US1797528A - Sound amplifier - Google Patents

Description

March 24, 1931. c N

SOUND AMPLIFI ER Filed Dec. 15, 1920 Patented Mar. 24, 1931 PATENT OFFICE CHESTER ALFRED LINTON, OF KANSAS CITY, MISSOURI SOUND AMPLIFIER Application filed December 13, 1920.

This application is a modification of an earlier co-pending application for patent filed by me November 16, 1920, Serial No. 424,847, in which I show various modified 6 forms each capable of many variations and modifications in structure while remaining within the spirit of my invention.

My invention relates to sound amplifiers and the like and particularly to means for improving the quality of sounds passing through sound amplifiers and the like having resonant Walls or parts.

My invention concerns a novel means of focusing sounds at certain desired points on an acoustical apparatus by and through elastic or resonant means that may be solid or substantially solid.

It is particularly adapted for use in connection with the sound-box of a talking machine recorder or reproducer, but my invention is not limited to such type of device or machine but may be applied to other forms.

I have discovered that by outwardly connecting resonant bars or members or sound conducting members to different portions of a resonant amplifier or acoustical apparatus in such manner that longitudinally the bodies of the resonant bars or members or sound conducting members will be largely free from interference of the air vibrations inside the tubular passage of the amplifier or, acoustical apparatus, the sounds passing through a resonant sound amplifier or acoustical apparatus maybe regulated prac tically as desired. In my co-pending application referred to above, I show resonant bars or members or sound conducting members connected in an elevated manner to differ ent portions of a sound amplifier or acoustical apparatus having a straight passage for sound, and by their use the quality and brilliancy of sounds were greatly improved.

I have further discovered that by connecting resonant bars or members or sound conducting members by one of their respective ends to predetermined places on a tubular throat portion of a sound amplifier or sound recorder and by connecting the other of their respective ends to a supplemental or cooperative amplifying or resonator member,

Serial No. 430,209.

sounds passing through a tubular throat portion of a. sound amplifier or sound recorder well be clarified with great facility and the distortion of sound caused by the curvature of a threat portions walls will be lessened. I have discovered that sounds may thus be transmitted to or from a supplemental or cooperative member and, also, that such transmitted sounds help reinforce other sounds issuing from out an orifice of a tubular throat portion of a sound amplifier or sound recorder and thus provide a more life-like effect of sound coming from a large instrument like a piano or from a group of players.

One object of my present invention is to provide a novel compact arrangement of sound conducting members on an amplifier for sounds.

Another object of my invention is to provide novel improvements in a sound amplifier, by means of which sounds will be diffused.

Another object of my invention is to provide a supplemental or co-operative amplifymg or resonator member or the like connected to a surface of an acoustical apparatus by suitable means that may be solid or substantially solid so that sounds may be recorded with greater facility and ease and many overtones that would otherwise be lost may be recorded on a suitable record.

Another object of this invention is to provide means for transmitting sounds to or from a sound amplifier or acoustical apparatus to or from a co-operative member whereby the sounds will not be distorted as they would he were they transmitted by' purely air means.

Further objects of this invention are to provide means to help regulate the pitch of sounds that may be transmitted; to provide means for obtaining resultant tones; to provide a novel plurality of resonators; to provide an improved sound apparatus which will be of durable construction; and to provide other improvements as hereinafter set forth in the following specification and accompanying drawings, considered together or separately.

In the accompanying drawings,

Fig. 1 is a side elevation of a sound amphfier, showing substantially solid sound con ducting members or bars or members and showing a diaphragm or a supplemental or co-operative member above or adjacent.

Fig. 2 is a top view of the same, showing angular bars or members or sound conducting members.

Fig.3 is a front elevation of Fig. 1, showing curved walls of two resonators.

F ig. l is a cross section on the line 1-4 of Fig. 2, showing a circular throat formation and showing web attachments of solid or substantially solid bars or members or sound conducting members. I

To illustrate this modification of my invention, I annex hereto one sheet of drawings. in which similar reference characters are used to designate similar parts in the difierent views.

