Eccentric disk grinder with a grinding disk brake

• US 5,679,066 A
• Filed: 05/01/1996
• Issued: 10/21/1997
• Est. Priority Date: 10/07/1992
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Frank, Mario, Stierle, Juergen, Heess, Stefan, Berger, Guenther, Butz, Dieter
• Primary Examiner(s): MORGAN, EILEEN P
• Application Number:
  US08/640,493
• Time in Patent Office: 538 Days
• Field of Search: 451/356, 451/357, 451/358, 451/359, 451/344
• US Class Current: 451/357
• CPC Class Codes: B24B 23/03 the tool being driven in a combined movement

Abstract

An eccentric disk grinder has a grinding disk, an eccentric shaft fixedly connected with the grinding disk, a motor, a shaft having an axis arranged so that the motor eccentrically, circulatingly and rotatably moves around the axis of the shaft, with the eccentric shaft being rotatable relative to the shaft, a braking device provided for delaying movement of the grinding disk and having a braking element which follows the movement of the grinding disk and is delayable relative to the grinding disk.

Claims

1. An eccentric disk grinder, comprising a rotatable grinding disk;

an eccentric shaft fixedly connected with said grinding disk;

a further shaft having an axis and an eccentric axial opening in which said eccentric shaft is arranged rotatably relative to said further shaft;

a motor rotating said further shaft and therefore moving said eccentric shaft eccentrically, circulatingly and rotatably around said axis of said further shaft;

a braking device for delaying a rotary movement of said grinding disk, said braking device having a rotatable braking element which delays the rotary movement of said grinding disk by being delayable relative to said grinding disk;

said braking device also having a hollow gear, said braking element being adjustably delayable relative to staid grinding disk and also rolling on said hollow gear.

2. An eccentric disk grinder as defined in claim 1, and further comprising a motor housing accommodating said motor.

3. An eccentric disk grinder as defined in claim 1, wherein said braking element is formed as a disk.

4. An eccentric disk grinder as defined in claim 1, wherein said braking element follows only the circulatory movement of said eccentric shaft and does not follow its rotation.

5. An eccentric disk grinder as defined in claim 1;

and further comprising an additional part, said braking element being elastically supported on said additional part.

6. An eccentric disk grinder as defined in claim 5, wherein said additional part is a motor housing which accommodates said motor.

7. An eccentric disk grinder as defined in claim 5;

and further comprising an angular transmission and an angular transmission housing accommodating said angular transmission and forming said additional part.

8. An eccentric disk grinder as defined in claim 1, wherein said braking element rolls on an additional part so that said braking element is subjected to a rotation opposite to said circulatory movement of said grinding disk.

9. An eccentric disk grinder as defined in claim 1, wherein said braking element is formed as a ring disk which is concentrically arranged on said eccentric shaft and is supported on at least one counter disk arranged on said eccentric shaft.

10. An eccentric disk grinder as defined in claim 9, wherein said braking element is rotatable on said eccentric shaft while said counter disk is fixed on said eccentric shaft.

11. An eccentric disk grinder as defined in claim 10, wherein said braking element and said counter disk are arranged axially displaceably on said eccentric shaft;

and further comprising means for axially holding said braking element and said counter disk relative to one another said axially holding means including spring means.

12. An eccentric disk grinder as defined in claim 1, wherein said further shaft is formed as a hollow shaft which is open at its both ends so that said eccentric shaft is arranged in said shaft and extends outwardly beyond said both ends.

13. An eccentric disk grinder as defined in claim 12, wherein said braking element of said braking device is formed as a disk.

14. An eccentric disk grinder as defined in claim 12;

and further comprising an angular transmission through which said grinding disk is driven; and

an angular transmission housing accommodating said angular transmission.

15. An eccentric disk grinder as defined in claim 14, wherein said braking device is arranged in said angular transmission housing on a side of said angular transmission which faces away from said grinding disk on said eccentric shaft.

16. An eccentric disk grinder as defined in claim 14, wherein said braking element is disengageable from said angular transmission housing so that said braking element cannot roll on said angular transmission housing in a disengaged position.

17. An eccentric disk grinder as defined in claim 14, wherein said angular transmission housing has a region coupled to it upon which region said braking element rolls and which is formed as a hollow toothed gear.

18. An eccentric disk grinder as defined in claim 17, wherein said braking element is adjustably delayable by axially displacing said hollow toothed gear.

19. An eccentric disk grinder as defined in claim 17, wherein said braking element is formed as a spur gear with a number of teeth corresponding to a number of teeth of said hollow toothed gear.

20. An eccentric disk grinder as defined in claim 17, wherein said braking element has a number of teeth which is different by at least one tooth from a number of teeth of said hollow toothed gear.

21. An eccentric disk grinder as defined in claim 17, wherein said hollow toothed gear has teeth, said braking element having tips, at least one of said teeth and tips having curved surfaces.

