US1951542A - Radioreceiver - Google Patents

Description

March 20, 1934. BRADLEY 1,951,542

RADIORECEIVER Filed April 14, 1933 2 Sheets-Sheet l W xix hig ATTORNEY.

March 20, 1934. F BRADLEY 1,951,542

RADIORECEIVER Filed April 14, 1933 2 Sheets-Sheet 2 Patented Mar. 20, 1934 UNITED STATES PATENT OFFICE This invention relates to radio receivers and the object of the invention is to provide a radio receiver arranged to receive all waves from the very short wave bands through the higher broad cast wave bands.

One of the particular objects of the invention is to provide a series of radio frequency coils arranged to cover the different wave bands and provided with selector means for connecting the different coils into a circuit to receive the desired wave band.

A further object of the invention is to provide a standard on which the different radio frequency coils are mounted and provided with transversely aligned pin contacts for each coil and also provided with a movable bridge adapted to engage the pin contacts to connect the respective coil into the circuit, the bridge being movable by a rotating shaft to engagement with the pin contacts of the different radio frequency coils.

A-further object of the invention is to provide a device of the character described in which the pin contacts are arranged in five rows of four as transversely aligned pin contacts, each row providing contacts for a single coil and the five rows providing contacts for the five radio frequency coils.'

Another object of the invention is to provide a 30 bridge adapted to be moved longitudinally of the standard and arranged to contact the contact pins for one coil at a time, the contacts to one coil being broken before the next coil is brought into the circuit.

A further object of the invention is to elimihate the dead end losses normally occurring with a device of this character.

These objects and the several novel features of the invention are hereinafter more fully described and claimed and the preferred form of construction by which these objects are attained is shown in the accompanying drawings in which- Fig. 1 is a side elevation of a radio receiver embodying my invention.

Fig. 2 is an enlarged section taken on line 2-2 of Fig. 1.

Fig. 3 is an enlarged section taken on line 3-3 of Fig. 1.

Fig. 4 is a diagrammatic circuit with which the device is used.

The device comprises an insulating standard 1 provided with end plates 2 and 3. A shaft 4 is rotatably mounted in the end plates 2 and 3 as and is provided with a spiral groove 5 out therein. The end plates are also connected by two guide rods 6 and 7, shown more particularly in Fig. 2, and a bridge 8 of insulating material is provided having guide brackets 9 secured thereto and movable longitudinally of the guide rods 6 and 7. A bracket 10 is also secured to the center of the bridge and is provided with a nut portion 11 carrying two pins 12 and 13 riding in the spiral groove 5 and engaging in said groove on opposite sides of the shaft 4. By this arrange 66 ment, the shaft 4 may be rotated to move the nut member 11 and bridge longitudinally of the shaft in either direction. A selector plate 14 is stationarily mounted on the panel 15 so that the shaft 4 is rotatable therein and this plate is provided with a series of five recesses 16 into which the spring arm 17 may engage by turning the knob 18. At each end of the standard 1, a pair of brackets 19 are provided and a pair of longitudinal insulating strips 20 are mounted on these brackets.

For use with this device a series of five radio frequency coils are provided in which one coil covers a range from sixteen to thirty meters, another coil covers a range from twenty-nine to fifty-eight meters, another coil covers a range from fifty-four to one hundred and five meters, another coil covers a. range from one hundred to two hundred meters and the remaining coil covers a range from two hundred to five hundred and ten meters. Two of these coils 21 and 22 are provided on one strip 20 on one side of the device, as shown in Fig. 1, and two coils are provided on the other strip 20 on the right side of the device of which only the coil 23 is shown in Fig. 2. The fifth coil 24 is mounted between the two insulating strips 20.

Each coil is provided with a primary and secondary winding and on the coil 23, the primary winding bears the number 25 while the secondary winding carries the number 26. At the bottom, each coil is provided with four pins 27 which extend through the insulating strips 20. The four pins are arranged to provide two terminal contacts for the primary and two terminal contacts for the secondary winding. The primary leads 28 and 29 are connected to the contact pins 30 and 31 and the secondary leads 32 and 33 are connected to the contact pins 34 and 35. These contact pins are mounted in the insulating standard 1 and extend downwardly therefrom and are arranged so that the four pins are in alignment transversely of the standard.

The bridge 8 carries a set of four contact brackets 36 adapted to be moved into contact with the standard 1.

four contact pins, the four contact brackets 36 being aligned on the bridge 8 so as to contact the four contact pins simultaneously.

As will be understood from Fig. 1,- each coil is connected to a series of four contact pins similar to those shown in Fig. 2 and the five rows, as shown in Fig. 1, are aligned transversely of the As shown in Fig. 2, the contact pins are also aligned in four rows longitudinally of the standard 1. A longitudinal contact strip 37 is supported beneath the standard 1 adjacent to and parallel with each longitudinal row of contact pins and each contact bracket 36 is provided with a spring contact arm 38 riding in contact with the respective contact strip 37. Each contact strip 37 is provided with a lead 39 which is carried out to the end plate 2 and connected to a terminal 40, as shown at the left of Fig. 1. By this arrangement, four contacts 40 are provided in the end plate 2 for the four contact strips 37.

