US1620244A - Variable condenser - Google Patents

Description

I 1,620,244 March 1927' F. E. SWOPE, JR

VARIABLE CONDENSER Filed May 18, 1923 ATTORNE.

. thereof with a saving Patented Mar. 8, 1927.

UNITED STATES PATENT OFFICE.

VARIABLE oon'nnivsnn.

Application filed May 18,

My invention relates to an improvement in variable condensers, for example, such as are used in connection with radio receiving apparatus. I

I The object of my invention is to provide novel means for securing the fixed and movable plates of a variable condenser in order to insure correct alignment of the plates, reduce the parts, and enable the assembly of time and labor.

' A further object o my invention is to pro vide a variable condenser, that is, one having fixed plates ,and relatively movable plates whereby the capadity may be varied,

which twill be of 'novelj construction and proof against warping with resultant short circuitingdue to misalignment of. the fixed and relatively movable lates. y

Further ob ects of my invention are to proi duce a variable condenser which may be readily attached to-the ordinary panel and which will bev relatively inexpensive to construct and at the same time be durable and I eflicient in use. Having now indicated in a general. way thenature, purpose and advantage of my invention, I will proceed to adetailed description of a preferred embodiment thereof with reference to the accompanying drawings, in which- Y Fig. -1 is a sectional view of a variable con denser embodying my invention.

Fi 2 is a face new of a fragment of a pane showing the application of the condenser. I

Fig. 3 is a sectional view on line 3-3 Fig. 1.

Fig. 4 is Fig. 1.

Fig. 5 is a view of a condenser plate. Fig. 6 is a view of a plate supporting rod.

a, a represent heads or end plates of insulating material between which the fixed and relatively movable plates of the condenser are carried. The fixed plates 0 are slottedas at z and a sectional view on line 44 are entered in slots or grooves 3 in rods (1, d.-

The rods are then squeezed longitudinally to close the slots 3 and secure the plates. The plates when secured'on' the rods 01, d'oare s d equidistant by the lands e-between the grooves 3 in the rods. The fixed plates are held against the head a by means of nuts f, and the rodsd, d carrying the plates 0 0' isthreaded on the end of shaft 1923. Serial No. 689,731.

are secured to the heads a, a by means of nuts. A rod 9 carrying a spacer h is secured to the heads a, a.

The relatively movable plates 11 of the condenser are carried on a rotatable shaft 1', be-

ing slotted, as are plates 0, for entry into slots or grooves similar to grooves 3 in rods d, d 1n the shaft 7'. The plates are secured to the shaft by squeezing it longitudinally A and when secured are spaced, by the lands k,

spring m secured to head. a, embracing shaft 7' and bearing on a head non shaft 7'. The spring mpresses shaft 7' against its hearing on head a, without exerting any pressure on head'a, which would tend to separate the heads and throw the movable and fixed plates out of line. The spring also acts as a brake on the. shaft 7' so that a fine adjustment may be made. The spring further may be used as an electrical contact, if desired.

The condenser is secured tothe panel 0 by means of an externally threaded bushing 7) provided with an enlarged head g. bushing passes through the panel and is threaded within the .hub Z, until-the head 9 bears against the panel. An indicator hand i i-is is a turning knob s.

Suitable leads 71 and ingIup the condenser.

aving now fully described my inveng serve for connect D The movable The tion, what I claim and desire to protect by Letters Patent is:

1. A variable condenser comprising .oppositely disposed heads. a solid rod rovi'ded with a circumferential slot exten ing within the slot in said rod, the material formingthe rod being expanded long1tud1- between the heads and a condenser plate having a laterally opening slot engaged nally adjacent opposlte sides of the plate 'to secure the plate in the slot.

2. A variable condenser comprising oppositely disposed heads, a solid rod provided with spaced circumferential slots extending between the heads, a plurality of condenser plates having laterally opening slots engaged within the slots in the rod, the maagainst the'plates and secure the plates therein.

4. A variable condenser comprising. oppositely disposed heads of insulating material, a plurality of fixed plates mounted'between said heads, amovable plate adapted to be moved between said fixed plates, and a spring secured to one of said heads and acting on said movable plates in a direction away from the opposite head, whereby said movable plates are positioned between said heads.- g I 5. A variable condenser comprising oppositely disposed heads of insulating material,

a plurality of fixed plates mounted between said heads,a. rotatable shaft a "plate mounted on said shaft, an end bearing for said shaft supported by one'of said heads, and

a spring adapted to actto hold said shaft in said end bearing, said spring being secured to and acting in a direction toward the head supporting said bearing. I 6. A variable condenser comprising oppositely disposed heads of insulating material, a plurality offixed platesmounted between said heads, a bushing in one of said'heads,

v a pin in the other head, a rotatable shaft passing through said bushing and provided with an end bearing for said pin, a plate mounted on said shaft, and a'spring secured to said lastmentioned head and embracing said shaft, said spring acting in a direction 4 toward said last mentioned head to hold said shaft againstsaid pin.

7. A variable condenser comprising oppositely disposed heads of insulating material, a plurality of fixed plates mounted between said heads, a bushing inone of saidheads, a pin in the other head, a rotatable shaft passing through said bushing and provided with an end bearing for said pin, a plate mounted on said shaft, a flange adjacent the end of said shaft, and a spring secured at one end ,to said last mentioned head, the

free end of said spring embracing said shaft and bearing against said flange, said spring acting in adirection toward said last mentioned head whereby said shaft is held against said pin and resistance to the rotation of the shaft is provided. 8. A variable condenser comprising oppositely disposed heads of insulating material, a plurality of fixed plates mounted between, said heads, a bushing, having an internally threaded portion, mounted in one of said heads, a panel, a bushing, having an internally threaded portion, adapted to thread into 'said first mentioned bushing, mounted in said panel, a rotatable shaft adapted to pass through. said bushings and extend between said heads, a plate mounted von said shaft, a pin supported by the other head and adapted to support the end of the shaft, a

spring secured to said last mentioned head and adapted to act on said shaft in a direction toward said last mentioned head to hold the, end of said shaft against said pin, and a knob on the end of said shaft adjacent said panel whereby said shaft may be rotated manually.

In testimony of which invention, I have hereunto set my hand, at Philadelphia, Pa, on this 12th day ofiApril, 1923.

I rnanniarcir' E. sworn, an; I

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