US1734717A - Automatic piano - Google Patents

Description

Nov. 5, 1929. J. HjmcKlNsoN 1,734,717

AUTOMATI O PIANO Filed Dec. 22. 1922 2 sheets-sheet 1 XII/4 06 75 ATTORNEY 7 I I lfENTOR I w'om 1929- I J. H. DICKINSCN 1,734,717

AUTOMATIC PIANO Filed Dec. 22. 1922 2 Sheets-Sheet 2 INVEVTOR Patented Nov. 5, 1929 UNITED STATES PATENT OFFICE,

J'OSEPH HUNTER DICKINSON, OF LARCHMONT, NEW YORK, ASSIGNOR TO THE AEOLIAN COMPANY, A CORPORATION OF CONNECTICUT AUTOMATIC PIANO Application filed December 22, 1922. Serial No. 608,524.

My present invention relates to improvements in automatic players, includin'gthe socalled reproducing piano, which reproduces the loud and soft expression or dynamic effects of the artist automatically from the music-roll. The means by which I accomplish this is eliective and at the same time relatively simple to manufacture, adjust and keep in order. Said means, embodied in what I have hereinafter called an expression-box, may take a variety of forms, that shown being the embodiment which at present I prefer.

In the drawings, Fi 1 is a longitudinal, vertical cross-sectional view of my improved expression-box in Combination with the related parts of an automatic or player plano, the latter and the interconnections being su'liiciently shown in a merely diagrammatic manner; Fig. 2 is a partial view in plan of the tracker bar of Fig. 1 and the music-sheet; Fig. 8 is a transverse section, partly in elevation, of the valve-box on any of the l1nes 8-3 in Fig. 1 looking in the direction of the :5 arrows; Figs. 4, 5 and 6 relate to the expression-box and are transverse sectional views,

partly in elevation, on the lines 4-4, 5 5

and 66, respectively in Fig. 1, looking in the direction of the arrows, and Fig. 7 is an enlarged sectional view partly in elevation on the line 7-7 in Fig. 1 looking in the direction of the arrows.

Describing now my invention in its setting as shown in the drawings, 1 is the tracker-bar having expression controlling ducts 2 and note-playing ducts 3, of which latter only a few are shown. 4 is the perforated music-sheet having expression controlling perforations 5 and note-playing perforations 6.

7 designates collectively thewell-known v parts of one of the hammer actions of the piano; 8 is the related piano string; and 9 designates collectively a well-known form of valve controlled striker pneumatic action, one for each hammer action of the piano to ac tuate same, said valve being itself controlled in well-known manner from the corresponding note-playing duct 3 of the tracker bar through the diagrammaticallyshown tube connection 10 so that when said tracker duct is closed by the musicsheet, the striker pneumatic is connected with the atmosphere and is expanded and quiescent, whereas when it is opened by the note-playing perforations of the sheet, saidpneumatic is cut off from the atmosphere and connected through the diagrammatically shown tube 11 with the ex hauster through the expression-means (next to be described) and is collapsed and operates the hammer action to strike the piano string and sound the given note.

The force with which the striker pneumatics propel the hammers is determined by the aforesaid expressionbox which in the preferred form shown comprises the following: 12 is a chamber connected with the striker pneumatic action by the aforesaid tube 11, and 13 is a second chamber connected through opening 14c with the exhauster. These chambers are connected with each other by a plurality of ports through the partition separating the two chambers. These ports are designated in the drawings FF (meaning fortissimo), F (forte), MF (mezzo-forte), and P (piano), and PP (pianissimo) because when the FF port, for example, is open it connects the full, untempered exhaust with the striker pneumatic action and the playing is therefore fortissimo; similarly, opening the port F makes the playing forte, and so on with the other ports in accordance with their designations.

