GB778663A - Improvements in or relating to vehicle braking systems - Google Patents

Abstract

778,663. Controlling vehicles. MASSEYHABRIS-FERGUSON (SALES), Ltd. April 20, 1954 [April 17, 1953], No. 10546/53. Classes 79(2) and 79(5). [Also in Group XXXIV] In a vehicle (particularly a tractor) braking system of the kind in which the brakes of both rear ground wheels are adapted to be actuated in unison by mechanism including a crossshaft 30 which traverses the tractor body and from which separate brake actuating connections extend to both brakes, the brakes may be actuated individually by means of the appropriate pedal 2 which when depressed actuates shaft 1, against the action of return springs 3, to apply the appropriate engine-driven rear ground wheels of the tractor or simultaneously by means of pedal 5 which acts as a main actuator. One of the pedals may be provided with an alternative actuator in the form of a hand lever 4 preferably secured to the left-handside pedal 2 to enable the driver to leave his left foot free for actuation of the clutch pedal. The pedal 5, which actuates both brakes simultaneously, has a hub 6 which is attached to a sleeve 7 rotatable in bearings in the tractor casing. The equalizing device comprises a floating compensator lever 20 which has diametrically opposed and equi-distant pivot joints 22 and 23 with reference to the axis of the cross-shaft 30 which rotates within the sleeve 7. The base of the lever 20 has a pressure receiving member 21 which has an abutment face 21A that is engageable by a pin 19 on the pedal 5. The pivot joint 22 connects the compensator lever 20 with an arm 29 fixed to the cross-shaft 30 and the pivot joint 23 connects the compensator lever 20 with an adjustable brake-actuating connection 24-27. The other end of the crossshaft 30 carries an arm 28 for actuating the left-hand brake through a similar brakeactuating connection 24-27. In operation, when the main pedal 5 is depressed, the pin 19 engages the abutment face 21A of the compensator lever 20 to resolve the pressure into two oppositely-directed parallel forces, i.e. a couple, on the pivot joints 22 and 23. Thus the lever 20 tends to rotate about the. pivot 22 pulling on the pivot 23 and applying the right-hand brake. Similarly, the lever 20 tends to pivot about the pivot 23 and push the pivot 22 rearwardly to apply the left-hand brake through the arm 28. Thus substantial equal braking efforts are applied to both vehicle wheels. A pawl-andratchet retaining mechanism 11 similar to that described in Specification 723,492 is provided for the main pedal 5.