US1876913A

US1876913A - Sound reproducing machine

Info

Publication number: US1876913A
Application number: US295029A
Authority: US
Inventors: Alfred N Goldsmith
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1922-09-09
Filing date: 1928-07-24
Publication date: 1932-09-13
Anticipated expiration: 1949-09-13

Description

Sept. 13, 1932; I ANGQLDSW'TH-Y] fi,s7 e,9134

SOUNDTREPRQDUCING'MACHINE 7 7 Original Filed Seprl. 9,1922 5 sheets-sheet 1 o o o i:

16 INVENTOR I ALFRED N- GOLDSMITH v BY ORNEY P 13, 2 A. N. GOLDSMITH 1,875,913

SOUND REPRODUCING MACHINE Original Filed Sept. 9, 1922 5 Sheets$heet 2 'INVENTOR ALFRED N OLDSMITH LQM 4% A TORNEY Sept. 13, 1932..

A. N. GOLDSMITH 500m) REPRODUCING magma inal Filed Sept. 9.

1922' 5 Sheets-Sheet 3 Orig INVENTOR ALFRED N. GOLD SMlTH BY ikflgwd TORNEY- Sept. 13, 1932. A. N. GOLDSMITH s'ounn REPRODUCING MACEINE Original Filed Sept. 9. 1922 5 Sheets-Sheet 4 INVENTOR ALFRED N. GOLDSMITH nagwm A ORNEY Sept. 13, 1932. A. n. GOLDSMITH SOUND REPRODUCING MACHINE Original Filed Sept. 9, 1922 5 Sheets-Sheet 5 INVENTOR A ED N. GOLDSMITH BY eb WM A ORN EY Patented Sept. 13, 1932 nmransraras Parser orrica oanrann n. eonnsnrrn, or ivrounr vnnnoimnnw YOBK,VA;SSIG1\TOR T0 RADIO coaronarion or AIJIERIGA,ACORPOBATIO1\T or DELAWARE SOUND REPRODU'GING MACHINE Original application filed September 9, 1922, Serial 'No. 587,067, now Patent No, 1,721,151, dated. July 16, 1929. Divided and this application-filed'l'uly 24, 1928. Serial No. 295,029.

This application is .aldivisional application of my copending application on a sound reproducing machine filed in the United States Patent Oflice September 9, 1922, Serial No, 587,067, which became'Patent No. 1,721,- 151, July 16, 1929. a

This invention relates to sound reproducing machines, and an object of'the invention is to provide a machine which will be very convenient in operation and willloe capable of aifording a Wider range of servlce thansound reproducing machines as formerly constructed: 7 1

To this end an important feature ofthe invent-ion resides in the provision of a casing in whicha horn is installed and a member mounted on the casing for movement rela-,

tively thereto and supporting a set of sound 3 reproducing apparatus. The invention contemplates more particularly the provision of radio receiving apparatus connectedto the horn of the machine and mounted in the cover, the cover being so mounted on the body portion of the machine casing and the radio receiving apparatus being so con structed and arranged that in the open position of the cover, the controlling elements of the radio receiving apparatus are disposed on the front face of the cover in convenient position for manipulation by the operator.

In accordance with another feature ofthe invention, a casing is provided comprising a plurality of portions connected together for relative movement, and sets of soundreproducing apparatus are mounted in respective portions of the casing. Preferably and in the illustrated embodiment of the invention, the sets of sound reproducing apparatusare provided with controlling elements, which in the normal positions of the portions of'the casing'are contained within the casing so as to be invisible, the controlling elements of the sound reproducing apparatus and the portions of the casing being, however, so constructed and arranged as to render the controlling elements visible upon relative move ment of the portions of the casing. The controlling elements of one set of sound reproducing apparatus in the normal positions of the portions of the casing are located close to'the controlling elements of the other set inorder to conserve space within the casing, and the controlling elements of the respective sets are separated from-each other upon relative movement of the portions of the casing, so as to render them readily accessible to the operator.

A further important feature of the invention resides in the provision in a casing comprising a main body portion and a cover portion of phonographic apparatus and radio receiving apparatus mounted respectively in the body portion and the cover portion.

The cover is preferably formed in two parts, I

one of which provides a top wall for the cover and the other of which is in the form of a member spaced from the top wall to provide a chamber between the wall and said member.v within which the radio receiving apparatus is mounted, and the controlling elements of the radio receiving apparatus are preferably extended through one of the parts of the cover for adjustment from outside of the chamber. In order to enable the exterior surface of the cover to present a smooth and unbroken appearance and to cause the controlling elements of the radio receiving apparatus to be disposed in a convenient position for actuation by the operator when the cover is opened, one of the parts of the cover is preferably formed as a panel supported within the other part, the radio receiving apparatus being mounted on the panel and comprising controlling elements extended through it for adjustment from the side of the panel which is exposed when the cover is opened, and the panel being perforated to receive thevacuum tubes of the radio receiving apparatus in order to en ablethe tubes also to be rendered accessible from the exposed side of the panel for inspection and replacement. The exposedside of the panel may be, and preferably is, also provided with means distinct from the controlling elements of the radio receiving apparatus for facilitating the adjustment of such elements.

