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Patent Searching and Data


Title:
WOODEN BLANK
Document Type and Number:
WIPO Patent Application WO/1996/000876
Kind Code:
A1
Abstract:
An elongate, wooden blank (1, 21, 31, 41) is formed in one piece and comprises one or more cavities (8, 22, 32). Each cavity is a throughgoing cavity and extends between two opposing long sides (2, 4) of the blank. Preferably, the cavities have a largest extension in the longitudinal direction of the blank and are formed before drying of the blank, thereby to achieve more rapid and favourable drying resulting in a higher-quality dried blank, inter alia, as regards straightness. The blank is particularly suitable for use as a spacer in a loading pallet or as a stud for construction work. A method for making the blank is also disclosed.

Inventors:
SANDGREN STURE (SE)
BERGSTROEM CHRISTINA (SE)
Application Number:
PCT/SE1995/000805
Publication Date:
January 11, 1996
Filing Date:
June 29, 1995
Export Citation:
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Assignee:
SANDGREN STURE (SE)
BERGSTROEM CHRISTINA (SE)
International Classes:
B27M1/00; E04C3/16; F26B1/00; F26B25/18; (IPC1-7): F26B1/00; B27M3/00; E04C3/12
Foreign References:
US0987392A1911-03-21
SE104540C1
Download PDF:
Claims:
CLAIMS
1. A wooden blank in one piece, said blank (1) being elongate and having four long sides (24) and two short sides (6, 7), c h a r a c t e r i s e d in that it com¬ prises a throughgoing cavity (8) whose openings are located in two opposing long sides (2, 4) of said long sides (24), that the cavity (8) has a largest extension in the longitudinal direction of the blank (1 ), and that the cavity (8) is made when the blank (1 ) is in fresh state prior to drying, thereby to achieve more rapid dry¬ ing and a straighter dried blank ( 1 ) .
2. A blank as set forth in claim 1, c h a r a c t e r i s e d in that it comprises one or more additional cavities (8), which are separated by partitions.
3. A blank as set forth in claim 1 or 2, c h a r ¬ a c t e r i s e d in that the cavity (8) takes up between 15% and 70% of the total volume of the blank (1), calcu lated on the basis of the outer dimensions of the blank (1).
4. A stud, for instance a wall stud, for construc¬ tion work, said stud (31) being a wooden stud in one piece, which is elongate and has four long sides and two short sides, c h a r a c t e r i s e d in that it has at least one throughgoing cavity (32), whose openings are located in two opposing long sides of said long sides, and that the cavity is made prior to drying of the stud, thereby to achieve more rapid drying and a straighter dried stud.
5. A stud as set forth in claim 4, c h a r a c ¬ t e r i s e d in that the cavity has a largest extension in the longitudinal direction of the stud.
6. A stud as set forth in claim 5, c h a r a c t e r i s e d in that the cavity or cavities take up between 15% and 70% of the total volume of the stud, cal¬ culated on the basis of the outer dimensions of the stud.
7. A base element for a loading pallet, said base element (21) consisting of a wooden blank in one piece, which is elongate and has four long sides and two short sides, c h a r a c t e r i s e d in that it comprises a throughgoing cavity (22) whose openings are located in two opposing long sides of said long sides, that the cavity (22) has a largest extension in the longitudinal direction of the base element (21 ), and that the cavity (22) is made when the base element (21) is in fresh state prior to drying, thereby to achieve more rapid drying and a straighter dried base element.
8. A base element as set forth in claim 7, c h a r a c t e r i s e d in that the cavity takes up between 15% and 70% of the total volume of the base ele ment, calculated on the basis of the outer dimensions of the base element.
9. A method for making a wooden blank, which is intended to be used e.g. as a stud for construction work or as a base element for a loading pallet, comprising the steps of sawing, from a log of wood, an elongate one piece blank having the shape of a rectangular parallel¬ epiped; and drying the blank, c h a r a c t e r i s e d by the step of making at least one throughgoing cavity in the blank prior to drying, thereby to achieve more rapid drying and a straighter dried blank.
10. A method as set forth in claim 6, c h a r a c ¬ t e r i s e d by the step of so forming the cavity or cavities that it or they have a largest extension in the longitudinal direction of the blank.
Description:
WOODEN BLANK

This invention relates to a wooden blank as set forth in the preamble to appended claim 1.

