HK1225786B - Piano extended soft pedal - Google Patents

Description

Piano extended soft pedal

Technical Field

The present invention relates to an upright piano, and in particular to a soft pedal assembly of the piano.

Background Art

Acoustic pianos employ various systems for transmitting energy from finger or actuator input forces into audible, vibratory forces. The transmission system (often referred to as the "piano action" or "action") is a network of rods, pads, and hammers that accept finger/actuator input forces through a collection of pivoting rods (called piano keys or keys). The piano keys and piano action concentrate this input force into hammers that are rotationally positioned to strike the strings in direct proportion to their density. The piano hammers and their corresponding piano strings are carefully constructed to match their acoustic properties, resulting in components that cumulatively produce a tapered or gradient "scale" of musical frequencies spanning multiple notes. The piano strings serve as the medium through which the vibrational energy is transferred to an amplifier, such as a soundboard or electric speaker, where it is ultimately converted into audible sound.

Pianos can produce a wide range of volumes. Larger pianos can further extend this range to include very loud sounds, such as those heard in concert pianos, which are intended to be played by an accompanying orchestra without the aid of electrical amplification. Pianos are present in many homes, schools, institutions, and the like. Inevitably, this proximity to the sound-producing instrument creates a need to control and dampen the sound. Many piano manufacturers offer pianos with sound-level reduction mechanisms that selectively limit volume levels. In upright pianos, these mechanisms typically include a lever that can be actuated to shift the resting position of the piano hammers relative to the strings, moving them closer to the strings so that the hammers strike the strings with less kinetic energy. This type of soft pedal lever, or hammer-back lever, reduces the piano volume to a level calculated to avoid disturbing the surrounding environment, such as an apartment, practice room, or the like.

Summary of the Invention

According to one aspect of the present disclosure, a piano that can be selectively played in a normal mode and in a soft mode comprises: a set of a plurality of piano keys; a set of a plurality of piano actions associated with the plurality of piano keys, each piano action comprising a piano linkage assembly actuated by depression of a corresponding piano key; a set of a plurality of piano hammers, each piano hammer being mounted for rotational movement and defining a forward throw direction toward at least one corresponding piano string, each piano hammer being driven by a corresponding piano linkage assembly to transmit a force applied to the associated piano key; a soft pedal system comprising: a soft pedal; a hammer backrest mounted for movement between a normal mode position and a soft mode position, wherein in the normal mode position, the set of a plurality of piano hammers The piano hammers are statically arranged at a certain distance from the corresponding piano strings, and in the soft mode position, the group of multiple piano hammers move to a static position relatively closer to the corresponding piano strings; a piano key lifter, which is installed to move between a normal mode position separated from the piano key lift contact of the group of multiple piano keys and a soft mode position set to contact and lift the piano keys together with the piano linkage rod assembly; and a soft pedal linkage assembly, which transmits/connects between the soft pedal and the hammer back and the piano key lifter, wherein actuation of the soft pedal causes the hammer back to move together with the piano hammers, and causes the piano keys together with the piano linkage rod assembly to move in a closed gap between the normal mode position and the soft mode position.

The piano of the present disclosure may also include one or more of the following embodiments. For example, the soft pedal linkage assembly includes: a generally horizontal soft pedal transmission rod, a hammer back lever, and a piano key lift lever. The hammer back lever and the piano key lift lever are mounted sequentially along the soft pedal transmission rod. Preferably, the hammer back lever and the piano key lift lever are mounted generally parallel to the soft pedal transmission rod. Actuation of the soft pedal lifts the hammer back lever and the piano key lift lever. Preferably, the piano lift lever includes a length-adjustable connecting rod. In a particular embodiment, the length-adjustable connecting rod includes a coaxial screw and a locking mechanism, and the length-adjustable connecting rod is independently adjustable relative to the length of the hammer back lever. The piano key lift lever is configured to engage with the rear bottom surface of the key of the group of multiple piano keys when actuated. The piano key lift lever is mounted for pivotal movement between its normal mode position separated from the piano key engagement of the group of multiple piano keys and its soft mode position in which it is in lift engagement with the piano key of the group of multiple piano keys. The piano key lifter is mounted at at least two pivot points (fulcrums), for example, three, four, or five pivot points or fulcrums. The piano key lifter is non-flexible. In soft play mode, the piano key lifter is positioned to move into engagement with a piano key of the plurality of piano keys via linear or rotational motion. The piano key lifter engages the piano keys of the plurality of piano keys via spring force, magnetic force, or electromechanical force. The piano also includes a plurality of strap and strap hook combinations, each strap and strap hook combination connecting a piano hammer to a corresponding piano linkage assembly, wherein actuation of the soft pedal tensions each strap and strap hook combination to promote movement of the associated piano linkage assembly and the associated piano hammer into a closed gap. Preferably, tensioning at least one of the strap and strap hook combinations comprises shortening at least one of the strap and strap hook, or tensioning at least one of the strap and strap hook combinations comprises bending an upper end of the strap hook below the strap or repositioning the entire strap hook.

According to another aspect of the present invention, a piano playable in at least a normal mode comprises: a plurality of piano keys; a plurality of piano actions associated with the plurality of piano keys, each piano action including a piano linkage assembly actuated by depression of a corresponding piano key; a plurality of piano hammers, each piano hammer mounted for rotational movement and defining a forward throw direction toward at least one corresponding piano string, each piano hammer driven by a corresponding piano linkage assembly to transmit a force applied to the associated piano key; and a plurality of strap and strap hook assemblies, each strap and strap hook assembly connecting the piano hammer to a corresponding piano linkage assembly, wherein the strap and strap hook assembly are mounted and adjusted to maintain the hammer assembly and the corresponding linkage assembly together in a movement that minimizes play when the associated piano key is played.

