Hemadynamometer Microphone

Abstract

A hemadynamometer microphone comprising a microphone cap, an elastic support member with the outer periphery thereof snugly fitted in the inner periphery of said microphone cap, a ceramic element having opposite ends supported on said support member via support base means, and a oscillating diaphragm mounted on the microphone cap and connected to said ceramic element via an elastic relay member located at the center of said ceramic element.

Description

BACKGROUND OF THE INVENTION

The prior-art hemadynamometer microphone has a construction as shown in FIG. 1, consisting of a microphone cap 100, an oscillating diaphragm 102 and a crystal element 103, these parts being set as illustrated. This construction of the prior-art hemadynamometer microphone, however, has some drawbacks. The crystal element 103 which serves to convert sound into electrical oscillation is poorly heat-resistant. Its normal function is impaired even by a human body temperature of about 40.degree. C imparted during the use of the hemadynamometer, thus adversely affecting the precision of the hemadynamometer. Also, the crystal element is supported at its opposite ends on separate support means, which adds to the number of component parts. Further, with this construction the positioning of the support means itself is very difficult, in addition to extreme difficulty encountered in positioning the crystal element and relay member in the central position, constituting the utmost drawback in the assembly.

SUMMARY OF THE INVENTION

A first object of the present invention is to provide a structure having improved physical resistance against heat and shocks.

A second object of the invention is to provide a structure, which readily and quickly permits the positioning of the ceramic element support member in the central position within the microphone cap, thus reducing the positioning failure and bettering the yield.

A third object of the invention is to provide a structure, which has a support consisting of a single part to minimize the number of parts within the microphone cap, thus saving the material, ensuring reliable assemblage and reducing the cost.

A fourth object of the invention is to provide a unique structure using a converting element made of a ceramic material, which is very immune to changes of the human body temperature and is capable of improving the pressure sensitivity to respond to diaphragm oscillations so that it can be utilized as the converting element sensitive to minute oscillations in a hemadynamometer.

A fifth object of the invention is to overcome the fragile character of the ceramic material that has heretofore constituted the main difficulty encountered when it is to be used as pressure sensor in the hemadynamometer by the provision of a unique support structure, which comprises an elastic relay member 4 made of such material as rubber and Neoprene rubber and a support member 5 of a single part made of rubber or a sponge-like material having a suitable rigidity or Neoprene rubber with hardness of 50, the converting element consisting of a ceramic material being supported on said support member, so that external shocks exerted to the ceramic material can be sufficiently absorbed.

A sixth object of the invention is to provide a structure, where the oscillating diaphragm 2 is formed with edge portion 2a to facilitate the mouting thereof on the microphone cap 1 and prevent strain from being developed in the microphone with the cap edge portion to thereby enhance the strength of the microphone.

A seventh object of the invention is to provide a structure, where the elastic support member 5 has a configuration capable of being snugly fitted in the inner periphery of the microphone cap so that the positioning of the support member 5 can be achieved simultaneously with the mounting thereof in the cap.

An eighth object of the invention is to provide a structure, which can be readily assembled without requiring any particular skill and ensures reliable positioning so that it permits efficiently manufacturing products of uniform quality and with high precision.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a conventional microphone for use with a hemadynamometer;

FIG. 2 is a front sectional view showing a dynamometer microphone according to the present invention in a complete state;

FIG. 3 is an exploded view partly in section showing the individual component parts of the microphone according to the invention; and

