US 2633481 A
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March 31, 1953 D. MEEKS 2,633,481
TERMINAL. BOARD FOR MULTITAP TRANSFORMER CONSTRUCTION Filed Nov. 9, 1949 INVENTOR. N440 L. fifisE/(S,
Patented Mar. 31, 1953 UNITED STATES PATENT OFFICE TERMINAL BOARD FOR MULTITAP TRANSFORMER CONSTRUCTION Application November 9, 1949, Serial No. 126,373
1 Claim. 1
This invention relates to multi-tap transformers. More spec ficay it relates to a method of construction and to a transformer having a plurality of taps and to the manner of making the connections between the taps and the leads.
Modern power transformers as used in various installations, asfor example in television sets, may have a considerable number of taps. Quite commonly such transformers may have up to sixteen and perhaps even more taps. The purpose of thetaps, of course, is to provide a number of different voltages for different specific purposes from a common winding on a common core.
In the past, such transformers have been wound with a-layer of insulating material between the convolutions of the coil, and the taps have been brought out at the appropriate places. The leads have then been simpl soldered to the taps to complete the construction of the transformer. The various soldered connections are generally quite close together, and if they become bent in one direction or the other arcing is very likely to occur since many of the taps will be carrying voltages on the order of several thousand volts.
Another difliculty that has been encountered in the construction of such multi-tap power transformers is the great danger of error in making the connection. The connections are usually made to coded leads to facilitate the installation of the transformer in the particular set. If, of course, the coded leads are connected to the improper taps, the code system breaks down.
With the foregoing considerations in mind it is an object of my invention to greatly simplify the construction of multi-tap power transformers. It is another object of my invention in connection with the simplification of construction to reduce the likelihood for error in making the connections between the taps and the coded leads.
It is yet another and highly important object of my invention to provide a construction whereby the soldered connections between the taps and the leads are restrained from movement so as to reduce to a minimum the likelihood of arcing and thereby to give a transform r having a. longer useful life.
It is still another object of my invention to provide a lead connection member for multi-tap transformers wherein the coded leads are secured to a lead connection member so that the lead connection member in its entirety can be assembled to the transformer, thus simplifying the connection of the taps to the leads.
These and other objects of my invention which I shall set forth in more detail hereinafter or which will become apparent to those skilled in the art upon reading these specifications, I accomplish by that certain construction and ar rangement of parts and by that sequence of method steps of which I shall now describe an exemplary embodiment.
Reference is made to the drawings forming a part hereof and in which:
Figure l is a perspective view of a lead connection member showing several leads secured thereto in accordance with my invention.
Figure 2 is a cross sectional view of the same taken on line 2-2 of Figure 1 on an enlarged scale.
Figure 3 is a perspective view of the coil of a multi-tap transformer, showing the taps ready for connection.
Figure 4 is a fragmentary perspective view on an enlarged scale showing the lead connection of Figure l secured to the coil of Figure 3 and showing the connections in the process of being completed.
Figure 5 is a fragmentary cross sectional view taken on the line 5-5 of Figur 4 on an enlarged scale, and
Figure 6 is a fragmentary perspective view of the complete transformer coil.
Briefly, in the practice of my invention I wind the coil in conventional manner with a layer of an insulating material between the convolutions of the coil. The taps are brought out in conventional manner to extend along opposed edges of the coil. I then provide a lead connection memher which is preferably a panel of insulating paperboard or the like having a series of apertures therein and having secured thereto the coded leads, each lead being secured opposite an aperture. The complete lead connection member is then secured to the coil and the connections between the lead ends and the taps are made and bent down so that the connections lie respectively within the apertures in the lead connection member. The entire coil, including the lead connection member, and the connections themselves is then covered with a covering convolution.
Referring now in more detail to the drawings, I have shown in Figure 3 at [0 the complete coil for a multi-tap transformer with the taps indicated at H. In the particular embodiment illustrated there are sixteen taps, eight on each side of the coil. It will be understood of course that the particular number of taps does not constitute a limitation upon my invention.
In Figure l I have shown at I2 a lead connection member which is preferably a panel of insulating paperboard or the like, preferably having a thickness of about .025 inch. In the particular embodiment shown there are provided two rows of apertures it. The particular length and width of these apertures is not critical, but they must be large enough to accommodate a conventional soldered lead connection. At It I have indicated several leads which are secured to the member in any desired manner. In the particular embodiment shown they are secured by means of the staples i5 as shown, each lead beingsecured to the panel l2 adjacent one of the apertures it. Preferably the lead is secured in such a way that it lies on the longitudinal axis of one of the apertures 53. The ends of the leads, as shown at Eta, are bent upwardly, passing through the apertures l3.
It will be understood that there will be as many leads secured to the panel I2 as there are taps on the coil. In some instances it may be desirable to have a single row of apertures and therefore the specific number of apertures and their placement do not form a limitation upon my invention.
The panel 12 with the leads is secured thereto, as shown, is then assembled to the coil 59, as best seen in Figure 4. Preferably, as there shown, the panel IE will have a width equal to that of the coil it so that it fits neatly thereon. The panel i2 may be secured to the coil by a strip of adhesive tape or the like as indicated at it, and the panel i2 will be disposed with the leads hi on the under side thereof and with the lead ends I la projecting upwardly through the holes it.
At this stage the various taps are brought up over the panel I2, laid alongside the lead ends Ma and the two wires are twisted together, soldered and then the connection is bent downwardly to lie in one of the apertures iii. In Figure 4 two of the connections indicated particularly at H are shown twisted together, and the connection at [8 is shown after it has been soldered. The connections at l9 show the connection after it has been bent downwardly to lie in its aperture l3. It will be understood that all the other connections are finished similarly as indicated at H, I8 and i9.
As a final operation the entire coil it together with the insulating lead connection panel 82 and including the connections i9 is covered with a covering convolution indicated generally at 2t.
This may consist of one or more convolutions as may be required.
It will be observed that each soldered connection it lies within one of the apertures l3 and is thereby held in place so that it cannot readily be bent to one side or the other and thus brought closer to an adjacent connection. In this way the distances between connections are assured at a point which will prevent cross arcing. As seen in Figure 6, the completed transformer coil is neat in appearance as compared with multi-tap transformer coils known heretofore. Those skilled in the art will realize how this manner of construction, as described above, simplifies the manufacturing of the coil and how it will tend to minimize errors in connections.
It will be clear that numerous minor modifications may be made without departing from the spirit of this invention, and I therefore do not intend to limit myself in any manner other than as set forth in the claim which follows.
Having now fully described my invention, what I claim as new and desire to secure by Letters Patent is:
A multi-tap electrical device having a plurality of taps, an insulating member having a number of oblong holes at least equal to the number of taps and having secured thereto on its under side in substantial alignment with the longitudinal axes of said holes, a number of leads equal to the number of tape, said insulating member lying upon the outermost surface of said device and spaced therefrom by the thickness of said leads, said taps extending over said insulating member and being connected respectively to said leads with said connections lying in said respective holes, and a covering convolution over said device, insulating member and connections.
DONALD L. MEE-KS.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,881,077 Hall Get. 4, 1932 2,072,635 Helgason Mar. 2, 1937 2,125,431 Dinion Aug. 2, 1938 2,159,269 Haase May 23, 1939 2,184,272 Drift-mover Dec. 26, 1939