U.S. patent application number 12/485422 was filed with the patent office on 2009-12-17 for power tool, in particular handheld power tool.
Invention is credited to Florian ESENWEIN, Manfred LUTZ, Joerg MAUTE.
Application Number | 20090311953 12/485422 |
Document ID | / |
Family ID | 40940855 |
Filed Date | 2009-12-17 |
United States Patent
Application |
20090311953 |
Kind Code |
A1 |
MAUTE; Joerg ; et
al. |
December 17, 2009 |
POWER TOOL, IN PARTICULAR HANDHELD POWER TOOL
Abstract
A power tool includes a guard hood to be fixed on a tightening
neck via a securing device thereof. The securing device has a
securing part, which is to be tightened via an actuation element,
and a detent component which is adjustable between a detent or
locked position and a nondetent or unlocked position. The actuation
element acts upon both the securing part and the detent
component.
Inventors: |
MAUTE; Joerg; (Sindelfingen,
DE) ; ESENWEIN; Florian; (Uhingen-Holzhausen, DE)
; LUTZ; Manfred; (Filderstadt, DE) |
Correspondence
Address: |
RONALD E. GREIGG;GREIGG & GREIGG P.L.L.C.
1423 POWHATAN STREET, UNIT ONE
ALEXANDRIA
VA
22314
US
|
Family ID: |
40940855 |
Appl. No.: |
12/485422 |
Filed: |
June 16, 2009 |
Current U.S.
Class: |
451/359 ;
451/451 |
Current CPC
Class: |
B24B 23/02 20130101;
B23Q 11/06 20130101; B24B 55/052 20130101 |
Class at
Publication: |
451/359 ;
451/451 |
International
Class: |
B24B 55/05 20060101
B24B055/05; B24B 23/00 20060101 B24B023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 17, 2008 |
DE |
10 2008 002 468.6 |
Claims
1. A power tool, in particular a handheld power tool, such as a
ring-angle sander, comprising: a guard hood, to be fixed to a
tightening neck via a securing part; a detent component that is
lockable in a detent position against the tightening neck; and a
actuation element which is common for the securing part and the
detent component, by way of which the securing pan and the detent
component are adjustable relative to the tightening neck.
2. The power tool as defined by claim 1, wherein the tightening
neck of the power tool has a set of teeth, extending in a
circumferential direction, which is engaged by a detent element of
the detent component in the detent position.
3. The power tool as defined by claim 1, wherein a circumferential
groove is provided on the tightening neck.
4. The power tool as defined by claim 2, wherein a circumferential
groove is provided on the tightening neck.
5. The power tool as defined by claim 3, wherein toothlike, axially
extending indentations are made in a jacket face of the tightening
neck, beginning at the circumferential groove on the tightening
neck.
6. The power tool as defined by claim 4, wherein toothlike, axially
extending indentations are made in a jacket face of the tightening
neck, beginning at the circumferential groove on the tightening
neck.
7. A guard hood for a power tool, in particular for a handheld
power tool, such as a ring-angle sander as defined by claim 1, the
guard hood is securable on the tightening neck of the power tool
via the securing device, which tightening neck has both the
securing part, to be adjusted via the actuation element, and the
detent component, which is adjustable into the detent position and
a nondetent position relative to the tightening neck, wherein the
actuation element acts upon both the securing part and the detent
component, and with the fastening of the securing part via the
actuation element, the detent component is to be put simultaneously
into the detent position.
8. The guard hood as defined by claim 7, wherein the securing part
of the securing device is a tightening ring, which is to be
tightened via the actuation element.
9. The guard hood as defined by claim 7, wherein the detent
component is retained on the securing part.
10. The guard hood as defined by claim 7, wherein the detent
component is supported in articulated fashion and is pivotable
between the detent position and the nondetent position.
11. The guard hood as defined by claim 10, wherein the actuation
element acts upon the detent component with spacing from a pivot
joint axis thereof.
12. The guard hood as defined by claim 10, wherein the pivot joint
axis of the detent component is located between a detent element of
the detent component which acts upon the securing part and a
contact point for the actuation element.
13. The guard hood as defined by claim 10, wherein the detent
element acting upon the securing part is located between a contact
point for the actuation element and the pivot joint axis of the
detent component.
14. The guard hood as defined by claim 7, wherein the detent
component is disposed on an outside of the securing part, and that
in the detent position, the detent element of the detent component
protrudes through the securing part.
15. The guard hood as defined by claim 7, wherein the actuation
element is retained translationally adjustably on the securing part
and in particular is embodied as a screw.
