Patent GB-1136662-A (GB)
Title: Improvements in or relating to quick release fasteners
Inventor: MYATT KEITH ERNEST
IPC: B64D29/08
Filed: 1966-04-23
Abstract: 1,136,662. Stud and socket fastenings. G.K.N. SCREWS & FASTENERS Ltd. 19 Oct., 1966 [23 April, 1966], No. 17866/66. Heading E2B. A releasable fastener for holding together apertured first and second sheets in face to face relation comprises a retaining piece 11 to be assembled to the first sheet, a turn piece 10 carried by the retaining piece and a cam piece 12 to be assembled to the second sheet for engagement by the turn piece, the turn piece comprising a shank 13, a head 15 at one end of the shank for engaging said retaining piece and a fastening projection 22, extending outwardly from the shank adjacent the other end thereof, the retaining piece and the cam piece each consisting of a single piece of resilient synthetic resinous material which presents a flange 24, 38 having a hole 25, 39 therein which has a central portion 26, 40 dimensioned to give passage to said shank and a lateral portion 27 or 41 dimensioned to give passage to said projection 22, a slotted member 28 or 42 projecting from the flange and providing a split bushing with the bore of said bushing in alignment with said central portion and the slot in the member in alignment with said lateral portions, a groove 34 or 47 in the outer surface of the bushing between the flange and the end of the bushing remote therefrom, the parts of the bushing being capable of being sprung towards one another so that its end portion can be sprung through the aperture in the sheet on which the piece is to be assembled and the edge of said aperture received in the groove, and lug means 37, 49 on the flange for engaging said sheet to prevent the piece rotating relative thereto when mounted thereon; the cam piece additionally having a cam surface 44, on the end of the bushing remote from the flange and inclined to the longitudinal axis of the shank to engage the fastening projection after the latter have entered the slot in said member and the turn piece has been subsequently turned, engagement of the fastening projection with the cam surface drawing the shank of the turn piece into said bore and spring means 18 being provided to resist the drawing of the shank into the bore. In the construction shown two projections 22 and two cam surfaces and the spring means is a skirt which is formed integral with the head of the turn piece; the shank is provided with four circumferentially spaced axially extending flats 20 which terminate in shoulders 21 and the retaining piece has flats 32 in the bore of its bushing which are engageable with the flats on the shank to locate the turn piece in successive 90 rotational positions. The shoulders 21 engage the surface of the bushing below the flats to retain the turn piece in assembly with the retaining piece. Each of _ the two cam surfaces is provided with a detent 45 to releasably hold the shank in the fastening position. The skirt 18 in the construction shown is conical but in a modification the skirt is flat and the retaining piece is provided with an upstanding skirt and it is used with a sheet which has a dished portion in which the aperture is provided.