GB773972A - Improvements in endless tracked tractors - Google Patents

Abstract

773,972. Endless track vehicles. BOMBARDIER, J. A. Nov. 19, 1952, No. 29185/52. Class 79(1). In an endless track tractor the track driving wheel 10 or, as shown, the track idler wheel 9 has its axle 8, Figs. 1, 4 and 6, mounted on the upper end of a rocker 7 pivoted at 6 to a strut 5 connected at 4 to the tractor frame, the lower end of the rocker 7 being connected to a resiliently and adjustably tensioned flexible member. As shown, the rear end of the strut 5 is pivoted at between ears of a plate 3 secured to the axle casing by shackles 2. The rocker 7 carries at its lower end a pin 15<SP>1</SP> to which is secured one end of a chain 15, the chain passing over a pulley 16 carried by ears 17 on a spring housing 12 connected by a lip 13 to the plate 3. Within the housing 12 the chain is connected to a shaft 14 which carries a washer 18 and a nut 19. A spring 20 is arranged between the washer 18 and the bottom of the housing so as to tension the chain 15 and hence the endless track 11, the tension being adjustable by means of the nut 19. A chain 21 is arranged between a fixed part 22 of the tractor and a hook 23 on the strut 5 to limit pivotal movement of the strut under the action of the spring 20. In a modification, Fig. 7, the strut 5. is replaced by a closed cylinder 30 containing a piston 31 carrying a pin 32 projecting through a slot 33 in the cylinder wall, the pin 32 being connected by a link 34 to the rocker 7<SP>1</SP>, fluid pressure being introduced into the cylinder 30 through a pipe 35 to pivotally adjust the rocker, and a chain 15a being connected to the rocker to function as the chain 15.