US785191A - Gramophone-record. - Google Patents

Description

No. 785,191. PATENTED MAR. 21, 1905.

H. S. BERLINER.

GRAMOPHONE RECORD.

APPLICATION FILED DBO.1, 1904.

UNITED STATES Patented March 21, 1905.

PATENT O FICE. A

eRAMoPHoNE-REcoRD.

SFECIFICATION forming part of Letters Patent No. 785,191, dated March 21, 1905.

Appl ati n fil d December 1,1904. Serial No. 235,067-

To all whom it concern: Be it known that I, HERBERT S. BERLINER,

a citizen of the United States, and aresident' of Washington, in the District of Columbia, have invented certain .new and useful Improvements in Gramophone-Records, of which the following is a specification.

My invention has reference to improve-' ments in gramophone sound-record tablets, and .is designed to overcome the gradual weakening and muffling' of the reproduction from any individual gramophone-record as the reproduction proceeds from one end of the record-groove to the other.

It is a common experience that when the reproduction from a gramophone-record is started the sounds emitted by the reproducer are full, clear, and loud and that as the reproduction continues, whereby the reprod ucing-style engages successive portions of the recordgroove, the reproduction becomes weaker and ever weaker as the end of the record is more and more approached. I have found that this lack of uniformity of the loudness and clearness of repr'oduction'is due to two causes,

which I will presently eXplain.-.

Gramophone-records are sinuous grooves produced inthe surface of a flat disk of hard I resisting material in a spiral which, beginning near the edge of the disk, gradually approaches the center thereof, so that the convolntions become gradually smaller as the end of the record is approached. In the act of recording the disk upon which the'record is made -isrotated with uniform velocity, -from which it follows that the surface speed of the-disk under the recording-style is greatest at the be-' ginning of the record and gradually diminishes and is smallest at the end of the record.

It follows also from this that any given sound will be represented on the record by the same number of undulations on all arcs of the spiral that are measured by the same angle from the center. Thus, for instance, if on anarc of, say, ten degrees on themnermost spiral there are, say, one hundred undulations for a'glven sound sound. In other words, the same angular meas-.

" reproduction is more perfect when the record disk moves 'at that higher surface speed under 7 the reproducing-style. As a consequence of this and since in reproducing the record-disk is again moved with uniform angular velocity from beginnning to end the reproduction at the beginning will be the loudest and clearest and will gradually weaken and become more indistinct as, the convolutions of the spiral under the style become smaller toward the end of the record. Another and still more powerful cause for the weak and indistinct reproduction obtained fromthe end part of the record is found in the fact that 'owing to the hard resisting material .of the disk .the reproduc ing-style isground off by the record-groove, so that a tongue is formed at the point of the style. groove rather snugly; butas the reproduction continues it becomes thinner and does not till the groove any more, whereby lost motion of the style and diaphragm is experienced. Now in the ordinary gramophone-record these two causes conspire to make the reproduction weaker and more indistinct toward the endot the record, for the reproducing-style which has been ground off and which thus becomes This tongue when firstformedlits the mutilated by the first and better part of the record has now to reproduce from the poorer part of the record. As a consequence of all this it has been found impracticable to make a record-groove of much greater length than is.

now ordinarily made, and particularly has it been found impracticable to continue the record-groove as close toward the center of the disk as might be done if the stylewere not ground off by the first and betterpart of the record-groove and if the decreasing diameter of the spiral toward the center did not result in a'weaker and less distinct record. By my invention this imperfection in gramophone reproduction is largely overcome, and the in 'vention broadly consists in agramophonethis construction reproduction is obtained by bringing the reproducing-style into engage ment with the inner end of the spiral at the start and then propelling it and its reproduc'erhead or sound-box gradually outwardly until the outer end of the spiral is reached. By this mode of reproduction, which follows of necessity from the new mode of recording, the new style'primarily engages the poorer part of the recordt hat part which is unavoidably the less perfect. :The needle is then gradually ground off at its point into a tongue by the hard resisting material of the disk, and the more it is ground ofl that is to say, the more the needle becomes deteriorateditengages gradually the more and more perfect part of the record-namely, the part which is inscribed in the-spiral of the greater and greater diameter. It will be seen from the foregoing that while in reproducing from the ordinary .gramophone-record tablet the style when in its best condition engages the--best part of the record and when in its poorest condition engages the poorest part of the record, with my invention the style when in its best condition e'ngages the poorest part of the record and when i in its poorest condition engages the best part of the record. At first sight it would seem that by thisarrangement the improvement of reproduction from the parts of the spiral of smaller diametersecured by my 'mventionis in a manner counterbalanced .by the weakening of the reproduction from'the parts of the spiral which has the greater diameters. This, however, is not the case, since the part of the record inscribed on the spirals of larger diameter will be reproduced by a style which has been ground ofi almost, if not quite, as wellas if the style were quite new and had .not been ground off, so that-as a matter of fact by my improvement the reproduction not only becomes uniform, but it becomes uniformly good.