In accordance with a still further feature of the invention, a two-branch horn is provided within the casing of the machine and two sets of sound reproducing apparatus are connected respectively to the branches of the horn. The machine also preferably comprises a device for controlling the operation of one of said sets of apparatus and means for automatically shutting off communication between the main body of the horn and one of its branches upon actuation of the device to cause communication of sound to the other branch. In another aspect, the invention contemplates the provision of a two-branch horn mounted in a casing and having phonographic apparatus connected with one of its branches and a telephone connected with its other branch, the telephone being in turn connected with radio receiving apparatus mounted in the cover portion of the casing.

The invention also aims to provide a radio receiver which may be employed as an attachment for phonographs, said attachment being constructed so as to enable it to be mounted in the casing of a phonograph without increasing the size of the casing or reducing the available size of any of its compartments. Preferably and as shown, the attachment comprises a panel constructed to fit within the cover of a phonograph casing and radio receiving apparatus carried by the panel and connected to the horn of the phonograph.

Still other novel and useful features of the invention, including the provision of a door removably mounted on one side of the phonograph casing to enable ready access to be obtained to the compartment which contains the horn and the parts associated therewith, will appear as the description proceeds and will be pointed out in the appended claims.

In the drawings, in which like reference numerals designate like parts throughout the various views Fig. 1 is a front view of the upper part of a machine embodying the invention with the cover of the machine in open position and with a portion of the machine casing broken away so as better to reveal the phonographic apparatus;

Fig. 2 is a view in perspective with the plate in the upper part of the casing removed so as to reveal the horn;

Fig. 3 is a perspective view of thepanel supported in the cover and the radio receiving apparatus carried by it;

Fig. 4 is a perspective View taken from the rear of the machine and with the door on the rear side of the upper compartment of the casing in open position so as to reveal the horn and parts associated with it;

Fig. 5 is a view in sectional elevation from front to rear of the machine:

Fig. 6 is a plan view, partly broken away, of the construction at the juncture of the main body of the horn and its branches;

Fig. 7 is a View of the machine in side elevation, partly broken away so as to show the radio receiving apparatus, the phonographic apparatus and the several compartments of the casing;

Fig. 8 is a view showing the switch mechanism embodied in the radio receiving apparatus; and

Fig. 9 is a diagrammatic representation of the circuit arrangement of the radio receiving apparatus.

The illustrated machine comprises a casing having a main body portion 2 and a cover portion 4 hingedly mounted at the top of the body portion 2, as indicated at 6. The body portion 2 of the casing is of cabinet form and comprises compartments 8 for containing phonograph records, etc., and a compartment 10 in its end in which is located a horn 12. The horn 12' flares outwardly from its rear end to its forward end, designated by 14, where it is connected with a wooden tube 16 which constitutes an extension of the horn 12 and is flared in continuation of the sides of the horn 12.

Preferably and as shown, the horn 12 is formed at its rear end with two

branches

18 and 20, the former extending upwardly and the latter extending first laterally and then forwardly within the compartment 10 of the casing. The branch 18 of the horn is seated at its upper end in the top wall 22 of the body portion 2 of the easing and is connected above the wall 22 with a tubular arm 24 of known construction in sound reproducing apparatus of the phonograph type. The arm 24 at its forward end carries a sound box 26 which may also be of known construction and arrangement. The phonographic apparatus of the machine further includes a plate 28 mounted in an opening 30 in the wall 22 and a turntable 32 journalled on the plate 28 and arranged to be rotated by a spring motor 34 supported on the under side of the plate. The turn-table 32, is adapted to have a phonographic record placed thereon, and in the operation of the phonographic apparatus the sound box 26, on the arm 24, is thrown forwardly from the position shown in Figs. 2, 5 and 7 in a known manner to cause a needle 35 on the sound box to engage with and ride upon the record.

The sound box 26 constitutes an element by means of which the operation of the phonographic apparatus may be controlled, and the phonographic apparatus also preferably comprises other controlling elements (not shown) of the kind usually provided for governing the rotation of the table 32.