Numerous ideas have been carried out in this invention, with recognition on my part that one or more novel elements or combinations, etc., can be employed separately. One discovery portrayed in the invention is that an element has certain latent potential vibratory or acoustic capabilities, and, furthermore, that when this idea is combined with structure having several elements,-say a plurality,-the latent yet workable potential acoustic or vibratory capabilities are adapted for causal purposes or finite control, with most any useful result novel by any of these or like means, and either with minimum or maximum structure, possible. The point of the application of force is not always terial, as will become clear in this specification. Factors of stress are known herein relative with what is made apparent and of simple application when following the intent of the description. The steps taken in the relationship of values of, or the comparative ratios of, elasticity, density, inertia, etc, of masses will be found of essence in understanding the interrelation or interdependence of acoustic factors, altho an expert in the art should understand the revolutionary nature of the invention that makes use of the discovery of the relativity of acoustic factors for the production of a. new result, or new results. The invention is foreseen as alterable and adapted for mutation, on a lar 'e scale. Therefore, when viewed broadly, the drawing clearly shows relevant phenomena in a diaphragm, plate, or rod, or sliver, etc, may be computed; and this marks a differen'ce between this invention and the prior art.

In the drawings which illustrate my improvements as applied to a sound amplifier or the like, 1 designates the tubular resonator or bell portion and 2 the tubular throat portion of the amplifier, or the like. 'These said portions are preferably of wood and, to provide an uninterrupted passage for sound, are, preferably, connected to adjacent ends, preferably by gluing or cementing. The amplememes tier may, if desired, be suitably curved and of flaring or tapering form.

Inner surfaces of the tubular throat portion 2 and the tubular bell portion 1 are in this instance provided with a hard coating, such as asphaltum or the like, this coating being, preferably, pumicated or sanded or roughened or the like to remove the glazed surface. This hard surface, thus treated, effects the best results. If desired the hard coa-ing, such as asphaltnm or the like, may be placed upon one or more coatings of varnish on the inner surfaces of the sound amplifier, or on the inner surfaces of the portions 1 and 2, and, also, if desired, upon one or more coatingsof varnish on the outer and rear sides of the tubular throat portion 2. Good results are attained without any coat ing in onstruction, therefore coating material of any kind may be dispensed with if preferred.

For increasing the purity of the sound waves and for adding new frequencies over tone effects 1 provide at opposite sides of the sound amplifier a number of sound conducting members or resonant bars, each plurality of which may consist of an inner body 8 and an outer body l. The ends of the bodies 3 and 4: are in this instance respectively connected, preferably by gluing or cenien 'ng, to the outside of the walls of the bell portion 1 and the tubular throat portion 2, as shown in Fig. 2.

In the arrangement selected for illustration, the bodies 3 and a of each plurality of sound conducting membersv or resonant bars are of substantial area in cross section and preferably of determined frequency and are connected to each other by a relatively thin resilient longitudinal web ormembrane or the like 5, as shown in the cross sectional view in l. Each body 3 is suitably con nected by the edges of a relatively thin resilient longitudinal web 6 to the outside of the walls of the said sortions 1 and 2v of the sound amplifier or recorder. The preferred arrangement of the web or membrane or the like? is shown in the cross sectional view in l selected for illustration of the principle employed. These webs may, if desired, be on ved and in the same plane or curved longitudinally or horizontally or in any position in keeping within the broad scope of this invention.

For conducting sound vibrations from the tubular throat portion 2 to the tubular bell portion 1, there is also preferably pro-' videda sound conducting member or resonant bar or member comprising a substantial body portion, 7, the ends of which are respectively connecte l, as by gluing or cementing, to in this instance an upper side of the tubular bell portion 1 and to a forward side of the throat portion 2. A relatively thin longitudinal web or membrane or'the like 8 which may be substantially rigid and vertical ifdesired may be arranged to form a connection between the body portion 7 and an upper side of the tubular bell portion 1 and a forward side of the tubular throat portion 2. Any impulse traveling through solids such as compose the member 7 and the element 2 may vibrate said web from opposite sides simultaneously. The body portion 7 and the web 8, when em loyed in the form shown, may serve the urther purpose of firmly uniting the said portions 1 and 2.