16. The guard hood as defined by claim 7, wherein the detent
component is subjected to force into the nondetent position via a
spring element.
17. The guard hood as defined by claim 16, wherein the spring
element is embodied in one piece with the detent component.
18. The guard hood as defined by claim 7, wherein the actuation
element rests loosely on the detent component.
19. The guard hood as defined by claim 7, wherein the actuation
element is connected to the detent component, in particular via a
slaving element.
20. The guard hood as defined by claim 7, wherein the detent
component, in the detent position, effects a form lock in the
circumferential direction.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based on German Patent Application 10
2008 002 468.6 filed Jun. 17, 2008.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a power tool, in particular a
handheld power tool, such as a ring-angle sander, and to a guard
hood for a power tool.
[0004] 2. Background of the Invention
[0005] From German Patent Disclosure DE 102 59 520 A1, an electric
handheld power tool with a disklike rotating tool is known over
which a guard hood fits that is retained with the aid of a
tightening ring on a tightening neck of the power tool. There is
also a tool receptacle in the tightening ring for the rotating
support of the tool. The tightening ring for fixing the guard hood
to the tightening neck is tightened with the aid of a screw.
[0006] On the outside of the tightening ring, a detent component is
also supported in articulated fashion. By means of a detent
element, the detent component protrudes through a recess in the
wall of the tightening ring and engages a set of teeth on the outer
jacket of the tightening neck. In this way, a form lock in the
circumferential direction between the tightening ring and the
tightening neck can be created, which prevents twisting of the
tightening ring and guard hood on the tightening neck. This
increases safety, particularly in the event of breakage of the
tool.
[0007] The detent element is disposed on a detent grip, which is
supported in articulated fashion on the outside of the tightening
ring and can be pivoted manually between the detent position, in
which the detent element is in engagement with the set of teeth on
the tightening neck, and a nondetent or unlocked position.
OBJECT AND SUMMARY OF THE INVENTION
[0008] The object of the invention is, with high functional safety,
to simplify a power tool, in particular a handheld power tool,
having a guard hood retained on a tightening neck via a securing
device, in its handling and structural makeup, as well as to create
a guard hood suitable as original equipment for such a power tool
but also suitable as a conversion part or retrofitting part of
power tools.
[0009] In the power tool of the invention, by means of the common
actuation of the securing part and the detent component via an
actuation element a common adjustment of the securing part and
detent component is attained, and thus in one work step, not only
is the securing part put in its securing position, but the detent
component is also put in its detent position relative to the
tightening neck.
[0010] Hence the actuation element is given a dual function: First,
the securing part is tightened, and second, the detent component is
adjusted into the detent position. A separate actuation of the
detent component can thus be omitted. It suffices, via the
actuation element, to put the securing part into the tightening
position, and at the same time, via the actuation element, the
detent component is adjusted into the detent position. The result
is considerably simpler handling, achieved by structurally simple
means. With the tightening of the securing part, this part exerts a
radial clamping force, by way of which the guard hood is firmly
clamped on the tightening neck. By way of the detent component
which is in engagement with the tightening neck, additional
securing is achieved, and this additional securing is embodied in
particular as a form lock which is operative in the circumferential
direction and/or the axial direction; for that purpose, the
tightening neck has a circumferentially extending set of teeth on
its jacket face that are engaged by the detent element in the
detent position.
[0011] A circumferential groove can moreover be provided on the
tightening neck and preferably extends over the entire
circumference of the tightening neck. In combination with the set
of teeth, this leads to an embodiment in which the toothlike
indentations forming the set of teeth extend in the axial
direction, originating at the circumferential groove.
[0012] The circumferential groove has the function of securing the
guard hood axially on the tightening neck in form-locking fashion.
This is preferably effected via the detent element of the detent
component, which thus besides the securing in the circumferential
direction is also given the function of securing in the axial
direction. When the guard hood is adjusted in the circumferential
direction, the detent element can be moved inside the
circumferential groove. However, in principle, it is also possible
for a further component, such as a pin or a peg on the guard hood
or the tightening ring, to engage the circumferential groove.
[0013] In an alternative embodiment, the circumferential groove is
embodied separately from the set of teeth; for instance, the
circumferential groove is axially offset from the set of teeth on
the jacket face of the tightening neck. In this embodiment, the
securing in the axial direction is effected via a separate
component, such as the aforementioned pin or peg.