Preferred embodiments of this aspect of the invention may include the following features: The piano is selectively playable in a normal mode and in a soft mode and further includes a soft pedal system comprising: a soft pedal; a hammer back guard mounted for movement between a normal mode position and a soft mode position, wherein in the normal mode position, the plurality of piano hammers are stationarily disposed a distance from the corresponding piano strings and in the soft mode position, the plurality of piano hammers are moved to a stationary position relatively closer to the corresponding piano strings; a piano key lift guard mounted for movement between a normal mode position spaced apart from the piano key lift contact of the plurality of piano keys and a soft mode position configured to contact and lift the piano keys together with a piano linkage assembly; and a soft pedal linkage assembly transmitting between the soft pedal and the hammer back guard and the piano key lift guard, wherein actuation of the soft pedal causes the hammer back guard to move together with the piano hammers and causes the piano keys together with the piano linkage assembly to move in a closed gap motion between the normal mode position and the soft mode position.

The present disclosure thus provides an improved upright piano that is selectively playable in normal and soft modes, having a soft pedal system that closes gaps experienced by the upright piano itself, such as between the hammer assembly and the top bar of the piano action and/or between the linkage assembly and the pin (or screw at the rear end of the piano key that contacts the linkage assembly), resulting in a significant improvement in the "lost motion" and undesirable contact feeling experienced during piano playing. In some embodiments, a tensioned strap and strap hook combination may also be additionally employed.

An object of the present disclosure includes providing an upright piano in which gaps in the piano action that cause an undesirable tactile sensation of "lost motion" to the pianist are reduced or eliminated. In one embodiment, this object can be achieved using a soft pedal system having a soft pedal that actuates a hammer back guard mounted for movement between a normal mode position, in which a group of piano hammers are stationarily positioned a certain distance from corresponding piano strings, and a soft mode position in which a group of piano hammers are moved to a rest position relatively closer to the corresponding piano strings; and a piano key lift guard mounted for movement between a normal mode position, in which a group of piano hammers are stationarily positioned a certain distance from corresponding piano strings, and a soft mode position in which a group of piano hammers are moved to a rest position relatively closer to the corresponding piano strings; and a piano key lift guard mounted for movement between a normal mode position, in which a group of piano hammers are spaced from piano key lifting contact, and a soft mode position, in which a group of piano hammers are positioned to contact and lift the piano key together with a piano linkage assembly. The soft pedal linkage assembly that transmits power between the soft pedal and the hammer back rail and piano key lift rail causes the hammer back rail to move together with the piano hammers when the soft pedal is actuated, and causes the piano keys together with the piano linkage rod assembly to move in a closed gap between the normal mode position and the soft mode position.

In combination with the above-described embodiment, or in another separate embodiment, for example, in a piano that is playable at least in a normal mode, play in a piano action that causes an undesirable tactile sensation of "lost motion" for a pianist can be reduced or eliminated by using a plurality of straps and strap hook assemblies, each strap and strap hook assembly connecting a piano hammer to a corresponding piano linkage assembly, wherein the straps and strap hook assemblies are mounted and/or adjusted to hold the hammer assembly and the corresponding linkage assembly together in a motion that minimizes play when the associated piano key is played. For example, in one embodiment, the tensioned straps are mounted so that the span of the tensioned straps (i.e., the effective length between the connections at opposite ends) is substantially constant between an initial position and a final position, and also during a transition between the initial position and the final position.

The effectiveness and degree of lost motion improvement can be expected to vary from instrument to instrument, or even within the same instrument, due to, for example, the skill, experience and habits of the player, the conditions of performance, the environment, the level of repair of the piano and its components, etc.

The details of one or more embodiments of the present disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present disclosure will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side cross-sectional view of a conventional (prior art) upright piano having a soft pedal system.

FIG. 2 is a side view of a piano action of conventional (prior art) design in an unplayed position.

3 is a side elevational view of the conventional (prior art) piano action of FIG. 2 in a position just played.

Figure 4A is a side elevational view of the conventional (prior art) piano action of Figure 2 returned from the playing position, and Figure 4B is a similar slightly enlarged side elevational view of the conventional (prior art) piano action of Figure 4A showing the gap between the jack and the hammer.

Figure 5A is a side view of the conventional (prior art) piano action of Figure 2 with the soft pedal depressed, and Figure 5B is a similar slightly enlarged side view of the conventional (prior art) piano action of Figure 5A showing the gap between the jack and the hammer.

6A is a side view, partially in section, of a first configuration of an extended soft pedal piano action of the present disclosure including a rigid lift.

6B is a side view, partially in section, of a second configuration of the extended soft pedal piano action of the present disclosure including a rigid lift.

7 is a front elevational view of the bottom of an upright piano including a rigid linkage system for raising an embodiment of the rigid lift rail of FIG. 6A.

8 is a close-up view of a portion of the rigid linkage system of FIG. 7 .

9 is a front elevational view of the bottom of an upright piano including a rigid linkage system for raising the rigid lift embodiment of FIG. 6A.

FIG. 10 is a close-up view of a portion of the rigid linkage system of FIG. 9 .

11 is a front elevational view of the bottom of an upright piano including a rigid linkage system for raising the rigid lift embodiment of FIG. 6A.

12 is a close-up view of a portion of the rigid linkage system of FIG. 11 .

FIG. 13 is a portion of an embodiment of a rigid linkage system.

14 is a side elevational view, partially in section, of the extended soft pedal piano action of the present disclosure including the frets in an unplayed position.

15A is a side elevational view of the soft piano action of FIG. 14 with the soft pedal depressed, and FIG. 15B is a similar, slightly enlarged side elevational view of the piano action of FIG. 15A showing the gap between the linkage assembly and the pins.

15C is a side view of the soft pedal piano action of FIG. 14 , with the gap that produces lost motion closed.

FIG. 16 is a top view of an upright piano including the extended soft pedal piano action of FIG. 14 .

17 is a side elevational view, partially in cross-section, of the extended soft pedal piano action of FIG. 14 including the lift spring assembly.

18 is a detailed side view of the shift lift spring assembly of FIG. 17 , partially in cross-section.

19 is a detailed side view of the embodiment of the soft pedal piano action of FIG. 15C.

20A to 20J show alternative cross-sectional views of a spring rail for the extended soft pedal piano action of FIG. 6A or FIG. 14 .

Like reference numbers in the various drawings represent like elements.

