Hand-Held Power Tool

Abstract

A hand-held power tool includes a housing, a drive motor, an intermediate shaft that can be driven by the drive motor, and a percussion mechanism. The percussion mechanism has a striker and at least one percussion mechanism spring which is connected to the striker in a rotationally fixed manner, and the percussion mechanism can be driven at least in part by the intermediate shaft. The hand-held power tool further includes a tool holder, which is configured for holding an insert tool, and can be driven by means of the percussion mechanism, in particular the striker and/or the intermediate shaft. The intermediate shaft includes at least one bearing, and the percussion mechanism spring is connected to the bearing in a rotationally fixed manner.

Claims

1. A hand-held power tool comprising: a housing; a drive motor; an intermediate shaft driven by the drive motor; a percussion mechanism comprising a striker and at least one percussion mechanism spring which is connected and rotationally-fixed to the striker the percussion mechanism configured to be driven at least in part by the intermediate shaft; and a tool holder configured to receive an insert tool, the tool holder configured to be driven by the percussion mechanism, wherein the intermediate shaft comprises at least one bearing, and the percussion mechanism spring is connected to the bearing in a rotationally fixed manner.

2. The hand-held power tool according to claim 1, wherein the intermediate shaft further comprises at least one planet carrier, and the bearing is disposed between the percussion mechanism spring and the planet carrier.

3. The hand-held power tool according to claim 1, wherein the bearing comprises a fastening element configured to connect the percussion mechanism spring to the bearing in the rotationally fixed manner.

4. The hand-held power tool according to claim 3, wherein the bearing comprises at least one stabilizing element configured to connect the fastening element to the bearing.

5. The hand-held power tool according to claim 1, wherein the percussion mechanism spring rests against a bearing race of the bearing.

6. The hand-held power tool according to claim 1, wherein the bearing comprises at least one centering element configured to center the bearing relative to the intermediate shaft.

7. The hand-held power tool according to claim 1, wherein the bearing comprises at least one retaining element configured to restrain rolling elements of the bearing.

8. The hand-held power tool according to claim 1, wherein the percussion mechanism further comprises at least one further percussion mechanism spring.

9. The hand-held power tool according to claim 1, wherein: the striker comprises a guide element, the bearing comprises a guide opening, and the guide element is configured to engage through the guide opening.

10. The hand-held power tool according to claim 1, wherein the striker comprises a projecting element that projects at least partly beyond the bearing.

11. The hand-held power tool according to claim 1, wherein the tool holder is driven by at least one of the striker and the intermediate shaft.

12. The hand-held power tool according to claim 4, wherein the at least one stabilizing element is configured to connect the fastening element to a bearing race of the bearing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The invention is explained in the following with reference to preferred embodiments. In the following, the drawings show:

[0041] FIG. 1 a schematic view of a hand-held power tool according to the invention;

[0042] FIG. 2 a longitudinal section of a first embodiment of a percussion mechanism of the hand-held power tool;

[0043] FIG. 3 a longitudinal section of a second embodiment of a percussion mechanism of the hand-held power tool;

[0044] FIG. 4 a longitudinal section of a third embodiment of a percussion mechanism of the hand-held power tool;

[0045] FIG. 5 a longitudinal section of a fourth embodiment of the percussion mechanism of the hand-held power tool;

[0046] FIG. 6 sectional views of a first embodiment of a rotationally fixed connection between a percussion mechanism spring and a striker;

[0047] FIG. 7 sectional views of a second embodiment of a rotationally fixed connection between the percussion mechanism spring and the striker;

[0048] FIG. 8 sectional views of a third embodiment of a rotationally fixed connection between the percussion mechanism spring and the striker;

[0049] FIG. 9 sectional views of a fourth embodiment of a rotationally fixed connection between the percussion mechanism spring and the striker;

DESCRIPTION OF THE EMBODIMENT EXAMPLES

[0050] FIG. 1 shows a hand-held power tool 100 according to the invention, wherein it is configured here as a cordless rotary impact screwdriver, for example. The hand-held power tool 100 comprises an output shaft 124, a tool holder 150 and a percussion mechanism 122, e.g. a rotary percussion mechanism or percussion-rotation mechanism. The hand-held power tool 100 comprises a housing 110 with a handle 126. To provide a mains-independent power supply, the hand-held power tool 100 can be mechanically and electrically connected to a power supply for cordless operation, so that the hand-held power tool 100 is configured as a cordless hand-held power tool 100. A hand-held power tool rechargeable battery pack 130 is used here as the power supply. The present invention is not limited to cordless hand-held power tools, however, but can also be used for mains-dependent, i.e. mains-operated, hand-held power tools.

