GB2185713A

GB2185713A - Composite writing instrument

Info

Publication number: GB2185713A
Application number: GB08631055A
Authority: GB
Inventors: Kazuhiko Sekiguchi
Original assignee: Zebra Co Ltd
Current assignee: Zebra Co Ltd
Priority date: 1986-01-04
Filing date: 1986-12-31
Publication date: 1987-07-29
Anticipated expiration: 2006-12-31
Also published as: IT8747501A0; GB2185713B; JPH0442154Y2; IT1205692B; GB8631055D0; DE3700170A1; JPS62111884U; FR2592614A1; KR890006805Y1

Abstract

A composite writing instrument which has an upper tubular casing 2 and a lower tubular casing 1 including a lead ejecting type mechanical pencil unit 3 and a ball point pen unit 4. These two units are alternately shiftable to writing and retracted position with the aid of a cam mechanism 20, 21. When the mechanical pencil unit is brought to the writing position, an axially reciprocative motion is given thereto through the cam mechanism, and a chuck mechanism 9 portion thereof functions to feed lead out from the tip of the mechanical pencil unit. The upper tubular casing is fitted to the lower tubular casing so as to be retractable into a stowage position, the upper tubular casing being formed with an axially extending notched groove that slidably receives a pin 7 installed at the rear end of the cam mechanism. The casing parts can be locked in an extended operative writing position by locating the pin 7 in an L-shaped extension (8a, Figure 3). <IMAGE>

Description

SPECIFICATION Composite writing instrument Background of the invention: Field of the invention: The present invention relates to a composite writing instrument in which an uppertubularcasing is retractable with respect to a lowertubular casing.

Description ofthepriorart: If a conventional composite writing instrument equipped with a lead ejecting type mechanical pencil unit and a ball point pen unit is made shortfor obtaining convenient portability, a writing condition is deteriorated as compared with that of the writing instrumentofan ordinary size.

Summary ofthe invention A primary object of the present invention which obviates the above-described problems is to provide, in a composite writing instrument wherein: a lead ejecting type mechanical pencil unit and a ball point pen unit are built in a lowertubularcasing, these units being alternately shiftable both to a writing position and to a retractive position by means of a cam mechanism fitted to the rear wends of the two units; when the lead ejecting type mechanical pencil unit is shifted to the writing position, an axially reciprocative motion is imparted to the lead ejecting type mechanical pencil unit; and subsequently a chuck mechanism portion of the lead ejecting mechanical pencil unit is made to function, whereby it is feasible to feed a lead from a mouth formed in the tip of the lead ejecting type mechanical pencil unit, an improvement characterized such that: the uppertubular casing is shiftably attached to the rear end of the lowertubularcasing and is retractable with respect the lower tubular casing; the uppertubularcasing is formed with a long and narrow notched groove which extends in the axial direction; a follow-up pin installed at the rear end of the cam mechanism is shiftably provided in the notched groove; and the upper tubular casing is slightly rotated round the axis thereof in the most extended state ofthis casing, whereby the follow-up pin is seized by a stopper formed in the front end of the notched groove.

These and other objects, features and advantages of the invention will become more apparent on reading the following detailed description with reference to the accompanying drawings.

