Patent GB-1202200-A (GB)
Title: Improvements in or relating to scaffold couplings
Inventor: LOWE JACK GRAHAM
IPC: E04G7/14
Filed: 1966-12-06
Abstract: 1,202,200. Clamps. BURTON DELING- POLE & CO. Ltd. 20 Nov., 1967 [6 Dec., 1966, 4 March, 1967; 25 May, 1967], Nos. 54519/66, 10338/67 and 24364/67. Heading E2B. [Also in Division B3] A scaffold coupling for connecting a pair of scaffold tubes in mutually transverse relationship and which is of the kind comprising a central body 9 having a pair of mutually transverse concavedly curved seatings 10, (not shown) and 11, with body is adapted to extend between the tubes, the body being provided with two mutually transverse pairs of lugs 12, 13, 14, 15 with the two lugs in each pair disposed at diametrically opposite sides of the central body, one of the two lugs 12, 14 in each pair having hinged thereto, one end portion of a tube embracing clamping jaw 22, 23 having a concavedly curved tube engaging seating, and which one end portion is forked to receive between the arms of the fork, part of the adjacent body lug 12 or 14; and the other lug 13 or 15 of each of the two pairs of lugs being recessed at the side thereof directed away from the jaw which is hinged to the first mentioned lug 12 or 14 of such pair, each recess providing a hinge bearing for the head of a T-shaped clamping bolt 17, which extends through a hole 19 in the recessed lug, and which bolt carries a nut 20 on its free end portion for clamping engagement with the free end portion of said hinged jaw, the central body together with its two pairs of lugs being formed as a forging, is characterised in that the periphery of the central body of the coupling is devoid of projecting corners at positions intermediate the lugs, and the bolt hinging lugs 13, 15 are each made of a depth sufficiently small that their respective said recesses can accommodate only a minor portion of the head of the T- shaped bolt, and the lugs 12, 14 to which the jaws are hinged are each devoid of oppositely extending flanges so as to be of substantially rectangular as opposed to T form in crosssection, with the mass of metal in each of the two diametrically opposed lugs in each pair being substantially the same and the opening movement of each jaw relative to the central body being limited by the free end 28 of each rectangular section jaw hinge lug engaging with the metal of the jaw at a position between the inner ends of the two arms forming the fork end portion of the jaw to which said substantially rectangular section lug is pivotally connected. In the construction shown each lug of each of the two pairs of lugs adjacent its junction with the central body has an integral reinforcing portion 12a, 13a, 14a, 15a extending from the central body in the direction of the extension thereof of the adjacent lug with the reinforcing portions of the one pair of lugs in each case forming a scaffold tube engaging extension of that central body seating which, in securing the tube, coacts with that hinge jaw which is associated with the other pair of the two pairs of lugs. The lugs 12a and 14a have an outer corner of right angle configuration in cross-section to provide a sharp edge 12b, 14b curved about the axis of curvature of the adjacent seating so that it can bite into the scaffold tube and in the case of a vertical tube prevent the coupling slipping down the tube when underload. During manufacture two of the central bodies 9 are formed simultaneously by a method which comprises a step of taking a length 31, Fig. 4, of round metal bar and at a position intermediate two round bar portions 33 locally deforming a section of the bar to substantially rectangular form in cross-section over a length great enough to provide in said deformed section sufficient metal to form two of said bolt hinging lugs 13, 15 each associated with a respective one of the two central bodies and by the said deforming step elongating the bar length 31 in the direction of the length thereof and subjecting the two round bar portions 33 joined by the deformed section to a subsequent forging operation in which each of the round portions 33 is forged between a pair of dies each conforming to the required configuration of a respective said central body and simultaneously forging the deformed section of the bar length to the configuration of the two said hinging lugs associated one with each of the pair of central bodies and at the same time forging the remainder of each central body including the other three lugs thereof from the metal of a respective one of the two round bar portions 33 so as to form the two central bodies simultaneously by the same forging operation.