Writing tool

Abstract: The present invention relates to a writing tool wherein a writing shaft (502) having a head member (501) is inserted in an outer sleeve (503) in such a manner that the head member is projected from the outer sleeve (503), a stair and a spiral groove (505) are provided on the forward inner surface and the rearward inner surface of a tubular cap, (505a) respectively, an inside diameter of the rear part of the spiral groove is larger, a bearing part (509) which is brought into contact with a lead tank (508) is provided inside a forward part (506a) of the tubular part so that the forward part of the outer sleeve is movable in the axial direction and is locked in the turning direction against an rearward inner surface of the outer sleeve, the rearward part (506b) ot the tubular body (506) is provided with a slit (510), holding pieces of a stickshaped object holder (511) are slidably inserted in said slit, a stick-shaped object (513) is held by the holding pieces, and the projection (514) which is provided on each holding (512) is engaged with the spiral groove of the tubular cap.

Description: BACKGROUND OF THE INVENTION The present invention relates to mechanical pencil in which an eraser can be drawn out from a rear end of a tubular cap by turning the tubular cap and a lead can be drawn out from a head member. The present invention relates to eraser holder of drawing-out type in which by turning of a tubular cap against a tubular body an eraser holder can be slid so that the eraser held by two holding pieces can be drawn out according to the turning direction. Furthermore, the present invention relates to mechanical pencil in which a stick-shaped object such as eraser, lead crayon, creyon pastel, chalk, rouge, eyebrow pencil lead can be drawn out of the rear end of the tubular body while lead can be drawn of the head member. The usual mechanical pencil is constructed so that an eraser can be used by removing a knock cap from an eraser holder put on a lead tank of a writing shaft and a lead can be drawn out from a head member by knocking the knock cap attached on the eraser holder when the eraser is not used. However, in the above usual instance, because the eraser cannot be drawn out, whenever the eraser was worn out, troublesome work was necessitated in which an eraser supporter was taken out from the eraser holder, the eraser supporter was opened, the eraser was drawn out to the amount of worn out eraser, and thereafter the eraser supporter was inserted in the eraser supporter and set therein by closing the eraser holder. Further, the mechanical pencil has an eraser holder in which an eraser supporter in which is an eraser is held with being pressed thereon is attachably and detatachably inserted in an eraser holding tubular part. However, in the above usual instance, whenever eraser is worn out, troublesome work was necessitated in which an eraser supporter was taken out from the eraser holding tubular part, the eraser supporter is opened, the eraser was drawn out to the amount of worn out eraser, and thereafter the eraser supporter was inserted in the eraser holding tubular part and set by closing the eraser supporter. There is known a pencil having an eraser feeding mechanism (see US-A-2 198 335) in which an eraser can be drawn out from the rear end of the pencil by turning a cap in respect to the barrel of the pencil. BRIEF SUMMARY OF THE INVENTION This invention refers to a writing tool wherein a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member is projected from the outer sleeve, a lead tank of the writing shaft has the structure that said lead tank is movable in the axial direction and can be locked in the turning direction against an inner surface of the outer sleeve, a tubular cap is provided with a tubular part which is engaged with the lead tank so as to be rotatable and able to be attached and dettached, a spiral groove is formed on an inner surface of the tubular cap, a projecting part of an eraser holder holding eraser is engaged with the spiral groove, and that said eraser holder is provided with a tubular body which is rotatable in the axial direction and can be locked in the turning direction against a rear part of the lead part. According to such a construction, because the tubular body of the eraser holder is movable in the axial direction and locked in the turning direction, turning of the tubular cap makes the eraser holder the projecting part of which is engaged with the spiral groove move along the spiral groove of the tubular cap turned in the axial direction so that the eraser can be drawn out from a rear end of the tubular cap or drawn therein according to the turning direction and it is a primary object of this invention to make disconstruction of the stick-shaped object, preferably an erase of such shape possible easily. It is a further object of this invention to provide writing tool with an eraser holder wherein an annular projection and spiral groove are provided on a tubular cap, a slit is formed in a tubular body having a retaining part which is engaged with the annular projection, a holding piece of an