DETAILED DESCRIPTION

1 , a conventional upright piano 100 includes a series (or group) of piano keys 110 and corresponding piano actions 120, which are connected to the rear sections 113 of the piano keys 110 and rest on a key frame 115 connected to a keybed 116. Each piano action 120 is actuated by depressing the exposed playing surface 114 of the corresponding key 110. A series (or group) of (piano) hammer assemblies 130 includes rotatable piano hammers 135, each defining a forward throw direction T. These hammers are driven by corresponding linkage assemblies 150 and transmit the force applied to the playing surface 114 of the corresponding key 110. Each piano hammer 135 is aligned to strike a corresponding piano string or group of strings 180 when struck. For example, a hammer 135 may strike one to three strings 180 to produce the desired tone of the corresponding depressed key 110.

1 to 3 , each hammer assembly 130 includes a hammer 135 mounted on the upper end of a hammer shank 131, with the lower end of the hammer shank mounted to a butt assembly 136. In these figures, the butt assembly 136 includes a butt 137, a pin 138, and a stop wood 139. Pressing or actuating a piano key 110 causes the jack 154 of the associated actuator assembly 150 to push the butt assembly 136 of the hammer 135. When the jack 154 pushes the butt assembly 136, the butt assembly 136 and the hammer shank 131 rotate in a forward throwing direction T, toward the piano strings 180 associated with the piano hammer 135. The piano hammer 135 strikes the piano strings 180, indirectly producing an acoustic sound. When the key 110 is in the rest position, as shown in FIG. 2 (eg, when the player is not depressing the key 110 ), the hammer 135 remains in position, resting on the soft pedal or hammer back 170 and/or the jack 154 .

A thin, flexible tether (referred to as a "climbing strap") 140 connects the respective hammer and linkage rod assemblies 130, 150 and restricts these assemblies from rotating apart. In previous embodiments, such as shown in FIG2 , one end of the climbing strap 140 is connected (e.g., permanently connected) to the hammer assembly 130 at the butt assembly 136. In other embodiments (not shown), the climbing strap 140 is connected to the butt assembly 136 at the intersection of the pin 138 and the stopper 139. During normal use, the conventional climbing strap 140 remains loose and does not lift the linkage rod assembly 150.

2 , when a key 110 is not played, the bridle strap 140 is generally bent and slack as it connects the hammer and linkage rod assemblies 130, 150, and has an indefinite span (or distance between the ends). When a key is pressed, as the key 110 pivots during playing, the distance between the two ends becomes smaller, and the bridle strap 140 becomes relatively looser (relaxed) to a minimum spacing as the key is pressed, i.e., the span of the bridle strap is smaller than when the key is not played.

FIG3 shows the moment when the key 110 has reached almost full depression. The key 110 has pivoted about its central pivot point (P), raising the linkage assembly 150. This movement, in turn, has rotated the hammer assembly 130 toward the piano strings 180 (not shown) located to the left of the hammer assembly 130. The flexible strap 140 is now significantly looser, i.e., the strap span has been significantly reduced from the initial span shown in FIG2 .

As shown in Figures 4A and 4B, having played a note and caused the piano hammer 135 to strike the appropriate piano string 180, the musician releases the key 110. The key weight 112 associated with (e.g., embedded in) the key's rear section 113 causes the key 110 to immediately pivot back to its original, unplayed position. With the key 110 no longer supporting the piano action 120, the linkage assembly 150 descends downward, while the hammer assembly 130 lags behind, in part because its center of gravity is nearly vertically above its center of rotation. Up to this point in the keystroke, the bridle strap 140 has no effect in the piano action. Only when the descending linkage assembly 150 tensions the bridle strap 140, which is at or near its maximum span, does the bridle strap activate and pull the hammer assembly 130 backward toward its rest position.

As best shown in FIG4B , during this release of the piano key, a temporary gap 145 opens between the jack 154 of the linkage rod assembly 150 and the hammer assembly 130 of the hammer assembly 130 due to the time interval between the return motions of these two assemblies (i.e., the linkage rod assembly 150 and the hammer assembly 130). If the key is played again before the gap 145 closes, the gap 145 causes an unwanted tactile sensation at the beginning of the next keystroke, known as "lost motion." If a second keystroke is initiated at this point, i.e., during the key release process, a distinct sense of lost motion can be detected because the new keystroke must cause the linkage rod assembly 150 to pass through the gap 145 before contacting the hammer assembly 130. This temporary change in the feel of the piano action is almost universally considered a negative characteristic of upright pianos.

Lost motion also occurs when the soft pedal is depressed. Referring again to FIG. 1 , when the soft pedal 160 of the upright piano 100 is depressed, an attached link or wire 165 actuates the back rail 170 to pivot all eighty-eight hammer assemblies 130 in a typical traditional (prior art) piano 100 upward and closer to the strings 180. This reduction in hammer travel distance creates a lower, "softer" feel to the piano 100.

As shown in FIG5A , the movement of the backrest 170 in the backrest motion direction (arrow 175) moves all of the hammer assemblies 130 upward and toward the piano strings 180. When the shift pedal 160 is fully depressed, the bridle strap 140 approaches a tensioned state with a shift pedal span 146 (note its straightened attitude); however, the bridle strap 140 conventionally does not exert any lifting force on the lower linkage assembly 150. In this lifted position, the shift pedal position of the hammer assemblies 130 again results in lost motion due to the gap 147 created between the jack 154 and the butt assembly 136 ( FIG5B ). Due to the rotation of the hammer assemblies 130, the gap 147 is uniformly generated across the entire keyboard of the upright piano 100 when the shift pedal 160 is depressed. When the shift pedal 160 is released, the hammer assemblies 130 rotate back to their original position, restoring their longer travel distance and eliminating the lost motion gap 147. The lost motion resulting from depression of the soft pedal 160 has long been viewed as an undesirable but necessary compromise in cost-constrained upright piano action design due to the lost motion produced by rapidly repeated keystrokes in the normal non-soft pedal mode.

6A , the currently disclosed piano key action arrangement reduces the undesirable sensation of lost motion by closing or even eliminating the gaps 145 and 147 between the hammers and the linkage rod assemblies 430, 450, and the undesirable gap 249 between the staples and the linkage rod assemblies may also cause the undesirable sensation of lost motion when the soft pedal is depressed (see FIGS. 15A and 15B ). To compensate for the gap 249, a key lift assembly including a rigid key lifter 400 is positioned under the key rear section 413 and lifts the key 410. The rigid key lifter 400 rotates about a fulcrum or pivot point 401. The lifter 400 supports the key 410 so as to keep the key at least in close proximity to, or more preferably in contact with, the linkage rod assembly 450. This arrangement significantly reduces or eliminates the gaps 249 and 147 (which would otherwise cause lost motion of the piano action 420 during piano playing).

