US1395278A

US1395278A - Air-motor for automatic musical instruments

Info

Publication number: US1395278A
Application number: US236425A
Authority: US
Inventors: Charles V Jameson
Original assignee: Individual
Current assignee: Individual
Priority date: 1918-05-24
Filing date: 1918-05-24
Publication date: 1921-11-01
Anticipated expiration: 1938-11-01

Description

C. V. JAMESON. AIR MOTOR FOR AUTOMATIC MUSICAL INSTRUMENTS. APPLICATION FILED MAY 24,1918.

C. V. JAMESON. y AIR MOTOR FOR AUTOMATIC MUSICAL INSTRUMENTS.

APPucATloN HLED MM2-1,1918.

1,395,278-l Patented Nov. 1, 1921,

4-7 2 SHEETS-SHEET 2,

UNITED STATES CHARLESI V. JAMESON,

PATENT OFFICE.

or CHICAGO, ILLINOIS.

l AIR-MOTOR FOR AUTOMATIC MUSICAL INSTRUMENTS.

To all whom t may concern:

Be it known that I, CHARLES V. JAMESON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful' Improvements in Air-Motors for Automatic Musical Instruments, of which the following is a specification.

This invention relates to the air motors employed for driving the music and take-up rolls of automatic musical instruments, such for instance as player-pianos.

Such motors are commonly provided with zgovernors for maintaining a uniform air tension therein, regardless of variations of tension produced by the main exhaust bellows, and also with a so-called tempo box containing tempo and rewind valves, the former for regulating the speed of the motor and the music sheet to suit the tempo of the music and the latter for admitting high orI ungoverned air tension to the motor pneumatics to rapidly re-roll the sheet.

Heretofore these several parts have been manufactured as separate elements, requiring considerable time to install them and correspondingly increasing the cost ofthe instrument.

One of the objects of my invention is to combine the several elements of the air motor, including the governor and the tempoboX, in a single and compact Structure, which can be readily installed as a complete unit and placed in a relatively small space.

Further objects are to improve the construction of the motor with a view of facili tating access to Ithe regulating means of the governor-spring, and to improve the motor in other respects.

In the accompanying drawings:

Figure 1 is a front elevation of the motor and parts associated therewith. Fig. 2 is a transverse vertical section on line 2 2, Fig. 1.' Fig. 3 is a horizontal section of the governor pneumatic on line 3-3, Fig. 2. Fig. 4 is an enlarged horizontal section on line 4 4, Fig. 3. v

Similar characters' of reference indicate corresponding parts throughout the several views. Y

1 and 2 indicate the music and take-up rolls of an automatic musical instrument, which rolls are driven from the usual horizontal crank shaft 3 of the improved air Specication f Letters Patent.

Patented N ov. 1, 1921.

191s. serial No. 236,425.

motor by the usual sprocket gearing shown in the drawings, or any other suitable'transmission mechanism. This crank shaft is supported by brackets 4 carried by a substantially upright-valve board 5 secured to a board 6 or equivalent support. In the preferred construction shown, the board 6 is rigidly mounted upon a horizontal base or channel-board 7.

8 indicates the customary motor pneumatics or bellows mounted vertically on the rear side of the board 6 and having their movable members connected with the cranks of the shaft 3 by the usual pitmen or connecting rods 9, this shaft being constantly rotated by the successive collapse of the series of motor pneumatics in a well known manner. The valve mechanism for controlling the action of these pneumatics may be of any suitable construction. That shown in the drawings comprises sliding valves 10 moving vertically in guides 11 secured to the face of the valve-board 5, and connected with the rods 9 respectively by links 12. In the preferred construction shown in the drawings, each link 12 is provided at its lower end with an adjustable head 13' seated in a notch 14 in the upper edge of the valve and pivoted thereinl by a transverse pin 15 passing through these parts. The link 12 and the head 13 may be connected by a screw thread, as shown, so that upon detaching the head from the valve, the head can be screwed up or down on the link to properly regulate the position of the valve with reference to the usual exhaust port 16 and flushing port 17 with which it coperates. This forms a neat and convenient connection between the valve and the link.

