US2806906A

US2806906A - Telephone mouthpiece attachment

Info

Publication number: US2806906A
Application number: US396271A
Authority: US
Inventors: Junghans Helmut
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-12-13
Filing date: 1953-12-04
Publication date: 1957-09-17
Anticipated expiration: 1974-09-17

Description

Sept. 17, 1957 H. JUNGHANS 2,806,906

' TELEPHONE MOUTHPIECE ATTACHMENT 2 Sheng-smet 1 Filed De; 4, 1953 l 1.7i., 195']` H. JUNGHANS v 2,806,906

TELEPHONE MOUTHPIECE ATTACHMENT Filednec. 4,1953 l 2 sheets-sheet 2 HELM /r n/l//VG HAMS' United States Patent 2,896,906 TELEPHONE Monrrnlncn ATTACHMENT Helmut Junghans, Schramberg-Sulgen, Eekenhof, Germany Application December 4, 1953, Serial No. 396,271

Claims priority, application Germany December 13, 1952 6 Ciaims. (Cl. 179-188) The present invention relates to a telephone apparatus, the cup-shaped mouthpiece of which can be placed against the mouth of the person, so that the space above the microphone is hermetically sealed to the mouth of the person.

Such a construction offers the following advantages: An unauthorized person cannot overhear the telephone conversation. If there are more persons present in the room, as for instance in an office room, the conversation will not cause annoyance to other persons working nearby. The invention furthermore offers better facilities for conversation in a room where noise is present as for example, when a telephone call is made from an automobile, an aircraft, a railway compartment or the like.

If under such circumstances the cup-shaped mouthpiece is placed against the mouth, air is dammed up in the small, closed cup space during the conversation due to the hermetic sealing and the sound is reflected from the inside walls of the cup, whereby reproduction of speech is more or less distorted or the voice is altered.

The present invention eliminates these disadvantages. Itis therefore an object of the invention to provide a structure in which an insert element merging at its upper end into the mouthpiece is not a plain surface, but the part to be inserted in the casing containing the valves and microphone is perforated like a sieve, so that it forms an almost complete sound-deadening wall.

Preferably, the perforations are not made of equal configuration but of different diameters, so as to provide satisfactory sound-deadening cross-sections of the holes for all sound frequencies.

The sound-deadening eect of the walls is enhanced by providing two co-axial cylinders, both of which are perforated, and by forming the bottom portion as a perforated plate.

To enhance the sound-deadening effect of the cup wall, air-permeable inserts of wadding, paper or the like may be placed in the cavity between the two cylinders and between the outer cylinder and the casing, and these should be replaced from time to time for hygienic purposes.

Good speech reproduction is sometimes distorted or impaired by speaking too loudly into the apparatus. When using the device, it is sufficient to speak with a subdued or soft voice, the strength of reception being equally as loud as in normal conversation. In order to control the loudness when speaking into the mouthpiece, means are provided for controlling its audibility.

Application of the device for preventing overheing has a somewhat fatiguing effect, especially for long conversations. This causes the speaker to fail to apply the mouthpiece with-sufficient firmness. In addition, there is the disadvantage that when the mouthpiece is used by different persons, it is not hygienic unless it is cleaned after each use.

To remove these disadvantages, it was proposed to insert a paper cup having the form of the mouthpiece. It has now been found that paper cups cannot be easily fltilfltiA Patented Sept. 17, 1957 rice drawn or extruded in this form, and they are too expensive, especially for single use. It is therefore a further object of the invention to provide a stamped out piece of paper of approximately oval shape. This piece of paper has a hole in the center and preferably a cardboard ring may be glued to it for reinforcement. Flexible crepe paper is preferably employed. The piece of paper can easily be inserted into the mouthpiece by hand, its outer edge being placed round the edge of the mouthpiece.

A soft crepe paper makes application to the mouth pleasantly soft and comfortable, even during long conversations; and it is also unnecessary to press the mouthpiece very tightly against the mouth in order to have a sufficient tight sealing.

Other features and advantages of the invention will be apparent from the following description of a number of examples of embodiments and from the drawings in which:

Fig. l is a longitudinal section of a device according to the invention, the mouthpiece and microphone forming a structure independent of the telephone receiver,

Fig. 2 is a side View partly in section showing the insert element,

Fig. 3 is a partial sectional view showing a detail of the mouthpiece,

Fig. 4 is a plan view of a protective paper sheet for the mouthpiece,

Fig. 5 is a section showing a modified form of the bottom of the mouthpiece,

Fig. 6 is a longitudinal section of a modified device which is placed on the mouthpiece of the ordinary telephone receiver, and

Fig. 7 is a cross section taken on line A-B of Fig. 6.