eraser holder is slidably inserted in the slit so that the holding piece is directed rearward, an eraser is held with the holding piece, and a projection which is provided on the holding piece is engaged with the spiral groove of the tubular cap. Because the projections provided on the holding pieces is inserted in the spiral groove of the tubular cap, turning the tubular cap against the tubular body makes the eraser holder travel in the axial direction with being guided along the slit of the tubular body in which the holding pieces is inserted so that the eraser can be drawn out and in of the tubular body according to the turning direction. It is a further object of this invention to provide writing tool wherein a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member is projected from the outer sleeve, a annular projection and spiral groove are provided on the forward inner surface and the rearward inner surface of a tubular cap, respectively, a retaining part which is engaged with said tubular projection is provided on an outer surface of a tubular body, a bearing part which is brought into contact with a lead tank is provided inside a part of the tubular part which is positioned forward of said retaining part so that the forward part is movable in the axial direction and is locked in the turning direction against the rearward inner surface of the outer sleeve, a slit is provided on the rear part of the tubular body, an eraser holder is slidably inserted in said slit. According to the invention a writing tool with a stick-shaped object holder of drawing -out type comprising a tubular cap having a spiral groove on its interior surface, a tubular body , a holding piece of a stick-shaped object holder , said holding piece being directed rearward, a stick-shaped object, preferably an eraser , held by the holding piece , said holding piece having a projection being engaged with the spiral groove of the tubular cap , said tubular body having a slit formed therein and said holding piece of said stick-shaped object holder being slidably inserted in said slit, whereby rotation of said tubular cap in respect to said tubular body extends or retracts said stick-shaped object held by the holding piece of the stick-shaped object holder, characterized in that said spiral groove on the interior surface of the tubular cap is enlarged at it's outer end and the stick-shaped object holder has at it's rear end holding pieces being formed to extend outwardly of the object so that the object can be held between the holding pieces is in that part of the spiral groove which is not enlarged, but can be separated from the object holder when said object holder with it's holding pieces is in the part of the spiral groove in which the diameter of the spiral groove is enlarged. In such a writing tool, when the tubular cap is turned, because the forward part of the tubular body is movable in the axial direction and is locked in the turning direction against the rearward part of the outer sleeve, and also because the eraser holder is slidably inserted into the slit of the rearward part of the tubular body, the eraser holder can be moved in the axial direction with being guided along the slit of the tubular body so that the eraser provided on the eraser holder can be drawn in and out of the tubular body. If the object holder has reached the part of the spiral enlarged groove, the holding pieces are expanding and give free the stick-shaped object so that this stick-shaped object can be disconstructed from the object holder easily. DRAWINGS In the drawings, Figure 1 is a vertical section showing an example of a mechanical pencil according to the invention; Figure 2 is a partial exploded perspective illustration thereof; Figure 3 is a perspective section showing the state that the stick-shaped object holder holding an eraser is inserted into a slit of a tubular body according to the invention; Figure 4 is a vertical section of the tubular cap according to the invention; and Figure 5(a) (b) shows a sectional view and a right side elevation of the stick-shaped object folder according to the invention. DETAILED DESCRIPTION An example according to the present device is ilustrated with reference to Figures 1 to 5 as under. In the drawings, numeral 502 designates a writing shaft. The writing shaft 502 comprises a chuck 521, a spring 520, a chuck ring 523, a sleeve 524 having a cushin part 524a, and a lead tank 508 connected with the chuck 521. The writing shaft 502 is provided in the outer sleeve 503 by screwing the head part of the outer sleeve 503 in the state that the head member 501 is projected out of the outer sleeve 503. Numeral 519 designates a tubular cap. A forward inner surface of the tubular cap 519 is provided with a stair 504 while a rearward inner surface is provided with a spiral groove 505. The inside diameter 505a at the rear part of the spiral groove 505 are enlarged (refer to Figure 4). Numeral 506 designates a tubular body which is inserted into the cap 519 from its rear end . On the outer surface of the tubular body 506 nearly in the center thereof, a projecting holder 515 formed by