US1147016A - Electromagnetic sound-producer. - Google Patents

Description

L. GRUBMAN.

ELECTROMAGNETIC SOUND PRODUCER. APPLICATION FILED JUNE 31, 1914.

l,14'?,0;16., Patented July 20, 1915.

WITNESSES." [Ni EN 70/? 1 ATTORNEY KINITED %TATE% LEO GRUBMAN, OF NEW YORK, N. Y., ASSIGNOR TO ELECTRIC SPARK APPLIANCE CO. INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTROMAGNETIC SOUND-PRODUCER.

Specification of Letters Patent.

Patented July 20, 1915..

Application filed June 11, 1914. Serial No. 844,401.

To all whom it may concern:

Be it known that I, LE0 GRUBMAN, a citizen of the United States, and a resident of the borough of Brooklyn, county of Kings, city and State of New York, have invented certain new and useful Improvements in Electromagnetic Sound-Producers, of which the following is a specification.

My improvements relate to the class of sound producing devices in which an elastic resilient diaphragm, or sound-wave vibrator, is actuated by electro-magnetic means, usually in conjunction with an armature'interposed between the electro-magnet and said elastic resilient diaphragm, the pulsations of the armature being transmitted to the said diaphragm through the medium of various instrumentalities. In all such cases, so far as I am aware, the hammer or armature has been positioned between the magnet and the diaphragm, and the diaphragm has derived its motion from the armature.

In the present case I position the diaphragm between the magnet and the armature or hammer, and thelatter derives its motion from the diaphragm, this being one of the, distinctive features of the invention.

Another is the provision of means for regulating the tone of the diaphragm by controlling the motion of the armature or hammer, all as hereinafter more fully de scribed and for purposes set forth.

In the accompanying drawings, Figure 1,-

is a rear view of, say, an automobile horn made in accordance with my present invention; Fig. 2, a central sectional elevation upon plane of line 22 Fig. 1; ,F ga sectional detail upon plane of line 33 'Ihe construction and arrangement of parts shown in the drawings is designed more particularly for use where an alternating electric current is available, as for instance on Ford automobiles, or elsewhere, where transformation of current is unnecessary; Thatis to say the usual and well known make and break means, or

interrupter used in connection with e ectro-magnetic horns supplied with continuous electric current 1s omitted, although such device maybe added when necessary without materially altering the construction and arrangement of parts, or the principle 'of action involved herein. Thus, if my present invention is to be embodied in a horn operated by means of a continuous current of electricity, the interrupter mechanism shown and described in either of my concurrent applications No. 825,114, filed Mar. 16th, 1914, or No. 810,431, filed May 23d, 1914:, may be added to the sound producing mechanism herein disclosed with but slight modification of either, if any at all,- it being immaterial in so far as my present invention is concerned, how the alternating current fed to the coil C, is attained.

The omission of interrupter mechanism of course enables me to simplify and cheapen the construction of an automobile horn, or similar alarm device, very materially, although this is only an incidental feature in connection with the present invention, one distinctive feature of which is the interposition of the diaphragm D, between the ele'ctro-magnet M, and the hammer H, and this whether the latter acts as an armature or not. That is to say, the hammer H, may or may not be formed of magnetic material, while the diaphragm D, is formed of magnetic material and is acted upon di rectly by the electro-magnet M. The latter consists by preference of a circular plate m, formed with an inturned center or hollow core m, an annular spacing block m and a disk m with a central aperture m, all said parts m, m, m and m being made of magnetic material. The electric coil C, is situated between the magnetic plates m, m and surrounds the hollow core m, and it is connected in electric circuit by means well known and not necessary to show or describe herein. The hollow .core m, extends to and through the central aperture m in the disk m its inturned edge being flush with the rear face of the latter, as shown in Fig. 2. A spacing washer d, or equivalent, is interposed between the diaphragm D, and the magnetic plate m and the armature or hammer carrying spring h, is mounted on a spacing block it, which is by preference made annular so as to form also a bearing or support for the bracket 6, upon which the tuning screws t, t, are mouhted. 22 is a nut lock plate for securing the tuning screw t, in a predescr bed position. These parts are all inclosed in a casing A, and held thereto on one side by anchor screw bolts a, a, passing through the front plate a, of the casing A, the magnet members m, m m the spacing washer (Z, the edge of the diaphragm D, the block it, andthe spring h,and on the other side by anchor bolts a a passing through the front plate of the casing, the magnetic members m, m m the spacing washer al, the edge of the diaphragm D, the block it, rise block b, and bracket 1), both sets of screw bolts (1,, a, and 41?, a being secured in place by nuts a a -A horn e, is attached to the frontal member a, of the casing A, opening therethrough into coincidence axially with the hollow core m, of the electro-magnet M, as shown in Fig. 1, so as to receive and transmit the air pulsations created by the diaphragm in action. The casing A, may be left open at the back to be closed by the part to which the instrument may be attached, (as by means of the flange (L3,) to the dash board or other fixed part of a Ford machine, to which for its simplicity, cheapness, and adaptability to a variable alternating electric current my device is particularly suited, although applicable for use generally for alarm or sound warning purposes.

