US1757307A - Sound-reproducting horn - Google Patents

Description

May 6, 1930. H. HARKlNs SOUND`REPRODUCING HORN Filed Feb. 28, 1927 when f Patented May 6, 1930 Mrs HARRY HARKINS, OF MONTPELIER, IOWA SOUND-REPRODUCING- HORN Application sied February 2s, 1927. 'serial No. 171,568.

The object of my invention is to provide a sound reproducing horn of simple, durable and comparatively inexpensive construction.

A further object of my invention is to provide a horn of the class described, of novel construction whereby mechanical vibration of the horn itself is reduced to a minimum and the production of clearer tones from a phonograph or radio loud speaker is possible.

More particularly' it is my object to construct the horn in sections and provide a means between the adjacent sections whereby the vibration of one section will not be transmitted to another section.

Still a further object is to provide a horn constructed of sections, the ends of which telescope together with a space left between the telescoped ends with a strip of material such as felt or the like secured between the telescoped parts of the sections to prevent the transmission of vibration from one section to another.

With these and other objects in view my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claim, and illustrated in the accompanying drawings, in which:

Figure 1 is a perspective view with parts broken away and other parts shown in section, illustrating one embodiment of my sound reproducing horn.

Figure 2 is a sectional View through a phonograph showing my improved horn applied thereto and Figure 3 is a side elevation of a radio loud speaker, the horn portion of which is constructed as described in my objects.

On the accompanying drawings, I have used the reference numeral 10 to indicate the downwardly projecting section of a sound reproducing horn. The section 10 is secured to the tone arm 12 of a phonograph 14. The motor of the phonograph is indicated at 16, the revolving plate at 18 and a record is indicated by the reference numeral 20. VThe diaphragm head 22 of the phonograph has secured thereto the needle 24 which coacts with the record 2O when in motion for producing sound.

The sound reproducing horn is indicated generally by the reference character A and is composed of the sections 10, 26, 28, 30 and 32. The external diameter of the section 26 is substantially smaller than the internal diameter of the section 28, as clearlyillustrated in Figure 1 of the drawings, whereby a peripheral space is left between the telescoped ends of the sections. A strip of felt 34 is glued or otherwise secured between the telescoped ends of the sections for fastening the sections together but preventing the transmission of vibration from one section to another. Rubber or similar material can also be used instead of felt and will accomplish the same purpose.

The remaining sections of the horn A are secured together in a similar manner whereby each section can vibrate independently.

I have found that by so constructing the horn in sections, the mechanical sound usually heard from a horn made of one section is eliminated and that a much better quality t of tone is given to the sounds introduced into the horn. Furthermore there is a tendency in a one piece horn for part of it to vibrate at one frequency and another part to vibrate at a different frequency which sets up a mechanical vibratory sound. A horn of my construction allows each section to vibrate at its own frequency which greatly improves the tone quality of music and the like emitted from the horn.

It is obvious that a horn of this type can be used for either phonographs or in the contruction of radio loud speakers as illustrated ,in Figure 3 of thedrawings. The base 36 of the loud speaker usually has a diaphragm mechanism therein and the horn is indicated generally by the reference character B. The horn B is composed of the sections 38, 40, 42, 44 and the liared section 46. Each of the sections is separated by a strip of felt or the like in the same manner as illustrated in Figure 1 of the drawing.

I preferably use a horn of fiber or paper pulp construction as l find it more suitable than a horn constructed of metal.

Some changes may be made in the construction and arrangement of the parts of my device Without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claim, any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

A horn of the character disclosed comprising the combination of va plurality of conical shaped horn sections, the external diameter of the large end of each section being,r smaller than the internal diameter of the small end of the next succeeding horn section and arranged therein whereby there is a peripheral space between said ends and a Vibration nonconductor'filler in each of said spaces, said iillers being of equal thickness throughout their length and adapted to seal said spaces but allow independent vibration of each horn section.

Des Moines, Iowa, February l0, 1927.

HARRY HARKINS.

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