US1339558A - Phonograph and analogous apparatus - Google Patents

Description

E. GRISSINGER.

PHONOGRAPH AND ANALOGOUS APPARATUS.

APPLICATION FILED JUNE 12, 1918.

1,339,558, Patented May 11,1920.

INVENT9R 1% 1 1 M 6M 1 a ATTORNEY UNITED STATES PATENT onnron,

ELWOOD GRISSINGER, OF BUFFALO, NEW YORK, ASSIGNOR TO LUCY ASH GRISSINGER, OF BUFFALO, NEW YORK.

PHONOGRAPH AND ANALOGOUS APPARATUS.

Application filed June 12,

To all whom it may concern:

Be it known that I, ELWOOD GRIssINonK, a citizen of the United States, and resident of Buffalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Phonograph and Analogous Apparatus, of which the following is a specification.

My present invention is shown as embodied in a phonographic sound box which is primarily adapted for mechanically reproducing sound from a record but it may be embodied in a phonographic recorder or other apparatus where rigid, frictionless, noiseless pivoting is necessary or desirable in order to insure faithful, undistorted mechanical receiving or transmission of high frequency or complex wave energy.

In In prior application, Serial No. 236,735,

ay 27th, 1918, I have disclosed a construction wherein the effects of mechanical resonance are eliminated from the vibratory system, by making the lever arm rigid and pivoting it upon spaced piano steel wires stretched to the safe limit of their tensile strength thereby insuring a predetermined, rigidly fixed path of movement for all parts or particles of the lever.

My present invention may include the above features but it relates more particularly to the use of the spaced stretched wires and it involves in addition thereto, a means for further predetermining and fixing the location of the pivotal axis of the lever. Broadly stated, the said means consists of a third element adapted to apply a thrust perpendicularly to the plane of the wires, and along a line parallel with and midway between them. The means employed for this purpose may be a knife edge or a cylinder of small diameter or a pair of alined steel balls.

By providingsuitable adjusting screws, the pivotal edge or surface may be powerfully forced against the lever thus affording a convenient and very effective means for transversely displacing the wires and thereby stretching them to any desired degree of tension.

By the above expedient, the knife edge or alined balls become the physical bearing surfaces for the pivotal movement of the lever. These bearing surfaces are forced into contact with relatively enormous pressure by the symmetrically applied stresses Specification of Letters Patent.

Patented May 11,1920.

1918. Serial N0. 239,512.

of spaced wires. This prevents all possibility of jumping or noise producing movements at the point of contact of the lever with its bearing. The bearing parts are preferably of very hard steel and are formed with smooth, preferably polished surfaces.

My invention will be more fully understood from the following detailed description thereof in connection with the accompanying drawings, in which Figure 1 is a face view of a phonographic sound box showing the spaced stretched wire suspension;

Fig. 2 is a section on the line 22, Fig. 1, the lever and pivotal mounting being shown in side elevation;

Fig. 3 is an enlarged vertical section on the hne 3-3, Fig. 1;

Fig. 4, is an elevation endwise of the lever.

In these drawings, the sound box comprises the annular ring 1, formed with the inwardly projecting annular flange 2, and the back-plate 3, secured to ring 1 by screws 4. In the recess between flange 2 and plate 3 is clamped the diaphragm 5 of mica or other suitable material, disposed between a pair of rubber cushioning rings 6 which may be of any known or desired material or construction.

The annular ring 2 is formed on one side with an enlargement 7 adapted to form a solid base support for the mounting of the stylus lever. The backplate 3, is shown as provided with an annular rubber collar 8 carrrying an internal ring 9 provided with lugs 10 adapting it for bayonet connection with slots on a phonograph arm where the device is used for reproducing or a mouthpiece where the device is used for recording.

The lever arm 11 may be attached to the diaphragm directly or through the screw and adjustable units shown in Fig. 2. The other end of the lever is provided with a socket 12 and binding screw 13 for holding a needle for reproducin or a cutting point for recording, as in icated at 14. This lever is preferably of an aluminum alloy, and the pivotal portion is relatively massive for purposes of strength, and because a certain amount of weight near the pivotal axis is not so objectionable and is in some respect advantageous so far as con cerns pure tone transmission.

