector port 76a. A projection of the channel
longitudinal axis 84a along the axis of rotation 24a preferably
rests tangentially on an outer contour of the fan 66a. The
projection of the channel longitudinal axis 84a along the axis of
rotation 24a preferably forms an angle of between 40.degree. and
50.degree., particularly preferably between 44.degree. and
46.degree., in relation to the assembly plane 50a. An inner wall,
situated opposite the separating edge 82a, of the ejector port 76a
extends preferably from the assembly plane 50a to an ejector
opening of the ejector port 76a, wherein a spacing between this
inner wall and the axis of rotation 24a in the assembly plane 50a
is matched to the spacing of the spiral track 72a and becomes
continuously greater in the direction of the ejector opening. The
channel longitudinal axis 84a of the ejector port 76a of the
connecting housing unit 20a forms an acute angle, in particular
between 15.degree. and 35.degree., preferably between 20.degree.
and 30.degree.with a plane which is perpendicular to the axis of
rotation 24a. The channel longitudinal axis 84a is inclined away
from the grinding device 12a in the direction of the axis of
rotation 24a, in particular proceeding from the mouth opening 78a.
At the mouth opening 78a, the ejector port 76a has in particular a
rectangular cross section perpendicular to the channel longitudinal
axis 84a. At the ejector opening, the ejector port 76a preferably
has a circular cross section perpendicular to the channel
longitudinal axis 84a. A protective device 146a, in particular in
the form of webs parallel to the channel longitudinal axis 84a, for
preventing a finger and/or other foreign bodies from entering the
ejector port 76a is preferably arranged in a portion of the ejector
port 76a that has the rectangular cross section.
[0064] In particular, the material collection device 116a is
arranged on the region of the ejector port 76a with the circular
cross section. The material collection container 112a has at least
one opening 120a for feeding the material into the material
collection container 112a. The opening 120a of the material
collection container 112a is arranged in an opening plane 122a. The
opening plane 122a preferably can be aligned at least substantially
perpendicularly to the longitudinal axis 92a in at least one state
of the material collection device 116a in which it is arranged at
the ejector port 76a. The material collection container 112a
preferably comprises exactly one opening 120a in the opening plane
122a. As an alternative, the material collection device 116a in the
opening plane 122a comprises a structural element, which divides
the opening 120a into small partial openings. The container
longitudinal axis 114a of the material collection container 112a is
preferably aligned at least substantially perpendicularly to the
opening plane 122a. In particular, the material collection
container 112a has the largest longitudinal extent parallel to, in
particular along, the container longitudinal axis 114a. In
particular, the material collection container 112a has a
rotationally symmetrical form about the container longitudinal axis
114a.
[0065] The material collection device 116a comprises at least one
assembly unit 124a for assembling the material collection container
112a on the hand-held grinding machine 10a. The assembly unit 124a
comprises a channel element 126a for connection to the ejector port
76a of the hand-held grinding machine 10a. The channel element 126a
is provided in particular to be arranged concentrically at the
ejector port 76a and has the same channel longitudinal axis 84a as
the ejector port 76a in a state in which it is arranged on the
ejector port 76a. The channel longitudinal axis 84a of the channel
element 126a is arranged transversely to the opening plane 122a of
the material collection container 112a in at least one sectional
plane running perpendicularly to the opening plane 122a. The
channel longitudinal axis 84a is arranged transversely to the
opening plane 122a in a further sectional plane which is
perpendicular to the sectional plane and the opening plane 122a. In
particular, the channel longitudinal axis 84a and the container
longitudinal axis 114a are arranged in a skewed manner. The
sectional plane in a configuration shown perpendicularly to the
axis of rotation 24a can be seen in FIG. 6. FIG. 7 shows the
further sectional plane, which is illustrated here in particular
offset to the container longitudinal axis 114a. In the state of the
material collection device in which it is assembled on the
hand-held grinding machine, the container longitudinal axis 114a
can be aligned at least substantially parallel to the assembly
plane 50a, in particular wherein the container longitudinal axis
114a is aligned parallel to the longitudinal axis 92a. When the
container longitudinal axis 114a is aligned parallel to the
longitudinal axis 92a, the further sectional plane is arranged in
particular parallel to the assembly plane 50a. The container
longitudinal axis 114a of the material collection container 112a
forms, relative to the assembly plane 50a, an angle which, when
added to an angle between the channel longitudinal axis 84a and the
container longitudinal axis 114a, forms a total angle of between
80.degree. and 100.degree., particularly preferably of 90.degree..
