US2156913A - Piano action - Google Patents

Description

May 2, 1939. w. s, FINHOLM PIANO ACTION 2 Sheets-Sheet 1 Filed Jan. 24, 1936 INVENTOR. MA A /AM 6. fi/l/h OA/W.

% ATTORNEYS 4 w. s. FINHOLM 2,156,913

PIANO ACTION May 2, 1939.

2 Sheets-Sheet 2 Filed Jan. 24, 1936 f5/ /Z9 M4,

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I f4 m5 I '1 I I v w 137 13.3 135 1915 I i ,4 H a f2? Patented May 2, 1939 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to new and useful'improvements in piano actions and more particularly it pertains to that portion of a piano action commonly known in the art as the repetition.

As in my prior application filed August 22, 1934, Serial No. 740,911, it is the object of the present invention to improve the construction and principle of operation of piano repetitions and so to construct such mechanisms that the mechanical results as well as the satisfaction of operation are greatly increased over any possible attainment with piano actions as they are generally constructed.

A feature of this invention resides in a novel construction and arrangement of parts whereby the periodicity of a complete note striking operation is materially reduced over that of the repetitions as generally constructed, thereby providing a greater rapidity of action than is possible with the so-called standard actions.

A further feature of the invention resides in a novel construction and arrangement of parts whereby the several keys of a piano action may be so adjusted that the touch throughout the entire keyboard will be uniform.

In standard actions as generally constructed, it is the common practice to weight the keys with lead which is known in the art as weighing off. Such practice, however, cannot be accurately enough accomplished to produce uniformity of touch throughout the entire keyboard. Furthermore, weighting the keys with lead causes the keys, when struck, to accelerate in their movement to effect an operation of the repetition mechanism. This acceleration of movement is caused primarily by the momentum of the leads when the key is struck and it produces a feeling on the part of the performer, of loss of control of the key.

A further feature of the present invention resides in a novel construction whereby this leading of the keys is entirely dispensed with, thereby removing all tendency of acceleration on the part of the key and consequently, making for absolute control of the key.

A further feature of the invention resides in a novel construction whereby an even balance and consequent even pressure is maintained throughout the entire note striking operation.

Still a further feature of the invention resides in a novel construction whereby a more perfect escapement of the fly with respect to the fly lever is obtained, thus making for perfect operation of the hammer even under very light touch or striking blows.

Still a further feature of the invention'resides I in a novel construction and arrangement of parts whereby a more permanent regulation of the entire mechanism may be maintained.

Other features of the invention relate to certain novel and improved constructions, arrange ments and combinations of parts hereinafter described and particularly pointed out in the claims, the advantages of which will be readily understood and appreciated by those skilled in the art.

' The invention will be clearly understood from the accompanying drawings illustrating the invention in its preferred form and the following detailed description of the constructions therein shown.

In the drawings:

Figure 1 is a View partly in section and partly in elevation of a piano action, illustrating a repetition mechanism constructed in accordance with the present invention,

Figure 2 is a fragmentary top plan View thereof,

Figure 3 is a view partly in elevation and partly in section on an enlarged scale, illustrating a repetition mechanism constructed in accordance with the present invention in a position of rest,

Figure 4 is a view similar to Figure 3, showing the several parts in the position they assume during a note striking stroke and just prior to the escapement of the fiy from the fly lever,

Figure 5 is a view similar to Figures 3 and 4, showing the parts in that position which they assume after the fly has escaped from the fly lever and just prior to engagement of the hammer with the string, and;

Figure 6 is a detail sectional view taken substantially on the line 6-5 of Figure 2.

In the accompanying drawings, the reference character. I50 designates the key frame of a piano action, which key frame is herein illustrated as of conventional construction or form. A balance rail IBI is carried by the key frame and the keys IE2 are mounted thereon by means of a balancing and adjusting pin I03. The inner ends I84 of the keys come to rest upon a key rest I05, and carried by the inner end of each key there is the conventional back check I06. Each key carries a conventional capstan screw I01.

The supporting frame is designated I08; and

this frame carries suitable supporting rails I09, H0, and II I. The supporting rail I09 provides for mounting of the hammer shank flange or lug I I2, which, as illustrated herein, differs from those of conventional form in a manner to be hereinafter described.

In my prior application, above identified, the hammer shank flange is secured to its supporting rail in the conventional manner which consists of a screw which passes through an opening in the hammer shank flange, which opening is of an internal dimension which will barely accommodate the screw, and therefore, does not permit of any adjustment of the hammer shank flange relatively to the supporting rail. In the present construction, I form each hammer shank flange H2, with a bifurcated end II3, and the screw H4 which secures the hammer shank flange to the supporting rail I09, is positioned between the furcations of the bifurcated end, as best shown in Figure 2. It will be readily apparent that such a construction permits of ready adjustment of the hammer shank flange relative to the supporting rail I03.

