JP6985035B2 - mechanical pencil - Google Patents

Description

The present invention relates to a mechanical pencil capable of writing by feeding out a predetermined amount of a writing core from the tip of a mouthpiece by a knock operation or the like.

Conventionally, there has been a problem that if a high writing pressure is applied to the writing core when writing with a mechanical pencil, the writing core exposed from the tip of the base is easily broken. If the writing pressure is constant, the writing core is broken so that the angle between the axial direction of the mechanical pencil and the paper surface becomes smaller (the more the cylinder is laid down), or the writing core is exposed from the tip of the base. The longer the length of, the more remarkable it is.

In response to such a problem, Japanese Patent Application Laid-Open No. 2015-123689 describes an axial component of the writing pressure and a component perpendicular to the axial direction of the writing pressure when a high writing pressure is applied to the writing core. A mechanical pencil that absorbs by different mechanisms and reduces the breakage of the writing core is described.

Specifically, in the mechanical pencil of Patent Document 1, the base is supported by an elastic body (spring) via an elastic body (spring), and the base is a cam slope whose diameter gradually decreases toward the rear in the axial direction of the shaft. have. Further, the shaft cylinder is formed with a pressing portion that presses the cam slope forward in the axial direction of the shaft cylinder. With such a configuration, the cam slope of the base is pressed forward by the pressing portion in the axial direction of the axle due to the writing pressure component (force in the outward direction of the axle diameter) in the direction orthogonal to the axial direction of the axle. Then, the base slides forward (jumps out) from the tip of the barrel. As a result, the length of the writing core exposed from the tip of the base is reduced.
Further, in the mechanical pencil of Patent Document 1, in a state where the lead feeding unit for feeding the writing core is urged forward in the axial direction (the front end direction of the base in the axial direction) by an elastic body (spring), the axial direction of the shaft cylinder It is supported by the shaft cylinder in a state where it can move relative to each other. Then, the core feeding unit including the writing core moves relative to the rear in the axial direction of the barrel, so that the component in the axial direction of the writing pressure is absorbed. As a result, the length of the writing core exposed from the tip of the mouthpiece is further reduced, and the breakage of the writing core is reduced.

In the mechanical pencil described in Patent Document 1, when a high writing pressure is applied to the writing core, the base is suddenly moved over the maximum length (stroke) at which the base can slide forward with respect to the barrel. It is designed to slide (jump out).

On the other hand, as disclosed in International Publication No. 2017/002731, the applicant has a base for the shaft cylinder when a high writing pressure is applied to the writing core. We have developed a configuration that slides in the radial direction and the writing core slides backward with respect to the base. With such a mechanical pencil, it is possible to effectively avoid breakage of the writing core, but it is also possible to set a situation in which the above function is activated according to the strength of the writing core or according to the preference of the user. There is a demand for mechanical pencils.

Japanese Unexamined Patent Publication No. 2015-123689 International Publication No. 2017/002731

The present invention is based on the above findings, and an object thereof is to surely avoid breakage of the writing core when a high writing pressure is applied to the writing core, and to apply a load to the writing core. The purpose is to obtain a mechanical pencil that allows the user to adjust the situation in which it operates when hung.

The present invention
" 1. Shaft tube and
A core feeding unit for feeding a writing core, in which a rear region is supported in the barrel so that the front region can be flexed and deformed or tilted in the barrel.
A front restricting portion provided on the outer peripheral surface of the front region of the core feeding unit,
A rear regulating portion provided on the inner peripheral surface axially rearward of the front regulating portion in the axle cylinder, and a rear regulating portion.
A stretchable elastic body arranged in a compressed state in the gap between the front regulating portion and the rear regulating portion,
Equipped with
The core feeding unit has a pressed portion on the outer peripheral surface of the front region.
The barrel has a pressing portion in the front region and has a pressing portion.
At least one of the pressed portion and the pressed portion is a tapered surface whose diameter gradually increases toward the rear in the axial direction.
Before the front region of the core feeding unit bends, deforms, or tilts in the shaft cylinder, the pressed portion and the pressed portion are in contact with each other, and the front region of the core feeding unit is inside the shaft cylinder. In the case of bending deformation or tilting, the pressed portion moves the pressed portion relative to the shaft cylinder in the axial direction.
A knock body that extends the writing core is provided at the rear end portion of the barrel, and an operating body that moves the rear regulating portion back and forth covers the outer periphery of the side surface of the knock body by exposing a part of the rear end of the knock body. and, wherein by operating the operating body that is provided continuously to the rear restricting portion, the rear regulating portion and moved back and forth, mechanical pencil which is characterized by structural changing the compression state of the elastic body.
2. 2. A scale provided along the circumference is formed on the outer peripheral surface of the operating body, and a base point mark rotating in the circumferential direction with respect to the scale is provided on the outer surface of the rear region of the barrel. The mechanical pencil according to the above item 1, characterized in a structure in which the amount of change in the gap between the regulating portion and the rear regulating portion can be visually recognized. ".

According to the present invention, when a high writing pressure is applied to the writing core, the front region of the core feeding unit is bent and deformable or tilted in the shaft cylinder by a component perpendicular to the axial direction of the writing pressure. As a result, the core feeding unit including the writing core is moved relative to the axially rearward with respect to the shaft cylinder against the urging force of the elastic body, so that the length of the writing core exposed from the tip of the base is reduced. To. Further, due to the axial component of the writing pressure, the core feeding unit including the writing core is further moved axially backward with respect to the barrel against the urging force of the elastic body, and the writing is exposed from the tip of the mouthpiece. The length of the wick is further reduced. As a result, breakage of the writing core is avoided when a high writing pressure is applied to the writing core. Further, at this time, the core feeding unit including the writing core is not moved (jumped out) axially forward with respect to the shaft cylinder, but is moved relative to the axially rearward with respect to the base. The length of the writing core exposed from the mouthpiece is reduced. This makes it possible to provide a mechanical pencil with a smooth writing feeling.

Further, according to the present invention, the gap between the front regulating portion and the rear regulating portion is expanded and contracted by operating the operating body provided on the barrel to move the rear regulating portion continuously connected to the operating body back and forth. Therefore, the compressed state of the elastic body can be changed.
When the compressed state of the elastic body is set small by operating the operating body, the core feeding unit including the writing core opposes the urging force of the elastic body even at a low writing pressure and moves backward in the axial direction with respect to the barrel. Since it is easy to move relative to each other, it is suitable for a writing core having low strength, or a state suitable for a user who wants to operate the function with a low writing pressure.
When the compressed state of the elastic body is set to a large value by operating the operating body, the core feeding unit including the writing core opposes the urging force of the elastic body at a low writing pressure and moves backward in the axial direction with respect to the barrel. Since it becomes difficult to move relative to each other, it is suitable for a writing core having high strength, or when it is not desired to operate the function at a low writing pressure.

