Initially one piece removable fastener

Claim 1

A fastener for removably joining a first and a second perforated member, comprising: a. an expansible grommet having complementary portions joined by a web, the complementary portions including a pair of confronting head portions and stem portions forming spaced confronting walls; b. opposed expansion cam shoulders adjacent the extremities of the stem portions; c. a latching lug projecting from at least one confronting wall; d. an expander plunger including a handle head disposed outwardly of the grommet head portions and a shank dimensioned to fit between the complementary walls; e. cam elements carried by the shank engageable with the cam shoulders to spread the cam portions upon inward movement relative to the grommet; f. a channel formed in the shank to receive the latching lug and including a shoulder engageable with the latching lug to restrain outward movement of the plunger; g. and means initially forming a frangible connection between the head portions of the grommet and the shank of the plunger to hold the plunger in an extended position relative to the grommet until the frangible connection is sheared; h. the grommet being insertable into the perforated first and second members and the plunger, upon being subjected to a connection shearing force, movable into expanding engagement with the cam sHoulders to expand the grommet into interlocking engagement with the first and second members; i. the plunger thereafter being outwardly movable until engagement between the plunger shoulder and grommet latching lug to permit contraction of the latching lug for removal from the second member.