US2227741A - Piano action - Google Patents

Description

W. G. BETZ PIANO ACTION Jan. 7, 1941.

Filed April 6', 1938 2 Sheets-Sheet 1 "Malia/2a 4// I Way Jan. 7, 1941. w. G. BETZ PIANO ACTION Filed April 6, 195&

2 Sheets-Sheet 2 v I E I Patented Jan. 7, 1941 UNITED STATES PATENT OFFICE PIANO ACTION Application April 6, 1938, Serial No. 200,297

12 Claims.

This invention relates to piano actions and particularly to actions for upright pianos. It has its greatest utility in connection with the low upright pianos, in which it is desired to reduce the height of the piano and also its depth or the distance that it extends outwardly from the wall. In some of its aspects, however, it relates to providing an improved touch for any piano.

In modern low upright pianos the height of the piano has been satisfactorily reduced by dropping the action down so that it extends below the level of the keys. There have been some difficulties in this type of action, however, in providing the most desirable degree of compactness in the action and also the desired lightness of touch.

It is an object of my invention to provide an improved action for a low upright type of piano.

A further object is to provide a compact action which is light in weight so that it will have the double advantage of being easy to handle and will occupy as small a space as possible, and also provide the least inertia possible to be overcome in the operation of the action.

An action embodying the present invention provides a lighter touch due to the provision of greater leverage at the front or striking portion of a pivoted key. This in turn is made pos- 30 sible by a compact action embodying structure providing the greatest possible mechanical advantage in transmitting the movement of the key to the hammer.

Additional objects and advantages will be evident from the following description and from the drawings, in which:

Fig. 1 is a fragmentary vertical sectional view taken through a piano and showing an embodiment of this invention in elevation.

Fig. 2 is a fragmentary vertical sectional view through the connection between the abstract and the key seen in Fig. 1.

Fig. 3 is a fragmentary top view of the key shown in Figs. 1 and 2.

Fig. 4 is a detailed front elevational view of the abstract wire and whip of the actions of Fig. 1 and Fig. 5.

Fig. 5 is a view similar to that of Fig. 1 of a modified embodiment of the present invention.

Although this invention may take numerous forms, only two have been chosen for illustration. The embodiment of Fig. 1 has been illustrated with an upright piano indicated by the strings II in a vertical or approximately vertical plane and a pivoted hammer l2 to Strike the strings The hammer I2 is of course actuated by a key I3 through an intervening system of levers and connecting members. The hammer I2 together with the mechanism for actuating it by the key I3 is called the action, 5

and this term may refer to the. action including a single hammer I2 or the assembled action including the individual actions for all of the keys of the piano.

The hammer I2 is mounted on a pivoted hammer butt |6 which is pivoted at H to a fixed support member I8, technically called a flange. The hammer I2 is actuated by the jack I9 which engages the hammer butt I6. The relationship between the jack l9 and the hammer butt l6 together with the elements between the playing end of the key I3 and the jack I9 is important in determining the nature of the touch of the piano. According to the present invention the first of these factors, namely the relationship between the jack I9 and the hammer butt I6, is unchanged since both parts are substantially the same as they have been heretofore. The leverage between the playing portion of the key l3 and the jack I9 is increased, and this increased leverage, as well as the transmission of the playing force is accomplished in a very different manner from any known heretofore.

The key l3 operates a whip 2| through an ab- 30 stract 22. The whip 2| is pivoted to a flange 23 by the pivot 24. Heretofore the jack I9 has been pivoted directly to the whip 2|. According to the present invention, however, it is pivoted instead to one end 25 (the front end, in an installation as illustrated in Figs. 1 and 5) of secondary whip 26 which is pivoted at its midportion to an extension flange or post 21 carried by the whip 2|. The other end of the secondary whip 26 is rounded as at 28 and engages a padded portion of the main support rail 29. The result is that as the whip 2| is raised it raises the flange 21 and this not only raises but pivots the secondary whip 26 so that the jack I9 is raised approximately twice as fast as is the flange 21 and hence considerably faster than it would be if it were pivoted directly to the whip 2| Likewise, to obtain the necessary movement of the hammer for striking the string, it now requires less movement of the whip 2| than heretofore due to the provision of the secondary whip 26. The distance of travel of the jack remains substantially the same as prior actions. However due to the faster action of the jack pivoted to the secondary whip, the 55 rear end of the key I3 and hence the main whip 2i itself need not travel as far as previously to give the same kick, so to speak, to the jack for pivoting the hammer into striking engagement with the string ll. Therefore, if the same length of key is retained as with a prior action, it is possible to pivot such key nearer the rear end thereof providing greater leverage in the front or playing portion. In one embodiment of this invention it has been found that the rear end of the key travels less than as contrasted to a normal travel of A and playing is accomplished with a lighter touch on the key. The end 28 of the secondary whip 26 is kept always in contact with the rail 29 by means of a spring 3|. A spring 32 urges the jack [9 into proper engagement with the hammer butt l6.

