Patent GB-418819-A (GB)
Title: Improvements in or relating to machines for finishing edges of sheet material
IPC: C14B11/00
Filed: 1933-03-31
Abstract: 418,819. Cutting, punching, and shrinking apparatus. BRITISH UNITED SHOE MACHINERY CO., Ltd., Belgrave Road, Leicester.-(United Shoe Machinery Corporation; 140, Federal Street, Boston, U.S.A.) March 31, 1933, No. 9676. [Classes 31 (i) and 31 (ii).] Relates to apparatus for performing, in succession, upon the margin of a workpiece such as a boot or shoe toe cap, the operations of skiving, shrinking, and perforating, whereby the said margin is finished and ornamented. The toe caps are carried by a series of carriers, which are driven frictionally independently to present the toe caps in succession to the operating mechanisms. Each carrier is driven positively at the operating stations, the frictional drive allowing slip for this purpose. The positive drive is continuous at the skiving and shrinking stations and intermittent at the perforating station. The carriers include toecap-gripping clamps which are so organized as automatically to vary the extent of marginal exposure of the toe caps at the different operating stations, and automatically to release the toe caps after all the operations have been completed. Means is provided whereby an accumulation of carriers at the loading station causes stoppage of other carriers in advance of the perforating station. The general organization of the machine is shown in plan in Fig. 2. The carriers D are, in turn, loaded with tips at a station A, and carry them first to a skiving and shrinking station B, then to a perforating station C, and finally to a discharge station E. The carriers and the operating mechanisms are supported adjustably on a frame 27, and are driven from an electric motor 473 through a main shaft 42. Each carrier D, Fig. 14, is mounted on a rod 21, the rods having hubs 28 rotatable upon a shaft 22 which is constantly driven by chain gearing 38. The hubs are fitted with washers 29 which engage, with a pressure applied by a spring 33 and nut 34, driving discs 30 keyed to the shaft 22. Thus, rotation of the shaft 22 causes rotation of any or all of the arms 21 which are free to be rotated, whilst any arm may be retarded or held stationary without stopping the frictional drive of the remainder. A counter 43 is driven by one of the arms 21 through a fork 48. Each tip carrier, Fig. 18, comprises a frame 53 which is vertically adjustable with respect to the rod 21 and is integral with a lower clamping jaw 54. A pivoted upper jaw 56 is arranged to be opened or closed by toggle levers 59, 60, springs 64 exerting a yielding clamping pressure when the jaw is closed. The toggle lever 59 has an operating extension 66. The jaws 54, 56 are of a size to leave exposed a considerable extent of the toe tip margin, to facilitate the punching operation. Auxiliary jaws 69, 70 for clamping a part of said margin during skiving and shrinking are mounted for forward and rearward sliding movement on the frame 53, and normally are held open by a spring 76 which also urges the upper main jaw 56 to open position. The slide carrying the jaws 69, 70 carries a depending pin 79, and the frame 53 carries a rack 55 forming part of the positive driving means. When a tip has been placed in a carrier at station A, the toggle 59, 60 is straightened, causing the upper jaw 56 to clamp the tip. Just before the skiving station is reached, a cam engages the pin 79 and pulls the auxiliary jaws forward, and another cam closes the said jaws so that only a narrow tip margin is exposed. After the shrinking operation, the auxiliary jaws are opened and retracted. Fig. 5 shows the skiving mechanism comprising a fixed blade 101 and an oscillating blade 102, and the shrinking mechanism comprising a guide 103 and the heated tool 104. 123 is the cam for pulling forward the auxiliary jaws by engagement with the pin 79, and 125, 132, 140 are pairs of rolls which act to support the carriers and to close the clamping jaws during skiving and shrinking. Two driven gears 107, 109 for co-operation with the carrier racks 55 in driving the carriers positively are mounted in a casing 111 which can rock slightly against a spring to facilitate engagement of the gears with the racks. The shear blades 101, 102 of the skiving mechanism are mounted for vertical adjustment and also for angular adjustment in a horizontal plane. A knob 177 on the driving gear permits the mechanism to be turned over by hand to facilitate adjustment of the shear blades. Chippings are deflected away from the shear blades into a discharge passage. The shrinking mechanism, Fig. 11, comprises the guide 103 which acts to bend up the edge of the toe tip and hold it against the electrically-heated tool 104, which may be similar to that described in Specification 193,936, [Class 16]. The tool is U-shaped and elongated, and is carried by terminal posts 204, 207. the