GB499292A - Trimming mechanism for sewing machines - Google Patents

Abstract

499,292. Sewing - machines. FAIRWEATHER, W. C. (Singer Manufacturing Co.) July 22, 1938, No. 21766. [Class 112] Actuating means for trimming - mechanism of the Barber type comprises a tubular shaft rotatably mounted on the loop-taker shaft and operated independently thereof. In the arrangement shown, the trimming-knife comprises a horizontal member 25 with a depending cutting lip 26 adjustably fixed to the top of a vertical tubular oscillating shaft 31 having at its lower end an arm 35 with a pin 37 for connection to an arm 46; the latter arm is mounted on a pivot concentric with the shaft 31 and has a downwardly-extending fork 47 engaging the upper end of a lever 50, this lever being oscillated by a cam 63 on a sleeve 54 which is mounted freely on the looper actuating shaft 19 and is driven by a belt 57 from a motor independent of the main machine motor. The pin 37 can be withdrawn against a spring, to put the trimmer out of operation, by a lever 39 which is pivoted on the arm 35 and actuated by a plunger 42 passing through the bore of the shaft 31 ; when the arms 35, 46 are thus disconnected, the knife 25 is moved to an inoperative position by a torsion spring 64 acting on the shaft 31, a finger-piece 66 being provided on the shaft for returning the knife to the operative position when required. Feed.-A feed-wheel 23 is driven by gearing as shown from the vertical shaft which drives the loop-taker shaft; and co-operates with a presser-wheel 24. The needle is laterally vibrated to assist in feeding the work.