US1627592A - Radio apparatus and current-control device therefor - Google Patents

Description

Filed Dec. 4, 1926 P. A. CHAMBERLAIN I RADIO APPARATUS AND CURRENT CONTROL DEVICE THEREFOR gm, A QN W @N M May 10, 1927.

Patented May 10, 1927.

UNITED STATES PATENT OFFICE.

PAUL A. CHAMBERLAINgOF CHICAGO, ILLINOIS, ASSIGNOR TO MOHAWK CORPORA- TION OF ILLINOIS, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS. l

RADIO APPARATUS AND CURRENT-CONTROL DEVICE THEREFOR.

Application filed December 4, 1926. Serial No. 152,682.

This invention relates to. improvements in radio apparatus, and more particularly to radio receiving sets, and has for its Drincipal object to provide an improved apparatus of the class described wherein the main control devices, as for example the tuning knob and the filament switch, may be conveniently and compactly arranged on the panel.

A further object of the invention is to provide a new and improved form of filament switch, as will, hereinafter more fully appear.

The invention may best be understood by reference to the accompanying drawing, in which- Figure 1 is a fragmentary sectional view of a tuning condenser in mounted position on a radio panel and with a filament switch combined therewith, in accordance with my invention.

Figure 2 is a detail View of the filament switch at the inner end of the condenser shaft.

Figure 3 is a plan view of the switch shown in Figure 2.

Referring now to details shown in the drawings, I have provided a tuning device indicated generally at 10. In the form shown, said tuning device consists of a multiple unit condenser including end frame members 1111 and a rotor shaft 12 having a plurality of rotor units 13-13 spaced longitudinally thereof, each of said rotor units comprising a set of parallel plates 14-44; adapted to be interleaved with coacting stator plates (not shown) in a well known manner. The multiple unit condenser herein illustrated, is especially adapted for use with a single control receiving set wherein a plurality of radio-frequency amplification stages are employed, all being tuned by rotation of the single rotor shaft 12. It will be understood, however, that my invention may be utilized in connection with a single unitcondenser, if desired. the multiple unit shown being utilized mainly to illustrate the possibilities of reducing the control devices of well known radio receiv ing sets to a minimum, and disposing these control members in the most advantageous relationship on the radio panel.

As shown herein, the rotor shaft 12 con-- sists of a sleeve 12 to which the rotor plates face of said member for holding said sleeve in various positions of adjustment. This sleeve 17 also carries part of the filament switch thereon, as will hereinafter more fully appear.

Control means for the condenser rotor shaft 12 comprises a disk or dial 20 mounted on the outer end of sleeve 15 and suitably secured thereto as by means of a set screw 21. In the form shown, the dial 20 is mounted in a recess 22 formed in a panel.

23. The usual dial markings are provided on the outer face 24 of the dial 20 and are visible through an aperture 2:) formed in an escutcheon plate 26 which is mounted on the outer front side of the panel 23 and forms a'cover for the aperture 22 in which the dial 20 is mounted. The dial is controlled by means of a knob 29 carried on a shaft 30 disposed eccentrically of the indicating dial 20. In the form shown, the shaft 30 is journaled in a bearing 31 carried by the escutcheon plate 26 and is provided with an enlarged roller portion 32 which frictionally engages a ring member 33 carried on the periphery of dial 20. In the form shown herein, the friction-ring 33 is made of rubber or its equivalent. A flexible spring 34- is mounted on the panel beneath the bearing portion 32 of shaft 30 in position to maintain said bearing portion or roller in frictional engagement with the bearing ring on dial 20 It will thus be seen that very fine tuning adjustment maybe provided for the dial 20 through the offset tuning knob 29.