latter of which is mounted at 209 to be capable of a swinging movement to allow for expansion and contraction of the tool. The posts are carried by a casting 205 which is pivoted on screws 213, 214 to allow adjustment of the tool, by means of a screw 216, horizontally with relation to the guide 103. Vertical adjustment of the tool is provided for by pivots 219, 220 and a screw 221, the latter mounting also allowing the casting to be turned up, e.g. for the replacement of the tool. The tool 104 is traversed at all times by a small current which maintains it at a low heat. Just before a tip reaches the shrinking station, its carrier, by engagement with the roll 126, rocks a shaft which acts to increase the current passing through the tool, by closing a switch to shunt a resistance from the tool circuit. The shrinking mechanism includes also a compacting hammer 105, Fig. 5, which is mounted on a floating pivot to provide for varying thicknesses of work. A receptacle, not shown, which is movable into and out of operative position at will, is provided at the skiving and shrinking station for applying oil to the margin of the tips, if desired. When the shrinking operation is completed, the auxiliary jaws are opened, and are retracted by a cam 296, Fig. 2, and the carrier rack 55 leaves the pinion 107, so that the carrier is again moved by the friction drive up to the perforating station C, where a block operates to close the auxiliary jaws in retracted position. A driven gear in a casing 303, similar to the casing 111, engages the rack 55 and takes charge of the carrier at the perforating station. This gear 302 is rotated intermittently, to feed the carrier between punching strokes, by a cam 436, Fig. 16, on a driven shaft 419, acting through linkage which includes a clutch casing 423, rod 425, levers 427, 429, Fig. 15, and toggle links 431, 432, the cam 436 acting in timed relation to a cam 418 which controls the strokes of a punch platen 404. The extent of the feed stroke is controlled by adjusting the position of the knuckle 433 of the toggle links 431, 432 by means of a member 439 co-operating with a perforated plate 441. The clutch which rotates the gear 305 in order to rotate the gear 302 through the gear 461, Fig. 20, comprises the moving part 423 which is driven by the rod 425, a driven disc 452 fast on the stem 304 of the gear 305, and a fixed part 453. The driving connection between the parts 423, 452 is established by spring-pressed rolls 458 engaged in angular recesses in the part 452. Similar rolls 457 co-operating with the part 453 prevent reverse movement of the feed gear 302. The perforating mechanism, Fig. 16, comprises a stationary die 401 carrying hollow punches 402, a yielding stripper plate 403, and a platen 404 which is reciprocated vertically by the cam 418 acting through the yoke 416, rod 413, and toggle links 406, 408. If carriers accumulate at the loading station A, a carrier might be held up at the punching station. To prevent this, an elongated bar 311, Fig. 15, is pivoted in front of the punching station with its leading end raised by a spring, and in such position that the pin 79 of each carrier will ride over the upper surface of the bar, depressing its leading end and raising its rear end as it passes. Consequently, until the leading end of the bar has been released by a carrier, any following carrier will be arrested by its rear end. The racks of the carriers are cut away so as to be capable of overlapping to some extent, so that the carriers can accumulate in close juxtaposition. After the punching operation, the carrier is again moved by the friction drive, and a stationary cam at the station E engages the lever extension 66 to open the clamp jaws. A finger 333, Fig. 2, then sweeps the finished toe tip out of the carrier into a receptacle 335. Finally, the carrier returns to the loading station A with its jaws open, and is arrested by the engagement of the extension 66 with a block 355, Fig. 14. The operator places a new tip in the carrier and depresses a treadle rod 363. This rocks an arm 357 which straightens the toggle 59, 60, thereby closing the jaws upon the tip, and releasing the extension 66 from the block 355, so that the carrier is again free to move under the friction drive. The punching mechanism is adjustable along the base 27 of the machine by a handwheel 471, and the friction driving mechanism together with the loading table A by bolts 475, Fig. 14. The shrinking mechanism is adjustable independently of the skiving mechanism towards and from the friction driving mechanism. When tips are to be operated on the rear margins of which have a different radius of curvature, a new set of tip carriers is installed, and the operating mechanisms are correspondingly adjusted. The main shaft 42 can be turned over by a hand crank 601 to facilitate adjustment of the punching mechanism. Specification 261,458, [Class 31 (ii)], also is referred to.