Arrangement in grand pianos damper system

Abstract

The present application concerns to grand pianos damper system in which the damper wire block is horizontally rotating, an innovative feature to accomplish "damper head to strings" regulation quickly and very precisely. The present invention aims to solve the deficiencies and difficulties imposed by the state of the art regarding the finalization of the adjustment of the grand piano dampers. The purpose of this constructive idea is to make independent the last adjustment, which is the correction of the rotational motion of the damper head, caused after definitive tightening of the screw securing the wire inside the block. The innovations proposed so far offer complexity in the constructive model and remarkable operational difficulty, reasons why they have presumably never been put into practice.

Description

"ARRANGEMENT IN GRAND PIANOS DAMPER SYSTEM" FIELD OF INVENTION

[0001] The present application concerns to grand pianos damper system in which the damper wire block is horizontally rotating, an innovative feature to accomplish "damper head to strings" regulation quickly and very precisely. A new mechanical device, namely a strategically inserted metal pin, turns the simple damper block, traditionally used on the state of the art, into a dual block, thus coupling two halves, a fixed lower one and a rotating upper one, connected to each other, but independent.

[0002] This new proposed mechanism retains all adjustment bending and functions already existing in the state of the art, exactly in the same protocol order as currently standardized. However, after final "locking" of the wire inside the damper block, when it is firmer tightened by means of its screw, the constructive arrangement proposed here quickly and precisely reverses the unwanted and inevitable scenario that arises in the state of the art. In currently standardized mechanisms, the reversal of this scenario makes this completion a long and tedious job which requires a lot of skill and patience from the piano technician, as well as a considerable increase in assembly time (by the manufacturer) until the position of the final clamping of the wire offers a perfect configuration (there are usually numerous trial and error operations per unit, for a total of approximately 70 units per piano) .

[0003] Furthermore, no substantial modifications tothe state of the art are required to achieve this mechanism with the proposed device and not even any tool other than the technician's traditional apparatus is necessary to carry out this adjustment.BACKGROUNDS

[0004] After the technician performs all the wire adjustments (bendings) to align the damper head to its strings, a final tightening, with greater pressure on the screw that fixes such wire inside the damper block (or damper flange) , ends up causing rotation in its long axis and spoiling the parallelism of the damper head to its strings, which has just been adjusted.

[0005] This being so, when the damper underlever is driven upwards by the inner edge of the key, the damper block rises and the damper felts leave their strings also in a vertical motion; however, for the reasons stated, almost always the damper head also performs a rotating movement to one side, causing a deficient damping on its return to stop the vibratory movement of that strings (sound is left over or complete stagnation is delayed) and usually with wheezing (felts touch strings at slightly different moments) . And to correct this deviation thus caused, a long course of attempts begins loosening and tightening the screw or twisting the wire on its long axis with pliers until the ideal position is found, since in the state of the art the damper block (also called damper flange or underlever top flange) is rotatable forward andbackwards, however fixed in the horizontal rotational direction .DESCRIPTION OF RELATED ART

[0006] In this regard, MARIO IGREC, in an acclaimed work entitled "Pianos Inside Out" - A Comprehensive Guide to Piano Tuning, Repairing and Rebuilding, In Tune Press, Mandeville USA, 2013, page 183, writes: "As you adjust the damper wires, you must keep the damper head parallel to the strings. Viewed from above, the damper should be parallel to the strings and should not rotate as you slowly lift its underlever . To correct this inadvertent rotation, hold the underlever top flange with parallel pliers and lift the damper all the way. Grasp the head at opposite ends and rotate it in the direction opposite of the unwanted rotation as far as you can. If this isn't enough (it usually isn't) , hold the top flange with parallel pliers and twist the wire with a pair of pliers just under bend 2. You can also loosen the screw, rotate, and hold the damper head, and guickly retighten the screw, but this may alter the lift height".

[0007] Another renowned author, ARTHUR REBLITZ, before addressing the subject warns, on its own emphasis, on page 189 of the 2nd. edition of his "Piano Servicing, Tuning & Rebuilding", that "You are now about to embark upon one of the most difficult procedures in the world of piano regulating" to give the following instructions ahead (op. cit . , page 190) check to see if the damper head rotates at themoment it lifts off the strings . If so, grasp the wire just above the damper wire block with pliers, and twist the wire a little. The gently-tightened screw should be loose enough to permit the wire to be turned without bending it. When you have regulated the damper just right, tighten the screw just a little more to lock the wire in place. If this causes the head to rotate again, twist the wire again as necessary. When the regulation is perfect , both ends of the damper head will come to rest on the strings without turning or twisting sideways . Repeat this procedure for every damper; when you're done, the dampers should rise uniformly and with a minimum of twisting as you slowly depress the pedal.