The operating body in the present invention moves the rear regulating portion back and forth by rotating or moving back and forth with respect to the shaft cylinder, and may be configured as a part of the shaft cylinder or a separate body from the shaft cylinder. can.
As a structure for moving the rear regulating portion back and forth by operating the operating body, the operating body is provided at the rear end of the barrel, and the operating body is rotated and moved back and forth to be continuously provided to the operating body. The structure can be such that the regulating member provided with the regulating portion can be moved back and forth, or the barrel is composed of a front shaft having a grip portion and a rear shaft serving as an operating body, and the rear shaft is provided with respect to the front shaft. By rotating or moving back and forth, it is possible to form a structure in which the rear regulating portion provided in front of the rear shaft is moved back and forth.

A knock body that extends the writing core is provided at the rear end of the shaft tube, and an operating body that moves the rear regulating portion back and forth covers the outer periphery of the side surface of the knock body by exposing a part of the rear end of the knock body. Due to the structure, the knock body and the operating body are concentrated on the rear end of the barrel, so the core is extended by knocking the knock body and the operating body is not much different from the design of the conventional mechanical pencil. It is possible to adjust the working load of the core breakage prevention function by operation.
By forming a locking groove on the regulating member as a spiral groove extending in the front-rear direction and locking the locking projection provided on the operating body to the locking groove, the rear regulating portion is moved back and forth by the rotation operation of the operating body. The structure can be moved to expand and contract the gap in the front-rear direction between the front regulating portion of the core feeding unit and the rear regulating portion connected to the operating body, and the compressed state of the elastic body arranged in the gap can be changed. .. By gently forming the inclination angle of the spiral groove, the gap between the front regulating portion and the rear regulating portion can be finely adjusted so that the locking projection moves in the front-rear direction with respect to the locking groove. The structure is such that the locked state is easily maintained even when an external force is applied. In addition, a locking projection may be provided on the regulating member, and a locking groove may be provided on the operating body.
Furthermore, by forming the locking groove with female screws having continuous spirals in the front-rear direction and forming the locking projections with male screws, the number of places to be locked to each other increases, so that the locked state can be stabilized. Can be done.
Further, a plurality of concave portions arranged in the front-rear direction along the axis are continuously formed on the regulating member or the operating body, and the convex shape can be stepwise locked to the plurality of continuous concave portions on the operating body or the regulating member. By providing a portion and locking each other at an arbitrary position, the gap in the front-rear direction between the front regulating portion of the core feeding unit and the rear regulating portion of the operating body is expanded and contracted, and the compressed state of the elastic body arranged in the gap is expanded and contracted. Can be made into a structure that changes.
Alternatively, a linear locking groove formed of a material that causes frictional resistance such as an elastoma is formed on the inner surface of the regulating member, and a locking projection formed slightly larger than the inner width of the locking groove is provided on the operating body to cause friction. By locking the locking protrusion with respect to the locking groove with a resistor at an arbitrary position, it is possible to create a structure that expands and contracts the gap in the front-rear direction between the front regulating portion of the core feeding unit and the rear regulating portion of the operating body. can.

When the rear axle is used as the operating body and the rear regulation part and the rear axle are integrally molded, the component configuration can be simplified, the inside of the axle cylinder can be simplified, and the core pipe can be simplified. It is also easy to use it in a swing-type mechanical pencil in which a heavy body is arranged between the outer surface and the inner surface of the barrel and the chuck is advanced by the back-and-forth movement of the heavy body to extend the writing core.
A locking groove is formed on the front shaft by a spiral groove extending in the front-rear direction, and a locking projection provided on the rear shaft (operating body) is locked to the locking groove to cause the rear shaft (operating body). A structure is provided in which the rear regulating portion provided in front of the rear axle is moved back and forth by a rotation operation to expand and contract the gap in the front-rear direction between the front regulating portion of the core feeding unit and the rear regulating portion of the rear shaft (operating body). Can be done. By gently forming the inclination angle of the spiral groove, the gap between the front regulating portion and the rear regulating portion can be finely adjusted so that the locking projection moves in the front-rear direction with respect to the locking groove. The structure is such that the locked state is easily maintained even when an external force is applied. A locking projection may be provided on the front shaft, and a locking groove may be provided on the rear shaft (operating body).
Furthermore, by forming the locking groove with female screws having continuous spirals in the front-rear direction and forming the locking projections with male screws, the number of places to be locked to each other increases, so that the locked state can be stabilized. Can be done.
Further, a plurality of recesses arranged in the front-rear direction along the axis are continuously formed on the front shaft or the rear shaft (operation body), and the plurality of continuous recesses are continuously formed on the rear shaft (operation body) or the front shaft. By providing a convex portion that can be locked in stages and locking each other at an arbitrary position, the gap in the front-rear direction between the front regulating portion of the core feeding unit and the rear regulating portion of the rear axle (operating body) can be expanded and contracted. It can be made into a structure to make it.
Alternatively, a linear locking groove formed of a material that causes frictional resistance such as an elastoma is formed on the inner surface of the front shaft, and a locking protrusion formed slightly larger than the inner width of the locking groove on the rear shaft (operating body). By providing a locking projection at an arbitrary position with respect to the locking groove by frictional resistance, a gap in the front-rear direction between the front regulating portion of the core feeding unit and the rear regulating portion of the rear shaft (operating body) is provided. Can be made into a structure that expands and contracts.

Preferably, the pressed portion of the core feeding unit is the tapered surface, and the tapered surface has any angle between 20 ° and 60 ° with respect to the axial direction of the barrel. The load required to move the pressed portion relative to the axially rearward with respect to the barrel against the urging force of the elastic body is any value between 0.5N and 8N. The amount of change in the gap between the front regulating portion and the rear regulating portion in the front-rear direction is 2 mm to 4 mm, and the change in the load due to the change is 2N to 5N.
In addition, since the user can perceive the change in load when a change of 0.5 N or more occurs, it is preferable to provide a gauge on the operating body so that a slight change in load can be recognized by operating the operating body. ..

According to the present invention, it is possible to reliably avoid breakage of the writing core when a high writing pressure is applied to the writing core, and the user can adjust the situation in which the writing core operates when a load is applied to the writing core. You can get a mechanical pencil that you can do.

