CN2671817Y

CN2671817Y - Ruler compasses

Info

Publication number: CN2671817Y
Application number: CN 200320105458
Authority: CN
Inventors: 邹存邈
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-11-20
Filing date: 2003-11-20
Publication date: 2005-01-19
Anticipated expiration: 2013-11-20

Abstract

The utility model relates to a teaching tool used on the glass blackboard to draw and the ruler compasses fixes a sucking disc (5) on the blackboard. The other end of the sucking disc is provided with a screw rod served as a freely rotary axis (4). The screw rod is arranged on the graduated scale through a fixing clamp (6) to be served as a compasses arm (3). The radius of a circle can be ascertained by an adjusting nut (2) and the fixing clamp (6). One end of the compasses arm (3) is provided with a fixing device (8) which can mount the chalk. When drawing, so long as the radius is well adjusted, the compasses rotates one circle, the desired circle can be drawn. If drawing the concentric circle, the compasses arm (3) can be provided with a demountable device (1) to draw up two circles. This ruler compasses is adopted to solve the problem that the center of circle can not be fixed on the glass blackboard and the users can directly know the radius of a circle and the ruler compasses can simultaneously draw the concentric circle to provide facility of classroom teaching for the teachers. The ruler compasses is an extraordinarily ideal teaching tool of compasses.

Description

Chi formula compasses

Affiliated field

The utility model relates to a kind ofly can draw round teaching aid on Glass blackboard.

Background technology

At present, the compasses of teaching usefulness are made up of two pin, and one is equipped with the iron point, and one is equipped with chalk, can freely draw circle on wooden blackboard.But just inconvenient at the Glass blackboard upper drawing circle, the one, the iron point can not lunge the fixedly center of circle of Glass blackboard, and the 2nd, can not directly know radius of a circle, draw bowlder, it is in a rush that both hands use together, extremely inconvenient.

Summary of the invention

The utility model purpose provides a kind of chi formula compasses at the Glass blackboard upper drawing circle, has promptly solved the fixedly problem in the center of circle, and can directly know radius of a circle, simultaneously can draw concentric circles, is the teachers ' classroom teaching condition of providing convenience.

The scheme that technology of the present utility model solves is: sucker (5) is set up lead screw can be used as the axle (4) that freely rotates, be contained on the compasses arm (3) by geometrical clamp (6) again, one end of compasses arm (3) is adorned a fixture (8) that chalk can be installed, also can adorn a dismountable device (1), be used for installing another chalk.

Embodiment

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

With the metal rule as compasses arm (3), rubber suction cups (5) one ends are set up lead screw as axle (4) free to rotate, be contained on the compasses arm (3) by geometrical clamp (6), geometrical clamp (6) can slidably reciprocate on compasses arm (3), adjust geometrical clamp (6) and can directly determine radius of a circle, one end of compasses arm (3) is adorned a fixture (8) that chalk can be installed, it is fixed on the chalk sleeve of interior dress chalk (7) on the compasses arm (3), as required, a detachable apparatus (1) can also be installed, it is fixed on the compasses arm (3) by the chalk sleeve of nut with interior dress chalk (7), is used for installing the another chalk, uses for the picture concentric circles.

When using, rubber suction cups (5) is fixing on blackboard, adjust adjusting nut (2) and geometrical clamp (6), determined center of circle radius, grasp chalk (7) and rotate a circle, just drawn required circle, if draw concentric circles, can go up at compasses arm (3) detachable apparatus (1) is installed, two circles can draw.

Use this utility model chi formula compasses, promptly solved can not be on Glass blackboard the fixing problem in the center of circle, solved again with a hand and drawn circle, the problem that move in the center of circle utilizes rule as the compasses arm, directly knows radius of a circle, reduce the trouble of measuring radius of circle once more, simultaneously can draw concentric circles, for the teacher classroom teaching condition of providing convenience, be a kind of very good compasses teaching aid.

Claims

1, chi formula compasses, it is characterized in that: sucker (5) is set up lead screw can be used as the axle (4) that freely rotates, be contained on the compasses arm (3) by geometrical clamp (6) again, one end of compasses arm (3) is adorned a fixture (8) that chalk can be installed, also can adorn a dismountable device (1), be used for installing another chalk.

2, chi formula compasses according to claim 1, it is characterized in that: compasses arm (3) is a kind of rule, it can be made by metal or plastic material.

3, chi formula compasses according to claim 1 is characterized in that: fixture (8) is that the chalk sleeve with interior dress chalk (7) is fixed on the compasses arm (3).

4, chi formula compasses according to claim 1 is characterized in that: detachable apparatus (1) is to be fixed on the compasses arm (3) by the chalk sleeve of nut with interior dress chalk (7).