US1679471A - Electric coil - Google Patents

Description

Aug. 7, 1928. 1,679,471

D. B. HILL ELECTRIC con.

Filed April 30, 1925 Patented Aug. 7,1928.

UNITED STATES PATENT OFFICE.

DWIGHT B. HILL, OF WINCHESTER, MASSACHUSETTS, ASSIGNOR OF ONE HALF TO HERBERT F. FRENCH, OF RANDOLPH, MASSACHUSETTS.

ELECTRIC COIL.

Application filed April 30, 1925.

This invention relates to coils adapted particularly for radio and other high-frequency uses and has for its principal object to provide a coil having both high inductance and low distributed capacity and also little tcndcni-y to produce stray fields and which is selfsustaining without being dipped or molded in varnish or bakelite or similar materials.

The invention is particularly applicable to coils of the type in which each turn is shaped like a figure 8, the winding looping in one direction (e. g. clockwise) and then crossing and looping in the reverse direction. In order to reduce the dimensions of the coils the cross-over portions of the figure 8 are ordinarily flattened out so that the two halves of each coil are approximately semi-circular segments with their bases together. In a coil of this kind the winding extends circumferentially of the coil (e. clockwise), thence crosses through the coil to another point in the circumference, thence extends circumferentially in the opposite direction (e. g. counter-clockwise), thence crosses to another point in the circumference, and so on. In the preferred form the winding crosses along a diametrical chord (i. e. aligned radii) first in one direction and then in the opposite direction.

According to this invention the circumferential portions have their boundaries (inner and outer peripheries) substantially spaced apart and succeeding turns of the winding cross back and forth between the boundaries throughout these portions, preferably at different points along the circumference in succeeding turns, thereby reducing the distributed capacity and physically strengthening the structure. Likewise succeeding turns preferably cross at different points throughout the length of the diametrical portion of the coil, whereby the distributed capacity is reduced to a minimum throughout the entire coil while the stray fields are at the same time largely eliminated.

For the purpose of illustration one concrete embodiment of the invention is shown in the accompanying drawings in which Fig. 1 is an end View, and

Fig. 2 is a side view with portions broken away.

Serial No. 26,997.

In the particular embodiment chosen for purpose of illustration the coil is wound upon pins which may be withdrawn after the coil is completely wound and the windings tied or bound together in suitable manner. Tracing the uppermost winding from the end A, it extends inside pin 1, thence along the inner periphery to pin 2, thence crosses to the outer periphery between pins 2 and 3, thence follows the outer periphery from pin 3 to pin 4, thence crosses to the inner periphery between pins 4 and 5, thence follows the inner periphery from pin 5 to pin 6, thence crosses t0 the outer periphery between pins 6 and 7, thence follows the outer periphery from pin 7 to pin 8, thence crosses to the inner periphery between pins 8 and 9, thence passes around pin 11 at the right-hand boundary of the diametrical portion, thence crosses to the left-hand boundary of the diametrical portion and passes around pin 20, thence crosses from the inner to the outer periphery of the lefthand circumferential portion between pins 22 and 23, thence follows the outer periphery from pin 23 to pin 24, thence crosses to the inner periphery between pins 24 and 25, thence follows the inner periphery from pin 25 to pin 26, thence crosses to the outer periphery between pins 26 and 27, thence follows the outer periphery from pin 27 to pin 28, thence crosses to the inner periphery between pins 28 and 29 thence passes around pin 31 and crosses .rom the left-hand boundary of the diametrical portion to the right-hand boundary at in 0, thus completing one complete turn (two half turns) at pin 0.

The second turn 6 crosses from the inner periphery to the outer periphery between pins 1 and 2, to the inner periphery between pins 3 and 4, to the outer periphery between pins 5 and 6 to the inner periphery between pins 7 and 8, to the outer periphery between pins 9 and 10, thence extends from the outer periphery at pin 10 to the inner periphery at pin 20, thence crosses to the outer periphery between pins 21 and 22, to the inner periphery between pins 23 and 24, to the outer periphery between pins 25 and 26, to the inner periphery between pins 27 and 28, to the outer periphery between pins 29 and 30, and thence crosses from the outer periphery at pin 30 to the outer periphery at pin 1.

The third winding extends along the outer periphery from the pin 1 to pin 2, thence crosses to the inner periphery between pins 2 and 3, to the outer periphery between pins 4 and 5, to the inner periphery be. .-:een pins (3 and 7, to the outer periphery :(.t\YCOI. pins 8 and 9, along the outer periphery from pin 9 to pin 10, thence crosses from the. outer periphery at pin 10 to the outer periphery at pin 21, thence extends along the outer periphery from pin 21 to pin thence crosses to the inner periphery between pins and 23, to the outer periphery between pins 21 and 25, to the inner periphery between pins 26 and 27, to the outer periphery between pins 28 and 29, along the outer periphery to pin 30, and theme crosses to the outer periphery at pin 1.

