MECHANICAL PENCIL
United States Patent 3836264
In a mechanical pencil an extension of lead is carried out by a resilient means operatively arranged in a side portion of a body casing. The resilient means comprises a push means and a force translating means cooperative with said push means and adapted to translate a radial force manually applied to the push means into an axial force for urging a lead tube downwardly thereby to extend the lead from a cap nozzle threadedly connected to a tip of the pencil body.
US Patent References:
Pencil
Bergen - September 1923 - 1467282

Auto-controlled continuously-fed magazine pencil
Nelson - June 1929 - 1716354

Magazine lead pencil
Woelm - July 1932 - 1866072

Mechanical pencil
Jacobs - February 1944 - 2340665

Pencil
Hoffman - September 1945 - 2385442


Inventors:
Saito, Akio (Kanagawa, JA)
Fukazawa, Kiyohiko (Kanagawa, JA)
Motoyama, Yukitoshi (Kanagawa, JA)
Application Number:
05/332744
Publication Date:
09/17/1974
Filing Date:
02/15/1973
View Patent Images:
Assignee:
Mitsubishi Pencil Co., Ltd. (Tokyo, JA)
Primary Class:
Other Classes:
401/99, 401/92, 401/94
International Classes:
B43K21/16; B43K24/08; B43K21/00; B43K24/00; B43K24/08
Field of Search:
401/55,56,65,66,67,82,88,92-94
US Patent References:
2461408Mechanical pencilFebruary 1949Brosseau
2523568Pencil with mechanical means for advancing the lead thereofSeptember 1950Halverson
2528839Mechanical pencilNovember 1950Mason
3181507Pen tip automatic retractionMay 1965Dannebaum
Primary Examiner:
Charles, Lawrence
Claims:
We claim

1. A pencil of lead-storage type comprising an outer elongated tubular body casing provided with a restricted opening at one end thereof, through which a length of lead is adapted to extend, and an axially extending opening in the side thereof, a lead tube disposed within said elongate body casing coaxially therewith for feeding lead, adapted to be charged within said tube at the opposite end of the casing body, through said restricted opening, said lead tube terminating short of the restricted opening, means to slidably mount said lead tube within said body casing for axial movement only therein, a chuck member carried by said lead tube for rectilinear axial movement therewith, said chuck member being proximate said restricted opening for both permitting advance of the lead through said restricted opening upon movement of said lead tube to a first position thereof and for preventing rearward movement of said lead through said restricted opening upon said axial movement only of said lead tube to a second position thereof, means engageable with said lead tube and at least in part operative within said axially extending opening for transforming a purely radially hand-applied force to an axially applied force on said lead tube for moving said lead tube from its normal second position to said first position thereof, said body having fixed thereto in coaxial relation therewith a sleeve formed with an axial opening in registration with said axial opening in said casing body, said force translating means extending through both said openings, said sleeve having a threaded extension at that end thereof nearest said restricted opening, said clutch member carrying a clamp ring within said sleeve extension and in relation to which said clutch member is reciprocated, and a nozzle cap threadedly engaging said threaded extension and being formed with said restricted opening.

2. A pencil according to claim 1, wherein said lead tube is formed with an integral flange on that side of said axially extending opening closer to said restricted opening, said flange having a face engaged by a spring encompassing the lead tube below the flange to move said lead tube to said second position thereof, said force translating means being operative within the axially extending opening acting on the flange on inward radial movement of said means to move said lead tube to said second position thereof against the action of said spring.

3. A pencil according to claim 2, wherein said means engageable with said lead tube comprises a radially movable push means and spring means of substantially U-shape and resiliently bearing at the interconnecting leg portion of the U-shape against said push means, one free portion of the U-shape spring means engaging said flange and the other free end of the U-shape spring means engaging said means to slidably mount said lead tube within said body casing, the latter means comprising a support ring fixed to the inner wall of said body casing spaced from said flange.

4. A pencil according to claim 2, wherein said means engageable with said lead tube comprises a radially movable push means and a pair of angularly related links symmetrically disposed on opposite sides of the lead tube and interconnected at their respective junctures by a common pivot to resiliently bear, under the influence of said spring against said push means, said link connections at one of their ends engaging said flange and at their other ends engaging said means to slidably mount said tube within said body casing, the latter means comprising a support ring fixed to the inner wall of said body casing spaced from said flange.

5. A pencil according to claim 2, wherein said means engageable with said lead tube comprises a radially movable push means and a pair of semi-circular cam plates symmetrically disposed on opposite sides of said lead tube and having upper portions which are interconnected and resiliently bear, under the influence of said spring, against the push means, said plates having lower portions which engage the flange.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to improvements in a lead storage type pencil, and more particularly to a pencil providing at its side portion a resilient means for effecting an extension of lead from the tip of the pencil.