In a preferred embodiment, at least three, for example four, five, or more, co-linear pivot points 401 are positioned along the length of the piano keybed and are used to support the rigid key lifter 400, which contacts all eighty-eight keys 410. The rigid key lifter 400 is lifted or pivoted by a rigid linkage system 480 (represented in the figure by force F). As shown in Figures 6A and 6B, force F can be applied behind or in front of the key rear section 413 as long as the rigid key lifter 400 rotates to contact the key rear section 413.

By way of example only, three co-linear pivot points 401 distribute the lifting force F along the keybed, reducing bending and ensuring that the rigid key lifter 400 lifts all keys 410 substantially the same distance. Because the rigid key lifter 400 is desirably non-flexible, the rigid key lifter 400 can lift all key rear sections 413 and the linkage rod assembly 450 uniformly. This improvement can be achieved, for example, by reducing the bending of the rigid rail 400, i.e., by employing multiple (for example, three or more, such as five, in this embodiment) pivot points 401, or by employing a rail 400 with relatively greater stiffness or rigidity, and/or by reducing or eliminating the flexibility brought about by the use of the spring assembly 310, as in other embodiments discussed below. The flexibility of the spring arrangement increases the difficulty of uniformly calibrating multiple, for example, more than two, springs, and therefore, for practical reasons, the support is limited to two springs. The springs can also experience changes in the spring lifting force over time. In contrast, the rigid key lifter 400 of the present disclosure is effectively inflexible and provides a constant, uniform lift that is spatially and predictable over time, e.g., with typical variations in lift force over time that would be undetectable even to an expert user of the piano 100, e.g., the lift distance being less than the thickness of a sheet of paper.

When the shift pedal 160 is depressed (shown in Figures 1 and 9), the rigid key lifter 400 is lifted in the direction indicated by arrow F (Figures 6A and 6B). Depressing the shift pedal 160 lifts the linkage rod assembly 450, thereby eliminating the gap 249 between the key rear segment 413 and the linkage rod assembly 450 (shown in Figures 15A and 15B), and closing the gap 145 of Figure 4B between the linkage rod assembly 450 and the hammer assembly 430. In some embodiments, contact between the rigid key lifter 400 and the key rear segment 413 can be observed to cause the key 410 to pivot, i.e., in response to the key rear segment 413 pivoting slightly upward, causing the front segment of the key 410 to move downward to a certain extent, for example, 3-5 mm of a total keystroke of approximately 10 mm measured at the leading edge of the key (or up to 2-7 mm in extreme adjustment), depending on the magnitude of the force F.

As shown in Figure 7, the linkage system 480 transmits the actuating motion (of the player's foot) applied to the soft pedal 160 to the rigid key lifter 400. Like the traditional piano 100 shown in Figure 1, the piano configuration of Figure 7 includes a connecting rod or hammer back guard 165, which actuates the hammer back guard 170 to pivot all eighty-eight hammer assemblies 430 upward, closer to the strings 180. In the embodiment shown in the accompanying drawings, the linkage system 480 also includes an additional piano key lifter rod 466, which is vertically positioned within the lower half of the piano case. In the embodiment shown in Figure 7, the bottom end of the piano key lifter rod 466 rests on the soft pedal transmission rod 462, while the top end pushes on the rigid piano key lifter 400. When the soft pedal 160 is actuated, force is transmitted along the soft pedal transmission rod 462 to the connecting rod or hammer back bar 165 (which lifts the hammer back bar 170 to pivot the hammer assembly 430) and the piano key lift bar 466, which raises the rigid piano key lift bar 400, and subsequently the piano key back section 413 and the linkage rod assembly 450.

To allow for two distinct motions to be actuated by depressing the shift pedal 160, the length of the lift rod 466 can be adjusted via a built-in length adjuster 464. The length adjuster 464 adjusts the lift heights of the two rods 165 and 466 independently of one another. In the embodiment shown in FIG8 , the length adjuster 464 comprises a coaxial adjustment screw with a locking mechanism, such as a locking nut or friction thread, as is known in the art, and the connecting rod 165 and the lift rod 466 are positioned to move longitudinally (i.e., sequentially) along the shift pedal transmission rod 462. In another embodiment shown in FIGS. 9 and 10 , the two rods 165 and 466 are located at the same longitudinal distance from the shift pedal 160, and this second embodiment of the length adjuster 464 still allows the length of the lift rod 466 to be adjusted independently of the connecting rod 165. In both embodiments, the length adjuster 464 modifies the maximum lift height of the key lift rail and can be adjusted after adjusting a nut (e.g., a wing nut) that is typically used on pianos to adjust the maximum lift height of the hammer back rail.

The linkage system 480 described herein includes a rigid lift rod 466. However, other embodiments are also contemplated; for example, a cable pulley system may alternatively be used to lift the rigid key lifter 400, and it may also be adjusted to operate in sync with the soft pedal movement of the conventional piano 100. For example, the hammer back 270 may be used to lift the rigid key lifter 400 via a cable or other link. When the soft pedal 160 is depressed, a conventional lift rod 165 lifts the hammer back 270, which pulls the key back 400 upward via the cable or link. Alternatively, a bicycle-type cable-in-shell may be provided to raise the key lifter, either with or without a pulley. In other embodiments, an electromagnetic actuator, such as is known in the art, may alternatively be used to lift the rigid key lifter 400, and it may also be adjusted to operate in sync with the soft pedal movement of the conventional piano 100.

The rigid key lifter 400 raises the linkage assembly 450 as a group and removes lost motion during depression of the soft pedal 160. For example, as described with respect to the prior embodiment, precise configuration adjustment of each strap hook 452 and strap 440 combination is significantly less important and is replaced by global raising of the key 410 and linkage assembly 450 with the rigid key lifter 400.

