US2229413A - Transformer construction and winding - Google Patents

Description

Jan. 21, 1941.

J. C. JOOST TRANSFORMER CONSTRUCTION AND WINDING Filed Nov. 3, 1938 3.9 5.9 Z @qj wzzya I INVENTOR j/m/ C. J'0057 ATTO NEY UNITED STATES PATENT TRANSFORMER CONSTRUCTION AND WINDING John C. Joost, New York, N. Y., assignor to Edwards and Company, Inc., Norwalir, Conn, a corporation of New York Application November 3, 1938, Serial No. 238,508

15 Claims. ((31. 175-356) This invention relates to transformer construc- In the accompanying drawing in which is tion, more particularly of the low voltage and shown a preferred one of the various possible emrelatively small capacity type such as is used for bodiments of the mechanical features of my inoperating low voltage devices, such as door bells,v vention,

buzzers, relays, low voltage appliances, and the Figures 1, 2 and'3 are plan views of top, side like, from the higher voltage of a household and end members, respectively, of a winding sup- 5 lighting circuit usually of 110 volts, and com port or bobbin;

cerns particularly the winding and core assembly Figure 4 is a perspective view of a conductorof transformers of this general character. anchoring member;

One of the objects of this invention is to pro- Figures 5, 6 and 7 are respectively top, front 10 vide an inexpensive, practical and reliable insuand end elevations of the assembled winding suplating and foundation structure for winding the port or bobbin; coil or coils and for mechanically anchoring and Figures 8 and 9 are plan views of illustrative electrically connecting terminal conductors to the forms or shapes of laminations that may be used end or ends of the winding or windings. Another in making up the core; 5

object is to provide a coil or winding construction Figure 10 is a top plan view of the final transthat may be constructed commercially at less cost former assembly, including the core, windings, than has heretofore been possible with known windi g supp t a d e i al-conductor mountmethods or types of construction, and also to imings or anchorag prove the electrical and mechanical efficiency of Figure 11 is a fragmentary central sectional 0 structures of this kind. Another object is to view as seen along the in of Figure provide a construction of the above-mentioned Similar reference characters refer to similar character in which assembly of the various parts parts throughout the several views in the drawmay be inexpensively and quickly carried on and ms.

in which strength of structure and reliability of P p o b e u t on of Ce ta n 25 action are achieved in a simple and effective way. e tu of y invention, let it be su ed t Another object is to provide a core or bobbin a coil or coils are to be related to an iron core, for supporting the coil or coils or upon which the such as, for example, the middle leg 20 (Figures coil or coils may be wound, that will be simple, l0 and 11) of a transformer core 2i, illustratively inexpensive, strong, durable and well adapted to of the shell typ and made p f la nat ons 39 withstand the handling accompanying quantity appropriately shaped to be pieced together, such production thereof. as the laminations 22 and 23 of Figures 8 and 9,

Another object is to provide a dependable and respect y. The Winding Should be dep ndinexpensive form of mechanical anchorage of ably supported on the middle leg 20 and well acrelatively heavy terminal conductors for electrical comm dated within the core windows 24 and 25. 35 connection with windings of fine or small or frag- Insueh ca I make p a Winding Support or ile wire, and thus to reduce breakage or damage bobbin, pr fer ly u of parts of h e nsulatin course of manufacture and in course of hanlng material, like fiber, hard rubber, or the like, dling, as well as in subsequent use of the compr f a y shaped a d conformed as shown in 4Q pleted winding or device. Another object is to Figures 2 d 3 which are D1811 e s of D ts provide a simple,,strong and reliable assembly of 27 and p c e y, e Winding o bin winding and core and of the terminal connection being preferably so constructed that two of each or connections of the winding, and capable of of these three parts are emp oy d i making it upbeing carried out in a rapid, efilcient and yet Th Da -S. eov re Shaped so that they simple manner in actual practice. Other. ob may easily n inexpensively be p nch ut of 45 jects will be in part obvious or in part pointed out Strip Sh Stock and P f rably he P 28 hereinafter. which is to function as an end member is of Th invention accordingly consi t i th fea heavier stock than the parts 26 and 27 which can tures of construction, combinations of elements, be Of e S e ge or thickness.

arrangements of parts, and in the several steps The part 28 is in general four-sided, though its 50 and relation and order of each of the same to corners may be beveled or cut off, as shown, and one or more of the others, all as will be illusit has stamped out of it a central hole 29, also tratively described herein, and the scope of the preferably four-sided, particularly where the application of which will be indicated in the 101- core part 20, as in the above-described type of lowing claims. transformer core, is in cross-section four-sided 55 and approximates a square. The hole 29 is dimensioned to be slightly greater than the crosssection of the core and suirlciently so to accommodate the thicknesses of the parts 26 and 21 and preferably, also, another part 30 of Figure 4 to be described later.

