US1783360A - Sound amplifier - Google Patents

Description

Dec. 2, 1930.

C. C. FLYNN SOUND AMPLIFIER Filed March 19, 1928 INVENTOR. Ccwles C, Fynn.

` n ATTORNEY.

Patented Dec. 2, 1930 CHARLES C. FLYNN, OF DETROIT, MICHIGAN SOUND AMPLIFIER Application filed March 19, 1928. Serial No. 262,616.

My invention relates to a new and useful improvement in a sound amplifier or sounding chamber intended for various uses where a sound amplifying device is required, such as sound chambers of phonographs, loud speakers on radios, etc.

.It is an object of the present invention to provide sound amplifying device of this kind in which reflecting surfaces of the device are arranged and curved to provide surfaces determining harmonic curves, to the end that thev natural oscillations in the sound waves may not be interfered With, but may be increased and amplified to produce the desired amplification in the device.

It is another object of the invention to provide a device of this kind which will be simple in structure, economical of manufacture and highly eiiicient in use.

Another object of the invention is the provision of passages through which the sound must pass-before emanating from the amplifying device and forming these passages With surfaces designed to amplify the sounds passing therethrough.

Other objects will appear hereinafter.

The invention consists in the combination and arrangement of parts hereinafter described and claimed.

The invention will be best understood from a reference to the accompanying drawings which `form a part of this specification and in which,

Fig. 1 is a longitudinal central sectional view of the invention.

Fig. 2 is a sectional view taken on line 2 2 of Fig. i.

Fig. 3 is a sectional view taken on line 3 3 of Fig. 1.

Fig. 4 is a fragmentary sectional view taken on line 4-i of Fig. 3.

The device as set out herein has proven from experience to be most efficient in amplifying and it has been attempted to construct the device along certain well defined mathematical lines based on the conception that sound is in the form of wave motion and that the vibrations or oscillations are in line with the direction of propagation of the sound, and

that these vibrations Vor oscillations are inV reality the result of the impact of the particles or molecules of the medium of propagation due to the elasticity of these particles. It is believed that the motion from a state of rest or a change in direction, or change in frequencyof oscillations along the direction of propagation, is due to the application of'a force or forces to the molecular structure of the medium of propagation, this molecular impact transmitting motion or vibration from the initial point of application to the ultimate end, the medium itself not being moved bodily but transmitting the motion from molecule to molecule.

To increase these oscillations or vibrations by reflection or refraction by the addition of resultant reflected or refracted oscillations along the axis of motion, is one of the objects of the invention, and this is accomplished by determining the profile of the various curves in the sound passages, so that these curves are harmonic in nature.

In the sound passages two sides are designed to be parallel and two sides curved, the curve being a harmonic one, and the curved sides terminating in parallel sides at the same point that the parallel sides begin to curve.

Ahead 7 which is designed for attachment to the conduit which leads from the sound producer, is attached by suitable screws 8 to the passage-forming walls 9 and 1() and the Wedges 13 and 14. The inner surface of these walls 9 and 10 are parallel for a portion of their distance as at 11, and are flaring outwardly at the portion 12, this curve being a harmonic one.

The inner surface of the wedge members 13 and 14 are inclined and their inclination terminates at the point where the surface 12 begins to curve outwardly.

The housing comprises side walls 15 and 16 which are made preferably of resonant material, such as wood, and secured to the inner, surface of each of these walls at the central portion thereof are the securing plates 17 and 18 which are formed preferably heartshaped, as appears in Fig. 1.

Hollow units are provided for positioning atopposite sides of the members 9 and 10,

as shown clearly in Figs. 1 and 2, these units comprising the side walls 19 and 20, which engage against the inner surfaces of the securing plates 18 and 17.

Connecting these side walls 19 and 20 is the transversely extended wall 21 which is adapted to engage against the sides of the members 9 and 10, so that sound passing inwardly betweenthese members .9 and is not permitted to escape except around the ends of Athese members, the ends of these members being curved, as clearly appears in Fig. 3. f

Engaging the outer edges of the side walls 19 and 20 and the upper and lower edges of the wall 21, so as to enclose this unit and form a closed hollow unit, is a diaphragm or closure 22 preferably made from paper or other similar material.

A similar unit is mounted at the opposite side of the members 9 and 10 and comprises the sidewalls 19 and 20', the transversely extended wall 21 and the covering 22.

Engaging the outer edges of the side walls and 16 so as'tovforin with these side walls a housing is a covering or diaphragm 23 preferably made from paper or the like.

