GB790625A - Improvements in or relating to toggle fasteners - Google Patents

Abstract

790,625. Releasable fasteners. K. A. C., Ltd. June 22, 1955 [June 21, 1954]. No. 18212/54. Class 44 A toggle fastener comprises a toggle lever 9 carried by linkage means intended for connection to one of the parts to be joined by the fastener, and a part for connection to the other of the parts to be joined by the fastener and for cooperation with the toggle lever, the co-operating p a r t having fulcrum means on which such toggle lever is adapted to pivot during the locking and release of the toggle fastener, and wherein retaining means are provided for reducing the danger of the locked toggle fastener, being released accidentally, such retaining means comprising a two-part spring retainer 15 and 17 or 22 operating in the manner of a push-pull catch and having one part carried by the co-operating part and the two parts of the retainer being adapted to snap into inter-engagement when the toggle lever is moved to its locked position. As shown the fastener is used for joining the ends of a pipe coupling of the type described in Specification 735,271, the coupling comprising three arcuate sections 1 of channel shaped cross section arranged end-to-end the sections being spot welded to a spring metal strap 2. The end of the strap 2 is doubled upon itself to form a loop 3 to receive a pivot pin 4 which carries a T-bolt 5, the stem of which passes at right angles through a pivot pin 4 and is adjustably secured therein, the head of the T-piece carrying a pair of toggle links 6. The toggle lever 9 is of inverted channel shape in cross section with a projecting finger piece 11 formed at one end and it is pivoted intermediate its ends to the links 6. The ends of the side cheeks 10 of the lever 9 have forks 12 at the end of the lever remote from the finger piece 11 to engage an anchorage block 8 contained in a second loop at the other end of the strap 2. The stud 15 is formed in a bent up end of the strap 2 adjacent the anchorage block 8 and the toggle lever 9 is provided with an opening 16 to receive the stud 15. The spring elements 17 are formed by the side limbs of a hairpin spring which passes through pairs of holes 18, 19 in the toggle lever 9 the ends of the spring being bent to retain it in the hole 19. When the toggle lever is in its locking position with the forks 12 engaging the anchorage block 8, the spring elements engage the stud 15. In a modification which avoids the provision of an opening in the lever 9, a hairpin spring 22 is used which at one end has an elongated narrow loop 23 to engage the finger piece 11 of the toggle lever and the two arms 24 of the spring end in helical coils, a pin 13 being passed through the coils and the side cheeks 10 of the toggle lever. The coils act as axially resilient spacers when the arms 24 engage the stud which in this embodiment is bulbous and riveted to the strap 2. Specifications 732,442, 736,879 and 769,402 [Group XXXVIII] also are referred to.