Said orts respectively have valves as follows: The valve of the port FF consists of a leather faced disk 15 whose foot 16 is glued to the pouch 17 ofa pouch chamber 18 connected to one of the expression control ducts in the tracker bar through any usual and well known valve means 19 (Figs. 3 and 1) whereby as long as said duct is closed by the music-sheet the aforesaid pouch-chamber 18 is connected with the atmosphere and has its pouch expanded, holding the valve closed against the port FF. Vice versa, as soon as an expression controlling perforation in the music-sheet opens said tracker duct, then the action of the valve means is reversed in well known manner, disconnecting the afore said pouch-chamber from the atmosphere for operation.

and connecting it with the exhaust so that the pouch collapses and pulls the valve away from the port FF, and thereby throws the full exhaust on the striker pneumatic action for fortissimo playing.

The valve is guided in its movement to and away from its port FF by four equally spaced pins surrounding it, only two of which, are shown in the drawings.

The valves of the ports F, MF and P, the guide pins, and the operating pouches are all the same as just described in. connection with the port FF, the only differences being that the valves for the ports F, MF and P are not glued or otherwise secured to their respective pouches; and furthermore are yieldingly held toward their ports by tension springs 22.

The respective pouch-chambers for the ports F, MF and P are operatively connected with the expression controlling tracker bar ducts 21, through the valve means 19 in an exactly similar way to that described in connection with the pouelrchamber 18 for the port FF, it being understood that each of said pouch-chambers for FF, F, MF and P is thereby connected through it own valve means with its own expression controlling tracker duct for independent operation and control from the music-sheet expression con trolling perforations.

The aforesaid tension springs 22 for the Valves of the ports F, MF and PPP are large diameter coiled springs which connect eyes 23 onthe valves with eyes on the ends of threaded rods 24 passing through holes in the cover of the chamber where they are each provided with a leather washer and nut.

The'design and adjustment of these springs is such that the spring for F is weakest, that for MFis stronger, that for P is stronger still, and that for the valve controlling the port PP is strongest of all.

The valve for the last named port PP dif fersfrom the others in not having any foot portion or any pouch chamber for operating it. Thus, this is the only valve of the series which is not controllable from the music-sheet but on the contrary is always normally ready This means that the instrumentplays normally soft when none of the expression ducts in the tracker bar is open.

The operation is as follows: \Vhen the exhauster is in operation with the music-sheet travelling across the tracker bar, all noteplaying perforations registering with the tracker bar ducts will sound their notes pianissimo if they have no expression controlling perforations adjacent their front ends in the music-sheet. This will be so because, when there are no expression controlling perforations, the music-sheet will seal all four of the expression ducts of the tracker bar. Therefore, all'of the valves 33 will be downso to admit atmosphere toall of the pouch chambers 18 which will, therefore, be expanded as shown in the drawings, causing their controlled valves to be seated positively against all the ports FF, F, MF and P. Therefore, the air from the striker pneumatic action must exhaust through the port PP past the valve of said port. But this is the valve having the strongest spring tension against opening and therefore all striker pneumatics in operation at this time will collapse with minimum force and operate their hammer actions pianissimo.

All succeeding music perforations will continue to play pianissimo until an expression controlling perforation uncovers one of the expression controlling tracker ducts 2. If this uncovered tracker duct be the one con nected with the pouch chamber of the port P, then the uncovering of said tracker duct will operate the related valve means 33 in well known manner to cut off the atmosphere from said pouch chamber and to connect the exhaust therewith, whereupon said pouch will collapse and leave the valve of said port P free to operate. This valve having a weaker spring tension than the valve of the port PP, the air from the striker pneumatic action will now exhaust through port P by opening its valve against said weaker spring tension. Therefore, the striker pneumatics then in play will sound their notes piano or somewhat louder than the playing when the exhaust took place through the port PP.

In exactly the same way, if an expression controlling perforation in the music-sheet uncovers the tracker duct connected with the pouch chamber of the port M'F, then said pouch will collapse and release the valve of said port MF into action, and because this valve has only a mezzo-forte spring tension, which is less-than the tension of the valves on the ports P and PP, the air from the striker pneumatics will be exhausted only past said MF valve and the playing of the striker pneumatics then in action will be mezzo-forte.

The same applies to an uncovering of the tracker duct connected with the pouch chamber of the port F. Releasing into action of the valve of this port causes the air from the striker pneumatic action to exhaust past the valve of this port and to play forte because its spring tension is the weakest of all.

