US622379A

US622379A - Megaphone

Info

Publication number: US622379A
Authority: US
Publication date: 1899-04-04
Anticipated expiration: 1916-04-04

Description

no. 622,379. Patented Apr. 4, I899. E. a. MERRIMAN.

IEGAPHONE.

(Application filed Aug. 12, 1898.)

(No Model.)

we wcnms PETERS co. nuuraurua, x-"snmmon. D. c.

UNITED STATES PATENT OFFICE.

EDWVARD BFMERRIMAN, OF BOSTON, MASSACHUSETTS.

M EGAPHONE.

SPECIFICATION forming part of Letters Patent No. 622,379, dated April 4, 1899.

Application filed August 12, 1898. Serial No. 688,423. (No model.)

1'0 alt w/wm it may concern:

Be it known that I, EDWARD B. MERRIMAN, a citizen of the United States, residingat Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Megaphones, of which the following is a specification.

My invention relates to megaphones, and more particularly to the mouthpiece and the rim thereof and the mannerof attaching them to the two ends of the body portion or shell of the instrument, Heretofore it has been usual to secure these parts togetherby means of rivets or screws; but it has been found in .practice that the slight projections formed on the inner surface of the body portion of the magaphone by the heads or ends of the rivets or screws are sufficient to impair the acoustic properties of the instrument, the interior of which should be as smooth and unbroken "as possible inorder to secure the best results in its use.

My present invention provides a megaphone which has its parts so constructed and united as to remedy the above defect and which at the same time is simple of construction and of great strength and durability.

A megaphone made in accordance with my invention is shown in the accompanying drawings, in whioh- Figure l is a side elevation of the complete instrument. the mouthpiece and adjacent parts, taken on the line 2 2 in Fig. 1. Fig. 3 is an enlarged section of the rim and adjacent parts, taken on the line 3 3 in Fig. 1. Fig. 4 is a view similar to Fig. 3, showing a slight modification. Fig. 5 is a central section of the mouthpiece proper; and Fig. 6 is a detail of the rim, showing these parts as they appear before they are secured to the body portion of the instrument.

The body portion of my megaphone consists of a conical tube 2 of the usual or any approved construction, it being ordinarily made of leather-board, chemical fiber board, or analogous material, although I have used metal for the purpose.

The mouthpiece proper consists of a cupshaped portion 3, provided with a short tubular extension 4., which is made of metal of medium softness, preferably brass, and is Fig. 2 is an enlarged section of- '2 and then inserting the tubular extension 4 within these-parts, after which said extension 4. is expanded by suitable means to fit tightly against the inner surface of the body portion 2. This expansionis of course ultimately resisted by the tube 5, the result being that the body portion 2 is very tightly clamped and securely held between said tube 5and the extension 4:. As thus constructed and combined these parts are obviously incapable of separation without destroying one or more of them, and at the same time the inner surface of the megaphone is rendered smooth and free from any projections whatever. At the opposite or large end of the body portion of a megaphone it has been customary to attach a stiffening and strengthening rim of wood or metal. My improved rim 6 consists of a strip of metal folded lengthwise to provide a. groove 7 for the reception of the edge of the body portion 2, and further provided with a bead 8 along its outer edge, which I prefer to form by turning the edge of the strip inward, as shown in Figs. 3, 4, and 6. I also preferto insert a wire 9 within the small tube which forms the head 8, thereby increasing the strength and stiffness of the rim; but this wire may be omitted if desired, as shown in Fig. 4, as the bead 8 itself greatly stifiens the rim. The rim 6 is secured to the body portion 2 by inserting the latter within the groove 7 and then forcing the inner portion of the rim outward against the inner surface of the body portion until the latter is firmly pressed against the outer portion of the rim and securely clamped'in place. It will be seen that the outer portion of the rim is perpendicular, or approximately so, to its diameter, so that with respect to the taper of the body portion 2 a depression is formed between the head 8 and the bottom of the groove 7, as indicated at 10, and the inner portion of the rim should be of such width as to reach about to the middle of said depression, so that in the operation of securing the rim to the bodyportion the substance of the latter is forced by the inner edge of the rim into the depression, being bent slightly outward under the head 8. In this manner a very firm union of these parts is secured.

My megaphone as above constructed is exceptionally strong for its weight and has a smooth finish on both its exterior and its interior, which improves its appearance as well as its acoustic qualities. It will be noted, also, that both the rim and the mouthpiece are firmly united to the body portion at every point of contact therewith instead of being united at isolated points only, as by rivets, so that said body portion cannot be forced either inward or outward away from the rim or mouthpieceat any point. Hence it results that it is practically impossible for the parts of the instrument to become separated from one another, thereby still further improving upon those prior megaphones which have their parts riveted or screwed together, in which the rivets or screws often work loose and have not infrequently been torn out of the shell under the rough usage to which these instruments are liable to be subjected.

I claim as my invcntion- 1. In a megaphone, the combination with a conical body portion of an external collar fitted to the small end thereof, and a mouthpiece having a tubular extension inserted within said body portion and expanded tightly against the same.

2. In a megaphone, a rim for the large end thereof comprising a strip of sheet metal folded to form a groove for the reception of the edge of the megaphone and having its outer edge turned inward to form a strengtheningbead, thereby forming a depression beneath said bead, for the purpose set forth.

3. In a megaphone, the combination with the body portion 2 of the rim 6 provided with the groove 7 and bead 8, forming a depression 10 into which said body portion is forced by pressing outward the inner edge of said Tim.

at. In a megaphone, the combination with the body portion 2 of the rim (3 provided with the groove '7 in which the edge of said body portion is clamped, said rim having also a bead 8 containing a wire 9.

In testimony whereof I have hereunto snbscribed my name this 11th day of August, 1898.

EDWARD 13. MERRIMAN.

Witnesses:

E. D. CHADWICK, E. B. TOMLINSON.