CN201592605U - Teaching compasses - Google Patents

Abstract

A pair of teaching compasses belongs to teaching appliances and comprises a base, a sucker is fixedly connected to one side of the base, the other side of the base is fixedly connected with a fixed plate, a rotary handle rotating around a fixed center is arranged on the other side of the base in a rotating manner, a movable drawing arm is arranged inside a groove of the rotating handle, the front end of the drawing arm is provided with a chalk sleeve, and a fastening device is arranged on the outer circumference of the chalk sleeve. Circle center is easy to be fixed without slipping when using the teaching compasses adopting the means of fixing a circle center position attached to a blackboard through the sucker, the drawing arm inside the groove of the rotary handle capable of rotating around a fixed center is telescopic, and the pair of teaching compasses has simple structure, firm absorption, fast circle drawing and fine size accurateness effect.

Description

A kind of educational compasses

Technical field

The utility model belongs to teaching aid, particularly a kind of educational compasses.

Background technology

The used blackboard of teaching adopts frosted glass to make mostly at present, this blackboard hardness is bigger, and smooth, and the compasses of two arms, one end radial type commonly used are when being used to impart knowledge to students, be used for generally determining that the pin in the center of circle easily skids, be difficult for fixing, thereby draw quite inconvenience of circle, need repeated multiple times to be drawn as round, quite lose time, even the circle of drawing sometimes Cheng Yuan not, and radius of a circle also is difficult for determining, brings quite inconvenience to teaching.

Summary of the invention

The purpose of this utility model is the deficiency at above-mentioned technology, provide a kind of can be easily the fixing compasses for teaching of center of circle pin.

Structure of the present utility model is: it comprises pedestal, side at pedestal is fixedly connected with sucker, the opposite side of pedestal is fixedlyed connected with price fixing, and this side also rotates and be provided with the turning handle that centering is rotated, and is provided with in the groove of turning handle and movably draws arm, drawing arm can freely stretch along groove, be provided with the chalk chuck at the front end of drawing arm, draw bowlder and chalk can be inserted in the chalk chuck, on chalk chuck excircle, be provided with fastener, be used for firm chalk, prevent to fall under the chalk.

Described price fixing is provided with the angle groove, and rotating the picture arm can cut apart circumference.

Described picture arm is provided with the length groove, stretches out the picture arm and can change drawn radius of a circle.

Advantage of the present utility model: this compasses for teaching can make position, the center of circle be adsorbed on the blackboard by sucker owing to having adopted, thereby the center of circle is fixing easily, can not slide, it is scalable that turning handle groove inside-paint arm is rotated in centering, and it is simple in structure, absorption is firm, picture circular velocity is fast, size is accurately effective.

Description of drawings

Fig. 1 is a structural representation of the present utility model;

Fig. 2 is the vertical view of Fig. 1;

1 is pedestal, the 2nd among the figure, sucker, the 3rd, turning handle, the 4th, price fixing, the 5th, picture arm, the 6th, fastener, the 7th, chalk chuck.

The specific embodiment

As shown in Figure 1 and Figure 2, it comprises pedestal 1 a kind of educational compasses, is fixedly connected with sucker 2 in a side of pedestal 1, and the opposite side of pedestal 1 is fixedlyed connected with price fixing 4, and this side is also rotated and is provided with the turning handle 3 that centering is rotated, in the groove of turning handle 3, be provided with and movably draw arm 5, draw arm 5 and can freely stretch, be provided with chalk chuck 7 at the front end of drawing arm 5 along groove, drawing bowlder can insert chalk in the chalk chuck 7, on chalk chuck excircle, be provided with fastener 6, be used for firm chalk, prevent to fall under the chalk.

Described price fixing 4 is provided with the angle groove, and rotating the picture arm can cut apart circumference.

Described picture arm 5 is provided with the length groove, stretches out the picture arm and can change drawn radius of a circle.

Claims (3)

1. educational compasses, it is characterized in that: it comprises pedestal (1), side at pedestal (1) is fixedly connected with sucker (2), the opposite side of pedestal (1) is fixedlyed connected with price fixing (4), and this side is rotated and is provided with the turning handle (3) that centering is rotated, in the groove of turning handle (3), be provided with and movably draw arm (5), be provided with chalk chuck (7), on chalk chuck (7) excircle, be provided with fastener (6) at the front end of drawing arm (5).

2. a kind of educational compasses according to claim 1 is characterized in that: described price fixing (4) is provided with the angle groove.

3. a kind of educational compasses according to claim 1 and 2 is characterized in that: described picture arm (5) is provided with the length groove.

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