Low profile electric sander

• US 20050245182A1
• Filed: 04/12/2005
• Published: 11/03/2005
• Est. Priority Date: 04/13/2004
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Gorti, Bhanuprasad V., Deshpande, Uday S., Rice, Gregory A., Wikle, David, Waikar, Shailesh P., Melvin, Jason R., Hilsher, William F.
• Granted Patent: US 7,318,768 B2
• Time in Patent Office: Days
• US Class Current: 451/357
• CPC Class Codes: B24B 23/03 the tool being driven in a combined movement

Abstract

A power tool is a “low profile” power tool, that is the overall height of the power tool is sufficiently small that a user can grasp the top of the power tool with the user'"'"'s hand and the hand will be positioned relative close to the bottom of the power tool compared with existing power tools. The low profile power tool uses a low profile motor having a diameter to lamination height ratio of at least 2:1. In an aspect of the invention, the motor is an electronically commutated “pancake” style motor. In an aspect of the invention, the power tool is a random orbital sander or an orbital sander having a motor that provides at least 40 watts of power. In an aspect of the invention, the sander has a mechanical brake that brakes the orbital mechanism and the motor is dynamically braked.

Claims

1. A low profile, hand held orbital electric sander, comprising:

a. a housing and an orbit mechanism disposed beneath the housing;

b. a motor disposed within the housing, the motor having a stator, the stator having a lamination stack having a height, the motor having a diameter wherein a motor diameter to stator lamination height ratio is at least 2;

1; and

c. the housing including a palm grip having a diameter and the sander having a height wherein a palm grip diameter to sander height ratio is at least 0.4;

1.

2. The apparatus of claim 1 wherein the sander is a random orbital sander.

3. The apparatus of claim 1 wherein the sander is a pad sander.

4. The apparatus of claim 1 wherein the sander is a corded sander having a maximum height of 120 mm and the palm grip diameter to sander height ratio is at least 0.6:

1.

5. The apparatus of claim 4 wherein the palm grip has a diameter in a range of 30 mm to 90 mm.

6. The apparatus of claim 4 wherein the palm grip has a diameter in a range of 70 mm to 90 mm.

7. The apparatus of claim 4 wherein the sander is a corded sander having a maximum height of 100 mm, the palm grip has a maximum diameter of 90 mm, the motor has a diameter to stack height ratio of at least 7.5:

1 and a rated power output of at least 120 watts.

8. The apparatus of claim 4 wherein the sander is a corded sander having a maximum height of 95 mm, the palm grip has a maximum diameter of 90 mm, the motor has a diameter to stack height ratio of at least 7.5:

1 and a rated power output of at least 120 watts.

9. The apparatus of claim 4 wherein the sander is a corded sander having a maximum height of 90 mm, the palm grip has a maximum diameter of 90 mm, the motor has a diameter to stack height ratio of at least 7.5:

1 and a rated power output of at least 120 watts.

10. The apparatus of claim 8 wherein the motor has a rated power output of at least 200 watts.

11. The apparatus of claim 4 wherein the palm grip diameter to sander height ratio is at least 1:

1.

12. The apparatus of claim 4 wherein the motor is an electronically commutated motor.

13. The apparatus of claim 12 wherein the electronically commutated motor is an AC synchronous motor.

14. The apparatus of claim 12 wherein the electronically commutated motor is a brushless DC motor.

15. The apparatus of claim 12 wherein the motor diameter to stator lamination height ratio is greater than 5:

1.

16. The apparatus of claim 12 including a five inch platen wherein the motor has a rated power output of at least 70 watts.

17. The apparatus of claim 12 including a five inch platen, the motor having a rated power output of at least 100 watts and a motor diameter to lamination height ratio of at least 3:

1.

18. The apparatus of claim 12 including a six inch platen wherein the motor has a rated power of at least 100 watts.

19. The apparatus of claim 12 including a six inch platen, the motor having a rated power of at least 120 watts and a motor diameter to lamination height ratio of at least 3:

1.

20. The apparatus of claim 19 wherein the motor has a rated power output of at least 200 watts.

21. The apparatus of claim 1 wherein the motor has a rated power output of at least 40 watts.

38. The apparatus of claim 1 including a switch coupled across windings of the motor that dynamically brakes the motor and a mechanical brake that brakes the orbit mechanism.