The hammer shank is designated IE5, and the hammer is designated M8. The hammer shank H5 is pivotally connected as at III to the hammer shank flange H2, in the conventional manner. With the parts in the position of rest, the hammer shanks engage and are supported upon a hammer rest 550. This hammer rest I56 consists of a rail 85f, which carries a suitable felt IEE, upon which the hammer shanks rest. As best illustrated in Figure 6, the rail I5I is supported by screws I53 of which there may be any desired number. To provide for adjustment of the hammer shank rest I50, the several screws are threaded into the supporting frame I38, as at I54, and each has an annular flange I55 against which the rail I5I may be secured by a nut i553.

The repetition mechanism per se includes a fly lever 558, a balancing lever H3 and a fly I23. Inasmuch as the repetition mechanism is substantially the same for each key, the description of but one will suflice. A vertically disposed lug or bracket I2i is secured by a suitable screw I22 to the supporting rail III. The fly lever IE8 is pivotally mounted as at I23 and the balancing lever H9 is pivotally mounted as at i24 between the furcations of the bifurcated lug or bracket I2I. As is illustrated, these pivotal points I23 and I24 are spaced with relation to each other, which construction causes the fly lever H3 and the balancing lever M9 to move in arcs excentric to each other during an operation of the repetition mechanism. The knuckle is designated 535 and is carried on the free end of the balancing lever H3, being preferably formed about the extremity of said free end in the manner illustrated. The fly stop is designated I26 and is preferably carried upon the under face of the balancing lever.

The fly lever is provided with the ordinary capstan screw cushion I272 for engagement by the capstan screw I0! and the free end of the fly lever is bifurcated as at E28 to provide for mounting the fly I20. The fly is pivotally mounted as at H0, between the furcations of the bifurcated end of the fly lever. The fly I20 has two oppositely projecting tail pieces I33 and I3I. The tail piece I 33 occupies a position between the furcations of the bifurcated end of the fly lever, the tail piece I3I projecting beyond the free end of the fly lever. The tail piece I30 carries a felt I32, and these parts are so shaped that an inclined face I33 is provided upon the upper face of this tail piece I30, the purpose of which will be hereinafter described.

Carried by the balancing lever and having engagement with the fly, there is a resilient member I35. This resilient member is preferably in the form of a flat spring and as illustrated in Figure 3, it is secured to the under side of the fly lever near its pivotal end as at I36. The opposite end of the resilient member is free and is provided with a downwardly disposed angular portion I31, the angle of which closely corresponds to the angle of the angular face I33 of the tail piece I30 of the fly. Means is provided for adjusting the tension of this resilient member, this means being herein illustrated as a screw I38 having threaded engagement with the balancing lever H9 and passing therethrough into engagement with the resilient member. A hooked member I39 having a hooked end I40 is adjustably carried by the fly lever IIB, the adjustment of the hooked member being provided by the threaded engagement MI. The hooked end I40 overlies the balancing lever H9, and engages, under certain operating conditions, an angular seat provided in the form of a cushion I42.

A resilient member I43 is also provided and it may be attached to the balancing lever II9 as at I44. This resilient member I43 is preferably in the form of a flat spring bowed substantially as shown and having an angularly extending free end I44. Having threaded engagement with the lug or bracket I2I, there is a hooked member I45, the hooked end of which embraces the angularly extending free end of the resilient member I43, and this hooked member I45 affords the means by which the tension of the resilient member I43 may be adjusted.

It is the function of the resilient members I35 and I43 to support the balancing lever and the hammer and by the provision of adjustments for the tension of these resilient members, a perfect balance of each repetition mechanism and a uniform touch throughout the entire set of repetition mechanisms, is possible of attainment.

Adjustably carried by the supporting rail IIO, there is a regulating button I46 so positioned that during the operation of the repetition mechanism, the tail piece i3I of the fly will engage the regulating button to effect an escapement of the fly relatively to the balancing lever II9. A fly stop I4! is provided to limit the escapement movement of the fly. The operation of the rep etition mechanism will now be described.

In Figure 3, the repetition mechanism is illustrated with its several parts in a position of rest. Upon the striking of a key I02 its inner end will be elevated carrying the capstan screw I0! with it. As the capstan screw is elevated the entire repetition is elevated, the fly lever and balancing lever being rocked about their respective pivotal points. During this pivotal movement of the fly lever and the balancing lever, these levers move through arcs which are excentric to each other. Such movement, however, does not tend to increase the tension of the resilient member I 35, since in the upward movement of the repetition mechanism the angular portion I37 of the resilient member I35 rides down the inclined face I33 of the tail piece I30 of the fly, thus compensating for the movement of the fly and balancing lever toward each other and thereby preventing increased tension in the resilient member I35.

