CN86210562U - Lead grinding type pencil sharpener - Google Patents

Abstract

The utility model discloses a pencil sharpener, a penholder of a pencil depends on rotary cutting, and a lead cord of the pencil depends on grinding. The lead grinding type pencil sharpener comprises a knife blade and a knife seat which is capable of supporting a knife blade and is provided with a rotary cutting groove which is in conical shape. A lead core grinding mechanism is also arranged on the pencil sharpener. At the same time, the relation of length L of the knife, half cone angle alpha of the rotary cutting groove, conical bottom semidiameter R of the cone and semidiameter r of the vertex of the cone is alpha =2 arcsin (R-r) /L. Consequently, when the pencil sharpener is used, only the wood part of the penholder is rotary cut. Moreover, the grinding mechanism mainly comprises a grinding stone, and the pencil point of the lead cord is ground by the grinding mechanism. The utility model has the advantages of simple structure and simple manufacture, and an ideal length and conicity of the lead cord are obtained by using the utility model. At the same time, the lead cord is difficult to broken by the utility model, and the lead grinding type pencil sharpener is especially adapted for primary and middle school students.

Description

Lead grinding type pencil sharpener

A kind of core grinding formula pencil sharpener belongs to the stationery class.

Existing pencil sharpener, the blade of trough rim is cut in commentaries on classics and the shell of pencil sharpener is formed by being contained in usually.The major defect of this pencil sharpener is, the pen core frangibility is changeed the short and point of the pen core of cutting out, tapering is little, writes not ideal enoughly, and using just needs to change soon again, so that the waste of pen is bigger.

The utility model provide a kind of penholder by commentaries on classics cut, pen core is by the pencil sharpener of grinding.Main points of the present utility model, the one, adjust blade and change the angle of cutting groove, making changes the wooden part of penholder of only pruning when cutting, but does not contact pen core, and pen core can intactly expose out after the penholder commentaries on classics is cut; The 2nd, the grinding mechanism of pen core is set on pencil sharpener, go out desirable pen core so as to grinding.Concrete structure of the present utility model now is illustrated in conjunction with the accompanying drawings.

The description of the drawings

The structure chart of Fig. 1, core grinding formula pencil sharpener

Pencil sharpener described in the utility model turns to the tool rest (3) of cutting groove (2) with truncated cone except blade (1) and supporting blade, also is provided with the grinding mechanism (4) of pen core on pencil sharpener. Be the wooden part that makes blade can just prune penholder, the length L of blade, truncated cone turn to that the relation of radius R and vertex of a cone radius r is taken as α=2arcsin (R-r)/(L) at the bottom of the cone of the semi-cone angle α that cuts groove (2), the frustum of a cone, wherein vertex of a cone radius r should be slightly larger than pen core radius usually commonly used, cut rear exposed pen core and can stretch out from vertex of a cone hole so that turn to, until the length of satisfying the demand. The sharpening of pen core is realized at grinding mechanism (4). The simplest grinding mechanism is to establish a plane grinding stone (5) at pencil sharpener. But for easy to use, grinding mechanism can adopt two symmetries, the grinding stone (5) of band semicircular platforms shape groove (8) is put together, and be located in the groove (6) of tool rest, be provided with spring (7) between groove (6) and the grinding stone (5), play fixing and supporting grinding stone, and make the certain elasticity that contacts between grinding stone and pen core. Radius r at the bottom of the cone of grind reliefs ' also should be slightly larger than the radius of pen core can extend in the grind reliefs pen core naturally. Pen core can be done rotation and rectilinear motion simultaneously in grinding stone, thereby realizes the grinding of pen core.

The utility model is simple in structure, makes easily, uses the utility model can obtain desirable pen core length and tapering, and the while pen core is frangibility not, can prolong the service life of pen, is particularly suitable for students in middle and primary schools and uses.

Optimal design of the present utility model is that the grind reliefs (8) of grinding mechanism (4) is disposed in series in the front portion that groove (2) are cut in commentaries on classics, coaxial line each other.

Claims (4)

1, the pencil sharpener that the tool rest [3] of groove [2] is formed is cut in a kind of truncated cone commentaries on classics that has by blade [1] and supporting blade, it is characterized in that, described pencil sharpener is provided with the grinding mechanism [4] of pen core, the length L of while pencil sharpener blade, changeing the pass of cutting groove semi-cone angle α, frustum of a cone awl end radius R and vertex of a cone radius r is α=2arcsin (R-r)/(L).

2, pencil sharpener according to claim 1 is characterized in that, described grinding mechanism structure (4) is a plane grinding stone.

3, pencil sharpener according to claim 1, it is characterized in that, described grinding mechanism (4) is put together by the grinding stone (5) of the band semicircle taper type grind reliefs (8) of two symmetries, and is located in the groove (6) of tool rest, is provided with spring (7) between groove (6) and the grinding stone (5).

4, pencil sharpener according to claim 3 is characterized in that, grind reliefs wherein (8) is disposed in series in changes the front portion of cutting groove (2), coaxial line each other.

Images