US1476850A - Stylus mounting for reproducers - Google Patents

Description

Dec. 11 1923.

C. SCRABIC STYLUS MOUNTING FOR REPRODUCERS Filed April 5, 1922 Patented Dee. M, 19230 anaestra'ranr u CARI; SCRABIC, F URBANA, 01 E110.

STYLUS MOUNTING FOR REPRODUGERS.

Application filed April 3, 1922. Serial .No. 548,977.

To all whom it may concern:

Be it known that CARL SoRABio, a citizen of the United States, residing at Urbana, in the county of Champaign and State of Ohio,

a has invented certain new and useful Improvements in Stylus Mountin s for Reproducers, of which the following 1s a specification.

This invention relates to an improved 1o stylus mounting for the reproducer or a sound box of a. talking machine, or other sound producing instrument, and has for its primary object the provision of a mounting of an extremely sensitive character, and

us yet of practical and durable formation, which will enable a stylus bar associated therewith to respond to all including the minute secondary, sound undulations provided in physical form within the grooves 2a of talking machine records.

Another object of the invention resides in the provision; of an improved stylus mounting which will not only be capable of oscillating about a substantially horizontal 2a pivotal axis but will also be capable of movmg for a limited distance in any direction for the purpose of enabling the stylus to properly and accurately respond to the multi-forin sound undulations of a record.

In a reproducer or sound box of usual form the stylusv bar is ordinarily mounted upon the frame or casing of a reproducer so that the stylus bar will be permitted to vibrate or oscillate on a single plane. As

85 a result of extended experiments it ismy belief that this ordinary construction does not result in the reproduction of all of the sound waves physically imposed or provided upon a record, since these waves in a lateral cut record not only provide horizontally extending projections or undulations of a major character o but include secondary sound wave impressions which extend on various angles or planes to the major im- 4 pressions, and which are not recorded or reproduced by astylus bar fixed to oscillate in a single plane. The present invention, therefore, consists in rovlding a stylus bar mounting which inc udes a air of outwardl extending studs carried thereby and capab e of being received within bearin sockets provided therefor in the casing o the reproducer, the said studs constituting fixed trunnions which enable the stylus bar to oscillate upon a. main plane, the ends of the studs being received within sleeves formed from rubber or other compressible material which will admit of slight movement on the part of the stylus bar in any direction, so that the needle of the stylus bar will respond to sound undulations of any character provided upon a record and will move faithfully in close conformity with the manifold and varying physical char; acteristics of such undulations so as to bring forth and accurately reproduce the fundamental and over tones thereof.

Another object of the invention resides in forming the trunnion studs of the main stylus bar axis with transversely extending pins which are received within the compressible sleeves of the mounting, the said pins serving, by cooperation with the resilient sleeves to maintain the stylus bar in a true normal position and to provide a gradually increasing resistance to the stylus bar as the latter oscillates from its normal or neutral position. I 4

Other objects of the invention rest in the provision of an improved and simplified construction for admitting of the above set forth functions and others, and wherein the assembly of the stylus and mounting in connection with a reproducer can be easily and properly carried out, the construction of the mounting being extremely simple so that unskilled labor may be employed in completing the operation and to permit the latter to be performed accurately mbut a minimum of time.

With these and other objects in view, as will appear as the description proceeds, the invention accordingly consists in the novel features of construction, combinations of elements, and arrangements of parts, hereinafter to be fully described and articularly pointed out in the appended claims.

In the accompanying drawings, forming a part. of this specification, and in which similar characters of reference denote like and corresponding parts throughout the several views thereo Figure 1 is a side elevation of a talking machine reproducer provided with the improved stylus bar mounting comprising 6* the present invention, I

tilt

Fi re 2 is a transverse horizontal sectiona view taken on the line 2-2 of Figure 1 Figure 3 is a vertical transverse sectional view on the line 3-3 of Figure 1,

Figure 4 is a perspective view of the stylus bar,

Figure 5 is a similar view of one of the sleeves employed in the pivotal mounting of the stylus bar,

Figure 6 is a similar view of one of the retaining blocks employed in the mounting,

Figure 7 is a diagrammatic view on a greatly enlarged scale of the sound undulations of a record groove.

.Referring more particularly to the specific embodiment of the invention illustrated in the accompanying drawings,the numeral 1 designates a reproducer or sound ,box of the type employed in conjunction with talking machines, and wherein is provided the usualmetallio casing or frame 2 having suitably mounted therein for vibration a diaphra- 3. The casing through the medium 0 a peculiarly formed mounting, hereinafter specifically described, pivotally carries a stylus bar 4, which has its upper end formed to be secured to or engage with the axial portion of the diaphragm 3, while the lower end of the stylus bar is suitably enlarged and provided with a socket for the reception of a removable needle 5 of any ordinary construction, the needle being retained within the stylus bar socket b means of the usual thumb screw 6. By is construction the stylus will be permitted to oscillate as usual in conformity with the sound undulations of a record groove and will, therefore, set up vibration on the part of the diaphragm 3, whereby atmospheric disturbances within the sound box will be created and amplified by usual appliances.

