HK1229944B - Sound post, sound post tool set, and method for assembling the sound post into a stringed instrument - Google Patents

Description

Sound post and sound post tool set and method for assembling a sound post into a stringed instrument

Technical Field

The invention relates to a sound post and a sound post tool set as well as a method for installing a sound post, in particular in a stringed instrument.

Background Art

It is known from the prior art that in some musical instruments, particularly stringed instruments, a soundpost is installed between the cover and base, specifically in the area below the right foot of the bridge. This is usually a small cylindrical wooden block. This soundpost influences the instrument's sound quality and stability, as it prevents the violin cover from deforming or even breaking. The difficulty in installing the soundpost lies in precisely determining the length of the small wooden block and ensuring that both ends of the small block rest against the inner curvature of the cover and base. If the soundpost has the wrong length or height, or if the curvature changes due to climatic conditions, this can negatively impact the instrument's sound quality.

Document DE 44 37 67 6 A1 discloses a bridge and soundpost system for improving the sound quality of stringed instruments, wherein the bridge and soundpost are supported on conical supports so that the end of the soundpost can abut against the inside of a cover or base plate. For precise installation of the soundpost, this system requires laborious adaptation of the soundpost length.

US Pat. No. 5,208,408 A describes a height-adjustable sound column constructed from multiple components. The first component comprises a first and a second component, wherein the first component has a hole. The second component comprises a support whose width and length correspond to the dimensions of the hole in the first component. The components can be plugged together so that the height of the sound column can be adjusted within a range of a few millimeters by using spacers of varying sizes.

Adjusting the height is complex, as the sound column must be assembled and disassembled several times for this purpose.

Summary of the Invention

Starting from this prior art, the object of the present invention is to provide a sound post, in particular for a stringed instrument, which is easy to install and improves the sound quality of the stringed instrument.

To this end, the present invention provides a sound fret, which is assembled from at least two sound fret members and has a pivotable end block on an end side of the sound fret, wherein the second sound fret member has a threaded section and the first sound fret member has an internal thread corresponding to the threaded section, so that the sound fret members can be screwed together and thus adjusted in height relative to each other. The characteristic is that the threaded section has a fine thread and a scale with equidistant graduations is provided on one of the at least two sound fret members, wherein the graduations of the scale correspond to the pitch of the fine thread.

Furthermore, the object of the present invention is to simplify the assembly of such a sound column.

To this end, the present invention further provides a sound fret tool set for mounting a sound fret according to the invention between a cover and a bottom plate of a stringed instrument, the sound fret tool set comprising the sound fret and at least one adjusting tool having a fork-shaped section, a rod, and a holding section, wherein the rod is bow-shaped and has a length corresponding to at least one length of a section corresponding to a predetermined position on the bottom plate of the stringed instrument from a predetermined F-hole of the stringed instrument to the sound fret.

A further object is to enable precise and rapid assembly of the sound column.

To this end, the present invention also provides a method for installing or removing a sound fret according to the invention from a stringed instrument by means of a sound fret tool set according to the invention, the method comprising the following steps: providing and pre-adjusting the sound fret at a predetermined height, the height being predetermined by the distance between a cover and a base of the stringed instrument; introducing the sound fret through a first F-hole of the stringed instrument using an introduction tool and positioning the sound fret in a predetermined position within the stringed instrument; introducing a fork-shaped section of a first adjusting tool into a second F-hole and holding the first fastening section of the sound fret using the first adjusting tool; introducing a fork-shaped section of a second adjusting tool into the first F-hole and grasping the second fastening section of the sound fret using the second adjusting tool, wherein the second sound fret member is gradually rotated and thereby presses the flat end surface of the end block against the cover and base of the stringed instrument or relaxes the flat end surface.

Developments or preferred embodiments of the sound column, the sound column tool set and the method are specified in the dependent claims.

One embodiment relates to a sound fret, particularly a sound fret for a stringed instrument, which is assembled from two or more sound fret members and has pivotable end blocks at the ends of the sound frets. The second sound fret member further comprises a threaded section, and the first sound fret member comprises an internal thread corresponding to the threaded section, so that the sound fret members can be screwed together and thus adjusted in height relative to one another. According to the present invention, the threaded section comprises a fine thread. Furthermore, a scale with equidistant graduations is provided on one of the two or more sound fret members, wherein the graduations of the scale correspond to the pitch of the fine thread.

