GB1122395A - Improvements in fasteners - Google Patents

Abstract

1,122,395. Carrying conductors through partitions. ITW Ltd. 27 Sept., 1965 [25 June, 1964], No. 24284/64. Heading H2E. [Also in Divisions E2 and F2] A fastener consists of a head 12 and a shank in which the shank consists of at least two resilient limbs 2 separated by a longitudinal slot or slots and each limb has on the outside a projection 11 with a shoulder 10 facing towards the head and an oblique face 9 facing away from the head, the shoulders being perpendicular to the axis of the shank or nearly so and the oblique faces being convergent, with the axis towards the free end of the shank at a considerably smaller angle than the angle of the shoulders to the axis and the cross-section of the shank through the crests of the projections being non-circular in outline; with a cooperating hole 6 which is related in shape to the cross-section of the shank so that if the axis of the shank is aligned with the centre of the hole and the shank is then rotated about the axis, there is at least one first attitude in which the shank can readily pass through the hole and at least one second attitude in which the shank can be forced axially into the hole, with the limbs being squeezed together by engagement of the oblique faces 9 with the edges of the hole, whereupon the shoulders will engage the rear face of the panel and resist withdrawal from the hole and rotation from the second attitude to the first attitude is resisted by engagement of edges of the hole with the limbs but can be accomplished with resilient distortion of the limbs. In the construction shown two limbs are provided and the hole is rectangular, the limbs in the fastening position engaging the long sides of the hole. The fastener shown is intended for securing together two apertured panels with the shank passing through the apertures, the aperture in the panel which is engaged by the head being circular and having a diameter at least as great as the diagonal dimension of the cross-section of the shank to permit the distortion of the shank when the fastener is twisted for release from the rectangular hole. When the fastener is only intended to be secured in a hole to act as a plug button the head has a convex under surface so that the head engages one side of the apertured panel and the shoulders the other. The fastener can also be modified to provide a strain relief grommet for a cable as shown in Figs. 6 and 7; for this use there is an axial bore 24 through the head 26 and the surfaces of the limbs 27 which face the axis are serrated so that when the fastener is secured to the panel the serrations engage the cable. The fastener has two limbs 27 and the hole is in the shape of an eight pointed star with alternate long and short points 34, 36; the outline of the star is in effect two superimposed rectangles and the shank is received in one rectangle in the fastening position and is rotated into the other rectangle for release. More than two limbs can be provided and the hole can have any related polygonal shape.