Eraser case

Abstract

An eraser case 100, wherein a cylindrical container 120 accommodates an eraser 160 having a cylindrical hole 162 in a manner that allows the eraser 160 to be deposited and retrieved. A draw-out base 140 is capable of sliding in the axial direction inside the cylindrical container 120, and the tip end of the eraser 160 accommodated in the cylindrical container 120 is secured. A screw shaft 130 can be inserted into the cylindrical hole 162 in the eraser 160, and inserting the screw shaft 130 into a screw hole formed through the draw-out base 140 and screwing the shaft 130 into the screw hole enables the shaft-rotating motion to be converted to axial motion of the draw-out base 140, allowing the draw-out base 140 to be pushed out. The draw-out base 140 has a protruding locking part 144 that protrudes in the direction of the eraser 160. The protruding locking part 144 locks into a recessed locking part provided in the inner wall surface of the cylindrical hole 162 in the eraser 160, thereby securing the eraser 160 to the draw-out base 140.

Description

Technical Field

[0001] The present invention relates to a storage device for erasers.

Background Art

[0002] Conventionally, as a device that can feed out a rod-shaped solid paste from a container for use, a rod-shaped solid paste feeding container that feeds out the solid paste by rotating a tail plug attached to the lower end of a cylindrical body is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique described in Patent Document 1, it is necessary to screw the end portion of the rod-shaped solid paste into a spiral rib provided on the inner peripheral surface of the cylindrical slider. Therefore, the end portion of the rod-shaped solid paste screwed into the slider is covered by the slider and does not protrude, making it difficult to use the rod-shaped solid paste until the end. When considering applying a technique such as that described in Patent Document 1 to the storage of solid objects such as erasers, it is assumed that it will be as difficult to use the eraser until the end as the rod-shaped solid paste.

[0005] The present invention has been made in view of such circumstances, and an object thereof is to provide an eraser case that facilitates the use of an eraser.

Means for Solving the Problems

[0006] In order to solve the above problems, an eraser case according to an aspect of the present invention includes a cylindrical container in which an eraser having a cylindrical hole is accommodated so as to be insertable and removable from an opening at the tip, and a feeding base that is slidable in the axial direction inside the cylindrical container and to which the end portion of the eraser accommodated in the cylindrical container is fixed, and a screw shaft body that is insertable into the cylindrical hole portion of the eraser and is inserted into and screwed into a screw hole penetrating the feeding base to convert the axial rotational movement into the axial movement of the feeding base so that the feeding base can be pushed out. The feeding base has a convex locking portion that projects in the direction of the eraser and locks to a concave locking portion provided on the inner wall surface of the cylindrical hole portion of the eraser to fix the eraser to the feeding base.

[0007] The convex locking portion of the feeding base may have a snap fit shape that projects upward from the upper surface of the base body. The concave locking portion may have a concave shape that fits the convex shape of the convex locking portion. According to this aspect, by locking the convex locking portion to the concave locking portion, the eraser can be fixed in a state of being placed on the upper surface of the base body of the feeding base. In that case, since the end portion of the eraser can be exposed without being hidden by the feeding base, it is easy to use the eraser up to near the end, and waste can be reduced.

[0008] The inner wall surface of the cylindrical container and the outer peripheral surface of the feeding base may each have a shape other than a perfect circle in the axial cross section, for example, a polygonal shape having a plurality of vertices such as a hexagon, a rectangle, a square, or an elliptical shape. According to this aspect, when the screw shaft body is rotated, it is possible to prevent the eraser from rotating axially together with the screw shaft body inside the cylindrical container and hindering the axial movement of the eraser.

[0009] The screw shaft body has a screw shaft portion provided with a spiral thread on at least a part of the outer peripheral portion that can be screwed into the screw hole of the feeding base, and on the screw shaft portion, at least one of the vicinity of the tip and the vicinity of the end in the axial direction has a free rotation section that does not screw into the screw hole, and a thread section that can screw into the screw hole other than the free rotation section, may be provided on the outer peripheral portion. The outer peripheral portion of the screw shaft portion may have, in the axial direction, a first thread section provided on a part of the vicinity of the tip, a free rotation section that does not screw into the screw hole provided in the vicinity of the tip excluding the first thread section, and a second thread section provided on a portion excluding the first thread section and the free rotation section. The axial length of the free rotation section may be equal to or greater than the axial length of the screw hole of the feeding base. According to this aspect, due to the free rotation of the screw shaft portion, it is possible to prevent the feeding base from being overfed and falling off from the cylindrical container, or the feeding base from being overfed and damaging other members on the inner bottom of the cylindrical container.

[0010] The cylindrical container may have a bottomed and lidless shape. The feeding base may be configured such that when the screw shaft body is rotated in the storage direction, it can contact other members on the inner bottom of the cylindrical container, and an elastic mechanism may be provided at the contact portion. Due to the deformation of the elastic mechanism, the section of the screw hole of the feeding base and the free rotation section may overlap. The feeding base may be provided with an elastic mechanism that partially protrudes in the direction of the inner wall surface of the cylindrical container and can contact the inner wall surface. According to this aspect, due to the deformation of the elastic mechanism, the feeding base is pressed against the inner wall surface of the cylindrical container, making it difficult for play to occur and preventing the generation of unnecessary abnormal noises. Also, when rotating the screw shaft body in the free rotation section, the repulsive elasticity of the elastic mechanism biases the feeding base located on the inner bottom of the cylindrical container upward and moves it to the second thread section, thereby releasing the free rotation.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide an eraser case that facilitates the use of an eraser.

Brief Description of the Drawings

[0012]

Figure 1

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Mode for Carrying Out the Invention

[0013] (First Embodiment) FIG. 1 shows the appearance of an eraser case according to the first embodiment. The eraser case 100 mainly includes a cylindrical container 120, a screw shaft body (not shown in this figure), and a rotation operation body 150. The cylindrical container 120 is a bottomed and lidless cylindrical resin member having an axially cross-sectional shape of a rounded flat hexagon with a large radius of curvature. The eraser 160 has a hexagonal prism shape with an axially cross-sectional shape of a rounded flat hexagon with a small radius of curvature, and a cylindrical hole portion 162 penetrating the central axis is formed. The outer diameter of the eraser 160 is slightly smaller than the inner diameter of the cylindrical container 120, and the eraser 160 can be housed in the cylindrical container 120 while leaving a minute gap around the eraser 160. The screw shaft body is a resin member having a screw shaft portion not shown in FIG. 1, and the screw shaft portion is inserted into the cylindrical hole portion 162 of the eraser 160 housed in the cylindrical container 120 and a hole portion provided at the bottom of the cylindrical container 120. The rotation operation body 150 is attached to the end of the screw shaft body. By rotating the rotation operation body 150 in a predetermined direction, for example, clockwise, the eraser 160 is fed out from the cylindrical container 120, and by rotating the rotation operation body 150 in the reverse direction, for example, counterclockwise, the eraser 160 is fed into the cylindrical container 120. The cylindrical container 120 has a concave shape such that the lateral edge end portion of the tip is shaved off toward the end side, and sufficiently exposes the corner portion of the eraser 160 exposed from the tip opening of the cylindrical container 120 and its periphery. Thereby, it is possible to prevent the cylindrical container 120 from interfering with the operation of applying the corner of the eraser 160 to paper to erase characters and the like.

