Patent GB-706048-A (GB)
Title: Improvements in or relating to mining machines
IPC: E21C27/26
Filed: 1951-09-24
Abstract: 706,048. Propelling vehicles. JOY MANUFACTURING CO. Sept. 24, 1951 [Oct. 19, 1950]. No. 22314/51. Class 79(3) [Also in Group XXI] To advance a mining machine, particularly of the type disclosed in Specifications 681,364 and 681,365, [Group XXI], which are referred to, through mine roadways with a step by step motion the propulsion means consists of two floor engaging supports that can be raised and lowered alternatively by power operated means with respect to the floor so that a substantial portion of the weight of the machine is transferred from one support to the other and power operated means for moving said frame bodily with respect to said first support when the second is relieved of the weight and for moving the first support relative to said frame while the frame is mainly supported by the other support. One of the supports includes power actuated relatively movable elements movable along an arcuate path over the mine floor for swinging the frame bodily about an upright axis located towards the other end of the machine. In one embodiment the first support comprises a pan 45 that can slide with respect of a frame 49 disposed centrally and longitudinally of the main frame 5 of the machine and be raised and lowered with respect thereof by hydraulic piston cylinder units 69. Secured to the pan 45 is the cylinder 57 of a double acting jack, the forwardly projecting piston rod of which is secured to the frame 50. The second support at the front of the machine comprises an arcuate plate 65 slidably mounted on a frame 68 attached by piston cylinder units 69 to the front of the frame 5, which is further supported so as to be able to turn about a vertical axis 25 on a pair of wheels 33. To advance the machine the cycle of operations is, starting with the piston 58 positioned at the rear of cylinder 57, to raise the front support 65 off the ground, advance the piston 58 forward through the cylinder 57 so that the frames 5 and 49 slide forward with respect to the pan 45, which is held stationary with respect to the ground by friction. The front support 65 is lowered and the pan 45 raised and advanced by admitting liquid under pressure to the other side of the piston 58 and then lowered into contact with the ground to permit the cycle of operations to be repeated. To turn the frame about the vertical axis 25 use is made of the jack units 78 connecting the frame 5 to either end of the plate 65; load being applied on said front support to permit movement of the plate 65 by the jacks 78 with respect to the frame. In the second embodiment the second floor engaging support consists of a downwardly projecting extension of the main frame and the first ground engaging supports is constructed to be similar to the second ground engaging support of the first embodiment, but is slidably mounted on the frame to be reciprocated longitudinally with respect thereto by a pair of hydraulic piston cylinder units. The hydraulic system of the machine may be manually controlled or may be so arranged that the sequence of operations is automatic. The vertical pivotal axis of the machine may be more. positively defined by a vertical hydraulic jack attached to the frame, the piston rod of which can be forced into engagement with the roof.