Electric pneumatic driving devices fora mechanism having to make a reciprocating movement of a limited length at determined times

摘要

631,181. Door-operating appliances. STIGCHEL, B. J. VAN DER. Sept. 18, 1946, No. 27972. [Class 65 (i)] [Also in Groups XV, XXVIII and XXX] A rigid door 9, Fig. 5, suspended from a frame by a cable 10 and balanced by a weight 11 is drawn up guides to lie in a plane adjacent to and parallel with a flat roof when air from a pressure fan 31 acting through a conduit 12 distends a bellows 14, Fig. 6, to tilt the door 9, after which the door responds to the weight 11 pulled downwards by upward movement of a piston 6 to which the weight is connected by a rope 7 ; the piston being subjected at its lower face to pressure from the fan 31 and at its upper face to suction from a fan 3. To lower the door 9 a pressure fan 2 and a suction fan 21 are energized to effect descent of the piston 6 and ascent of the weight 11. Near the end of the door descent an arm 15 is engaged by a bellows crutch 16 and simultaneously a cock 13 is opened to connect the bellows 14 to the cylinder 5 at sub-atmospheric pressure and thereby draw the door into its frame. In a modification the need for cable packing glands at the cylinder ends is eliminated by replacing the piston 6 and cylinder 5 by a pair of inverted air chambers a, a1, Fig. 10, having a flexible connection p to a casing c in which is mounted the pressure and suction fans. The chambers a, a1 guided for vertical movement in a constant level reservoir e are connected by cables f , f and pulleys to a counterweight g which in turn is connected by cables and pulleys to the door d.