Patent GB-508653-A (GB)
Title: Improvements in or relating to methods of and machine for surfacing or scalping workpieces
IPC: B23C3/14
Filed: 1938-12-08
Abstract: 508,653. Milling-machines. STEVENS, A. H. (Ingersoll Milling Machine Co.) Dec. 8, 1938, No. 35827. [Class 83 (iii)] In a method of, and machine for, scalping or surfacing work-pieces such as billets, ingots, slabs or the like, two opposite sides and a pair of opposite corners are first faced or cut, and then the work piece is rotated on its axis and the remaining sides and corners machined. For scalping or, surfacing billets of square section a reciprocating table 33 moves on round guides 34 and is reciprocated either rapidly by a traverse motor 36 or slowly by a feed motor 36a through gearing 37 and feed screw 37a. The work is loaded in a forward position of the table and behind the loading position are a pair of multiple-spindle tool.heads 41, 41a. The tool-head 41 has a face-milling cutter 42 driven by a motor 39 and a bevelled cutter 43 driven by another motor 44 and adapted to surface one corner of the work, both cutters being independently adjustable. The head itself is moved to and from the 'work by a hydraulic cylinder 46, Fig. 9, supplied from a pump 48 under the control of a valve operated through solenoid coils VS1 and VS2. The right-hand tool-head is of similar construction, its associated bevelling cutter being arranged diagonally opposite the cutter 43, so that four sides and the four corners of the billet may be faced in two passes between which the billet is rotated through 90‹. The cuttings from the work are removed by a pair of endless chain type conveyers operated, in troughs 51, 51a arranged on opposite sides of the table. The table carries a work-support 52 provided with a detachable top piece 53 to which the work is firmly secured by a number of hydraulically-operated hold-downs 57, the cylinders 60 of which are supplied by a pump 62. Fig. 9, under the control of a valve V2 operated by solenoid coils VS3 and VS4. Work-handling devices 66, 66a are mounted on each side of the machine and of similar construction. Each unit comprises a base 67 movable on ways 68 opposite the loading station by means of a screw. The base carries a roller runway 81 to and from which the billets are moved by other conveying means. From the runway the billets are transferred to the table by transfer members consisting of adjustable pushers 84 having removable tips 86 and rack teeth for operation by splined pinions 92 on a longitudinal rod 91 actuated hydraulically by a cylinder 94 supplied by the pump 48 under the control of a valve V3. The cylinder acts through a rack 97 on a pinion 100 carried by the shaft 91, a stop on the rack serving to limit the advance of the pushers. The two sets of pushers hold the work in position until the clamping means is operated. The turning mechanisms are arranged at each side of the machine between the runways and the loading station and each of these comprises radial arms 107, 108 arranged on a common rock shaft 10 and located so that arms 107 when horizontal lie just below the tops of the rollers 81. The arms 108 bridge the gap between the rollers and the work table and when in the bridging position they rest on supports 114. For turning the work, the arms are arranged at 90‹ but to permit transfer of work from runway to table the two arms may both be moved simultaneously to a horizontal plane. For this purpose the arms 107 are releasably connected to the shaft 109 by clutch mechanisms 115 which - are all operated simultaneously by a‹ rod 119, Fig: 8. Thus when the arms 107 are in the Fig. 6 position and the clutches are disengaged the shaft 109 may be rotated to bring the arms 108 to the horizontal position without affecting the arms 107. The clutchshifting bar 119 is operated by a hydraulic cylinder 118 supplied by the pump 48 through control valve V4 operated by solenoids VS5 and VS6 and the shaft 109 is operated by a cylinder 125 supplied from the pump 48 through a control valve V5 which also controls the supply of the cylinder 125a of the opposite turning mechanism. For convenience of operation, two billets are preferably treated at the same time and the various steps in an operating cycle are controlled by a dial 149 on a cam shaft 142 which carries cams for operating the valves V3, V3a and V5 and also other cams actuating the switches of the solenoid circuits. Twenty one steps are performed in succession to complete the machine cycle. In Fig. 10, the first billet 25 is seen on the runway with the turning arms 107, 108, both' horizontal. The left-hand push-rods are then advanced to move the work against the other push-rods which are held securely in their extended position. The clamp cylinders are now operated, then the push-rods retracted and the tool-heads advanced. The arms 108 are now moved to vertical position by movement of shafts 109 and this starts the table movement consisting of rapid approach followed by a slow feed past the cutters. During this operation another billet 25a is positioned on the runway 81. After the cutting is completed the tool-heads are withdrawn and the work returned and unclamped. The left hand push-rods are' now advanced, Fig. 13, thus pushing the new billet on to the table and forcing the first billet on to the turning- arms 108a. The second billet is then partially machined while the first one is turned. Then the first billet is pushed back on to the table and the second one forced on to the turning-arms Fig. 15. The second and final machining is then performed on the first billet while the second one is turned. Now the second billet is pushed back on to the table and the first one, -now completed, pushed on to the turning-arms 108a for removal from the machine. During the second operation on the second billet, a third billet 25b is placed on the table 81 and then pushed on to the table, to force the completed second billet 25a on to the turning-arms, Fig. 19. The cycle is then repeated. In the case of taper billets, one of the tool-heads is rendered inoperative and four passes are necessary to complete the work.