Patent GB-190811170-A (GB)
Title: Improvements in and relating to Induction Coils.
Inventor: BROOKS JOHN BOULTBEE
Filed: 1908-05-22
Granted: 1909-05-20
Abstract: 11,170. Brooks, J. B., and Alston, F. H. May 22. Transformers.-Relates to sectionally - w o u n d induction coils and to apparatus for winding the same. The wire is passed from the top of one section to the bottom of the next section, and between the insulating and divisional partitions, so that the wire passing between the partitions is c o mpletely insulated from the higher-potential part of the wire at the top of the next compartment, and so as to admit of the continuous winding of the ccil. The sections comprise a series of inner insulating-disks 3 with slits 8 at the outer peri. phery, and a series of outer insulating-disks 4 with slits 9 at the iuner periphery ; the disks 3, 4 are separated by rubber distance-rings 7, the wire being wound in the space 6 between the disks. In building up the coil, the wire is first threaded through a number of disks 4. One or more of these disks 4 are placed against an end cheek on the insulating-tube 5 separating the primary from the secondary, a ring 7 is placed against the disks 4, and an inner disk 3 against the ring 7, the parts being held close together in position by a false cheek. The wire first passing through a bath of melted paraffin wax &c. is wound in the space between the disks 3, 4. When the section is filled, the false cheek is removed, and the wire is passed through the outer slit 8 in the disk 3, another disk 4 is slipped on the tube 5, the wire is passed between the disks 3, 4 and through the inner slit 9 in the disk 4, and another ring 7 and disk 3 are slipped on the tube 5 together with the false cheek, and this section is then filled with wire, the same process being repeated until the whole coil is wound..Means are provided whereby the depth of the wire in each section can be regulated. The wire 10 passes from a bobbin, Figs. 4 and 5, provided with a brake comprising a pivoted lever 82 provided with an upright rod 87 engaged by the wire, which when taut keeps the brake shoe 84 away from the drum. When the wire is slack, a spring 85 brings the shoe against the'drum and stops it. The wire passes through a hollow tube 15 carrying several disks 4, and through a bath of melted paraffin wax &c. heated by hot water between a double bottom ; it then passes over pulleys 21, 23, 24, the superfluous wax being thrown off by centrifugal force and caught by guards 25, 26, and between a forked rod 58. This rod guides the wire during winding and is given a reciprocating motion by a rod 60 connected to a spring 61 pressing against a face-cam 62 driven by reduction gear 64, 65 from the spindle 28 of the winding-apparatus. The latter is provided with fast and loose pulleys 30, 31, a fly-wheel 33, and a forked lever 32 to shift the belt. The mandrel is screw-threaded at 34, and a nut 35 provided with flanges 36, 37 works on the screw - thread. The disk 37 serves to rotate the nut along the mandrel, the pitch of the screw-thread being equal to the width of the coil sections. The sleeve 35 is provided with a spring catch adapted to engage a groove 42 in the mandrel 34. The disk 36 serves as a false cheek to support the coil sections. To wind the coil, the insulating-tube 5 is placed on the plain end of the mandrel 28 and is inserted in a recess 45 in the nut 35. A sleeve 50 provided with a flange 51 serving as a false cheek to the coil sections is slid over the tube 5, and is detachably held in position by a spring catch 52. To ensure a tight fit, the tube 5 is pressed outwards by a spring 46 and a ball 47 engaging the tube 5 and inserted in a hole in the mandrel 28. The insulating-disks 3, 4 and rubber rings 7 are previously placed on the mandrel between the cheeks 36, 51, and the first section is wound. The sleeve 50 is removed and the wire disengaged from the guide-pulleys in the wax bath and from the guide-rod 58. Another disk 3, ring 7, and disk 4 are slid on the tube 5, and the sleeve 35 is rotated once. The sleeve 50 is slid over the tube 5 and the wire is engaged with the guide-rod and pulleys. The coil section is in the same position as the first section, and is filled similarly. This is repeated throughout the whole length of the coil, when the ordinary end cheeks are fixed on. Means to stop the machine when the section has been filled to the required depth comprises a follower 77, wiping over the wire in the section being filled and hinged to one end of a lever 78 pivoted at 79, the other end 80 of the lever being adapted to contact with a screw 74 and to complete the electric circuit of a magnet 73 adapted to stop the machine. The screw 74 is carried by one end of a pivoted lever 75, the other end of which 96 engages a profile plate 88 sliding on a bar carried by brackets 91, 92, and having the same longitudinal section as the induction coil. A plate 93 attached to the profile plate 88 engages a groove 95 in the sleeve 35, and as the latter moves along the mandrel as the winding of the sections proceeds, so the profile plate 88 causes the screw 74 to move towards or away from the lever 80 and to cause the machine to stop when the required depth of winding has been reached at that part. The stopping- means comprise an electro-magnet 73, which, when energized, trips a catch 71 at one end of a lever 68 pivoted on the same pivot as the forked lever 32, the other end of the lever 68 compressing a spring at 69, which, when the catch. 71 is tripped, moves the levers 68, 69 and so the belt to the loose pulley, thereby stopping the machine. When the machine is driven by an electric motor, the arm 80 may be arranged to open the motor circuit. Instead of the coil sections comprising two disks, they may comprise four or more ; also the wire may pass through the wax bath before passing through the tube 15. According to the Provisional Specification, the mandrel may be driven by hand or power, and the inner cheek may be fixed and the sleeve of the false cheek may be provided with a spring catch adapted to engage with a series of transverse notches or teeth on the mandrel separated by a distance .equal to the width of a coil section. The wax bath may be heated by a burner and the stripper may consist of a piece of rubber cut or slit for a short distance, the wire passing through the slit; or the wire may pass over or between one or more wicks dipping into the wax. The stripper and guides-are preferably connected together so that they can be traversed along the length of the bath by means of a screw or worm carrying a nut attached to the guides and stripper. The guides may comprise a vertical guide on the edge of the bath and another guide carried by a hanging bracket, which may also carry the stripper. The mandrel may slide through the bearings, or the whole frame carrying the bearings may move, a spring catch and a series of notches being arranged at the other end of the mandrel as before. To stop the apparatus when the section is filled, the follower may be arranged to release a clutch, either electrically'or mechanically, so as to disconnect the source of power from the winder. When the inner cheek is adapted to rotate on the screwed mandrel, the cheek may be separate from the nut.