JP4426788B2 - Eraser and other feeding devices - Google Patents

Description

  The present invention relates to a feeding device such as an eraser which is provided on a writing instrument such as a mechanical pencil or a composite writing instrument or the like and which can feed a stick-shaped object such as an eraser.

  In a mechanical pencil or a composite writing instrument, various feeding devices such as an eraser that can feed a stick-shaped object such as an eraser or another writing instrument from the rear end of the shaft tube are used. As a feeding device using a screw pair, a cam main body in which a spiral groove is formed on the inner periphery of the rear portion of the cylindrical body, and a guide cylinder that is rotatably fitted to the cam main body and has a guide groove formed in the axial direction. And a slider provided in the guide cylinder and provided with an engaging projection for engaging with the spiral groove of the cam body, and holding a rod-like object and slidable in the axial direction along the guide groove of the guide cylinder A writing instrument is known in which a rod-like object such as an eraser can be moved in and out by rotating the guide cylinder (see, for example, Patent Document 1).

The spiral groove of the cam body is formed on the inner periphery of the cylindrical body. To mold the cylindrical body having such a spiral groove with a plastic material, a core pin having a male thread-like thread portion at the time of molding. Therefore, a motor drive mold of a type in which the core pin is extracted while being rotated after molding must be used, which necessitates a mold cost and a part cost, and the molding is troublesome and cannot be obtained economically.
JP-A-8-34196

  The problem to be solved by the present invention is that, in the feeding device such as an eraser using a screw pair as described above, a member corresponding to a female screw can be formed without using a motor drive mold, and the eraser is obtained economically. Etc. to provide a feeding device.

According to the present invention, the outer cylinder and the inner cylinder are rotatably fitted, a receiving base is provided on the inner cylinder so as to be movable in the axial direction, and an outer periphery of the receiving base is engaged with a female screw provided on the outer cylinder. In a feeding device such as an eraser for feeding a rod-like object such as an eraser provided on the pedestal when the inner cylinder or the outer cylinder is rotated, the pedestal moves on the inner surface of the outer cylinder. forming a flat portion extending in the axial direction, a small window corresponding to a part of the screw groove of the female screw on the flat surface portion is opened in the axial direction at a predetermined pitch to form a rack window, cylindrical the cradle A feeding device such as an eraser is provided , in which a male screw is provided in the portion, and the male screw is screw-engaged with the rack window portion to move the cradle in the axial direction.

  The feeding device such as the eraser of the present invention does not form a female screw on the inner surface of the outer cylinder as in the prior art, so it is easy to mold and can be manufactured with a normal mold and core pin without using a motor drive mold. Therefore, it is possible to reduce the die cost and the part cost, and it can be obtained economically.

  The drawing shows a composite writing instrument having a plurality of refills equipped with an eraser feeding device according to the present invention, but the present invention is a writing instrument having a single refill such as a mechanical pencil, a writing instrument other than an eraser, and other appropriate tools. The present invention can also be applied to an article in which a rod-shaped object is fed out.

  Referring to FIGS. 1 and 2, the writing instrument body (1) includes a grip part (4) having a hole (3) for projecting the writing tip of the refill (2), and a rear end of the grip part (4). And an upper main body (6) connected to the rear of the inner main body (5), and an eraser unit (7) is provided in the upper main body (6). Is provided.

  Refills (2) such as a ballpoint pen refill, mechanical pencil refill, refill type stylus (input pen), etc. are inserted into the middle main body (5) through a guide groove (9) provided in the partition wall (8). A slide piece (10) is connected to each rear end, and each slide piece (10) is fixed in a circumferential position by a partition rib (11) formed on the inner surface of the middle body so as to be fitted between adjacent slide pieces. (See FIGS. 3 and 4). Further, a spring (12) for urging the slide piece (10) rearward is provided between the partition wall (8) and the slide piece (10), and a cam of the slide piece (10) is known as is well known. The slide piece (10) is selectively advanced by the cam portion (14) of the actuating cam (13) in contact with (not shown) so that the writing tip of the desired refill is passed through the hole (3) of the grip portion (4). It can be infested. A screw (15) for connecting the grip part (4) is formed at the front part of the middle body (5), and a front cylindrical part (17) of an outer cylinder (16) described later is formed at the rear part. ) Are formed in the circumferential direction. A knock actuating rib (20) extending in the axial direction is formed in a part of the intermediate step part (19). It is configured to be able to.

