Patent GB-1187421-A (GB)
Title: Fasteners
Inventor: FISHER JULIAN VERNON
IPC: F16L3/23
Filed: 1967-04-06
Abstract: 1,187,421. Stud fasteners, clamps. ILLINOIS TOOL WORKS Inc. 6 April, 1967 [24 Oct., 1966], No. 15913/67. Heading E2B. A one-piece fastener, made of a resilient plastics material, has a head 14 adapted to bear against one side of a workpiece, and a shank 12 extending from the head; the shank. including a generally tubular portion which is formed by a wall and is open-sided, and which is capable of insertion through an aperture in the workpiece; the shank also including a longitudinal strut member 20 which, considered in planes perpendicular to the length of the shank, extends from the medial part of the inner periphery of the said wall towards the open side in a direction substantially normal to a tangent at the medial part, and which divides the wall into two wall sections 20, 22, one of which is laterally yieldable and carries a shoulder facing towards the head and capable of engaging the workpiece to resist withdrawal; the longitudinal strut member also extending along the shank towards the head, beyond a plane penpendicular to the length of the shank and containing the shoulder, the strut member at the side of the plane nearer the head being related to the wall at the side of the plane further from the head in such a way that the strut member, viewed along the length of the shank, extends from the medial part of the wall beyond an imaginary line betewen the free extremities of the two wall sections; and the shank having a tapering end portion to facilitate insertion of the shank into the aperture in the workpiece. In the construction shown each of the wall sections is yieldable and each has a said shoulder defined by a notch 25, the notches being adjacent the head; the shank in cross section is U shaped and extends through somewhat more than a complete semicircle so that when the shank is inserted in the aperture, the diameter of which is slightly less than the maximum width across the wall sections 20, 22, the wall sections yield radially inwardly as the shank approaches its final position within the work piece and eventually the shoulders spring radially outwardly to secure the fastener to the workpiece; the head 14 has a central body portion 26 with two arms (not shown) extending from opposite margins thereof and inclined slightly with respect to the surfaces of the portion 26, thus as the free extremities of the arms are brought into engagement with the workpiece surface they flex and permits the central body portion 26 to be drawn into engagement with the surface of the work piece and also hold the shoulders in engagement with the other surface of the workpiece. As shown the head includes a portion 32 flexibly connected with the bottom margin of the portion 26 to define a pocket in which a plurality of conductors 30 can be positioned; a lip 33 extends from the upper margin of the head portion 26 and this is engageable with the extremity 34 of the portion 32. In a modification instead of the lip 33 extending downwardly as shown it extends upwardly and is engageable with a slot in the member 32. A construction is also described in which instead of the portion 26 having a lip it has a member which projects laterally and engages a slot in the member 32. The arm 32 and the lip or other means are omitted if the fastener is intended for securing two workpieces together each of which has an aperture through which the fastener can pass. The shank can be modified by providing it with axially spaced shoulders so that the shank is engageable with work pieces of a range of thicknesses; the shoulders can be arranged in pairs or they can be arranged alternately on the two wall sections. The shank can be provided with a transverse rib near its entering end to render the entering end less flexible laterally.