US1680822A - Sound reproducer - Google Patents

Description

2 Sheets-Sheet Aug. 14, 1928.

` G. STROBINO SOUND REPRGDUCER Filed oct. 29, 1926 Aug. 14, 1928.

G. STROBINO SOUND REPRODUCER Filed Oct. 29, 1926 2 Sheets-Sheet 2 WITNESS rofry Patented Aug, 1.4, 1928.

UNITED STATES.

GASTON STROBINO, OF PATERSON, NEW JERSEY.

SOUND REPRODUCER.

Application led October 29, 1926. Serial No. 144,986.

In my application for patent for a sound Teproducer, Serial No. 74,276, tiled Dec. 9, 1925, I have disclosed a sound reproducer of the type in which van elastic vibratory. structure including a resonator is intermittently tensioned and thereby vibrated by electromagnetic means thereon, such sound reproducer distinguishing from others in its class by said structure being normally tensioned and as thus tensioned holding the elements (electro-magnet and armature) of said means in operative relation to each other and by the presence of .elastic means holding said structure thus normally tensioned. The 0bjeet of the invention is to provide a reprodncer which shall reproduce in more faithful imitation of the originals than ordina-ry reproducers or receivers sounds diifering from each other through a wide range of frequency. In this application I 'claim one of the species of the invention set forth in said application Serial No. 74,276.

In the drawings` Fi g. 1 is a side elevation of a resonator-including vibratory structure embodying the invention;

Fig. 2 is a view of said structure as seen when viewed from the right in Fig. 1;

Fig. 3 is a plan of vsaid structure with the resonator removed; and

Figs. 4 and 5 are views illustrating two modifications and in which the resonator appears in each case in section and the remainder of the structure in side elevation.

The vibratory structure including a resonator in the example illustrated in Figs. 1 and 2 is represented bv the U-shaped elastic metal member 1, which may be a permanent magnet, and the resonator 2. preferably of wood, member L being suitably secured at 3 to the resonator so that it stands in a plane perpendicular thereto and so that one arm, 1. is therefore free to vibrate independently of the resonator: the arm 1a will of course be the freer to vibrate if as little as possible of the other arm, 1", is damped, wherefore I form the latter arm with a. projecting base,

as shown, affording limited contact with the resonator.

Said structure is normally tensioned by elastic means, as thus tensioned holding the elements of the electro-magnetic means for intermittently tensioning it in operative relation toeach other. In the present case this tensioning means is as follows: 4 is an elongated stiff elastic flexible piece here in the form of a leyer which is fulcrumed and thereby has a bearing on theset-screws 5 in a projection of the arm 1a of member 1 so as to oseillate in the plane of member 1 and has its shorter arm 4a bent toward arm l",v of member 1 and its longer arm bent ofi' in the same direction and preferably engaged in a' notch 1X of said member. An adjusting screw 6, tapped into arm lb of member l.'

bears against the adjacent side of lever 4 at about the middle of its longer arm, and between this screw and the bent or closed end of member 1 another adjusting screw 7 is tapped into arm la of said member and bears against the longer arm of said lever. The electro-magnetic meansor actuator here includes two electro-magnets, either of which may be treated as the armature of the other,

.nected at 8a. The power and eiiiciency of the device being described, which is designed for use especially in connection with radio apparatus where the operating current is weak, depend veryv largely on the tension developed in member 1, the fact that said tension is maintained by elastic means, and also on the possibility of nicely calibrating the gap or spaeingbetween the elements of the electro-magnetic actuator. In effecting adjustment for these purposes the screw 7 may first be turned to press the longer arm of elastic lever 4 downward, which elevates its shorter arm and opens the gap, and then screw 6 turned to bow said arm between screw 7 and fulcrnm 5, which depresses its shorter arm and closes the gap. The present construct-ion is such `that adjustment can be i effected so that for any given gap required between said elements the tension may be varied, or for any given tension the gap may be varied, and always the tensioned structure is Vheld tensioned by elast-ic means. vWhile it isof course an advantage that an instrument be aorded which, as herein shown, is self-contained, still this is not indispensable, for the invention also contemplates a rsystem to' be vibrated including the elastic iexible vibratory structure and means (as 4 and 6 7) to exert variable elastic flexing pressure thereon at either of two points thereof in substantially a common plane of fiexure, in combination with electro-magnet and armature elements arranged one on the part of said system which is moved on flexing said structure and the other on another part of said system. And in this broad statement it is to be observed that it is not material that said means to exert pressure on said structure have its elasticity afforded by a fulcrumed or lever-like part (4), though such a construction lends itself to a movement-together as against a movementapart in forming the gap and also a veryv nice Calibrating of the gap, which is necessary when the mechanism is used in radioreception, where very weak currents must be depended upon to energize the electromagnet.

In Figs. 4 and 5 I show two different applications of my invention to sound reproducers of the so-called loud-speaker type for use in connection with radio-receiving apparatus: Fig. 4: Two concavo-convex parts 10, as of suitable wood, bear against each other at their peripheries, being there held together by the screw-bolts 11, which may be arranged at suitable intervals. The upper one has sound outlet means 12 andthe lower one supporting legs 13, which may if desired be composed of the same material as such resonator and thus form resonating extensions thereof. The member 1 is contained within the casing formed by these two resonators, being secured to the lower one. A screwl 14 is secured to and extends up from the otherwise free arm 1 of said member through a suitable aperture in the upper resonator and on its upper threaded end is a knurled nut 15. Fig. 5: The parts 16 are formed the same as parts 10, and the member 1 is contained and secured in the casing they form the same as in Fig. 4; but here a turn-buckle adjustment 17 (comprising a nut screwed onto the adjoining ends of rcversely threaded screws one lof which is fixed in arm 1 of member 1 and the other of which bears against the upper resonator) is interposed between arm 1 and the central oint of the upper resonator 16, tending to iiold it tilted as shown (one or two of the screw-bolts 18 which penetrate the peripheries of the two resonators being drawn 'up more or less tight and the others left loose or serving mainly as guides and to limit the upward or opening movement of the upper resonator), and there is means to draw the upper resonator downward consisting of a screw 19 in the lower resonator penetrating the upper one and having a thumb-nut 20 bearing on the latter.

