US2424018A - Piano action - Google Patents

Description

A. P. BROWN PIANO-ACTION July 15, 1947.

Filed Dec. 22, 1945 IN VEN TOR. ALEXANDER R BROWN ATTORNEY Patented July 15, 1947 i 1 UNITED STATES PATENT OFFICE PIANO ACTION Alexander P. Brown, Beechhurst, N. Y.

Application December 22, 1945, Serial N 0. 636,657

My invention relates topiano actions and, more particularly, to actions for spinets of restricted dimensions. An object of my invention is to provide an action which can be inserted in a piano of a height not much' exceeding the height of the keys.

In the prior art, this object has been attained by providing mechanisms connecting the key with an actuating element positioned at a lower level whereby the height of an action of otherwise more or less conventional structure is reduced. Such devices are known as underslung actions. They have several severe disadvantages. 'I'hemechanism interposed between the key and the proper action increases the number of parts required, requires higher expenses, makes the structure more complicated, makes the proper adjustment more diflicult and less reliable and results in a mushy touch and tones of poor quality.

Further objects of my invention are to avoid these drawbacks, to actuate the proper action by direct blow or stroke of the key, and, thereby, to

obtain tones of perfect quality.

Other objects are to provide a jack with a lower end positioned considerably below the level of the key; to provide a hammer with a pivoted butt positioned at its lower end; to provide for a co-operation between the jack and the hammer whereby the jack releasably engages the hammer butt and swings the hammer from the position of rest toward the sound string, and can be disengaged from the hammer when the latter rebounds; to provide means driving the hammer back into the position of rest; to provide a wippen having an arm struck upward by the key and havin another part moving down at the same time and carrying a back check; to providea jack hinged to this latter part and moving down when the key is struck; and to arrange these parts in a narrow's'pace located at the back side of the key. 1

Further objects are to provide a pivoted damper with an extension which is engaged by the jack atthe'end of a stroke. Still other objects are to arrange the hammer and the jack at a short horizontal distance from each other; to facilitate, thereby, the proper engagement between these parts; to provide, thereby, for a small horizontal measure of the action and of the piano; and to provide a structure of the hammer rest which can be positioned in the narrow space between the hammer and the jack. Still further objects are to provide the wippen and the jack with extensions contacting each other at the end of a key stroke and, thereby,

7 Claims. (Cl. 84-240) tripping the jack out of engagement with the hammer butt; and. to provide means urging the jack into the engagin position.

Still other objects are to provide the front side of the hammer butt with a recess, and to provide the lower end of the jack with a back projection engaging this recess.

Still further objects are to reduce the number of parts, and to simplify the structure of a piano action of this type.

Still other objects and advantages will appear from the following description of an exemplifying embodiment of my invention, from the appended claims and from the accompanying drawin in which the figure shows a vertical, partially sectional side view of this embodiment.

It should be noted that, throughout this specification and claims, the front side is understood to bethe side facing the performer or the left side in the drawing, and the backside to be the side facing the sound string or the right side in the drawing.

Referring to the drawing, numeral I indicates a key of conventional structure shown broken ofi, the front part of this key being omitted.

The key I can be operated either by the hand of a performer or by a pneumatic action which may move-a wire 2 in vertical direction. The wire 2 may pass slidably through an opening of a block 3 affixed,by a screw 48, to the key bed 4 and may have an upper end provided with a head 5 contacting a padded lower surface of the key I. In both kinds of operation, the back end of the ke l moves upward when the key is struck.

A wippen 6 has a fixed pivot 1. The pivot I connects the wippen 6 rotatably to a part 49 which is afiixed, by a screw 50, to a bar 5| forming a part of the pianos stationary structure. Anarm 8 of the wippen 6 extends about horizontally over the back end of the key I and carries an'adjustable screw 9 contacting a padded upper surface of the key whereby the wippen 6 is turned clockwise around the pivot 1 when the key is struck. Another part Ill of the wippen is positioned at the back side of the pivot 1, carries a back check I I and has an extension l2. Theback check may comprise a wire l3 which is bendable for adjustment of the position of the back check. 'A spring I4 has a stationary end which may be inserted in a disk l'5 afiixed to an adjustable screw l8, and has a movable end which contacts the wippen arm 8 and may be inserted in a recess'of the upper surface of this arm. The screw l6 may pass through a bar 51 forming a part of the pianos stationary structure. The spring l4 urges the wippen B in counter-clockwise direction toward the position of rest.

A jack [1 is hinged to the wippen 6 at a pivot point l8 of the part II]. The fixed pivot 'l is positioned between the pivot 18 and the screw 9. A spring [9 is positioned between the wippen 6 and a projection 20 of the jack I! and urges the jack in counter-clockwise direction around the .pivot I8.