6A , a conventional loose sling 440′ can be repositioned to a more tensioned state 440 by shortening and/or bending a conventional sling hook 452′ to a use position, i.e., the sling hook 452. As described with respect to other embodiments, the tensioned sling hook 452 and sling 440 serve to reduce dynamic lost motion (i.e., eliminate gap 145). The rigid key lift 400 removes dynamic lost motion (i.e., eliminates gap 145) and also reliably eliminates static lost motion (i.e., gap 147), which occurs only in soft mode.

In this embodiment, adjustment of the strap hook 452/strap 440 can be simple and durable, without requiring precise or repetitive adjustments. Consequently, the tensioning function can be achieved without precise adjustments. For example, the optimal height of the strap hook 452 (and its angle and position) can be determined during the manufacturing process, rather than during manual adjustment of the strap hook 452 after the piano has been assembled (or in addition to, if desired), resulting in the advantages described herein. Tensioning the strap hook 452 to a specified setting can be performed during standard adjustment operations without additional adjustment effort, or it can be optionally performed entirely in advance, completely relying on the soft pedal system of the present disclosure.

Thus, the configuration disclosed herein allows an upright piano to obtain the performance advantages of reducing or eliminating lost motion in normal play mode, without having to rely on a climbing strap to precisely lift the linkage rod during soft pedal mode performance.

Referring to Figures 11 and 12, in another embodiment of the soft pedal system, a single rod 365 is mounted on the soft pedal transmission rod 462. The single rod 365 is formed by two stacked rod segments 365a and 365b. The lower rod segment 365a lifts the rigid key lifter 400 and simultaneously lifts the upper rod segment 365b, thereby lifting the hammer back rail 270. The rod 365 is configured so that the upper rod segment 365b only lifts the hammer back rail 270, while the lower rod segment 365a lifts both the upper rod segment 365b and the rigid key lifter 400. The movement of closing the gap described above is achieved by the two stacked rod segments 365a and 365b. The length of the upper rod segment 365b can be adjusted independently of the length of the lower rod segment 365a. In this embodiment, a length adjuster 464 modifies the maximum lift height of the key lifter and can be adjusted after adjusting the nut (e.g., a butterfly nut) that is commonly used on pianos to adjust the maximum lift height of the key lifter and hammer back rail. Alternatively, because the embedded axial adjuster is located at the rod-rail junction, a conventional nut (e.g., a butterfly nut) can first be used to adjust the maximum lift height of the hammer back rail and key lift rail, after which the fixed length rod 365 can be rotated to finally adjust the maximum lift height of the key lift rail.

13 shows a further embodiment of the present disclosure in which a conventional shift pedal link 165 spans from the shift pedal transmission rod 462 to the hammer back rail 270. An appendage 385 located approximately two-thirds of the way up the rod 165 pushes upward on a short rod or link 390, which in turn pushes on a rigid key lift rail 400, resulting in the gap-closing motion discussed above.

In another embodiment of an upright piano, such as the upright piano 200 shown in FIG. 14 , the upright piano 200 includes a relatively more tensioned bridle strap 240 and bridle hook 252 combination than conventional (prior art) upright pianos. Specifically, one or both of the bridle strap 240 and the bridle hook 252 are tensioned, or at least relatively more tensioned, within the piano action 220. Specifically, the respective lengths of the bridle hook 252 and the bridle strap 240 are selected to maintain tension across the entire span of the bridle strap 240 between its respective ends, the bridle hook 252, and the hammer assembly 230, with the span of the tensioned bridle strap being approximately constant between the initial and final positions and also during the transition between the initial and final positions. This allows the bridle strap 240, which has little or no slack in the rest position, to maintain relatively constant tension through key depressions and releases. The gap 145 that in prior art pianos primarily results from slack straps is largely eliminated, thereby greatly reducing or eliminating lost motion between the piano hammers and the piano linkage rod assemblies 230, 250 during rapid, repetitive keystrokes in normal, non-soft pedal mode.

The relatively more tensioned bridle strap 240 and bridle strap hook 252 combination also significantly increases the functionality of the shift pedal 260 by reducing or eliminating the undesirable feeling of lost motion when the shift pedal is depressed by reducing or eliminating the gap 147 ( FIG. 5B ) between the hammers and the linkage rod assemblies 230, 250. During the ascent of the hammers 235 with the shift pedal 260, the hammers and linkage rod assemblies 230, 250 are maintained in close proximity or engagement with each other at all times because the bridle strap 240 is now at least approximately tensioned in the rest position (as shown in FIG. 14 ).

15A , due to the relatively more tensioned bridle strap 240 and bridle strap hook 252 combination, depressing the soft pedal 260 rotates the back rail 270 and hammer assembly 230, as in a conventional design (e.g., in the direction of motion 275). However, now the relatively more tensioned bridle strap 240 and bridle strap hook 252 combination lifts the linkage rod assembly 250, which is in series with the hammer assembly 230, removing the entire weight of the piano action 220 from the key 210. The bridle strap 240 remains proximate to the piano action 220 or tensioned during its movement (i.e., the span 246 remains relatively constant during the movement of the action 220). Furthermore, the soft pedal bridle strap span 246 remains relatively constant compared to the bridle strap span 243 in the normal mode (see FIG. 14 ).

Upright pianos, such as piano 100, are typically weighted at the rear end 113 to achieve a desired level of touch resistance in the keys (compared to grand piano keys, which are typically weighted at the front end). In the embodiment of the upright piano 200 of the present disclosure, as shown in FIG15A , the keys 210 have key weights 212 at the rear end 213. As a result, the upright piano keys do not exert an upward force against the hammer and linkage assemblies 230, 250, and thus any lost motion that exists (either due to the use of the soft pedal 260 or due to rapid, repetitive keystrokes) is not mitigated by the keys. In other embodiments, the keys 210 may not include weights 212 and may therefore be unweighted at the front or rear end of the key.

