US2459038A - Combined toy railroad and sound producing means therefor - Google Patents
Combined toy railroad and sound producing means therefor Download PDFInfo
- Publication number
- US2459038A US2459038A US649877A US64987746A US2459038A US 2459038 A US2459038 A US 2459038A US 649877 A US649877 A US 649877A US 64987746 A US64987746 A US 64987746A US 2459038 A US2459038 A US 2459038A
- Authority
- US
- United States
- Prior art keywords
- sound
- record
- producing means
- sound producing
- means therefor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63H—TOYS, e.g. TOPS, DOLLS, HOOPS OR BUILDING BLOCKS
- A63H19/00—Model railways
- A63H19/02—Locomotives; Motor coaches
- A63H19/14—Arrangements for imitating locomotive features, e.g. whistling, signalling, puffing
Definitions
- This invention relates to a sound producing means for use with toy railroads.
- An object of this invention is to provide an electrical sound producing means whereby a loudspeaker may be placed in a moving car and different types of sound may be transmitted to the speaker as the car is moving over a track.
- Anotherl object of this invention is to provide a sound producing means of this type including a rotatable record having a sound track therein, and a pick up means for converting the sound track induced vibrations to electrical frequencies.
- a further object of this invention is to provide in combination with a loudspeaker and an amplier, an improved record and' operator therefor which is so constructed and arranged that a child can manually operate the operator and produce selected sounds impressed or cut in the sound tracks of the record.
- Figure 1 is a diagrammatic View of a device constructed according to an embodiment of this invention
- Figure 2 is a plan view of the record operator
- Figure 3 is a plan view partly broken away and in section of a modied form of the record operator.
- Figure 4 is a sectional view taken on the line 4-4 of Figure 3, y
- Figure 5 is a fragmentary sectional view taken on the line 5-5 of Figure 3.
- Figure 6 is a fragmentary sectional View taken on the line 6--6 of Figure 3.
- the numerals IIJ and I I designate a pair of rails over which a toy train is adapted to engage and the rails I and II are connected together by one or more connecting members I3.
- the connecting members I3 may constitute the ties for holding the rails I0 and Il in spaced parallel relation and these rails I0 and II may be of the sectional and disconnectible type.
- a third or intermediate r.rail I2 is disposed between the two rails I0 and II and is electrically insulated from these two rails.
- a loud speaker I4 shown in the diagrammatic view of Figure 1 is adaptedto be mounted on one of the cars or any element which is movable over the rails I0 and I I.
- the loud speaker I4 has connectedv thereto a pair of conductors I and I6 which are connected to rolling contacts I1 and I8 respectively which are engageable with the rails II 'and I2.
- An electrolytic condenser I9 is interposed in the vconductors I5 and is preferably a condenser having a capacity of 40 mfd.
- a record 20 In yorder to provide a means whereby theloud speaker I4 may be energized and sound produced therefrom, I have provided a record 20.
- the record in the present instance is in the form of ya disk which is mounted on a rotatable spindle l 2l operated by a conventional phonograph operating means 22.v A needle 23 engages in the.
- the amplifying unit 21 is of conventional construction and may embody one or more electronic tubes with associated apparatus.
- the output side of the amplifying unit 21 is connected by means of a pair of conductors 29 and 29 tothe rails III and I2.
- a condenser 39 is interposed in the conductor 29 and is here shown as ⁇ a condenser ⁇ having a capacity of 20 mfd.
- the transformer 3l includes a primary 32 having the opposite ends thereof connected by conductors 33 an-d 34 to a source of alternating current supply.
- also includes a secondary coil 35 which has the opposite ends thereof connected by means of conductors 36 and 31 to the rails II) and I2.
- a choke coil 38 ⁇ is interposed in conductor 36 and a second choke coil 39 is interposed inv conductor 31.
- These choke coils 38 and 39 are designed for the purpose of preventing the audio frequency from feeding back into the secondary coil 35.
- aL condenser 40 may be interposed between the two conductors 36 and 31 and between the choke coils 38 and 39y and the secondary 35.
- a second condenser 4I may be connected across the conductors 36 and 31 between thechoke coils and the rails I0 and I2.
- a simplified form of audio frequency generation in the form of record and operator thereof has been disclosed in Fig ures 3 to 6.