The part 28 is provided in two opposed sides of the aperture 29 with centrally disposed preferably rectangular recesses 31! and 32, and is preferably also pierced at appropriate points to permit the passage therethrough of the ends of the wires of which the winding is to be made. Thus, I may provide two relatively small holes 33 and 34, one positioned close to the hole 29 and the other positioned near the outer periphery of the part 28, and two holes 35, 36 which may be larger and also appropriately positioned, for example, as indicated in Figure 3.

I In making up and assembling the bobbin, two end members 28 are employed and they first have related to them two members 26 which are placed so as to rest adjacent their ends against the straight or unrecessed edges 3'5, 38, respectively, of the hole 29 in the two end members.

The member 26 is in general wider than the length of the edge 31 or 38 of the end member 28, and along its longitudinal edges it is cut away to provide opposed pairs of recesses or notches 39, the bottoms of each pair being spaced by the dimension equal to the length of the edge 3'! or 38, and also preferably a single pair of elongated notches 40, 40 whose bottom edges are spaced from each other by preferably the same dimension.

Two members 26 may thus be passed into the holes 29 of two end members 28, the latter being appropriately held spaced from each other (see Figure the wider end portions of the members 26 being passed preferably along a diagonal of the holes 29; the members 26 may then be moved or swung to bring one of them against the edges 31, 31 of the holes 29 of the two members 28, and the other one against the edges 38 thereof, appropriate portions of the members 28 taking into and snugly fitting in the opposed notches 39 whose width closely matches the thickness of the members 28. In Figure 5 this relationship is clearly shown. This assembly may be achieved in any suitable way and if desired a mandrel (not shown) may be slid into position between the two members 26 to hold them in spaced relation from each other and to facilitate assembly of the remaining parts.

The remaining parts preferably comprise two members 21, shaped as shown in Figure 2. The member 21 is generally rectangular and at its narrow ends is provided with tongues 4|, 4| dimensioned to snugly fit into the recesses or notches 3|, 32 in the opposed edges of the hole 29, and in its opposed longitudinal edges is provided with tongue- like extensions 42, 42 dimensioned to be snugly received in the notches 48 of the members 26.

With two end members 26 and two side members 26 assembled as above-described, two members 21 may now be assembled to the above-described sub-assembly, and this may be done by first entering one end tongue 4! into a notch 3| or 32 of one end member 28, and for that pur-' pose a snugly fitting mandrel, as above described, is helpful; in Figure 5 I have indicated in dotted lines such an initial position of a member 21 with one end tongue 4| thus entered into a notch in the left-hand end member 28. Then the member 21 may be swung in clockwise direction and pressed downwardly to snap its opposed end tongue 4| into the notch in the member 28, the parts yielding sufiiciently, even though they snugly interflt, for this purpose, whence the longitudinal tongues 42, 42 enter and rest in the notches 48, 49 of the two members 26. The other member 21 may be put into place in the same way, resulting in a structure better shown in Figures 5, 6 and 7.

The resultant structure is unitary, rigid, free from play, strong, and has its parts dependably interlocked so that all are held in place and each contributes to maintaining rigidity of construction. The notches 39 of the two members 26 hold the end members in spaced relation, members 27, with their tongues 42 fitting into the notches 48 of the members 26, and in fact with the contiguous appropriately configured edges of the members 26 and 21 in mutually overlapping relation, hold the members 28 against movement toward each other while this interrelationship causes the members 26 to hold the members 21 against movement toward each other. The tongues 4! of the members 21, in taking into the notches 3|, 32 of the end members, cause the latter to hold the members 21 against outward movement and thus to insure the maintenance of the above-described mutually overlapping relationship of the contiguous edges of the members 26 and 21. Also, the end edges of the members 21 to either side of the tongues 4| are butt-ended against the faces of the members 28 and thus prevent the rightangled relationship between the end members 28 and the members 26 from being changed.

