U.S. patent application number 17/417606 was filed with the patent office on 2022-03-17 for hand-held power tool.
The applicant listed for this patent is Robert Bosch GmbH. Invention is credited to Jens Zieger.
Application Number | 20220080548 17/417606 |
Document ID | / |
Family ID | |
Filed Date | 2022-03-17 |
United States Patent
Application |
20220080548 |
Kind Code |
A1 |
Zieger; Jens |
March 17, 2022 |
Hand-Held Power Tool
Abstract
A hand-held power tool, in particular a grinder, for
simultaneously driving multiple grinding discs, includes at least
one output shaft housing which surrounds multiple output shafts
orthogonally to their output shaft axes, and a motor housing which
at least substantially surrounds a motor orthogonally to the motor
shaft axis. A cross-sectional surface of the motor housing running
orthogonally to the motor shaft axis, in a narrower region of the
motor housing, is less than 70% of the area of a cross-sectional
surface of the output shaft housing running orthogonally to the
output shaft axes, in a wider region of the output shaft housing,
and/or one, in particular two, of the output shaft axes, are
located outside the motor housing, preferably outside a concavely
indented region of the hand grip, of the motor housing, and/or of
the transition region between the hand grip and the motor
housing.
Inventors: |
Zieger; Jens; (Altbach,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Robert Bosch GmbH |
Stuttgart |
|
DE |
|
|
Appl. No.: |
17/417606 |
Filed: |
December 19, 2019 |
PCT Filed: |
December 19, 2019 |
PCT NO: |
PCT/EP2019/086389 |
371 Date: |
June 23, 2021 |
International
Class: |
B24B 7/18 20060101
B24B007/18; B24B 23/04 20060101 B24B023/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 27, 2018 |
DE |
10 2018 251 718.5 |
Dec 27, 2018 |
DE |
10 2018 251 730.4 |
Claims
1-12. (canceled)
13. A hand-held power tool for simultaneously driving a plurality
of grinding disks, comprising: a plurality of output shafts
defining output shaft axes; at least one output shaft housing
enclosing the plurality of output shafts orthogonally to the output
shaft axes; a motor having a motor shaft axis; and a motor housing
which at least substantially encloses the motor orthogonally to the
motor shaft axis, wherein a first sectional area of the motor
housing orthogonal to the motor shaft axis in a constricted region
of the motor housing amounts to less than 70% relative to a second
sectional area of the output shaft housing orthogonal to the output
shaft axes in an extended region of the output shaft housing.
14. The hand-held power tool as claimed in claim 13, wherein a rear
region of the second sectional area of the output shaft housing is
covered to an extent of less than 75% by the first sectional area
of the motor housing projected along the motor shaft axis.
15. The hand-held power tool as claimed in claim 14, wherein the
rear region is in a region of at least one rear output shaft axis
of the output shaft axes, and the extent to which the rear region
of the second sectional area is covered by the first sectional area
is less than 25%.
16. The hand-held power tool as claimed in claim 13, wherein a
front region of the second sectional area of the output shaft
housing is covered to an extent of more than 70% by the first
sectional area of the motor housing projected along the motor shaft
axis.
17. The hand-held power tool as claimed in claim 16, wherein the
front region is in a region of a front output shaft axis of the
output shaft axes, and the front region is entirely covered by the
first sectional area.
18. The hand-held power tool as claimed in claim 13, wherein a
circumferential length of the motor housing orthogonal to the motor
shaft axis in the constricted region of the motor housing is less
than 80% of a circumferential length of the output shaft housing
orthogonal to the output shaft axes in the extended region of the
output shaft housing.
19. The hand-held power tool as claimed in claim 18, wherein the
circumferential length of the motor housing orthogonal to the motor
shaft axis in the constricted region is less than 70% of the
circumferential length of the output shaft housing orthogonal to
the output shaft axes in the extended region of the output shaft
housing.
20. The hand-held power tool as claimed in claim 13, wherein at
least one of the output shaft axes is located outside the motor
housing.
21. The hand-held power tool as claimed in claim 20, wherein the at
least one of the output shaft axes located outside the motor
housing includes two rear output shaft axes that are located
outside the constricted region of the motor housing.
22. The hand-held power tool as claimed in claim 20, wherein the at
least one of the output shaft axes located outside the motor
housing is located outside a handle of the hand-held power tool,
outside the motor housing, and/or outside a transitional region
between the handle and motor housing.
23. The hand-held power tool as claimed in claim 22, wherein
another one of the output shaft axes is located inside the motor
housing and/or inside the handle.
24. The hand-held power tool as claimed in claim 13, wherein a
height of the hand-held power tool in a direction of the output
shaft axes deviates by less than 50% from a length of a
substantially bar-shaped handle.
25. The hand-held power tool as claimed in claim 13, wherein a
total length of the hand-held power tool orthogonally to the drive
axis or the output shaft axes is at least 10% greater than a height
of the hand-held power tool in at least one direction of the drive
axis or output shaft axes.
26. The hand-held power tool as claimed in claim 13, wherein the
first sectional area is less than 55% of the second sectional
area.
27. The hand-held power tool as claimed in claim 13, wherein the
hand-held power tool is a grinder configured to drive the plurality
of grinding disks in a rotating and/or oscillating and/or randomly
circular manner.
28. The hand-held power tool as claimed in claim 13, further
comprising: a grinding machine housing comprising: at least one
housing shell element; and at least one further housing shell
element connected to the housing shell element, the at least one
housing shell element and the at least one further housing shell
element at least partially forming a handle, wherein at least one
air vent is defined at least partially in a region of a separating
edge of the at least one housing shell element and the at least one
further housing shell element such that the air vent extends over
two regions that are arranged at an angle of between 90.degree. and
120.degree. relative to one another.