The lateral branch 20 of the horn 12 is connected to a second sound reproducing apparatus which is of the radio receiving type. As shown, the branch 20 is gradually tapered inwardly to its forward end where it'is provided with a telephone 36 connected with the radio receiving apparatus. The cover por tion 4 of the casing of the machine is prefer ably constructed in two parts, one of such parts being in the form of a panel 40 sup ported within the other part and spaced from the top Wall 42 of the other part to provide a chamber 44 between the parts. The chamber 44 of the two-part cover is adapted to contain radio receiving apparatus, and in order to enable the chamber to be made of sufiicient size to contain the radio receiving apparatus and yet avoid mechanical interference With the phonographic sound box 26, even though the space within the cover is small, the panel 40 may be inclined downwardly from the rear end to the forward end of the cover, with relation to its top wall 42, as clearly shown in Figs. 5 and 7. 2

In the illustrated construction, the radio receiving apparatus comprises a primary inductance coil 46 mounted on the panel 40. 3, in coupled relation with a smaller coil 48, which is interposed in the circuit of a secondary inductance coil 50. The primary and secondary circuits of the radio receiving apparatus include

condensers

52 and 54 respectively. As shown, the condensers are of the type comprising semi-circular plates which are alternately fixed and movable. The movable plates of the condenser 52 in the primary circuit are mounted on an arbor 56 which extends through the panel 40 of the cover and is provided on the exposed side of the paneloutside of the chamber 44 with a disc 58 co-acting with a pointer 60 carried by the panel. Fast on the end of'the arbor 56 Within the chamber 44 of the cover is arelatively large spur gear 62 meshing with a small pinion 64 fixed to the end of a stud shaft 66. The shaft 66 is also extended through the panel 40 and is provided on the exposed side of the panel with a knob 68 which may be turned to adjust the condenser.

The condenser 54 in the secondary circuit of the radio receiving apparatus is similar in general construction to the condenser 52 in the primary circuit and includes an arbor 70 extended through the panel 40 and provided on the exposed side of the panel outside of the chamber 44 with'a disc 72. In order to guide the uses of the machine in adjusting or tuning the radio receiving apparatus. the disc 7 2 is preferably graduated or indexed with its front face, as clearly appears from Fig. 1, and has associated with it a pointer 74 carried by the panel 40. Mounted on the end of the arbor 70 within the chamber 44 is a spur gear 76 which meshes with a small pinion 7 8 on a stud shaft 80, also extended through the panel 40 of the cover and provided on the exposed side of the panel with a knob 82 by which the condenser 54 may be readily adjusted.

i The radio receiving apparatus comprises are employed, and the panel 40 is formed with a single rectangular opening 94, extendin substantially from side to side of the cover 4 and containing a similarly shaped plate 96 spaced at its edges from the edges of the opening 94 so asto be freely movable relatively to the panel 40. The plate96 is provided on its'exposed face with supports 98, Figs. 5 and 7, upon which the vacuum tubes are mounted in substantial parallelism With the plate 96. An apertured plate 99 is mounted on the panel 40' within the chamber 44 in such a position as to prevent access to the parts within the chamber 44 from being obtained by pushing back the plate 96 in the opening 94 of the panel. In order to prevent shocks to which the cover'4'fof the casing may be subjected from being transmitted to the vacuum tubes 84-92, the plate 96 is yieldably supported on the panel 40; As shown, the supporting means comprises posts 98 located adjacent to the corners of the plate 96 and connected by relatively stiff coiled springs 100 with posts or screws 102 mounted onthe panel. The springs 100 may be filled with absorbent cotton or other suitable material for damping any vibrations of the plate 96, caused by movement of the cover. It is recognized that the arrangement of the vacuum tube with relation to the panel 40 may be widely varied; for example, the tube may be located in separate openings in the panel and may be disposed at right angles to it.

The circuit of the secondary inductance coil 50 .and condenser 54 is connected to the grid of one of the vacuum'tubes, for example, the tube 84, the plate circuit of the tube 84 including a switch 104 at the left hand end of a switch block 106, Fig. 3, mounted on the panel 40. As shown, the switch 104 includes a segment 108 composed of brass or other suitablemetal, four contact studs 110, and a contact member 112 carried by a member 114 pivoted centrally on the switch block 106 and composed of insulating material.

The contact member 112 comprises parts are ranged for engagement with the segment 108 and one of the four contact studs 110 depending upon the position of the member 114 on the switch block 106.

Each of the four contact studs is'connected with the primary coil of one of four radio" frequency transformers 116, supported on the panel 40 within the chamber 44 of the cover 4, the secondary coils of the transform ers 116 being connected to each of four contact studs 118 of a switch 120 at the other end of the switch block 106. The switch 120 also comprises a segment 122 arranged to be connected with any one of the studs 118 by a contact member 124 carried by the pivoted member 114 and having parts arranged for engagement respectively with the segment 122 and one of the studs 118.