A jack trip screw 2! is adjustably inserted in the extension 12 of the wippen and, at the end of a key stroke, contacts a padded surface of another projection 22 of the jack whereby the latter is slightly turned around the pivot l5 in clock-' wise direction.

The jack I'I extends from the pivot l8 down in an oblique direction and has a lower end positioned considerably below the level of the key'or of the key board. This lower end is provided with a back projection 23 for releasable engagement with a hammer as will be described later. The jack ll has another projection or nose 24 at itsfrbnt side. This nose serves for the operation of the damper as will be described later. Thehammer has a shank 25 which, in the position of rest, is situated at a short distance from "the jack I! and at the back side thereof. A butt 26 is affixed to the lower end of the shank 25 and has apart 21 passing below the jack l1 and havinga fixed pivot 29 positioned farther to the front side than the lower end of the jack IT. The pivot 23 connects the butt '26 rotatably to a part 52 ,whi'chis afiixed, by a screw 53, to a bar 54 forming a part of the pianos stationary structure. The butt 26 has a recess 30 at the front side, facing-theprojection 23. This recess is releasably engaged by the projection 23 which pushes the butt, 26- down when the key is struck and the jack movesdownward, and pushes the butt 25 up when the key is released and the jack moves upward. Thesurfaces of the recess 33 which are contacted by the projection 23 may be padded-with felt layers, and a thin layer 3| of suitable protective material, for example, buckskin, may be placed over these felt layers and adjoining parts of the butts surface.

Additional means urging the hammer into the position of rest may be provided. For example, a. spring 32 mayhave a stationary end 33' afiixed to-axpart 58 of the pianos'stationary structure,

and may have a movable end 34 contacting the butt 2'6 and urging the hammer in counter-clockwise direction. While not indispensable for the operation of the action, the spring32 makes it possible touse a relatively small or weak spring Wand to 'obtain, nevertheless, a quick, reliable and; forceful return of the action into the position ofrest.

Ahead 35 is affixed to the upper end or the shank 25- and is positioned below the back check in theyposition of rest. When the hammer swings around the pivot 29 in clockwise direction, the head 35 hits a sounding String 28 in the position. shown indotted lines. When the hammer rebounds from the latter position, a rounded surface3fi-of the head 35 engages wedgingly a padded surface 31 of the back check whichrat the same time, is positioned as shown in dotted lines.

A, hammer rest 38 forms a stop for counterclockwise movement of the hammer. In the position of rest, the shank 25 contacts a padded surfa'cerof the hammer rest 38. The latter is positioned in the narrow space between the shank 25 and: the jack i1, and suitable clearance is-left between the hammerrest and the jack. In order toz'make this arrangement possible, the structure of the hammer rest comprises, in contradistinction from the usual wooden bar or nail, a steel rail 39 which has a U-shaped cross-section having short legs bent into tight engagement with the pad of the hammer rest 38. This structure can be made sufficiently strong without requiring much space in the direction perpendicular to the shank 25 and makes it possible to arrange the jack H and the shank 25 about parallel and at a short distance from each other.

A damper comprises a preferably vertically positioned lever 40 turnable around a fixed pivot 4|, a head 42 and a. wire 43 connecting the head 42 with the upper end of the lever 40. The pivot 4| connects the lever 40 rotatably to a part 55 which is aflixed, by a screw 56, to a part of the 'pianos stationary structure, for example, to the 7 bar 54. A spring 44 has a fixed end and a movable end 45 urging the damper into contact with' the string 28.

the nose 24. This nose is positioned over the freeend of the wire 46 and may havo'a padded lower surface. The wire 46 is so adjusted, that the nose .24 hits .the free end of the wire at the end of a key stroke.

' The described piano action'operates as follows: 'When the key I is struck; its back end-drives the wippen 6 inclockwise direction,'raising the wippen arm 8 andloweringthe part l0 andthe back check H. The part i0 pushes the jack down whereby the projection 23, engaging the recess, 3|] and'pushing the lower surface thereof, turns the hammer around the pivot 29 into the position where the hammer head 35 strikes the string 28 as' shown in dotted lines.

Thejacktrip screw 2l,'is so adjusted tha ha short timebefore thekey stroke is completed, the jack is turned in clockwise direction around the hinge I 8 suificiently to withdraw {the projection 23 and the. lower end of the jackrll'fromthe butt recess 30. Simultaneously, the nose 24; contacts the wire, 46 and turns the damper. a little in counter-clockwise direction around thexpivot 4 l whereby'the damper head 42'iswithdrawnfrom the string 28. Then, the hammer, being disengaged from the projection 23 of the jack, rebounds and is caught by the back check I l as described before;

When the, key 'I is released, it returns intozthe shown position. of rest. At the same time, the spring l4 urges the wippen 6 back into the shown position, the projection 23 entering again the V recess 30 and pushing the'upper surface thereof up whereby the hammer is returnedinto the position shown in full lines;

I desire'it understood that my invention is not confined to the particular embodiment shown and bodiment shown and described is only one'o'f the many that may be employed to attain the objects of my invention.