29. A grinding machine housing comprising: at least one housing
shell element; and at least one further housing shell element
connected to the housing shell element, the at least one housing
shell element and the at least one further housing shell element at
least partially forming a handle, wherein at least one air vent is
defined at least partially in a region of a separating edge of the
at least one housing shell element and the at least one further
housing shell element such that the air vent extends over two
regions that are arranged at an angle of between 90.degree. and
120.degree. relative to one another.
30. The grinding machine housing as claimed in claim 29, wherein
the housing shell element and the further housing shell element are
fixed together along an at least substantially entire contact line
and/or face of the at least one housing shell element and the at
least one further housing shell element, at least substantially
without visible fastening elements.
31. The grinding machine housing as claimed in claim 29, wherein
the handle is formed at least substantially without a separating
edge at least on a side of the handle that faces toward and/or
faces away from a tool side.
32. A grinding machine housing comprising: a motor housing portion
and a bar-shaped handle housing portion, wherein the grinding
machine housing has a concave recess in a transitional region
between the bar-shaped handle housing portion and the motor housing
portion such that said concave recess serves as an ergonomic
contact face for a finger or a thumb of a user.
Description
[0001] The present invention relates to a hand-held power tool, in
particular a grinder, for simultaneously driving a plurality of,
preferably for driving three, in particular tiltable grinding disks
that are driven in a rotating and/or oscillating and/or randomly
circular manner.
PRIOR ART
[0002] Hand-held power tools of this kind are known for example
from EP1466698.
DISCLOSURE OF THE INVENTION
[0003] A hand-held power tool having the features of claim 1 is
proposed. Advantageous configurations, variants and developments of
the invention can be found in the dependent claims.
[0004] The invention is based on a hand-held power tool, in
particular a grinder, for simultaneously driving a plurality of,
preferably for driving three, in particular tiltable grinding disks
that are driven in a rotating and/or oscillating and/or randomly
circular manner, having at least one output shaft housing which
encloses at least three output shafts orthogonally to the output
shaft axes, and a motor housing which substantially encloses the
motor orthogonally to the motor shaft axis. It is proposed that a
sectional area of the motor housing orthogonal to the motor shaft
axis in an in particular constricted region of the motor housing
amounts to less than 70%, in particular less than 65%, preferably
less than 55%, relative to a sectional area of the output shaft
housing orthogonal to the output shaft axes in an in particular
extended region, in particular in the most extended region of the
output shaft housing. The constricted region is located in
particular in the region of a motor shaft or a region orthogonal to
the motor shaft of the motor. The constricted region should be
understood as being a narrowed region, in particular the region
with the smallest sectional area. Advantageously, the visibility of
the surface to be machined is increased. The hand-held power tool
can be gripped more easily in different gripping positions. The in
particular bar-shaped handle extends to above the grinding disks,
with the result that the force application point is shifted to the
middle of the plurality of, in particular three grinding disks. The
grinder can optionally also be gripped in the constricted region
and/or a palm can be placed on the output shaft housing. As a
result, the force application point can be shifted very close to
the surface to be ground. Multiple gripping positions, for example
gripping the bar-shaped handle, placing the palm in particular from
above on the motor housing, gripping the constricted region of the
motor housing and/or placing the palm in the region of the output
shaft housing.
[0005] It is proposed that the sectional area of the output shaft
housing in a rear region of the hand-held power tool is covered to
an extent of less than 75%, in particular less than 50%, preferably
less than 25%, by the sectional area, projected along the motor
shaft axis, of the motor housing. The rear region is in particular
the region facing a bar-shaped handle of the hand-held power tool.
By contrast, the front region faces in particular away from the
handle. The region that corresponds to a preferred direction of
movement of the hand-held power tool could also be at the front.
The front can also be located where an output shaft comes to lie in
a plane of mirror symmetry of the hand-held power tool. At the
rear, the output shafts are spaced apart from the plane of mirror
symmetry. Advantageously, the motor housing is arranged
asymmetrically with respect to the output shaft housing. In
particular, the motor is arranged asymmetrically with respect to
the center of the output shaft housing, in particular shifted in
the direction of the front, preferably shifted in an eccentric
manner. Thus, the motor represents a counterweight to the in
particular bar-shaped handle, preferably to the bar-shaped handle
projecting toward the rear. The position of the center of gravity
of the hand-held power tool can be positively affected as a result.
In addition, the visibility of the rear grinding disk is improved.
As a result, the grinder can be controlled or guided better.
Undesired damage caused for example by elements vertically
adjoining the surface to be ground can be avoided. Furthermore, a
gripping capability can be achieved as a result, in particular a
capability of gripping the bar-shaped handle over or between the
output shaft housing and the bar-shaped handle. The force
transmission or guiding of the hand-held power tool can take place
as close as possible to the grinding disks.
[0006] It is proposed that the sectional area of the output shaft
housing in a front region of the hand-held power tool is covered to
an extent of more than 70%, in particular more than 90%, preferably
entirely, by the sectional area, projected along the motor shaft
axis, of the motor housing. As explained above, the location of the
center of gravity, the force application point and/or the balancing
of the motor weight and handle, which accommodates in particular a
rechargeable battery, is positively affected as a result.
