GB816114A - Improvements in or relating to coke oven control gear - Google Patents

Abstract

816,114. Discharging coke ovens. WOODALL-DUCKHAM CONSTRUCTION CO. Ltd. May 15, 1957 [May 18, 1956], No. 15673/56. Class 51 (2). [Also in Group XXXVII] Control gear preventing premature operation of the ram of a coke pusher machine before the pusher machine and coke guide machine are correctly aligned, with an over-riding control from the coke locomotive or coke car, comprises interconnected contact members 20 at the end of each oven, engaging contacts 18 and 19 on said guide and pusher machines respectively to establish a first control circuit linking the machines and adapted, when incomplete, to prevent advance of the pusher ram into an oven, and a second control circuit openable at the coke locomotive or the coke car to prevent advance of the pusher ram into the oven. The control circuits operate relays R2 and R3 on the pusher machine with make contacts 28 and 37 in series in the circuit controlling forward movement of the ram by operation of the ram motor. They have a common electrical power supply constituted by the secondary winding of a transformer 10, said secondary winding being connected across a pair of overhead conductors 11 and 12 on opposite sides of the coke oven battery engaged by trolley contacts 13 and 14 on the pusher and guide machine respectively. A third overhead conductor 15 over the locomotive track is engaged by a trolley contact 16 thereon and is connected to the conductor 12. In operation, a relay R1 on the guide machine is energized by an operating circuit including a push-button switch 22 closed by the operator, travel " off " contacts 23, guide interlock contacts 24 closed by positioning the flopper plate, and an emergency stop switch 25. The relay R1, which incorporates a warning lamp 27, closes make contacts 26 to shunt the switch 22, and make contacts 17 to close the first control circuit thus energizing relay R2. This closes make contacts 28 and lights a warning lamp 29. The second control circuit comprises trolley contact 16, a push-button switch 30 and a second trolley contact 31 on the locomotive, an overhead conductor 32, emergency switches 33, 34, an overhead conductor 35 engaged by a trolley contact 36 on the pusher machine, relay R3, and the trolley contact 13. This circuit is normally closed, energizing relay R3 and thus closing its make contacts 37 and lighting a warning lamp 38, but the locomotive driver can open the circuit at switch 30 and thus prevent or interrupt a pushing operation. The circuit controlling forward ram movement incorporates travel " off " contacts 39, which are only closed when the pusher machine is at rest. Relay make contacts 28 and 37 are shunted by ovenface interlock contacts 40, which open when the ram is advanced to an oven mouth, thus enabling the ram to be used as a heat shield. When contacts 40 open, further movement of the ram cannot take place until relay make contacts 28 and 37 are closed. A shunted pushbutton switch 41 is also provided, said switch being normally open and kept padlocked. It is used in the event of failure of the control circuits or to enable a ram to be changed at the end of the battery. In a modification, Fig. 2 (not shown), the transformer 10 is mounted on the pusher machine, and a further transformer on the locomotive for the second control circuit, the warning lamps 27 and 29 being connected in series in the first control circuit. Relay R3 has a second set of make contacts shunted by a resetting switch, which is normally open, and which is closed by the pusher machine operator to re-establish the circuit. In a further modification, Fig. 3 (not shown), the transformer 10 on the pusher machine energizes both control circuits.