[0051] The housing 110 comprises a drive unit 111 and the percussion mechanism 122, wherein the drive unit 111 and the percussion mechanism 122 are disposed in the housing 110. The drive unit 111 further includes an electrically commutated drive motor 114, which is supplied with current by the hand-held power tool rechargeable battery pack 130, and a gear unit 118. The gear unit 118 is configured as at least one planetary gear 166, see also FIGS. 2 to 5. The drive motor 114 is designed such that it can be actuated, for example via a manual switch 128, so that the drive motor 114 can be switched on and off. The drive motor 114 can advantageously be electronically controlled and/or regulated, so that a reversing mode and a desired rotational speed can be implemented. For the reversing mode, the hand-held power tool 100 comprises a rotation direction switching element 121 configured as a rotation direction changeover switch. The rotation direction switching element 121 is configured to switch the drive motor 114 between a clockwise direction of rotation and a counterclockwise direction of rotation. The design and mode of operation of a suitable drive motor are sufficiently well-known to those skilled in the art, which is why they will not be discussed in more detail here.

[0052] The gear unit 118 is connected to the drive motor 114 via a drive shaft 116. The drive shaft 116 is mounted in the housing 110 by means of a bearing 180. The gear unit 118 is provided to convert a rotation of the drive shaft 116 into a rotation between the gear unit 118 and the percussion mechanism 122 via an intermediate shaft 120. This conversion preferably takes place in such a way that the intermediate shaft 120 rotates relative to the drive shaft 116 with increased torque, but at a reduced rotational speed, see also FIGS. 2 to 5. The intermediate shaft 120 drives the percussion mechanism 122 at least partly. The gear unit 118 comprises a gear housing 119, which is disposed in the housing 110. The hand-held power tool 100 comprises a tool axis 102, wherein here an axis of rotation of the drive shaft 116 forms the tool axis 102.

[0053] The percussion mechanism 122 is connected to the intermediate shaft 120 and comprises a striker 300 and at least one percussion mechanism spring 320 which is connected to the striker 300 in a rotationally fixed manner, wherein, during a percussive operating mode, the percussion mechanism 122 generates high-intensity impact-like rotary pulses, see also FIGS. 2-8. The intermediate shaft 120 comprises a bearing 200, see also FIG. 2-5. The percussion mechanism spring 320 is connected to the bearing 200 in a rotationally fixed manner. These impact-like rotary pulses are transmitted to the output shaft 124, for example a work spindle, via the striker 300. The percussion mechanism 122 comprises a percussion mechanism housing 123, wherein the percussion mechanism 122 can also be disposed in another suitable housing, such as the gear housing 119. The percussion mechanism 122 is configured to drive the output shaft 124. A tool holder 150 is provided on the output shaft 124. The tool holder 150 is preferably molded onto and/or configured on the output shaft 124. The tool holder 150 is preferably disposed in an axial direction 132 facing away from the drive unit 111. The tool holder 150 is configured here as a hexagon socket, in the form of a bit holder, which is provided to accommodate an insert tool 140. The insert tool is configured in the form of a screwdriver bit with a polygonal external coupling 142. The type of the screwdriver bit, for example HEX type, is sufficiently well-known to those skilled in the art. The present invention is not limited to the use of HEX screwdriver bits, however; other tool holders that appear useful to the those skilled in the art, such as HEX drills, SDS quick-insert tools or round-shank drill chucks, can be used as well. The design and functioning of a suitable bit holder are sufficiently well-known to those skilled in the art as well.

[0054] The hand-held power tool 100 comprises a control unit 170 at least for controlling the drive unit 111, in particular the drive motor 114. The housing 110 at least partly accommodates the control unit 170. The control unit 170 comprises a not further depicted microprocessor. The housing 110 also comprises a power supply holding device 160. The power supply holding device 160 accommodates the hand-held power tool rechargeable battery pack 130 and forms a base 162 comprising a standing surface. The hand-held power tool rechargeable battery pack 130 can be released from the power supply holding device 160 without tools. The housing 110 also comprises the handle 126 and the power supply holding device 160. The handle 126 can be grasped by the user. In one embodiment, the power supply holding device 160 is disposed on the handle 126. The hand-held power tool 100 can be set down on the base 162.