[0007] It is proposed that one, in particular two of the three
output shaft axes, in particular the rear two output shaft axes of
the hand-held power tool, are located outside the motor housing, in
particular outside a or the constricted region of the motor
housing. As a result, the motor housing has a very slim structure
compared with the output shaft housing. The visibility of the
material to be ground is increased. The hand-held power tool, in
particular the bar-shaped handle, can be gripped better. An
additional hand support surface is brought about on the output
shaft housing, in particular in the region above the two rear
output shafts.
[0008] It is proposed that one, in particular two of the three
output shaft axes, in particular the rear two output shaft axes of
the hand-held power tool, are located outside a handle, in
particular a bar-shaped handle, preferably outside an indented
region of the handle or an indented transitional region between the
handle and motor housing. The force application point or the
position of the center of gravity of the hand-held power tool is
positively affected as a result. The handle and motor housing can
be embodied in a very compact and/or narrow manner.
[0009] It is proposed that the third, in particular the front
output shaft axis of the hand-held power tool is located inside the
motor housing and/or inside the handle. In this way, an asymmetry
between the motor housing and output shaft housing is created or
eccentricity of the motor relative to the center of the output
shaft housing is brought about. This affords the advantages as
mentioned above.
[0010] An invention is also based on the fact that a grinding
machine housing at least partially forms a handle with at least one
housing shell element and with at least one further housing shell
element connected to the housing shell element, characterized by at
least one air vent, in particular a ventilation slot, formed at
least partially in the region of a separating edge of the housing
shell element and the further housing shell element. The air vent
extends in particular over two regions that are arranged preferably
at an angle, in particular an angle of between 90.degree. and
120.degree., preferably between 100.degree. and 105.degree., to one
another. The length of the region regions differs in particular by
no more than 50%, and preferably they are approximately the same
length. The air vent can be arranged in particular on the right and
left of the abovementioned motor housing. The air vents provide in
particular an intake air and exhaust air capability, in particular
of motor cooling air and exhaust air. Thus, it is possible for
example for cooling air for the motor and/or the electronics of the
hand-held power tool to enter through one air vent and to emerge
through the other air vent. Furthermore, the air vent(s) can be
intended to cool a user's hand and/or potentially evaporate sweat
on the palm that arises when using the hand-held power tool. This
takes place with a preferably with a region of the air vent that is
arranged substantially horizontal and/or parallel to the handle
orientation. The user-friendliness can thus be increased.
[0011] It is proposed that the housing shell element and the
further housing shell element are connected together, in particular
fixed together, in particular along an at least substantially
entire contact line and/or face of the housing shell element and
the further housing shell element, at least substantially without
visible fastening elements. As a result, externally visible screw
holes (for example for connecting conventional housing shells) are
avoided. The appearance and ergonomics are enhanced.
[0012] The tool can be cleaned more easily. Bothersome holes in the
region of the gripping faces are dispensed with.
[0013] It is proposed that the handle of the grinding machine
housing is formed at least substantially without a separating edge
at least on a side of the handle that faces and/or faces away from
a tool side. The ergonomics are enhanced in this way, too. It is
easier to assemble the hand-held power tool. Externally visible
screw-fastening elements can be avoided. Air vents can be
integrated into the in particular lateral separating edges.
[0014] Furthermore, a grinding machine housing having a motor
housing portion and a bar-shaped handle housing portion is
proposed, wherein the grinding machine housing has a concave
recess, in particular an indentation, in a transitional region
between the bar-shaped handle housing portion and the motor housing
portion. As a result, an ergonomic contact face for a finger, in
particular a thumb of the user can be created. The grinding machine
housing can be gripped even better, the hold is improved and
slipping made difficult. When the motor housing is gripped with the
palm, too, the concave recess, in particular on both sides, serves
as an ergonomic contact face for the thumb and/or index finger.
[0015] Furthermore, a hand-held power tool, in particular a
grinder, having an abovementioned grinding machine housing is
proposed.
DRAWINGS
[0016] The invention is explained in more detail in the following
text by way of exemplary embodiments illustrated in the drawings,
in which:
[0017] FIG. 1 shows a front view of the hand-held power tool;
[0018] FIG. 2 shows the hand-held power tool in a sectional
illustration A-A;
[0019] FIG. 3 shows the hand-held power tool in a sectional
illustration B-B;
[0020] FIG. 4 shows a side view of the hand-held power tool in a
rest position;
[0021] FIG. 5 shows a side view of the hand-held power tool;
[0022] FIG. 6 shows a rear view of the hand-held power tool;
[0023] FIG. 7 shows a perspective view of the dust extraction
hood;
[0024] FIG. 8 shows a side view of the system made up of the
hand-held power tool and dust extraction hood;
[0025] FIGS. 9a-9d show four views of the hand-held power tool in
shaded illustration;
[0026] FIG. 10 shows the sectional area and the sectional area
ratio of a constricted and an extended region of the hand-held
power tool;
[0027] FIG. 11 shows a perspective illustration of the hand-held
power tool.
[0028] FIG. 1 shows a front view of the hand-held power tool in the
form of a grinder 10. The grinder 10 is intended for the
simultaneous driving of three grinding disks 12, 14, 16; one front
grinding disk 12 and two rear grinding disks 14, 16. As a result of
a universal-shaft-like or gimbaled mount (cf. FIG. 2) of the
grinding disks 12, 14, 16, the latter are mounted in a pivotable or
tiltable manner. They are driven in rotation and are highly
suitable for grinding even curved surfaces. The grinder 10 is able
to be activated via an actuating switch 18. An identification
element 20 assigns this tool advantageously to a range of tools
and/or a manufacturer.
[0029] FIG. 2 shows the hand-held power tool in the form of a
grinder 10 in a sectional illustration A-A through the plane A (cf.
