Torque indicator ratchet wrench for dentistry

• US 20010005576A1
• Filed: 01/08/2001
• Published: 06/28/2001
• Est. Priority Date: 12/23/1998
• Status: Active Grant

• Current Assignee: Biomet 3i LLC (Zimvie Incorporated)
• Original Assignee: Dan Paul Rogers, Thomas Tait Robb
• Inventors: Robb, Thomas Tait, Rogers, Dan Paul
• Granted Patent: US 6,398,552 B2
• Time in Patent Office: Days
• US Class Current: 433/141
• CPC Class Codes: A61C 1/186 with torque adjusting or limiting means
• CPC Class Codes: A61C 8/0089 Implanting tools or instruments
• CPC Class Codes: B25B 13/462 the ratchet parts engaging in a direction radial to the tool operating axis
• CPC Class Codes: B25B 23/0035 Connection means between socket or screwdriver bit and tool
• CPC Class Codes: B25B 23/1422 torque indicators or adjustable torque limiters

Abstract

This present invention relates to a ratchet wrench and a torque indicator combined concentrically in a single housing. The ratchet wrench is useful for driving a fastener used in dentistry, such as an abutment screw that holds an abutment on a dental implant. In operation, the handle of the wrench can be rotated in one direction (e.g. clockwise) to impart torque on the fastener. When the handle is rotated in the opposite direction (e.g. counterclockwise), no torque is applied to the fastener as the handle is returned to a position where it is easy for the clinician to again rotate the handle to apply additional torque to the fastener. The return motion of the handle (e.g. counterclockwise rotation) may be stepless in operation which is brought about through a coiled clutch spring located in an annular space within a housing between the housing and a concentric driver member. To provide an indication of torque, a rotor body is supported coaxially within the driver member. Torque indicator marks on the rotor body and the driver member indicate angular displacement of the driver member around the common axis relative to the rotor body when a tool held in the rotor body is restrained from turning under load. The housing and with it the drive member may be turned by hand around their common axis when the housing is turned in the latched direction, or a handle fixed to the housing may be used. A lubricating washer is supplied to reduce friction within the ratchet wrench.

Claims

1. A dental ratchet wrench for applying torque to a fastener that is used in a dental prosthesis, comprising:

a housing;

a drive member located within said housing;

a slip clutch spring coupled to said housing and said drive member, said slip clutch spring causing said drive member to rotate with said housing when said housing is rotated in one direction, said slip clutch spring causing said drive member to rotate relative to said housing when said housing is rotated in the opposite direction;

a rotor coupled to said drive member via a straight coil torsion spring, said rotor including means for receiving a tool for rotating said fastener; and

torque indicators on at least one said drive member and said rotor at known angular positions corresponding to predetermined torque values, said torque indicators progressively illustrating the amount of torque being exerted by said rotor.

2. The dental ratchet wrench of

claim 1

, wherein said housing and said driving member define a region having an annularly shaped cross-section, said annularly shaped cross-section having a narrower portion.

3. The dental ratchet wrench of

claim 2

, wherein said narrower portion is dimensioned to catch a free end of said slip clutch spring when said housing is rotated in said one direction, while allowing said free end to rotate with respect to said housing when said housing is rotated in said other direction.

4. The dental ratchet wrench of

claim 1

, wherein said torsion spring has two free ends that extend in the axial direction with respect to said housing.

5. The dental ratchet wrench of

claim 1

, wherein said rotor includes a lower hub, said torsion spring being connected to said lower hub and passing internally through said drive member to an upper flange of said rotor, said torsion spring being connected to said upper flange.

6. The dental ratchet wrench of

claim 1

, wherein said rotor and said drive member have complementary confronting surfaces that rotate relative to each other, said dental ratchet wrench further including a lubricating region between said confronting surfaces for reducing friction.

7. The dental ratchet wrench of

claim 6

, wherein said rotor and said drive member each have lower hubs, said complementary confronting surfaces being located on said lower hubs.

8. The dental ratchet wrench of

claim 7

, wherein said lubricating region is a washer is made of Teflon.

9. The dental ratchet wrench of

claim 8

, wherein said torque indicators are placed on said dental ratchet wrench before final assembly.

10. The dental ratchet wrench of

claim 1

, wherein said receiving means includes at least two different regions for receiving two types of tools.

11. The dental ratchet wrench of

claim 10

, wherein a first region includes a polygonal socket and a second region includes an ISO-type tool holder.

12. The dental ratchet wrench of

claim 11

, wherein said second region is accessible by an ISO-type tool by extending said ISO-type tool through said first region.

13. A dental ratchet wrench for applying a known amount of torque to a fastener that is used in a dental prosthesis, comprising:

a housing;

a drive member located primarily within said housing, said housing and said drive member defining a first region therebetween;

a tool receiving component for receiving a tool to exert torque on said fastener, said tool receiving component located primarily within said drive member, said tool receiving component and said drive member defining a second region;

a torsion spring located within said second region, said torsion spring having one end connected to said drive member and the other end connected to said tool receiving component, a certain angular displacement of said one end relative to said other end producing a certain torque on said tool receiving component;

a slip clutch located within said first region, said slip clutch causing said drive member to rotate with said housing when said housing is rotated in one direction, said slip clutch causing said drive member to rotate relative to said housing when said housing is rotated in the opposite direction; and

torque indicators on at least one of said drive member and tool receiving component corresponding to predetermined torque values, said torque indicators progressively illustrating the amount of torque being exerted by said tool receiving component.

