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Publication numberUS3412207 A
Publication typeGrant
Publication dateNov 19, 1968
Filing dateAug 30, 1965
Priority dateAug 30, 1965
Publication numberUS 3412207 A, US 3412207A, US-A-3412207, US3412207 A, US3412207A
InventorsNoboru Sugawara
Original AssigneeFedtro Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Loudspeaker device
US 3412207 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

1968 NOBORU SUGAWARA 3,412,201

LOUDSPEAKER DEVI CE Filed Aug. 30. 1965 MEGAPHONE mQR a O O. 2 O 4 4 R O a H m 3 m R L m 0 S FIG. 3.

INVENTOR SOURCE ivja a eu SUGHWflRA' ATTORNEY.

United States Patent 3,412,207 LOUDSPEAKER DEVICE Noboru Sugawara, Kobe-shi, Japan, assignor to Fedtro, Inc., Rockville Centre, N.Y., a corporation of New York Filed Aug. 30, 1965, Ser. No. 483,704 2 Claims. (Cl. 179-1) ABSTRACT OF THE DISCLOSURE A hand-held loudspeaker comprising a megaphone connected to the output terminals of an amplifier, A micro phone or an oscillator are selectively connectable to the input terminals of the amplifier by a first switch. A source of potential is selectively connectable to the amplifier to energize the same by a second switch. A pistol-grip depends from the megaphone and contains a trigger pivotally connected thereto which, when operated, closes the second switch to apply an energizing potential to the amplifier. An elongated slot is received in the pistol-grip through which said first switch projects so that the operator easily may connect the microphone or the self-contained oscillator to the input terminals of the amplifier by moving the first switch with his thumb thereby to provide a compact and efiicient loudspeaker which may be operated by one hand.

This invention relates to improvements in electrically operated loudspeakers of the hand-held type.

Hand-held electrically operated loudspeakers have been utilized in the past to amplify and direct speech signals. These devices have been :found to be particularly useful for the transmission of speech in noisy areas. For example, law enforcement otficials have used such devices to issue directions to police officers to maintain order in an unruly mob. However, a primary drawback to such use of these loudspeakers is that the mob can hear the issued orders as well as the officers and they can accordingly circumvent such orders and render the action on the part of the police otficers nugatory.

Accordingly, it is an object of the present invention to provide an electrically operated hand-held loudspeaker which is adapted to produce coded tone signals.

It is another object of the present invention to provide a loudspeaker of the type described which amplifies and transmits coded tone signals as well as speech signals.

A preferred embodiment of the present invention includes an amplifier which is connected to the input of a megaphone. A switch is selectively operable to connect the amplifier to either a microphone or an oscillator. A source of potential is adapted to be connected to the amplifier through a trigger switch which is located in a pistol-grip depending from the megaphone. To provide a compact device the majority of the above-described electrical circuit components of the present invention are contained within a member mounted on the rear of the megaphone.

When it is desired to utilize the loudspeaker to amplify and transmit voice or speech signals, the microphone is connected to the amplifier. The source of potential is applied to the amplifier by operating the trigger switch in the pistol grip. Thereafter the user need only speak into the microphone to transmit his voice signals. When it is desired to transmit signals by code rather than by voice, the amplifier input terminals are connected to the oscillator. The potential may then be applied to the amplifier in a predetermined sequence by operating the trigger switch in said predetermined sequence. Hence, the loudspeaker will transmit the tone produced by the oscillator as determined by the sequential energizing of the amplifier. If, for example, the potential is applied to the ampli- 3,412,207 Patented Nov. 19, 1968 fier to produce bursts of tone in accordance with the Morse code, the sounds transmitted by the amplifier can than be read by those people who can decode the Morse co e.

It is a feature of the present invention to provide a dual-purpose loudspeaker for electronically amplifying voice signals or tones in accordance with the desires of the user.

Additional objects and advantages of the present invention will become more apparent from a consideration of the following detailed description when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a side elevational view of the loudspeaker of the present invention;

FIG. 2 is a rear elevation, with parts broken away, of the loudspeaker shown in FIG. 1; and

FIG. 3 is a schematic circuit wiring diagram of the illetrifal components in the loudspeaker illustrated in The dual purpose loudspeaker of the present invention is illustrated in FIG. 1 and is designated generally by the numeral 10. The device 10 includes a megaphone 12 which is provided with a rear depending socket 14. The socket 14 is adapted to receive a conventional pistol-grip 16 which may be affixed in place by any conventional means, as by screws (not shown) passing through the sides of the socket 14 and the pistol-grip 16. The pistol-grip 16 is adapted to be grasped by the hand of the user to facilitate holding the device 10. Preferably, the pistol-grip 16 is fabricated from a plastic material.

A single-pole single-throw switch 18 is provided in the pistol-grip 16. The armature 18 of the switch is connected to a trigger 18a which is pivotally mounted on the pistolgrip 16. Thus, squeezing of the trigger 18a will close the switch 18. Additionally, biasing means (not shown) may be included to bias the trigger outwardly to a position whereby the switch 18 is open.

Additionally, the side of the pistol-grip 16 is provided with an elongated slot 22. The armature 20a of a singlepole double-throw switch 20 is slidably received in the slot 22.

A casing 24 is removably connected to the rear of the megaphone 12 by any conventional means. The casing 24 receives the electrical components of the dual-purpose loudspeaker 10 therein and protects the circuit from adverse weather conditions. The rear surface of the casing 24 is provided with an opening 26 which, preferably, may be covered with a fabric.

