Patent GB-981036-A (GB)
Title: Brake actuating device
IPC: B60T7/04
Filed: 1962-01-08
Abstract: 981,036. Brake actuating devices. W. C. BLATCHFORD (L. W. Nenzimer). Jan. 8, 1962, No. 636/62. Heading F2E. In a brake actuating device a locking mechanism is provided for holding an actuating mechanism in an actuating position, and a release mechanism is movable for release of the locking mechanism from the actuating mechanism, the release mechanism being provided with a predetermined amount of preliminary motion before the release position occurs, which amount provides an indication of completion of an initial portion and the movement of the actuating mechanism. In the vehicle parking brake arrangement shown in Figs. 1 and 2 the brake may be applied by suecessive clockwise strokes of a pedal lever 34. On the first clockwise stroke of the lever 34 a resilient stop 64 attached to the lever 34 will contact an abutment 58 on a ratchet plate 48 causing the latter to rotate with the lever 34 about a pivot 36 in a clockwise direction and a pawl 62 will ratchet over teeth 56. During the clockwise movement of the plate 48 on the first stroke of the lever 34, a pin 118 secured to the ratchet plate 48 is moved in an arcuate slot 120 in the frame plate 10 in contact with a straight cam surface 122 to pivot the lever 96 about its pivot pin 100 thereby axially moving a release rod 28. At the end of its first stroke, the lever 34 is returned to the position shown in Figs. 1 and 2 wherein a projection 76 on a mounting plate 10 causes a pawl 60 to disengage from teeth 54 on the ratchet plate 48. At the same time the locking pawl 62 is spring biased into engagement with one of the teeth 56 on the ratchet plate 48 to prevent counter-clockwise rotation of the ratchet plate 48 and thereby to maintain at the tension on the cable 14. On the second and subsequent strokes of the lever 34, the pawl 60 is spring urged into engagement with the teeth 54 causing the ratchet plate 48 to move further in a clockwise direction around its pivot 36. At the end of each stroke of the lever 34 the locking pawl 62 will lock the plate 48 in the furthest clockwise position which it has attained during successive strokes of the lever 34. The pin 118 moves along an arcuate slot 120 in contact with the cam surface 122 on subsequent strokes of the lever 34 thereby pivoting the lever 96 about its pivot pin 100 to a greater degree with each successive stroke of the lever 34 until a predetermined axial movement of the release handle 110 in the direction of the arrow 111 is attained. In this position the pin 118 will engage a cam surface 124 and further movement thereof along the cam surface 124 will not cause further pivoting of lever 96 or further movement of the handle 110 in the direction of the arrow and the brake has then been fully applied. The position of the release handle 110 gives an indication to the operator that the brake has been set. To release the brake the operator then pulls the handle 110 to pivot the lever 96 about pivot pin 100 to cause counter-clockwise rotation of the pawl 62 to disengage its nose from the teeth 56 to allow counter-clockwise rotation of the plate 48 to release the tension on the cable 14 and thereby release the brakes of the vehicle.