WRITING TOOL

Abstract: Writing tools in which the core casing 3 or 3a is inserted in the outer sleeve 2, an end 6 of the core casing 3 or 3a can be held projected out of an end of the outer sleeve 2 by handling an operating end 4a projecting out of a rear end of the outer sleeve 2. and wherein the end 6 of the core casing 3 or 3a can be drawn in by reverse operation of the operating end 4a. A revolution-to-linear movement conversion arrangement for converting a revolutional movement of an operating end 4a to a axial movement between a core casing 3 or 3a and an outer sleeve 2. A retracting spring 5 is provided between the outer sleeve 2 and the core casing 3 or 3a and the operating end 4a projecting out of a rear end of the outer sleeve 2 can be forcibly operated against the force of a retracting spring 5. The operating end 4a is integral with the rear end of the core casing 3 or 3a, a boss 9 is provided on an outside of a rear portion of the core casing 3, 3a or inner sleeve 31, a herical slit, slot or groove 12c is provided at the rear end of the outer sleeve 2, said boss 9 is fitted into the helical slit, slot or groove 12c. A rear part 41a of the outer sleeve 41 has smaller diame­ ter and a rear sleeve 47 of same diameter to said outer sleeve 41 is mounted on the rear part 41a for cigarette like appear­ ance.

Description: Field of the Invention This invention relates to writing tools including a mechanical pencil and a ball-point pen, particularly to writing tools the tip of which can be projected out of an end of a tube by a revolutional movement and retracted by reversing said movement. Background of the Invention Conventional writing tools uses a double-push arrangement, for example Japanese Patent Publication No. 34-7181, to project the tip out of or retract it into the end of the tube. Fig. 20 is a longitudinal cross-sectional view of the double-push arrangement, and Figs. 21 (a) and 21(b) are exploded views for illustration thereof. Figs. 20, 21(a) and 21(b) show a core casing 3 contained in an outer sleeve 2. The outer sleeve 2 has a cylindrical cam 14 fitted or shaped inside a rear portion thereof. The cylindrical cam 14 has some , say three, axial projecting stripes 15 separated at an equal angle inside the rear portion thereof, each projecting stripe 15 having a shallow groove 16a shaped and having a root 17 at an edge thereof. The conventional writing tools have a push cap 4, which comprises a push cam 18 and a push rod 19. The push cam 18 has six axial stripes 20 outside a cylinder portion of the cylindrical cam 14 which are fitted into deep grooves 16b formed between the respective shallow groove 16a of the cylindrical cam 14 and the respective stripes 15 thereof. The stripes 20 are made to form a crown which has peaks 21 and roots 22 on an end of the cylinder portion of the cylindrical cam 14. The push rod 19 projects out of rear end of the outer sleeve 2. The core casing has a rotation cam 23 fitted in a rear portion thereof. On an outside thereof the rotation cam 23 axial stripes 24 which can be fitted into the deep grooves 16b of the cylindrical cam 14. The stripes 24 are made to form a crown which has peaks 25 and roots 26 alternatively on an end of the cylindrical portion of the rotation cam 23. The push rod 19 can be pressed against the force of retracting spring (see Fig. 1). The rotation cam 23 and core casing 3, then, can be pressed dito the retracting spring to which slopes of the peaks 25 of the rotation cam 23 are fitted, but which deviate a little from slopes of the peaks 21 of the push cam 18. The stripes 24 of the rotation cam 23, then, can be detached from the deep grooves 16b of the cylindrical cam 23 which is in the state shown in Fig. 21(a). In this state, the retracting spring presses the slopes of the peaks of the rotation cam 23 to the slopes of peaks 21 of the push cam 18. This causes the rotation cam 23 to revolve to make the respective peaks and respective roots fit. In turn, the slopes of the peaks of the rotation cam 23 press the slopes of the roots 17 of the cylindrical cam 14 to further revolve the rotation cam 23. The respective peaks 25 of the rotation cam 23, then can fit with the respective roots 17 of the cylindrical cam 14 as shown in Fig. 21(b). The end of the core casing 3, thus, can be help projecting out of the end of the outer sleeve 2. In the state shown in Fig. 21 (b), when the push rod 19 is pressed again against the force of the retracting spring, the rotation cam 23 and core casing 3 can be pressed against the rectracting spring where the slopes of the respective peaks 25 are fitted to, but deviated a little, the slopes of the respective peaks 21 of the push cam 18. This detaches the peaks 25 of the rotation cam 23 from the roots 17 of cylindrical cam. This allows the rotation cam 23 to turn, which in turn allows the peaks and roots of the rotation cam 23 to fit with the respective peaks and roots of the push cam 18. In turn, the force of the retracting spring makes the slopes of the peaks 25 of the rotation cam 23 press the slopes of the respective