This was Montal's first patent, and it dealt with the application of the principle of "double escapement" to a variety of actions, for upright, grand and square pianos. Montal shows how a spring loaded lever, that he calls a receiver, can be applied to a variety of existing actions, producing the effect of double escapement, or re-setting of the action when the key is only allowed to rise part way. In his design, the escapement jack leaves the butt of the hammer and moves to the receiver, which gives because of the spring, and the hammer escapes and goes into check. When the key is allowed to rise, the receiver acts against the escapement (as opposed to the knuckle in Érard's design), allowing the escapement jack to re-set.
The pdf contains all the illustrations. The text version below does not, but they can be found under the images menu.
This patent introduces several things. There is a grand piano design with the strings and soundboard above the hammers; the principle of "counter-tension," with adjustable length rods pulling behind the case beams, countering the tension of the strings; more "continuous escapement" ('double escapement') action designs; and, in the addendum of 1851, the expression pedal and the transposing keyboard.
Montal, Patent 9883, May 7, 1842
Since the introduction of escapement to the piano action, pianists have always complained of being unable to produce a strong or weak tone except by playing more strongly or weakly and allowing the key to rise to the level of the other keys of the keyboard.[i] This leads to great difficulty in repetition of notes, cadences, and expression while playing. It is in order to reduce these problems and to give artists the ability to produce a stronger or weaker tone, depending on the level to which the key is allowed to rise, that I have invented a simple and certain means, which is applicable to the escapement mechanisms of all pianos, upright, vertical, square and grand.
This means consists of a moving part supported by a spring, which I name escapement receiver because it is designed to receive the escapement after it leaves the nose. This receiver can take many forms and its pivot can be in many different places (fig. 1-5), depending on the design of the mechanism to which it is adapted.
The supporting spring can be a spiral made of metallic wire (fig. 6) or, as usual, extended from a metallic wire circle (fig. 7), or flat like a watch spring (fig. 8).
When escapement occurs below,[ii] the receiver and its spring will be attached to the key, or on a part attached to the key, or on a lever moved by the key. When escapement occurs above, it will be attached close to the hammer shank or close to the hammer butt.
The receiver will always be attached so that one of its extremities A (figs. 1-5) will be placed at the level of the butt, or close to the place where escapement occurs, so that when the escapement leaves the nose, the receiver will give and allow escapement to occur.
Let us begin by looking at its application to an upright piano action, to demonstrate clearly the repetition of notes at different levels of key dip, and the force of the hammer blow proportional to those levels (fig. 9 represents a key at rest, i.e. risen all the way).
If the key is played to its entire depth, the escapement E will leave the nose N, go through its course, and arrive on the receiver R, which will be lowered by means of the pilote PP, raised for this purpose by the key. So the escapement will escape by descending from the top of the nose, the hammer will have gone through its entire course, and the blow, which I will represent in this case by 1, will have been at full force (see fig. 10, which represents the key fully depressed). If now you allow the key to rise by a certain amount, for example one quarter of its dip, the pilote PP will lower proportionally with the key, allowing the receiver R to rise by means of the spring R’ that presses it upward, and the escapement E will be lifted by the receiver and will return onto the nose N at a quarter of its course. It will be supported by the receiver which is a little slanted. If you replay the key, the hammer will be propelled again and the blow will have only one quarter of the force of the first blow represented by 1. Similarly, if you allow the key to rise by half of its dip, the escapement, helped by the receiver, will return onto the nose at one half its course, and the key, played again, will give the hammer blow a force that will be half that represented by 1. This time the hammer will have traveled half its distance. You can see that the force given to the key by the finger will impart to the hammer a force proportional to the degree you have allowed the key to rise.
I will note also, as part of my invention, the placement at a slant of a spiral spring, with felt punchings on each end, riding on a broach BB, together with a bushed mortise in the escapement, with one end placed against a slanted rail in which the broach is secured, the other on a shoulder made on the back of the escapement, the function of which spring is to return the escapement to its place, and at the same time to return the hammer. By this means I replace with great advantage the spring ordinarily placed behind the hammer butt, as well as the bridle tape used to return it to rest, which together with the brass flange F holding the hammer butt gives my action an unquestionable solidity, superior to that of all upright actions, and a promptness in the repetition of notes, resulting from the simultaneity of the movement of the hammer and the escapement, one being connected to the other by means of the spring. I will note that this action, which is particularly aimed at upright pianos and pianinos, can be used in square and grand pianos, by making a change in the design of the butt that allows the hammer shank to be horizontal.
Application to square and grand pianos (Fig. 11 represents the action at rest).
In this action, if you play the key to its full depth, the escapement E goes through its entire course, and is now held only by the receiver R, which lowers under the weight of the hammer and escapement, and allows the escapement to fall below the nose (see fig. 12, which shows the key fully depressed).