22. An eccentric disk grinder as defined in claim 21, wherein said surfaces are spherical.

23. An eccentric disk grinder as defined in claim 17, wherein a part of said braking device is formed as a spur gear which is couplable with said hollow toothed gear and fixed on said eccentric shaft, said spur gear having a number of teeth smaller than a number of teeth of said hollow toothed gear and teeth of said spur gear having end-side tips with curved surfaces.

24. An eccentric disk grinder as defined in claim 23, wherein said curved surfaces are spherical.

25. An eccentric disk grinder as defined in claim 17;

and further comprising guiding means through which said hollow toothed gear is coupled with said angular transmission housing; and

actuating means displacing said hollow toothed gear.

26. An eccentric disk grinder as defined in claim 25, wherein said guiding means is formed as at least one slot provided in said angular transmission housing, said actuating means being formed as a pin which extends through said slot and is displaceable along said slot together with said hollow toothed gear.

27. An eccentric disk grinder as defined in claim 26, wherein said guiding means is formed as a ring wedge-shaped inclined surface which extends inclinedly relative to an axis of said eccentric shaft.

28. An eccentric disk grinder as defined in claim 27, wherein said inclined surface is formed as a slot.

29. An eccentric disk grinder as defined in claim 25, wherein said guiding means is formed as an inclined surface which is provided on said hollow toothed gear and is displaceably guided on a guiding element.

30. An eccentric disk grinder as defined in claim 29, wherein said inclined surface is provided on a periphery of said hollow toothed gear.

31. An eccentric disk grinder as defined in claim 29, wherein said inclined surface is provided on an axial end side of said hollow toothed gear.

32. An eccentric disk grinder as defined in claim 29, wherein said guiding element is formed as a pin.

33. An eccentric disk grinder as defined in claim 17;

and further comprising a pin which is displaceably guided on said hollow toothed gear parallel to an axis of said eccentric shaft.

34. An eccentric disk grinder as defined in claim 33, wherein said pin is elastically bendable perpendicular to a displacement direction as a sheet-spring.

35. An eccentric disk grinder as defined in claim 34, wherein said pin is pre-stressed.

36. An eccentric disk grinder as defined in claim 33;

and further comprising a ring which is rotatable only about its axis and is axially non-displaceable and has an inner region, said pin being mounted on said ring, said hollow toothed gear being located in said inner region and having on an end-side a ring wedge-shaped inclined surface which is guided so that an axial displacement and rotation are performed through separate and independent parts which are easy to seal from each other.

37. An eccentric disk grinder as defined in claim 36;

and further comprising a lug extending in said inner region and guiding said inclined surface.

38. An eccentric disk grinder as defined in claim 36;

and further comprising an elastic sleeve which surrounds said pin so as to seal the latter.

39. An eccentric disk grinder as defined in claim 38, wherein said elastic sleeve is formed as a bellows.

40. An eccentric disk grinder as defined in claim 1, wherein said further shaft has a groove;

and further comprising a compensating weight which is supported on said further shaft and has a claw engaging in said groove in a form-locking and force-transmitting manner.

41. An eccentric disk grinder as defined in claim 40, wherein said further shaft has an outer wall provided with a ring groove and an axial groove intersecting one another.

42. An eccentric disk grinder as defined in claim 40, wherein said further shaft is formed as a hollow shaft.

43. An eccentric disk grinder as defined in claim 1;

and further comprising an angular transmission provided between said motor and said shaft;

an angular transmission housing accommodating said angular transmission;

a bearing arranged in said angular transmission housing at a side facing away from said grinding disk and displaceable against a spring force together with said shaft.

44. An eccentric disk grinder as defined in claim 43, wherein said angular transmission has a bevel gear, said bearing being axially displaceable together with said bevel gear.

45. An eccentric disk grinder as defined in claim 43;

and further comprising an adjusting element arranged in said angular transmission housing for displacing said bearing together with said shaft.

46. An eccentric disk grinder as defined in claim 45, wherein said adjusting element is formed as a screw element.

47. An eccentric disk grinder as defined in claim 45, wherein said bearing has an outer ring which is displaceable by said adjusting element.

48. An eccentric disk grinder as defined in claim 45, wherein said angular transmission housing has an inner thread, said adjusting element being formed as a threaded ring which is screwed in said inner thread of said angular transmission housing and supported on one end side of said bearing;

and further comprising a spring ring against which another side of said bearing is supported.

49. An eccentric disk grinder as defined in claim 48, wherein said threaded ring is arrestable in at least one rotary position from turning relative to said angular transmission housing;

and further comprising arresting means for arresting said threaded ring in at least one rotary position.

50. An eccentric disk grinder as defined in claim 49, wherein said arresting means includes arresting openings and arresting projections which engage in said arresting openings.

51. An eccentric disk grinder as defined in claim 45, wherein said bearing has an outer ring with one side supported on said threaded ring and another side supported on said spring ring.