For sympathetic vibration or for rendering audible the sound waves from a suitable source, there may be provided a diaphragm or a supplemental or co-operative member having a thin wall or walls and comprising in this instance a concave or bell member 9 of circular form, which has in this instance an orifice or its open end facing in the same general direction as the tubular bell portion 1 and which has in this instance its closed end pointed in a general direction toward the tubular throat portion 2. It is obvious the relative positions of the members named may be varied. A method and means are being illustrated and the description in general and the drawing'used in conjunction therewith are not intended for limiting purposes, but for making obvious and plain a revolutionary invention. The bell member 9 may be and, in the form shown is, preferably, connected to and supported by a sound conducting member10,whichis pref- ..z; erably attached firmly to the said member 9 and the said portion 1 adjacent the forward ends thereof. lVhen supported in this way, the wall of the member 9 will be at an angle to a wall of the bell 1 and allow of sound reflection and sound interference in the air space between said walls.

A plurality of suitably directed and, in this example, forwardly converging resonant members or bars or sound conduct- 1 ing members 11 and 12, which may be com therein,'or to introduce a tuned strain therein, for purposes of controlling nodal lines or values, as shown in Fig. 2.

It may as well be noted here that it is best to have the relative proportions of the parts with which to effect selection of the frequen cies desired in said resonator, or hell member, or the like. One of the advantages of this arrangement of resonance is that it is applicable to vibrating systems in which the amplitude of the vibrating members is at times quite small. The members 11 and 12 are preferably in association and of like structure and of approximately equal length.

It is clear this acoustical device may employ a diaphragm in any suitable manner and relative therewith a plurality of acoustically scaled and balanced vibratory means, and the rate of frequency of any or every part of the device, or a modification thereof, may be of computed phase relation relative with the frequency employed. As illustrated in Fig.

3, the bell member 9 is, preferably, small in comparison with the main amplifying or hell portion 1 but it may be of equal size or larger and its shape and form and acoustic surface resistance may be determined by experiment.

All or desired parts of the walls of the tubular bell portion 1 and the tubular throat portion 2 being resonant and the walls of the co-operative bell member 9 being resilient or resonant and the members or bars 11 and 12 being resilient or resonant and the sound conducting members or bars 3, 4 and 7 with their respective webs being resilient or resonant, sound vibrations will be transmitted from the throat portion 2 to the tubular bell portion 1 and the co-operative bell member 9 by the sound conducting members or bars in a novel manner partly or largely independent as the case may be to the vibrations which pass directly through the air in the throat port-ion 2 and the bell portion 1. By means of operable parts of this arrangement as shown, for example, a special result may be attained; or with certain combinations of the elements new over tones are delivered to the listener, the form of sound waves is changed, the effective acoustic range of frequencies is increased, and the amplified sounds coming from a suitable source are clearer and more natural than without the use of the different units or of the sound conducting members or bars and the co-operative bell member 9, when one form of the device, for example, is used in connection with a sound-box of a talking machine reproducer or the like.

When an amplifier or acoustical apparatus constructed in accordance with one form of this invention is used for transmitting sounds to a recording medium, the sounds received at said medium are clearer, more natural and of different wave form and period than would be the case if the sound conducting members or bars, were not used. The employment of the device therefore enables the production of a superior record.

While, in the scientific sense, sound is propagated like one ball hitting another, (a jarring process, I might say) I want it understood I do not limit my invention by the use of the words or terms sound conducting member or sound conducting means or similar words or terms of similar meaning.

In applying this invention the particular form to be used in any case to give the best results may be determined experimentally. The drawings are not in scale and therefore are not to be taken as shop drawings. I have proved by experimenting with this invention that a small periodic force is continued long enough may set my resonant bars or boards or sound conducting members vibrating forcibly if the free .period of the resonant bars or boards or sound conducting members coincides or nearly coincides with the period of the force. Equivalent substances of stress may be employed instead of resonant substances Where found interchangeable in any part of the device,'or in any modification thereof.

\Vhilea certain number of resonant members or sound conducting means produces a different result than by the employment of a less-number, I want it understood that I do not limit my invention to a certain number of resonant members or sound conducting means, for the obvious reason that different people have different tastes for music and demand diflerent tone qualities. I desire to connect the resonant bars or members or sound conducting members 3 L at forward points longitudinally on the sound amplifier or sound apparatus, but I do not wish to limit myself or invention to connections made only in that manner.