Of importance also is the possibility of reducing the length of the key while maintaining the fulcrum 34 at the same position on the keyboard, and still obtain a touch which certainly is no heavier than that with the previous actions. In shortening the key, a reduction can also be made in the depth of the piano. This reduction is accomplished by shortening the rear end of the key, i. e. the portion of the key between the fulcrum 34 on which the key rocks and the abstract 22. This in effect increases the leverage of the playing portion of the key. In one embodiment of my invention it has been found possible to reduce the length of the key from l2 inches for a prior action to 10% inches in combination with my action.

The abstract 22 is pivoted to the whip 2i and it is highly desirable that it be removable with ease from the key [3. Various separable connections between the abstract 22 and the key l3 have been proposed heretofore. One of the most common connections was to provide a slot vertically through the rear end of the key 13 and insert the abstract wire 22 therein with a button screwed on the end of the wire abstract and resting on the key. It will be recognized, however, that with such a construction there was quite a little movement between the wire and the key at the bottom of the key. If the slot were too narrow, there would be binding between the abstract and the key, and, if the slot were too wide, there would be an opportunity for play. With some constructions there was a tendency for the abstract to become disconnected from the key accidentally or to bounce off of the key. According to the present invention a wire extension 35 is driven into the rear portion of the key, this wire extension being provided with an eyelet or circular portion 3'! through which the abstract 22 extends, and a leg 35 driven into the top of the key and grooved vertically to prevent the member from turning in the key. The abstract wire 22 is provided at its end with a wood nut 38 which is threaded onto such abstract wire 22 before adjustment. The nut 38 has a dowel recess 39 cut therein, and a felt bushing 4i is glued in this recess and extends downwardly therefrom through the eyelet 31. A felt washer 42 is provided between the nut 38 and the eyelet 31 so that there will be no play between them in a lateral direction although. the felt will have enough resiliency to permit the slight pivoted motion necessary. Of course, the eyelet can be large enough so that it does not fit the felt snugly, although there should not be any extensive lateral play since this would vary the leverage ratio. It will be apparent that since the abstract engages the key structure only in the narrow zone of the eyelet 31 the necessary motion between the abstract 22 and the key is extremely slight.

The eyelet 31 is not quite closed but instead is provided with a narrow opening 43 wide enough for the passage of the wire 22 therethrough but too small for the passage of the felt bushing 4| therethrough. The result is that when the eyelet 3'! is seated against the washer 42 the abstract cannot be removed from the key. However, when it is desired to remove the abstract from the key it is merely necessary to raise it up until the bushing 4| has passed upwardly through the eyelet 31, at which time the abstract may be shifted laterally so that the abstract wire 22 will pass through the opening 43. The bushing 41 may be sufficiently long so that there is no danger of the abstract bouncing sufficiently far away from the eyelet 31 to permit the abstract to fall out of the eyelet accidentally.

From the foregoing it is seen that, because of the smaller degree of movement required in the main whip 2 I, as a result of the secondary whip 25, to move the jack IS the required distance in pivoting the hammer I2, a shorter key portion l3 to the rear of the balance rail or fulcrum 34 is satisfactory. If the same key length is retained, the front portion [3 is relatively greater than in prior art actions and the leverage of the key greater. If approximately the same leverage as obtained with the prior art actions is satisfactory the length of the key may be reduced, and consequently the depth of the piano. A lighter touch is possible, as explained above, with this whip structure, and the provision of the wire extension 36 for the key also aids to this same end by reducing the weight of the key. It furthermore has the additional advantage of providing a satisfactory connection between the key and the abstract, and one which is substantially free from friction but which is nevertheless of such nature that there is no danger of excessive play or of accidental separation of the abstract from the key.

A modified embodiment of the invention is illustrated in Fig. 5. Except for the modification in the abstract head and guide structure therefor, the elements of the action of Fig. 5 are identical with those elements illustrated in Figs. 1 to 4, inclusive. As to the modified structure, this comprises an abstract head 45 having a body portion 46 with a threaded cavity therein for screwing onto the top of the abstract or lifter wire 22. The body portion 46 has a forward extension 4'! overhanging a capstan 48 which engages directly a felt pad 49 on the underside of the extension 41. The key attack, therefore, is direct upon the abstract head 45 and movement of the key raises the abstract to in turn pivot the whip and the related mechanism as can be readily understood.

