Plastic device for spacing and holding two or more plates

Claim 1

A plastic fastener for spacing and holding two or more plates each having a slot-like aperture with a predetermined width, comprising: a head portion; at least two adjacent shank portions each having a predetermined length the first of which has a relatively large cross-section and is integrally connected to and extending from said head portion and the other of which has a relatively smaller cross-section and is integrally connected to and extending from said first shank portion; a shoulder portion formed at the transition point between said adjacent shank portions; and at least one non-return element integrally connected to said first shank portion at the end opposite said head portion and to said second shank portion at the end opposite said shoulder portion, each said non-return element having a free end with all such free ends extending toward said head and each being adapted to yieldingly deform in passing through an associated aperture of one of said plates and return to its original form after passing through said aperture, each said nonreturn element being a diverging branch whose free end has a shoulder to catch the edge of said associated aperture, each of said shank shoulder portions having a transverse dimension equal to or less than the predetermined width of the slot in the plate through which it must pass but larger than the predetermined width of the slot in the next adjacent plate whereby said plates are retained in predetermined spaced relation controlled by the predetermined lengths of said shank portions.