roots 17 of the cylindrical cam 14 to turn the rotation cam 23. The stripes 24 of the rotation cam 23, then, can be pressed in the respective deep grooves 16b of the cylindrical cam 14 as shown in Fig. 21(a). This allows the push rod 19 having the push cam 18 to be retracted. At the same time, the end of the core casing 3 is drawn in from the end of the outer sleeve 2. Other well-known writing tools are of a rotational slide type having front and rear relatively rotatable bodies with a lead case disposed therein (US-A-4,362,410). A chuck which is rigidly coupled to the case firmly grips the lead in writing position. A slider can be moved back and forth over a predetermined distance. From this writing tool the idea of converting the rotational movement of the operating end of a writing tool into the linear movement of the writing end is well-known in general. This idea is also known in general from another writing tool, but in this instrument a ball point is used for writing and it is described especially under the aspect of the arrangement of the ink reservoir (US-A-2,603,186). And again another retractable writing instrument is known (US-A-3,436,160) having a cartridge that projects through a barrel of the instrument and is interconnected to a carrier having a lug formed thereon that is received in a slot formed on a sleeve that is held in a relatively fixed position and the lug being further received in a helical track on the inside of an operating member that is located in coaxial relation to the sleeve, the operating member being held against axial movement but being rotated for producing a corresponding axial movement of the carrier and the cartridge interconnected thereto. However, the above-described conventional writing tools are involved in such serious problems as complicated structure, difficult assembling work, high manufacturing cost and undependability. These difficulties are due to use of the double-push arrangement comprising the complicatedly shaped cylindrical cam 14, the push rod 19 having the push cam 18 and the rotation cam 23. Brief description of the Invention In order to solve the above-mentioned problems, an object of present invention is to provide writing tools that can be easily assembled at lower cost. This object is accomplished by providing writing tools comprising a revolution-to-linear movement conversion arrangement for converting a revolutional movement of an operating end to an axial movement between a core casing and an outer sleeve. A second object of this invention is to provide writing tools wherein the core casing is inserted in the outer sleeve, an end of the core casing can be held projecting out of an end of the outer sleeve in a way that an operating end projecting out of a rear end of the outer sleeve can be forcibly operated against a retracting spring, and wherein the end of the core casing can be drawn in by force of the retracting spring by reverse operation of the operating end. In these writing tools, the operating end can be turned. This revolutional movement is converted to a linear movement by the revolution-to-linear movement arrangement, which is transmitted to the core casing to move the core casing in an axial direction. The end of the core casing, thus, can be made to project out of the end of the outer sleeve. When the operating end is turned in reverse direction, the core casing can be moved in the opposite direction. This allows the end of the core casing to be rectracted into the end of the outer sleeve. A third object of this invention is to provide writing tools comprising a revolution-to-linear movement conversion arrangement for converting a revolutional movement of an operating end to an axial movement between a core casing and an outer sleeve, wherein the core casing is inserted in the outer sleeve, an end of the core casing can be held projecting out of an end of the outer sleeve by handling an operating end projecting out of a rear end of the outer sleeve. and wherein the end of the core casing can be drawn in by reverse operation of the operating end. A fourth object of this invention is to provide writing tools of simpler design wherein the core casing is inserted into the outer sleeve, an end of the core casing can be held projecting out of an end of the outer sleeve by handling an operating end projecting out of a rear end of the outer sleeve. and wherein the end of the core casing can be drawn in by reverse operation of the operating end, the operating end is integral with the rear end of the core casing, a boss is provided on an outside of a rear portion of the core casing or the operating end, a helical slit or groove is provided at the rear end of the outer sleeve, said boss is fitted into the helical slit or groove. A fifth object of this invention is to provide writing tools wherein a sliding front is mounted in an outer sleeve, a front end of a writing tool member is inserted into and secured to the front tool, a rear part of the outer sleeve has smaller diameter and a rotating sleeve is inserted in the rear part rotatably and