US 1751356 A
Description (OCR text may contain errors)
March 18, 19390 A. P. PINKLER DIAPHRAGM Filed July 21, 1925 ATTORNEY Patented Mar. 18, 1930 UNITED STATES ARTHUR R IPINKLER, OF WATERIBURY, CONNECTICUT, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO WM. H. BRISTOL TALKING PICTURE CORPORATION, OF 'W'ATERBUIRY,
. CONNECTICUT, A. CORPORATION OF CONNECTICUT DIAPHRAGM Application filed July 21,
The invention relates to diaphragms for use with sound producing or sound reproducing devices, for example as employed in telephone receivers, loud spealn'ng receivers, phonographic sound boxes and the like. It has for its object to provide a diaphragm of sufiicient strength to take a substantial load yet withal be extremely light so as to be readily responsive to the variations in intensity of the actuating force applied thereto. A further object of the invention resides in a construction which will admit of the diaphragm responding over a wide range of sound frequencies, that is to say, there will be no sacrifice of quality, as both the high and low notes are equally well reproduced notwithstanding the substantial construct-ion involved.
The nature of the invention, however, will best .be understood when described in connection with the accompanying drawings, in which Fig. 1 is an underneath view proved diaphragm.
Fig. 2 is a plan thereof.
- Fig. 3 is a vertical section therethru taken on the line 33, Fig. 1.
Fig. 4 is a vertical transverse section thru a sound box illustrating the novel manner of of the immounting the improved diaphragm.
Referring to the drawings, the diaphragm is shown as circular in form, as is the usual practice; and is composed of two membersa substantial and more or less rigid member 10, and a flexible non-resonant annular member 11 carried thereby and secured thereto in any suitable manner as by means of an adhesive, cement or the like. The member 10 may consist of a thin disk of light metal such as aluminum, while the annular memberll is of non-resonant material such as paper, parchment, celluloid, etc., and which is of greater flexibility, either inherently or due to its reduced thickness, than the supporting disk member 10. The latter member, further, is formed with a plurality of equidistantly spaced and radially disposed arms 13 upon which is secured the annulus 11 to close over the lntervening spaces. Moreover, it is desirable to render the central portion of the 1925. Serial No. 44,991.
member 10 more rigid than the outer porwith a series of concentric corrugations 14.
In mounting the novel diaphragm, as in a sound box 15, Fig. 4, the same is to be held substantially at its circumference between two rings 16 and 17 of resilient material, for example soft rubber. Moreover, the upper ring, and which is arranged to bear against the paper annulus, is solid throughout; while the lower ring 17 arranged to be located on the under side of the diaphragm is preferably made hollow.- The two rings are designed to clamp the diaphragm over its circumference thru pressure exerted thereon by the two separable members of the sound box 15, which clamping action may be accomplished by taking up on the screws 18. When pressure is thus applied by the screws, the soft rubber material will conform perfectly to the differences in the surface of the diaphragm due to the notched out portions of the metal supporting member 10, the hollow ring 17 tending. to fill up the spaces in forcing the paper of the flexible annulus of the diaphragm against the solid upper ring 16. In this manner, an air-ti ht seal is provided about the diaphragm, o viating any losses of sound waves thru leakage around the circumference of said diaphragm.
In thus providing a diaphragm of WhlCh a portion of the supporting member 10 is notched out as set forth and covered with an annulus of light, non-resonant material, the weight of same is considerably reduced without sacrificing appreciably its strength; and the radial arms resulting therefrom provide for the desired flexibility at the outer portion'of the diaphragm while the corrugations 14 at its central portion maintain the stiffness ofthe diaphragm at this portion. It will be noted that this isaccomplished without increase of weight or by making up the diaphragm of laminations of different thicknesses and diameters as has heretofore been proposed. Moreover, in thus providing the radial arms, a beneficial result is obtained in that all radial stresses in the diaphragm material are substantially eliminated, the diaphragm retaining its original flat condition.
tions; and to this end, the same is provided Three or four concentric corru ations of a m depth of some .018 have been ound to satisfactorily stiffen the central portion of the diaphragm, a suitable thickness of which, when aluminum is employed, being .020". I have found, also, that the paper annulus will give satisfactory results if of an approximate thickness of .0035; and the two members thus combined into a single diaphragm provide an extremely light member which, however, is sufiiciently substantial to Withstand heavy loads such .as are frequently encountered in connection with the operation of loud speaking receivers. Furthermore, the diaphragm is constructed to respond both to the high pitched notes and to the low pitched notes, the former being taken care of by arms 13 and the annulus 11 while the central and stifiened corrugated portion 14 responds to the latter.
I claim 1. A diaphragm for sound recording or reproducing units, comprising a thin substantially flat disk having a plurality of integral free-ended arms extendin radially outward therefrom in the plane 0 said disk, and an annular member of non-resonant material and more flexible than said disk secured to its arms to cover the intervening free spaces thereof.
2. A diaphragm for sound recording or reproducing units, comprising a thin substantially flat disk circularly corrugated at its central portion and having a plurality of integral free-ended arms extending radially outward therefrom in the plane of said disk, and an annular member of non-resonant ma terial and more flexible than said disk secured to its arms to cover the intervening free spaces thereof. 7
3. A diaphragm for sound recordin or reproducing units, comprising a thin su stantially flat metal disk having a plurality of integral free-ended arms extending radially outward therefrom in the plane of said disk, and an annulus of paper secured to said arms to cover the intervening free spaces thereof.
In testimony whereof I afiix my signature.
ARTHUR P. PINKLER.