GB547697A - Improvements in or relating to sewing machines - Google Patents

Abstract

547,697. Sewing-machines. JACKSON, L. MELLERSH-. (International Button Hole Sewing Machine Co.). March 4, 1941. No. 8757/42. Divided out of 547,678. [Class 112] A needle-bar slides in a sleeve mounted on cross pivots and is laterally vibrated in two directions at right angles from cam-grouves 54, 55. The motion is communicated by means of a bar 63 sliding in a pivoted block 61. The groove 55 gives the bar a longitudinal motion by means of a lever 78 and a link 83. The groove 54 gives it an oscillatory motion through a lever 71, 74 and link 68 and the amplitude may be varied by shifting the connection of the link 68 with the arm 71. The shuttle and shaft are given an axial movement corresponding to the longitudinalmovement of the bar 63 by means of a lever 115 fast on the shaft 77 carrying the lever 78 and a pair of collars 112 on the shuttle shaft 110. The cyclical position of the shuttle beak is advanced and retarced to suit the transverse vibration of the needle by the relative displacement of helical toothed wheels 121, 122 by which the shuttle shaft is driven from a shaft 124. The wheel 121 is held from axial movement with the shuttle shaft 110 and the wheel 122 is carried by a sleeve 135 which is moved axially upon the shaft 124 by a third cam groove 56 acting through a quadrant lever 146, link 143 and a lever 138. The shuttle is supported and driven by six levers 99 carried by the shaft and caused to move into and out of recesses in the shuttle body by a cam surface enclosing the levers and formed within a non-rotating block 96. The block 96 and a throat plate attached to it move axially with the shuttle shaft 110. The bobbin-case is held from rotation by the alternate engagement of arms with a groove in the bobbin-case front. These arms are carried on a shaft 170 which is oscillated by means of a lever 179 and a crank-pin 181 which may be adjustable. The shuttle may be replaced by a rotary chain-stitch looper, Fig. 9, which is driven by the levers 99. In place of the bobbin-case retainer a needle-thread loop spreader 225 is mounted on the shaft 170. The shuttle makes two revolutions for each stitch and the chain-stitch looper one revolution for each stitch. Specification 547,696 is referred to.