CN203511072U - Simple ellipsograph - Google Patents

Abstract

The utility model relates to a drawing implement for drawing elliptic curves, in particular to a simple ellipsograph. The simple ellipsograph comprises two locating pillars, a soft rope and a threading pen cap, wherein each locating pillar comprises a hollow magnet and an axis pillar, one end of the soft rope is fixed to one axis pillar, and the other end of the soft rope penetrates through the pen cap and is fixed to the other axis pillar. The simple ellipsograph is fixed to a blackboard through the magnets, and an ellipse can be drawn just by tensioning the soft rope and sliding the pen cap. The simple ellipsograph has the advantages of being simple in structure, convenient to use and fix and capable of assisting teachers in classroom teaching well.

Description

Simple ellipse drawing instrument

Technical field

The utility model is mainly teachers ' classroom teaching articles for use, and it can draw oval on magnet board.

Technical background

Instructors, when upper analytic geometry, is drawn ellipse by trace-point method or approximation method conventionally, and this method is accurate not, and setting-out speed is slow.For this reason, provide a kind of not only economy but also practical Novel ellipsograph.

Summary of the invention

The purpose of this utility model is to provide a kind of ellipsograph and on blackboard, draws the accurate not problem of ellipse for solving current teacher.For achieving the above object, the utility model adopts ellipsograph, comprises two locating dowels, a tightrope, a threading pen cap.Below the pen cap, insert drawing pen, tension cord, the slip pen cap can draw elliptical orbit.

Accompanying drawing explanation

Accompanying drawing is the utility model structural representation.

(11) (12) locating dowel in figure, 2, tightrope, 3, the threading pen cap

The specific embodiment

Below in conjunction with accompanying drawing, the utility model is further described.

Tightrope one end is fixed on to axle center post (11) upper, it is upper that the other end lies in another axle center post (12) through left hole, the right hole of the pen cap 3 successively, has scale on tightrope, can adjusting rope long.While drawing ellipse, below locating dowel, there is magnet, two locating dowels are pulled open to certain distance and be fixed on magnet board, tension tightrope, the slip pen cap, can draw ellipse.

Use principle: define according to ellipse: " track (this fixed length is greater than distance between two points) that equals the point of fixed length to the distance sum of two fixed points in plane is called ellipse ".At tension tightrope, in the process of the slip pen cap, it is long that the distance sum of drawing pen to two locating dowel equals rope all the time, and the track therefore drawing is for oval.In addition can also be by regulating distance or the rope length of two locating dowels to change oval size.

Claims (3)

1. an ellipsograph, it is characterized in that comprising two locating dowels (11,12), a tightrope (2), a threading pen cap (3), locating dowel comprises hollow magnet and axle center post, axle center post inserts in magnet, it is upper that tightrope (2) one end is fixed on axle center post (11), and the other end is fixed on another axle center post (12) through hole, pen cap left and right successively.

2. ellipsograph as claimed in claim 1, is characterized in that tightrope (2) is marked with scale.

3. ellipsograph as claimed in claim 1, is characterized in that the threading pen cap (3) is all porose up and down.