An American Family History

UNITED STATES PATENT OFFICE.,130,943.
BARTHOLOMEW T. TREAHY, OF DETROIT, MICHIGAN.
PNEUMATIC ACTION FOR PIANOS.
Specification of Letters Patent. Patented Mar. 9,1915.
Application filed May 20,1913. Serial Wo. 768,787.

To all whom it may concern:

Be it known that I, Bartholomew T. Teahy, a subject of the King of Great Britain, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Pneumatic Actions for Pianos, of which the following is a specification. This invention relates to pneumatic ac tions for pianos, and has for its object to provide a structure which permits the installation of the pneumatic actuating units without taking off. the scale, and laying out channel boards, etc., to conform to different makes and styles of pianos.

The invention also has for its object to provide a separate and independent unit for each note, so that each unit may be taken out of the instrument without disturbing the remaining units, and which may be opened up for adjustment or repairs and returned, by releasing the tension of two screws and tightening them up again when the unit is replaced.

These objects are attained by means of a novel combination and arrangement of parts to be hereinafter described and claimed, reference being had to the accompanying drawings, in which—•

Figure 1 is a sectional view of a fragment of the case of a piano showing the supporting frame of the pneumatic units. Fig. 2 is a vertical section on the line 2—2 of Fig. 1. Fig. 3 is a longitudinal section of one of the units. Fig. 4 is a vertical section on the line 4—4 of Fig. 3, and Fig. 5 is a vertical section on the line 5—5 of Fig. 4.

Referring specifically to the drawings 10 denotes the side walls of the case of a piano,said walls supporting the key-bed 11 carrying the key-rail 12. These parts, as well as the keys 13, are all constructed and arranged in the ordinary manner, and nothing is claimed with respect thereto.

On the key-bed 11, adjacent to each end of the bank of keys 13, are mounted front and rear uprights 14 and 15, suitably spaced apart and connected by top and intermediate cross rails 16, which latter support the pneumatic actuating units to be presently described. A supporting frame for the units is thus had which can be readily mounted in the piano without alteration in the structure thereof. The units are separate, there being one for each note, and each unit may be taken out of the instrument entirely independent of any other unit, as will be presently described. Each unit includes a main supporting block 17 to the top of which is fastened by screws, or otherwise, go a valve block 18. To one of the bottom edges of the block 17 is hinged a leaf 19 having means for engaging the abstract rod 20 of the piano action. The edges of the leaf are connected to the block 17 by a 65 flexible fabric 21, which latter, with said block and the hinged leaf, form a bellows chamber 22. The block 17 is recessed and in said recess is mounted a flexible diaphragm 23, which divides the recess into upper and 70 lower diaphragm chambers 24 and 25, respectively. In the block 18 is a valve chamber 26 into the upper end of which is screwed a metallic bushing 27 having a valve seat 28 provided with a port 29 opening into the 75 atmosphere. The bottom wall of the valve chamber has a valve seat 30 from which a port 31 leads into the upper diaphragm chamber 24. In the chamber 26 is located a valve 32 having a stem 33 which passes 80 through the port 31 and bears loosely on the diaphragm 23.

To one end of the blocks 17 and 18 is secured by screws, or otherwise, a breech block 34 having passageways 35 and 36, respec- 85 tively, opening at one end through the top edge of the breech block, and at their other ends through the side of said block which fits against the end of the block 17. From the upper diaphragm chamber 24 a pas- 90 sage-way 37 leads to and communicates with the passage-way 35, and from the lower diaphragm chamber 25 a passage-way 38 leads to and communicates with the passage-way 36. The passage-ways 35 and 36 are connect- 95 ed by a duct 39, the area of which is controlled by a small screw 40 threaded through the block 34 from the outer face thereof. From the valve chamber 26 a passage-way 41 leads to and communicates with a pas- 100 sage-way 42 in the block 17, said passageway 42 opening into the bellows chamber 22. To the end of the passage-way 35 which opens through the top of the block 34 is connected a nipple 43, and to the corresponding 195 end of the passage-way 36 is connected a nipple 44. The nipple 43 is connected by means of a flexible tube 45 to a vacuum chamber or tube 46, the latter having a nipple 47 for attachment of the flexible tube. HO The nipple 44 is connected by means of a flexible tube 48 to the tracker board, the latter not being shown as it forms no part of the present inventiona. Aunit as herein described is provided for each note of the instrument. The number of g nipples 47 corresponds to the number of pneumatics to be used, each nipple- being connected to a corresponding unit. Should a unit be taken out for any cause, the corresponding nipple can be stopped up, and its

10 loss will riot be felt except that the particular note would not be sounded.

In Order that each unit may be taken out of the instrument without disturbing any of the o'ther units, I mount the same on the

15 rails 16 as shown in Figs. 1 and 2. The rear portion of the block 18 has an upstanding flange 49 in the inner face of which is a groove 50 to receive the rear edge of the rear rail 16. The top of the block fits

20 against the bottom of the rail. The front end of the block 18 has a recess 51 in which the front rail 16 seats, and the front edge of said rail has a groove 52 to receive the points of set screws 53 which are threaded through

25 the block 34 from the front face thereof, said block rising above the recessed front portion of the block 18, so that the front rail 16 lies between the top portion of the block 34 and the shoulder formed by the re

SO cess 51. Upon tightening the set screws 53, the units are securely held in place, and if they are to be removed, it is necessary only to back the set screws and disconnect the tubes 45 and 48. The units are all inde

35 pendent and each one is secured as herein described, in view of which any one or more of the units may be removed without disturbing the others. The units can also be easily alined and properly positioned with

40 respect to the piano action.