Brief description of the drawings: Figure 1 is a cross-sectional view of a composite writing instrument according to the present invention, showing a state wherein a lead ejecting type mechanical pencil unit is broughttoawriting position undersuch a condition that an upper tubularcasing is extended most; Figure 2 is a cross-sectional view of the composite writing instrument according to the present invention, showing a state wherein the lead ejecting type mechanical pencil unit is brought to the writing position under such a condition thatthe upper tubular casing is shrinked most; Figure3 is a view showing a situation wherein a follow-up pin of the upper tubular casing engages with a substantially L-shaped crook integral with a long and narrow notched groove;; Figure 4(a) is a perspective view of the composite writing instrumentaccording to the present invention, showing a state wherein both the lead ejecting type mechanical pencil unit and a ball point pen unit are in a neutral position under the condition thatthe uppertubularcasing isshrinked most, Figure 4(b) is a perspective view showing a state corresponding to Figure2, and Figure 4(c) isa perspectiveviewshowing astatewherein a lead is fed out by reciprocating the uppertubularcasing in the disrection indicated by an arrowhead A underthe condition shown in Figure 4(b);; Figure 5(a) is a perspective view of the com posite writing instrument according to the present invention, showing a state wherein both the lead ejecting type mechanical pencil unit and the ball point pen unit are in the neutral position (retractive position) underthe condition that the uppertubular casing is extended most, Figure 5(b) is a perspective view showing a state corresponding to Figure 1, and Figure 5(c) is a perspective view showing a state wherein the lead is fed out by reciprocating the uppertubular casing in the direction indicated by an arrohead B underthe condition shown in Figure 5(b); and Figure 6(a) is a perspective view of the composite writing instrument according to the present invention, showing a state wherein the ball point pen unit is brought to the writing position under the condition that the uppertubular casing is shrinked most, and Figure 6(b) isa perspectiveviewofthe composite writing instrument according to the present invention, showing a state wherein the ball point pen unit is brought to the writing position undercondition thatthe uppertubularcasing is extended most.

Description of the preferred embodiment: A composite writing instrument according to the present invention will hereinafter be described at full length with reference to the accompanying drawings.

In the Figures, the reference numeral 1 represents a lowertubularcasing in which a lead ejecting type mechanical pencil unit3 and a ball point pen unit4 are built. These units 3,4 are alternately shifted in the axial direction of the lowertubular casing and are brought to writing, neutral and retractive positions by means of a well known cam mechanism consisting of a guide sleeve 5 and a cam 6. The lead ejecting type mechanical pencil unit 3which is in the writing position reciprocatingly moves the above-mentioned cam mechanism in the axial direction of the lower tubular casing 1, whereby a chuck mechanism portion 9 of the mechanical pencil unit 3 is operated. With this process, the lead of the mechanical pencil unit is fed out.

The numeral 2standsforan uppertubularcasing so fitted to the lower tubular casing 1 asto be retractable in the axial direction ofthis lowertubular casing 1. The upper tubular casing 2 is formed with a long and narrow notched groove 8 extending in the axial direction thereof. A stopper like, for instance, a substantially L-shaped crook 8a, is formed in the tip end portion ofthe notched groove. Afollow-up pin 7 provided on the outer peripheral portion of the rear end ofthe cam 6 is fitted in the notched groove 8.

When sliding in the direction in which the upper tubular casing 2 is retractable with respect to the lower tubular casing 1,thefollow-up pin 7 is so arranged as to be shiftable within the notched groove 8.

Where the writing instrument according to the present invention is used in the maximum state of extension, the follow-up pin is made to slide on the lowertubularcasing 1 inthedirectioninwhichto stretch the uppertubular casing 2; and in the most extended state ofthe uppertubularcasing 2 the follow-up pin 7 is arranged to be seized bythe substantially L-shaped crook 8a formed in the front end ofthe notched groove 8 when slightly rotating the upper casing 2 round the axis thereof. The upper tubular casing 2thus remains in the mostextended state.

It is to be noted that the rotation of the upper tubular casing round the axis thereof is propagated to the cam mechanism,wherebythe aforementioned two units shift to the writing, neutral and retractive positions, alternately.

Inasmuch as the composite writing instrument according to the present invention is so constructed as shown above, if writing instrument is unused for a writing operation, the uppertubularcasing 2 is, as illustrated in Figure 4(a), slidden to the side of the writing tip so that the writing instrument is minimized in length with a viewto obtaining convenient portability. When the instrument is in use forthe writing operation, the uppertubular casing 2 is, as depicted in Figure 5(a), kept in the most extended state, and the mechanical pencil unit 3 is brought to the writing position (see Figures 4(a) to 4(c)), orthe ball point pen unit4 is broughtto the writing position (Figure 6(b)) by rotating the upper tubular casing 2.If the writing instrument is employed in such a state, the writing is effected with high efficiency.

