Tool torque limiter

Patent metadata

Field	Value
Publication number	US-11097404-B2
Application number	US-201715809661-A
Country	US
Kind code	B2
Filing date	Nov 10, 2017
Priority date	Nov 11, 2016
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

A torque limiter can include a housing and a shaft. The housing can include a housing magnet enclosed within the housing. The shaft can be at least partially surrounded by the housing and can be rotatable within the housing. The shaft can include a shaft magnet integrated with the shaft to magnetically couple with the housing magnet to transmit a torque between the housing and the shaft and configured to uncouple from the housing magnet allowing the shaft to rotate within the housing when a threshold torque is reached.

First claim

The invention claimed is:

1. A torque limiting driver for driving a workpiece, the torque limiting driver comprising:
a housing comprising:
a housing bore comprising a central axis; and
a housing magnet located proximate the housing bore;

a shaft located within the housing bore, the shaft comprising:
a shaft magnet located within the housing bore, the shaft magnet facing the housing and radially alignable with the housing magnet to generate a magnetic coupling to the housing magnet to enable transmission of a torque between the housing and the shaft, wherein the magnetic coupling is configured to uncouple from the housing magnet allowing the shaft and the shaft magnet to rotate about the central axis within the housing when a threshold torque is reached; and
a clutch connected to the shaft and configured to transfer the torque from the shaft to a workpiece unidirectionally;

a coupler removably coupleable to a distal end of the clutch, the coupler configured to releasably receive a driver therein;
a proximal bearing coupled to a proximal portion of the housing and a proximal portion of the shaft to enable rotation of the housing relative to the shaft; and
a distal beating coupled to a distal portion of the housing and a distal portion of the shaft to enable rotation of the housing relative to the shaft;
wherein the shaft defines a shaft bore extending through the shaft along a longitudinal axis of the shaft, the shaft bore defines a first diameter adjacent the proximal bearing, a second diameter adjacent the housing magnet, and a third diameter adjacent the distal bearing, wherein the second diameter is larger than the first diameter and the third diameter.

2. The torque limiting driver of claim 1 , further comprising:
a handle coupleable to the housing to transfer a torque thereto.

3. The torque limiting driver of claim 1 , wherein the housing magnet further comprises:
a plurality of housing magnets disposed around the housing bore.

4. The torque limiting driver of claim 3 , wherein the shaft magnet further comprises:
a plurality of shaft magnets disposed within the shaft and, the shaft magnets coupleable with the plurality of housing magnets.

5. The torque limiter of claim 2 , wherein the plurality of shaft magnets are arranged in alternating polarity and the plurality of housing magnets are arranged in alternating polarity to resist uncoupling between the housing magnets and the shaft magnets.

6. The torque limiting driver of claim 1 , wherein the clutch includes a ratcheting mechanism.

7. The torque limiting driver of claim 1 , the clutch further comprising:
a driving member connected to a distal portion of the shaft, the driving member rotatable with the shaft when the shaft receives a torque from the housing; and
a driven member engaging the driving member, the driving member configured to rotate the driven member using the torque when the torque is in a first direction about the central axis and configured to rotate independently of the torque when the torque is in a second direction about the central axis.

8. The torque limiting driver of claim 7 , the driven member further comprising a driver releaseably engageable with a workpiece to transfer a torque from the driver to the workpiece.

9. The torque limiting driver of claim 1 , wherein the clutch and the housing are not in contact with each other.

10. The torque limiting driver of claim 1 , the shaft further comprising:
the shaft bore extending axially through the shaft.

11. The torque limiting driver of claim 10 , wherein the shaft bore comprises a diameter that varies between a proximal end and a distal end of the shaft.

12. The torque limiting driver of claim 1 , wherein an outer surface of the housing is axially fluted.

13. The torque limiting driver of claim 1 , wherein the housing is configured to substantially shield magnetic fields from extending beyond the torque limiter.

14. A torque limiting driver for driving a workpiece, the torque limiting driver comprising:
a housing comprising:
a housing bore comprising a central axis; and
a housing magnet located proximate the housing bore;

a shaft located within the housing bore, the shaft comprising:
a shaft magnet located within the housing bore, the shaft magnet facing the housing and radially alignable with the housing magnet to generate a magnetic coupling to the housing magnet to enable transmission of a torque between the housing and the shaft, wherein the magnetic coupling is configured to uncouple from the housing magnet allowing the shaft and the shaft magnet to rotate about the central axis within the housing when a threshold torque is reached; and
a clutch connected to the shaft and configured to transfer the torque from the shaft to a workpiece unidirectionally;

a coupler removably coupleable to a distal end of the clutch, the coupler configured to releasably receive a driver therein;
a proximal bearing coupled to a proximal portion of the housing and a proximal portion of the shaft to enable rotation of the housing relative to the shaft; and
a distal bearing coupled to a distal portion of the housing and a distal portion of the shaft to enable rotation of the housing relative to the shaft;
wherein the proximal bearing includes an inner race connected to the shaft, an outer race connected to the housing, and a plurality of rollers located between the inner race and the outer race of the proximal bearing, and wherein the distal bearing includes an inner race connected to the shaft, an outer race connected to the housing and a plurality of rollers located between the inner race and the outer race of the distal bearing.

15. The torque limiting driver of claim 14 , further comprising:
a handle coupleable to the housing to transfer a torque thereto.

16. The torque limiting driver of claim 14 , wherein the housing magnet further comprises:
a plurality of housing magnets disposed around the housing bore.

17. The torque limiting driver of claim 16 , wherein the shaft magnet further comprises:
a plurality of shaft magnets disposed within the shaft and, the shaft magnets coupleable with the plurality of housing magnets.

18. The torque limiting driver of claim 14 , wherein the clutch includes a ratcheting mechanism.

19. The torque limiting driver of claim 14 , the clutch further comprising:
a driving member connected to a distal portion of the shaft, the driving member rotatable with the shaft when the shaft receives a torque from the housing; and
a driven member engaging the driving member, the driving member configured to rotate the driven member using the torque when the torque is in a first direction about the central axis and configured to rotate independently of the torque when the torque is in a second direction about the central axis.

Assignees

• Zimmer Biomet Spine Inc

Inventors

• Farmer Samuel James

Classifications

• A61B2090/031

  torque limiting · CPC title

• A61B2017/00477

  Coupling (A61B2017/0046 takes precedence) · CPC title

• B25B23/1427

  by mechanical means · CPC title

• B25B23/141 Primary

  Mechanical overload release couplings · CPC title

• A61B2017/00876

  magnetic · CPC title