GB555705A - Improvements in latches and in combined locks and latches - Google Patents

Abstract

555,705. Latches. EREBUS MANUFACTURING CO., Ltd., JAMES, J. E., and GLOTHAM, A. June 13, 1942, No. 8103. [Class 44] In a latch or combined latch and lock the latch spindle carries a sprocket wheel in place of the usual follower and a chain or perforated belt meshing with the wheel serves to transmit retractive movement to the bolt. Fig. 1 shows the sprocket wheel F meshing with a chain G the ends of which are connected to rods H. H<1> slidable through the talons a<2> of the bolt tail and terminating in collars h bearing against the talons. Spring J, J<1> connected to these collars and to studs j, j<1> are in tension normally serving to keep the chain taut, in conjunction with the springs D, D<1> which shoot the bolt. Outward movement of the bolt is limited by the collars h and inward movement by a fixed stop E. When the sprocket wheel is rotated clockwise, rod H moves to the right, withdrawing the bolt, whilst spring J<1>, in taking up the slack of the chain, pulls rod H' idly to the left. With anticlockwise rotation rod H<1> retracts the bolt and rod H moves idly. In a modification the rods H. H<1> are replaced by runner plates. Fig. 4 shows a form in which an endless chain meshes with additional sprocket wheels P, P' secured to toothed wheels, not seen, which mesh with racks on runner plates S, S' bearing against the bolt tail talons a<2>. Rotation of wheel F in either direction moves one runner to the right, retracting the bolt, and the other to the left. In a further form in which the sprocket is rotatable in one direction only to retract the bolt, the chain has its ends riveted to the bolt tail and is straight, its limbs serving as a rack.