Connecting the side walls 15 and 16l at' their lower edges adjacent their ends are the rails 24 and 25 which also serve Vas a support for a suitable closure or screen 26 which may or may not be used, as desired.

Engaging at its opposite ends the inner surface of the plates 17 and 18, adjacent their lower ends, is the refiecting plate 27 which is formed on its inner surface with recesses 28 and'29, these recesses having a surface which is curved, the curve'being a harmonic one. The surfaces of these recesses 28 and 29 meet at a point which is central between the members 9 and 10.` Y

In use the sound is transmittedinto the head 7 and thence inwardly of the housing between the members 9 and 10, the inclined surface of the wedge members permitting a diverging of the sound waves, thesesound waves engaging the surface 12, passing inwardly and thence around the curved ends of the members 9 and 10, and reflecting from the curved surfaces of the recesses 28 and 29,

and thence backwardly so that the surfaces 30 and 31, which are alsoV curved slightly at a harmonic curve, will serve as a reflecting body. The sound then travels to the right or left of the device shown in over thetop of the plates 21 or 21 into the space 33V or 33.

In this regard, it will be noted that the inner vsurface of the covering 23, at opposite sidesfof the transverse medial line of the main housing, is also curved at a harmonic curve and the covers 22 and 22 are also curved at a harmonic curve to afford the refieoting surface 34C which cooperates with the surface 33.

lIn this way the sound, after being consageways in which the sound travels is substantially a continuation of the passage lead- Y ing thereto, each succeeding passage increasing harmonically across two sides. In other words, each succeeding passage has a cross section width such that it increases harmonicaly ly from the start of the first section before the sound reaches the recesses 28 and 2,9 and continues until the sound is transmitted from the chambers 33 and 33. The two final openings which are the ends of the chambers 3,3. and 33 are provided with a view to produc` Y ing the sensation of depth or space not obtainable by a single horn or device.

in this ainplifyingrdevice there are pro# Yvided a pair'of cooperating sound transmitters or amplifiers, receiving the sounds from the same source, and constructed on their inner or reflecting surface harmonically.

While I have illustrated and describedV the preferred form of my invention, I do not-V Y wish to limit myself to the precise details of structure shown, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Let-tersV Patent is: Y

1. A device of the class described, com' prising: a housing; a pair of passage forming oppositely disposed walls spaced apart; a pair 'of oppositelyV disposed wedges co-operating with said walls andfenclosing a passage, the inner surfaces of said wedges being inclined to their longitudinal axis, the inner surfaces of said wall forming membersthroughout the major portion of said wedges being parallel and throughout the rest of their length being fiared outwardly from each other on harmonic curves.

2. A device of the class described, comprising: a housing; a pair of passage forining oppositely disposed walls spaced apart; a pair of oppositely disposed wedges co-operating with said walls and enclosing a ,pas-

sage, the inner surfaces of said wedges be ing inclined to their longitudinal axis, theinner surfaces of said walll forming members. throughout the major portion of said wedges being parallel and throughout the rest of their length being fiared outwardly from each other on harmonic curves; areflecting plate positioned vadjacent the ends of said wall forming members in spaced relation thereto and extended across the passage formed thereby and provided at opposite sides of the longitudinal medial line of said passage with curved recesses, the curve of said recesses being harmonic.

3. A device of the class described, cornprising: a housing having side walls in spaced relation; a covering engaging the edges of said side walls on all sides except one and enclosing the space between said side walls; securing plates mounted on the inner surface of said side walls; a reflecting plate joining said securing plates adjacent the open side of said housing; a pair of hollow members projecting inwardly of said housing and engaging adjacent their outer ends the sides of said reflecting plate; and passage forming members projected through one side of said housing and extending inwardly between said hollow members and forming a sound passage between the same terminating adjacent said refiecting plate.

l. A. device of the class described, comprising: a housing having side walls in spaced relation; a covering engaging the edges of said side walls on all sides except one and enclosing the space between said side walls; securing plates mounted on the inner surface of said side walls; a reflecting plate joining' said securing' plates adjacent the open side of said housing; a pair of hollow members projecting inwardly of said housing and engaging adjacent their outer ends the sides of said reflecting plate; and passage forming members projected through one side of said housing and extending inwardly between said hollow members and forming a sound passage between the same terminating adjacent said reflecting plate, said reflecting plate having at opposite sides of the medial line of said passage grooved recesses formed therein.

In testimony whereof I have signed the foregoingl specification.

CHARLES C. FLYN N.

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