slidably, a rear end of the writing tool member is inserted into and secured to the rotating sleeve, and a pin is provided on the rotating member, a rear sleeve of same diameter as said outer sleeve is mounted on the rear part, a helical slot for engaging said pin is provided on the one of inner face of the rear sleeve or rear part of the outer sleeve and longitudinal groove is provided on the other of inner face of the rear sleeve or rear part. A sixth object of this invention is to provide writing tools with a cigarette like appearance. The above and other objects, advantages and novel features of the invention will be more fully understood from the following detailed description and the accompanying drawings. Like reference numbers indicate like or similar parts throughout the description. Brief Description of the Drawings Fig. 1 is a longitudinal cross-sectional view of a first embodiment of writing tools according to the present invention. Fig. 2 is a perspective view of components of a revolution-to-linear movement arrangement for use in the first embodiment. Fig. 3, is a longitudinal cross-sectional view of a second embodiment according to the present invention. Fig. 4 is a perspective view of components of a revolution-to-linear movement arrangement for use in the second embodiment. Fig. 5 is a longitudinal cross-sectional view of a third embodiment for writing tools according to the present invention. Fig. 6 is a perspective view of components of a revolution-to-linear movement arrangement for use in the third embodiment. Fig. 7 is a longitudinal cross-sectional view of a fourth embodiment according to the present invention. Fig. 8 is a perspective view of components of a revolution-to-linear movement arrangement for use in the fourth embodiment. Figs. 9 (a) is an illustration of essential parts of the revolution-to-linear movement arrangement of the fourth embodiment. Figs. 9 (b) and (c) are illustrations of essential parts of the revolution-to-linear movement arrangement of a fifth embodiment according to the present invention. Fig. 10 is a longitudinal cross-sectional view of an sixth embodiment according to the present invention. Fig. 11 is a perspective view of components of a revolution-to-linear movement arrangement for use in the sixth embodiment. Fig. 12 is a longitudinal cross-sectional view of a seventh embodiment according to the present invention . Fig. 13 is a perspective view of components of a revolution-to-linear movement arangement for use in the seventh embodiment. Fig. 14 is a longitudinal cross-sectional view of a eighth embodiment according to the present invention. Fig. 15 is a perspective view of components of a revolution-to-linear movement arrangement for use in the eighth embodiment. Fig 16 shows a longitudinal cross section of an ninth embodiment according to the present invention. Fig 17 shows a side view of the rear part of the sleeve of the ninth embodiment. Fig 18 is a cross section of the front tool of a tenth embodiment according to the present invention. Fig 19 is a cross section of the rear part of a eleventh embodiment according to the present invention. Fig. 20 is a longitudinal cross-sectional view of a double-push arrangement as an example of conventional writing tools. Figs. 21(a) and 21(b) are exploded illustrations of the double-push arrangement of the conventional writing tools. Detailed Description of The Invention First, the design of the first embodiment of a mechanical pencil according to the present invention is described with reference to Figs. 1 and 2 as follows. Fig. 1 shows a core casing 3 that is inserted into an outer sleeve 2 in axial direction of the outer sleeve 2. The core casing 3 is forced toward the rear of the outer sleeve 2 by a rectracting spring 5. The core casing 3 of the mechanical pencil is arranged as follows. The core casing 3 comprises an inner sleeve 31 and a lead container 27 inserted therein. An end portion 31a is fitted to the threaded front end of the inner sleeve 31. The lead container 27 in the inner sleeve 31 of the core casing 3 can be moved in an axial backward or forward direction and is biased backward by the force of a pushing spring 28. A chuck 30 consisting of three pieces of component parts is fixed to the front end of the lead container 27. A sliding ring 29 is fitted around the chuck 30. When the chuck ring 29 engages at the front end of the chuck 30 as shown Fig. 1, the chuck 30 clamps the lead. When the chuck 30 is moved forward, forward movement of the chuck ring 29 is prevented by an inner annular edge portion 31b of the core casing 3, and moved backward relative to the chuck the chuck 30 releases the lead. This makes the chuck 30 within the inner sleeve 31 close or open by the chuck ring 29 fitted thereon. This allows the lead to be fed out of the lead container 27 to a desired length, thereby also feeding the lead out of an end 6 of the end portion 31a of the inner sleeve 31 to the desired length. Fig. 1 also shows a push cap 4 that is fitted to the outside of a rear and of the lead container 27 of the core casing 