RU2348986C1 - Harp - Google Patents

Abstract

FIELD: physics, acoustics.

SUBSTANCE: invention concerns string musical instruments and can be used for simplification of process of harp manufacturing. The harp contains joined among themselves the basis - a pedestal, a column in the form of a vertical rack variable on height of traversal section, the resonator - a resonant box, a box - spiked frame and strings. The column is executed structural on the basis of a composite material - fibreglass. The column contains an outside stratum in the form of a bearing shell from the difficult polyester polymetric compound - polyester tar with density of 1200÷1400 kg/m³, strengthened by glass fibrils - fiber glass fabric, and an inside layer from made foam rigid polyurethane with density of 450÷550 kg/m³. The thickness of an outside stratum - a bearing shell in a medial part of a column on height makes 0.1÷0.2 from diameter - the spotting size of a column.

EFFECT: making technologically simple in manufacturing and a harp robust construction.

2 cl, 2 dwg

Description

The invention relates to stringed musical instruments and can be used to simplify the manufacturing process of harps.

A harp is known from the prior art, containing interconnected bases — a pedestal, a column in the form of a vertical column of variable cross-sectional height, a resonator — a resonance box, a box — a peg frame and strings (SU 301733, G10D 1/04, 1971; SU 862185, G10D 1/04, 1981). The disadvantage of the known structural embodiment is the technological complexity and the complexity of manufacturing a column glued from wood, usually from maple, which mainly provides structural rigidity and does not significantly affect the acoustic characteristics of the harp.

The invention is aimed at creating a technologically simple to manufacture and durable construction of a harp with a column of composite materials.

The solution to this problem is provided by the fact that in a harp containing interconnected bases - a pedestal, a column in the form of a vertical stand of variable cross-sectional height, a resonator - a resonance box, a box - a peg frame and strings, according to the invention, the column is multilayer based on composite material - fiberglass and contains an outer layer in the form of a carrier shell made of a complex polyester polymer - polyester resin with a density of 1200 ÷ 1400 kg / m ³ reinforced with glass fibers - fiberglass y, and the inner layer of foamed rigid polyurethane with a density of 450 ÷ 550 kg / m ³ , while the thickness of the outer layer - the bearing shell in the middle of the column in height is 0.1 ÷ 0.2 of the diameter - the determining size of the column.

In addition, the exterior of the column is covered with decorative wood veneer.

The implementation of the two-layer harp columns with a fiberglass support based on polyester resin significantly simplifies the technology and speeds up the process of manufacturing the harp columns. Moreover, the experimentally selected combination of synthetic polymeric materials for the shell and the inner layer and the geometric parameters of the column provides high strength characteristics without compromising the acoustic qualities of the harp.

Figure 1 presents a General view of the harp; figure 2 is a section aa in figure 1 in the middle part of the column.

The harp contains a base - a pedestal 1, a column 2 in the form of a vertical stand of variable cross-sectional height, a resonator - a resonance box 3, a box - a peg frame 4 and strings 5. The column is multilayer based on a composite material - fiberglass and contains an outer layer in in the form of a supporting shell 6 of a complex polyester polymer - polyester resin with a density of 1200 ÷ 1400 kg / m ³ , reinforced with glass fibers - fiberglass 7, and the inner layer 8 of foamed rigid polyurethane with a density of 450 ÷ 550 kg / m ³ . The thickness of the outer layer - the bearing shell "Δ" in the middle part of the column in height is 0.1 ÷ 0.2 of the diameter - the determining size "D" of the column 2. It is possible to make the column 2 with a cross section in the form of an octagon (not shown in the drawing) .

Outside, the supporting shell 6 of the column 2 is covered with decorative wood veneer 9. The resonator - resonance box 3 and the box - ring frame 4 are made of wood according to known technology.

Column 2 for harp is made by molding in matrices of two halves as follows.

Fiber glass fiber - fiberglass (weighing 450 g / m ² ) and polyester resin with a density of 1200 ÷ 1400 kg / m ^{3 of} grade 440 - M855 (NORPOL) are laid in a prepared matrix. After post-curing, the resulting halves of the supporting shell 6 of the column 2 in the matrices are glued, for example, with ED-20 epoxy adhesive and the inner layer 8 is formed by foaming inside the formed column of polyurethane foam (Barton'S) (FIX 65) with a density of 450 ÷ 550 kg / m ³ . Then the matrix is disassembled and the veneer shell 6 of the column 2 is veneered with decorative wood veneer 9.

The prepared column 2, the resonator — the resonance box 3, the box — the ring frame 4 and the base — the pedestal 1 of the harp are assembled into a single structure using known technology.

Claims (2)

1. A harp containing a interconnected base - a pedestal, a column in the form of a vertical stand of variable cross-sectional height, a resonator - a resonance box, a box - a peg frame and strings, characterized in that the column is multilayer based on a composite material - fiberglass and contains an outer layer of a membrane carrier of the polyester resin - polyester resin with a density of 1200 ÷ 1400 kg / ^m3, reinforced with glass fibers - glass fabric and an inner layer of rigid foam polyuria ana a density of 450 ÷ 550 kg / m ^3, the thickness of the outer layer - carrying shell in the middle of the column height is 0.1 ÷ 0.2 of the diameter - which determines the size of the column. 2. The harp according to claim 1, characterized in that the outside of the shell of the column is covered with decorative wood veneer.

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