RU2443447C1 - Elongated wood article and method of its production - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to woodworking and may be used in producing billiard cues, curtain holders, furniture elements, etc. Proposed method comprises selecting square-section long wood workpiece to saw four square-section parts in symmetry out on over its entire length. Then, every sawed-out part is turned through 180 degrees relative to lengthwise axis and glued in the points where it was sawed out from. Then, workpiece is machined to produced required shape. Note here that sizes of sawed out parts after final processing, the sum of cross section areas of sawed-out parts on medium diameter equal cross section area of now sawed-out part.

EFFECT: higher stability of wood structures, better operating properties.

2 cl, 4 dwg

Description

The invention relates to woodworking industries and can be used in the manufacture of cues for playing billiards, their parts, as well as for the manufacture of cornices, furniture parts.

All manufacturers of elongated wooden structures, when the length of structures significantly exceeds their cross-sectional dimensions, in particular billiard cues, shaft shafts (percussion), are faced with the stability problem of these structures. This problem is caused by always occurring internal stresses in wooden blanks, bars from which they are made. The aforementioned problem may be further complicated by the effect on the workpiece of the environment (temperature and humidity). Internal stresses lead to unpredictability of the behavior of structures during operation. In particular, the behavior of the shaft during the game is unpredictable, as vibrations appear during shock. In addition, the unidirectional effect of the internal stresses of the workpiece, increasing in length, leads to the curvature of wooden structures, cue, shaft, unpredictable violation of their geometric characteristics, which degrades their performance, playing properties of the cue. When a cue impacts from the side of the ball, internal stresses lead to a wedging effect, which causes cracking of the cue material and to the appearance of cracks and fractures in it, which leads to its short life.

Compound structures of cues are widely known, in which inserts of different types of wood are used, which have different internal stresses of different directions of action, which should eliminate the large resulting stress that manifests itself along the length of the cue. In particular, the cue construction is known, which is a truncated cone consisting of three parts: a striker, a turner and the middle part between them (see Utility Model Certificate No. 16908 “Billiard Cue”, IPC A63D 15/08, published February 27, 2001) . In this design, the drummer is made of one wood species, the turnstile is made of another, and the middle part is composed of alternating inserts made of the material of the drummer and the turnstile. This design destroys the structure of unidirectional moments of the internal stresses of the initial billet and reduces the harmful effect of these stresses, reduces the effect of curvature of the cue. Improving the game properties of the cue. However, this design requires a long and careful selection of wood species, and does not always provide the desired effect. For the most part, stresses are preserved, and if materials are mistakenly selected, they can even increase with their unidirectional (single-sign) summation.

The objective of the invention is to increase the stability of elongated wooden structures, improving their operational properties by compensating for internal stresses in products.

The problem is solved by a method of manufacturing an elongated wooden product, in particular a shaft, in which an elongated wooden blank of square section is taken, in which four parts of square section are cut symmetrically from the corners along its entire length. In this case, the unsawed part of the workpiece acquires a cruciform shape. Then each sawn part is turned 180 degrees relative to its longitudinal axis and glued to the same place from which they were sawn. In this case, the former internal sides of the sawn parts are outside the workpiece. After that, the workpiece is processed to obtain the desired shape. Cue, shaft is processed in the form of a truncated cone. The dimensions of the parts to be sawn are chosen so that after processing (turning the cone), the sum of the cross-sectional areas of the sawn parts - segments on the average diameter of the product (shaft) - is equal to the cross-sectional area of the remaining cruciform, uncoated part. This method of manufacturing the product (shaft) will compensate for the initial stresses in the workpiece, eliminating completely or minimizing their impact on it, ensuring their stability, in particular the same elasticity when the cue rotates around its axis in the player’s hand. In this case, due to compensation of the internal stresses of the product, the cue, the likelihood of its distortion, cracking will decrease, and its service life will increase.

The problem is also solved by the design of an elongated wooden product, in particular, a truncated cone shaped shaft, which is a composite longitudinal structure, the middle part of the product is cross-shaped in cross section, and the segment parts are located in the outer quadrants of the cross and are rigidly fastened with faces with the middle part, each segment part formed by sawing it out of its quadrant and installed in it with a 180 degree turn. The cross-sectional area is equal to the sum of the cross-sectional areas of the segment parts on the middle part of the product.

