GB472595A - Improvements relating to draw-bar connections for tractors - Google Patents

Abstract

472,595. Draw-gear connections for vehicles. McBAIN, W. J. March 26, 1936, No. 28677/35. [Class 103 (v)] A connection between a tractor and a plough or other trailer whereby, on excessive pull on the draw-bar, the tractor is stopped, e.g. by declutching the motor, comprises a spring-loaded member or sleeve 6 subject to the draw-bar load, trip mechanism operated when the pull becomes excessive and a second spring-loaded member 16 controlled by the trip mechanism and arranged to operate the clutch. As shown, the sleeve 6 is rotatably mounted on a rod 8a and is provided with a tooth 5 normally abutting against a projecting lug 4 on a hollow portion 1 of the draw-bar which is slidable in a housing 3. Rotation of the sleeve 6 is obstructed by the engagement of a cammed plate 7 integral with the sleeve with a fixed cam plate 8, and can take place against the effort of a spring 10 only when the selected maximum load is exceeded. When the sleeve 6 is thus rotated a trip lug 11 thereon is moved out of contact with a stop 12 on a pivoted double-arm lever 13, one arm of which bears against the member 16 subject to the pressure of a spring 17, while the other arm is connected to cable or other clutch-operating mechanism 15. Resetting of the mechanism is effected by moving a handle 20 associated with a rotatable sleeve 19, which carries a projecting roller 21 adapted to contact with a finger 22 on the lever 13. Provision is made by means of a nut 8b and a screw 17b, for adjusting respectively the compression of the springs 10, 17.