If you allow the key to rise by a certain amount, the receiver R will rise by the force of the spring B’ placed below it, and will make the escapement E return on top of the nose N at a level proportional to that of the rising of the key, and the hammer blow will have a force relative to the level of the key, in keeping with what was described in the preceding action.
As for square and grand pianos that escape above, whose actions are known as the English action, Petzold action, etc. (see figure 13 that shows a note of the English action at rest with the receiver adapted to that hammer shank), the receiver R is adapted to the shank A and if you press the key all the way down, the escapement E will pass from the nose N onto the receiver R, complete its course, and lie on the receiver, which the weight of the hammer will cause to go give way, allowing escapement to occur (see fig. 14 that represents a key in the down position).
It is unnecessary to explain here the movement of the escapement E, which is similar to that of the same part in the other actions. I will remark as well that the receiver could be attached to the butt (fig. 15) rather than being fixed to the check that is glued to the shank. I will mention here that this adaptation of the receiver to the hammer that I have just described can be applied to pianos that are already made.
Application to actions under the specific name of pianino actions (fig. 16 represents a note with the key at rest).
You should observe that here the receiver R as well as the spring R’ are attached to the butt N’ by a part that also serves at the same time to bring the hammer into check. The functioning of this action is the same as that of the preceding and produces the same effect. When you press the key and the escapement leaves the nose N, the extension of the receiver R will meet a button or pilote that will make it rock to allow escapement (see fig. 17 that shows a key at full dip). In this action the receiver R returns the hammer by force of its spring and allows one to omit the bridle tape used ordinarily to return it. The action known as tape check because of the strip of silk or leather used to return the hammer, and that is often used in obliquely strung upright pianos and pianinos, only differs from the one I described in the escapement button and the position of the damper. I will dispense with providing a drawing and description, as repetition at different heights of the key is produced in the same manner as in that of pianinos.
In the application to the action known as Mercier (fig. 18 shows a note with the key at rest), you can see that the receiver R is placed by the nut N’ of the hammer, and that it is pushed by the spring that here is found behind the butt. The repetition of notes at different heights is produced in the same way as in the preceding.
We could remark that in this action the receiver can be placed in the same way as in that of the pianino (fig. 16 and 17), which will allow you to omit the spring placed behind the hammer. This action will suffice to show how the receiver can be adapted to other actions in which the escapement is on the key, and which will only differ from this in the way escapement is effected, which has no consequence for the application to and the effect of the receiver.
In its application to the Roller action, which escapes below (see fig. 19 that shows a note with the key at rest), you can see that the receiver R is situated below the part that includes the nose N, and at the same level. When you press the key, the pilote P meets the button B and the receiver is lowered, to allow escapement to occur. Besides this, the movement of the escapement to produce repetition functions in the same way as in the preceding.
In this action I will mention that you can omit the spring G placed behind the bracket, as well as the spring H placed behind the hammer butt, to make the escapement and the hammer function, and replace them with a spiral spring P’ placed at a slant and described in figures 9 and 10, to return the escapement and the hammer.
As all actions require great precision in key dip, I have invented the placement of an adjustable capstan screw under the front of the key, so as to regulate dip with much more precision and ease than by ordinary means. It is marked in the drawings by the letter D.
It remains for me to say that you can adapt the receiver to downward striking actions in square and grand pianos, to achieve the repetition of notes at different key depths in the same way. For whenever there is an escapement and a nose in any action whatsoever, you can conceive that a mobile part I call a receiver can be adapted, having the effect as I have explained, of holding the escapement until the key has fully depressed, and of making it re-set in proportion as you allow the key to rise, to produce a tone that has greater or lesser force.
I will mention in closing that the receiver can be placed higher than the nose if escapement occurs below (fig. 20) or lower than the nose if escapement occurs above (fig. 21) to receive the escapement on an edge or nose, when it leaves the true nose N.
The length of this description seemed necessary if one considers that there are a great number of piano actions, that my procedure is very simple, that the result obtained is very important, and that I have needed to seek to generalize the application in order to assure myself of exclusive rights by means of a patent.
The attached drawings are on pages numbered 1 to 10.
By M. Montal, maker of pianos, rue Dauphine, 36, passage Dauphine Escalier C.
[i] [Montal’s perspective is based on the square piano without escapement, in which one can always repeat a note, however little the key is allowed to rise. Thus, the technique for playing such a piano expressively would include varying how high the key is allowed to rise, and thereby varying how far the key and hammer move to create the next tone. It is very important to understand this perspective, as otherwise Montal’s assertions can seem nonsensical to a modern reader. He seeks to join the advantages of the non-escapement action with those of escapement. Montal would have learned to play piano on a non-escapement square.]
