US1631226A - Variable condenser - Google Patents

Description

June 7, 1927.

E. J. SCHRODER VARIABLE CONDENSER Filed April 20, 1925 Patented June 7, 1927.

EDWARD J. SCHRODER, OF LOWELL, INDIANA.

VARIABLE connnnsnn.

Application filed April 20, 1925.

The invention has reference to condensers such as are employed in radio communication, and has especial reference to condensers of the type which are composed of two sets of plates mounted for relative swinging movement into and out of interleaved relation.

The primary object of the invention is to produce a condenser of the type referred to having a greater range of ad uStment than has heretofore been possible of attainment, whereby a wider range of selectivity may be obtained.

With this object in view, a feature of first importance is the provision of means for effecting relative movement between the two sets of plates which is compound in character, viz., a lateral movement of the rotor plates in the spaces provided between the stator plates, effected during the rotary movements of the rotor lates through the medium of a screw, the latter also serving to hold the rotor shaft against endwise play in. its bearing.

A further object of theinvention is to provide a construction for the condenser insuring a low absorption loss. To attain this object I have provided a two point suspension for the stator plates upon the supporting frame and a single point of suspension for the rotor plates, the stator bein insulated from the frame at its points 0 suspension.

A general object of the invention is to produce a condenser of relatively simple construction capable of being cheaply manufactured.

In the accompanying drawings I have illustrated a preferred embodiment of the invention but it is contemplated that other embodiments with various changes in the construction and arrangement of the parts may be made by those skilled in the art without departing from the spirit and scope of the invention as expressed in the appended claims.

Figure 1 of the drawings is a side view of Serial No. 24,347.

' generally the stator element and 11 the rotor element.

The stator 10 comprises a plurality of plates 12 approximately rectangular in form having apertures at their lower corners to receive supporting screws 13 and secured in position on said screws by means of a air of nuts 14 with spacing collars or was ers 15 interposed between the plates. The forward ends of the screws 13 are sup orted in the frame 7 at the lower corners t ereof in a manner such that the stator is insulated from the frame 7. The construction herein employed is illustrated in Fi 6 and consists of a pair of disks or was ers 16 of insulating material arranged on opposite sides of the frame 7 and at opposite ends of an aperture 17 which is somewhat smaller than the disks 16 but substantially larger than the screws 13. A pair of nuts 18 and washers 19 serve to clam the disks 16 against the opposite sides 0 the frame, and to assist in positioning the screws in place in the opening 17 the lnner one of the disks 16 is preferably countersunk into the frame as indicated at 20. This construction serves to insulate effectually the stator from the frame 7, thus insuring against excessive loss through absorption.

The plates '12 of the stator are spaced apart a distance somewhat greater than has heretofore been the case to permit of the combined lateral and rotary movements of the plates of the rotor element 11 as above indicated. Said element 11 comprises a plurality of segmental plates 21 mounted upon the rear end of a shaft22 and held in position thereon between an annular shoulder 23 formed on the shaft and a nut 24 screw-threaded on the rear end of the shaft, suitable spacing washers 25 being provided between the end plates and the shoulder and nut respectively and also between the intermediate plates.- Said shaft 22 has an enlarged intermediate portion 26 externally screw-threaded and engaging in an internally screw-threaded bearing 27 formed in this instance integral with the frame 7, but the shaft may, if desired, be suitably insulated from the frame.

The bearing 27 and the corresponding screw-threaded portion 26 of the shaft are made of substantial length so as to provide ample support for the shaft and hold it in true perpendicular relation to the stator plates 12. The forward end of the shaft 22 is equipped with a suitable turn button or knob 28. It will be seen that in the rotary movements imparted to the shaft 22 not only will the plates 21 swing into and out of interleaved relation with the plates 12 of the stator, but will simultaneously move laterally in the spaces provided between the stator plates to vary the positions of the rotor plates relative to the stator plates. By this arrangement a greater range of adjustment is provided so that greater selectively is obtained. Also the greater spacing between the plates renders them more readily accessible for cleaning purposes.