  As shown in FIG. 6, the upper body (6) has an anti-rotation rib (21) in the axial direction of the inner surface, and a fixing rib (22) in the circumferential direction is formed at the rear, and the outer surface is formed on the outer surface. A clip (23) is provided. The eraser unit (7) provided in the upper body (6) includes an outer cylinder (16), an inner cylinder (24) rotatably inserted into the outer cylinder (16), and the inner cylinder (24 ) Includes a cradle (25) incorporated so as to be movable in the axial direction.

The the outer tube (16), as shown in FIGS. 7 to 10, the planar portion (26) extending in the axial direction in a part of the circular inner peripheral surface, Ru Oh provided opposite state (26). The flat window portions (26) and (26) have rack window portions (28) by opening small windows (27) corresponding to a part of the thread groove of the female screw at a predetermined pitch in the axial direction. Is formed. Core pin such small windows (27) ... are, to a projection corresponding to said small window is formed on the inner surface of the mold during plastic molding, forming the inner peripheral surface of the outer tube of the outer tube to the tip of該Tokki If the outer cylinder is molded in contact with the outer surface, it can be easily molded with a normal mold (not shown). Note that three or more plane portions may be provided, and three or more rack window portions may be formed.

  A retaining rib (29) for retaining the inner cylinder (24) is provided behind the inner surface of the outer cylinder (16), and the inner cylinder (30) formed on the front inner surface is provided with the inner cylinder. A guide cylinder (31) and an annular groove (32) for guiding the rotation of (24) are provided, and a protrusion (33) engaging with a fixing rib (22) of the upper body (6) on the outer surface, A long groove (34) that fits into the rotation-preventing rib (21) is provided.

  An operating cam (13) is formed in front of the inner wall (30) of the outer cylinder (16), and has an outer diameter substantially inscribed in the upper body (6) so as to surround the operating cam (13). The front cylindrical portion (17) is provided, but in the case of a normal mechanical pencil or the like that is not a composite writing instrument, it is not necessary to provide an operating cam. The front cylindrical portion (17) is provided with a locking claw (35) that engages with a locking portion (18) provided in the middle main body (5). The locking claw (35) is formed by forming a flat portion on a part of the inner peripheral surface of the front cylindrical portion (17) and providing a margin by opening a window hole (36) in the flat portion. Is formed. Further, when the cam portion (14) of the operating cam (13) advances the mechanical pencil refill, a knock operating groove (opening forward) facing the knock operating rib (20) of the middle main body (5) ( 37) is formed, and in this state, the knocking operation of the operating cam is allowed and the lead can be fed out.

  As shown in FIGS. 11 to 13, the inner cylinder (24) has a knob part (38) at the rear part, and a side frame piece (40) having a semicircular arc cross section facing with a gap (39). (40) extends in the axial direction. Between the knob portion (38) and the side frame piece (40) is provided an annular groove (41) that rotatably engages the retaining rib (29) of the outer cylinder (16), When the inner cylinder (24) is connected to the outer cylinder (16), the ends of the side frame pieces (40), (40) are inserted into the annular groove (32) of the outer cylinder (16), and the guide cylinder (31 ) Is slidably contacted with the outer periphery. The knob portion (38) is formed with a lateral groove (42) communicating with the gap (39).

  As shown in FIGS. 14 to 16, the cradle (25) has a cylindrical portion (43) having an outer diameter substantially inscribed in the outer cylinder (16), and the cylindrical portion (43) includes A male screw (44) that engages with the rack window (28) is formed. The male screw (44) has an appropriately shaped thread, pitch, and the like so as to be combined with a screw groove corresponding to the female screw formed by the rack window portion, and the single screw is always engaged with the male screw and the rack window portion. In the case of a screw, it is provided on the entire circumference with a length of at least one pitch or with multiple threads.

