GB733317A - Improvements in or relating to sewing machines - Google Patents

Abstract

733,317. Variable-speed ratchet-gear; adjustable couplings. HILBER, M., and REINER, W., [trading as HILBER & CO. KOMM.-GES.]. Dec. 23, 1952 [Jan. 16, 1952], No. 32644/52. Class 80 (2). [Also in Group VII] In a cup-feed sewing-machine the drive for the cups includes means whereby the stitch-length can be adjusted while the machine is in operation. In the mechanism shown, the cup-shaft 7 is driven by a ratchet clutch 10, actuated by a link 12 from an arm 13 which is oscillated by a crank-pin 19 on the main shaft of the machine through a pitman 18 and double ratchet clutch 17. The latter includes clutch balls 16, 16<SP>1</SP> which are effective in opposite directions, so that normally the shaft 14 carrying the arm 13 is oscillated by the pitman 18 as if by a rigid connection. However, if a member concentric with the shaft 14 and carrying two pins 23 is shifted angularly by means of a control lever, one of the balls 16, 16<SP>1</SP> will be disengaged, by contact with the corresponding pin 23, for part of one stroke, the ensuing lost-motion resulting in the arm 13 taking up a new position relative to the driving-pin 18<SP>1</SP>. When the arm 13 and pin 18<SP>1</SP> are in line the effect of the constant oscillation of the member 17 on the link 12 is nil, and when they are mutually perpendicular the effect will be a maximum. The control lever may be moved by hand or by a knee lever; it may have clamping means, and may move between adjustable stops, being biased by a spring against one of them.