Patent GB-191518103-A (GB)
Title: Improvements in Filament Winding Machines.
IPC: B21F3/04
Filed: 1915-12-28
Abstract: 18,103. Westinghouse Metal Filament Lamp Co., [Assignees of Eisler, C.]. Dec. 29 1911, [Convention date]. Wire, covering by winding.-A machine for helically coiling metal filaments comprises a spool of mandrel wire, a rotating carrier for a supply of filament wire which is thus wound on the mandrel wire, and a positively driven drum receiving the mandrel wire with the wound filament. At intervals, the speed of the drum is increased to produce openly-wound portions between closelywound filament sections, for attachment to supports, and at greater intervals, the speed is increased for a longer period to form coersely-coiled lengths for the end of the filaments. A filament to be used in a vertical position may be more openly wound towards its lower end to prevent shortcircuiting owing to sagging. The filament wire is electrically heated while being wound, a cherryred heat being suitable for tungsten. Subsequently, the mandrel wire, which may be of copper or steel, may be cut into filament lengths and dissolved by acid. In the construction shown, the mandrel wire 1, Fig. 2, from a spool 2, which is carried by vertically adjustable bearings, passes through an eye 35 to a tensioning-device consisting of serrated blocks 36, 37 optionally faced with fibre or like material to increase friction. The upper block 37 is mounted on a vertical stem passing loosely through a bracket 40 and surrounded below the bracket by a compression spring and above the bracket by adjusting and lock nuts. On leaving the tensioning-device, the mandrel wire passes through a guiding quill tube 4, which, with the tensioning-device, is carried by a vertical rod adjustable in the end of an horizontal adjustable bar. The mandrel wire next travels through a central opening in a rotating disk 6 to the take-up drum 7. A drilled jewel may be fitted in the opening in the disk. On the face of the disk 6 is a pin bearing a filament spool 9 held between a compression spring 62 and screw 61. An arm 10, also mounted on the disk 6, carries interchangeable plates 65 for guiding the filament wire near the mandrel wire. Jewels with apertures of different sizes may be fitted in the plates, except for very small and very large filament wires. A weight 58 on the disk 6 balances the filament spool and other attached pacts. The disk 6 is mounted on, but insulated from, a spur-wheel 50 gearing with a wheel 55 on a main shaft 14, which is driven through variable-speed pulleys 28. Current from a transformer and rheostat is conveyed to the edge of the disk 6 by a spring-urged brush, so that the filament wire is heated between the spool 9 and the mandrel wire. If the spool 9 is of wood instead of metal, the filament wire is carried partly around a metal pin, pulley, &c. on the disk 6. Electric connexion from the mandrel wire is made through the frame. The vertical shaft 80 of the take-up drum 7 slides in two bearings, from the lower of which it is separated bv a loose sleeve 84, Fig. 6, carrying a bevel-wheel 85. A bevel-pinion meshing with this wheel is continuously driven from a worm 100, Fig. 2, on the main shaft 14, through toothed wheels 103, 104, 107, the middle one of which is carried by an angularly adjustable slotted arm to allow of changing one of the other wheels and thus altering the speed of the bevel-wheel 85. Worm gear may replace the bevel-gear. Six pawls 92, spaced on the upper face of the bevel-wheel so as to allow minimum back-lash, normally drive a ratchet-wheel 86 fast on a sleeve 87 splined to the drum shaft 80. The sleeve 87 is kept in place by the lower bearing of the drum shaft and by a tube 97 extending to the upper bearing. Other pawls 94 engaging the same ratchet-wheel are mounted on the lower s de of a disk 93 loose on the sleeve 87. An arm 110, Fig. 2, integral with the pawl disk 93 carries at its end a roller 119, which is held in contact with an internal camsurface of a disk 113 by a spring bearing on the arm 110 within a slotted guide 118 for the arm. The cam 113, Fig. 7, is made with steps 120 for causing rapid motion of the arm 110, pawl disk, and drum shaft 80 at intervals corresponding to the length of the filament sections, and with a larger and more inclined step 121 for similarly forming the loosely wound filament ends. One revolution of the cam 113 may correspond to one filament, as shown, or to two shorter filaments. The cam may also be shaped so as to vary the pitch of winding in each section. The cam 113 is attached to a disk 114 on a shaft driven from a worm 125 on the main shaft 14 by means of bevel-gear and toothed wheels 131, 132, 135, the middle wheel being mounted on a slotted angularly adjustable arm 134 to allow of exchanging one of the other wheels. A similar set of three wheels conveys motion from a worm 147 on the lower sleeve 84, Fig. 6, surrounding the drum shaft 80, to a heart shaped cam 141. A block 140 loose on the drum shaft is slotted to embrace this cam, which engages a roller in the block. A cross bar and springs 157 draw the block downwards. The drum shaft 80 is thus reciprocated at any desired speed so as to coil the mandrel wire and filament in layers on the drum 7. Bearing on the coils on the drum is a roller carried by a vertical shaft attached to a spring- urged horizontal arm. By exchanging gear-wheels, the pitch of the filament coil and the number of turns can be varied, and the machine adapted for mandrel wires of different sizes. Reference is made to a method of opening out a continuous close filament coil at intervals by means of a hot wire or blade.