GEAR HEAD AND HAND-HELD POWER TOOL

Abstract

A gear head for a hand-held power tool for machining workpieces, in particular for an angle grinder. The gear head including a gear plate, a housing closable by the gear plate, in which a power take-off is accommodated, which is connectable to a drive of the hand-held power tool, the power take-off including a tool shaft protruding from the gear plate, which is at least partially surrounded by a safety guard fastenable to a gear flange of the housing. A securing lever locks the safety guard on the gear flange, the securing lever being adjustable around a pivot axis between a first position, in which the safety guard is rotatably fixedly connected to the gear flange and a second position, in which the safety guard is rotatable with respect to the gear flange against a force of a restoring element acting in a direction of the first position.

Claims

1. A gear head for a hand-held power tool for machining workpieces, the gear head comprising: a gear plate; a housing closable by the gear plate, in which a power take-off is accommodated, which is connectable to a drive of the hand-held power tool, the power take-off including a tool shaft protruding from the gear plate, which is at least partially surrounded by a safety guard fastenable to a gear flange of the housing; a securing lever locks the safety guard on the gear flange, which is supported on the gear plate, the securing lever being adjustable around a pivot axis between a first position, in which the safety guard is rotatably fixedly connected to the gear flange and a second position, in which the safety guard is rotatably with respect to the gear flange against a force of a restoring element acting in a direction of the first position; and a securing device that limits an adjustment of the securing lever beyond the first position, the securing device having a contact surface.

2. The gear head according to claim 1, wherein a gap, whose width is between 0.5 mm and 1.0 mm, is formed between the securing lever and the contact surface in the first position.

3. The gear head according to claim 1, wherein the ratio between a length of the contact surface and a length of the securing lever is between 1:8 and 1:4.

4. The gear head according to claim 1, wherein the contact surface is formed in the area of the pivot axis.

5. The gear head according to claim 1, wherein the securing device having the contact surface has an essentially wedge-shaped cross section.

6. The gear head according to claim 1, wherein the securing device is formed as a single piece with the gear plate.

7. The gear head according to claim 1, wherein the securing device is detachably connected to the gear plate.

8. The gear head according to claim 7, wherein the securing device is screwed to the gear plate.

9. The gear head according to claim 7, wherein the securing device has an S-shaped design with a first leg, which forms the contact surface and with a second leg, which is accommodated in the gear plate.

10. The gear head according to claim 1, wherein the securing device has a securing engagement formed on the gear plate and a securing hook formed on the securing lever.

11. The gear head according to claim 10, wherein the securing hook is disposed in the area of the end of the securing lever facing away from the pivot axis.

12. The gear head according to claim 1, wherein the pivot axis is oriented in parallel to the tool shaft.

13. A handheld power tool, in particular an angle grinder, comprising a gear head according to claim 1.

13. The gear head according to claim 1, wherein the hand-held power tool is an angle grinder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0023] FIG. 1 shows a perspective view of a hand-held power tool;

[0024] FIG. 2 shows a top view from below of an exemplary embodiment of a gear head according to the invention;

[0025] FIG. 3 shows a perspective view of a gear plate;

[0026] FIG. 4 shows a perspective view of a securing lever;

[0027] FIG. 5 shows a perspective view of the gear plate of an exemplary embodiment of the gear head according to the invention;

[0028] FIG. 6 shows a perspective view of a securing lever;

[0029] FIG. 7 shows a perspective view of an exemplary embodiment of the gear head according to the invention;

[0030] FIG. 8 shows a perspective view of a gear plate; and

[0031] FIG. 9 shows a securing component of the gear head.

DETAILED DESCRIPTION

[0032] FIG. 1 shows a perspective view of a gear head 1, which is assigned to a hand-held power tool 2 for machining workpieces, which is formed, in the exemplary embodiment, as an angle grinder 3. It is also apparent from FIG. 1 that a safety guard 4 is fastened to gear head 1, whose rotational position on a gear flange 5 is lockable with the aid of a securing lever 6. As is further apparent, in particular, from FIGS. 4 and 6, securing lever 6 has two latching tabs 7, which engage with recesses 8, which are formed on safety guard 4.

[0033] FIG. 2 shows a top view from below of gear head 1, which comprises a housing 10, closable by a gear plate 9, in which a power take-off is accommodated. This power take-off, in turn, is connected to a drive of hand-held power tool 2 and comprises a tool shaft 11 protruding from gear plate 9, on which a tool 12 may be fastened, as is apparent from FIG. 1. Securing lever 6 is provided on gear flange 5 to secure safety guard 4, which is not illustrated for the sake of clarity. Securing lever 6 is supported on gear plate 9, adjustable around a pivot axis 14 between a first position, in which safety guard 4 is rotatably fixedly connected to gear flange 5, and a second position, in which safety guard 4 is rotatable with respect to gear flange 5, against the force of a restoring element 13 acting in the direction of the first position. In the view illustrated in FIG. 2, pivot axis 14 is oriented collinearly with the longitudinal axis of screw 15 and thus in parallel to tool shaft 11. To prevent an adjustment of securing lever 6 beyond first position in the first position of securing lever 6, which would be associated with a mechanical deformation thereof, a securing device 16 is provided, which has a contact surface 17, with which securing lever 6 comes into contact if it is adjusted beyond the first position.

[0034] As is apparent, in particular in the view illustrated in FIG. 3 of gear plate 9 in the first specific embodiment of gear head 1 according to the invention, this securing device 16 is formed as a single piece with gear plate 9 and has an essentially wedge-shaped cross section. Contact surface 17 is formed in the area of pivot axis 14 of securing lever 6. In the illustrated exemplary embodiment, the ratio between the length of contact surface 17 and the length of securing lever 6 is between 1:8 and 1:4, namely approximately 1:6. A receptacle 22 for the screw defining pivot axis 14 as well as latching tabs 7, with the aid of which the rotational position of safety guard 4 may be fixed on gear flange 5, are apparent from FIG. 4, which shows securing lever 6.

[0035] FIG. 5 shows a gear plate 9 in a second specific embodiment of gear head 1 according to the invention. In this specific embodiment, contact surface 17 is shorter than in the first specific embodiment according to FIG. 3, while a securing engagement 18 is additionally formed on gear plate 9, with which a securing hook 19 engages, which is apparent, in particular, from FIG. 6 and which is situated in the area of the end of securing lever 6 facing away from pivot axis 14, if securing lever 6 is adjusted beyond the first position. Securing engagement 18 and securing hook 19 are ultimately part of securing device 16 in this specific embodiment. It would also be possible to form securing device 16 exclusively from securing engagement 18 and securing hook 19 and to dispense with a contact surface 17.

[0036] In the third exemplary embodiment of gear head 1 illustrated in FIG. 7, securing device 16 is screwed to gear plate 9. For this purposeas is apparent from FIG. 8an indentation 24, which at least partially represents a negative shape of securing device 16, is worked into gear plate 9. It has an S-shaped design with a first leg 20, which forms contact surface 17, and with a second leg 21, which is accommodated in a recess 23 formed in gear plate 9. First leg 20 and second leg 21 are each oriented perpendicularly to gear plate 9, and the area between the two legs 20, 21 rests in indentation 24 in gear plate 9.

[0037] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.