| 摘要 |
A low profile thin seam miner includes a main frame mounting a lower transverse axis rotary cutter and a parallel axis conveyor rearwardly of the lower cutter. The main frame also mounts a forward transverse axis rotary cutter somewhat above the lower cutter, the forward upper cutter being supported on a longitudinal boom pivoted to the main frame and being vertically swingable under influence of a single cylinder. The main frame and all of its parts is incrementally advanced into the seam by the alternating action of two horizontal longitudinal parallel axis cylinders connected between the main frame and a pair of floor-engaging plates. Two vertical axis jacks are connected between the two floor-engaging plates and two cooperating overhead roof plates, connected with the floor-engaging plates by separate toggle linkages. Two more generally upright cylinders connected between the floor plates and the rear of the main frame can tilt the main frame on a transverse pivot axis to vary the depth of cut of the lower rear cutter responsive to the control of a sensing tooth on such cutter. The single cylinder connected with the boom of the forward upper cutter can swing the boom on its transverse pivot axis to vary the depth of cut of the forward upper cutter, responsive to the control of a sensing tooth on such cutter.
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