The resilient members adapted to permit resilient pivotal movements of the lever while powerfully opposing movements in other directions are shown as comprising 2 wires 15, 16, symmetrically arranged with respect to the pivotal axis and also with respect to the longitudinal axis of the lever. The wires are secured to the lever arm in any desired way, as for instance, by thread ing them through passages 17, 18 (Fig. 2%.

These passages are preferably parallel. with each other and with the diaphragm.

The ends of the wires are secured to clamping posts 19, 20 by clamping plates 21, 22, each secured preferably by a central bolt 23, passing downward between the wires so that the clamping plates will bind equally on both of the wires to be secured thereby.

As shown in the drawings, the wires are comparatively close together where they pass through the lever and are spread apart to a considerably wider distance at their clamping points so that when highly tensioned, they have considerable effect in bracing or staying the lever against longi* tudinal movement and also against any skewing of its pivotal axis.

Such spaced wires when very highly tensioned afford a frictionless, noiseless mounting for pivotal movement of the lever about an axis parallel with and midway between the Wires. According to my present invention, I use a physical means for determining the axis consisting of a transverse member 24, having a thin or V or knife edge 25 applied agamst the lower side of the lever at 26 so-as to have line contact therewith in a plane midway between the spaced wires. The member 24: is shown in the form of a blade slidably mounted in the frame and adapted to be thrust upward vertically against the lever as powerfully as may be desired, by means of screws 27, 27.

The blade may be set with the bearing edge thereof at the desired height with reference to the clamping points of the wires by means of the set screws or it may be permanently fixed in such position with the wires strung loosely through the lever and clamps. Then the wires may be stretched to the desired tension by any suitable tensioning appliances, after which the clamps may be screwed tight. The maximum tensioning with least displacement of the wires and: least danger of breaking them, may be obtained by the same method except that the bearing will first be retracted, and after stringing, highly tensioning and clamping the wires in a single plane, the bearing screwed up to deflect the wires and thereby increase the tension to the desired extent. The adjustable bearing may be used as the sole tensioning appliance, the wires being drawn snug by hand in a single plane so as to get them practically equal and symmetrical, then clamped and bearing screwed up until the desired tension is applied.

The bearing edge of member 2a need not he a 90 angle as indicated in Fig. 3 but may be a 60 angle, or even sharper. The extreme edge affording the straight lline contact with the lever may be a sharp convergence of the planes or may be slightly smooth or rounded, an edge coresponding to a cylinder of say one-lmndredth of an inch, more or less, being in some respects the equivalent of and in other respects superior to the sharp edge angular convergence.

The spacing as well as the divergence of the wires may be varied within wide limits, provided only, that they be spaced apart so as to afford spaced apart planes of opposition to the thrust of the bearing edge or surface which takes effect in the plane between them in order to produce the desired condition of stable resilient stresses.

From one viewpoint, the preferred embodiment of my present invention may be considered as involving the use of the highly tensioned wires which are claimed broadly in my said prior application, Serial No. 236,735, in combination with a solid physical means for determining the pivotal axis and as a substitute for the noisy, imperfectly acting springs, etc., which have been employed heretofore in phonographic apparatus, in the vain attempt to prevent jumping, rubhing and shifting of the pivotal bearing surfaces of the lever. The wires employed by me when stretched to sufiiciently high tension, eleminate all noises due to the imperfect or rubbing contact of the bearing surfaces and they introduce no noises of their own because the free portions thereof are of such small mass and of such high tension that any natural frequency vibrations which may be set up in them are of very small total energy and are of too high frequency and too musical in quality to be observable among the wave forms transmitted therethrough either in recording or re n'oducing.

Furthermore, my physical. bearing and stretched wire combination is remarkably effective in reducing and practically elimis nating needle noises which are so often disagreeably prominent in reproduction of sounds from ordinary records. There is some reason to believe that the relatively massive proportions of the part of the lever arm utilized for sustaining the thrust of the bearing and the stress of the stretched wires, in combination with extreme light ness of the remainder of the lever arm contribute to some extent to eliminating of needle noises.

The instrument being substantially free from needle, bearing, spring and other disturbing noises, damping, which is commonly employed for the purpose of reducing such noises, is unnecessary. The damping in my device is extremely small, and is limited mainly to internal molecular friction which operates substantially equally for all frequencies. This avoids the unequal damping out of the higher frequencies and the resulting distortion which is inevitable where the damping is due to friction.