[ii] [This means the escapement is attached to the hammer butt, and its lower part escapes, as will be seen in fig. 9.]
Montal, Patent 7070, January 17, 1848
Specifications in support of an application for a 15-year patent, by M. Montal (Claude), piano maker, living in Paris, rue Dauphine, no. 36, for diverse improvements introduced into grand pianos, square pianos, and upright pianos with vertical, oblique and semi-oblique strings.
Section One, First Plate, Grand piano
Fig. 1, Horizontal projection showing the bottom of the interior of the grand piano.
Fig. 2, Vertical cross section following the length of the instrument, of which the hinged body is shown partly raised.
Fig. 3, Detail of the pivots that serve to rotate the body of the instrument.
Fig. 4, Two projections of one of the tuning wedges serving to tune each note of the section strung with four strings.
Fig. 5, Side view of one of the tuning wedges serving to tune the section with three strings.
The grand piano shown in this illustration includes several important improvements that I will describe successively. The design of a grand piano in which the string is pushed by the hammer striking upward toward the soundboard has been considered as preferable, both for quality of tone and its propagation, and with respect to the solidity of the piano, in which there is no need to cut the soundboard to allow the hammers to pass, nor to suspend the pin block.
The strings a, being placed below the soundboard b, leave the other side of the board exposed and in contact with a large mass of air, which is set into vibration and sends the sound more strongly and with more amplitude to the listener. Trials [of this kind of design] have been made during various eras, but without complete success, due to the difficulty of tuning these instruments, of having them hold their tuning, and of replacing broken strings easily.
In my instrument, represented in this first plate, the body c is movable, and enters its case as into an étui, with the help of two metal pivots d that serve as an axle, placed in such a way that they ride in metal bearings, and the tail serves as a counter-weight, so that one can easily lift the instrument from the front and support it with a prop. By this means, the strings are exposed, and those that are broken can easily be replaced. When the strings have been replaced, you return the instrument into the case after lowering the support prop, and fasten the body of the instrument by means of wing bolts e, or perhaps by hooks or screws that could substitute for the bolts. The tuning pins f, placed two by two, three by three, or four by four, depending on the number of strings used for each note, are in front, on a slope created at the end of the pin block. A system of muting wedges g, placed for each note, so that an iron stem g’ for each one, passing through the soundboard b, and attached to the knob h [the letter h seems to have been omitted from the drawing. It refers to the wooden part at the top of fig. 4], located above the soundboard, with the aid of which one pulls the wedge g to mute one, two, three strings at will, depending on the number used on each note. These wedge mutes have different numbers of wedges, depending on whether the piano is double, triple or quadruple strung. If needed, one wedge mute could be used for two notes by being rotated, which would reduce the number by half.
Ordinarily, grand pianos are reinforced with iron bars or struts. These bars, which are set above the strings or between certain notes, make it necessary to create gaps in the action, which makes construction more difficult; and, in addition, the ends of the bars being pulled by the tension of the strings, they often give toward the middle. We are obliged to place iron spacers at certain distances to maintain them in place.
I have applied to the construction of this piano a counter tension system in which straight iron rods i are pulled from each end in the direction of their lengths, rather than being pushed, and have, thereby, much more strength. They are each placed behind and facing a beam of wood j, and at a certain distance from it. They go through the end beams [sommiers], and are provided at their extremities with flanges or nuts, so that they can be shortened or lengthened at will by screwing in either direction. You can, if you wish, use one or the other of these means, or both at once. Below the piece of wood is found the soundboard; then, under the board are the strings that are attached to an extended hitchpin plate in iron m, which has curved flanges that are pierced by the counter-tension rods, so that if the tension of the strings causes the wooden beams j or buttresses providing resistance in the body of the instrument to flex, by tightening the nuts mentioned above, situated at the ends or middle of the rods, you can pull back these wood beams to straighten them, and similarly restore the soundboard if it has suffered from the sagging of the body of the instrument. In this way the soundboard, placed between two forces of which one balances the other, will be influenced less by the pull of the strings than in common designs, an immense advantage for the duration of tuning and preservation of the soundboard. I have also applied, in the bass of this grand piano, a suspended bridge l, used in some upright pianos. In this design I glue the portion l’ to the full soundboard without being required to shorten the string, which gives me more vibration in the bass of my instrument, and the portion l”, supported by the bridge l, allows me to shorten the wrapped strings at will, without interfering with the length of the plain strings. To tune this instrument, you also can use the moving keyboard, which operates by means of a pedal, to strike successively 1, 2, 3, or 4 strings. This keyboard can also be displaced one or more key widths by the use of a lever or a key, to make the piano transpose by one or several semitones.
