Patent GB-945344-A (GB)
Title: Improvements in or relating to sewing machines
IPC: D05B19/00
Filed: 1960-01-08
Abstract: 945,344. Sewing machines. ANKERPHOENIX NAHMASCHINEN A.G. Jan. 8, 1960 [June 13, 1959], No. 830/60. Heading D1G. A zig-zag sewing machine comprises a set of rotary pattern cams co-operating with one or more cam followers, and a single manually-operable member which is capable only of rotary or rectilinear movement and which is adapted to effect disengagement between said follower or followers and the cam, and also selective engagement between and follower or followers and different oneof the cams. The upper arm 1 of the sewing machine contains a shaft 2 which drives in the usual manner a needle bar 4 mounted in a gate 5 pivoted at 6 to the machine frame. Arm 1 is closed by an end cover 7 and an upper cover 8. Gate 5 is connected by links 72 and 75 to a crank 77 on a shaft 78 which is journalled in the machine frame and carries a handle 79. Link 72 is pivoted at 70 to a block 71 slidable in a groove 69 formed in an arm 68 pivoted at 67 to the machine frame. A cam follower 66 rigid with arm 68 co-operates selectively with cams on a rotary shaft 44 to effect oscillation of the gate 5, follower 66 being biased against the cams by a spring 80. Block 71 may be moved along groove 69 by means of handle 79 to vary the amplitude of the oscillations. A feed dog 10 is carried by a feed bar 17 pivoted to a crank 16 on one end of a feed shaft 14. A crank 13 on the other end of shaft 14.is pivoted to the lower end of a bar 11, the upper end of which is forked to embrace an eccentric 9 on the arm shaft 2. Bar 11 is pivoted at 19 to a block 20 slidable in a groove 21 formed in an arm 23 pivoted at 22 to the machine frame. The inclination of arm 23 thereby determines the direction and rate of work feed. Arm 23 is connected by a link 85 to an arm 83 pivoted at 82 to the machine frame. A two-armed lever, also pivoted at 82, has one arm adjustably secured to arm 83 and is formed on its other arm with a cam follower 81 which co-operates selectively with cams on shaft 44 for varying the work feed. A spring 42 acts on arm 23 to bias follower 81 against said cams. A bar 26 is pivoted at its upper end to arm 23 and is formed at its lower end with a slot 27 which embraces an eccentric pin 28 adjustably fired in one end of a lever 30 pivoted at 38 to the machine frame. A spindle 40, journalled in the machine frame, may be rotated by a knob 39 and carries two cams 41 and 41a adapted to co-operate with respective follower noses on lever 30 for manual control of the forward and reverse feed respectively. While the machine is being automatically controlled, cam 41 is set to the position of maximum feed, when pin 28 will be normally free in slot 27. For manual control, follower 66 is engaged with a cam effecting uniform oscillation of the gate 5, and follower 81 then does not engage any cam. Spring 42 then engages the upper end of slot 27 with pin 28 and the forward feed is controlled by cam 41. To effect reverse feed of equal value, lever 30 is swung, against the bias of spring 42, by means of a handle 35 on pin 28, to engage the. follower lever 30 with cam 41a. Shaft 44 is driven by glass 42 and 43 from the arm shaft 2, and is formed with a splined end 49 slidably engaged by a sleeve 50 which carries cams 51 to 57. The followers 66 and 81 are spaced apart by the width of four cams, whereby while follower 66 is co-operating with one of the cams 51 to 53, follower 81 is simultaneously co-operating with one of the cams 55 to 57, and when follower 66 co-operates with cam 54 to produce uniform zigzag stitches follower 81 is disengaged from the cams. A ring 60, journalled on sleeve 50, carries a symbol disc 62 and also carries an upstanding finger 64 adapted to prevent rotation of ring 60. An annular knob 92, journalled concentrically with shaft 44 on a fixed member 98, has secured thereto by screws 95 a member formed with radial cam lobes 93 and an axially directed cam surface 94. A bar 108 is spring-biased against finger 64 to engate the latter with cam 94. When knob 92 is turned between successive positions of angular adjustment, determined by the engagement of a spring-biased ball 113 with spaces grooves 96 in knob 92, cams 93 co-operate with pins 100, 101 on the followers 66 and 81 respectively for initially raising the latter from the cams engaged thereby, cam 94 then co-operates with finger 64 to shaft sleeve 50 the width of one of the cams 51 to 57, and cams 93 finally lower the followers 66 and 81 to the newly selected cams. A pointer on knob 92 indicates the appropriate symbol on disc 62. When knob 92 is moved to align an axial slot 97 therein with finger 64, the latter is moved into slot 97 by bar 108 to engage the nose of a spring-biased pivoted latch 102. A batten 104, carried by a leaf spring 105, may then be depressed to release latch 102, when sleeve 50 may be withdrawn and replaced by a sleeve carrying alternative cams. Bar 108 also enters slot 97 to prevent rotation of knob 92 when sleeve 50 is removed. It is stated that the cams can be arranged for the production of buttonholes. It is also stated that selection of the cams can alternatively be effected by moving the followers, and that the control knob may alternatively be arranged for linear movement.