Figure 1 shows the workpiece before processing, where the arrows indicate the internal stresses of the workpiece. Figure 2 shows the workpiece after sawing into five parts. Figure 3 shows the workpiece after gluing its middle part with sawn parts turned upside down by 180 degrees. Figure 4 shows the cross section after undercutting the shaft cone in its middle part, where the cross-sectional area of the sawn segments is equal to the cross-sectional area of the cruciform, not sawn part.

The shaft is made of the middle 1 part of the workpiece, which after cross-cutting has a cross-shaped shape, and four identical peripheral parts 2, each of which is designated 2A, 2B, 2B, 2G. In Fig.2, the peripheral parts are shown before a turn, therefore, the directions of the arrows indicating the presence of internal stresses coincide with the directions of the arrows on the cross-shaped part 1 of the workpiece. In Fig. 3, the peripheral parts 2A, 2B, 2B, 2G are mounted on the middle cross-shaped part after turning them 180 degrees, therefore, the directions of the arrows of internal stresses on the sawn parts are opposite to the stresses of the cross-shaped part.

A method of manufacturing a shaft or other wooden products is implemented as follows. Take an elongated wooden one-piece blank of square cross section with the internal stresses present in it. Since this blank is not composite, the stresses in it are unidirectional. Then carry out its sawing as follows. For its entire length, four parts of a square section are cut symmetrically from the corners. As a result of such a cut, five parts of the workpiece are obtained: the middle one is of a cross-shaped shape and four external square 2A, 2B, 2B, 2G (Fig.2). Since all the parts 1, 2A, 2B, 2B, 2G are made from one bar, the internal stresses in them have one direction, as shown by the arrows in FIG. 2. Next, each sawn part of a square section 2 is turned exactly 180 degrees around its axis. And the internal faces of these parts become external, and the external - internal. The direction of internal stresses in the unfolded parts 2, remaining the same, with respect to the part 1 changes by 180 degrees, i.e. to the opposite. Next, the external sides of the cross-shaped part are treated with glue, on which the former external ones before sawing, which became internal after sawing the edges of the parts 2, are installed. Figure 3 shows such a workpiece after turning its peripheral parts, assembled and glued. Figure 3 shows the opposite directions of the internal stresses of the deployed peripheral parts relative to the internal cruciform details. After this assembly, the workpiece is machined to give it the desired shape. For a shaft, this is the shape of a truncated cone. The multidirectionality of the internal stresses of various parts of the shaft, the sizes of the sectors of which in cross-section are equal to the size of the cross-section of the cross-shaped part (figure 4), leads to almost complete mutual compensation of the internal stresses of the parts, which will not affect the cue in any way. With a difference in the cross-sectional areas of the sawn parts and the cruciform part, there is also a compensation of internal stresses, but not complete.

Thus, the method of manufacturing an elongated wooden product, in particular a shaft cue, does not remove the internal stresses themselves, but mutually compensates them. When using an elongated wooden product made in this way, its distortion is eliminated or minimized, and its geometric and operational characteristics are stable. When using a cue, a shaft made in the described way in the game, the stability of their game characteristics is ensured, vibration on the shaft is eliminated or minimized, a hit on the ball will not depend on the player’s cue being caught. It excludes many hours of selection of cue material for the manufacture of inserts for it, repeated processing of the cue to sequentially relieve its internal stresses.

Claims (2)

1. A method of manufacturing an elongated wooden product, in which an elongated wooden blank of square cross section is taken, four square sections are cut symmetrically from the corners along its entire length, then each sawn part is rotated 180 ° relative to its longitudinal axis and glued to the same place where they were cut from, after which the workpiece is processed to obtain the desired shape, while the dimensions of the parts to be sawn are chosen so that after the final processing of the product, the sum of the cross-sectional areas is turned parts on the average diameter of the product was equal to the cross-sectional area of the not sawn part. 2. An elongated wooden product, in which its middle part is cross-shaped in cross section, and the segment parts are located in the outer quadrants of the cross-shaped part and rigidly glued to it, each segment part being formed by sawing it from its own quadrant and installed in it with a 180 ° turn relative to its longitudinal axis, and the cross-sectional area of the cross-section is equal to the sum of the cross-sectional areas of the segment parts on the middle part of the product.

Images