Torque limiting mechanism with lock bushing
AssigneeGreatbatch Ltd.
InventorSteve Landowski
Life of this patent
Estimating the term…
Abstract
A torque limiting mechanism used for securing fasteners is described. The torque limiting mechanism consists of a shaft, a torque gear having a plurality of ball bearings, a threshold bearing and a variable force applying subassembly. The torque limiting mechanism further consisting of a lock bushing and retaining ring placed circumferentially around the proximal end of the shaft. The lock bushing and retaining ring reduce structural misalignments and increase the accuracy of the device.
Claims31
A torque limiting device comprising:
- a) a housing, having a proximal end spaced apart from a distal end, the proximal end connectable to a handle;
- b) a shaft having a longitudinal axis extending along a shaft proximal end spaced apart from a shaft distal end, the shaft proximal end residing within the housing;
- c) a torque gear, having a torque gear distal surface spaced from a torque gear proximal surface, a torque gear throughbore therebetween, an inner surface of the torque gear throughbore in frictional contact with an outer surface of the shaft, and a plurality of ball bearings residing between the torque gear and the housing, the ball bearings being in contact with the proximal surface of the torque gear and an internal surface of the housing;
- d) a variable force applying subassembly positioned circumferentially around the shaft, proximal of the torque gear, the subassembly engagable with the torque gear;
- and
- e) wherein rotation of the handle causes rotation of the torque gear and the shaft until a maximum threshold force value provided by the variable force applying subassembly is exceeded.
A torque limiting mechanism, the mechanism comprising:
- a) a shaft having a longitudinal axis extending along a shaft proximal end spaced apart from a shaft distal end;
- b) a torque gear, having a torque gear throughbore therebetween, an inner surface of the torque gear throughbore in frictional contact with an outer surface of the shaft, and a plurality of ball bearings, each of the ball bearings being in contact the torque gear;
- c) a variable force applying subassembly positioned around the shaft, the subassembly engagable with the torque gear;
- and
- d) wherein the variable force applying subassembly exerts a biasing force against the torque gear and the ball bearings.
The torque limiting mechanism of 19 wherein when a torque exceeding the biasing force is applied to the housing, the frictional contact relationship between the ball bearings and the internal surface of the housing is overcome such that the housing is independently rotatable of the plurality of the ball bearings.
A torque limiting device comprising:
- a) a housing having a proximal end spaced apart from a distal end, the proximal end being connectable to a handle;
- b) a shaft having a longitudinal axis extending along a shaft proximal end spaced apart from a shaft distal end, the shaft proximal end positioned within the housing;
- c) a torque gear having a torque gear distal surface spaced from a torque gear proximal surface, the torque gear being positioned circumferentially around the shaft distal of the handle and a plurality of ball bearings residing proximal of the torque gear and positioned circumferentially around the shaft such that each of the ball bearings contact a proximal surface of the torque gear and a surface within the housing;
- d) a variable force applying sub-assembly positioned circumferentially around the shaft, the sub-assembly engagable with the torque gear;
- e) a lock bushing positioned circumferentially around the shaft, distal of the handle and proximal of the ball bearings and a first retaining ring positioned circumferentially around the shaft, proximal of the lock bushing;
- and
- e) wherein rotation of the handle causes rotation of the torque gear and the shaft until a maximum threshold force value determined by the variable force applying subassembly is exceeded.
Dependencies are inferred from the claim text.