The fourth turn 61, starting at pn l, crosses to the inner periphery between pins 1 and 2, thence to the outer periphery between pins 3 and 4, to the inner periphery between pins and 6, to the outer per phery between pins 7 and 8, to the inner periphery between pins 9 and 10, thence extends from the inner periphery at pin 11 to the outer periphery at pin 21, thence to the inner periphery between pins 21 and 22, to the outer periphery between pins 23 and 24, to the inner periphery between pins 25 and 26, to the outer periphery between pins 27 and 28, to the inner periphery between pins 29 and 30, and thence crosses from the inner periphcry at 31 to the inner periphery at pin 0.

The next turn 6, and every fourth turn thereafter, follows the same course as the first turn a except that they start from pin 0 instead of pin 1. Likewise every fourth turn after turn 6, 0 and d respectively, follows the same course. As shown in Fig. 1 the windings cross at different points along the diainetrical portion, thereby reducing the distributed capacity in ths portion.

If desired, two or more coils may be wound together. In Fig. 1 two separate windings are shown, one beginning at A and ending at B, and the other beginning at C and ending at D. Starting at A one wire is wound as aforesaid up to the point where the loop L beg'ns, the winding of the first wire then being temporarily discontinued while a second wire is wound from D to C n the same manner and preferably though not l'iccessarily in the same direction as the first wire, and the first wire is then looped across as shown at L and the winding continued in the same manner and direction to the end B. The central winding CD may be employed as a primary and the windings AL and L-B on opposite sides of CD may be used as a single secondary. By placing the primary between the two portions of the secondary the magnetic effect of the coil on adjacent devices is still further reduced. \Vhen wound as aforesaid the outer periphery of the coils appears as a s'ngle continuous unitary coil shown in Fig. 2.

After the coil is wound as aforesaid, the pins 1 to 31 may be withdrawn and the wires bound together axially of the coil by threading a cord back and forth through the spaces originally occupied by the pins.

t will of course be understood that different numbers of pins may be employed, and that the wlrc may follow the inner and/or outer periphery of the coil a plurality of spaces between pins instead of a single space as illustrated. However, the number of pins along each of the two semicircles should be a multiple of the number of pins spanned by each winding before it crosses from one to the other periphery.

From the foregoing it is evident that sueceed'ng half-turns of the two circumferential portions cross between inner and outer pe-- ripheries the same number of times but alternate half-turns of each circumferential portion cross different numbers of times. F or example, in the right-hand circumferential portion the turn a crosses four times (between pins 2 and 3, 4, and 5, 6 and 7, and 8 and 9) and likewise in the left-hand circumferential portion; whereas in the next turn 5 the winding crosses five times in each circumferential portion (between pins 1 and 2, 3 and 4, 5 and 6, 7 and 8, and 9 and on the right-hand portion and on the left-hand portion between pins 21 and 22, 23 and 24, and 26, 27 and 28, and 29 and Moreover succeeding turns cross between inner and outer peripheries at different points along the circumferential portions or at different longitudinal lines. For example turn a (and every second turn thereafter) crosses at lines extending parallel with the axis of the coil between pins 2 and 3, 4 and 5, 6 and 7, 8 and 9, 22 and 23, 24 and 25, 26 and 27, and 28 and 29, whereas, turn I) (and every second turn thereafter) crosses at lines between pins 1 and 2, 3 and 4, 5 and 6, 7 and 8, 9 and 10, 11 and 12, 13 and 14, 15 and 16, 17 and 18, and 19 and 20. Thus turns a, 0 etc., cross eight times in the circumferential portions, four times on each side, and turns 6, 03 etc, cross ten times, five times on each side.

I claim:

1. An electric coil comprising a continuous winding which extends circumferentially of the coil throughout approximately 180, thence substantially diametrically from side to side, thence approximately 180 in the opposite direction, thence substantially diametrically in the opposite direction, and so on throughout succeeding turns, the circumferential portions having an inner and outer periphery, the winding cross- IOU ing back and forth between the inner and outer peripheries throughout the circumferential portions, the diametrical portions of some of the turns spanning the inner periphery and the diametrical portions of others of the turns spanning the outer periphery.

2. An electric coil comprising a continuous Winding which extends circumferentially of the coil throughout approximately 180, thence substantially diametrically from side to side, thence approximately 180 in the opposite direction, thence substantially diametrically in the opposite direction, and so on throughout succeeding turns, the circumferential portions having an inner and outer periphery, the Winding (rinsing back and forth between the inner and outer peripheries throughout the circumferential portions, the diametrical portions of some of the turns spanning the inner periphery, the diametrical portions of other of the turns spanning the outer periphery, and the diametrical portions of other of the turns extending from inner periphery to outer periphery.

3. An electric coil comprising a continuous Winding which extends circumferentially of the coil throughout approximately 180, thence substantially diametrically from side to side, thence approximately 180 in the opposite direction, thence substantially diametrically in the opposite direction, and so on throughout succeeding turns, both the circumferential and diametrical portions having boundaries substantially spaced apart transversely of the axis of the coil and succeeding turns of the winding crossing from boundary to boundary throughout both circumferential and diametrical portions, and a second winding electrically insulated from the first Winding but mechanically forming a like continuation of the first Winding.

Signed by me, at Boston, Mass. this tuenty-eighth day of April, 1925.

DXVIGHT B. HILL.

Images