| 摘要 |
1,139,400. Extrusion-roller dies. FARREL CORP. 24 May, 1967 [26 July, 1966], No. 24091/67. Heading B5A. In an extrusion-roller die including an extruder 15 supplying plastics or rubber material to a pair of rolls 13, 14 mounted in a movable frame 22 as described in Specification 998,725, the frame is yieldingly connected to the extruder and there is a sensor for detecting excessive relative movement therebetween, brought about by pressure of the material delivered to the rolls. The resilient connecting means comprises two plungers (32) normally urged outwardly from and held respectively in members (27), 28 on either side of the extruder by Belleville washers (33), Figs. 4, 5 (not shown). The extruder and frame are normally locked a predetermined distance apart by two hydraulically actuated, vertically reciprocating keys (43), each acting laterally and sliding in a channel of the extruder, and in the locked position a switch (49) comprising the sensor is closed by a stop (50) on a column 25 of the frame. In operation, the frame 22 is moved to the extruder until a block (52) on each of columns (25), 26 contacts a portion (53) of a bracket (47) supporting an hydraulic cylinder (46), which then acts to lower the key to a locking position, when a lower limit switch (55) signals that locking is effected and an upper switch (55a) is allowed to close. If pressure builds up, relative movement is opposed by the plunger (32) until a limit is reached when the stop (50) allows the switch (49) to go "off", which de-energizes a relay (R) to de-energize a motor (M) driving the extruder screw 16. When the arm (49) is again closed by the stop (50), the motor is re-energized. In a modification, a strain gauge (60) comprising the sensor in a bridge circuit detects the relative movement. Switches (55), (55a) are in the motor circuit and prevent operation of the extruder and rolls until locking is effected. |