[0008] Which is easily apparent from these excerpts, as well as from the practice in this type of regulation is that in the traditional system: 1) the wire usually ends up rotating inside the block at the moment of final tightening; 2) this rotation leads to an unwanted displacement in the alignment (parallelism) of the damper head relative to its string (s) , rotating as it rises; 3) when returning, damper head is "rotated" and its felt has difficulty to fitting accurately and quietly into the string (s) , leaving sound or causing unwanted noises; 4) to get around the problem, and in order not to mess with what is already done, twists with pliers on the long axis of the wire are performed, deforming it; 5) the results of these twists in the long axis of the wire are experienced by trial and error, since they are not ideal solutions to remedy a situation for which there is no adequaterecourse and, for this reason, accepted by technicians and described in the manuals; 6) aware of this inaccuracy inherent in the traditional system, sometimes a "minimum rotation" after the completion of the entire procedure is inevitable and, therefore, tolerated (REBLITZ, id. ibid. ) ; aiming to avoid the longitudinal torsion of the wire, as an option it is oriented to loosen the screw, reposition the wire and retighten it, admitting, however, in the use of this second resource, possible modification to a previously made adjustment (IGREC, id. ibid. ) .

[0009] In June 2008, KAWAI MUSICAL INSTRUMENTS - JAPAN, by its inventor Michinori Abe, filed a PCT application under No. JP2008129158 , presenting a proposal to avoid deviations and twists in the long axis of the damper wire during this type of adjustment. In that device, the wire is kept in its position (inside its block or flange) thanks to the action of two tiny steel blades, or some other elastic material, which act with opposite forces against the wire (they are leaning against it tangentially) as if they were springs holding it, keeping it "clipped" or "stapled" (PCT cited,

[0014] ) . A special tool must be inserted between the blades to keep them "open" to allow correct positioning of the wire during adjustment (PCT cited,

[0027] ) . At the end of this adjustment, the tool that opens the blades is removed, so that the blades return to exert joint pressure and the wire is again stapled inside the block where it is inserted (PCT cited,

[0027] .

[0010] Curious to note, however, that although it isstated that the traditional screw can be dispensed with (PCT cited,

[0029] ) , further on (PCT cited,

[0031] ) the inventor suggests that a screw can be installed on the damper block (or damper flange) for a firmer final tightening, even with the return of the actuation of the blades and, therefore, after completion of all adjustments concerning the wire. Taking it for granted and indisputable that no wire, not even minimally, can rotate or move vertically inside the damper block during a musical performance (an occurrence that would fatally lead to a performative disaster) , such an expedient (final tightening by screw) is prudently necessary, as already occurs in the state of the art.

[0011] Also, Abe' s invention makes the installation way construction and damper wire adjustments considerably more complex on a grand piano. Damper block machining (the block where the damper wire is inserted) becomes more complicated and detailed and tiny elastic blades are installed inside the block or flange, which is already diminutive (about 10 mm wide) . Both for an initial assembly, in the factory or workshop, and for a broader maintenance that requires complete disassembly and reassembly of the system (at which point all the wires need to move freely inside the block or flange) , about 70 units of the same tool (to release the wire) would be required. Finally, it does not dispense, in a 100% safe way, with the fixing of the wire via screw (PCT cited,

[0031] ) , for the reasons set forth in paragraph

[0010] of this document.SUMARY

[0012] On the other hand, the idea of the presentinvention does not require substantial modification in the state of the art, but only the "separation" into two parts of an already existing mechanical component and the insertion of a pin to connect these two parts, making them independent, but intimately integrated. Regarding the fixing of the wire inside the block or flange, no internal modification is necessary in comparison to the state of the art since it remains fixing the damper wire by means of a screw and socket. The lower portion of the block, this block now divided by virtue of this constructive proposal, also does not undergo any essential modification, receiving only the insertion of the pin that will make the connection with the upper portion.

