Hand power tool, in particular drilling screwdriver

• US 20060086514A1
• Filed: 10/24/2005
• Published: 04/27/2006
• Est. Priority Date: 10/26/2004
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Aeberhard, Bruno
• Granted Patent: US 7,225,884 B2
• Time in Patent Office: Days
• US Class Current: 173/48
• CPC Class Codes: B25B 21/00 Portable power-driven screw or nut setting or loosening tools; details or components, e.g. casings, bodies, of portable power-driven tools not particularly related to the operation performed B25F5/00; for mounting or dismounting wheels B60B29/006; Attachments for drilling apparatus serving the same purpose machines B23P19/06
• CPC Class Codes: B25B 21/023 for imparting an axial impact, e.g. for self-tapping screws
• CPC Class Codes: B25B 23/14 Arrangement of torque limiters or torque indicators in wrenches or screwdrivers couplings for transmitting rotation or clutches F16D; devices for measuring torque per se G01L
• CPC Class Codes: B25D 11/106 cam member and cam follower having the same shape B25D11/104 takes precedence
• CPC Class Codes: B25D 16/003 Clutches specially adapted therefor
• CPC Class Codes: B25D 16/006 Mode changers; Mechanisms connected thereto
• CPC Class Codes: B25D 2216/0023 Tools having a percussion-and-rotation mode
• CPC Class Codes: B25D 2216/0038 Tools having a rotation-only mode
• CPC Class Codes: B25D 2250/165 Overload clutches, torque limiters

Abstract

A hand power tool has a power tool housing, a tool spindle supported rotatabley in the housing, a drive train via which the tool spindle is drivable to rotate, a cam device located in the drive train and having two cam discs in engagement with one another for transmitting axial percussion motions to the tool spindle, an overlocking coupling located in the drive train and having two coupling parts which are in engagement with one another and are overlockable counter to an axially exerted force, a coupling spring exerting the axial force, a blocking device which upon its activation blocks a relative rotation of the coupling parts of the overlocking coupling to one another, and an operating mode setting device for setting “percussion drilling”, “drilling” and “screw driving” operating modes, and also a magnitude of an overlocking moment upon screwdriving, the operating mode setting device having two adjusting rings located on the power tool housing and rotatable manually to define setting positions and acting on the cam device, the overlocking coupling and the blocking device, wherein one of the adjusting rings is a torque adjusting ring and sets the “drilling” operating mode and the “screwdriving” operating mode, with preselection of the magnitude of the overlocking moment, while the other of the adjusting rings is embodied as a function adjusting ring and switches the “percussion drilling” operating mode on and off, and in its position that switches the “percussion drilling” operating mode on, it overrides any operating mode set by the torque adjusting ring.

Claims

1. A hand power tool, comprising a power tool housing;

a tool spindle supported rotatably in said housing;

a drive train via which said tool spindle is drivable to rotate;

a cam device located in said drive train and having two cam discs in engagement with one another for transmitting axial percussion motions to said tool spindle;

an overlocking coupling located in said drive train and having two coupling parts which are in engagement with one another and are overlockable counter to an axially exerted force;

a coupling spring exerting said axial force;

a blocking device which upon its activation blocks a relative rotation of said coupling parts of said overlocking coupling to one another; and

an operating mode setting device for setting “

percussion drilling”

, “

drilling” and

“

screw driving”

operating modes, and also a magnitude of an overlocking moment upon screwdriving, said operating mode setting device having two adjusting rings located on said power tool housing and rotatable manually to define setting positions and acting on said cam device, said overlocking coupling and said blocking device, wherein one of said adjusting rings is a torque adjusting ring and sets the “

drilling”

operating mode and the “

screwdriving”

operating mode, with preselection of the magnitude of the overlocking moment, while the other of said adjusting rings is embodied as a function adjusting ring and switches the “

percussion drilling”

operating mode on and off, and in its position that switches the “

percussion drilling”

operating mode on, it overrides any operating mode set by said torque adjusting ring.

2. A hand power tool as defined in claim 1, wherein said torque adjusting ring has a plurality of setting positions and accesses said overlocking coupling and said blocking device in such a way that in a setting position that sets the “

drilling”

operating mode, said blocking device is activated, and in other setting positions the blocking device is deactivated, and said coupling spring of said overlocking coupling is prestressed variously strongly, said function adjusting ring having two setting positions and accesses said cam device and said blocking device in such a way that in one setting position said “

percussion drilling”

operating mode is switched on and said blocking device is activated, and in the another setting position, said percussion drilling function is switched off and said blocking device is deactivated.