3 and projects out of a rear of the outer sleeve 2. The lead container 27 has an eraser 32 fitted therein. Between the core casing 3 and the outer sleeve 2 there is a revolution-to-linear movement conversion arrangement 7 of the following design. The revolution-to-linear movement conversion arrangement 7 comprises a linear movement sleeve 8 having a boss 9 provided on an outside of a rear portion thereof. The linear movement sleeve 8 is fitted on the lead container 27 between the inner sleeve 31 of the core casing 3 and an operating end 4a. The outer sleeve 2 has a guide groove 10 extending in axial direction on its inside, in which the end of the boss 9 is engaged to guide the linear movement sleeve 8 in axial direction. A rotating revolution sleeve 11 is fitted to the rear end of the outer sleeve 1. The operating end 4a of the rotation sleeve 11 has a clip 1 provided on an outside of the revolution sleeve 11. The revolution sleeve 11 has a ring 13a on the outside, which is fitted in a annular groove 13b provided on an inside of the outer sleeve 2. The revolution sleeve 11 has an insertion slit 12a opened in axial direction on its front end , a circular end slit 12b connected to the insertion slit 12a, a helical slit 12c of a half circular length connected to the end slit 12b, and a circular start slit 12d connected to the helical slit 12.c. The boss 9 of the linear movement sleeve 8 can be inserted into the slits of the revolution sleeve 11 via the insertion slit 12a, 12b , 12c, and 12d. The following describes an operation of the first embodiment. When turned the operating end 4a, revolves the revolution sleeve 11, which allows the boss 9 of the linear movement sleeve 8 to be positioned at the start slit 12d to move forward via the helical slit 12c against the force of the retracting spring 5 (on left-hand side of figure) within the guide groove 10. As an result of this the linear movement sleeve 8, the core casing 3 and push cap 4 can be moved forward and stopped where the boss 9 reaches the end slit 12b. In this state, the end 6 of the core casing 3 projects out of an end of the outer sleeve 2. When the push cap 4 is pressed in, the lead container 27 of the core casing 3 can be moved forward or backward in axial direction against or by the action of the pushing spring 28. This allows the chuck 30 fitted in the chuck ring 29 to open or close, which makes the lead within the lead container 27 come out to a desired length out of the chuck 30. The lead, thus, can be fed out of the end 6 of the core casing 3 to the desired length. To retract the lead into the end 6 of the core casing 3, the push cap 4 can be pressed against the pushing spring 28. This opens the chuck 30, so that the lead can be drawn in by pressing an end of the lead. To draw in the end 6 of the core casing 3, the operating end 4a is turned in reverse direction, which in turn reversely the rotating movements of the revolution sleeve 11. This moves the boss 9 of the linear movement sleeve 8 positioned at the end slit 12b backward (on right-hand side of figure) along the guide groove 10 and the helical slit 12c by the force of the retracting spring 5. This causes the linear movement sleeve 8, the core casing 3 and push cap 4 to move backward and stop where the boss 9 reaches the start slit 12d. In this state, the end 6 of the core casing 3 is within the end of the outer sleeve 2. Figs. 3 and 4 show a embodiment for a ball point pen, in which same numerals are used for same parts and different parts. The following describes the revolution-to-liner movement conversion arrangement. The ball point pen of the embodiment uses a refill-type core casing 3a. The core casing 3a has a revolving ball held in a end 6 thereof and has ink therein. The design of the second embodiment is as follows. The second embodiment has an insertion groove 35a formed at a rear end of the outer sleeve 2 which extends from a rear edge of the outer sleeve 2 on an inside of a rear portion thereof, a circular start groove 35b connected to the insertion groove 35a, a half-circular helical groove 35c connected to the start groove 35b, and a circular end groove 35d connected to the helical groove 35c. A boss 9 of a linear movement sleeve 8 is inserted into the insertion groove 35a and the linear movement sleeve 8 is fitted to a rear end of the core casing 3a so that the boss 9 can be positioned at the start groove 35b. A revolution sleeve 11 having an operating end 4a has an axially extending cut-out guide slit 37 formed at a front portion thereof. The boss 9 is put in the guide slit 37. The revolution sleeve 11 is fitted between the outer sleeve 2 and the linear movement sleeve 8 so that the revolution sleeve 11 cannot move in axial direction, but can be turned. Operation of the second embodiment is described as follows. When turned the operating end 4a makes the revolution sleeve 11 rotate. This causes the boss 9 of the linear-movement sleeve 8 positioned at the start groove 35b to move forward (on left-hand side of figure) inside the guide slit 37 along the helical groove 35c