CN201002430Y - Folding-proof chalk sheath - Google Patents

Abstract

The utility model relates to a folding-proof chalk protective cover used to write on the blackboard smoothly, and the utility model is composed of an internal cover and an external cover which can be extended; the internal cover is provided with an elastic adjusting seam, an expansion ring and an external step; the external cover is provided with an extending mouth and an internal step, and a helical spring is provided between the external step of internal cover and the internal step of external cover; whether the whole chalk or remaining chalk is inserted, it can be clamped at the extending mouth, and the chalk is easy to hold, to write and to use.

Description

Anti-folding chalk sheath

Technical field

The utility model relates to can clamp whole or residual chalk fast to help being held in the hand the anti-folding chalk sheath of writing smoothly on blackboard.

Background technology

Technically, the full electronic blackboard comes out, and ripe projection computer is generally adopted.But populous, vast in territory on a large scale in, chalk still can be the most cheap with it and the characteristics of most convenient, by the first-selection as the most frequently used instrument of school instruction writing on the blackboard, will be extensive use of by people in very over a long time very long.

But holding chalk writing one is the hand of making dirty, the 2nd, and frangibility, and the cutting back after fractureing causes a large amount of wastes because of bad by often being dropped.

This is early had the chalk sheath scheme of some kinds of each patterns put forward by people, wherein be typically Mrs's imitation lipstick (lipstick) mode the most, promptly interior cover bottom clamps chalk, and front end can be sent continuously outward.But, very easily fracture so stretch out that part of chalk of front end because the overcoat front end does not have clamp; And if with overcoat whole bind round too tightly then chalk send not smooth.As seen this scheme is also impracticable.How similar scheme is also all unresolved well not only clamps chalk but also make the not problem of frangibility of chalk.

Summary of the invention

Can not effectively clamp and cause shortcoming easy to break, the utility model to formulate a cover new technology measure to chalk in order to overcome aforementioned schemes, only chalk front end (being use side) fully be clamped, not only conveniently write but also frangibility not.

The utility model addresses this problem the technical scheme that is adopted: be made of the inside and outside cover stack that has following function respectively: interior cover front end has flexible adjustment seam, tensioner ring, and outer rank are established in interior cover rear end; The overcoat front end is established constricting nozzle, and interior rank are established in the overcoat rear end, between the rank helical spring is set outside rank and the interior cover in overcoat.

To push away before the interior cover earlier before using, allow flexible adjustment seam nature magnify, loose one's grip after waiting to put into chalk, by the effect of spring restoring force, interior cover retraction is till being reduced to tensioner ring and being retracted mouth and blocking, at this moment chalk is tightly clamped by tensioner ring then, it is general that the human finger has pinched the chalk tip seemingly, and the writer only need hold the hard coat middle part in fact, only relies on the rigidity of whole chalk sheath just to be enough to guarantee to write smoothly.After the tip chalk weares and teares, only need slightly interior cover is pushed away forward, pull out a little budgust pen, just can continue again, and extremely very short chalk head also can be utilized.

The beneficial effects of the utility model are: the ingenious combination of cover overcoat in utilizing, and the anti-folding of this chalk sheath can clamp chalk and can prevent that again chalk from fractureing, and can also save and utilize the cutting back chalk, and simple in structure, be easy to produce, popularize easily.

Description of drawings

Below in conjunction with drawings and Examples the utility model is further specified.

Fig. 1 is the monnolithic case schematic diagram.

Fig. 2 is interior nested structure schematic diagram.

Fig. 3 is the jacket structure schematic diagram.

Fig. 4 is the constricting nozzle A-A cutaway view of overcoat.

Fig. 5 is the tensioner ring B-B cutaway view of interior cover.

Fig. 6 is an overcoat rear end C-C cutaway view.

Among the figure, cover in the 1-, 2-tensioner ring, 3-flexible adjustment seam, the outer rank of 4-, 5-turn, 6-bonnet, 7-overcoat, rank in the 8-constricting nozzle, 9-, 10-chalk.

The specific embodiment

Among the figure, the front end of interior cover (1) has tensioner ring (2), as long as clamped chalk, interior cover front end is stopped at the front of the constricting nozzle (8) of overcoat with regard to expanding naturally; If but can not draw back by the contraction of flexible adjustment seam (3) when clamping chalk by constricting nozzle (8); Between the outer rank of overlapping in turn (5) just is stuck in (4) and the interior rank (9) of overcoat; Cover afterbody in bonnet (6) is held in, chalk (10) can shrink the inside of p-adic extension p ring (2) fully when not using, treat time spent row extraction again.

Claims (1)

1 one kinds for writing " the anti-folding chalk sheath " that letter written with chalk uses smoothly on blackboard, it is characterized in that: by the interior cover that can stretch, overcoat combination, in be arranged with flexible adjustment seam, tensioner ring and outer rank, be arranged with constricting nozzle and interior rank outward, put helical spring between the rank in outer rank of interior cover and the overcoat.

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