US3215965A

US3215965A - Layer wound inductance coil

Info

Publication number: US3215965A
Application number: US199727A
Authority: US
Inventors: Steven J Subik
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1962-06-04
Filing date: 1962-06-04
Publication date: 1965-11-02
Anticipated expiration: 1982-11-02

Description

Nov. 2, 1965 5. J. SUBIK 3,2

LAYER WQUND INDUCTANCE COIL Filed June 4, 1962 INVENTOR STEVEN J. SUBIK,

IS ATTORNEY.

United States Patent 3,215,965 LAYER WOUND INDUCTANCE COIL Steven J. Subik, North Syracuse, N.Y., assignor to General Electric Company, a corporation of New York Filed June 4, 1962, Ser. No.199,727

1 Claim. (Cl. 336-408) This invention relates to layer wound inductance coils and more particularly to an improvement in layer wound inductance coils for facilitating the manufacture of such coils.

- Layer wound inductance coils find advantageous use in many applications. Because of their reduced cost relative to the cost of pancake type coils having a universal Winding, the layer wound coil has recently replaced the former type coil as the tertiary winding in the horizontal output transformer in some television receivers.

V For this and other similar applications, a known economical arrangement of the layer wound coil comprises a narrow tubular pressed paper coil form having a continuously wound coil of relatively fine polyurethane insulated wire, such as No. 36 AWG gage, wound thereupon. The coil is arranged in multiple relatively narrow layers having a plurality of turns of wire in each layer. The'layers are radially disposed from a longitudinal axis of the form and an insulating medium, such as a strip of paper, is positioned between each of the layers. The assembled coil, as described, resembles a thin disk.

' A manufacturing difiiculty is experienced when layer .wound coils of the type described are machine fabricated in quantity. In one manufacturing arrangement, a plurality of coils are simultaneously wound side by side upon a single tubular coil form. The individual built up coils are subsequently separated by a cutting operation. An initial turn of fine wire of each coil, which is a terminal lead for the coil, lays adjacent to the form and is buried by the successively wound layers and burrs created on the form by the cutting operation. Prior attempts for recovering this lead have consisted in wedging a tool between the form and a first insulating paper layer and A further object of this invention is to provide a layer I wound inductance coil in which a buried initial turn of wire representing a terminal lead may be easilyv recovered from beneath successively wound layers.

In accordance with the present invention, a layer wound coil is provided having a coil form and a coil of relatively fine insulated wire which is continuously wound upon the form in a plurality of radially disposed insulated layers. A pair of terminal leads for the coil consists of an easily accessible end turn on an outer layer of the coil and an initially wound turn of the coil which is buried by the coil layers. The coil form includes an access passageway to the buried turn for permitting insertion of a tool for grappling and leading out the buried turn to a point without the coil.

In one embodiment of the present invention, a tubular coil form is provided having a longitudinal groove in an outer surface of the form. A first turn is helically wound in a longitudinal direction upon the form and traverses the groove in the surface. A segregating medium for facilitating grappling of the lead is positioned on the turn in the area of the groove intermediate the lead and successively wound turns of the coil.

Patented Nov. 2, 1965 Further objects, features and the attending advantages of the invention will be apparent with reference to the following specification and drawings in which:

FIGURE 1 is a perspective view of an automatic coil winding machine for winding layer wound coils,

FIGURE 2 is a front view of a conventional layer wound coil which has been wound on the machine of FIGURE 1,

FIGURE 3 is a side view of the coil of FIGURE 2,

FIGURE 4 is a front view of a coil form utilized in an embodiment of the present invention,

FIGURE 5 is a side view of the form of FIGURE 4,

FIGURE 6 is a side view of a fabricated coil embodying the present invention,

FIGURE 7 is an enlarged front view of a coil form illustrating features of the present invention, and

FIGURE 8 is a side view of the form of FIGURE 7.

In order that the features of this invention may be fully appreciated, the fabrication of a layer wound coil of the type referred to will be briefly described with reference to FIGURE 1. In the manufacturing arrangement illustrated therein, a tubular stock 11 of pressed paper having a suitable length for fabricating a plurality of coil forms therefrom is mounted horizontally intermediate drive and support mandrels 12 and 13 on a bed 14 of a coil winding machine 15. A plurality of spools of wire, not shown, are stationed relative to the, machine for providing the necessary wire 16 for simultaneously winding individual coils 17 at equally spaced positions along the stock. A wire guide mechanism consisting of a support structure 18 and having multiple wire guides 19 positioned on a cross bar 20'for feeding wire to and guiding the winding of the coils 17 is positioned on a track 30. The support 18 is driven with a slow reciprocating motion along the track by means, such as a rotating screw driven shaft, not shown. In addition, an apparatus for automatically measuring, cutting, and inserting a strip of insulating paper between successively wound layers of the coils being fabricated is provided. For purposes of clarity, FIGURE 1 illustrates only a cutting table 31, two

cutting blades

32 and 33 and a strip of paper 3 being fed to the apparatus.

