Patent GB-102579-A (GB)
Title: Gathering Feed Devices for Sewing Machines.
Inventor: FAIRWEATHER WALLACE
IPC: D05B27/02
Filed: 1916-05-30
Abstract: 102,579. Fairweather, W., (Singer Manufacturing Co.). May 30, 1916. Sewing-machines; feed by dogs; presser-feet.- A feeding-device capable of gathering or fulling the work comprises a four-motion feed-dog with which co-operates a stripper adapted to lift the work out of range of the action of the advance part of the feed-dog during the initial part of the feeding movement thereof. The invention is described as applied to a cylinder-bed double-chain-stitch machine as described in Specification 26065/09, and the looper mechanism shown is as described in Specification 8670/10. The feed-dog is formed with spaced full-length outer members 55, Fig. 3, and short intermediate members 56. The feeding-surfaces of the outer members are interrupted at 57 to form feeding-sections 58, 59. The shank of the feed-dog is secured to a carrier 50 working in guides in the forward bearing 3<1>, Fig. 1, of the work-supporting arm, and derives its longitudinal movements from an eccentric 31 on the main shaft through a rod having a ball-connexion with the arm 36 of a rocking sleeve 37 to which is secured an arm 40, Fig. 3, having a sliding ball-connexion with the feed-bar 48, and its vertical movements from a sleeve 61 embracing the feed-bar and pivoted at the sides between the arms of a forked rod 65, with a sleeve embracing the eccentric 67 on the main shaft. An arched cross-bar 69 is secured in notches in the horn 3 and has pivoted to it at 71 a member 73 with spaced parallel arms 72 provided at their forward ends with work-stripping blades 74, which lie adjacent to the inner edges of the feed-members 55 and extend to just in front of the sections 59. A stripper-lifting plate 80 is slidingly mounted in the recess in the bearing 3<1> which houses the feed-carrier 50, and carries upright posts 81 having lugs 82, which, when required, are caused to engage over the carrier and under the arms 72 of the stripper to convey to it the movements of the feed-dog. The plate 80 is under control of the operator through a bar 84 connected to the arm 86 of a rocking sleeve 87 journaled on a stud screw secured to a bracket 89 and carrying an arm 91 connected to a knee-treadle or the like. The plate 80 is held in its forward or inoperative position by a spring surrounding the sleeve 87, and the limits of movement are determined by the lugs 80<1> abutting on the end of the bearing 3<1> and a projection 94 on the sleeve 87 engaging an adjustable stop 95. The presser-foot 119, Figs. 1 and 5, is formed with a recess in its lower face containing a heel-plate 122 maintained in position by a screw stud 123 and a spring 124. The presser-bar is held down by an arched spring bearing on an adjusting-screw. In the normal feeding operation, the plate 80 is held in its forward position, with the lugs 82 clear of the carrier 50, and the entire face of the feed-dog engages the under surface of the material m. When it is desired to full the work, the plate 80 is drawn back to a position in which the lugs 82 engage the upper surface of the carier 50 during the initial stages of the feeding movement of the dogs, thus causing the part of the work over the feed-members 56, 59 to be stripped therefrom and clamped between the strippers 74 and the heel-plate 122 of the presser-foot, while the feed-members 58 feed forward and full the work. When, in its continued feeding movement, the carrier 50 leaves the lugs 82, the stripping-member 74 falls by its own weight, assisted by a spring 99, and the fulled work is fed forward as a whole. In order to compensate for the feeding motion of the dogs lost during the fulling action and ensure uniformity of stitchlength independent of the amount of fulling, the ball connexion of the feed-bar with the arm 40 is moved away from the fulcrum of the arm 40 against the action of a spring to an extent proportionate to the time during which the lugs 82 of the plate 80 are in engagement with the feed-dog carrier 50. For this purpose, an arm 101 carried bv the sleeve 87 engages one arm 102 of a lever pivoted between the arms 108 of a bracket and provided with another forked arm 103 engaging the ball connexion of the feed-bar and arm 40.