GB958173A - Improvements in or relating to a method and apparatus for forming and seaming hems - Google Patents

Abstract

958,173. Sewing. R. G. TIMM. Aug. 15, 1962 [Aug. 15, 1961], No. 31255/62. Heading D1G. Workpieces W are advanced in succession towards a sewing machine 13, a longitudinal edge of each advancing workpiece is folded into S-shape form, and a stitched seam W<SP>1</SP> is applied along a fold line of the S-shaped fold and the overlying face edge thereof. Preferably the stitching is so positioned in the fold as to constitute blind stitching which is not visible on the exposed surface of the workpiece. Blind stitching, seams, stand, work feed, work supports and guides, illuminating. A stand 11 supports an L-shaped table 10, on the shorter limb of which is mounted an overedge sewing machine 13 driven by a belt 17e from a motor and clutch unit 16 controlled by a treadle 17. On the longer limb is mounted a platform 10a which is co-planar with the throat plate 13a of the sewing machine, and which supports the upper run of an endless conveyer belt 12. The sewing machine main shaft is coupled to the input shaft of reduction gearing 19, the output shaft of which carries a pulley 20 coupled by a V-belt 21 to a pulley 22 journalled on a shaft 25 on a lever 24 pivoted on a fixed frame 23. A pulley 25a, rigid with pulley 22, is coupled by a V-belt to a pulley on a shaft 28 carrying a driving roller for belt 12. Turning lever 24 to tighten belt 21 thereby serves to increase slightly the rate of advance of belt 12, and slackening belt 21 serves to reduce the rate of advance. A workpiece W is laid on the advancing belt 12, a projecting edge of the workpiece being supported by platform 10a and being aligned with a guide line or rib 36 on the latter. The workpiece is thereby carried through a folding-guide 15 which folds the projecting edge into S-shaped form having an outer fold W<SP>11</SP> and an inner fold W<SP>111</SP>. The folded edge then passes into an adjustable edge-guide 13K associated with the sewing machine, and after the face edge of the fold is trimmed into alignment with fold W<SP>11</SP>, the latter is so presented to the needle 13g, threaded underlopper 13h and overedge spreader 13j, as to result in the formation of overedge blindstitching as described in U.S.A. Specification 2,067,680. The stitching area is illuminated by a lamp 62. Folding, movement of air. Folding-guide 15 comprises a pair of horizontal, vertically-spaced plates 40 and 40a separated by a bar 40b, and a horizontal plate 41 positioned in part between plates 40 and 40a. The lower plate 40a curves upwardly at its inlet end, and its inner edge is parallel with the line of feed. The inner edge of the upper plate 40 is positioned, at its inner end, over plate 40a, and is parallel to the line of feed, but towards the outlet end it is inclined to the line of feed to project outwardly of plate 40a. The inlet end of plate 41 curves downwards into engagement with platform 10a, and its inner edge is inclined to the line of feed, being positioned at the inlet end outwardly of plates 40 and 40a, and at the outlet end between the latter. Plate 40 is connected adjustably to plate 41 by brackets 42 and 43 positioned adjacent the inlet and outlet ends respectively. A wire 48 extends downwards from bracket 42 to a position in advance of plate 41 and then extends substantially horizontally, and inclined to the line of feed, to a position of attachment to plate 40 adjacent bracket 43. A pin 45 rising vertically from the inlet end of plate 40 engages a notch in a fixed bracket 46, and a notch 44d in a spring bracket 44, fixed to the outlet end of plate 40, engages a fixed pin 44e to hold the folder 15 releasably in operative position. A blower 47 directs air on to a downwardly inclined surface 41c of plate 41 adjacent the inlet end whereby the longitudinal edge of a workpiece is folded at W" upwardly about the inner edge of plate 40a and is positioned against the wire 48. Progressive movement of the workpiece forms a reverse fold W<SP>111</SP> about the inner edge of plate 41 to complete the S-shaped fold in the edge of the workpiece. A blower 49 directs air across plate 41 adjacent the outlet end to assist in completing the formation of the fold. An alarm, which may be either visual or auditory, is arranged to be actuated when a knot or other enlargement in the needle thread 50a is detected at considerable distance from the needle. A tall column 53 carries at its upper end a bracket 54 having a pair of V-shaped formations 54a and 54b through which the thread passes on its way from a cop 50 to the needle. A V-shaped member 54d, pivoted at its apex to bracket 54 between the formations 54a and 54b, is formed on a long limb with a triangular opening 54h which extends upwardly into a slot 54i, and carries on the other and shorter limb a normally open mercury switch 54g. Thread 50a normally passes freely through slot 54i, but an enlargement in the thread is arrested at the latter, whereby member 54d is rocked to close switch 54g for actuating the alarm. Rocking of member 54d also causes the enlargement to be deflected into and through the opening 54h to allow continued running of the sewing machine, the latter then being stopped by the operator on completion of the workpiece being currently sewn. Specifications 691,894, 730,118 and U.S.A. Specification 2,952,227 also are referred to.