US3892495A

US3892495A - Push type mechanical pencil

Info

Publication number: US3892495A
Application number: US524673A
Authority: US
Inventors: Takeo Naruse; Junichi Hashimoto; Hideaki Oikawa
Original assignee: Pentel Co Ltd
Current assignee: Pentel Co Ltd
Priority date: 1972-03-03
Filing date: 1974-11-18
Publication date: 1975-07-01
Anticipated expiration: 1992-07-01
Also published as: DE2310573B2; US3883253A; DE2310573C3; DE2310573A1

Abstract

A push type mechanical pencil with which a user can push out a lead with a fingertip work while keeping a writing posture and a grasping position unchanged. In this mechanical pencil, a hole is formed at fingertip portion of the outer cylinder and a leverlike push member is fitted in the hole with the lower end thereof extending into the inside of the outer cylinder. The push member has an inner engaging portion and an outer push portion, which are arranged forming a certain angle relative to each other. An enlarged portion is secured to the inner cylinder in contact with or in close proximity to the lower end of the push member whereby when the user pushes the push member down-wardly toward the inner cylinder, the lower end of the push member pushes the enlarged portion to move forwardly against the spring force to thereby force out the lead.

Description

United States Patent m Naruse et a1.

[ 1 July 1,1975

l l PUSH TYPE MECHANICAL PENCIL (75] Inventors: Taken Naruse, Koshigaya;

Junichi Hashimoto; Hideaki Oikawa, both of Tokyo all of Japan [73] Assignee: Penlel Kahushiki Kaisha, Tokyo,

Japan [22] Filed: Nov. 18, 1974 [211 Appl. No; 524,673

[30] Foreign Application Priority Data Mar. 2 1973 Germany 2310573 l 56] References Cited UNITED STATES PATENTS 5/1931 Garankin 401/93 X 2,340,665 2/1944 Jacobs i 401/65 3,558,233 1/1971 Zepell 401/106 FOREIGN PATENTS OR APPLICATIONS 1,086,929 8/1954 France 401/106 366,739 1/1939 ltaly 40/92 Primary ExaminerLawrence Charles Attorney, Agent, or Firm-Eliot S. Gerber [57] ABSTRACT A push type mechanical pencil with which a user can push out a lead with a fingertip work while keeping a writing posture and a grasping position unchanged. In this mechanical pencil, a hole is formed at fingertip portion of the outer cylinder and a lever-like push member is fitted in the hole with the lower end thereof extending into the inside of the outer cylinder, The push member has an inner engaging portion and an outer push portion, which are arranged forming a certain angle relative to each other. An enlarged portion is secured to the inner cylinder in contact with or in close proximity to the lower end of the push member whereby when the user pushes the push member down-wardly toward the inner cylinder, the lower end of the push member pushes the enlarged portion to move forwardly against the spring force to thereby force out the lead.

8 Claims, 5 Drawing Figures PUSH TYPE MECHANICAL PENCIL This application is a divisional of Application Ser. No. 334.731 filed Mar. 3. 1973, entitled PUSH TYPE MECHANICAL PENCIL." which is presently pending.

This invention relates to a push type mechanical pencil with which a user can push out a lead with a fingertip work while keeping a writing posture and a grasping position unchanged.

In a conventional push type mechanical pencil, it was suggested that a push member to push out a lead into a writing position is constructed with two members which are a striker plate and a fanshaped crank arm as disclosed in US. Pat. No. 3.558.233. In this conventional construction. a clip ball is manually pressed inwardly to contact a pair of the crank arms that straddle a cartridge and rotate to press against a shoulder of a cartridge to extend a writing tip. A compression spring normally retracts the writing tip within a barrel. The clip is hinged to the barrel and slides so that the clip ball is moved out of alignment with the crank arms when the pen is not in use.

However, the two-article construction of the push member is complex in structure and operation. Further, since a spring force ofthe spring is received by the striker plate through the crank arm plate, the push member must be made stronger in mechanical strength. Accordingly. a smooth operation was hardly accomplished.

