GB923206A - Coal breaker - Google Patents

Abstract

923,206. Coal breakers. A. OELLRICH, [trading as MASCHINENFABRIK UND EISENGIESSEREI A. BEIEN.]. Feb. 11, 1960 [Feb. 12, 1959 (2)], No. 4898/60. Class 59. A coal breaker the drive for the breaker elements of which is provided with a safety coupling which has at least one safety element adapted to be loaded to breakage and in which the passage cross-section is adjustable or variable by means of a lifting device is characterized in that a reversal safety device connected between the safety coupling and the lifting device is connected to a propellant line and constructed as a control system which in the event of breakage of the safety coupling automatically reverses and in so doing brings the lifting device into the open position. The reversal device preferably has associated therewith a warning device which may be an acoustic signal. The breaker shown in Fig. 1 comprises a breaker roller 6 mounted in a member 3 which is rockable about an axis 2 relative to a base frame 1. The roller 6 is driven by a motor 4 through a transmission 5. Cylinders 7 are pivotally connected between the frame 1 and the free end of the member 3. In normal operation, the lower chambers of the cylinders are operated by means of compressed air, or pressure liquid, supplied from a line 9 through a four-way cock 10 and a control slide 12 while the upper chambers of the cylinders are vented through the slide 12 to the cock 10. A branch line 17, 17<SP>1</SP> leading to an end chamber 19 of the slide 12 contains an operating member 18 in the form of a shut-off cock disposed on the housing of the transmission 5. A whistle 20 is connected to the line 17<SP>1</SP>. A crown wheel 23, Fig. 2, driven by the motor 4 drives the shaft 22 of the transmission 5 through a coupling bush 24, a breaking element 25 and a claw coupling 29. The breaking element has an annular recess 30 which predetermines the breaking point. When an undesirably high resistance occurs in the region of the breaker roller, the breaking element divides into two parts 25a, 25b. The part 25a remains coupled to the shaft 22 while the part 25b continues to be rotated by the crown wheel 23. An eccentric sleeve 31 secured to the shaft 22 then pushes outwardly a pin 32 slidably mounted in the bush 24 so as to move angularly a spring- influenced rocking lever 34 mounted on the member 18 thereby connecting the lines 17, 17<SP>1</SP>. This has the effect of venting the lower cylinder chambers and of supplying compressed air to the upper cylinder chambers to lift the member 3 and thereby increase the passage cross-section of the breaker. At the same time, the whistle 20 sounds. The motor 4 is then stopped and a main shut-off valve 21 closed. After replacement of the element 25, the pin 32 is pushed inwardly to break the connection of the lines 17, 17<SP>1</SP>. The motor 4 is then started and the valve 21 opened whereupon the breaker resumes normal operation.