The length, width and thickness and the volume elasticity and density of the resonant members or sound conducting members 3, 4t and. 7, with their respective webs, and 11 and 12, have a direct relation to the desired pitch of the tone and the volume of sound transmitted. In other words, the kind or sort of a member employed in construction, or in a in dification thereof, effects the result obtained. Amplifiers for recording and reproducing sound that are of different sizes and shapes andof different wall thicknesses may require one or more sound conducting members or resonant bars or members of different shapes, lengths, widths or anyone or more or thieknesses'or all four differences, including differences in volume elasticity and density. Nor do I limit my invention to a sound conducting member or members or bars made of wood any good stable substance that may conduct or influence sound, when connected properly, in an advantageous manner may be used.

I do not desire to be limited or restricted to any particular substance employed for the web or membrane 8 or the webs or. membranes 5 and 6, as any particular web or membrane may be of any suitable substance,

as the case requires. Nor do I desire to be l1m1ted to any particular s1ze or shape or elastimty, or the equivalent of elasticity, of

the web or membrane employed, for the mod" While I have shown only two resonantmembers or bars or sound conducting members connected to a vibratory body or tube or tothe tubular throat portion of the sound amplifier and connected to a diaphragm or to a co-operative resonator member, yet I do not desire to limit my invention toa given number of members or bars or sound conducting members so connected, for the obvious reason that the principle and method of transmitting sound vibration to or from vibratory bodies or to or from a sound amplifier or recorder and to or from an aux,- iliary member or the like is herein shown and described. Although different results are produced by a larger number of resonant bars or member or sound conducting members connected at places which may be predetermined on the sound amplifier, I do not want the use of the word predetermined to limit this invention in anyway.

Nor do I limit or restrict this invention to resonant bars or members that are merely glued or cemented to asurface of an acoustical apparatus or sound amplifier. The resonant bars or members or sound conducting members may be fastened on as integral parts or otherwise, as may be deemed expedient.

Nor do I want it understood that I limit my invention to a sound amplifier or sound recorder made of wood; any good resonant substance formed integrally or otherwise may be used and with satisfactory results. I also wish it to be understood that the several features of this invention may be used either singly or collectively without departing from the scope of the claims.

I realize that many modifications of this invention are possible, therefore I say my in? vention is not limited to these particular constructions shown and described and it is my intention to cover all other .modifications which may be made without departing from the spirit of my invention or the scope of the claims. y i s V That I claim as new, and desire to secure by Letters Patent of the United States, is, as follows: 7

1. A sound amplifier comprising a tubular throat portion having resonant wall'sadapted to convey sound to or from a reproducing means, a small sound resonator a distance apart, and suitable sound conducting means amplifying member a distance apart, and a plurality of suitable resonant members con necting said resonant walls outwardly to said sound amplifying member.

3. A sound amplifier, or the like, comprising a tubular member having resonant walls directly adapted to transmit sound to or from a sound source, a co-operative bell member supported apart from said walls, and sound transmitting means firmly secured to a surface of said resonant walls and firmly secured to said co-operative bell member.

4. In combination with a resonator, a supplemental amplifying member a distance apart provided with a single orifice said supplemental amplifying member having a plurality of sound conducting members extending away therefrom.

5. A sound amplifier comprising a tubular throat portion and a tubular bell portion connected at adjacent ends and forming a curved passage for sounds, a supplemental amplifying member having comparatively thin walls, said walls being resonant, and outward sound transmitting means attached to said tubular throat portion on approximately opposite sides thereof, said sound transmitting means being elevated bridge-like approximately side by side and connecting said supplemental amplifying member to said tubular throat portion.

6. In a sound amplifier provided with a tubular passage for sounds, said tubularpassage having resonant walls provided with an inlet and an outlet, a supplemental member having resonant walls, and elevated sound conducting means having predetermined lengths, widths and thicknesses to help regulate the pitch and volume of sound transmit ted to said supplemental member, and said sound conducting means firmly attached to said resonant walls of said tubular passage and having an elasticity and density similar in kind to the elasticity and density of said resonant walls of said tubular passage.

