Patent GB-602707-A (GB)
Title: Improvements in or relating to machines for performing trimming operations on shoe parts
IPC: A43D23/06
Filed: 1945-11-10
Abstract: 602,707. Shoe-upper trimming machines. BRITISH UNITED SHOE MACHINERY CO., Ltd., PRATT, J. W., and BRAY, W. N. Nov. 10, 1945, Nos. 30054/45 and 10515/46. [Class 17(i)] A shoe is supported in a shoe-upper trimming machine heightwise relatively to a trimming device by means which engage the shoe bottom, against which means it is clamped by a member movable into engagement with a portion of the shoe opposite the bottom face, the whole being then moved relatively to the trimming device so that the upper material is trimmed progressively from a portion of the shoe. In the form illustrated, the shoe, the toe end of the lasted upper of which is to be trimmed, is presented bottom upwards with its opposite side portions engaging two gauge members 31 which depend one from each of a pair of thin wiper -like upper engaging plates 25 which are secured to the forward ends of levers 23 pivoted on a plate 7 and which levers are urged together by a coiled compression spring connected to their rear ends. A shoe support 3 is slidably mounted on the plate 7, being normally urged forwards by springs 9, forward movement being limited by a pin 17. The arrangement is such that for all widths of shoe the inner edges of the plates 25 extend substantially the same distance inwardly across the shoe bottom, and surplus upper material to be trimmed away projects above the plates 25 through an opening therein and above a lip 35 on a toe rest 33 mounted on the plate 7. The plates 25 engage the shoe bottom and determine the heightwise position of the shoe relative to the trimming knife 5. A treadle controlled by the operator first rocks a toe pad 37, consisting of a rubber pad 45 mounted in a metal block, through a chain 51 and levers 39 secured to the forward portion of plate 7 to clamp the shoe against the underside of the plates 25 and then, on continued pressure thereon, to draw the plate 7, pad 37 and shoe to be trimmed beneath the knife 5. This latter is dished centrally and of diameter about twice the width of an average shoe at the toe. The edge is undulating so as to have a drawcut action and is ground off horizontally to present an outer cutting edge. The knife is secured on the lower end of a short vertical shaft 83 rotatable in a bearing 85 on a carrier 89 which.rests on a rearwardly and upwardly inclined face 91 of a bracket 4. The carrier 89 is adjustable forwardly and rearwardly on the face 91 by a hand nut 97 to rise or fall in relation to the upper face of the work support, being clamped in adjusted position with the knife close to the work by a bolt 99. A horizontal grinding disc on the upper end of a constantly rotating shaft and normally out of contact with the cutting edge of the knife, at a position below and to one side of it, is provided to re-sharpen the knife without requiring to disturb its position. A block in which the shaft is mounted is vertically adjustable by a stem, being locked in adjusted position for sharpening by a bolt. A reciprocating uppertrimming knife for trimming the upper materials along the sides of forepart of shoe may be associated with the machine on the same base plate. Specification 470,749 is referred to. The first Provisional Specification describes also a machine wherein the trimming tool comprises a rotary cylindrical cutter or rasp similar to, that described in Specification 1440/08, [Class 17], but consisting of a series of relatively narrow toothed discs clamped together side by side and of relatively large diameter to extend across the toe.