- a cylindrical record 42 is mounted on a platen 43 carried by a shaft 44.
- the shaft 43 is rotatably mounted in a housing 45 which is here shown as a rectangular housing embodying a bottom wall 46, opposite side Walls 41 and i3 and opposite end walls 49 and 50.
- the record 42 is provided with a plurality of circular grooves- 5I, 52 and 53, which are cut into the record 42 and which are designed for producing different types of sounds.
- groove 5I may be designed for producing the sound of a locomotive engine starting up, whereas groove 52 may have cut therein a sound track embodying a bell or other selected sound. It will be understood, of course, that there may be as many of these grooves as may be desired.
- a needle "56 which'r is carried ⁇ by eanelectrical pickup unit ⁇ 55 mounted on an arm 56 is adapted to engage in a selected one of the sound grooves.
- the pickup unit 55 is adapted to be connected by means of conductors 25@l and .26e tor'anframplifying unit for amplifying the sound'tozthefdesired amplitude.
- Arm 56 is carried by a sleeve 51 which is loosely mounted on a rod58.
- the rod-58 is disposed in a horizontal position and 'is iixedly secured by means of a bushing 59 to the end wall 5D.
- the sleeve is slidable and rotatable on the rod 58.
- the sleeve 57 engages through an opening-'68. whichis formed infthe end .wal1 49. andhas secured :to the-extended end thereof va -thandle or.
- Rocking of the-handlel ina-clockwise :direction zas' viewed @ Figure 5 will raise the-needlevd from 'one soundtrack and endwise movementoifthesleeve 5l ⁇ will shift thepickup mechanism :to'another soundtrack.
- a child .-may -readily fchange the 'needle 54.5 from onev sound track to another have provided aibarrBZ.
- the barf621 is oftriangular oonguration-eand 'is formed* with, a f plurality ⁇ ,of V- shapeda-notchesS .andoppositely inclined: ridges 63 between thenotches.
- Thebar-"BZ is *supportedzat the opposite'zend by the-end .wall :49.
- the farm 156 which carries: they electrical ypickup member-55-isi of triangular .configuration so that this Earm'rnayreadily engage in aselected one of the iV-.shaped ynotches 63.; c
- the indicati-ons ,-651 may be a-ppoint orwgraduatiorr line and may-alsoiincludefalegend designating the particularfsound trackassociated therewith.
- the indications Iiy are Ispaced lapart a distanceequal to fthe spacing Abetween the notches 63.
- .Transformer 3i is usedfor furnishing power to the engine motor 73.
- .Motor 'I3' has a conductor I4 connected to one side thereof, and a conductor I5 connectedto ,the opposite side thereof.
- ductor'II has apair of rolling contacts 'I6 connected thereto which engage rail I2 and conductor 'I5 has a rolling contact 'I'I connected thereto 'which engages'rail Ii.
- the loud speaker I4 will be mounted on one 'of the cars and this speaker is electrically connected through-appropriate shoes or wipers I'I and I8 to tracks Il and I2.
- the soundtrack ofv record 26 may be either -a-l spiral soundtrack ormay be of the continuous groove type, such asis shown in Figure :3 by thenumerals 5
- the sound which :is being reproduced in the loud speaker I4 is preferably a sound which will represent-the'conventional sounds of a steam locomotive fas 'the 'locomotive is starting up, the sounds ⁇ after the locomotive'has beenset inmotion and also the sound of thelocomotive'stopping.
- the sound may'be either a Whistleor a'bell, talking, singing, music, or a combination 'or'succession of these sounds.
- a sound I producing means comprising -an .fenclosed housing including-top, bottornfiront-rear and side Walls, aplaten rotatablycarried by said housing and having a driving connection -withan electric motormountedon said bottom wall, a record on said platen formed with aplurality of spaced apart sound tracks, ⁇ a soundpickup means including an arm of triangular-cross section for a portion-of its length, apickup member carried by said arm, and r'ockable supporting means ⁇ for said arm, said supportingmeans including a supporting ba'rxe'd 'relative to said housing and formed .with a plurality "of spaced notches, 'corresponding tothe 'spaced 'apart sound tracks on said record, with opp'ositely inclined ridges between sai'd notches in a selected one of which said triangularportion of said arm is adapted to engage, va pair vof horizontally ltelescoping members, the inner member
Description
Jan. 11, 1949;
J. H. MCKNIGHT 2,459,038 COMBINED TOY RAILROAD AND SOUND PRODUCING MEANS THEREFOR Filed Feb. 25, 1946 2 sheets-sheet 1 IN VEN TOR.