[0014] The guard hood of the invention is preferentially used in
handheld power tools, in particular electrically operated handheld
power tools, with a rotating, preferably disklike tool, such as a
ring-angle sander, in which the guard hood that surrounds the
rotatingly supported tool of the power tool, is to be fastened via
the securing device on a tightening neck of the power tool. The
securing device of the guard hood has a securing part, which is to
be tightened via an actuation element, and also has a detent
component, which is to be adjusted by the tightening neck between a
detent position and a nondetent or unlocked position.
[0015] In the guard hood of the invention and its securing device,
it is provided that the actuation element acts upon both the
securing part and the detent component, and with the fastening of
the securing part via the actuation element, the detent component
is to be put simultaneously into the detent position. Despite the
dual function of the securing device, the result is a simple
construction of the guard hood, which as a functional unit with its
securing device also forms a spare part and retrofitting part
that--at least without major requirement for adaptation--can also
be used to replace guard hoods of different construction in many
power tools.
[0016] The securing par is preferably embodied as a tightening
ring, which is laid around the tightening neck and tightened via
the actuation element. In principle, however, structurally
different securing with which the guard hood is to be secured to a
component of the power tool can also be considered.
[0017] In a preferred embodiment, the detent component is retained
solely on the securing part, so that the securing part and the
detent component form a common module which is to be adjusted by
the actuation element. The actuation element too can be retained
directly on the securing part, particularly when embodied as a
screw that in the case of an embodiment as a tightening ring
connects two radially upward-bent end portions of the tightening
ring in a known manner. The free face end of the screw preferably
acts as the contact face with which the screw is in contact with
the detent component and adjusts the detent component from the
nondetent position into the detent position.
[0018] In principle, however, it is also possible to retain the
detent component on some other tool component, for instance
directly on the guard hood or on a housing part of the power tool.
It is furthermore possible for the actuation element to be embodied
not as a screw but instead as a toggle fastener, and the toggle
fastener acts on the detent component during the tightening
process. Optionally, the actuation element is retained not on the
tightening ring but on some other component, such as the guard hood
or a housing part.
[0019] Various possibilities of movement for the detent component
upon the transfer from the nondetent position to the detent
position can be considered. Preferably, the detent component
executes a pivoting or rotary motion then, but within the scope of
the invention a translational adjusting motion or a mixed
translational-rotary adjusting motion is possible.
[0020] In the case of articulated support, the engagement or
contact point is located between the actuation element and the
detent component, spaced apart from the joint axis of the detent
component, so that it is assured that a resultant torque becomes
operative about the joint axis, and by means of this torque the
detent component is adjusted into the detent position.
[0021] It may furthermore be expedient to associate a spring
element with the detent component, the spring element
advantageously being braced on the same component as the detent
component, in particular on the tightening ring, and subjecting the
detent component to force in the direction of the nondetent
position. It is thus assured that the detent component is
automatically restored to the nondetent position by the action of
the spring element as soon as the actuation element is adjusted
into the release position, in which the tightening ring is also
located in the relaxed state. Thus with a single adjusting motion
of the actuation element, on the one hand the tightening ring is
tightened and simultaneously the detent component is adjusted into
the detent position, and on the other, upon an opposite motion of
the actuation element, the tightening ring is relaxed and at the
same time the detent component is adjusted into the detent
position.
[0022] However, it may also be expedient, in addition or
alternatively to the spring element, to provide mechanical coupling
between the actuation element and the detent component, by way of
which coupling the detent component, upon a releasing motion of the
actuation element, is pulled by the actuation element into the
nondetent position. The coupling can be effected via a slaving
element, for instance.
[0023] In the case of articulated support, the pivot joint of the
detent component can assume various positions relative to the
detent element, which arrives in contact with the tightening neck,
and to the actuation element, as long as a spacing both between the
pivot joint and the detent element and between the pivot joint and
the contact point between the actuation element and the detent
component is assured. For instance, an arrangement in which the
detent element is located between the pivot joint and the contact
position with the actuation element can be considered. However,
positioning the pivot joint between the detent element and the
actuation element is also possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will be better understood and further objects
and advantages thereof will become more apparent from the ensuing
detailed description of preferred embodiments taken in conjunction
with the drawings, in which:
[0025] FIG. 1 is a section through an electric handheld power tool
in an embodiment of the invention, of a ring-angle sander, in the
region of the tool over which a guard hood fits that is retained on
a tightening neck of the power tool;
[0026] FIG. 2 shows the tightening neck and guard hood in a section
perpendicular to the axis of the tool;
[0027] FIG. 3 shows the securing device of the guard hood according
to the invention, by way of which the guard hood is secured to the
tightening neck, with a tightening ring, a screw tightening the
tightening ring, and a detent component that is to be adjusted by
the screw into a detent position;
[0028] FIG. 4a shows a further securing device, in which the detent
component has a modified embodiment;
[0029] FIG. 4b shows a spring element which exerts force on the
detent component of FIG. 4a;
[0030] FIG. 5 shows a further securing device in an alternative
embodiment;
[0031] FIG. 6 shows a bearing flange with a tightening neck, in
which a bearing for the tool is received, and a circumferential
groove, with a set of teeth with which the detent component is to
be put into the detent position, is made in the outer jacket face
of the tightening neck; and
[0032] FIG. 7, similarly to FIG. 6, shows a bearing flange, but
with a separate, axially offset embodiment of the circumferential
groove and of a set of teeth extending over the circumference.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] In the drawings, identical components are identified by the
same reference numerals.
