Cannulated disposable torque limiting device with plastic shaft

Patent metadata

Field	Value
Publication number	US-10279146-B2
Application number	US-201514728945-A
Country	US
Kind code	B2
Filing date	Jun 2, 2015
Priority date	Jun 2, 2015
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

A torque-limiting device may include a shaft extending axially through upper and lower shanks, a spring, and a nut to an end opening of a handle. The upper and lower shanks may be under a force from the spring and further configured to selectively engage within a predetermined torque limit and disengage at above the predetermined torque limit. Accordingly, the shaft may receive torque up to the predetermined limit as provided by a user operating a handle of the torque-limiting device. The torque-limiting device may be disposable, reusable, economical, and have high torque capabilities. The shaft may be of a plastic material and include a lumen extending there through, and through which a variety of devices and materials may be delivered to a workpiece.

First claim

The invention claimed is:

1. A torque-limiting driver comprising:
a body having a handle comprising a first lumen;
an upper cylindrical shank;
a lower cylindrical shank having a square drive socket;
a nut;
a spring between the upper cylindrical shank and the nut, wherein the spring is configured to apply a force across the upper cylindrical shank and the lower cylindrical shank;
a shaft having a workpiece-engaging tip and a square drive connection engaged within the square drive socket of the lower cylindrical shank, the shaft extending axially through the lower cylindrical shank, the upper cylindrical shank, the spring, and the handle with an end portion of the shaft disposed within the first lumen, the shaft having a plurality of thread rests on a portion of the shaft, the thread rests cut and engaged by a threading in the nut, the shaft having a second lumen extending across an axial length of the shaft, and the shaft comprising a plastic material or a composite including plastic; and,
wherein the upper cylindrical shank and the lower cylindrical shank engage for relative rotation, and wherein the upper cylindrical shank and the lower cylindrical shank disengage when a predetermined torque limit is exceeded;
wherein the second lumen extends along the entire length of the shaft, with the second lumen having a lumen tip opening disposed at the workpiece-engaging tip and a second lumen end opening disposed at the opposite end of the shaft at the end portion.

2. The torque-limiting driver of claim 1 , wherein the second lumen encloses a tube advanceable within the second lumen.

3. The torque-limiting driver of claim 2 , wherein the tube is configured to deliver a biologic material.

4. The torque-limiting driver of claim 3 , wherein the biologic material is an adhesive.

5. The torque-limiting driver of claim 3 , wherein the biologic material is a growth stimulant.

6. The torque-limiting driver of claim 1 , wherein the second lumen encloses a guidewire advanceable within the second lumen.

7. The torque-limiting driver of claim 1 , wherein the plurality of thread rests consist essentially of four thread rests aligned with the corners of the square drive connection.

8. The torque-limiting driver of claim 1 , wherein the shaft includes a medial segment disposed between the thread rests and the square drive connection having the full thickness of the thread rests.

9. The torque-limiting driver of claim 1 , wherein a force provided by the spring securely maintains the square drive connection of the shaft engaged within the square drive socket of the lower cylindrical shank.

10. The torque-limiting driver of claim 1 , wherein the nut includes a lower portion having an outer diameter substantially equal to an inner diameter of the spring and extending axially through at least a portion of the spring.

11. The torque-limiting driver of claim 1 , further comprising at least two washers between the spring and the upper cylindrical shank.

12. The torque-limiting driver of claim 1 , further comprising a washer between the lower cylindrical shank and the body.

13. The torque-limiting driver of claim 1 , further comprising a washer between the spring and the nut.

14. The torque-limiting driver of claim 1 , wherein the upper cylindrical shank and the lower cylindrical shank each have a plurality of teeth and an axial bore, the teeth having a vertical face, an inclined face and a substantially flat peak, wherein the inclined face is defined by a first radius of curvature that transitions to the substantially flat peak and wherein the teeth spiral around the axial bore.

15. The torque-limiting driver of claim 14 , wherein the vertical face terminates in a second radius of curvature that transitions to the substantially flat peak and wherein the second radius of curvature is smaller than the first radius of curvature.

16. The torque-limiting driver of claim 14 , wherein the substantially flat surface is wider at the outer radius than at the inner radius and wherein the substantially flat surface is perpendicular to the axis of the upper and lower shank.

17. The torque-limiting driver of claim 15 , wherein the transition from the first radius of curvature and second radius of curvature to the substantially flat peak is smooth.

18. The torque-limiting driver of claim 1 , wherein the predetermined torque limit is at least 1 inch-ounce.

19. The torque-limiting driver of claim 1 , wherein the predetermined torque limit is between about 16 inch-ounces and about 40 inch-ounces.

20. The torque-limiting driver of claim 19 , wherein the torque-limiting driver is capable of functioning within the predetermined torque limit for a predetermined number of torque-limit actuations before the drive socket, the shaft at one or more points within or between drive connection and thread rests, or a combination of two or more of those elements together, fails structurally.

21. The torque-limiting driver of claim 20 , wherein the predetermined number of torque-limit actuations is no more than about ten.

22. The torque-limiting driver of claim 20 , wherein the predetermined number of torque-limit actuations is no more than about twenty.

23. The torque-limiting driver of claim 20 , wherein the predetermined number of torque-limit actuations is no more than about forty.

24. The torque-limiting driver of claim 1 , wherein the square drive connection and square drive socket are each provided with a square geometry with four substantially planar walls with truncated corners interposed between the substantially planar walls.

25. The torque-limiting driver of claim 24 , wherein each of the four substantially planar walls has a nominal side length and each opposing pair of truncated corners are separated by a truncated diameter distance, wherein the truncated diameter distance is between about 1% and about 20% less than an untruncated diameter distance equal to the nominal side length times the square root of two.

26. The torque-limiting driver of claim 25 , wherein the truncated diameter distance is between about 5% and about 15% less than the untruncated diameter distance.

27. The torque-limiting driver of claim 25 , wherein the truncated diameter distance is between about 8% and about 12% less than the untruncated diameter distance.

28. The torque-limiting driver of claim 25 , wherein the truncated diameter distance is about 10% less than the untruncated diameter distance.

29. The torque-limiting driver of claim 1 , wherein the lumen tip opening and the second lumen end opening are in fluid communication with each other.

Assignees

• Eca Medical Instr

Inventors

• Ivinson David
• Nino John

Classifications

• Y10T403/4966

  Deformation occurs simultaneously with assembly · CPC title

• Y10T403/4958

  Separate deforming means remains with joint assembly · CPC title

• B25B23/1422

  torque indicators or adjustable torque limiters · CPC title

• B25B23/18

  Devices for illuminating the head of the screw or the nut · CPC title

• A61M25/0113 Primary

  Mechanical advancing means, e.g. catheter dispensers · CPC title