As shown diagrammatically in Figure 7 a record groove of the so called lateral cut variety is provided with sound undulations 7 suitably formed in said groove by any ordinary recording process which need not be herein described These undulations possess major and minor variations, the major variations are designated bythe numeral 8 and are of maximum depth and extend generally, 1n lateral out records, on a horizontal v plane. I These variations, according to my experiments, are the ones that are reproduced by an ordinary stylus bar, which is fixed to pivotin a single plane, but which do not respond to the minor variations 9, in which are, included the fine over-tones and other delicate tonal shadings which should be reproduced to insure-a fair degree of naturalness. It will be observed that the minor variations may be inset or disposed on var ing planes with respect to the major variations, and therefore I provide a mounting for the stylus bar which will enable its needle extremity to follow closely the undulating or serrated outlines of both the major and minor variations.

To secure these results the casing of the reproducer is provided with a depending web 10, in which is formed a pair of space sockets 11, separated b an enlarged recess 12 provided centrally in the web 10. The sockets 11 open into the recess 12 and are also provided with open bottom portions, the web 10 being extended so as to form the sockets with top, side and end walls 13, 14 and 15 respectively. The stylus bar 4 has its lower enlarged extremity 16, above the needle 5, provided with a fixed transversely extending stud 17, which has its ends projected laterally from said stylus bar to constitute trunnions by means of which the stylus bar may be supported for vibration in connection with thereproducer. The outer ends of the studs 17 are received within the spaced sockets 11 of the web 10, and the said outer ends of the studs, which are received within the sockets 11, are provided with fixed transversely extending pins 18, extending on planes at right angles to the longitudinal axis of the studs 17. These pins are formed to receive compressible sleeves 19, which are ordinarily formed from rubber and are positioned within curved depressions 20 provided in the walls of retaining blocks 21.

By this construction it will be observed that when the blocks 21 are secured within the sockets 11, which is accomplished by means of the screws 22 the stylus bar will be so mounted that the same will oscillate from a position defined by the studs 17 and may freely vibrate back and forth in response to the undulations of the major variations 8, in a manner common to reproducer construction. By the inclusion of the pins 18 and the compressible gasket sleeves 19 oscillation on the part of the stylus bar from a neutral position will be resisted more and more as the stylus bar swings from its neutral position by the action of the sleeves 19, which will be compressed to a more or less extent by the pins 18. However, by reason of the sleeves 19 a universal mounting will be provided for the stylus bar which will admitof limited movement on the part of the latter in any direction, that is, vertically, laterally-or to a given extent in any other direction, thus enabling the needle of the stylus bar to closely follow and conform to the minor variations of the record as well as the major. It is for this reason primarily that the present construction is believed to be capable of reproducing a record with far neraeso ducing machines. Another important phase of the present invention rests in its simplicity in construction, and the ease with which. the stylus bar mounting may be assembled, without requiring the services of expert or skilled workers, as is now common in reproduoer manufacture. The mounting may be assembled by providing the pins 18 with the rubber sleeves 19, in placing the pins and sleeves within the depressions 20 of the retaining blocks 21, and then by securing the blocks Within the sockets 11 through the medium of the two screws 22. it is apparout that this operation can. be very quickly accomplished and that setting or adjustment of the mounting, which must in ordinary constructions be carefully performed, is entirelv eliminated.

What is claimed is:

1. lo a sound reproducer for talking machines, a casing", spaced bearings provided upon said casing, a stylus bar movable with respect to said casing, outwardly extending trunnions fixed to said stylus bar and arranged to be received within said bearinis, transversely extending pins carried by t e outer ends of said trunnions, and compressible means situated in said hearings in engagement with said pins.

2. In a sound reproducer for talking machines, a casing including spaced bearings, a stylus bar mounted for vibratory movement between said bearings, said stylus bar including laterally extending trunnions having the outer ends thereof received within said bearings, projections extending at right angles to the longitudinal axis of said trunnions, and resilient means surrounding said projections and serving to rotate said trunnions to maintain said stylus bar in a normal position.

3. In a sound reproducer for talking machines, a casing including spaced sockets on the perimeter thereof, a stylus bar subject to oscillation relative to said casing, said stylus bar including a pivotal mounting formed to embody aligned studs projecting laterally from said stylus bar and having the outer ends thereof received Within said sockets, means extending transversely with respect to the longitudinal axis of said studs, and sleeves of resilient material cooperative with said-means to admit of limited move ment in any direction on the part or" said stylus bar and normally maintaining the latter in a neutral position.

a. In a sound reproducer for talking machines, a casing having" spaced sockets provided in the outer portion thereof, a stylus bar mounted for oscillation relative to said casing between said sockets, trunnion studs projecting laterally from opposite sides of said stylus bar, the outer ends of said studs being received within said sockets, pins passing transversely through the outer ends of said studs, sleeves or" a resilient material surrounding said pins, and means for removably retaining said studs within said sockets.

5. In a sound reproducer for talking machines, a casing having spaced sockets pro vided. in the outer portion thereof, a stylus bar mounted for vibration relative to said casing and "positioned substantially between said sockets, trunnion studs extending laterally from opposite sides of said stylus bar and having the outer ends thereof positioned within said sockets, pins fixed to rotate with said studs and extending transversely with respect thereto, sleeves of a re silient material surrounding said pins, and retaining blocks having depressions formed till lit

therein for the reception of said pins and sleeves. said retaining blocks serving to re movably retain the outer ends of said studs within said sockets.

In testimony whereof I afix my sigrmturea CARL SCRABIC.

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