against action of a retracting spring 5. This allows the core casing 3a to move forward until the boss 9 reaches the end groove 35d. In this state, the end 6 of the core casing 3a projects out of the end of the outer sleeve 2. The ball point pen then can be used to write. To draw in the end 6 of the core casing 3a, the operating end 4a is turned in reverse direction which in turn reversely rotates the revolution sleeve 11. The boss 9 of the linear movement sleeve 8 positioned at the end groove 35d is moved backward (on right-hand side of figure) inside the guide slit 37 along the helical groove 35c by action of the retracting spring 5. This causes the linear movements sleeve 8 and core casing 3a to move backward until the boss 9 reaches the start groove 35b. In this state, the end 6 of the core casing 3a is rectracted into the end of the outer sleeve 2. The revolution-to-linear movement conversion arrangement 7 of the mechanical pencil shown in Fig. 1 can be replaced with that of the ball point pen shown in Figs. 3 and 4 and vice versa. Of course, it should be noted that grooves mentioned in the embodiments can be replace by slits or slots and the slits can be replaced by grooves or slots. Figs. 5 and 6 show a third embodiment according to the present invention applied to a mechanical pencil in which same numerals are used for same parts of the first embodiment. Only different parts are described below. The core casing 3 and the outer sleeve 2 have a revolution-to-linear movement conversion arrangement 7 between them, as the first embodiment, design of which is as follows. In this embodiment, the boss 9 is provided on the inner sleeve 31 instead of the linear movement sleeve 8. The core casing 3 has a boss 9 provided on an outside of a rear portion of an inner sleeve 31. The outer sleeve 2 has a guide groove 10 inside which guides the boss 9 fitted therein to move the inner sleeve 31 in axial direction. Insertion slits 12a, 12b, 12c and 12d of the revolution sleeve 11 are same as in the first embodiment. But a convex 38 is formed between the insertion slit 12a and 12b. The following describes an operation of the fourth embodiment. When turned, the operating end 4a revolves the revolution sleeve 11, which allows the boss 9 of the inner sleeve 31 positioned at the start slit 12d to move along the helical slit 12c forward (on left-hand side of figure) within the guide groove 10. As a result of this the core casing 3 and push cap 4 are moved forward and where the boss 9 climbs over the convex 38 and reaches the end slit 12b. In this state, the end 6 of the core casing 3 projects out of an end of the outer sleeve 2. When the push cap 4 is pressed in, the lead within the lead container 27 is forced out of the chuck 30 to a desired length and lead is, thus, forced out from the end 6 of the core casing 3 to the desired length as in the first embodiment. To retract the lead into the end 6 of the core casing, the push cap 4 is pressed against the pushing spring 28, to open the chuck 30, so that the lead can be drawn in by pressing an end of the lead as in the first embodiment. To drawn in the end 6 of the core casing 3, the operating end 4a can be turned in reverse direction, as a result of which the revolution sleeve 11 is also turned is reverse direction. This allows the boss 9 of the inner sleeve 31 positioned at the end slit 12b to climb over the convex 38 and to move backward (on right-hand side of figure) in the guide groove 10 along the helical slit 12c. This causes the core casing 3 and push cap 4 to move backward and stop where the boss 9 can reach the start slit 12d. In this state, the end 6 of the core casing 3 is within the end of the outer sleeve 2. In content of this embodiment, it should be noted that the retraction spring 5 used in the first embodiment can be eliminated. Figs. 7, 8 and 9 (a) show a fourth embodiment for a ball point pen. The ball point pen of the fourth embodiment uses a refill-type core casing 3a. The core casing 3a has a revolving ball held in an end 6 thereof and is filled with ink. The design of the fourth embodiment is almost same as that of the second embodiment but the boss 9 is fitted to an outside of a rear portion of the inner sleeve 31 on a rear portion of the core casing 3a. The operating end 4a has a guide slit 37 shaped for accommodating the boss 9 from a front edge of the revolution sleeve 11. The design comprises an insertion groove 12a from a rear edge of an outer sleeve 2 on an inside of a rear portion thereof, a circular start groove 12d connected to the insertion groove 12a, a convex 38 between the start slit 12d and the helical slit 12c, and a half-circular end groove 12b connected to the helical groove 12c. The revolution sleeve 11 of the operating end 4a has a stud 13a on an outside thereof, and the outer sleeve 2 has a ring groove 13b provided to fit the stud 13a therein on an outside thereof. The revolution sleeve 11 is fitted to the inner sleeve 31 where the boss 9 of the inner sleeve 31 should be fitted into the guide slit 37 of the revolution sleeve 11. The core