Heretofore, the push means for effecting an extension of lead has generally been provided at the tail end of the body casing. When an extension of lead is desired during the writing operation, the user grips a portion of the pencil body casing with four fingers except the thumb and then depresses the push means downwardly with the thumb for purpose of extending the lead. This pushing operation is cumbersome for the busy writer and rather inconvenient for the draftsman as a change of orientation of lead abrasion during the drawing operation brings undesired variations in size and density of the line to be drawn.

A principal object of the invention is to provide a novel pencil in which a desired extension of lead may be effected with the normal finger positions in gripping the pencil body without entailing any turning of the latter.

It is a feature of the present invention that the lead may be extended by a gentle depression of a resilient means which is operatively arranged in a side portion of the pencil body.

It is another feature of the invention to provide a pencil of lead storage type comprising an outer body casing having an elongated recess at its side portion, an inner sleeve means coaxially arranged in said outer body casing and having an intermediate recess corresponding to the recess provided in the outer body casing, a constricted open end with a threaded portion and an opposite open end of a larger diameter than that of said constricted open end, a lead tube coaxially and slidably arranged in said inner sleeve means and providing at its one end a lead chucking means for selectively chucking or releasing the lead and a flange means integrally encompassing a periphery of the lead tube and being slidably supported at its opposite end by a support ring fixed to an inner circumferential wall of said inner sleeve means, a spring means mounted between said flange means and an inwardly facing shoulder formed in the inner sleeve means for always urging the lead tube upwardly, a resilient means operatively associated with the lead tube for urging the lead tube downwardly against the function of the spring means, and a cap nozzle threadedly connected to the constricted open end of the inner sleeve.

The resilient means in accordance with the present invention is generally comprised of a push means and a force translating means cooperative with said push means and adapted to translate a radial force manually applied to said push means into an axial force for urging the lead tube downwardly against the function of the spring means. This resilient means is preferably positioned in the finger gripping zone on the pencil body for ensuring a smooth and quick depression of the pushing means.

A further feature of the invention is to provide a pencil of lead storage type comprising an outer body casing having elongated recess at its side portion, an inner sleeve means coaxially arranged in said outer body casing and having an intermediate recess corresponding to the recess provided in the outer body casing, a constricted open end with a threaded portion and an opposite open end of a larger diameter than that of said constricted open end, a lead tube coaxially and slidably arranged in said inner sleeve means and providing at its one end a lead chucking means for selectively chucking or releasing the lead and a flange means integrally encompassing a periphery of the lead tube and being slidably supported at its opposite end by a support ring fixed to an inner circumferential wall of said inner sleeve means, a spring means mounted between said flange means and an inwardly facing shoulder formed in the inner sleeve for always urging the lead tube upwardly, a resilient means providing a push means operatively arranged in the elongated recess provided on the side portion of the body casing and a force translating means cooperative with said push means and adapted to translate a radial force applied onto said push means into an axial force for urging the lead tube downwardly against the function of the spring means, and a cap nozzle threadedly connected to the constricted open end of the inner sleeve.

The force translating means is most preferably comprised of a semi-elliptic leaf spring which resiliently bears at its curved top portion the push means and is engaged at its one end with the flange means provided around a periphery of the lead tube and at the opposite end thereof with a support ring interiorly fixed to the body casing. When the push means is subjected to a gentle depression, one end of the leaf spring in abutment with the flange means urges the flange means thereby to urge the lead tube downwardly along an axis of the pencil.

Still a further feature of the invention is to provide a pencil of lead storage type comprising an outer body casing having an elongated recess at its side portion, an inner sleeve means coaxially arranged in said outer body casing and having an intermediate recess corresponding to the recess provided in the outer body casing, a constricted open end with a threaded portion and an opposite open end of a larger diameter than that of said constricted open end, a lead tube coaxially and slidably arranged in said inner sleeve means and providing at its one end a lead chucking means for selectively chucking or releasing the lead and a flange means integrally encompassing a periphery of the lead tube and being slidably supported at its opposite end by a support ring fixed to an inner circumferential wall of said inner sleeve means, a spring means mounted between said flange means and an inwardly facing shoulder formed in the body inner sleeve for always urging the lead tube upwardly, a resilient means providing a push means operatively arranged in the elongated recess provided on a side portion of the body casing and a force translating means cooperative with said push means and including a semi-elliptic leaf spring means which resiliently bears at its curved top portion the push means and its engaged at its one end with a flange means and at its opposite end with a support ring and a cap nozzle threadedly connected to the constricted open end of the inner sleeve.

