CN2418016Y

CN2418016Y - Compasses for teaching

Info

Publication number: CN2418016Y
Application number: CN 99249598
Authority: CN
Inventors: 张桂林
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-10-27
Filing date: 1999-10-27
Publication date: 2001-02-07
Anticipated expiration: 2009-10-27

Abstract

The utility model relates to a pair of novel teaching compasses, which comprises a central shaft, a rotating arm rotated around the central shaft and a magnetic chuck connected below the central shaft. Structure is extremely simple, but the problems that the existing teaching compasses are bulky and not suitable for a blackboard made of etched glass are effectively solved by the utility model. Radius length can be conveniently adjusted, a centre point is firmly fixed on the blackboard, the radius length can be displayed, and use is quite easy and free. The utility model is an advanced teaching appliance.

Description

The new teaching compasses

The utility model belongs to teaching aid, and it is the educational compasses of drawing and using on blackboard.

On the classroom, lecture courses such as mathematics, often need be at the blackboard upper drawing circle.Existing compasses for teaching is wooden bisecting compasses, and a leg has tip made of iron, can penetrate wooden blackboard and determine the center of circle, and another leg is equipped with chalk.But present classroom blackboard is used the ground glass manufacturing more, and the surface is hard and smooth, and bisecting compasses use inconvenience, and the center of circle is difficult for definite, makes the teacher make bowlder on blackboard, also needs remove fixedly compass foot with a hand, and is very bothersome; Existing bipod compasses can not directly be determined radius length simultaneously.

The purpose of this utility model provides the new teaching compasses that use in a kind of suitable modern classroom, and it is easy to use, and is time saving and energy saving.

The technical solution of the utility model is such: it comprises central shaft, is movably arranged on the pivoted arm on the central shaft, and pivoted arm one end has the pen cap, and main points are to be connected with sucker below central shaft; On pivoted arm, be shaped on the chute of regulating radius length and corresponding set screw is installed;

On pivoted arm, also be shaped on scale, and on central shaft, fix a radius length indicating device;

On the central shaft below the pivoted arm, be provided with supporting plate.

The center line of the pen cap is aimed at scale " 0 " point of pivoted arm, the axis of the datum line centering adjustment axle on the indicating device.

Be shaped on the line of determining the center of circle at the chuck surface edge.

The utility model has the advantages that, it is simple in structure, but effectively solved the deficiency of existing educational compasses, be adapted at comprising on the various blackboards of Glass blackboard and map, during mapping sucker with the stationkeeping of central shaft on blackboard, fixation, easy to use, radius is adjustable, and the radius length clear display is novel advanced person's a teaching aid.

Details of the present utility model provides by following examples and accompanying drawing thereof:

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

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

With reference to the accompanying drawings, pivoted arm 1 of the present utility model is installed on the central shaft 4, and is upper and lower with nut 5 and 6 lockings, and it can be rotated around central shaft 4.This routine pivoted arm 1 is a dull and stereotyped chi shape, and a lateral edges is shaped on scale 14, and in-plane is shaped on chute 13 along its length.The right-hand member head is shaped on the hole, garden, the interior iron chains pen cap 11, and fixing chalk 10 in the pen cap 11, the center line of the pen cap 11 is over against " 0 " point of dull and stereotyped chi scale 14.The lower end of central shaft 4 is connected with sucker 8, and it is the hollow thin-wall cone that flexible plastic or rubber are made, and the edge of cone is shaped on cross groove 15, so that determine the garden heart on blackboard.When pushing downwards, the air in the cone is extruded, and just can be adsorbed on the smooth flat firmly.On the central shaft above the pivoted arm 1, fixing an indicating device, this example is a rectangle indicating piece 7, it has a rectangular indentation, the datum line of indentation, there is parallel with dull and stereotyped chi scale mark 14, and the axis of centering adjustment axle 4, distance between the center line of it and the pen cap 10 is the radius size in drawn garden, so indicating piece 7 can be indicated radius size.Below pivoted arm 4, fix a supporting plate 9, it be one with the wide short slab of pivoted arm 1, also be locked in central axis with nut 5 and 6.In addition, set screw 3, setting nut 2 are arranged in the outside of central shaft 4, with indicating piece 7, pivoted arm 1, supporting plate 9 are fixed as one, and set screw 3 and central shaft 4 all are positioned among the chute 13.When regulating radius length as required, open setting nut 2 earlier, spur pivoted arm 1 then, make to reach the length that needs between chalk 10 and the indicating piece 7 indentation, there datum lines 12, again setting nut 2 is tightened, make constant radius.By being pressed on the blackboard, it is sucked in sucker, pinch chalk 10 this moment on the other hand, promotes pivoted arm 1 and rotate a circle around central shaft 4, promptly finished the action of drawing circle.

Claims

1, new teaching is advised with the garden, and it comprises central shaft, is movably arranged on the pivoted arm on the central shaft, the pen cap of pivoted arm one end, and feature is: be connected with sucker below central shaft; On pivoted arm, be shaped on the chute of regulating radius length and corresponding set screw is installed;

2, compasses according to claim 1 is characterized in that being shaped on scale on the pivoted arm, and fix a radius length indicating device on central shaft;

3, compasses according to claim 1 is characterized in that being provided with supporting plate on the central shaft below the pivoted arm.

According to claim 1,2 described compasses, it is characterized in that 4, the center line of the pen cap is aimed at pivoted arm high scale " 0 " point, the axis of the datum line centering adjustment axle of indicating device.

5, compasses according to claim 1 is characterized in that, are shaped on the line of determining the center of circle at the chuck surface edge.