FIG. 1). The front grinding disk 12 is arranged in front of a
central gear axis 22. It is arranged opposite a handle 24 with
regard to a central gear axis 22. The two rear grinding disks 14,
16, of which only the grinding disk 16 can be seen in this
illustration, are arranged on a side of the central gear axis 22
facing the handle 24. The three grinding disks 12, 14, 16 are of
identical construction and configured in an interchangeable manner.
A motor 26 has a drive shaft 28. The motor 26, or the drive shaft
28 thereof, defines a motor shaft axis 30. Via a pinion 32, the
motor 26 drives a central gear 34 that defines the central gear
axis 22. The central gear 34 is driven by the pinion 32 via a spur
gear 36. The central gear 34 has a toothing 38, with which it
drives three output shafts 40, of which only the front one can be
seen in the section A-A. These output shafts 40 in turn define
output shaft axes 42. Each output shaft 40 is in turn intended to
at least indirectly drive a respective grinding disk 12, 14, 16.
The central gear 34 drives, via the toothing 38, three spur gears
44 (of which the spur gear 44 driving the grinding disk 12 can be
seen in the section and the spur gear 44 driving the grinding disk
16 can be seen in the side view). The front spur gear 44 drives the
output shaft 40; the drive mechanism can be assigned analogously to
all the spur gears 44 driving the grinding disks 12, 14, 16. The
output shaft 40 is mounted here for example via at least one
grooved ball bearing 46 in one housing part 60. A plain bearing 48
additionally supports the output shaft 40 in a further housing part
62. The two housing parts 60, 62 form an output shaft housing 202.
The output shaft housing 202 forms, together with a motor housing
200, which substantially encloses the motor 26, a main housing 64,
which accommodates at least the motor 26, the central gear 34 and
the drive and output shafts 28, 40. The output shaft 40 engages,
via a catch 50 in coupling means 52 of the grinding disk 12. The
grinding disk 12 can be clipped into a grinding disk receptacle 56
by means of latching hooks 54. The grinding disk receptacle 56 is
arranged in the region of an opening 100 in the housing part 60.
Through the opening 100, the coupling means 52 of the grinding disk
12 and the latching hooks 54 can be plugged into the grinding disk
receptacle 56 and onto the catch 50, respectively. The grinding
disk receptacle 56, in addition to allowing the low-friction
rotational mounting of the grinding disk 12 (in this case with a
grooved ball bearing 58), also allows pivoting (in this case by way
of a spherical plain bearing in a spherical receptacle in the
housing part 60). The universal-shaft-like drive allows the
grinding disk to be tilted with respect to the housing part 60 or
relative to the grinder 10. The central gear 34 drives the grinding
disks 12, 14, 16 forcibly in rotation. In principle, however, it is
also possible for the grinding disks 12 to be driven in oscillation
or in a randomly circular manner, for example by way of output
shafts 40 that are accommodated eccentrically in the spur gear 44
and drive the grinding disks 12, 14, 16 in rotation in a positively
coupled or random manner, or an eccentric which generates an
oscillating movement by restricting the degrees of freedom of the
grinding disk and/or of the output shaft--or the like (not
illustrated in more detail here).
[0030] The drive shaft 28 or the motor shaft axis 30 is arranged
eccentrically with respect to the central gear 34 or to the central
gear axis 22, respectively. It is arranged between the front output
shaft axis 42 and the central gear axis 22. The two axes 22, 30 are
intersected by the plane A or come to lie therein. The motor 26 has
been shifted in the direction of the front grinding disk 12 or the
grinding disk receptacle 56 thereof. The motor 26 or the motor
shaft axis 30 thereof is arranged opposite the handle 24 with
regard to the central gear axis 22. The handle 24 is likewise
intersected centrally by the plane A, and ideally divided in a
mirror symmetric manner. The motor shaft axis 30, the central gear
axis 22 and the output shaft axes 42 are oriented parallel to one
another. The handle axis 66, or the central axis 86 or longitudinal
axis 84 of the in particular bar-shaped handle 24 is arranged
transversely to the central gear axis 22. The angle .alpha. is
around 45-135.degree., in the present exemplary embodiment around
100.degree.. The handle 24 projects from the main housing 64. The
plane A or the section plane A-A is, to a certain extent, also
defined by the handle axis 66 and the central gear axis 22. The
handle 24 is bar-shaped, substantially round or oval or the like.
It is formed by the handle housing 68, which can be formed at least
partially in one piece with the main housing 64. The handle 24 is
intended to accommodate a rechargeable battery 70. The latter can
be integrated permanently or be in the form of an exchangeable
rechargeable battery 70. In the present exemplary embodiment, it is
in the form of an exchangeable slide-in rechargeable battery 72. It
is slid into the free end 74 of the handle 24 and is connected to
the handle housing 68 in a releasable manner via latching elements
that are not illustrated here. Optionally, a rotational speed of
the motor 26 can be set via a setting dial 76. Furthermore, the
handle 24 and the main housing 64 are shaped in an ergonomic
manner. The concave indent 78 at the transition from the handle 24
to the main housing 64 serves for intuitively gripping with the
index finger. This region can also be covered with a soft grip 80.
Of course, it is also possible for other regions of the hand-held
power tool to be covered with specifically haptic and/or tactile
materials. However, the top side 82 of the main housing 64 is also
intended for a hand in particular the palm to rest on, in order to
guide the hand-held power tool with two hands or one hand, simply
by gripping the main housing 64.