In particular, the channel longitudinal axis 84a intersects the
opening plane 122a in the sectional plane at an angle of between
40.degree. and 50.degree., preferably between 44.degree. and
46.degree.. In particular, the channel longitudinal axis 84a
intersects the opening plane 122a in the further sectional plane at
an angle of between 15.degree. and 30.degree..
[0066] The channel element 126a is preferably plugged onto the
ejector port 76a along the channel longitudinal axis 84a. An inner
wall of the channel element 126a and/or an outer wall of the
ejector port 76a preferably has structural elements for the purpose
of a force fit, which in particular can be released and established
by hand, of the channel element 126a with the ejector port 76a, for
example webs or nubs with an interference fit and/or a sheathing
with an elastic material or the like. The material collection
device 116a is preferably arranged on the ejector port 76a such
that it can rotate, in particular at least with a moderate
expenditure of force. In particular, the moderate expenditure of
force necessary for rotating the material collection device 116a at
the ejector port 76a exceeds a weight of the material collection
device 116a, in particular in a state of the material collection
container 112a in which it is filled with material removed by the
grinding device 12a. The moderate expenditure of force can
preferably be applied by a hand without a tool, in particular
smaller than 200N, preferably smaller than 125 N, particularly
preferably smaller than 75 N. In particular, the material
collection device 116a remains in a current rotational position
with respect to the ejector port 76a without manual actuation. A
rotation of the material collection device 116a about the channel
longitudinal axis 84a causes a relative position of the container
longitudinal axis 114a in relation to the axis of rotation 24a
and/or of the longitudinal axis 92a to change. In particular, the
material collection device 116a is arranged pivotably on the
ejector port 76a relative to the drive housing 16a. This makes it
possible to advantageously flexibly align the material collection
device 116a during the grinding operation such that even surfaces
which are difficult to access can be processed.
[0067] The assembly unit 124a comprises an adapter housing 128a.
The adapter housing 128a has an asymmetrically tapering form from
the opening plane 122a in the direction of the channel longitudinal
axis 84a. The channel element 126a projects at least partially into
the adapter housing 128a. The channel element 126a has an in
particular rotationally symmetrical form in relation to the
longitudinal axis 92a. The channel element 126a is preferably
recessed completely in the adapter housing 128a. The channel
element 126a and the adapter housing 128a are particularly
preferably formed in one piece. The adapter housing 128a preferably
has an assembly element for fixing the material collection
container 112a to the adapter housing 128a. For example, the
assembly element is in the form of a thread, preferably an external
thread. In particular, the material collection container 112a has
an air-permeable container region 168a for collecting the removed
material and a fastening ring 164a for fastening the container
region 168a to the assembly unit 124a. The fastening ring 164a
preferably has an assembly element, for example a thread, in
particular an internal thread, for connection to the adapter
housing 128a. The container region 168a is preferably fixed to the
fastening ring 164a by means of a latching and/or screw connection
166a. In particular, the fastening ring 164a delimits the opening
120a. The fastening ring 164a and the adapter housing 128a are
preferably arranged at least substantially flush with one another.
The adapter housing 128a is in particular in the form of a
truncated cone which rests on the fastening ring 164a in a skewed
manner and the cone axis of which is aligned coaxially with the
channel longitudinal axis 84a. A radius of a top surface of the
frustoconical adapter housing 128a is preferably the same as an
outer radius of the channel element 126a.
