Patent GB-837221-A (GB)
Title: Improvements in or relating to sewing machines
IPC: D05B71/00
Filed: 1957-01-14
Abstract: 837,221. Sewing machines. UNION SPECIAL MACHINE CO. Jan. 14, 1957 [Jan. 17, 1956], No. 1273/57. Class 112 [Also in Groups XVIII and XXXIV] In a lubrication system for a sewing machine, lubricant is delivered from a main lubricant reservoir 15 to the needle head 13 and the delivery means include a plurality of wick elements arranged in series so that the lubricant is transferred from one wick element to another by capillary action, means being provided to separate adjacent wick elements in order to interrupt the supply into the needle head 13. A belt 53, which connects a drive shaft 50 with a drive shaft 25 located in the overhanging arm 12, on operation of the machine creates a lubricant mist within the vertical standard 11. A rib 86, located at the top of the standard, collects lubricant from the mist and delivers it into a trough 88, Fig. 4, which is connected by a conduit 89 with a hollow fitting 90 containing a lubricant storage wick 91. The wick 91 passes over a projection into a pocket 94 and has a downwardly extending end portion 91a which lubricates a bearing sleeve 27 for the shaft 25. Within the pocket 94 there is a felt disc 95 which on one side contacts the wick 91 and on the other side contacts a felt wick 96 which normally feeds lubricant to a felt pad 102 and a series of wicks 104, 105 and 106 in communication with the crank-pin 38, pitman 32 and pivot 42 for an arm 41. The upper end of the wick 96 is carried by a spring plate 101 which normally urges the wick into contact with the wick 102. The contact between the wicks may be broken by rotation of a disc 122, Fig. 26, carrying a shank 117 having at its lower end a face cam 118 which is arranged to co-operate with an upwardly extending propection 119 on the spring plate 101. When the contact has been broken, as shown in Fig. 26, an opening 120 in the disc 122 permits the introduction of oil from an oil can into a wick 121 to deliver a limited amount of lubricant to the felt pad 102. Excess lubricant which may be delivered to the conduit 89 is discharged through an opening 93 in the wall of the fitting 90 and is returned by gravity to the reservoir 15. Excess lubricant which accumulates in a pocket in the bottom of the needle head is returned to the main reservoir 15 by an automatic priming siphon of the kind described in Specification 779,774 comprising tubes 143, 145 and an upper cup 146. Lubricant collected by the rib 86 is also delivered into a pocket 87 communicating with a bearing sleeve for the shaft 25 through a passage containing a felt plug 87a. A felt strip 123 is positioned along the front wall of the head and has its lower end within the lubricant pocket at the bottom of the needle head. The strip 123 delivers lubricant to a felt strip 134, supported on a bracket, having a part 134a which is held by a spring clamp 135 against a felt block 136 which lubricates the surface of the needle bar 34, Fig. 8. A hood 138 is provided over the vertically extending slot 137 through which the take-up arm 40 extends, and the hood is lined with a felt strip 140 which serves to collect lubricant mist thrown outwardly through the slot 137 and return it to the reservoir via a wick element 141. The shaft 50 is hollow and has a plug 161, having a tapered opening, fitted in the end. Lubricant mist from the main standard is caught by a member 162, Figs. 1 and 32, and is delivered into the plug 161 from which it passes along the bore of the shaft 50 and is delivered to the shaft bearings through radial bores in the shaft. Means for delivering lubricant to the hook raceway comprise a disc-like wick member 167 which is partially immersed in the lubricant and spring-pressed into engagement with an annular wick element 172 which is mounted adjacent the end of the hook shaft 45 and feeds lubricant to the bore thereof. A groove 183, Fig. 35, is provided in the end face of the shaft 45. The wick element 172 is secured to a part-annular strip metal supporting element 173 in which a disc 175 is secured. A gap 174 is provided in the outer periphery of the element 172 adjacent one end of the element 173. The disc 175 is urged against the end of the shaft 174 by a spring-pressed pin 179 located in a bore in a shaft 176 which is mounted in a bearing 177. Shaft 176 may be turned by gears 184, 185, and carries a disc 178 having a pin 178d which egages a notch 175a in the disc 175. Turning the shaft 176 varies the point of contact between the wick members 167, 172 and hence the length of capillary path and rate of delivery of the lubricant. A restricted passage is formed in the bore of the shaft 45 by a groove 45b in the surface of a pin 45a which fits snugly in the bore. A float-operated oil gauge 147 is provided, a lever 149, Fig. 6, carrying a cork float 148, being rockably mounted on a pin 149a whose height may be adjusted to facilitate calibration of the gauge. The pin 149c extends from a disc 149b, having a screw stud 149c by which it is secured to the forward wall of the reservoir, at a point which is eccentric to the axis of the stud 149c so that rotation of the latter effects the height adjustment. Specification 775,069 also is referred to.