The alternating current is. transmitted to the coils C, through the medium of binding nuts 2', i, and screws 2', i, mounted on the bracket Z2, and insulated therefrom as shown in Fig. 3.

It is well known that it is difficult to construct an automobile horn that will respond uniformly or satisfactorily to' the varying frequency of an alternating current not 'produced and regulated by an interrupter or make and break device, but derived for instance from the uncertain and changeable speed of an alternating current auto-magneto, largely because the weight of the armature is not mechanically responsive to currents of high frequency. Furthermore, as heretofore arranged, the diaphragm has derived its motion from the armature, and the latter, owing to its weight, has not always been responsive to the fluctuations of an alternating current, especially one of high frequencies. If to obviate this, armatures of very light weight are used theylack the requisite power ofimpact with the diaphragm to insure'volume and tone. I obviate this difficulty mainly by interposing the elastic resilient magnetic diaphragm between the electro-magnet and the hammer, which lat ter need not necessarily be of magnetic material in this arrangement, and hence need not act as an armature. In fact I reverse the order of arrangement and operation by making the diaphragm impart motion to the hammer. Improvement results from the fact that the diaphragm will always respond to all frequencies of magnetic attraction, the mechanical vibration of the diaphragm being assured irrespective of variable electrical conditions. The vibrations thus positively and directly produced in the diaphragm by the magnetic pulsations not necessarily being sufficient to afford the requisite loudness or volume of sound, are mainly utilized by me to effect the vibration of the hammer, be the latter magnetic ornon-magnetic. As a result dynamic power is imparted to and accumulated by the slower moving hammer, which reacts on the diaphragm with suflicient force to intensify, augment, and accentuate the resultant tone or volume 'of sound. In efiect the hammer thus used becomes a tone-strengthening device, or intensifier, in contra=distinction to the old use of the armature as a tone producer per 86. When the hammer is magnetic the dynamic energy imparted thereto is augmented by the magnetic influence, but it still derives its main impetus from contacting with the diaphragm. In this connection it may be noted that either the diaphragm D, or the hammer H, (or both) is preferably provided with a contact protuberance p, as may be preferred, for the purpose of limiting and centralizing the point of contact between said parts.

The vibrations of the hammer being relatively slower than those of the diphragm, as above indicated, it is desirable to insure synchronous concordance of contact and vibration between the two, and for this reason I furnish the adjustable tuning screw 25, by means of which the scope of vibration of the retractile spring h, may be restricted or amplified as may be found necessary to bring the hammer and diaphragm into average uniformity of accord. The screw 2 is locked in the prescribed position by any suitable means, as by the nut plate 25 and pinching screw t, as will be understood by reference particularly to Fig. 2.

It will thus be seen that my invention involves not only anew combination and arrangement of parts, but a new method of operation also, 2'. e. the imparting of motion to the hammer through the medium of the diaphragm, and the reaction of the hammer against the diaphragm as an intensifier as hereinbefore set forth,the hammer in such case by its acquired dynamic force and inertia amplifying and accentuating the resultant tone and volume of sound thus produced by the magnetic pulsations. The method also of attaining harmonious synchronism between the diaphragm and the heavier and slower moving hammer by regulatlng the area or scope of vibration .of the latter I also believe to be original with myself, and of special value in connection with the use of alternating electric currents of variable frequency as herein set /forth.

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

1. In electro-magnetic sound producers of the character designated, in combination,

an electro-magnet, a retractile armature, and an elastic resilient diaphragm movable independent of said armature and interposed between said magnet and armature, for the purpose described.

2. In electro-magnetic sound producers of the character designated,in combination, an electro-magnet, a retractile hammer, and an elastic resilient diaphragm movable independent of said armature and interposed between said magnet and armature, for the purpose described.

