US1090050A - Mechanical piano-player and like instrument. - Google Patents

Description

W. H. GRIMSDALB, MECHANICAL PIANO PLAYER AND LIKE INSTRUMENT.

APPLICATION FILED OCT. 31, 1912.

Patented Mar. 10, 191 i five x257 20 keys are actuated.

' To all whom it may concern Be it known that I,

UNITED STATES PATENT OFFICE.

WILLIAM HENRY GRIMSDALE,

OF TWICKENHAM, ENGLAND, ASSIGNOR TO GRIMS- DALES PATENTS ILIMITED, OF LONDON, ENGLAND.

' nism the strength with which the several keys of the piano or the like are struck corresponds with the areas respectively of the air passages through the music sheet into the tracker bar apertures, through. which the In the British Specification No. 4942 of 1908, I have described the application of dampin devices whereby the varying areas of the air passages through the music sheet are made effective in producing "varying strengths of blow on the keys of the piano or the like, said damping devices consisting for each note of a variable capacity chamber or damping pneumatic mechanically connected to the stri connected to an aperture in the tracker board, the usual aperture being also provided in the tracker bar for the purpose of actuating the key striking pneumatic through" relays in the usual manner; The trackerbar aperture which is connected to the damping pneumatic is placed just in front of-the usual aperture, so that a perforation of the music sheet traveling over the tracker bar first opens the'aperture in connection with a damping pneumatic, and be.- fore this is closed, opens the aperture operating the key striking mechanism. Asthe striking pneumatic collapses, it extends the damping pneumatic, which draws air in through the tracker bar aperture connected therewith, a perforation of large area allowing the damping pneumatic to extend more easily than a. small perforation, and thus varying the'strength of blow on the key. I have found that this method of varying the strength of the blow on the key is satisfactory, provided the size and pitch of the tracker bar apertures are such as to allow Specification of Letters Patent.

Application filed dctober 31,1912. Serial No. 728,826.

ing pneumatic and pneumatically MECHANICAL PIANQ-PLAYER AND LIKE INSTRUMENT.

Patented Mar. 10,1914.

for perforations in the'music sheet, having perforations in the music sheet.

The invention consists in providing an air chamber in pneumatic connection with the damping pneumatic, such chamber being provided with a valve operated pneumatically from the tracker bar, and when opened adapted to connect the damping pneumatic through the chamber with the atmosphere.

The invention further consists in provid-' ing an air chamber in pneumatic connection with the damping pneumatic, and having an aperture to atmosphere, on the outside of which is a valve operated by a pneumatic in the chamber, such pneumatic being connectfed to the damping aperture in the tracker bar, a bleed hole being provided leading from the passage connecting the pneumatic and tracker bar into the air' chamber.

The invention further consists in providing each damping pneumatic with a valve opening to atmosphere, and controlled by hand, so that the retarding 'efi'ect of the damping pneumatic can .be varied as desired. The control of the hand operating valve niay be separate for each note, or groups of notes, or a single control may be used for all the notes,-as desired.

Referring .to the accompanying drawings-Figure 1 is a section of mechanism for actuating one of the keys of the piano; Fig. 2 is a plan showing a hand-control; and Fig. 3 shows a portion of the music sheet used with the apparatus.

In the form of the invention shown in the figures the tracker bar a is provided with the usual apertures 6 leading to *the pneumatics 0, d, controlling the strikin pnoumatics e, and in close proximity and in front of each of the apertures b in the tracker bar is an aperture f leading to the pneumatic g, which controls the valve h bywhich air can be admitted through an air chamber A to the damping pneumatic Z on the correspondingnote-playing pneumatic c. The damping pneumatic Z. may be provided with an outwardly opening flap valve m to allow quick variably admit air to open the valves 72. when it is desired to sound a louder note independently of' the size of the perforation over the aperture f. If the pneumatics g and the valves h are correctly proportioned the lift of the valves Ii vTill vary with the variation of the opening of the apertures 0 in the bar 9%,

resulting with small perforations over theapertures f in variation of the strength of notes to any degree from the softest to. the loudest.

