FR2780805A1 - Musical instrument keyboard adjuster - Google Patents

Abstract

The regulator consists of a balance arm (1) for each note, supported by a rod (10) connected to a balance bar (2) beneath it. The rod is joined by a threaded tip to an insert (18) set in the balance bar and carries spherical supporting shims (11) for the balance arm. By rotating the rod by means of a tool inserted in a slot in its upper end the position of the balance arm and note can be adjusted. At the same time the insert is able to incline by its rounded lower end rotating in the balance bar cavity.

Description

DEVICE FOR ADJUSTING THE LEVEL OF A KEYBOARD IN PARTICULAR

PIANO

  The present invention relates to pianos or the like and is aimed more

  especially the level adjustment of the keyboard of such instruments.

  Adjusting the keyboard level, more technically called keyboard training, consists of the individual leveling of each key with the adjacent keys as well as the leveling of the complete keyboard. The regularity of the height, from touch to touch, and on all the extent

  of the keyboard, is an absolute condition for the accuracy of the game.

  The initial leveling of the black keys and white keys is done in the factory at the manufacturing, but periodically, during the life of the piano, it is necessary to adjust the height of a certain number of keys in order to have these perfectly aligned and get for each of

  touches the same depression, of the order of ten millimeters.

  The misalignment of the keys is due to variations in temperature and hygrometry which contribute, with the impacts on the felts of flies and key linings, to compact these felts and therefore to modify the regularity of

the height of the keys.

  Keyboard training is a painstaking and time-consuming process. It consists of correcting the height of the keys relative to each other by sliding fine paper flies around the pendulum tips, under the felt pendulum flies, to increase the thickness on which the key is pressed to switch , or by removing these same

  paper flies to reduce said thickness.

  Factory straightening consists, for upright pianos, of removing each key to insert, on the tip of the pendulum, one or more paper flies, depending on the height compensation to be carried out. The control is done at

  using a ruler placed on the keys.

  Such an operation easily takes an hour and a half.

  It is of the order of two hours or more for grand pianos, whose keys are not extractable and for which flies are used

  slits engaged laterally to the pendulum points.

  During the life of the piano, the adjustment of the level of the keyboard generally only relates to a certain number of keys and takes less time, of the order of ten to thirty minutes, such an operation being carried out in

  average every 3-4 years, depending on the use of the instrument.

  The object of the present invention is to reduce the time necessary for these key setting operations, both in the factory and at the user's, and to

facilitate them.

  To this end, the invention relates to a device for adjusting the level of a keyboard, in particular a piano, comprising keys each consisting of a pendulum resting on a pendulum bar of the keyboard chassis, on a point of pendulum, a pendulum fly being threaded on the tip and interposed between the pendulum and its fulcrum, characterized in that it consists of an insert mounted fixed in said pendulum bar and on which said pendulum tip is axially adjustable, the

  tip supporting said pendulum fly.

  Preferably, the insert is provided with a tapped hole and the balance tip comprises, at one of its ends, a part of enlarged diameter supporting said balance fly, extended by a threaded part engaged in the tapped hole of the insert, the other end of the point being provided with an imprint for the engagement of a tool allowing the

screwing / unscrewing the tip.

  Thus, by a simple screwing or unscrewing of the balance tip, the height position of each can be very quickly and conveniently adjusted.

  touch and its alignment with others.

  Other characteristics and advantages will emerge from the description which

  will follow of a preferred embodiment of the device of the invention,

  description given by way of example only and with reference to the drawing

  attached in which: - Figure 1 is a side elevational view of a piano key equipped with the adjusting device of the invention; - Figure 2 is a partial sectional view of the key adjustment device of Figure 1, and - Figure 3 is a cross-sectional view along line 111-111 of the

button in Figure 1.

  In Figure 1, there is shown in 1 the balance of a piano key, in 2 the balance bar of the keyboard frame, in 3 the front bar and in 4 the

chassis rear bar.

