Patent GB-632551-A (GB)
Title: Improvements in or relating to tools having a spring loaded scissor-like action
IPC: A01G3/02
Filed: 1947-12-18
Abstract: 632,551. Hinges. SMYTH, L. J. Dec. 18, 1947, No. 33395. [Class 65 (ii)] [Also in Groups XIV and XXIIII] In a tool having scissorlike action against spring means, the pivot comprises an axially-movable spring- loaded element with one or more projections adapted to enter apertures or slots in superposed parts of the tool, certain of the apertures or slots being aligned or closing togetner of the handles, so that the projections can be pressed into all the apertures or slots to lock the handles together, being retained by pressure of the spring-loading of the tool, and means are provided to relieve this pressure, whereupon the spring-loaded element withdraws the projections to release the handles. A bush 1, Fig. 2, and bearing pin 9 disposed therein pass through central pivot holes in arms a, b of a bifurcated extension 4, Fig. 1, of a handle 7 and in arms c, d of an extension 5 of a handle 6, and are secured in place by a nut 12, a shoulder 31 in the bush, and a flange 2 of the bush seated in a counterbore 8 in the arm a. The bush extends slightly beyond the faces of the arms a, d to allow some clearance. A member 13 slidable on the pin 9 has two pins 15 extending through apertures 16 in the arms a, b and arcuate slots 17 in the arm c, whereby movement of the handles and blades is limited by the extent of the slots 17. When the handles are closed, similar apertures 16 in the arm d are aligned with those in the arms a, b, and the member 13 can be pressed inward so that the pins 15 pass into the apertures 16 in the arm d to lock the handles together. A spring tending to urge the handles apart causes the pins 15 to be held by friction in the apertures in the arm d. On slightly further moving the handles together to release the pins 15, the member 13 is moved outwards clear of the arm d by a spring 19 housed in an annular recess 18 in the member 13 to unlock the handles. Alternatively, one pin 15 may be used, each arm having one aperture or slot. In another form, apertures are provided only in the arms a, c, the pins releasing the arm c on retraction, and in this case the handle extensions 4, 5 may each comprise only one arm. One extension may comprise one arm between two arms of the other, there being slots in one such outer arm and apertures in the other two arms, or the inner and one outer arm only may have apertures. In a further form, with only two arms, one arm has a slot or aperture to fit a projection or lip of the member 13, and the other arm has a similar slot with a recessed portion half the depth of the slot, whereby the retracted projection or lip slides in the recess. Two opposite lips and corresponding slots may be provided. In another form, Fig. 8, the arms have circular enlargements 24 with peripheral slots 25, 28, 29, 30, the slot 28 in the arm c being elongated, and the member 13 having a corresponding lip; alternatively the arms a, c only could have slots. Where slots or apertures are provided in only two arms, limitation of opening movement is not effected. Specification 608,191, [Group XIV], is referred to.