The construction is light yet very strong and the individual parts are easily and inexpensively stamped and assembly is simple and rapid, it being noted that I make it possible to eliminate the use of tools or securing devices or other cumbersome means of fastening or securing. The

interlocking or mutual overlapping of the contiguous edges of successive members 26 and 21 also insures that throughout the length thereof no inward yielding takes place particularly under any tensioning or tightness of insulated wire as the latter is subsequently wound onto the bobbin and between the end members 28; the latter also are dependably held against movement away from each other and thus dependably resist any tendency on the part of the wire being wound to push them outwardly.

Upon the resultant bobbin and between the end members 28, the coil or coils may now be wound. Where the device is to function in a transformer, as above described, two coils are wound on the bobbin, one of them, the high voltage winding, usually 110 volts, being usually of relatively fine wire which, depending upon design and power requirements, may range, for example, from No. 25 to No. 40, or so. This winding is preferably wound onto the bobbin first and any standard or usual practice may be employed in the winding process. One end of the winding is preferably brought out through a hole 33 (Figures 3 and 7) in one end member, and when the required number of turns is wound, the remaining end is brought out through a hole 34 in the opposite end member.

The low voltage winding usually comprises less delicate or fragile wire and a lesser number of turns. Either winding may be wound first and illustratively the low voltage winding may be wound on top of the high voltage winding, again using any standard or known practices in effecting the winding and superimposition of one winding in layers upon the other. Being of heavier wire, the ends of the low voltage winding are brought out through an opening 35 in one end member and an opening 36 in the other end member, it being noted that these ope i s are larger to accommodate the heavier wire, suitable lengths of end portions being left free for ultimate connection to appropriate binding posts (not shown).

The ends of the low voltage winding are brought out through the above-described openings, but the latter are so positioned and selected that the wire ends come out below the lower member 26, as viewed in.Figures 6 and 7, while a similar selection is made of the smaller openings to bring the fine and delicate ends of the high voltage winding out above the upper mem ber 26, as viewed in Figures 6 and 7.

Now one of the difficulties heretofore encountered and which my invention effectively and dependably overcomes is the connection of these fine end wires to suitable and heavier terminal conductors or wires, usually heavily covered with insulation. Heretofore such difliculty has included not merely coping with the delicacy of the operation but also with the mechanical obstacles presented and which frequently resulted in breaking of the fine wire. Having completed the structure as thus far described, noting first that the end edges of the members 2G are provided with notches 44 of a depth such that their bottoms are appropriately spaced from the outer faces of the end members 28 (see Figure 5), I next put into position the member 30 of Figure 4; that member is preferably made of sheet metal, is generally rectangular, and is provided with upwardly bent tongues 45 of suitable width, the notches 44 being of a width snugly to accommodate the tongues 5.

Member 30 is slid into the hollow bobbin and brought flush up against the upper member 26 to the outer side of which the fine wire ends of the high voltage winding extend, the tongues 45 passing upwardly through the notches 44 so that they project upwardly from the two end portions of the member 26, as is clearly shown in Figure 6.

Suitable lengths of heavy wire, usually No, 14, usually heavily insulated as is typical of 110-volt circuits, as indicated at 46 in Figure 10, are now provided but with their extreme end portions 47 bared; they are so placed as to bring them in between the ears or tongues 45 and the end members 28 and thus rest against the member 28 which, it is to be noted, is backed up on its under side and including those portions thereof that project beyond the end members 28 by the main body part of the sheet metal member 30. This relationship is also well shown in Figure 11-. The tongues 45 are now bent over and down upon the insulated conductors 46, respectively, by any suitable means, and sunicient pressure is applied so that the insulated conductor is securely clamped between the tongue and the sheet metal part 30, thus giving this relatively heavy and stifl conductor a strong and durable mechanical anchorage and holding the bared ends 41 rigidly against displacement or movement. The same operation also fixes the member 30 in position which, as shown in Figure 11, becomes inescapably interlocked-with the member 26.

To these bared ends the bared end portions of the fine wire ends of the high voltage winding are now soldered, as indicated in Figure 10, preferably first taking a few turns of the fine wire about the bared end portions of the heavy wire. The resultant electrical connection is, due to the strong mechanical anchorage of the heavy terminal wires 48, safeguarded against breakage, particularly during the subsequent handling of the assemblage.

