GB283983A - Improvements in or relating to sewing-machine-thread waxing or other wax heating devices - Google Patents

Abstract

283,983. British United Shoe Machinery Co., Ltd., (United Shoe Machinery Corporation). Sept. 15, 1926. Thermal cut-outs.-Apparatus for heating wax, more especially for applying it to sewing-machine thread, comprises a thermostatically-controlled electric 'heating device depending into the wax-pot, to keep the temperature of the wax between certain definite adjustable limits. As applied to a sewing machine, two electric heating coils 13, and a thermostatic device comprising an expansion coil of metal 30, are placed respectively in two spaced apart vertical columns 16, 31, depending from a cover plate 4 into the wax pot 6. Fig. 2 shows the arrangement in elevation in a view at right-angles to that of Fig. 1. The heating coils 13 are connected in parallel across mains 60, 61, and the thermostat 30 controls a switch member 70 to cut one of the coils suddenly out of circuit when the temperature rises above a certain limit, and to return it suddenly into circuit when the temperature falls below another limit. One end of the thermostatic coil 30 is clamped to a bracket 36 mounted rigidly in the column 31 and the other end is secured to a vertical shaft 40 journaled in horizontal lugs 42, 44 at the top and bottom of the bracket 36. Rotation of the shaft 40 is transmitted by an arm 94 and a coiled spring 90 to move the pivoted switch member 70 suddenly into and out of contact with adjustable stud members 82, 83 enclosed in a casing 64 on the cover plate 4 to cut out of and put in circuit respectively one of the heating coils 13. The setting of the arm 94 relatively to shaft 40 may be adjusted to change the limiting temperatures within which the thermostat acts, without changing the range of temperature. Specifications 22546/12, 107,655, and 251,262 are referred to.