US466531A - Friedrich wilhelm aschendorf - Google Patents

Description

(No Model.)

' P. W. ASOHENDORR v 'BAKTRUMPET. No. 466,531. Patented Jan. 5, 1892.

UNITED STATES.

PATENT OFFICE.

FRIEDRICH WILHELM ASOHENDORF, OF WIESBADEN, GERMANY.

EAR-TRU M PET.

SPECIFICATION forming part of Letters Patent No. 466,531, dated January 5, 1892.

Application filed July 6, 1891. Serial No. 398,616. (No model.)

To all whom it may concern:

Be it known that I, FRIEDRICH WILHELM AsOHENDORF, a resident of Wiesbaden, in the Kingdom of Prussia and German Empire,have

invented certain new and useful Improve ments in Ear-Trumpets; and I do hereby declare the following to be a full, clear,-and exact description of the said invention, such as will enable those skilled in the art to which it appertains to make and use the same.

My invention is an improvement in eartrumpets; and it consists in the novel features hereinafter fully described.

In the accompanying drawings 1 have shown one form in which I have contemplated embodying my invention, and the said invention is fully disclosed in the following description and claims.

In the said drawings, Figure 1 represents a perspective View of an ear-trumpet constructed according to my invention, and Fig. 2 represents a central longitudinal section of the same.

The object of my invention is to produce an ear-trumpet which shall be simple in con struction and which can be cheaply and easily made, and also one which will have such a construction as to give a great amount of resonance.

In carrying out my invention I employ two shells or cones-an outer shell 1 and an inner shell orconem-havingtheirlarge ends united,

by burnishing one over the other at n or by soldering or other preferred means. The outer shell or cone Z has an ear-piece or extension 19, adapted to fit the ear and having a passage through it communicating with the inclosed space 0 between the inner surfaces of the two shells.

The inner shell m is provided with a series (preferably three) of slots or openings 0* r r, as shown in the drawings, which communicate with the inclosed space between the two shells. The inner shell is closed at q adjacent to the ear-piece p of the outer shell, as shown in Fig. 2. By this construction the sound undulations cannot pass into the open end of the inner shell and directly to the car through the ear-piecep, (the inner shell having no opening adjacent to the ear-piece, as before stated,) but the sound will be forced to pass through the slots 4" r and be communicated to the air inclosed between the walls of the shells, thereby causing the air in such inclosed space to vibrate and greatly increasing the resonance of the instrument. The walls of the shells co-operating with the vibration of the air inclosed in the space between said walls, will produce a resonance which will render the instrument very effective. It will also be seen that the instrument can be Very cheaply and easily manufactured. The tubular ear-piece 1) may be covered with iudia-rubber, leather, or other suitable substance to enable it to be held in the ear without the support of the hand.

What I claim, and desire to secure by Letters Patent, is

'1. An ear-trumpet consisting of an outer and an inner shell having an inclosed space between, the inner shell having a series of apertures communicating with .the said space, and an ear-piece connected to the outer cone and communicating with said air-space at a distance from said apertures, substantially as described.

2. An ear-trumpet consisting of an outer shell and an inner shell within the same, said shells having their larger ends connected together and forming an air space between them, an ear-piece secured to the outer shell and communicating with the air-space adjacent to a closed portion of the inner shell, said inner shell having a series of apertures in the same at a distance from saidear-piece, substantially as described.

In witness whereof I have hereunto set my hand in presence of two witnesses.

FRIEDRICH WILHELM ASOHENDORF. Witnesses:

ALVESTO P. HOGUE, JEAN GRUND.

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