JPS5821754Y2 - ellipse compass - Google Patents

Description

[Detailed description of the invention] This invention relates to an elliptical compass that can draw all kinds of ellipses.

Traditionally, when drawing an ellipse on a drawing, you can draw an ellipse using an ellipse ruler, or insert two pins at the focal point of the ellipse, wrap a ring system around this, place a writing instrument on a part of the thread, and draw the line to the focal point. They were drawn using the property that the sum of lengths is constant, or they were drawn approximately by combining circles with different radii using a circular compass.

Among these methods of drawing ellipses, when using an ellipse ruler, it is necessary to prepare rulers of various angles and various sizes, and even if you prepare a large number of them, it is difficult to draw ellipses with special angles or large ellipses. In addition, when using a pin and ring system, it is difficult to draw an accurate ellipse due to the meandering of the line, and it is extremely difficult to draw a small ellipse. Furthermore, when using a circular compass, it is only an approximate ellipse, not an exact one, and it has the disadvantage of requiring circles with different diameters to be drawn several times.

In other words, it has fatal flaws that cannot be eradicated by any method, and the inventor of this invention conducted research in light of these flaws and completed the elliptical compass, a completely new compass-shaped ellipse drawing tool that has never existed before. It is something.

The aim is to easily and quickly draw ellipses of all types and sizes by applying the ellipse principle that an ellipse can be drawn by projecting an inclined circular motion locus perpendicularly onto the drawing surface. The purpose of this invention is to provide an elliptical compass that can draw accurately.

Next, the elliptic compass of the present invention will be described in detail below based on an example of implementation shown in the drawings.

First, the gist of the proposed elliptical compass is that a rotary arm 2 is pivotally supported on a fixed leg 1 by a tilted support shaft 3, and the rotary arm 2 is connected to the rotary arm 2 via an appropriate length from the support shaft 3. A sliding body 4 is provided,
In addition, by forming the rotary arm 2 so that its inclination angle can be adjusted with respect to the drawing surface, and the length of the arm can be freely adjusted, the sliding body 4 can move an appropriately set inclined circular motion locus with respect to the drawing surface. Furthermore, the sliding body 4 is provided with a vertical leg 6 equipped with a vertical holding structure 5 so as to always maintain a state perpendicular to the drawing surface, and a writing instrument 7 is provided at the lower end of the spread leg 6 to form an inclined circle. It is formed so that the locus of motion is converted into an ellipse and depicted by vertical projection onto the drawing surface.

Here, the fixed leg 1 is, as shown in FIGS. 1 and 2,
Although it is formed of a single rod-shaped body with two insertion needles 1a and la provided at the lower end, it is not limited to the embodiment. Any structure that can pivot can be used.

As shown in FIGS. 1 and 3, the rotating arm 2 includes a rotating plate 9 that is inserted into a sliding tube 8 and fixed to the tube 8, and a slope provided at the upper end of the fixed leg 1. Although the rotating arm mounting structure of the embodiment is such that the frame 10 is pivotally supported by the support shaft 3, other mounting structures may be used.

Further, as shown in FIGS. 1 and 2, the sliding body 4 has a structure in which it is slidably fitted to the vertical leg 6, and in the embodiment, the rotating arm 2 and the sliding body 4 are connected to each other. An angle plate 11 and an angle indicator 12 are interposed therebetween, so that the inclination angle of the rotating arm 2 can be read.

In addition, as shown in FIGS. 1 and 2, the vertical leg 6 has a writing instrument mounting body 13 at its lower end, and has a structure in which the writing instrument 7 can be attached to the side near and far from the fixed leg 1, Although it is preferable because it can be used for drawing small ellipses and large ellipses, it is not limited to the embodiment, and a structure in which a single writing instrument 7 is provided may be used.