[0013] This being so, the present invention aims to solve the deficiencies and difficulties imposed by the state of the art regarding the finalization of the adjustment of the grand piano dampers. The purpose of this constructive idea is to make independent the last adjustment, which is the correction of the rotational motion of the damper head, caused after definitive tightening of the screw securing the wire inside the block (or flange) . In the prior art, the possible alternatives for the correction of this unwanted and recurrent rotational movement run into difficulties that transform this final step into a tedious, long, mentally and physically tiring path for the technician (position of curved spine and arms stretched under the strings) . On the other hand, the innovations proposed so far offer complexity in the constructive model and remarkable operational difficulty,reasons why they have presumably never been put into practice.

[0014] In the state of the art, therefore, only two (both by trial and error) are the alternatives feasible by piano technicians worldwide so that the final tightening of the wire is consolidated without any interference in the movement of the damper head (which must leave the strings without rotation) and in its parallel settlement on the strings when at rest: 1) loosen and retighten the screw over and over again; 2) twist the wire longitudinally, properly holding its damper block with pliers and, with the other hand, rotate or twist the wire in the opposite direction to the unwanted rotational movement that is intended to be eliminated. It should be remembered that, in the first option, at the moment of untightening (followed by retightening) the wire can slide vertically inside the block, ruining one of the previous adjustments of the wire (IGREC, id. ibid. ) ; in the second option, a twisted wire along its axis may, in future maintenance and disassembly, offer other difficulties in one of the several previous stages of this type of adjustment.

[0015] Given the above, the solution proposed here is precisely to make this final correction independent, in the sense that such correction is realized without the screw, which has just been tightened definitively, having to be loosened and retightened numerous times or having the wire to be twisted along its axis. Thanks to the existing connector pin in this constructive proposal, the upper part of the block can be rotated independently along its own axis (with a long-nose pliers, a fixed wrench or, depending on the circumstances,even with the hand) , rotating together and in the same direction, the wire already definitely tightened by the screw. This final adjustment corrects, with total precision and enormous speed, any rotational movement perceived when the damper arises and returns to the strings, recovering therefore its parallelism with the strings and without moving the screw inside the block, an act that causes the unwanted scenario described above in the prior art.

[0016] Also important to mention that the invention now proposed dispenses with any additional or different tool from the common arsenal of the piano technician, in addition to representing hours less in the time required when on the factory assembly line or maintenance in the workshop.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 presents an isolated overview of what is the damper (1) of a grand piano, composed of the head (la) , felts (lb) and wire (1c) .

[0018] Figure 2 presents the damper (1) in its functional and interactive context with other components of the piano.

[0019] Figure 3 makes a comparison between the block (7) of the damper (1) , as unitarily conceived in the prior art, with that of the construction now proposed, divided into upper (top rotator block - 7a) and lower (bottom fixed block - 7b) , as well as the connection between them.

[0020] Figure 4 shows how the top rotator block (7a) is connected to the bottom fixed block (7b) through the connector pin (13) .

[0021] Figure 5, in turn, presents in detail the constructive structure of the top rotator block (7a) .

[0022] Figure 6 and 6-A show, from the front (position of the technician for adjustment on the piano) , the rotational movement of the top rotator block (7a) , as well as the possible tools used in this operation.

[0023] Figure 7 shows the effect of the rotation of the top rotator block (7a) relative to the head (la) of the damper (1) with respect to its settlement on the piano string (2) .DETAILED DESCRIPTION

[0024] Figure 1 shows the damper (1) of a grand piano, seen in isolation and in profile, before being installed on the piano. It is composed of a damper (1) head (la) , damper (1) felts (lb) and the damper (1) wire (1c) which, once perfectly adjusted, causes the head (la) , together with the felts (lb) , to perform perfectly rectilinear vertical movements of descent and ascent.

[0025] Figure 2 shows the other components that, in the prior art, interact with the damper (1) here at rest, such as the string (2) , the damper (1) wire (lc) rail (3) , the damper (1) wire (lc) bushing (4) , the damper (1) underlever (5) , the damper (1) underlever (5) flange (6) , the damper (1) underlever (5) flange (6) bushing (6a) , the damper (1) block (7) , the damper (1) block (7) bushing (12) , the damper (1) wire (lc) fixing screw (8) , the sostenuto tab (9) of "sostenuto pedal system" (not shown) and its respective bushing (9a) , damper (1) underlever (5) balancing leads (10) , right pedaltray (11) , suspending the dampers (1) collectively when the right pedal (not shown) is engaged, and, finally, the inner edge of the key (15) (not entirely shown) with its damper (1) lifting felt (15a) . It is important to remark that the functional apparatus presented in Figure 2 is only one assembly of a set formed by approximately 70 equal units, arranged side by side, each corresponding to a piano key, and composing, thus, what is called the "damper mechanism" . When driven by the inner edge of the key (15) (not entirely shown) via felt (15a) , the underlever (5) , which rotates on the underlever (5) axis (6a) of the underlever (5) flange (6) is propelled upwards, taking with it the damper (1) block (7) which, rotating on the damper (1) block (7) axis (12) , conducts the damper (1) wire (1c) vertically upwards and thus causes the separation of the damper (1) felts (lb) with the string (2) , rested on it when in time-out. Once the whole system has been relaxed (at which point the pianist removes his / her finger from the front portion (not shown) of the key