Elongate wooden blanks are used in many different fields. For instance, such blanks are employed as beams or studs in construction work and as component parts in loading pallets, in which case they serve as spacers enabling goods to be handled with the aid of a fork-lift truck or the like. Frequently, fairly high straightness requirements are placed on the blank, i.e. the blank must not be bent or twisted. In many contexts, cracks in the wood are unacceptable or acceptable but to a small extent. It is, however, a difficult task to produce elon¬ gate wooden blanks meeting these high requirements. The drying of the blanks is here of crucial importance, since it is primarily during the drying operation that problems arise. At present, excessive amounts of the dried blanks have to be scrapped, reworked in an effort to remedy the deficiencies, or be used in low-rate applications where the quality requirements are lower. Naturally, this is a waste of resources reducing the profit from the produc¬ tion of blanks.

A basic object of the invention is to provide elon¬ gate wooden blanks which are better equipped to withstand the drying operation than today's blanks, and hence meet the highest quality requirements in greater numbers, and whose production involves a lower energy consumption.

According to the invention, this object is achieved by a blank as set forth in appended claim 1. This blank becomes straighter and exhibits less crack formation as a result of drying than do prior-art blanks, because it exposes a greater surface to the surrounding air than does a blank having the same outer dimensions but no cavities. Furthermore, the blank according to the inven¬ tion has a lower weight, while maintaining essentially the same strength. Also, the drying time is reduced. As a

result, the energy consumption is also reduced, which is an important factor in view of the fact that the drying operation is expensive as well as energy-intensive, that a larger amount of wood can be dried per 24 hours, and that the harmful effects on the environment are reduced, as seen per unit of volume.

The blank according to the invention may be used as a stud in construction work, especially as a wall stud. A conventional stud is rather heavy and further obstructs cable and pipe installations, since holes have to be bored in the stud on site to enable passage past the stud.

Another object of the invention is, therefore, to provide a stud for construction work, which is lighter than a conventional stud and which enables one stage of the cable and pipe installations to be dispensed with.

According to the invention, this object is achieved by a stud as set forth in appended claim 5.

The blank according to the invention may also be used as a base element or batten in a loading pallet. In this application, two or three blanks may advanta¬ geously be used to form a loading pallet with loose battens. Patent Specifications US-2,614,689 and US- 3,331,496, amongst others, teach loading pallets with loose battens. However, these loading pallets cannot be lifted from all four sides, which is a disadvantage in the narrow spaces frequently offered by storerooms and transport vehicles. Furthermore, the weight of the load¬ ing pallet is essential, since any reduction in weight of the pallet may instead be used for the effective load. The prior-art loading pallets are not optimal in this respect. Besides, the straightness is vital also in this application.

Yet another object of the invention is, therefore, to provide a base element or batten for a loading pallet, which enables the pallet to be lifted from all four sides and is lighter than known base elements.

According to the invention, this object is achieved by a base element as set forth in appended claim 6.

The invention is further advantageous in that the wood removed from the blank may serve other purposes, which saves raw material at the same time as processing becomes more profitable.

The invention will now be described in more detail with the aid of a few embodiments, reference being had to the accompanying drawing, in which like elements are designated by the like reference numerals. In the draw¬ ings,

Fig. 1 is a perspective view of an embodiment of the blank according to the invention,

Fig. 2 shows the inventive blank when used as a base element in a loading pallet,

Fig. 3 is a plan view of another embodiment of the blank according to the invention, and

Fig. 4 shows the inventive blank when used as a stud for e.g. a wall. Thus, Fig. 1 shows an embodiment of the inventive blank 1, which is elongate and has the shape of a rectan¬ gular parallelepiped with four long sides 2, 3, 4, 5 and two short sides 6, 7. The blank 1 is made in one piece and thus does not comprise several interconnected compo- nent parts. The blank 1 is formed with a cavity 8, which is throughgoing, so that it extends between two of the long sides 2, 4, and is elongate in the longitudinal direction of the blank 1, i.e. has its largest extension in the longitudinal direction of the blank 1. Alterna- tively, two or more cavities 8 can be made in the blank 1, as is illustrated in Fig. 2. The blank 1 is formed with the cavity 8 when fresh, i.e. prior to drying, thereby to achieve the advantages indicated above.

