JPS6411477B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an ellipse delineator using thread.

Japanese Patent Publication No. 53-37771 by the present applicant describes an ellipse delineator that uses a thread to draw an ellipse according to the mathematical theorem that a locus with a constant sum of distances from two points is an ellipse. There is. The problem solved in this patent is that, as is well known, when attempting to draw an ellipse using thread, the thread twists. To explain this with reference to FIG. 9 of the drawings, for example, fixing both ends A and B of one thread,
If you put that thread around a pencil and rotate it, an intersection like the one shown at C will occur. Said Special Public Service 1973
-The invention of No. 37771 is designed to naturally untwist the thread while drawing an ellipse, but it is not possible to attach a long writing instrument, and there are large errors due to the inclination of the main axis. However, since it is not possible to shorten the distance between the thread hook and the tip of the writing instrument, there are disadvantages such as increased errors, a need for a special structure, and increased manufacturing costs.

The object of the present invention is to provide an ellipse delineator that eliminates such drawbacks.

The present invention will be explained using the drawings.

In FIG. 1, an elongated lug plate 2 having a substantially pentagonal shape with one end tapered, which is rotatably attached to one end of the main shaft 1, is placed along the edge opposite to the tapered side. Two fulcrum members, such as studs or ball bearings, are mounted spaced apart 3, 3'. At the tapered end, a writing instrument 4, such as a pen or pencil lead, is obliquely fixed to the lug plate by means of a hole and a writing instrument support structure 13, such as a fixing member. The writing instrument support structure is such that the length of the tip of the writing instrument protruding below the lug plate can be adjusted. A rotating shaft 6 having a threading ring 5 at one end is rotatably supported by a support 7 fixed to a lug plate. At one end of the rotating shaft 6 on the opposite side from the threading ring 5, a rotating shaft end member 8, such as a gear or wheel with a slightly larger diameter, is attached. Main shaft 1
Alternatively, the handle 9 fixed to the main shaft is attached with a tongue-like member 10 that engages with or frictionally contacts with the end member of the rotating shaft, and the horizontal length of the tongue-like member is equal to the length of the handle. Therefore, when the main shaft is rotated relative to the lug plate, the tongue member rotates in contact with the end member of the rotating shaft, and has a length such that it rotates half a rotation.

When operating the ellipse drawer with the structure shown in Figure 1, as shown in Figure 4, properly support both ends of the thread threaded through the threading ring, and rotate the thread A, B while pulling it so that it does not slacken. . The lug plate rotates relative to the main axis, and when the ellipse delineator comes to a nearby point on the extension line of , for example, point C, the tongue-shaped member starts to contact the end member of the rotating shaft, and the ellipse delineator comes into contact with the end member of the rotating shaft When you reach the point, leave it. As a result, the rotating shaft rotates by half a rotation, and the twist in the thread is eliminated.

In the ellipse delineator having the structure shown in FIG. 1, the two fulcrum members 3, 3' and the tip of the writing instrument 4 constitute three points that determine one plane, thereby making it possible to prevent the main axis from tilting. Furthermore, the threading ring 5 and the tip of the writing instrument can be kept very close together, making it possible to reduce errors. Additionally, this ellipse drawer allows the use of long pencil lead.

FIG. 5 shows another embodiment of the present invention. In the ellipsograph shown in FIG. 5, a rotating shaft 6 with a threading ring 5 is rotatably supported by a support 7 at a smaller angle with respect to the lug plate than shown in FIG.
At the end of the rotating shaft 6 opposite to the threading ring 5, a first
Rotating shaft end member 11 like a curved arm instead of the wheel shown in the figure
is attached, and a tongue-like member 1 is attached to the main shaft or handle.
2 is installed. When the tongue-like member 12 is rotated, it comes into contact with the curved arm, and when further rotated, the tongue-like member 12 pushes the curved arm and rotates it approximately 180 degrees, as shown in FIG. 7, and then separates from the curved arm. This makes it possible to turn the threading ring half a turn and untwist the thread. In the ellipsoidal drawer of FIG. 5, the pen or pencil lead is placed so that it does not impinge on the main axis, thereby allowing the use of a longer pencil lead than that shown in FIG.

In addition, although FIGS. 1 and 5 each have a tongue-like member, after drawing half of the ellipse,
The rotary shaft end members 8, 11 may be rotated by hand, in which case the tongue member may be omitted. or,
As shown schematically in FIG. 8, the axis of rotation 6 may be positioned at any angle between perpendicular and parallel to the lug plate. (Supporting members are not written.) Pens, pencil leads, etc. are not supported by writing instrument supporting structures such as holes and fixing members in the lug plate, but by a separate member 13' fixed to the lug plate. They may be supported by structural members so that their tips extend outside the lug board. (Figure 8).

The lug plate, support body, writing instrument support structure, etc. may be integrally formed of plastic or the like. Also, items that perform the same functions as studs, writing utensil support structures, lug boards, etc. can be made from materials such as wire.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a specific example of an ellipse delineator according to the present invention. FIG. 2 is a front view of the ellipse delineator of FIG. 1. FIG. 3 is a plan view of the ellipse delineator of FIG. 1. FIG. 4 is an operational diagram of the ellipse delineator shown in FIG. 1. FIG. 5 is a perspective view showing another specific example of the ellipse delineator according to the present invention. FIG. 6 is a plan view of the ellipse delineator of FIG. 5. FIG. 7 is a diagram showing the relative movement relationship between the tongue-shaped member and the rotating shaft end member of the ellipse drawer of FIG. 5. FIG. FIG. 8 is a schematic diagram showing the angular range when attaching the rotating shaft to the lug plate. Figure 9 is a diagram to show the problem that occurs when drawing an ellipse using thread. 1... main shaft, 2... lug plate, 3, 3'... fulcrum member,
4...Writing utensil, 5...Threading ring, 6...Rotary shaft, 7...
Support body, 8, 11... Rotating shaft end member, 9... Handle,
10... Tongue-shaped member, 12... Tongue-shaped member, 13, 13'
...Writing instrument support structure.

Claims (1)

[Claims] 1 A main shaft, a lug plate rotatably attached to one end of the main shaft so that it can rotate in a plane perpendicular to the axis, and a rotating shaft rotatably supported by a support fixed to the lug plate. and has a threading ring at one end, a rotating shaft end member for rotating the rotating shaft at the other end, and a rotating shaft for positioning the threading ring outward from one end of the lug plate. and a writing instrument support structure for holding a writing instrument diagonally to the lug plate at one end of the lug plate near the position of the threading ring so that the tip of the writing instrument is directly below the threading ring. and two fulcrum members attached at a distance from each other near the edge of the lug plate on the side opposite to the side where the threading ring is located, and the rotating shaft end member attached to the main shaft. An ellipse delineator consisting of a tongue-like member for.