[0068] A maximum adapter longitudinal extent of a portion of the
assembly unit 124a that projects beyond the material collection
container 112a in a direction of the container longitudinal axis
114a is at least substantially the same as a maximum adapter
transverse extent of the assembly unit 124a in the opening plane
122a. In particular, a ratio of the adapter longitudinal extent to
the adapter transverse extent is between 50% and 80%, preferably
between 60% and 70%. In particular, the adapter housing 128a, in
particular an inlet opening 130a of the channel element 126a,
projects at most slightly beyond the material collection container
112a in a projection along the container longitudinal axis 114a. In
particular, a projection of the adapter housing 128a along the
container longitudinal axis 114a is completely inside a smallest
imaginary square which specifically completely encloses a
projection of the material collection container 112a. In
particular, a maximum distance of the inlet opening 130a from the
container longitudinal axis 114a is smaller than 2 times an outer
radius of the material collection container 112a in the opening
plane 122a. In FIG. 6, the material collection container 112a is
divided by the sectional plane in a ratio of more than 1:4, and
therefore here the diameter of the material collection container
112a is not illustrated and the adapter housing 128a only seemingly
projects significantly beyond the material collection container
112a in the direction of the grinding device 12a.
[0069] The outlet opening of the channel element 126a assumes a
maximum outlet opening width between 35% and 55%, in particular
between 44% and 47%, of a maximum opening width of the opening 120a
in the opening plane 122a. A ratio of an internal diameter of the
channel element 126a compared to the opening width of the opening
120a preferably amounts to between 35% and 60%, preferably between
45% and 55%. The container longitudinal axis 114a preferably runs
through an outlet opening, facing the material collection container
112a, of the channel element 126a. The outlet opening in the
channel element 126a is preferably arranged in a plane which runs
at least substantially perpendicularly to the channel longitudinal
axis 84a and transversely to the opening plane 122a. A geometric
center point of the outlet opening in the channel element 126a is
arranged offset at least in the further sectional plane in
particular with respect to the container longitudinal axis 114a, in
particular by a magnitude of 10% to 30% of the maximum opening
width.
[0070] The inlet opening 130a of the channel element 126a extends
in a plane which runs at least substantially perpendicular to the
channel longitudinal axis 84a and in particular transversely to the
opening plane 122a. The inlet opening 130a engages in particular
around the region of the ejector port 76a with the circular cross
section. The ejector port 76a preferably projects into the channel
element 126a at least as far as the container longitudinal axis
114a. The inlet opening 130a in the channel element 126a is
arranged spaced apart from the container longitudinal axis 114a,
running perpendicularly to the opening plane 122a, of the material
collection container 112a.
[0071] FIG. 8 shows a flow diagram of a method 170a for assembling
the hand-held grinding machine 10a. The method 170a comprises in
particular a preassembly step 172a. The method 170a preferably
comprises a connection step 174a. The method 170a preferably
comprises a main-shell arrangement step 176a. In particular, the
method 170a comprises a fixation step 178a. In the preassembly step
172a, in particular the drive device 14a and/or the grinding device
12a are preassembled, in particular independently of one another.
In the preassembly step 172a, the drive device 14a is arranged in
the drive housing 16a, in particular in a half-shell to be
assembled of the drive housing 16a, of the hand-held grinding
machine 10a. In the connection step 174a, the gear mechanism
element 58a is preferably pressed onto the drive shaft 26a. In the
connection step 174a, the grinding device 12a is preferably screwed
on the gear mechanism element 58a. In the main-shell arrangement
step 176a, a form fit, parallel to the axis of rotation 24a, of the
connecting housing unit 20a with the docking interface 22a is
formed by means of the axial form-fitting element 28a, 29a, 30a,
32a, arranged in the fixing plane 27a, of the docking interface
22a. In the main-shell arrangement step 176a, the connecting
housing unit 20a is arranged on the docking interface 22a so as to
engage around the docking interface 22a in the fixing plane 27a
which is perpendicular to the axis of rotation 24a. In particular,
in the main-shell arrangement step 176a, the main shells 46a, 48a
are placed on the docking interface 22a. In particular, the mating
surfaces of the main shells 46a, 48a are placed onto the contact
surface 52a, wherein the grinding device 12a is arranged at least
partially in the connecting housing portion 20a. In the main-shell
arrangement step 176a, the sleeve of the main shells 46a, 48a is
preferably plugged in the fixing recesses 34a, 36a in the docking
interface 22a. The main shells 46a, 48a are placed against one
another in particular in the assembly plane 50a. In the fixation
step 178a, the separately formed fixing element 42a, 44a is
arranged in the sleeve arranged in the fixing recess 34a, 36a and
as a result presses the main shells 46a, 48a against one another
and in particular the contact surface 52a against the docking
interface 22a. The fixing elements 42a, 44a, the additional fixing
elements 150a, 152 and optionally drive housing fixing elements for
connecting the half-shells to be assembled of the drive housing 16a
are preferably assembled on the main shells 46a, 48a, the docking
interface 22a and/or the drive housing 16a in all cases from the
same, single direction which is at least substantially
perpendicular to the assembly plane 50a.