Guide means for the abstract is provided in a rearward extension 5| on the abstract head 45 with such rearward extension having a substantially oval-shaped aperture 52 of such a size as to fit very loosely over a guide pin 53. The guide pin 53 is rigidly secured in a rail 54 mounted directly on the mounting bracket M for the piano action. The guide pin 53 is secured in the rail 54 in a position so that it is parallel to the lifter wire 22 in the position of such lifter wire illustrated in Fig. 5. This, of course, is the position of rest just as is the full line position in Fig. 1. When the key I3 is depressed the capstan 48 moves forward slightly in following the normal arcuate path'df movement therefor and with the aperture 52 in the abstract extension 5| substantially oval in shape, a corresponding forward movement of the abstract head on the capstan 48 is possible with such head at the same time being maintained in longitudinal alignment with the key by the guide pin in the aperture. As a result of this forwardv movement of the abstract head on the capstan so that the two members remain together all possible friction between the two elements is eliminated. As is apparent from a consideration of Fig. 4, the abstract or lifter wire 22 is in alignment over the greater portion of the body thereof with the transverse center point of the whip 2|. This is made possible by off-setting the wire at 5'! so that it extends down along the side of the pivot portion 58 of the whip, which latter portion is apertured to receive the hook 59 of such wire.

In the structure of Fig. 5, I provide-a compact lightweight action with all of the .playing advantages of the secondary whip 26 as explained in detail above, and in addition, an action in which all of the elements are assembled together in a manner so that it may be inserted into the piano as a unit. Similarly, the keys may be inserted and removed very readily from the piano without any connecting or disconnecting operation with the action.

In addition to the above, in the embodiment of Fig. 5 as well as in that of Fig. 1, a simple relatively inexpensive action is provided with a very desirable light touch. The front portion 25 of the secondary Whip travels faster than the main whip 2|, due to its mounting and engagement at the rear portion 28 with the rail 28. As is apparent from the above description, this results in the stroke of the hammer being quickened in relation to the movement of the key. Hence the return of the jack l9 under the hammer butt [6 is more rapid and puts the latter in position for a repetitive stroke. Repetition may therefore be more rapid to provide in all a more desirable action for the piano.

The disclosures of this application are illustrative and the invention is notto be limited by them. In fact, if modifications or improvements are not at once obvious, they may be devised in the course of time to make additional use of the ,broad ideas taught and covered by this application. The claims are intended to point out novel features and not to limit the invention except as may be required by prior art.

I claim:

1. A piano action including a pivoted hammer, a pivoted main whip, a secondary whip pivotally mounted on said main whip, means intermediate the secondary whip and said hammer for actuating the latter, a stationary rail above said whip extending in a direction transversely of the whip, an abstract connecting said main whip and a key corresponding to said action, said abstract including a lifter portion pivoted to said main whip and a head on said lifter portion, said head having a striker portion and an apertured guide portion, and stationary guide means on said stationary rail slidably supporting said head at the apertured guide portion.

2. The combination of a key, an abstract support having a leg driven into the end of the key and an eyeleted portion substantially at right angles thereto extending beyond the end of the key, and an abstract having an enlarged head resting on top of said eyelet with a downwardly extending shaft in said eyelet.

3. In a piano having keys and an action including wippens located below the level of said keys, means for transmitting motion from a key to its respective wippen comprising a rod-like member located essentially behind said key, said rod-like member being pivoted to said wippen whereby it is supported in a vertical direction and having a rigid arm overlying the end of said key, said arm having a bearing on said key solely at a point displaced from the axis of said rod-like manner, and means above said keys permitting longitudinal movement of said rodlike member while preventing substantial displacement thereof about said pivot, said means including a rail-like member, and a guide rod carried by one of said members and extending into a conforming aperture in the other of said members-whereby said key may be removed from said piano without essentially disturbing the position of said rod-like member.

4. A piano action for an upright piano having keys including in combination, a hammer,

means for transmitting the motion of a key to said hammer including an abstract member having a substantially upright connecting portion rearwardly of the rear end of a key and a rigid striking portion overlying the rear end of said key for operative striking connection therewith, guide means for said abstract at the top thereof including a rail-like member, and a substantially rigid guide rod on one of said two members extending into a conforming aperture in the other member, and means for operatively connecting said abstract with said hammer upon guided movement of said abstract.