Any suitable means may be provided for limiting the relative movements between the plates, that herein employed comprising a stop pin29 projecting rearwardly from the bearing 27 and interposed in the path of movement of opposed stop shoulders 30 and 31 formed in a head 32 on the shaft. The arrangement is such that as the rotor plates move from a position above the stator plates as indicated in Fig. 4 through an arc of substantially 180 degrees to the interleaved relation shown in Figs. 1, 3 and 5 they simultaneo'usly move laterally in their respective spaces from a position approximately centrally thereof to a position near the other side thereof.

In order that the upper edges of the two sets of plates may lie in the same plane when the plates are in interleaved relation, the stator plates 12 are cut away or notched at their upper edges as shown at 12 and the rotor plates 21 have ears 21* formed intermediate their straight edges, which are apertured to receive the shaft 22. The arrangement is such that the axis of the shaft is disposed substantially in the plane of the upper edges of the plates, and the notches 12 are of a. depth to provide ample clearance between the spacing washers 25'of the rotor element and the stator element. J

In order to provide the desired frictional resistance to the movement of the. rotor element I employ an adjusting screw 33 entered radially through a boss 34 in the upper side of the bearing 27 and adapted to exert va-- riable pressure upon a friction, disk or slug 35 of leather or the like at the inner end of the screw hole bearing upon the screwthreaded portion 26 of the shaft.-

Additional variation in capacity capable of more delicate adjustment is provided by .stator element, and an adjustin means of a Vernier attachment which comprises a plate 36 suspended from the frame by means of a spring arm 37 which may be secured to a projection 38by a bolt 39, said projection being formed upon the under side of the bearing 27. The lower end of the plate 36 has a depending arm 40 adapted to be engaged by the inner end of an adjusting screw 41 threaded in a bearing 42 at the lower end of the frame and provided with a turn button or knob 44, with a sleeve 45 rigid therewith to limit the extent of adjustment and prevent contact between the plate 36 and the first or forward stator plate 12.

The construction which I have provided is relativel simple in character and is particularly a vantageous because of the greater range of adjustment and selectivity which it renders possible through compound movement of the rotor element relative to the stator element. The stator element being supported on the frame at two points only,

absorption losses are reduced to a minimum and by providing an elongated bearing for the rotor element it is possible to dispense with a frame surrounding the stator and rotor elements. The screw-threaded mountr ing of the rotor element also serves to hold it against endwise play in its support.

I claim as my invention:

1. A condenserhaving a supporting frame, a stator element comprising a plurality of spaced lates secured to said frame but insulated t erefrom, a rotor element also comprising a plurality of plates carried by said frame, and a vermer attachment comprising a plate mounted on said frame for movement toward and from the screw mounted in said frame and adap to engage with said plate, said vernier plate hav ing a leaf spring connection with the frame.

2. A- condenser having rotor and stator elements, a support for said elements including a frame, said rotor element having a shaft, said frame having an elongated bearing with which said shaft engages, said bearing having a hole in one side, a screw threaded into said hole, and a slug of leather in said hole adapted to be forced by the screw into engagement with the shaft to retard rotary movement thereof.

3. A condenser comprising in combination with an u right panel, a metallic frame rigidly secure to one side of said panel and having a pair of screw-threaded members rigidly secured thereto but insulated therefrom, said members extending in a direction from the frame opposite the panel, a stator element comprising a plurality of spaced plates rigidly secured together on said members, said frame also having an elongated bearing extending arallel to said members in spaced relation tiereto, a shaft extending through said bearing in screw-threaded relation therewith, one end of said shaft extendin throughsaid panel, and the other end 0 said shaft extending in parallel relation with said members, a urality of plates rigidly mounted in space relation on said shaft and constituting a rotor element adapted to coact with the stator element, the arrangement beirifi such that in th} rotation of the shaft e plates on the rotor element move into and out of interleaved rela- 10 tion with the plates of the stator element and also move laterally in the s aces between the stator plates, and means or limitin the extent of rotation of said shaft.

11 testimony whereof, I have hereunto 5

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