GB143276A - Improvements in or relating to sewing machines - Google Patents

Abstract

143,276. Vickers, Ltd., and Francis, C. E. March 20, 1918. Sewing-machines; needles, vibrating.-Relates to sewing-machines having mechanism for laterally vibrating the needle, of the kind comprising a lever or similar device connected to the needlebar and oscillated by a cam or the like. The invention consists in mounting the lever b on a member such as the slide c capable of being moved relatively to the body of the machine to vary the position of the " neutral " line of the stitches, i.e. the line of stitching made by the needle when the mechanism is set so as to produce no lateral vibration thereof, and in providing means, such as an axially movable cam a, for determining whether the needle vibrations take place across the neutral line, or terminate thereon on either side, operated by a camber such as a slide e capable of movement independently of the levercarrying member. The slide e is mounted on the slide c working in fixed guides on the frame of the machine, and has a fork e<1> engaging a groove in the cam. The cam-follower b<4> has a rectilinear movement in fixed guides and is connected to the lever by a pin-and-slot device. Spring plungers e<2>, e<3>, c<2> are provided on the slides, by which they may be locked in any adjusted position relatively to the machine frame or connected together for simultaneous adjustment A hand-lever g<3> pivoted on the frame carries similar spring plungers g<1>, g<2> by which :.t may be connected to either or both of the slides. Automatic adjustment according to a pattern may be obtained by a suitable cam i driving a lever i<1> connected by a link i<2> with an arm g<5> of the lever g<3>. The amplitude of lateral vibration of the needle is varied by moving the connexion between the lever b and the connecting-rod b<2> to or from the lever fulcrum b<1> through the medium of a link f<1>, lever f, link f<3>, and treadle-rod f<5>, which is moved upwards against the action of a spring f<6> and carries stopcollars f8, f<9>. The adjusting-lever g<3> may be connected to this mechanism by an arm g<4> linked to a lever h which is connected by a link h<2> to a block h<3> adjustably clamped in an arcuate slot in a member h<4>, which is mounted in vertical guides on the lever f and may be clamped thereto by a pin h<5> and nut.