Gearless spring torque drive

Patent metadata

Field	Value
Publication number	US-10618149-B2
Application number	US-201815946308-A
Country	US
Kind code	B2
Filing date	Apr 5, 2018
Priority date	Oct 7, 2015
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

Disposable torque-limiting devices having an upper shank component with a torque-limiting interface, a lower shank component with a torque-limiting interface, and a spring element. Torque-limiting interfaces having a plurality of undulations arranged around an axial bore or drive socket and separated by a plurality of transition regions, with each undulation having an upslope, a peak, and a downslope. The torque-limiting interfaces are configured to engage and disengage to provide torque transmission with predetermined torque limits at various rotational speeds and for amounts of actuations while remaining within a specified operational range. The encasement provides mounts for a tool and for a drive shaft which may be connected to a powered device.

First claim

The invention claimed is:

1. A disposable torque-limiting device comprising:
a generally hollow cylindrical body with a partially closed distal end;
an upper shank formed inside the partially closed distal end of the cylindrical body;
a circumferential rim formed on the outside of the partially closed distal end;
an upper torque-limiting interface formed on the inside of the partially closed distal end having an axial bore;
a lower shank component within the cylindrical body comprising a proximal end, a distal end, a neck extending from the distal end, a drive socket fluidly connecting the proximal end and the distal end, and a lower torque-limiting interface disposed on the proximal end, wherein the upper shank component and the lower shank component are aligned along an axis in the direction of the axial bore and the drive socket with the upper torque-limiting interface in contact with the lower torque-limiting interface;

a coil spring placed above the lower shank on at least partially around the neck configured to apply compressive force (F) along the axis to compress the upper torque-limiting interface against the lower torque-limiting interface;
a tool collar with a flange extending radially, a front on one side of the flange, a square leg formed on the opposite of the flange and a shaped channel there through rotatably fit into the circumferential rim;
a tool shaft with a threaded back portion and a front end having a tool channel therein;
catches formed on the tool shaft configured to mate with the shaped channel whereby the tool shaft can be inserted through the tool collar and precluded from rotating within the shaped channel;
a threaded retaining member configured to engage the threaded back portion; and,

wherein the tool shaft and threaded retaining member cooperate to apply a predetermined force to the lower and upper shanks by affixing the tool shaft through the tool collar, the axial bore, the drive socket and the coil spring and affixing the retaining member thereto,
wherein the upper torque-limiting interface comprises a first plurality of undulations arranged around the axial bore and separated by a first plurality of transition regions, the lower torque-limiting interface comprises a second plurality of undulations arranged around the drive socket and separated by a second plurality of transition regions, with the first and second pluralities being equal in number,
wherein each undulation comprises an upslope, a peak, and a downslope,
wherein each downslope has a declination angle of between 5 and 45 degrees,
wherein the downslope mitigates degradation of the upper and lower torque-limiting interfaces,
wherein the undulation further includes a slot on one or more of the upslope, peak, and downslope; wherein the slot is configured to receive debris generated during operation of the device.

2. The device of claim 1 wherein:
the coil spring configured to apply compressive force (F) along the axis to compress the upper torque-limiting interface against the lower torque-limiting interface;
the upper shank component and the lower shank component are configured to engage to rotate together when torque is applied to the lower shank component via the drive socket; and,
the upper shank component and the lower shank component are configured to disengage when a predetermined torque limit is exceeded.

3. The device of claim 1 further comprising a plastic high lubricity washer between the flange and the circumferential rim.

4. The device of claim 1 further comprising a roller bearing washer between the flange and the circumferential rim.

5. The device of claim 1 further comprising a tool in the tool channel.

6. A disposable torque-limiting device comprising:
a generally hollow cylindrical body with a partially closed distal end;
an upper shank formed inside the partially closed distal end of the cylindrical body;
a circumferential rim formed on the outside of the partially closed distal end;
an upper torque-limiting interface formed on the inside of the partially closed distal end having an axial bore;
a lower shank component within the cylindrical body comprising a proximal end, a distal end, a retaining cavity formed thereon, a drive socket fluidly connecting the proximal end and the distal end, and a lower torque-limiting interface disposed on the proximal end, wherein the upper shank component and the lower shank component are aligned along an axis in the direction of the axial bore and the drive socket with the upper torque-limiting interface in contact with the lower torque-limiting interface;
a coil spring placed above the lower shank inside the retaining cavity configured to apply compressive force (F) along the axis to compress the first torque-limiting interface against the second torque-limiting interface at a predetermined torque limit;
a tool collar with a flange extending radially, a front on one side of the flange, a square leg formed on the opposite of the flange and a shaped channel there through rotatably fit into the circumferential rim;
a tool shaft with a threaded back portion and a front end having a tool channel therein;
catches formed on the tool shaft configured to mate with the shaped channel whereby the tool shaft can be inserted through the tool collar and precluded from rotating within the shaped channel;
a threaded retaining member configure to engage the threaded back portion; wherein the tool shaft and threaded retaining member cooperate to apply a predetermined force to the lower and upper shanks by mounted the tool shaft through the tool collar, the axial bore, the drive socket and the coil spring and affixing the retaining member thereto,
wherein the upper torque-limiting interface comprises a first plurality of undulations arranged around the axial bore and separated by a first plurality of transition regions, the lower torque-limiting interface comprises a second plurality of undulations arranged around the drive socket and separated by a second plurality of transition regions, with the first and second pluralities being equal in number,
wherein each undulation comprises an upslope, a peak, a downslope, and a slot on one or more of the upslope, peak, and downslope, the slot being configured to receive debris generated during operation of the device.

7. The device of claim 6
wherein the coil spring is configured to apply compressive force (F) along the axis to compress the upper torque-limiting interface against the lower torque-limiting interface;
wherein the upper shank component and the lower shank component are configured to engage to rotate together when torque is applied to the lower shank component via the drive socket; and,
wherein the upper shank component and the lower shank component are configured to disengage when a predetermined torque limit is exceeded.

8. The device of claim 6 further comprising a roller bearing washer between the flange and the circumferential rim.

9. The device of claim 8 further comprising a tool in the tool channel.

10. The torque-limiting device of claim 6 , wherein each upslope has an inclination angle between 3 degrees and 15 degrees.

11. The torque-limiting device of claim 6 , wherein each upslope has an inclination angle between 5 degrees and 9 degrees.

12. The torque-limiting device of claim 6 , wherein each upslope has an inclination angle between 6 degrees and 8 degrees.

13. The torque-limiting device of claim 6 , wherein the predetermined torque limit is between 0.1 Newton-meter and 3.0 Newton-meter.

14. The torque-limiting device of claim 6 , wherein the predetermined torque limit is between 3.0 Newton

Assignees

• Eca Medical Instr

Inventors

• Nino John
• Ivinson David
• Tory David

Classifications

• F16D43/213

  with axially applied torque-limiting friction surfaces · CPC title

• B25B23/141 Primary

  Mechanical overload release couplings · CPC title

• B25B23/1475

  for impact wrenches or screwdrivers · CPC title

• A61B2090/031

  torque limiting · CPC title

• B25B23/147

  specially adapted for electrically operated wrenches or screwdrivers · CPC title