It is a schematic vertical sectional view which shows the mechanical pencil by 1st Embodiment of this invention. FIG. 3 is a schematic vertical sectional view of a front region showing a first state in which the operating body of FIG. 1 is operated. FIG. 3 is a schematic vertical sectional view of a front region showing a second state in which the operating body of FIG. 1 is operated. FIG. 3 is a schematic vertical sectional view of a front region in a state where writing pressure is applied to the writing core of the mechanical pencil of FIG. 1. It is a schematic vertical sectional view which shows the mechanical pencil by the 2nd Embodiment of this invention. FIG. 5 is a schematic vertical sectional view of a front region showing a first state in which the operating body of FIG. 5 is operated. FIG. 5 is a schematic vertical sectional view of a front region showing a second state in which the operating body of FIG. 5 is operated. FIG. 5 is a schematic vertical sectional view of a front region in a state where writing pressure is applied to the writing core of the mechanical pencil of FIG. It is a side view which shows the 1st state of the mechanical pencil by the 3rd Embodiment of this invention. It is a side view which shows the 2nd state of the mechanical pencil by the 3rd Embodiment of this invention.

Hereinafter, the first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic vertical sectional view of a mechanical pencil 1 according to a first embodiment of the present invention, and FIG. 2 is a schematic vertical sectional view of a front region showing a first state in which the operating body of FIG. 1 is operated. 3 is a schematic vertical sectional view of a front region showing a second state in which the operating body of FIG. 1 is operated, and FIG. 4 is a writing pressure applied to the writing core of the mechanical pencil of FIG. It is a schematic vertical sectional view of the front area in the state of being.

As shown in the figure, the mechanical pencil 1 of the present embodiment has a shaft cylinder 10 and a core for feeding out a writing core 70 which is supported in the shaft cylinder 10 and whose front region can be tilted in the shaft cylinder 10. It is provided with a feeding unit 40. The axle cylinder 10 of the present embodiment is composed of a rear shaft 20 and a front shaft 30 whose rear region is fixed (screwed) to the front region of the rear shaft 20.

The core feeding unit 40 of the present embodiment has a core pipe 41 extending in the axial direction of the shaft cylinder 10 inside the shaft cylinder 10 and a chuck 43 fixed to the front end portion of the core pipe 41 via a connector 49. A tightening ring 42 fitted in the front region of the chuck 43, an outer cylinder 45 surrounding the chuck 43, and a return spring 44 for urging the core pipe 41 axially rearward with respect to the outer cylinder 45. is doing.

Specifically, the outer cylinder 45 has a rear cylinder 45a that supports the chuck 43 on the inner peripheral surface of the front region and has a flange-shaped front restricting portion 21 that overhangs the outer peripheral surface of the rear region, and the front end of the rear cylinder 45a. It has a front cylinder 45b that is screwed into the region and extends axially forward beyond the front end of the chuck 43. Further, the rear cylinder 45a has an inner collar 45c at the front end portion, and a return spring 44 is arranged in a compressed state between the inner flange 45c and the connector 49, and the core is arranged with respect to the outer cylinder 45. The pipe 41 is urged rearward in the axial direction. In this state, the chuck 43 is fastened by the tightening ring 42 and holds the writing core 70 so as not to retract.

Further, the mechanical pencil 1 has a rear regulation unit 22 that restricts the backward movement of the coil spring 60 axially rearward from the front regulation unit 21 of the outer cylinder 45, and the rear regulation unit 22 and the front regulation unit 21. The telescopic coil spring 60 is arranged in a compressed state in the gap L with the coil spring 60. With such a configuration, the core feeding unit 40 including the writing core 70 can move backward in the axial direction with respect to the barrel 10 against the urging force of the coil spring 60.

Further, the inner diameter of the rear region of the front shaft 30 is larger than the outer diameter of the front regulating portion 21 protruding like a flange, and is between the inner peripheral surface of the front shaft 30 and the outer peripheral surface of the front regulating portion 21. A gap is formed. This allows the core feeding unit 40 to tilt with respect to the barrel 10.

Further, a base 52 is attached to the tip region of the core feeding unit 40. The base 52 of the present embodiment is arranged in the tip region of the core feeding unit 40, and is movable relative to the core feeding unit 40 in the axial direction of the shaft cylinder 10. The base 52 is composed of a cylindrical front region 52a that guides the writing core 70, and a sleeve-shaped rear region 52b having a diameter larger than that of the front region 52a. The rear region 52b has a front small diameter portion 52c and a rear diameter expansion portion 52d, and the small diameter portion 52c and the diameter expansion portion 52d are connected by a shoulder portion 52e.
The base 52 is the tip of the core feeding unit 40 in a state where the front cylinder 45b and the tubular holding member 40b to which the front cylinder 45b is internally fitted and fixed are in a state of being prevented from coming off and in a state of being slidable in the axial direction of the shaft cylinder 10. Attached to the area. Specifically, the holding member 40b has a cylindrical main body portion 40c that surrounds the rear region 52b of the base 52, and a stopper 40d formed in the rear end region of the main body portion 40c.
The inner surface of the main body 40c has a reduced diameter portion 40e whose inner diameter is smaller than that of other regions of the main body 40c. A flat surface 45d facing forward in the axial direction is formed on the outer surface of the outer cylinder 45 axially behind the reduced diameter portion 40e, and can be expanded and contracted between the shoulder portion 52e and the flat surface 45d of the base 52. A spring 55 in a compressed state is arranged.
With such a configuration, the base 52 is slidably held inside the holding member 40b in the axial direction of the main body 40c, and is prevented from being undesirably pulled out from the main body 40c. Further, the front end of the main body portion 40c is an opening, and the front region 52a of the base 52 projects forward from this opening.

The holding member 40b has a pressed portion 53 at the front end portion. The pressed portion 53 of the present embodiment is configured as a tapered surface having an angle of 40 ° with respect to the axial direction of the barrel 10. Further, the shaft cylinder 10 (front shaft 30) has a pressing portion 31 protruding from the inner peripheral surface in the front region. In the present embodiment, the pressing portion 31 and the pressed portion 53 are in contact with each other before the core feeding unit 40 is tilted. Then, when the core feeding unit 40 is tilted, the pressed portion 31 moves the pressed portion 53 relative to the axle cylinder 10 in the axial direction rearward. In the present embodiment, the spring constant of the coil spring 60 is 1600 N / m, and the pressed portion 53 (tapered surface) is axially rearward with respect to the axle cylinder 10 against the urging force of the coil spring 60 shown in FIG. The load required for relative movement is 5N. Further, the spring constant of the spring 55 is 1000 N / m, and by setting the urging force of the spring 55 to be smaller than the urging force of the coil spring 60, the base from the state where the outer cylinder 45 is stationary to the state where the outer cylinder 45 starts to move. The contact state between the 52 and the inner flange 32 of the barrel 10 is maintained. As a result, when the core feeding unit 40 including the writing core 70 is moved relative to the shaft cylinder 10 in the axial direction, the length of the writing core 70 exposed from the front end portion of the base 52 is reduced. It has become.