3. In electro-magnet sound producers of the character designated, in combination, an electro-magnet, a retractile hammer, an elastic resilient diaphragm positioned between said magnet and said hammer to receive direct impact from the latter, and means for controlling the tone of the diaphragm by regulating the scope of vibration of the hammer, for the purpose described.

4. In electro-magnetic sound producers of the character designated, in combination, an electro-magnet, a hammer mounted on a flat retractile spring, an elastic resilient diaphragm positioned between said magnet and said hammer to receive direct impact from the latter, and.means for controlling the tone of said diaphragm by regulating the scope of vibration of said hammer and retractile spring, for the purpose described.

5. In electro-magnetic sound producers of the character designated, in combination, an electro-magnet, a retractile armature, an elastic resilient diaphragm positioned between said magnet. and said armature, and means for controlling the tone of the diaphragm by regulating the scope of vibration of said retractile armature, for the purpose described.

6. In electro-magnetic sound producers of the character designated, in combination, an electro-magnet, an armature mounted on a fiat retractile spring, an elastic resilient diaphragm positioned between said magnet and said armature, and means for controlling the tone of said diaphragm by regulating the scope of vibration of said armature and retractile spring, for the purpose described.

7. In electromagnetic sound producers of the character designated, in combination, an electro-magnet, a hammer mounted on a flat retractile spring, an elastic resilientdiaphragm positioned between said electromagnet and said retractile hammer to receive direct impact from the latter, and an adjustable screw positioned to limit the scope of vibration of said retractile spring and hammer, for the purpose described.

8. In electro-magnetic sound producers of the character designated, in combination, an electro-magnet, a hammer mountedon a fiat retractile spring, an elastic resilient diaphragm positioned between said electromagnet and said retractile hammer to receive direct impact from the latter, an adjustable screw positioned to limit the scope of vibration of said retractile spring and hammer, and means for locking said adjusting screw in a prescribed position.

9. In electro-magnetic sound producers of the character designated, in combination, an electro-magnet, a hammer mounted on a fiat retractile spring, an elastic resilient diaphragm positioned between said electromagnet and said retractile hammer, an adjustable screw positioned to limit the scope of vibration of said retractile spring and hammer, means for locking said adjusting screw in a prescribed position, consisting of a lock nut plate and binding screw for clamping said lock nut plate, for the purpose set forth.

10. In electromagnetic sound producers of the character designated, an electro-magnet comprising a magnetic plate formed' with an inturned central hollow core flange, an annular ring of magnetic material supported upon said plate, a magnetic disk supported upon said ring and formed with a central opening concentric to said hollow core, and an electric coilpositioned within the magnet thus constituted and concentric to the hollow core, in combination with a retractile hammer and an elastic resilient diaphragm positioned between said magnet and hammer to be actuated by said electromagnet, for the purpose described.

11. In electro-magnetic sound producers of the character designated, an electro-magnet comprising a magnetic plate formed with an inturned central hollow core flange,

an annular spacing ring of magnetic material supported upon said plate, a magnetic disk supported upon said ring and formed with a central opening concentric to said hollow core and through which the latter eXtends, and an electric coil positioned within the magnet thus constituted and concentric to the hollow core, and with an elastic resilient diaphragm and an armature positioned to be actuated by said electromagnet, said diaphragm being independent of the armature and disposed'between the latter andthe magnet to receive direct impact of said armature.

12. In electro-magnetic sound producers of the character designated, an electromagnet comprising a magnetic plateformed with an inturned central hollow core flange, an annular spacing ring of magnetic material supported upon said plate, a magnetic disk supported upon said ring and formed with a central opening concentric to said hollow core and through which they of said armature and interposed between the same and the magnet to receive the direct impact of said armature.

13. In electro-magnetic sound producers of the character designated, an electro-magnet comprising a magnetic plate formed with an inturned central hollow core flange, an annular spacing ring of magnetic material, and a magnetic disk formed with a central opening concentric to the said hollow core, in combination with an elastic resilient diaphragm positioned upon one side of the electro-magnet and with a horn positioned upon the other side of said electro-magnet in axial alinement with, and opening into, the hollow core of said electro-magnet and a hammer upon the side of the diaphragm opposite said electro-magnet for the purpose described.

LEO GRUBMAN.

Witnesses:

G120. WM. MIATT, DOROTHY MIATT.

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