[0055] FIG. 2 shows a longitudinal section 400 of a first embodiment of the percussion mechanism 122 of the hand-held power tool 100. The percussion mechanism 122, the intermediate shaft 120, the gear unit 118 and the output shaft 124 are shown, wherein, in this example, the intermediate shaft 120 forms part of the gear unit 118. The intermediate shaft 120 is disposed between the drive motor 114 and the tool holder 150; the drive motor 114 and the tool holder 150 are not shown here. The gear unit 118 is configured as the planetary gear 166, and a planetary gear stage is formed here as an example. In addition to the gear housing 119, the gear unit 118 comprises a gear cover 125. The gear cover 125 is provided here to at least partly close the gear unit 118 with respect to the drive motor 114. The gear cover 125 is disposed between the planetary gear 166 and the drive motor 114. The planetary gear 166 also comprises a ring gear 129, wherein the ring gear 129 and the gear cover 125 are one piece as an example. The intermediate shaft 120 comprises an intermediate shaft bearing 164. The gear cover 125 comprises a receptacle for the intermediate shaft bearing 164, so that the receptacle for the intermediate shaft bearing 164 accommodates the intermediate shaft bearing 164. The intermediate shaft bearing 164 enables the intermediate shaft 120 to be rotatable relative to the gear cover 125.

[0056] The percussion mechanism 122 is connected to the drive motor 114 by means of the planetary gear 166. The percussion mechanism 122 is configured here as a V-groove percussion mechanism, see also FIGS. 3 to 5. The percussion mechanism 122 is disposed between the drive motor 114 and the tool holder 150. The striker 300 and the percussion mechanism spring 320 are disposed in the percussion mechanism housing 123. The percussion mechanism 122 comprises a percussion mechanism cover 127, wherein the percussion mechanism cover 127 closes off the percussion mechanism 122 in the direction of the drive motor 114. The percussion mechanism cover 127 is disposed between the drive motor 114 and the planetary gear 166. In this case, the percussion mechanism cover 127 and the gear cover 125 are one piece for example, and the percussion mechanism cover 127 then forms the ring gear 129.

[0057] The striker 300 and the percussion mechanism spring 320 are disposed in circumferential direction around the intermediate shaft 129 and are connected to the striker 300 in a rotationally fixed manner. In this example, the percussion mechanism spring 320 is configured as a spiral spring. The striker 300 is mounted on the intermediate shaft 120 by means of percussion mechanism balls 310, see also FIGS. 3 to 5. The percussion mechanism balls 310 is provided to move the striker 300 at least partly in the direction of the drive motor 114. FIG. 2 shows the striker 300 in a position facing the tool holder 150. The striker 300 can also be disposed in a position facing the drive motor 114, see FIGS. 4 and 5. In the position facing the tool holder 150, the striker 300 rests against a rear end of the tool holder 150, i.e. the output shaft 124, by means of two percussion cams 312. In the position facing the drive motor 114, the striker 300 is disposed spaced apart from the tool holder 150.

[0058] The drive motor 114 comprises the drive shaft 116, wherein the drive shaft 116 is mounted in the housing 110 by means of a drive shaft bearing 117. The drive shaft 116 is not shown in FIG. 2. In this example, the drive shaft bearing 117 is configured as a needle bearing. The drive shaft bearing 117 is disposed here at an end of the drive motor 114 facing the tool holder 150. The drive shaft 116 projects into the intermediate shaft 120 through the planetary gear 166. The drive shaft bearing 117 is disposed in the intermediate shaft 120.

[0059] The percussion mechanism spring 320 can be rotated relative to the intermediate shaft 120 by means of the bearing 200. In this example, the bearing 200 is configured as a needle bearing 202. The planetary gear 166 comprises a planet carrier 280. The bearing 200 is disposed axially between the percussion mechanism spring 320 and the planet carrier 280. In addition to the planet carrier 280, the planetary gear 166 comprises a plurality of planet gears 282 and bearing bolts 284. The bearing bolts 284 are provided to rotatably connect the planet gears 282 to the planet carrier 280. The intermediate shaft 120 and the planet carrier 280 are one piece as an example.

