US1732879A - Automatic piano - Google Patents

Description

1929- J. H. DICKINSON AUTOMATIC PIANO 4 Filed Dec. 22, 1922 m [Jig/(240 A TTORNE Y \w E III" MW Q sectional view, partly in elevation,

2-4 in Fig. 1 looking in Patented Oct. 22, 1929 UNITED STATES PATENT OFFICE JOSEPH HUNTER DICKINSON, OF LARCHIIIONT, NEW YORK, ASSIGNOR TO THE AEOLIA'N COMPANY, A CORPORATION OF CONNECTICUT AUTOMATIC PIANO Application filed December 22, 1922. Serial No. 608,525.

My present invention relates to improvements in automatic players including the socalled reproducing player piano which reproduces the loud and soft expression or dynamics effects of the artist automatically from the music-sheet. The means by which I accomplish this is effective and at the same time has the advantages of relative simplicity. My said improved expression controlling means may take a variety of forms, that shown being the embodiment which at present I prefer.

In the drawings, Fig. 1 is a vertical crossof my improved expression means in combination with the related parts of an automatic player for a piano, the latter and the interconnections being sufficiently shown largely in a merely diagrammatic manner, together with a fragment of a perforated music-sheet adapted for use in connection with my improvements; Fig. 2 is a transverse section, partly in elevation, on either of the lines the direction of the arrows the punch being shown collapsed with the valves in their down position; and Fig. 3 is a top plan view of the expression means, said view being taken as if looking down on top of the corresponding device shown in Fig. 1. Fig. t is a sectional detail.

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 some are shown. 4 isthe perforated musicsheet having expression controlling perforations 5 and note-playing perforations 6.

7 designates collectively the well known 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 actuate same, said valve being itself controlled in well known manner from the corresponding note playing duct 3 of the tracker bar through the diagrammatically shown tube connection 10 so that when said tracker duct is closed by the music-sheet, the striker pneumatic is connected with the atmosphere and has three leaves is expanded and quiescent, whereas when it is opened by the note-playing perforations in the music-sheet, said pneumatic is out off from the atmosphere and connected through the diagrammatically shown tube 11 with the exhauster through the expression means (next to be described) and is collapsed and operates the hammer action to strike the piano string and to sound the given note.

The force with which the striker pneumatics propel the hammers is determined by the aforesaid expression means which, in the preferred form shown, comprises the fol lowing: 12 is a chamber connected with the striker pneumatic action by the aforesaid tube 11; and 13 is a second chamber connected through the opening 1 1 with the xhauster. These chambers are connected with each other by a hole 15 through a partition sep arating the two chambers.

16 is a leather-faced disk in the chamber connected with the exhaust constituting a valve for the mouth or port of the hole 15. Said valve is pulled yieldingly towards said port by a large diametered coiled tension spring attache at one end to the center of the valve and at the other end to an eye on a rod 17 which passes with sliding it through preferably a leather bushed hole 18 through the top of the chamber 12. V

The free end of said rod outside said chamber is screw-threaded and passes through a hole in the cross piece of a U-shaped metal bracket 19 screwed to one end-board or leaf of an accordion bellows 20. Two leather nuts 21 on said screw-threads adjustably secure the rod 17 to the. said bracket and accordion bellows. The other end leaf 22 of the accordion bellows is secured by screws (Figs. 3 and 1) to the cross-piece of another larger U-shaped metal bracket 23 whose free ends are secured by screws 2st to the sides of the chamber 12 (Fig. 3).

The particular accordion bellows shown 25 intermediate its aforesaid end leaves. Said five leaves are spaced apart as shown in Fig. 1; and air-tight fabric 26 is glued to all the edges of the leaves so that the accordion bellows has four independently collapsible pneumatic compartments 27 to 30 inclusive.

31 designates nipples connected with ducts 32 in four of the aforesaid accordion bellows leaves, leading each to the interior of one of the compartments 2? to 30 of said bellows.

Said four accordion bellows compartments are connected respectively to the four expression controlling ducts 2 in the tracker bar through any usual and well known valve means 33 of which there are four units, one for each related tracker duct and accordion bellows compartment, whereby preferably as long as said ducts are closed by the musicsheet, said compartments are connected to the exhaust and are all collapsed, this being preferably their normal condition so that the instrument normally plays pianissimo when there are no expression controlling perforations adjacent the note perforations being played.

Vice versa, if all of said expression tracker ducts 2 are open, which is the condition shown in Fig. 1, then the action of the valve units is reversed in well known manner, re-

sulting in disconnecting all of the accordion bellows compartments from the exhaust and connecting them with the atmosphere so that all of said compartments expand away from the fixed leaf of the bellows, thereby relaxing all pull on the spring 34 and reducing its tension on the valve to that of only the spring itself which, it will be seen later, produces fortissimo playing.

The four valve units 35 referred to are all alike and are mounted in the box 33 as shown in Fig. 1 (plan view) and Fig. 3 (transverse section). Being standard construction, they need scarcely be described, but for the benefit of those unskilled in the art it may be stated that the chamber 36 within the box is permanently connected at 37 with the exhauster. There are four holes 38 through the cover of the box. Four ducts 39 in said cover connectrespectively with these holes and at their other ends connect respectively with the ducts 31 leading to the four accordion bellows compartments. 40 is a valve stem in each hole 38 supporting a pair of valves, one valve 35 controlling the outside or atmosphere mouth or port of the hole, and the other 35' controlling the inside or exhaust mouth or port of said hole.

The valves are spaced far enough apart so that only one can be in action at one time.

