CN200963987Y

CN200963987Y - Compasses ruler for blackboard

Info

Publication number: CN200963987Y
Application number: CN 200620157254
Authority: CN
Inventors: 蔡靖
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-11-09
Filing date: 2006-11-09
Publication date: 2007-10-24
Anticipated expiration: 2016-11-09

Abstract

The utility model relates to a teaching-use bow compass, in particular to a blackboard-use bow compass-ruler which can directly draw a circle according to the prearranged radius without using the bow compass legs. The utility model which comprises a plastic box with a hole, and a straight ruler connected with the plastic box, is characterized in that a magnet block with a hole in the middle is provided inside the plastic box; a cover groove is movably arranged on the straight ruler; a nonius clamp seat is arranged on the cover groove; a chalk cap is arranged in the nonius clamp seat. The utility model which is simple in structure and convenient in operation and production has the functions of common bow compass and has a radius-setting device. Without using bow compass legs, the utility model can directly draw a circle according to the prearranged radius and read out the radius of the circle. Moreover, when in operation, the circle center will not be displaced and the blackboard paint will not be damaged. The utility model can be directly used as drawing tools for other graphics.

Description

Blackboard compasses chi

Technical field

The utility model relates to a kind of compasses of the usefulness of imparting knowledge to students, and is a kind of blackboard compasses chi that need not advise pin, directly justify by predetermined radii value picture specifically.

Background technology

At present, compasses for teaching is the bipod type, draws bowlder and will fix a pin, and following deficiency is arranged in the use:

1, can not directly press the predetermined radii value and draw circle.Mark justifying or reading the radius of a circle numerical value of drawing of certain radius, instrument is many, efficient is low.

2, draw bowlder one pin on metal or Glass blackboard and be difficult to fix, home position moves easily in stroke circle process, influence mapping effect.

3, draw bowlder on wooden or cement blackboard, rule pin pin damages blackboard paint easily.

4, can not directly make other figure with compasses.

Summary of the invention

The purpose of this utility model is exactly the defective at existing product, and a kind of blackboard compasses chi is provided, to remedy the deficiency of existing product.

The purpose of this utility model is realized by following scheme: it comprises that one has the plastic casing in hole and the ruler that links together with plastic casing, it is characterized in that: the magnet piece that has the hole in the middle of being equipped with in the plastic casing, catching groove is equipped with in activity on the ruler, vernier card seat is housed on the catching groove, is provided with chalk sleeve in the vernier card seat.The fixedly screw of chalk is housed on the chalk sleeve; Described vernier card seat is provided with hold-down nut.

It directly is connected hollow ruler with porose plastic casing, loads onto the hollow magnetic patch of trough of belt in the porose plastic casing of one on ruler, determines the center of circle from the magnetic patch hollow center; On hollow ruler, load onto porose vernier card, to determine radius of a circle and fixing chalk; These compasses chi is inhaled on the metal blackboard, rotated one week of ruler along the porose plastic casing that hollow magnetic patch is housed, can mark with vernier card position value is the circle of radius.

The utility model is simple in structure, use and easily manufactured, its existing compasses function commonly used, the radius setting device is arranged again, it does not advise pin, directly draws circle and reads drawn radius of a circle value by the predetermined radii value, draws the bowlder center of circle and is not shifted, do not damage blackboard paint, and can directly make the drawing tool of other figure.

Description of drawings

Fig. 1 is a schematic diagram of the present utility model.

Fig. 2 is a plane structure chart of the present utility model.

Fig. 3 is a sectional structure chart of the present utility model.

Fig. 4 is the sectional structure chart of magnet piece.

Among the figure: 1, plastic casing, 2, magnet piece, 3, hole, the center of circle, 4, catching groove, 5, the ruler scale, 6, ruler, 7, hold-down nut, 8, chalk sleeve, 9, the fixing screw of chalk, 10, vernier card seat.

The specific embodiment

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

As shown in Figure 1 and Figure 2, the utility model comprises that one has the plastic casing 1 in hole and the ruler 6 that links together with plastic casing 1, have the magnet piece 2 in hole in the middle of being equipped with in the plastic casing 1, activity is equipped with catching groove 4 and is carved with ruler scale 5 on the ruler 6, vernier card seat 10 is housed on the catching groove 4, is provided with chalk sleeve 8 in the vernier card seat 10.The fixedly screw 9 of chalk is housed on the chalk sleeve 8; Described vernier card seat 10 is provided with hold-down nut 7.During use, at first determine the center of circle, then operation according to the following steps by hole, the center of circle 3:

1, loosening vernier card nut, the moving cursor card is determined work done in the manner of a certain author figure radius, tightens vernier card nut again, fixedly the vernier card;

2, insert chalk, tighten fixedly chalk screw, fixedly chalk;

3, the utility model is lain in the appropriate location of work done in the manner of a certain author figure on the metal blackboard, rotate one week of ruler, can mark with vernier card position value and be radius, be the circle in the center of circle with the plastic casing hole heart along porose plastic casing.

When 4, mapping on nonmetal blackboard, the utility model is lain in the appropriate location of work done in the manner of a certain author figure on the blackboard, left hand passes plastic eyelet with chalk and determines the center of circle and pin that the right hand rotates one week of ruler, and can mark with vernier card position value is the circle of radius.

5, directly rule along the ruler limit, can make multiple shape figure.

Claims

1, a kind of blackboard compasses chi, it comprise a plastic casing that has a hole and with the ruler that plastic casing links together, it is characterized in that: have the magnet piece in hole in the middle of being equipped with in the plastic casing, catching groove is equipped with in activity on the ruler, vernier card seat is housed on the catching groove, is provided with chalk sleeve in the vernier card seat.

2, blackboard according to claim 1 compasses chi is characterized in that: the fixedly screw of chalk is housed on the chalk sleeve.

3, blackboard according to claim 1 compasses chi, it is characterized in that: vernier card seat is provided with hold-down nut.