US2808458A - Portable electric megaphone - Google Patents

Description

OC- l, 1957 R. M. TURPIN ErAL PORTABLE ELECTRIC MEGAPHONE Filed May 25, 1953 mvemvk.- recel. 'VIR P1P/ RAPHAEL 07A ANU P? AKQEL ACHILLE LEGER PORTABLE ELECTRIC MEGAPHONE Raphael Marcel Turpin and Marcel Achille Leger, Paris, France Application May 25, 1953, Serial No. 357,128

1 Claim. (Cl. 179-1) This invention is concerned with portable electric megaphones.

Portable electric megaphones hitherto known necessitate, for being electrically energized, the employment of a separate direct-current source such as a` battery or a direct-current distributing network.

The object of the present invention is to provide a portable electric megaphone having its source of energization confined therein and, consequently, being entirely selfcontained, while having an amplifying power at least equal to that of the portable megaphones with separate source of energization; and further having a weight and volume such as to permit of manipulating the megaphone easily by one hand.

Accordingly, kthe megaphone of the invention is provided with an exchangeable battery disposed in an inner Ihousing and constituted by a number of cells, such for example as those used in pocket dash-lamps, serially connected by means of appropriate conductors in a manner to form an electric circuit into which is branched, on one hand, an amplifying coil and, on the other hand, a microphone opened into the megaphone mouth-piece, the megaphone being further provided with a hand and a cooperating switch whereby this circuit is held broken as long as the megaphone is inoperative and re-established when the latter is in operation.

Other features of the present invention will be apparent from the following description with reference to the accompanying schematic drawings which show a preferred form of megaphone and in which:

l is a general aspect of the megaphone;

Flg. 2 is an axial section, thereof on an enlarged scale, with parts broken away; and F Fi 3 is a cross-section through the line III- III of the Similar numerals refer to similar three views.

Referring to the drawings, it will be seen that 1 is the megaphone mouth-piece, 2 the microphone housing, 3 the removable cylindric casing rigid with both the mouth piece and the microphone, 4 the loudspeaker horn that may be of exponential or semi-exponential configuration and whose portion 5 receives, removably mounted thereon, the corresponding megaphone elements.

Denoted by reference 6 is a handle cooperating with a switch 7 adapted to make up the electric circuit at the moment when the megaphone is set in operation and to break this circuit when the megaphone is out of operation.

The energizing source (Fig. 2) is constituted by a battery of cells S of standard type, such for example as those used in pocket hash-lamps, contained in a housing 9 whose walls are non-conductive but locally provided with elastic conductive lamellae 10, 11, 12 for connecting the cells serially. This housing 9 is removably secured to the support 5.

Two conductors pass through the housing 9 and lead to two springs 13 in contact with two terminals 14 of the parts throughout the y United States Patent() winding 15 of a permanent magnet loudspeaker having a compression chamber 16 and a rellection cone 17, so that the megaphone hasia high sensitivity and is mounted with a great facility, the electric connections being effected automatically, merely by causing the springsV 13 to contact the terminals 14 at the moment of mounting.

One of the springs 13 is connected to the terminal conductive lamella 10 of housing 9, while the other spring 13 is connected to one of the lamella of contactor 18 controlled by the switch 7. The other lamella of contactor 18 is connected to a conductive axial nut 19 rigid with the housing 9 which further has an axial contactor 20 connected with the second terminal conductive lamella 12 of housing 9, as clearly shown in Fig. 2.

It will be particularly noted that the mouth-piece 1, microphone 2 and cylindric casing 3 constitute a removable assembly normally secured to the remainder of the megaphone, by merely screwing a tubular axial screw 21 innerly lined with an insulating tube 22 containing a conductive rod 23 which is normally connected on one hand with the contactor 20 and, on the other hand, with the microphone 2.

In this form of megaphone dismantling and mounting, with a view to replacing the battery cells or 'overhauling the megaphone interior are particularly easy and rapid.

Fig. 3 is a sectional view, taken substantially along the line III-III in Fig. 2, of one of the cells 8 in the housing 9 as it appears when the megaphone is horizontally held but it handle in the course of a use. The cell is turned upside down, the contact lamellae 24, 25 being bent inwardly and in contact with the conductive lamella, for example 11, of the housing 9. The latter has a at 26 serving as bottom for the said housing without coming into contact with the lamellae 24 and 25. The whole is surrounded with the cylindric casing 3 so as to limit eventual displacements of the cells in the course of manipulating the megaphone, without risking to break the circuit on account of large dimensions given to the lamellae 10, 11 and 12.

In Fig. 3 is further shown, schematically, the real position of the switch 7 cooperating with the handle 6, this switch being shown laterally in Fig. 2 for the sake of simplifying the description.

As to the microphone 2, this should preferably be of high capacity carbon type and capable of withstanding a high output current.

It is to be noted that the electrical characteristics of the microphone and the loudspeaker should be selected correspondingly and by taking into account the employment of an energizing source limited to a small number of serially connected cells. The combination of all these electric conditions is an essential point owing to which it has been possible to reduce to the utmost both volumeV and weight so as to provide va megaphone easily handled by one hand. It is clear that for the various outer elements of the megaphone use may be made either of light metals or of plastic materials.

To comply with the art, all the assemblies in the megaphone according to the invention' will be provided, at appropriate points, with electrically insulated or vibrationless joints, particularly around the microphone.

Finally, it is to be understood that the invention ls not limited to the particular dispositions of parts described and shown, as the same may be modified in various particulars without departing from the spirit and scope of the invention.

What is claimed is:

A portable electric megaphone comprising in combination anY outer casing; a mouthpiece secured to said outer casing; a horn; a loudspeaker unit removably mounted in said horn; a battery casing secured to the rear end of said horn and being at least partly located in said outer casing; a plurality of batteries insaid battery easing; a microphone unit arranged in said outer casing adjacent said mouthpiece rmly secured to said outer easing;` attaching means for detachably attaching; said microphone unit, said outer casing and? sadmouthpiece toithe Arear end;` of said battery casingtai switch;` and an electric circuit including inv series saidswithLsaidmicrophone unit, said battery and said loudspeaker unit.

References Cited in the le of this patent

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