The sound post can be used in any type of stringed instrument, including historical instruments, plucked instruments, and other instruments with a sound post, and can advantageously be retrofitted. The sound post can be precisely adjusted in height, particularly for retrofit installation. Furthermore, the sound post can harmonize the vibrations of the instrument's cover and base through precise height adjustment, significantly improving the instrument's sound quality and internal stability. The dimensions of the sound post can be precisely adapted to violins, violas, cellos, and double basses.

The fine thread provided according to the invention produces greater friction and finer graduations than with conventional threads, as a smaller thread pitch can be used. Consequently, no additional or separate fastening structures are required. For a violin sound post, the thread pitch can be set in the range of 0.5 mm to 1 mm, preferably 0.8 mm, and for a cello, the thread pitch can be set in the range of 1 mm to 1.5 mm, preferably 1.25 mm.

The scale can be embossed on the foil with a clear contrast and furthermore be dimensioned so that it covers the open part of the threaded section. Thus, the threaded section can be reliably protected from dirt.

In a further development, the present invention provides that the sound fret assembly can be made of fiber-reinforced plastic, preferably carbon (carbon fiber reinforced plastic). This material offers the advantage of being able to cut fine threads with a small pitch. The prior art previously could not provide such fine scale divisions, as precisely fine threads could not be cut into previously used materials, such as wood. The processed carbon surface has a defined roughness, which prevents the sound fret from shifting due to the play of the instrument, as the threads have high friction under string pressure. Materials with a plastic matrix made of thermosetting resins, such as epoxy resins, or thermoplastics, with a variable fiber content, can also be used.

Furthermore, it can be provided that the sound post is essentially cylindrical. It can have two or more fastening sections with a polygonal cross-section, preferably an octagonal one. This cross-section allows for easy gripping with tools, so that the sound post can also be adjusted in length later, even through the narrow F-holes of a violin. However, other cross-sections, such as a hexagonal or decagonal one, are also possible.

In one embodiment of the present invention, each end piece can have a partially spherical section and a flat closing surface. In this case, a partially spherical recess is provided on each end face of the sound column, in which the partially spherical section is received. The end piece can thus be supported in a tiltable manner in the recess. The flat closing surface can rest flatly against the tilted wall of the cover or base plate, thereby preventing indentations or potential damage to the cover, particularly on the inside of a soft pine cover.

Furthermore, the invention can provide that the partially spherical recess has a flange at the edge for securing the end piece. Alternatively, the recess and the corresponding end piece can have magnetic fastening means that are polarized relative to one another so that the end piece can be magnetically held within the recess. The magnetic fastening means serves to securely hold the movable end piece during assembly and initial positioning.

Because the sound column according to the invention can be easily adjusted in length or height and a good vibration coupling can be established between the cover and base of the instrument, an improved musical instrument sound quality compared to previous sound columns is advantageously produced.

To precisely install the sound fret, a sound fret tool set according to the present invention is provided for assembling the sound fret between the cover and base of a stringed instrument. In addition to the sound fret, the sound fret tool set also includes one or more adjustment tools, each of which has a fork-shaped section, a rod, and a retaining section, particularly a loop-shaped retaining section. The rod, which implements the respective fastening section of the sound fret, is arched and has a length that corresponds to at least the length of a section from a predetermined first string instrument F-hole to a predetermined position on the base of the stringed instrument. This allows for easy installation and adjustment of the sound fret at a predetermined position below the right foot of the bridge. The predetermined position, according to the present invention, is an area within the interior of the instrument below the right foot of the bridge, typically below the highest-pitched string of the instrument (e.g., the E string on a violin), approximately 5 mm deeper than the bridge. A conventional sound fret tool set can also be used as an alternative adjustment tool to the sound fret tool set described herein, with the active area of the sound fret tool set corresponding to the active area of the adjustment tool.