[0014] Figure 2 shows the configuration of the eraser case 100 and the eraser 160. The cylindrical hole portion 162 of the eraser 160 is a cylindrical hole that penetrates the central axis. Note that since the opening itself on the tip side of the cylindrical hole portion 162 of the eraser 160 does not have any particular function or role, as a modification example, the cylindrical hole portion 162 extends near the tip of the eraser 160 but does not completely penetrate the tip, that is, it may have a configuration with an opening only on the end side. However, by adopting a configuration in which the cylindrical hole portion 162 penetrates to the tip side, the cross-sectional shape of the eraser 160 can be made constant from the tip to the end, and it can be manufactured by extrusion molding or injection molding, thus simplifying the manufacturing process.

[0015] The feeding base 140 is a resin member having a base body 142 in the shape of a hexagonal prism with at least a part of its cross-sectional shape being generally a rounded flat hexagonal shape, and a convex locking portion 144 protruding upward from the center of the upper surface of the base body 142. The convex locking portion 144 has a shape of an annular snap fit folded back like an umbrella at the tip, that is, a claw is provided that is folded back in a tapered inclined shape around the tip of the protrusion, and the folded-back end portion is formed at about 90 degrees. When the convex locking portion 144 is press-fitted into the cylindrical hole portion 162 of the eraser 160, the folded-back end portion is locked to a concave locking portion (details will be described later) near the end of the cylindrical hole portion 162 and is fixed. A cylindrical base hole portion 146 that penetrates the base body 142 and the convex locking portion 144 is formed at the center of the base body 142. The base hole portion 146 is a threaded hole with a threaded groove formed spirally on its inner wall. The outer diameter of the base body 142 is slightly smaller than the inner diameter of the cylindrical container 120, and the base body 142 is slidable in the axial direction inside the cylindrical container 120.

[0016] The cylindrical container 120 has a concave shape at the periphery of the tip opening, where the side edge portion 123 corresponding to the short side is shaved off toward the end side with respect to the tip edge portion 121 corresponding to the long side of the six sides of the rounded flat hexagon. The concave shape of the side edge portion 123 sufficiently exposes the corner portion of the eraser 160 exposed from the tip opening of the cylindrical container 120 and its periphery. Thereby, it is possible to prevent the side edge portion 123 from interfering with the operation of pressing the corner of the eraser 160 against the paper to erase characters or the like. A bottom hole portion 126 is provided at the center of the bottom portion 124 inside the cylindrical container 120.

[0017] The screw shaft body 130 includes a screw shaft portion 132 which is a rod-shaped member having a spiral thread formed on the outer peripheral portion, a pair of protruding pieces 133 and a pair of latching pieces 137 protruding in the end direction of the screw shaft body 130, and a disc portion 136 provided at the base of the screw shaft portion 132. The shaft diameter of the screw shaft portion 132 is smaller than the inner diameter of the cylindrical hole portion 162 of the eraser 160 such that the outer peripheral portion of the screw shaft portion 132 does not contact the inner wall surface of the cylindrical hole portion 162 when the screw shaft portion 132 is inserted through the cylindrical hole portion 162 of the eraser 160. Also, the shaft diameter of the screw shaft portion 132 is smaller than the inner diameter of the pedestal hole portion 146 of the feeding pedestal 140 such that it can be screwed into the pedestal hole portion 146.

[0018] A rotation operation body 150 is attached to the pair of protruding pieces 133 and the pair of latching pieces 137. The rotation operation body 150 is attached to the end side of the screw shaft portion 132 and functions as a screw head. The pair of latching pieces 137 have a snap fit shape and are press-fitted into the bottom hole portion 126 which is narrower than the maximum width portion of the pair of latching pieces 137 while being deformed, and are fitted together with the protruding pieces 133 into the cross-shaped mounting hole portion 152 of the rotation operation body 150. The rotation operation body 150 is a resin member having a rounded flat hexagon with a large radius of curvature in at least a part of the axial cross-sectional shape, similar to the cylindrical container 120.

[0019] The disk portion 136 is provided between the screw shaft portion 132, the protruding piece 133, and the latching piece 137, and has a disk shape with an outer diameter wider than the shaft diameters of the screw shaft portion 132 and the protruding piece 133. The lower end of the feeding base 140 fed in the storage direction can abut on the upper surface of the disk portion 136. That is, the disk portion 136 has a function of a stopper that stops the feeding base 140 fed in the storage direction at its lowermost position. Since the outer diameter of the disk portion 136 is larger than the hole diameter of the bottom hole portion 126 of the cylindrical container 120, it does not pass through the bottom hole portion 126, and the lower surface of the disk portion 136 abuts on the bottom portion 124. In this way, the disk portion 136 and the rotation operation body 150 sandwich the bottom portion 124 of the cylindrical container 120, and the rotation operation body 150 is attached to the screw shaft portion 132, and the rotation operation body 150 becomes integral with the screw shaft body 130. The user grips the periphery of the rotation operation body 150 and rotates it clockwise to unwind the eraser 160, or rotates it counterclockwise to wind the eraser 160 into the cylindrical container 120.

[0020] Figure 3 shows the structure of the screw shaft body 130. The screw shaft body 130 has a pair of protruding pieces 133 and a pair of latching pieces 137 that protrude in the terminal direction on the terminal side. A disk portion 136 is provided between the screw shaft portion 132, the protruding piece 133, and the latching piece 137. The pair of protruding pieces 133 are provided at positions facing each other around the axis of the screw shaft body 130. The pair of latching pieces 137 are also provided at positions facing each other around the axis of the screw shaft body 130. The protruding piece 133 and the latching piece 137 are alternately provided at positions every 90 degrees so as to be adjacent to each other along the lower surface arc of the disk portion 136.

[0021] The screw shaft portion 132 is divided into a first threaded section 170, a first free rotation section 171, a second threaded section 172, and a second free rotation section 173. In the first threaded section 170 located near the tip of the screw shaft portion 132, threads 134 are formed only in a short section corresponding to about one turn on the outer peripheral portion of the screw shaft portion 132. In the first free rotation section 171 adjacent to the end side of the first threaded section 170, threads are not provided in a section corresponding to about two turns of the threads and do not engage with the threaded hole. In the second threaded section 172 adjacent to the end side of the first free rotation section 171, threads 134 are formed for about seven turns. In the second free rotation section 173 adjacent to the end side of the second threaded section 172, threads are not provided in a section corresponding to about two turns of the threads and do not engage with the threaded hole. Thus, when the screw shaft portion 132 is screwed into the pedestal hole portion 146 of the feed pedestal 140, the feed pedestal 140 can be moved up and down when the first threaded section 170 or the second threaded section 172 engages with the thread groove of the pedestal hole portion 146. However, when the feed pedestal 140 reaches the first free rotation section 171 or the second free rotation section 173, it rotates freely because it does not engage with the pedestal hole portion 146.

[0022] FIG. 4 shows a state in which the eraser 160 and the feed pedestal 140 are extended to the tip of the screw shaft body 130. In this figure, for convenience, an example is shown in which the cylindrical container 120 and the rotation operation body 150 are formed of a translucent resin member, and the eraser 160, the feed pedestal 140, and the screw shaft body 130 can be visually recognized through the cylindrical container 120 and the rotation operation body 150.

[0023] When the user rotates the rotation operation body 150 of the screw shaft body 130, the axial rotation motion of the screw shaft body 130 is converted into the axial motion of the feed base 140, that is, linear motion, by the screwing of the screw shaft portion 132 and the feed base 140. For example, when the rotation operation body 150 is rotated counterclockwise, the eraser 160 and the feed base 140 are fed into the bottom direction of the accommodating portion 122 and stored. When the rotation operation body 150 is rotated clockwise, the eraser 160 and the feed base 140 are fed out toward the front end opening of the accommodating portion 122. As the eraser 160 and the feed base 140 are fed out, the tip of the eraser 160 is pushed out and exposed to the outside of the cylindrical container 120. When the rotation operation body 150 is rotated once, the eraser 160 moves up and down by about 3.0 mm, and the exposure amount of the eraser 160 to the outside can be freely adjusted according to the rotation amount of the rotation operation body 150. When the use of the eraser 160 progresses and it wears down and becomes shorter, the tip of the eraser 160 can be exposed to the outside of the cylindrical container 120 by rotating the rotation operation body 150 clockwise by the amount of shortening.

