US2073463A - Piano - Google Patents

Description

March 9, 1937. c. H. DAsENBROoK PIANO Fiied Dec. so; 1955 2 Sheets-Sheet l NVENTOL/ Mm k .w m m .0 T fm ao 0W un., n0

March 9, 1937. C, H, DASENBROO.; 2,073,463

PIANO Filed Dec. 30, 1935 2 Sheets-Sheet 2 4 no. l J.

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Patented Mar. 9, 1937l Y UNITED STATES PATENT orrics4 to Thayer-Action Com corporation of Illinois pany, Rockford, Ill., a

Application December 30, 1935, Serial No. 56,67%

' 9 claims. (ci. ca -24e) length of string and therefore allow greater,

latitude in the design of the piano case while at the same time maintaining the necessary key level.

IAnother object is to provide a novel key motion transmitting mechanism for a vertical grand piano permitting the action and the keyboard to be constructed as structurally separate units and operatively connected in proper relation as an incident to assembly of the units in the piano case whereby to permit of ready removal and replacement of the key frame unit or the lndividual keys.

The invention also resides in the novel character of the construction which enables the key motion transmitting mechanism to be manufactured and adjusted at low cost and frlctional resistance between the moving parts to be reduced to a minimum.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which Figure 1 is a vertical cross sectional view of a vertical grand piano embodying the novel features of the present invention.

Fig. 2 is a fragmentary sectional View illus- ,ti-ating a modified form of key motionl transmitting mechanism.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but

it is to be understood that I do not thereby intend to limit the invention to the specific forms disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

In the drawings, the invention is embodied inl a vertical grand piano comprising an elongated horizontal case having side walls 3 supporting a key bed 4, a forward wall formed in part by a sa fall board 5, and a removable or hinged top wall 77. The side walls are supported at their forward ends by legs 2 and at their rear ends by legs (not shown) or by a vertical housing having a front wall 9 and a sounding board I0 between which is mounted a plate il on which the strings i2 are stretched. By virtue of the at top, the piano case presents a frontal appearance simulating that of an ordinary grand piano, and by-arranging the strings in vertical position, the case is of narrow horizontal depth.

The key frame, which is formed as a structurally separate unit, has keys I3 fulcrumed at I4 in the usual way on a balance rail I 5 supported by the bed and detachably secured thereto. At its rear end, each key carries a capstan screw I6 and in the released position shown, rests against a pad il.

The action proper is of the general design used in upright pianos and includes a metal frame bracket I8 supported at its upper end through the medium of a series of bolts I9 rigid with and projecting forwardly from the string plate II and at its lower end by mounting screws 20 threading into a rail 2l and mounted on lugs cast on the string plate. Pivotally mounted on a flange 22 attached to a main rail 23 on the bracket I8 are a series of hammers 24 arranged to be projected against the respective strings I2 by depression of the corresponding keys I3. In the released position shown, the hammer shanks 25 rest against a cushion 26 on a hammer rail 2l. The butt 28 of the hammer carries a leather surfaced knuckle 29 which is engaged eccentrically of the hammer pivot 30 by the end of a jack 3l pivoted at 32 on a whip 33. The latter is disposed in a generally horizontal position and is supported at its rear end from a ange on the rail 23 so as to swing about a xed pivot 3Q. h

As the whip 33 is swung upwardly from the idle position shown, the jack 3l is raised thereby projecting the hammer forwardly until an arm 35 on the jack strikes a regulating button 36 as the hammer approaches the string. The whip carries theusual back check 3'! which coacts in a well known manner with a catcher 38 carried by the butt 23. The action also includes the usuai string damper 3e on the upper end of a lever 40 which operates in a well known manner in conjunction with a spoonr 4l upstanding from the rear end of the whip.

To enable the point 42 at which the hammers strike the s trings to be lowered to the degree necessary for enabling a flat top to be formed on the piano case, the action unit is mounted with the whips 33 disposed substantially below the keyboard. The present invention contemplates theprovision between the capstan screw I6 and the whip 33 of a novel motion transmitting connection which permits thewhips to be located below the keys and which is so arranged that the proper connection between each key and whip will be established ,automatically as an incident to assembly of the .keyboard unit in the plano CaSe.

In the preferred form shown in Fig. 1, the motion transmitting mechanism is supported from the action frame I8 and comprises a vertically extending link 43 pivotally connected at its lower end to the forward end 'of the whip 33 and at its upper end to the rear end lof a horizontally disposed lever 44 which projects over the rear end of the key I3 and is supported at its forward end to turn about a xed pivot 45.