Section 2, Plate 2
Figure 6 provides a horizontal projection of the bottom of the interior of the grand piano, capable of being opened from the left side by the aid of hinges that allow this movement.
Figure 7 shows the body of the instrument entirely opened and set to the side of the case.
Figure 8 presents a cross section following the length of the instrument.
With the exception of the way in which the body of the instrument leaves the case, the construction is the same as in the piano described in the first section. a, strings; b, soundboard; c, body of the instrument; d, core of ordinary or split hinges; e, wing bolts for fastening the body of the instrument to the case; f, tuning pins. This design also includes the system of wedge mutes g described in the preceding section; i, straight rods used for counter-tension; j, wooden beams; k, nuts for the rods i; l, l’, l”, suspended bridge; m, extended hitchpin rail in iron; n’, flanges of this rail pierced by the counter-tension rods.
Section 3, Plate 3
Figure 9 presents a horizontal projection of a piano designed for a downward striking mechanism, where the tuning pins, strings, soundboard, pinblock, etc. can be seen.
Figure 10 gives a vertical cross section along the length of the instrument, in which the hammers must strike downwards and the system is reversed. The strings a are on top, under the strings comes the soundboard b; under the soundboard are the beams c, beneath these beams are found the counter-tension rods d. I will remark that the strings are attached to the extended rail e situated above the soundboard, and flanges of this rail e’ descend to be pierced by the rods d, and act in conjunction with the strings, the sound board, and the beams, in the same way as in the preceding sections. g is the tuning pin, and h the bridge. I will remark that in figure 9, the part l of the bridge is suspended in the bass, as in the preceding figures.
Section 4, Plate 4.
Figure 11 shows a new action with continuous escapement, also called double escapement, designed to make a note repeat at all levels of the key. It produces a sound that is stronger or weaker in proportion to whether the key is higher or lower, following the movement of the finger.
Figure 11 bis [inset] shows an escapement unit designed to function with a spiral spring m’ replacing the double armed spring m” in figure 11.
Figure 12 shows another new action, with the same function.
Figure 13, Plate 5, shows yet a third action producing the same effect.
All these actions are applicable to grand and square pianos, in which the hammers strike upward, with modifications of the dampers for square pianos.
Figure 11, Plate 4.
b. Rocker to regulate the height of the escapement.
c. Escapement pivot.
c’. Heel of the escapement.
d. Escapement button.
e. Bushed hole in the butt.
e’. Nose of the butt.
f. Flange of the butt.
g. Hammer rest rail.
k. Lever flange.
l. Button to regulate the height of the lever.
m. Double branched spring to make both the lever and the escapement function.
n. Connecting rod connecting the lever to the hammer butt via a bend that enters the bushed hole e.
o. Flange of the connecting rod that can be opened or closed with a screw.
p. Connecting rod regulation button.
q. Connecting rod guide.
r. Damper lever.
s. Damper lever flange.
t. Damper wire.
z. Forte pedal tray.
When you press the key a, the hammer g is propelled to the string by the escapement that pivots on c, and leaves the nose e’ by means of the heel c’ rubbing on the button d; the hammer, falling, fixes itself on the check i by the catcher h. If you allow the key to rise a bit, the catcher will leave the check, and the hammer, left free, is lifted by the spring m, which, by means of its upper branch, pushes the lever j, so as to lift the hammer by means of the connecting rod n, bent at its upper end, and inserted in the bushed hole e’ in the butt, to a height limited by the button p that stops against its guide q. At the same time, the lower branch of the spring m will return the escapement under the nose by means of a little strap, and the hammer can again be propelled to the string, weakly if the key has been allowed to rise a little, and with more force if the key has risen more. By this means, you can create nuances easily, repeat the same note more rapidly, and make a cadence better. At the moment when the hammer is propelled, the damper felt v is moved away from the string to leave it free, by the effect of the key, which, pressing the lever r, lowers its back portion, and pulls toward it the damper u by its wire t; and, when the keys are released, the spring y raises the damper felt against the strings to stop the sound.
Figure 12, second action
b. Rocker to regulate the height of the escapement.
c. Escapement pivot.
c’. Escapement heel.
d. Escapement button.
e. Bushed hole in the butt.
e’. Nose of the butt.
f. Butt flange.
g’. Rest rail.
k. Flange of this lever.
l. Button to regulate the height of the lever.
m. Double branch spring for the escapement lever.
n. Connecting rod connecting the lever to the hammer butt by means of a bend that enters the bushed hole of the butt e.
o. Flange of the connecting rod, that can be opened and closed by means of a screw.
p. Button to regulate the height of the connecting rod.
q. Guide for the connecting rod.
p’. is a pressure screw to regulate the height of the lever j.
Figure 12, second action.
