GB668600A - Sewing machine lubrication - Google Patents

Abstract

668,600. Sewing-machines. SINGER MANUFACTURING CO. June 30, 1950 [Feb. 25, 1950], No. 16381/50. Class 112. [Also in Group XXXIV] Lubricating.-In a sewing-machine having a hollow head with a lubricant sump and a horizontal shaft running in a bearing bush at the junction of the head with the arm, excess lubricant is removed from the sump by a wick dipping into the sump and held in communication with a member on the shaft provided with means for feeding lubricant towards a recess in the bearing, whence it is led into the arm on the side of the bearing away from the head, to drain into a main reservoir in the frame; provision is made for easy renewal of the wick. Means are provided for lubricating the mechanism within the head. In the embodiment shown, oil fed to an axial bore in the needle-bar shaft 22 by a pump passes through a radial bore 37 to the surface of the bearing bush 21, along which it is carried back into the arm 15 by a helical groove in the shaft 22 ; oil leaking from the lefthand end of the bush 21 collects in an annular groove 43 therein and is discharged into the arm 15 through a passage 44. A second radial bore 46 communicates with bores in the crank-disc 23 and pin 24 to lubricate the bearing surfaces of the latter, and leakage from these surfaces lubricates the bearing surface of the needle-bar collar 27; any excess oil from these moving parts collects in a sump 53 in the bottom of the head 16, and is removed therefrom by a wick 54 which is held at its upper end in contact with a frustoconical extension 87 of the crank disc 23, formed with a spiral groove to fling oil into the recess 43. The wick 54 is held in place at its lower part by a member 56 projecting from the presser-bar bushing, and its upper end is doubled and lies horizontally in a holder 57 pivotally mounted on a plug 59 in the rear wall of the head 16 and spring urged to hold the wick against the part 87. In a second embodiment, Fig. 5 (not shown), the wick holder 57 is spring-hinged to the bearing bush 21, which is cut away to accommodate it, and the mechanism in the head 15 is lubricated by wicks carried in a tray and arranged so that one end of each rests in a well in the frame and the top of the bush 21, supplied with oil from the bore 39, and the other end hangs down to make contact with one of the moving parts. In a modification of this form, Fig. 12 (not shown), the upper end of the wick is not directly in contact with the part 87 but an oil conducting felt pad is interposed ; the wick holder is vertically slidable under spring action on a support which is fixed in the head 15 by a slot and screw, and the holder can be readily withdrawn from this support through a plugged aperture in the head. In a further form, Fig. 9 (not shown), the wick is in the form of a loop passing over the member 87 with both ends in the sump 53, being kept in place by a wire arm towards its upper part and pulled downwards by a pair of claws engaging its limbs and connected by a tension spring with a clip on the presser-bar bushing.