Non-penetrating roofing membrane fastener

Abstract

A fastener adapted to secure a roof membrane to a roof surface without penetration of the membrane includes an anchor disc having an inverted frustoconical button, an externally threaded tined retainer adapted to fit over the button with the membrane trapped between the retainer and the button and an internally threaded cover adapted to screw over the retainer and hold it in place over the button. The anchor disc includes a plurality of ribs which extend from the base up to the button. The tined retainer includes a number of tines corresponding to the areas between the individual ribs so that one tine fits between each pair of adjacent ribs. These ribs thereby prevent the rotation of the retainer when the cover is screwed over the retainer. The retainer also includes an upper ring portion and a lower tined portion which permits the tines to flex outwardly but not upwardly. Therefore the threads on the tined portion cannot become misaligned. The ring portion also includes an upper peripheral ridge or a thread which permits the cover to be pre-threaded onto the retainer prior to assembly. This pre-threading does not interfere with the flexibility of the tines since the ridge is up at the top portion of the ring above the tined portion. The tined portion can also be flared outwardly to facilitate easier placement of the retainer over the membrane and button.