US1634171A - Pneumatic player mechanism for musical instruments - Google Patents

Description

1,6 4,171 June 28, 1927. T. P. BROWN 3 PNEUMATIC PLAYER MECHANISM FOR MUSICAL INSTRUMENTS Filed Sept. 5. 1923 4 sh nts-Sheet 1 12 Fla. 1.

INVENTOR. 77/60 fez ore P 57171072 ATTORNEY.

June 28, 1927;

T. P. BROWN ruzumuc PLAYER macamsm FOR MUSICAL ms'muusu'rs Filed Sept. 5. 1923 4 Sheets-Sheet 2 an W 0/. mwm 0 0 3 E A TTORNEY.

1 192 June 7 r. P. BROWN PNEUMATIC PLAYER uncamsm FOR uusIcAp msmuusurs Filed Sept. 5. 1923 4 Sheets-Sheet 3 mmvrm 77/9040)? P 57mm? BY J fl ATTORNEY.

June 28 1927.

Filed Sept. 5. 1923 4 Sheets-Sheet 4 ATTORNEY.

- Patented June 28, 1927.

UNITED, STATES PATENTSOFFICE.

THEODORE 1?. BROWN, OF-WORCESTER, MASSACHUSETTS, ASSIGNOR, BY MESNE .AS-

SIGNMENTS, TO SIMPLEX PLAYER AGTION 00., OF WORCESTER, MASSACHUSETTS.

PNEUMATIC PLAYER MECHANISM FOR MUSICAL INSTRUMENTS.

Applicati'on filed september 5, 1923. Serial No. 661,092.

My invention relates to pneumatic player mechanisms for musical instruments and has forits object to provide an improved .con-

struction of the bellows andpneumatic mechfl anism for actuating the player action, whereby the operation of the instrument is greatly improved. l

hen operating pneumatioplayer pianos of the type covered by the present invention,

it is of the utmost importance that the bellows device which controls .the operation of theIplayer action be adapted to readily respond to the .will of the operator, so as to; produce the great range of pressure intensities required in order to play the instrument with the proper expression. It has been found that when'the air reservoir or bellows is completely collapsed by the oper ation of the pump, thesuction produced becomes very great, and that it is then very diflicult'for the-operator, to move the foot treadles which. operate thepump. Obviously, with such a condition, it; is impossible for the operator to produce the variations of pressure so necessary for playinggwith expression, without exertingun'due effort in I movingthe foot, treadles. p Y According to the presentinvention I provide an improved bellows device which is so constructed that as the reservoir collapses, the resistance offered to the movement of thefoottreadles by-the operator does not exhibitaany marked increase, so that the operatoris able to maintainat all-times a complete control over thepressure, without unduly exerting. himself. My invention further. contemplates .an improved construction of; the. pneumatic mechanism controlling the player action,-the individual pneumaticsbe- .ing constructedas uniits easily removed from the instrument, and the entire pneumatic mechanism being adapted to be readily removed from the pianowithout disturbing the adjustments ofthe same. The above and other advantageous features of my-invention .Wlll hereinafter more fully appear, reference being had to the accompanying drawings in which a "Fig. 1.,is 'a view, partially insection' and partially in side-elevation, ofa player piano embodying my invention. I s

Fig. 2.-is.a view showing on an enlarged scale, thezbellows device-shown. in Fig. 1, one of the feeders being in section.

Fig. 3 is a view in perspective of'the bellows device shown in Fig. 2.

Fig. 4c is a view, on an enlarged scale, of a. portion of the pneumatic mechanism shownin Fig. 1.

:Fig 5 is a perspective view of one of the pneumatic units shown in Fig. 4.

Fig. 6 is a sectional view along the line of Fig. 5.

s Fig. 7 is a plan view of the diaphragm block of the pneumatic unitshown in Fig. 6.

Fig. 8 is an enlarged sectional viewof the valve of the unitshown in Fig. 6.

Fig. 9 is a plan view of the guide for the valve, shown in 8.

Like referencev characters refer to like partsin the different figures.

