US1324700A

US1324700A - Piano-player

Info

Publication number: US1324700A
Authority: US
Publication date: 1919-12-09
Anticipated expiration: 1936-12-09

Description

C. H. SPENCER.

PIANO PLAYER.

APPLICATION FILED APR. 19, 1919.

1,324,700, Patented Dec. 9,1919.

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APPucA .19. 1918. 1,324,700. Patented Dec. 9,1919.

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UNITED s ra'trns PATENT OFFICE.

CHARLES H. SPENCER, 0F BALTIMORE, MARYLAND, ASSIGNOR TO HENRY S. DULANEY,

r OF BALTIMORE, MARYLANDv lPIANC-PLAYEB.

Application filed April 19, 1918.

To all whom it may-concern.-

Be it known that 1, CHARLES H. SPENCER, a citizen of the United States of America, residing in the city of Baltimore, State of Maryland, have invented certain new and useful Improvements in Piano-Players, of which the following is a specification.

Apparatus of this type, while it has attained a wide sale and a high degree of pop ularity, :is found objectionable by many people of sensitive musical perception on account of the so-oalled automatic or mechanical effect. This is largely due to the fact that while the mechanical eifort necessary to playing the different notes is widely varying from bass to treble, the force supplied by the playing apparatus is the same throughout so that the higher notes are most sharply actuated or struck. This gives a harsh, hard, metallic tone, resulting in the well-known effect, generally termed mechanical. To avoid this objectionable effect, I have by means of my improved apparatus provided a playing impulse which is graduated or varied in accordance with the resistance offered at the different notes, that is, the pressure applied by the playing means or pneumatic at the bass notes is the maximum produced by the apparatus, and the playing efiort or pressure is reduced on a ratio corresponding to the reduction in resistance for each succeeding higher note up to the treble end of the key-board.

In the form of the invention shown, the pneumatic. player apparatus is preferably connected directly to the piano action, each pneumatic unit contacting with the piano action at some convenient point and moving the action operatively each time the particular pneumatic unit is actuated. The actual force or energy generated by each pneumatic member may be varied in any suitable and convenient manner, as by varying the length of the lever arm by which the pneumatic pressure from each unit is supplied to the piano action, or by varying the size of the bellows or striker embodied in each unit, or more particularly the area of the internal surface of the moving member of the bellows or striker exposed to the air pres sure or vacuum of the wind chest. In the preferred form of the apparatus, as illustrated herein, this result is obtained by combining these two elements, that is, increasing both the leverage which the air pressure Specification of Letters Patent.

Patented Dec. 9, 1919.

Serial No. 229,517.

is applied to the piano action and increasing the size of the bellows by means of which the vacuum or air pressure, the vacuum being merely counted as negative pressure, is applied to the piano action, the size of the bellows and the length of the leverage cor responding o and varying directly with the pressure which must be applied to the piano action for each note in order to play that note. I

In the accompanying drawing, I have illustrated a pneumatic unit, the preferred manner of connecting the same to the piano action, and a full set of pneumatics installed in a piano according to the preferred embodiment of my invention.

Figure 1 is a vertical, central, longitudinal section through a single pneumatic unit;

Fig. 2 is a fragmentary vertical section through a piano showing a single unit of the piano action in elevation, and illustrating the manner of applying a pneumatic unit thereto; and

Fig. 3 is a plan view of a piano withportions of the casing broken away, showing a series of pneumatics in place, the playing effort being graduated to correspond to the resistance offered at the respective notes.