As shown in Fig. 1, the supporting frame of the units may be in two or more sections as desired, so that an entire section may be removed if access to a corresponding sec

45 tibn of the action, strings or other parts, is desired. In order to strengthen the frame, the rails 16 are connected at suitable intervals by cross braces 54. The units are partly of wood and partly

50 of metal. The parts i7 and 19 are made of wood, and the parts 18 and 34 are die cast, the valve seat 30 being a raised portion or ring which is cast integral with the part 18. The bushing 27 can be readily adjusted to

55 allow proper movement of the valve 32.

The operation of the pneumatic units is as follows: When the tracker board openings are closed, the chambers 24 and 25 connect with the vacuum tube 46, and the valve 32

60 is down on the seat 30, it being held there by the atmospheric pressure entering through the port. When a tracker board opening is exposed by the perforated music sheet, air under atmospheric pressure enters the cham

65 ber 25 through the passage-way 38 and

blows up the diaphragm 23, which latter then raises the valve 32 off its seat 30. The valve now closes the port 29 and allows the bellows compartment 22 to connect with the vacuum through the passage-ways 42 and 41, 70 valve chamber 26, port 31, chamber 24 and passage-ways 37 and 35. The leaf 19 is therefore raised and the abstract 20 connected thereto is actuated. When the tracker board opening is again closed the pressures 75 in the chambers 24 and 25 equalize, and the valve 32 returns to its seat 30 to shut off the bellows chamber from the vacuum, and reconnect said chamber with the atmosphere,, whereupon the leaf 19 drops and the parts 80 are restored to their normal position.

It is very rarely that the scale of two pianos of different makes are alike. Thus, the bass section or overstrung portion of the; scale may have twenty sis notes in it, the 85 center section thirty and the treble section thirty two-. A scale like this would have two breaks or spaces in the action one between the bass and center sections and one between; the center and the treble. Some actions have 80 three breaks or spaces between different sections. Now when a pneumatic action is to be built for a piano where connection between the pneumatic action and the piano action is made to the abstract rods or wip- 95 pens, or in fact at any point to the rear of the balance rail of the key-board, it is necessary, in present constructions, to have the pneumatic action laid out to correspond to the scale of the piano in which it is to be installed, and borings and windways in the channel boards upon which the pneumatics are mounted and through which they are actuated, must be laid out and made so that each section or actuating pneumatic will register with its corresponding section in the piano action. With the herein-described system of mounting and supporting the actuating units it is only necessary to place the units in the frame rails 16 and to slide them lieright or left as may be necessary to bring the same in registration with the respective action units, and then tighten the set screws 53, after which everything is ready to connect the tubing. Then, should it be necesary at any time to remove any one of the Units, all that is necessary is to slacken the set screws, allow the flange 47 to drop off the adjacent rail 16, and draw the unit out. I claim: 120

1. A pneumatic action for pianos comprising independent pneumatic actuating units having each a flange, a supporting frame for the units along-which the units are adjustable, said frame having front and rear 126 parts, one of said parts engaging the flanges of the actuating units^ and clamping means carried by the units and engaging the other part of said supporting frame, and being adjustable toward the flanges and cob'perat- 130

ing therewith to. fix the units in adjusted position on the frame.

2. A pneumatic action for pianos comprising independent pneumatic actuating units,

5 a supporting frame for the units, said frame being composed of separate longitudinally alined sections on which the actuating units are separately mounted and adjustable longitudinally, and means for fixing the units 1° in adjusted position on the frame.

3. A pneumatic action for pianos comprising independent pneumatic actuating units having each a flange, a supporting frame for the units along which the units are ad

15 justed, said frame having front and rear parts, one of said parts engaging the flanges of the actuating units, and set screws carried by the actuating units and engaging the other part of said supporting frame, and co

20 operating with the aforesaid flanges to fix the units in adjusted position on the supporting frame.

4. A pneumatic action for pianos comprising independent pneumatic actuating units

25 having each a flange, a supporting frame having front and rear cross-rails, one of said rails engaging the flanges of the actuating units, and set screws carried by the actuating units and engaging the other cross-rail.

5. A pneumatic action for pianos compris- so ing independent pneumatic actuating units having each a flange which is grooved, a supporting frame having front and rear crossrails, one of said rails having its edge seating in the groove of the aforesaid flange, 35 and set screws carried by the actuating units and engaging the other cross-rail, the edge

of said rail being grooved to receive the points of the set screws.

6. An actuating unit for pneumatic pianos 40 having a diaphragm block provided with top and bottom diaphragm chambers and a diaphragm between said chambers, said block also having passage-ways extending from the diaphragm chambers, a breech 45 block mounted on the diaphragm block and having passages leading, respectively, to the passage-ways of the diaphragm block, and

a duct connecting the passages, and a screw threaded through the breech block to enter 50 the duct and regulate the area thereof.

In testimony whereof I affix my signature in presence of two witnesses.

BAETHOLOMEW T. TREAHY.

Witnesses:

Corinne Treahy,
Eosa A. Slocum.

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