The inductance of the primary and secondary coils 46 and 50 may be respectively regulated by suitable switches. As shown in Fig. 8, the switch for the primary inductance coil 46 comprises a contact post 126 connected with the antenna circuit, and a contact member 128 fulcrumed on the post 126 and movable into engagement with any one of a series of four contact points 130 connected to suitably spaced taps along the coil 46. The switch for controlling the inductance of the secondary coil 50 comprises a post 132 in circuit with the coupling coil 48 and having fulcrumed thereon a contact member 134 movable into engagement with any one of four contact studs 136 electrically connected to the secondary inductance coil at spaced points along the coil. The contact members 128 and 134 extend beyond their

fulcrum posts

126 and 132 respectively and are connected to a bar 138, which in turn is operatively connected to a lever 140 fixed to a stud shaft 142 mounted upon and extending through the panel 40 of the cover. The lever 140 is formed with a laterally extending portion 144 pivotally joined to one end of a bar 146, the other end of which is pivotally connected to the member 114 of the

switches

104 and 120 so as to operate the

switches

104 and 120 simultaneously with the movement of the bar 138 and the consequent operation of the switch members 128 and 134 of the inductance coils. The stud shaft 142 is provided on the side of the panel outside of the chamber 44 of the cover 4 with a knob 148, and arranged for movement with the knob 148 is a pointer 150 coacting with a segmental scale bar 152 fixed on the exposed side of the panel 40 and preferably graduated to indicate the wave lengths for which the inductances of the coils 46 and 50 are adjusted.

The segment 122 is connected to the grid of vacuum tube 86, the plate circuit of which includes the primary of a step-up transformer 152 supported by a bracket 154 on the inner side of the panel 40. The secondary of the step-up transformer 152 is interposed in the grid circuit of the vacuum tube 88, and the plate circuit of the tube 88 in turn includes the primary of a transformer 156 sup ported by a bracket 158 mounted on the panel 40 adjacent to the transformer 152. The secondary of the transformer 156 is connected in circuit with the grids of both of the

vacuum tubes

90 and 92, and the plate circuit of the tubes 90and 92 comprises the primary of a transformer 160 supported on the panel 40 by a bracket 162. As shown, the

brackets

154, 158, and 162 of the

transformers

152, 156 and 160 respectively are mounted on the panel 40 adjacent to the edge of the plate 99 which surrounds the opening 94 in which the vacuum tubes are located.

Mounted on the inner surface of the panel 40 between the radio receiving apparatus and the panel is a metal plate 164 which serves as an electrostatic and magnetic shield for the radio receiving apparatus. The metal plate 164 further provides a convenient means for grounding certain of the circuits of the apparatus. The parts of the radio receiving apparatus which are not grounded are insulated from the metal plate 164 and may be supported on posts or legs 165, such as are shown in connection with the primary inductance coil 46. The metal plate 164 is connected to ground by means which will be hereinafter more fully described, and which includes

terminal blocks

168 and 170 located respectively on the panel 40 and in the upper part of the main body of the casing, of the ma chine and at the rear of the machine.

As shown most clearly in Figs. 5 and 7, the primary inductance coil 46, coupling coil 48 and primary condenser 52- are housed in a metallic shield 171 shaped to correspond with the inner surfaces of the cover 4. The secondary inductance coil 50 and the secondary condenser 54 are housed in a similar shield (not shown). The shields 171 are mounted on the ground plate 164 in spaced relation to each other and act not only to prevent physical injury to the enclosed parts during the insertion or removal of the panel 40, but also to shield the two circuits from electrostatic and magnetic fields produced by external agencies and to prevent electrostatic or magnetic interaction between the two circuits.

The circuit arrangement and manner of operation of the radio receiving apparatus will be best understood by reference to Fig. 9 in which the antenna is designated generally by 172 and is joined to a connecting stud 174 on the terminal block 170 supported on the main body portion 2 of the casing. From the connecting stud 17 4 the antenna current passes along a flexible lead 17 6 to a connecting stud 17 8 on the terminal block 168 located on the panel 40. A wire 180 conducts current from the stud 178 to the contact ost 126 of the switch 128 of the primary inductance coil 46. From the switch 128 the current passes through a smaller or larger portion of the length of the inductance coil 46, according as the switch is arranged to engage the contact point 130A, 130B, 130C or 1301). As shown, the switch. 128 is in contact with the point 130C, so that a relatively large portion of the inductance of the primary coil 46 is included in the antenna circuit. The antenna circuit is continued through the primary tuning condenser 52 and'then'ce to ground through the metal plate 164. The connections between the metal plate 164 and ground include a wire 181 attached to a connecting stud 182 on the terminal'block 168, a flexible lead 184 connecting'the stud 182 to a stud 186 on the terminal block 17 O and a wire 187 leading from the connecting stud 186 to ground. A second wire 188 connects the stud 186 to the negative side of a battery 166 (Fig. 9). V

