US3322876A - Electro-acoustic generator adapted to produce low frequency signals transformable into musical sounds by means of any amplifiers - Google Patents

Description

May 30, 1967 c. MARTIN 3,322,876

ELECTRO-ACOUSTIC GENERATOR ADAPTED TO PRODUCE LOW FREQUENCY SIGNALS TRANSFORMABLE INTO MUSICAL SOUNDS BY MEANS OF ANY AMPLIFIERS Filed Feb. 20, 1964 United States Patent M 3,322,876 ELECTRO-ACOUSTIC GENERATOR ADAPTED TO PRODUCE LOW FREQUENCY SIGNALS TRANS- FORMABLE INTO MUSICAL SOUNDS BY MEANS OF ANY AMPLIFIERS Constant Martin, 36 Ave. de Saint-Cloud, Versailles, France Filed Feb. 20, 1964, Ser. No. 346,241 Claims priority, application France Feb. 26, 1963, 925,962, Patent 1,357,713 4 Claims. (Cl. 84-1.15)

My invention has for its object an electro acoustic generator adapted to produce low frequency signals transformable into musical sounds by means of any amplifier.

My improved arrangement includes chiefly at least one movable elastic projection adapted to move over a predetermined path and associated with members adapted to vibrate, each time they meet said movable elastic projection and are shifted thereby out of an inoperative position by the thrust exerted on the member considered by said elastic projection, said operation being immediately followed by a release.

My invention includes furthermore electric collectors secured in proximity with the vibratory members and translating the vibratory movements of the latter into electric currents of a reduced intensity.

The vibratory members may be of any nature and shape depending on the particular requirements of each embodiment and they may assume the shape of rods of any desired cross-section, said rods being rectilinear or curvilinear or else I may resort to vibratory strings or to plates or various articles adapted to vibrate under the action of the transient thrust exerted by an elastic projection. Such vibratory members are preferably made of magnetic material in the case of electromagnetic collectors and their number may vary according to the embodiment considered.

The elastic projection or projections forming part of my improved arrangement may assume more particularly a circular movement so that the end of the projection may move along a circular line, but its path may as well assume the shape of an ellipse or any other suitable closed curve.

The drive of the projections may be ensured by any suitable means, whether directly or otherwise, or else they may be shifted by hand.

My improved arrangement may be modified in various manners and leads to various applications. It is more particularly adapted to be associated with an acoustic amplifier or system of amplifiers whereby the weak modulaited currents produced by the collectors, are raised to a suitable amplitude so that they may actuate loudspeakers and produce thus musical sounds or else they may act on the modulating circuits of a remote transmission station or remote control station or an acoustic recording apparatus. v 7

Other advantages and features of my invention will appear from the reading of the following description of an embodiment disclosed by way of a mere indication and by no means in a limiting sense.

Said embodiment is illustrated in the accompanying drawings, the single figure of which is an exploded perspective view of said embodiment which is constituted chiefly by the following parts:

An electric motor 1, associated with speed reducing means, and the shaft of which is adapted to revolve at a low speed, said motor being secured to the vertical flange of a supportingmember 2 which is Ushaped and the opposite flange of which is lined by a preferably metallic plate 3. The shaft 4 of the mot-or 1 extends through the space separating the two flanges of the sup- 3,322,876 Patented May 30, 1967 porting member 2 and its terminal section engages a perforation 5 formed in the plate 3. Two rectilinear rods of a suitable size 6, 7, 8 are locked each at one end by means of cooperating screws 9, 10 and 11 in the corresponding perforations 12, 13 and 14 formed in the flange of the supporting member 2 associated with the plate 3 and in said plate, said perforations being distributed over a circumference of which the center registers with the first mentioned perforation 5.

A projection 18 constituted by a wire or a flat preferably metallic member, acting as a spring, is rigidly secured to the shaft 4 controlled by the motor through the agency of an intermediate member 15 and of the securing screws 16 and 17. The length of the elastic projection or finger 18 is such that its free end is adapted to meet in succession the rods 6, 7 and 8 during the rotation of the shaft 4.

The relative arrangement of the'rods 6, 7 and 8 and of the elastic projection 18 and the shape given to the end of the projection are such that, when said end of the projection engages a rod, it causes the vibration of the latter.

The rods 6, 7 and 8 are made of a magnetic metal although this is not esesntial if the collectors described hereinafter, are not constituted by electro-magnetic collectors.

A plate 19 which, for sake of clarity of the drawing, is illustrated as shifted away from the upper section of the plate 3 is, in practice, secured to the latter by securing means illustrated at 20 and 21. On the other hand, said plate 19 carries three magnetized bars 22, 23 and 24 in perforations of the plate 19 in which they are suitably locked by the corresponding screws 28, 29 and 30.

The lower end of the magnetized bar 22 is surrounded by a winding 25 and is located immediately above the rod 6 and at a short distance with reference to the latter.