casing 3a and the revolution sleeve 11 with its operating end 4a are inserted into the outer sleeve 2 from the rear edge. The boss 9 of the inner sleeve 31 is fitted into the insertion slit 12a of the outer sleeve 2. The revolution sleeve 11 is fitted to the rear portion of the outer sleeve 2 with the boss 9 positioned at the start slit 12c so that the revolution sleeve 11 cannot move in axial direction as a result of the engagement between the stud 13a and the ring groove 13b, but can revolve. The operation of this embodiment is identical to that of the previous embodiment. Operation of the fourth embodiment is described as follows. When turned, the operating end 4a makes the revolution sleeve 11 rotate. This causes the boss 9 of the inner sleeve 31 positioned at the start slit 12d to climb over the convex 38 and to move forward (on left-hand side of figure) inside the guide slit 37 along the helical slit 12c. This allows the inner sleeve 31 and core casing 3 to move forward until the boss 9 reaches the end slit 12b. In this state, the end 6 of the core casing 3a projects out of the end of the outer sleeve 2. The ball point pen then can be used for writing. To draw in the end 6 of the core casing 3a, the operating end 4a is turned in reverse direction, which in turn causes the revolution sleeve 11 to rotate in reverse direction. The boss 9 of the linear movement sleeve 8 positioned at the end slit 12b, then, is moved backward (on right-hand side of figure) inside the guide slit 37 by the helical slit 12c. This causes the inner sleeve 31 and core casing 3a to move backward until the boss 9 runs beyond the convex 38 and reaches the start groove 12d. In this state, the end 6 of the core casing 3a is retracted into the end of the outer sleeve 2. In the present invention, no retracting spring 5 is needed for the core casing 3, but it may be used for supporting the retracting movement. In a fifth embodiment according to the present invention, as shown in Figs.9 (b) and (c), for improving the handling characteristics of the operating end, a convex 38 may be provided between the end slit 12b and the helical slit 12c, and may also be provided on the helical slit 12c side and the insertion slit 12a side of a boundary between the helical slit 12c and the insertion slit 12a. These convexes 38 produce a click sound when the boss 9 passes to take up its position. The revolution-to-linear movement conversion arrangement 7 of the mechanical pencil in the third embodiment shown in Figs 5 and 6 can be replaced with that of the ball point pen in the fourth embodiment shown in Figs 7 and 8 and vice versa. It should be noted that the grooves mentioned in the embodiments can be replaced by slits or slots and the slits can be replaced by grooves or slots. It can be clearly seen from the above description that the third and fourth embodiments of this invention provide such superior effects as simple contruction, easy assembling work, low manufacturing cost and minimum trouble rate as the present invention uses the revolution-to-linear movement arrangement 7 as an arrangement for making the end 6 of the core casing 3 or 3a project from or retract into the end of the outer sleeve 2. In addition, the present invention is effective in view of the fact that the retracting spring 5 can be eliminated. Figs. 10 and 11 show a mechanical pencil as an sixth embodiment of the writing tools according to the present invention. First, the design of the sixth embodiment is described below. Fig. 10 shows a core casing 3 that is inserted into an outer sleeve 2. The core casing 3 of this mechanical pencil is identical to previous embodiments. Fig. 10 also shows a push cap 4 that is fitted to a rear end of the lead container 27 of the core casing 3 and projects from a rear end of the outer sleeve 2. The lead container 27 has an eraser 32 fitted therein. A rear portion of the inner sleeve 31 of the core casing 3 projects from a rear end of the outer sleeve 2 and is combined with an operating end 4a having a clip 1. The rear portion of the inner sleeve 31 has a boss 9 on the outside. The outer sleeve 2 has an axial insertion slit 12a on a rear portion formed from the rear end thereof, a circular start groove 12d connected to the insertion slit 12a, a helical slit 12c connected to the start groove 12d, a convex 38, provided between the insertion slit 12a and the start groove 12d, a convex 38 provided between the start groove 12d and the helical slit 12c, and a circular end slit 12b connected to the helical slit 12c. The slits 12a through 12c may be replaced by grooves or slots and the groove 12d may be slits or slots as shown. The boss 9 provided on the outside of the rear portion of the core casing 3 can be fitted in via the insertion slit 12a of the outer sleeve 2. The boss 9 can climb over the convex 38 to be fitted into the start groove 12d. There is a clearance d provided between the rear end of the outer sleeve 2 and the operating end 4a so that the core casing 3 can move in axial direction to allow the front end 6 to project from the front end of the