[0072] FIGS. 9 to 14 show further exemplary embodiments of the
disclosure. The following descriptions and the drawings are
substantially restricted to the differences between the exemplary
embodiments, it being possible to make reference fundamentally also
to the drawings and/or the description of the other exemplary
embodiments, in particular FIGS. 1 to 8, with respect to components
with the same designation, in particular with respect to components
with the same reference signs. In order to make a distinction
between the exemplary embodiments, the letter a is appended to the
reference signs of the exemplary embodiment in FIGS. 1 to 8. The
letter a is replaced by letters b to d in the exemplary embodiments
in FIGS. 9 to 14. FIG. 9 shows an external view and FIG. 10 shows a
longitudinal section of a hand-held grinding machine 10b in the
form of an eccentric grinder. The hand-held grinding machine 10b
comprises a grinding device 12b, which is in particular identical
to the grinding device 12a of the previous exemplary embodiment.
The hand-held grinding machine 10b has a drive device 14b, in
particular with an electric motor 134b. In particular, the electric
motor 134b incorporates a rated voltage of 18 volts. An electrical
power supply interface 136b of the drive device 14b and a
longitudinal-axis portion 90b of a drive housing 16b of the
hand-held grinding machine 10b is preferably designed for receiving
an 18-volt rechargeable battery pack 138b. The hand-held grinding
machine 10b comprises an interface device 18b with a docking
interface 22b and a connecting housing unit 20b. The connecting
housing unit 20b preferably has a counterbalance, which compensates
a torque caused by a weight of the rechargeable battery pack 138b,
in particular in order to prevent an axis of rotation 24b of the
drive device 14b from tilting. The counterbalance is preferably
arranged on main shells 46b, 48b of the connecting housing unit
20b, in particular is integrated therein. The main shells 46b, 48b
are optionally manufactured from metal in order to form the
counterbalance, in particular by means of an aluminum/zinc
die-casting process. As an alternative, the main shells 46b, 48b
have metal inclusions in a plastic body as counterbalance. The
counterbalance and the electrical power supply interface 136b are
arranged in particular on different sides of a plane which is
perpendicular to a longitudinal axis 92b of the hand-held grinding
machine 10b and contains the axis of rotation 24b. A portion of the
connecting housing unit 20b with the counterbalance preferably
rests against a docking interface 22b of the interface device 18b.
In particular, the portion of the connecting housing unit 20b with
the counterbalance has a greater wall thickness than a portion of
the connecting housing unit 20b that is arranged on the side
situated opposite the plane which is perpendicular to the axis of
rotation 92b and encompasses the axis of rotation 24b. The portion
of the connecting housing unit 20b with the counterbalance
preferably has an outer surface which faces the drive housing 16b
and is inclined in the direction of the grinding device 12b by
15.degree. to 30.degree. with respect to a plane which is
perpendicular to the axis of rotation 24b. Reference should be made
to FIGS. 1 to 8 and the description thereof in terms of further
features of the hand-held grinding machine 10b.