15A and 15B , the undesirable gap 249 between the staple 211 and the linkage assembly 250 can also result in an undesirable feeling of lost motion when the soft pedal 260 is depressed. To compensate for the gap 249 in the piano action 220, a key lift assembly including a lightly spring-supported lifter 300 is positioned below the key rear section 213. The lifter 300 is mounted for movement in the direction of the lifter motion (arrow 302) between a first position, in which it preferably touches the bottom surface of all 88 keys rather than lifting them, and a second position, in which the lifter 300 pivots (or otherwise moves) to lift the key rear sections 213 so that they follow the movement of the linkage assembly 230, thereby eliminating lost motion. Because the keys 210 pivot very easily, only a light spring force is applied by the lifter 300 of the present disclosure, and therefore does not interfere with the tactile characteristics of the piano action 220.

15C , the action 220 of the piano 200 of the present disclosure is shown with the soft pedal 260 depressed and the lifter 300 engaged. The lifter 300 supports the key 210 so as to maintain the key in at least close proximity to or contact with the linkage assembly 250. The lifter 300, in combination with the relatively tensioned bridle 240 and bridle hook 252 combination, maintains contact between the key 210 and the linkage assembly 250, and between the jack 254 and the hammer assembly 236. During the movement of the piano action 220, the span 246 of the bridle 240 and bridle hook combination remains approximately constant, including at the beginning and end points of travel and during the process. This design results in a significant reduction or elimination of the gaps 249 and 147 that cause the piano action 220 to move in vain during piano performance.

In FIG16 , a top view of the key and keybed area of an upright piano 200 of the present disclosure is shown, including the keys 210 and their playing surfaces 214. The keys 210 rest on a supporting key frame 215, which is supported by a keybed 216. A lift rail 300 (shown in cross section in FIG15A ) spans the eighty-eight keys 210 of the upright piano, beneath the rear sections 213 of the keys 210.

Two or more lift spring assemblies 310 (which are also part of the key lift assembly) are located at different selected locations below the keys along the length of the keyboard to provide a force sufficient to lift the keys 210. For example, the lift spring assemblies 310 may be located near the first key and the last key, such as at location 218. Alternatively, the lift spring assemblies 310 may be located at other locations along the keys, such as at one-quarter and three-quarters along the length of the keyboard, or at one-third and two-thirds along the length of the keyboard. More than two lift spring assemblies 310 may also be arranged at different locations along the keyboard. Similarly, the embodiment shown in Figure 16 may have a contact point such as location 218, or have three or more contact locations.

17 , in another embodiment of the shift lift spring assembly of the present disclosure, a cross-section of the key 210 above the shift lift spring assembly 310 is shown in an unlifted position. The key 210 (and each key 210) rests against the shift lift 300. Each shift lift spring assembly 310 is secured (e.g., using a screw countersunk into a hole 217 provided in the key base 216) into position (e.g., position 218 as shown in FIG8 ). An adjustment member, such as a knob 314, is provided for raising (and/or lowering) the shift lift 300 and, therefore, the set position of the key 210 upward (and/or downward), thereby increasing (and/or decreasing) the lifting force applied by the shift lift spring assembly 310. Alternatively, the adjustment member 314 may be, for example, a thumb screw, a hexagonal bolt adjustable by a wrench, a screw adjustable by a screwdriver, or other suitable rotatable threaded or otherwise adjustable member.

17 and 18 , the lifter spring assembly 310 includes four portions: a knob portion 312, a keybed insert portion 322, a keybed recess 332, and a lifter portion 342. An assembly bore 219 at the base of the assembly counterbore 217 of the keybed 216 is fixedly received by a threaded insert 324. A machine screw 318 is threaded through the threaded insert 324 in the assembly bore 219 such that the machine screw 318 extends above and below the keybed 216 within the assembly counterbore 217. A user (desiring to adjust the relative lift force of the lifter 300) loosens the locking nut 320, advances or retracts the adjustment knob 314 attached to the bottom end of the machine screw 318 (secured by the locking nut 316), and then retightens the locking nut 320. Advancing or retracting the machine screw 318 (i.e., relative to the threaded insert 324 and the locking nut 320) changes the position of the machine screw 318 relative to the keybed 216. For example, advancing the machine screw 318 causes the machine screw 318 to move upward, along with the components of the key seat recess 332 housed in the assembly counterbore 217. The key seat recess 332 includes a compression spring 338 coaxially arranged around the screw 340 and resting on either end on a spring cap 336 (the spring cap 336 being secured at the lower end by a lock nut 334). The lift rail 300 rests against the upper spring cap 336 and supports the keys 210 above, which rest on a suitable cushioning material 344, such as a felt or foam sheet, on the upper surface of the lift rail 300.

The biasing characteristics of the spring 338 are selected so that the spring 338 applies a force sufficient to lift the combined weight of the lift rail 300 and the key. The force applied by the spring 338 causes the lift rail 300 to remain in contact with the key 210 and push upward thereon, which in turn causes the key to remain in close proximity to or engage with the linkage assembly 250 and the hammer assembly 230.

The piano user or owner may choose to adjust the position of lift rail 300 and/or the force applied by spring 338, such as when piano 200 is manufactured, or at some later point during the life of the piano.

To adjust the key lift assembly, the key lift assembly is positioned to sit on the keybed 216 (not supported by the spring 338), with the lift rail 300 disengaged from the bottom surface of the key 210. The user then presses and holds the shift pedal 260, thereby lifting the hammer back rail 270 and the hammer 235. Because the bridle strap 240 is tensioned, the linkage rod assembly 250 is lifted along with the hammer 235, and a gap 249 occurs that creates lost motion. To close the gap 249 between the staple 211 and the linkage rod assembly 250, the user continues to hold the shift pedal 260 while turning the adjustment knob 314 that controls the embedded portion 322 of the lift rail 300 that supports the compression spring 338. Turning the adjustment knob 314 lifts the embedded portion 322, which lifts and compresses the spring 338, thereby lifting the lift rail 300. As the lift rail 300 is lifted, it lifts the key 210 and closes the gap 249. While holding the soft pedal 260, the user continues to raise the lift gear 300 (by turning the knob 314) until the gap 249 under all 88 keys is closed. At this point, the lost motion gap generated between the key pin 211 and the linkage rod assembly 250 disappears.