Referring first to Figs. 1, 2 and 8, thebottoinboardof the pianois indicated at 1 and carries a pair ofblocks 2 for supporting the air pump and reservoir. The air'pump consists of a pair of feeders, each of which comprises a stationary leaf 3 and a movable leaf 4 connected by a suitable collapsible web 5, asbest shown in Fig. The movable leaf is normally held in a collapsed position against the stationary lea-f. 3by means of a spring 6 .mounted on the outside of the feeder. The spring 6 consists of oppositely curvedarms 7 ,which are adapted to engage lugs Sprovided on theleaves 3 and 4 respectively, so'that the spring 6 is adapted to be readily removed from the feeder for the purpose of adjusting or replacing the same.

The movable leaf 4 ofv each feeder is conlink 10, and thetreadles Q are mounted for pivotal movement on a cross barll. As.

best shown in Fig. 3, the cross bar 11- is U- shaped in form and its ends are plvotally ;mounted in sockets 12 carried by the blocks '2. The cross bar 11 is adapted to be supported above the level of-the floor by means of downwardly extending-feetl which are adapted to be securedin position on the bar 1]. by set screws'14. By means of the set screws 14, the feet.13 may be secured in different angular positions on the bar 11, so

as to compensate for variations in the distance between thebottom board 1: of the piano and the floor on which the piano rests. lVhen the cross bar 11 is supported above the floor in front of the piano, as shown in Fig. 1, it is obvious that the treadles 9 may be operated by foot pressure to cause the movable leaves 1 of the feeders to be moved baclt and forth to exhaust; air from the col lapsible bellows. or reservoir, to which the feeders are connected. The reservoir consists of a stationary leaf 15 and a movable leaf it; connected by a collapsible web 17. The movable leaf 16 is normally held away from the stationary leaf 15 by means of springs 18 carried at the ends of the reservoir. Each spring 18 consists of divergent curved arms 19, the ends of which are in engagement with lugs :20 carried by the leaves 15 and 16 respectively, and the springs 18 may be readily removed from the reservoir for adjustment and replacement. The movable leaf 16 of the reservoir is formed of a number of separate laminations 16. so that the leaf possesses a certain amount of inherent resiliency, the advantage of which will be hereinafter referred to with reference to the operation of the pump and reservoir. as will now be described.

hen the operator pushes down a treadle i), the corresponding feeder is expanded due to the movement of the leaf 4, and the atmospheric pressure on the outside of the feeder serves to hold a valve 21 in position to close the ports 22 in the leaf 4. The ere pansion of the feeder is adapted to exhaust: air from the reservoir through a port 23 and a valve 2 1 which opens to suction. As soon as the operator releases a treadle 9, the action of the corresponding feeder spring 6 re turns the movable leaf 4 to its collapsed position, whereupon the valve 21 opens to release the air through the ports 22 while the valve 2-1- closes to lock the suction created in the reservoir by the previous expansion of the feeder. It is apparent then, that when the operator pushes first one treadle 9 and then the other. the suction within the reservoir will be progressively increased so as to cause the same to collapse againstthe fo ce of the springs 18. The tension of the springs 18 is so adjusted, that the amount of suction required to initiate the movement of the leaf 15 toward the leaf 16. is only sutlicient to operate the pneumatic action of the piano so as to produce medium tone effects.

It has been found that with the type of reservoir heretofore employed, the amount of resistance encountered by the operator in moving the treadles 9, remains about the same, until the reservoir is completely collapsed. at which time the resistance to movement of the treadles increases very greatly, owing to the fact that the movable leaf 16 can move no farther. It is also well known that when operating a player piano of the type to which my invention relates. the expression with which a piece is played, depends almost entirely upon the operation of the treadles 9. It therefore follows that when the resistance to the movement ot the treadles increases suddenly. following the a-essure intensities without oppof-iii'ig undut resist ance to the movement of the treadies one ating the feeders. To this end. T eoust :"i the movable leaf 16 of the reservoir of a number of laminations 16". and in addition. provide a bumper project iug outwarll i from the face of the stationary leaf 1?. When the reservoir is partially collap ed by operation of the pump, the uwvablc leaf 16 strikes the bumper thereb v arresting the movement of the leaf 16. The creation of additional suction within the reservoir. after the leaf 16 has engaged the bumper '12:). causes the leaf 16 to yield toward the ea f 15, owing to its t'exible nature. The flexing of the leaf l6 permits a high pressure to be built up and maintained without a sudden increase in the resistance to movement of the treadles. as would follow if the leaf 16 were entirely rigid and unyielding. i-Yith mv improved reservoir functioning as described. the operator can play the notes with a wide range of pressure intensities. without ever encountering any great resistance to movement of the treadles. as when us completely collapsible reservoirs of the t pc previously constructed. 7