To enable the motion transmitting mechanism to be formed and assembled as a part of the action unit, the pivot 45 is supported by a flange 46 attached to a rail 46' extending across the rear end of the keyboard and clamped by screws 41 against the vertical front face 48 on the upper ends of' a series of arms 49 formed as integral extensions of the action bracket I8. The screws 41 thread into the arms 49 and project through slots 50 in the rail 46 which slots allow for vertical adjustment of the rail. After the rail has been located properly, fiut'ed pins 5I Asnugly received in holes in the arms4 49 are driven into the rail thereby locking the latter securely against displacement under the vibration encountered in service. p

Intermediate its ends and on the underside thereof, the lever 44 carries a curved pad 52 of cloth or the like which, in the assembled positions of the action and keyboard units, bears against the rounded head 53 of the capstan screw I6. It will be seen that the upward movement of the rear end of the key lever resulting from depression of the key will swing the lever 44 upwardly and, through the medium of the link 43, this motion will be communicated to the whip 33 resulting in actuation of the latter in the desired manner.

Since the operative connection between the key lever and the motion transmitting connection is at a point of abutment or bearing engagement between the capstan screw and the pad 52, this connection will be established automati- -cally as an incident to movement of the keyboard assembly into proper position. For the same reason, the individual keys may be. removed and replaced if desired, and adjustment of the motion transmitting connections may be effected conveniently by'turning the capstan screws, the heads of which are readily accessible while the keys are in place. Moreover, the motion ltransmitting parts are supported and joined together by pivotal connections of simple yet rugged character which will not settle or become displaced in normal operationof the piano. Accurate adjustment will thus be maintained through long periods of service use.

By locating the point of pivotal connection between the lever 44 and the link 43 beyond the point of engagement with the capstan screw and by connecting the link to the whip forwardly of the jack pivot 32 a distance ysuiflcient to enable the link to clear the back check properly, the multiplication of the key movements necessary for effecting proper movement of the hammer is produced. It has been found that the standard key construction may be employed and the piano case kept at the desired small depth when the parts for transmitting the key motion to the jack are proportioned approximately as shown in the drawings.

If desired, the motion transmitting mechanism may be constructed and mounted as a separate unit as shown in Fig. 2. In this embodiment, each connection includes a horizontally disposed lever 54 overlying the rear end of each key I3 and pivoted at 55 on a ilange 56 fastened to a rail 51 supported above the keyboard on the upstanding arm 58 of a frame 59 secured by screws 69 to the key bed 4. The forward end of the lever carries a pad 6I bearing against the head53 of the capstan screw, The end of the lever which projects rearwardly from the keyboard is pivotally connected to the upper end of a vertically extending link 62 the lower end of which is connected to the forward end of a horizontal lever 63 which is disposed below the whip 33 andpivoted intermediate its ends on a flange 64 on a rail 65 secured to a downwardly projecting arm 66 of the bracket 59. The rear end of the lever 63 bears upwardly against a pad 61 on the underside of the whip.

Since the levers 54 and 63 and `their connecting link are carried by the separate frame 59 and have bearing engagement with the capstan screw and Whip respectively, the action and key frame remain as structurally separate units which may be assembled independently of each other. When a key is depressed, the r'earv end of the lever 54 is swung downwardly and its motion communicated to the lever 63 resulting in upward movement of the Whip and projection of the hammer against the string in the desired manner.

I claim as my invention:

l. A vertical grand piano having, in combination, a key frame having a plurality of vdepressible keys thereon, a substantially vertical plate disposed behind said key frame and having strings thereon one for each of said keys, a bracket opposite said key frame, hammers pivoted on said bracket to strike against the respective strings, vertically swingable whips pivotedv on said bracket below the level of said keys, a rail extending across and disposed abovethe rear ends of said keys and supported by said bracket, levers pivoted on said rail above the rear ends of said keys, capstan screws on the rear ends of the keys bearing upwardly against the respective levers, and means connecting each of said levers to the free end of the corresponding whip including a vertically extending link pivotaliy connected to the lever.

2. A vertical grand piano having, in combination, a key frame having a plurality of depressible keys thereon, a substantially vertical plate disposed behind said key frame and having strings thereon one foreach of said keys, an action unit having a hammer and an actuating whip for each string respectively disposed above and below the level of said keys and a frame bracket, and motion transmitting connections between the rear ends of said keys and the re spective whips established automatically as an incident to location of said frame in operative position, each of said connections including a lever having a point of bearing engagement with the rear end of one key and pivotally supported by said bracket.

