GB1271765A - Improvements in or relating to sewing machines - Google Patents

Abstract

1,271,765. Linkwork. NECCHI S.p.A. 13 April, 1970 [14 April, 1969], No. 17404/70. Heading F2K. [Also in Division D1] A linkage providing an adjustable transmission ratio in a sensing machine comprises two pivotable members 38 and 44 on parallel axes and each having at least one arm 40 or 42 extending radially therefrom, the arms 40 and 42 being linked by an articulation device 41 which is displaceable on the arms 40 and 42 to vary the transmission ratio. The articulation device (Fig. 3, not shown) comprises a series of superposed discs (53), with diametral bores through which pass the arms 40 and 42, pivotably mounted within a cylindrical housing 52 with slots through which the arms 40 and 42 pass. As shown, the linkage described is actuated by a follower 36 engaging an upper cam track 33 in a disc 32 of the sensing machine and controls, through a further arm 45 extending from the pivotable member 44, movements, parallel to a free arm 12, of a plate 47 of a work clamp. A second linkage controls movements of the work clamp perpendicular to the free arm 12 and comprises a first pivotable member 66 actuated by a follower engaging a lower cam track 34 in the disc 32, arms 68, 70 interconnected by a second articulation device 69 and a second pivotable member 72 from which extends an arm 73 with a pin 74 engaging a groove 75 below the plate 47. The articulation devices are adjustable on the arms 40 and 42 and 68 and 70 respectively by levers 58 and 83 extending through slots in a plate 61 of the machine frame and having spring retaining members 59 and 84 respectively which are engageable with grooves 60 on the inner wall of the plate 61.