Referring now to Figs. 1 and 1. the suction produced by the reservoir is transmitted through a tube 26 to the wind chest 52? by means of a passage 28 provided in the action block 29. A channel board 30 torusone side of the wind chest 27 and has secured thereto two sets of pneumatic units for op erating the player action. As previously set forth. my invention contemplates an improved coustruction of the pneun'iatic units. and as all these units are identical in construction, only one will now be described in detail, withreference to Figs. 4: to 9 inclusive. 7

Each pneumatic unit provides a chamber 31 which is connected to the wind chest 27 through a channel 32 in the board 30. as shown in Fig. 6. The top of the chamber 3! is provided with an opening, the rim which is surrounded by a metallic annular valve seat 33, upon which is seated a valve member 34. As best shown in Fin. 8, the valve member 8 1 is provided with a downwardly extending stem 34;. upon which closely tits a metallic guide 35. which as best till - valve, and at the same time, render it air tightwhen high pressures are developed, as will hereinafter be described.

The top of the valve 34 is covered'with a leather washer 38, which, when the valve 34 is'raiscd "from itslower seat, is adapted to engage an upper seat 39 having an opening 40'therein, as bestshown in Fig. '5. hen the valve '34 is in its lower position, as shown, the opening 40 connects the'interior of the powerpneumatic 41 with the atn'iosphere, so that the latter is maintained in. an expanded condition. T he movable leaf 42 of the power pneumatic provided with a finger 43 which, as best shown'in Figs. 4 and 5, is cupped shape in form, witha slot extending 'therethrough for receiving the pneumatic wire 4.4. Nuts45 are provided on the wire 44 for adjusting the same'on the finger 43, and the upper end of thewire 441s connect;

ed to a striking lever 46. The lever 46 is provided with a capstan or stud 47 which, as best shown inFig. 1, is adapted to engage the wippen 48 of the piano action, which is illustrated as being of the usual form. A limit or stop, 49 is provided above the striking member 46 to limit upward movement of the. latter, so that the power pneumatic 41 will move the wippen 4S exactly the same amount that it is moved by the key 50 of the piano when the pneumatic is actuated, will now be described.

A flexible diaphragm 51 divides the chamber 31 into two parts, and that portion of the chamber below the diaphragm 51 is connect-- ed to a vertical duct 52 in the channel board 30- by a horizontal passage 53. The diaphragm is normally maintained in the position shown by reason of the suction in the chamber 31 through the channel 32 and through the bleeder vent 57 extending from the duct 52, the valve 34 then being tightly held against the seat 33 by atmospheric pressure on top of the valve 34. The duct 52 is connected by a tube 54 to the tracker bar 55 of the piano, the opening at the end of the tube 54 being normally closed by the music sheet 56. lVhen, however, an opening in the sheet 56 registers with the opening at the end of the tube 54, atmospheric pressure will be admitted through the duct 52 into the space below the diaphragm 51. This pressure will overcon'ie the suction through the vent 57 and will cause the diaphragm 5,1 to be raised, thus lifting the valve 34 away tromthe seatl-33tinto engagement with the upperseai 39. Theopening 40 is thus closed, and suction is exerted ontheinside ot the power pneumatic 41, which causes it to collapse. The resulting upward movement of the leaf 42 is t 'ansmitted to the wippen 48 through the wire 44, andthe striking member 46, thus causing the note to be struck. As soon as the movement of the music sheet covers theopening in the tube 54, the diaphragm 51 falls, the valve 34 closes, and the pneumatic 41 is again expanded.

