Patent GB-751464-A (GB)
Title: Roller mill feed and roll positioning control apparatus
Inventor: WOODY GUY VIMONT
IPC: B02C4/28
Filed: 1954-10-14
Abstract: 751,464. Roller mills. ALLIS-CHALMERS MANUFACTURING CO. Oct. 14, 1954, No. 29663/54. Class 59. [Also in Groups XXIX and XXX] In a roller mill having material delivering means including feeder means to direct the flow of material to the grinding rollers, automatically operative and inter-related means are provided responsive to an interruption in the flow of material first to part the grinding rollers and retain them in parted position and then to stop the operation of said feeder means, and responsive to a flow of material sufficient to prevent metal to metal contact of the grinding rollers, first to actuate the feeder means and then to restore the rollers to the grinding position. The mill shown comprises fixed rollers 4, 5 and movable rollers 8, 9 the bearings of which form part of levers 12 which are oscillatable about pivots 13 by pneumatic motors 15, 16. Each motor comprises a fluid chamber 18 having a flexible diaphragm 17 to which is attached one end of a connecting rod 20 the other end of which is attached to a lever 12. The diaphragms are biased by compression springs 23 so as to tend to move the rollers 8, 9 away from their cooperating rollers 4, 5. Material to be ground is fed through a spout 37 to flaps 51, 52 and then to vibratory feeders 38 driven by pneumatic motors 39, 40. The motors 15, 16, 39, 40 are connected to a conduit 22 which is supplied with fluid under pressure from a conduit 43 through the intermediary of a solenoid valve 46. The flaps 51, 52 are attached to rotatable shafts 53, 54, Fig. 2, having attached thereto crank arms 55, 56 connected by a link 57. The shaft 54 has attached thereto an arm 58 which tends to maintain the flaps 51, 52 closed. A switch 60 is adapted to be closed on rotation of the shaft 53. Stops 29, 33 prevent the grinding rollers from making metal to metal contact. In operation, with no material flowing through the spout 37, the flaps 51, 52 will be held closed by the arm 58. The switch 60 will be open and the solenoid valve 46 closed. As long as the flaps 51, 52 remain closed, the springs 23 will hold the movable rollers 8, 9 away from their co-operating fixed rollers 4, 5. When material begins to flow through the spout 37 and the weight of material upon the flaps 51, 52 reaches the predetermined minimum necessary to ensure sufficient material being fed to the grinding rollers, the flaps will open and rotate shaft 53 to close the switch 60. Solenoid valve 46 will then be opened upon energisation and fluid will be supplied to the motors 15, 16, 39, 40. This will cause the feeders 38 to direct material between the grinding rollers. When the pressure in the chambers 18 of the motors 15, 16 becomes sufficient to compress the springs 23, the rollers 8, 9 will be moved towards the rollers 4, 5 into the grinding position. If the flow through the spout 37 should be interrupted, the flaps 51, 52 will swing to a closed position, rotating shaft 53 to open switch 60. This will de-energise and close the solenoid valve 46 to cause the conduit 22 to be vented to the atmosphere through pipe 47. The springs 23 will then cause the rollers 8, 9 to separate from the rollers 4, 5 and the closing of the solenoid valve 46 will also stop the feeder motors 39, 40.