The electric circuit of the present invention is shown schematically in FIG. 3 and includes an amplifier 28. The output terminals of the amplifier 28 are connected to the megaphone 12 by a lead 30. A source of potential 32 is connected to the amplifier 28, through the switch 18, by a lead 34. The source of potential or power 32 may comprise a plurality of dry cell batteries which are received either in the piston-grip 16 or within the casing 24. Thus, when the trigger 18a is squeezed inwardly to close the switch 18, the source of power 32 will be connected to the amplifier 28.

The input terminals of the amplifier 28 are connected to the armature 20a of the switch 20 by a lead 36. The terminal 20b of the switch 20 is connected to a microphone 38 by a lead 40. The terminal 20c of the switch 20 is connected to a conventional oscillator 42 by a lead 44. The microphone 38 is mounted within the casing 24 adjacent the opening 26. Movement of the armature 20a within the slot 22 in one direction will connect the armature to terminal 20b while movement of the armature 20a in the opposite direction will connect the armature to terminal 2017. Hence, either the microphone 38 or the oscillator 42 will be connected to the amplifier 28 at any one time.

When the device of the present invention is to be utilized to amplify and'transmit voice or speech signals, switch 20 is operated so that the armature 20a is con nected to the terminal 20b. Thus, the microphone 38 will be connected to the input terminals of the amplifier 28 through the circuit comprising the lead 40, switch 20, and the lead 36. Thereafter, the operator grasps the pistolgrip 16 and lifts the dual-purpose loudspeaker to position the opening 26 adjacent his month. When the trigger 18a is squeezed, switch 18 connects the source of power 32 to the amplifier 28. The voice signals applied to the microphone 38 will be amplified by the amplifier 28 and applied, through the lead 30, to the megaphone 12 which will amplify and transmit these voice signals.

When it is desired to send coded signals rather than voice signals, the operator moves the armature 20a of the switch 20 so that the armature 20a is in contact with the terminal 200. The oscillator 42 will then be connected to the input terminals of the amplifier 28 through the circuit comprising the lead 44, the switch 20 and the lead 36. When the switch 18 is operated to close the circuit between the amplifier 28 and the source of power 32, the amplifier 28 and the oscillator 42 will be energized to produce a single frequency tone in the conventional manner. The tone will then be amplified and transmitted through the megaphone 12. It is obvious that when the switch 18 is operated in a predetermined sequence to alternately energize and deenergize the amplifier 28, the device 10 will produce tones which follow the same pattern. That is, when the amplifier is energized, a tone will be produced. When the amplifier is deenergized, no tone will be produced. Thus, coded information may be transmitted by the device 10 when the trigger 18a is operated in accordance with a prearranged system of signals.

Accordingly, a dual-purpose electrically operated hand-held loudspeaker has been provided which will amplify and transmit coded tone signals as well as speech signals.

While a preferred embodiment has been shown and described herein it will become obvious that numerous 4O additions, changes and omissions may be made in such embodiment without departing from the spirit or scope of the invention.

What is claimed is:

1. A sound amplifying device comprising an amplifier having input and output terminals, a megaphone connected to said output terminals, a microphone, an oscillator circuit for producing an oscillatory signal at its output, first means connected to said input terminals and being selectively operable to connect said oscillator output or said microphone to said amplifier, a source of potential, and second means operable to connect said source of potential to said amplifier for energizing said amplifier, whereby sounds having a predetermined sequence are emitted from said megaphone when said first means is operated to connect said oscillator to said amplifier and said second means is operated to connect said source of potential to said amplifier in said predetermined sequence, a pistol-grip depending from said megaphone, a trigger pivotally connected to said pistol-gn'p, and means connecting said trigger to said second means, whereby the squeezing of said trigger operates said secamplifier, said second means comprising a single-pole single-throw switch, and an elongated slot in said pistolgrip, said first means projecting through said slot and movable in one direction to connect said microphone to said amplifier, and movable in the other direction to connect said oscillator to said amplifier.

2. A sound amplifying device as in claim 1, and a removable housing connected to the rear of said megaphone, said housing receiving said amplifier and oscillator therein, and an opening in the rear of said housifig receiving said microphone therein.

References Cited UNITED STATES PATENTS 2,808,458 10/1957 Turpin et al. 179-1 FOREIGN PATENTS 929,851 6/1963 Great Britain.

ROBERT L. GRIFFIN, Primary Examiner.

I. T. STRATMAN, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,412,207 November 19, 1968 Noboru Sugawara It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line'ZO, before "amplifier" insert ond means to connect' said" source of potential to said Signed'an'd sealed'thisfird day of March 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2808458 *May 25, 1953Oct 1, 1957Achille Leger MarcelPortable electric megaphone
GB929851A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3558822 *May 22, 1968Jan 26, 1971Listening Inclocator
US5070539 *Jul 17, 1989Dec 3, 1991Cheng Peter S CWashable mug with self-contained sound system
US9014389 *Mar 13, 2013Apr 21, 2015Nielsen-Kellerman Co.Megaphone
US20140029760 *Mar 13, 2013Jan 30, 2014Thomas DooleyMegaphone
Classifications
U.S. Classification381/75
International ClassificationH04R27/04, H04R27/00
Cooperative ClassificationH04R27/04
European ClassificationH04R27/04