Each pneumatic unit is secured to the channel board 30 by means of screws 58, and inerder to remove a unit from the pianoit is only necessary to remove the screws 58 and to slip the wire 44 out o'f the slot in the cupped-shape finger 43. The units are interchangeable, and being aranged in only two tiers, occupy a minimum amount of space hepiano. Forthis reason thedia- 51, together with its float 51 is al in form, asshown in'Fig. 7, thus materially reducing the width of my improved unit as COHIPLH'GCllZO previous unit einployinga circular diaphragm. prc ously pointed out, the valve 34 of eachpneumatic unit is adapted to seat very tightly on tlie annular valve seat 33 by reason of the fact that the rim of the seat 33 engages the unglued portion of the cov'ei"='36.

lhe/l actthat there is always a very-small clearance between the unglued portion of the cover 36 and the washer 37 insures that when the valve 34 is seated by suction in the chamber 31, the layers of leather will compress slightly and provide a substantially air tight closure for the chamber. Obviously, the greater the suction to which the valve is subjected, the more tightly it will be seated, so that the type of valve described herein particularly adapted for use in con nection with my improved air reservoir. As previously pointed out, the provision of the flexible leaf 16 in my reservoir permits a strong suction to be created Without the exertion of undue effort on the part of the operator to move the foot treadles, and in order that the suction be maintained, it is most essential that the valves in the pneumatic units be air tight. By using a tight seating valve in connection with a suction creating device which can be operated without undue ellort, I am able to employ and maintain extremely high pressures for operating the penumatic player action. As a result, the pneumatic units can be reduced in size as compared to those previously employed, which permits the very compact arrangement of the pneumatics in two tiers. For the same reasons, the proportions of the entire pumping device can be reduced, which results in a smaller and more compact arraugen'rent of the entire instrument.

From the foregoing then, it is apparent that by my invention I have provided an improved suction creating mechanism that is particularly adapted for use in connection with an improved form of pneumatic unit, whereby the playing qualities of the instrument are bettered and its ease of ope 'ation greatly increased.

I claim:

1. In a player for musical instruments, the combination with a valve mechanism for controlling a pneumatic player action, and a suction creating crevice, of a collapsible reservoir adapted to be exhausted by the operation of said suction creating device, said reservoir comprising a substantially rigid leaf and a movable leaf of material having marked resiliency as compared to said rigid leaf.

2. In a player for musical instruments a collapsible air reservoir comprising a substantially rigid leaf, a movable leaf of material havinn' marked resiliency as compared to said rigid leaf, and means for partially limiting the movement of said resilient leaf in the direction of said rigid leaf when the reservoir has collapsed a predetermined amount.

3. In a player for musical instruments, at collapsible air reservoir comprising a substantially rigid leaf, a movable leaf of material having marked resiliency as compared to said rigid leaf, and a stop for limiting the movement of a portion of said resilient leaf when the reservoir has collapsed a predetermined amount. whereupon the remainder of said resilient leaf is adapted to yield in the direction of said rigid leaf.

4. In a player for musical instruments, a collapsible air reservoir comprising a sub stantially rigid leaf, a movable leaf of material having marked resiliency as compared to said rigid leaf, a spring for holding said leaves apart, and means for partially arresting the movementof said resilient leaf after it has moved a predetermined amount against the force of said spring, whereupon the said movable leaf adapted to yield further by reason of its resilient nature.

5. In a player for musical instruments, the combination with a valve mechanism for controlling a pneumatic player action, a suction creating device, of a collapsible reservoir adapted to be exhausted by the operation of said device, said reservoir comprising a substantially rigid leaf, a movable leaf of material having marked resiliency as compared to said rigid leaf, and means for partially limiting the movement of said re sili-ent leaf after said reservoir has been collapsed a predetermined amount by said enction creating device, whereupon said movable leaf is adapted to yield toward said rigid leaf in response to further operations of said suction creating device. i

THEODORE P. lilltm i

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