3. A hand power tool as defined in claim 1, wherein a plurality of said setting positions are located on said torque adjusting ring such that said overlocking moment increasing from one setting position to a next one, and said second position for setting position for setting the “

drilling”

operating mode is located at an end of a path of rotation of said torque adjusting ring.

4. A hand power tool as defined in claim 2, wherein two of said setting positions of said function adjusting ring are visible as symbols in a display window embodied in said function adjusting ring.

5. A hand power tool as defined in claim 4, wherein in the setting position of said function adjusting ring for the “

percussion drilling”

operating mode, a red face is visible and in another setting position a triangle with a tip pointing toward said torque adjusting ring is visible as symbols in said display window.

6. A hand power tool as defined in claim 4, wherein said function adjusting ring is split in two and has an outer ring and an inner ring which are connected to one another in a manner fixed against relative rotation, said display window being located in said outer ring;

and further comprising a flat segment carrying the symbols and located nonrotatably in a region of said display window between said outer ring and said inner ring.

7. A hand power tool as defined in claim 5, wherein said torque adjusting ring is provided with markings identify said setting positions of said torque adjusting ring, some of said setting positions whose markings are aligned with said triangular tip in said display window in said function adjusting ring being set with said torque adjusting ring.

8. A hand power tool as defined in claim 2, wherein said setting positions of said function adjusting ring and said torque adjusting ring are visible in a display window provided in said function adjusting ring.

9. A hand power tool as defined in claim 1, wherein said torque adjusting ring has a radially offset annular collar on which markings identifying said setting positions of said torque adjusting rings are located, said annular collar being covered by an end portion, carrying said display window, of said function adjusting ring;

and further comprising a flat segment protruding into an overlapping region of said function adjusting ring and said torque adjusting ring and having a segment cutout with dimensions corresponding to dimensions of said display window and also having a hammer symbol located adjacent to said segment cutout in a direction of rotation.

10. A hand power tool as defined in claim 1, wherein one coupling part of said overlocking coupling is formed by a ring gear of a planetary gear having internal toothing and an external detent lock with detent lugs and detent gaps, the other coupling part of said overlocking coupling being formed by an axially displaceable transmission ring fixed against relative rotation, that is acted upon by said coupling spring, said blocking device having at least two axially displaceable slide wedges fixed against relative rotation, which are insertable counter to spring force into said detent gaps of said detent lock on said ring gear.

11. A hand power tool as defined in claim 10, wherein said inner ring of said function adjusting ring on its face end toward said slide wedges has a number corresponding to a number of said slide wedges of control cams, offset from one another by same circumferential angles as said slide wedges for axially displacing said slide wedges.

12. A hand power tool as defined in claim 2, wherein said torque adjusting ring is coupled in a slaving fashion to a threaded ring that is screwable onto a guide sleeve, said threaded ring on its end face toward said slide wedges having a number corresponding to a number of said slide wedges of control cams offset from one another by same circumferential angles as said slide wedges, for axially displacing said slide wedges into said detent gaps of said detent lock of said ring gear.

13. A hand power tool as defined in claim 12, wherein said coupling spring of said overlocking coupling is received on said guide sleeve and is braced between said transmission rings and said threaded ring.

14. A hand power tool as defined in claim 1;

and further comprising an actuating unit configured for bringing said cam discs of said cam device into and out of engagement with one another and controlled by said function adjusting ring.

15. A hand power tool as defined in claim 14, wherein said actuating unit has a control disc with a slaving means for rotary slaving by said function adjusting ring and has at least two slits offset from one another in a circumferential direction, a control ring with an annular end face toward said control disc, humps offset from one another by same circumferential angles as said slits, and a holder that holds said tool spindle via a bearing and that rests with overfitting tabs on a disc face facing away from said control ring of said control disc, said function adjusting ring being coupled to said control disc via slaving means in such a way that upon setting of said function adjusting ring to its setting position identifying the “

percussion drilling”

operating mode, said control disc is rotated such that said humps on said control ring extend through said slits in said control disc and thereby put said cam discs into detent engagement with one another, and with a setting of said function adjusting ring into its another setting position, said control disc is rotated such that said humps emerge from said slits and slide onto said discs face facing away from said overfitting tabs of said control discs and thereby put said cam discs out of engagement with one another.