JPH0226710Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a drawing board, and more specifically, is an improved structure of a conventionally known wooden drawing board whose surface is provided with a synthetic resin sheet or the like.

[Prior art and its drawbacks]

Conventionally, this type of drawing board is constructed by constructing a plurality of inner frames 2 parallel to each other at appropriate intervals in the longitudinal direction of the outer frame 1 within an outer frame 1 assembled into a rectangular shape, as shown in FIGS. 3 and 4. A rim material 3 made of hard wood or aluminum is fixed to the outer surface of the frame 1 by adhesive or the like, a veneer plywood 4 circumscribing the rim material 3 is glued to the outer frame 1 and the inner frame 2, and the surface of the veneer plywood 4 is There have been proposed structures in which a thin plate 5 made of synthetic resin or the like is adhered to the outer frame 1, and a paper core 6 formed in a honeycomb cross-section as a core inside the outer frame 1 is bonded with veneer plywood 4. Also, recently, as in Utility Model Publication No. 50-22754, a structure in which muntins are sandwiched between boards with small pieces of wood stuck together like a mosaic as a core has been proposed.

In the first of these conventional drawing boards, the inner frame 2 installed on the outer frame warps due to its weight, and in the second one, the inner core 6 is made of paper so it does not warp. It absorbs moisture from the outside and loses its elasticity, and it also lacks rigidity and cannot withstand large loads, and when the veneer plywood 4 that is the surface material is pressed, it dents, resulting in poor drawing accuracy, and it is not suitable for long-term use. It was not suitable. Furthermore, the structure made up of the third set of plates has the disadvantage that the structure is complicated and the manufacturing cost is inevitably high.

〔the purpose〕

This invention eliminates the drawbacks of conventional drawing boards, and is highly rigid, lightweight, and does not warp.
The object of the present invention is to provide a drawing board that can be manufactured at low cost and can withstand long-term use.

〔composition〕

In this invention, in order to achieve the above object, a plate-shaped core made of synthetic resin foam is provided inside a wooden outer frame, and short frames made of short wooden pieces are placed around this core at appropriate intervals. The short frame is characterized by having a plurality of surface plates fixed to both outer surfaces of the outer frame.
It does not warp due to moisture, and this short frame, together with the synthetic resin foam, provides rigidity that will not deform even under large loads applied to the surface of the drawing board, resulting in a drawing board with extremely high stability. It provides:

〔Example〕

Hereinafter, details of the present invention will be explained based on drawings showing one embodiment.

In Figs. 1 and 2, 20 is an outer frame forming four sides, each made of hard wood having the same thickness, forming a rectangle of arbitrary size such as A1, A2, etc., and the outer side is made of synthetic resin, A border material 21 made of a thin piece of wood, aluminum, etc. is fixed by adhesive or the like.

One surface material 22 made of metal or plywood is fixed to the entire surface of the outer frame 20, and a core and a short frame body are provided on the inner surface of this surface material 22.

That is, the core 23 is a plate-shaped synthetic resin foam such as expanded polystyrene, and is adhered to the center of the surface material 22. The size of this center core 23 is the same as that of the outer frame 20.
It occupies around half of the area within the outer frame 20 in the example.
It is formed into a substantially rectangular shape with four sides parallel to the four sides of
The distance between the four sides of the center core 23 and the inner side of the outer frame 20 is approximately 20
cm, and the thickness is slightly thicker than the outer frame 20. Several rows of short frames are provided around this core 23.

Reference numeral 24 is a short frame body which is cut from the same square lumber that forms the outer frame 20, is made of a rectangular cross-sectional wooden strip of an appropriate length, and has the same thickness as the outer frame 20. The short frames 24 are arranged in three to four rows substantially parallel to the four sides of the outer frame 20. That is, the short side 2 formed by the outer frame 20
0a, the first short frame body row 24a is inserted at an appropriate interval.
However, a second short frame body row 24b and a third short frame body row 24c are provided in this row at appropriate intervals, for example, 2 cm. Each short frame body in the same row has an appropriate interval in the longitudinal direction, and a position where a part of each short frame body in a different row sequentially overlaps at a position facing the gap between the short frame bodies in the next row. will be placed in

In this way, short frame body rows are arranged on each of the four sides of the outer frame.

As described above, the core and the plurality of short frame body rows are arranged and formed, and then the core, which is slightly thicker than the outer frame, is pressed, and the other surface material 2
5, each short frame 24, core 23, and outer frame 20 are bonded to the surface of each member using an adhesive so as to be sandwiched between one surface material 22.

and the one and/or the other surface material 22,
A synthetic resin sheet 26 containing a known magnetic material or a magnetic metal sheet 26 is adhered onto the magnetic material 25 to form the entire structure.

The one indicated by the two-dot chain line in Fig. 1 relates to another embodiment of the present invention, and shows a structure suitable for manufacturing a comparatively large drawing board of AO or larger. 23 is divided at its center and formed into two sides, each with a central core 23a, 2
There are also two or three rows of short frame bodies 24 in the space between 3b.
Column 24d is arranged. This takes into consideration the overall rigidity and strength.

〔effect〕

As described above, the present invention provides a plate-shaped core made of synthetic resin foam within a wooden outer frame, and a plurality of short frames made of short wooden pieces are arranged around this core at appropriate intervals. In addition, since the surface plate is fixed to both outer surfaces of the outer frame, it is easy to manufacture and can be made lightweight, and since the short frames are arranged in a plurality of rows, warping does not occur. Accurate drawing is possible without disrupting plane accuracy, material yield is good, and the synthetic resin foam center core is located in the center, which provides excellent strength and rigidity, and can withstand large loads applied to the surface material. It also has high restoring force and is extremely useful in practical use as it can withstand long-term use.

[Brief explanation of the drawing]

Fig. 1 and Fig. 2 show an embodiment of the present invention, Fig. 1 is a partially cutaway plan view, Fig. 2 is a cross-sectional view taken along the line of Fig. 1, and Fig. 3 and Fig. 4 are conventional techniques. It is a partially cutaway enlarged view of. 20...outer frame, 21...edge material, 22, 25...
Surface material, 23, 23a, 23b... Core, 24...
...Short frame body, 24a, b, c, d...Short frame body row, 2
6...Sheet.

Claims (1)

[Claims for Utility Model Registration] (1) A plate-shaped core made of synthetic resin foam is provided within a wooden outer frame, and short frames made of short wooden pieces are placed around the core at appropriate intervals. 1. A drawing board characterized in that a plurality of drawing boards are arranged, and surface plates are fixed to both outer surfaces of the outer frame. (2) The drawing board according to claim 1, wherein the plate-shaped center core is slightly thicker than the outer frame. (3) The drawing board according to claim 1, wherein the outer frame has a rectangular shape, and short frames are arranged in a plurality of rows parallel to the four sides of the outer frame. (4) The drawing board according to claim 3, wherein the center core is formed in the center of the outer frame in the shape of a rectangle with four sides parallel to the outer frame.