[0060] The bearing 200 comprises a bearing race 210. The percussion mechanism spring 320 rests against the bearing race 210. The bearing 200 further comprises rolling elements 220. The bearing race 210 is disposed in the percussion mechanism housing 123 in the direction toward the tool holder 150. The bearing race 210 is disposed axially between the rolling elements 220 and the percussion mechanism spring 320. In this example, the bearing race 210 is substantially disk-shaped, as a kind of disk. The rolling elements 220 are configured as needles 222 in this example. The bearing race 210 has a side 211 facing the percussion mechanism spring 320 and a side 212 facing the drive motor 114. The side 211 of the bearing race 210 facing the percussion mechanism spring 320 is substantially flat here as an example. The side 212 of the bearing race 210 facing the drive motor 114 comprises a rolling element holder 213. The rolling element holder 213 is provided to accommodate and support the rolling elements 220 of the bearing 200. In this example, the rolling element holder 213 is configured to be one piece with the bearing race 210 and is substantially flat.

[0061] The bearing 200 comprises a fastening element 350. The fastening element 350 is provided to connect the percussion mechanism spring 320 to the bearing 200 in a rotationally fixed manner. The bearing 200, in particular the bearing race 210, forms the fastening element 350 here, so that they are one piece. In this example, the fastening element 350 is disposed in a radial direction between the intermediate shaft 120 and the percussion mechanism spring 320. The percussion mechanism spring 320 rests against the fastening element 350 and forms a press connection. The fastening element 350 is configured as a circumferential web 352, for example. The percussion mechanism spring 320 has an inner perimeter and an outer perimeter. In this example, the percussion mechanism spring 320 rests against the fastening element 350 via the inner perimeter. The fastening element 350 engages in the inner perimeter of the percussion mechanism spring 320.

[0062] The bearing 200 also comprises a stabilizing element 370. The stabilizing element 370 is provided to connect the fastening element 350 to the bearing race 210. The stabilizing element 370 is disposed axially between the bearing race 210 and the fastening element 350. The stabilizing element 370 is disposed as a kind of arch 372 between the fastening element 370 and the bearing race 210, for example. The bearing race 210 forms the stabilizing element 370 and the fastening element 350 here, for example, so that they are one piece.

[0063] The planet carrier 280 of the planetary gear 166 is configured at least partly as a bearing cover disk 240 of the bearing 200, wherein the planet carrier 280 and the bearing cover disk 240 are one piece. In addition to the bearing race 210, the bearing 200 comprises the rolling elements 220 and the bearing cover disk 240. The bearing cover disk 240 is disposed here opposite the bearing race 210. The rolling elements 220 are disposed, in particular axially, between the bearing race 210 and the bearing cover disk 240. The bearing cover disk 240 is also disposed in the percussion mechanism housing 123 in the direction toward the drive motor 114. The bearing cover disk 240 has a side 241 facing the tool holder 150, wherein the side 241 of the bearing cover disk 240 facing the tool holder 150 is disposed opposite the side 212 of the bearing race 210 facing the drive motor 114. The side 241 of the bearing cover disk 240 facing the tool holder 150 also comprises a further rolling element holder 242, wherein the further rolling element holder 242 is provided to accommodate and support the rolling elements 220. The rolling elements 220 can be accommodated and supported by the rolling element holder 213 of the bearing race 210 and the further rolling element holder 242 of the bearing cover disk 240. The bearing race 210 can be rotated relative to the bearing cover disk 240. The further rolling element holder 242 is shaped complementarily to the rolling elements 220 and accommodates the rolling elements 220 in a form-locking manner, for example, wherein the further rolling element holder 242 is one piece with the bearing cover disk 240 in this example. The further rolling element holder 242 is substantially flat, for example. The rolling element holder 213 and the further rolling element holder 242 are configured in the same way.