Further, the core feeding unit 40 further has a knock portion 46 for pressing the core pipe 41 forward in the axial direction with respect to the outer cylinder 45. The knock portion 46 of the present embodiment has a tubular shaft member 46a that pushes the core pipe 41 in the front in the axial direction, and holds the columnar eraser 80 in the rear in the axial direction so as to be removable. It has a holder portion 46b, and the holder portion 46b has a sleeve portion 46c that is externally fitted to the rear end region of the shaft member 46a. The internal space of the shaft member 46a and the internal space of the holder portion 46b are communicated with each other by an opening. As a result, by removing the eraser 80 from the holder portion 46b, the writing core 70 can be inserted into the core pipe 41 through the opening. Further, a dome-shaped knob 81 that covers the rear of the eraser 80 is detachably fitted to the holder portion 46b.

The crown 23 is fixed to the rear end region of the rear shaft 20. An operating body 24 having an operating portion 24a exposed from the rear end of the rear shaft 20 is rotatably inserted inside the crown 23. The knock portion 46 is inserted inside the operating body 24 so as to be movable back and forth.
A step portion 24b facing rearward in the axial direction is formed on the inner peripheral surface of the operating body 24. Further, a flange portion 46d is formed on the outer periphery of the holder portion 46b, and a stretchable spring 46e is arranged in a compressed state between the flange portion 46d and the step portion 24b.

The operating body 24 includes an operating member 24c having the operating portion 24a and an inner shaft 24d located in front of the operating member 24c, and a female screw 24e and an inner shaft 24d provided on the front inner surface of the operating member 24c. It is fixed so that it cannot rotate by being screwed with a male screw 24f provided on the rear outer surface of the above, so that it can rotate integrally.
A cylindrical regulating member 25 is arranged in front of the operating body 24. The rotation operating member 24 has a female screw 25a formed in the rear screwed with a male screw 24g formed in the front of the operating body 24.
Two protrusions 25b that project at positions facing each other in the radial direction are formed on the outer surface of the regulating member 25, and the protrusions 25b are locked to the key groove 30a provided on the inner surface of the front shaft 30 to lock the operating body 24. The restricting member 25 is prevented from rotating even if it rotates, and the restricting member 25 moves back and forth by rotating the operating portion 24a of the operating body 24.
A protrusion 46f is formed on the outer surface of the flange portion 46d of the holder portion 46b, and the protrusion 46f is locked to a keyway 24h extending in the front-rear direction provided on the inner surface of the operation body 24, so that the knock portion 46 becomes the operation body 24. It can move back and forth and cannot rotate.
Further, a protrusion 24i is formed on the outer surface of the operating body 24, and the protrusion 24i is locked to the annular recess 23a provided on the inner surface of the crown 23 so that the operating body 24 moves back and forth with respect to the crown 23a. It is immovably rotatable.
In the present embodiment, the front of the restricting member 25 is the rear regulating portion 22 that regulates the rearward movement of the coil spring 60 described above, and by rotating the operating portion 24a, the rear regulating portion 22 of the regulating member 25 is formed. It is possible to change the gap L in the front-rear direction with the front restricting portion 21 of the core feeding unit 40 by a maximum of 2 mm, and the compressed state of the coil spring 60 also changes by 2 mm due to the change of this gap L by 2 mm. The structure is such that the working load changes by 2N from the state in which the outer cylinder 45 is stationary to the state in which the outer cylinder 45 starts to move. L in the state of FIG. 1 is 8.7 mm.

FIG. 2 is a diagram showing a state in which the clearance L1 in the front-rear direction between the rear regulating portion 22 of the regulating member 25 and the front regulating portion 21 of the core feeding unit 40 is set to 7.7 mm by operating the operating body. The working load from the state in which the outer cylinder 45 is stationary to the state in which the outer cylinder 45 starts to move is 6N.
FIG. 3 is a diagram showing a state in which the clearance L2 in the front-rear direction between the rear regulating portion 22 of the regulating member 25 and the front regulating portion 21 of the core feeding unit 40 is set to 9.7 mm by operating the operating body. The working load from the state in which the outer cylinder 45 is stationary to the state in which the outer cylinder 45 starts to move is 4N.

Although not shown, a scale provided along the circumference is formed on the outer peripheral surface of the operating body 24, and a base point mark provided on the outer surface of the crown 23 and rotating in the circumferential direction with respect to the scale is referred to. In addition, the amount of change in the gap L, that is, the change in the working load can be visually recognized.
Further, a step portion 24j facing rearward in the axial direction is formed on the outer peripheral surface of the inner shaft 24d, and a stretchable spring 26 is compressed between the step portion 24j and the front end of the crown 23. It is arranged in. This provides an appropriate sense of resistance during the rotation operation (see FIG. 1).

Next, the operation of the mechanical pencil 1 according to the embodiment of the present invention will be described.

First, prior to writing on the paper surface, if necessary, the knob 81 and the eraser 80 are removed from the holder portion 46b, and the writing core 70 passes through the opening that communicates the shaft member 46a and the holder portion 46b. It is put into the core pipe 41. Then, the eraser 80 and the knob 81 are attached to the holder portion 46b, and the knock portion 46 (knob 81) is pressed (knocked) toward the front in the axial direction with the front end of the base 52 facing downward.
As a result, the core pipe 41, the connector 49, the chuck 43 and the tightening ring 42 are advanced against the urging force of the return spring 44 via the shaft member 46a. In the middle of this advancement, only the tightening ring 42 abuts on the contact step portion 45f formed on the front cylinder 45b of the outer cylinder 45. As a result, the tightening ring 42 is removed rearward from the chuck 43, the chuck 43 is opened, and the writing core 70 is extended. At the time of pressing (knock operation), an appropriate resistance feeling is brought about by the urging force of the spring 46e arranged between the flange portion 46d of the knock portion 46 and the step portion 24b of the operating body 24.
In the present embodiment, since a gap S1 of 2 mm between the shaft member 46a and the core pipe 41 and a movement amount of 4 mm when the chuck 43 extends the writing core 70 are required, the knock stroke of the knock portion 46 is required. Requires 6 mm.

Then, when the pressed state of the knock portion 46 (knob 81) is released, the core pipe 41 is retracted together with the chuck 43 by the urging force of the return spring 44. Along with this, the tightening ring 42 is fitted again in the front region of the chuck 43, and the chuck 43 is tightened. As a result, the writing core 70 is sandwiched so as not to retract, and the state in which the writing core 70 is extended is maintained. Then, by repeating this series of pressing operations as appropriate, the writing core 70 is exposed (delivered) to a desired length from the tip of the base 52. Then, the front shaft 30 is gripped by the user, and the writing is performed by moving the shaft cylinder 10 as desired while bringing the writing core 70 into contact with the paper surface.