During this upward movement of the repetition mechanism, the angularly extending free end I44 of the resilient member I43 tends to move to the left in the drawings, or away from the hooked member I45, and it will be obvious that as the upward movement of the repetition mechanism continues, the tension of this resilient member I43 will be gradually reduced. Thus, it will be readily apparent that as the leverage increases, the supporting tension of the resilient member I35 remains constant while the tension of the resilient member I43 decreases and an unvarying or constant resistance and uniformity throughout the entire stroke results. Further, it will be obvious that by adjustment of the screw I38 and the hooked member I45, the touch of the several keys of a piano action may be regulated as desired and can be brought into absolute uniformity.

Upon continued upward movement of the repetition mechanism as a unit, the tail piece I3I engages the regulating button I45, as illustrated in Figure 4. From this point on, the repetition mechanism ceases to move upwardly as a unit and the elements thereof begin to function independently of one another in the following manner. The fly is rocked about its pivotal point I29, causing its escapement from beneath the balancing lever I I9, as shown in Figure 5 and the balancing lever II9 continues in its movement to carry the hammer into engagement with the string S, as shown in dotted lines in Figure '1. After the hammer has contacted the string S it settles into engagement with the back check I06, and as the key is released, the back check passes out of engagement with the hammer, leaving the shank of the hammer resting upon the hammer rest I50, and permitting the several parts to return to the position of rest in which position they are shown in Figure 1 and in Figure 5.

During the operation of the mechanism as above described, the hooked member I39, by reason of the excentricty of the arcs through which the fly lever and the balancing lever move, moves away from and out of engagement with the balancing lever II9, as illustrated in Figure 5. As the parts are returning to the position of rest, the resilient members I35 and I43 support the balancing lever H9 in the position in which it is shown in Figure 5 until, by reason of the downward movement of the fly lever, the fly will pass beneath the knuckle I25. After the fly has reached position beneath the knuckle I25, the hooked member I39 engages the angular seat formed by the cushion I42, pulling downwardly the balancing lever H9, and permitting all the parts to return to the position of rest.

The construction and arrangement of parts just described acts to return all parts quickly to their position of rest and thus makes for rapid repetition action of the mechanism.

While the invention has been herein described in its preferred form, it is to be understood that it is not to be limited to the specific construction herein shown, and that it may be carried out in many other forms which rightfully fall within the scope of the appended claims.

Having thus described the invention, what is claimed, is:

1. In a piano action, a repetition mechanism including a fly lever and a balancing lever, means for pivotally mounting said fly lever and said balancing lever independently of each other, a fly pivotally mounted on the fly lever, said fly having a free upper end for engagement beneath the balancing lever, a resilient member carried by the under side of the balancing lever and having engagement with the fly, means for adjusting the tension of said resilient member, and means for preventing increase in tension upon said resilient member during an operation of the repetition mechanism.

2. In a piano action, a repetition mechanism including a fly lever and a balancing lever, means for pivotally mounting said fly lever and said balancing lever independently of each other, a fly plvo-tally mounted on said fly lever, said fly having a free upper end for engagement beneath the balancing lever, a tail-piece projecting from said fly in the direction of the pivotal points of the balancing lever and the fly lever, an angular face on said fly tail-piece, a resilient member carried by the balancing lever and projecting into engagement with the tail-piece of the fly, and an angular extension on the fly engaging end of said resilient member for operative engagement with the angular face on the fly tail-piece to prevent increase of tension upon the resilient member during an operation of the repetition mechanism.

3. In a piano action, a repetition mechanism including a fly lever and a balancing lever, means for pivotally mounting said fly lever and said balancing lever independently of each other, a fly pivotally mounted on said fly lever, said fly having a free upper end for engagement beneath the balancing lever, a tail-piece projecting from said fly in the direction of the pivotal points of the balancing lever and the fly lever, an angular face on said fly tail-piece, a resilient member carried by the balancing lever and projecting into engagement with the tail-piece of the fly, an angular extension on the fly engaging end of said resilient member for operative engagement with the angular face on the fly tail-piece to prevent increase of tension upon the resilient member during an operation of the repetition mechanism, and means for adjusting the tension of the resilient member.

4. In a piano action, a repetition mechanism including a fly lever and a balancing lever, means for pivotally mounting said fly lever and said balancing lever independently of each other, a fly pivotally mounted on said fly lever, said fly having a free upper end for engagement beneath the balancing lever, a tail-piece projecting from said fly in the direction of the pivotal points of the balancing lever and the fly lever, an angular face on said fly tail-piece, a resilient member carried by the balancing lever and projecting into engagement with the tail-piece of the fly, an angular extension on the fly engaging end of said resilient member for operative engagement with the angular face on the fly tail-piece to prevent increase of tension upon the resilient member during an operation of the repetition mechanism, and means carried by the balancing lever at a point closely adjacent the point of attachment of the resilient member and having engagement with the resilient member for adjusting the tension of the resilient member.

WILLIAM S. FINHOLM.

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