When you press the key a, the hammer g is propelled to the string by the escapement that pivots on c, and leaves the nose e’ in a forward direction by means of contact of the heel c’ with the button d. The hammer, falling, becomes fixed on the check i by the catcher h. If you allow the key to rise a little, the check will leave the catcher, and the hammer, left free, will be raised by means of the double spring m whose upper branch presses against the lever j so as to raise the hammer by means of the connecting rod n, bent at its upper end, and entering into the bushed hole in the butt e’, to a height limited by the button p, that bears against the guide q, and the screw p’ together with the button p regulates the height of the lever. At the same time, the lower branch of the spring m returns the escapement backwards under the nose of the butt by means of a little strap, and can propel the hammer again to the string, weakly if the key has been allowed to rise a little, and with more force if it has risen higher, so that this action produces the same effect as the preceding, and the same damper can be applied to it.
Plate 5, fig. 13
a key, b rocker that regulates the height of the escapement, c escapement pivot, d spiral spring with leather punchings on either end that makes the escapement function, e button and broach that regulates the escapement from the front, f screw threaded button that stops the escapement from behind, g escapement heel, h let off button, i butt, j butt flange, k drop screw [literally, screw between the shank and the repetition lever], l half roller serving as the nose, m hammer, n bushed mortise serving as catcher, o check, p lever to raise the hammer, q bushed and pinned pivot of this lever, r mortise in the lever allowing the escapement to pass, s button and threaded wire to regulate the height of the levers, t lever spring, u damper underlever, v damper wire, x damper lever, y damper lever pivot, z damper spring.
When you press the key a, the hammer m is propelled to the string by the escapement that pivots on c, and leaves the half round [knuckle] l that serves as the nose to the rear, when the heel of the escapement g rubs against the button h; the hammer, falling back, is fixed on the check o that enters the bushed mortise n. If you allow the key to rise a little, the hammer leaves the check, and left to itself, is lifted by the spring t that pushes the lever p, so as to raise the hammer by the screw k [this seems to be an error – k is the drop screw, that limits the lever’s travel. Probably the knuckle or roller l is intended]. At the same time, the spiral spring d returns the escapement forward under the roller l, and can propel the hammer to the string again, weakly if the key has been allowed to rise a little, and with more force if the key has been allowed to rise more, so that this action produces the same effect as the preceding two. I will remark that the spring t, as well as the two armed spring m of the two preceding actions, can be replaced by spiral springs. At the moment when the hammer is propelled, the end of the key lifts the damper under-lever u, which raises the damper wire v which, bearing on one end of the damper lever x from beneath, causes the other end to be lowered as it pivots on y; by this movement, the damper pad x’ moves away from the string, allowing it to vibrate. When you raise the finger from above the key, everything returns to its place, and the damper spring z presses the damper against the string to stop its vibration. This damper design, as well as any other, can be applied to the preceding actions. We will remark here in passing that in figures 2 and 8, grand pianos with counter-tension, ordinary actions have been shown because of the reduction of scale, and to demonstrate that while we have the intention of adopting in this type of piano our continuous escapement actions that we have just written about, we could equally use any other action that we might choose, and that our double escapement actions could be applied to pianos that do not include counter-tension.
Fig. 14, Section 5, Plate 6
Interior plan of a square piano, laid out for an upward striking action, seen from the side of the strings.
Fig. 15 Plan of the square piano from below, i.e., the side opposite the strings.
Fig. 16 Cross section of the piano.
In this piano you can see that the counter tension rods and the frame members are placed obliquely to the rectangle of the case, and parallel to the strings, in order to resist their tension directly.
a case rim, b wooden beam serving as a frame member, c counter tension rods, d reverse threaded nut to shorten or lengthen the rods, e ends of the flanges of the extended hitch pin plate that holds the ends of the strings, f bolt heads or flanges at the end of the rods c.
You can see from this layout that the square piano is constructed on the same principles of counter tension as the grand pianos described above, and must hold its tune better than square pianos of the common design and construction. You can adapt to these pianos any upward striking action that you wish. You can see that you could also construct pianos with counter tension in which the strings are beneath the soundboard, the structural beams and rods above, and in which the body of the instrument can leave the case by means of hinges placed at the rear. This disposition would be analogous to those described above for grand pianos. And for this second type of square pianos, you could use the continuous escapement actions described above or any other ordinary action.
Section 6, Plate 6, fig. 17.
Section of an upright piano with vertical strings, allowing you to see the strings, soundboard, etc. from the front.
Fig. 18, Elevation showing the back of a counter tension piano with vertical strings, with the beams, the counter tension rods, etc.
Fig. 19, Vertical transverse section of the same piano.