In the first embodiment (Figs. 1 to 5), 1 denotes the mouthpiece of the insert element, which is inserted in the casing containing the inhale valve 11 and the exhale valve 12, as well as the microphone diaphragm 8. Behind the exhale valve 12, spaced perforate discs 14 are diposed one above the other to form a sound-damping labyrinth 13. In front of the microphone diaphragm, a diaphragm 2 is provided for preventing the breath of the speaker from reaching the microphone 8.

According to the invention, the part of the insert element projecting into the casing 4 is formed as a doublewalled

perforated cylinder

1a and 3, and the bottom 15 is a perforated plate, thereby avoiding undesirable reflections at these parts of the wall. The mouthpiece 1 can be made in one piece with its cylinder 1a, for example of Plexiglas, and the cylinder 3 may be securely mounted or detachable.

Cylinders

1a and 3 may also be made as a separate cup 1. The outer cylinder 3 may also be formed in one piece with the mouthpiece cup 1, and the inner cylinder 1a is inserted in a fixed or replaceable position in the cup 1. The possibility of replacing or removing the

cylinder

3 or 1a is for the purpose of enabling better cleaning, for example in a liquid. For cleaning, it is possible to use a small glass or plastic container of appropriate size, containing a liquid for hygienic cleaning and having a well fitting cover which is ground in or has a rubber seal.

To avoid excessive loud speaking into the device, a small measuring instrument 5, similar to a pressure gauge, is provided as shown in Fig. 1. In the cup 1 is a hole 1b, through which the dammed up air or air pressure inside the cup is directed to a pressure gauge 5. The scale has a red mark 5a and a pointer should not move beyond this mark or should be deflected as far as that point to obtain good speech reproduction.

Fig. 3 shows another warning device operative on the acoustic principle. A whistle is mounted on the casing wall 4 but this whistle could also be mounted, for example, at the point where the hole 1b is situated (see Fig. l). The whistle consists of a tube 6 with a narrow air outlet orifice 6a. The whistle cap 7 has an outlet orice 7a, as is usual in whistles. The crosssections of the air outlet orifices 6a and 7a are so dimensioned that for a certain loudness or air pressure, a whistling sound is produced, indicating that the user is speaking too loudly into the mouthpiece. The whistle shown in Fig. 3 is represented diagrammatically only since any note producing device known from the construction of musical instruments may be used for this purpose.

Fig. 4 shows a protective sheet of paper 9 which is placed in the mouthpiece 1 for hygienic reasons. The paper, which may be made of exible crepe paper, has a hole in the center surrounded by a cardboard ring 10. The paper is held by the cardboard ring and easily inserted in the mouthpiece 1 with one hand, and the outer edge of the paper placed round the edge, as shown in Fig. 2. The oval shape or stamping of the paper adapts it to the shape of the oval mouthpiece 1.

Certain embodiments are proposed, wherein the device with the sound-tight mouthpiece is either pivoted to an ordinary telephone receiver or is used connected in parallel to an exisiting normal telephone receiver. In the latter case, therefore, the microphone incorporated in the device is connected in parallel with the microphone of the usual telephone receiver. With the microphone connected in parallel, the sound in the earpiece Vof the receiver is considerably reduced during normal conversation. However, only the -earpiece of the usual telephone receiver can be used, and by suitably holding or placing the earpiece against the ear, the mouthpiece of the device can be brought to the mouth. The weakening of the microphone current is not then perceptible as a drawback, or the same sound is obtained at the earpiece as during normal conversation.

In order to take into account the requirements for both cases, i. e. for normal conversation or when using the device with the sound-tight mouthpiece, it is proposed to provide on the casing 4 a small button which can be pressed by the finger when holding the device. The mouthpiece 8 is switched on by means of the small button or electric switch. When, therefore, the device is not used, i. e. the button is not pressed and only normal conversation is carried on, only the mouthpiece of the normal telephone receiver is switched on, so that no Vdeterioration or weakening of the sound can occur in the receiver. Similar arrangements are usual in telephone apparatus provided with a second earpiece. As a rule, the second earpiece carries a button, by means of which the earpiece is switched on, so that weakening of the loudness in the earpiece can occur only when the second earpiece is switched on.

