GB2364426A

GB2364426A - A capodastro

Info

Publication number: GB2364426A
Application number: GB0004639A
Authority: GB
Inventors: Terence Gould
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-02-29
Filing date: 2000-02-29
Publication date: 2002-01-23
Anticipated expiration: 2020-02-29
Also published as: GB0004639D0; GB2364426B

Abstract

A Capodastro has a pressure bar (C) with a lower face (L) which is vertically concave at one longitudinal edge, and straight at the other edge. The longitudinal contours of the lower face reduce from maximum curvature to straight, permitting it to be used on flat or convex fingerboards. In use the pressure bar is fixed to the fingerboard by a strap and lever arrangement. To minimise flexibility when in use, the upper longitudinal side walls (U1, U2) have paired recesses (T1, T2, T3) rather than being pierced by slots, to receive one end (P) of the lever (Q) which secures the strap around the neck of the instrument.

Description

2364426 Improved Capodastro ADP No - 01085745001 Int Class - GIOD 3/04 Ref

- 98/1 SideWa1lSpec2 Date - 23 Februry 2000

T Gould's Specification

Description

A Capodastro is also known as a Capo Tasto, or simply as a Capo. It is a device used on the fingerboard of plucked stringed instruments such as guitars or banjos. It is similar in effect to a clamp which may be removably fitted around the neck of the instrument in order to press the strings onto the fingerboard at any desired position, so that the portion of the strings which vibrates when plucked may be shortened or lengthened, in order to raise or lower the pitch without requiring the player to alter the fingering.

In order to achieve this aim a Capodastro must at least consist of a member which acts as a pressure bar upon the strings, and a means of attachment around the neck of the instrument.

Some stringed instruments have fingerboards with flat surfaces, and some have fingerboards with transversely convex surfaces. The degree of curvature of a convex fingerboard, while not great, is sufficient to preclude the maintenance of equal pressure over all the strings by a Capodastro the pressure bar of which is straight.

My United Kingdom Patent No GB 2047939 describes my invention of a Capodastro which has a pressure bar which is adapted to be effective in an improved manner on instruments having a flat fingerboard, and also on instruments having a convex fingerboard. The lower face of the pressure bar has two generally parallel long edges, one of which is straight, and the other of which has a vertical concave curvature sufficient to complement a fingerboard convexity of maximum curvature. The longitudinal contour lines of the said lower face decrease progressively in curvature from the concave edge to the opposite straight edge. A second version of the invention has a pressure bar with a number of longitudinal ridges on its lower face..

The pressure bar of a Capodastro may be made of various materials, including wood, metal, and thermoplastic or thermosetting materials. My present improvement concerns those made of thermoplastic or thermosetting materials. Although the various types of these materials have certain advantages in manufacture over other materials, they have a disadvantage in that they tend to remain slightly flexible, which can lead to distortion when the pressure bar is attached to the fingerboard of an instrument. Such distortion may result in an undesirable buzzing noise when the strings are plucked.

I have now devised an improved pressure bar which may be moulded from thermoplastic or thermosetting material and yet which is sufficiently less flexible than the pressure bar described in my prior patent GB-A- 2047939.

in the Capodastro of GB-A-2047939 the means of attachment of the pressure bar to the neck of the instrument consists of a strap which is fim-dy attached to one end of the pressure bar, and which passes around the neck of the instrument, and which may be removably attached to the other end of the said bar. The means of removable attachment is a lever, to which the strap is fastened. One end of the lever is adapted to fit into a variety of pairs of transversely opposed slots which pierce the longitudinal side walls of the pressure bar. This end of the lever, once seated in a convenient pair of transversely opposed slots, acts as a fulcrum, permitting the other end of the lever to be rotated into a position in which the strap is tightened, and the pressure bar presses the strings onto the fingerboard.

The positions in the side walls of the pressure bar at which the transversely opposed slots are situated are points of weakness in the structure of the bar, and contribute to the flexibility of the said bar.

My present improvement is a Capodastro in which the side walls of the pressure bar are not totally pierced by the slots into which the lever fits. The slots have been replaced by transversely opposed pairs of recesses in the walls, which walls are continuous, thus considerably reducing, or eliminating, the flexibility which was previously a problem.

The principal object of my improvement is to provide a Capodastro with a pressure bar adapted to fit equally well onto an instrument the fingerboard of which is either flat or convex, which bar is made of thermoplastic or thermosetting material and which remains substantially inflexible when applied to the fingerboard of a plucked musical instrument.

The invention will now be more particularly described by reference to the accompanying draAring, wherein Figure I is a perspective view of part of the neck of a plucked musical instrument, with a Capodastro mounted thereon; Figure 2 is a perspective view of an embodiment of the invention described in GB-A-2047939; Figure 3 is a plan view illustrating the pressure bar of the preferred embodiment of the present invention-, Figure 4 is a perspective view of a Capodastro incorporating the pressure bar of Figure 3; and Figure 5 shows a modification of the pressure bar which may be used in connection with the present invention.

Referring firstly to Figure 1, neck A has fingerboard F on which the pressure bar C of a Capodastro is held in place on strings E, by strap D.

Figure 2 shows an embodiment of the invention described in United Kingdom Patent No GB 2047939, in which lower face L has straight edge I and curved edge K. The side walls NI and N2 are pierced by transversely opposed pairs of slots 0 which are adapted to -receive fulcrum P of lever Q which is attached to one end of strap D.

Referring now to Figure 3, there is illustrated in plan view the pressure bar of an improved Capodastro in accordance with the present invention the pressure bar C, in which side walls UI and U2 are provided with a convenient number of transversely opposed pairs of recesses TI, T2, and T3. Such recesses do not pierce the side walls, and permit greater resistance to distortion of the shape of the pressure bar.

Figure 4 is a perspective view of my present improvement, according to Figure 3, in which paired recesses T I, T2, T') are adapted to receive fulcrum P of] ever Q.

Figure 5 shows an elevation of one end of a second embodiment of my invention in which lower face L is provided with a convenient number of longitudinal ridges A

Claims

Claims 14.

1 A Capodastro for stringed musical instruments comprising: a pressure bar which is adapted to be effective on both flat fingerboards and on fingerboards having a transverse convexity with a range of curvature up to a maximum, the pressure bar having a lower face with two generally parallel long edges one of which edges is straight and the other of which edges has a vertical concave curvature to complement a fingerboard convexity of said maximum curvature, the longitudinal contour lines of which lower face decrease progressively in curvature from the concave edge to the straight edge; and means for removably mounting the pressure bar upon the fingerboard of the said instruments, the mounting means comprising a strap which is attached to one end of the bar, and a lever attached to the other end of the strap, one end of which lever is adapted to fit into any of a plurality of transversely opposed pairs of recesses in the upper longitudinal side walls of the said pressure bar, which recesses do not pierce the said side walls.

2 A Capodastro as in Claim 1, wherein the lower face of the pressure bar is provided with a number of longitudinal ridges.