7 In combination with a sound amplifier a supplemental member having resonant walls and individual angular resonant bars of elevated structure, said bars being symmetrical and largely of uniform cross section throughout their major lengths, said bars having tapered ends, each of said bars having a length, width, thickness, volume elasticity and density which may be predetermined to help regulate the pitch of sounds passing through said amplifier and through said resonant bars, said resonant bars having a natural period of vibration adapted to harmonize with the natural period of vibration of said sound amplifier and adapted to increase the effective acoustic range thereof.

8. A sound amplifier comprising a tubular throat portion and a tubular resonator portion arranged to transmit sound from one to theother, said tubular portions having resonant walls, and a resonant member having a substantial body portion projecting away from said tubular portions, the ends of said body portion being respectively connected a distance from each other to the walls of said tubular portions, and a thin web connecting said body portion with the walls of said tubular portions, thereby to produce a different composition of the sound.

9. A sound amplifier comprising a tubular passage for sound, said passage having resonant walls, and a resonant member having a substantial body portion in spaced away relation to said walls, said member having a given length to help regulate the pitch of sound transmitted through said body portion, the ends of said body portion being respectively connected to the walls of said tubular passage, and a thin web connecting said body portion with the walls of said tubular passage thereby increasing the volume of sound by utilizing its energy in having sympathetic vibration in said body portion and in said web.

10. In an amplifying device, the combination with a tubular throat portion. of a resonator having thin walls, and a series of resonant sounding boards separated a slight distance from each other by thin webs and arranged in substantially parallel planes, and means for connecting the outer and inner ends of said boards securely, said boards being supported at one of their respective ends by said tubular throat portion and at the other of their respective ends by the said thin walls of said resonator, and said series including outer boards long compared to inner boards in the series.

11. In a sound reproducing device adapted for introducing sympathetic vibration in a desired volume in a resonator having a closed end, a method of controlling the vibratory effects delivered to said resonator which consists in having elevated vibratory spaced means connected to said resonator relative to the natural frequency thereof and capable of delivering to said resonator frequencies of sound different than directly impressed at the opposite ends of said means and of having the relative proportions of the parts with which to effect selection of the frequencies desired in said resonator.

12. A sound amplifier including a longitudinally curved resonant tube and a separate bell member having resonant curved walls and a raised resonant member extending from an exterior surface of said tube and connected to said walls of said bell member to introduce a tuned strain therein.

13. In a sound amplifier like an acoustical apparatus for a talking machine or similar inventions, resonant walls forming a sound orifice resonator member supported beside said orifice, and a sidewise homogeneous member extending from said walls to said CPI resonator member, said sidewise homogeneous member being proportioned to influence sound impulses in said resonator member.

14. A sound amplifier having a resonant portion and an adjacent bell member having resonant walls of determined natural frequency, and in combination therewith means for conducting sound impulses from said resonant portion to said bell member, said means adapted to deliver sounds of determined frequency relative to the frequency of the sounds progressing through said resonant portion when in operation, the middle portions of said means being free to vibrate.

15. In combination in a sound device, a hollow body, webs, and resilient members, said members being secured to said hollow body, and at least one of said members being secured to said webs.

16. In combination in a sound device, a resonator, and members having webs, said members being secured in spaced acoustic relation to said resonator and to said webs.

17. A sound amplifier comprising a curved tubular body, and an outside resonator, said tubular body having a portion connected transversely to said resonator, said tubular body and said resonator having walls of response frequencies arrived at by comparison with what is necessary for a true simulation of the original sounds, said tubular body and said resonator being acoustically a unit. 7

18. A sound amplifier comprising a tubular body adapted for direct communication with a sound box, adjacent resonators connected to said tubular body, one of said resonators being closed at one of its ends.

19. In a sound device, the combination with a bell member adapted to be in direct communication with a sound box, of a resonator exteriorly adjacent said bell member and in secure connection therewith, said resonator having one wall at an angle to a wall of said bell member, for purposes of sound reflection and sound interference.

20. An acoustical apparatus consisting of spaced connected bell members, each of said bell members provided with means projecting therefrom for effectively controlling at a plurality of points the frequency peaks therein. V

21. In an acoustical apparatus for a talking machine, a vibratory member, and a thin circular resonant body concave from its center, sound transmitting means between said member and said body and connected to said member, said means comprising a plurality of exterior raised spaced vibratory members of like structure and of approximately equal length, said means being secured to said body in a manner whereby resonance peaks adjacent said center will be controlled.

