CN2581196Y

CN2581196Y - Dust-proof blackboard

Info

Publication number: CN2581196Y
Application number: CN 02249674
Authority: CN
Inventors: 胡振华
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-11-21
Filing date: 2002-11-21
Publication date: 2003-10-22
Anticipated expiration: 2012-11-21

Abstract

The utility model relates to a dust free blackboard which can not produce dust. The utility model is formed by three different layers of surfaces; a bottom surface is of a thin iron plate, a surface layer is of a transparent hard plastic board, a middle layer is formed by the tight and flat arrangement of a plurality of micro cylindrical permanent magnets, wherein, the polar direction of the cylindrical permanent magnets is one of the diametrical directions along the bottom surface, and two different polar parts are respectively coated with two different colors. The pen used by the blackboard is a magnetic pen, and the magnetic polarity of a pen point is the same with the polarity that when the cylindrical permanent magnets face outwards at ordinary times.

Description

Dust-free blackboard

Affiliated technical field

The utility model relate to a kind of by the control rotation of cylindrical permanent magnet the teaching tools of displaying symbol.

Background technology

At present, known blackboard is made by plastics or plank, need use chalk during use.So the classroom back warp is often filling the air chalk dust.Teachers and students work, learn under such environment for a long time, give healthy bring infringement, particularly respiratory system, wherein to teacher's infringement more so.

Summary of the invention

For overcoming the deficiency that existing blackboard can produce dust, the utility model provides a kind of dust-free blackboard, and this kind blackboard can not only show various symbols, and does not produce any dust.

The technical scheme that its technical problem that solves the utility model adopts is: use a large amount of small cylindrical permanent magnet, the characteristics of this magnet are: the high and bottom surface equal diameters of post, its length can be selected the number millimeters long according to the requirement of definition.The south of cylindrical permanent magnet, direction to the north pole are the wherein directions of a diameter along the bottom surface.South, arctic part are coated with respectively with white, black dichromatism.With the tight flat raft of these cylindrical permanent magnet together, constitute the intermediate layer of blackboard, bottom is a sheet iron, and superficial layer is the transparent hard plastic plate.From in appearance, blackboard is made up of a large amount of very little grids.Change color by the rotation of controlling these cylindrical permanent magnet, displaying symbol.

The beneficial effects of the utility model are, when can show various symbol, can also avoid producing dust, body health benefits, and also easy to use.

Further specify below in conjunction with accompanying drawing the utility model.

Fig. 1 is the bottom view of cylindrical permanent magnet.

Fig. 2 is the side view of cylindrical permanent magnet.

Fig. 3 is a time writer.

Fig. 4 is a Magnetic brush.

Fig. 5 is the profile of dust-free blackboard.

1. sheet irons among the figure, 2. cylindrical permanent magnet, 3. transparent hard plastic plate.

The post height of cylindrical permanent magnet and bottom surface diameter appearance etc. are decided black part and are divided into magnetic north, and white portion is the South Pole, and the first half of Magnetic brush is a magnetic north, and the nib of time writer partly is a magnetic north.

The specific embodiment

The magnetic north of now deciding cylindrical permanent magnet (2) is a black, at ordinary times owing to the black part that himself sucking action of sheet iron (1) is kept all magnets (Fig. 5) outwardly.When writing with time writer, when nib contact blackboard, circuit is connected and produced nib partly is the stronger magnetic of the arctic.Because the same sex of magnetic is repelled each other, principle of opposite sex attraction, under the effect, the cylindrical permanent magnet in the zonule that time writer streaked is rotation 180 degree rapidly, stay white vestige on the blackboard, demonstrate symbol when this scolds one to inhale.In like manner, when Magnetic brush (Fig. 4) was brushed the blackboard surface, can make postrotational magnet rotate same angle once more, blackboard reverts to unified black.Wherein the cylindrical permanent magnet on polar orientation and not exclusively vertical blackboard plane can obtain correcting by himself attraction to sheet iron.

Claims

1. blackboard, it is characterized in that: be made of three different aspects, bottom is a sheet iron, and the serve as reasons tight flat raft of small cylindrical permanent magnet of big quantity of intermediate layer forms, and superficial layer is the transparent hard plastic plate.

2. blackboard according to claim 1 is characterized in that: the magnetic direction of the cylindrical permanent magnet in intermediate layer is the wherein diametric(al) along the bottom surface, and two different polarity are coated with respectively with two kinds of different colors.

3. blackboard according to claim 1 is characterized in that: use magnetic pen, the polarity of nib is with cylindrical permanent magnet is identical towards the polarity of blackboard superficial layer at ordinary times.