Preload release mechanism

Claim 1

A preload release mechanism comprising: a preload spring assembly adapted to apply a preload to a connector member mounted on a support structure, said connector member being adapted for blind mated connection with a second connector member affixed to an object to be mounted to said support structure, said preload spring assembly comprising a pair of cylindrical bushings arranged in sleeved telescopic relation with the innermost bushing having an axial opening therethrough which defines an opening through said preload spring assembly and a coiled compressive preload spring arranged in sleeved relation to said telescoped bushings; means for mounting said compressive preload spring in compressed condition on the telescoped bushings whereby the compressive spring applies a biasing force urging the separation of the telescoped bushings; a tubular shaft extending through said opening through the preload spring assembly and through aligned openings provided in the connector plate member and said supporting structure, said tubular shaft having a plurality of lateral openings extending through the wall of the shaft and each adapted to receive an actuator detent therein; means for clamping said tubular shaft in fixed position on said support structure; a plunger in the form of a plunger rod slidably mounted in said tubular shaft, said plunger rod having an annular shoulder formed near one end thereof by a first reduced diameter portion which forms a tip end of the plunger, said plunger rod having a second reduced diameter portion forming an annular recess in the plunger rod near the other end thereof; a plunger retainer fixed to one end of said tubular shaft and having an internal annular flange extending radially and providing an annular stop surface adapted to be engaged by said plunger rod shoulder and thereby preclude passage of the plunger rod through said shaft in one axial direction of said shaft; an end cap fitted on the end of the tubular shaft opposite said tip end and closing the bore of the shaft, said end cap having an external annular flange providing an annular shoulder abutting the end of the tubular shaft and radially extending beyond the external longitudinal surface of the shaft; a plunger return spring located in the bore of said tubular shaft in compressed condition therein with one end of the plunger return spring abutting said end cap and the other end of said return spring abutting one end of the plunger rod to thereby bias the plunger rod against the plunger rod retainer; a preload spring assembly return spring mounted in sleeved relation to said tubular shaft with one end thereof abutting said cap shoulder and the other end thereof abutting one end of the preload spring assembly; and a plurality of actuator detents received in said plurality of lateral openings in the tubular shaft, each of said detents being held captive in a different one of said lateral openings by engagement with the side surface of the rod intermediate said recess and the end of the rod engaged by the plunger return spring and by engagement with an annular end surface formed about the axial opening through the inner bushing, said detents locking the preload spring assembly in position on said tubular shaft whereby the preload spring assembly applies a preload to the connector member whereby upon completion of the connection a contact of the plunger tip with said object to be connected with a force sufficient to depress the plunger rod causes the detents to move against the recessed portion of the plunger and to release the preload spring assembly for movement on the tubular shaft in counteraction to the preload spring assembly return spring and thereby release said preload.