US3013189A

US3013189A - Electro-mechanical transducer

Info

Publication number: US3013189A
Application number: US839185A
Authority: US
Inventors: Vaughan A Bernier
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-09-10
Filing date: 1959-09-10
Publication date: 1961-12-12
Anticipated expiration: 1978-12-12

Description

Dec. 12, 1961 l v. A. BERNIER 3,013,189

ELECTRO-MECHANICAL TRANSDUCER Filed Sept. l0, 1959 2 Sheets-Shea?l 1 [38 w 4f 24 l 4 l V/\///| 7/ N \1,

/0 l; 54 *y 5 s Ak /y H 1 1 2 Z 50 %H/" 4 Dec. 12, 1961 v. A. BERNIER 3,013,189

ELECTRO-MECHANICAL TRANSDUCER Filed Sept. 10, 1959 2 Sheets-Sheet 2 IN V EN TOR.

f l 4. Val/ga? A' 5er/71?);

United States Patent O 3,013,189 ELECTRO-MECHANICAL TRANSDUCER Vaughan A. Bernier, Kankakee, Ill.

(505 Coralina Ave., Clinton, N.C.) Filed Sept. 10, 1959, Ser. No. 839,185 8 Claims. (Cl. 317-173) This invention relates to an electro-mechanical transducer, and has for one purpose the provision of means for transforming variations in an electrical signal into mechanical movement.

Another purpose is an electro-mechanical transducer which may be used on a loud speaker unit.

Another purpose is an electro-mechanical transducer which can change electrical energy into mechanical movement or mechanical movement into electrical energy.

Another purpose is an electro-mechanical transducer having improved operating characteristics, and wlhen used in a speaker unit eliminates the necessity of coupling transformers.

Another purpose is a method of transforming electrical signal variations into corresponding mechanical variations in which the permanent or biasing field comprises two elds of energy having parallel lines of fiux but opposite polarity.

Another purpose is an electro-mechanical transducer having two generally constant opposed parallel fields which may be modulated by a third field such that when one field increases, the other decreases.

Another purpose is to provide a sound reproducing unit having two opposing fields impressed on the armature thereof.

Other purposes will appear in the ensuing specification, drawings and claims.

The invention is illustrated diagrammatically in the following drawings wherein:

FIGURE l is a Vertical section of my improved electro-mechanical transducer,

FIGURE 2 is a horizontal section taken along line 2-2 of FIGURE 1,

FIGURE 3 is a vertical section of a variant form of my electro-mechanical transducer, and

vFIGURE 4 is a vertical section of a further form of electro-mechanical transducer embodying the principles disclosed herein.

Referring now to FIGURES l and 2, a generally cylindrical non-magnetic housing has a bottom wall 12, as shown in the drawings, and a top wall 14 having a generally central aperture or opening 16 therein. The bottom wall 12 has a central upwardly projecting portion 18 upon which is positioned a permanent magnet 20, suitably bonded to the portion 18. A second permanent magnet 22 is positioned above the magnet 20 and is similarly bonded thereto to provide a rigid strong structure.

lThe direction of the magnetic fields or the polarity of the two permanent magnets and 22 should be so arranged that either the two northpoles or the two south poles are positioned adjacent each other at the point where the magnets are bonded together. Two magnetic fields will therefore be formed by the permanent magnets which will have lines of flux that are generally parallel but of opposite polarity.