The coupling coil 48 in the secondary circuit of the radio receiving apparatus is connected at one of its ends to ground by a wire 194 and at its other end to the contact post 32 of the switch 134 of the secondary inductance coil 50. Assuming that the switch 128 of the primaryinductance coil 46 is set to contact with thestud 130 .C, then by re'a-. son of the common operating bar 138 for the switches 128 and 134, the switches 134 of the second inductance coil 50 will be set to contact with stud 136 C so as to cause the inductance in the secondary tuning circuit of the radio receiving apparatus to correspond with the inductance in the primary or antenna circuit. The end of the inductance coil 50.0pposite from its connection with the switch 134 is connected with the grid of the Vacuum tube 84, and the secondary tuning condenser 54 is connected in shunt with the coupling coil 48 and inductance coil 50. j

' The vacuum tube 84 acts as a-radio frequency amplifier, and its plate circuit is taken from the battery 166 through a wire 196 at a suitable voltage, for example, volts, to a connecting stud 198 on the terminal block 170. The stud 198 is joined by a flex: ible lead 200to a connecting stud 202 on the terminal block 168 of the cover 4. A wire 204 connects the stud 202 to a conductor206 which is in turn connected to the primary coils of the radio frequency transformers 116. As shown, the current passes through the primary coil of the transformer 116 C to the contact stud 110 G of the switch104. The contact member 112 of the switch 104 conducts thecurrent to segment 108 of the switch, and from thence to the plate of the vacuum tube 84. The plate circuit ofthe tube 84 is completed by connecting the filament of the tube to groundthrough the metal;

plate 164. e 7

Each of the secondary coils of the radio frequency transformers 116 is connected at one end to ground through the metal plate 164 and at its other end to one of the contact studs 118 of the switch120. In the illustrated position of the parts, the current passes from the secondary coil of the transformer 116 C to the stud'118 C then through the contactmember 124 of the switch 120 to the segment 122 and from thence to the grid of thevacuum tube 86. The illustrated ma-v "chine is particularly designed to receive As clearlyappears from Fig. 3, the radio frequency transformers 116A, 11613, 1169 and 116Dprogressively-increase in size from 116A to116D and have varying constants corresponding respectively to the constants of the primary and secondary tuning circuits when the switches 128 and 134 are in engagement with the contact studs (130, 136) A, B, C and D. It will also be understood that,rif the contact members. 112 and 124 of the.

switches

104 and 120 are in contact with the studs 110A and 118A, the plate current of the vacuum tube 84 will not pass through the transformer 1160 but will pass througlrthe primary coil of the transformer 116A, and the grid of the detector tube 86 will be connected to the secondary of the transformer 116A insteadof to the transformer 116G; Manifestly, if the switches 104and 120 are set at the contact posts (110, 118) B or D, the radio. frequency transformer 116B or D respectively will be connected in the radio re-;. X

ceiving circuit. It will be apparent from the description heretofore given of the connec' tions between the

switches

128, 134, 104 and 120 not only that the constants of the secondary tuning circuit are changed in accordance with changes in the tuning of the primary circuit, but also that the constants of the radio frequency transformer apparatus are correspondingly changed simultaneously with changes in the constants of the tuning circuits. Y The plate circuit of the vacuum tube 86 includes the conductor206 and its connections with the battery 166 and further includes a wire 214 leading from the conductor 206to one end of the primary coil of the step-up transformer152. The other end of the primary of thetransformer ;152;is connected with the plate of the tube 86, and the plate leading to a connecting stud 222 on the terminal block 168. The connecting stud 222 is in turn joined by a flexible lead 224 with a stud 226 on the terminal block 170, and a wire 228 leads from the stud 226 to the battery 166. As indicated in Fig. 9, the wire 228 is connected to the battery 166 at a point having a potential of 3 volts with respect to the negative end of the filament, inasmuch as excellent results have been obtained in practice from the use of such potential.

The plate circuit of the audio frequency amplification tube 88 includes the primary coil of the transformer 156 and a wire 230 connecting the coil with the conductor 206. The above circuit is completed through the filament to ground at the metal plate 164.

The secondary coil of the transformer 156 is arranged in the grid circuits of both of the

vacuum tubes

90 and 92, the arrangement being similar to the so-called-push-pull circuit, already known in the art. The secondary coil of the transformer 156 is also connected by a wire 232 to the conductor 220 leading to the battery 166 through the wire 228. The plate circuits of the

vacuum tube

90 and 92 include the conductor 206 which is common to all of the tubes. The connection of the filaments of the

tube

90 and 92 to ground at the metal plate 164 completes their plate circuits. The circuits of the

vacuum tubes

90 and 92 afford a second step of audio frequency amplification in addition to the first step produced by the tube 88.

The current for heating the filaments of the vacuum tubes 8492 is taken from the battery 166 at relatively low potential, such as, for example, 4, 5 volts, and is conducted along a wire 234 to a connecting stud 236 on the terminal block 170 and from thence through a flexible lead 238 to a connecting stud 240 on the terminal block 168. The current then passes to a conductor 242 common to the filaments of all of the vacuum tubes. The heating circuits are completed through the connection of the filaments to the metal plate 164.