[0064] The bearing 200, in particular the bearing race 210, comprises a centering element 214. The centering element 214 is provided to center the bearing 200 relative to the intermediate shaft 120. The bearing race 210 forms the centering element 214 here, so that they are one piece. The centering element 214 is provided to center and align the rolling elements 220 relative to the intermediate shaft 120. In this example, the centering element 214 is configured as an at least partly circumferential web 215. The centering element 214 at least partly surrounds the rolling elements 220 in axial direction. The centering element 214 is configured on an inner perimeter 201 of the bearing 200, wherein the centering element 214 is then disposed radially between the tool axis 102 and the rolling elements 220. The fastening element 350 and the centering element 214 are disposed and formed opposite to one another on the bearing race 210. The fastening element 350 is disposed on the inner perimeter 201 of the bearing 200 here, and the centering element 214 is disposed on an outer perimeter of the bearing 200.

[0065] The bearing 200, in particular the bearing cover disk 240, comprises at least one retaining element 244. The retaining element 244 is provided to radially restrain the rolling elements 220. The bearing cover disk 240 forms the retaining element 244, so that they are one piece. Thus the planet carrier 280 forms the retaining element 244 in this example. The retaining element 244 is configured as a circumferential step 245, for instance. The retaining element 244 is disposed radially between the rolling elements 220 and the tool axis 102. The rolling elements 220 are disposed radially between the retaining element 244 and the centering element 214.

[0066] The striker 300 comprises a spring receptacle 302. The percussion mechanism spring 320 comprises a connecting element 322. The spring receptacle 302 is provided to at least receive the connecting element 322 in a form-locking manner and connect it to the striker 300 in a rotationally fixed manner. The striker 300 has a free end 306 directed in the direction of the tool holder 150 and a free end 308 directed in the direction of the drive motor 114. The percussion cams 312 are configured on the free end 306 directed in the direction of the tool holder 150, see also FIGS. 3 to 5. The percussion mechanism spring 320 is disposed on the free end 308 of the striker directed in the direction of the drive motor 114. On the free end 308 directed in the direction of the drive motor 114, the striker 300 has an inner perimeter 301. The spring receptacle 302 is formed on the inner perimeter 301 of the free end 308 directed in the direction of the drive motor 114. The spring receptacle 302 is disposed on the striker 300 in circumferential direction and axially to the percussion cams 312. In this example, the striker 300 forms the spring receptacle 302, so that they are one piece. As an example, the spring receptacle 302 is configured here as a cylindrical opening, see FIGS. 3 to 9.

[0067] The percussion mechanism spring 320 forms the connecting element 322, for example, so that they are one piece. The connecting element 322 is configured as a pin-like insertion end on a free end of the percussion mechanism spring 320 in the direction toward the tool holder 150, see FIGS. 3 to 9. In this example, the connecting element 322 and the spring receptacle 302 are connected to one another in a form-locking manner. The spring receptacle 302 is formed in the striker 300 axially along the intermediate shaft 120, so that it is aligned axially along the tool axis 102.

[0068] The striker 300 comprises a guide element 303. The bearing 200, in particular the bearing race 210, comprises a guide opening 203. The guide element 303 is provided to engage through the guide opening 203. The striker 300 forms the guide element 303 here, so that they are one piece. The guide element 303 is also provided to guide the striker 300 on the intermediate shaft 120 at least during the percussive operating mode. The guide element 303 is disposed at least partly in circumferential direction around the intermediate shaft 120. The guide element 303 is configured as a sleeve in this example. The bearing race 210 forms the guide opening 203 here, wherein the guide opening 203 configured as a circular central opening in the bearing 200. The rolling elements 220 can be moved in circumferential direction around the guide opening 203.

[0069] The striker 300 comprises a projecting element 309. The projecting element is provided to project at least partly beyond the bearing 200, in particular the bearing race 210, very particularly the bearing race 210 and the rolling elements 200. In this case, the striker 300 forms the projecting element 309, so that they are one piece. The projecting element 309 is configured as an at least partly circumferential step, for example. The projecting element 309 projects beyond the bearing 200, in particular the bearing race 210, when the striker 300 is disposed in the position facing the drive motor 114.

[0070] FIG. 3 shows a longitudinal section 402 of a second embodiment of the percussion mechanism 122 of the hand-held power tool 100. FIG. 3 shows the striker 300 in the position facing the tool holder 150. The fastening element 350 is disposed here on the inner perimeter 201 of the bearing 200, and the centering element 214 is disposed on an inner perimeter 201 of the bearing 200. The retaining element 244 is configured here as an at least partly circumferential web 245, for example. The retaining element 244 is disposed radially between the rolling elements 220 and the percussion mechanism housing 123.

