Patent GB-506901-A (GB)
Title: Improvements in or relating to machine for and method of surfacing a work piece
IPC: B23D3/04
Filed: 1938-12-09
Abstract: 506,901. Milling-machines. STEVENS, A. H. (Ingersoll Milling Machine Co.) Dec. 9, 1938, No. 35964. [Class 83 (iii)] A machine for surfacing a work-piece such as a slab comprises a number of movable abutments arranged to define a vertical plane and engaging one side of the slab, which is first pressed between the said abutments and universally mounted positioning means which are withdrawn after clamping the work-piece whereupon the work is traversed past a milling cutter which removes a layer from the work-piece in a plane parallel to that of the abutments. The work carriage 22 is traversed on ways 38 by means of a screw 41 engaging a rack 42, a feed motor 39a acting in conjunction with a reversible rapid traverse motor 39 to give feed or traverse speeds to the carriage. A billet or slab 10 is thus moved past a rotary facing-cutter 14 on a spindle 35 driven by a motor 36 and a predetermined layer is removed. For placing the work in a vertical position it is first placed on a tiltable platform 20 and positioned against movable end stops 65 and a side stop 65a. The platform is universally mounted on a ball point 74 on a member 68 which is vertically adjustable to determine the depth of cut by means of a screw operated by a hand wheel 70 and coacting with a gauge 73. Springs 76 allow tilting of the platform 20 and pins 78 passing through the supporting bracket prevent rotation. After positioning the work the platform is swung round on axis 57 to a vertical position determined by abutments. This is effected by a pair of fluid pressure cylinders 58 supplied through a valve 53 from a pump 59. The piston rods of these cylinders have rack teeth engaging toothed segments 64. In the vertical position, the weight of the slab 10 is transferred from the pins 65 to supports 26 and the pins are then withdrawn by means of rack-and-pinion gearing. The side of the work away from the cutter rests on a number of pins 16 passing through holes in a plate 81a on the work support. The rear ends of these pins rest on a pressure plate 82 which is advanced towards the vertical platform 20 by screw and nut gearing 84 driven from a motor 88 through worm-gearing 89 and a friction clutch which slips when the work has been forced firmly against the platform. The pins are all of the same length so that their work-engaging ends define a vertical plane parallel to the cutting plane 12. If the slab is thicker at its lower end than at the top the tilting of the platform enables the inner work face correctly to engage the pins. The plate 81a is provided with a number of holes and the pins are positioned according to the size of the work. For very small slabs the platform 20 may have a pressure shoe mounted in a hole 161 to coact with the pins in positioning the work: After positioning, the slab is clamped'by upper jaws 24 actuated by hydraulic cylinders 95 controlled from a hand lever 101, the jaws sliding in guides of a vertically adjustable rail 98. If the clamping jaws are lowered when there is no work on the carriage an arm 112 actuated a switch 111 to interrupt the feed motor circuit. After the work is clamped the pins 65 are withdrawn and the platform 20 lowered after which the work carriage is operated first with a fast approach movement and then with a slow feed past the cutter to an unloading station. Here the work is unclamped and received onto an unloading platform 28 similar to the platform 20 and tiltable about an axis 115 by hydraulic cylinders 118 controlled from a lever 119. After the work has been lowered to the horizontal position it is turned over by a device comprising a pair of arms 30 pivoted at 130 and projecting into slots in platform 28 and another pair of arms 131 pivoted at 132 and provided with rollers 139. The two pairs of arms are interconnected by gears 136, 137 operated by hydraulic cylinders 133, Fig. 6, the gears being of different sizes so that when the two pairs of arme are raised the arms 30 move faster and push the work to the Fig. 6 position where it is received by the arms 131 which are then lowered. The work is then returned along a runway 34 to the platform 20 while the work carriage is returned to loading position. The operation is then repeated on the other side of the slab. Various interlocks are provided for ensuring that the operative steps can only be performed in the proper sequence.