Patent GB-608320-A (GB)
Title: Spiral stitching sewing machine
IPC: D05B23/00
Filed: 1946-02-19
Abstract: 608,320. Sewing-machines. FAIRWEATHER, W. C. (Singer Manufacturing Co.). Feb. 19, 1946, No. 5234. [Class 112] ' Feed by dogs and by clamps; feeding operations, special. For spiral stitching of hat brims, an ordinary sewing-machine is provided with auxiliary feed attachment comprising a pivot to which the work is clamped and mechanism whereby rotation of the pivot, caused by, movement of the work under the action of the usual feed dogs of the machine, produces lateral shifting of the pivot. This lateral shifting may be regular or may be cyclically reversed and varied to produce elliptical, wavy, or otherpattern of stitching. In the arrangement shown, the base 22, Fig. 2, of the machine fits,in an opening in the table, to which it is hinged in the usual way, and the base 43 of the attachement fits into an extension of the opening, being similarly hinged at 45. with provision for fore-and-aft adjustment; the attachment carries a sliding carriage 50, to which is pivoted at 49 an arm carrying the work pivot 47, the work W being clamped between two plates 63 mounted on the pivot so to be non- rotatable thereon. The position of the work-pivot-carrying arm 48, Fig. 3 (underneath view) relative to the carriage 50 is determined by a cam 76 on the pivot 47 engaging a pin 78 on the carriage; cams of different forms are used for different shapes of work and patterns of stitching. To produce the continuous slow lateral movement of the work necessary to space each-circuit of stitching from the previous one in spiral stitching, a pinion 65 on the pivot 47 is connected by a gear train 66, 67, 70 to a pinion 71, on the pivot spindle 49, which engages a rack 75 fixed to the attachment base 43. Interchangeable sets of the wheels 70, 71; with pinions 71 having different numbers of teeth, may be used to give different rates of feed, and the gear-wheels 66, 67 may be mounted - on a shift lever 69 carrying idler pinions 133, 134, 135 so that the direction of movement of the carriage may be reversed. The rack 75 is mounted in a block 109 adjustably mounted beneath the attachment base. ,43, and is movable laterally against spring pressure by a cam 120 actuated by a finger lever 118 to disengage the rack from the pinion 71 to allow the work to be shifted by hand; fixed positions of adjustment for the block 109 are provided corresponding to the positions of the rack for engaging the different pinions 71. Stopping-gear; frames. The machine is belt-driven, with fast and loose pulleys and a belt-shipper 97, Fig. 1, carried by a rod 94 which slides in a bracket 88 mounted on a cover 90 on the back of the machine; the rod is spring-pressed to the loose-pulley position and provided with a handle 98, an extension 99 of which carries a brakeblock which engages the fast pulley in,this position. The rod is held in the driving, position by a detent (not shown) on an arm 86 pivoted on the bracket 88 and extending downwards into the path of an arm 85 fixed on a rod 81 which has a second adjustable arm 79 projecting into the path of the carriage 50, so that the machine is stopped automatically when the carriage has moved a predetermined distance.