| 摘要 |
<p>1,176,102. Tensioning endless tracks. INTERNATIONAL HARVESTER CO. 20 Feb., 1968 [20 Feb., 1967], No. 8180/68. Headings B7H and B7J. The longitudinally extending endless track on each side of a crawler vehicle is tensioned by an hydraulically operable track adjuster mechanism including an hydraulic system comprising a one-way inlet valve 104 for tightening the track and a dual function valve comprising a sleeve valve element 64 which is movable in a bore 68 and which carries a second valve element 86, the sleeve valve element being manually operable to unseat, hydraulic fluid escaping around the element 64, and the element 86 being preset to open automatically should the track be overloaded when fluid escapes through a bore within the sleeve valve element. As shown each track is tensioned by an idler wheel 22 mounted in a fork 26 which incorporates an hydraulic cylinder 42 enclosing a piston 46. The rod 30 of the piston 46 abuts the front seat 24 of a spring which is mounted at the other end on the track frame 16. A stop is provided on the track frame for the front spring seat 24 if insufficient fluid is present in the chamber 56 of the cylinder 42. Fluid, such as grease, is injected through a nipple 102, the valve 104 and a passage 98 into the chamber 56 to increase the track tension and escapes from the chamber 56 when the track is overloaded through a passage 54, past the ball valve 86, through the interior of the valve sleeve 66, the port 80, annular passage 92 and port 50 to the atmosphere. To empty or vent the chamber 56 the valve sleeve 66 may be rotated manually to disengage the conical end 74 of the sleeve 66 from a seat 72 when the fluid passes to the port 50 round the outside of the end of the sleeve 66. Alternatively the body of the valve 104 may be unscrewed when fluid is vented through a port 52. The valves are mounted parallel to one another in a crosshead 32 which closes the cylinder 42. An idler scraper 40 is mounted on the crosshead 32.</p> |
