Releasable lock for telescoping members

A locking device for securing first and second elongated telescoping members in selected relative telescoped disposition, the device comprising:

• a tubular base having a longitudinal axis and an axially extending opening through the base, the base being adapted to be fixed to one end of the first member with the second member extending through the opening and telescoping into the first member, there being an outer surface on said second member, said opening being defined by an annular surface extending around the outer surface of the second member;
• said base being configured to present a resilient, deflectable element integral with the base and extending in cantilevered disposition circumferentially of the annular opening of the base, the element being movable radially inwardly from said annular opening defining surface to engage the outer surface of said second member, said element having a curved outermost surface;
• a tubular collar having a bore therethrough disposed to receive the second member through the bore, said collar being rotatably mounted on the base for rotation about the axis of said opening;
• a projection carried by the collar for rotation therewith, said projection having an inner inclined cam surface, the projection moving on a path of travel when the collar is rotated in one direction to engage the cam surface of the projection against the outermost surface of the element to deflect the element into frictional locking engagement against the outer surface of the second member.