GB1537115A - Drum cutter or tunnelling machines for underground mining - Google Patents

Abstract

1537115 Cutter drum type mining or tunnelling machine EICKHOFF MASCHINENFABRIK UND EISENGIESSEREI mbH Gebr 17 Sept 1976 [19 Sept 1975] 38521/76 Heading E1F A multi-ratio transmission for a rotary cutter mining or tunnelling machine comprises a main shaft 5 having two co-axial parts 5a, 5b which may be rotable or fixed relative to each other, and a counter shaft 19 having a rotatable and axially slidable gear 26 which may be positively connected, when subjected to an axial thrust, to a gear 18, via dogs 30, the gear 18 being non-rotationally and non- slidably disposed on the counter shaft. A manually operated control fork 14 moves a gear 12 between the position shown in Fig. 2, in which rotary motion of a prime mover is transmitted from the shaft part 5a to the shaft part 5b via gears 12, 18, 26 and 25, and a position in which the gear 12 is disengaged from the gear 18 and rotary motion is transmitted between the shaft parts via a coupling ring 20 on the part 5a and internal teeth 21 on the part 5b. The gear 12 is in constant mesh with a driving wheel 16 of a fluid pump, the latter being connected via an hydraulic accumulator to a jack cylinder 31. When the drive is transmitted through the gears 12, 18, 26 and 25, the resultant torque is limited by the axial thrust applied by the cylinder 31 and by the angle of inclination of the flanks of the dogs 30. If the motor torque exceeds this value, the axial component acting on the flanks of the dogs 30, will become greater than the oppositely acting axial thrust of the cylinder 31 so that gears 18 and 26 disengage and remain disengaged.