In both cases the. instrument contained in the casing formed by the two resonators may be pre-adjusted (as by the manufacturer) to such an extent that the user has only in Fig. 4 to turn nut 15 in the direction to pull the arms 1n and l" apart, or in Fig. 5 to turn nut 20 in the direction to force said arms together, until the best sound-reproduction results; and when the mechanism is not in use a turning back of the nut will in each instance remove the strain from the resonators so that they may be relaxed when idle and so will not become set from remaining in a strained state and lose their resonating quality. In my application Serial No. 88.835 I have disclosed a combination comprising an elastic vibrator (here afforded by 1--4-6-7), means to intermittently tension the same including electro-magnet and armature elements arranged thereon, said vibrator being yieldable to vary the gap bctween said elements, and adjustable means to cause such yielding of the vibrator and maintain the same in its thus-yielded state including a hollow shell housing the vibrator. But in that case said elements were not adjustable independently of the means to cause `yielding of the Vibrator.

In Figs. 4 and 5 I note that each resonator gradually varies in thickness from a substantially central point in all directions to its margin; in the present instance the construction is such that one of the extremes in thickness (i. c., its thinnest portion) is coincident both with its center and with the point of contact between it and what is in eti'ect a prolongation (14-15 or 17) of the member 1. In extensive experiments with resonators operated by a vibratory structure in contact therewith I have found that it is indispensable, in order to reproduce different qualities of sound in the one reproducing apparatus without adjustment thereof (for example, the low-pitched tones of the cello and the high-pitched tones possible with the violin) that the reproducer should have this form.

Having thus fully described my invention what I claim and desire to secure by Letters Patent is:

1. In a sound reproducing apparatus, a system to be vibratcd including an elastic flexible vibrating structure and means for exerting variable elastic fiexing pressure on said structure at either of two points thereof in substantially a common plane of flexure, in combination with eoactive electromagnet and armature elements arranged one on a part of said system which is moved on iiexing of said structure and theothcr on another part of said system.

2. In a sound reproducing apparatus` a system to be vibrated including an elastic Hexible vibrating structure and means, wholly supported by said structure, for exerting variable elastic flexing pressure on said structure at either of two points thereof in substantially a common plane Aot flexure, in combination with coactive electro-magnet and armature elements arranged one on a part of said system which is moved on ilexparts of said system of which one moves relatively to the other on flexing said structure.

' 4. In a sound reproducing apparatus, a system to be-vibrated including an elongated elastic flexible vibratory structure, an elastic flexible lever fulcrumed therein, and means connecting said lever and structure and arranged to flex the former transversely of its length, for exert-ing variable flexing pressure on said structure, in combination with coactive velectro-magnet and armature elements arranged respectivelyon parts of said system of whichone moves relatively to the other on flexing said structure.

In a sound reproducing apparatus, an elastic flexible vibratory structure, an elastic flexible lever fulcrumed therein and means, connecting said lever and structure and arranged to flex the former, for exerting variable flexing pressure on said structure, 1n

combination with coactive electro-magnet and armature elements arranged respectively on a part of said lever and apart of said structure as to which the former part is movable relatively to the latter on flexing of said lever.

6. In a sound reproducing apparatus, an elastic flexible vibrato structure, an elastic flexible lever fulcrume therein and separate means, connecting said 'lever with said structure at two points thereof insubstantially a common plane of flexure, for exerting variable flexing pressure on said structure, in combination with coactive electro-magnet and armature elements arranged respectively on a part of said lever and apart of said structure asto which the former art is movable relatively to the latter` on exing of said lever. A 'l 7. Ina sound reproducer, a bent elastic member, an elastic lever bearing a ainst one extremity of Said. member and aving a pivotal support on the other, an electromagnet and its armature carried one by the first-named extremity and the other by said lever and opposed to each other, and means, connected with the lever remote from its bearing and pivoting points, to flex the same from one of said extremities toward the other and thereby adjust the spacing between the magnet and its armature.v

8. In combination, and elastic vibrator, means to intermittently tension the same in cluding electro-magnet and armature elements arranged and one being .adjustable thereon-toward and-from the other to-vary the gap between them, saidV vibrator being yieldable to also vary said gap, and adjustable means to cause such yielding of the vibrator and maintain the same in its thus-- yielded state including -a hollow shell housing the vibrator.

9.111 combination, an elastic vibrator, means to intermittently tension the same including electro-magnet and armature elements arranged and one being adjustable thereon toward and from the other to vary thegap between them, said vibrator being yieldable to also vary said gap, and means to cause such yielding of the vibrator and maintain the same in its thus-yielded state 4 including a resonant hollow shell housing the vibrator and an adjustable connection between the vibrator and shell. l0. A sound reproducer including, in combination, a concavo-convex integral resonator shell formed to gradually vary in thickness from substantially the center thereofin substantially all directions to its margin, and a vibrator having contact with the shell at one of its extremes of thickness, said shell being normally held by the vibrator in a state of flexing tension. j.

11. A sound reproducer including, in-combination, an integral-hollow resonatin casing formed with a portion thereof gra uall increasing in thickness in substantially a directions radiating from the samepoint and a vibrator contained in the casing and having contact with such` portion at substantially said point and holding the casing normally in a state of tension. j

In testimony whereof I alix my signature.

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