Regardless, however, of explanations as to causes, it is a fact that a phonograph reproducer made in accordance with my present disclosure, faithfully produces, without needle noises and without any internally originated noises or notes, all of the more delicate overtones traced in the record not observably reproduced by any phonograph apparatus now on the market and it does this in louder volume and without the needle noises and without adding any internally generated noises or notes of its own. This superiority holds even when the tension of the wires is decreased very far below the safe limit of tensile strength. of the wire.

For the resilient tension members, I prefer to use wire approximately like No. 6 piano wire which is fine quality steel wire about .011 to .012 inch in diameter, but the material and size of the wire may be varied within wide limits and I have at different times and with various objects in view used finer wires and also larger wires up to .02 and even .034 inch in diameter. It is obvious also that tension members other than wire may be employed and that the cross section need not be circular.

I claim:

1. I11 an apparatus of the class described, a lever, means for vibrating said lever, a suitable support, and means for pivotally mounting said lever on said support, said means comprising bearings, one of which is formed with an edge bearing having pivotal contact with the surface of the other bearing on a line at right angles to the plane of the pivotal movement, in combination with wires of great tensile strength secured to the support and engaging said lever symmetrically with respect to the pivotal line and extending in directions adapted to stress said lever against said bearing, and adjustable means for stretching said wires to a tension approaching the limits, of safe elastic stress.

2. In an apparatus of the class described, a lever, means for vibrating said lever, a suitable support and bearings, one of which is a knife or V-edge bearing having pivotal contact with the lever on a line at right angles to the plane of its pivotal movement, in combination with highly tensioned wires secured to the support and engaging said lever symmetrically with respect to the pivotal line and extending in directions adapted to stress the pivotal bearing surfaces into perfect non-slip engagement.

3. In an apparatus of the class described, a lever, means for vibrating said lever, a suitable support and bearings, the latter having straight line elements in pivotal contact with the lever on a line at right angles to the plane of its pivotal movement, in combination with longitudinally lengthened piano wire secured to the support, engaging said lever adjacent said line of pivotal contact and extending in directions adapted to stress the pivotal bearing surfaces into perfect non-slip engagement and means for stretching said wire to a tension approaching the limits of safe elastic stress.

4:. In an apparatus of the class described, a lever, means for vibrating said lever, a suitable support, a solid bearing having line contact with the lever on a line at right angles to the plane of its pivotal movement, in combination with highly tensioned wires secured to said support and engaging said lever symmetrically with respect to the line of pivotal contact and extending in directions adapted to stress said lever against said bearing.

5. In an apparatus of the class described, a lever, means for vibrating said lever, a suitable support, a solid bearing having line contact with the lever on a line at right angles to its plane of movement, in combination with highly tensioned wires secured to said support and engaging said lever adjacent said line of pivotal contact and extending in directions adapted to stress said lever directly downward against said bearing and to aiford balanced lateral stresses adapted to prevent skewing of the lever upon the bearing.

6. A sound box having a diaphragm, a lever secured to the diaphragm, bearings on the box and on the lever having line con tact with each other on a line parallel with the diaphragm and at right angles to the lever, in combination with wires secured to the sound box and engaging the lever from different directions such as will afford tension stresses cooperating to press the lever bearing downward upon the box bearing, but mutually opposed and approximately balanced in other directions, and adjustable means for moving said bearings and lever substantially against the downward pressure to increase the longitudinal tension of the wires and the amount of said downward pressure without substantially disturbing the approximate balance of their tensions in other directions.

7. A sound box having a diaphragm, a lever secured to the diaphragm, bearings on the box and on the lever having line contact with each other on a line parallel with the diaphragm and at right angles to the lever, in combination with resilient tension members secured to the sound box and engaging the lever from different directions such as will afford tension stresses cooperating to press the lever bearing downward upon the box hearing, but mutually opposed and approximately balanced in other directions, and adjustable means for moving said bearings and lever substantially against the downward pressure to increase the longitudinal tens1on of the resilient tension members and the amount of said down ward pressure Without substantially dis turbing the approximate balance of their tensions in other directions.

Signed at Buffalo in the county of Erie and State of New York, this 10th day of June, A. D. 1918.

ELWOOD GRISSINGER.

Images