Fig. 20, Horizontal section made at the level of the keyboard.
a strings, b soundboard, c bottom section of treble bridge, c’ bridge portion positioned to shorten the wound strings, d Iron hitchpin plate, e iron strut to support this plate in the bass, f pin block, g nut, h case beam, I counter tension rods, j reverse threaded nut, k nut or bolt head bearing on the bottom of the hitchpin plate, l heads or nuts at will, m top cross member, n bass cross member.
You can see that, in this piano, the counter tension rods face the frame members at a certain distance, that they go through the top and bottom cross members, as well as the bottom portion of the iron hitchpin plate, and that they are parallel to the beams and strings for which they maintain the tension. You can shorten the rods if the case should give, either with the nut k if the rods are of one piece, or with the reverse threaded nut j, situated at the midpoint of each rod when they are divided into two parts. In the counter-beam end grain wooden insets are placed, without which the wood of the beam would indent. These pianos, constructed in this way, are infinitely more solid and hold their tuning better than those of ordinary construction, where the tension of the strings is resisted only by the support of the strong pieces of wood habitually used in the construction of the body of the instrument. The large part of the bridge c is glued directly to the inner portion of the soundboard at c’, only following the dotted lines in the drawing, and all the rest of its width is removed below, which makes this part of the bridge more elastic, being glued away from the rim, without shortening the bass strings. This procedure, with some changes, is already known; but here, there is the difference that the extremity c’’’ is cut at an acute angle to lengthen the gluing surface of the wood that is vertical to the board, so as to gain more elasticity, and that the part c”, attached to the part c, allows the wound strings to be shortened at will in the direction of the thinner ones, so as not to deny the length for the plain wires, and to obtain more vibration in the bass.
Section 7, Plate 8,
Fig. 21 Section of an upright piano with oblique strings, showing the strings, the soundboard, etc.
Fig. 22 Elevation showing the counter-tension back of a piano with oblique strings, with the oblique beams and rods creating counter-tension.
Fig. 23, Transverse vertical section of the same.
Fig. 24 Horizontal section made at the bottom of the keyboard.
a strings placed obliquely, b soundboard, c and c’ bridge, d and d’ iron hitch pin plate, f pin block, g nut, h case beams placed obliquely in line with the strings, I oblique rods providing counter-tension, j reverse threaded nut, k nut or inclined bolt heads, l nut or inclined flanges, m top cross beam, n bottom cross beam.
You can see that in this oblique piano, the counter-tension rods also face the case beams at a certain distance; that they run obliquely between the top and bottom cross beams, as well as the flanges of the iron hitch pin plate, and that they are, like the case beams, parallel and in line with the strings. The flanges at the top, being parallel to the top of the piano, are placed obliquely to receive the rods; the bolt heads, at the other end, are also oblique like the rods, as needed. If the case gives or moves, the rods can be shortened by the reverse threaded nut j, situated around the middle at the point joining the two parts, or by a nut at the end, if the rods are of one piece. In the top beam are found wooden pieces placed under the flanges. By this means, the top and bottom beams are acted upon as levers, and one can withstand the tension of the strings, restore the case, and even the soundboard within the case if it has been warped by the movement of the case. You can see that the same effect is produced by the counter tension rods as in the upright pianos with vertical strings described in the preceding section. These piano, produced in this way, are infinitely more solid and hold their tuning better than those of ordinary construction, where the tension of the strings is only resisted by the pieces of wood used habitually to build the back of the instrument. I will remark here that, as in the preceding upright pianos, the beams and the counter tension rods are always in line with the strings, and can resist the tension of the strings better; this advantage is especially noticeable in pianos with oblique strings, in which the cases, yielding in a harmful manner to the string tension, the strings no longer remain in front of their hammers, and cause misstrikes harmful to the durability of the instrument. With the help of this counter tension, the case, strings and soundboard can be returned to their original condition; you can see that the same construction design is applicable to semi-oblique pianos, by placing the beams and the counter tension rods in line with the strings and following the obliquity.
Strings. In the three kinds of upright pianos we have spoken of, vertical, oblique and semi-oblique, the back of the case could be movable, and open on one side or the other on hinges or another kind of pivot, so that the body of the instrument – consisting of the strings, soundboard, case beams, end beams, and rods – can come out of the outer case as from an étui; in this design, the end beams, being held at their extremities by the sides of the case, will respond more freely to the two opposing forces. In the various counter tension designs described in this document, the case beams indicated as wooden could be cast iron or wrought iron; they can butt against either wooden beams or against a metal chassis on the perimeter of the body of the instrument. The mobile beams could be placed on this chassis and move forward or backward, in response to the two forces, i.e., of the strings and the rods; the soundboard could also be glued on a wooden chassis prepared for that purpose, which, being screwed to the interior of the instrument, could be removed at will.