The plate circuit of the second audio frequency amplification unit comprising the

vacuum tubes

90 and 92 is transmitted by the transformer 160 to a circuit including a wire 244 joined at one end to the groundplate 164 and at its other end to a connecting stud 246 on the terminal block 168. The stud 246 is in turn connected by a flexible lead wire 248 to a stud 250 on the terminal block 170, from which a Wire 252 leads to a switch 254. The switch 254 is normally closed so that the current induced in the wire 244 is conducted through a binding post 256 and wi're'258 to the telephone 36 mounted on the lateral branch of the horn 12. The return circuit of the telephone is through a wire 260 to the wire 188 and thence to the battery 166 and ground. A condenser 262 is preferably arranged in shunt with the telephone 36 to im prove the tone of the speech or music delivered thereby.

In order that external headband or ear telephone receivers may be employed, when desired, to enable reception from distant broadcast stations or to enable one or more persons to receive speech or music from the radio receiving apparatus without emission of sound from the horn 12 of the machine, ametal sleeve 264, Fig. 7, is mounted in the body portion 2 of the casing in electrical connection with the wire 260 between the telephone 36 and the ground wire 188. As shown, the metal sleeve 264 is arranged to receive a plug connected with the headband or ear telephones, and the switch 254 in the circuit of the telephone 36 is arranged in the machine with reference to the sleeve 264, so that the insertion of'the plug into the sleeve breaks the circuit of the telephone 36 at the switch 254 and com pletes a connection from the wire 252 through the headband telephone and the sleeve 264 to the wire 260 and thence to ground.

The radio receiving apparatus of the machine is thrown into and out of operation by a main switch 266, Fig. 1, mounted on the panel 40 of the cover 4 and connected to any desired part of the circuit arrangement of the apparatus. As shown in Fig. 9, the switch 266 is connected in the circuit 234-242, which conducts the heating current to the filaments of'the vacuum tubes.

In order to prevent sound communicated to the horn 12 through one of its

branches

18 and 20 from entering the other branch and setting up vibrations therein which might interfere with or deleteriously affect the quallty of the sound emitted from the horn, the horn is provided with a valve 267, Fig. 6, pivotally mounted at the junction of the

branches

18 and 20. The valve 267 is arranged to swing between two positions, in one of which as shown in full lines in Fig. 6, it allows communication between the upright branch 18 and the body of the horn and shuts off-communication between the body of the horn and-the lateral branch 20, and in the other of which, as shown in broken lines in said figure, it allows communication between the main body of the horn and the lateral branch 20 and shuts off communication between the horn and the upright branch 18. Means is preferably provided for automatically operating the valve 267 so as at all times to allow communication between the main body of the horn and the branch to which sound is being communicated and to shut off communication between the body of the horn and the other branch. As shown, said means comprises an arm 268 fixed to the valve 267 and normally maintained by a spiral spring 270 in theposition shown in full lines in Fig. 6, in which the main body of the horn 12 is in communication with the upright branch 18 leading from the phonographic' apparatus and is shut off from communication with the lateral branch 20 connected with the tele-v phone 36 of the radio receiving apparatus. In order to cause the valve 267 to be moved from the full line position to the broken line position, as shown in Fig. 6, upon operation of the radio receiving apparatus, an electromagnet 27 2 of the solenoid type is mounted on the horn adjacent to the arm 268, and the arm 288 is formed with a projection composed of magnetic material and extended within the electromagnet 27 2. As shown most clearly in Fig. 9, the electromagnet 272 is interposed in the filament heating circuit of the vacuum tubes, so that when the switch 266 is thrown in to initiate the operation of the radio receiving apparatus, the current is caused to flow through the electromagnet. The consequent attraction of the arm 268 by the electromagnet 2Y2 swings the valve 267 from the full line position, shown in Fig. 6, to the broken line position, thereby placing the body or" the horn 12 in communication with the branch 20 and shutting oii' communication between the main body of the horn and the upright branch 18.

As shown in the drawings, the terminal block 168 on the panel 40 of the cover a is arranged centrally of the rear end oi the panel, and the

flexible lead wires

18 i, 200, 248 etc. are led from the terminal block 168 along the rear inner surface or" the cover, where they may be held in place by asuitable cleat274: to