Jan. 1l, 1949. J H McKNlGHT 2,4'9,038`
COMBINED TOY RAILROAD AND SOUND PRODUGING MEANS THEREFOR Filed Feb. 25, 1946 2 Sheets-Shet 2 Z5 ya.
IN VEN TOR.
Patented Jan. 11, 1949 UNITED sTATEs PATENT OFFICE COMBINED TOY RAILROAD AND SOUND PRODUCING MEANS THEREFOR Joseph H. McKnight, Pittsburgh, Pa.
Application February 25, 1946, Serial No. 649,877
1 Claim. 1
This invention relates to a sound producing means for use with toy railroads.
An object of this invention is to provide an electrical sound producing means whereby a loudspeaker may be placed in a moving car and different types of sound may be transmitted to the speaker as the car is moving over a track.
Anotherl object of this invention is to provide a sound producing means of this type including a rotatable record having a sound track therein, and a pick up means for converting the sound track induced vibrations to electrical frequencies.
A further object of this invention is to provide in combination with a loudspeaker and an amplier, an improved record and' operator therefor which is so constructed and arranged that a child can manually operate the operator and produce selected sounds impressed or cut in the sound tracks of the record.
To the foregoing objects, and others which may -hereinafter more `fullyy appear, the invention consists of the novel construction, combination rand arrangement of parts, as will be more specifically referred to and illustrated in the accompanying drawings, but it is to be understood that changes, variations, and modifications may be 'resorted to which fall within the scope of the invention as claimed. f
In the drawing:
Figure 1 is a diagrammatic View of a device constructed according to an embodiment of this invention,
Figure 2 is a plan view of the record operator,
Figure 3 is a plan view partly broken away and in section of a modied form of the record operator.
Figure 4 is a sectional view taken on the line 4-4 of Figure 3, y
Figure 5 is a fragmentary sectional view taken on the line 5-5 of Figure 3, and
Figure 6 is a fragmentary sectional View taken on the line 6--6 of Figure 3.
Referring to the drawing, the numerals IIJ and I I designate a pair of rails over which a toy train is adapted to engage and the rails I and II are connected together by one or more connecting members I3. In practice the connecting members I3 may constitute the ties for holding the rails I0 and Il in spaced parallel relation and these rails I0 and II may be of the sectional and disconnectible type. A third or intermediate r.rail I2 is disposed between the two rails I0 and II and is electrically insulated from these two rails. A loud speaker I4 shown in the diagrammatic view of Figure 1 is adaptedto be mounted on one of the cars or any element which is movable over the rails I0 and I I. The loud speaker I4 has connectedv thereto a pair of conductors I and I6 which are connected to rolling contacts I1 and I8 respectively which are engageable with the rails II 'and I2. An electrolytic condenser I9 is interposed in the vconductors I5 and is preferably a condenser having a capacity of 40 mfd.
In yorder to provide a means whereby theloud speaker I4 may be energized and sound produced therefrom, I have provided a record 20. The record in the present instance is in the form of ya disk which is mounted on a rotatable spindle l 2l operated by a conventional phonograph operating means 22.v A needle 23 engages in the.
groove or grooves vof the record 2li and is carried by an 'electrical pickup `24 which is of conventional construction and is connected by means of `a pair of conductors and 26`to an input side of audio amplifying unit 21. The amplifying unit 21 is of conventional construction and may embody one or more electronic tubes with associated apparatus. The output side of the amplifying unit 21 is connected by means of a pair of conductors 29 and 29 tothe rails III and I2. A condenser 39 is interposed in the conductor 29 and is here shown as `a condenser` having a capacity of 20 mfd. The transformer 3l includes a primary 32 having the opposite ends thereof connected by conductors 33 an-d 34 to a source of alternating current supply. The transformer 3| also includes a secondary coil 35 which has the opposite ends thereof connected by means of conductors 36 and 31 to the rails II) and I2. A choke coil 38 `is interposed in conductor 36 and a second choke coil 39 is interposed inv conductor 31. These choke coils 38 and 39 are designed for the purpose of preventing the audio frequency from feeding back into the secondary coil 35. If desired aL condenser 40 may be interposed between the two conductors 36 and 31 and between the choke coils 38 and 39y and the secondary 35.
