US3804536A

US3804536A - Slide type mechanical pencil

Info

Publication number: US3804536A
Application number: US00127492A
Authority: US
Inventors: O Torii; S Torii; Y Hashimoto
Original assignee: Ancos Co Ltd; SKATER FOUNTAIN PEN CO Ltd
Current assignee: Ancos Co Ltd; SKATER FOUNTAIN PEN CO Ltd
Priority date: 1971-03-24
Filing date: 1971-03-24
Publication date: 1974-04-16
Anticipated expiration: 1991-04-16

Abstract

A slide type mechanical pencil, comprising a body having the desired length and diameter, a tubular push-rod slidably accommodated in said body and continuously urged towards the rear thereof. A chuck is supported by said push-rod, a gripping member is fixedly provided in the body opposite the tapered part of the chuck, and a slider is accommodated in the front part of the body in such a manner that it can slide a fixed length. By cooperative working of said chuck, said gripping member and said slider, automatic exposure of the lead for continuous writing is made possible.

Description

United States Patent [191 Torii et al.

1451 Apr. 16, 1974 SLIDE TYPE MECHANICAL PENCIL [75] Inventors: Osamu Torii; Sugako Torii, both of Kyoto; Yasuyuki Hashimoto, I-lyogo, all of Japan [73] Assignees: Ancos Co., Ltd.; The Skater Fountain Pen Co., Ltd., both of Osaka, Japan [22] Filed: Mar. 24, 1971 21 Appl. No.: 121,492

[52] [1.8. CI. 401/58, 401/65, 401/93 [51] Int. Cl. 543k 21/16 [58] Field of Search 401/65, 67, 58, 92-94 [56] References Cited UNITED STATES PATENTS 11/1970 Sakamotomm .;-.....-40l/67 10/1949 1 Mustard 401/67 3,205,862 9/l965 Brewer 401/58 Primary Examiner-Lawrence Charles Attorney, Agent, orFirm-Wende:roth, Lind & Ponack [5 7] ABSTRACT 5 Claims, 3 Drawing Figures PQATENTEDAPR :6 e914 SHEET 1 BF 2 INVENTORS OSAMU TORII SUGAKO TORII and YASUYUKI HASHIMO'IO ATTORNEY 5 PATENTEDAPR 16 I974 sum 2 or z OSAMU TORII, SUGAKO TORII and YASUYUKI HASHIMOTO,

INVENTOR s BY a mludi,

ATTORNEYS SLIDE TYPE MECHANICAL PENCIL This invention relates to a slide type mechanical pen cil, wherein a slider recedes automatically at the same that rate the lead wears away, due to writing pressure, and thus continuous writing is possible without the necessity of frequently pushing out a lead by pressing the rear end of the pencil with a thumb. When a lead of a fixed length or the length corresponding to the slidable length of the slider has worn away, a further length of the lead corresponding to the slidable length of the slider can be pushed out at once, together with the slider, by pressing the rear end of the pencil. More particularly, this invention relates to a pencil of slide type comprising a tubular body having a desired length and desired internal and external diameters, a tubular pushrod which is slidably mounted in said tubular body and which carries at its front end a chuck to hold the lead, a coiled spring which continuously urges said push-rod to rearward, a gripping member provided in said tubu- 5 to be described hereinafter, so as to continuously lar body which, when the push-rod recedes, hits on the tapered part of the chuck and throttles the chuck, and a slider which is slidably accommodated in the front end of the tubular body and carries a lead gripping means to hold the lead. According to this arrangement, in proportion to the consumption of the lead during writing, the slider recedes automatically due to the writing pressure, making it possible to continue writing without the need of frequently pushing out a lead during writing. Furthermore, when a fixed length of a lead or the length corresponding to the slidable length of the slider has been consumed, another fixedlength of the lead can be pushed out, together withthe slider. The pencil according to the present invention is so designed that the slider slides smoothly without play as described hereinafter, with the resultthat a lead is entirely free from breaking off. Furtheremore, it has the advantages that a lead'can be useduntil it becomes the accompanying drawings showing an embodiment of the present invention, in which:

FIG. 1 is a longitudinal sectional view of the pencil, according to the present invention, which is ready for writing with its slider forward. i