[0031] FIG. 3 shows the grinder from FIG. 1 in a sectional
illustration B-B in the plane (B). The drive shaft 28 drives the
central gear 34 via the pinion 32. The motor shaft axis 30 and thus
the motor 26 is arranged eccentrically with respect to the central
gear 34. Specifically, it has been shifted in the direction of a
front side 90 of the grinder 10. The central gear axis 22, the
motor shaft axis 30 and the output shaft axis 42 of the front
output shaft come to lie in the plane A. The plane B is defined
orthogonally to this plane A. The output shafts 40 arranged
mirror-symmetrically to the plane A come to lie in the plane B. The
central gear axis 22 is arranged in the center of a regular
triangle 92, in the corners of which the three output shaft axes 42
are arranged. Via the central gear 34, the three spur gears are
driven in rotation. The spur gears 44 in turn drive the output
shafts 40, which at least indirectly drive the grinding disks 12,
14, 16 or grinding disk receptacles 56 (cf. FIG. 2). Furthermore,
parts of the main housing 64, or of the housing part 60 and the
further housing part 62, which keep the drive and output elements
of the grinder 10 in position, are illustrated.
[0032] FIG. 4 shows the grinder 10 in a rest position on a support
surface 94, for example a workpiece to be machined. The grinder 10
rests on three points, specifically on a free end 96 of the
slide-in rechargeable battery 70 (alternatively, it could also rest
on the free end 74 of the handle 24, in particular in the case of a
rechargeable battery 70 permanently installed in the handle 24) and
on the rim 98 of the rear grinding disks 14, 16, in particular the
two rims 98, facing the free end 74, 96 of the handle 24 or
slide-in rechargeable battery 72, of the grinding disks 14, 16
(wherein only the grinding disk 14 is visible since it conceals the
grinding disk 16). In principle, the same reference signs are
allocated to identical components in the various figures, but they
are not necessarily explained again for each figure.
[0033] FIG. 5 shows a side view of the hand-held power tool or a
grinder 10. The housing part 60 has three grinding disk receptacle
regions 102, of which only two can be seen in FIG. 5. A grinding
disk receptacle region 102 is defined as being the region of the
housing part 60 that supports the grinding disk receptacle 56 and
the components thereof, for example bearings. For example, this is
the region with the envelope circle diameter 104 around the
grinding disk receptacle regions 102. In the present exemplary
embodiment, this region is offset from an in particular immediately
surrounding housing region 106 of the housing part 60, in the
direction of the grinding plane 112 (for accommodating the
bearings, improved accessibility and/or for improving the freedom
of movement of the grinding disks 12, 14, 16 for example during
tilting/pivoting). Put another way, the surrounding housing
region(s) 106 is/are set back with respect to the grinding disk
receptacle region(s) 102. This set-back should not be understood as
being a cavity 108 within the meaning of the invention. The
grinding disk receptacle regions 102 each have openings 100,
through which the removable grinding disks 12, 14, 16 can be
connected to the grinder 10. Thus, the coupling means and/or
latching hooks 54 can be connected to the output shafts 40 and/or
grinding disk receptacles 56 (cf. sectional illustration in FIG.
2). Alternatively, however, the grinding disk receptacles 56 or the
output shafts 40 can also project through the grinding disk
receptacle regions 102. If only output shafts 40 project through
the housing part, be this because the grinding disks 12, 14, 16 are
received outside the housing part 60 of the hand-held power tool,
or because the grinding disks 12, 14, 16 are connected permanently
to the output shafts 40, the grinding disk receptacle region 102
can also be understood as being only the region that represents the
opening 100; or the region that mounts the output shafts 40 in the
housing part 60 of the hand-held power tool.
[0034] Between two adjacent grinding disk receptacle regions 102 or
the openings 100 (so to speak in the intermediate space 122), the
housing part 60 has an air duct 120. The latter is formed by a
cavity 108. In the region of the air duct 120 or of the cavity 108,
the distance 110 between the housing part 60 and a grinding plane
112 is increased, in particular increased compared with the
distance 111 of the housing region 106 from the grinding plane 112.
The cavity 108 is accordingly set back with respect to the housing
region 106. The cavity 108 has a concave shape 118. It extends in
the direction of the center of the housing part 60, or becomes
narrower in the circumferential direction. In addition, a dimension
of the cavity decreases in this direction. The housing part is thus
indented or recessed in the direction away from the grinding plane
112. Starting from a central region 114 of the housing part 60, in
particular a central region 114 at the center between the grinding
disks 12, 14, 16 or in the region of the central gear axis 22
intersecting the housing part 60, the distance 110 between the
housing part 60 and grinding plane 112 increases outwardly in the
radial direction, i.e. in the direction of the rim 116 of the
housing part 60, along the air duct, or the cavity 108. The cavity
108 is thus larger in the outer region of the housing part 60 than
in a central region. The cavity 108 serves for better air guidance.
The cavity 108 forms at least a part of an air duct 120, in
particular for dust extraction.
[0035] Similarly to the cavity 108 between the grinding disks 12,
(front and rear grinding disk) or the associated grinding disk
receptacle regions 102, a cavity 108 is also provided between the
rear grinding disks 14, 16 or the associated grinding disk
receptacle regions 102 (cf. FIG. 6). It is also apparent from FIG.
6, which shows a rear view of this cavity, that the cavity or the
distance 110 increases from the central region 114 of the housing
part 60 to the rim 116 of the housing part 60 or radially outwardly
from the center. The rear cavity 108 is constructed in a
mirror-symmetric manner to the plane A (cf. also section A-A
according to FIG. 2). The cavity 108 also allows contact-free
tilting 124 of the grinding disks 12, 14, 16 relative to the
housing part 60. Thus, for example during operation of the grinder
10, a rim of the grinding disk 12, 14, 16 does not rub against the
housing part 10. The three cavities 108 between the grinding disks
12, 14, 16 or the grinding disk receptacles 56 are arranged in a
manner offset from one another in each case by 120.degree. starting
from the center.
