GB835739A - Improvements in or relating to devices for mechanically extending and retracting thedrawers or the like arranged in desks, file cabinets or the like - Google Patents

Abstract

835,739. Drawers. BECKER, O. A. June 12, 1956 [June 13, 1955; March 16, 1956], No. 18114/56. Class 52(1) [Also in Group XXV] Desk drawers are operated by flexible operating means extending lengthwise of the drawers to which any drawer is coupled as required. A driver strip 12 is fixed vertically between two horizontal endless chains 15, 16 set at the top and bottom of the pedestal, coupled together by a chain 35 and driven by an electric motor. A pin 17 on the driver strip is engaged by a pivoted spring biased catch 18 at the back of the drawer, the catch normally being held clear of pin 17 by a catch 23 at the back of the pedestal and released by actuation of a press button appropriate to the drawer. Simultaneously the button closes contacts energizing an electric motor, this causing the drawer to be opened. On reaching the end of its outward travel the driver strip 12 contacts a buffer 40 opening a contact and de-energizing the motor. A latch holds the drawer in the opened position. Depressing a return button closes a switch reversing the direction of the current flow to the motor, which thus closes the drawer. In the fully closed position the drawer pivots a bellcrank lever 46 which releases the depressed buttons and closes the contacts associated with the buffer 40. A stop button is also provided which on depression holds open the circuit to the electric motor by a pivoted catch, released only by depression of a release button. In a modification each drawer is extended by spring force derived through cable wound on a spring-loaded drum fixed at the back of the pedestal and passing over a pulley at the front of the pedestal to be secured to the back of the drawer. The drawer is returned by a motor driven rod similar to the rod 12 already described and normally positioned at the front of the pedestal, to which position it is returned after closing the drawer. In further embodiments modifications are made to allow the use of spring force in both opening and closing the drawers, the electric motor tensing the spring in the cable drum used for opening the drawer. Alternatively, using the electric motor directly as in the first embodiment, provision is made for automatically closing one drawer on selection of another to be opened. The device may also be adapted for opening a drawer either from the front or back of a pedestal. The chain drive for the driver strip may be replaced by a friction- or toothed-wheel drive.