Patent GB-537110-A (GB)
Title: Improvements in and relating to fasteners for securing apertured members together
IPC: F16B5/10
Filed: 1939-11-08
Abstract: 537,110. Stud fastenings. UNITED-CARR FASTENER CORPORATION. Nov. 8, 1939, No. 29656. Convention date, Nov. 10, 1938. [Class 44] In a fastening for securing together apertured plate members, particularly in aeroplanes, of the kind comprising a stud, rotatably mounted on one of the plates, which is passed through registering apertures in the other plate and in a spring strip member and rotated to engage projections on the stud with a spring, the spring is mounted so that one or both of its ends can slide on the plate, and the edges of the aperture in the spring have bent-up cam portions which guide the stud projections to a retaining depression in the spring and stops to prevent over-rotation of the stud in fastening direction. As described, when the stud is rotated in release direction beyond the release position, to give a plate-separating action. The plates 7, 19 have countersunk portions 3, 8 which nest together, part 3 forming a seating to receive a flush conical head of the stud. The stud may have a cylindrical shank with a transverse pin 6 to provide the projections, the stud being rotatably held on plate 7 by a spring ring. As shown, however, in Figs. 1-3 the stud is of flat material with integral spring-engaging shouldered projections 15 and a part 2 with bevelled ends forming part of the head which is completed by a disc 1 having a slot 4 in which part 2 nests, a transverse slot 5 being formed in parts 1, 2 to receive an operating tool. The stud is held on plate 7 by a washer 10 with an open ended slot slid laterally on to the shank below shoulders 12, tongues on the washer being then bent across the mouth of the slot to retain the washer in place. Fig. 17 shows a stud made by folding a sheet-metal blank to provide double thickness of metal at the nose 32 and shoulders 35, the upper ends having semi-circular parts 33 bent outwards and engaged in the rim of a separate cup portion 30 provided with a tool-receiving slot 31. This form is retained on the plate by an apertured washer slid over the nose 32 and shank until it snaps past retaining tongues 39 formed on the blank. The spring member 17 of arched form is secured at one end to plate 19 by rivet 23 through circular aperture 22, and at the other end by a shouldered rivet 25 passed through a slot 24 to allow sliding movement of the spring. Aperture 22 may also be replaced by a slot. The stud-receiving aperture in the spring is shown as rectangular with cam members 27 guiding the stud projections to transverse depressions 28 in which the projections engage to prevent accidental release, and with stop members 29 to limit rotation of the stud. Alternative forms of aperture and cam and stop members are described. The form used with the cylindrically shanked stud referred to above has a central circular aperture merging into oppositely disposed longitudinally slots which allow passage of the transverse pin of the stud, the outer ends of the slots receiving the shouldered fixing rivets. The ends of the spring member may be pointed to allow fixing close to the corner of a plate member.