FIG. 2 is a longitudinal sectional view of the same pencil with its slider receded entirely due to writing pressure, in proportion to the wearing of a lead, and

FIG. 3 is a longitudinal sectional view of the same pencil with its slider and lead pushed out. In the drawings, numeral 1 denotes a pipe-shaped body made of metal, synthetic resin or other material and having a desired length and a desired diameter. This body comprises a metallic cap 1a, a front axis 1b and a rear axis- 1c, all connected together by screwthreading. Provided through this body is a tubular push-rod 2 (alsoserving as a lead-case), at the tip of which is provided a lead-guide 3 whereby leads 1.. in the lead case 2 are fed outone by one. Connected to the tip of this lead-guide 3 is a chuck 4 split in three parts to grip a lead at its top portion. This chuck 4 is not limited to a three-split type but can be split into any desired plural parts. At the rear part of the lead-case or the tubular push-rod 2 is an annular bulge 2a. A cap C is put on the push-rod 2 until it hits the bulge 2a so as to act as a pushing member. Detachably mounted in the extreme rear end of the push-rod 2 is an eraser R held by a metallic piece M. Stuck in this eraser R is a cleaner-pin P which can be used to clean the top part of the slider or the chuck as described hereinafter. A coiled spring S is provided around the periphery of the leadguide 3, between a projection 3a of the lead-guide. 3.

and a stepped portion 5b of a gripping member receiver urge the push-rod 2 (and the chuck) to recede. Other arrangements could be adopted for the same purpose. For example, a coiled spring S could be sandwiched between a stepped portion l d provided in the body and the bulge 2a mentioned above. A gripping member 6 is provided at the position corresponding to the threesplit chuck 4 within the body 1. This gripping member 6 is so designed that it is held within the body by a gripping member receiver 5 having a fixing member 5a by which it is fixed to the body. Formed inside the abovementioned gripping member receiver 5 is a stepped portion 5b to receive the coiled spring S. The gripping member 6 is connected to the from inner surface of the gripping member receiver 5. This gripping member 6 should be made of such material and in such shape (as with'the gripping member receiver 5, which is made integral with the fixing partSa. The fixing member Sais appropriately fixed in the body.

A slider 7 is slidably provided at the front portion of the body 1, between the body 1 and the gripping member receiver 5. The top portionof the slideris made smaller to correspond to the inner surface of the tapered metallic cap. At the tip of the slider is provided a thin pipe 7a with its tip rounded, through which a lead can be passed without any trouble. The diameter of the pipe 7a is such that it can be slid in and out of the metallic cap while it is in sliding contact with the inner surface of the bore at the tip of the metallic cap 1a. Alternatively the tip portion of the slider 7 can be made with a smaller diameter so that it can be slid in and out of the metallic cap (in this case, therefore, a larger portion of the slider is always kept within the metallic cap). A lead-holding member 7b which is made of rubber, synthetic resin or other elastic material and which lightly holds a lead ispressed into the inner surface at i the tip of the. slider.

In the pencil of the above-mentioned construction, if writing is continued in such a condition that the slider,

together with a lead, is in the forward state as shown in FIG. 1, the thin pipeat the tip of the slider runs on the surface of the writing paper, together with a lead which is gripped by the three-split chuck. Accordingly, in proportion to the amount of wearing of the lead, theslider recedes automatically against the gripping force of the lead holding member 7b, whereby continuous writing is made possible until thelead of a fixed length in the slider is used up, without the necessity of pushing out additional lead. When the lead within the slider has worn away an amount equal to the slidable length of the slider. and the pencil is in the state as shown by FIG. 2, the push given to the pencil or pressing of the cap C of the push-rod in the direction of the arrow Y, causes the push-rod 2 to shift by one stroke toward the direction of the tip of the body. At this time, the chuck 4 is released from engagement with the gripping member 6 and accordingly releases the lead from being gripped, whereupon the slider advances by its own weight or due to the force in the direction Y applied continuously to .the push-rod 2, the tip of the chuck hits upon and pushes the inner surface of the slider 7, which causes the slider 7 to move forward by one stroke, together with the lead L which is held lightly by the lead-holding member.

