US 2251776 A
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Aug. 5, 1941- R. c. BALLARD METHOD AND MEANS FOR WINDING COILS Filed Dec. 30, 193B 2 Sheets-Sheet l (Ittorneg 5, 1941- R. c. BALLARD 2,251,776
METHOD AND MEANS FOR WINDING COILS Filed Dec. 30, v1938 2 Sheets-Sheet 2 Zhwentor Patented Aug. 5, 1941 METHOD AND MEANS FOR WINDING COILS Randall C. Ballard, Audubon, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application December 30, 1938, Serial No. 248,561
My invention relates to deflecting coils for cathode ray tubes and particularly to an improved means for and method of winding distributed deflecting coils of the general character described in Patent 2,167,379, issued July 25, 1939, to William A. Tolson, and assigned to the Radio Corporation of America.
Prior to my invention, it was the practice to obtain rectangular or straight-sided distributed windings of the type described in the abovementioned Tolson patent by employing a winding jig in which pins were inserted from time to time as the winding progressed, thereby correcting periodically for the tendency of the succeeding turns to round out instead of remaining straight-sided. It will be apparent that deflecting coils could not be wound very rapidly in this way and that the production costs for such coils would be rather high.
It is accordingly an object of my invention to provide an improved means for and method of winding distributed deflecting coils.
A further object of my invention is to provide a means for and method of winding deflecting coils of the above-mentioned type wherein the insertion of pins during the winding of the coil is unnecessary.
A further object of my invention is to provide an improved winding jig for cathode ray tube defleeting coils.
In practicing my invention, I employ two plates which are positioned face to face, with a small space between them and adapted to be rotated for winding a coil in the space between the two plates. coil shall be obtained rather than a substantially round pancake coil, I provide a plurality of ribs on the adjacent faces of the two plates, whereby there is a constriction in the space between the two plates at each point Where a bend in the 1 constructed in accordance with my invention;
Figure 5 is a side view of the winding jig shown in Figure 4;
Figure 6 is a side view of a modification of the winding jig shown in Figures 1 and 2;
Figures 7 and 8 show the deflecting coils as they appear when taken off the jigs shown in Figures 1 and 4, respectively;
Figure 9 shows the winding of Figure 8 after In order that the desired straight-sided it has been formed for assembly in the deflecting yoke;'
Figures 10 and 11 illustrate different distributed windings which may be obtained by the winding jigs constructed in accordance with my invention; and
Figures 12a to 12c illustrate how the cross-section of a distributed winding may be changed by changing the shape of the ribs on a winding job.
Referring to Figs. 1 and 2, there is illustrated a winding jig constructed in accordance with my invention and designed for winding the horizontal deflecting coils of a deflecting yoke. This winding jig comprises plates I and 2, which are positioned face to face and which are separated a small amount by suitable means such as a spacing boss on the plate I. In this particular design, each plate is provided with four ribs 6 spaced circumferentially around the jig, the ribs on one plate being opposite the ribs on the other plate, as clearly indicated in Fig. 3, to provide for a constriction in the spacing between plates 1 and 2 at four points.
The plate I may be provided with two guide pins 1 which engage openings 8 in the plate tube.
The plates 1 and 2 may be provided with bosses ii and I2 respectively. The assembled jig is rotatably mounted and the two plates are held together by means of a shaft having a shoulder 13. The end of the shaft is threaded and has a nut 14 thereon, which clamps the plates I and 2 against the shoulder IS.
The inner periphery of the deflecting coil is determined by the four pins l6, which may be removable or which may be fastened at one end either to the plate l or to the plate 2.
In each of the plates 1 and 2 thereis a rectangular section cut away as indicated at I1 and :8, whereby the ends of the deflecting coils, after they have been wound, may be taped to hold the coil together while it is being transferred from the jig to an impregnating bath and later to a forming device or mold which curves the coil to provide a preformed coil ready for assembly in a deflecting yoke. The impregnating material preferably is such that it hardens in the mold when heat is applied.
It will be understood that a coil is wound by securing one end of a spool of wire to a point on the jig near the axis, as to one of the pins 16, and then rotating the jig to wind wire off the spool and fill the space between the plates I and 2. It will be apparent that because of the constrictions formed by the ribs 6, there will be a comparatively sharp end in each turn of the wire in a space between opposite ribs, the wire being crowded together and rather tightly packed at this point. The finished coil is substantially as shown in Fig. 7. In Fig. 7 the ribs 6 are indicated by the dotted lines 28 to illustrate how my improved jig causes the turns of wire to bend sharply at the desired points.
