US1718353A - Loud-speaker - Google Patents

Description

June 25, 1929. M; R. HUTCHlS ON LOUD SPEAKER Filed March 2;), i926 M01517 ML) INVENTOR BY/M ATTORN EY Patented June 25, 1929.

UNITED, STATES PATENT OFFICE.

MILLER REESE HurcmsoN, or LLEWELLYN PARK, was: ORANGE, NEW JERSEY, AS-

SIGNOR, BY MESNEASSIGNMENTS, T ACOUSTIC raonucrs. COMPANY, on NEW YORK N. Y., A conronn'rroN OF'DELAWARE.

LOIlD-SPEAKER. 1

Application filed March 20, 1926. snai No. sages.

' k This invention relates to improvements in sound producing or sound reproducing instruments, usually referred to in thefarts as loud speakers, and has for its objects to improve the volume, qualityand tone, as

well as the truth of vocal and instrumental music and render it free from the customary confusions and distortions of sounds over instruments heretofore proposed or constructed.

Through the widespread introduction of- Q suitable sounding devices as Therein indicate, I plan scientifically to utilize resonance rather than try to. overcome resonance, as heretofore attempted in other loud speakers onthe market. It is as impossible to expect one diaphragm, or one diaphragm horn unit faithfully to reproduce all notes of the register as it is to expect one organ pipe so to function. I V In a co-pending patent application, Serial Number 87073, filed February 9th, 1926, loud speakers, I have set forth specifications, drawings and claims, covering a consider ably more elaborate invention adaptedfor the concert hall and stage, and the present invention concerns a modification of'comparatively low cost for home use.

With the foregoing and other ob ects 1n view,-the invention now described consists in the novel "parts or-arrangement of parts constituting an improved loud speaker, and one adapted to superior radio'rcc'eption for home installation, all as hereinafter Wlll be more fully 'disclosed and particularly pointed out inthe claims. Referring tothe '1 accompanying drawings forming a partof this specification in which like numerals designate like parts in all theviewse-e Figure "1, isa front view of one design of one of myldud speakers partially in section.

Figure 2, is a side'view of one of 'my' instrunients in elevation, turned ninetydegrees i ht. i

s3, is a sectional view ionizing down upon a cross out along the dotted line 3+3, of Figure 1.

' With further reference to Figure 1, 5, 6, 7, 8, 9, 10 and 11, are the throat outlets of seven resonating pipes or tubes 46, 47, 48, 49, 50, 51, three curving off to the left, and

three cur'vingotf tothe right of a central standard tube. The three pipes 47, 49 and 51, curve in a comparatively simple bend to the right, but the three pipes 46, 48 and 50, not only curveto the left, but arebentalso into a compound curve, bending backward as.

well as to the left'in order to increase their lengths. 'By this construction the pipe 47, is the shortest, measuring from the throat opening 6, to the common lower outlet or end 19, and the pipe 46 is consequently a little longer measuring from the. throat opening 5, to the common lower outlet or end 19, by virtue of the longer compound.

bend in the said pipe 46. The next longer pipe is 49, measuring from thethroat 8, to the common outlet or'end 19 with its simple bendf The next longer pipe is 48, measuring from the throat 7 to the common outlet or end 19, with its double or compound bend. The next longer pipe is 51 measuring from the throat 10, to the common outlet or end 19, with its simple bend. The next longer pipe'is 50, measuring from the throat 9. to the commonoutlet or end 19, with its double or compound bend. The-next longer pipe is 52 with no ben s. The common outlet lower end of all of tliese resonating pipes is seated in the socket or receptacle 20, and against the shoulder 21, thereof leading'to the open throat 34.

The projecting socket 29. is an extension of the top of the casing 28. -Within this casiiig is a diaphragm seating ring 29, of,

v33, above the diaphragm and communicating v with the throat outlet 34, common to all of the resonating horns. 35 and 36 are perma nent magnetsof hardened steel suitablychar'gedtvith magnetism, and 39 and 40, are

softiron pole pieces wound with coils of insulated ma et wire, 42 and43, the said-'- pole pieces orming a magnetic circuit-01 connection with the permanent magnets. 37 and 38 are the soft iron pole pieces or pole ends in close proximity to the diaphragm 30. 44 and 45, are binding posts anchoring the ends of the coil windings in' the usual way. This device is therefore a conventional telephone receiver, or sound propagator, or loud speaker unit, such as I employ in my previously described invention double cofnpoundbent resonating pipes. is the supporting .socket on'top of the casing 28, containing the telephone receiver, or loud speaker unit, and 44 is one of the binding posts anchoring one end of the winding of the loud speaker coil, which coil is adapted for convenient and ready connection to a source of electrical current or energy having speech, song, or instrumental music characteristicsm' V I In my previously filed patent application referred to, I employ twelve horns or more of different resonating characteristics ,and twelve or more telephone receivers, or loud speaker units with their individual diaph'ragms.

In my present patent application I employ a plurality of horns or sounding devices of different resonance characteristics with a single diaphragm or a diaphragm common to all of the horns orsounding devices as a less elaborate and expensivecompromise over my more scientifically complete twelve horn and twelve diaphragm design.