cutting is retained to the stair 504 of the tubular cap 519. Similarly a bearing part which is brought into contact with the lead tank 508 of the writing shaft 502, for example, a bearing plate 509 is provided inside a forward part 506a of the tubular body 506. A rear inner surface of the outer sleeve 503 is formed with a polygonal part 517 while an outer periphery of a forward part 506a of the tubular body 506 is formed with a polygonal part 518 which is inserted into the polygonal part 517. Accordingly, the forward part 506a of the tubular body 506 is movable in the axial direction and is locked in the turning direction against the rear part of the outer sleeve. Means for locking the forward part 506a of the tubular body 506 however so as to be movable in the axial direction does not need to restrict to means with the polygonal parts 517,518, for example means with a key groove and key. Slits 510 are formed in the corresponding parts of the rear part 506a of the tubular body 506. Into the two slits 510, two holding pieces 512 of an eraser receiver 511 are slidably inserted with being directed rearward. An eraser 513 is held between said two holding pieces 512. A projection 514 which is provided on the holding pieces 512 is inserted into the spiral groove 505 of the tubular cap 519. Numeral 525, 526 designate annular stoppers of the eraser receiver 511 formed at forward part and rearward part of the slits 510. Therefore the eraser receiver 511 can be moved in the axial direction until the eraser 511 is brought into contact with the annular stoppers 525, 526 at the forward and rear parts of the slit 510. Each holding pieces 512 of the stick-shaped object holder 511 which is slidably inserted into the two slits 510 of the tubular body is slightly curved outward as shown in Figure 5(a). The two holding pieces 512 are deformed in the large inside diameter part 505a of the rear part of the spiral groove 505 in the tubular cap 519 so that the eraser 513 can be released from the two holding pieces 512 while as the stick-shaped object holder 511 is moved forward from this state, the two holding pieces 512 are deformed inward so that the eraser 513 can be held. A method of assembling the mechanical pencil having the above construction according to the device is illustrated as under. First, as both sides of the slit 510 of the tubular body 506 are bent toward the outer side, the stickshaped object holder 511 is inserted from said slit 510 so that its both holding pieces 512 are directed toward the rearward portion and said both holding pieces 512 are slidably inserted in both slits 510. Then the eraser 513 is inserted from the rear end of the tubular body 506 so as to be held to said both holding pieces, the tubular body 506 is inserted from the rear end of the tubular cap 519 whereby the projecting pieces 515 are bent inward and go over the stair 504 of the tubular cap 519 and thereafter are retained to the stair 504. Holding of the eraser 513 with both holding pieces 512 may be carried out after the tubular body 506 is attached to the tubular cap 519. When the stick-shaped object holder 511 is located at the large inside diameter portion 505a of the rear part of the spiral groove 505 and the two holding pieces 512 are opened, the eraser 513 is inserted in the two holding pieces 512, and then as the stickshaped object holder 511 goes forward, the eraser 513 is held with the two holding pieces 512. When attachment of the tubular body 506 to the tubular cap 519 has ended, the annular stopper 526 of the tubular body 506 is brought into contact with the rear end of the tubular cap 519. It does not need to say that sizes of parts should be determined so that the above state is obtained. Thereafter, the polygonal part 518 which is provided on the outer surface of the forward part 506a of the tubular body 506 is inserted into the polygonal part 517 which is provided on the rearward inner surface, thereby the assembly of the mechanical pencil is ended. In this case, it goes without saying that said insertion is tightly done so that the tubular body 506 does not slip out of the rear portion of the outer sleeve 503. Then, function of the eraser receiver according to the device is illustrated. When the eraser 513 is not used, as shown in Figure 1, the stick-shaped object holder 511 is brought into contact with the annular stopper 525 of the forward part of the tubular body 506, and the top of the eraser 513 just coincides with the end surface of the annular stopper 526 on the rear part of the tubular body 506. Under this condition, when the tubular cap 519 is turned, because the forward part 506a of the tubular body 506 is movable in the axial direction and is locked in the turning direction against the rearward part of the outer sleeve 503, and the projection 514 which is provided on the holding piece 512 of the stick-shaped object holder 511 is inserted into the spiral groove 505 of the tubular cap 519, the stick-shaped holder 511 is moved in the axial direction with being guided along both slits 510 of the tubular body 506 in which the two holding pieces 512 is inserted so that the eraser 