[0071] The percussion mechanism 122 comprises a further percussion mechanism spring 340 here, wherein the further percussion mechanism spring 340 is connected to the striker 300 in a rotationally fixed manner. The further percussion mechanism spring 340 is configured as a spiral spring in this example. The further percussion mechanism spring 340 also rests against the bearing 200, wherein the fastening element 350 engages in the inner perimeter of the percussion mechanism spring 320. The percussion mechanism spring 320 has an outer perimeter, wherein the percussion mechanism spring 320 receives the further percussion mechanism spring 340 on the outer perimeter, so that the further percussion mechanism spring 340 at least partly encloses the percussion mechanism spring 320. The percussion mechanism spring 320 and the further percussion mechanism spring 340 are then disposed substantially concentrically in the percussion mechanism 122 along the tool axis 102. The percussion mechanism spring 320 and the further percussion mechanism spring 340 are disposed in the percussion mechanism housing 123 in circumferential direction to the intermediate shaft 120. The percussion mechanism spring 320 has a winding direction and the further percussion mechanism spring 340 has a further winding direction. The winding direction is wound to the right and the further winding direction is wound to the left, for example.

[0072] The further percussion mechanism spring 340 can also be rotated relative to the intermediate shaft 120 by means of the bearing 200. The bearing 200 is disposed axially between the further percussion mechanism spring 340 and the planet carrier 280. The bearing race 210 is disposed axially between the rolling elements 220 and the further percussion mechanism spring 340.

[0073] The striker 300 comprises a further spring receptacle 304. The spring receptacle 302 and the further spring receptacle 304 are configured substantially concentric to one another in the striker 300, wherein the spring receptacle 302 and the further spring receptacle 304 are configured next to one another in radial direction from the tool axis 102, see also FIGS. 6 to 9. The spring receptacle 302 and the further spring receptacle 304 are separated from one another here by means of a web 305, see also FIGS. 6 to 9. The further percussion mechanism spring 340 comprises a further connecting element 342. The further spring receptacle 304 is provided to at least receive the further connecting element 342 in a form-locking manner and connect it to the striker 300 in a rotationally fixed manner. The further percussion mechanism spring 340 is also disposed on the free end 308 of the striker directed in the direction of the drive motor 114. The further spring receptacle 304, too, is formed on the inner perimeter 301 of the free end 308 directed in the direction of the drive motor 114. The spring receptacle 302 and the further spring receptacle 304 are disposed on the striker 300 in circumferential direction and axially to the percussion cams 312, see also FIGS. 6 to 9. In this example, the striker 300 also forms the further spring receptacle 304, so that they are one piece. The further spring receptacle 304 is formed as a cylindrical opening, for example.

[0074] The further percussion mechanism spring 340 forms the further connecting element 342, for example, so that they are each one piece. The further connecting element 342 is configured as a pin-like insertion end on a free end of the further percussion mechanism spring 340 in the direction toward the tool holder 150. In this example, the further connecting element 342 is connected to the further spring receptacle 304 in a form-locking manner. The further spring receptacle 304 is formed in the striker 300 axially along the intermediate shaft 120, so that they are aligned axially along the tool axis 102. The spring receptacle 302 and the further spring receptacle 304 are configured substantially parallel and radially offset to the intermediate shaft 120 in the striker 300, see also FIGS. 6 to 9.

[0075] FIG. 4 shows a longitudinal section 403 of a third embodiment of the percussion mechanism 122 of the hand-held power tool 100. The striker 300 is shown in the position facing the drive motor 114. The fastening element 350 is configured here on the outer perimeter of the bearing 200, and the centering element 214 is configured on the inner perimeter 201 of the bearing 200. The fastening element 350 rests against an outer perimeter of the further percussion mechanism spring 340 here and forms a press connection with it. The fastening element 350 is moreover one piece with the bearing race 210.