the terminal block 170 which dependsifromthe top plate 22 of the main body portion 2 of the casing. The connecting wires between the terminal blockl'YO and the ba tery 166 preferably contained in a single vcable2'? 6 extending downwardly to the bottom of the compartment 10 or" the casing and leading to contacts 278, Fig. 2 secured to the floor of the compartment 10 and having .the wires connected therewith. The radio receiving apparatus is so organized that it requires no external source of power, only replaceable dry batteries being needed for the vacuum tubes, so that the machine may be used irrespective of any external power supply. .The batteries may be installed in a single container or box 280, Fig. 1, provided on ts bottom with suitable contact plates arranged to engage the contacts 27 8 when the battery is inserted Within the casing. The insertion and removal of the batteries may be further l acilitated by the provision of tracks 282 secured to the floor of the compartment 10 and adapted to slidably engage suitably formed parts on the battery box 280. To the end that shocks may be avoided, the closing moyement of the cover l is controlled. by a device 284, Fig. 4e, mounted in the compartment 10 of the body portion 2 of the casing and op eratively connected with the cover 4 by a link 286, Fig. 2. Further. disclosure of the battery 1'66'and the means for controlling the movement of the cover t is believed to be unnecessary, inasmuch as the construction and arrangement of such parts constitute per se no part of the present invention.

Ready and convenient access is permitted to the compartment 10 of the body portion 2 of the casing of the machine by means of a door 286 hinged at 288 at the rear side of the compartment. By reason of the PI'OViS'. ion of the hinged door 286 the battery box 280'may be easily replaced, and any necessary or desired repairs or adjustments may be readily made to the partscontained in the compartment 10, including the horn 12, the cover controlling means and the telephone 86.

The amplitude of the speech or music emitted by theradio receiving apparatus may be increased or decreased by effecting a closer or looser coupling between the coil 48 of the secondary tuning. circuit and the primary coil d6 of the antenna circuit. Such an adjustment may be effected by turning the knob 290 mounted on the exposed side of the panel 40, Fig. l and provided with suitable means for indicating the appropriate adjustment for rendering the sound louder or softer.

From the foregoing, it will be understood thatthe

condensers

52 and 54 in the primary and secondary tuning circuits respectively, of the radio receiving apparatus, the knob 148 for operating the switches 128 and 134; of the inductance coils 46 and 50- and the switches 10% and 120 of the radio frequency transformers 116, the main switch 266, and the knob 290.constitute controlling elements for the radio'receiving apparatus and that these elements-are extended through the panel 40 of the cover l so as to enable them,

to be operated "from the exposed side of the panel. It will also be understood by reference particularly to Fig. 5 that by the provision of the radio receiving apparatus on a movable member, such as the cover 4 of the machine, the controlling elements of the radio receiving apparatus may normally, that is, in the closed positionof the cover or other movable mounting be arranged in close juxtaposition to the controlling, elemerits of the phonographic apparatus so as to conserve spacewithin the machine casing.

For the sake of clearness of illustration, the cover 4: as shown in Fig. 5 of the drawings, is relatively deep, and the controlling elements oi": the radio receiving apparatus are spaced somewhat further than is necessary from the phonographic apparatus. It will, therefore be seen that the radio receiving apparatus may be installed in a cover of considerably less depth than that shown in F i n. 5 without danger of interference with the sound box 26 or other parts of the phonographic apparatus of the sound reproducing machine. When the cover 4 is in its normal or closed position, the controlling elements of the radio receiving apparatus are invisible, so that-the sound reproducing machine of the present invention may be caused to present a smooth and unbroken appearance over its entire exterior surface. It will be noted, however, that when the cover 4 is opened, the controlling elements of the radio receiving apparatus are moved away from the phonographicapparatus so as to render them not only visible, but also readily accessible to the operator. In fact, when the cover 4 is fully opened, the controlling elements of the radio receiving apparatus are mounted on the front face of the cover, Fig. 1 in an extemely convenient position for actuation by the operator. Furthermore, the provision of theradio receiving apparatus in the cover of the machine casing enables a sound reproducing machine comprising both phonographic and radio receiving apparatus to be constructed with no greater expense as to the cabinet part of the machine than in the case of a phonograph only, inasmuch as the radio receiving apparatus is mounted in a space, which in a phonograph is totally unused.

The operation of the controlling elements of the radio receiving apparatus is facilitated in the illustrated machine, not only by mounting the radio receiving apparatus on the machine in such a manner as to render its controlling elements extremely convenient for normal operation, but also by the provision of means for indicating the order in which the controls of the radio receiving apparatus should be adjusted. Such indicating means is shown most clearly in Fig. 1 wherein the

numerals

1, 2, 3, 4 and 5 are applied respectively to the main switch 266, the wave length controlling means 148, the tuning condenser 54 of the secondary circuit, the condenser 52 of the primary circuit and the knob 290 for regulating the loudness of the sound emitted from the machine. The

numbers

1, 2, 3, 4 and 5 indicate to an unskilled operator that in the operation of the radio receiving apparatus the main switch 266 should first be closed, that the knob 148 should then be set in accordance with the wave length of the station which it is desired to receive; that the secondary condenser 54 should next be also adjusted to the desired wave length, and that the condenser 52 which may or may not be graduated should then be turned to the position which affords the best response, the knob 290 being finally set in the proper position depending upon whether it is desired that the speech or music being emitted from the machine be loud or soft. The provision of the above-described means distinct from the controlling elements of the radio receiving apparatus for indicating the order in which the controls should be operated, enables the production for the first time, so far as applicant is aware, of a radio receiving set which can be operated by an unskilled or uritrained person with practically as good results as by a skilled operator, and hence constitutes an important practical advance in the development of radio receiving apparatus for purposes of public information and entertainment.