A suitable electric coil 24, which is connected to coil leads 26 and 28 extending through

small holes

30 and 32 Vrespectively in the wall of the housing, is positioned outside of the permanent magnets and adjacent the non-magnetic housing wall. The magnets and the coil 24 define a generally annular chamber or space 34. ln the chamber or space 34 is a generally cylindrical driving element or armature 36 extending generally throughout the length Yof the chamber and formed of a suitable magnetic material having high permeability. The armature has an axial slot or opening 37 running throughout the length thereof which prevents shorting of the magnetic fields formed therein. Attached to the armature is a cylindrical connecting element or connecting tube 38 which is formed of a suitable non-magnetic material. The upper portion of the connecting element 38 is suitably connected to a pair of spaced generally annular diaphragme or support

members

40 and 42. Whereas I have shown two diaphragms, it should be understood that one may be sufficient. The diaphragms or support members may be corrugated, such as shown in the drawings, or they may be otherwise, as the particular shape of the diaphragms or support members is not essential to the invention. It is important however, that the diaphragms or support members be generally flexible so that they will support the connecting element and the armature or driving element but yet permit movement of these elements in a generally vertical path or in a path generally parallel to the magnetic field.

In the operation of the device shown in FGURES l and 2, there are two generally constant magnetic fields formed by the two permanent magnets. These fields are of opposite polarity and have generally parallel lines of fiux. The strength of the two magnets may be the same or they may vary one from the other, the important thing is that they be opposite. When an electric signal is applied to the coil leads, a magnetic field will be formed in the coil due to this electric signal. Since it is the purpose of my invention to provide a means to allow movement of the connecting element in response to variations in the electric signal, the signal supplied to the coil will usually be a variable signal. As this signal varies, the polarity, frequency and relative strength of the field fromed at opposite points on the coil will change. When, for example, the electrical signal has a polarity and strength such that the upper portion, as shown in the drawings, of the coil takes on a north polarity and the bottom portion of the coil takes on a south polarity, the strength of the field in the coil due to the electric signal will add to the strength of the field formed by the top magnet and will subtract from the strength of the field formed by the bottom permanent magnet. Therefore the armature and the connecting element will move upward, as shown in the drawings. When the polarity of the field formed in the coil reverses there will be reverse movement of the driving element and connecting element. As the strength of the field formed in the coil varies according to the strength and frequency of the electric signal the amplitude and rate of movement of the connecting element and driving element will vary. With no signal applied to the coil, the opposite fields will hold the armature in one position, generally intermediate the ends of the magnets. For convenience I may refer to the relatively constant field formed by the center magnets as the biasing fields and the field formed by the coil and the electric signal as the modulating field.

Referring now to FIGURE 3, wherein parts common to the FIGURE l and 2 forms are indicated by like numerals, the only difference from the structure shown in FIG- URES 1 and 2 is that instead of lusing a pair of permanent magnets to establish my biasing fields I have provided an electro-magnet. The electro-magnet comprises an upper coil 44 and a lower coil 46 suitably wound on a core element 48. The coils are fed through suitable coil leads 50 and 52 which reach the coils through

suitable holes

54 and 56 in the non-magnetic housing 10 and the core 48. The coils are connected together by a suitable lead S8. The coils shown in FIGURE 3 should be so wound that the magnetic fields established thereby'are similar to the magnetic fields of FIGURES l and 2. In other words, the magnetic fields should provide lines of notarse flux which are generally parallel but of opposite direction or polarity. The operation of the device shown in FIG- URE 3 is substantially similar to that shown in FIGURES l and 2, however in this case, the biasing or relatively constant fields are formed by the electro-magnet rather than by the permanent magnets. As was the case in the forni of FEGURES l and 2, the magnetic field formed in the coil 24 will add to one of the biasing magnetic fields while subtracting from the opposite field so as to provide additional attracting force and so movement of the armature and connecting element in the chamber 34.