Alternatively, a different protocol may be employed to adjust the position of the lifter 300 and/or the force applied by the spring 338. Specifically, from a position where the lifter 300 is disengaged from the bottom surface of the key 210, the user turns the adjustment knob 314 located below the keybed to lift the spring lifter assembly 310 upward (relative to the lifter 300). When all of the hammers 235 are observed to be lifted off the lifter 300, the user then turns the adjustment knob 314 in the opposite direction until the affected hammers are no longer lifted. The locking nut is then retightened to secure the adjustment.

A number of embodiments of the present invention have been described. However, it should be understood that various modifications may be made without departing from the spirit and scope of the present invention. For example, other means for elevating the linkage rod assembly 250 and piano hammers 235 as a unit when the soft pedal 260 is depressed are also within the scope of this disclosure. For example, a relatively longer or shorter bridle strap 240 than a typical bridle strap in the prior art and/or a relatively longer or shorter bridle strap hook 252 than a typical bridle strap hook in the prior art may also be employed. The mass distribution in the piano linkage rod assembly 250 may also be rearranged or otherwise modified to encourage or facilitate movement of the piano linkage rod assembly under gravity to rotate in a forward pitching direction (arrow T in FIG. 3 ). Alternatively or in addition, other means, such as mechanical, magnetic, or electromechanical linkages, may be employed to impart an upward lifting force, a downward thrust, or a rotational force to encourage movement of the piano linkage rod assembly 250 and the piano hammers when the soft pedal is depressed.

While a lift 300 has been described, mechanisms for lifting (or rotating) the rear section 213 of a piano key 210 upward or pushing (or rotating) the front section (in front of the pivot) of a piano key downward while the key is not being played are also within the scope of the present disclosure. For example, this can include one or more downward-pushing elements engaging the front section of the key 210, producing rotational motion about a pivot point P (shown in FIG3 ), such as by engaging with the upper surface of the key, or by applying an attractive or other force to the front or rear section of the key, such as by a lightweight magnet embedded in the key or an electromagnetically attractive material embedded in the key for interacting with one or more magnetic elements in the key frame 215 or keybed 216. The mass distribution in the piano key 210 can also be rearranged or otherwise modified, such as by shifting the weight balance toward the front section of the piano key.

In another embodiment, as shown in FIG. 19 , lost motion can be reduced by adjusting the positioning of the upper end of the bridle hook 253 to which the associated end of the bridle strap 240 is pinned, such as by bending the body of the bridle hook 253 or a portion of its body (generally toward the player), and/or by adjusting, for example, extending or shortening the body of the bridle hook 253.

The force applied by the tensioned strap 240 and strap hook 252, along with the biasing force applied by the spring 338 when the piano is used in soft mode, can reduce or eliminate lost motion caused by the separation of the elements of the piano key action. The soft pedal design of the present disclosure thus improves the normal mode performance of the upright piano action by improving its touch characteristics to more closely resemble that of a grand piano.

In some embodiments, combining one or more of the above-described techniques and devices can result in an upright piano with improved lost motion characteristics. For example, in the embodiment of FIG. 11 , a curved bridle hook 253 with a relatively shortened bridle hook 252 and a shortened bridle strap 240, as well as a lifter 300, are shown for use with piano 200. However, it should be understood that variations in the span of bridle strap 240 can result in varying reductions (improvements) in controlled lost motion. For example, variations in the length of bridle strap 240 and bridle hook 252, as well as the curvature (angle) of bridle hook 253 (along with lifter 300), can be optimized so that the gap is reduced to or near 0 mm during normal and soft pedal modes of performance, resulting in a 100% reduction in lost motion perception. In other embodiments, the gap can be reduced to less than 3 mm, such as less than 2 mm, or less than or equal to 1 mm.

In the example shown in FIG. 15C , only the relatively shortened bridle hook 252 , the relatively shortened bridle strap 240 , and the lifting gear 300 are used.

In further embodiments, using only the curved strap hook 253 can reduce lost motion by up to 60% or 70% in normal mode, and using the curved strap hook 253 and the shift lifter 300 can reduce lost motion by 60% to 70% in both normal mode and in soft pedal mode.

In other embodiments, the lifting rail 300 can have other suitable cross-sections besides rectangular bars. For example, as shown in Figures 20A to 20J, the lifting rail 300 can have a cross-section configured as an I-beam 352, a C-shaped channel 354, a rectangular tube 356, a rectangular bar 358, a square tube 360, a square bar 362, an N-shaped channel 364, a U-shaped channel 366, a circular tube 368, a circular bar 370, or any other suitable configuration. The lifting rail 300 can be formed from metal, plastic, wood, or other suitable materials.

The rigid key lift rail 400 can have various cross-sections as shown in Figures 20A-20J and can be formed from metal, plastic, wood, or other suitable materials. Alternatively, rather than a separate rail, the rigid key lift rail 400 can be integrated into the rear portion of the keybed 216. In this case, a portion of the keybed 216 becomes a liftable surface.

In a further embodiment, the rigid lifter 400 mechanism can include a section adjustment for adjusting the key lifter height in different sections of the piano. For example, a long key lifter base with three short key lifter caps can be connected to the base with two screws. The height and angle of the three caps can be adjusted independently.

In other embodiments of a piano that is playable in at least a normal mode and selectively playable in a soft mode, possibly but not necessarily, the piano has a plurality of strap and hook combinations. Each strap and hook combination connects a piano hammer to a corresponding piano linkage assembly, and the strap and hook combination is mounted and adjusted to hold the hammer assembly and its corresponding linkage assembly together in motion that minimizes play when the associated piano key is played.

In other embodiments of the piano described above, such as in examples where the piano is selectively playable in soft mode as well as in normal mode, the piano may also include a soft pedal system, such as has been described.

Accordingly, other implementations are within the scope of the following claims.