Referring to Figs. 4 and 5, there is shown a slightly different embodiment of my invention, where additional constricting ribs are employed. This particular winding jig is designed for winding the vertical deflecting coils which are used in the same deflecting yoke as the horizontal deflecting coils previously referred to. It may be noted that the horizontal deflecting coils are placed on top the vertical deflecting coils and between the upturned ends or the vertical deflecting coils. The jig shown in Figs. 4 and 5 comprises two plates 2| and 22 spaced apart in parallel relation, the spacing being determined by a boss or spacer plate 23 on the plate 22. The plates 2| and 22 are provided with guide pins 24 which, in the particular design illustrated, are also utilized to determine the inner periphery of the deflecting coil.
In order that the vertical deflecting coil may be thin enough at the ends to bend the ends upwardly in the forming molds, two ribs 26 and 21 are provided at each corner of the jig. The thickness of the coil end may be varied by varying the position of the ribs 21; for example, the end of the coil being made thicker if the rib 21 is rotated towards the rib 26 to decrease the angle between them.
Rectangular sections of the plates 2| and 22 are cut away as indicated at 28 and 29 to permit taping the sides of the deflecting coils before they are removed from the jig for transfer to the forming mold.
If desired, the winding jig may be provided with studs 3| and wing nuts 32 for fastening the plates 2| and 22 together.
The shape of the vertical deflecting coil which is provided by the jig shown in Figs. 4 and 5 is indicated in Fig. 8, where the positions of the constricting ribs are indicated by the dotted lines.
As shown in Fig. 9, the vertical deflecting coil in its finished form for assembly in the deflecting yoke preferably has its ends turned up as shown at 20, the spacing between the upturned ends 20 being such that the horizontal deflecting coil fits in between these ends.
In some deflecting yoke designs, it may be desirable to have the thickness of the deflecting coil varied from the inner periphery to the outerl periphery for the purpose of obtaining a difierent distribution or the deflecting field than can be obtained by a deflecting coil of uniform thickness. The cross-section of the deflecting coil may be given any thickness or shape desired by changing the shape of the constricting ribs 26.
For example, in Fig. 6, there is shown a winding jig in which the height of the ribs decreases from the inside to the outside of the jig. Thus, there may be wound a coil such as shown in Fig. 11 having a cross-section on the line |2-|2 which increases uniformly in thickness from the ,inner periphery to the outer periphery as indicated at 4|! in Fig. 12a. Figs. 12b to 12c indicate other cross-sections at 4| to 44 respectively, which could be obtained on the line |2-|2, merely by changing the shape of the constricting ribs.
It will be apparent that the deflecting coils may be wound to satisfy various requirements by changing the number and position of the constricting ribs. For example, as indicated by the dotted lines I! in Fig. 11, the constricting ribs may be located at right angles to a comparatively long section of straight-sided coil. Also, as indicated in Fig. 10, only three constrictions in the winding jig will be employed, as indicated by the dotted lines 35, if a coil of triangular shape is desired.
From the foregoing description, it will be apparent that various modifications may be made in my invention without departing from the spirit and scope thereof.
I claim as my invention:
1. A winding jig tor a deflecting coil, said jig comprising a pair of plates in face-to-Iace relation whereby there is a space between them, said jig being adapted to be rotatably mounted, and means for constricting said space at, at least, three circumferentially spaced points.
2. A winding jig for a deflecting coil, said jig comprising a pair of rotatable plates secured in iace-to-face relation, and rib-like means for constricting the space between adjacent races of said plates at, at least, three places spaced circumferentially about the jig.
3. The method of winding a distributed deflecting coil which comprises winding said coil in a constricted space and crowding the winding at, at least, three circumferentially spaced points where the turns of the winding are to be bent, whereby a straight-sided winding is produced.
4. The method of winding a deflecting coil between substantially paraliel plate faces which comprises crowding the turns of said coil at, at least, three circumferentially spaced points as the coil is wound whereby a straight-sided coil is produced.
5. A winding jig for a coil, said jig comprising at least three pairs of ribs or constricting elements spaced apart to permit winding said coil therebetween, said pairs of ribs being spaced circumferentially about the center of the jig.
6. A winding jig for a coil having straight sides, said jig comprising at least four pairs oi ribs or constricting members spaced apart to permit winding said coil therebetween said ribs being spaced circumferentially about the center of the 7. The method of producing a distributed deflecting coil which comprises winding said coil in a constricted space and crowding the winding at, at least, three circumferentially spaced points where the turns of the winding are to be bent, whereby a straight-sided winding lying in a certain plane is produced, and next bending said straight-sided winding about an axis parallel to said plane to make said winding conform to a substantially cylindrical surface.
8. The method of winding a distributed deflecting coil which comprises winding said coil in a space which is constricted in an axial direction and with so many turns that its radial dimension is large compared with its axial dimension, and crowding the-winding at, at least, three circumierentially spaced points where the turns of the winding are to be bent whereby a straightsided winding is produced, said radial dimension being taken at a point other than a point where the winding is being crowded.
RANDALL C. BALLARD.