GB774374A - Improvements in or relating to vehicle differential gears - Google Patents

Abstract

774,374. Controlling tractors. MASSEYHARRIS-FERGUSON (SALES), Ltd. Feb. 9, 1953, No. 3552/53. Classes 79(1) and 79(5). [Also in Group XXIV] In a tractor having an implement power lift with a manual controller 12 and having a differential gear lock, the lock can be rendered operative by movement of the controller into the implement lowered position. The invention is applied to a hydraulically operated power lift in which either the pump and sump are, or only the sump is, common to a hydraulic system for actuating a lock on the tractor differential gear, Figs. 1 and 2 (not shown) ; the lock may alternatively be actuated mechanically or electrically. As shown in Figs. 4 and 5 the hydraulic power lift controller 12 is carried by a shaft 32 and a valve 17 actuating the hydraulic system for the differential lock is controlled by a handle 22 through a sleeve 31 and a cam 35, friction pads 34 being provided for holding the members 12, 22 in the positions to which they are set and both members 12, 22 working in a slotted quadrant 33. Movement of the controller 12 to one side of a neutral position lifting the implement and to the other side permitting the implement to drop to its working position, and in corresponding arcs of movement the handle 22 effects unlocking and locking, respectively, of the differential gear, the close proximity of the members 12, 22 permitting the tractor driver to actuate easily both simultaneously by one hand. As shown in Fig. 7 a spring loaded bolt 40 carried by the handle 22 can positively engage the controller 12 to lock the handles together, the bolt carrying pins 44 being engaged by axial slots in a sleeve 45 carried by the handle, and in the position shown the pins 44 being disengaged from the slots and engaging the head of the sleeve to permit independent movement of the members 12, 22. In Fig. 9 the positive coupling between the members 12, 22 has a one-way action, the coupling being formed by a catch 48 pivotally carried by a block 47 on the controller 12, so that with the catch in its full line position movement of the controller 12 into its implement lift arc positively moves the handle 22 into its differential gear unlocked arc. When the members 12, 22 are not coaxial, the arrangement shown in Fig. 13 may be used in which the controller 12 is positively linked to an arm 51 on a shaft 52 carrying the handle 22, the handle 22 carrying a spring-loaded bolt 40 similar to that shown in Fig. 7. Another arrangement for when the members 12, 22 are not coaxial is shown in Fig. 14, the members being interconnected by a telescopic link, the parts 53, 54 of which can be positively coupled by a pin 55. Specifications 470,069, and 687,341 are referred to.