[0024] The eraser 160 in this figure is already worn down by use and is in a state where its overall length has become shorter. To use the eraser 160 until its overall length becomes short like this, that is, until near the contact point between the eraser 160 and the feeding base 140, it is necessary to expose the entire part up to the end portion of the eraser 160 outside the cylindrical container 120. In this regard, since the screw shaft portion 132 of the screw shaft body 130 is long so that its tip extends near the tip opening of the cylindrical container 120, the feeding base 140 can be fed upward near the tip opening of the cylindrical container 120. Also, since the eraser 160 is fixed in such a way that the entire eraser 160 is exposed so as to be placed on the upper surface of the feeding base 140, if the feeding base 140 is fed near the tip opening of the cylindrical container 120, the entire part up to near the end of the eraser 160 can be exposed outside the cylindrical container 120. As a result, the end of the eraser 160 is not hidden by the cylindrical container 120 or the feeding base 140, the eraser 160 can be used until the very end, and the eraser 160 can be used without waste. Also, when the eraser becomes too large to be comfortably picked up with a finger for normal use, it becomes difficult to use. However, if the eraser case 100 of this embodiment is used, even if it becomes extremely large, the eraser can be used. In this sense, the eraser can be easily used until the end and can be used without waste.

[0025] When the rotation operation body 150 is rotated clockwise to feed out the eraser 160 and the feeding base 140 to the maximum extent to the tip of the screw shaft body 130, the feeding base 140 reaches the first free rotation section 171 and is in the state as shown in the figure. As shown in the figure, when the positions of the first free rotation section 171 and the screw groove 145 of the base hole portion 146 overlap, the screwing state between the screw shaft body 130 and the screw groove 145 is released and the screw shaft body 130 rotates freely. Due to the free rotation of the screw shaft body 130, even if the rotation operation body 150 is further rotated clockwise, the feeding base 140 and the eraser 160 are no longer fed out, and it is possible to prevent the feeding base 140 from falling off the cylindrical container 120 due to excessive feeding out.

[0026] The length of the first idling section 171 is equal to or greater than the axial length of the internal thread section where the thread groove 145 is provided on the inner wall surface of the pedestal hole section 146. Even if the eraser 160 is pulled up in the state shown in the figure, since the thread groove 145 of the pedestal hole section 146 catches on the first thread mountain section 170 of the screw shaft body 130, the extended pedestal 140 does not easily fall off. By providing the first thread mountain section 170 near the tip of the screw shaft portion 132 in this way and having the thread crest 134 of the first thread mountain section 170 catch on the thread groove 145 of the pedestal hole section 146, it is possible to prevent the extended pedestal 140 from easily coming off the screw shaft body 130. That is, when removing the eraser 160 from the extended pedestal 140 that has been extended to the maximum extent, it is possible to prevent the extended pedestal 140 from coming off the screw shaft body 130 and falling off together with the eraser 160.

[0027] After removing the used eraser 160 from the extended pedestal 140, when the rotation operation body 150 is rotated clockwise while pinching and pulling the convex locking portion 144, the first thread mountain section 170 starts to engage with the thread groove 145 of the pedestal hole section 146 and the extended pedestal 140 is extended again, so it is possible to remove the extended pedestal 140 from the screw shaft body 130. Also, by providing the first thread mountain section 170, which is a short-section thread on the thread shaft, near the tip of the screw shaft portion 132, in the component assembly of the eraser case 100, the extended pedestal 140 can be easily inserted into the inside of the cylindrical container 120 by simply screwing the extended pedestal 140 onto the tip of the screw shaft body 130 and rotating it slightly.

[0028] Figure 5 is a perspective view of the extended pedestal 140 seen from obliquely below. On the upper surface of the pedestal main body 142 of the extended pedestal 140, a convex locking portion 144 is provided, and on the side surface of the pedestal main body 142, two pairs of elastic mechanisms 147 are provided. The elastic mechanism 147 is provided so that a part thereof protrudes in the direction of the inner wall surface of the cylindrical container 120 and can come into contact with the inner wall surface. Also, the elastic mechanism 147 is provided at a portion that can come into contact with other members at the inner bottom of the cylindrical container 120 when the screw shaft portion 132 is rotated in the housing direction. The elastic mechanism 147 is composed of an L-shaped protruding piece 148 that bends at a right angle from the lower end of the line connecting the upper and lower corners of the pedestal main body 142 and extends to the center of the side portion and a tip bulging portion 149 at its tip.

[0029] On one side of the pedestal body 142, a first elastic mechanism 147a composed of a first L-shaped protruding piece 148a and a first tip bulging portion 149a, and a second elastic mechanism 147b composed of a second L-shaped protruding piece 148b and a second tip bulging portion 149b constitute a pair of elastic mechanisms. The first L-shaped protruding piece 148a and the second L-shaped protruding piece 148b extend in directions facing each other. On the opposite side of the pedestal body 142, a third elastic mechanism 147c composed of a third L-shaped protruding piece 148c and a third tip bulging portion 149c, and a fourth elastic mechanism 147d composed of a fourth L-shaped protruding piece 148d and a fourth tip bulging portion 149d constitute another pair of elastic mechanisms. The third L-shaped protruding piece 148c and the fourth L-shaped protruding piece 148d extend in directions facing each other.

[0030] Each of the L-shaped protruding pieces 148a - d is a resin piece having flexibility and resilient elasticity, and can be bent by pressing deformation in the vertical and horizontal directions, and exhibit a repulsive force against the pressing deformation. Each of the tip bulging portions 149a - d has a shape bulging in the outer direction OD and the lower direction DD from the side surface of the pedestal body 142, and protrudes outward in the outer direction OD and the lower direction DD from the outer contour line of the pedestal body 142 by the amount of the bulge. When the protruding portion of the tip bulging portion 149 is pressed against another member, the L-shaped protruding piece 148 bends to generate a repulsive force.

[0031] Figure 6 is a cross-sectional view of the feeding pedestal 140. The upper part of the figure shows a cross-section of the feeding pedestal 140 in a state where the convex locking portion 144 is fitted into the cylindrical hole portion 162 of the eraser 160. The lower part of the figure shows a cross-section in a state where the feeding pedestal 140 and the eraser 160 are attached to the tip of the screw shaft body 130 inside the cylindrical container 120.

[0032] As shown in the upper part of the figure, the convex locking portion 144 of the feeding pedestal 140 has the shape of an annular snap fit that protrudes upward from the pedestal body 142 in a cylindrical shape. That is, the outer diameter of the convex locking portion 144 from the base to the end (near the contact point with the pedestal body 142) is slightly smaller than the inner diameter of the cylindrical hole portion 162 of the eraser 160. Further, the outer diameter near the axial center of the convex locking portion 144 rises radially so as to bulge substantially perpendicularly from the outer diameter of the base to the end, and has a folded-back shape like an umbrella that tapers conically in the tip direction from there. The pedestal hole portion 146 that penetrates the centers of the pedestal body 142 and the convex locking portion 144 is a threaded hole in which a thread groove 145 is formed spirally on its inner wall, and its inner diameter is slightly larger than the outer diameter of the threaded shaft portion 132 and is sized such that the threaded shaft portion 132 can be screwed in.