FIGS. 4 and 5 show other examples of the mounting of ceramic element on elastic support member.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be described in conjunction with the accompanying drawings. Referring to FIGS. 2 and 3, reference numeral 1 designates a microphone cap or house. Reference numeral 2 designates an oscillating diaphragm mounted on the microphone cap with its flange 2a in contact with the outer periphery of the cap. The flange 2a of the oscillating diaphragm 2 is provided to reinforce the mechanical strength of the diaphragm and it serves to prevent excessive strain in the cap 1 to expect the perfection of the mounting of the oscillating diaphragm 2 on the microphone cap 1. Reference 3 designates a ceramic element utilized as a converting element to convert sound into electric oscillation. Unlike the usual crystal element, it is strongly heat-resistant and has good oscillating performance. On the other hand, the ceramic element is very fragile. This drawback is effectively overcome by the following construction utilizing an elastic relay member 4 and an elastic support member 5. It has been experimentarily found that Neoprene rubber with hardness of 50 is most suitable as the elastic material for them. These elastic rubber members also absorb external shocks to thereby perfectly protect the physically fragile ceramic element 3 supported between them. The elastic relay member 4 intervening between oscillating diaphragm 2 and ceramic element 3 transmits the oscillation of the oscillating diaphragm 2 to the ceramic element 3. The elastic support member 5 supports the ceramic member 3 within the microphone cap 1. The elastic support member 5 has its lower portion portion snugly fitted in bottom edge of the cap. With the above construction of the microphone, the ceramic element 3 can be readily positioned in the center of the cap 1 to greatly simplify the assemblage. Also, since the support member 5 consists of but a single part rather than two parts as in the prior art, the number of parts can be reduced, so that the assembly can further be facilitated while ensuring the reliable positioning. Support member 5 is formed with support grooves 5a for supporting the opposite ends of the ceramic element 3 and also a central bore 5b utilized to visually facilitate the correct mounting of the relay member 4 in the central position. The elastic support member 5 is characterized by its configuration: It consists of centrally recessed elongate body comprising a pair of upwardly and inwardly opening grooves 5a, 5a longitudinally and symmetrically formed near the ends thereof, so that the ceramic element 3 may easily be supported on the support member 5 with its opposite ends fitted in the grooves and its major central portion spaced from the support member 5. Numeral 6 designates a microphone cord electrically connected to the ceramic element 3. The coupling of the above parts, for instance the coupling between microphone cap 1 and elastic support member 5 and coupling between microphone cap 1 and oscillating diaphragm 2, is all done by means of bonding. A typical example of the assemblage consists of mounting the elastic support member 5 in the microphone cap 1, mounting the ceramic element 3 in the support member 5, soldering the element 3 to the microphone cord 6, bonding the relay element 4 to the ceramic element 3 and mounting the oscillating diaphragm 2 on the microphone cap 1 with the diaphragm bonded to the microphone cap 1 and to the relay member 4 in the mentioned order.

FIG. 4 shows another example, in which ceramic element 3 is bonded to elastic support member 5 by means of adhesive.

FIG. 5 shows a further example, in which ceramic element support member 5 of elastic material is formed with a longitudinal elongate groove 5a, in which the element is wholly received. While the mounting means for mounting the elastic support member 5 with respect to the microphone cap 1 is obtained from the snug fit between microphone cap 1 and elastic support member 5, an adhesive may sometimes be also used. Since the elastic support member has a simple construction, it can be readily produced on the mass production scale. Also, it permits reliable and ready positioning, thus facilitating the assembly, and also it serves to protect the ceramic element 3.

Claims

What is claimed is:

1. A hemadynamometer microphone comprising:

a. a housing;

b. a support member in said housing, said support member being made of an elastic material and being constituted by a centrally recessed elongate body made of a single part and first and second longitudinal grooves symmetrically formed near the ends of said body in upwardly and inwardly opening fashion, said body having such a configuration as to permit the support member to be snugly and integrally fitted in the inner periphery of said housing;

c. a ceramic element positioned in and centrally of the housing, with the opposite ends thereof fitted in said first and second grooves and a substantially major central part thereof held in spaced relation from said support member, for serving to convert sounds into electrical oscillations;

d. an oscillating diaphragm means mounted over said housing; and

e. a relay member made of an elastic material disposed centrally of the ceramic element, between and interconnecting said ceramic element and said diaphragm, for transmitting the oscillation of said diaphragm to said ceramic element.

2. The hemadynamometer according to claim 1, further comprising an upwardly opening bore formed on the elastic support member centrally thereof, the size of the bore being of such extent as to visually facilitate the correct mounting of said relay member centrally between said ceramic element and said oscillating diaphragm.

3. The hemadynamometer microphone according to claim 1, wherein said elastic support member and relay member are made of Neoprene rubber.

4. The hemadynamometer microphone according to claim 1, wherein said oscillating diaphragm has the peripheral edge formed with a flange, said flange being kept in contact with the outer periphery of the housing.