[0036] They are each mirror-symmetric to the angle bisector of the
regular triangle.
[0037] FIGS. 5 and 6 also show a housing separating edge 126. The
housing separating edge 126 is arranged between the housing part 60
and the further housing part 62. The two housing parts 60, 62 are
part of the output shaft housing 202 or of the main housing 64. The
housing separating edge 126 represents in particular a housing
parting line 130. The housing separating edge 126 or the housing
parting line 130 is formed by the assembled housing shells of the
hand-held power tool or grinder 10. It forms a set-back in the
housing surface. It encircles the output shaft housing 202. It
represents a form-fitting element 132, in particular a latching
groove 134, serves for receiving a corresponding form-fitting
element 136 of a dust extraction hood 138 (cf. FIG. 7), preferably
a latching protrusion 140 of a dust extraction hood 138. The
form-fitting element 132, rather than a groove or recess, could in
principle also be in the form of a protrusion or male form-fitting
element. Similarly, rather than a male form-fitting element, a
female form-fitting element may be provided on the dust extraction
hood 138. Furthermore, the cavity 108 in the housing part 60 serves
as a further form-fitting element 142, in particular as a stop
element 144 for a further corresponding form-fitting element 146 on
the dust extraction hood 138. When the dust extraction hood 138 is
plugged, as intended, from the grinding disk plane 112 onto the
output shaft housing 202 or is fitted over the housing part 60, the
form-fitting element(s) 146 serve(s) as a stop or stopper. Thus,
the dust extraction hood 138 is not pushed too far onto the output
shaft housing 202. As soon as the form-fitting elements 146 come
into contact, the form-fitting elements 136 also engage in their
intended position or in the corresponding form-fitting elements
132.
[0038] FIG. 7 shows a perspective view of the dust extraction hood
138. A removable dust-extraction hood 138 for a hand-held power
tool, in particular for the grinder 10, is, in particular wherein
the hand-held power tool is configured to drive a plurality of, in
particular tiltably mounted, grinding disks 12, 14, 16 that are
drivable in rotation and/or oscillation and/or in a randomly
circular manner. The dust extraction hood 138 has a connecting
piece 148 for connecting to a dust extraction device (not
illustrated here)--typically a mobile or stationary vacuum cleaner
or dust extraction device. The connecting piece 148 projects
towards the outside 149 of the dust extraction hood 138. The dust
extraction hood 138 has an extraction opening 150 starting from the
connecting piece 148, said extraction opening 150 being open toward
the inside 152 of the dust extraction hood 138. The dust extraction
hood 138 has a substantially triangular geometry, in particular a
substantially regular triangular geometry. The term "substantially"
should be understood here as meaning that the corners 154 of the
"triangle", as illustrated in FIG. 7, can be rounded. In addition,
the legs 156 can also deviate to a certain extent from a straight
form, for example be slightly arcuate or the like.
[0039] In the region of the extraction opening 150, the dust
extraction hood 138 has an extension 158. The latter serves to
avoid a transverse airflow, in particular from beneath 184 (cf.
FIG. 8) the extension 158, i.e. beneath that side of the extension
158 that faces away from the extraction opening 150. The extension
158 projects into the inside 152 of the dust extraction hood 138.
Starting from the extraction opening 150, the extension 158 has a
main extension direction 160 into the inside 152 of the dust
extraction hood 138. Furthermore, the extension 158 has at least
one, in particular two walls 162. The latter serve(s) to reduce
transverse airflow, in particular to reduce transverse airflow from
beneath 184 the dust extraction hood 138 and/or from the side 164
within the dust extraction hood 138. The extension 158 and/or the
wall 162 can, however, also be open at least partially at the side
166, 168, in particular to allow transverse airflow in at least
this region 170, 172. The extension 158 forms a part of an air duct
159. In particular, the part of the air duct 120 and the other part
of the air duct 159 together form an air duct 120, 159.
[0040] The dust extraction hood 138, or the frame 174 of the dust
extraction hood 138, is flexible, in particular transversely to the
underside or top side of the dust extraction hood 138 or in the
direction of the inside 152 or the outside 149 of the dust
extraction hood 138. This allows spring-elastic preloading and/or
pressing of the dust extraction hood 138 against the hand-held
power tool, in particular the grinder 10, or the housing thereof.
As a result, a tool-free and/or secure and/or low-gap connection to
the grinder 10 can be established.
[0041] The frame 174 or the dust extraction hood 138 narrows from
bottom to top. In the region of the form-fitting elements 136, for
connecting to the form-fitting elements 142 of the hand-held power
tool, the frame 174 or the dust extraction hood 138 is narrowed.
This ensures that an upper rim 186 of the frame 174 or of the dust
extraction hood 138 can bear as far as possible without a gap
against the housing of the hand-held power tool. The preloading
force of the dust extraction hood 138 in this region can thus act
particularly efficiently.
