GB805040A - Improvements in hand brakes for motor vehicles, more particularly lorries and omnibuses - Google Patents

Abstract

805,040. Vehicle hand brakes. MASCHINENFABRIK AUGSBURG - NURNBERG A.G. Sept. 30, 1955 [Oct. 6, 1954], No. 27850/55. Class 103 (1). In a hand brake mechanism for taking up the idle movement before the actual brake applying movement during the first short portion of a stroke of the hand brake lever, a spring is connected to the hand brake lever and to the brake linkage and relaxes thereby to remove the brake play during the first portion of a stroke of the hand brake lever. In the embodiment illustrated, a vehicle hand brake mechanism is illustrated in the brake released position wherein a spring 27, secured at one end to coupling member 9 and at the other end to'the chasses of the vehicle, is tensioned. When pawl 3 is lifted out of engagement with toothed segment 6 and hand brake lever 2 is moved in the direction of the arrow 11, toothed segment 7, freely mounted on shaft 1 disposed in the chassis, is taken along by pawl 4 which is urged into engagement with the teeth on segment 7 by spring 5. At the same time abutment 22 secured to hand brake lever 2 is moved away from roller 21, mounted on short arm 20 of lever 17, permitting movement of lever 17 in the direction of arrow 28 to follow the abutment 22 under the action of relaxing spring 27. Arm 23 of lever 17 is, in this example, three times longer than arm 20 and lever 8 is actuated by movement of lever 17 and lever 9 in direction of arrow 28 to move toothed segment 7 under pawl 4 of the hand brake lever to take up the slack in the brake linkage. When the spring 17 has been relaxed the pawl 15 engages the toothed segment 7 and further movement of the hand brake lever 2 in the direction of the arrow 11 causes the pawl 4 to rotate the toothed segment 7 and permit movement of the lever 8 about pivot 1 to actuate brake linkage; bolt 25 moving in slot 24 in coupling member 9 to permit movements of lever 8 without movement of lever 17 and coupling member 9. Normally, only about one-third of the stroke of the brake lever is used up in removal of the brake play; the remainder of the stroke being available for full braking application. However, if the hand brake lever 2 has to be operated again for the purpose of increasing the braking power, the hand brake lever 2 is not moved back up to the point where the pawl 15 is removed from the toothed segment 7, but its backward movement is stopped and reversed before it reaches that point. In this way, the deflection of the toothed segment 7 reached already with the first stroke is increased during the subsequent second stroke beyond the pawl 4, corresponding to the second stroke of the hand brake 2 or part thereof, whereby the pawl 15 again ensures engagement in any position of the segment 7.