Patent GB-290352-A (GB)
Title: Improvements in and relating to the adjustment of brake and clutch mechanism
IPC: F16D65/56
Filed: 1927-02-10
Abstract: 290,352. Wilson, W. G. Feb. 10, 1927. Clutches, friction; operating clutches.-An automatic sla.ck adjuster for brakes and clutches is shown in connection with a band brake 20, Fig. 10, adapted to be operated by a toggle lever 29 and a rod 25 on which a nut 27, Figs. 1 and 2, comprised in the automatic adjuster is turned to take up slack in the brake. The nut 27 is adapted to be turned by means of a ball clutch under such spring control that pressure is exerted on the clutch balls in a determined direction and also pressure is produced to prevent movement through vibration. The ball clutch is surrounded by an actuating collar 38 projections 46, 47 on which engage adjustable abutments 48, 49, Fig. 10, when the brake operating gear moves abnormally due to slack. The nut 27 fits in a coned seating in a collar 28 engaged by the toggle lever 29 and at its upper part is formed with three flats and is surrounded by a ball cage 35, Figs. 1 and 2, carrying balls 36 in openings opposite the flats. The balls touch the flats and the inside of the actuating collar 38 and are drawn towards the narrower spaces between the ends of the flats and' the inside of the collar by springs 42 acting on th ball cage 35. The springs pass through holes in a triangular undercut top flange 40 and into the groove beneath the flange are looped at 43 and pass into the groove again and are hooked round a lug 44 on the ball cage. The collar 38 rests on a flange 39 on the ball cage. The projection 47 is adapted to strike the abutment 48 and impart a rotary adjustment to the collar 38 which corresponds to an idle stroke of the ball clutch, the balls, however, being prevented from slacking back by the springs 42. The projection 46 is adapted to engage the abutment 49 and imparts rotary movement to the collar 38 which corresponds to an operating stroke of the ball clutch which turns the nut on the rod 25. The collar 38 is acted on by a spring 50 on a stud 51 on the collar 28 to retain the one-way ball clutch in action and to prevent movement through vibration. In a modification the coned part of the nut 27 is extended to form a flange on which stands the collar 38 and the upper part of the nut is provided with two flats only. The ball cage is formed by a washer 56, Fig. 12, resting on the collar 38 and retaining the balls 36 by depending forks 57. Two springs 61, Fig. 12, are used having one end 61a secured to a flat face of the nut, the spring is doubled back and fits in a groove in the nut, is looped again at 62 where it presses on a fork 57 and is hooked on a lug 63 on the washer 56. The spring loops are confined by lugs 64 on the washer 56. The coned seating of the collar 28 may be extended by bosses on which the ball cage 35 rides with a minimum of friction. Another form of spring is shown which presses on a flat face of the nut, is looped round one lug and the end hooked on another lug, both lugs forming part of the ball cage washer 56. In a further modification a single spring is used attached at its ends to the collar 38 and collar 28 respectively, the central part encircling the nut 27 in an annular groove and having a central bowed part to increase its resiliency. The tendency of the spring is to wind the nut on the rod 25. The toggle lever 29 engages an abutment on a hooked finger 23 which connects one end of the brake band to a fixed anchorage 22. Any number of balls and flats may be used including one.