[0042] Furthermore, the dust extraction hood 138 can be in the form
of a spacer and/or impact protector for the hand-held power tool or
grinder (cf. also FIG. 8). Rather than the housing of the grinder
10, the frame 174, or the rounded corners 154 and/or legs 156
serve(s) as impact protector. The dust extraction hood 138 also has
a gripping contour 176. The gripping contour 176 represents a
slight elevation on the leg 156 or the frame 174. The friction
between finger and dust extraction hood 138 when the dust
extraction hood 138 is pushed onto or pulled off the grinder 10 is
improved as a result. In addition, the gripping contour 176
resembles the silhouette contour 178 at least of a region of the
hand-held power tool or grinder (cf. FIGS. 5 and 6). The silhouette
contour is formed in this case by the contour of the rim 116 of the
housing part 60, in particular in the region of the cavity 108, in
particular when the rim 116 or the grinder 10 is viewed from the
side.
[0043] FIG. 8 illustrates the system made up of the hand-held power
tool or grinder 10 and the connected or plugged-on dust extraction
hood 138. In addition to the above-described components, the dust
extraction hood 138 or the hand-held power tool or grinder 10 has
an in particular elastic connecting element 179, in particular an
elastic band 180, preferably a rubber-elastic band 180, for
connecting the connecting piece 148 or a connecting-piece adapter
182 and the grinder 10. The elastic band 180 is tensioned in
particular between a free end 74, 96 of the handle 24 or
rechargeable battery 70, 72 of the grinder and the connecting piece
148 or connecting-piece adapter 182. Preferably, the elastic band
is fastened captively to the connecting piece 148, connecting-piece
adapter 182 or handle 24. In this case for example by being
adhesively bonded to or injection molded on the connecting-piece
adapter. Alternatively, the band can also be releasable on one
side, such that, in the open state, it can be attached to or
wrapped around the respectively other component and be fixed
again--for example by way of a snap fastener, a locking mechanism
or the like.
[0044] FIG. 9, subfigures a-d, shows the hand-held power tool or
grinder 10 from the preceding figures in a shaded illustration in
order to also make curves visible. Subfigure 9a shows the grinder
10 in a side view, subfigure 9b shows it in a rear view, subfigure
9c in a perspective view and subfigure 9d in a plan view. The
grinder 10 is for the simultaneous driving of three, in particular
tiltable, grinding disks 12, 14, 16 that are driven in rotation
and/or oscillation and/or in a randomly circular manner, having at
least one output shaft housing 202, which substantially encloses
three output shafts 40 (not illustrated here, cf. in particular
FIG. 2) orthogonally to the output shaft axes 42, 202, 204, 206,
and a motor housing 200 which substantially encloses the motor 26
orthogonally to the motor shaft axis 30. The grinder 10 has a
handle 24. The front output shaft axis 42, 204 can be distinguished
better from the rear output shaft axes 42, 206, 208 by the
additional reference signs. The output shaft housing 202 encloses
the three output shafts 40 at least substantially orthogonally to
the output shaft axes 42. The motor housing 200 encloses the motor
26 at least substantially orthogonally to the motor shaft axis
30.
[0045] A sectional area 210 of the motor housing 200 orthogonal to
the motor shaft axis 30 in a constricted region 212 of the motor
housing 200 amounts to less than 70%, in particular less than 65%,
preferably less than 55%, relative to a sectional area 214 of the
output shaft housing 202 orthogonal to the output shaft axes 42 in
an extended of the output shaft housing 202, in particular in the
most extended region 216 of the output shaft housing 202. In the
illustrated FIG. 10, it amounts to around 52%. The extended region
216 should be understood as being in particular the region with the
greatest sectional area 214 of the output shaft housing 202. Thus,
in this region 216, an extent for example the length 218 of the
circumferential distance or length 215 around the output shaft
housing 202, is at a maximum. Furthermore, in the side view, rear
view and plane view in subfigures 9a-c, a length and a width of the
motor housing 200 in the constricted region 212 and of the output
shaft housing 202 in the extended region 216 are provided with the
following reference signs: output shaft housing 202: length 218,
width 220; motor housing: length 222, width 224. In terms of ratio,
the extended region 216 of the output shaft housing 202 with
respect to the constricted region 212 of the motor housing 200 is
around 30% longer and around 65% wider. The sectional area ratio of
the extended region 216 of the output shaft housing 202 with
respect to the constricted region 212 of the motor housing 200 also
amounts to around 190% (cf. FIG. 10).
[0046] The sectional area ratio of certain regions is also apparent
from FIG. 10. The sectional area 214 of the output shaft housing
202 in a rear region 226 of the hand-held power tool or grinder 10
is covered to an extent of less than 75%, in particular less than
50%, preferably less than 25%, by the sectional area 210, projected
along the motor shaft axis 30, of the motor housing 200, in
particular in the constricted region 212. Similarly, the grinding
area 232 of grinding disks 14, 16 applied to the rear of the
grinder 10 is covered to an extent of less than 75%, in particular
less than 50%, preferably less than 25%, by the sectional area 210,
projected along the motor shaft axis 30, of the motor housing 200,
in particular in the constricted region 212. In a front region 228
of the hand-held power tool, the sectional area 210, projected
along the motor shaft axis 30, of the motor housing 200, in
particular also in the constricted region 212, covers the sectional
area 214 of the output shaft housing 202 to an extent of more than
70%, in particular more than 90%, preferably entirely. Similarly,
the grinding area 234 of a grinding disk 12 applied at the front of
the grinder 10 is covered to an extent of more than 70%, in
particular more than 90%, preferably entirely, by the sectional
area 210, projected along the motor shaft axis 30, of the motor
housing 200, in particular also in the constricted region 212.