At the time of writing, the barrel 10 is generally gripped so that its axial direction makes an acute angle with respect to the paper surface (see FIG. 4). Therefore, a writing pressure including a component perpendicular to the axial direction of the barrel 10 and a component in the axial direction is applied to the writing core 70. When a high writing pressure is applied to the writing core 70 during writing, the mechanical pencil 1 of the present embodiment absorbs a component perpendicular to the writing pressure and a component in the axial direction, respectively, from the tip of the base 52. Avoid breaking the exposed writing core 70.

Specifically, as shown in FIG. 4, the front region of the core feeding unit 40 is tilted by a component perpendicular to the axial direction of the writing pressure, and the pressed portion 53 of the holding member 40b is tilted by the pressing portion 31 of the front shaft 30. The tapered surface) is pressed backward in the axial direction. As a result, the coil spring 60 was deformed by the writing pressure, and the core breakage prevention function could be activated.

Further, the situation when the core breakage prevention function is activated will be described in detail with reference to FIG.
The front region of the core feeding unit 40 is tilted by a component perpendicular to the axial direction of the writing pressure, and the pressed portion 53 (tapered surface) of the holding member 40b is pressed rearward in the axial direction by the pressing portion 31 of the front shaft 30. As a result, the core feeding unit 40 including the writing core 70 is relatively moved rearward in the axial direction with respect to the shaft cylinder 10 against the urging force of the coil spring 60.
On the other hand, since the base 52 is pressed forward in the axial direction with respect to the outer cylinder 45 by the urging force of the spring 55, the base 52 is not moved relative to the rear in the axial direction with respect to the shaft cylinder 10. As a result, the length of the writing core 70 exposed from the tip of the base 52 is reduced.
In the mechanical pencil 1 shown in FIG. 4, the clearance L1 in the front-rear direction between the rear regulating portion 22 of the regulating member 25 shown in FIG. 1 and the front regulating portion 21 of the core feeding unit 40 is set to 7.7 mm. When a working load of 6N was applied due to the writing pressure, the outer cylinder 45 started to move and the core breakage prevention function could be activated.

Further, as described above, the mechanical pencil 1 of the present embodiment has the rear regulation unit 22 of the regulation member 25 and the front regulation unit 21 of the core feeding unit 40 by rotating the operation unit 24a of the operation body 24. The clearance in the front-rear direction can be changed by a maximum of 2 mm from 7.7 mm of L1 shown in FIG. 2 to 9.7 mm of L2 shown in FIG.
When the gap L1 in FIG. 2 is 7.7 mm, the coil spring 60 is compressed, so that the outer cylinder 45 is more difficult to move than in the state shown in FIG. 1, and a working load of 6 N is applied due to the writing pressure. At that time, the outer cylinder 45 started to move, and the core breakage prevention function could be activated.
When the gap L2 in FIG. 3 is 9.7 mm, the coil spring 60 is stretched, so that the outer cylinder 45 is easier to move than in the state shown in FIG. In addition, the outer cylinder 45 started to move, and the core breakage prevention function could be activated.
In addition to the states shown in FIGS. 1, 2, and 3, the mechanical pencil 1 of the present embodiment is an operating body with reference to the scale on the outer peripheral surface of the operating body 24 and the base point mark on the outer surface of the crown 23. By operating 24, it is possible to appropriately set the situation in which the core breakage prevention function is activated.

Next, a second embodiment of the present invention will be described in detail with reference to the accompanying drawings.
The same members and parts as those in the first embodiment are designated by the same reference numerals.

FIG. 5 is a schematic vertical sectional view of the mechanical pencil 100 according to the second embodiment of the present invention, and FIG. 6 is a schematic vertical sectional view of a front region showing a first state in which the operating body of FIG. 5 is operated. FIG. 7 is a schematic vertical sectional view of a front region showing a second state in which the operating body of FIG. 5 is operated, and FIG. 8 shows a writing pressure applied to the writing core of the mechanical pencil of FIG. It is a schematic vertical sectional view of the front area in the state of being.

As shown in the figure, the mechanical pencil 100 of the present embodiment has a shaft cylinder 110 and a core for feeding out a writing core 70 which is supported in the shaft cylinder 110 and whose front region can be tilted in the shaft cylinder 110. It is provided with a feeding unit 40. The axle cylinder 110 of the present embodiment is composed of a rear shaft 120 and a front shaft 130 whose rear region is fixed (screwed) to the front region of the rear shaft 120.

The core feeding unit 40 of the present embodiment has a core pipe 41 extending in the axial direction of the shaft cylinder 110 inside the shaft cylinder 110, and a chuck 43 fixed to the front end portion of the core pipe 41 via a connector 49. A tightening ring 42 fitted in the front region of the chuck 43, an outer cylinder 45 surrounding the chuck 43, and a return spring 44 for urging the core pipe 41 axially rearward with respect to the outer cylinder 45. is doing.

Specifically, the outer cylinder 45 has a rear cylinder 45a that supports the chuck 43 on the inner peripheral surface of the front region and has a flange-shaped front restricting portion 21 that overhangs the outer peripheral surface of the rear region, and the front end of the rear cylinder 45a. It has a front cylinder 45b that is screwed into the region and extends axially forward beyond the front end of the chuck 43. Further, the rear cylinder 45a has an inner collar 45c at the front end portion, and a return spring 44 is arranged in a compressed state between the inner flange 45c and the connector 49, and the core is arranged with respect to the outer cylinder 45. The pipe 41 is urged rearward in the axial direction. In this state, the chuck 43 is fastened by the tightening ring 42 and holds the writing core 70 so as not to retract.

Further, the shaft cylinder 110 has a rear regulation unit 122 that regulates the rearward movement of the coil spring 60 axially rearward from the front regulation unit 21 of the outer cylinder 45, and the rear regulation unit 122 and the front regulation unit 21. The telescopic coil spring 60 is arranged in a compressed state in the gap L with the coil spring 60. With such a configuration, the core feeding unit 40 including the writing core 70 can move backward in the axial direction with respect to the barrel 110 against the urging force of the coil spring 60.

Further, the inner diameter of the rear region of the front shaft 130 is larger than the outer diameter of the front regulating portion 21, and a gap is formed between the inner peripheral surface of the front shaft 130 and the outer peripheral surface of the front regulating portion 21. There is. This allows the core feeding unit 40 to tilt with respect to the barrel 110.

