GB571094A - Improvement in blind-stitch sewing machine - Google Patents

Abstract

571,094. Sewing-machines. LEWIS INVISIBLE STITCH MACHINE CO. Nov. 18, 1943, No. 19305. Convention date, July 29. [Class 112] In a blind-stitch sewing-machine the worksupport may be moved away from the presserfoot independently of the work-bender. Additionally, a single manual means may be operated to move the work-support and the workbender away from the presser-foot to provide an opening for the insertion or removal of the work. The invention is applicable to either chain-stitch or look-stitch machines. Worksupporting platens 16, 17, Figs. 4 and 10, are independently and resiliently supported. The platen 17 is supported on a lever 18, pivoted at 19, and held up by a light spring 21. The platens are lowered to the position shown in Fig. 10 by operation of a knee-press which, through levers, causes the rotation of a shaft 26 by rotating a shaft 30 and lowering a link 32. A work-bender 34 is mounted on the end of a shaft 35, journalled in bearings 36, 37 in a cradle 38. The latter is pivotable about pins 39, 40, Fig. 4. The cradle is held in operative position by a heavy spring 43. The workbender is oscillated through rotation of the shaft 35 by means of an eccentric 61, Fig. 7, acting on levers 63, 64 and connecting-rod 68, which is pivoted to one end of a lever 69, The latter is pivoted between its ends on a shaft 70, Fig. 8, that is formed integral with, and eccentric with respect to, a shaft 71. Fig. 8 shows the connection to the bender 34 which is in its upper position. A link 73, connecting the lever 69 and the crank-arm 74, allows the shaft 35 to move substantially vertically, when it is necessary for the work-bender to yield. The depth of penetration of the needle is adjusted by adjustment of the cradle 38, to limit the movement of the cradle under the action of the spring 43. The adjustment is secured by rotation of a knob 60<1> to rotate a screw 60 and move levers 57<1>, 55 and rod 52 to cause an arm 47, supporting the cradle 38, to rotate slightly. Manual retraction of the bender 34 is effected by rotating the shaft 71, and so shifting the pivot 70, by means of a gear 75 meshing with a gear 76 on a shaft 77. This is done, when the machine is stopped, by the operator pressing the knee-press to the fullest extent, a shoe 79, Fig. 11, engaging a stud 78 and rotating the gear 76 to cause the lowering of the pivot pin 70. A finger lever 85, Fig. 5, may be moved to the dotted position shown, causing a circular block 84 to move from one detent notch 86 to another 87, co-operating with a detent 88 on a spring-held disc 81. Rotation of 84 causes the shifting of the pivot 70 for the lever 69, affecting the vertical height reached by the work-bender, and thus the depth of penetration of the needle.