[0033] The cylindrical hole portion 162 of the eraser 160 is formed with a concave locking portion 164 having a shape into which the convex locking portion 144 can be fitted near the end of its inner wall surface. That is, the end side of the concave locking portion 164 is recessed slightly vertically or in the radial direction so that the hole diameter of the cylindrical hole portion 162 is maximized at the position of the concave locking portion 164, and the hole diameter of the cylindrical hole portion 162 decreases toward the tip side. The hole diameter of the cylindrical hole portion 162 is slightly larger than the outer diameter of the root to the end of the convex locking portion 144 at portions other than the convex locking portion 144. Also, the portion of the convex locking portion 144 having the maximum outer diameter is larger than the hole diameter of the portion other than the concave locking portion 164 in the cylindrical hole portion 162. Therefore, when the convex locking portion 144 is inserted into the cylindrical hole portion 162, the convex locking portion 144 can be press-fitted into the cylindrical hole portion 162 due to the deflection of the concave locking portion 164 and the elastic deformation of the eraser 160. When the tip of the convex locking portion 144 reaches the concave locking portion 164, the large-diameter portion of the convex locking portion 144 expands in the radial direction and is fitted in a locked manner to the concave locking portion 164. In this state, even if an attempt is made to pull out the feeding base 140 or the convex locking portion 144 in the end direction, the large-diameter portion of the convex locking portion 144 is locked in the recess of the concave locking portion 164 and cannot be easily pulled out. Thereby, the eraser 160 can be stably fixed to the feeding base 140. Note that since the eraser 160 has a higher hardness than rod-shaped objects such as solid paste, lipstick, and lip cream, the convex locking portion 144 is firmly locked to the concave locking portion 164, and there is a low possibility that the portion of the concave locking portion 164 will collapse and the convex locking portion 144 will separate when the eraser is used with normal strength.

[0034] When using the eraser 160 housed in the eraser case 100, that is, when performing the operation of erasing the characters written with a pencil or the like with the eraser 160, the user applies a certain amount of strong force necessary to erase the characters by the friction of the eraser 160 to the eraser 160. Therefore, the eraser 160 needs to be firmly fixed to the feeding base 140 so that the eraser 160 does not easily come off from the feeding base 140. In this regard, the convex locking portion 144 of the feeding base 140 is shaped to fit into the concave locking portion 164 of the eraser 160 and the convex locking portion 144 locks into the concave locking portion 164, so that the eraser 160 does not easily come off from the feeding base 140 even if the user applies a certain amount of strong force to the eraser 160.

[0035] The feeding base 140 and the eraser 160 fixed to the feeding base 140 are housed in the housing portion 122 formed inside the cylindrical container 120 by screwing the feeding base 140 onto the screw shaft portion 132 as shown in the lower part of the figure. The outer diameter of the eraser 160 is slightly smaller than the inner diameter of the housing portion 122, and is small enough to be movable axially within the housing portion 122 while leaving a minute gap around the eraser 160. The hole diameter of the cylindrical hole portion 162 of the eraser 160 is sufficiently larger than the shaft diameter of the screw shaft portion 132.

[0036] As shown in the upper part of the figure, the outer diameter of the base body 142 of the feeding base 140 is slightly smaller than the inner diameter of the cylindrical container 120, and is an outer diameter such that the feeding base 140 can slide axially inside the cylindrical container 120. However, the tip bulging portion 149 of the elastic mechanism 147 protrudes beyond the outer contour line of the base body 142 and also protrudes beyond the extension line 180 from the inner wall surface of the cylindrical container 120 shown in the lower part described later. As shown in the enlarged view 181 of the enlarged tip bulging portion 149, the tip bulging portion 149 protrudes by an amount D1 more than the extension line 180 from the inner wall surface of the cylindrical container 120. The amount of protrusion D1 is, for example, 0.5 mm.

[0037] As shown in the lower part of the figure, when the feeding base 140 is housed in the cylindrical container 120, the tip bulging part 149 of the elastic mechanism 147 abuts against the inner wall surface of the cylindrical container 120, and the L-shaped protruding piece 148 is pressed inward in the ID direction by the amount of bulging D1 and is in a deflected state. In this state, the tip bulging part 149 is pressed against the inner wall surface of the cylindrical container 120 by the repulsive elasticity of the L-shaped protruding piece 148. In the state of the figure, all the thread grooves 145 of the pedestal hole part 146 are located in the first free rotation section 171 of the screw shaft part 132, do not engage with any thread crests 134, and are in a state of free rotation even when the rotation operation body 150 is rotated clockwise. Here, since the tip bulging part 149 is pressed against the inner wall surface of the cylindrical container 120, it is possible to prevent the generation of unnecessary abnormal noise due to play occurring inside the cylindrical container 120 between the feeding base 140 even though the thread crest 134 and the thread groove 145 are not engaged.

[0038] Figure 7 shows the positional relationship when the feeding base 140 is located on the end side of the screw shaft part 132. In this figure, for the sake of clarity of the positional relationship between the feeding base 140 and the screw shaft part 132, for convenience, the eraser 160, the cylindrical container 120, and the rotation operation body 150 are simplified and shown by dashed lines.

[0039] The left side of the figure shows a state where the rotation operation body 150 is rotated counterclockwise to house the eraser 160 and the feeding base 140 in the cylindrical container 120, and the tip bulging part 149 of the elastic mechanism 147 abuts against the disc part 136 of the screw shaft body 130. In this state, the thread crest 134 at the end of the second thread section 172 is engaged with the thread groove 145 at the end of the internal thread section 143, and when the rotation operation body 150 is further rotated counterclockwise from here, the state shown on the right side of the figure is obtained.

[0040] On the right side of the figure, as the L-shaped protruding piece 148 bends and deforms, the pedestal body 142 sinks further until it contacts the upper surface of the disc portion 136. The length of the second free rotation section 173 is equal to or greater than the length of the internal thread section 143. The thread 134 at the end of the second thread mountain section 172 disengages from the thread groove 145 at the tip of the internal thread section 143, and the internal thread section 143 overlaps with the second free rotation section 173. Even if the rotation operation body 150 is further rotated counterclockwise, the screw shaft body 130 idles. By the screw shaft body 130 idling, the feeding pedestal 140 is not excessively pressed against the disc portion 136, and damage to the feeding pedestal 140 can be prevented.

[0041] The tip bulging portion 149 that contacts the upper surface of the disc portion 136 in the state on the left side of the figure bends the L-shaped protruding piece 148 upward in the UD direction as the feeding pedestal 140 further moves downward as shown on the right side of the figure. With the contact portion between the tip bulging portion 149 and the disc portion 136 as a fulcrum, an upward biasing force is generated on the pedestal body 142 due to the resilient elasticity of the L-shaped protruding piece 148. When the rotation operation body 150 is rotated clockwise, the pedestal body 142 begins to move upward using the upward biasing force due to the resilient elasticity of the L-shaped protruding piece 148, and the thread 134 engages with the thread groove 145 as shown on the left side of the figure, and the feeding pedestal 140 can be fed out again.

[0042] In this embodiment, an example where the tip bulging portion 149 of the elastic mechanism 147 contacts the disc portion 136 is shown. However, in a modified example, the structure may be such that the tip bulging portion 149 contacts the bottom portion 124 of the cylindrical container 120. Also in that case, an upward biasing force due to the resilient elasticity of the L-shaped protruding piece 148 with the contact portion between the tip bulging portion 149 and the bottom portion 124 as a fulcrum is generated on the pedestal body 142. Thereby, when the rotation operation body 150 is rotated clockwise, the pedestal body 142 moves upward, and the thread 134 engages with the thread groove 145 to feed out the feeding pedestal 140.

