Patent ID: 8714056
Filing Date: 2014-05-06
Classification: A61B,B25B,F16D

Abstract:
1. A torque limiting device comprising: a) a housing comprising a housing sidewall extending along a longitudinal axis from a proximal housing portion to a distal housing portion having an annular housing edge spaced from the axis to provide an open distal end, wherein the proximal housing end supports a handle and wherein an internal housing recess provided by the housing sidewall extends from the open distal housing end to the proximal housing portion; b) a first shaft partially housed inside the housing and extending from a proximal shaft portion to a distal shaft portion having a distal socket opening, wherein the proximal shaft portion is supported by the proximal housing portion with the distal shaft portion extending axially beyond the open distal housing end; c) a lock bushing supported on the first shaft and seated against an inner surface of the housing sidewall, wherein the lock bushing has a distal bushing face that angles distally and inwardly toward the longitudinal axis; d) a torque gear friction fit on the first shaft and having a distal torque gear face spaced from a proximal torque gear face, wherein the proximal torque gear face has at least two divots recessed therein; e) at least two first ball bearings residing in the respective torque gear divots, wherein the two first ball bearings contact the angled distal bushing face and are seated in bearing recesses formed in the internal surface of the housing sidewall; f) a thrust bearing supported op the first shaft and comprising a disc thickness extending to opposed proximal and distal disc faces, wherein the thrust bearing comprises at least two second ball bearing supported by the disc with the second ball bearings being of a greater diameter than that of the disc thickness so that the second ball bearings contact the proximally positioned torque gear and extend beyond the distal disc face; g) a first spring supported on the first shaft; h) a nut threaded into engagement with the inner surface of the housing sidewall at the distal housing portion, wherein the nut forces the first spring into biased relationship against the second ball bearings of the thrust bearing and in turn the torque gear including the first ball bearing seated in the bearing recesses of the housing sidewall and contacting the angled distal bushing face; and i) an enclosure comprising an enclosure sidewall extending from a distal enclosure portion an having an open distal enclosure end to a proximal enclosure portion providing an open proximal housing end, wherein the proximal enclosure portion is mated to the distal housing portion with the distal first shaft portion including the distal socket opening extending axially beyond the open distal enclosure end; j) wherein the nut is threadingly adjustable to adjust the bias of the first spring against the thrust gear and the torque gear including the first ball bearings; k) wherein rotation of the handle causes rotation of the torque gear and the friction fit first shaft inside the housing until a maximum threshold torque force provided by the adjustable bias of the first spring is exceeded, and l) wherein when the maximum threshold torque force is exceeded, the first shaft and torque gear cease to rotate in unison with the handle as the torque gear rotates on the first ball bearings seated in the bearing recesses of the housing sidewall and contacting the angled distal bushing face.