[0076] FIG. 5 shows a longitudinal section 404 of a fourth embodiment of the percussion mechanism 122 of the hand-held power tool 100. The striker 300 is shown in the position facing the drive motor 114. The bearing 200 comprises a further fastening element 360. The bearing race 210 forms the fastening element 350, the further fastening element 360, and the centering element 214. The fastening element 350 and the further fastening element 360 are each formed as a circumferential web 352, 362. The centering element 214 is formed on the inner perimeter 201 of the bearing as a circumferential web 215. The fastening element 350 engages in the inner perimeter of the percussion mechanism spring 320 and forms a press connection with it. The further fastening element 360 surrounds the outer periphery of the further percussion mechanism spring 340 and forms a press connection with it. The retaining element 244 is formed here as the circumferential web 245.

[0077] FIG. 6 shows sectional views 420 of a first embodiment of a rotationally fixed connection between the percussion mechanism spring 320 and the striker 300, in which the further percussion mechanism spring 340 is shown as well. FIG. 6a shows a cross-sectional view and FIG. 6b shows a longitudinal sectional view of the first embodiment of the rotationally fixed connection. The spring receptacle 302 and the further spring receptacle 304 are configured offset to one another in circumferential direction, for example in an angular range of substantially 180. The spring receptacle 302 and the further spring receptacle 304 are each formed as a cylindrical opening and are both configured substantially axially and parallel to the tool axis 102. The connecting element 322 is configured here as a pin-like insertion end and is connected to the spring receptacle 302 in a form-locking manner. The further connecting element 342 is configured here as a pin-like insertion end here and is connected to the further spring receptacle 304 in a form-locking manner. The spring receptacle 302 and the further spring receptacle 304 are each formed in the striker 300 axially along the tool axis 102.

[0078] FIG. 7 shows sectional views 430 of a second embodiment of a rotationally fixed connection between the percussion mechanism spring 320 and the further percussion mechanism spring 340 and the striker 300. FIG. 7a shows a cross-sectional view and FIG. 7b shows a longitudinal sectional view of the second embodiment of the rotationally fixed connection. The spring receptacle 302 and the further spring receptacle 304 are configured offset to one another in circumferential direction. The spring receptacle 302 is configured as a polygonal opening in this example, and the further spring receptacle 304 is configured as a Z-shaped opening. The connecting element 322 is configured here as a V-shaped leg and is connected to the spring receptacle 302 in a form-locking manner. The further connecting element 342 is configured here as a Z-shaped leg and connected to the further spring receptacle 304 in a form-locking manner. The spring receptacle 302 and the further spring receptacle 304 are each configured in the striker 300 transverse to the tool axis 102.

[0079] FIG. 8 shows sectional views 440 of a third embodiment of a rotationally fixed connection between the percussion mechanism spring 320 and the further percussion mechanism spring 340 and the striker 300. FIG. 8a shows a cross-sectional view and FIG. 8b shows a longitudinal sectional view of the third embodiment of the rotationally fixed connection. The spring receptacle 302 and the further spring receptacle 304 are configured offset to one another in circumferential direction. The spring receptacle 302 and the further spring receptacle 304 are both configured as a ring-shaped groove, for example. The connecting element 322 is configured here as a ring-shaped spring end and is connected to the spring receptacle 302 by means of a press fit. The further connecting element 342 is configured here as a ring-shaped spring end and is connected to the further spring receptacle 304 by means of a press fit. The spring receptacle 302 and the further spring receptacle 304 are each configured in the striker 300 transverse to the tool axis 102.

[0080] FIG. 9 shows sectional views 450 of a fourth embodiment of a rotationally fixed connection between the percussion mechanism spring 320 and the further percussion mechanism spring 340 and the striker 300. FIG. 9a shows a cross-sectional view and FIG. 9b shows a longitudinal sectional view of the fourth embodiment of the rotationally fixed connection. The spring receptacle 302 and the further spring receptacle 304 are configured offset to one another in circumferential direction. In this example, the spring receptacle 302 is configured as a ring-shaped groove and the further spring receptacle 304 is configured as a cylindrical opening. The connecting element 322 is configured here as a ring-shaped spring end and is connected to the spring receptacle 302 by means of a press fit. The further connecting element 342 is configured here as a pin-like insertion end here and is connected to the further spring receptacle 304 in a form-locking manner. In this case, the spring receptacle 302 is configured in the striker 300 transverse to the tool axis 102 and the further spring receptacle 304 along the tool axis 102.