  On one side of the cylindrical portion (43) of the cradle (25), a pressing piece (46) that supports a rod-shaped object such as an eraser (45) is formed in an opposing state, and the pressing piece (46) The inner cylinder (24) has a width that can be inserted into the gap (39) between the side frame pieces (40), (40). Further, insertion holes (48), (48) for allowing the side frame piece (40) to pass therethrough are formed in the bottom portion (47) of the cylindrical portion (43).

  Referring to FIG. 17, in order to assemble the eraser unit, the outer cylinder (16) is inserted from the front of the upper main body (6), and the outer cylinder is assembled in the upper main body (6) in a non-rotating state. Next, after inserting into the outer cylinder while rotating the cradle (25) from the rear, the side frame pieces (40), (40) of the inner cylinder (24) are pushed into the insertion hole (48) while being inserted, The inner cylinder (24) is rotatably connected to the outer cylinder (16). Then, an eraser (45) or other appropriate rod-shaped object may be inserted into the inner cylinder (24) and clamped by the pressing pieces (46), (46) of the cradle (25).

  The eraser unit assembled as described above is configured as shown in FIG. 18 in the case of a composite writing instrument, and as shown in FIG. 19 in the case of a writing instrument such as a mechanical pencil. 18 and 19, the outer cylinder (16) and the inner cylinder (24) are provided with a locking claw (49) at the tip of the side frame piece (40) of the inner cylinder (24). (49) is retained by engaging the inner wall (30), thereby omitting the retaining rib (29) and the annular groove (41).

  When the cradle (25) is incorporated into the outer cylinder (16) as described above, the male screw (44) provided on the cradle (25) is opened inward in the rack window (28) as shown in FIG. Since the edge (50) is threaded and engaged with this, by rotating the inner cylinder (24), the cradle (25) moves in the axial direction, and the eraser (45) moves from the rear end of the writing instrument body. Infested.

Sectional drawing which shows one Example of this invention. The principal part enlarged view which cuts FIG. 1 in the AA line. Sectional drawing of a main body. The top view of an inside main part. FIG. Sectional drawing of an upper main body. Sectional drawing of an outer cylinder. The front view of an outer cylinder. The right view of an outer cylinder. The left view of an outer cylinder. The top view of an inner cylinder. The half sectional view of the inner cylinder. The right view of an inner cylinder. The top view of a receiving stand. The front view of the cradle which cut down a part . The right view of a cradle. Explanatory drawing which shows an assembly state. The partially cutaway perspective view of an eraser unit. The partial notch perspective view of the other Example of an eraser unit. The expanded sectional view of a rack window part part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Writing instrument main body 2 Refill 4 Grip part 5 Middle main body 6 Upper main body 7 Eraser unit 10 Slide piece 13 Actuating cam 16 Outer cylinder 24 Inner cylinder 25 Receptacle 26 Plane part 27 Small window 28 Rack window part 38 Knob part 40 Side frame piece 43 Cylindrical part 44 Male thread 45 Eraser

Claims (4)

An outer cylinder and an inner cylinder are rotatably inserted, a receiving base is provided on the inner cylinder so as to be movable in the axial direction, an outer periphery of the receiving base is engaged with a female screw provided on the outer cylinder, and the inner cylinder or the outer cylinder is engaged. A flat portion extending in the axial direction on the inner surface of the outer cylinder in a feeding device such as an eraser that feeds a rod-like object such as an eraser provided on the cradle by moving the cradle in the axial direction when the cylinder is rotated. is formed and a small window corresponding to a part of the screw groove of the female screw on the flat surface portion is opened in the axial direction at a predetermined pitch to form a rack window, a male screw is provided in the cylindrical portion of the receiving table, A feeding device such as an eraser, wherein the male screw is screw-engaged with the rack window portion to move the cradle in the axial direction.   The delivery device for an eraser or the like according to claim 1, wherein the rack window portion is provided in an opposing state.   The side frame piece formed on the inner cylinder extends in the axial direction through the bottom of the cradle, and the inner end of the side frame piece is rotatable to the outer periphery of the guide cylinder formed in the outer cylinder. The feeding device such as an eraser according to claim 1 or 2, which is supported. The said outer cylinder has an operation cam, The writing tip was made to protrude and retract from the front-end | tip of a writing instrument main body by moving the slide piece provided in the rear end of several refills to an axial direction with this operation cam. 3. A feeding device such as an eraser according to any one of 3 above.

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