US1773605A

US1773605A - Loud-speaker

Info

Publication number: US1773605A
Application number: US192256A
Authority: US
Inventors: Sefton Wilfred; Sefton Pennington
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-05-18
Filing date: 1927-05-18
Publication date: 1930-08-19
Anticipated expiration: 1947-08-19

Description

Aug. 19, 1930. W, SEFTON 5T Al. 1,773,605

LOUD SPEAKER 'Filed May 18y 1927 f 1 Wm Patented Aug. 19, 1930 UNITED STATES PATENT OFFICE LOUD-SPEAKER Application filed Hay 18, 1927. Serial No. 192,256.

This invention relates to certain new and useful improvements in loud speakers.

T he main object of the invention is the pro-- duction'oi:` a loud speaker of improved characteristics in the production and amplifica-- tion of sounds, especially in that the reproduction is clearer, more distinct and accurate, particularly as to sounds of comparatively low pitch, and sounds of comparatively high pitch.

A further advantage resides in the provision of two diaphragms of different sizes and formed of dierent materials and each adapted for more eective reproduction of sounds of articular pitches.

ther objects and advantages relate to the details of the structure and the arts thereof, all as will more fully appear trom the following description, taken in connection with the accompanying drawings, in which:

Fi ure l is a front elevation of an apparatus o this invention.

Figure 2 is a sectional view on line 2 2, Figure 1.

Figure 3 is a. sectional View similar to Figure 2, but of a somewhat modified form of apparatus Loud speaking devices, including'a cone diaphragm and a motor for actuating the same, are well-known, and in the a paratus here shown the motor is generally illustrated at -A-. The form and structure of the motor forms no portion of this invention, and any of the commonly used motors may be provided.

The apparatus as illustrated in Figures l and 2 comprises a hollow circular frame 1 mounted on a base -Q-. One of the diaphragrns, as -3-, has its outer `edge clamped to the frame --1-- and the diaphragm itself is of frusto-conical form, and is preferably made from some suitable paper, such as stencil aper.

he diaphragm -3- as illustrated, 1s of annular form,'andrlp\rovided with an opening at its center. is opening is closed by a second or inner diaphragm -4- as shown of conical shape and preferably formed of a material such as sheet-metal suiiiciently thin to constitute a vibratory body for accurately reproducing tones or sounds of comparatively high pitch.

The outer edge of the metallic diaphragm --4- may be secured to the inner ed e of the paper diaphragm -3- in an suita le manner, as by over-lapping the e ges of the dia-- phragms and securing them together in overapped position by an adhesive or'other suitable means. The metallic diaphragm J1- at its central portion may be formed with a hub 5 mounted upon actuating rod -6- connected in the usual manner to the motor A and suitable connection may be made between the red (5- and the hub -5- as by means of a set screw --7.

This construction of apparatus is found highly eicient in the accurate reproduction of sounds of varying pitch as the outer paper diaphragm -3 acts eectively to repro-- duce the tones of lower pitch, While-the iniier diaphragm --4- acts to effectively re-l proflluce the tones of comparatively high pito f In Figure 3 modified form of apparatus is shown in that the two diaphragms, altho actuated simultaneously from the same motor A, are arranged separately.

The apparatus of Figure 3 comprises the same frame -1-, base --2 and motor A, but the diaphragm t3- is in this structure a substantially complete cone, and is mounted at its central portion in any suitable manner upon the rod -9- connected to motor A. The diaphragm 8 is preferably formed of suitable paper, such as stencil paper, Iand constitutes in itself a complete operable apparatus, but in addition thereto a second ,diaphragm -10 is provided which may be flat, as shown, or of other forms, secured at its central portionto the rod -11- in any suitable manner, so as to be actuated by the latter from the motor A simultaneously with the actuation of the rod -9-.

The edge of diaphragm l0- may be clamped between the rings 12- and -l3-, the latter of which may be carried from the frame -1-- in any suitable manner, as by brackets 14-. In this structure both diaphragm arran ements are operable struc- Vtures in themse ves, but are simultaneously actuated to produce unitary sound, the diaphragm -8- acting to more eectively reproduce the lower tones, while the diaphragm -lO- which is preferably formed of thin sheet metal, and is of lesser diameter, acts more effectively to reproduce the higher tones.

Altho we have shown and described specific structures as constituting perhaps preferred embodiments of our invention, it will be apparent that various and other modifications may be made in the details of the structure,and the forni and arrangement thereof, all within `the scope of the appended claims.

W'e claim:

l. A loud speaker including a diaphragm comprising two concentric connected vibratory members formed of different material and having portions which do not overlap.

E2. A loud speaker including a diaphragm comprising two concentric connected vibratory members formed of different material and each havingt a portion free to vibrate without contact with the other, and means for simultaneously actuating the vibratory members.

3. A loud speaker comprising a cone diaphragm consisting of two concentric vibratory sections formed of different materials, one 01' said sections being of irusto-conicai form and the other being in the shape of a cone closing the central smaller opening of the other section.

i. A loud speaker comprising a cone diaphragm consisting of two concentric vibra- 'tory sections of different sound reproducing characteristics, one of said sections being or' :truste-conical form, and the other being formed of thin metal in the shape of a cone closing the central smaller opening; of the other section and secured to the adjacent edge thereof.

A loud speaker including a cone dia phragm comprising two sections, the outer one ot' which is i'rusto-conical and the inner one of which is conical, and closes the smaller open end or" the other section.

5. i loud speaker including a cone diaphragm comprising two sections, the outer one of which is 'frusto-conical and the inner one ot which is conical and closes the smaller open end of the other section, and is formed or thin sheet metal.

in witness whereof we have hereunto set our hands this 12th da;v of May, 1927.

PENNNGTN SEFTN. TVVELFRED SEFTUN.

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