The valve controlling the port FF has no spring opposing its opening and, therefore, when its pouch chamber is collapsed by an expression controlling perforation in the musicsheet registering with the related tracker duct, said valve is completely unseated from the port FF and the full exhaust acts directly on the striker pneuinatics then in play, causing them tosound their notes fortissiino.

The coils of the tension springs are purposely made large in diameter because I have discovered that by so doing I can make the tensioned valves maintain thegiven degree of loudness or softness unchanged irrespective of thefnumber of striker pneumatics in action, whether one only or any increased number up to the maximum ordinarily required to be operated simultaneously I in reproducing hand-played pianoforte compositions. When many striker pneumatics are in simultaneous action at PP, P, MF, etc., it means that pro portionately more air mustbe passed by the given valve than'if only one striker pneumatic werein action.' This in turn means that the given valve must momentarily move further away fromits port PP or P, etc., but this would increase the tension of the springs and change the dynamics of the playing if the coils were small in diameter instead of relatively large, as I make them. In short, the advantage of the large diameter springs is that they do not substantially change their tension on the valves when the latter open to a greater or less distance to accommodate for the passing of a greater or less volume of air according to the number of striker pneumatics in simultaneous action.

The valve means 19 heretofore referred to between the expression controlling tracker ducts and the pouch chambers of the valves controlling the ports P, MF, F and FF, be ing so well known in this art need not be described. However, for those not skilled in the art it may be briefly said to'comprise four valve units. all alike, mounted in a box as shown in Fig. 1 (plan view) and Fig. 3 (transverse'section). The chamber within the box is permanentl connected with the exhauster. 2G-26 are saucer-shaped metal members mounted as shown in pairs in the mouths of holes through the top of the valve box. The bottom of each saucer-shaped member has a hole or port through it which alines with the port through the other member of the pair. The upper ports 31 connect with the atmosphere and the lower ports 32 with the exhaust in the chamber.

For each pair of ports there is a valve 33 located between said ports on a valve stem .84 having a foot portion resting on a pouch covering a chamber 36 in the bottom board of the box. Each of said pouch chambers is connected by a duct 37 and a tube 88 with one of the expression controlling tracker bar ducts. Each is also permanently connected wiih the exhaust chamber by a small so-called bleed opening 40. Each hole 30 through the top board between the ported members 2626 is connected by a duct 39 and a tube 21 with one of the pouch chambers 18 controlling the valve of one of the ports P, MF, F or FF.

The operation of the described valve means is well understood by those skilled in the art. The exhaust in the chamber 25 acting through the bleeds 4:0 exhausts the pouch chambers 36, the ducts 37 and the tubes 38. This is their normal condition while the music-sheet seals the expression controlling tracker ducts. The

pouches are therefore collapsed with the valves 33 sealing the exhaust ports 32 and opening the atmosphere ports 31 so that atmosphere is on the pouch chambers 18 re lated to the ports P, MF, F and FF of the expression box, keeping said pouches raised as shown in Fig. 1.

Should now an expression controlling perforation or perforations in the music-sheet uncover one or more of the expression tracker bar. ducts, then atmosphere will rush into the given tube 38, duct 37, and pouch chamber 36 and will lift said pouch and its valve, thereby sealing the latter against its atmosphere port and opening its exhaust port 32 so that now the related pouch chamber in the expression box is connected with the exhaust and its pouch therefore collapses, and depending upon which pouch chamber is connected, either releases for action the valve or valves of the related ports P, MF, F or opens the valve of the port FF.

The expression means has been so far described as being controlled automatically from the music-sheet but it can also be manually controlled. One form of said manual means is shown in plan view at L1 in Fig. 1 and in section in Fig. 7. The device comprises a block having ducts 42 connected by tubes 143 respectively with the tubes 38, said ducts at their other ends opening through the bottom of the block as shown in Fig. 7. The ports thus formed are kept normally closed by valves 43 on leaf-springs 44 secured at 4.5 to the block. Each of the four leaf-springs has an attached button 46 which projects loosely up through a hole in the block. Thus, the operator can manually depress any of these buttons 46 at will to open the corresponding valve 43 and duct 42 so that atmosphere will be admitted to the corresponding tube 38 Fig. 1) with the same operative consequences as if the corresponding expression tracker duct had been opened by an expression perforation 5 of the music-sheet.

hat I claim is:

1. In combination with the tracker bar, the striker-pneumatic action and the exhauster of an automatic piano, an expressionmeans comprising two noncollapsible chambers respectively connected with the strikerpneumatic action and the exhauster, said chambers being connected by a plurality of ports, valves for said ports in the chamber connected with the exhauster, and springs having graded tensions arranged to actuate said valves yieldingly to said ports.