[0015] that has just been pressured) , the gravitational actuation of the underlever (5) , its leads (10) and the damper (1) itself, composed of (la) (lb) (1c) , make it return, thus properly accomplishing its role as opener & closer of the string (2) , according to the requirements in the performance of a musical piece .

[0026] Figure 3 compares the damper (1) block (7) , as conceived in the prior art (lower drawing) , with that of the proposed invention (upper drawing) , now with this damper (1) block (7) "divided" into bottom fixed block (7b) and toprotator block (7a) , interconnected by a connector pin (13) . As can be seen, the innovation basically consists of dividing the damper (1) block (7) existing in the prior art into two portions: a fixed lower one (bottom fixed block [7b] ) and a rotating upper one (top rotator block [7a] ) , in order to allow the top rotator block (7a) to perform rotating movements of the wire (1c) inserted in it and fixed by the screw (8) without the need to loosen this screw (8) .

[0027] Figure 4 explains the separation of prior art block (7) and shows how, through the connector pin (13) , occurs the interconnection of these two new blocks, namely (7a) and (7b) , separate but interactive. In the prototype built, the connector pin (13) (bottom design) measures 13 mm long and 2 mm thick. The striated portion (13b) of the connector pin (13) is inserted 6 mm into the top of the bottom fixed block (7b) through the hole (14b) ; the smooth portion (13a) is also inserted at a depth of 6 mm into the top rotator block (7a) through the hole (14a) , so that the space separating the top rotator block (7a) from the bottom fixed block (7b) should be approximately 1 mm (no more than that) , this measurement being controlled by the exact depth of the hole (14a) made in the top rotator block (7a) . The insertion of the connector pin (13) , by its ends (13a) and (13b) , is performed by pressing into the holes (14a) and (14b) , and a tiny hole (14) , of approximately 0.30 mm in diameter, connects the hole (14a) with the hole (8b) of the wire (1c) to allow air escape when the connector pin (13) is pressed / inserted into the top rotator block (7a) , thus ensuring that the smooth portion (13a) fillsthe entire length of the hole (14a) . The striated portion (13b) will be automatically attached statically inside the bottom fixed block (7b) , while the smooth portion (13a) , inserted in the top rotator block (7a) , should be hermetically pressed inside it, very firmly, but allowing rotational movement of the top rotator block (7a) after the overcoming of a certain frictional resistance, just as it happens in the rotating movements when adjusting the front pins of the keys of an upright or grand piano in the state of the art. It should be noted that no type of screw thread can be used in this portion of the connector pin (13) introduced in the top rotator block (7a) , under penalty of indirect alteration in the other aspects of the adjustment, although the rotational movement required is tiny, possibly between 5 and 10 degrees on average (theoretically, the system allows rotation of 360°) , but sufficient to operate the correction of the rotation suffered by the wire (1c) at the time of the final tightening of the screw (8) . In other words, the rotation of the top rotator block (7a) must necessarily occur in the same horizontal plane.