5. A drop-type piano action for a piano having keys, said action including bracket means, a plurality of action units supported thereon, a stationary action rail rigidly secured to said bracket means and common to all of said action units, each of said units including a whip flange secured to said rail and a first whip pivotally secured adjacent one end to said flange, a post rigidly secured tosaid first whip intermediate the ends thereof, a pivoted jack and a secondary whip pivotally supported on said post and pivotally supporting said jack at one end, having the other end thereof extending under said action rail with said extending end engaging said action rail during operation of said first whip, and an elongated upwardly extending abstract operatively connected with said first whip at the end opposite the pivoted end thereof to pull said first whip upwardly and raise said secondary whip at the jack mounting end while the other end is maintained in relatively the same position by engagement with said stationary action rail.

6. In the action of claim 5 with the keys for the piano using said action each having an eyelet member formed in the end thereof, said abstralct including a wire member passed through the eyelet, a head on the wire, and a bushing supported on one of said members and positioned between said two members to prevent direct contact therebetween.

7. In a piano having keys and a mechanism including a plurality of hammers, means for transmitting the motion of said keys to said hammers including a series of substantially vertically extending and substantially vertically movable lifter members, said members each having means in the nature of rigid arms secured to said members respectively and extending forwardly over said keys respectively, each of said arms having a bearing on its respective keys solely at a point displaced from the axis of its lifter member, means including an apertured guideway to guide said members in substantially up and down movement, means operatively connecting said members and said hammers, and means limiting the displacement of said members in a downward direction whereby said keys may be removed from said piano without disturbing the relationship of said members therein.

8. In a piano having keys and mechanism including a hammer, means for transmitting the motion of a key to a corresponding hammer, including a substantially axially movable and substantially vertically disposed lifter member, a head having aportion rigidly extending from said member near one end thereof in a direction so as to overlie the end of the corresponding key and have a point of operative bearing engagement therewith substantially offset from the axis of said lifter member, and means effective during the movement of said lifter member to maintain the said head portion in a position overlying the end of said key including a guide portion having an opening therein and a corresponding guide-rod portion in said opening, with said guide portion and guide-rod portion adapted for relative movement therebetween.

9. In apiano having keys and mechanism including a whip located below the level of said keys, means for transmitting motion from a key to a corresponding whip comprising a lifter member located essentially behind said key, said lifter member being pivoted to said whip and supported in a substantially vertical direction, said member having a rigid arm overlying the end of said key, and said arm having an operative connection with its key solely at a point displaced from the axis of its lifter member, and means displaced from said keys for preventing substantial displacement of said lifter member about said pivot while permitting longitudinal movement of said lifter member whereby the keys may be removed from said piano without essentially disturbing the position of said lifter member, said means including a guiderail member and rod-like means, with one of said two members having a guideway opening therein, and said rod-like means being on the other member and positioned in said opening.

10. In an action for a piano having the usual keyboard with a plurality of keys, action frame means, a pivoted whip corresponding to one of said keys, an abstract having a guideway therein, with such abstract pivotally supported on said whip and having a portion overhanging the rear end of a corresponding key, and means for centering said abstract over said key, said centering means including a guide pin supported by said action frame means and operating in said guideway- 11. In a piano having a plurality of keys and a striking portion on the end of each key, the combination of a plurality of abstract members each having an extension overhanging the rear end of a key and operatively engaging the striking portion thereon, stationary means common to all of said abstract members, and a plurality of rigid guide members mounted on said stationary means rigid with respect thereto, and extending laterally therefrom corresponding in number to said abstract members with a guide member individual to and corresponding with each abstract member, with one of each of said two corresponding members having a guide opening therein and the other of said members having a portion slidably maintained in said guide opening upon playing movement of the abstract member.

12. In a piano having a plurality of keys and a striking portion on the end of each key, the combination of a plurality of abstract members positioned rearwardly of the rear ends of the keys, each having an extension overhanging the rear end of a key and operatively engaging the striking portion thereon, stationary means common to all of said abstract members positioned below the tops of the overhanging extensions, and a plurality of rigid guide members mounted on said stationary means, rigid with respect thereto, and extending laterally therefrom corresponding in number to said abstract members with a guide member individual to and correspending with each abstract member, with one of each of said two corresponding members having a guide opening therein and the other of said members having a portion slidably maintained in said guide opening upon up and down playing movement of the abstract member.

WILLIAM G. BETZ.

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