In operation, a tubular stock is mounted between the mandrels 12 and 13 and a lead wire 16 from each spool of wire is initially secured at equally spaced positions along the stock by an adhesive medium. Sufficient spacing is provided between immediately adjacent positions for permitting the build up of a desired width of the coils and for allowing subsequently assembled coils to be separated by a cutting operation without damaging the fabricated windings. The stock 11 is automatically rotated .about its axis by the drive mandrel 12 having a prime mover not shown, while the wire guide is simultaneously driven parallel to the axis of the stock, by a prime mover not shown, for causing a single layer of a desired number of turns to be wound at each coil position. When a layer has been wound, a strip of insulating paper having a width equal to the length of the stock is automatically measured, cut from the strip 34, and positioned on the stock. The wire guide then reciprocates and a succeeding layer for each coil is wound upon the insulating paper as each of the wires 16 traverse the stock 11 in the opposite direction. The described winding operation is then successively repeated until a desired layer wound coil configuration has been built up. Each loose coil end-lead is taped to its coil body and the wires 16 are then severed. The entire assembly is removed and the individual coils are separated from the assembly by cutting the assembly in a plane perpendicular to the longitudinal axis of the stock.

A single coil 35 which has been manufactured by the above described procedure is shown in the views of FIG- URES 2 and 3. The coil 35 includes a form 36, the built up layers of wire and insulating papers which are radially disposed from a longitudinal axis 37 of the form, an outer layer of wire turns 38, a terminal lead 39, and a strip of tape 40 which secures the lead 39. In order to satisfy a variety of requirement-s, namely, to provide structural coil support, to provide the desired electrical characteristics for the coil, and to provide the necessary clearance for severing individual coils from the above described assembly, the width of the assembled coil 41 is generally greater than the width of each layer of turns 42. Consequently, the initial turn of fine wire 16 which constitutes a terminal lead for the coil 35 and which was secured to the stock 11 on the winding machine 15 is buried beneath the multiple layers of insulating paper and wire turns and behind a flared edge of the form created by the cutting operation. A pressure exerted on an outer surface 43 of the form by the successively built up layers of paper and wire turns makes this turn relatively inaccessible and difiicult to retrieve. As previously indicated, prior attempts at recovering the buried lead have consisted in wedging a tool between the outer surface 43 of the form and an adjacent layer of paper and turns 44 and probing for the hidden lead.

In accordance with a feature of the present invention, a coil form is provided for the coil which includes access to the buried lead for a grappling tool. FIGURES 4 and illustrate a coil form 50 for a single coil having a longitudinal groove 51 in a thickness of the form and which communicates with the outer surface 52 of the form. FIG- URE 6 illustrates an assembled coil 53 of the-type described embodying the invention. A grappling tool may be inserted in the groove 54 of the coil 53 to recover the buried lead in a minimum amount of time and without causing damage to the coil. The coil 53 may be conventionally manufactured by the above described procedure by providing the stock 11 of FIGURE 1 with a groove extending longitudinally on the length of the stock.

In accordance with another feature of this invention, a segregating means is provided for facilitating the grappling of the desired hidden lead without interfering with other turns of the coil. Referring to FIGURES 7 and 8, a single coil form is shown having a groove 55 and the first two and one-half turns of a coil wound upon the form. A segregating means 56, which may consist of an adhesive tape preferably having an adhesive surface positioned away from the surface of the form, is positioned between a length of lead wire 57-58, which is drawn along the lower surface of medium 56 until a portion of wire 57-58 is grasped without interfering with i or grasping other turns of the coil.

In accordance with another feature of this invention,

the initial lead length 57-58 is wound helically along the surface of the form 55 in the direction of the longitudinal axis 60 of the form. Thus, when a grappling tool is inserted in the groove 55 from side 61 of the form, wire section 62 will first be contacted and the entire lead 57-58 is retrieved by pulling wire section 62. This is more advantageous than first. grappling a segment 63 of wire lead 57-58, in that the necessary operator motions for recovering the entire lead are consequently reduced.

The above described features may be incorporated into the automatic coil winding procedure which was described hereinbefore by utilizing a stock 11 with a groove running longitudinally for its length, already referred to, by taping the lead wires 16 on an outer surface of the stock 11 at an angle 6 from the groove as indicated in FIGURE 8 and in FIGURE 7 by the tape 64, by winding two and one-half turns of lead wire or as many turns as are necessary to provide a desired lead length, and by then positioning an insulating medium over the groove and securing it by any convenient method, as by winding additional turns over it to secure it in place.

Although I have described the present invention with relation to a pressed paper coil form, other coil form material may be utilized and incorporate the invention. For example, the coil form may consist of phenolic or plastic and the slot 51 indicated in FIGURE 5 may be incorporated into the form during a molding fabrication process.

While I have illustrated and described and have pointed out in the annexed claim certain novel features of my invention, it will be understood that various omissions, substitution-s and changes in the forms and details of the system illustrated may be made by those skilled in the ,art without departing from the spirit of the invention and thescope of the claim.

What I claim as new and desire to secure by Letters Patent of the United State-s is:

An inductor comprising: a cylindrical tubular paper coil support element having an outer surface, said outer surface having a groove extending longitudinally in the surface; a coil of relatively fine insulated wire wound upon said support element, said coil comprising an initial turn wound adjacent to said surface and transverse to said groove and succeeding turns wound in insulated radially disposed layers, means for separating a segment of said initial turn from succeeding turns in the area of said groove comprising a strip of insulating material positioned upon said initial turn intermediate said initial and succeeding turns and covering a surface area of said support including said groove whereby said initial turn may be retrieved from said coil through said groove .to form a terminal lead.

References Cited by the Examiner UNITED STATES PATENTS 644,311 2/00 Anderson 336-192 X 2,122,894 7/38 Sager 336-192 2,166,841 7/39 Helgas-on et al 336-l92 2,859,000 11/58 McLellan 242-125.2 2,985,950 5/61 Du-man 29155.57

' 2,999,990 9/61 Zack 336-208 JOHN F. BURNS, Primary Examiner.