513 which is held by the two holding pieces 512 of the stick-shaped holder 511 can be drawn in and out of the tubular body 506 according to the turning direction . Further, when the rear end of the tubular body 506, the lead tank 508 which is brought into contact with the bearing plate 509 with the tubular cap 519 can be moved forward or rearward so that the lead 522 can be drawn out of the head member 501 against the spring 520 or the spring force by opening and shutting of the chuck 521 as the known mechanical pencil. Drawing-out of the eraser 513 can be performed by turning the tubular cap 519 to the amounts of worn out eraser whereby the eraser holder 511 can be moved to the axial direction, on the right direction as in the example shown in the drawings. After the eraser has been used, if turning of the reverse direction is performed so that the stick-shaped holder 511 is moved on the left direction, the eraser 513 can be drawn in. With the eraser 513 being consumed, the stickshaped object holder 511 is moved backward. When the two holding pieces 512 of the stickshaped holder 512 are largely deformed outward, because the inside diameter 505a is larger. Therefore the eraser 513 is released from the holding pieces so that the eraser can be easily taken out from between the two holding pieces 512. When the tubular cap 519 is turned so as to move forward the stick-shaped object holder, the projection 514 which is engaged with the spiral groove 505 leaves the large inside diameter part 505a of the rear part of the spiral groove, and thereafter the two holding pieces 512 are held by the tubular cap, thus holding the eraser 513. Further, as shown in Figures 1 and 2, the inner surface may be provided with a projection 527 which is cut into the eraser 513. In this device, as the stick-shaped object 513, lead, crayon, creyon pastel, chalk, rouge, eyebrow pencil lead and the like can be applied besides eraser. As the above-mentioned, according to the device, the stick-shaped holder 511 can be moved in the axial direction by turning the tubular cap 519 against the outer sleeve 503 and can be drawn in and out of the tubular body 506 according to the turning direction. Therefore when the stick-shaped object is used, the eraser can be drawn out to the necessary amount so that the stick-shaped object can be used while, when eraser is not used, the stick-shaped object 513 can be drawn in, thus drawing-in-and-out of the stick-shaped object 513 can be simply performed. Therefore, the usual troublesome work does not need to be carried out repeatedly. Further the numbers of parts are few, and the mechanical pencil according to the device can be produced at a low price. Further because the two holding pieces 512 are opened in case of the stick-shaped object holder 511 being located at the large inside diameter part 505a of the rear part of the spiral groove 505 which is provided in the tubular cap 519. Therefore exchange of stickshaped object can be easily performed, however without falling off of the stick-shaped objects being during using of the mechanical pencil.

Claims: Writing tool with a stick-shaped object holder of drawing -out type comprising a tubular cap (519) having a spiral groove (505) on its interior surface, a tubular body (506), a holding piece (512) of a stick-shaped object holder (511), said holding piece (512) being directed rearward, a stick-shaped object, preferably an eraser (513), held by the holding piece (512), said holding piece (512) having a projection (514) being engaged with the spiral groove (505) of the tubular cap (519), said tubular body (506) having a slit (510) formed therein and said holding piece (512) of said stick-shaped object holder (511) being slidably inserted in said slit (510), whereby rotation of said tubular cap (519) in respect to said tubular body (506) extends or retracts said stick-shaped object (513) held by the holding piece (512) of the stick-shaped object holder (511), characterized in that said spiral groove (505) on the interior surface of the tubular cap (519) is enlarged at it's outer end and the stick-shaped object holder (511) has at it's rear end holding pieces (512) being formed to extend outwardly of the object so that the object can be held between the holding pieces in that part of the spiral groove which is not enlarged, but can be separated from the object holder (511) when said object holder with it's holding pieces (512) is in the part of the spiral groove (103) in which the diameter of the spiral groove is enlarged. Writing tool as claimed in claim 1, wherein annular stopper means (525, 526) are provided on the tubular body (506) at both ends of the slit (510), respectively. Writing tool as claimed in claim 1 or 2 wherein at least one projection (527) is provided on the inner surface of each of the holding pieces (512).

Inventors: SHUHEI KAGEYAMA, TOSHIHIKO KAGEYAMA, YOSHIHIDE MITSUYA, YOUICHI NAKAZATO, SHUHEI, KAGEYAMA, TOSHIHIKO, KAGEYAMA, YOSHIHIDE, MITSUYA, YOUICHI, NAKAZATO
Applicants: KOTOBUKI & CO LTD, KOTOBUKI & CO., LTD.
Application year: 1988
Main classification: B43K29
IPC codes: A45D40, B43K29, B43K21