Patent GB-777442-A (GB)
Title: Improvements relating to material shifting apparatus
IPC: E02F3/32
Filed: 1952-06-07
Abstract: 777,442. Shovel excavators. CLARK, J. Dec. 7, 1953 [June 7, 1952], No. 14415/52. Class 68 (1). Material shifting apparatus comprises an upright mounted for swivelling movement, a lifting boom mounted selectively at a top or bottom position on the upright for pivoting movement in a vertical plane, an arm with a material engaging implement mounted on the boom for pivoting movement in a vertical plane, and top and bottom hydraulicallyoperated piston-and-cylinder devices pivotally connected to the upright such that with the boom in the bottom position, for digging, the top piston and cylinder device is pivotally connectible to the boom to operate it and the bottom piston and cylinder device is pivotally connectible to the arm below the latter's pivotal mounting to operate the arm, and with the boom in top position, for loading, the bottom piston and cylinder device is pivotally connectible to the boom to operate it and the top piston and cylinder is pivotally connected to the arm above the latter's pivotal mounting to operate the arm. Fig. 1 shows the apparatus mounted on a tractor and comprising a rotatable pole 4 on which is pivoted a boom 1 connected by a hydraulic cylinder 12 to the top of the pole. An arm 9 carrying a digging scoop 10 is pivoted to the boom 1, the arm 9 being controlled by a hydraulic cylinder 13 connected to the lower part of the pole. For use as a loading apparatus, the boom 1 is attached to the top of the pole and is controlled by the cylinder 13 and the arm 9 is connected by the cylinder 12 to the top of the pole. The device is removably mounted on the tractor by means of a hitch 41. The hitch comprises two triangular frames secured at their lower ends to the front of the tractor and to a base 6 on an upright tube on which the pole 4 rotates and at their upper ends to a triangular frame secured at its apex to the top of the tube. Alternatively a transverse member at the top of the tube supports a pair of downwardly diverging stays secured to the base and a pair of parallel stays secured to the front of the tractor. Hydraulically operated jacks mounted at the ends of the base have feet which are lowered to the ground to support the tractor weight. The pole 4 is rotated by an hydraulic cylinder supported on the base 6 and having a toothed rack on the piston rod which engages a pinion on the pole. Alternatively the piston rod is fixed and the cylinder is movable over the piston and has teeth engaging a pinion on the pole. The tractor, Fig. 1, is stabilized by arms 56 toothed at the bottom which engage a member forming part of the base 6. The arms have eccentric straps mounted on discs rotatable on a cross shaft rotatable in brackets on the rear axle casing. The shaft is rotated by a hand lever to expand the arms to transfer the tractor weight to the base and the disc has a flange with lugs to limit rearward swinging of the handle when the lugs engage pins on the arms and further lugs on the discs engage the pins when the lever is rotated to a position in which thrust on the arms is removed, continued movement of the lever causing disengagement of the teeth of the arms from the base. The apparatus can then be lifted to transport position. The hydraulic cylinders are supplied with oil from a hydraulic pump on the tractor connected to a control valve box which houses four piston type valves 80 to 83, Fig. 14. The valves 80 and 82 are operated by a handle and operate cylinders 12 and 13. Valve 81, operating slewing, is actuated by a foot pedal. By-pass valve 83 is operated automatically by a series of tappet arms 93 projecting from a sleeve 94 rotatable on a cross shaft 95. Pins 96 screwed into the ends of arms 93 have slotted heads 97 and arcuate cams 98 at the bottom of levers 84, 86 engage in the slots. A lever arm 99 on the end of the sleeve 94 is connected by links 100 to arm 101 pivoted on the pivot shaft 87, of the operating lever. A link 102 connects the arm 101 to the valve stem. Springs 104 connect arm 99 to cross rod 105 to maintain the heads 97 against cams 98. A handle hinged to the tops of arm 101 allows manual actuation. Operating any lever 84 to 86 closes the by-pass valve by causing the cam and tappet mechanism 97-98 to move the stem of the by-pass valve through members 99 to 102. The valve chest has inlet and outlet bores for oil and each of the three bores for the valves has central inlet ports, two sets of outlet ports connected to opposite ends of the cylinder and a further pair of outlet ports. The by-pass valve in the inlet port allows oil to flow to one end of the cylinder and opens the other end to the oil reservoir. Operating a lever by closing the by-pass valve diverts the oil to the required bore. In a modification, the valve chest has five bores, the central one being the by-pass valve and the fourth for a spare valve. The valves are maintained in holding position by compression springs surrounding the rods of the operating levers and located between abutments on the rods. Cam and tappet mechanism operates the by-pass valve, the cams, one secured to each rod, are cylindrical with a central groove in which the tappet arms engage. The tappet arms are secured to the rod of the by-pass valve. Operating a valve lever closes the by-pass valve.