GB712486A - Improvements in and relating to sewing machines - Google Patents

Abstract

712,486. Sewing-machines. SUMMERTON, T. F. July 14, 1952 '[April 13, 1951], No. 8718/51. Class 112 Grouped machines; frames; Lubricating. Two parallel rows of stitching are produced by two sewing-heads mounted so that at least one is adjustable towards and away from the other, both machines being driven, in any position of adjustment, by a common telescopic drive mechanism. In the apparatus shown, for hemming the opposite edges of a length of material, the two sewing-heads 1, 2 are clamped on a base 7, the head 1 being permanently clamped while the head 2 may be moved along the base, when its clamping means are released, by means of a screw 139. Each machine has a conventional needle and presser-foot, and a loop-taker on a horizontal shaft which is connected by toothed gearing to one half of a telescopic shaft mounted in the base 7. This shaft is driven at one end (the two halves being splined together), and a hand-wheel may be provided on it also. The two parts of the shaft may run in oil wells in the bases of the respective heads 1, 2, each of which may have a dip-stick 60 passing down through its standard. Feeding long lengths of fabric; workguides; folding devices. The material is drawn from a roll mounted low on the front of the supporting table, by a pair of rollers 148, one of which is driven by adjustable friction-ratchet gearing from the shaft in the base 7; the two rollers may be geared together. The pressure between the rollers may be adjusted independently at each end. The finished work is wound on a roller 46 driven from the rollers 148 through a friction clutch 61 and belt 47. The fabric passes from the supply roll to the machine heads between the bars 67 of a tensioning device, and then between a pair of guides 52, adjustable longitudinally, each comprising a plate folded over and having its folded margin progressively folded over to fold the edge of the material. Needles, driving. The needle-bar of each sewing-head is actuated from a rock-shaft in the upper arm of the head oscillated by an eccentric on the lock-taker shaft. An extension of the pivot-pin connecting the needle-driving link to the needle-bar slides in a slot in a fixed member 'to prevent turning of the needle-bar.