3. A vertical grand piano having, in combination, a substantially vertical plate with strings thereon, an action unit having hammers for striking the respective strings and whips swingable about horizontal pivots to actuate said hammers and having forwardly projecting free ends, a key frame disposed forwardly from and above the level of said whips and having vertically swingable keys thereon, a rail stationarily supported above and extending across the rear ends of said keys, a plurality of horizontally disposed rearwardly projecting levers; one for each key bearing downwardly intermediate its ends against the rear end of the-key and pivoted at its forwardfend on said rail, and a link pivotally connected at opposite ends to the rear end of said lever and the forward end of one whip respectively whereby the whip will be swung upwardly by depression of one of said keys.

4. A vertical grand piano having, in combination, a key frame having a plurality of depressible keys thereon, a substantially vertical plate disposed behind said key frame and having strings thereon one for each of said keys, a bracket, hammers pivoted on said bracket to strike against the respective springs, vertically swingable whips pivoted on said bracket below i the level of said keys, a stationary Arail extending across and disposed above the rear ends of said keys, a lever for each of said keys pivoted at its forward end on said rail and bearing downwardly intermediate its ends against a capstan screw on one of said keys, said lever projecting horizontally and rearwardly from the associated key, and means pivotally connected to the rear end of said lever for transmitting the movements thereofto the corresponding end of said whips.

5. A vertical grand piano having, in combination, a key frame having a plurality of depressible keys thereon, a substantially vertical plate disposed behind said key frame and having strings thereon one for each of said keys, a bracket opposite said key frame, hammers disposed above said keys and pivoted on said bracket to strike against thel respective strings, vertically swingable whips pivoted on said bracket below the level of said keys, and motion transmitting connections between the rear ends of said keys and the free ends of said whips, said connections being supported by said bracket and each including a vertical link disposed behind said keys.

6. A vertical grand piano having, in combination, a substantially vertical plate with strings thereon, an action unit having hammers for striking the respective strings and whips swingable about horizontal pivots to actuate said hammers and having forwardly projecting free ends, a key bed, a key frame on said bed disposed forwardly from and above the level of said whips and having vertically swingable keys thereon, two rails extending across the rear ends of lsaid keys and respectively supported by said bed above and below said key frame, a plurality of horizontally disposed rearwardly projecting levers pivoted intermediate their ends on said upper rail and eachbearing downwardly against the rear end of the key, a plurality of horizontally disposed rearwardly projecting levers pivoted on said lower rail and connected vto the respective whips, and a vertically extending link for each key pivotally connected at opposite ends to the respective levers associated with such key.

7. A vertical grand piano having, in combination, a substantially vertical plate with strings thereon, an action unit having hammers for striking the respective strings and whips swingable about horizontal pivots to actuate said hammers and having forwardly projecting free ends, a key frame disposed forwardly from and above the level ,of said whips and having vertically swingable keys thereon, a rail stationarily supported above and extending across the rear ends of said keys, a plurality of horizontally disposed rearwardly projecting levers, one for each key bearing downwardly at its forward end against the rear end of the key and pivoted intermediate its ends on said rail, a vertically extending link pivotally connected at its upper end to the rear end of said lever, and a second horizontally disposed lever pivoted intermediate its ends below one of said whips and pivotally connected at one end to the lower end of said link, the other end of said second lever bearing upwardly against the free end of the whip whereby to swing the latter upwardly when the corresponding key is depressed.

8. A piano of the 'vertical string type having, in combination, a key unit with a plurality of depressible keys thereon, an action having a unitary rigid frame supporting a hammer and a whip for each of said keys, and connections having bearing engagement with' the rear ends of the respective keys for transmitting the key motions to said whips, said connections being supported solely from said frame whereby to constitute said action and said connections a self-contained operating structure adapted to be assembled as a unit before mounting thereof in the piano case and for transmitting the motions of said keys to the respective whips and each including as an element thereof a lever having a readily disengageable connection with the Arear end of one of said keys.

9. A piano of the vertical string type having, in combination, akey unit with a plurality of depressible keys thereon, an action having a unitary rigid frame supporting a hammer and a whip for each of said keys, and connections for transmitting the motions of said keys to the respective whips and each including as an element thereof a lever pivoted at one end and having a readily disengageable connection intermediate its end with the rear end of one of said keys, said connections being supported solely from said frame whereby to constitute said action and said connections a self-contained operating structure adapted to be assembled as a unit before mounting thereof in the piano case.

CHARLES H. DASENBROOK.

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