Patent GB-831724-A (GB)
Title: Improvements in means for fixing objects to supports
Inventor: CHALK THOMAS GEORGE
IPC: B64D11/06
Filed: 1957-05-08
Abstract: 831,724. Stud and socket fastenings. BRENT METAL WORKS Ltd. April 28, 1958 [May 8, 1957], No. 14599/57. Class 44 A fixing device for removably securing an object to a support of the kind comprising a longitudinally slotted tubular member 1 the slot 6 in which is enlarged at regular spaced intervals to form a series of substantially identical apertures 7 in the wall of the tubular member, comprises a bearing surface 12, Figs. 3 and 5, adapted to bear against the tubular member, at least one stud 13 projecting from the bearing surface and having a cross-sectional shape substantially the same as that of the apertures 7, and clamping means 15 adapted to be inserted through the slot 6 into the hollow interior of the tubular member 1 and to clamp the bearing surface 12 against the tubular member with each of the studs 13 engaged in one of the apertures 7. As shown, the surface 12 is constituted by the underside of the foot 11 of a table or chair-leg. The clamping means 15 comprises a plate 17 having a shape substantially identical with that portion of the slot 6 which lies between the centre of one of the apertures 7 and the centre of the next but one aperture 7 and is attached to a rod 21 by which the plate is movable vertically between a clamping and a release position by means of a toggle mechanism 23, 24, 25 located within the leg. In use, the plate 17 is first lowered to a position in which it lies below the lower surface of the studs 13. The plate is then inserted through the slot 6 in the support and the foot 11 is slid along until the studs 13 lie directly above two apertures 7 in the support. The foot is then lowered until the surface 12 rests on the surface of the slotted side 4 of the support. The plate 17 is then raised by means of the toggle mechanism so that the plate bears firmly against the underside of the support on both sides of the slot 6. The leg is disengaged from the support by first lowering the plate 17 and then raising the foot 11 to allow the plate to be slid back to a position in which it can pass upwardly through the slot 6. In another arrangement Figs. 6 and 7, in which the bearing surface is provided by a foot 31, the clamping means comprises two spring-loaded slidable plungers 34 connected together by a rod 38 which is supported in a sleeve portion 39 of a link 40. The lower end of the latter includes a cam portion 41 which is urged by the plunger springs 37 into contact with the head of an adjustable bolt 42 mounted in the foot. The upper end of the link 40 is pivotally supported in slots 44 of a lever '46 of U-shape in cross-section. The lever is disposed in a slot 47 of the leg 30 and is biased into engagement with the top and bottom edges of the slot by a spring 53. In use, the lever is pressed inwards and then moved bodily to release it from the slot whereby the lower end of the lever may be pulled away thereby to lower the plungers 34. The plungers are then engaged with the support, the leg is slid therealong and lowered and the lever 46 returned to the position shown whereby the plungers 34 firmly engage the underside of the slot in the support.