The push-button is not shown in Fig. l, since it is merely a matter of a simple step in switching technique.

In the secondrernbodiment (Figs. 6 and 7), the device is formed without a mircophone, i. e. it is adapted to be placed on a usual telephone receiver, with the sound damper 100 fast in the casing 101, and the mouthpiece 102 with the perforated cylinder 102a is inserted in telescopic fashion. Furthermore, there is inserted in the mouthpiece 102 a second perforated removable cylinder 103, which may be provided with a perforated bottom 103er. The perforated cylinders are designed lin principle as in Fig. 1 with the sole difference that it is the inner cylinder 103 which is replaceable, not the outer cylinder.

The mouthpiece 102 is pressed upward by a spring 104. During speech, the mouthpiece assumes the optimum position by the pressure of the mouth, the earpiece of the telephone receiver also taking up the optimum position relative to the ear. The resilient application of the mouthpiece 102 against the mouth ensures that the application is always uniform and that the hermetic il closure `is uniform and that no sound can escape to the outside.

Interposed between the mouthpiece and the microphone of the telephone receiver there is provided a diaphragm and a diaphragm 106, as well as a perforated plate 107. The perforated plate 107 also contributes in improving speech reproduction and is necessitated by the size of the sound space 101a in the casing 101. The number of perforated cylinders and perforated discs, e. g. 102er, 103, 103a, 107 depends upon the size of the inner spaces of the mouthpiece and must be determined in each case by experiment. The diaphragm 108 on the cylinder 102er, as well as the

diaphragm

105 and 106 Serve for preventing speech moisture from entering the microphone and sound damper. Apart from the diaphragm 108, it is also sutiicent if one of the

diaphragms

105 and 106 is mounted in the passage of the microphone. The drawing shows various possible ways of assembly. The

parts

105, 106 and 107 may be mounted in a replaceable manner.

I claim as my invention:

l. A telephone device comprising a cylindrical casing provided with a mouthpiece adapted for enclosing the mouth of the conversing person in a soundproof manner, said casing having a sound-damping air-outlet for the air expired by the conversing person, an inlet valve to close an air-inlet opening during expiration of air by the conversing person and to permit the entry of air there through during the inspiration of air by the conversing person, an outlet valve insaid mouthpiece disposed between said sound-damping air outlet and said air inlet opening and operative to prevent the ow of fair into said mouthpiece through said outlet during inspiration of air by the conversing person, a moisture-proof sound transmitting protective diaphragm interposed between the interior of said mouthpiece and a microphone, and a hollow insert body in the mouthpiece having a flaring mouth-engaging portion at one end and a cylindrical portion adapted to be inserted into the cylindrical casing on the other end, the said cylindrical portion consisting of two coaxial sievelike perforated cylindrical side-walls and a bottom diaphragm portion.

2. A telephone device according to claim l, in which the microphone is mounted adjacent to and below the bottom diaphragm of the insert body.

3. A telephone device according to claim l, in which the insert body consists of two coaxial perforated cylinders anda bottom portion consisting of a perforated plate.

4. A telephone device according to claim l, in which a diaphragm covered sieve plate is arranged adjacent the cylindrical walls of the insert body and the microphone is provided in a sidehollow portion of the casing which hollow side portion is closed by the said diaphragm covered sieve plate.

5. A telehone device comprising a cylindrical casing provided with a mouthpiece adapted for enclosing the mouth of the conversing person in a soundproof manner, said casing having an air inlet valve and a sound-damping air-outlet for the air expired by the conversing person, a hollow insert body in the said mouthpiece having a flaring mouth-engaging portion at one end and a cylindrical portion adapted to be inserted into the cylindrical casing on the other end, the said cylindrical portion consisting-of two coaxial sieve-like perforated cylindrical sidewalls, a microphone disposed below the said insert body, and separating means interposed between the interior of said mouthpiece and the microphone for preventing a direct impingement of the expired air by the conversing person against the microphone.

6. A mouthpiece device according to claim 5 in which the mouthpiece formed as an insert element in the casing containing the exhale `and inhale valves, the insert element being mounted so as to be axially and resiliently movable in the casing.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Sherburne Nov. 15, 1910 Higuchi Mar. 26, 1918 Van Houte Sept. 9, 1924 Gamoty Sept. 13, 1927 6 Siez et a1. Iuly 7, 1942, Hart Aug. 5, 1947 Webb Ian. 13, 1953 Junghans July 10, 1956 FOREIGN PATENTS Italy June 11, 1931