Patent GB-317425-A (GB)
Title: Improvements in strand coating apparatus
IPC: H01B13/30
Filed: 1928-05-16
Abstract: 317,425. Beatty, W. E., (Bell Telephone Laboratories, Inc.). May 16, 1928. Coating threads, cords, and wires.-In apparatus for coating strands with liquid material, particularly apparatus for treating electrical conductors with insulating material, the strand to be coated is passed through a bath of the coating liquid by means of a feeding device, and is then passed through a pair of positively driven companion rolls for removing excess coating material. These rolls are preferably driven independently and at a speed different from that of the coated strand, so that a wiping action is effected. The, strand or wire is drawn from a reel 20, Fig. 1, and passes over a, sheave 22 at the top of the, heating chamber 23. The strand is then passed round a series of sheaves 25, 26 at the bottom and top of the chamber respectively, after which it passes over a sheave 27, around a capstan 28 and on to a take-up reel 30. In the lower part of the chamber 23 is a container 31 holding the coating material, which is supplied from a tank by means of a pump 33. The container 31 is divided into compartments by means of a dam, so that a constant level is maintained in one part as the material is pumped in through the pipe 35 Mounted within the container 31 is a frame 41, Figs. 5 and 7, which is provided with a downwardly extended arm 45 carrying a horizontal shaft 46. A second frame 47, comprising arms 48. 50 and cross bars 51, 52 is pivotally mounted on the shaft 46 and is secured thereon by means of a plate 53. The arm 50 has an extending finger 56, Fig. 5, and a spring 57 which normally holds The frame 47 against a stop member 58 on the arm 45. A number of arms 60, Fig. 7, having hub portions 61, 62 formed at opposite ends thereof are mounted by means of the hub portions 61 upon the shaft 46. Gears 63 having sockets formed therein are mounted on the hub portions 62 of the arms 60. Grooved rollers 67 which engage the thread being coated are screwed on to the gears 63. A spring 70 keeps the gears in position. The arms 60 and the gears and rollers 67 thereon are individually pressed to the left as viewed in Fig. 5 by springs 68. The sheaves 25, Fig. 5, are rotatably mounted on shafts secured to an arm 72 depending from a frame 73 slidably mounted in guides 75 at the back of the heating chamber. The frame 73 has a number of baffle plates 76 mounted thereon and is provided with a handle 77 by means of which it may be raised and lowered. A spring-pressed latch 78 engages in apertures in the heating chamber to hold the frame 73 in its upper and lower positions as shown in Figs. 5 and 3 respectively. Each sheave 25 is provided with a Y-shaped groove 83, Fig. 11, which is intersected at points near the bottom thereof by a series of apertures 85, and a series of pins 86 extend across the groove and form a false bottom which supports the strand 21. An auxiliary frame 87, Fig. 5, is removably secured within a groove 88 in the frame 73 and is provided with arms 91, 92. The latter carries a horizontal shaft upon which are rigidly secured a number of gears 95, Fig. 8, separated by L- shaped arms 96 loosely mounted on the shaft 93. The arms 97, Fig. 5, of the members 96 have forked ends with adjusting nuts 101 running on rotatable bolts 102 mounted in the frame 87. The arms 98, Fig. 8, of the members 96 carry rotatable gears 106, slightly larger than the gears 63, and meshing with the gears 95, and strand engaging rollers 107. A spiral gear 108 secured to the shaft 93 engages a driving gear when the frame 73 is lowered. The heating chamber 23 comprises an elongated channel member 115, Fig. 4, forming the back, -and a pair of L-shaped doors 116. Heating units 117 comprising electrical resistances are mounted in the chamber and partly surrounded by a partition 121 and a wire screen 122. A screened aperture 123, Fig. 3, is provided in the channel 115 below the lowest heating unit, and is connected to the inlet of a blower, the outlet of which is connected to a vertical conduit 128, Fig. 4, which is provided with a series of pipes 130, Figs. 3 and 4, extending into the chamber 23 at points near the heating units 117. The upper end of the conduit is closed, but a small! pipe leads therefrom to a condenser for the recovery of solvent. The capstan 28, Fig. 1, and the take up reel 30 are driven in synchronism by a chain 132 which passes also over a sprocket driven from the driving motor. In operation, the frame 73, Fig. 3, is raised to its elevated position, and the strand is threaded over the sheave 22, Fig. 1, around the sheaves 25, 26 and 27, around the capstan 28 and secured to the take up reel 30. The frame 73 is then lowered, when the end of the arm 72, Fig. 5, engages a finger 56 extending from the frame 47, rotating the latter about the shaft 46, and causing the gears 63 to mesh with the gears 106, and bringing the rollers 67 and 107 into contact to form a circular engaging surface surrounding the strarid. The circuit through the heating units is then closed and the blower started, forcing air in the direction shown by the arrows in Figs. 3 and 4. When the chamber is heated, the reels and capstan are started. The strand is coated in its passage through the coating material, and excess material is removed by the rollers 67 and 107 which are positively driven at a speed less than that of the strand, and at individually different speeds. Interchangeable sets of rollers may be provided.