In the embodiment shown, the slider7 is slidably provided within the metallic cap la which is screwthreaded into the tip of the body 1 and its smaller part at the top end hits the inner surface of the metallic cap, causing the thin pipe 7a to project from the metallic cap. However, it is possible to make the rear end of the slider larger so that the thin pipe and the tip of the slider may project from a metallic cap having a larger bore.

The lead-holding member 7b may be made of most any material having a high coefficient offriction, for example, soft rubber, and can adopt various holding structures. 7

According to the present invention, by pressing the push-rod 2 a lead is pushed out by a .fixed length, together with the slider, and the consumption of a lead during writing is covered by corresponding automatic recession of the slider and resultant automatic exposure of the lead. Thus, automatic exposure of a lead during writing can be executed by the combination. of the slider and the push-rod. In more detail, by the sliding of the push-rod, a fixed length of a lead can be pushed forward, together with the slider. The slider then recedes automatically little by the little by writing pressure at the same rate as the lead wears away. Furthermore, since the slider protects the lead up to the lead-point, the lead is prevented from breaking off during writing.

What is claimed is: l

1. A slide type mechanical pencil comprising a tubular body member having predetermined interior and chuck and said gripping member.

l l l l exterior diameters and a tapered metallic cap positioned at its forward end, a tubular push rod slidably accommodated in said body and being continuously urged towards the rear end thereof, a chuckmember supported by said push rod and having a tapered section facing rearwardly, a gripping member fixedly secured to said body member opposite said chuck member, said gripping member having a tapered inner section for receiving the tapered section of said chuck member, and a slider member carrying a lead holding member positioned at the forward end of said body member, said slider member being capable of sliding forwardly and rearwardly for a fixed length, whereby by cooperative working of said chuck member, said gripping member and said slider member, automatic feeding of lead to the pencil point for continuous writing is made possible.

2. A slide type mechanical pencil as claimed in claim 1 wherein said slider member has a bore at the forward end thereof through which a lead can be passed and a thin pipe to protect the lead positioned within said bore, said pipe being automatically retractable, together with said slider, in proportion to the wearing of the lead during writing so as toeffect an automatic supply of said lead.

' 3. A slide type mechanical pencil as claimed in claim 2 wherein said slider member is tapered at its forward end to correspond to the tapered inner part of said metallic cap, and the forward movement of said thin pipe protecting said lead is limited by the tip of said slider hitting the inner surface of said metallic cap.

4. A slide type mechanical pencil as claimed in claim 1 wherein a coiled spring is positioned between said push rod and said body member to continuously urge said push rod rearwardly.

5. A slide type mechanical pencil as claimed in claim 1 wherein said slider member has a tapered forward section and a hollow cylindrical rearward section, said cylindrical rearward section normally surrounding said

Claims

1. A slide type mechanical pencil comprising a tubular body member having predetermined interior and exterior diameters and a tapered metallic cap positioned at its forward end, a tubular push rod slidably accommodated in said body and being continuously urged towards the rear end thereof, a chuck member supported by said push rod and having a tapered section facing rearwardly, a gripping member fixedly secured to said body member opposite said chuck member, said gripping member having a tapered inner section for receiving the tapered section of said chuck member, and a slider member carrying a lead holding member positioned at the forward end of said body member, said slider member being capable of sliding forwardly and rearwardly for a fixed length, whereby by cooperative working of said chuck member, said gripping member and said slider member, automatic feeding of lead to the pencil point for continuous writing is made possible.

2. A slide type mechanical pencil as claimed in claim 1 wherein said slider member has a bore at the forward end thereof through which a lead can be passed and a thin pipe to protect the lead positioned within said bore, said pipe being automatically retractable, together with said slider, in proportion to the wearing of the lead during writing so as to effect an automatic supply of said lead.

3. A slide type mechanical pencil as claimed in claim 2 wherein said slider member is tapered at its forward end to correspond to the tapered inner part of said metallic cap, and the forward movement of said thin pipe protecting said lead is limited by the tip of said slider hitting the inneR surface of said metallic cap.

5. A slide type mechanical pencil as claimed in claim 1 wherein said slider member has a tapered forward section and a hollow cylindrical rearward section, said cylindrical rearward section normally surrounding said chuck and said gripping member.