The assemblage may now be assembled to the core which, as above noted, may take the form of the shell type where the winding is to function in a transformer. the core being usually laminated and assembled out of appropriately shaped laminations like the laminations 22 and 23 of which the lamination 22 provides the middle core leg 20, it being understood, of course, that the laminations 22 are assembled to the completed winding structure alternately from the two end of the latter. Thus, one lamination 22 has its core leg 20 entered into the hollow bobbin from one end thereof, while the next lamination 22 has its core leg 20 entered into the bobbin from the opposite end of the latter, a lamination 23 in each instance completing the individual magnetic circuits. The core may thus be built up to the desired extent, preferably snugly to fill up the space within the bobbin, suitable wedging means being employed, if desired, to secure tightness of ultimate interfitting. The core may thus be made to coact with the parts of the bobbin to hold the parts assembled. Thereafter, the completion of the transformer construction may be carried on in any suitable way, as by providing a suitable casing or mounting therefor.

Thus, it will be seen that there has been provided in this invention a winding support and winding structure and transformer construction in which the various objects hereinbefore noted, together with many thoroughly practical advantages are successfully achieved. It will be seen that the construction is simple, inexpensive, and thoroughly dependable in action and well adapted to meet the conditions of hard practical use. Bobbin parts can be inexpensively stamped, as is also true of the sheet metal part 30 of Figure 4,

and it will be seen that assembly thereof can be carried on quickly and inexpensively and with thoroughly reliable results.

As many possible embodiments may be made of the mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinabove set forth, or shown in the accompanying drawing, is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. A construction of the character described comprising a core with a winding thereon made of relatively small wire, said winding being supported by a bobbin made of insulating material having a sleeve-like portion through which the core extends and about which is the winding and end members at the respective ends of the winding, said sleeve-like portion having extensions beyond said end members, a sheet metal member interposed between said core and said sleeve and having bendable portions capable of being bent respectively over said extensions, two relatively heavy insulated lead wires having their insulated end portions resting each against one of said extensions and each having one of said bendable portions bent over the insulated end portion to clamp it against the extension, for thereby anchoring said lead wires against said extensions, the ends of said relatively small wire winding being electrically connected respectively to bared ends of said lead wires, the anchorage of which protects said relatively small wire ends against breakage and the insulation of said insulated lead wires against which said bendable portions are bent preventing said sheet metal member from short-circuiting said two lead wires and from grounding either of them to said core.

2. A construction as claimed in claim 1 in which the extensions of said sleeve-like portion have cut away parts through which the bendable portions of said sheet metal member extend from the core side of said extensions to the opposite side thereof.

3. A construction as claimed in claim 1 in which said sleeve-like portion of the bobbin is made up of a plurality of sheet-like members, said end members having polygonal openings therein through which said sheet members extend, said sheet members and said end members having respectively interfitting parts, one of said sheet members being longer than the spacing between said end members and projecting beyond each of the latter, thus to provide said extensions.

4. A construction as claimed in claim 1 in which said sleeve-like portion of the bobbin is made up of a plurality of sheet-like members, said end members having polygonal openings therein through which said sheet members extend, said sheet members and said end members having respectively interfitting parts, one of said sheet members being longer than the spacing between said end members and projecting beyond each of the latter, thus to provide said extensions, said longer sheet member having in its projecting ends slots for the passage therethrough oi. the bendable portions of said sheet metal member.

5. In construction of the character described, in combination, a bobbin made of insulating material and comprising two axially spaced end members and an intervening sleeve-like portion for receiving on the latter and between said end members a winding, said sleeve-like portion being extended beyond both of said end members to provide end extensions, and a conductorclamping element extending lengthwise of said sleeve-like portion and having bendable end members related respectively to said end extensions and bendable relative to the latter to hold itself in assembled relation to said sleeve-like portion.

6. In construction of the character described, in combination, a bobbin made of insulating material and comprising two axially spaced end members and an intervening sleeve-like portion for receiving on the latter and between said end members a winding, said sleeve-like portion being extended beyond both of said end members to form end extensions, each end extension hav ing a slot therein, and a sheet metal member extending through said sleeve-like portion and provided with bendable parts extending through the slots in said extensions for clamping conduc tors against the latter and for holding said sheet metal member in place.

7. In construction of the character described, in combination, a bobbin made of insulating material and comprising two axially spaced end members and an intervening sleeve-like member for receiving on the latter and between said end members a winding, a conductor connected to said winding, one of the members of said bobbin having exposed opposed end portions with a bendable conductor-clamping element extending flatwlse thereagainst, said clamping element hav,- ing bendable end members respectively related to said opposed end portions and respectively bent over the latter to hold itself assembled thereto, said conductor being related to one of said bent elements and by it clamped and anchored against movement.

