Patent GB-575848-A (GB)
Title: Improvements in or relating to bag corner sewing and like operations
IPC: D05B15/00
Filed: 1944-04-15
Abstract: 575,848. Suit-case sewing-machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation). April 15, 1944, No. 6976. [Class 112] In a machine for sewing the edges of suitcases and the like and applying a binding strip at the same time by a lockstitch seam passing through the margins of the binding strip and the case parts as indicated in Fig. 9, the internal work-engaging member has a roughened ball tip rotatable in one direction only so that there is no tendency for the thin edge of the work to be squeezed out from the supporting devices at the beginning of a seam; the external worksupport has means for distributing the fullness of one margin of the binding strip on corners so that it is flattened by the stitches, and the strip-guiding devices are arranged so that presure on the strip is relieved during feed of the work. The external work-support 2, Figs. 7 and 9, which is adjustably mounted on an arm 126, holds the binding strip 30 closely against the edges of the case parts 16 and guides it by means of a pair of spring clips 42, Fig. 7, fixed to adjustable blocks 46 on the work support. Each clip 42 has tongues which hold the margin of the strip 30 against the work-support and guiding tongues 50 which enter the slots in the worksupport and guide the edge of the strip. In order that the strip may be supported close to the paths of the needle and awl for any given length of stitch, the needle and awl slots 41, Fig. 9, in the work-support 2 are formed in separate discs 40 fixed to the work-support, a set of interchangeable discs having different lengths of slot being provided. To accommodate the fullness of the margin of the binding strip when sewing round a corner, the disc 40 in that limb of the work-support which engages the end of the case 16 is formed with a recess 36 to receive the fullness corresponding to one stitch-length, this fullness being flattened when the stitch is tightened; the recesses 36 in the interchangeable discs 40 may be of different dimensions to suit different qualities of binding strip as well as different stitch-lengths. The awl may be set to avoid piercing the margin of the binding strip 30 that lies on the end of the case while still penetrating it sufficiently to prevent it from slipping on the case during feed of work. The internal work-support comprises a horn 4, Fig. 1, carrying a spring-pressed pivoted arm 64 with a ball 60 rotatable on its end with a ratchet to prevent rotation of the ball in the direction opposite to the feed; the ball is roughened to grip the surface of the sides of the case, but has a smooth top to allow easily sliding of the case ends. The horn 4 is adjustably mounted on a block 76 pivoted on a vertical axis to a member 82 which is mounted on a spindle 84 secured to a shaft 88; the member 82 can rock on the spindle 84 to allow the tip of the horn to move to a limited extent in the line of feed, to facilitate sewing on corners of radius smaller than that of the ball 60, and is automatically returned to its central position by a spring-pressed plunger 100 engaging a flatsided collar on the spindle 84. The shaft 88 is actuated to relieve pressure on the work during feed by a lever 94 and mechanism similar to that described in Specification 23478/10, [Class 112]. Specifications 174,419, 198,430, and 240,225, [all in Class 112], also are referred to.