Claims (22)

1. A piano that can be selectively played in normal mode and soft mode, comprising: A set of multiple piano keys; A set of multiple piano actions associated with the plurality of piano keys, each of the piano actions including a piano linkage assembly actuated by pressing the corresponding piano key; A plurality of piano hammers, each hammer mounted for rotational motion and defining a forward throwing direction toward at least one corresponding piano string, each hammer being driven by a corresponding piano linkage assembly to transmit a force applied to the associated piano key; and The soft pedal system includes: Soft pedal; Hammer backstop, which is installed for moving between a normal mode position and a soft mode position, wherein in the normal mode position, the set of multiple piano hammers is stationary at a distance from the corresponding piano string, and in the soft mode position, the set of multiple piano hammers moves to a stationary position relatively closer to the corresponding piano string. A piano key lift position, configured to move between a normal mode position separated from the key lift contact of the set of multiple piano keys and a soft mode position configured to contact and lift the piano keys together with the piano linkage assembly; and A soft pedal linkage assembly includes a soft pedal drive rod, which drives the soft pedal, the soft pedal, the hammer backstop, and the piano key lift-off point. Actuation of the soft pedal causes a pivoting motion of the soft pedal drive rod, and this pivoting motion causes i) the hammer backstop, ii) the piano key, iii) the piano hammer, and iv) the piano linkage assembly to move simultaneously between a normal mode position and a soft mode position, closing the gap formed between the piano hammer and the piano linkage assembly. Knob (314) is used to raise and lower the set position of the piano keys, thereby increasing or decreasing the lifting force applied by the lift spring assembly. 2. The piano as claimed in claim 1, wherein the soft pedal linkage assembly comprises: The soft pedal drive lever is roughly horizontal. Hammer back stop lever, and Piano key lever. 3. The piano as claimed in claim 2, wherein the hammer back stop and the piano key lift stop are successively installed along the soft pedal transmission rod. 4. The piano as claimed in claim 2, wherein the hammer backstop and the piano key lifter are mounted substantially parallel to the soft pedal drive rod. 5. The piano as claimed in claim 2, wherein actuation of the soft pedal raises the hammer backstop and the piano key stop. 6. The piano as claimed in claim 2, wherein the piano key lever includes a length-adjustable linkage. 7. The piano of claim 6, wherein the length-adjustable link comprises a coaxial screw and a locking mechanism. 8. The piano of claim 6, wherein the length-adjustable link is independently adjustable relative to the length of the hammer backstop. 9. The piano as claimed in claim 1, wherein the piano key lift is configured to engage with the rear bottom surface of the set of multiple piano keys when actuated. 10. The piano of claim 1, wherein the piano key lift is configured to pivot between its normal mode position, spaced apart from the piano key engagement of the plurality of piano keys, and its soft mode position, engaged with the piano key lift of the plurality of piano keys. 11. The piano as claimed in claim 1, wherein the piano key lift is mounted at at least two pivot points. 12. The piano as claimed in claim 1, wherein the piano key release is non-flexible. 13. The piano of claim 1, wherein, in soft playing mode, the piano key lift position is positioned for linear movement to engage with the piano keys of the set of multiple piano keys. 14. The piano of claim 1, wherein, in soft playing mode, the piano key lift position is positioned for engagement with the piano keys of the set of multiple piano keys by rotational movement. 15. The piano as claimed in claim 1, wherein the piano key release engages the piano key of the group of multiple piano keys by spring force. 16. The piano as claimed in claim 1, wherein the piano key lift engages the piano keys of the group of multiple piano keys by magnetic force. 17. The piano as claimed in claim 1, wherein the piano key lift engages the piano keys of the group of multiple piano keys via electromechanical connection. 18. The piano of claim 1, wherein each of the piano action mechanisms further comprises a piano hammer assembly, and the piano further comprises a plurality of clapper and clapper hook assemblies, each of the clapper and clapper hook assemblies connecting the piano hammer to a corresponding piano linkage assembly, wherein actuation of the soft pedal tensions each of the clapper and clapper hook assemblies to enhance the movement of the associated piano linkage assembly together with the associated piano hammer assembly in a closed gap. 19. The piano of claim 18, wherein tensioning of at least one of the climbing strap and the climbing strap hook assembly includes shortening at least one of the climbing strap and the climbing strap hook. 20. The piano of claim 18, wherein tensioning of at least one of the climbing strap and the climbing strap hook assembly includes bending the upper end of the climbing strap hook below the climbing strap or by repositioning the entire climbing strap hook. 21. The piano of claim 1, wherein each of the piano action mechanisms further comprises a piano hammer assembly, and the piano further comprises a plurality of cleats and cleat hook assemblies, each of the cleats and cleat hook assemblies connecting the piano hammer to a corresponding piano linkage assembly, wherein the cleats and cleat hook assemblies are mounted and adjusted to keep the hammer assembly and the corresponding linkage assembly in a movement that minimizes clearance when the relevant piano key is played in normal mode. 22. A piano playable at least in normal mode, comprising: A set of multiple piano keys; A set of multiple piano actions associated with the plurality of piano keys, each of the piano actions including a piano hammer assembly and a piano linkage assembly actuated by pressing the corresponding piano key; A plurality of piano hammers, each hammer mounted for rotational motion and defining a forward throwing direction toward at least one corresponding piano string, each hammer being driven by a corresponding piano linkage assembly to transmit a force applied to the associated piano key; and A set of multiple cleats and cleat hooks, each of the cleats and cleat hooks connecting the piano hammer to the corresponding piano linkage assembly, wherein the cleats and cleat hooks are installed and adjusted to keep the hammer assembly and the corresponding linkage assembly in a movement that minimizes clearance when the relevant piano key is played; The piano can be played selectively in normal mode and soft mode, and also includes: The soft pedal system includes: Soft pedal; Hammer backstop, which is installed for moving between a normal mode position and a soft mode position, wherein in the normal mode position, the set of multiple piano hammers is stationary at a distance from the corresponding piano string, and in the soft mode position, the set of multiple piano hammers moves to a stationary position relatively closer to the corresponding piano string. A piano key lift position, configured to move between a normal mode position separated from the key lift contact of the set of multiple piano keys and a soft mode position configured to contact and lift the piano keys together with the piano linkage assembly; and A soft pedal linkage assembly includes a soft pedal drive rod, which drives the soft pedal, the soft pedal, the hammer backstop, and the piano key lift-off point. Actuation of the soft pedal causes a pivoting motion of the soft pedal drive rod, and this pivoting motion causes i) the hammer backstop, ii) the piano key, iii) the piano hammer, and iv) the piano linkage assembly to move simultaneously between a normal mode position and a soft mode position, closing the gap formed between the piano hammer and the piano linkage assembly.