Further, as shown in FIGS. 1 and 2, the vertical holding structure 5 has one end side of two cross-pivotally connected links 5 a and 5 a attached to an outer cylinder 14 rotatably provided on the fixed leg 1. and the other end side of the links 5a, 5a was supported on the vertical leg 6.
Although the structure is such that the vertical leg 6 is held vertically in any state by using the fixed leg 1 fixed vertically by a so-called parallel link structure, various structures other than the embodiment can be used. In short, any structure may be used as long as the vertical leg 6 can be made perpendicular to the drawing surface.

In addition, the tilt angle adjustment structure of the rotating arm 2 is based on a structure in which a tightening tool 15 is provided on the inclined frame 10 and the fixed frame 1, and the rotating arm 2 is tightened and fixed by the tightening tool 15. It is not limited to the embodiment as long as it can be adjusted and fixed to the set angle.

Further, the length adjustment structure of the rotating arm 2 is such that the rotating arm 2 inserted into the sliding tube 8 is adjusted by a fixing screw 16 provided on the sliding tube 8, and this structure is also used in the embodiment. Other structures may be used without limitation.

Therefore, when drawing an ellipse with the compass of this invention, first fix the fixed leg 1 perpendicular to the drawing surface A, then fix the fixed leg 1
and the rotating arm 2 are at right angles, and the fastener 15 and the fixing screw 16 are
loosen.

Then, using the fact that the perpendicular direction between the fixed leg 1 and the rotating arm 2 is the long axis direction of the ellipse (the direction of the solid line in Figure 5), adjust the length to a predetermined length and tighten the fixing screw 16. Set the

Then, the inclination angle of the rotary arm 2 is set so that the length of the minor axis is a predetermined length at the minor axis position, which is a position moved by 90 degrees from the major axis position, and the fastener 15 is fixed at that angle.

In this way, by setting the length of the rotating arm 2 in the major axis direction and setting the angle of the rotating arm 2 in the minor axis direction, the rotating arm 2 is rotated about the support shaft 3 as shown in FIG. The sliding body 4 performs an inclined circular motion, and the length of the vertical leg 6 in the radial direction changes as the angle of the arm 2 changes, so that it can draw an ellipse as shown in FIG. It is.

In other words, the principle that an ellipse can be drawn by projecting an inclined circular motion locus perpendicularly to the drawing surface A is applied, and since the length and angle of the rotating arm 2 can be freely adjusted, any size or shape can be drawn. It is possible to draw ellipses with any ratio of major axis to minor axis.

Since the compass of the present invention is constructed and used as described above, it has the effect that ellipses of all types and sizes can be drawn easily, quickly, and accurately with a single compass. It is.

[Brief explanation of drawings]

Fig. 1 is a front view showing an embodiment of the elliptical compass of the present invention, Fig. 2 is a bottom view of the compass, Fig. 3 is a partially enlarged view showing the spindle of the compass, and Fig. 4 is a view of the compass. FIG. 5 is a front view showing the compass in use, and FIG. 5 is a plan view showing the compass in use. 1... Fixed leg, 2... Rotating arm, 3...
...Spindle, 4...Sliding body, 5...
Vertical holding structure, 6... Vertical leg, 7...
Writing implements.

Claims (1)

[Scope of utility model registration request] A rotating arm 2 is pivotally supported on a fixed leg 1 by an inclined support shaft 3,
A sliding body 4 is provided on the rotating arm 2 via an appropriate length from the support shaft 3, and the rotating arm 2 is formed so as to be able to freely adjust its inclination angle with respect to the drawing surface, and the length of the arm is also adjustable. By freely forming the slider 4, the slider 4 draws an appropriately set oblique circular motion locus with respect to the drawing surface, and furthermore, a vertical holding structure 5 is provided on the slider 4 so that the slider 4 always maintains a state perpendicular to the drawing surface. This elliptical compass is characterized in that a vertical leg 6 is provided, and a writing instrument 7 is provided at the lower end of the open leg 6, so that an inclined circular motion locus is converted into an ellipse and drawn by vertical projection onto the drawing surface.