GB1266350A - - Google Patents

Abstract

1,266,350. Structural joints; clamps. J. F. A. HUTCHINGS and M. HOCKTON. 22 Jan., 1970 [25 Jan., 1969], No. 4354/69. Headings E1K and E2B. [Also in Divisions A4 and F2] A means for making connections to tubular members e.g. in building frames comprises a spigot 7 adapted to fit within the tube end 5, said spigot comprising a block 1 of wedge shaped cross section extending in a direction parallel to the axis of the tube end 5 and having screws 3 in holes tapped in a direction perpendicular to the axis of the tube end, one or two wedge plates 2 extending parallel to the wedge block 1 and having a complementary wedge surface, the outer surface of the wedge plates being adapted to fit the interior of the tube end, a flexible binding material 4 to keep the spigot parts together while allowing it to expand into frictional contact with the tube end 5 when screws 3 are rotated to bear against the walls of the tube and thereby move the wedge block relative to the wedge plate or plates, and holes in the tubular member corresponding to the position of the screws. The screws 3 may bear on the inside walls of the tube, being tightened through holes which are small compared to the head of the bolt so that the screws are in compression, or may pass through the holes in the wall to be tightened in the usual way (Fig. 8). The spigot may be secured to another member in a framework by the wedge block or a wedge plate being formed integrally with a framework junction piece. The outer surfaces of the wedge plates may be roughened to increase friction with the tube walls. The binding material (e.g. of plastics or rubber) is formed round the spigot and shaped to make it easily insertable in the tube end, and may be of waterproof material to prevent ingress of moisture to the joint. The holes in the tube walls may be axially elongated to allow for adjustment when butt joining two tubes. In the case where the screws bear on the inside walls of the tube the joint may be loosened by tightening the screws through the wedge block to bear on the opposite inside wall of the tube. Any shape of cross section of tube may be joined.