Each of said valve stems has a foot 41 rgsting on a separate pouch 12 covering its own pouch chamber 43 in the bottom board of the box. Each of said pouch chambers is connected by a duct 44 and tube 415 with one of the expression controlling tracker bar ducts 2 as in Fig. 1. Each is also permanently connected with the exhaust chamber by a small so-called bleed opening 46.

The operation of the aforesaid standard valve means is well understood.

Obviously, through said valve means the accordion bellows compartments can be collapsed or expanded from the tracker bar expression ducts controlled by the music-sheet so that all of the compartments can be collapsed or expanded either simultaneously or seriatim, or they may be collapsed or expanded in various combinations and permutations of any one, any two, or any three compartments, etc.

in fact, there are fifteen different permutations possible with the accordion bellows shown whose four compartments 27, 28, 29 and 30 have respective distances of collapse which have the same relations to one another as the Figures 1, 2, 4 and 8.

The foregoing gives fifteen different ex tents of collapse of the accordion bellows as a whole or as an entirety, which in turn means that fifteen different tensions can be given to the spring 34 and to the valve 16 to which it is attached.

This makes possible fifteen different de grees of dynamics playing effects because these vary with the tension of the spring. The greater the spring tension, the softer the playing, and vice versa.

Fifteen different combinations of expression controlling perforation 5 are shown in the nnisic-sheet of Fig. 1 to give said fifteen degrees of dynamics. To these is added still another degree which is the normal or pianissimo ell'ect heretofore referred to as being the condition when. there are no expression controlling perforations at all adjacent the note-sounding perforations 6, at which time it will be recalled that all the accordion bellows compartments are collapsed and the spring 34 and valve 16 are put under maximum tension.

Maximum tension of said spring makes the instrument play pianissimo because the air from the striker pneumatic action can only exhaust with maximum diliiculty through the hole 15, past the valve 16, due to the fact that the resistance of said valve to being opened is maximum and therefore all the striker pneumatics in operation at that time will collapse with minimum force and operate their hammer actions pianissimo.

Thus, assuming that the exhauster is in operation with the music-sheet travelling across the tracker bar, the first row of note-sounding perforations 6 would play pianissimo when they reach their tracker ducts. The succeed note perforations would play increasingly louder in a rapid crescendo which reaches fortissimo at the last note perforation shown on the sheet, the expression controlling perforation having been purposely arranged, as shown, to produce said effect. Ob 'iously, they can, and will be in practice, arranged to produce all possible dynamics effects as called for by the composition as written or played.

Four expression perforations 5 in a row produce fortissimo because they operate their respective valve means 35 to connect their respective accordion bellows 2O compartments with the atmosphere so that the accordion bellows is fully expanded, and therefore the spring tension on the valve 16 is minimum, which means that the air from the striker pneumatics can exhaust most easily past said valve because of said minimum spring tension, and therefore all the striker pneumatics in operation at that time will collapse with maximum force and operate their hammer actions fortissimo.

Between no expression perforations at all in the music-sheet and said full row of four of said perforations, there is the entire intermediate series of combinations shown in the music-sheet of Fig. 1 which produce the same number of different extents of collapse of the accordion bellows, and therefore eon respondingly 'diiferent degrees of playing effects graded about equally apart between pianissimo and fortissimo.

The valve 16 is guided in its movement to and away from its port by four equally spaced pins 47 surrounding it, only two of which are shown in the drawings.

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 48 in Fig. 1, and in section in Fig. 4. The device coniprises a block having ducts 49 connected by tubes 50 respectively with the tubes 45, said ducts at their other ends opening through the bottom of the block as shown in Fig. 4. The ports thus formed are kept normally closed by valves 51 on leaf-springs 52 secured at 53 to the block. Each of the four leaf-springs has an attached button which projects freely up through a hole in the block. Thus, the operator can manually depress any of these buttons 54 at will to open the corresponding valve 51 and the duct 49 so that atmosphere will be admitted to the corresponding tube 50 (Fig. 1) with the same operative consequences as if the corresponding expression tracker duct 2 had been opened by an expression perforation 5 of the music-sheet.

The particular embodiment of my invention illustrated in the drawings shows expression controlling perforations 5 only on the left hand side of the music-sheet. However, an additional series of expression controlling perforations may be provided, for example, on the right side of the sheet to function through a second set of expression apparatus in all respects similar to that shown and described, if it be desired to controlthe dynamics of the melody notes independently of the accompaniment notes, as

will be well understood by those skilled in the art.

What I claim is:

1. 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; a valve for said port in the chamber connected with the exhauster said valve being movable bodily to and awayfrom the plane of said port; a spring arranged to act on said valve to move it yieldingly to its port; and pneumatic means connected with said spring operable to adjust the strength of said spring.

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 port; a valve for said port in the chamber connected with the exhauster, said valve being movable bodily to and away from the plane of said port; a spring arranged to act on said valve to move it yieldingly to its port; and means for adjusting the strength of said spring comprising an accordion bellows connected therewith and having selectively controllable compartments so that the joint and several collapse and expansion of said compartments will selectively adjust the strength of said spring.

3. 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 re spectively connected with the striker pneumatic action and the exhauster, said chambers being connected by a port, a valve for said port in the chamber connected with the exhauster, said valve being movable bodily to and away from the plane of said port; pneumatic means, and a coiled spring connecting said pneumatic means with said valve, said pneumatic means being controllable to hold said valve through said spring yieldingly to its seat with different degrees of force; and said coiled spring being large diametered so that its tension does not substantially change with the valve opening a greater or less dis tance regardless of the number of striker pneumatics normally in 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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