Further, a base 52 is attached to the tip region of the core feeding unit 40. The base 52 of the present embodiment is arranged in the tip region of the core feeding unit 40, and is movable relative to the core feeding unit 40 in the axial direction of the shaft cylinder 110. The base 52 is composed of a cylindrical front region 52a that guides the writing core 70, and a sleeve-shaped rear region 52b having a diameter larger than that of the front region 52a. The rear region 52b has a front small diameter portion 52c and a rear diameter expansion portion 52d, and the small diameter portion 52c and the diameter expansion portion 52d are connected by a shoulder portion 52e.
The base 52 is the tip of the core feeding unit 40 in a state where the front cylinder 45b and the tubular holding member 40b to which the front cylinder 45b is internally fitted and fixed are in a state of being prevented from coming off and in a state of being slidable in the axial direction of the shaft cylinder 110. Attached to the area. Specifically, the holding member 40b has a cylindrical main body portion 40c that surrounds the rear region 52b of the base 52, and a stopper 40d formed in the rear end region of the main body portion 40c.
The inner surface of the main body 40c has a reduced diameter portion 40e whose inner diameter is smaller than that of other regions of the main body 40c. A flat surface 45d facing forward in the axial direction is formed on the outer surface of the outer cylinder 45 axially behind the reduced diameter portion 40e, and can be expanded and contracted between the shoulder portion 52e and the flat surface 45d of the base 52. A spring 55 in a compressed state is arranged.
With such a configuration, the base 52 is slidably held inside the holding member 40b in the axial direction of the main body 40c, and is prevented from being undesirably pulled out from the main body 40c. Further, the front end of the main body portion 40c is an opening, and the front region 52a of the base 52 projects forward from this opening.

The holding member 40b has a pressed portion 53 at the front end portion. The pressed portion 53 of the present embodiment is configured as a tapered surface having an angle of 40 ° with respect to the axial direction of the barrel 110. Further, the shaft cylinder 110 (front shaft 130) has a pressing portion 31 protruding from the inner peripheral surface in the front region.
In the present embodiment, the pressing portion 31 and the pressed portion 53 are in contact with each other before the core feeding unit 40 is tilted. Then, when the core feeding unit 40 is tilted, the pressed portion 31 moves the pressed portion 53 relative to the axle cylinder 110 in the axial direction rearward. In the present embodiment, the spring constant of the coil spring 60 is 1600 N / m, and the pressed portion 53 (tapered surface) is axially rearward with respect to the axle cylinder 110 against the urging force of the coil spring 60 shown in FIG. The load required for relative movement is 5N. Further, the spring constant of the spring 55 is 1000 N / m, and by setting the urging force of the spring 55 to be smaller than the urging force of the coil spring 60, the base from the state where the outer cylinder 45 is stationary to the state where the outer cylinder 45 starts to move. The contact state between the 52 and the inner flange 32 of the barrel 10 is maintained. As a result, when the core feeding unit 40 including the writing core 70 is moved relative to the shaft cylinder 10 in the axial direction, the length of the writing core 70 exposed from the front end portion of the base 52 is reduced. It has become.

Further, the core feeding unit 40 further has a knock portion 146 for pressing the core pipe 41 forward in the axial direction with respect to the outer cylinder 45. The knock portion 146 of the present embodiment has a tubular shaft portion 146a that pushes the core pipe 41 in the front in the axial direction, and holds the cylindrical eraser 80 in a removable manner in the rear in the axial direction. The holder portion 146b is provided, and the shaft portion 146a has a plurality of locking protrusions 146c for fitting the rear end region of the core pipe 41. The internal space of the shaft portion 146a and the internal space of the holder portion 146b are communicated with each other by an opening. As a result, by removing the eraser 80 from the holder portion 146b, the writing core 70 can be inserted into the core pipe 41 from the opening. Further, a dome-shaped knob 81 that covers the rear of the eraser 80 is detachably fitted to the holder portion 146b.

A crown 123 is fixed to the rear end region of the rear shaft 120. The knock portion 146 is inserted inside the crown 123 so as to be movable back and forth.
The rear shaft 120 and the front shaft 130 are rotatably screwed with a male screw portion 120a formed in the front region of the rear shaft 120 and a female screw portion 130a formed in the center of the front shaft 130. When the protrusion 120b formed on the inner surface of the shaft 120 is loosely fitted into the annular groove 130b formed on the outer peripheral surface of the front shaft 130 and the rear shaft 120 is rotated with respect to the front shaft 130, the front shaft 130 On the other hand, the rear shaft 120 is prevented from being screwed off. A step portion 130c facing rearward in the axial direction is formed on the inner peripheral surface of the front shaft 130. Further, a flange portion 120c is formed on the outer periphery of the rear shaft 120, and a stretchable spring 146e is arranged between the flange portion 120c and the step portion 130c in a compressed state, and the front shaft 130 and the rear shaft 120 are arranged in a compressed state. Rattling with is prevented.

In the present embodiment, the rear shaft 120 is used as the operating body 124, and the outer surface thereof is used as the operating unit 124a. Further, the front of the rear shaft 120 is provided as a rear regulating unit 122 that regulates the rearward movement of the coil spring 60 described above, and by rotating the operating portion 124a of the rear shaft 120 with respect to the front shaft 130, the rear regulating unit 122 is operated. It is possible to change the gap L in the front-rear direction with the front restricting portion 21 of the core feeding unit 40 by a maximum of 2 mm, and the compressed state of the coil spring 60 also changes by 2 mm due to the change of this gap L by 2 mm. The structure is such that the working load changes by 2N from the state in which the outer cylinder 45 is stationary to the state in which the outer cylinder 45 starts to move. L in the state of FIG. 5 is 8.7 mm.

In FIG. 6, the operating body 124 (rear shaft 120) is operated so that the clearance L1 in the front-rear direction between the rear regulating portion 122 of the rear shaft 124 and the front regulating portion 21 of the core feeding unit 40 is set to 7.7 mm. It is a figure of the state, and the working load from the state where the outer cylinder 45 is stationary to the state where the outer cylinder 45 starts to move is 6N.
FIG. 7 is a diagram showing a state in which the clearance L2 in the front-rear direction between the rear regulating portion 122 and the front regulating portion 21 of the core feeding unit 40 is set to 9.7 mm by operating the operating body 124 (rear shaft 120). The working load from the state in which the outer cylinder 45 is stationary to the state in which the outer cylinder 45 starts to move is 4N.

Although not shown, a scale provided along the circumference is formed on the outer peripheral surface of the operating body 124 (rear shaft 124), and is provided on the outer surface of the front shaft 130 and rotates in the circumferential direction with respect to the scale. The amount of change in the gap L, that is, the change in the working load can be visually recognized with reference to the reference point mark.
Further, the spring 146e arranged in a compressed state between the flange portion 120c of the rear shaft 120 and the step portion 130c of the front shaft 130 provides an appropriate resistance feeling during the rotation operation.

Next, the operation of the mechanical pencil 100 according to the second embodiment of the present invention will be described.