outer sleeve 2 when turned. This means that the inner sleeve 31 can be made to project from the rear end of the outer sleeve 2 by a length of the clearance d. The following describes an operation of the sixth embodiment. The operating end 4a is turned, the core casing 3 can be moved forward when turned while the boss 9 thereof can move from a position of the start groove 12d, climb over the convex 38 and move along the helical slit 12c to the end slit 12b. The front end 6 of the core casing 3, then, projects from the front end of the outer sleeve 2. When the push cap 4 is pressed in, the lead container 27 of the core casing 3 can be moved backward or forward in axial direction against or by the pushing spring 28. This allows the chuck 30 in the chuck ring 29 to open or close, which makes the lead within the lead container 27 come out of the chuck 30 to a desired length. The lead, thus, can be forced out of the front end 6 of the core casing to the desired length. To retract the lead into the front end 6 of the core casing, the push cap 4 is pressed against the force of the pushing spring 28. This opens the chuck 30, so that the lead is retracted when pressure is exerted on its end. When the front end 6 of the core casing 3 is rectracted, the operating end 4a can be turned in reverse direction. The core casing 3, then, moves backward while the boss 9 starts from the end slit 12b, moves along the helical slit 12c, climbs over the convex 38, and reaches the start groove 12d. In this state, the front end 6 of the core casing 3 is inside the front end of the outer sleeve 2. In this embodiment, operating end 4a forms an integral part of the inner sleeve 31 so that the linear movement sleeve 8 is eliminated. Moreover, slits 12a, 12b and 12c and a groove 12d are provided in the outer sleeve so that the revolution sleeve 11 can be eliminated. Therefore, the design of this embodiment is very simple as compared to the previous embodiment. Figs. 12 and 13 show a seventh embodiment of a ball point pen according to the present invention. The ball point pen of the seventh embodiment uses a refill-type core casing 3a. The core casing 3a has a revolving ball held in an end 6 thereof and is filled with ink. The design of the seventh embodiment is as follows. The seventh embodiment has a boss 9 on an outside of a rear portion of the inner sleeve 31 fitted on a rear portion of the core casing 3a. Slits 12a, 12b and 12c and a groove 12d are provided on the outer sleeve 2. Figs. 14 and 15 show an eighth embodiment according to the present invention of ball point pen. This eighth embodiment is also almost identical with the last mentioned of the previous embodiments, but the revolution sleeve 11 is employed for avoiding protrusion of the inner sleeve 31 by a distance d. This eighth ebodiment has a boss 9 on an outside of a rear portion of the inner sleeve 31 fitted on a rear portion of the core casing 3a. The revolution sleeve 11 with an operating end 4a has an axially extending guide slit 37 and opens to the rear edge for fitting the boss 9 from a rear edge of the revolution sleeve 11. Hindrance projections 37a and 37a are provided at the open end of the guide slit 37 for holding the boss 9, the inner sleeve 31 and others in the revolution sleeve 11. There is an insertion slit 12a from a rear edge of an outer sleeve 2 on an inside of a rear portion thereof, a circular start groove 12d is connected to the insertion slit 12a, and a half circular helical slit 12c, the half circular helical slit 12c is connected to the end slit 12b. Convexes 38 and 38 are provided between the start groove 12d and the insertion slit 12a, the circular slit 12c. The revolution sleeve 11 of the operating end 4a has a stud 13a provided on the outside, and the outer sleeve 2 has a ring groove 13b provided to accommodate the stud 13a. For fitting the revolution sleeve 11 onto the inner sleeve 31, the boss 9 of the inner sleeve 31 of the core casing 3a should be fitted into the guide slit 37 of the revolution sleeve 11. Then the core casing 3a and the revolution sleeve 11 with the inner sleeve 31 fitted inside are inserted from the rear edge of the outer sleeve 2. The boss 9 of the inner sleeve 31 is fitted into the outer sleeve 2 via the insertion slit 12a. Thus the revolution sleeve 11 is fitted to the rear portion of the outer sleeve 2 with the boss 9 positioned at the start slit 12c and the stud 13a is connected to the ring groove 13b so that the revolution sleeve 11 cannot be moved in axially direction, but can revolve. Operation of this eighth embodiment is the same as that of second embodiment shown in Figs 3 and 4. Figs. 16 and 17 show an ninth embodiment according to the present invention. The design of the embodiments is described below An outer sleeve 41 in the form of a small white cigarette-type circular sleeve in which a sliding front tool 42 is installed. The front end of a writing tool member 43 of a refill-type ball point pen or a mechanical pencil is inserted into and secured to the center bore of the front tool 42. The rear part 41a of the outer