22. In combination in a sound reproducing device, a resonant body havingan orifice and a plurality of outside raised fairly elastic members connected to spaced apart places on said body, for purposes of controlling reso nance peaks in said body, and the device as claimed adapted for response to vibratory impulses from a suitable source.

28. A sound amplifier comprising a hollow body, an elastic web secured thereto, said web having a structure shape and dimensions such that it is capable of responding with the exact amplitudes of sound desired in a. par

ticular instance, said hollow body being adapted to longitudinally vibrate said web in the direction of the length of said hollow body, when the latter is vibrated by suitable means.

24. An acoustical device, comprising a body, an elastic web secured to said body, said web having a density elasticity and inertia directly relative with the associated structure and the use for which it is employed and is thus adapted for responding with the particular frequencies of sound desired, said body beingadapted to vibrate said web in the direction of its width by the sides of said web.

25. A sound amplifier for a reproducing device, comprising vibratory members that are essentially adapted for the transmission of desired vibrations of sound, each of said tory means adapted to impart the necessary I forced frequencies whereby said web will vibrate throughout substantially as desired when in operation.

27. An acoustical device comprising a diaphragm and vibratory members of computed phase relation when in connection therewith, said members being attached to said diaphragm, whereby resonant peaks in said diaphragm will be under finite control.

28. An alterable acoustic device comprising a diaphragm and a vibratory member attached to an edge thereof, said member capable of being tuned relative with the pos sible overtones that can be delivered by said diaphragm, for the purpose of obtaining the most complete range of overtones thereby.

29. An acoustical device comprising a diaphragm and relative therewith a plurality of acoustically scaled and balanced vibratory means, said means respectively connected by their ends to points on said diaphragm equidistant from each other, the necessary remaining acoustic factors being taken into consideration in the construction of the device.

30. A sound amplifier for a reproducing device, comprising resonant elements of equal kind opposite each other and having an elastic web of determined frequency therebetween, for purposes of vibrating said web from opposite sides simultaneously.

31. A sound amplifier comprising sound conducting means having a web connected therebetween, said means being adapted to deliver vibratory impulses varying from each other, said means having structures adapted to alter the vibratory impulses that can be delivered to said Web, substantially as set forth.

32. A sound amplifier comprising a tube, a web curved to follow the contour of said tube, and a sound conveying member, said member connected to both said tube and said web and adapted to vibrate said tube and said web under the influence of sound.

33. A sound amplifier adapted to be con nected to sound reproducing means and comprising a hollow body provided with a plurality of elastic webs on opposite sides thereof and longitudinally thereof, said webs being adapted to vibrate in sympathy with said hollow body, said webs having periods of frequency needed for a full rendition of the tones and overtones prefigured in construction and accomplished by the use of the dev1ce.

34. An acoustic device comprising a dia phragm member adapted to be firmly held by a part thereof, and a vibratory member of computed stress attached to one point of said diaphragm, the members when in connection being relative with the desired rate of frequency of said point of said diaphragm and relative with the computed potential and desired frequencies of said diaphragm and relative with various tested points on said diaphragm when at least one of these said tested points is acoustically connected with a source of sound.

35. An acoustical device comprising diaphragm means and interconnected vibratory means adapted for free vibration, the latter means being connected with said diaphragm means in an opposed manner, said interconnected means being of alterable nature, and said diaphragm means and said interconnected means having masses and forms of computed values one with another, so that the phase relations, one with another, of different parts of said diaphragm means are restricted when subject to a given frequency and so that said diaphragm means shall vibrate in the exact manner required.

36. The method of introducing new frequencies from a source of sound in a diaphragm, which comprises contact means for transmitting a given amount of vibration to said diaphragm, of having adjacent said means a computed point of stress in said diaphragm dependent on an element connected therewith, and of having a computed mass of said diaphragm adapted to transmit a given amount of vibratory energy across said point of stress and in computed phase relation therewith, and of having the several masses selected with regard for their acoustic structural interdependence and their collective ability to respond and react in a given acoustic design.

In testimony whereof I have signed my name to this specification.

CHESTER ALFRED LINTON.

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