| 摘要 |
1,249,507. Tracking conveyer belts; feeding webs. W. R. GRACE & CO. 26 June, 1969 [5 Sept., 1968], No. 32474/69. Headings B8A and B8R. [Also in Division F2] A guidance system for a belt 1 running over drums 11, 12, 13, 15, comprises adjusting means 46 for tilting the axis of the drum 12, a signal device 18 for engagement by the belt when it wanders from its required path of travel, the adjusting means being operable in response to a signal from the signal device 18, and an interrupter 50 for interrupting the signal from the signal device 18 to cause the adjusting means 46 to return the axis to its rest position, the interrupter 50 being operable in response to a predetermined advance of the adjusting means 46. The latter comprises an hydraulic cylinder 46 having a piston 56, the rod 54 of which bears on the shaft 31 of the drum 12. There may be two cylinders 46 and associated devices 18, and interrupters 50 respectively provided on opposite sides of the belt. The device 18 comprises a switch 18 operated by lateral movement of the belt so as to energize a magnetic valve 64. This alters an hydraulic valve 60 so that the end 55 of the cylinder 46 is connected to a pump 80. After consequent predetermined movement of the piston 54, the interrupter (a switch 50) is operated. This de-energizes the magnetic valve 64. The rest position of the piston 56 may be adjusted by a screw 58. The rest position may however be adjusted by means of an automatic control system. An indicator light 82 indicates when the valve 64 is energized. The device 18 may be manually overridden by a switch 84. |
