WO1998010409B1

WO1998010409B1 - A striking mechanism for a string instrument

Info

Publication number: WO1998010409B1
Application number: PCT/DK1997/000338
Authority: WO
Filing date: 1997-08-21
Publication date: 1998-07-02

Abstract

A striking mechanism for a string instrument, such as a piano or a grand piano, comprises, for each string (4), a hammer (3), which, via a power transmission, is brought to strike the string when the associated key in the keyboard of the instrument is depressed. The mechanism furthermore comprises a first and a second check (27; 29) having, respectively, a first and a second check zone (28; 30) for, in mutual engagement, stopping and temporarily retaining the hammer during rebound. On each check zone, a magnetic or magnetizable material (32; 34) is placed, this material generates a magnetic field which causes the hammer during rebound to obtain a much safer and softer braking than is the case in conventional striking mechanisms whereby the risk of the hammer rebounding and striking the string in an unintended repetition strike is eliminated.

Claims

AMENDED CLAIMS[received by the International Bureau on 31 March 1998 (31.03.98); original claim 1 amended; remaining claims unchanged (3 pages)]

1. A striking mechanism for a string instrument, such as a piano or a grand piano and of the type which comprises, for each string, a hammer which is made to strike the string via a power transmission when the associated key in the keyboard of the instrument is depressed, and also with a first and a second check having, respectively, a first and a second check zone for, in mutual engagement, stopping and temporarily retaining the hammer during rebound for as long as the associated key is depressed, whereby the power transmission is compising a lower rod downwardly resting against an abutment on the key and swingably journalled in a fixed instrument part by means of a rearwardky extending arm; an upper rod upwardly connected swingably with the hammer butt; as well as at least one intermediate rod swingably connected with the others rods characterized in that a magnetic or magnetizable material is placed on both check zone.

2. A striking mechanism according to claim 1, characterized in that, along the outer side of at least one of the check zones, a relatively thin layer of an elastically deformable, relatively soft, noise-reducing material, for example felt, is put.

3. A striking mechanism according to claim 1 or 2, characterized in that a magnet is mounted on at least one of the outer sides of the check zones facing the other check zone and that a piece of magnetizable material, e.g. soft iron, is placed on the corresponding outer side of the other check zone.

4. A striking mechanism according to claim 1, 2 or 3, characterized in that a magnet is placed on both check zones 16 and that these magnets are of opposite polarity at the outer side of the check zones .

5. A striking mechanism according to claim 1, 2 or 3, characterized in that a magnet is placed on both check zones and that these magnets are of identical polarity at the outer side of the check zones.

6. A striking mechanism according to each of the claims 1 - 5 and where the string instrument is a grand piano and where the first check is a first swingably placed, upwards turning rod with the first check zone placed at its upper end, and the second check is a downwards turning, second check rod on the hammer with the second check zone placed mainly at its lower end whereby the striking mechanism brings the two check zones into mutual engagement when the hammer during rebound is close to the string, characterized in that a magnet is placed on the first check zone and a piece of soft iron e.g. in the shape of a wire hoop on the other.

7. A striking mechanism according to claim 6, characterized in that the rod is placed on one end of one mainly vertical rocker arm whose other end is pressed down by a power transmission when the hammer is close to the string.

8. A striking mechanism according to each of the claims 1 - 5 and where the string instrument is a piano and where the first check is a strip extending crosswise all of the sets of hammers and having a catch zone and the second check is a second rod of the hammer swingably connected to the hammer butt with a second check zone whereby the striking mechanism brings the check zones of the two checks into mutual engagement when the hammer during rebound is close to the string, characterized in that a magnet is placed on the first check zone and a piece of soft iron on the other. 17

9. A striking mechanism according to claim 8, characterized in that an elastic compressible, mainly damping unit is fitted between the second check and a fixed instrument part of the piano .

10. A striking mechanism according to claim 8 or 9, characterized in that the outer surfaces of the zones facing each other are flush with each other at the engagement position and that they, in this position in relation to the swing direction, have an inclination causing the outer surface of the second zone also to be removed crosswise to the outer surface of the first check when the second check returns to its starting position.