[0043] FIG. 8 shows the relationship between the shape of the eraser case 100 viewed from the tip side and the eraser 160. The cylindrical container 120 is formed in a hexagonal cylindrical shape in which the axial cross-sectional shape of the accommodating portion 122 has a flat hexagonal shape. The eraser 160 is also formed in a hexagonal columnar shape in which the axial cross-sectional shape has a flat hexagonal shape. The outer diameter of the eraser 160 is slightly smaller than the inner diameter of the accommodating portion 122 of the cylindrical container 120, and the eraser 160 can be stored in and taken out of the cylindrical container 120 from the tip opening while leaving a minute gap around the eraser 160. The inner wall surface of the accommodating portion 122 of the cylindrical container 120 and the outer peripheral surface of the eraser 160 are formed such that their respective axial cross-sections have a shape other than a perfect circle like a hexagon. Thereby, it is possible to prevent the eraser 160 from rotating inside the cylindrical container 120 according to the rotation operation of the rotation operation body 150. Also, when erasing characters with the eraser 160, a force is applied to prevent the eraser from rotating with respect to the feeding base 140. Furthermore, the convenience can be enhanced by increasing the number of corner portions that are advantageous for erasing characters and the like.

[0044] Also, the axial cross-sectional shape of the rotation operation body 150 (not shown) substantially coincides with the axial cross-sectional shape of the cylindrical container 120 and has a flat hexagonal shape. By making the cross-sectional shapes of the cylindrical container 120 and the rotation operation body 150 flat hexagonal, it is easy to grasp the half-rotation position according to the relative rotation position of the rotation operation body 150 with respect to the cylindrical container 120 when the rotation operation body 150 is rotated, and it is also easy to count how many rotations have been made, which is different from the case where the cross-sectional shape is a regular hexagon. Also, different from the case where the cross-sectional shape is a regular hexagon, it is difficult for the user to hold it in the same way as holding a pencil, and since it is more likely to be held naturally in the palm, it is easier to apply force in the operation of erasing characters and the like.

[0045] FIG. 9 shows the relationship between the shapes of the cylindrical container 120 and the feeding base 140 when the eraser case 100 is viewed from the tip side. The base body 142 of the feeding base 140 is formed in a hexagonal column shape having a generally rounded flat hexagonal shape in the axial cross-sectional shape, similar to the cylindrical container 120. The outer diameter of the base body 142 is slightly smaller than the inner diameter of the accommodating portion 122 of the cylindrical container 120, and the feeding base 140 can be slid axially inside the accommodating portion 122. The inner wall surface of the accommodating portion 122 of the cylindrical container 120 and the outer peripheral surface of the base body 142 are formed such that their respective axial cross-sections have a shape other than a perfect circle, like a flat hexagon. Thereby, it is possible to prevent the feeding base 140 from rotating inside the cylindrical container 120 according to the rotation operation of the rotation operation body 150 and the feeding base 140 from being moved axially. Note that the cross-sectional shape of the base body 142 strictly has a shape like a double arrow, but the overall shape including the elastic mechanism 147 is generally like a flat hexagon. However, the tip bulging portion 149 has a shape protruding from the outer contour line of the base body 142 toward the inner wall surface of the accommodating portion 122, abuts against the inner wall surface of the accommodating portion 122, and is stored in the accommodating portion 122 in a state where the L-shaped protruding piece 148 is deformed and bent.

[0046] (Second Embodiment) FIG. 10 shows the appearance of the eraser case in the second embodiment. The eraser case 10 mainly includes a cylindrical container 20 and a screw shaft body 30. The cylindrical container 20 is a bottomed and lidless cylindrical resin member having a generally rounded hexagonal shape in the axial cross-sectional shape. The eraser 60 has a hexagonal column shape with a generally rounded hexagonal shape in the axial cross-sectional shape, and a cylindrical hole portion 62 penetrating the central axis is formed. The outer diameter of the eraser 60 is slightly smaller than the inner diameter of the cylindrical container 20, and the eraser 60 can be stored in the cylindrical container 20 while leaving a minute gap around the eraser 60. The screw shaft body 30 is a resin member having a screw shaft portion not shown in FIG. 10, and the screw shaft portion is inserted into the cylindrical hole portion 62 of the eraser 60 stored in the cylindrical container 20 and the hole portion provided at the bottom of the cylindrical container 20. By rotating the screw shaft body 30 in a predetermined direction, the eraser 60 is fed out from the cylindrical container 20, and by rotating the screw shaft body 30 in the reverse direction, the eraser 60 is fed into the cylindrical container 20.

[0047] FIG. 11 shows the internal structure of the eraser case 10 excluding the cylindrical container 20. The cylindrical hole 62 of the eraser 60 is a cylindrical hole penetrating the central axis. Note that since the opening itself on the tip side in the cylindrical hole 62 of the eraser 60 does not have any particular function or role, as a modification, the cylindrical hole 62 may extend to near the tip of the eraser 60 but not completely penetrate the tip, that is, it may have a configuration with an opening only on the end side. However, by adopting a configuration in which the cylindrical hole 62 penetrates to the tip side, the cross-sectional shape of the eraser 60 can be made constant from the tip to the end, and it can be manufactured by extrusion molding or injection molding, thereby simplifying the manufacturing process.

[0048] The feeding base 40 is a resin member having a pedestal body 42 having a hexagonal prism shape with a cross-sectional shape of a rounded hexagon, and a convex locking portion 44 protruding upward from the center of the upper surface of the pedestal body 42. The convex locking portion 44 has a shape of an annular snap fit folded back like an umbrella at the tip, that is, claws are provided on the periphery of the tip of the protrusion and folded back in a tapered inclined shape, and the folded-back end portion is formed at about 90 degrees. When the convex locking portion 44 is press-fitted into the cylindrical hole 62 of the eraser 60, the folded-back end portion is locked to a concave locking portion (details will be described later) near the end of the cylindrical hole 62 and fixed. A cylindrical pedestal hole 46 penetrating the pedestal body 42 and the convex locking portion 44 is formed at the center of the pedestal body 42. The pedestal hole 46 is a threaded hole having a thread groove formed spirally on its inner wall. The outer diameter of the pedestal body 42 is slightly smaller than the inner diameter of the cylindrical container 20, and the pedestal body 42 is axially slidable inside the cylindrical container 20.

[0049] The stopper 50 is an annular member for preventing the threaded shaft body 30 inserted into the cylindrical container 20 from falling out of the cylindrical container 20. The stopper 50 is formed of, for example, a flexible resin. The threaded shaft body 30 is inserted through the hollow portion of the stopper 50 and passed to near the end of the threaded shaft body 30. The axial cross-sectional shape of the stopper 50 is a long hexagonal shape with rounded corners, where some parallel sides are longer than the other sides. Details regarding the stopper 50 will be described later. In the example of this figure, the stopper 50 is formed in an annular shape, but in a modified example, it may be formed in a shape with a notch provided in a part such as a U-shape.

