Patent GB-517104-A (GB)
Title: Improvements in or relating to apparatus for reproducing characters, designs or the like
IPC: D05B3/24
Filed: 1938-08-31
Abstract: 517,104. Sewing - machines. TILLETT, F. G. Aug. 31, 1938, No. 25539. [Class 112]. In a sewing-machine for stitching a predetermined design, character or group of characters into material reproducing apparatus, o‹ the kind comprising a toothed rack shaped to the form of the design or character, a rotatable pinion engaging the rack and carried on a movable control rod, and guide means associated with the rack and pinion to ensure that the pinion, as it rotates, moves over the rack in a course determined by the shape of the rack to cause corresponding movement of the control rod, is connected to the sewing- machine so as to produce relative movement between the work-support and the needle over a course corresponding to that followed by the pinion. In the arrangement shown in Figs. 1 and 3 (the machine and bench being omitted from Fig. 1 but their positions being indicated at A and B respectively), the work is secured to a plate C by a spring-pressed clamping plate C', both these plates having a substantial aperture C<2> beneath the needle of the machine. A plate D<1>, pivoted beneath the bench at D and supported by wheels running on an arcuate rail D<3>, has pivoted to it a bracket E which pivotally supports the work-plate C ; the other end of the plate D<1> pivotally carries a control arm F extending above the bench B to a head K<2> connected with a pattern device. The work-plate C is constrained to follow the movements of the head K<2> on a reduced scale bv a rod E' secured to the work-plate and pivoted to an arm moving with the control arm F, the arrangement forming a pantograph linkage. As shown in Fig. 3, the control arm F is secured to a plate G<2> pivotally mounted bv a tube G<3> on a plate G secured to the plate D<1>, and the rod E<1> is pivoted to a member E<3> on the plate G<2> and steadied by a link E<4>; the plate G<2> is steadied by a pillar G<5> and link G‹, and the control arm F is supported by a resilient bracket F<3> allowing limited vertical movement. The pattern device J, Figs. 3 and 4, comprises an interchangeable letter or figure .formed by a row of pins J<3> surrounded by a groove J<1>, and the control head K<2> has a depending spindle K<1> which engages the groove J<1> and carries a pinion K engaging the pins J'. The pinion K is driven from a motor on the plate D' through a belt L, a shaft inside the tube G<3> gears F', a shaft inside the arm F and gears in the head K<2>, so that the head is moved round the pattern J automatically until the stitching of the character is complete, when the head is lifted and another pattern put in place for a subsequent operation. Several pattern characters may be arranged side by side, and the characters may be formed so that the pinion K can run from one to another, repeated automatic stitching of the characters being obtained if desired by arranging a rack and groove in the frame containing the patterns to lead the pinion back from the last character to the first. For ease in changing the characters, they may be formed on plates hinged together to form endless chains M, Fig. 1, which are individually adjustable by knobs P to bring the required character to the top. The teeth J' of the pattern J may be integral with the plate, or may be formed on a separate strip which is bent to shape and inserted in a groove in the plate; in a modified form, Fig. 9, the rack is in the form of a comb S<2> along the side of the guide slot S<1>, the pinion K being free to be lifted from the slot only at the end of the character. In a simpler form of the guiding mechanism the motor driving the pinion K is fixed to the inner end of the arm F, being rockable about a horizontal axis in a fork secured to the top of the member G<3>, to which the arm E<4> is secured, the member E' being omitted. In order to avoid distortion in the copying owing to the fact that the stitching point does not always coincide with the intersection of the members E, E', the linkage may be elaborated as shown in Fig. 11 to prevent rotation of the work-plate C on its axis. The work-plate C is secured to a post U on a disc U<1>, the member E is supplemented by a pair of links E<9> connected to a disc D<11>, pivoted on the rod D<6> which replaces the plate D<1> and the rod E' is duplicated and attached to a disc T which is pivoted on the control arm F and guided by a double parallelogram linkage V. The motor L driving the pinion K is carried on the arm F and has a flexible drive which allows the arm F to be hinged to permit the lifting of the pinion K from the pattern. In this arrangement the weight of all the mechanism is taken by castors on extensions of all the pivot pins of the linkage resting on a platform below the work-bench. In a modification, the castor supporting the disc U' may be placed directly beneath the pillar U and the other side of the work-plate C may be steadied by a jointed arm pivoted to a fixed pillar. Instead of the work-clamp moving, the work may be fixed and the machine moved by the means described. The machine may be driven by an individual motor or from a line-shaft, and may have a clutch in its drive, released by a Bowden wire or other remote-control means. Means for stopping the needle in its highest position, for example as described in Specification 497,893, may be provided; the work-clamping plate C<1> may be raised by a Bowden wire or other remote-control means. for example as described in Specification 497,894. A single pedal or other control member may be arranged to actuate in the appropriate sequence the work clamp, the needle-stopping device, the clutch, the switch for the motor L for driving the pinion K, and if desired, the switch for the machine motor. Specification 354,320 also is referred to.