JPS6076397A - Thread holder for ellipse drawing instrument - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on patent application No. 58-109190 filed by the same applicant.
This invention relates to an improvement of the thread holder for an ellipse delineator described in No.

Patent No. 956200 and Japanese Patent Application No. 1983 by the same applicant
No. 109386 describes an ellipse drawer that draws an ellipse using a thread. The ellipse drawer thread holder described in Japanese Patent Application No. 58-109190 is used to hold the thread for those ellipse drawers.

However, the ellipse drawer described in Japanese Patent Application No. 58-109190 can be used simply to draw a rough ellipse, but it can be used only under given conditions, such as rotating a circle drawn on the plane P by an angle θ. Under the condition that the ellipse projected onto the original plane P (hereinafter referred to as the ellipse of angle θ) is drawn so that it has a determined center and a given major or minor axis,
It is not suitable for accurately drawing an ellipse. To explain this point in more detail, assume that the center O and the major axis direction AB of the ellipse to be drawn are given. And the length of the major axis is r
Suppose we are given the problem of drawing an ellipse with angle θ. In this case, the two points holding the thread used in the ellipse delineator (hereinafter referred to as focal points f and f') should be placed on the line AB, and the distance between the focal points ff' should be set to rsinθ, and the midpoint between them should be placed on the line AB. The ellipse drawer thread holder must be positioned so that O coincides with O. However, the patent application No. 58-109386
In the holder described in the above issue, the two holding members that hold the thread corresponding to the focal points f and f' have a structure as shown in Figure 1, and the points corresponding to f and f' are the two holding members that hold the thread. It is very difficult to bring the points corresponding to f and f' onto the given line AB correctly because it is hidden directly below the rod-shaped arm that passes through the line AB. Furthermore, when the ellipse delineator is rotated, the thread hits the edge of the thread holding member, creating a bend such as P or P', which causes the ellipse to be inaccurate.

The present invention relates to a thread holder for an ellipse drawer for accurately drawing an ellipse under such given conditions.

In the following explanation, for the sake of simplicity, the arm is assumed to be a rod with a rectangular cross section. However, a similar structure can be made, for example, with a rod-shaped arm having a polygon, L-shape, I-shape, semicircle, etc., or an ellipse. This applies to all arms in which the thread holding member requires an inner wall surface perpendicular to the plane of the paper.

FIG. 2 shows a specific example of the thread holding member of the present invention. One thread holding member (10) of the pair of thread holding members (10, 10') has an edge (1) perpendicular to the long axis of the arm, and a line at the inner corner of the edge On the extension of 22', a focal hole member (4) having a hole (hereinafter referred to as focal f hole) (3) through which the thread passes is attached to the lower surface of the thread holding member. In that case, the exit below the focusing hole f should be exactly on the extension of the line 22', and its diameter should be just large enough to match the thread used. The exit above the focal f-hole may have a larger diameter and does not necessarily lie on an extension of line 22'. The other thread holding member (10') has an edge (1') perpendicular to the long axis of the arm, and the thread passes along the extension of the inner corner line 2''2'''. Hole (hereinafter referred to as focal point f'
A focusing hole member (4') having a hole (3') is attached to the underside of the thread holding member below its edge. The thread holding members (10), (10') have screw holes (5), (5') for thread fastening and thread holes (6), (6') for stopping the thread holding member on their upper surfaces, respectively. It's open. Further, thread threading grooves (7) and (7') are formed on the side surface. These thread holding members (10), (10') are arranged in a rectangular cross-sectional shape having a thickness that exactly fits the inner width of the thread holding member, but a height that is lower than the inner height of the thread holding member. Pass it through the rod-like arm of the thread holding member stop screw (16), (16')
15) and (15') respectively. By turning the thread holding member stopping screw, the thread holding member can be stopped at any desired location. A tongue-like member is placed under the thread-clamping screw, so that when the thread is threaded through the thread-hanging groove and the screw is turned, the thread can be narrowed and fastened under it.