It is therefore an object of the present invention to provide a novel push type mechanical pencil in which the lead can be smoothly propelled with a simple fingertip work of one of the users fingers grasping the pencil holder while maintaining a writing posture.

It is another object of the present invention to provide a mechanical pencil of the type, in which the propelling of the lead can be effected with a relatively small pressing force.

A further object of the present invention is to provide a mechanical pencil of the type mentioned above, which is easy to be assembled, simple in construction and can be manufactured at a low cost.

The present invention provides a push type mechanical pencil which generally comprises an outer casing, an inner casing having at its fore end a lead gripping chuck means and also formed with a lead passage communicated with the chuck means and a spare lead housing tube, and a spring means adapted to press the inner casing rearwardly along its axis. The inventive push type mechanical pencil further comprises a hole on the outer casing at which user's fingertip is positioned in writing posture, a push member formed from a lever composed of an inner engaging portion and an outer push portion which are arranged so that they form a certain angle relative to each other. The lever is pivoted to the outer casing through the hole at its angled portion. The inner engaging portion of the push member comprises forked portions striding over the inner casing and is cooperable with a ring-like member which is fitted to the inner casing. In the inventive push type mechanical pencil, when the user pushes the outer push portion of the push member downwardly, the inner engaging portion of the push member pushes the ringlike member to move forwardly against the resisting force of the spring to push out the lead into a writing position.

The aforementioned and other objects and features of the present invention will be apparent from the following detailed description of a specific embodiment thereof, when read in conjunction with the accompanying drawings, in which:

FIGS. 1 to 5 show respective embodiments of the push type mechanical pencils according to the present invention, wherein FIG. 1 is a partially sectioned side view, and FIGS, 2 to 5 are exploded perspective views of the essential parts of the present pencils.

An outer cylinder 1 has at its fore end a ferrule 2 which is threadedly secured to the fore end through an annular threaded member 3, and an opening at the rear end of said outer cylinder is closed with a plug 4. A small guide pipe 5 for a lead 6 is provided extending through the fore end portion of the ferrule 2. Inside of the outer cylinder 1 is disposed an inner cylinder 10 having at its fore end a chuck means 1] and also forming a lead passage 12 communicated with the chuck means 11 and a tube 13 containing spare leads. In these embodiments, the lead passage 12 of the inner cylinder 10 is constructed with a lead guide pipe 14 integral with the chuck means 11 and an engaging member 25, the rear end of which is fitted in the spare leads containing tube 13 and the fore end is threadedly secured to the tube 13. Chuck means 11 is arranged to be engaged with a ring 15 in the annular threaded member 3 in a known way. A spring 16 is compressedly interposed between an enlarged annular front end 26 of the engaging member 25 and the inner wall at the fore part of the outer cylinder 1, so as to press the inner cylinder 10 rearwardly along its axis.

A hole 30 is formed at the portion where the fingertip is positioned on the outer cylinder 1. In case of constituting the outer cylinder 1 from two members as shown in FIGS. I to 3, the hole 30 may be formed by suitably spacing apart the both members, while in case of constituting the outer cylinder from a single member as shown in FIGS. 4 and 5, such a hole may be formed by perforating the member.

Passed through said hole 30 is a bent lever 50 having an inner engaging portion 51 and an outer push portion 52 which are arranged forming a certain angles to 135 relative to each other, and the lever 50 is swingably pivoted at its angled portion to the outer cylinder 1. Preferably, the inner engaging portion 51 is formed bifurcated and is pivotally secured to the outer cylinder 1 in such a manner that the fork strides over the tubular engaging member 25 and is positioned behind and normally in close proximity to the enlarged annular portion 26.

