GB745986A - Feeding mechanism for sewing machines - Google Patents

Abstract

745,986. Sewing-machines. SINGER MANUFACTURING CO. Feb. 16, 1954 [March 4, 1953], No. 4536/54. Class 112. Working feeding means in a sewing-machine comprise a feed-roller 32 fixed to a shaft 60, a rocker 61 in which are journalled shaft 60 and a driving-shaft 47, the axes of the shafts being parallel to one another, a rotary driving- element 66 fixed to shaft 47 and co-operating with a rotary driven-element 67 fixed to shaft 60, and means for oscillating the feed-roller and driven-element about the axis of the driving- shaft, in timed relation to the rotation of the latter, for modifying the effective rotation of the feed-roller about its axis, said means including an actuating-shaft 20 carrying an actuating-element connected to the rocker. Shaft 47 is driven from a main driving-shaft 13 via a double worm reduction gearing comprising gears 50, 51, 59. The rocker is oscillated from shaft 20 via an eccentric 65 and a pitman 62. The arrangement is such that when the rocker moves in the direction of rotation of shaft 47, indicated by an arrow B, the periphery of the feed-roller is stationary relative to the work, although the feed-roller continues to rotate about its axis in the direction indicated by an arrow C; and when the rocker moves in the opposite direction, the feed-roller operates to move the work in the direction indicated by an arrow D. As shown, the feed-roller is timed to perform its feeding stroke simultaneously with the feeding stroke of a four-motion feeddog 24, by means of adjustment of the eccentric 65. In a sewing-machine of the needle-feed type, the feeding would be timed to coincide with the feeding stroke of the needle while it is in the work. The feed-dog 24 is adjustably attached to a feed-bar 23 pivoted at 22 to a rocker 21 fixed to shaft 20. The latter is oscillated from shaft 13 via an eccentric and pitman, whereby feed-advance movement is imparted to the feed-dog. An arm 31, integral with the feed-bar, is connected by a link 30 to a crank 29 fixed to a shaft 28, the latter being oscillated from shaft 13 via an eccentric and pitman, whereby feed-lift movement is imparted to the feed-dog. It is stated that the feedroller may alternatively be oscillated by direct connection with the feed-bar 23, the feedrocker 21 or the feed-dog 24; or by any suitable crank means or other source of oscillation derived from the feed-shaft 20. Work holding.-Co-operating with the feedroller is a presser-wheel 33 journalled in a yoke 34 carried by a presser-bar 35 slidably mounted in a bracket 37 fixed to the head of the machine. The presser-bar is biased downwardly by a coil spring 39, one end of which abuts a collar 40 fixed to the presser-bar and the other end of which abuts an adjustable bearing 41. A pin 42 carried by collar 40 enters a slot 43 in bracket 37 to prevent rotation of the presser bar. A handle 44, pivoted to bracket 37, carries a cam 45 which co-operates with a laterally extending lug 46 on collar 40 for raising the presser bar.