[0050] The threaded shaft body 30 has a threaded shaft portion 32 which is a rod-shaped member with a spiral thread formed on its outer peripheral portion, and a rotation operation portion 34 which is a portion corresponding to the screw head formed at the end of the threaded shaft portion 32. The shaft diameter of the threaded shaft portion 32 is smaller than the hole diameter of the cylindrical hole portion 62 of the eraser 60 to such an extent that the outer peripheral portion of the threaded shaft portion 32 does not contact the inner wall surface of the cylindrical hole portion 62 when the threaded shaft portion 32 is inserted through the cylindrical hole portion 62 of the eraser 60. Also, the shaft diameter of the threaded shaft portion 32 is smaller than the hole diameter of the pedestal hole portion 46 of the feeding pedestal 40 to such an extent that it can be screwed into the pedestal hole portion 46. The rotation operation portion 34 has a disk shape with an outer diameter sufficiently larger than the shaft diameter of the threaded shaft portion 32 and sized to be inscribed in the outer shape in the cross-sectional shape of the cylindrical container 20. Anti-slip vertical grooves are formed on the outer periphery of the rotation operation portion 34, and the user grips around the rotation operation portion 34 to perform a rotation operation for feeding out or feeding in the eraser 60.

[0051] At a predetermined position near the end of the screw shaft body 30, a protruding piece 36 that partially extends in the radial direction of the screw shaft portion 32 is provided. The protruding piece 36 is provided to press-fit the stopper 50 around the end of the screw shaft portion 32 and to hold the stopper 50 at the end portion of the screw shaft portion 32. The distance between a part of the parallel long sides in the axial cross-sectional shape of the stopper 50 is slightly longer than the diameter of the screw shaft portion 32, but shorter than the diameter at the portion of the protruding piece 36. Since the stopper 50 has flexibility, the distance between the parallel long pieces can change somewhat when pressure is applied. Therefore, when the screw shaft portion 32 is inserted through the hollow portion of the annular stopper 50 and the stopper 50 is passed to near the end of the screw shaft portion 32, when the stopper 50 hitting the protruding piece 36 is further press-fitted, the interval of the hollow portion opens due to the deflection of the stopper 50 and gets over the protruding piece 36, and thus the stopper 50 is arranged between the protruding piece 36 and the rotation operation portion 34. The protruding piece 36 has the shape of an annular snap fit. Since the axial tip side of the protruding piece 36 is inclined and has a shape that is locked from the axial end side, the stopper 50 is difficult to come off from the axial tip side.

[0052] Figure 12 shows the process of attaching the screw shaft body 30 and the stopper 50 to the cylindrical container 20. The cylindrical container 20 in this figure is illustrated in a form that allows internal penetration for the sake of convenience. With the screw shaft portion 32 of the screw shaft body 30 inserted downward into the hole provided at the bottom of the cylindrical container 20, the stopper 50 (the stopper 50a in the figure) is inserted from the opening at the tip of the cylindrical container 20 in such a way that the screw shaft portion 32 passes through the hollow portion of the stopper 50. Then, the stopper 50 is moved to near the end of the screw shaft portion 32, and the stopper 50 hitting the protruding piece 36 is pushed to the position of the stopper 50b so as to get over the protruding piece 36. Even when a force in the direction of pulling out the screw shaft body 30 from the cylindrical container 20 is applied, since the protruding piece 36 is locked to the stopper 50, unintentional dropping of the screw shaft body 30 can be prevented. The stopper 50 is shaped such that at least a part of the side surface, for example, a plurality of vertices in the axial cross-sectional shape can lightly contact the inner peripheral surface of the cylindrical container 20. Also, since the vertical width of the stopper 50 is slightly smaller than the distance from the lower end of the protruding piece 36 on the screw shaft portion 32 to the bottom, the stopper 50 is arranged in a form sandwiched between the protruding piece 36 and the bottom of the cylindrical container 20. Thereby, there is no excessive play at the position of the stopper 50b, and it is difficult to generate unnecessary noise.

[0053] FIG. 13 is a cross-sectional view showing the internal structure of the eraser case 10. First, the shape of the feeding base 40 will be described. The outer diameter of the base body 42 of the feeding base 40 is slightly smaller than the inner diameter of the cylindrical container 20, and is such an outer diameter that the feeding base 40 can slide axially inside the cylindrical container 20. The convex locking portion 44 of the feeding base 40 has the shape of an annular snap fit that projects upward from the base body 42 in a cylindrical shape. That is, the outer diameter of the convex locking portion 44 at the base to the end (near the contact point with the base body 42) is slightly smaller than the inner diameter of the cylindrical hole portion 62 of the eraser 60. Also, the outer diameter near the axial center of the convex locking portion 44 rises radially so as to bulge substantially vertically from the outer diameter of the base to the end, and has a folded-back shape like an umbrella that slopes in a conical shape tapering toward the tip from there. The base hole portion 46 penetrating the centers of the base body 42 and the convex locking portion 44 is a threaded hole having a screw groove formed spirally on its inner wall, and its hole diameter is slightly larger than the outer diameter of the screw shaft portion 32 and is of such a size that the screw shaft portion 32 can be screwed in.

[0054] The cylindrical hole portion 62 of the eraser 60 is formed with a concave locking portion 64 having a shape into which the convex locking portion 44 can be fitted near the end of its inner wall surface. That is, the end side of the concave locking portion 64 is recessed slightly vertically or in the radial direction so that the hole diameter of the cylindrical hole portion 62 is maximized at the position of the concave locking portion 64, and it has a shape that inclines so that the hole diameter of the cylindrical hole portion 62 decreases toward the tip side. The hole diameter of the cylindrical hole portion 62 is slightly larger than the outer diameter of the base or the end of the convex locking portion 44 in the portion other than the convex locking portion 44. Also, the portion of the convex locking portion 44 where the outer diameter is the largest is larger than the hole diameter of the portion other than the concave locking portion 64 in the cylindrical hole portion 62. Therefore, when the convex locking portion 44 is inserted into the cylindrical hole portion 62, the convex locking portion 44 can be press-fitted into the cylindrical hole portion 62 due to the deflection of the concave locking portion 64 and the elastic deformation of the eraser 60, and when the tip of the convex locking portion 44 reaches the concave locking portion 64, the large-diameter portion of the convex locking portion 44 expands in the radial direction and is fitted in a locked manner to the concave locking portion 64. In this state, even if an attempt is made to pull out the feeding base 40 or the convex locking portion 44 in the end direction, the large-diameter portion of the convex locking portion 44 is locked in the recess of the concave locking portion 64 and cannot be easily pulled out. Thereby, the eraser 60 can be stably fixed to the feeding base 40. Note that since the eraser 60 has a higher hardness than a solid paste, lipstick, lip cream, or other rod-shaped objects, the convex locking portion 44 is firmly locked to the concave locking portion 64, and there is a low possibility that the portion of the concave locking portion 64 will collapse and the convex locking portion 44 will separate when the eraser is used with normal strength.

[0055] The winding base 40 and the eraser 60 fixed to the winding base 40 are accommodated in the accommodating portion 22 formed inside the cylindrical container 20 by screwing the winding base 40 onto the screw shaft portion 32 of the screw shaft body 30 into which the stopper 50 is fitted in a state of being inserted through the hole portion at the bottom of the cylindrical container 20 as shown in FIG. 12. The outer diameter of the eraser 60 is slightly smaller than the inner diameter of the accommodating portion 22, and is small enough to be movable axially within the accommodating portion 22 with a minute gap left around the eraser 60. The hole diameter of the cylindrical hole portion 62 of the eraser 60 is sufficiently larger than the shaft diameter of the screw shaft portion 32. The maximum outer diameter of the stopper 50 is smaller than the inner diameter of the accommodating portion 22. The stopper 50 is arranged so as to be sandwiched between the lower end of the projecting piece 36 and the bottom of the accommodating portion 22. When the user rotates the rotation operation portion 34 of the screw shaft body 30, the axial rotation motion of the screw shaft body 30 is converted into the axial motion, that is, the linear motion of the winding base 40 by the screwing of the screw shaft portion 32 and the winding base 40. For example, when the rotation operation portion 34 is rotated counterclockwise, the eraser 60 and the winding base 40 are fed into the bottom direction of the accommodating portion 22 and stored, and when the rotation operation portion 34 is rotated clockwise, the eraser 60 and the winding base 40 are fed out in the opening direction of the accommodating portion 22. As the eraser 60 and the winding base 40 are fed out, the tip of the eraser 60 is pushed out and exposed to the outside of the cylindrical container 20. When the rotation operation portion 34 is rotated once, the eraser 60 moves up and down by about 3.0 mm, and the exposure amount of the eraser 60 to the outside can be freely adjusted according to the rotation amount of the rotation operation portion 34. When the use of the eraser 60 progresses and it wears down and becomes shorter, the tip of the eraser 60 can be exposed to the outside of the cylindrical container 20 by rotating the rotation operation portion 34 clockwise by the amount of shortening.

