Patent GB-531813-A (GB)
Title: Improvements in mechanism for effecting movement of linearly or angularly movable devices and for locking such devices in required positions
IPC: E05F11/40
Filed: 1939-08-03
Abstract: 531,813. Bowden mechanism. BIERLICH, J. H., and SMITH & DAVIS, Ltd. Aug. 3, 1939, No. 22506. [Class 80 (iii)] [Also in Group XXXI] The invention relates to flexible transmission mechanism of the push-pull type for operating linearly and angularly movable devices and locking them in required positions, e.g. for opening, closing and locking hinged windows &c. and comprises the use of a spring-pressed washer embracing a linearly-movable member and adapted when in a tilted position to grip such member and prevent it from moving in one direction, motion in the opposite direction being allowed, e.g. to take up slack in a tension cable under the action of a spring ; the linearlymovable member may be actuated directly, or through an oscillatable lever imparting its motion through similar one-way clutch washers. In the form shown in Fig. 1, a casement window &c. 2 is operated by means of a helical spring 5 secured to a pivoted block 6 and passing through an elbow 4 into a fixed tube 3, in which it is secured at 10 to a slidable tubular member 9 provided with an actuating handle 11. An inner cable 12 is secured at one end to the block 6 and at the other end to a rod or tube 13, and is subjected to continuous tension by a stiff compression spring 14. Slack in the cable 12 is taken up by means of a spring 14 and a clutch washer 17, which by the action of a grub screw 18 and a spring 19 is tilted so as to allow movement of the rod 13 in a downward direction only. In the form shown in Fig. 2, the transmission members, which are actuated by repeated oscillations of a lever 48 are similar to those shown in Fig. 1, and comprise an outer coil spring 5a passing through a guide tube 3a, and an inner cable 12a tensioned by a spring 14a and fitted with a tilting clutch washer 17a. A slidable tube 9a secured to the spring 5a is engaged by oppositely-disposed tilting clutch washers 23, 24 under the action of springs 27, 28, these washers being controlled by cams 29, 30, which are carried by a rotary spindle 33 having an actuating handle 34 and are formed with inclined faces adapted to force the associated washer into a non-tilted and non-engaging position. As shown, both washers 23, 24 engage the tube 9a and lock it; in another setting of the handle 34, the washer 23 is free and the washer 24 engaged, thus allowing the tube 9a to move to the right ; in a third setting, the washer 23 is engaged and the washer 24 free, thus allowing the tube 9a to move to the left. These movements of the tube 9a are effected by oscillations of the hand lever 48, through a reciprocating saddle member 36 and a tilting-washer one-way clutch 35, which is acted upon by two opposed springs 43, 44 adapted in the balanced position shown to hold the washer 35 in the inoperative position. According to the setting of he handle 34, the outer end of one of the springs 43, 44 is allowed to expand into a recess in one of the two cams 39, 40, thus causing the other spring to tilt the washer 35 in the direction necessary to impart the required one-way movement to the slidable tube 9a.