In operation, by turning the shaft 4, the bridge 8 is moved to bring the contact brackets 36 into engagement with the four contact pins 30, 31,

34 and 35. When this is done, the secondary.

contact pins 34 and 35 are electrically connected through the brackets 36 and spring arms 38 to the respective contact strips 37 and these contact strips arearranged to be connectedinto a radio receiving circuit by means of the terminals 40 to which the circuit leads may be electrically connected. At the same time, the primary contact pins 30 and 31 are also electrically connected by means of the contacts 36 and 38 to the respective contact strips v37 which are also connected by means of the terminals 40'into a receiving circuit.

Should the operator desire to receive another wave band, he continues rotating the shaft 4 to move the bridge 8 to contact the contact pins for the succeeding coils until the desired coil is properly connected into the circuit. i 1 By means of the spring arm 17 and the recesses 16 in the selector plate 14, the different tuning coils may be readily selected as the spring arm 17 drops into the respective recess as the contact brackets 36 contact the contact pins for the respective coils. By this arrangement, the operator may feel and see when the desired tuning coil is connected into the circuit.

A circuit for use in connection with this device is shown diagrammatically in Fig. 4. in which 25a, b, c, d and e represent the primary windings of the five radio frequency coils, while 261:, b, c, d and 4 represent the five secondary windings. The tuning condensers 41, 42 and 43 may be arrangedon separate shafts and a detector tube 44 is provided as well as an amplifier tube 45 and a rectifier tube 46 which is used in conjunction with the usual 110 volt alternating current supply. The out-put contacts 4'7 may be connected to a speaker or head phones as desired.

It will be noted in moving the bridge that the bridge may be moved in one direction by turning the shaft 4 in a clockwise direction and may be moved in the opposite direction by turning the shaft 4 in a counter-clockwise direction and the guide rods 6 and 7 act as guides to prevent twisting action of the bridge and hold the contact brackets on the bridge in position to contact the four respective contact pins of each coil simultaneously.

As will be noted from Figs. 1 and 2, the coils 'are arranged in different angular positions in in Figs. 1 and 3 may, if desired, be provided with indications on the face thereof to indicate the wave lengths or kilocycles of the different coils so that in turning the knob 18 and arm 17 the operator may readily see which coil is connected into the circuit.

From the foregoing description it becomes evi dent that the device is very simple and efficient in operation, will not easily get out of order, provides a positive means for connecting different radio frequency tuning coils into a circuit by rotationof a knob and provides a device which accomplishes the objects described.

Having thus fully described my invention, its utility and mode of operation, what I claim and desire to secure by Letters Patent of the United States is-- 1. In a radio receiver, a standard, a series of radio frequency coils mounted on the standard, a row of contact pins for each coil mounted in alignment transversely of the standard and electrically connected to the respective coil, the contact pins of the different coils being also mounted in alignment longitudinally of the standard, a contact strip mounted parallel with and in spaced relation with each row of longitudinally aligned contact pins, a bridge extending transversely of the standard and provided with aligned contact brackets arranged to engage each row of transversely aligned contact pins simultaneously, each contactbracket being provided with a spring arm electrically connected thereto and riding in engagement with the adjacent contact strip, the electrical connections for the contact strips being mounted at one end of the standard and means for moving the bridge longitudinally of the standard to bring the contact brackets into engagement with the successive transverse rows of contact pins.

2.'In a radio receiver, a standard, a series of radio frequency coils mounted on the standard, a row of contact pins for each coil mounted in alignment transversely of the standard and electrically connected to the respective coil, a bridge extending transversely of the standard and provided with aligned contact brackets arranged to engage each row of transversely aligned contact of the series may be placed in circuit through the positioning of the spring arm with the corresponding recess of the selector plate.

3. In a radio receiver, a standard, a series of radio frequency coils mounted on the standard, a series of contact pins for each coil and extending to the under side of the standard and arranged in rows both longitudinally and transversely of the standard and electrically connected to the respective coil, a contact strip for each longitudinal row of pins, a bridge extending transversely of the standard and provided with aligned contact brackets arranged to engage each row of transversely aligned contact pins and each contact strip simultaneously, a rotatable shaft, means for moving the bridge longitudinally of the standard by rotation of the shaft, a stationary selector plate, a knob for rotating the shaft and a pointer carried by the knob and movable over the face of the selector plate.

4. In a radio receiving set, a standard, a series of radio frequency coils differing one from another as to frequency and each having a primary and a secondary winding, a series oi-pins for each coil, two providing terminal contacts for the primary winding and two providing terminal contacts for the secondary winding, the said pins of each coil being mounted in the standard in a row transversely thereof, similar contact pins for each coil lying in longitudinal rows, a contact strip for each longitudinal row of pins connected with the receiving circuit of the set, a bridge moveable longitudinally of the standard having a series of contacts equal in number to the number of pins 01' a coil and positioned in a row transversely oi the standard, said standard also having a contact adjacent each of the last named contacts for the contact strips companion to each longitudinal row 01' pins, means for causing movement of the bridge longitudinally of the standard to place the successive coils in the receiver circuit, and an indicator in connection with said operating means enabling the operator to determine the coil in circuit with the set.

FREDERICK H. BRADLEY.

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