[0056] When using the eraser 60 housed in the eraser case 10, that is, when performing an operation of erasing the characters written with a pencil or the like with the eraser 60, the user applies a certain amount of strong force necessary to erase the characters by the friction of the eraser 60 to the eraser 60. Therefore, the eraser 60 needs to be firmly fixed to the feeding base 40 so that the eraser 60 does not easily come off from the feeding base 40. In that regard, since the convex locking portion 44 of the feeding base 40 is shaped to fit into the concave locking portion 64 of the eraser 60 and the convex locking portion 44 locks into the concave locking portion 64, the eraser 60 does not easily come off from the feeding base 40 even if the user applies a certain amount of strong force to the eraser 60.

[0057] FIG. 14 is a cross-sectional view showing a state where the eraser is worn down to the maximum extent. When the eraser 60 is worn down to the maximum extent using the eraser 60, the eraser 60 remains in a shape like a "mountain" that slopes from around the opening of the convex locking portion 44 as the top to around the upper surface of the feeding base 40 as shown in the figure. Until this state is reached, that is, until near the contact point between the eraser 60 and the feeding base 40, it is necessary to be able to expose the entire eraser 60 up to the end portion outside the cylindrical container 20. In this regard, since the screw shaft portion 32 of the screw shaft body 30 is long so that its tip extends near the opening of the accommodating portion 22, the feeding base 40 can be fed upward to a position where the upper surface of the feeding base 40 can be exposed outside the cylindrical container 20. Also, since the eraser 60 is fixed in such a way that the entire eraser 60 is exposed so as to be placed on the upper surface of the feeding base 40, if the feeding base 40 is fed out to near the opening of the cylindrical container 20, the entire eraser 60 up to the end can be exposed outside the cylindrical container 20. As a result, the end of the eraser 60 is not hidden by the cylindrical container 20 or the feeding base 40, and the eraser 60 can be used until the very end, and the eraser 60 can be used without waste. Also, an eraser that has been worn down to a very small size and become small in this way is originally too small to be comfortably picked up with a finger and used, and it is difficult to use. However, if the eraser case 10 of the present embodiment is used, even an eraser that has been worn down to the smallest size can be easily picked up with a hand or finger and used, so in that sense, the eraser can be easily used until the end and can be used without waste.

[0058] FIG. 15 shows the relationship between the shape of the cylindrical container 20 and the eraser 60 when the eraser case 10 is viewed from the tip side. The cylindrical container 20 is formed in a hexagonal cylindrical shape in which the axial cross-sectional shape of the accommodating portion 22 has a hexagonal shape. The eraser 60 is also formed in a hexagonal columnar shape in which the axial cross-sectional shape has a hexagonal shape. The outer diameter of the eraser 60 is slightly smaller than the inner diameter of the accommodating portion 22 of the cylindrical container 20, and the eraser 60 can be stored in and taken out of the cylindrical container 20 from the tip opening while leaving a minute gap around the eraser 60. The inner wall surface of the accommodating portion 22 of the cylindrical container 20 and the outer peripheral surface of the eraser 60 are formed such that their respective axial cross-sections have a shape other than a perfect circle, such as a hexagon. Thereby, it is possible to prevent the eraser 60 from rotating inside the cylindrical container 20 in accordance with the rotation operation of the rotation operation portion 34. Further, when erasing characters with the eraser 60, a force is applied to prevent the eraser from rotating with respect to the feeding base 40.

[0059] FIG. 16 shows the relationship between the shape of the cylindrical container 20 and the feeding base 40 when the eraser case 10 is viewed from the tip side. The base body 42 of the feeding base 40 is formed in a hexagonal columnar shape in which the axial cross-sectional shape has a hexagonal shape with rounded corners, similar to the cylindrical container 20. The outer diameter of the base body 42 is slightly smaller than the inner diameter of the accommodating portion 22 of the cylindrical container 20, and the feeding base 40 can be slid axially inside the accommodating portion 22. The inner wall surface of the accommodating portion 22 of the cylindrical container 20 and the outer peripheral surface of the base body 42 are formed such that their respective axial cross-sections have a shape other than a perfect circle, such as a hexagon. Thereby, it is possible to prevent the feeding base 40 from rotating inside the cylindrical container 20 in accordance with the rotation operation of the rotation operation portion 34 and the feeding base 40 from being prevented from moving axially.

[0060] Figure 17 shows the relationship between the shapes of the cylindrical container 20 and the stopper 50 when viewed from the tip side of the eraser case 10. The axial cross-sectional shape of the stopper 50 is a long hexagonal shape with rounded corners, and the parallel first side 51 and second side 52 are formed in an annular shape that is longer than the other sides. The inside of the annular portion of the stopper 50 forms a long hexagonal hollow portion 39, and the distance 53 between the first side 51 and the second side 52 is slightly smaller than the projection diameter 38, which is the maximum diameter of the projection 36 of the screw shaft body 30. Therefore, when passing the screw shaft portion 32 of the screw shaft body 30 through the hollow portion 39 of the stopper 50, if the stopper 50 that hits the projection 36 is further press-fitted, the deflection of the stopper 50 will open the distance 53 of the hollow portion 39 to be equal to the projection diameter 38 and overcome the projection 36, so that the stopper 50 will be arranged between the projection 36 and the bottom of the accommodating portion 22.

[0061] (Third Embodiment) The eraser case of the third embodiment is different from the eraser case of the second embodiment formed in a hexagonal prism shape in that the eraser, the cylindrical container, and the feeding base are formed in a rectangular parallelepiped shape, and the other points are common to the eraser case of the second embodiment. Hereinafter, the description will focus on the differences from the second embodiment, and the description of the common points will be omitted. Also, the reference numerals of each component in the third embodiment are the same as the corresponding components in the second embodiment.

[0062] Figure 18 shows the appearance of the eraser case in the third embodiment. The eraser case 10 includes a cylindrical container 20, a screw shaft body 30, a feeding base 40, and a stopper 50, and an eraser 60 is accommodated in the cylindrical container 20 so as to be insertable and removable. In this figure, for the sake of convenience, the inside of the cylindrical container 20 is shown in a transparent form.

[0063] The cylindrical container 20 is a bottomed and lidless cylindrical member with a rectangular cross-section in the axial direction with rounded corners. The eraser 60 also has a rectangular cross-section in the axial direction with rounded corners, and a cylindrical hole 62 penetrating the central axis is formed. The eraser 60 is sized to fit into the accommodating portion of the cylindrical container 20, and the eraser 60 can be accommodated in the cylindrical container 20 while leaving a minute gap around the eraser 60 in a state of being fixed to the feeding base 40. The feeding base 40 is also sized to fit into the accommodating portion of the cylindrical container 20, and is slidably accommodated on the inner wall surface of the cylindrical container 20. The shapes and structures of the screw shaft body 30 and the stopper 50 are the same as those in the second embodiment.

