Dustless chalk sleeve

Abstract

The invention provides a dustless chalk sleeve. The dustless chalk sleeve comprises a hollow sleeve body and a moving component which can move along the longitudinal direction of the sleeve body, wherein the front end of the sleeve body is provided with a chalk plugging port and a holding mechanism for holding the chalk; the side face of the sleeve body is provided with a plurality of lock holes along the longitudinal direction; the moving component comprises a moving seat and a lock catch; the moving seat is arranged in the sleeve body; the lock catch is hinged with the moving seat; a spring is arranged between the lock catch and the moving seat; the front end of the moving seat is provided with a connecting piece for connecting the chalk; the lock catch is provided with a key which is extended out of the sleeve body and a clasp which can be matched with the lock hole; and the side face of the sleeve body is provided with a guide groove for moving the key. Compared with the prior art, the dustless chalk sleeve of the invention has the advantages of simple structure, convenient use, flexible movement of the chalk, free advancing and retreating, reliable positioning of the chalk and no backing phenomenon during the writing; and because the chalk is held tightly by using an elastic hoop, the chalk is prevented from falling, and the problem of damage or even breakage of the chalk is overcome.

Description

technical field [0001] The invention relates to the technical field of stationery and educational supplies, in particular to a dust-free chalk cover which can clamp the dust-free chalk and freely control the stretching length of the dust-free chalk. Background technique [0002] Chalk is a tool widely used in daily life and is generally used for writing on blackboards. The composition of chalk is a white precipitate of calcium sulfate, which is not easily decomposed, and the particles are larger than dust. At present, the chalks used in China mainly include ordinary chalk and dust-free chalk (water-based chalk). Dust-free chalk is an improved product of ordinary chalk, which aims to eliminate chalk dust pollution in classrooms. [0003] Dust-free chalk is made of special polymer materials and pigments. It can be written on a dry blackboard or a wet blackboard. No dust will be produced. [0004] The common way to use chalk is to hold the chalk directly for writing. On the ...

AI Technical Summary

Problems solved by technology

[0004] The common way to use chalk is to hold the chalk directly for writing. On the one hand, when the chalk is relatively long, it is easy to break. The discarded chalk heads are really a waste of resources

In addition, due to the high alkalinity of chalk, it also causes some pollution to the user's skin after being handled for a long time, and the powder on the surface is also easy to stick to the surface of the clothes, which is not easy to carry.

[0005] In order to overcome the above problems, a chalk case has appeared on the market, which can prevent the user from directly holding the chalk to write. However, this kind of chalk case still has various problems such as difficulty in telescopic adjustment, unreliable positioning, and easy pinching of the chalk.

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