First, prior to writing on the paper surface, if necessary, the knob 81 and the eraser 80 are removed from the holder portion 146b, and the writing core 70 passes through the opening that communicates the shaft portion 146a and the holder portion 146b. It is put into the core pipe 41. Then, the eraser 80 and the knob 81 are attached to the holder portion 146b, and the knock portion 146 (knob 81) is pressed (knocked) toward the front in the axial direction with the front end of the base 52 facing downward.
As a result, the core pipe 41, the connector 49, the chuck 43 and the tightening ring 42 are advanced against the urging force of the return spring 44 via the shaft portion 146a. In the middle of this advancement, only the tightening ring 42 abuts on the contact step portion 45f formed on the front cylinder 45b of the outer cylinder 45. As a result, the tightening ring 42 is removed rearward from the chuck 43, the chuck 43 is opened, and the writing core 70 is extended.
The crown 123 has a protrusion 123a provided on the outer surface of the crown 123 fitted in a through hole 120d formed in the rear shaft 120 so as to be incapable of rotating and moving back and forth. Further, the knock portion 146 locks the protrusion 146d provided on the outer surface of the knock portion 146 to the key groove 123b provided on the inner surface of the crown 123 so that the knock portion 146 can move back and forth without rotation. Therefore, at the time of pressing (knock operation), the knock portion 146 can be moved back and forth without rotating.
In the present embodiment, since the movement amount of 4 mm when the chuck 43 extends the writing core 70 is required, the knock stroke of the knock portion 146 requires 4 mm.

Then, when the pressed state of the knock portion 146 (knob 81) is released, the core pipe 41 is retracted together with the chuck 43 by the urging force of the return spring 44. Along with this, the tightening ring 42 is fitted again in the front region of the chuck 43, and the chuck 43 is tightened. As a result, the writing core 70 is sandwiched so as not to retract, and the state in which the writing core 70 is extended is maintained. Then, by repeating this series of pressing operations as appropriate, the writing core 70 is exposed (delivered) to a desired length from the tip of the base 52. Then, the front shaft 130 is grasped by the user, and the writing is performed by moving the shaft cylinder 110 as desired while bringing the writing core 70 into contact with the paper surface.

At the time of writing, the barrel 110 is generally gripped so that its axial direction makes an acute angle with respect to the paper surface (see FIG. 8). Therefore, a writing pressure including a component perpendicular to the axial direction of the barrel 110 and a component in the axial direction is applied to the writing core 70. When a high writing pressure is applied to the writing core 70 during writing, the mechanical pencil 100 of the present embodiment absorbs a component perpendicular to the writing pressure and a component in the axial direction, respectively, from the tip of the base 52. Avoid breaking the exposed writing core 70.

Specifically, as shown in FIG. 8, the front region of the core feeding unit 40 is tilted by a component perpendicular to the axial direction of the writing pressure, and the pressed portion 53 of the holding member 40b is tilted by the pressing portion 31 of the front shaft 130. The tapered surface) is pressed backward in the axial direction. As a result, the coil spring 60 was deformed by the writing pressure, and the core breakage prevention function could be activated.

Further, the situation when the core breakage prevention function is activated will be described in detail with reference to FIG.
The front region of the core feeding unit 40 is tilted by a component perpendicular to the axial direction of the writing pressure, and the pressed portion 53 (tapered surface) of the holding member 40b is pressed rearward in the axial direction by the pressing portion 31 of the front shaft 130. As a result, the core feeding unit 40 including the writing core 70 is relatively moved rearward in the axial direction with respect to the shaft cylinder 100 against the urging force of the coil spring 60.
On the other hand, since the base 52 is pressed forward in the axial direction with respect to the outer cylinder 45 by the urging force of the spring 55, the base 52 is not moved relative to the rear in the axial direction with respect to the shaft cylinder 100. As a result, the length of the writing core 70 exposed from the tip of the base 52 is reduced.
In the mechanical pencil 100 shown in FIG. 8, the clearance L1 in the front-rear direction between the rear regulating portion 122 of the rear shaft 130 shown in FIG. 5 and the front regulating portion 21 of the lead feeding unit 40 is set to 7.7 mm. When a working load of 6N was applied due to the writing pressure, the outer cylinder 45 started to move and the core breakage prevention function could be activated.

Further, as described above, the mechanical pencil 100 of the present embodiment rotates the operation unit 124a of the operation body 124 (rear shaft 120) to rotate the rear regulation unit 121 of the rear shaft 120 and the lead feeding unit 40. The clearance L in the front-rear direction with the front restricting portion 21 can be changed by a maximum of 2 mm from 7.7 mm of L1 shown in FIG. 6 to 9.7 mm of L2 shown in FIG.
When the gap L1 in FIG. 6 is 7.7 mm, the coil spring 60 is compressed, so that the outer cylinder 45 is more difficult to move than in the state shown in FIG. 5, and a working load of 6N is applied by the writing pressure. At that time, the outer cylinder 45 started to move, and the core breakage prevention function could be activated.
When the gap L2 in FIG. 7 is 9.7 mm, the coil spring 60 is extended, so that the outer cylinder 45 is easier to move than in the state shown in FIG. 5, and when a working load of 4N is applied due to writing pressure. In addition, the outer cylinder 45 started to move, and the core breakage prevention function could be activated.
In addition to the states shown in FIGS. 5, 6, and 7, the mechanical pencil 1 of the present embodiment has the scale on the outer peripheral surface of the above-mentioned operating body 124 (rear shaft 120) and the base point mark on the outer surface of the crown 123. For reference, it is possible to appropriately set the situation in which the core breakage prevention function is activated by operating the operating body 124 (rear shaft 120).
In the mechanical pencil 100 of the present embodiment, a tubular heavy body 90 is arranged on the outer periphery of the core pipe 41, and by shaking the shaft cylinder 110 back and forth, the heavy body 90 advances to the connector 49. It is also possible to abut and advance the chuck 43 by the inertial force of the heavy body 90 to extend the writing core 70.

