GB628941A - Improvements in or relating to door closers - Google Patents

Abstract

628,941. Door-operating appliances; stays for hinged articles. ROLLINGS, R. E., and BELL, F. A. Oct. 6, 1947, No. 26834. [Class 65 (i)] A spring door-closer combined with air-dashpot check means is provided with an additional opening for the escape of air from the check cylinder and with a valve adapted to be unseated by the check piston as the door approaches the closed position to control the escape of air. As shown, a cylinder 17 contains a closing spring 18 and check piston 21, whilst the cylinder head 23 is provided with a check opening 24 controlled by a non-return ball valve 25 and a needle valve 26. An additional opening 28 in the cylinder head, communicating with an annular groove 27, is controlled by a valve 41 which comprises a centrally apertured stem 42 arranged to slide within a split sleeve 45 fixed in the cylinder, and a flexible annular part 43. The valve 41 is urged by a spring 46 towards the cylinder head and engages the latter on both the inner and outer sides of the annular groove to prevent communication between the cylinder and the opening 28, whilst leaving the cylinder in communication with the opening 24. Bell-crank levers 51 pivoted to the sleeve 45 are arranged with radially extending arms connected to the valve stem 42 and with axially extending arms adapted to be moved apart by a boss 52 on the piston when the latter approaches the head 23. The opening 28 is provided with a valve disc 56 pressed on a seating by a spring 58 and formed with a central orifice controlled by a needle valve 61. During opening of the door, when the piston moves away from the head 23, valves 41 and 56 lift off their seats, allowing free ingress of air through the opening 28. Movement of the piston to effect closure of the door forces air through the restricted opening 24 until the boss 52 moves the bell-crank lever arms apart to unseat the valve 41, when the opening 28 is connected to the cylinder and air can escape through the orifice in the valve 56 to provide a greater closing force for overcoming the resistance of the door latch. The head 23 is pivoted to the door whilst the piston rod is pivoted to an elbow linkage, the ends of which are connected respectively to the door and door frame. The head at the other end of the cylinder is provided with means adapted to clamp the piston rod relative to the cylinder for holding the door in any desired position. The Provisional Specification states that checking may be effected by liquid instead of air, the inlet and outlet passages in the cylinder head being, in that case, connected to a liquid reservoir.