[0047] Furthermore, a circumferential length 211 of the motor
housing 200 orthogonal to the motor shaft axis 30 or the output
shaft axes 42 in an in particular constricted region 212 of the
motor housing 200 relative to a circumferential length 215 of the
output shaft housing 202 orthogonal to the output shaft axes 42,
204, 206, 208 in an in particular extended region 216 of the output
shaft housing 202 can be seen in FIG. 10. It amounts to less than
80%, in this case approximately 70%. Put another way, the
circumferential length 215 of the output shaft housing 202 compared
with the circumferential length 211 of the motor housing 200 in the
constricted region 212 amounts to around 145%.
[0048] Furthermore, one, in particular two of the three output
shaft axes 42, in particular the rear two output shaft axes 206,
208 of the hand-held power tool, is/are located outside the motor
housing 200, in particular outside the constricted region 212 of
the motor housing 200. These output shaft axes 206, 208 thus at
least do not intersect the motor housing 200 in the constricted
region 212, and in particular do not intersect the motor housing
200 anywhere. Furthermore, in particular one, preferably two of the
three output shaft axes 204, 206, 208, in particular the rear two
output shaft axes 206, 208 of the hand-held power tool or grinder
10, are located outside the handle 24, in particular outside the
bar-shaped handle 24. They are also located outside an indented
region 230 or a concave recess in the handle 24 and/or motor
housing 200 or outside an indented transitional region 276 between
the handle 24 and motor housing 200. The front output shaft axis
204 of the hand-held power tool or grinder 10 is located inside the
motor housing 200 and/or inside a motor housing handle 236--and
therefore intersects it/them.
[0049] It is also apparent from the side view according to FIG. 9a
that the ratio of the height 238, 240 of the hand-held power tool
in the direction of the output shaft axes 42, 204, 206, 208, in
particular a height 238 of a motor and output shaft housing 200,
202, to the length 242 of a substantially bar-shaped handle 24, in
particular a length 242 of a bar-shaped handle 24 projecting
substantially orthogonally with respect to the motor housing 200 or
the drive and output shaft axis 30, 204, deviates by less than 50%,
in particular by less than 75%, preferably by less than 85%, in
particular is more or less identical. A bar-shaped handle
projecting substantially orthogonally with respect to the drive and
output shaft axis/axes 30, 204 should be understood here as being
in an angular range from 60.degree.-120.degree., in particular from
75.degree.-105.degree., preferably 90.degree. with regard to the
drive and output shaft axis/axes 30, 204, 206, 208. Advantageously,
a very compact hand-held power tool can be provided as a result.
The center of gravity S thus moves as close as possible to the
grinding disks 12, 14, 16. Furthermore, a ratio of a total length
244 of the hand-held power tool orthogonal to at least one drive or
output shaft axis 30, 42, 204, 206, 208, in particular from an end
of the motor housing 200 to an end of the handle 24 projecting in a
bar-shaped manner, relative to a height 238, 240 of the hand-held
power tool in at least one direction of the drive or output shaft
axis 30, 42, 204, 206, 208, in particular from a grinding disk
plane 112 to the end of the handle 24 or motor housing 200, is
greater than 10%, in particular greater than 25%, preferably around
40% greater.
[0050] Furthermore, the weight of the rechargeable battery 72
relative to the components of the power train, in particular
comprising the motor 26, the pinion 32, the central gear 34, the
output shafts 40 and spur gears 44, amounts to around 10-50% more,
in particular 30-40% more. As a result, the position of the center
of gravity S can be positively affected. A volume of the motor and
output shaft housing 200, 202 compared with the bar-shaped handle
housing 68 amounts to around 20-70% more, in particular around 50%
more.
[0051] Furthermore, a grinding machine housing 250 having at least
one housing shell element 252 and having at least one further
housing shell element 254 connected to the housing shell 252, which
at least partially form a handle 24, 258, can be seen in the side
view and the perspective view according to FIGS. 9a, d and FIG. 11.
The grinding machine housing 250 is characterized by at least one
air vent 262, in particular a ventilation slot, formed at least
partially in the region of a separating edge 260 of the housing
shell element 252 and the further housing shell element 254. The
air vent 262 extends advantageously over two regions 264, 266 that
are arranged at an angle 268, in particular an angle 268 (cf. FIG.
10, side view) of between 90.degree. and 120.degree., preferably
between 100.degree. and 105.degree. to one another. Advantageously,
the angle is based on the orientation of the bar-shaped handle with
respect to the motor housing. The air vent regions are
advantageously oriented parallel to the main extent thereof.
Advantageously, the air vent 262, in particular the one of the
portion 266 in the region of the handle 258, is intended to blow
air around a user's hand, in particular to cool, heat and/or dry
it.
[0052] The housing shell element 252 and the further housing shell
element 254 are connected together, in particular fixed together,
in particular along an at least substantially entire contact line
and/or face of the housing shell element 252 and the further
housing shell element 254, at least substantially without visible
fastening elements. Furthermore, the handle 24, 258 is formed at
least substantially without a separating edge on a side of the
handle 24, 258 that faces and/or faces away from a grinding disk
12, 14, 16 or tool side.
[0053] Furthermore, the grinding machine housing 250 has a motor
housing portion 270 and a bar-shaped handle housing portion 272,
wherein the grinding machine housing 250 has a concave recess 278
or an indentation (cf. FIG. 10) in a transitional region 276
between the bar-shaped handle housing portion 272 and the motor
housing portion 270. Said recess or indentation serves as an
ergonomic contact face for a finger, in particular a thumb of the
user. The indentation is readily apparent in particular from the
side view in FIG. 9a. The shading indicates the curved regions.
Preferably, the air vent(s) 262 is/are able to be formed by an
offset of a housing edge of the housing shell element 252 and of
the further housing shell element 254.
* * * * *