[0073] FIG. 11 shows an external view and FIG. 12 shows a
longitudinal section of a hand-held grinding machine 10c. The
hand-held grinding machine 10c has a drive device 14c and a drive
housing 16c, which are formed in particular identically to the
drive device 14a and the drive housing 16a, respectively, of the
first exemplary embodiment. As an alternative, a grinding device
12c of the hand-held grinding machine 10c, in particular without
further adaptation, may also be combined with a drive device and a
drive housing 16c, as were shown in the second exemplary
embodiment. A grinding pad 132c of the grinding device 12c has a
diameter of between 70 mm and 80 mm, preferably between 77 mm and
78 mm, for example. In particular, the entire grinding device 12c
and an interface device 18c of the hand-held grinding machine 10c
in a projection along an axis of rotation 24c of the drive device
14c lie inside the drive housing 16c. A docking interface 22c of
the interface device 18c is formed in particular identically to the
docking interfaces 22a, 22b of the previous exemplary embodiments.
A connecting housing unit 20c of the interface device 18c is
adapted in particular to a height of the grinding device 12c
parallel to the axis of rotation 24c. A maximum transverse extent
of the connecting housing unit 20c perpendicular to the axis of
rotation 24c is preferably insignificantly larger than a maximum
transverse extent of the docking interface 22c, in particular is
larger only by a wall thickness, in particular twice the wall
thickness, of the connecting housing unit 20c. In particular, a
portion of the connecting housing portion 20c that runs at least
substantially parallel to the axis of rotation 24c is arranged
directly on the docking interface. In particular, additional fixing
elements 150c, 152c are arranged in a plane parallel to the axis of
rotation 24c with a contact surface 52c of the docking interface
22c. A gear mechanism element 58c of the interface device 18c
engages through an optional fan 66c along the axis of rotation. In
particular, the gear mechanism element 58c is formed integrally
with an eccentric of the grinding device 12c to form a drive of the
grinding pad 132c. The gear mechanism element 58c engages around an
eccentric bearing 158c of the grinding device 12c, in particular in
a plane which is perpendicular to the axis of rotation 24c. The
eccentric bearing 158c preferably engages around a grinding-pad
holder 156c of the grinding device 12c in a plane which is
perpendicular to the axis of rotation 24c. The grinding-pad holder
156c receives in particular a continuation of the grinding pad 132c
in a direction parallel to the axis of rotation 24c.
[0074] Reference should be made to FIGS. 1 to 10 and the
description thereof in terms of further features of the hand-held
grinding machine 10c.
[0075] FIG. 13 shows an external view and FIG. 14 shows a
longitudinal section of a hand-held grinding machine 10d. The
hand-held grinding machine 10d is in the form in particular of an
oscillating grinder. The hand-held grinding machine 10d has a drive
device 14d and a drive housing 16d, which are formed in particular
identically to the drive device 14a and the drive housing 16a,
respectively, of the first exemplary embodiment. As an alternative,
a grinding device 12d of the hand-held grinding machine 10d, in
particular without further adaptation, may also be combined with a
drive device and a drive housing, as are shown in the second
exemplary embodiment. A grinding pad 132d of the grinding device
12d is fastened to a connecting housing unit 20d of an interface
device 18d of the hand-held grinding machine 10d, in particular by
means of an elastic mount 160d. A fan 66d of the grinding device
12d is arranged in a fan housing of the grinding device 12d, which
is arranged in particular inside the connecting housing unit 20d.
The elastic mount 160d is arranged in particular between the fan
housing and the connecting housing unit 20d. A gear mechanism
element 58d of the interface device 18d is preferably formed
integrally with an eccentric of the grinding device 12d. An
eccentric bearing 158d of the grinding device 12d engages in
particular around the gear mechanism element 58d in a plane which
is perpendicular to an axis of rotation 24d of the drive device
14d. The eccentric bearing 158d is arranged in particular in a
guide ring, able to be deflected by the eccentric bearing 158d, of
the grinding pad 132d and connected to the guide ring preferably in
a force-fitting manner. Reference should be made to FIGS. 1 to 12
and the description thereof in terms of further features of the
hand-held grinding machine 10d.
* * * * *