Section 8, Plate 9
Figure 25 gives an elevation of an upright continuous escapement action, also called double escapement, to allow repetition at all key heights. a key; b rocker to regulate the height of the escapement; c extension of the escapement [sticker]; d articulation of the sticker and its guide; d’ articulation of the guide and its flange; e articulation of the sticker and the wippen; f articulation of the wippen and its flange; g spoon that raises the damper; h escapement pivot; j escapement heel; k escapement button; k’ bar under which connecting rod x is supported to limit the movement of the lever; l butt and bushed hole in the butt; m nose of the butt; n butt flange and pivot; o hammer; o’ rest rail; p catcher; q check screwed to the escapement; r lever; s flange and articulation of this lever; t button and broach to regulate the height of the lever; u connecting rod bent at its top, inserted in the bushed hole I of the butt; u’ guide for the rod; v articulation of the rod and the lever; x threaded rod at the end of the lever v; y spring acting on lever v; z damper pivot and lever, curved on its bottom portion; z’ damper spring; z” damper pad.
When you press the key a, the hammer o is thrown forward to the string, by the escapement that pivots on h, and leaves the nose of the butt by the effect of the rubbing of the heel j on the button k; the hammer, falling back, is fixed on the check q by the catcher p. If you allow the key to rise a little, the check will leave the catcher, and the hammer, left to itself, will be raised by the action of the spring y that pushes the lever v, so as to raise the hammer by the connecting rod u, bent at its top and inserted in the bushed hole l drilled in the butt, up to a point limited by the threaded rod x that contacts the bottom of the rail k’. At the same time, the spring I returns the escapement under the nose of the butt, and can throw the hammer to the string, weakly if the key has risen a little, and with more force if it has been allowed to rise more. By this means, one can create nuances on an upright piano easily, repeat each note more rapidly, and make a cadence with more precision and speed. This action, which the drawing shows with a hammer for a vertically strung piano, can also be applied to oblique and semi-oblique upright pianos, by angling the damper lever and the hammerhead, as required by the angle of the strings. In this action, the sticker can be omitted, as it only serves to add height to actions in tall pianos, and in that case the wippen e can be propelled directly by a capstan screw or rocker of whatever form, placed on the key.
The double escapement action for upright pianos that we have just described can also be applied to upright pianos without counter tension, and in the counter tension pianos described earlier, any other action can be used.
17 January, 1848
Montal (personally signed)
Descriptive memoir in support of a request for a third certified addendum to the fifteen-year patent granted on January 18, 1848 to Mr. Montal (Claude), piano maker, then living at 36 Rue Dauphine, Paris, now on Boulevard Montmartre, for various improvements introduced into grand pianos, square pianos, and upright pianos with vertical, oblique, and semi-oblique strings.
The improvement consists first in a pedal with the name of “expression,” or “nuance,” which allows the sound to be diminished or augmented gradually, depending on how much or little the foot depresses it; at the same time the dip of the keys is modified in proportion to the weakness or strength of the sound, i.e., when the sound is weak the key move down little, and when the sound is louder the keys move farther, without ever exceeding the natural dip of the keys.
This system not only makes the execution of nuances easier, but it can also reduce the amount of study needed to develop independence of the fingers, from the point of view of delicacy of touch.
Plate 1, fig. 1 gives a frontal view of the parts that communicate the movement of the pedal to the mechanism of the keyboard.
Fig. 2 gives a transverse section of the keyboard action, made perpendicularly to fig. 1.
a pedal; b b’ levers doubly articulated at c c’; d d vertical rods to which is fixed a transverse bar covered with felt e, with the aid of screws and elongated slots to make it possible to regulate it to different heights. These rods d d’ rest at their lower end on the extremities of the levers b b’, which extremities can be regulated for height by the rockers f f using adjustment screws.
The upper end of the rods d d is felt or leather covered, and butts against wooden or metal levers g attached to the hammer rail h to make them pivot on themselves at i so as to reduce the throw of the hammers, by moving them nearer to the strings by a second felted bar h’, fixed to the bar h by screws through its slots. At the same time this takes place, the transverse bar e raises the backs of the keys at j, so as to lower their fronts and thus to reduce the key dip proportionally to the reduction of the hammer blow, and to maintain the escapements without a gap and close to the nose of the butt, whatever key dip the artist wishes to use.
Plate 2 fig. 1 is a cross section of the action in actual size, where you can see the key and the action at rest in black lines and their proportional movements produced by the lowering of the pedal marked by red lines. You can see under the key j a screw k that bears on the felted rail l when this moves, and which is intended to allow the keyboard to be adjusted for the reduced dip. You can also see that the spoon l of the wippen intended to raise the damper is found (when the action is at rest) a short distance from the lower part o of the damper, and that it bears against this o when the pedal is lowered all the way, so that the damper only rises by the action of the key, and not by that of this pedal, in order that the damper should always bear against the string, whether the pedal is raised or lowered.