i have shown a further form of my invention in FIG- URE 4 wherein like parts are again indicated by like numerals. In this form of the invention, instead of providing a pair of magnetic fields having opposite polarity, l have provided two electric fields, again of opposite polarity. Batteries or other suitable sources of direct current titl and 62 are so wired that like terminals, and in this case the negative terminals, are common. The electric fields or electro-static fields are formed by suitable conductors, which may be in the form of annular rings or the like. The-re is an upper electric field and a lower electric field, both parallel, and having opposite polarity. The upper field may be formed by an. outer ring 54, which has a positive charge as it is connected to the positive terminal of the battery 6h, and a spaced lower outer ring do connected to the opposite side of the battery and so having a negative charge. The upper electric field is completed by an inner ring 68 having a positive charge and a lower inner ring 7@ having a negative charge. Wire 69 connects outer ring 64 and inner ring 68 and wire 71 connects outer ring 66 with inner ring 70. The lower electric field, which has opposite polarity, is formed by `outer and

inner rings

66 and 70 and outer and

inner rings

74 and 76 which have a positive charge. Wire 73 connects rings or

conductors

74 and 76. The housing 10 has an upwardly projecting center portion 72 upon which the inner rings are positioned and which in the preferred form should be formed of a non-magnetic material. I have placed suitable spacer elements 75 adjacent each of the annular rings or conductors to provide a larger area or surface for the electric charge. The elements 75 may be of the same material as the annular conductors or they may be otherwise. The action of the electric fields formed by the annular conductors is similar to that of a capacitor in that I have provided longitudinally spaced surfaces or plates having opposite charge or polarity. These spaced, oppositely charged surfaces will provide electric fields, which fields, as shown in the drawings, will be parallel and of opposite direction. The fields will be generally parallel to the connecting element 3S or generally parallel to the outwardy projecting center portion 72.

The connecting element or connecting tube 38 has upper and

lower conductor elements

78 and 80. Each of these conductor elements may receive an electric signal through suitable wires 82 and 84, so that an electric field will be set up between the elements 78 and 80'. This electric field will be similar to a capacitor type action in that there are two oppositely charged plates or surfaces spaced from each other. The electric field will be generally parallel to the biasing fields formed by the ring elements. In this for-m of the invention the operation is similar to that described before in that the electric field formed on the connecting element, or the modulating field, will either add to or subtract from each of the more constant or biasing electric fields and so cause movement of the connecting element in a path generally parallel to the electric fields.

Use, operation and function `of the invention are as follows:

The electro-mechanical transducer shown and described herein may have particular application to sound reproducing units or loud speakers. There are however many other applications for the device Iand method, such as in recording devices, for example, in cutters and galvanometers. It also has use in positioning units and in any other type of assembly wherein it is desired to transform either variation in mechanical motion into variations in an electrical signal or the reverse.

The description of the invention has been directed to a device wherein variations in amplitude and frequency of an electrical signal applied to the coil or to the elements 73 and fifi caused corresponding mechanical movement of a connecting member or element. it should be understood however, that my invention also includes a device wherein mechanical movement of the armature or driving element will cause variations in the lines of flux passing through the coil and so induce a signal in the coil having a frequency and amplitude proportional to the movement of the armature. The device shown herein is equally suitable for either type of operation, and its description as changing electrical variations to mechanical is merely for purposes of illustration.

My invention, regardless of which form, operates on a general principle wherein two fields of energy which are relatively constant, and produce lines of flux which are generally parallel and of opposite polarity, are either decreased or increased by the variations of a third field of energy which has lines of liuX generally parallel to the constant or biasing fields. The biasing fields oppose each other with parallel lines of flux. The modulating field lwill add to the strength of one of the biasing fields and subtract from the strength of the other. The increase in the strength of one field will provide a stronger attraction or driving force for the armature or other driving member spaced between the fields. Thus the diving element will have movement corresponding to the variations in the strength and frequency of the modulating field which may be varied by a suitable electric signal.

When the device is being used to change mechanical movement into an electrical signal, the movement of the armature along the parallel lines of flux of the two biasing fields will vary the strength of the field induced in the coil Iby the biasing fields. Thus an electrical signal will be produced in the coil which will correspond to the mecham'cal movement of the armature.

In one form of the invention both the modulating and the biasing fields are magnetic fields and I have placed an armature having high permeability between the biasing and modulating fields. This armature is moved in a path generally parallel to the fiuX lines and moves according to variations in strength and frequency of the modulating field.