The set can also include an insertion tool suitable for installation, for inserting a sound fret into a stringed instrument, wherein the insertion tool comprises a curved rod and a pliers-like section. The insertion tool can have an operating device in the form of a spring-loaded post. For small sound frets in smaller instruments, the pliers-like section can be a simple pair of pliers with two jaws. If a larger sound fret is used, such as one for a cello or double bass, the pliers-like section of the insertion tool is a double pliers, thus having a total of four jaws. This allows the sound fret to be securely held and carefully inserted into the instrument through the first F-hole.

The tool set according to the present invention allows for easy subsequent use of the sound post, not only during assembly during the construction of a stringed instrument, but also after the bridge and strings have been installed. Due to its curved shape, the aforementioned adjustment tool readily reaches the desired position within the stringed instrument. Consequently, the sound post does not need to be disassembled to adjust the length, etc., based on the inclination or curvature of the cover and base plates; it can remain in place. This allows the instrument maker to avoid additional, time-consuming work steps.

In a preferred embodiment of the present invention, the rod of the adjusting tool and the curved rod of the insertion tool are coated with plastic. This plastic can preferably be the same plastic used for shrink tubing. This protects the fragile side edges of the F-holes and the wooden, painted cover of the stringed instrument. Advantageously, the color of the plastic coating can be specified depending on the instrument type. Thus, for example, the insertion tool can be generally black, while the adjusting tool for violins can be red and the adjusting tool for violas can be yellow. However, these colors are freely selectable.

The first adjustment tool can also have a longer shaft than the second adjustment tool. This advantageously allows for optimal positioning of the sound fret, as it is typically located below the highest-pitched string and is therefore closer to one F-hole than another. Alternatively, the shafts of the tools can be of the same length, with the shafts having different bending radii. This allows for simple and precise installation of the sound fret.

The method for assembling the above-described sound fret according to the present invention can be performed using the above-described sound fret adjustment tool set for a stringed instrument. In a first step, the sound fret is provided and pre-adjusted to a predetermined height, which is determined by the distance between the cover and base of the stringed instrument. To this end, the height between the cover and base can be measured using a sound fret bore gauge. If replacing an old wooden sound fret, the strings can first be loosened and the wooden sound fret removed.

In this case, the length of the sound post according to the present invention can be adjusted according to the length of the wooden sound post.

Afterwards, the sound post is inserted through the first F-hole of the stringed instrument using an adjusting tool and positioned in a predetermined position within the stringed instrument. The sound post is then easily clamped between the cover and base plates based on its pre-adjusted length. The first adjusting tool, or alternatively, a sound post installer, can also assist. The scale is now visible through the first F-hole or also through the second F-hole. The sound post should be inserted so that the scale is clearly visible through the first F-hole. The tool is then removed from the instrument, the strings are tightened or tuned to the desired pitch, and the acoustics are checked.

To adjust the sound fret length, the fork-shaped section of the first adjusting tool is then inserted into the second F-hole, and the first adjusting tool is used to hold the first fastening section, and thus the first sound fret member, on the first fastening section. Furthermore, the fork-shaped section of the second adjusting tool is inserted into the first F-hole, and the second fastening section is grasped by the second adjusting tool. The second sound fret member is then rotated gradually according to a scale, thereby tightening or loosening the flat end surfaces of the end blocks on the bottom and cover plates of the stringed instrument. Tightening or loosening here refers to increasing or decreasing the stress exerted by the sound fret on the cover and bottom plates by lengthening or shortening the sound fret, respectively. This rotation is continued until the optimal sound quality is achieved, and the instrument can be played after each rotation.

In addition to the installation during the manufacture of the instrument, this also allows for subsequent assembly, where the bridge and strings no longer have to be removed but can remain in place. Furthermore, the method can also be used in reverse to dismantle the sound post; in this case, the process of the method is reversed.

BRIEF DESCRIPTION OF THE DRAWINGS

Other embodiments and some of the advantages associated with the aforementioned and other embodiments will become clear and better understood through the following detailed description with reference to the accompanying drawings. Substantially identical or similar objects or components may be provided with the same reference numerals. The drawings are only schematic illustrations of one embodiment of the present invention.