As best shown in' Figs. 2 and 4, the flushing port 17 'of each motor pneumatic opens. into the outer atmosphere at the face of the valve board 5, while the exhaust port 16 communicates with a. suction channel 18 formed horizontally in the valve board and extending from end to end thereof. Each' slide valve is provided on its inner side with the usual recess 19 of the proper length to bridge or connect the

companion ports

16 and 17 when the valve is lowered, so as to exhaust the corresponding motor pneumatic 8, while when said valve is raised to the kpomain exhaust bellows.

port 17, causing the inflation of said pneumatic in a well known manner.

The suction channel 18 is connected by a tube or conduit 20 with the suction or valve chamber 21 of a tempo box 22, preferably arranged on the front side of the channel board 7 and suitably secured thereto. Arranged in the lower or base portion of the tempo box is a suction-recess or chamber 23 connected through a suitable governor 24 with a suction-trunk 25 leading to the usual main exhaust bellows, not shown in the drawings. During the operation ofthe instrument the suction chamber 23 is constantly exhausted. Connecting the valve chamber 21 of the tempo-box with the suction chamber 23 is a tapering port 25a controlled by a sliding or other suitable valve 26 operated by a rod 27 extending through the end wall of the tempo-box. The playing speed of the air motor may be controlled by opening the tempo valve more or less, in a common manner.

Thegovernor 24 maintains a uniform air tension in the suction chamber 23, irrespective of variations of tension produced by the This governor consists of a bellows or pneumatic preferably arranged horizontally on the rear side of the channel board 7i and glued or otherwisey secured thereto. Arranged within this governor is a block 28 secured to its fixed board 29 and provided with a governing port 30 opening at one side of the block and communicating by a passage 31 with a channel 32 formed lengthwise in the board 7. This channelis closed at one end and communicates at its opposite end with a box or chamber 33 to which the suction trunk 25 is connected. The port 30 is controlled by a vertically-swinging valve 34 pivoted at one end to the block 28 and caused to bear at its free end against the movable'board of the governor pneumatic 24 by a suitable spring 35 which latter tends to open the valve. A tube or conduit 36 extending across the channel 32 connects the valve chamber 21 of the tempo box with the interior of the governor pneumatic. The collapse of this pneumatic is resisted by the customary coiled spring 37 connected with an arm 38 secured to its movable board. i The front end of this spring is adjustably connected to a fixed lug 39 by any suitable adjusting means by which its tension may be regulated. In the construction shown, this spring passes through an opening in said lug and is stretched more or less by a rotary nut 40 engaging its convolutions and bearing against the face of said lug.

41 indicates a stop-spring for the movable board of the governor-pneumatic arranged `to encounter an adjustable stop or button 42 when the resistance of the main spring 37is overcome, so as to prevent complete collapse of said pneumatic and full closure of the governing-valve 34. This stop spring preferably consists of a flat steel strip secured to the movable board of said pneumatic. This construction renders the closing action of this pneumatic practically noiseless.

, 43 indicates a rewind port or passage connecting the chamber 21 of the tempo-box directly with the exhaust passage 32 and controlled by a sliding rewind valve 44 within said chamber.

In the normal operation of the motor, the

rewind valve 44 is closed, as shown in Fig.V

4, and the tempo valve 26 is opened more or less, to place the motor pneumatics 8 under the control of the reduced or governed air tension in the chamber 21 of the tempo-box. Under these conditions, assuming the valve 10 to be lowered, the air current passes from the motor pneumatic through the passage 17, valve recess 19, passage 16, channel 18, tube 20, suction chamber 21, tempo port 25a, suction chamber 23, tube 36, governing port 30, passage 31, channel 32 and suction box 33 to the suction trunk 25. l/Vhen the air tension produced by the main suction bellows rises above the normal, the governor pneumatic 24 partly collapses and overcomes the normal resistance offered by the spring 37, thereby partly closing the governor valve and reducing the air tension in the suction chamber'23 accordingly, while when the tension falls below normal, the spring 37 opens the governor pneumatic farther, thereby uncovering the port 3() to a greater extent and restoring' the tension inv said channel to normal.

