GB2172552A - Pencil with integral sharpening device - Google Patents

Abstract

An inner sleeve 8 for accommodating a lead 7 is axially movable inside an outer sleeve 4 which is axially movable in a casing 1. A lead clamp 5 on the front end of the outer sleeve 4 contains a lead sharpening device 6. An actuating cap 9 is used to rotate the inner sleeve 8 together with the lead 7 so as to sharpen it on the sharpening device, to move the outer sleeve 8 axially so as to open and close the clamp 5, and to push the lead 7 through the open clamp 5. <IMAGE>

Description

SPECIFICATION Pencil The present invention relates to an automatic or propelling pencil and a lead-sharpening device, particularly a device in which a cap on the top of the pencil can be pressed and turned to sharpen the lead for writing.

Currently conventional pencils can be approximately classified into 3 major categories. The first category comprises wooden pencils, which often need to be sharpened by a razor blade or pencil sharpener during use and thus are easy to hurt the user's fingers and conisdered inconvenient and unsafe. The second category comprises nosharpening lead refill pencils in which, say 10 lead pieces are over-lapped and inserted into the pencase; although they do not need to be sharpened, not even one third of each of such lead pieces can be used before it becomes very blunt, and if any one of such lead pieces is lost or missed, the entire pencil can no longer be used, so these pencils are considered wasteful and impractical.The third category comprises propelling pencils with a fine lead; this kind of pencil ofter uses a lead with a diameter of 0.5 mm, which is easily broken, so half of a lead may not be used, and its cap easily becomes loose and may fall off, and thus is also impractical. Evidently, although the conventional pencils are in a wide variety, they have many defects.

The present invention provides an automatic pencil with a lead-sharpening device, the lead joins the lower end of the pencil case, a compression spring is provided in the pencil case, the outer pipe sleeve is positioned on the upper end of the compression spring, the clamp claw joins the lower.

end of the outer pipe sleeve, a round through hole is provided in the centre of the clamp claw, the lower end of this hole is in a conic form in which a knife holder is provided to sharpen the lead, the lower end of the clamp claw slits into several pieces stretching out and opening up at usual times; an inner pipe sleeve is provided in the outer pipe sleeve, the lower end of the inner pipe sleeve is also in a split form, the lead is accommodated in the inner pipe sleeve, the top of the pencil case joins the cap, a round hole is provided in the top face of the cap to accommodate and hold the lead, a plug plugs up the said round hole to avoid the lead from falling out.When the lead becomes dull, the user presses and turns the cap to sharpen the lead properly, when he pushes the cap to the possible extreme extent, the lead is made to protrude out, and after he releases the said pressure imposed against the cap, the lead is secured, when he presses and turns the said cap again, he can retract the lead back into the pencil case, thus preventing the lead falling out and being broken to pieces due to the user's carelessness.

When, for example a 2 mm lead is inserted into the pencil casing, the lead is not easily broken during use, and a lead-sharpening knife holder is provded on the front end of the pencil head; thus whenever the lead becomes blunt, the user can retract the lead back, and press and turn the cap to sharpen the lead again, so it is safe, convenient, and practical.

The invention will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross sectional view of a pencil in accordance with the invention; and Figure 2 is an exploded view of the pencil.

The pencil illustrated comprises a casing 1, a head 2, a compression spring 3, an outer pipe sleeve 4, a clamp claw 5, a knife holder 6, a 2 mm diameter lead 7, and inner pipe sleeve 8, a cap 9, and a plug 10.

The pencil casing 1 is a hollow plastics product, on the end of which a flange 11 is provided. The interior of the head 2 is hollow and the pencil casing 1 is sleeved on the top of the head as a tight fit. The compression spring 3 is provided inside the pencil casing 1; the lower end of the compression spring 3 presses against the top of the head 2. A screwthread is provided in the lower end of the outer sleeve 4, which is sleeved into the casing 1; the lower end of the outer sleeve 4 is directly pressed by the compression spring 3; the upper end of the outer sleeve 4 protrudes out of the casing 1.An external screwthread is provided on the clamp claw 5, whose lower end is split into 4 pieces with elasticity, which stretch open outwardly when free, but when the claw 5 is sleeved in from the lower end of the head 2 and screwed up to the flange 12 it is radially inwardly retracted, since it is pressed upward by the compression spring 3. The flange 12 abuts the head 2 and connot retract back into the casing 1. A through hole is provided in the clamp claw 5 with its lower diameter tapered to a conic shape; the leadsharpening knife holder 6 is provided in the lower end of this hole to sharpen the lead 7.