Referring to the drawings by numerals, each of which is used to indicate the same or similar parts in the diflerent figures, the pneumatic unit, illustrated in section in Fig. 1, includes a diaphragm casing and valve casing 1 secured to the transversely extending wind box 2 which is supported at its ends on the piano frame and otherwise suitably braced, carrying all the pneumatic units, and a bellows or striker consisting of a fixed plate a and a swinging plate or lever arm 5, and an accordion-plaited fabric connection 13. The diaphragm and Valve casing 1 is formed of two portions or sections, 6 and 7 split on a horizontal plane at 8 to provide convenient access to and support for the diaphragm 9. This diaphragm is substantially horizontal and intermediately placed in the diaphragm chamber 10 which is formed partly in the top section 6 and partly in the bottom section 7 of the casing 1, the edges of the diaphragm being between the adjacent surfaces of the two sections and secured to the surface of one sec-- may occupy each but a single key space and at the same time have the diaphragms 9 of the requisite area required to actuate the valves as hereinafter described, the latter are made long and narrow, the requisite area being at least five or six times the area of the valve. To permit the diaphragm to return to normal position after opening the valve, it has a very small bleeder or equalizing opening 11, preferably formed in a piece of mica or other hard material 12 set in the diaphragm near the center. The wind or pneumatic chamber 2, as already pointed out, extends the full length of the piano supporting all the pneumatics and is in turn itself supported on the frame of the piano at the sides. The inside of this wind box 2 from which the air is exhausted by suitable apparatus well-known to the art, is connected to the diaphragm chamber of each of the pneumatics by a nipple or passage 14 which leads from the top of the diaphragm chamber, and this same top section 15 of the diaphragm chamber is inturn connected to the Valve chamber 16 by an opening 17 con trolled by a valve 18. This valve 18 rests on an upwardly disposed seat 19 and is lifted from this seat in the operation of the pneumatic by means of a flat plate lever 20 which rests on the diaphragm 9 and is actuated thereby. This plate 20, as shown, has an opening 21 over the bleeder opening to prevent blocking of the latter during operation, allowing a free air passage in bleeding. The opening 17 is directly beneath a second valve opening 22 leading upward to the outside a1r and having a downwardly disposed seat 23 with which a valve 24 cooperates, the same having a screw stem 25 projecting through the valve preferably having its upper end flattened to be engaged by a key and its lower end depending so that it is normally in contact with the valve 18, the upper valve being opened by gravity and outside air pressure when the lower valve is closed and closed by the action of the lower valve against the stem 25 when the latter valve is opened.

Leading to the valve chamber 16 from the striker or bellows 3 is an opening 26 and each pneumatic has a. nipple 27 for the connection of a suitable tube 28 leading to the tracker bar, the said nipple being connected to the bottom section of the diaphragm chamber by a tube 29.

In the operation of the pneumatic unit or individual pneumatic, the air is exhausted from the wind chest or passage 2 by a suitable pump actuated by the pedals or other means, and the perforated sheet of music is passed over the tracker bar. The tubes 28 are connected each to a corresponding opening in the tracker bar. W hen a slot or openmg in the sheet of music comes into registration with the corresponding opening in entrance of air to the bottom side of the dia-.

phragm or lower half of the diaphragm chamber. As air is at the same time exhausted from the passa e 2, much faster than it can pass through the bleeder o ening 12 in the diaphragm, the latter is sue ed up against the upper side of the upper wall of the chamber, lifting the lever 20 and opening the valve 18.- The lifting of this valve at the same time closes the valve 24 so that the existing vacuum or negative pressure in the passage 2, maintained by a suitable pump, exhausts the air from or sets up a vacuum in the striker 3, the air being drawn through the passage 26, the valve chamber 16, the passage 17 which is controlled by the valve 18, theupper half of the diaphragm chamber 10, and the nipple 14. This causes the immediate collapse of the striker in response to the external air pressure, lifting or swinging the bottom plate 5 and the lever 30 to their uppermost position in which the bottom plate 5 rests against the stop screw 70. In the form of the invention shown, the lever 30 is connected to the piano action and actuates the correspondin note as it rises. As soon as the opening in the music roll passes out of registration with the corresponding opening in the tracker bar, the entrance to the tube 28 is closed, the supply of air to the under side of the diaphragm is cut off and the bleeder opening 15 in the diaphragm permits the pressure on the two sides to immediately become equalized when the valve lever 20 is dropped. The valve 18 also drops uponits seat to which it is guided by the depending prongs 31, and the valve 24 opens in response to gravity and outside air pressure, admitting the outside air which fills the striker bellows permitting the lever 30 and the plate 5 to drop to the bottom position shown in Fig. 1.

In Fig. 2 I have illustrated roughly a piano action for a single unit or note. According to the usual practice, each unit of the piano action is actuated by a depending abstract 36 guided by a guide lever 37 pivoted to a depending bracket 38 and to a low point on the connecting rod at 39. In the manual operation of the piano, this rod is raised, actuating a striker not shown by means of the usual pivoted key 40 which engages the rod 36 from beneath each time the corresponding note is played and imparts to it an upward thrust when the forward end 41 of the key is depressed.

As a means for operating the piano automatically, a series of player pneumatics, as already described. is in the preferred form of the invention placed on a single supporting bar extending across the piano in the vicinity of the action, the supporting bar in t e p es t instance being the wind box or lgo 1 matic units'has an actuating or lever arm 30 attached to the bottom plate 5. This, in the assembled form of the apparatus, is placed beneath the swinging end of the extension 44, a suitable felt pad being interposed, so

: that when the bellows is collapsed and the bottom plate 5 drawn up, the lever 30 contacting with the extension A of the guide lever 37 raises the rod 36 and plays the note corresponding to the particular penumatic and rod 36 actuated, it being understood that there is one rod 36 and one action, such as illustrated in Fig. 2, to each note of the piano and one pneumatic unit corresponding to each note and each rod 36.