7 In order to accomplish scientific and superior results with a single diaphragm, over instruments heretofore designed or constructed, I embody certain principles in the science of musical sounds with a plurality of horns. In order to accomplish new results and approximate as a compromise performance with seven horns ipstead of twelve horns, the seven horns in the present instrument are tuned to take advantage of all of the vibration characteristics of any single diaphragm. One diaphragm possesses a far greater flexibility and range of note and tone producing vibrations than any single horn orsound projector. It has been repeatedly shown by experiment that different areas of one and the same diaphragm may simultaneously undergo different rates of vibration. l/Vhen fine sand is strewn on a vibrating diaphragm. it may be observed that portions are moving up and down. There 7 are certain lines towardwhich the sand gathers, indicating that these parts are relatively at rest; the lines on which the sand accumulates are called nodal lines, and form operate as many as twelve patterns and figures which are alwaysthe same for the same note, but differ for each change of'pitch or quality. It isthus shown that a diaphragm vibrates in various sub divisions. I v

A horn is. an air resonator, and operates through the enclosed air column. The horn reacts upon the diaphragm, causing it to have a period different from that which it had before the horn wasapplied. Therefore, when a horn is added to *a diaphragm,

the response is greatly altered. A long horn A seems to respond nearly as'well to high tones as does a short one, While the response to low tones is much greater than is that of a short horn; the response below the fundamental of a horn is very feeble. A horn acts very much like the sounding box associated with a tuning fork. They both serve a double purpose; to produce a louder sound, and to purify. the tone by reinforcing only the fundamental. A horn itself cannot originate any component. tone and hence cannot add anything to the composition of the sound. It can only take up the energy of vibration of some'gene'rator, a dia-- phragmfor example, and give it out in a different loudness. A diaphragm, as has been pointed out' may not only undergo different vibrations at different localities in its area, but the whole diaphragm, if properly supported by pasteboard, cork or rubber rings, is free to be driven notonly to its natural period, but by forced vibration into a great range of vibration periods, a range far greater. than the resonating air column of any horn.

A sound producing or sound projecting instrument, with one horn associated with one diaphragm, is the worst of combinations since diaphragms resp nd with remarkable facility to tones of a wide range of pitch and to a great variety of tone combinations, whereas horns respond to sounds of particular quality only.-

Two horns, each turned to. a different note, I found were an improvement when associated with a single diaphragm, yet theoretically and in my experimental work the single diaphragm exceeds the note and tone flexibility of two horns, even when they are tuned to a middle register and, are capable of resonating above and below their fundamental notes.

Three horns give superior results on one diaphragm to two horns, and fourhorns give still better results than three horns, and Ihave found that I may to advantage I horns upon a single or common diaphragm, but seven horns give satisfactory results.

With seven horns of difierent resonance periods or different musicalcharacteristics associated with .a single or common .diaphragm, I am enabled for the first time to associated with a single or common dia-,

utilize and project with great volume, truth and beauty the numerous and complex natural and forced diaphragm vibrations. Not only do I give volume to and reinforce the natural vibrations of a diaphragm supported between suitable rings to allow for elasticity and freedom of movement, but I utilize important vibrations'localized at various points in the area of the dia hragm.

Again through my plurality ot horns, each of a different musical characteristic and phragm, I do not dampen or modify the free'inherent qualities of the diaphragm. In fact my horns of different characteristics with their common throat, when the said common throat is in communication with a single elastically supported diaphragm, allow said diaphragm to vibrate substantially as it would vibrate Without the association of any horn at all, and at the same time reinforcing all of the notes, tones and overtones generated in the diaphragm.

Having described my invention, I claim a 1. A radio receiver comprising a casing, a diaphragm, a shallow cup-shaped front cover with throatopening therein, means for actuating saiddiaphragm, and a plurality of sounding devices, each sounding device having a resonating tube of different length to tune said tube to a single but different fundamental note.

2. A musical instrument comprising a support having a sound responsive element therein, a central horn with outer horns sur rounding it, said horns being connected to said support and each comprising a tube portion and a mouth, saidmouths all facing the same direction, said tube portions being of different lengths and the mouthsof the outer horns being arranged vertically in pairs one on each side of the central horn. 3. A sound device comprising a base hav-. ing a sound responsive element therein, a central horn with outer horns surrounding it, said horns each comprising a tube portion and a mouth, the central horn rising from said base, .said outer horns branching out from the tube portion of said central horn, around the entire periphery thereof, said tube portions being of different lengths and the mouths of the outer horns being arranged vertically in pairs one on each side of the central horn.

4. A musical instrument comprising a base having a SOUIld lGSIJOIlSlVB element.

therein, a central horn with outer horns surrounding 1t, said horns each comprising a tube port on and a mouth, the central horn rising from said base, said outer horns branching out from the tube portion of said central horn, around the entire periphery thereof, said mouths all facing the same direction, said tube portions being of different lengths and the mouths of the outer horns being arranged vertically in pairs one on each side of the central horn.

MILLER REESE HU'roHIsoN,

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