Patent GB-101142-A (GB)
Title: Process and Apparatus for Forming and Tempering Metal.
IPC: C21D1/673
Filed: 1916-04-26
Abstract: 101,142. Rockfeller Motor Co., (Assignees of Fay, T. J.). Aug. 11, 1915, [Convention date]. Springs.-In a process for tempering and bending metal plates for spring construction, the plate is heated to a temperature above recalescence, clamped between suitable dies or forms, and subjected to the action of a rapidly moving stream or streams of liquid directed longitudinally of the plate. The plate is then moved into and through a body of quenching liquid such as oil, and into a second body of liquid such as water. In the apparatus shown, the plate 36 to be tempered, is clamped between curved forms 7, 29, each comprising a pair of verticallydisposed plates, the edges of which grip the plate 36. The gripping edges may be serrated as shown at 7b, 29b in Fig. 8 to minimize the surface of contact with the plates, and a fixed eccentric 35 at each end of the form 7 supports the end of the plate. Lateral movement of the plates is prevented by grids 9, 31 at the side of each of the forms 7, 29, and a pin 8 engages the centre hole of each plate. The lower forms 7 are carried by a table 4 slidable on a standard 2 into and out of a tank 1, and the upper forms 29 are carried by a cross-head 11 supported from a head 13 by bolts 14, interposed springs 16, and a spring 17 on a post 18, which, when the springs have been compressed a certain distance by the descent of the head 13, is engaged by the head. The plate is then held between the forms 7, 29 under a yielding pressure which is sufficient to resist a change in the shape of the plate, but does not prevent the movements which occur during recalescence, the pressure being obtained by means of removable counterweights 28, connected by chains 25 to the table 4. The descent of the head 13 is effected by means of a screw 19 having a nut 20 operated by means of worm gear &c. from a motor 22. The plate passes through horizontal streams of water from pipes 40, 41 into the tank 1, which contains water with a layer of oil thereon. The water pipes 40, 41 are supplied by a pump 38 from the tank, and the depth of oil in the tank may be varied by means of a two-way valve 70 which cuts off the pipes 40, 41. Water is then pumped to waste and oil is poured in the tank. When the plate reaches i sufficient depth, the motor is automatically stopped and reversed by means indicated in Figs. 10 and 11. The head 13 is provided with rods 12, 42a adapted to engage the handles of switches 43, 44, 47, 48. The switches 43, 44, for stopping the motor are connected by chains 45 and an interposed spring 46 tending to maintain the switches closed. The switches 47, 48 for reversing the motor are connected by a link 49, so that when one is open the other is closed. A magnetic brake 50 is applied to the rear end of the armature shaft of the motor 23, the armature winding of which is indicated at 56 and the field winding at 62. When the head 13 descends, the rod 42<a> engages and opens the switch 44, cutting out the motor and applying the brake 50, which retards but does not prevent the further descent of the head 13. The rod 42a next engages the switch 48, closing it and opening the connected switch 47. The motor circuit is thus reversed and the head 13 and associated parts ascend out of the tank. The switch 44 may then be closed by a spring. The motor runs until the rod 42 opens the switch 43, and is reversed when the rod 42 closes the switch 47. A hand-actuated switch 22a is provided for starting and stopping the motor. The brake 50 may be set to vary its resistance, and the positior of the switches may be varied, to alter the time and extent of the immersion of the plate in the quenching fluid. In an example of the process, a plate of steel having a temperature of recalescence of about 1460‹ F. is heated to about 1535‹ F., subject to oil for 3 seconds and water for 57 seconds, the depth of the oil being 12 inches and the temperature after withdrawal from the bath 850‹ F.