Patent GB-724419-A (GB)
Abstract: 724,419. Sewing-machines. FAIRWEATHER, W. C. (Singer Manufacturing Co.). Feb. 18, 1953, No. 4539/53. Class 112. Feed by dogs and needles. In a sewing-machine comprising a work support 1, a lower feed mechanism, a needle feed mechanism including a needle-oscillating shaft 52 spaced from the work support, an oscillatory needle-carrier frame 51, and actuating mechanism for shaft 52 including a rock lever 54 fixed at one end to the shaft and at the other end articulated to a crank 56 carried by a feed-advance rock-shaft 42, the length of the rock lever exceeds the vertical distance between shaft 52 and the line of feed. Feed advance motion is transmitted to a feed bar 38 by means of a rocker 41 carried by shaft 42, the ratio of the length of rocker 41 to the length of crank 56 being substantially equal to the ratio of the distance between shaft 52 and the line of feed to the length of rock lever 54. A main shaft 15 carrying a combined handwheel and belt pulley 18 drives a shaft 19 through a belt 22 and pulley 23, 24. Shaft 19 carries an eccentric 40 straddled by the forked end 39 of the feed bar 38 to impart feed lift motion to a feed dog 37. An adjustable eccentric 45, carried by shaft 19, is connected by a pitman 46 to a crank 47, carried by shaft 42 for oscillating the latter. Crank 56 is connected by a link 55 to rock lever 54. Frame 51 is secured to the end of shaft 52. Needles driving. A needle bar 48 is slidably mounted in spaced bearings 50 carried by the frame 51. A pin 60, secured at one end to the needle bar and slidably disposed at its other end in a slot 62 formed in the frame 51, is connected by a pitman 57 to a hollow crank pin 58 carried by a disc 59 fixed to the end of shaft 15. Presser bars. A presser foot 25 is carried by a presser bar 26 slid able in a fixed sleeve 27, the upper end of the presser bar having an arm 30 disposed in a slot 31 in a fixed rod 32 mounted parallel to the presser bar. Frames. The head 4 of the machine is closed by a cover 5 hinged to the head at 6, the upper part of the bracket arm 3 of the machine is closed by a cover 8 hinged at 9, and the standard 2 has an opening closed by a cover plate 11 held by a bolt 12, which passes through the bracket arm. Lubricating. An oil reservoir 64 is closed by a cover 65 fastened by screws 66 on one of which is pivoted a shut-off lever (not shown) having a depending ear 71 disposed in a well 69 containing an absorbent pad 74 having an upstanding portion 75. A wick 68, disposed in the reservoir 64, is threaded through the ear 71, and the end of the wick may thereby, through operation of the shutoff lever, be brought into contact with the portion 75 to convey lubricant to the pad 74. The well 69 communicates with the bearing 17 of shaft 15, and lubricant from said bearing flows to a sump 80 in the head 4. A wick 81 conveys lubricant from the sump to the upper one of the needle bar bearings 50, and a second wick 82 conveys lubricant to the bearings 53 of shaft 52, and also to the pivotal connections between the lever 54 and crank 56. A wick 79 conveys lubricant from the well 69 through a bore in the pivot pin 77 of a take-up lever 78. Specifications 278,582, 491,083 and 565,071 are referred to.