14. The dental ratchet wrench of

claim 13

, wherein said first region has an annularly shaped cross-section, said annularly shaped cross-section having a narrower portion.

15. The dental ratchet wrench of

claim 14

, wherein said slip clutch is a spring and said narrower portion is dimensioned to catch a free end of said spring when said housing is rotated in said one direction, while allowing said free end to rotate with respect to said housing when said housing is rotated in said other direction.

16. The dental ratchet wrench of

claim 13

, wherein said tool receiving portion includes a lower hub and said drive member has an upper flange, said lower hub and said upper flange at least partially defining said second region, said one end of said torsion spring being connected to said lower hub and said other end of said torsion spring being connected to said upper flange of said rotor.

17. The dental ratchet wrench of

claim 13

, wherein said tool receiving portion and said drive member have complementary confronting surfaces that rotate relative to each other, said complementary confronting surfaces including a lubricating region for reducing friction.

18. The dental ratchet wrench of

claim 17

, wherein said lubricating region includes a washer that is made of Teflon.

19. The dental ratchet wrench of

claim 13

, wherein said tool receiving portion has two distinct portions for receiving two distinct tools.

20. The dental ratchet wrench of

claim 19

, wherein a first portion includes a polygonal socket and a second portion includes an ISO-type tool holder.

21. The dental ratchet wrench of

claim 13

, wherein said torsion spring has two free ends that extend in the axial direction.

22. The dental ratchet wrench of

claim 13

, wherein said tool receiving portion includes an ISO-type tool holder.

23. The dental ratchet wrench of

claim 22

, wherein said ISO-type tool holder includes a cylindrical body having a plurality of cut-outs and a spring for wrapping around said body, portions of said spring extending within said cut-outs.

24. The dental ratchet wrench of

claim 23

, wherein said spring has a D-shape.

25. The dental ratchet wrench of

claim 23

, wherein said spring is a coil spring.

26. The dental ratchet wrench of

claim 22

, wherein said ISO-type tool holder includes a rotatable latch for locking the tool in place.

27. The dental ratchet wrench of

claim 22

, wherein said ISO-type tool holder includes a cylindrical detent within one of said cut-outs.

28. The dental ratchet wrench of

claim 13

, wherein a diameter of said housing is less than about 0.75 inch.

29. The dental ratchet wrench of

claim 13

, wherein said torsion spring is made of a stainless steel.

30. The dental ratchet wrench of

claim 29

, wherein said torsion spring is made of stainless steel wire stock having a diameter of about 1.25 mm.

31. The dental ratchet wrench of

claim 13

, wherein said torque indicators includes a plurality of torque-number markings on said drive member and one marking on said tool receiving component, said one marking on said tool receiving component moving relative to said plurality of torque-number markings while said torque is being exerted.

32. The dental ratchet wrench of

claim 13

, wherein said tool receiving component has upper and lower tool receiving portions allowing said wrench to be used to reverse the torque on said screw.

33. A dental wrench for applying torque to a fastener used in a dental prosthesis, comprising:

a housing;

a drive member located primarily within said housing;

a tool receiving component coupled to and located adjacent to said drive member, said tool receiving component for receiving a tool to exert torque on said fastener, said tool receiving component including an ISO-type tool holder for holding a dental tool having an ISO-type latch; and

torque markings representing corresponding torque values on at least one of said drive member and said tool receiving component.

34. The dental ratchet wrench of

claim 33

, wherein said ISO-type tool holder includes a cylindrical body having a plurality of cut-outs and a spring for wrapping around said body, portions of said spring extending within said cut-outs.

35. The dental ratchet wrench of

claim 34

, wherein said spring has a D-shape.

36. The dental ratchet wrench of

claim 34

, wherein said spring is a coil spring.

37. The dental ratchet wrench of

claim 33

, wherein said ISO-type tool holder includes a rotatable latch for locking the tool in place.

38. The dental ratchet wrench of

claim 33

, wherein said ISO-type tool holder includes a cylindrical detent within one of said cut-outs.

39. A ratchet wrench for applying torque to a fastener, comprising:

a drive member;

a rotor coupled to and located adjacent to said drive member, said rotor for exerting said torque on said fastener;

a ratcheting mechanism allowing said drive member to move said rotor in one direction; and

a plurality of torque markings representing corresponding torque values on at least one of said drive member and said rotor, said torque markings progressively illustrating the torque that said rotor places on said fastener.

40. The ratchet wrench of

claim 39

, wherein said plurality of torque markings includes a plurality of torque-number markings on said drive member and a single marking on said tool receiving component, said single marking on said rotor moving relative to said plurality of torque-number markings while said torque is being exerted.

41. The ratchet wrench of

claim 39

, wherein said rotor and said drive member are coupled through a straight coil torsion spring located between said rotor and said drive member.