In another embodiment of the invention, the resilient means is preferably comprised of a pair of link connections which are symmetrically arranged across the lead tube and interconnected at their top ends through a common pivot and at their lower ends through two symmetrical support arms one of which is engaged with the flange means integrally encompassing around a periphery of the lead tube and the opposite arm is engaged with the support ring interiorly fixed to the inner sleeve means. When the push means is subjected to a gentle depression, one of the support arms in abutment with the flange means urges the flange means against the function of the spring means mounted between the flange means and the inwardly facing shoulder formed in the inner sleeve means thereby to urge the lead tube downwardly along an axis of the pencil.

The other feature of the invention is to provide a pencil of lead storage type comprising an outer body casing having an elongated recess at its side portion, an inner sleeve means coaxially arranged in said outer body casing and having an intermediate recess corresponding to the recess provided in the outer body casing, a constricted open end with a threaded portion and an opposite open end of a larger diameter than that of said constricted open end, a lead tube coaxially and slidably arranged in said inner sleeve means and providing at its one end a lead chucking means for selectively chucking or releasing the lead and a flange means integrally encompassing a periphery of the lead tube and being slidably supported at its opposite end by a support ring fixed to an inner circumferential wall of said inner sleeve means, a spring means mounted between said flange means and an inwardly facing shoulder formed in the body casing for always urging the lead tube upwardly, a resilient means providing a push means operatively arranged in the elongated recess provided on a side portion of the body casing and a force translating means cooperative with said push means and including a pair of link connections arranged symmetrically across the lead tube and interconnected at their tops through a common pivot adapted to resiliently bear the push means and at their lower ends through two support arms one of which being engaged with the flange means and the other arm being engaged with the support ring, and a cap nozzle threadedly connected to the constricted open end of the inner sleeve.

In further embodiment of the invention, the resilient means is preferably comprised of a pair of semi-circular cam plates symmetrically arranged across the lead tube and having top corner portions resiliently bearing the push means and lower corner portions in engagement with the flange means. When the push means is subjected to a gentle depression, the lower corner portions urges the flange under the camming action against the function of the spring means mounted between the flange means and the inwardly facing shoulder formed in the body casing thereby to urge the lead tube along an axis of the pencil.

It is therefore an additional feature of the invention to provide a pencil of lead storage type comprising an outer body casing having an elongated recess at its side portion, an inner sleeve means coaxially arranged in said outer body casing and having an intermediate recess corresponding to the recess provided in the outer body casing, a constricted open end with a threaded portion and an opposite open end of a larger diameter than that of said constricted open end, a lead tube coaxially and slidably arranged in said inner sleeve means and providing at its one end a lead chucking means for selectively chucking or releasing the lead and a flange means integrally encompassing a periphery of the lead tube and being slidably supported at its opposite end by a support ring fixed to an inner circumferential wall of said inner sleeve means, a spring means mounted between said flange means and an inwardly facing shoulder formed in the inner sleeve means for always urging the lead tube upwardly, a resilient means for extending the lead providing a push means operatively arranged in the elongated recess provided on a side portion of the body casing and a force translating means cooperative with said push means and including a pair of semi-circular cam plates symmetrically arranged across the lead tube and having top corner portions interconnected through a connection for resiliently bearing the push means and lower corner portions in engagement with the flange, and a cap nozzle threadedly connected to the constricted open end of the inner sleeve means.

In another embodiment of the invention, the lead storage pencil according to the invention may be dispensed with the inner sleeve means and the lead tube may be directly and coaxially arranged in the body casing.

It is therefore a further additional feature of the invention to provide a pencil of lead storage type comprising an outer body casing having an elongated recess at its side portion and terminating at a constricted open end, a lead tube coaxially and slidably arranged in said body casing and providing at its one end a lead chucking means for selectively chucking or releasing the lead and a flange means integrally encompassing a periphery of the lead tube and being slidably supported at its opposite end by a support ring fixed to an inner circumferential wall of the body casing, a spring means mounted between said flange means and an inwardly facing shoulder formed in the body casing for always urging the lead tube upwardly, a resilient means operatively associated with the lead tube for urging the lead tube downwardly against the function of the spring means.

Objects and advantages of the invention will in part be obvious and will in part appear hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and object of the invention a reference should be had to the following detailed description taken in connection with the accompanying drawings, in which the same reference numerals designate the same or similar parts throughout the drawings:

FIG. 1 is a partially and longitudinally sectioned view of the first embodiment of the lead storage pencil according to the invention;

FIG. 2 is a partially and longitudinally sectioned view of the second embodiment of the lead storage pencil according to the invention;

FIG. 3 is a partially and longitudinally sectioned view of the third embodiment of the lead storage pencil according to the invention; and

FIG. 4 is a partially and longitudinally sectioned view of the fourth embodiment of the lead storage pencil according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now in more detail to the drawings, wherein like parts are indicated by like reference numerals and initially to FIG. 1, there is illustrated therein in longitudinally sectioned view an outer body casing of the lead storage pencil 10 made of steel, synthetic resin or other materials and shaped into a hollow tube of predetermined diameter and length.