' Having described the nature of my invention;

what I claim and desire to protect by Letters Patout is: a i

1. In a piano action, a combination comprising a key having a back end moving up-when the key is struck, a wippen having'a fixed pivot and an arm with a lower surface-drivingly 'contactediby said key. end; ajack hinged to said wippen, said wippen, pivot being positioned between 7 said arm 7 and said jack hinge whereby said jack moves down when the key is struck, said jack having a lower end positioned considerably lower than said key and having a back projection, and a hammer having a shank positioned at the back side of said jack, and having a butt affixed to the lower end of said shank, said butt having a front recess engageable by said jack projection and having a fixed pivot positioned farther to the front side than said recess.

2. In a piano action, a combination comprising a key having a back end moving up when the key is struck, a wippen having a fixed pivot and an arm with a lower surface drivingly contacted by said key end, a back check affixed to said wippen and extending to the back side, a jack hinged to said wippen, said wippen pivot being positioned between said am and said jack hinge whereby said jack moves down when the key is struck, said jack having a lower end positioned considerably lower than said key and having a back projection, and a hammer having a shank positioned at the back side of said jack, having a head afilxed to the upper end of said shank and engageable by said back check, and having a butt afiixed to the lower end of said shank, said butt having a front recess engageable, by said jack projection and having a fixed pivot positioned farther to the front side than said recess.

3. In a piano action, a combination comprising a key having a back end moving up when the key is struck, a wippen having a fixed pivot and an arm with a lower surface drivingly contacted by said key end, a jack hinged to said wippen, said wippen pivot being positioned between said arm and said jack hinge whereby said jack moves down when the key is struck, said jack having a lower end positioned considerably lower than said key and having a back projection, a hammer having a shank positioned at the back side of said jack, and having a butt afiixed to the lower end of said shank, said butt having a front recess engageable by said jack projection and having a fixed pivot positioned farther to the front side than said recess, and a spring positioned between said wippen and said jack and urging the latter around its hinge in that direction in which the lower end of said jack engages said hammer butt, said wippen and said jack having projections contacting each other at the end of a key:

stroke whereby said jack is turned against the pressure of said spring.

4. In a piano action, a combination comprising a key having a back end moving up when the key is struck, a wippen having a fixed pivot and an arm with a lower surface drivingly contacted by said key end, a jack hinged to said wippen, said wippen pivot being positioned between said arm and said jack hinge whereby said jack moves down when the key is struck, said jack having a lower end positioned considerably lower than said key and having a back projection, a hammer having a shank positioned at the back side of said .jack, and having a butt affixed to the lower end of said shank, said butt having a front recess engageable by said jack projection and having a fixed pivot positioned farther to the front side than said recess, said jack having a nose at its front side, and a damper having a fixed pivot and an extension reaching into the path of said nose.

'5. In a piano action, a combination comprising a key having a back end moving up when the key is struck, a wippen having a fixed pivot and an arm with a lower surface drivingly contacted by said key and, a jack hanged to said wippen, said wippen pivot being positioned between said arm and said jack hinge whereby said jack moves down when the key is struck, said jack having a lower end positioned considerably lower than said key and having a. back projection, a hammer having a shank positioned at the back side of said jack, and having a butt affixed to the lower end of said shank, said butt having a front recess engageable by said jack projection and having a fixed pivot positioned farther to the front side than said recess, and a hammer rest positioned between said shank and said jack and comprising a steel rail of U-shaped cross-section.

6. In a piano action, a combination comprising a key having a back end moving up when the key is struck, a wippen having a fixed pivot and an arm with a lower surface drivingly contacted by said key end, a spring urging said wippen arm toward said key end, a jack hinged to said wippen, said wippen pivot being positioned between said arm and said jack hinge whereby said jack moves down when the key is struck, said jack having a lower end positioned considerably lower than said key and having a back projection, and a hammer having a shank positioned at the back side of said jack, and having a butt affixed to the lower end of said shank, said butt having a front recess engageable by said jack projection and having a fixed pivot positioned farther to the front side than said recess.

7. In a piano action, a combination comprising a key having a back end moving up when the key is struck, a wippen having a fixed pivot and an arm with a lower surface drivingly contacted by said key end, a jack hinged to said wippen, said wippen pivot being positioned between said arm and said jack hinge whereby said jack moves down when the key is struck, said jack having a lower end positioned considerably lower than said key and having a back projection, a hammer having a shank positioned at the back side of said jack, and having a butt affixed to the lower end of said shank, said butt having a front recess engageable by said jack projection and having a fixed pivot positioned farther to the front side than said recess, and a spring urging said hammer in the direction to the front side.

ALEXANDER 1?. BROWN.

Images