In the attached figure:

FIG1 shows a partial longitudinal section of a sound column according to the present invention,

FIG2 shows another longitudinal section of the sound column,

FIG3 shows a cross-section of a violin in a predetermined position of the sound post,

FIG4 shows a cross-sectional view of the introduction tool of the fret tool set, and

FIG. 5 shows a view of the adjustment tool of the fret tool set.

DETAILED DESCRIPTION

According to Figures 1 and 2, the sound fret 1 has a first fret member 2 with a first fastening section 9a in the lower area of the figure. The sound fret 1 also has a second fret member 3 with a second fastening section 9b. The fastening sections 9a, 9b are octagonal in cross section to enable easy gripping with a tool and also to enable movement or rotation relative to one another at a small angle.

The second fret member 3 has a threaded section 7 which engages in a corresponding internal thread 8 of the first fret member 2. Both threads (external thread of the threaded rod 7 and internal thread 8) are designed as fine threads.

The fine thread on the threaded section 7 is cut so that the graduations of the scale 10 correspond to the pitch of the fine thread. Below the scale 10, a scale line 10a is provided on the first fret member 2. Here, the scale 10 is coupled to the second fret member 3 so that when the second fret member 3 is rotated relative to the first fret member 2, the scale 10 moves along with it and the scale line 10a remains in place.

Rotation of one scale mark of one fret member relative to the other causes the fine thread to rotate one revolution and thus the entire fret 1 to lengthen or shorten, so that the fret is extended or shortened by one scale mark with each complete rotation of one member relative to the other. The scale should be able to achieve a step of 0.022 mm, so that rotation of one scale mark causes the fret 1 to increase or decrease by this amount.

A partially spherical recess 6 is provided in each of the sound post members 2, 3, and thus in both end faces 4 of the sound post, into which an end piece 5 can be received. The end piece 5 has a partially spherical section 5a, the dimensions of which correspond to the dimensions of the recess 6. Thus, when the end piece 5 is inserted into the recess 6 with the partially spherical section 5a, the end piece 5 is supported in a foldable manner in the recess. The respective end piece 5 is closed with a flat closing surface 5b, projecting upward or downward in the figure. This closing surface is intended to rest against the inner surface of the cover or base plate when installed in a stringed instrument. The foldable support allows the end piece 5 to adapt the aforementioned curvature of the inner surface to the curvature of the cover or base plate, even under climatic conditions.

A first magnetic element may be provided on the bottom of the groove 6, which together with a second magnetic element having a polarity opposite to that of the first magnetic element may form a magnetic fastening device (not shown in the figure) on the corresponding surface of the end piece. The edges of the groove 6 may also be curled to hold the end piece 5 in the groove 6 and guide the tilt support.

All components of the sound column 1 can be made of carbon or similar materials having high strength and hardness.

FIG3 shows a cross-sectional view of a violin into which a sound post 1 is inserted, wherein the sound post 1 is clamped between a cover plate 21 and a bottom plate 22. The sound post 1 is positioned between the cover plate 21 and the bottom plate 22, below the right foot 23a of the bridge 23. The bridge 23 has an opening on its left and right sides, respectively, a first F-hole 24 on the right and a second F-hole 25 on the left.

4 and 5 below show the different components of a sound post kit, with which the sound post 1 can be installed in a stringed instrument.

4 shows an insertion tool 16 belonging to the tool set, which has a bent shaft 17 and an engagement area with a tong-like section 18. An actuating device in the form of a spring-loaded column 19 and a handle 20 is provided on the end of the insertion tool 16 facing the tong-like section 18.

FIG5 shows further components of the tool set according to the present invention, which also includes adjusting tools 11 and 12. Both adjusting tools 11 and 12 are essentially identical: each has a tool fork 14 at its active end, the dimensions of which are adapted to the respective sound fret to be inserted. Furthermore, the tool fork 14 is dimensioned so as to correspond to the dimensions of the fastening sections 9a and 9b. Furthermore, the adjusting tools 11 and 12 have a retaining loop 15 at their ends opposite the fork 14, which allows the string instrument maker to grasp the adjusting tools 11 and 12. The retaining loop 15 is connected to the tool fork 14 via a curved rod 13. The curved rod 13 of the first tool 11 is longer than the rod 13 of the second tool 12. Thus, the string instrument maker can use the first adjusting tool 11 to insert the sound fret 1 or to hold it in place within the instrument, and the second adjusting tool 12 for rotation and height adjustment. Since the sound post 1 must be positioned at a predetermined location within the instrument, as shown in FIG3 , it is closer to the first F-hole 24 than to the second F-hole 25 , this difference can be compensated by the different lengths of the tools, and the sound post 1 can be easily reached and adjusted using the two adjusting tools 11 , 12 . This also enables subsequent adjustments.

