JPS6359398B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a circular ruler.

[Conventional technology]

Conventionally, circular rulers have a central fixed needle attached to the inner circumference of a cylindrical handle member so as to be able to move forward and backward, and a thin ruler plate is rotatably attached to this handle member, and this ruler plate has the above-mentioned A plurality of small holes or grooves were bored at different distances from the needle tip of the center-fixed needle.

[Problem to be solved]

However, with a circle ruler having this configuration, it is natural that the length of the ruler plate must be long in order to be able to draw a wide range of circles from small diameter circles to large diameter circles. However, when drawing a circle with a small diameter, the long ruler plate causes a correspondingly large frictional load, making it difficult to draw a circle with a small diameter and requiring skill to draw an accurate circle.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a circle ruler that not only allows easy drawing of various types of circles, from small diameter circles to large diameter circles, but also makes it particularly easy to accurately draw even small diameter circles.

[Means to solve the problem]

A feature of the present invention is that a thin ruler plate rotatably attached to the handle member is provided with a plurality of small holes at different distances from the needle tip of the centrally fixed needle. The rulers have a plurality of different lengths, and are mounted one on top of the other, with the shorter ruler plate at the bottom and the longer ruler plate at the top.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings.
The ruler plates 1a and 1b are two long and short thin plates formed into elongated shapes, with the short one 1a facing down.
The long pieces 1b are stacked one on top of the other, and a mounting hole 2 is bored in one end. The center of the mounting hole 2 (more precisely, the tip 12b of the center fixed needle 12, which will be explained later) is placed on the short ruler plate 1a.
A plurality of small holes 3 are formed at different distances from each other, and small holes 4 similar to the small holes 3 are formed in the long ruler plate 1b.

Note that the diameters of the small holes 3 and 4 are approximately 0.5 mm.

The ruler plates 1a and 1b have a handle member 6 and a mounting body 7.
It is rotatably attached. The handle member 6 has a cylindrical shape, and has a female thread 8 bored in the lower part of its inner periphery, and a stepped part 9 for determining the degree in the upper part of the inner periphery. The mounting body 7 also has a cylindrical shape, and a male thread 10 is formed on its outer periphery to be screwed into the female thread 8, and a collar portion 11 is formed on the lower end.
is formed.

Fit the mounting holes 2 of the ruler plates 1a and 1b into the mounting body 7, and insert the female thread 8 into the male thread 10 of the mounting body.
By screwing them together, the ruler plates 1a and 1b are rotatably supported in the mounting hole 2 in an overlapping state.

A center fixed needle 12 is attached to the handle member 6 and the attachment body 7.
The upper end 12a of this central fixing needle protrudes from the upper end of the handle member 6 without being able to escape, and the lower end is formed with a needle-like tip 12b, which coincides with the center of the attachment hole 2, It can protrude through the mounting body 7. Return spring 13 for center fixed needle 12
applies an upward elastic force to this center fixed needle.

A positioning member 14 is interposed in the center fixed needle 12 so that it can be positioned in the lowered position. The positioning member 14 consists of a piece 14a that is rotatably and slidably fitted to the center fixed needle 12, and a boss 14b that is rotatably and slidably fitted to this piece, and has a heart-shaped groove 15 and a boss on the outer peripheral surface of the piece. A protrusion 16 is formed on the inner circumferential surface of the groove, and is slidable within the groove.

When assembling, first insert the center fixing needle 12 with the positioning member 14 attached and the return spring 13 into the cylindrical hole of the handle member 6 from below, fit the ruler plates 1a and 1b into the mounting body 7, and tighten the male screw 10. Screw together the female screw 8. This causes the return spring 1
3 is in a compressed state and pushes the center fixed needle 12 upward, so that the needle-like tip 12b at the lower end is retracted without protruding from the lower surface of the attachment body 7.

To draw a circle, push down the center fixed needle 12, place the needle-like tip 12b at the center point of the circle to be drawn, select the small hole 3...or 4... at the desired distance from the needle-like tip 12b, and insert 0.5 of the writing instrument. All you have to do is pass the tip of the mm core through this small hole and rotate the ruler plate.

When drawing a circle with a short diameter, as shown in the second diagram,
The short ruler plate 1a is rotated and removed from the position where it overlaps the long ruler plate 1b, and a circle is drawn using the small holes 3 of the short ruler plate 1a. When drawing a long-diameter circle, by passing a writing instrument through the small hole 4 of the long ruler plate 1b, the paper and the lower surface of the ruler plate will come into close contact, making it easy to draw a correct circle.

When the center fixed needle 12 is released after drawing, the needle-like tip 12b is retracted from the bottom surface, so that it will not damage the paper or the like.

In addition, since it is desirable that the distance from the center of each small hole 3 changes little by little, the ruler plate 1c shown in the third figure is used.
If the small holes 5 are formed in multiple rows in a staggered manner as shown in the figure, space efficiency is good and a large number of small holes can be provided.

〔effect〕

As described above, according to the present invention, since a plurality of long and short ruler plates are provided, and only the short ruler plates can be used when drawing a circle with a small diameter, the frictional load from the long ruler plates is reduced, and therefore the small diameter It is easy to draw a circle, and it is also possible to draw a correct circle without deformation. Also, since the needle tip does not protrude except when in use, it will not damage paper or other materials.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional view, FIG. 2 is a plan view, and FIG. 3 is a plan view showing another example of the ruler plate. 1a, 1b, 1c... ruler board, 3, 4, 5...
Small hole, 6...Handle member, 12...Center fixed needle, 1
2b...needle tip.

Claims (1)

[Scope of Claims] 1. A cylindrical handle member, a central fixed needle that is attached to the inner circumference of the handle member so as to be able to move forward and backward, and whose needle-like tip can protrude from the lower end of the handle member, and A thin ruler plate that is rotatably attached,
In this circular ruler, the ruler plate is made up of a plurality of small holes at different distances from the needle-like tip of the center-fixed needle, and the ruler plate is made up of a plurality of pieces of different lengths, and a shorter ruler A circular ruler characterized by being attached with the board facing down and the long ruler board facing up. 2. The circular ruler according to claim 1, characterized in that the small holes provided in the ruler plate are formed in multiple rows in a staggered manner.