39. The apparatus of claim 38 wherein the combined dynamic and mechanical braking brakes the orbit mechanism to a desired speed in no more than about two seconds.

40. The apparatus of claim 39 wherein the desired speed is stop.

41. The apparatus of claim 39 wherein the desired speed is an idle speed.

42. The apparatus of claim 38 including a resistor that is coupled across windings of the motor by the switch in dynamically braking the motor.

43. The apparatus of claim 38 wherein the switch shorts the motor windings to dynamically brake the motor.

44. The apparatus of claim 12 including a motor controller that electronically commutates the motor by switching switches that switch power to the motor in an electronic commutation sequence, the sander including a mechanical brake that brakes the orbit mechanism and the motor controller switching the switches to electronically brake the motor.

45. The apparatus of claim 44 wherein the mechanical brake mechanically braking the orbit mechanism and the motor controller electronically braking the motor brakes the orbit mechanism to a desired speed in no greater than about two seconds.

46. The apparatus of claim 45 wherein the desired speed is stop.

47. The apparatus of claim 45 wherein the desired speed is an idle speed.

48. The apparatus of claim 44 including a resistor that is coupled across windings of the motor when the motor controller electronically brakes the motor.

49. The apparatus of claim 12 including an on/off switch and a motor controller that electronically commutates the motor by switching switches that switch power to the motor in an electronic commutation sequence, the motor controller sensing collapse of an input voltage when the on/off switch is turned off and switching the switches to electronically brake the motor.

51. The apparatus of claim 49 wherein the mechanical brake mechanically braking the orbit mechanism and the motor controller electronically braking the motor brakes the orbit mechanism to a desired speed in no greater than about two seconds.

54. The apparatus of claim 49 including a resistor that is coupled across windings of the motor when the motor controller electronically brakes the motor.

22. A low profile, hand held orbital electric sander, comprising:

d. a housing and an orbit mechanism disposed beneath the housing;

e. an electronically commutated motor disposed within the housing, the motor having a stator, the stator having a lamination stack having a height, the motor having a diameter wherein a motor diameter to stator lamination height ratio is at least 2;

1;

f. a power cord coupled to the motor for connecting the motor to a source of AC; and

g. the housing including a palm grip having a diameter and the sander having a height wherein a palm grip diameter to sander height ratio is at least 0.6;

1.

23. The apparatus of claim 22 wherein the sander has a maximum height of 120 mm.

24. The apparatus of claim 23 wherein the electronically commutated motor is an AC synchronous motor.

25. The apparatus of claim 23 wherein the electronically commutated motor is a brushless DC synchronous motor.

26. The apparatus of claim 23 wherein the palm grip diameter to sander height ratio is at least 1:

1.

27. The apparatus of claim 23 wherein the motor diameter to stator lamination height ratio is greater than 5:

1.

28. The apparatus of claim 23 including a five inch platen and the motor having a rated power output of at least 70 watts.

29. The apparatus of claim 23 including a five inch platen, the motor having a rated power output of at least 100 watts and a motor diameter to lamination height ratio of at least 3:

1.

30. The apparatus of claim 23 including a six inch platen, the motor having a rated power of at least 100 watts.

31. The apparatus of claim 23 including a six inch platen, the motor having a rated power of at least 120 watts and a motor diameter to lamination height ratio of at least 3:

1.

32. The apparatus of claim 31 wherein the motor has a rated power output of at least 200 watts.

33. The apparatus of claim 22 wherein the motor has a rated power output of at least 40 watts.

34. The apparatus of claim 29 wherein the sander is a random orbital sander.

35. The apparatus of claim 29 wherein the sander is a pad sander.

36. The apparatus of claim 31 wherein the sander is a random orbital sander.

37. The apparatus of claim 31 wherein the sander is a pad sander.

50. The apparatus of claim 22 including a motor controller that electronically commutates the motor by switching switches that switch power to the motor in an electronic commutation sequence, the sander including a mechanical brake that brakes the orbit mechanism and the motor controller switching the switches to electronically brake the motor.

52. The apparatus of claim 50 wherein the desired speed is stop.

53. The apparatus of claim 50 wherein the desired speed is an idle speed.

55. The apparatus of claim 22 including an on/off switch and a motor controller that electronically commutates the motor by switching switches that switch power to the motor in an electronic commutation sequence, the motor controller sensing collapse of an input voltage when the on/off switch is turned off and switching the switches to reverse commutate the motor to electronically brake the motor.