CN2356858Y - Automatic chalk cover - Google Patents

Abstract

The utility model belongs to an automatic chalk cover, which comprises an outer cover tube and an inner cover tube. The automatic chalk cover is characterized in that the head part of the inner cover tube extends out of the head part of the outer cover tube; the inner cover tube is grooved; the outer side wall is a surface with the shape of a circular table to form a clamping head; a lug boss is also arranged on the outer side wall; a spring is arranged between the lug boss and a lug boss on the inner wall of the head part of the outer cover tube; a lug boss which corresponds to a convex end part ring at the rail of the outer cover tube is also arranged on the side wall of the part of the tail of the inner cover tube, wherein, the part is positioned in the outer cover tube. The utility model has the advantages that hands can be effectively avoided from being polluted by chalk dust through the mode of using the automatic chalk cover to clamp chalk for writing; the regulation of chalk is convenient. The utility model is widely used as a chalk writing clamping tool, and is suitable for being used by teachers, etc.

Description

Automatic chalk sleeve

The utility model relates to a kind of chalk clamping device.

At present, domestic and international a large amount of chalks of producing and using mostly are garden platform shape or garden column, are all when the user uses directly to hand to be used to write, and still do not see report and use that special-purpose chalk clamping device is arranged.This occupation mode exists a defective that can't overcome, and Here it is, and the user is stained with chalk dust on hand easily, the removing that now washes your hands after the use, this concerning must often using powder the author and numerous teachers, very trouble and inconvenience beyond doubt.

The purpose of this utility model provides a kind of automatic chalk sleeve that can avoid the user to be stained with chalk dust on hand.

The purpose of this utility model realizes by following technical solution:

Chalk sleeve described in the utility model comprises outer tube and the inner sleeve that matches with it, the head that is characterized in inner sleeve stretches out outside the outer tube, and its internal diameter and chalk diameter are complementary and become clamping head, have several uniform grooves on the clamping head, its lateral wall is a garden platform shape face that is tilted to afterbody by head; Also be provided with a boss on the corresponding lateral wall of this inner sleeve and clamping head, and also be provided with a boss on the corresponding outer tube head of this boss inwall, between this two boss, be provided with spring; Be positioned at the afterbody of this inner sleeve on the lateral wall of part of outer tube and also be provided with a boss, outer tube afterbody end tube wall correspondingly is circlewise projecting inward to pipe, and the afterbody end of inner sleeve is passed this bulge loop and stretched out outside the outer tube.

Another characteristics of the above-mentioned technical solution of the utility model are several uniform grooves of offering on the described clamping head, are at least two.

The utility model has the advantages that, after chalk being loaded in the clamping head of its inner sleeve, under the elastic-restoring force effect of spring, make clamping head generation elastic deformation and chalk is clamped in the outer tube, hand-held this chalk sleeve can be write, hand can not contact chalk when writing, thereby has avoided chalk dust adversary's pollution.Hand-held this chalk sleeve makes holding head down, and when pushing inner sleeve compression spring with hand, clamping head stretches out outer tube, and chalk is protruding under its deadweight effect, and is then again that chalk is stuck when stretching out, so can regulate the overhang of chalk automatically.Thereby use very convenient.Especially be suitable for the teacher and wait the clamping device of writing as chalk.

Below in conjunction with an embodiment technical solution of the present utility model is described further:

What Fig. 1 provided is structure cross-sectional schematic of the present utility model.

In the drawings, the 1st, outer tube can be made into polyhedron-shaped or other shapes for ease of hand-held its lateral wall.The 7th, inner sleeve, the head of this inner sleeve stretches out outside the outer tube, and the diameter of its internal diameter and chalk is complementary, and forms clamping head 6, has several uniform grooves 4 on this clamping head, and for guaranteeing the clamping effect, this groove is at least 2; Its lateral wall is made by the garden platform shape face 5 of head to the afterbody inclination.The 2nd, the boss that is provided with on the inner sleeve lateral wall, the 8th, the boss that is provided with on the outer tube madial wall is provided with a spring 3 between this two boss, be placed in (this moment, this spring 3 was in confined state) on the inner sleeve outer wall.The partial sidewall that the afterbody of inner sleeve 7 is positioned at outer tube 1 is provided with boss 9, and the afterbody tube wall of outer tube is to the projecting inward formation ring-type bulge loop 10 of pipe, and the afterbody end of inner sleeve 7 is passed this ring-type bulge loop 10 and stretched out outside the outer tube afterbody.Its operation principle is as follows: during use, the afterbody that elder generation pins inner sleeve 7 with hand promotes inner sleeve forward, and then inner sleeve compression spring 3 stretches out outside the outer tube its head clamping head 6, at this moment, loads onto chalk in clamping head.Unclamp hand, then will promote inner sleeve 7 at the elastic-restoring force effect lower spring 3 of spring 3 stretches out to afterbody, elastic deformation will take place (for increasing deformation in inner sleeve head clamping head 6 at this moment, guarantee the clamping effect, on clamping head, opened groove 4, and this groove 4 is at least 2), its lateral wall garden platform shape face 5 will shrink in outer tube, thereby the press nip head increases deformation.When the axial component of the suffered outer sleeve inner wall extruding force of platform shape face equated with the elastic-restoring force of spring, deformation no longer took place in spring.The radial component of extruding force is with stuck chalk.At this moment, hand-held this chalk sleeve can be write.After stretching out chalk outside the clamping head 6 and using up, for continuing to write, then push inner sleeve once more, with the clamping head of this chalk sleeve down, then chalk will stretch out outside clamping head under its self-gravity action, when stretching out when reaching aequum, unclamp hand, then chalk will be as described above process be stuck, can continue to use.The unlikely clamping head that skids off fast when guaranteeing that chalk stretches out, the clamping head material selection is so that the chalk deadweight is slightly larger than the suffered friction of chalk gets final product.Simultaneously, for guaranteeing that clamping head can produce enough elastic deformations, the clamping head material will have elastic deformation performance preferably.The effect that the utility model is provided with boss 9 is when it does not adorn chalk, for guaranteeing that spring is unlikely after pressurized is replied inner sleeve to be ejected outside the outer tube.Because boss 9 will be stopped by the afterbody ring-type bulge loop 10 of outer tube 1 when the inner sleeve resilience, thereby it is unlikely with its ejection outer tube to have guaranteed to push when it is unloaded inner sleeve.

Claims (2)

1, automatic chalk sleeve comprises outer tube (1) and the inner sleeve (7) that matches with it, it is characterized in that the head of inner sleeve (7) stretches out outside the outer tube, and internal diameter and chalk diameter are complementary and constitute clamping head (6); Have several uniform grooves (4) on the clamping head (6), its lateral wall is a garden platform shape face (5) that is tilted to afterbody by head; Also be provided with a boss (2) on this inner sleeve (7) and the corresponding lateral wall of clamping head (6), and also be provided with a boss (8) on the inner portion wall of the corresponding outer tube of this boss (2) (1), between this two boss, be provided with a spring (3); The afterbody of inner sleeve (7) is positioned on the lateral wall of part of outer tube and also is provided with a boss (9), outer tube correspondingly (1) afterbody end tube wall is to pipe projecting inward formation ring-type bulge loop (10), and the afterbody end of inner sleeve (7) is passed this bulge loop (10) and stretched out outside the outer tube (1).

2, the chalk sleeve according to claim 1 is characterized in that the groove of offering on the described clamping head (6) (4) is at least 2.