  In 5 is shown the front tip with the front fly 6 in 7 is shown the rear bar trim; at 8 the rear lining of the balance carrying the connecting screw 9 acting on the hammer mechanism

(not shown).

  The pendulum 1 further comprises, in the known manner, a tip 10 of the pendulum secured to the pendulum bar 2 and carrying a pendulum fly 11 on which the pendulum 1 rests in its rocking movement. At 12, the capsule pierced with a passage for the

  travel of tip end 10.

  According to the invention, the tip 10 is adjustable in position

  axially with respect to the balance bar 2.

  To this end, according to the preferred embodiment illustrated by the drawing, the tip 10 has at its lower part a part 13 of enlarged diameter forming a support member and retaining the pendulum fly 11, which is conventional. Preferably, the face 14 of the support member 13 facing the balance 1 and on which the fly 11 rests is curved, while the

opposite face 1 5 is flat.

  The fly-carrying part 13 is extended by a threaded part 16, coaxial with the tip 10 and capable of being screwed into a tapped hole 17 formed in an insert 18 forcibly engaged or glued in a bore 19 made

in the balance bar 2.

  Preferably, the internal end of the insert 18 is in the form of a spherical ball joint 20 with a diameter slightly greater than that of the remaining part 18a of the insert, while the external face of the insert is flush with the face.

top of bar 2.

  Finally, the other end of the tip 10, slightly protruding from the upper face of the capsule 12, is provided with an imprint allowing, using an appropriate tool, the rotation in one direction or the other of said tip,

  for example a slot 21 for receiving a screwdriver.

  During the rocking movement of the pendulum 1 while resting on the fly 11, a housing 22, produced in the known manner in the pendulum

  and its capsule 12, allows the free movement of the tip.

  The instructions for use of the device of the invention are obvious and

particularly simple.

  Without it being necessary to remove the keys and to manipulate dunnage flies, it suffices to turn the point 10 of each key, in one direction or the other, by the simple engagement of the end d '' a screwdriver in the slot 21, accessible on the top of the keys, to modify the height position of the part 13 supporting the fly 11 and

  therefore the height position of the key (1) relative to the keyboard chassis.

  The training of the keyboard level is therefore easy and fast and takes

  much less time than with conventional technique.

  The device of the invention also has the advantage of possibly allowing the elimination of the lateral tilt of a key. This operation is carried out just as easily and quickly, by a simple tilting by force of the tip 10, the anchoring insert 18 pivots, on one side or the other, thanks to the ball joint 20 which can pivot in his accommodation. Finally, the invention is obviously not limited to the embodiment shown and described above, but on the contrary covers all its variants, in particular with regard to the shapes and dimensions of the insert 18, the shapes and dimensions of the enlarged support-retention part 13 of the balance fly 11, as well as the shape of the imprint (21) of

screwing / unscrewing the tip 10.

Claims (4)

  1. Device for adjusting the level of a keyboard, in particular a piano, comprising keys each consisting of a pendulum (1) resting on a pendulum bar of the keyboard chassis, on a pendulum tip (10), a balance fly (11) being threaded on the point (10) and interposed between the balance (1) and its fulcrum, characterized in that it consists of an insert (18) mounted fixed in said bar balance (2) and on which said balance point (10) is mounted in an axially adjustable manner, the   tip (10) supporting said balance fly (1 1).   2. Device according to claim 1, characterized in that the insert (18) is provided with a tapped hole (17) and the balance point (10) comprises, at one of its ends, a part of diameter enlarged (13) supporting said balance fly (11), extended by a threaded part (1 6) engaged in the threaded hole (17) of the insert, the other end of the point (10) being provided with a imprint (21) for the engagement of a tool allowing the screwing / unscrewing the tip.   3. Device according to claim 2, characterized in that the face (14) of said portion (13) supporting the fly (11), facing this last, is curved.   4. Device according to claim 2 or 3, characterized in that said insert (18) has an internal end in the shape of a ball joint (20) in order to   allow a possible inclination of said insert.