When reciprocating the uppertubular casing 2 by pressing the rear end thereof in the axial direction, this reciprocative movement is conveyed to a chuck mechanism portion 9, designedforfeeding outthe lead ofthe mechanical pencil unit3 interlocked with the cam mechanism through the intermediary ofthe follow-up pin 7, thereby feeding out the lead.

Incidentally, the constitution of a composite writing instrument of this type had already been disclosed in detail in the specification of G.B. Patent No. 2002295 pertaining to the application made by the present applicant and hence the description is omitted. By way of precaution, however, the respective components are designated as follows.

Referring to Figure 1 the numeral 9 denotes the chuck mechanism pOrtion, 10 stands for a shift sleeve, 11 represents a connecting sleeve, 12 designates a coiled spring, 13, 14 stand for a rod, 15, 16 denote a holder, 17,18 representthecoiled spring, 19, 20 denote a slider, 21 denotes a sector stop, 22 represents a fixing ring, 23 stands for a spring, 24 denotes a mouth, 25 denotes a tip, 26 is the lead, and 27 represents a ball point tip.

The composite writing instrument according to the present invention yields the following effects. Since the uppertubular casing is, as described above, axially retractable with respect to the lowertubular casing, the instrument as a whole can be shortened for the sake of convenient portability. Furthermore, when the writing instrument is used for the writing operation, there is produced a practical advantage in which the instrument can be extended to a desired length suited to necessary writing conditions.

Claims

1. A composite writing instrument comprising an elongate casing including first and second relatively reciprocal parts, first and second writing units within the casing, and drive means responsive to relative reciprocation of the casing parts to movethewriting units selectively to an operative writing position protruding from the casing, wherein said casing parts are movable relative to one anotherfrom a stowage position in which the casing has a relatively short length to an operative writing position wherein the casing has a relatively long length.

2. A composite writing instrument accordingto claim 1 wherein one of said writing units isan inkpen unitandtheotherofsaid units isa pencil unit.

3. An instrument according to claim 1 or 2 wherein said drive means is operative in response to successive reciprocations of said casing partsto cause lead to be shifted out of said pencil when in said operative writing position.

4. An instrument according to any preceding claim wherein the housing parts are formed with a longitudinally extending guide slot and a cooperating guide pin sliding in the slot, and means for releasably locking the pin at one end ofthe slotto hold the casing parts in said relatively long length writing position.

5. An instrument according to claim 4wherein said slot is formed with a transverse extension to releasably hold said pin for said writing position.

6. In a composite writing instrument wherein a lead ejecting type mechanical pencil unit and a ball point pen unit are built in a lower tubular casing, said two units being alternately shiftable both to a writing position and to a retractive position by means of a cam mechanism fitted to the rear ends of said two units; when said lead ejecting type mechanical pencil unit is shifted to the writing position, an axially reciprocative motion is imparted to said lead ejecting type mechanical pencil unit; and subsequently a chuck mechanism portion of said lead ejecting type mechanical pencil unit is made to function, whereby it isfeasible to lead outa lead from a mouth formed in the tip of said lead ejecting type mechanical pencil unit, an improvement characterised in that; said upper tubular casing is shiftably fitted to the rear end of said lowertubular casing and is retractable with respect to said lowertubularcasing; said upper tubular casing is formed with a long and narrow notched groove which extends in an axial direction; afollow-up pin installed atthe rearend of said cam mechanism is shiftably provided in said notched groove; and said upper tubular casing is slightly rotated round the axis thereof in the most extended state thereof, whereby said follow-up pin is seized by a stopper formed in thefrontend of said notched groove.

7. A composite writing instrument substantially as herein before described with reference to the accompanying drawings.