US1692331A - Variable inductance - Google Patents

Description

Nov. 20, 1928.

N. H. CLOUGH VARIABLE INDUCTANCE Filed Jan. 1925 INVENTOR NEWSOME H. CLOUGH /d(www ATTORN EY Patented Nov. 20, 1928.

UNITED STATES PATENT OFFICE.

-NEWSOME HENRY CLOUGH, OF CHELMSFORD, ENGLAND, ASSIGNOR TO PORATION OF AMERICA, A CORPORATION OF DELAWARE.

RADIO COR- VARIABLE InnUo'rANoE.

Application filed January 3. 1925. Serial No The object of this invention is to provide a that it covers varying portions of the coil the inductance of that coil may be continuously varied.

Alternatively I may wind the inductance in the fashion of a solenoid around a short cylindrical former and mount a shield in the form of a ring so that it can rotate about an axis perpendicular to the axis of the former.

The invention is illustrated by the acco1npanying drawing, Figure 1 of which is an inverted plan of a variable inductance constructed in accordance therewith; Fig. 2 shows a modification in which three coils of different values of inductance are used; Fig. 3 is a side elevation of another modification;

Fig; 4 is a plan of the modification shown by Fig. 3; Fig. 5 is a sectional view of still another modification; Fig. 6 is a view. partly in section of still a further modification and Fig. 7 is a diagrammatic representation of a switch for connecting in circuit the desired inductance when the modification shown by F ig. 2 is used.

The coil A is wound upon a former B in the shape of a ortion of a sphere, and a metallic shield C su stantially in the shape of a hemispherical shell is mdunted upon a pin-the axis of which coincides with a diameter of the former B, so that by turning the shield it can be made to cover a varying portion of the coil and thus the inductance of the coil may be varied.

The edge of the shield may be shaped so as give any desired inductance law. it is understood that the shield may be placed inside of the coil as well as outside.

An inductanc'e thus constructed has the advantage that inasmuch as the windings are stationary there is no need to employ a commutator or-sli rings, that a rotary control is obtained, and that inasmuch as the distance between the shield and the winding or windings can be made very small, the range of inductance is large.

Figure 2 shows three separate coils A, A A, wound upon different-portions of a spher- 401. and in Great Britain January 14, 1924.

ical former B with a shield C which is mounted as in the case of Figure 1 and may thus be used in conjunction with any one of the three coils A, A A the ranges of inductance of the various coils being different. A suitable switch may be provided for putting into cirwit that coil whichcit is desired to use at any time.

Figure 3 is a side elevation and Figure 4 is a plan of a modification, inwhich the coil A is wound in the fashion of a solenoid around a short cylindrical former E while the shield C is in the form of a ring and is supported on a spindle F by which it can be turned to cover more or less of the coil. The formerE is carried by a support G, the support having grooves in which the former can be slidden. Thus the coil can readily be removed and replaced by another of a different value. v

, Figure 5 is a section of a modification, in

-which'thecoil A is carried by a frame H,

while the shield C is in the form of a ring and is mounted on a spindle F, the axis of which is inclined at an angle a to the plane of coil A. The plane of shieldC isinclined to the axis of spindle F at an angle [3. As illustrated a and B are each equal to 45 and when spindle F is turned 180 the planes of coil A and shield C-will coincide and shield C will lie wholly inside coil A.

Figure 6 is a section partly in elevation of another modification in which as in Figure 5 coil A is carried by a supportH but in which the shield C takesthe form of a coil of wire wound on a sphere of insulating material the ends of the wire being interconnected. The axis of the sphere is inclined at an angle or to the plane of coil A, while the lane of shield C is inclined to the axis of the sphere at an angle )3. The angles a and B being each equal. to 45, the shield will be wholly operative when given a turn of 180 Having described my invention what I claim is: i

1. A variable inductance com rising at plurality of coils wound upon a sp erical former and a spherical cap mounted to turn about a diameter of the former to cover varying portions of any of the coils.

2. A variable inductance comprising a plurality of coils wound upon a s herical former and a single shield member or varying the inductance of any of the coils.

3. A device for varying the inductance of a circuit comprising a plurality of coils of different inductances, each of said coils being adapted to be separately connected in the circuit, and a shield for varying the inductance of any of said coils.

4. A device for varying the inductance of a circuit comprising a plurality of coils having different inductances Wound upon a spherical former, each of said coils being adapted to be connected in the circuit, and a metallic shield for varying the inductance of the coil which is connected in the circuit.

5. A variable inductance comprising a plurality of coils Wound upon a spherical former, each of said coils having a different inductance, and a spherical shield member mounted to rotate to cover varying portions of any of said coils. I

6. A variable inductance comprising three coils arranged so that their axes intersect at a common point and a shield mounted on an axis perpendicular to the plane of the axes of the coils and at their common point of intersection, said shield being rotatable to vary the inductance of said coils.

'2'. A variable inductance according to claim 6 in which the coils have inherently NEWSOME HENRY CLOUGH.

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