A second condenser 4I may be connected across the conductors 36 and 31 between thechoke coils and the rails I0 and I2. A simplified form of audio frequency generation in the form of record and operator thereof has been disclosed in Fig ures 3 to 6. A cylindrical record 42 is mounted on a platen 43 carried by a shaft 44. The shaft 43 is rotatably mounted in a housing 45 which is here shown as a rectangular housing embodying a bottom wall 46, opposite side Walls 41 and i3 and opposite end walls 49 and 50. The record 42 is provided with a plurality of circular grooves- 5I, 52 and 53, which are cut into the record 42 and which are designed for producing different types of sounds. In other words, groove 5I may be designed for producing the sound of a locomotive engine starting up, whereas groove 52 may have cut therein a sound track embodying a bell or other selected sound. It will be understood, of course, that there may be as many of these grooves as may be desired.
A needle "56 which'r is carried `by eanelectrical pickup unit^55 mounted on an arm 56 is adapted to engage in a selected one of the sound grooves. The pickup unit 55 is adapted to be connected by means of conductors 25@l and .26e tor'anframplifying unit for amplifying the sound'tozthefdesired amplitude. Arm 56 is carried by a sleeve 51 which is loosely mounted on a rod58. The rod-58 is disposed in a horizontal position and 'is iixedly secured by means of a bushing 59 to the end wall 5D. The sleeve is slidable and rotatable on the rod 58. The sleeve 57 engages through an opening-'68. whichis formed infthe end .wal1 49. andhas secured :to the-extended end thereof va -thandle or. crank member E ltrnounted Vat an angle caiculatedttoJpartiallybalancathe weightof the pickup larrrrit. Rocking of the-handlel ina-clockwise :direction zas' viewed @Figure 5 will raise the-needlevd from 'one soundtrack and endwise movementoifthesleeve 5l `will shift thepickup mechanism :to'another soundtrack. In Aorder that a child .-may -readily fchange the 'needle 54.5 from onev sound track to another,'1 have provided aibarrBZ. The barf621 is oftriangular oonguration-eand 'is formed* with, a f plurality` ,of V- shapeda-notchesS .andoppositely inclined: ridges 63 between thenotches. Thebar-"BZ is *supportedzat the opposite'zend by the-end .wall :49. The farm 156 which carries: they electrical ypickup member-55-isi of triangular .configuration so that this Earm'rnayreadily engage in aselected one of the iV-.shaped ynotches 63.; c
:In-'orderl that theruser ofthis device may readily-determine-the-positionvof -the-needle 54, I have provided a plate-which issecured to the outer side-of the end Wall 49 Iand'is'provided With-indications 66 whicharecorrelated with a pointer STcarried-by the handle 6I. The indicati-ons ,-651may be a-ppoint orwgraduatiorr line and may-alsoiincludefalegend designating the particularfsound trackassociated therewith. The indications Iiy are Ispaced lapart a distanceequal to fthe spacing Abetween the notches 63.
NIn order toprovide .for rotation of --shaft I and platen VIIS, shaft isextendedthrough the end ,fwallB Aand has a crank-f'secured tothe extended portion thereof. "In this Vmanner a person .can manually -rotate the .platen Vand `record sofas to Vproduce :the desired ksound which is)l emitted fromvthelloud speaker showninFigure 1. .Theshaft A4 may'also be optionally rotated by.means..of an .electric motor 68 vwhichis disposed in ,the housing 45. .Thomctorf isconnected to the shaft 44 by means v,of1-a-coupling 10. The .motor EB .has connected vthereto a pair of conductors YII and '.12 which .are connected to a supply source.