The radio receiving apparatus of this invention may not only be incorporated in new.

sound reproducing machines comprising radio receiving apparatus and phonographic apparatus, but it may also be applied as a radio adjunct or receiver to phonographs already constructed and in use. Moreover, by reason of the construction and arrangement of the radio receiving apparatus, it may be applied to existing phonographs having compartments for containing phonographic apparatus and record albums respectively, without increasing the size of the phonograph casing or reducing the available size of any of its compartments, so that the usefulness of the phonograph is in no way affected or its operation interfered with by the addition of the radio receiver. The radio receiver is also so constructed that it may be applied to any suitable phonograph by a local electrician or carpenter.

Having described my invention, What I claim 1s:

1. In a sound reproducing machine, a casing comprising a main body portion and a member mounted on the body portion for movement relatively thereto, a horn mounted in said body portion, and radio receiving apparatus mounted on said movable member and comprising controlling elements normally contained within the casing so as to be invisible, said member and said controlling elements being so'constructed and arranged as to render the controlling elements visible and readily accessible to the operator upon movement of the member relatively to the body portion of the casing.

2. In a sound reproducing machine, a casing, a horn supported by the casing, a panel normally mounted on the casing with its under side facing toward the horn, and radio receiving apparatus mounted on the upper sideof the panel and comprising controlling elements extended through the panel for adjustment from the under side of the panel, said panel being so mounted on the casing as to enable it to be swung upwardly into a position in which the under side of the panel faces forwardly of the machine so as to cause the controlling elements of the radio receiving apparatus to be disposed in convenient positions for manipulation by the opera tor.

3. In a sound reproducing machine, a cas- 'ig comprising a main body portion and a cover portion, a horn installed in the main body portion of the casing, a panel mounted on the cover and spaced from the top wall are of the cover to provide a chamber between said panel and said top. wall, and radio receiving apparatus mounted on the panel within said chamber, said cover being mounted on the body portion of the casing so as to enable it to be swung upwardly and backwardly to an open position in which the exposed side of the panel faces forwardly of the machine, said radio apparatus comprising vacuum tubes and also comprising controlling elements extended through the panel for adjustment from the exposed side of the panel when the cover is in open position, and said panel being perforated to receive said tubes and thereby enable them to be rendered accessible from the exposed side of the panel.

4. In a sound reproducing machine, a casing, a panel connected to the casing for movement relatively thereto between closed and open positions and arranged in its closed position with one of its sides facing towards the body of the casing, and radio receiving apparatus mounted on the opposite side of the panel from said first mentioned side and comprising controlling elements extended through the panel for adjustment from the first-mentioned side when the panel is in open position.

5. In a sound reproducing machine, a casing, a panel hingedly connected to the casing for movement relatively thereto, and radio apparatus mounted on one side of the panel and comprising vacuum tubes and controlling elements, said panel being perforated to receive the vacuum tubes and thus enable them to be rendered accessible from the opposite side of the panel and said radio apparatus having its controlling elements extended throug.1 the panel for adjustment from the opposite side of the panel.

6. In a sound reproducing machine, a casing, a two-part cover hingedly connected to the casing and comprising a top wall and a member spaced from said top wall to provide a chamber between said wall and said member and radio receiving apparatus mounted on the cover within said chamber and comprising controlling elements extended through one ofthe parts of the cover for adjustment from an exposedside of the cover.

7. In a sound reproducing machine, a cas ing, a two-part cover hingedly connected to the casing and comprising a panel spaced from the top wall of the cover, and radio receiving apparatus mounted on the panel between said panel and said top Wall, said radio apparatus comprising controlling elements extended through the panel for adjustment from the exposed side of the panel.

8. In a sound reproducing machine, a casing comprising amain body portion and a cover portion, a panel mounted on the cover portion and spaced from the top wall of the cover portion to provide a chamber between said panel and said top wall and radio receiving apparatus mounted on the panel within said chamber, said radio apparatus comprising vacuum tubes and also comprising controlling elements extended through the panel for adjustment from the exposed side of the panel, and said panel being perforated to receive said tubes and thereby enable them to be rendered accessible from the exposed side of the panel.

9. In a sound reproducing machine, a casing comprising a body portion and a two-part cover formed to provide a chamber, radio apparatus mounted within the chamber of the two-part cover and comprising vacuum tubes and controlling elements extending through one of the parts of the cover for replacement and adjustment respectively from a position outside of said chamber.

ALFRED N. GOLDSMITH.