When drawing an ellipse, first place the side of the arm on the side where the focal hole is located, so that it lines up with line AB in the major axis direction when viewed from above. That is, place the arm so that its side surface and line AB are approximately on the same plane. This necessarily results in the focal aperture being supported on line AB. Also, the distance between the focal points is (1), (1)
') can be easily measured using the scale on the arm. Also, the scale of the midpoint between the two is the point O on AB.
All you have to do is position your arms so that they match up when viewed from above. By this method, it becomes possible to easily and accurately draw an ellipse given the center O, major axis direction, angle θ, and major axis.

Furthermore, while drawing an ellipse, the thread does not come into contact with anything other than the focus hole of the thread holding member, so that an accurate ellipse can be drawn.

The focus hole may be centered on the same plane as the side surface of the arm, or may be located on and above the same plane. In the former case, the side of the arm and line A
Align them so that the center line of the width of line B is on the same plane when viewed from above, and in the latter case, align them so that the side of the arm and the lower edge of the width of line AB are on the same plane.

The focus hole member may be attached directly to the end of the arm as shown in FIG. 6, in which case the thread retaining member (10') would be unnecessary. Therefore, when the present application refers to "two thread holding members", it also includes the case where one thread holding member corresponds to the thread holding member at the end of the arm.

The structure for stopping the thread holding member and the structure for securing the thread are shown as examples, and may not be the structures shown in FIGS. 2 and 4.

For example, the thread fastening structure may be such that the thread is narrowed and fastened by an L-shaped plate (8) that can be opened and closed with a screw, as shown in FIG.

If the arm is a rod with an I-shaped cross section, the thread holding member may have an opening with a rectangular cross section as described above, or it may have an I-shaped opening as shown in Figure 9. . In that case, the line connecting the two points on the inside corner as shown in Figure 9 (18) and (18') should be perpendicular to the plane of the paper, and the focal hole exit should be on the extension of that line. Attach the focal hole member.

On the other hand, the edges corresponding to (18) and (18') of the arm are made to coincide with (18) and (18') when the thread holding member is stopped.

An example of the arm support used in the present invention is shown in FIG.
These structures are clear from the description in Japanese Patent Application No. 58-109190. In FIG. 8, the arm support (9) has a hole (11) through which the arm passes, and a screw (12) for fastening the arm.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the thread holding member described in Japanese Patent Application No. 58-109190. FIG. 2 is a perspective view of a thread holding member according to the present invention. FIG. 3 is a plan view of the end of the thread holding member (10) shown in FIG. 2. FIG. 4 is a side view of the arm fitted with the thread holding member shown in FIG. 2. FIG. 5 is a plan view of the arm fitted with the thread holding member shown in FIG. FIG. 10 is a diagram showing how to bring the focal hole onto line AB by aligning the lenses so that they are substantially on the same plane. FIG. 6 is a perspective view of the arm end when the focal hole member is attached directly to the arm end so that it functions in the same way as the focal hole member when one thread holding member is fixed to the arm end. . FIG. 7 is a sectional view of the thread holding member to show another embodiment of the thread clamp. FIG. 8 is a perspective view showing an example of the arm support. FIG. 9 is a sectional view of the I-type thread holding member. 1, 1'-edge, 22', 2''2'''-line of inner corner of edge, 3, 3'-focal hole, 4, 4'-focal hole member, 9-
Arm support, 11-arm hole, 12-screw, 17-thread. Patent applicant Mikio Ito

Claims (1)

[Claims] A rod-shaped arm and an arm support for horizontally supporting the arm at a height sufficient to allow the thread passed through the ellipse delineator to pass under the arm when drawing an ellipse, and having a hole through which the rod-shaped arm can pass. In the thread holder for an ellipse drawer, the thread holder is composed of an arm support member having a screw for fastening the arm through the side wall of the hole, and a thread holding member fitted into the arm, wherein the thread holding member is The opening edge has an opening edge such that a straight line passing through at least two points on the inside corner thereof is perpendicular to the plane of the paper in which the ellipse is drawn, and the focus is on the lower surface of the thread holding member below the edge. A hole member is mounted such that the lower exit of the focal hole of the member is on an extension of the straight line, and the arm holds the thread holding member at least one of the at least one A thread holder for an ellipse drawer, characterized in that it has an edge that can be stopped by bringing the edge of an arm into contact with the corners of two points.