GB564468A - Improvements in and relating to sewing machines - Google Patents

Abstract

564,468. Sewing machines. UNION SPECIAL MACHINE CO. July 1, 1943, No. 10661. Convention date, Nov. 9, 1942. [Class 112] Lubricating reservoirs.-In a sewing-machine of the lockstitch type, lubricant is fed from a reservoir 94 in the standard 11, to the raceway of each vertical rotary hook and to associated parts. The supply may be shut off by a valve, and adjustable regulating means are provided. The supply pipe 106 being long and substantially vertical, air contained in the lubricant bubbles back to the reservoir. Curves 124 in the pipes feeding the hook parts 38, 39, allow longitudinal adjustment of the hook shafts towards, or away from each other. A further small reservoir of lubricant is contained in each chamber C at the base of a hook shaft for lubricating escapement mechanism 84, 85, actuated by an eccentric 86 to rock a vertical shaft upon which a finger is oscillated to carry its end into engagement with a projection on the bobbin carrier for the purpose of turning the latter slightly against the frictional drag of the rotary hook. Another supply of lubricant is contained in the base of the standard 11 to be dipped into by a gear 34 and rocking arm 26. A dipstick 135 is provided. The hook shafts 42 are driven by spiral gearing 40, 41 through a shaft 35, and supported in brackets 43 which are adjustable towards or away from each other. The pipes 108 supply lubricant to inlets 60, Fig. VIII, each leading to a chamber 63, 64. From this chamber, during rotation of a hook shaft, lubricant flows through one or more holes 74 to lubricate a raceway 59 which supports a stationary bobbin - holder 57. An annular channel is arranged under the frusto-conical hook-shaft head. An oil sling 72 prevents oil from leaking outside a cover-plate 65. A spiral groove 75 allows some lubricant to pass downwards and lubricate the bearing for the hookshaft and the teeth of the gears 40, 41. During rotation the sense of the groove 75 tends to cause lubricant to be pumped upwards. The pitman 85, used to oscillate a vertical shaft as described above, is a tight fit on a pivot 88, but a loose fit on its driving eccentric 86. An oil passage leads to the vertical shaft and seeps down to the chamber C. Some oil will work upwardly into a bearing 51. The reservoir 94 may be of sheet metal or plastic material and have an opening 100. A tapered dipstick 101 may be provided. A spring-pressed valve may be operated by a hand wheel 127 to admit, or shut off, lubricant supply to the pipe 106, which may be of brass or plastic material. The lubricant flow to the inlets 60 is controlled'by adjustable needle valves in a manifold 112. The lubricant in 94 is preferably of a light stainless type. That in the base of the standard is preferably heavier.