[0028] Figure 5, in turn, presents in detail the constructive structure of the top rotator block (7a) , which can be square, cylindrical, or even cylindrical with a square lower portion (for tool fitting) . For an optimal result in the interaction of the binomial "friction of the connector pin (13) versus precisely controlled rotational movement of the top rotator block (7a)", the top rotator block (7a) must be of ABS, nylon, Delrin, Teflon or other composites (such as carbon fiber with certain resins) , whose coefficient of expansion andcontraction are zero for the context on screen, in addition to offering ideal lightness in order not to interfere with the adjustment of the weight of the underlever (5) by means of the leads (10) inserted in it (Figure 2) . In addition, its properties offer permanent hermeticity during and after the introduction of the connector pin (13) through the hole (14a) (Figure 4) , to ensure optimal internal friction. As already mentioned in Figure 4, contributing to this scenario, a tiny hole (14) , approximately 0.30 mm in diameter, connects the hole (8b) with the hole (14a) to allow air escape at the time of insertion of the connector (13) in the top rotator block (7a) , thus ensuring that the smooth portion (13a) of the connector pin (13) enters its entire length and eliminates any amount of air present there. The connector pin (13) , in turn, can be of any metal that maintains the properties for contraction and dilation within the analyzed context, such as iron, for example. The screw (8) which fasten the damper wire (1c) remains identical to that of the prior art, that is, introduced frontally until it reaches the hole (8b) and threaded into a socket (8a) to press the wire (1c) , when it is inserted into the top rotator block (7a) via hole (8b) .

[0029] Figures 6 and 6-A show (from the perspective of the technician, from the front, when proceeding to the adjustment) the rotational movement of the top rotator block (7a) , to the left or right, which will take place only after the final tightening ("locking") of the wire (1c) , via screw (8) , that is, only when all the previous adjustments have already been performed. And this correctional movement, nowoffered by the proposed device, avoids what is required in the prior art: the release of the screw (8) (which is already "locked") to correct deviations that the wire (1c) suffers because of the final tightening, and which takes the damper (1) head (la) from its newly achieved parallelism. By holding the bottom fixed block (7b) with a parallel pliers, basic care that the technician needs to take to avoid any damage to the bushings (12) and (6a) of the axes on which the system components rotate (Figure 2) , the top rotator block (7a) can be precisely and easily rotated with simple tools, according to the geometric construction adopted for the top rotator block (7a) : 1) with a common long-nose pliers, in the case of a fully cylindrical top rotator block (7a) (Figure 6) ; 2) with a fixed wrench, in the case of a cylindrical top rotator block (7a) with a square lower portion for the wrench fitting (Figure 6- A) , as well as in the case of a fully square top rotator block (7a) . In cases where the system is being assembled for the first time (at the factory) or after complete disassembly for more comprehensive maintenance, during (re) assembly there will be room for rotation of the top rotator block (7a) even with one's own hand, without major difficulty. While the bottom fixed block (7b) remains static by the striated portion (13b) of the connector pin (13) (Figure 4) , the top rotator block (7a) can be rotated to the left or right as needed, since the portion of the connector pin (13) that makes its coupling is the smooth portion (13a) (Figure 4) . As already noted there, no type of screw thread is used in this smooth portion of the connector pin (13) introduced into the top rotator block (7a)to ensure that any rotation of the top rotator block (7a) always occurs in the horizontal plane, to the left or to the right. And this correction, as can be seen from the figures presented, does not imply, as in the prior art, in releasing the wire (1c) to reposition it again to correct its location, nor even in twisting it in its long axis, because the top rotator block (7a) is who now makes this corrective rotation of the wire (1c) , which is preserved perfectly fixed and static inside the top rotator block (7a) .

[0030] In a top-down view, Figure 7 refers to the position that the damper (1) head (la) assumes on the string (2) due to the practically inevitable rotation that the wire (1c) undergoes immediately after the final tightening of the screw (8) (larger design) , in the state of the art. This effect translates into the lack of parallelism of the damper (1) head (la) with the string (2) when it detaches from it, because the head (la) , via wire (1c) , rotates to the left or to the right when it rises to release the sound emitted by the string (2) struck by the hammer - not shown. If not corrected, this scenario will impair the damping / stagnat ion of the sound, because, when it returns, the damper (1) head (la) , through the felts (lb) (Figure 1) , does not achieve a parallel, perfect, and calm settlement on the string (2) , offering deficient sound stagnation and unwanted noise in this deficient contact. And thanks to the proposal of this idea presented here, the correction of this setback is carried out with the simple turning of the top rotator block (7a) which, by longitudinally rotating the wire (1c) inserted in it andalready definitively fixed in the immediately previous step, brings back the damper (1) head (la) to the correct position in an easy, fast and efficient way (overhead view of the damper (1) head (la) after correction made by the simple rotational movement of the top rotator block (7a) . In this way, it is no longer necessary, through "trial and error" and even a few hours of spare work, to loosen and retighten the wire numerous times (at the risk of damage in the previous adjustments) , and not even, separately, or together, any longitudinal twisting of the wire (at the risk of deformation) .