The accompanying drawing, which forms a part of this specification, shows a diagram illustrating my improved construction of gramophone-record tablet.

On the ordinary .gramophone-record disk thesound-groove starts near the edge of the plate and continues in a spiral line in a counter-clockwise direction toward the center of the disk, and the record terminates with or near the inner end of the spiral. In reproducing from-such record the reproducing-style is brought into engagement with. some part .of' the outer turn of the spiral groove, and the rec:

trail in the record-groove.

ord-disk is rotated in the clockwise direction. I

As is Well known, the style, with the sound-. box on which it is mounted, is propelled by the record-groove itself inwardly across the record-tablet, and thereby its point comes successively in engagement with allparts of the record. I

In my improved gramophonerecord disk 1 the record-groove starts or may start with or in the first innermost turn of the spiral groove 2, and this spiral continues outwardly counter-clockwise and terminates with .or in the last outer turn of the spiral. In reproducing from this plate the style 3' is at the start placed in engagement with some part of the inner spiral, and the plate is rotated, as in the machines now on the market, in the direction-of the arrow namely, clockwise. It will be seen from this that my improved gramophone-rec ord tablet may be used with the ordinary ,gramophone-reproducer machine now on the market.

In reproducing from any gramophone-rec- 0rd tablet the style must incline at an acute angle to the plane of the gramophone-diskin the direction opposed to that of the movement of the disk, so that thepoint of the style may By reference to the drawing it will be seen that-with the record-groove constructed in accordance with'my invention the inclination of the reproducingstyle will bep'recisely the same as that in the old form of ,gramophone-record, so that no changewhatever has to be made in theordi- .nary' gramophone reproducing machine to adapt it for use With my improved record-tablet, ,so long as the precaution is observed to place the style in engagement with the recordgroove on the same side of the centerof the disk as is now done with the ordinary recordtablet.

proceedscounter': clockwise from the outer turn inwardly in myimproved tablet the-record-groove proceeds spirally counter-clockwise from the inner turn .ofthe spiral ou't-' wardly. I I x I am of course not limited to this particular arrangement of the spiral, for I may just as well make the record-groove to proceed from the inner turn outwardly in a clockwise direction; but in that, case either the direction of rotation of the disk in the act of reproducing or both the direction of rotation of the disk and .the direction of inclination of the style have tobe changed, so that the ordinary reproducing apparatus wouldh'ave to be modi= tied to adapt for use with my improved record-tablet. p I

Ha'ving'now fully described my invention, I claim and desire to secure by Letters Patent- 1. Agramophone record tablet having a sound-record groove progressing spirally outwardly, substantially as described. 2. A gramop'hone-record tablet composedp This is due to the fact that whereas the record spiral in the old gramophone-disk of a disk of hard resisting material having a sound-record groove progressing spirally outwardly, substantially as described.

3. A gramophone-record tablet having a sound-record groove progressing-spirally out 'wardly in counter -clockwise direction, substantially as described.

4t. A gramophone-record tablet having a sound-record groove progressing spirally outwardly and having for the same sound the same number of undulations in the same angular measure of arc of the splral, substantially as described.

same number of undulations in the same angular measure of arc of the spiral, substantially as described. p

6. A gramophone-record tablet having a sound-record groove progressing spirally outwardly in counter-clockwise direction and having for the same sound the same number of undulations in the same angular measure of arc of the spiral, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses. a

HERBERT S. BERLINER;

VlKitnesses:

F. T. CHAPMAN, EDWIN S. OLARKSON.

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