| 摘要 |
931,620. Mineral-mining machines. A. OELLRICH, [trading as MASCHINENFABRIK UND EISENGIESSEREI A. BEIEN]. Jan. 13, 1960 [Oct. 30, 1959], No. 1210/60. Class 68 (1). The plough bits 9, 9<SP>1</SP> of a double-ended plough are slidably mounted at 1<SP>1</SP> on the opposed ends of the plough body so that the leading bits can be percussed on the bits encountering in the seam being mined an abnormal resistance to penetration that would result in the advance of the plough normally being stopped or slowed. Slidably mounted in the plough body are one or more double-ended strikers 13, 16, 13<SP>1</SP>, the or each of the strikers on the advance of the plough being pushed rearwards by the associated leading bits to compress two spring assemblies 14 within the body. On the plough encountering abnormal resistance the or each striker is or are urged further rearwards by the constantly moving haulage chain of the plough overcoming the resistance of the spring units to drive through a sprocket wheel and shaft a cam 7. The cam engages a spring-biased detent 17 coupled with the part 16 of the striker and moves the striker rearwards until the cam rises clear of the detent to allow the striker to spring forward to strike the bits. The cycle is repeated until the abnormal resistance is overcome. |