In the embodiment shown in FIG. 1, a small hole 30 is formed through the rear portion of the ferrule 2 adjacent to the outer cylinder 1. The lever 50 has a detent 53 integrally formed at the upper part of its inner engaging portion 51 and is disposed through the hole 30 such that the detent will be positioned inside of and in close proximity to the outer cylinder 1 when the two members of said outer cylinder are threadedly joined together. The lever is bent with an angle of about at the junction of the inner engaging portion 51 and the outer push portion 52 and, therefore, the outer push portion 52 projects outside of the outer cylinder 1 with an engle of about 30.

In the embodiment of FIG. 2, shoulders 54 are formed at the top of inner engaging portion 51 of the lever 50 such that the shoulders will be positioned in the inside of and in close adjacency to the edges of a hole 30 formed in the outer cylinder 1. In the arrangements of the lever 50, the outer push portion 52 is projected outside of the outer cylinder 1 as shown.

in an embodiment shown in FIG. 3, a pin 55 is provided such that it fits at its both ends in the horizontal grooves 56 formed in opposed relation in the inner wall of the outer cylinder 1 and is also engageable in the slant grooves 57 formed at the angled portion of the lever 50.

In still another embodiment shown in FIG. 4, a bridge-like portion 33 bridging a hole 32 in the outer cylinder 1 substantially at its middle portion to divide the hole 32 into two parts is provided integral with the outer cylinder 1 such that the bridge-like portion 33 will engage in a convolute groove 58 formed in the angled portion of the lever 50. If necessary, the fore portion 32a of the hole 32 may be filed up with a cover member 34.

In another embodiment of FIG. 5, a bearing plate 36 is attached to the inner wall of the outer cylinder I having a hole 35, and a pin 59 adapted at the angled por tion of the lever 50 so as to swingably support the lever is received in and supported by slots 37 formed in the bearing plate 36. A pin 59 swingably supports the lever 50 in the outer cylinder 1, the pin being supported in the slots 37 as shown in FIG. 5.

In the embodiments shown in FIGS. 3 to 5, the lever 50 is mounted swingable about the

55 or 59 or the bridge-like portion 33, and hence the outer push portion 52 of the lever 50 can be normally positioned substantially flush with the external surface of the outer cylinder 1 so that it will not spoil the external appear ance of the pencil. Preferably, arrangement is made such that when the chuck means 11 is not gripping the lead 6, the enlarged annular portion 26 of the engaging member 25 may stay in direct abutment against the inner engaging portion 51 of the lever 50. Even if such arrangement is used, when the chucking means 11 once grips the lead 6, the chucking means is expanded out by an amount of thickness of the lead 6, thus partly preventing returning to the chuck guide ring 15, and as a consequence, there is formed a slight gap between the enlarged annular portion 26 of the engaging member 25 and the inner engaging portion 51 of the lever 50 as shown in FIG. 1. Therefore, in order to prevent rattling of the lever 50, it is desirable to dispose a weak torsion coiled spring 40 between the lever 50 and the inner wall of the outer cylinder 1 with the bridge 33 or the

55, 59 as a fulcrum, or a supporting position, as shown in FIGS. 3 and 4.

The push type mechanical pencil having a lever-like push member 50 according to the present invention is constructed as substantially same as described above, so that when the user pushes the outer push portion 52 of the lever 50 with one of his fingers grasping the outer cylinder 1 in a writing posture, the inner pressing portion 51 is turned about the bearing of its angled portion, with the end of the pressing portion 51 pushing the enlarged annular portion 26 of the engaging member 25 forwardly, thereby urging the lead out from the foremost end of the pencil with the aid of the chucking means ll. When the pressing force on the outer portion 52 of the lever 50 is released, the engaging member is forced to move back by the action of the spring 16 and its enlarged annular portion 26 pushes back the inner pressing portion 51 of the lever 50, causing the lever 50 to turn about its bearing section to return to its normal position. It is thus possible to push the lead 6 out to a desired length by repeating the abovedcscribed operation.