[0034] The handheld power tool 1 shown in FIG. 1 is embodied as a
right-angle or cutting sander, which in a tightening neck 2 has a
bearing 3 for rotationally supported reception of a drive spindle 4
that is the carrier of a tool 5 embodied as a sanding wheel or
cutting wheel. The tool 5 is partly surrounded by a guard hood 6,
which has an integrally formed-on cylindrical collar 7 that is
slipped onto the outside of the tightening neck 2. The collar 7 is
firmly clamped to the tightening neck 2 via a tightening ring 8 of
a securing device; an additional detent component for securing in
the circumferential direction and/or the axial direction is
provided, and the detent component 9 protrudes through a recess in
the collar 7 and into a toothlike indentation 10 that is made in
the jacket face of the tightening neck 2.
[0035] As can be seen from FIG. 2, the tightening ring 8, in a
manner known per se, on its face ends has end portions 8a, 8b bent
radially upward, in each of which a recess is made through which a
screw 11 is passed that forms an actuation element. The screw is
secured to the tightening ring via a nut, so that when the screw 11
is turned, the tightening ring 8 is tightened and presses against
the tightening neck 2 with increasing, radially acting tightening
force.
[0036] The free face end 12 of the screw 11 is in contact with a
portion of the detent component 9 that is to be put into a detent
position by the tightening neck 2. As can be seen from FIG. 2 in
conjunction with FIG. 3, the detent component 9 is embodied as a
lever, and a detent element 13 is embodied in one piece with the
detent component 9 and, compared to the approximately
circumferentially extending base body of the detent component 9,
extends radially inward in the direction of the outer jacket face
of the tightening neck 2. A recess 14 is made in the tightening
ring 8 and the detent element 13 protrudes through this recess.
[0037] The base body of the detent component 9 is supported
rotatably or pivotably via a pivot joint 15 on the side facing away
from the screws 11 and at the same time is retained on the
tightening ring 8. The pivot joint 15 is located on the outside of
the tightening ring 8 and is connected to the tightening ring 8. A
spring element can additionally be provided, which exerts force on
the detent component 9 into the nondetent position, in which
position the detent element 13 of the detent component 9 is at
least partially raised out of the recess 14. The pivot joint 15
enables the detent component 9 to execute a rotary motion about an
axis that is parallel to the axis of rotation of the tool.
[0038] On the side toward the actuation element, the base body of
the detent component 9 has a contact portion 9a, which is bent in
hooklike fashion and is contact with the fee face end 12 of the
actuation element that is embodied as a screw 11. The hooklike
contact portion 9a is embodied such that as the screw 11 is screwed
increasingly in, the base body of the detent component 9 and thus
the detent element 13 as well are adjusted into the detent position
by way of the contact between the free face end 12 and the portion
9a. The detent position is shown in bow FIG. 2 and FIG. 3. If a
spring element is provided that exerts force on the detent
component 9 into the nondetent position, then a leg spring that is
placed around the pivot joint 15 can for instance be employed.
[0039] In the exemplary embodiment of FIGS. 2 and 3, the pivot
joint 15 is located on the side facing away from the screw 11. The
detent element 13 on the detent component 9 is located between the
pivot joint 15 and the contact point between the free face end 12
of the screw 11 and the hooklike contact portion 9a of the detent
component 9.
[0040] Instead of a separately embodied spring element it is also
possible to make the detent component 9 from a resilient material,
such as spring steel, and to prestress it such that the detent
component 9 in the mounted position is adjusted by its own tension
into the nondetent position. This has the advantage that a spring
element embodied as a separate component can be dispensed with.
