US1009268A - Piano-playing mechanism and the like. - Google Patents

Description

A. R. TRIST. PIANO PLAYING MECHANISM AND THE LIKE. APPLIOATION'FILEDJAN.5,191&

' Patented Nov. 21, 1911.

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UNITED STATES PATENT OFFICE.

ARTHUR RONALD TRIST, OF LONDON, ENGLAND, ASSIGNOR TO TRIST PIANO PLAYER LIMITED, OF LONDON, ENGLAND.

PIANO-PLAYING MECHANISM AND THE LIKE.

Specification of Letters Patent.

Patented Nov. 21, 1911.

Application filed January 5, 1910. Serial No. 536,535.

To all whom it may concern:

Be it known that I, ARTHUR RONALD Tmsr, a subject of the King of Great Britain and Ireland, residing at London, England, have invented new and useful Improvements in and Relating to Piano-Playing Mechanism and the Like, of which the following is a specification.

This invention relates to piano-playing mechanism and has for its object the provision of means for accentuating certain notes, for example, the melody of the composition being played, and further the construction of the mechanism in a simple and effective manner. The record sheet by which the operation is controlled may be of any form in which specific notes can be defined, so that the note perforations or confacts in the case of electrical operating mechanism control the amount of impact of the striking mechanism of each note respectively.

To carry the invention into effect I arrange the piano-playing apparatus with two systems of air pressure which may be either on a plenum or a vacuum system or a combination of the two, and I arrange two sets of primary valves one set controlled by the tracker mechanism for ordinary notes and the other set by the tracker mechanism for the accentuated notes in conjunction with a record music sheet. In connection with each set of primary valves I arrange a set of secondary valves one set being connected to the high pressure reservoir and the other to the low pressure reservoir.

Both sets of secondary valves are connected to the pneumatic motor elements of the striking mechanism and each said mechanism is providedwith an automatic control or intercepting valve arranged so that when one secondary valve is moved by the air pressure controlled by its particular primary valve, such air pressure operates the intercepting valve and cuts off all communication between the pneumatic motor element and the secondary valve of the other pressure, thus allowing only the particular pressure of air controlled by the primary valve to operate on the pneumatic motor ele ment so as to produce the desired efiect. In this way the pressure of air used is that selected. by the record sheet in operating any high or low pressure primary valve as the case may be.

In order to reduce the volume taken up by the striking mechanism and its various parts, instead of using pneumatics of the ordinary bellows type, I form each motor element as a piston sliding within a cylin der. The whole of the air containing parts of the apparatus are constructed in metal, vulcanite or other impermeable material. To this end I arrange the cylinders of the motor elements in a row along the length of a frame or body and on each side I arrange the high and low pressure secondary valves respectively. In the passage between the said high and low pressure secondary valves leading to the motor element I arrange the intercepting valve which is adapt ed to co-act with two seatings one leading to the high pressure secondary valve chamber and the other to the low pressure secondary valve chamber. It will thus be seen that where one secondary valve say the low pressure, is operated, the difference of pressure set up on the two sides of the intercept ing valve will close the intercepting valve on the seating leading to the high pressure secondary valve and allow the low pressure air to act on the motor element and vice versa.

In order that the invention may be the better understood I will now describe the same in relation to the accompanying drawings, reference being had to the letters and figures marked thereon.

Like letters refer to like parts in the various figures.

Figure 1 is a plan view of the complete action for one note. Fig. 2 is a part sectional elevation on the line 2-2 of Fig. 1, including a diagrammatic representation of the electrical arrangements, circuits, and tracker board in connection with a music sheet.

In order to carry out my invention in reference to the piano-playing mechanism I will describe it in relation to mechanism in which vacua of two different pressures are used and in which one pressure is controlled pneumatically and the other pres sure is controlled electrically.

Referring to Figs. 1 and 2 a is the low pressure vacuum chest and b is the high pressure vacuum chest having secondary valves a Z2 respectively. These valves are controlled in the usual Way by means of primary valves 0 and cl respectively. The valve 0 is controlled by an electrically operated valve 6, while the valve (Z is controlled by the tracker f through the connecting pipe 9 leading to the primary valve (Z of usual construction. Disposed between the secondary valves a b is an intercepting valve in which has two valve faces disposed opposite to one another adapted to bear against the valve seats 7L [1. arranged on the dividing partition if. A passage leads from the secondary valves to the power pneumatic is which is connected to the keys by the usual means Z. The trunks m m are connected with the atmosphere. The music sheet a which may be of the form in which an electrically conducting layer a and pneumatic perforations a are provided, the conducting layer being exposed for certain notes so that electrical contact can be made, thus enabling two different and independent mechanisms to be operated by the control of the music sheet. Above the tracker f is arranged an insulated support carrying a series of brushes 0 one only being shown, and each brush is included in a circuit comprising a source of current 7) and an electromagnetic device 1 adapted to operate the valve 6 through a lever 9 The operation is then as followsz-JVhen during the passage of the music sheet on the tracker f the perforation a uncovers the hole in the tracker the primary valve (Z is actuated and in turn actuates the secondary valve 6 in the usual manner. This action permit-s the difference of pressure set up by the vacuum to act upon the intercepting valve 7L so that it comes off its seat 7L and closes down on the seat 7%, thus putting the pneumatic 76 into direct communication with the high pressure vacuum and causing the note to be sounded loudly. As the movement of the sheet progresses the brush 0 comes in contact with the exposed metallic layer a and completes the electric circuit. This causes the electromagnetic device 9 to open the valve 6 and to admit air to the primary valve 0 which in turn allows the secondary valve a to be operated, and the low pressure vacuum to draw the intercepting valve to the right of the seat It immediatedy the perforation a on the music sheet has passed away from the hole in the tracker f. In this way the note is held on for the required time.

It will be understood that when no perforation occurs in any note on the music sheet but only the metallic layer is exposed, the primary valve 0 and seconardy valve a are the only ones operated in which case the note is sounded with the low pressure vacuum.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is In piano playing mechanism, the combination of pneumatically operated playing mechanism including power pneumatics, two wind chests for different pressure of wind and tracker means and connections for controlling individually the pressure of wind to each power pneumatic by the perforation. in the music sheet, with a set of control valves for each wind chest for controlling the operation of each power pneumatic of the playing mechanism, and a three way check valve disposed between the said two sets of control valves and the power pneumatics constructed to automatically cut olf one pressure supply and put into action the other pressure supply as selected by the music sheet by the direct application of the pressure selected acting upon said intercepting valve, substantially as described.

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

ARTHUR RONALD TRIST. Witnesses:

H. D. J AMESON, T. L. RAND.

Copies of this patent maybe obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. v

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