US 11,931,270 B2
Prosthetic digit actuator
Rodrigo Mercader Rivera, Livingston (GB); and Hugh Gill, Paisley (GB)
Assigned to Touch Bionics Limited, Livingston (GB)
Filed by Touch Bionics Limited, Livingston (GB)
Filed on Nov. 13, 2020, as Appl. No. 17/098,045.
Claims priority of provisional application 63/064,614, filed on Aug. 12, 2020.
Claims priority of provisional application 62/935,852, filed on Nov. 15, 2019.
Prior Publication US 2021/0145610 A1, May 20, 2021
Int. Cl. A61F 2/58 (2006.01); A61F 2/68 (2006.01)
CPC A61F 2/586 (2013.01) [A61F 2/68 (2013.01); A61F 2002/587 (2013.01); A61F 2002/6836 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An actuator for a prosthetic digit, the actuator comprising:
a gearbox housing;
a motor;
an output shaft extending proximally along a rotation axis, wherein the motor is in mechanical communication with the output shaft and is configured to cause a rotation of the output shaft about the rotation axis, the output shaft including a worm gear that is unibody with and axially fixed on the output shaft proximally of the gearbox housing, the worm gear comprising threads, wherein a first gap is defined between a distal-facing side of a distal end of the threads of the worm gear and a proximal-facing side of a proximal end of the gearbox housing;
a radial bearing supported along the output shaft proximally of the worm gear, wherein a second gap is defined between a distal-facing side of a distal end of the radial bearing and a proximal-facing side of a proximal end of the threads of the worm gear, and the radial bearing comprising an inner race in mechanical communication with an outer race;
a 4-point contact bearing located within the gearbox housing at a distal end of the output shaft distally of the worm gear and distally of the first gap, the 4-point contact bearing comprising at least one outer race and at least one inner race, wherein the at least one outer race contacts a step on an inner sidewall of the gearbox housing that prevents distal translation of the 4-point contact bearing, and the at least one inner race contacts the distal end of the output shaft and is configured to rotate with the output shaft relative to the at least one outer race, such that rotation of the output shaft rotates the at least one inner race about the rotation axis, and the at least one outer race is axially compressed by the gearbox housing and a preload ring, the preload ring being disposed within the gearbox housing proximally of the 4-point contact bearing and contacting only a single proximal-facing surface of the 4-point contact bearing; and
a worm wheel configured to be attached with a prosthetic hand, wherein the worm wheel is in mechanical communication with the threads of the worm gear such that rotation of the worm gear about the rotation axis causes the worm gear to travel along an arcuate outer perimeter of the worm wheel to thereby rotate the gearbox housing about the worm wheel.