In one form of magnetic electro-mechanical transducer, I have used two permanent magnets positioned so that either both north poles or both south poles are adjacent each other whereby I have two fields of opposite polarity. In the other form of magnetic transducer my biasing field is formed by electromagnets. I have a core upon which are wound two coils. The coils being so connected that I form magnetic fields of opposite polarity.

In the third form of the invention I provide electric or electrostatic fields by placing oppositely charged surfaces longitudinally spaced frorn each other. An electric field will be established between these oppositely charged surfaces, much like in a capacitor. These electrical fields will be generally parallel to the connecting element. Instead of a coil such as I have used in the magnetic forms to establish my variable fields, I have opposite charged surfaces spaced longitudinally of each other and so positioned that they may either add to or subtract from the strength of the more constant or biasing electric fields. The change on these surfaces is supplied by an electric signal which may vary both in polarity, frcquency and amplitude such as a voice signal. These variations will vary the strength of the opposed biasing electrical fields which in turn will cause corresponding movement of the connecting element.

There are many modifications, substitutions and alteraltions which may be made to the invention without departaclaran ing from the scope of the following claims. For example, I have shown a generally cylindrical construction for my transducer. It should be realized however that the particular shape of the members herein is not essential. Nor is it essential that the polarity of the fields be as shown in the drawings, as it is only essential that the polarity be opposite so that the fields oppose each other. Additionally, although I show the biasing fields as being parallel, It is possible to have the fields formed at a slight angle Without departing from the scope of the invention. I may make a further modification to my invention by reversing the placement of the coil and constant magnetic afield and have the coil within the armature and the constant field on the outside. Either form is satisfactory.

I claim:

1. An electro-mechanical transducer including a diaphragm, a connecting element supported thereby, a driving element connected to said connecting element, means for producing two generally constant fields or" energy so positioned that the lines of flux produced thereby are generally parallel but with opposite polarity, means for producing a third iield of energy, the flux lines of said third ield being generally adjacent and parallel to the flux lines of said generally constant fields of energy, said driving element and connecting element being positioned between said constant fields of energy and said third iield of energy, means for varying said third named iield of energy to simultaneously vary said constant fields of energy in opposite directions, said driving element being responsive to said variations in the eld strengths whereby said connecting element is moved in a path generally parallel to said flux lines.

2. The structure of claim l wherein said fields of energy are magnetic fields.

3. The structure of claim l wherein said fields of energy are electric fields.

4. An electro-mechanical Vtransducer including a diaphragm, a generally cylindrical connecting element supported thereby, an armature positioned on said connecting element, means for producing two generally constant magnetic fields on one side of said core element, said magnetic fields being so positioned that the lines of flux produced thereby are generally parallel, but of opposite polarity, means for producing a third magnetic iield on the opposite side of said core element, said third magnetic field having lines of iiux parallel to said generally constant tiux lines and parallel to said armature, means for varying said third magnetic lield to simultaneously increase one of said generally constant fields and decrease the other to thereby move said armature in a path generally parallel to said magnetic lines of flux.

5. The structure of claim 4 wherein said constant magnetic iields are positioned within said connecting element and armature, and said third magnetic field surround said connecting element and armature.

6. The structure of claim 5 wherein the means for producing said constant magnetic fields includes a pair of permanent magnets positioned with like poles adjacent each other.

7. The structure of claim 5 wherein the means for producing the constant magnetic fields includes an electromagnet.

8. An electro-mechanical transducer including a diaphragm, a generally cylindrical connecting element Supported by said diaphragm, a generally cylindrical armature connected to said connecting element, a pair of permanent magnets positioned one on top of the other inside of said armature, the magnetic elds formed by said magnets being generally equal and of opposite polarity, and a coil positioned outside of said armature such that the magnetic eld produced thereby will be generally parallel to the magnetic fields of said magnets.

References Cited in the file of this patent UNITED STATES PATENTS