GB671096A - Rolling mill for rings - Google Patents

Abstract

671,096. Rolling. LOEWY ENGINEERING CO., Ltd. March 30, 1950, No. 7996/50. Class 83 (iv). [Also in Group XXIX] A ring-rolling mill having an inner and an outer working roll has hydraulically controlled guide means which maintain a blank in position and which automatically recede when the blank expands during rolling. In one embodiment of the invention, 10 is an outer and 11 an inner power-driven working roll and 13 and 14 are guide rolls connected by cranks 22 and links 21 to a hydraulic ram 17 movable in a cylinder 18. The ram 17 is hollow at one end so as to form a cylinder 19 which co-operates with a stationary ram 20 to enable the ram 17 to be moved in both directions to open or close the guide rolls. The crank for roll 13 consists of two sections 221 and 222 hinged at 23, and section 221 carries a spring-loaded relief valve 25 which can be opened by a spring-loaded actuating rod 29 which engages a flange on the section 222. In operation, the guide rolls 13 and 14 are opened by supplying pressure fluid to cylinder 19 and when the blank has been placed over the working roll 11 the guide rolls are closed by supplying pressure fluid to cylinder 18. These operations are carried out by means of a lever 46 and valve block 36. When the guide roll 14 has contacted the blank the lever 46 is placed in the " Automatic " position which closes all valves in block 36 except valve 45 so that cylinder 18 is placed in communication with the exhaust line 38 whenever the valve 25 is opened. As the blank increases in diameter due to the rolling the section 222 of the crank 22 carrying roll 13 opens the valve 25 and the ram moves to accommodate the rolls 13 and 14 to the increased diameter at which point the movement of crank 22 closes the valve 25 and the rolls are temporarily locked in position again. As the roll 13 mainly operates valve 25 it has an initial clearance from the blank when the roll 14, which applies the guiding pressure, is touching the blank. In a further embodiment, guiding rolls 63, Fig. 2, are carried by levers 66, 67 respectively and one end of lever 66 is connected to a doubleacting ram 70 displaceable in a hydraulic cylinder 71 the rearward extension 72 of the ram 70 being displaceable in a cylinder 73 of smaller diameter than cylinder 71. Pivoted to the lever 67 is a casing 74 of a relief valve 75 which has two ports 76, 77 connected to cylinder 71 and an exhaust line 79. The relief valve actuating rod 84 is connected by a link 85 to an S-shaped lever 86 pivoted at 87, the lever 86 being in turn connected to the lever 66. Hydraulic pressure fluid is supplied to cylinder 71 through a valve block 92 controlled by a lever 98 and the guide rolls are controlled as previously described. The opening and closing of the relief valve may be controlled electrically.