.Transformer 3i is usedfor furnishing power to the engine motor 73. .Motor 'I3'has a conductor I4 connected to one side thereof, and a conductor I5 connectedto ,the opposite side thereof. ductor'II has apair of rolling contacts 'I6 connected thereto which engage rail I2 and conductor 'I5 has a rolling contact 'I'I connected thereto 'which engages'rail Ii. An impedance choke 'I8 may .be interposed in `conductor 'I4 between motor 'uand'contacts .'IB, and a ,condenser 'I9 is connected across conductors 'I4 and 'I5'be- Consupply source is connected through transformer l23! to rails- Iii-and' I2. =more"carsthereof is moved over the tracks IIJ When the train or one or and II, the loud speaker I4 will be mounted on one 'of the cars and this speaker is electrically connected through-appropriate shoes or wipers I'I and I8 to tracks Il and I2. When record 2B is rotated the impressions in the track thereof will be converted by the needle 23, to motion an'drby the electrical .pickup'memberto audio frequency currentan'd :passed to the` 'amplier 2l. #The initial current'passed'to the `ampliiier 21'wi`l1.then -be 'raised in amplitude to'the most satisfactoryievel 'andthis 'ampliedaudio frequencyfwillthenbepicked.up by'the wipers I'I and I8 an'dloud'speaker I4 will'then be'energized andi thesoundv reproduced from record 28 Willbe emitted from' the' loud speaker. It will, of course, be'v understood that the soundtrack ofv record 26 may be either -a-l spiral soundtrack ormay be of the continuous groove type, such asis shown in Figure :3 by thenumerals 5|,T52-'and '53. The sound which :is being reproduced in the loud speaker I4 ispreferably a sound which will represent-the'conventional sounds of a steam locomotive fas 'the 'locomotive is starting up, the sounds `after the locomotive'has beenset inmotion and also the sound of thelocomotive'stopping. In additionythe soundmay'be either a Whistleor a'bell, talking, singing, music, or a combination 'or'succession of these sounds.
The exact conijgurationillustrated is regarded as'theoptimum, but 'some of thedesirable results inherent in this disclosuremay be obtained'- by various slight modifications including somef'departure vfrom the exact configuration shown,\-and it is therefore requested that thescope ofthe invention should beregarded as'limited'only-by the terms of the claim.
What I claim is:
A sound I producing means comprising -an .fenclosed housing including-top, bottornfiront-rear and side Walls, aplaten rotatablycarried by said housing and having a driving connection -withan electric motormountedon said bottom wall, a record on said platen formed with aplurality of spaced apart sound tracks,` a soundpickup means including an arm of triangular-cross section for a portion-of its length, apickup member carried by said arm, and r'ockable supporting means `for said arm, said supportingmeans including a supporting ba'rxe'd 'relative to said housing and formed .with a plurality "of spaced notches, 'corresponding tothe 'spaced 'apart sound tracks on said record, with opp'ositely inclined ridges between sai'd notches in a selected one of which said triangularportion of said arm is adapted to engage, va pair vof horizontally ltelescoping members, the inner member beingxedly carried by said housing andthe outer member at one end thereof being 'xed 4to said arm and'having rotatable and slidable engagement -lwith 'said inner member 'and said phousing, theopposite end of said butertelescoping member ext'endingthrough 6 a side wall of said housing and having a com- REFERENCES CITED bined operating crank arm and indicating pointer xedly attached thereto at right angles to said mrghf fllligwlgeferences are of record in the arm, a plate, having indicia corresponding to said n p spaced apart sound tracks, attached to the side 5 UNITED STATES PATENTS wall through which said outer member extends Number and disposed substantially below said indicat- 454 504 Sunlgrlet al Junzaelagl ing pointer whereby an external indication is had 1 8764'24 Kenyon Sept 6 1932 of the sound track With which said pickup mem- 25008,279 Hopkins July 16 1935 bel 1S 1n engagement 1o 2,216,114 Johnson et al oct. 1, 1940 JOSEPH H- MCKNIGHT 2,247,418 Smith July 1, 1941
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US649877A US2459038A (en) | 1946-02-25 | 1946-02-25 | Combined toy railroad and sound producing means therefor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US649877A US2459038A (en) | 1946-02-25 | 1946-02-25 | Combined toy railroad and sound producing means therefor |