`When it is desired to rewind the music sheet, the valve 44 is opened, thus placing the chamber' 21 and the motor pneumatics connected therewith under the high air tension in the channel 32 and operating the pneumatics more rapidly, in the usual manner.

It is sometimes desirable to sustain a note or chord for a longer period than is effected by the cutting of the corresponding music sheet perforations. When there are no imperfections in the,- parts-of the tempo-box, this can be successfully done by fully closing the tempo valve so as to stop the music sheet and continuing to pump the instrument to sustain the music. Vhen, however, leakage occurs past the tempo valve under these conditions, owing to its being warped or otherwise defective, the motor pneumatics continue to act slowly, causing the sheet to creep or advance more or less and prematurely stopping the note or chord to be sustained. In order to overcome this objection, notwithstanding imperfections in the tempo valve or its seat, I provide suitable means for automatically flushing the tempol box when said valve is fully closed, preferably consisting of a port or passage leading from the bottom of this box to the outer atmosphere. The inner end of this port is so arranged as to be fully closed by the tempo valve when the latter is open to any extent, as shown in the drawing, and to be uncovered when the valve is fully closed. The tempo boX and the motor pneumatics connected therewith are thus flushed and the music sheet is promptly stopped, the instant said valve is closed, thereby enabling the performer to sustain a given note or chord as long as desired.

By arranging the tempo-box 22 on one side of the channel board 7 and the governor on the opposite side thereof, preferably the rear side, these parts and the board 6 carrying the motor pneumatics and their controlling valves are all compactly combined in aI unitary structure which may be installed or removed as a single unit. This greatly Jfacilitates the installation of the motor and enables the several parts to be placed in. a small space beside the usual tracker-box.

The easy accessibility of the governorspring 37 permits convenient manipulation of its regulating nut 4t() While playing the instrument.

I claim as my invention:

l. In an air motor of the character described, the combination of a base-board having a suction-chamber, a governor pneumatic connected With said chamber by a port, a governing valve cooperating with said port and controlled by the governorpneumatic, a tempo-box having a valve chamber and a suction chamber, said suction chamber being in communication with said governor-pneumatic, said valve chamber communicating with the last-named suction chamber by a tempo-port, and a regulating valve controlling said tempo-port, said tempo-bor` and said governor-pneumatic being arranged, the one on the front side and the other on the rear side of said base-board.

2. ln an air motor of the character described, the combination ot' a base-board having a suction-chamber, a governor-pneumatic connected with said chamber by a port, a governing valve coperating with said port and controlled by the governorpneumatic, a tempo-box having a valve chamber and a suction chamber, said suction-chamber being in communication with said governor-pneumatic, said valve chamber communicating with the last-named suction chamber by a tempo-port and with the channel of said base-board by a rewind port, and valves controlling said tempo and rewind ports, respectively', said tempo-box and said governor-pneumatic being arranged, the one on the frontside and the other on the rear side of said base-board.

In an air motor oi' the character described, a governor pneumatic, a resistance spring therefor, an adjustable stop for the movable board and of said pneumatic, and a second spring carried by said movable board and arranged to encounter said stop When the resistance of the first-named spring is overcome.

4. ln an air motor of the character described, the combination of the motor pneumatics, the tempo box, the tempo-valve, and means for flushing said box when the tempovalve is closed.

5. In an air motor' of the character described, the combination of the. motor pneumatics, the tempo-box having a tempo-port and a flushing port, and a valve controlling said tempo-port and arranged to close said flushing port when the tempo-port is opened and vice versa.

CHARLES V. JAMESON.