US1523670A

US1523670A - Sound-reproducing diaphragm

Info

Publication number: US1523670A
Application number: US618200A
Authority: US
Inventors: James H Sutlive
Original assignee: C W REDPATH
Current assignee: C W REDPATH; Cw Redpath
Priority date: 1923-02-10
Filing date: 1923-02-10
Publication date: 1925-01-20
Anticipated expiration: 1942-01-20

Description

J. H. SUTL-JVE SOUND REPRODUCING DIAPHRAGM Filed Feb. 10, 1923 )4 T ORNEY i Pat nted; ham 1925.

P UNI ED STATES PATE T oF'ncE.

ules 1E; surmvn, or KANSAS crrr, mrsso-unr, assmnonor ONE-FOURTH 'ro cgw nnnra'rn, or KANSAS crrY, mrssounr. I

sounn-nnrnonucmo nmr'nnneu.

' Application and February 10,1923. Serial No. 618,200.

To all whom it may concern:

Be it known that I, JAMES H. SUTLIVE, a citizen of the- United States, residing at Kansas City, in thecounty of Jackson and 5 State of Missouri, have invented certain new and useful Improvements in Sound-Repro-' ducing Diaphragms and I dodeclare the following to be a full, clear, and exact description of the invention, such as will enable 10 others skilled in the art to'which itappertains'to make and use the same, reference being had'to the accompanying drawings, and to the figures of reference marked thereon, which forma part of this specification.

This invention relates to sound reproducing diaphragms and it is particularly designed for use in connection with a mechanically operated sound reproducing machine in which the diaphragm is operated by-a vibratory arm toreproduce sound.

Heretofore diaphragms have been gen- 7 erally constructed ofvarious materials but theyhavev been more orlessinefficient due, I'believe, to the fact that the whole dia phragm or the major portion of the diaphragm at least does not respond to the vibrations of the arm. The diaphragms heretofore used have consisted of relatively stiff material withthe arm fastened in the center; the result is that only a part of the diaphragm about the center is vibrated so that the tones are more or less thin; that is, they are not rounded out with full resonance which has been recognized. as the desirable end sought by diaphragm manufacturers.

I have provided a diaphragm which, while of stiff material is so constructed that it is flexible enough to permit bodily movement of the major portion of the diaphragm so that a relatively large amount of air isdisplaced and so that the movement of the diaphragm is practically a full body movement as distinct from the fractional diaphragm movement common with diaphragms now in use. In actual practice I have demonstrated that, as compared with present day diaphragms, a diaphragm constructed-in accordance with my invention will produce a very marked result and that when a comparison is made between the diaphragm forming the subject matter of this invention and known makes of dia hragms, the tones resulting from the use 0 my diaphragm are broader and rounder, not necessarily louder but with a of a very fiat cone having a straight end or 5 base and an inclined or cone face; there belng circumferential grooves on opposite faces .of the cone, the grooves on one face being offset with respect to those on the other so that the central solid portion of the diaphragm can have a free body move-- ment as distinct from a tilting or pivot movement common to present day dia phragms- In a former application filed by me on or described a diaphragm which was in eifect cone-shaped but. it did not contain the grooves. I, therefore, intend that this application shall be a continuation in part of my former application to obtain thebencfit ofthe filing date of the former application for anything common in the two applications.

The invention will be better appreciated by reference to the following description in connection with the accompanying drawings, in which Fig. 1 is a sectional view through a sound box of a sound reproducing machine to which my invention is applied.

gig. 2 is a face view of the diaphragm, an

Fig. 3 is a cross sectional view on the line 33 of Fig. 2, the diaphragm being greatly magnified.

The diaphragm is shown as consisting of a flat cone preferably of rubber. The base side 1 is the inside of the diaphragm and the cone side 2 is the outside. The cone side is truncated,-that' is, the apex is cut off to form a central disk portion 3, having an opening 4 to which-the stylus arm 5 may be secured. The diaphragm on the cone side merges from the edge of the central solid portion to the edge in an incline, providing a progressively uniform variable thickness, the thinnest portion being at the periphery of the disk within the outer ring and the thickest portion at the center.

On the respective sides or faces of the disk about June 17, 1920, Serial No. 389,639 I are

peripheral grooves

6 and 7 respectively, the grooves 6 being ofl'set with respect to the grooves 7, as will be clearly seen in Fig. 3. I prefer to {cut the grooves so that their floor portionswill be relatively flat and their outer 'wall'portions, for example,'at 8 and- 9, at-substantially right angles tothe floor illustrated in the drawings.

portionsto provide shoulders, the

shoulders

8 and 9 being ofiset, as are the

grooves

6 and 7.

At the periphery of the disk is a sealing ring 10, within which is the thinnest portion of the disk, and it is fastened in the sound box 11 in the usual way, the stylus arm be-- ing secured in the hole 4 by any suitable means so that when the stylus 12 vibrates, a vibratory movement will be imparted to the disk but instead of the central portion 3 only of. the disk vibrating, the entire inner portion, that is, the entire body portion surrounding the ring 10 will have a movement back and forth in response to the vibrations due to the movement of the needle or stylus 12in the undulated grooves in the record.

The body movement of the disk within the ring portion 10 produces a very markedly superior tone over known types of diaphra-gms, the tone being. fuller and richer due, I believe, to the fact that more air is displaced on account of the body movement of the diaphragm caused by its peculiar construction. v I

I have illustrated what I consider the best form ofmy invention although I do not wish to be limited to the exact construction In actual practice I have constructed the disk of hardTrtIbber and I find this admirably serves as a material form which to construct the disk; the web consisting of the corrugations made by the offset grooves and connecting the solid central portion to the outer ring being quite flexible. I do not wish to be limited, however, to hard rubber in all instances because other materials might be used. y What I claim anddesire to secure by Letters-Paten't is:

1. A sound reproducing diaphragm consisting of a single piece in theform of a diskhaving a flat central portion of uniform cross section, the portion surrounding the v central portion having progressively de-' creasing cross section toward the periphery and a peripheral ring shaped portion integral with the second mentioned portion, the ring shaped portion being adapted to be clamped in position to. hold the diaphragm in place the portion of the disk immediately within the peripheral ring being the thinnest portion of the diaphragm so that all that portion of the diaphragm within the peripheral ring is adapted to move bodily with respect to the peripheral ring.

2. A sound reproducin diaphragm con sisting of a disk having a at central portion of uniform cross section, the remaining portion of the disk having a progressively decreasing cross section, the disk having circumferential rooves about its center on opposite faces, the floors of the grooves on opposite faces converging toward the periphery of the disk.

3. A- sound'reproducing diaphragm conslstmg of a disk harm a central portion of uniform cross section, t 1e remaining portion 1 of the disk having pro ressively decreasing cross section, the disk' raving circumferential grooves about its center, the Walls of the grooves being formed with sharp angles and the grooves being on opposite sides of the disk, those on one side being ofiset with respect to those on the other side the floors of the grooves on opposite faces of the disk converging toward the periphery of the disk.

4. A sound reproducing diaphragm consisting of a disk having a central port-ionofuniform cross section, the remaining portion of the disk having a progressively decreasing cross section toward theeriphery, the disk vhaving circumferentia grooves about the central portion of uniform cross section, the grooves being on opposite sides of the disk and offset with respect to one another, the grooves having flat floor portions, the outer Walls being at substantially right angles to the floor portion, the floor portions merging ofi so that their inner edges have no walls. 1

In testimony whereof I afiix'm signature.

JAMES S TLIVE.