The action of the apparatus is as follows:-With a narrow perforation over the damping aperture f, when the key-striking pneumatic e is actuated, the damping pneumatic Z is extended, and forms a vacuum .or partial vacuum in the air chamber k. There is also a small pressure in the pneumatic g in the air chamber, because owing to the small perforation over the aperture, the air in this pneumatic is exhausted through the bleed hole 9 as fast as it enters from the tracker .bar f, and consequentlythere is not sufiicient thrust on the'valve k to open it against the pressure of the atmosphere,

which tends to keep it closed. It follows therefore that the only way in which air;

can enter the damping pneumatic Z is through the perforation and tracker bar aperture f and through the bleed hole 9 in series with it, resulting in a large amount of resistance to the extension of. the damping pneumatic Z, so that a soft note is produced. If, however, there is a wider perforation over the damping aperture f, the pressure in the pneumatic g situated 1n the air chamber will be greater, and the bleed hole 9 can he so proportioned that the pressure in the pneumatlc will be suflicient to open the valve it against .the atmospheric pressure, and so open the damping pneumatic direct to atmosphere, with the result that there is a small resistance to the extension of the damping pneumatic, and a loud note is produced. a

By providing a bleed hole g of suitable size, sufiicient pressure can be attained in the pneumatic g to open the valve h to atmosphere by a 'very small increase in width of the perforation. It is desirable but not necessary to provide an adjustable v bleed hole, so that each note can be adjusted individually. I "It will be readily seen that by opening, partially closing or closing the manually controlled valves leading to the damping pneumatics Z, or the apertures in the bar '22, the operator, when playing, 1 can render notes represented by narrow perforations with any degree of strength between the softest and loudest notes, so that for instance in playing a piece of music in which the air or melody is represented by wide perforations, and the accompaniment notes by narrow perforations, it is possible to vary the-latter to any degree between the softest and loudest notes.

' Having now described my invention, what I claim as new and desire to secure by Letters Patent is 1. In a mechanical player, in combination, a striking pneumatic for causing a note to be sounded, a variable capacity chamber connected to said striking pneumatic, an air chamber in communication with said variable capacity chamber, an opening leading from said' air chamber to atmosphere, a valve controlling said opening, a tracker bar, two apertures in said tracker bar for each note, said apertures being in the line of travel of the music sheet, a vacuum chamber, a valve between said striking pneumatic and said vacuum chamber, a pneumatic controlling said valve, one of the said apertures in said tracker bar being in communication with said pneumatic controlling said last mentioned valve, means for controlling said opening and a passage from said second aperture in said tracker bar to, said controlling means as set forth.

2. In a mechanical piano player, in combination, striking. pneumatics for causin a note to be sounded, a variable capacity chamber connected to each of said striking pneumatics, an air chamber in communication with said variable capacity chamber, an' opening leadin from each of said air chambers to atmosp ere, a valve controlling one of said openings, a tracker bar, apertures in said tracker bar, a pneumatic in said air o chamber controlling said valve, and a pas sage leading from said apertures in said pneumatic 1n said air tracker bar to said chamber, as set forth.

3. In a mechanical piano player, in combination, striking pneumatics for causing a note to be sounded, a variable capacity chamberconnected to each of said striking pneumatics, an air chamber in communication with said variable capacity. chamber,

an opening leading from each of said air chambers to atmosphere, a valve controlling one of said openings, a tracker bar, apertures in said tracker bar,a pneumatic in said air chamber controlling said valve, a

passage leading from said aperture in said tracker bar to said pneumatic in said air chamber, and a bleed hole leading from iaidhchamber into said air chamber, as set ort 4. In a mechanical piano player, in combination a striking pneumatic for causing a note to be sounded, a variablev capacity chamber connected to said striking pneumatic, an air chamber in communication with said Variable capacity chamber, an opening leadingfrom said air chamber to atmosphere, a valve controlling one of said openings, a tracker bar, an aperture in said tracker bar for each note, a pneumatic in said air chamber controlling said valve, a passage leading from said aperture in said tracker bar to said pneumatic in said air chamber, a bar, an aperture for each note in said bar leading to said valve actuating 15 WILLIAM HENRY GRIMSDALE.

Witnesses:

BERTRAM H. MA'rrHEws, W. T. SWERTEN.

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