GB516016A - Improvements in sewing machines - Google Patents

Abstract

516,016. Sewing-machines. UNION SPECIAL MACHINE CO. June 18, 1938, No. 18143. Convention date, June 22, 1937. [Class 112] In a sewing-machine, the needle-bar driving shaft is hollow and is fed with oil by gravity from a reservoir, the oil being led by the shaft to the shaft bearings, the eccentrics for driving the looper and feed mechanisms, and a sump in the machine head from which the needle-driving connections are lubricated, this sump overflowing into a main sump in the frame; a pump is provided to return oil from the main sump to the reservoir. Needles, driving; frames.- In the machine shown, of the feed-off-the-arm type having two needles on one needlebar 17, the main shaft 7, mounted in four bearings in the frame 1, is connected by bevel gears 28 to a transverse shaft 23 passing into the head 22 which is formed separately from the main frame. A balanced crank 30 on the end of the shaft 23 is connected to the needle-bar 17 by a link 32 and pin 33; an extension of the pin 33 engages a guide 35 in the head to prevent rotation of the needle-bar. The head 22 has a bearing boss 24 fitting into an aperture in the wall of the frame 1, and has its opposite side open, with a cover plate 5. The gears 28 are covered by a plate 72 and a top cover 74. The intermediate bearings of the shaft 7 are carried by partitions 12, 13 of the frame, forming three compartments, of which the middle one contains the thread tensions and take-ups and has a hinged cover. The right-hand compartment also has a removable cover. Lubricating.-The right-hand compartment of the frame contains an oil reservoir 51 held in place by a stud 56 and a nipple 52 through which passes a wick conducting oil to a passage in the end bearing of the shaft 7 and thence to a bore 47 extending along the axis of the shaft, the end of the bearing being closed by a diaphragm 50. The bore 47 of the shaft conducts oil to the eccentrics driving the looper and feed mechanisms and to all the bearings of the shaft. Excess oil from the left-hand bearings drains into the bottom of the compartment containing the gears 28, which dip into this oil for lubrication, and thence through a passage 80 into the bottom of the head 22, the needle-bar actuating mechanism being lubricated by a splash disc 82 on the shaft 23 and a scoop 84 on the link 32 communicating with a bore in the link. The bearings of the shaft 23 are lubricated by oil thrown by the gears 28 into a port 76 in the top of the boss 24. Oil from the gear compartment overflows through passages in the partitions 12, 13 into a main sump 87 in the rear end of the work-supporting arm, this sump also receiving oil dripping from the eccentrics and the right-hand bearings of the shaft 7. A hand pump is provided for returning oil from the sump 87 through a passage 99 to the interior of the shaft 7 and the reservoir 51.