Similarly, the lower ends of the bars 23 and 24, are surrounded respectively by the winding 26 and by the winding 27 and are located immediately above and at a short distance from the corresponding rods 7 and 8 respectively,

A member 31 which is rigidly secured to the driving shaft 4, carries a stud 32 terminating with an en-dpiece of an insulating material 33 adapted to engage the elastic section of an electric switch constituted by the contact blades 34 and 36 carried respectively by the insulating supports 35 and 37.

The electric connections between the motor 1, the contact-making blades 34 and 36, the switch 40 and the terminals 41 and 42 of a suitably supply of current, are executed in conformity with the drawing.

Lastly the windings 25, 26 and 27 are inserted in series and connected with the input of an amplifier 38 followed by a loud-speaker 39.

In the example illustrated, the windings of the collectors are inserted in series but it is possible also to insert them in parallel or in accordance with any other suitable arrangement.

Similarly, the collectors of the present example are equal in number with the vibrating members, but it is possible to provide a number of collectors which is smaller than that of the vibrating members or even a single collector may serve for the whole system of vibratory members.

The operation of the arrangement disclosed is as follows:

In the position illustrated, the terminal section 33 of the stud 32 engages the blade 34 of which the end is spaced thus with reference to the blade 36, the result of which is that the motor 1 is not connected across the terminals 41 and 42 of the supply of current.

If the switch 40 is then closed transiently, the motor is fed and the shaft 4 revolves and carries along in its rotation on the one hand, the elastic projection 18 and on the other hand, the stud 32 the end 33 of which releases the blade 34 which engages now the blade 36 and closes thus the circuit feeding the motor throughout the duration of a complete revolution.

During said revolution, the end of the elastic projection 18 engages the rod 6 and shifts it consequently out of its inoperative position and by reason of the elasticity of said rod and of that of the projection 18, the latter releases suddenly the rod which starts vibrating; the elastic projection continuing its rotary movement, acts now in succession on the rods 7 and 8 so as to produce vibrations similar to those produced by action on the rod 6.

The vibrations of the rods 6, 7 and 8 produce in the windings 25, 26 and 27, induced currents which are amplified by the amplifier 38 and are translated into musical sounds by the loud-speaker 39.

At the end of its stroke, the stud 32 returns into the position illustrated and switches off the circuit between the blades 34 and 36, which has for its result a stopping of the motor.

Of course, various modifications in shape and in detail arrangements may be required according to the case and to the application considered and this may be perforated without widening the scope of the invention, as defined by the accompanying claims.

What I claim is:

1. An electro-acoustic generator of low frequency signals adapted to produce through amplification musical sounds, comprising an elastic elongated member, an electric motor, a shaft controlled by said motor and driving the elastic elongated member along a circular path, vibratory members engaging the path of said elongated member and each adapted to vibrate immediately after they have been shifted out of their inoperative position by the passage of the elastic elongated member in registry with them, electric collecting means located in proximity with said vibratory members and adapted to transform the vibrations of the latter into weak electric currents, and means amplifying said currents and transforming them into musical sounds.

2. An electro-acoustic generator as claimed in claim 1, comprising a rigid part radially carried by the shaft and the free outer end of which carries the elastic member.

3. An electro-acoustic generator as claimed in claim 1 wherein the vibratory members are constituted by rods of magnetic metal parallel with the shaft and removably secured in position.

4. An electro-acoustic generator as claimed in claim 1 comprising a circuit energizing the motor, a switch inserted in said circuit, means controlled by said shaft and adapted to control said switch to close the circuit throughout one revolution of the motor and to deenergize it after said revolution.

References Cited UNITED STATES PATENTS 2,769,361 11/1956 Kunz 841.25

ARTHUR GAUSS, Primary Examiner.

JAMES BUSCH, Assistant Examiner.

Claims (1)

1. AN ELECTRO-ACOUSTIC GENERATOR OF LOW FREQUENCY SIGNALS ADAPTED TO PRODUCE THROUGH AMPLIFICATION MUSICAL SOUNDS, COMPRISING AN ELASTIC ELONGATED MEMBER, AN ELECTRIC MOTOR, A SHAFT CONTROLLED BY SAID MOTOR AND DRIVING THE ELASTIC ELONGATED MEMBER ALONG A CIRCULAR PATH, VIBRATORY MEMBERS ENGAGING THE PATH OF SAID ELONGATED MEMBER AND EACH ADAPTED TO VIBRATE IMMEDIATELY AFTER THEY HAVE BEEN SHIFTED OUT OF THEIR INOPERATIVE POSITION BY THE PASSAGE OF THE ELASTIC ELONGATED MEMBER IN REGISTRY WITH THEM, ELECTRIC COLLECTING MEANS LOCATED IN PROXIMITY WITH SAID VIBRATORY MEMBERS AND ADAPTED TO TRANSFORM THE VIBRATIONS OF THE LATTER INTO WEAK ELECTRIC CURRENTS, AND MEANS AMPLIFYING SAID CURRENTS AND TRANSFORMING THEM INTO MUSICAL SOUNDS.

Images