The volume of the cavity 8 is maximised in relation to the total volume of the blank 1, measured as a mul¬ tiplication of the outer dimensions of the blank 1, i.e. b x h x 1 in the embodiment shown in Fig. 1, wherein b is

the width of the blank, h is the height of the blank, and 1 is the length of the blank. The length 1 may constitute a fixed basic measurement, a blank having a length of one or more l's, as indicated by dashed lines in Fig. 1. When making the cavity 8, one leaves an upper supporting por¬ tion 9 and a lower supporting portion 10 of a certain thickness, as well as end posts 11 of a certain width a. Naturally, these measurements vary according to the application. In the most common applications as battens or studs, these measurements vary as follows: 1: one or a few metres, b: 30-150 mm, h: 45-250 mm, d: 12-30 mm, and a: 20-110 mm. As mentioned in the foregoing, the cavity 8 should take up as much as possible of the total volume of the blank 1. The larger b and h are, the larger the volume the cavity 8 takes up. The cavity 8 takes up between approximately 15% and 70% of the total volume of the blank. For instance, the volume of the cavity 8 in a batten where b=75 mm and h=75 mm is approximately 35% of the total volume of the batten, whereas the cavity 8 takes up approximately 60% of the volume of a batten where b=200 mm and h=200 mm. It is the strength of the blank 1 that restricts the volume of the cavity 8. How¬ ever, the strength of the blank 1 is only marginally reduced in the embodiment described. If one knows what the blank 1 is to be used for when making the cavity 8, the volume of the cavity 8 can be adjusted accordingly.

In addition to the advantages enumerated above, the blanks 1 according to the invention can be stacked more closely in the drying operation than conventional blanks, owing to the increase in air circulation due to the pro¬ vision of the cavities 8.

Fig. 2 illustrates the use of the blank according to the invention as a base element in a loading pallet. This use of the blank 21 enables special problems associated with loading pallets and accounted for above to be solv¬ ed. Thus, a loading pallet 20 may, for instance, be com¬ posed of three blanks 21, as shown in Fig. 2. Depending

on the type of load at issue, the blanks or base elements 21 may be used as they are or in combination with a load¬ ing platform (not shown) in the form of, say, corrugated fibreboard, wood fibreboard, sheet metal or the like. The cavities 22 in the blanks 21 are used for lifting the loading pallet 20 from the two sides that are closed when using blanks of conventional design, such as the blanks taught in the patent specifications mentioned above. The size and the position of the cavity or cavities 22 are thus, in this embodiment, chosen while taking into consi¬ deration the accessibility for various trucks. This improved access to the loading pallet is very useful in the narrow spaces offered by storerooms and transport vehicles. The cavities 22 are also used for strapping the load with the aid of straps 23. This operation can be rapidly performed, owing to the fact that the cavities 22 are fairly large. In order to permit additional strapping perpendicular to the first-mentioned strapping, each blank 21 is, in this embodiment, provided with grooves 24 (also shown in Fig. 1 at 12) running along the blank 21 in the two long sides not perforated by the cavities.

As shown in Fig. 3, several cavities 32 having an optional largest extension may, in an alternative embodi¬ ment, be formed in the blank 31. Such a blank 31 can be especially adapted for use as a stud (see Fig. 4), since the cavities 32 may be designed in view of the cable and pipe installations. However, the basic inventive concept is manifested also in this blank 31, in that the cavities 32 are made prior to drying of the blank 31. As illustrated in Fig. 4, the blank according to the invention may also be used as a building element in the form of a stud 41. As mentioned in the foregoing, conven¬ tional solid studs are heavy. A stud 41 according to the invention is much easier to handle than a solid stud and thus reduces the risk of the person handling the stud contracting any musculo-skeletal disorders. In addition, the time required for cable and pipe installations is

reduced, in that no holes have to be made in the studs 41.

A blank 1, 21, 31, 41 according to the invention is produced in the following manner. Raw blanks are sawed from a log and so divided as to obtain the aimed-at dimensions. Thus, blanks of fresh wood have been obtained. These block-shaped blanks (beams) are to be dried before further processing. Prior to the drying operation, cavities 8, 22, 32 are made in the blanks 1, 21, 31, 41, as shown in the Figures, in order to enhance the quality of the dried blanks. The cavities are pro¬ vided by milling or some other suitable, conventional method. The cavities take up approximately 15-60% of the total volume of the blank, depending on the size of the blank and the envisaged application. The form of the cavities is not of decisive importance, but it is prima¬ rily the increase in the surface exposed to the surround¬ ing air that produces the good results.