Patent GB-712579-A (GB)
Title: Improvements in wire and like grinders and to a method of abrasively processing wire and the like therein
IPC: B24B21/02
Filed: 1952-09-27
Abstract: 712,579. Grinding wire and the like. ILLMER, L. Sept. 27, 1952, No. 24261/52. Class 60 A wire or like grinding machine comprises a tractor reel 10, Fig. 1A, grinding means 32 to treat a reel-oncoming portion of the wire 19, and two stator means 21A, 21B located at opposite ends of the reel 10 to support two series of rollers 20, 27, one roller series serving to thrust the last-laid coil in the axial direction of the reel and the other series being disposed to counteract the thrust imposed by the first series. Work-drive means. The wire 19 is formed into an endless loop with its abutting ends smoothly welded together and travels round a closed circuit including the reel 10, a slewmounted sheave 28, Fig. 1B, a triple-roller straightening device 36 and the grinding means 32. The reel is driven through reduction gearing by an electric motor 15A and has its periphery shaped as shown in Fig. 8, the oncoming wire being first wound on to a raised portion 17D from which the turns are successively displaced by the rollers 20 on to a portion 17H of reduced diameter. This portion may be of aluminium to provide low frictional resistance to the axial traverse of the coils towards a conical portion 17F on to which they are driven by a further series of rollers 37 so that the return run to the sheave 28 is tensioned. Two jacks 35 connected for simultaneous adjustment by a remotely-controlled, reversible electric motor displace the sheave 28 to establish any desired tension in the workpiece. The rollers 20 and 37 are held in contact with the reel by spring pressure while the two stators 21A, 21B are connected by rods 31 to form a cradle which may be rotated to bring a particular roller into position for servicing. Wedges (not shown) normally hold the stators against rotation. Grinding means. The means 32 are mounted in pairs on shafts 44 driven by toothed gearing from a shaft 41 directly rotated by an electric motor 43. A second shaft 42 driven by gearing from the shaft 41 is connected through further toothed gearing to an abrasive tape feeding mechanism mounted in each means 32. This mechanism comprises two tape supply reels 57A, 57B, Fig. 3, two tape feed rolls 50, two idler rolls 60 and two take-up reels 58 to drive two abrasive tapes 59 at constant speed. Each roller 50, which controls the tape speed; has a yieldable surface and co-operates with an auxiliary spring-pressed roller 56 to provide an adequate frictional grip on the tape while each take-up reel 58 is driven through a slipping cone clutch and mounted on an inclined axis to equalize the drag tension along both tape edges. Two shaped shoes each provided with tape guide rollers (not shown), a soft rubber cushioning strip 79, Fig. 7, and a thin metallic cover plate (not shown) to prevent wear of the strip are pivotally mounted on trunnions 74 to hold the tapes against the work. One of these trunnions is connected to a spring-loaded piston 73 which applies pressure to the work while the other is connected to a rod 88 which is radially adjustable to keep the work centralized. The whole of the tape feeding mechanism is housed in a drum 45B closed by a circular transparent cover provided with a central replaceable split bushing to guide the wire therethrough. When the drums are opened surplus ground particles may be dumped into storage pans (not shown). The supply and take-up reels are interchangeable to facilitate repeated use of a single tape and timing switch means may be connected to the motor 43 to reverse or stop the tapes when they are approaching their ends. The tapes are soaked in oil before use. Replacement of the workpiece. The renewal batch of wire is placed on a freely-mounted drum 94, the original splice of the prior batch severed by the use of a clamp 36A or the like and one terminal thereof attached to one end of the renewal batch while the other is threaded through a crimper device and attached to a take-off drum 95. The latter is then rotated by a motor 97 to drag the renewal batch through the machine. If the renewal batch is shorter than the original batch, the number of coils on the reel 10 is reduced by stopping the latter when the splice has reached a medial position thereon, clamping the splice to the reel 10 by a T-bolt, severing the original batch and running the motor 97 until the surplus coils have been removed, whereupon re-splicing is effected and the remainder of the original batch wound on to the drum 95. If the renewal batch is longer than the original, extra coils are wound on to the reel 10 by inching the latter over or driving it at reduced speed from an auxiliary motor 16A after severing and clamping have been effected in the manner described above.