[0041] The detent component 9 has an end stop 23, which originating
at the pivot joint 15 is disposed on the side of the pivot joint
remote from the actuation element embodied as a screw 11. The end
stop 23 has the function of limiting the upward pivoting motion of
the detent component 9 about the axis of rotation of the pivot
joint 15. To that end, the end stop 23, preferably embodied in one
piece with the detent component, protrudes at an angle from the
outside of the tightening ring 8, and the angle with the outside of
the tightening ring 8 defines the maximum upward pivoting angle of
the detent component 9. In the maximally upward-pivoted position,
the end stop 23 rests on the outside of the tightening ring 8.
[0042] In the exemplary embodiment of FIG. 4a, the detent component
9 is shown in an alternative embodiment. The pivot joint 15 of the
detent component 9 is located between the detent element 13 and the
contact point on the free face end 12 of the actuation element. The
base body of the detent component 9 is constructed in angular form,
and the free face end, facing away from the pivot joint 15,
simultaneously forms the detent element 13, which is passed through
the recess 14 in the tightening ring 8. Near the angular region in
the base body, the free face end 12 of the screw 11 is in contact
with the detent component 9.
[0043] In FIG. 4b, a spring element 16 embodied as a leg spring is
shown in detail; it can be placed around the pivot joint 15 of FIG.
4a and in the mounted position it exerts force on the detent
component 9 into the nondetent position.
[0044] In FIG. 5, a further exemplary embodiment is shown, in which
it is fundamentally possible to dispense with a separate spring
element that urges the detent component 9 into the nondetent
position. The adjustment of the detent component 9 both from the
nondetent position into the detent position and in the opposite
direction, that is, from the detent position into the nondetent
position, is effected via the adjusting motion of the actuation
element embodied as a screw 11. For that purpose, the screw 11 is
connected in the region of its face end to the base body of the
detent component 9 via a slaving element 17. On the side opposite
the slaving element 17, there is a spring element 18, which is
embodied as a compression spring and presses the detent component 9
axially against the slaving element 17. It is thus assured first
that upon a screwing-in motion of the actuation element 11, the
detent component 9 is adjusted into the detent position, and second
that with the aid of the spring element 18 and of the axial
displacement motion of the detent component 9 on the actuation
element, play and flexibility in the components can be compensated
for. The detent element 13, which in the detent position is in
engagement with the set of teeth on the jacket face of the
tightening neck, is as in the preceding exemplary embodiment
embodied in one piece with the base body of the detent component
9.
[0045] The axial displacement capability of the detent component 9
along the axis of the screw 11 offers the farther advantage that
upon a relative rotation of the tightening ring 8 clockwise in
terms of FIG. 5, self-locking occurs, and hence the form lock
between the detent component and the set of teeth on the tightening
neck increases. In the opposite direction, conversely, the detent
component can execute a relative motion because of the free travel
on the actuation element, and as a result a limited play is
achieved.
[0046] In FIG. 6, a bearing flange 19 is shown, including a base
plate 20 and the tightening neck 2 embodied in one piece with the
base plate, the bearing 3 for the drive spindle 4 being received in
this tightening neck. A set of teeth 21 is made in the outer jacket
face of the tightening neck 2 and comprises a plurality of axially
extending toothlike indentations, distributed over the
circumference, which are associated with the detent element of the
detent component; in the detent position, the detent element
protrudes into a respective toothlike indentation. As a result, a
form lock in both the circumferential direction and the axial
direction is attained.
[0047] The toothlike indentations each extend axially from a
circumferential groove 22 that extends over the entire
circumference of the tightening neck 2. The detent element of the
detent component can be displaced along the circumferential groove
22. However, optionally, a component embodied separately from the
detent element, such as a pin or the like, protrudes into the
circumferential groove and thereby secures both the tightening ring
and the guard hood in the axial direction on the tightening
neck.
[0048] In the exemplary embodiment of FIG. 7, which also shows a
bearing flange 19 with a base plate 20 and a tightening neck 2, the
set of teeth 21 is embodied separately from the circumferential
groove 22. The set of teeth 21 is located adjacent to the top side
of the base plate 20; conversely, the circumferential groove 22 is
located adjacent the face end of the tightening neck 2. In this
embodiment, it is absolutely necessary that a component embodied
separately from the detent component protrude into the
circumferential groove 22, this component for instance being a pin
or the like.
[0049] The foregoing relates to preferred exemplary embodiments of
the invention, it being understood that other variants and
embodiments thereof are possible within the spirit and scope of the
invention, the latter being defined by the appended claims.
* * * * *