Publications (1)
Publication Number | Publication Date |
---|---|
US2459038A true US2459038A (en) | 1949-01-11 |
Family
ID=24606588
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US649877A Expired - Lifetime US2459038A (en) | 1946-02-25 | 1946-02-25 | Combined toy railroad and sound producing means therefor |
Country Status (1)
Country | Link |
---|---|
US (1) | US2459038A (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2791972A (en) * | 1951-10-15 | 1957-05-14 | Gilbert Co A C | Vibrator excited loud speaker for toys |
US2882834A (en) * | 1956-05-03 | 1959-04-21 | Gilbert Co A C | Toy locomotive sound effects |
US3492004A (en) * | 1968-01-03 | 1970-01-27 | Gen Electric | Guiding structure for phonograph tone arms |
US3697086A (en) * | 1971-02-08 | 1972-10-10 | Marvin Glass & Associates | Phonograph index means |
US3791656A (en) * | 1972-09-21 | 1974-02-12 | Marvin Glass & Associates | Phonograph index means |
FR2559399A1 (en) * | 1984-02-13 | 1985-08-16 | Kassai Kk | Toy producing imitation smoke and producing a sound, for use in childrens vehicles |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US454504A (en) * | 1891-06-23 | Signal attachment for telephones | ||
US1876424A (en) * | 1932-09-06 | Talking vending machine | ||
US2008279A (en) * | 1932-05-10 | 1935-07-16 | Rca Corp | Program distribution for trains |
US2216114A (en) * | 1938-06-15 | 1940-10-01 | Informat Inc | Apparatus for furnishing audible information |
US2247418A (en) * | 1939-04-21 | 1941-07-01 | William R Smith | Toy railway with sound effects |
-
1946
- 1946-02-25 US US649877A patent/US2459038A/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US454504A (en) * | 1891-06-23 | Signal attachment for telephones | ||
US1876424A (en) * | 1932-09-06 | Talking vending machine | ||
US2008279A (en) * | 1932-05-10 | 1935-07-16 | Rca Corp | Program distribution for trains |
US2216114A (en) * | 1938-06-15 | 1940-10-01 | Informat Inc | Apparatus for furnishing audible information |
US2247418A (en) * | 1939-04-21 | 1941-07-01 | William R Smith | Toy railway with sound effects |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2791972A (en) * | 1951-10-15 | 1957-05-14 | Gilbert Co A C | Vibrator excited loud speaker for toys |
US2882834A (en) * | 1956-05-03 | 1959-04-21 | Gilbert Co A C | Toy locomotive sound effects |
US3492004A (en) * | 1968-01-03 | 1970-01-27 | Gen Electric | Guiding structure for phonograph tone arms |
US3697086A (en) * | 1971-02-08 | 1972-10-10 | Marvin Glass & Associates | Phonograph index means |
US3791656A (en) * | 1972-09-21 | 1974-02-12 | Marvin Glass & Associates | Phonograph index means |
FR2559399A1 (en) * | 1984-02-13 | 1985-08-16 | Kassai Kk | Toy producing imitation smoke and producing a sound, for use in childrens vehicles |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2459038A (en) | Combined toy railroad and sound producing means therefor | |
US2882834A (en) | Toy locomotive sound effects | |
US3061973A (en) | Sound system for model railways | |
US2826996A (en) | Vibrator operated load and signal system | |
US2214482A (en) | Phonograph trip apparatus | |
US788790A (en) | Phonographic apparatus. | |
US2710787A (en) | Apparatus for indicating and recording time intervals | |
US2359489A (en) | Sound recording and reproducing | |
US2791972A (en) | Vibrator excited loud speaker for toys | |
GB1173096A (en) | Radial Phonograph and Pickup Assembly | |
US2572221A (en) | Portable public address system | |
US2462435A (en) | Apparatus for uninterrupted reproduction of disk phonographrecords | |
US2675430A (en) | Signal generating and switching circuit for recording devices | |
US2698882A (en) | Sound recording or reproducing apparatus | |
US1941668A (en) | Electric control system and recording device | |
US2780678A (en) | Magnetic recording and reproducing circuits | |
US1965913A (en) | Sound reproducing system | |
GB261698A (en) | Improvements in sound reproducing apparatus | |
US2048482A (en) | Telephone adapter | |
US1625918A (en) | Electric phonograph | |
US1470812A (en) | Gramophone | |
US1658479A (en) | Loud speaker | |
US2199420A (en) | Sound recording and reproducing apparatus | |
US3428759A (en) | Push-pull oscillator and indicating means for a stereo magnetic tape recorder | |
US2905102A (en) | Current rectified signalling system |