Patent GB-779021-A (GB)
Title: Improvements in or relating to automatic embroidering and the like machines
Inventor: SCHEIBEL KURT
IPC: D05C9/06
Filed: 1954-12-31
Abstract: 779,021. Sewing machines. VEB SPEZIALNAHMASCHINENWERK LIMBACH. Dec. 31, 1954, No. 37820/54. Class 112. [Also in Group XXIV] A jacquard mechanism for controlling the movement of the work frame of an embroidery machine and in which said movement is effected via a toothed wheel driven by a toothed rack, the rack being alternately connected and disconnected from the wheel, and the latter being held against rotation by a locking tooth when so disconnected, is characterized in that a crank and connecting rod drive serves to operate both the jacquard needles and the alternate engagement and disengagement, of the tooth and rack, the latter being actuated by two lever systems so arranged that the tooth and rack are engaged in the two dead centre positions of the crank. The jacquard needles 57, Fig. 1, which are mounted in the manner described in Specification 773,520, are curved and are carried by segmental plates 7 pivoted at 8 and yieldingly coupled by means of respective spring-biased plungers 47 to an arm 4 also pivoted at 8. Arm 4 is oscillated by a connecting rod 3 from a crank 2 carried by a rotary shaft 1, whereby the needles are driven towards a pattern card carried by a perforated drum 63, the plates 7 carrying those needles which do not pass through the drum moving relatively to the arm 4. Plates 7 are connected by links 10 to levers 11 pivoted to an integrating lever 14, and the latter imports longitudinal movement through a bar 16 to a rack 17. The rack is arranged to be coupled and uncoupled to a toothed gear wheel 19 connected to the work frame, and a tooth 36, carried by a lever 37, is adapted to engage gear 19 for preventing movement thereof when the rack and wheel are uncoupled. Crank 2 is connected by a link 22 to an arm 23 of a three-armed lever 23, 23<SP>1</SP>, 44, and arm 23<SP>1</SP> is connected by a link 26 to the junction of toggle links 28, 29, link 29 being pivoted to a lever 31 the outer end of which is pivoted at 34 to a slide' engaged in a guideway 35 in rack 17. Arm 44 is connected by a link 45 to a pair of toggle links 40, 41, link 40 being pivoted to lever 37. The arrangement is such that when crank 2 and connecting rod 3 move through the dead centre position as shown, with crank 2 rotating clockwise, tooth 36 becomes engaged with gear 19 and rack 17 becomes disengaged from the latter, while the reverse operations occur when the connecting rod and crank pass through the dead centre position displaced 180 degrees from the position shown. The movement of plates 7 is limited by stops 9 and 49, the angular distance between which is less than the angle of oscillation of arm 4. Shaft 62 carrying drum 63 also carries a toothed gear wheel 64 which engages an annular rib 65 on a disc 58 driven from the shaft 1, the rib being gapped and one end being offset from the other end by a distance equal to the pitch of the teeth on gear 64, whereby shaft 62 is rotated in steps equal to the teeth pitch. In a modification, Fig. 4, arms 44 and 231 are respectively connected by links 50, 50<SP>1</SP> to the ends of a bell-crank lever 52, 52<SP>1</SP>, fulcrumed at 53. Link 50 is connected at 54 to one end of a link 55 the other end of which is connected at 55 to one arm of a bell-crank lever 37<SP>1</SP>, the other arm of which carries the locking tooth 36. Link 50<SP>1</SP> is connected at 54<SP>1</SP> to one end of a link 55<SP>1</SP> the other end of which is pivoted at 56<SP>1</SP> to one arm of a bell-crank lever 31<SP>1</SP>, the other arm of which is pivoted to the rack 17. The arrangement is such that when lever 23, 23<SP>1</SP>, 24 turns anti-clockwise, pivot 56 and, consequently lever 37<SP>1</SP> remain stationary to hold tooth 36 engaged, pivot 54 moving along curve a, while pivot 54<SP>1</SP> moves along curve b thereby rocking lever 31<SP>1</SP> to disengage rack 17. When lever 23, 23<SP>1</SP>, 44 turns clockwise, pivot 54 moves along curve b to disengage tooth 36, while pivot 54<SP>1</SP> moves along curve a to hold rack 17 engaged.