2. In combination with the tracker bar, the striker-pneumatic action and the exhaust-er of an automatic piano, an expression-means comprising two non-collapsible chambers respectively connected with the striker-pneumatic action and the exhauster, said chambers being connected by a plurality of ports, valves for said ports in the chamber connected with the exhau'ster', springs having graded tensions arranged to actuate said valves yieldingly to said ports, and means for individually controlling said valves to put same into and out of action.

3. In combination with the tracker bar, the striker-pneumatic action and the exhauster o1 an automatic piano, an expression-box comprising two non-collapsible chambers respectively connected with the striker-pneuinatic action and the exhauster, said chambers being connected by a plurality of ports, valves for said ports in the chamber connected with the exhauster; and means for yieldingly actuating said valves to said ports with different pressures for the difierent valves.

l In combination with the tracker bar, the striker-pneumatic action and the exhauster of an automatic piano, an expressionbox comprising two non-collapsible chambers respectively connected with the striker-pneumatic action and the exhauster, said chambers being connected by a plurality of ports, valves for said ports in the chamber connected with the exhauster; and means for yieldingly actuating said valves to said ports with d1 r'erent pressures for the different valves, and means for individually controlling said valves to put same into and out of action.

5. In combination with the tracker bar, the strikerpneumatic action and the exhauster 01" an automatic piano, an expression-box comprising two non-collapsible chambers respectively connected with the striker-pneuniatic action and the enhauster, said chambers being connected by a port; a valve for said port in the chamber connected with the exhauster; a spring arranged to actuate said valve yieldingly to its port; and means for controlling said valve to put it into and out of action.

6. In combination with the tracker bar, the striker-pneumatic action and the exhauster of an automatic piano, an expressionmeans comprising two non-collapsible chambers respectively connected with the strikerpneumatic action and the exhauster, said chambers being connected by a port; a valve for said port in the chamber connected with the exhauster; a coiled spring arranged to actuate said valve yieldingly to its port, the diameter of said spring being relatively large so that its tension does not substantially change with the valve opening a greater or less distance regardless of the number of striker-pneumatics normally in action; and.

means for controlling said valve to put it into and out of action.

7. In combination with the tracker bar,. the striker-pneumatic action and the exhauster of an automatic piano, an expression-box comprising two non-collapsible chambers respectively connected with the striker-pneumatic action and the exhauster, said chambers being connected by a plurality of ports, a valve from one of said ports controlled from the tracker bar for connecting the exhauster directly with the striker-pneumatic action for loud playing, graded spring tensioned valves for the rest of said ports in the chamber con nected with the exhauster, and means for selectively controlling said valves to put same into and out of action with the exception of one valve having the strongest spring tension which is not so controlled and is always ready for action.

8. In combination with the tracker bar, the striker-pneumatic action and the exhauster of an automatic piano, an expression-means comprising two non-collapsible chambers respectively connected with the striker-pneumatic action and the exhauster, said chambers being connected by a port; avalve for said port; a coiled spring arranged to actuate said valve yieldingly to its port, the diameter of said spring being relatively large so that it's tension does not substantially change with the valve opening a greater or less distance regardless of the number of striker-pneuniatics normally in action.

9. In combination with the tracker bar, the striker-pneumatic action and the exhauster of an automatic piano, an expression-box comprising two non-collapsible chambers respectively connected with the striker-pneuniatic action and the eXha'uster, said chambers being connected by a port a valve for said port; means for yieldingly actuating said valve to its port; and means for controlling said valve to put it into and out of action.

In: testimony whereof, I have signed my name to this specification, this 20th day of December, 1922.

JOSEPH HUNTER DICKINSON.

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