US1159374A - Pneumatically-operated piano. - Google Patents

Description

C. GULBRANSON. PNEUMATICALLY OPERATED PIANO.

APPLICATION FILED SEPT. 1, I91 I.

Patented Nov. 9, 1915.

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CHRISTIAN GULBRANSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO GULBR-ANSEN- DICKINSON COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PNEUMATICALLY-OPERATED PIANO.

Application filed September 1, 1911.

To all whom it may concern:

Be it known that I, CHRISTIAN GULBRAN- SON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Pneumatically-Operated Pianos, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to pneumatically operated pianos and is concerned with the contents of the roller box. It is well known that in pneumatic piano actions, a roller box is disposed in front of the hammers in alinement with an opening in the front panel of the piano casing. This box contains the tracker board and the means for passing a music strip or sheet from one roll, over the tracker board, to another roll.

My invention is directed toward an im proved arrangement for guiding the music strip, of paper, so that it may always bear the proper relation to the tracker and so that it will bear such a relation that the paper will not tend to stick to vthe face of the tracker, either because of its composition or because of the difference in pressure on the two sides which is created by action of the pneumatic mechanism. It has been found in practice that many grades of paper tend to stick to the face of the tracker, particularly in warm weather or in a warm room, and this is ascribed to the composition of the paper or to its lack of porosity. The paper may carry adhesive particles which produce this undesirable result or it may be so firm in its composition that the pneumatic potential produced by the bellows draws it firmly to the face of the tracker through which the suction is applied. The tendency for the music sheet to stick retards the action of the roller driving mechanism and the drag is often su'liicient to seriously mar the tempo of the music.

It is the object of my invention to avoid this difficulty and I do this by guiding the music sheet in a certain position relative to the face of the tracker, which position is maintained regardless of the extent to which the roll becomes wound or unwound, so that the area of contact between the music strip and the tracker is limited as far as possible Specification of Letters Patent.

Patented Nov. 9, 1915.

Serial No. 647,158.

to the zone in which the tracker openings are provided. To this end, I provide a guiding roller, parallel to the tracker, and I have found it particularly desirable to mount this roller on the departing side of the tracker. There is also an advantage in mounting such a roller on the approaching side of the tracker and rollers may be provided in both places if desired. These rollers are adjustable in a manner to be described in order that the positioning of the music sheet may be regulated to a degree.

My invention is embodied in the structure illustrated in the accompanying drawings, in which Figure 1 is a front elevational view of the roller box with its contents and some of the directly associated parts; Fig. 2 is a cross sectional view taken on the plane of the line 2-2 of Fig. 1, looking in the direction indicated by the arrows and drawn on a larger scale; Fig. 3 is a view of one of the parts for mounting the roller, drawn on a still larger scale; and Fig. 4: is another view of this mounting piece, parts being shown in section to further illustrate the construction.

The roller box is illustrated at 5 and is divided into two compartments each for the reception of a roll. In each compartment there are dead bearings 6, 6, extending inwardly from one of the side pieces, and these bearings are adapted for the reception of the rollers 7, 7. Live spindles 8, 8 are mounted in bearings 9, 9 and these spindles are provided with chain and clutch mechanism 10, 10 for driving either of them. \Vhen the instrument is playing, it is usual to make the upper roller the feeding one and the lower roller the receiving one. The chain and clutch mechanism is not concerned with this invention, so it is shown more or less diagrammatically.

The tracker piece 11 is mounted parallel to the roller axes, at the front of the roller box, and this tracker piece is provided with the usual series of openings 12, 12 which, by means of suitable piping 13, 13, are connected to the pneumatic action members. The face of the tracker piece is convex, traced by a line moving parallel to the axes of the rollers, and the music sheet a is run from one roller to the other in the manner clearly illustrated in Fig. 2.

On each of the side pieces of the roller box, just belowthe tracker piece, a support.- ing block 14 is pivotally mounted by means of a screw 15 near the bottom thereof. This supporting block, which is shown in detail in Figs. 3 and a, may be swung about the pivot member 15 and may be clamped inany v adjusted position by means of a screw 16 passing through an arcual slot 17 in the block. A washer 18 may intervene between the head of the screw and the block in-order that the latter may not be injured. The two supporting blocks register with each other, longitudinally of the ,roller box, and between them, at the top thereof, the auxiliary roller 19 is mounted, this roller having the trunnions 20, 20 which rest in suitable hearing openings in the blocks. The blocks are so adjusted that the roller 19, over which the music sheet is thus made to pass, holds the music sheet away from the face of the tracker except for that part at which it controls the tracker openings. Thus, the music sheet leaves the tracker boardat a tangent, and gradually and not only does not pass over an edge in leaving, but is confined to a limited area on the face of the tracker. Furthermore, regardless of the angle at which the sheet approaches the receiving roll, depending upon the extent to which the roller has been wound, the sheet will always leave the face of the tracker at the same angle. The same sort of an arrangement maybe provided above the tracker piece and, for convenience, I have applied the same reference characters to the structure which I have shown in that position.

Here, regardless of the angle at whichthe paper strip leaves the feeding roll, it will always approach the face of the tracker at the same angle,.will be-confined to a limited area, and will approach it at a tangent rather than over an edge. It is apparent that any adjustment may be made by loosen- 7 ing the screws 16, swinging the blocks 14, and again tightening the screws 16 so that the paper strip may bear any desired relaion to the face of the tracker. It is to be understood that the paper travels in a down ward direction while the instrument is play ing and that, in the rewinding operation,

there is no suction applied to the inner face of the paper so the drag which has. been referred to will not occur. If but one roller is to be employed, I believe it preferable that this roller be mounted uponthe power side, that is, if the paper travels in a clownward direction the lower roll is the power roll and the roller 19 is provided under the "tracker.

I claim as new and desire to secure by Letters Patent:

1. In a pneumatically operated piano, a supporting frame, a tracker member mounted on said frame, a music roll on each side of saidtracker, an elongated guiding member extending parallel to the tracker and over. which the music strip may pass, said guiding member being on the same side of said music strip as said tracker, swinging 'arms carrying said guiding member, and means for securing said arms in any adjusted position.

2. In a pneumatically operated piano, a supporting frame, a tracker member with a convex surface in which ducts lead mounted on said frame, a music roll on each side of said tracker, and an adjustably mounted elongated guiding member extending parallel to the tracker and over which the music strip may pass, said guiding member being on the same side of said music strip as said tracker, the guiding surface of the guiding member lying in substantially the same plane as the edges of said ducts.

3. In a pneumatically operated piano, a roller box, a tracker mounted within said roller box and having a series of openings therein, rolls adaptedto carry a perforated music sheet over said tracker, the perforations in said sheet being adapted to cooperate with said openings, and a guiding roller mounted above and below said tracker board on the same side of the music sheet with the tracker to engage the music sheetto prevent the music sheet from sticking to the said tracker board.

4. In a device of the class described, a'

CHRISTIAN e LBRANsoN.

Witnesses:

A. G. GULBRANSON, ARTHUR H. BOETTGHER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

.Washington, D. C. V

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