Patent GB-763643-A (GB)
Title: Fasteners for panels and the like
IPC: F16B39/32
Filed: 1954-04-09
Abstract: 763,643. Stud-and-socket fastenings; screw fastenings. CUSS, J. F. March 18, 1955 [April 9, 1954; Sept. 6, 1954], Nos. 10599/54 and 25852/54. Class 44. A fastener comprises separable mating parts including a socket and a spigot engageable therewith, the spigot being adapted to be introduced into the socket to engage a bearing surface 13 therein which prevents further introduction of the spigot into the socket, the spigot comprising a fastening-pin 4 extending axially thereof and adapted to enter an aperture 16 in the socket to secure the spigot therein in engagement with the bearing surface 13, securing of the fastening-pin in the aperture 16 being effected by at least partial rotation of the fastening-pin to a locked position thereof, the fastener also including a disc-like locking washer 17 rotatably carried by the socket and having an aperture 18 aligned with the socket aperture 16 adapted to be engaged by the fastening pin upon introduction of the spigot into the socket so that subsequent rotation of the fastening pin to its said locked position rotates the washer, co-operating means 19, 21 on the washer and socket retaining the washer resiliently in the position thereof corresponding to the locked position of the fastening pin. In the construction shown the fastening pin is provided with a pair of diametrically-opposed radial lugs 5 which upon partial rotation of the pin after the lugs 5 have been passed through the aperture 16 engage a radial surface 15 which surrounds the aperture and so prevents the spigot from being withdrawn from the socket. The bearing surface 13 of the socket body 12 is of frusto-conical formation and the part of the spigot body 1 which engages this bearing surface is of corresponding frusto-conical formation. The washer 17 is pressed against a rim 20 of the surface 15 by a spring 23 which is trapped between a cap 22 and the washer, the cap being secured to the socket body 12. The washer aperture 18 is elongated to receive the radial lugs 5 on the fastening pin 4 so that as the pin is turned the washer turns with it. The co-operating retaining means consist of a pair of locking notches 21 on the rim 20 which are engaged by tongues 19 on the washer when the pin 4 is in its locking position and which act to retain the pin in this position. If desired, the locking notches may have a sawtooth form so that rotation of the pin 4 beyond the locking position is prevented by abutment of the tongues 19 and walls 24 of the notches. To ensure that the washer 17 is held with the aperture 18 aligned with the aperture 16 when the fastening pin and spigot body are withdrawn from the socket the rim 20 is also provided with a pair of grooves 25 which receive the tongues 19 to keep the apertures 16 and 18 in alignment. The grooves 25 also have a sawtooth formation to limit the rotation of the washer. To facilitate the introduction of the spigot into the socket the surface 15 is chamfered or bevelled as indicated at 26 so that shoulders formed by the lugs 5 on the fastening pin initially engage the chamfered or bevelled surfaces with the result that the said shoulders ride up the surfaces 26 and thus draw the spigot forcibly home into the socket. The fastening pin 4 has a head 7 provided with a screwdriver slot 11 and it is retained in an aperture in the spigot body 1 by a ring 10a which engages a flange 10. A spring 9 is positioned between the head 7 and the other side of the flange 10 so that the ring 10a is normally trapped between the lugs 5 and the flange 10. The washer 17 may have a single tongue instead of the two shown. In another form the washer may have two tongues but these are arranged as object and mirror image with respect to the plane containing the axis of the aperture in the washer; when this washer is used with suitably-arranged notches and grooves in the locking surface the arrangement is such that the washer can only be rotated through 90 degrees. In a modification the washer 17 comprises a cast-metal disc having a diametrically-slotted central boss adapted to locate the disc axially by seating within the rib 20. This disc has a pair of lugs in place of the tongues 19. In another construction, instead of the fastening pin having lugs which project beyond the shank of the pin to provide shoulders as in the previous construction the pin is locked to the socket by means of a screw thread which engages a screwthreaded aperture in the socket. The pin is provided with a non-circular extension beyond its screw-threaded portion which engages a similarly-shaped aperture in the locking washer. The locking washer is, however, arranged so that it can be rotated in either direction without limit and it is provided with plurality of equiangularly-spaced radial depressions which seat in locking notches in the rib 20 (e.g. with six depressions and twelve locking notches the washer may engage in any one of twelve rotational positions with respect to the socket body).