FIG. 9 is a side view showing a first state of a mechanical pencil according to a third embodiment of the present invention. FIG. 10 is a side view showing a second state of the mechanical pencil according to the third embodiment of the present invention.
The description of the members, parts and mechanisms similar to those of the first embodiment will be omitted.
The mechanical pencil 200 of the present embodiment has a rear shaft 220 having a knock portion 246 (knob 81) located behind the core feeding unit 40 protruding from the rear end, and a front shaft 230 connected to the front of the rear shaft. With, the shaft cylinder 210 is configured.
A substantially oval-shaped through hole 230b is provided on the side surface of the front shaft 230, and the operation portion 224a of the operation body 224 housed in the front shaft 230 so as to be movable back and forth is exposed from the through hole 230b. The operation body 224 of the present embodiment is a cylindrical body, and the operation portion 224a having a substantially oval shape is projected on the outer surface thereof, and a plurality of lateral grooves 224b are formed on the surface of the operation portion 224a so that a finger can easily catch it. It has been done. Further, a convex portion 224c protruding in the width direction is formed in the middle portion of the outer surface of the operation portion 224a, and by moving the operation body 224 back and forth, the convex portion 224c is formed on the inner surface of the through hole 230b. It is designed so that it can be locked stepwise in the recesses 230c formed so as to be continuous in a plurality of intermediate portions.
In FIG. 9, the convex portion 224c of the operating body 224 is locked to the concave portion 234c at the foremost end of the four concave portions 230c, and in FIG. 10, the convex portion 224c of the operating body 224 is the rearmost end of the four concave portions 230c. It is locked to the recess 231c of.
The four recesses 231c, 232c, 233c, and 234 are provided at intervals of 0.5 mm.

In the present embodiment, the front of the operating body 224 is a rear regulating unit 222 that regulates the rearward movement of the coil spring 60 as in the above embodiment, and by moving the operating unit 224a back and forth, the rearward regulation of the operating body 224 is performed. It is possible to change the gap in the front-rear direction between the portion 222 and the front regulating portion 21 of the core feeding unit 40 by a maximum of 2 mm, and the compression state of the coil spring 60 also changes by 2 mm due to the change of this gap by 2 mm. The structure is such that the working load changes by 2N from the state in which the outer cylinder 45 is stationary (see FIG. 1) to the state in which the outer cylinder 45 starts to move (see FIG. 4).

FIG. 9 is a view showing a state in which the clearance L1 in the front-rear direction between the rear regulating portion 222 of the operating body 224 and the front regulating portion 21 of the core feeding unit 40 is 7.7 mm, and the outer cylinder 45 is stationary. The working load from the state (see FIG. 1) to the state in which the outer cylinder 45 starts to move (see FIG. 4) is 6N.
FIG. 10 is a diagram showing a state in which the clearance L2 in the front-rear direction between the rear regulating portion 222 of the operating body 224 and the front regulating portion 21 of the core feeding unit 40 is set to 9.7 mm by operating the operating body. The working load from the state in which the outer cylinder 45 is stationary (see FIG. 1) to the state in which the outer cylinder 45 starts to move (see FIG. 4) is 4N.

1 ... Mechanical pencil,
10 ... Shaft tube,
20 ... Rear axle,
21 ... Front regulation department, 22 ... Rear regulation department,
23 ... crown, 23a ... recess,
24 ... Operating body, 24a ... Operating unit, 24b ... Step portion, 24c ... Operating member, 24d ... Inner shaft, 24e ... Female screw, 24f ... Male screw, 24g ... Male screw, 24h ... Key groove, 24i ... Protrusion, 24j … Dan part,
25 ... Regulatory member, 25a ... Female screw, 25b ... Protrusion,
26 ... Spring,
30 ... front axle, 30a ... keyway,
31 ... Pressing part, 32 ... Inner collar,
40 ... Core feeding unit, 40a ... Core feeding unit main body, 40b ... Holding member, 40c ... Main body part, 40d ... Stopper, 40e ... Reduced diameter part,
41 ... Core pipe,
42 ... Tightening ring,
43 ... Chuck,
44 ... Return spring,
45 ... outer cylinder, 45a ... rear cylinder, 45b ... front cylinder, 45c ... inner collar, 45d ... flat surface, 45e ... contact step portion,
46 ... Knock part, 46a ... Shaft member, 46b ... Holder part, 46c ... Sleeve part, 46d ... Flange part, 46e ... Spring, 46f ... Protrusion,
49 ... Connector,
52 ... Mouthpiece, 52a ... Front area, 52b ... Rear area, 52c ... Small diameter part, 52d ... Diameter expansion part, 52e ... Shoulder part,
53 ... Pressed part,
55 ... Spring,
60 ... Coil spring,
70 ... Writing core,
80 ... Eraser,
81 ... Knob,
100 ... Mechanical pencil,
110 ... Shaft tube,
120 ... rear shaft, 120a ... male screw part, 120b ... protrusion, 120c ... flange part, 120d ... through hole,
130 ... front shaft, 130a ... female screw part, 130b ... groove part, 130c ... step part,
122 ... Rear Regulation Department,
123 ... crown, 123a ... protrusion, 123b ... keyway,
124 ... Operation body, 124a ... Operation unit,
146 ... Knock part, 146a ... Shaft part, 146b ... Holder part, 146c ... Locking protrusion, 146d ... Protrusion,
146e ... Spring,
90 ... heavy body 200 ... mechanical pencil,
210 ... Shaft tube,
220 ... Rear axle,
222 ... Rear regulation department,
224 ... Operating body, 224a ... Operating unit, 224b ... Horizontal groove, 224c ... Convex portion,
230 ... front axle, 230b ... through hole,
230c, 231c, 232c, 233c, 234c ... recesses,
231c ... recess,
246 ... Knock part.

Claims (2)

With the shaft tube
A core feeding unit for feeding a writing core, in which a rear region is supported in the barrel so that the front region can be flexed and deformed or tilted in the barrel.
A front restricting portion provided on the outer peripheral surface of the front region of the core feeding unit,
A rear regulating portion provided on the inner peripheral surface axially rearward of the front regulating portion in the axle cylinder, and a rear regulating portion.
A stretchable elastic body arranged in a compressed state in the gap between the front regulating portion and the rear regulating portion,
Equipped with
The core feeding unit has a pressed portion on the outer peripheral surface of the front region.
The barrel has a pressing portion in the front region and has a pressing portion.
At least one of the pressed portion and the pressed portion is a tapered surface whose diameter gradually increases toward the rear in the axial direction.
Before the front region of the core feeding unit bends, deforms, or tilts in the shaft cylinder, the pressed portion and the pressed portion are in contact with each other, and the front region of the core feeding unit is inside the shaft cylinder. In the case of bending deformation or tilting, the pressed portion moves the pressed portion relative to the shaft cylinder in the axial direction.
A knock body that extends the writing core is provided at the rear end portion of the barrel, and an operating body that moves the rear regulating portion back and forth covers the outer periphery of the side surface of the knock body by exposing a part of the rear end of the knock body. and, wherein by operating the operating body that is provided continuously to the rear restricting portion, the rear regulating portion and moved back and forth, mechanical pencil which is characterized by structural changing the compression state of the elastic body. A scale provided along the circumference is formed on the outer peripheral surface of the operating body, and a base point mark rotating in the circumferential direction with respect to the scale is provided on the outer surface of the rear region of the barrel. The mechanical pencil according to claim 1, wherein the amount of change in the gap between the regulating portion and the rear regulating portion can be visually recognized.

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