In the embodiments employing such a lead push-out lever 50, it is possible to perform the lead push-out operation with a relatively small pressing force by providing a greater distance between the pivot of the lever 50 and the end of the outer push portion than the distance between the pivot and the end of the inner pressing portionv What is claimed is:

1. In a push type mechanical pencil comprising an outer casing; an inner casing having at its fore end a lead gripping chuck means and also formed with a lead passage communicated with said chuck means and a spare lead housing tube; and a spring means adapted to press said inner casing rearwardly along its axis, wherein said push type mechanical pencil further comprises a hole formed at a part of said outer casing at which users fingertip is positioned when the user grasps said outer casing in writing position, a push member formed from a lever composed of an inner engaging portion, and an outer push portion which are arranged forming a certain angle relative said inner engaging portion, said lever being pivoted to the outer casing through said hole at its angled portion, said inner engaging portion of said push member having forked portions striding over said inner casing and being cooperable with an enlarged portion of said inner casing, whereby when the user pushes said outer push portion of said push member downwardly, said inner engaging portion of said push member pushes said inner casing to move forwardly against the resisting force of said spring, thereby to push out the lead into a writing position.

2. A push type mechanical pencil as claimed in claim 1, wherein said lever has a detent at the upper part of the engaging portion thereof, said detent being positioned inside of and in close proximity to said outer casing.

3. A push type mechanical pencil as claimed in claim 1, wherein said inner engaging portion of said push member has shoulders at the top thereof, said shoulders being positioned inside of and in close adjacency to edges of said hole.

4. A push type mechanical pencil as claimed in claim 1, wherein said push type mechanical pencil further comprises horizontal grooves inside of said outer casing, a pin fitted at its both ends in said horizontal grooves, and slant grooves at said angled portion of said lever, said pin being engageable in said slant grooves.

5. A push type mechanical pencil as claimed in claim 1, wherein said hole is in elongated slot devided into a fore larger hole and a rear smaller hole by a bridge formed integral with said outer casing, said lever being a convolute groove at the angled portion thereof to swingably engage said bridge with said groove.

6. A push type mechanical pencil as claimed in claim 1, wherein said lever has a pin at the angled portion, said pin being supported by a bearing plate attached to the inner wall of said outer casing, said lever being pivotably supported by said pin.

7. A push type mechanical pencil as claimed in claim 4, wherein said pin has a spring disposed between said lever and the inner wall of said outer casing to prevent said lever from rattling.

8. A push type mechanical pencil as claimed in claim 5, wherein said bridge has a spring disposed between said lever and the inner wall of said outer casing to prevent said lever from rattling,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 5892u95 Dated July 1, 1975 Inventor) Takeo Naruse et a1.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Heading, beneath "Foreign Application Priority Data" insert Mar. 3, 1972 Japan 47-26301 July 10, 1972 Japan 47-81359 July 10, 1972 Japan 47-81360 Nov. 10; 1972 Japan 47-129536 Signed and Scaled this fourteenth D ay Of October 1975 [SEAL] Attesr:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner ufParenrs and Trademarks

Claims

1. In a push type mechanical pencil comprising an outer casing; an inner casing having at its fore end a lead gripping chuck means and also formed with a lead passage communicated with said chuck means and a spare lead housing tube; and a spring means adapted to press said inner casing rearwardly along its axis, wherein said push type mechanical pencil further comprises a hole formed at a part of said outer casing at which user''s fingertip is positioned when the user grasps said outer casing in writing position, a push member formed from a lever composed of an inner engaging portion, and an outer push portion which are arranged forming a certain angle relative said inner engaging portion, said lever being pivoted to the outer casing through said hole at its angled portion, said inner engaging portion of said push member having forked portions striding over said inner casing and being cooperable with an enlarged portion of said inner casing, whereby when the user pushes said outer push portion of said push member downwardly, said inner engaging portion of said push member pushes said inner casing to move forwardly against the resisting force of said spring, thereby to push out the lead into a writing position.

8. A push type mechanical pencil as claimed in claim 5, wherein said bridge has a spring disposed between said lever and the inner wall of said outer casing to prevent said lever from rattling.