Claims (13)

1. A sound post (1), said sound post being assembled from at least two sound post components (2, 3) and having a pivotable end block (5) on the end side (4) of said sound post. The second sound post component (3) has a threaded section (7), and the first sound post component (2) has an internal thread (8) corresponding to the threaded section (7), so that the sound post components (2, 3) can be screwed together and thus can be adjusted relative to each other in height. Its features are, -The threaded section (7) has fine threads and - One of the at least two sound post members (2, 3) is provided with a scale (10) having equidistant graduations, wherein the graduations of the scale (10) correspond to the pitch of the fine thread. 2. The sound column (1) according to claim 1, Its features are, The sound post (1) is used for stringed instruments. 3. The sound column (1) according to claim 1, Its features are, The components of the sound column (1) are made of fiber-reinforced plastic. 4. The sound column (1) according to claim 3, Its features are, The components of the sound column (1) are made of carbon fiber reinforced plastic. 5. The sound post (1) according to any one of claims 1 to 4, Its features are, The sound column (1) is substantially cylindrical and has at least two fastening sections (9a, 9b) having polygonal cross-sections. 6. The sound column (1) according to claim 5, Its features are, The fastening sections (9a, 9b) are octagonal in cross-section. 7. The sound column (1) according to any one of claims 1 to 4, Its features are, Each end block (5) has a partially spherical section (5a) and a flat closed surface (5b), and a partially spherical groove (6) is provided on the end side (4) of the sound post (1), wherein the partially spherical section (5a) is accommodated in the groove. 8. The sound column (1) according to claim 7, Its features are, The corresponding groove (6) has a rolled edge or magnetic fastening device on the edge side for fastening the end block (5). 9. A tool set for assembling a soundpost (1) according to any one of claims 1 to 8 between the cover plate and the base plate of a stringed instrument. The sound column tool set includes The sound column (1) and At least one adjusting tool (11, 12) having a forked section (14), a rod (13) and a holding section, wherein the rod (13) is bow-shaped and has a length corresponding to at least one length of a section that corresponds to a predetermined position of the soundpost (1) on the bottom plate of the string instrument from a predetermined F-hole (24, 25) of the string instrument. 10. The sound post tool set according to claim 9, Its features are, The soundpost tool set includes an introduction tool (16) for introducing the soundpost (1) into a stringed instrument, wherein the introduction tool (16) has a curved rod (17) and a pincer-shaped section (18). 11. The sound post tool set according to claim 10, Its features are, The rod (13) of the adjustment tool (11, 12) and the bent rod (17) of the inlet tool (16) are covered with plastic. 12. The sound post tool set according to any one of claims 9 to 11, Its features are, The first adjustment tool (11) has a rod (13) that is longer than the second adjustment tool (12). 13. A method for assembling or removing a soundpost according to any one of claims 1 to 8 from a stringed instrument using a soundpost tool kit according to any one of claims 9 to 12, the method comprising the steps of: - The soundpost (1) is provided and pre-adjusted at a predetermined height, which is determined in advance by the distance between the cover plate and the base plate of the stringed instrument. - Using the import tool (16), the sound post (1) is imported through the first F hole (24) of the stringed instrument and positioned in a predetermined position inside the stringed instrument. - Insert the fork-shaped section (14) of the first adjusting tool (11) into the second F hole (25) and use the first adjusting tool (11) to hold the first fastening section (9a) of the sound post (1) in place. - Insert the forked section (14) of the second adjustment tool (12) into the first F hole (24) and use the second adjustment tool (12) to grasp the second fastening section (9b) of the sound post (1), whereby the second sound post component (3) is rotated gradually and thus the flat closed surface (5b) of the end block (5) is pressed against the cover plate and the bottom plate of the stringed instrument or the flat closed surface is loosened.