8. In construction of the character described, in combination, a bobbin made of insulating material and comprising two axially spaced end members and an intervening sleeve-like portion for receiving on the latter and between said end members a winding, said end members having four-sided apertures to form two pairs of opposed edges, said sleeve-like portion comprising two pairs of sheet members one pair of which is longer than the desired spacing between said end members and each of said one pair having opposed recesses into which opposed edges of said two end members are received to hold the latter in spaced relation, the other pair of sheet members and said end members having interfitting parts in the form of interfitting tongues and recesses and the contiguous edge portions of all of said sheet members having interfitting parts whereby said sheet members are mutually supported against movement inwardly toward the axis of said bobbin, said end members holding said sheet members against movement outwardly from said axis, one of said sheet members extending at both ends beyond said two end members to form two end extensions, two relatively heavy terminal conductors having electrical connection with the ends of said winding, and a single bendable clamping means extending along said extended sheet member to the respective ends thereof and having clamping means at its two ends for respectively clamping the ends of the extended sheet member and said two heavy terminal conductors.

9. In construction of the character described, in combination, a bobbin made of insulating material and comprising two axially spaced end members and an intervening sleeve-like portion for receiving on the latter and between said end members a winding, said end members having four-sided apertures to form two pairs of opposed edges, said sleeve-like portion comprising two pairs of sheet members one pair of which is longer than the desired spacing between said end members and each of said one pair having opposed recesses into which opposed edges of said two end members are received to hold the latter in spaced relation, the other pair of sheet members and said end members having interfitting parts in the form of interfitting tongues and recesses and the contiguous edge portions of i all of said sheet members having interfitting parts whereby said sheet members are mutually supported against movement inwardly toward the axis of said bobbin, said end members holding said sheet members against movement outwardly from said axis, at least one 01' said sheet members being extended at at least one end beyond an end member, a relatively heavy terminal conductor in electrical connection with said winding, and a sheet metal member resting against said extended sheet member and having two spaced clamping portions bendable against the opposite face of said extended sheet member, at least one of said bendable portions engaging the extension of said sheet member and also clamping said terminal conductor thereto.

10. In construction of the character described, in combination, a core and a winding thereabout, a sheet-like member of insulating material and a sheet metal member interposed between said winding and said core and both extending beyond an end of said winding, said sheet metal member being between said sheet member and said core, and a terminal conductor for said winding and in electrical connection with the latter, said terminal conductor being clamped in position by a bent-over portion of said sheet metal member and said bent-over portion coacting to hold said sheet metal member against movement relative to said core.

11. In construction of the character described, in combination, a winding support of insulating material comprising two axially spaced end members between which the winding is received and an insulating member extending between said end members for underlying the winding, said lastmentioned member being extended beyond both of said end members to provide end extensions, and a sheet metal member underlying said member and its end extensions and having portions bent over said end extensions, and a conductor, one of said sheet metal portions engaging and clamping said conductor.

'12. In construction of the character described, in combination, a winding support of insulating material comprising two axially spaced end members between which the winding is received and an insulating member extending between said end members for underlying the winding, a conductor, and a sheet metal member underlying said mem her and having end portions extending beyond said end members, said end portions of said sheet member being bent relative to said bobbin to hold 40 itself assembled thereto and at least one of said portions engaging and clamping said conductor.

13. In construction 0! the character described, in combination, a winding support of insulating material comprising two axially spaced end members between which the winding is received and an insulating member extending between said end members for underlying the winding, said lastmentioned member being extended beyond both of said end members to provide end extensions, and a sheet metal conductor-securing member underlying said member and its extensions and having bent end portions overlying said extensions for' holding said sheet metal member and said insulating member together.

14. In construction of the character described, a sub-assembly comprising a bobbin made of insulating material and comprising two axially spaced end members and an intervening sleevelike portion for receiving on the latter and between said end members a winding, said sleevelike portion being extended beyond both of said end members to form end extensions, and a sheet metal member extending through said sleeve portion and provided with bendable parts at its ends respectively overlying said end extensions for holding said sheet metal member in place and for clamping a conductor by at least one of said bendable parts.

15. In construction of the character described, in combination, a winding support of insulating material comprising two axially spaced end members between which the winding is received and an insulating member extending between said end members for underlying the winding, said member being extended to expose at least two edges thereof, a lead wire, and a sheet metal member lying along one face of said extended member and having clampingportions extending about said edges to the other face thereof for holding itself assembled .to said extended member and for clamping said conductor in position.

, JOHN C. J OOST.

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