Patent GB-402591-A (GB)
Title: Improvements in or relating to mechanically operated folding doors
IPC: E05F11/12
Filed: 1932-11-10
Abstract: 402,591. Door-operating mechanism; fastenings; doors. LONDON PASSENGER TRANSPORT BOARD, 55, Broadway, Westminster, CHAMBERS, W. E., 58, Manor Drive, Wembley Park, and LUNGHI, P., 70, King's Road, Camden Town, both in London. Nov. 10, 1932, No. 31778. [Classes 44,65 (i), and 65 (ii).] In operating- mechanism for twin folding doors having one leaf hinged to the door frame and the second leaf hinged to the free edge of the first, of the kind co mprising a jointed operating lever connected at its ends to afixed support and to the door respectively, the operating lever is coupled directly to both leaves of the door by two members of a toggle coupling, one member to each door-leaf. The toggle coupling is so arranged that the door-closing thrust of the operating lever tends to spread the coupling members and the door-leaves to which they are attached. In Fig. 2 the door leaves 10, 11 are hinged together at 19, and the leaf 10 is hinged to the door frame at 14, the leaf 11 carrying at top and bottom rollers 17 which engage guidetracks 18. The operating lever comprises two sections 20, 21, both adjustable in length, connected by a forked joint provided with a handle 53 for manual operation of the mechanism. The member 21 is pivoted to a fixed bracket 22, and the member 20 is pivoted to the tail 27 of a link 25 hinged to the doorleaf 11, another link 24 being hinged to the leaf 10 and to the link 25 intermediately in the length of the latter ; the point of connection of lever member 20 to link 25 is thus nearer to the hinge 14 when the door is closed than the point of connection of the two links 24, 25 which form the toggle coupling. The operating lever members 20, 21 are forked at their common joint, as shown in Fig. 3, the limbs of the forks being connected by a pin 48, on which the handle 53 is mounted between the limbs of the forks. The pin 48 has a head 49 with a flat on one side to engage a lug 51 on the outside fork member to prevent rotation of the pin in this member ; the pin is secured at the other end by a screwed cap 52. The bosses of the forks are provided with lugs 54, 55 to limit the motion of the mechanism in the closing direction. The doors are held in the open position by a pivoted hook 65, Figs. 2 and 8, engaging the lever member 21 ; the pivot of the hook is provided with a cam lug which co-operates with a spring-pressed ball 70, mounted in the pivot bracket, to hold the hook member in the engaged or disengaged position. The joint 19 between the door-leaves 10, 11 is provided with a finger-guard comprising curved plates 36, 35, Fig. 3, hinged together and to the door leaves in the same way as the toggle links 24, 25. In the arrangement shown, the toggle links are separate from the finger-guard sections, which finish with beads 39 above and below the toggle-coupling, but in a modification the finger-guard sections are continuous and themselves form the toggle-coupling, the lever 20 being connected to a bracket fixed to the guard section 36 and corresponding in shape to the tail 27 of the link 25 shown.