Patent GB-565427-A (GB)
Title: Improvements in and relating to machines for skimming metal billets
IPC: B23B5/12
Filed: 1943-07-05
Abstract: 565,427. Lathes; skimming ingots. BYRNE, E. L. W. (American Smelting & Refining Co.). July 5, 1943, No. 10905. [Classes 83 (ii) and 83 (iii)] In a machine for skimming copper billets so as to produce a smooth surface prior to being made into seamless tubing by a piercing process, the billets are placed on an inclined shoot 32, Fig. 1, from which they are allowed to pass singly to a rack 41 by means of an escapement device. A billet is then pushed axially along the rack by a plunger 66 so as to pass through a roller steady 82 which prevents it from rotating and then through a hollow cutter-head 102 and the billet on emerging from the cutter-head is gripped by a clamping head 88 which draws it through the cutter to complete the machining and finally allows it to drop onto a conveyer which removes it to a storage or shipping station. The moving parts of the machine control its operation automatically by means of switches controlling the driving motors. The escapement device comprises two star-shaped members 42, each having three arms spaced 120 degrees apart and being mounted on a shaft 44 rotated intermittently by an electric motor 48. The feeding plunger 66 is carried by a head 62 slidable along guides 100 on the machine bed by a screw 64 rotated through reduction gearing 72 from an electric motor 68 and the clamping head 88, whose jaws are actuated by a motor 84, is also slidable along the guides 100 by a screw 90 driven by gearing 96 and a motor 92. The clamping head comprises brass facings 180, Fig. 13, on jaws 186 which are movable along guides 190 on the head by a right- and left-handed screw 194 connected by a worm and belt drive 198, 206 to the motor 84. The worm-shaft 202 is pressed axially by a spring to maintain the drive, but when the jaws have gripped the billet 35 with the required degree of clamping force, the worm screws itself axially against the pressure of the spring to rock a switch lever 246 and stop the. motor. Hollow cutter-heads; cuttings, catching and removing.-The cutter-head comprises a stationary casing 102 and base 76, Fig. 7, containing bearings 104, 106 for a sheave 77 driven by multiple V-belts 80 from the motor 78. A cap 120 secured to the sheave has three broad cutters 122 clamped by screws 126 and adjusted radially by screws 124. Cuttings can escape by passages 136 in the cap, which also provide air vents to cool the cutters, and ingress of cuttings to the interior of the head is prevented by a sealing plate 128 carried-by a casting 130 attached to the base 76. The finished part of the billet is supported within the head by three rollers 146 carried by levers 142 pivoted at 144 in the base 76 and adjusted radially by a coned sleeve and nut 155, 156 screwing in the base. Lubricating-passages.-Lubricant is supplied under pressure at 110, Fig. 7, to an annular passage 108 in the base 76 of the cutter-head, from whence it proceeds to the bearing 106 and then by annular passages 112, 114, 116 to the bearing 104 and between the fixed and moving parts of the head. Steady-rests; non-rotating work supports.- The stationary work-support 82 has a base 163, Fig. 11, containing radial guides 174 for three jaws 158 at each end of the base the jaw carrying rollers 154 engaging the billet 35 and being adjustable by scrolls 160 rotated by three radial bevel pinions 168, two of which are provided with sockets for rotation by a hand wrench. The rollers 154 have concave surfaces for engaging the billet to exercise a grip thereon and prevent it from rotating with the cutterhead as well as supporting it in alignment with the tools. Operation.-With the motor 78 running for driving the cutter-head 80 continuously, the lowermost billet as it rolls down the shoot 32 depresses a switch 224 to start the motor 48 and rotate the escapement cams 42 through 120 degrees, thus allowing the billet to roll onto the rack 41, in which position it actuates switch 232 to start motor 68 and rotate the screw 64 for feeding a billet in the rack' towards the cutters. The billet passes through the steady 82 and into the cutter-head 76 and as the trimmed end of the billet emerges from the cutter-head it passes into the clamping jaws 186. The feeding-head 62 during its traverse first engages a switch 238 to slow down the rate of traverse to the cutting speed and then engages a switch 242 to start the motors 84, 92 for closing the jaws 186 and causing the clamping head 88 to be fed by the screw 90 so as to draw the billet through the cutter-head at cutting speed. When a switch 248 is engaged by the feeding head 62, the motor 68'is stopped and the head comes to rest. As the rear end of the billet emerges from the cutters, the head 88 engages a switch 252 to increase the speed of the motor 92 and cause the head to be traversed rapidly until it engages a switch 256. This stops motor 92 and starts motor 84 to unclamp the finished billet which then drops on a conveyer (not shown). The outer clamping jaw, in its fully-open position, rocks a lever 260, Fig. 13, to start motor 92 in the reverse direction and return the clamping head 88 ready for receiving the next billet, the motor being stopped when the head engages a switch 262 at the end of its traverse. The motor 68 is started by the same switch, actuated by the lever 246, which stops the clamping motor 84 and thus the .feeding-head 62 is returned to its starting position when the head 88 assumes the feed, and on reaching its retracted position, head 62 engages a switch 270 to start motor 48 and rotate the escapement mechanism for feeding another billet to the rack 41. A cam 228 on the escapement shaft stops the motor 48 when the escapement has rotated through 120 degrees. The machine is adjustable to suit billets of different diameter and length, and the billets may be cast in separate moulds or may be produced by a continuous casting process and cut into lengths.