sleeve 41 has a rather smaller diameter, and a rotating sleeve 44 is inserted into the rear part 41a in such a manner that is can rotate and slide. A helical slit 45 is provided on the rear part 41a, and a pin 46 engaging with the helical slit 45 is provided on an outside face of said rotating sleeve 44. A rear sleeve 47 of yellow ochercolor like the filter of a cigarette is mounted on the rear part 41a so that it can rotate. A longitudinal groove 48 is provided on the inner face of the rear sleeve 47 and the end of said pin 46 is connected with the longitudinal groove 48. An annular recess 41b is provided at the base of the outside of the rear part 41a, and an annular projection of the rear sleeve 47 is connected to the annular recess 41b for holding the rear sleeve 47 in such a way that it can rotate. Another means may be used for this purpose. The color of the rear sleeve 47 can be different, for example, white. The operation of the device is as follows. By the rotation of said rear sleeve 47 in one direction, the rotation sleeve 44 revolves as a result of the engagement of the pin 46 and the longitudinal groove 48 and is made to slide forward by the helical slit 45. Then the writing tool member 43 and the front tool 42 slide, forward and the front end of the writing tool member 43 projects from the outer sleeve 41 and can be used for writing. Rotating the rear sleeve 47 in reverse direction, reverses the movement of each part and the end of the writing tool member 43 retracts into into the outer sleeve 41. As shown in Figs, 16 and 17, the shape of the front end of the front tool 42 is spherical, but the shape may be conical like in the front tool 42a in the tenth embodiment shown in Fig.18. Fig. 19 shows a eleventh embodiment according to the present invention in which the longitudinal groove 48 is provided on the rear part 41a of the outer sleeve 41 and a helical recess 45a in which the end of the pin 46 engages is provided at the inside of the rear sleeve 47. Operation is same as that shown in Figs. 16 and 17. The shape of a cross section of the outer sleeve 41 may be flat. As explained above, in these embodiments according to the present invention, interesting writing tools of cigarette-like appearance can be obtained by coloring the sleeve in white and rear sleeve 47 in yellow ocher. These writing tools can be kept in a cigarette casing together with cigarettes. Moreover, the writing tools of these embodiments are simple in design and cheap.

Claims: Writing tool in which a core casing (3,3a) is inserted into an outer sleeve (2) and in which a boss (9) is provided on the outside of the core casing (3,3a) projecting in to a first guiding groove (12) arranged in a first sleeve (11) and defined by a start slit (12a), an end slit (12b) and a helical slit (12c) between start slit and end slit, the boss (9) further projecting into a second groove means (10) arranged in another sleeve (2) and extending in the longitudinal direction of the tool characterized in that a front end (6) of the core casing can be held inside or projecting out of the front end of the outer sleeve by handling an operation end (4a) projecting out of the rear end of the outer sleeve and that a revolution sleeve (11) is part of the operation end (4a) inside the outer sleeve (2) and a ring (13a;17a) is provided on the outside of the revolution sleeve (11), projecting into an annular groove (13b;17b) on the inside of the outer sleeve (2). Writing tool according to claim 1 in which the boss (9) is provided on the outside of the core casing (3) and the first guiding groove (12) is provided on the inner side of the revolution sleeve (11). Writing tool according to claim 1 in which the boss (9) is provided on the outside of the core casing (3) and the first guiding groove (12) is provided on the inner side of the outer sleeve (2), the boss is projecting into the groove having extended through a slot (37) extending in the revolution sleeve in the longitudinal direction of the tool. Writing tool according to claim 2 in which the outer sleeve (2) has a guide groove (10) extending in axial direction on the inside, and in which the outer end of the boss (9) is engaged to guide the linear movement of a linear movement sleeve (8) in axial direction, which is part of core casing (3). Writing tool according to claim 2 in which the start slit (12a) is directed in the longitudinal direction of the revolution sleeve (11) and is open at the front part of the revolution sleeve. Writing tool according to claim 3 in which the start slit (12a) is directed in a circumferential direction of the outer sleeve (2) and the end slit (12b) is directed in the longitudinal direction of the outer sleeve. Writing tool according to claim 1 in which the helical slit (12c) of the groove (12) is of half the circular length. Writing tool according to claim 1 in which the front end of the core casing (3) is a chuck (30) surrounding a lead (6).

Inventors: KAGEYAMA, SHUHEI
Applicants: KOTOBUKI & CO., LTD.
Application year: 1986
Main classification: B43K24
IPC codes: B43K27, B43K24