GB249970A - Improvements in feeding mechanisms for sewing machines - Google Patents

Abstract

249,970. Armstrong, J. J. V., (Union Special Machine Co.). Feb. 4, 1925. Duplex feed by dogs.-In a feed-mechanism of the kind in which a feed-bar lying in a, substantially horizontal plane is supported at its rear end on rocking arms and carries an auxiliary feed-bar the bars are raised, and lowered by a crankmember set eccentrically on a shaft arranged tranversely beneath the forward end of the feed bar. The main feed-dog 24 is carried by a bar 27 connected to a pin 30 supported by arms 32 loosely mounted on a pin 33. Feed movements are given to the bar 27 by a link 43 adjustable in the slotted arm 35 of a lever rigidly mounted on the pin 33. The auxiliary feed-dog 25 is carried by a bar 29 slidably mounted on the bar 27 so as to share in its vertical movements but to have independent feed movements. The feed movements are given to the bar 29 by a link 51, adjustable in a slotted arm 35 rigid with the pin 33. The pin 33 is oscillated by an eccentric 56 on the main shaft 2. The common lifting movements of the feed-dogs are effected by mechanism comprising a bracket 37 depending from the bar 27 and formed with a rectangular yoke 40 which receives bearing blocks 41 formed with a conical recess for a conically headed driving pin 42 mounted eccentrically on the end of the main-shaft 2. The shank 42<a> of the pin is secured by a grub-screw 42<b> in a socket in the shaft so that it may be moved endwise to take up wear. A washer 42<c> on the shank prevents the bearing blocks from sliding off the yoke. Work-supports. - The feed bars are laterally off-set and the dogs operate in slots in a work-plate of restricted size which allows tubular articles to pass beneath it without obstruction. Trimming mechanism is provided comprising a fixed blade 12 and a movable blade 13 carried by an arm 14 mounted on a shaft 15 oscillated by mechanism comprising a lever 18, link 19, lever 20 secured on a shaft 21 and a lever 23 fast on the shaft 21 connected to an eccentric 22 on the shaft 2. Specification 249,969 is referred to.