The outer body casing at its one side portion and usually in the finger gripping zone is provided wtih an elongated opening 12 for receiving a push member hereinafter described.

In the body casing 10 is coaxially arranged an inner sleeve 14 of metal sheet which is also provided with an intermediate opening 16 corresponding to the opening 12 provided in the body casing 10. The inner sleeve 14 at its one end is constricted and provided with a threaded extension 18 for threadedly connecting with a cap nozzle 20. The opposite end of the inner sleeve (not shown) is opened with a larger diameter than the constricted end for insertion of a lead tube hereinafter described and some spare leads to be storaged.

In the inner sleeve 14 is coaxially and slidably arranged a lead tube 22 carrying at its one end a chuck member 24 for selectively chucking or releasing a lead 26. Around the periphery of the lead tube 22 adjacent to the constricted portion of the inner tube 14 a flange 28 is provided which is integral with tube 22.

Between the flange 28 and an inwardly facing shoulder 30 formed in the constricted portion of the inner sleeve 14 is mounted a spiral spring 32 which always urges the lead tube 22 upwardly against the action of resilient means effective to move the lead tube downwardly against the action of spring 32 as hereinafter described.

The lead tube 22 at its opposite end is slidably supported by a support ring 34 fixed to an inner circumferential wall of the inner sleeve 14 adjacent to the recess 16.

The resilient means operative to extend the lead includes a depression cover 36 which is operatively arranged in the elongated opening 12 provided in the body casing 10 and an arched leaf spring 38. One end of the leaf spring 38 is in engagement with the flange 28 whereas the opposite end thereof is abutted to a stepped portion 40 provided in the support ring 34. As best shown in FIG. 1, a curved top portion of the leaf spring 38 resiliently bears on the inner surface of the depression cover 36.

When an extension of the lead is desired, the depression cover 36 is pushed inwardly by the user of the pencil. The radial force thus applied by the user is converted by the leaf spring 38 into an axial force along the axis of the pencil whereby the end of the leaf spring 38 urges the flange 28, against the action of the spiral spring 32, in a direction to cause disengagement of the chuck member 24 from clamp ring 42 secured within to the constricted portion of the inner sleeve adjacent to the threaded portion 18 thereby to release a length of lead as an extension of the latter to permit continuation of a writing operation.

In FIG. 2, the resilient means operative to extend the lead includes a depression cover 36 which is operatively arranged in the elongated opening 12 provided in the body casing 10 and a pair of link connections 44 symmetrically arranged on opposite sides of the lead tube. The link connections at their apices are pivotally interconnected by means of a common pivot 46 and at their divergent outer ends by means of connection arms 48, 50. The apices of the link connections 44 bear on the inner surface of the depression cover 36 and the divergent ends thereof are respectively in engagement with the flange 28 and the bottom face of the support ring 34.

When an extension of lead is desired, the depression cover 36 is pushed inwardly by the user of the pencil. The radial force thus applied by the user is converted through the link connections 44 into an axial force along the axis of the pencil whereby the bottom ends of the link connections as viewed in FIG. 2 urge the flange 28, against the action of the spiral spring 32, in a direction to cause disengagement of the chuck member 24 from clamp ring 42, secured to within the constricted portion of the inner sleeve adjacent to the threaded portion 18 thereby to release a length of lead as an extension of the latter to permit continuation of a writing operation.

In the embodiment shown in FIG. 3, the resilient means operative to extend the lead includes a depression cover 36 which is operatively arranged in the elongated opening 12 provided in the body casing 10 and two semi-circular cam plates 52 symmetrically arranged on opposite sides of the lead tube 22 and interconnected at their top portions through a connection (not shown).

The top corners 54 of the cam plates 52 support an inner surface of the depression cover 36 whereas the lower corner portions 56 thereof are in engagement with the flange 28.

When an extension of lead is desired, the depression cover 36 is pushed inwardly by the user of the pencil. The radial force thus applied is converted through the semi-circular cam plates 52 into an axial force along the axis of the pencil whereby the lower corner portions 56 of the semi-circular cam plates 52 urge the flange 28 against the action of the spiral spring 32, in a direction to cause disengagement of the chuck member 24 from clamp ring 42 secured within the constricted portion of the inner sleeve adjacent to the threaded portion 18, thereby to release a length of lead as an extension of the latter to permit continuation of a writing operation.

In another embodiment of the lead storage pencil as best shown in FIG. 4, the lead storage, the inner sleeve 14 and the cap nozzle 20 are dispensed with and the lead tube 22 is directly and coaxially arranged in the body casing 10.

According to the invention, a lead extension may be effected in a simple construction and with an easy operation.

While certain preferred embodiments of the invention have been illustrated by way of example in the drawings and particularly described, it will be understood that modifications may be made in the construction and that the invention is in no way limited to the embodiments shown.




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