Referring now to Fig. 3, we have the keys and pneumatics corresponding to the lower or bass notes on the left, and the keys and pneumatics corresponding to the treble on the right. As has already been pointed out, the resistance offered by the piano action in playing the bass notes is greater than that offered by the piano action in playing the treble notes. In other words, the nearer the treble, the more sensitive, quicker, lighter and weaker the touch and in order to produce a natural playing effect, the impulse or efi'ort supplied in playing the notes should correspond. In this way, the so-called mechanical efl'ect incident to all automatic players is redu ed or avoided. This may be accomplished by a variety of methods; a shortening of the striker chamber of the pneumatic gives exactly the desired effect.

In the present instance, I vary the length of the bellows, or more properly the length or area of the internal surface of the moving member of the bellows or striker, using a short bellows for the treble and a long bellows for the bass. The actual thrust and force applied with a given air pressure, either positive or negative, varies directly with the length of the bellows or exposed surface of the moving member, provided it is of a given width, as in the present instance. I thus have the greater effort or thrust applied to the bass notes and a reduced effort or thrust applied to the treble, it being understood that I use the word exposed to mean exposed to the internal pressure of the pneumatic or bellows. Further, in the present instance, I have the upward thrust developed at the bellows applied to the rod 36 by means of a lever arm composed of the plate 5 and actuator 30. The length of the actuator 30 being constant and the length of the plate 5, which is the bottom of the pneumatic, being varied and reduced toward the treble, eflects a corresponding change of ratio of the moment arm or lever arm of the point of application of the force to the moment arm of the point of delivery of the work, 2'. 0., the moment arm at the center of the bottom of the bellows about the pivot 46 and the moment arm at the end of the extension 30 about the same pivot. With the length of the bellows, the ratio of the moment arm of the force applied to the moment arm of the resistance or work done increases giving from this cause a proportionately increased pressure or effort to overcome the playing resistance.

In the form of the invention shown, I thus have the force developed by the bellows, as well as the leverage of its application, reduced from the bass toward the treble, illustrating the application of the two principles, that is, change of leverage and change of force applied to correspond to the playing resistance, in a single embodiment of the invention.

The operation, functions served and the resulting advantages of the device have been fully discussed in connection with the description.

I have thus described my invention specifically and in detail in order that its nature and operation may be fully understood; however, the specific terms herein are used descriptively rather than in their limiting sense and the scope of the invention is defined in the claims.

I claim 1. In a piano-player, a series of units, each being approximately of key width so as to occupy a single key space, one correspond ing to each note of the piano to be operated by the player, the units being arranged side by side in a single row, the positions of the units relative to the piano action of the cor responding notes being uniform, each unit including a strikerbellows, the length of the bellows being varied for the different notes, the longer bellows corresponding to the lower notes.

2. In a piano-player, a series of automatic player units of key width, one for each note of the piano to be operated by the player, the units being set side by side in a single row, each unit including a bellows of graduated length, the longer bellows operating the lower notes, the length decreasing as the tone rises and the resistance decreases, supporting means to which each unit is secured, the series of player units thus mount ed forming a tapering member approximately the length of the keyboard, substan- -tially as shown and described.

3. In a piano-player, a series of automatic player units equal in nu nber to the number of notes of the piano to be operated by the player and set in a horizontal line extending across the piano parallel to the line of keys, each unit including a bellows of graduated length having a moving member actuated by the air pressure within the bellows, the bellows being of key width and the moving members of graduated length, means connecting the moving members to the piano action corresponding to the respective notes, the moving members having the longer exposed area operating the lower notes, the length decreasing as the tone rises and the resistance decreases.

4. In a piano-player, a series of player units of key width equal in number to the number of notes of the piano to be operated by the player and arranged in a single line across the piano, each unit corresponding to a note and each including a bellows, the bellows having a moving member which swings with a lever-like action in correspondence with the inflation and deflation of the bellows, a swinging lever corresponding to each unit of the player, the swinging end of the lever being in cooperative relatlon with the outer or swinging end of said movin member of the bellows so that it is actuate by the bellows, the swinging lever being in cooperative relation with the piano action of the corresponding note to actuate the same, the lengths of said levers in the respective units bein graduated so that the leverage with whic the pneumatic pressure is applied to the piano action is decreased from the bass toward the treble end of the action.

Signed by me at Baltimore, Maryland, this 16 day of April, 1918.

CHARLES H. SPENCER. W'itnesses:

ZELLA KUHN, ALICE G. DONEGAN.