Referring now to the switch mechanism utilized in connection with the condenser above described, details of the switch are shown in Figures 2 and 3 from which it will be seen that the sleeve member 17 at the rear end of the condenser is providedwith a supporting piece 40, preferably of insulating material. This piece is suitably secured on the outer surface of sleeve 17, as shown in Figures 1 and 3, and forms a support for a pair of spring contact members 41-41 secured thereto by suitable means, such as rivets 4242. These spring contact members project outwardly or rearwardly in position to be engaged under tension by a switch member mounted on the rear end of a shaft 45. This switch member includes two main paf'ts, the inner part consisting of a rectangularly shaped metallic plate l6 and the outer part. an overlapping rectangularly shaped insulating piece 47. As seen in Figure 2, the arrangement is such that the insulating piece is wider in one direction than the metallic piece 46 so that when the switch shaft 45 is turned into the position shown in this figure, the spring contacts 4l41 engage only the sides of the insulating piece 47, and the circuit will be broken. The metallic piece 46 has opposite sides projecting above and below said insulator piece as shown in this figure, however, so that when the shaft 45 is turned at an angle of 90 from that shown in Figure 2, the projecting margins of metallic piece 46 is then engaged with the terminal members 4141 to bridge the circuit, as shown in Figure 3. The metallic piece 46 is preferably provided with a pair of projections ME -d6 extending from opposite corners thereof so as to limit the movement of the switch shaft to two positions, namely, on and off. The terminal contacts 414t1 are provided with suitable conductors 48-48 connected in series in the filament circuit (not shown) in any suitable manner so as to provide the desired control thereof. In the form shown, the condenser is of the grounded rotor type in which the rotor is electrically common with the end plates 11, so that it is possible to connect one of the terminal conductors 48 directly to the adjacent end plate 11, as shown in Figure 3. 1

As seen in Figure 1, the control shaft 45 extends coaxially through the entire length of the condenser shaft and has its front end 50 extending through and projecting beyond the escutcheon plate 26. A control knob 51 is suitably secured to this projecting end of the switch shaft 45 in position to be readily manipulated in the usual manner.

The construction above described affords an extremely simple form of switch mechanism which may be incorporated as a part of the main tuning condenser and form therewith a most compact structure capable of being readily assembled as a unitary structure. The-main tuning knob 29 is carried by the escutcheon plate 26 but may also be readily assembled with the associated tuning dial 20 of the condenser in a most simple and economical manner.

I claim as my invention:

1. In radio apparatus, the combination of a control panel, a rotative tuning unit including a frame and a rotor shaft, a dial for said rotor shaft visible from the exterior of said panel, a current control switch mounted on said frame including a control shaft extending eoaxially through said rotor shaft. manual control means for said switch control shaft in front of said dial, and a control knob for said rotor shaft disposed eccentrically thereof and operatively connected with the latter.

2. In radio apparatus, the combination of a panel, a rotative tuning unit mounted on said panel and including a frame and a rotor shaft, the latter extending through said panel and having an indicating dial thereon, an escutcheon plate on the front of said panel having an aperture therethrough registering with the periphery of said indicating dial, a current control switch mounted on the end of said frame opposite said panel including a control shaft extending coaxially through said rotor shaft, and projecting through said escutcheon plate, a control knob on the front end of said switch control shaft, and a control knob for said rotor shaft journalled in said escuteheon plate eccentrically of said rotor shaft and operatively connected with the latter.

3. In radio apparatus, the combination of a rotative tuning unit including a frame, a rotor shaft, and a rotor shaft bearing on one end of said frame, a current control switch mounted on said rotor shaft bearing outside of said frame, a control shaft for said switch extending coaxially through said rotor shaft bearing and rotor shaft, and independent switch and rotor control means both disposed at the opposite end of said frame.

4. In radio apparatus, the combination of a rotative tuning unit including a frame, a rotor shaft and a rotor shaft bearing on one end of said frame, a current control switch mounted on said rotor shaft hearing outside of said frame including an insulating piece carried by said bearing and having a pair of oppositely disposed spring contact members projecting rearwardly therefrom, and a rotatable switch member interposed between said contact members, a control shaft for said switch member extending coaxially through said rotor shaft bearing and rotor shaft, and independent switch and rotor control means both disposed at the opposite end of said frame.

Signed at Chicago, 111., this 2nd day of Dec., 1926.

PAUL A. CHAMBERLAIN.

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