[0064] Also in this embodiment, the axial cross-sections of the inner wall of the cylindrical container 20, the outer periphery of the eraser 60, and the outer periphery of the feeding base 40 are non-circular shapes. Thereby, it is possible to prevent the feeding base 40 from rotating inside the cylindrical container 20 according to the rotation operation of the rotation operation portion 34 and the feeding base 40 from not being moved in the axial direction.

[0065] As described above, the eraser case in the second and third embodiments includes a cylindrical container in which an eraser having a cylindrical hole is accommodated so as to be able to be taken in and out from the opening at the tip, a feeding base that is axially slidable inside the cylindrical container and to which the end portion of the eraser accommodated in the cylindrical container is fixed, and a screw shaft body that can be inserted into the cylindrical hole of the eraser and is inserted into and screwed into a screw hole penetrating the feeding base to convert the axial rotation motion into the axial motion of the feeding base and push out the feeding base. The feeding base has a convex locking portion that projects in the direction of the eraser and locks to a concave locking portion provided on the inner wall surface of the cylindrical hole of the eraser to fix the eraser to the feeding base.

[0066] The convex locking portion of the feeding base may have the shape of a snap fit that protrudes upward from the upper surface of the base body. The concave locking portion may have a concave shape that fits the convex shape of the convex locking portion. According to this aspect, by locking the convex locking portion to the concave locking portion, it is possible to fix the eraser in a state where it is placed on the upper surface of the base body of the feeding base. In that case, since the end portion of the eraser can be exposed without being hidden by the feeding base, it is easy to use the eraser up to the vicinity of the end, and waste can be reduced.

[0067] The inner wall surface of the cylindrical container and the outer peripheral surface of the feeding base may each have a shape other than a perfect circle in the axial cross-section, such as a hexagonal shape, a rectangular shape, a square shape, or a polygonal shape with a plurality of vertices, or an elliptical shape. According to this aspect, when the screw shaft body is rotated, it is possible to prevent the eraser from rotating axially together with the screw shaft body inside the cylindrical container and hindering the axial movement of the eraser.

[0068] A stopper for preventing the screw shaft body inserted into the cylindrical container from falling out of the cylindrical container may be further provided. The cylindrical container may have a bottomed and lidless shape and may have a hole portion into which the screw shaft body is inserted at its bottom. The screw shaft body may have a screw shaft portion provided with a spiral groove on its outer peripheral portion, and a protruding piece may be provided at a predetermined position on the outer peripheral portion of the screw shaft portion. The stopper has a hollow portion with a width into which the screw shaft body and the protruding piece can be press-fitted, and is arranged in such a manner that the protruding piece of the screw shaft body inserted through the hollow portion and the hole portion of the cylindrical container is sandwiched between the bottom of the cylindrical container, and the protruding piece may be locked to the stopper when a force in the direction of pulling out the screw shaft body from the cylindrical container is applied. According to this aspect, even when a force in the direction of pulling out the screw shaft body from the cylindrical container is applied, the protruding piece is locked to the stopper, so that unintentional dropping of the screw shaft body can be prevented.

[0069] The stopper may be formed in a shape such that a plurality of vertices of the axial cross-sectional shape can contact the inner peripheral surface of the cylindrical container. According to this aspect, the stopper does not play more than necessary between the bottom of the cylindrical container and the protruding piece of the screw shaft body, and it is difficult to generate unnecessary noise.

[0070] Above, the eraser case 100 and the eraser case 10 according to the embodiment of the present invention have been described. It should be understood by those skilled in the art that this embodiment is merely an example, and various modifications are possible for the combination of each of these components, and such modifications are also within the scope of the present invention.

Industrial Applicability

[0071] The present invention relates to a storage device for erasers.

Explanation of Reference Numerals

[0072] 100 Eraser case, 120 Cylindrical container, 130 Screw shaft body, 132 Screw shaft portion, 134 Thread, 140 Rewinding base, 143 Internal thread section, 144 Convex locking portion, 145 Thread groove, 146 Base hole portion, 147 Elastic mechanism, 147a First elastic mechanism, 160 Eraser, 162 Cylindrical hole portion, 164 Concave locking portion, 170 First thread section, 171 First free rotation section, 172 Second thread section, 173 Second free rotation section.

Claims

1. A cylindrical container in which an eraser having a cylindrical hole is housed so as to be insertable and removable through an opening at the tip, A feeding base that is slidable in the axial direction inside the cylindrical container and to which the end of the eraser housed in the cylindrical container is fixed, A screw shaft body that can be inserted into the cylindrical hole of the eraser and is inserted into a screw hole penetrating the feeding base and screwed therein to convert the axial rotation motion into the axial motion of the feeding base and push out the feeding base, Comprising, The feeding base has a convex locking portion that protrudes in the direction of the eraser and locks to a concave locking portion provided on the inner wall surface of the cylindrical hole of the eraser, thereby fixing the eraser to the feeding base. The eraser case is characterized by this.

2. The inner wall surface of the cylindrical container and the outer peripheral surface of the feeding base each have a shape other than a perfect circle in the axial cross section. The eraser case according to claim 1 is characterized by this.

3. The convex locking portion has a snap fit shape. The eraser case according to claim 1 or 2 is characterized by this.

4. The screw shaft body has a screw shaft portion provided with a spiral thread that can be screwed into the screw hole of the feeding base on at least a part of the outer peripheral portion. In the screw shaft portion, at least one of the vicinity of the tip and the vicinity of the end in the axial direction has a free rotation section that does not screw into the screw hole, and a thread section that can be screwed into the screw hole outside the free rotation section. The eraser case according to any one of claims 1 to 3 is characterized by this being provided on the outer peripheral portion.

5. The cylindrical container has a bottomed and lidless shape, The feeding base can contact other members on the inner bottom of the cylindrical container when the screw shaft body is rotated in the housing direction, and an elastic mechanism is provided at the contact portion. The eraser case according to any one of claims 1 to 4 is characterized by this.

6. The screw shaft body has a screw shaft portion provided with a spiral thread that can be screwed into the screw hole of the feeding base on at least a part of the outer peripheral portion. In the screw shaft portion, a free rotation section that does not screw into the screw hole is provided near the end in the axial direction, and a thread section that can be screwed into the screw hole outside the free rotation section. The outer peripheral portion is provided with, The cylindrical container has a bottomed and lidless shape, When the winding base is rotated in the storage direction, it can contact other members on the inner bottom of the cylindrical container, and an elastic mechanism is provided at the contact portion, and the section of the screw hole of the winding base and the idle section can overlap due to the deformation of the elastic mechanism. The eraser case according to any one of claims 1 to 3, characterized in that.

7. The screw shaft body has a screw shaft portion provided with a spiral thread on at least a part of the outer periphery thereof that can be screwed into the screw hole of the winding base. The outer periphery of the screw shaft portion has, in the axial direction, a first thread section provided in a part near the tip, an idle section that is provided near the tip excluding the first thread section and does not engage with the screw hole, and a second thread section provided in a part excluding the first thread section and the idle section. The eraser case according to any one of claims 1 to 3, characterized in that.

8. The length of the idle section in the axial direction is equal to or greater than the length of the screw hole of the winding base in the axial direction. The eraser case according to claim 4 or 7, characterized in that.

9. The winding base is provided with an elastic mechanism that partially protrudes in the direction of the inner wall surface of the cylindrical container and can contact the inner wall surface. The eraser case according to any one of claims 1 to 8, characterized in that.

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