Rotary drill for surgeons

Claim 1

In a rotary tool of the type described, the combination of: a manually graspable housing having an open ended socket, a rotary drive gear positioned at the end of the socket remote from the open end thereof, a rotary bur having a cutting element on one end of a shank and having a driven gear on the other end of said shank adapted to mesh with said drive gear, a sleeve encompassing said shank and having axially spaced bearings therein rotatably supporting said shank, said sleeve and bur being removably positioned as a unit in said socket in a position in which the gears are in mesh, said housing having an opening in a side thereof, said sleeve having an annular shoulder adjacent said opening, a latching device for releasably locking said sleeve against removal from said socket, said latching device including a latch mounted on the housing in said opening to turn about an axis parallel to the rotary axis of said bur, said latch being mounted for limited movement along its own axis, resilient means opposing axial movement of said latch in one direction, said latch having a taper surface engageable with said annular shoulder whereby turning of the latch about its axis serves to insure proper meshing of said gears, the latch having an arcuate detent for reception of a portion of said shoulder to hold the latch against turning movement, said resilient means acting to maintain said arcuate detent in contact with said annular shoulder.