Claims

C L A I M S1. "ARRANGEMENT IN GRAND PIANOS DAMPER SYSTEM", comprising a damper (1) that includes a head (la) , felts (lb) and wire (1c) , which interacts with the string (2) , the rail (3) for passing the wire (1c) , the bushing (4) of the wire (1c) , the underlever (5) of the damper (1) , the flange(6) of the underlever (5) , the bushing (6a) of the flange (6) , the block (7) of the damper (1) , the bushing (12) of the block(7) , the screw (8) securing the wire (lc) of the damper (1) , the tab (9) of the "sostenuto" pedal system and its respective bushing (9a) , leads (10) for balancing the underlever (5) , tray (11) of the right pedal that suspends the dampers (1) collectively when the right pedal is activated and, the inner end of the key (15) with its felt (15a) for activating the damper (1) , characterized in that the damper arrangement (1) comprises a block (7) divided into a fixed lower block (7b) and a upper rotator block (7a) , interconnected by a connector pin (13) , which allows the upper rotator block (7a) to perform rotational movements of the wire (lc) inserted into it and fixed by the screw (8) without the need to loosen this screw(8) , with the connector pin (13) having a striated portion (13b) inserted into the top of the fixed lower block (7b) through the hole (14b) ; the smooth portion (13a) is also inserted into the upper rotator block (7a) through the hole (14a) , which is connected to the hole (8b) by a hole (14) .

2. "ARRANGEMENT IN GRAND PIANOS DAMPER SYSTEM", according to claim 1, characterized in that the connector pin (13) measures 13 mm in length and 2 mm in thickness; thestriated portion (13b) of the connector pin (13) is inserted 6 mm into the top of the fixed lower block (7b) through the hole (14b) ; the smooth portion (13a) is also inserted to a depth of 6 mm into the upper rotator block (7a) through the hole (14a) , so that the space separating the upper rotator block (7a) from the fixed lower block (7b) it must be no more than 1 mm and the hole (14) is approximately 0.30 mm in diameter .

3. "ARRANGEMENT IN GRAND PIANOS DAMPER SYSTEM", according to claim 1, characterized in that the upper rotator block (7a) can be square, cylindrical or even cylindrical with a square lower portion (for fitting the tool) ; where the friction of the connector pin (13) versus the controlled rotational movement of the upper rotator block (7a) , is carried out by the fact that the upper rotator block (7a) is made of ABS, nylon, Delrin, Teflon or other composites (such as carbon fiber with certain resins) .

4. "METHOD", characterized by being carried out by inserting the connector pin (13) , through its ends (13a) and (13b) , by pressure, into the holes (14a) and (14b) , with the hole (14) , connects the hole (14a) with the hole (8b) of the wire (1c) to allow air to escape when the connector pin (13) is pressed / inserted into the upper rotator block (7a) , in a manner such that the striated portion (13b) will automatically be statically secured within the fixed lower block (7b) , while the smooth portion (13a) , inserted into the upper rotator block (7a) , must be hermetically pressed within it, in a secure manner firm, however allowing rotationalmovement of the upper rotator block (7a) after the expiration of a certain frictional resistance, even if the rotational movement required is tiny, possibly between 5 and 10 degrees on average, but sufficient to operate the correction of the rotation suffered by the wire (1c) during the final tightening of the screw (8) , and the rotation of the upper block (7a) must necessarily occur in the same horizontal plane.

5. "METHOD", according to claim 4, characterized by, when adjusting, the rotational movement of the upper rotator block (7a) , to the left or right, which will take place only after the final tightening or locking of the wire (1c) , via screw (8) , that is, only when all previous twists have already been carried out, this rotation prevents the screw (8) from loosening, and then, by holding the fixed lower block (7b) , the upper rotator block (7a) can be precisely and easily rotated with simple tools, according to the geometric construction adopted for the upper rotator block (7a) : 1) with common long-nose pliers, in the case of an upper rotator block (7a ) entirely cylindrical; 2) with a fixed key, in the case of a cylindrical upper rotator block (7a) with a square lower portion to fit the key, as well as in the case of an entirely square upper rotator block (7a) .

6. "METHOD", according to claim 4, characterized in that the correction of the lack of parallelism of the head (la) of the damper (1) with the string (2) when it is released from it, is carried out by simply turning the upper rotator block (7a) which, by longitudinally rotating the wire (1c) inserted into it and already definitively fixed inthe immediately previous step, brings the head (la) of the damper (1) back to the to the correct position .

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