The lower end of the inner sleeve 8 is also in a split form with elasticity, stretches outwardly when free, and is inserted into the outer sleeve 4, while its lower end is positioned in the conic hole of the clamp claw 5 and its upper end extends out of the outer sleeve 4 and is welded to the top of the cap 9, which is sleeved on the top of the casing 1 and whose lower rim bends inwardly to catch a flange 11 on the top of the casing 1. A compression spring 13 is located between the flange 11 and the top of the cap 9. A small round hole 14 is also provided in the top face of the cap 9. The lead 7 is inserted into the inner sleeve 8 through the hole 14, and the plug 10 is provided on the top of the cap 9 to plug the hole 14 to prevent the lead 7 falling out.

When the user wants to sharpen the lead 7, he presses the top of this structure: the cap 9 and the inner sleeve 8 move down together, but at this time the outer sleeve 4 does not move, the lower end of the inner sleeve 8 gradually retracts radially inwards to clamp the lead 7. Then the user turns the cap 9 together with the lead 7; the knife holder 6 in the lower end of the clamp claw 5 sharpens the lead 7.

When he presses the cap 9 down further, the outer sleeve 4 gradually moves down together with the clamp claw 5, which stretches out from the lead and opens up; at the same time, the inner sleeve 8 also stretches out and opens up; then the lead 7 can be protruded out. Upon relief of the compression, under the action of the springs 3 and 13, the cap 9 and the inner and outer sleeves 4 and 8 return to their original positions; meanwhile, the clamp claw 5 fixes the lead 7 for writing . Upon completion of writing, the user presses the cap 9 down to the extreme extent and pushes the lead 7 back, thus preventing the lead falling off and being fractured.

Summing all the the above up, the pencil is simple in structure and easy to use, especially without any trouble involved to sharpen the lead during use.

Claims (7)

1. An automatic pencil comprising a hollow elongate body, an outer sleeve mounted for axial movement inside the body, and an inner sleeve for accommodating a lead, the inner sleeve being mounted for axial movement inside the outer sleeve, the front end of the outer sleeve having a clamp for clamping the lead in a projecting position for writing, the clamp containing a lead sharpening device, actuating means being provided for opening and closing the clamp and for rotating the inner sleeve together with the lead so as to sharpen the lead on the sharpening device in the closed clamp.

2. An automatic pencil as claimed in claim 1, in which spring means urge the outer sleeve rearwardly towards a position in which the clamp is closed by the action of the hollow body on the clamp.

3. An automatic pencil as claimed in claim 1 or 2, in which the front end of the inner sleeve has a clamping formation which clamps the lead when the inner sleeve is moved forwardly.

4. An automatic pencil as claimed in any of claims 1 to 3, in which the sleeves are spring urged to a position in which the outer sleeve projects beyond the rear end of the body and the inner sleeve projects beyond the rear end of the outer sleeve, the rear end of the inner sleeve being provided with an actuating member capable of abutting the rear ends of the outer sleeve and the body successively.

5. An automatic pencil substantially as described with reference to, and as shown in ,the accompanying drawings.

6. An automatic pencil with a lead-sharpening device comprising: a hollow pencil casing, a flange provided on it rear end, a head joined to the front end of the casing, a compressiong spring provided on the rear of the head in the casing, an outer pipe sleeve positioned behind the compression spring, its rear end protruding slightly out of the casing, and a screwthread being provided in its lower end, a clamp having a screwthread on its rear end and being coupled to the front end of the outer pipe sleeve, an inner pipe sleeve accommodated in the outer pipe sleeve, its rear end protruding slightly longer than the outer pipe sleeve, its front end split into several pieces with elasticity stretching out and opening up when free, an inner pipe sleeve accommodated in the outer pipe sleeve, its rear end protruding slightly longer than the outer pipe sleeve, its front end split into several pieces with elasticity stretching out and opening up when free, and a cap coupled to the flange of the casing, a compression spring being provided in the cap, a hole being provided in the centre of the cap to allow insertion of the lead, the cap being welded to the top of the inner pipe sleeve, and a plug being positioned on the cap and plugging the hole through which the lead is to be inserted.

7. An automatic pencil as claimed in claim 6, wherein a flange is provided close to the front of the clamp, and its front end splits into several pieces with elasticity which stretch out and open up when free, but when joined to the outer pipe sleeve are retracted back to their closed status, as they are directly lifted up by the compression spring, and a knife holder being provided in the clamp to sharpen the lead.