Fig. 2 is a vertical cross section of a so-called English action, with the damper above the hammers; here the hammer rest rail pivots in the same way as in the previous figure, and the distance between the felt on the head of the rod m and the top of the damper n is designed to produce the same effect as that resulting from the distance between the spoon l and the lower portion of the damper lever in the preceding figure, i.e., when the expression pedal is depressed, the rod m approaches the damper n without causing it to rise, and only the lowering of the key by the finger makes the damper move away from the string to let it vibrate.
The metal or wooden pivot can be fixed in the rail h and pivot in bushed holes drilled into the sides of the action, or fixed on the outside of the action sides, with the help of a drilled plate arranged so that the pivot I passes through the sides, and enters a bushed hole in the metal or in the wood of the rail h itself; by this means, the hammer rail can be removed by removing the plates, without needing to remove one side of the action.
You can see by this description that the lowering of the pedal makes the hammers approach the strings, reduces the key dip, keeps the escapement close to the nose of the butt, and that the strength of the sound resulting from the larger or smaller hammer movement is proportional to the movement the key makes under the finger, depending how much the pedal is lowered. The same effect can be produced in square and grand pianos by modifying the pedal mechanism to the actions of these pianos.
Secondly, an improvement of counter tension that, in upright pianos, consists of reducing the front and top of the pin block by adding a metal plate curved so as to form along its entire length an angle or arc, depending on the application, so as to give it more solidity, to keep it from splitting, coming unglued, or pulling upward.
This plate is pierced in front by as many holes as there are tuning pins, so as to allow these to pass and enter into the wood, and when the pins are pulled down by the strings, they are supported on the lower parts of their respective holes, which holds them, avoids fatiguing the wood, and contributes to solidity and tuning stability. This metal plate is attached by screws or bolts to hold it, the counter tension rods pass through the upper portion of this plate, and the heads or flanges at the ends of the rods bear against the metal, and hold it against the wood to aid and augment the solidity of the pin block. Next to each rod, one can place above and below the metal plate attachments also in metal to keep it from bending or curving across the block.
You can see then that by the use of this plate the pin block acquires more solidity, and that the piano will last longer and hold tune longer. You could add several metal bars to the ends of this plate or between the strings, placed parallel to the strings, and with the other end attached to the hitch pin plate by screws allowing you to lengthen or shorten the bars, or these bars could also be cut in the middle and furnished with a reverse thread nut allowing them to be lengthened or shortened as needed. The bars serve as an aid to counter tension due to their ability to be lengthened or shortened at will.
Thirdly, an improvement for the purpose of making pianos transpose, i.e., to give each key the ability to play many notes rising or lowering by semitone from one to as many as twelve, i.e., the span of an octave, whether all twelve are in the same direction, or some are upward and some are downward, by the displacement of the keyboard and the disengagement of the action during displacement.
See Plate 3, figure 1, which shows an elevation of the system that serves to isolate the action from the keyboard during its displacement. Bar h is attached to the keyboard by two metallic or wooden supports ii and follows the lateral movement of the keyboard. At its extremities, this bar h has a tooth marked with the letter a. Above this bar is found another bar j, covered in felt on the side that slides up and down in the mortises kk, cut in the sides of the action. Bar j raises the wippens and other parts of the action. This bar also has teeth toward its extremities, which mesh with those of the first bar [h] when the keyboard is moved from left to right and from right to left, by the use of a lever under the key bed.
Bar h follows the movement of the keyboard, its teeth a rub against the teeth of bar j, which rise to the height of the tooth during half the movement and allow it to descend during the second half. Each movement being of the width of a key or of a tooth, the keys are moved under the neighboring note without fail, the bar having raised all the wippens and parts attached to them during the movement. You can see that each movement of the keyboard to the left will lower by a semitone, and each movement to the right will raise it by the same amount.
The interval of each tooth in this bar is designated on the right by the letters a, a#, b, c, c#, and d, on the left by the letters g#, g, f#, f, e, d#, these letters designating in music the notes of the chromatic scale so as to know the names of the notes and the number of semitones one has transposed.
Fig. 2 shows the design of the keyboard with the accessories that regulate its movement. To the right and left of the keyboard is found a little button ll, each of which moves an interior slide mm. Next to these slides are fixed slotted plates nn.
Fig. 3 shows another means to isolate the action from the keyboard. Here, two fixtures oo of which only one is shown, each have on their upper extremity a tooth a that meshes with the teeth in the upper bar d, similar to bar j in all respects, and produces the same effect.
In place of moving the keyboard by the lever placed under the key bed as described earlier, I can also use an apparatus called a transposition lock, that moves by means of a key that is turned to the right to raise and to the left to lower.
July 12, 1851