JP2023035225A - mechanical pencil - Google Patents

Abstract

[Problem] To prevent lead clogging in a mechanical pencil. [Solution] A mechanical pencil 10 includes a first storage chamber C1 capable of storing a writing lead 80, a second storage chamber C2 located behind the first storage chamber C1 and capable of storing the writing lead 80, and a connecting member 40 that connects the first storage chamber C1 and the second storage chamber C2 and has a passage 42 through which the writing lead 80 can pass from the second storage chamber C2 to the first storage chamber C1. [Selected Figure] Figure 1

Description

The present invention relates to mechanical pencils.

2. Description of the Related Art Conventionally, a mechanical pencil is well known that includes a barrel, a lead storage chamber that stores a writing lead, and a chuck that forwards the writing lead from the lead storage chamber. In such a mechanical pencil, when the user presses the rear end of the mechanical pencil, the writing lead is fed forward from the lead storage chamber by the chuck, and the tip of the writing lead protrudes from the tip of the mechanical pencil. In this state, the user rubs the tip of the writing lead against a writing surface such as paper to form a handwriting on the writing surface with the writing lead. A writing lead other than the writing lead in use, ie, a spare lead, can be accommodated in the lead accommodation chamber. When the writing lead in use is exhausted, one of the spare leads accommodated in the lead accommodation chamber is forwarded by the chuck and used for writing. Patent Document 1 discloses an example of a conventional mechanical pencil.

JP-A-2001-63281

In a conventional mechanical pencil, a user may put a large number of spare leads in the lead storage chamber in order to save the trouble of replenishing spare writing leads (spare leads). In this case, when the writing lead in use is exhausted, the many spare leads accommodated in the lead accommodation chamber inhibit each other from moving forward, and the tip of the spare lead does not protrude from the tip of the mechanical pencil. So-called core clogging may occur.

If the tip of the writing lead protrudes too much from the tip of the mechanical pencil, the user presses the rear end of the mechanical pencil, for example, so that the tip of the writing lead is placed on the writing surface while the chuck remains open. The writing lead may be retracted by pressing it against the surface. Also, when replenishing a mechanical pencil with a writing lead, the writing lead may be inserted while retracting from the tip side of the mechanical pencil while the chuck remains open. In such a case, the spare lead may be caught between the rear end of the receding writing lead and any member in the lead storage chamber, and the spare lead may break. The broken spare lead moves to the front portion of the lead storage chamber during writing. In this case, when the writing lead in use is exhausted, the broken spare lead prevents the other spare lead from moving forward, and in this case also a so-called lead jam may occur.

SUMMARY OF THE INVENTION The present invention has been made in consideration of such points, and an object of the present invention is to suppress the occurrence of lead clogging in mechanical pencils.

The mechanical pencil according to the present invention is
a first storage chamber capable of storing a writing lead;
a second storage chamber located behind the first storage chamber and capable of storing a writing lead;
a connection member that connects the first storage chamber and the second storage chamber and has a passage through which the writing lead can pass from the second storage chamber to the first storage chamber. .

In the mechanical pencil according to the present invention,
The passage may be radially offset from the central axis of the mechanical pencil.

In the mechanical pencil according to the present invention,
The passageway may include a hole provided in the connecting member.

In the mechanical pencil according to the present invention,
The connection member has a main body and a rear projection that projects rearward from the main body,
The passageway may include a groove provided on the outer surface of the rearward protrusion.

In the mechanical pencil according to the present invention,
The connection member may have a guide portion that guides the writing lead to the passage.

In the mechanical pencil according to the present invention,
having a clip
The passage may be located on the opposite side of the clip with respect to the central axis of the mechanical pencil.

The mechanical pencil according to the present invention is
a storage chamber capable of storing a writing lead;
a retraction space located behind the storage chamber in which the writing lead in the storage chamber can be retracted;
A dimension of the evacuation space in a direction orthogonal to the central axis is smaller than a dimension of the storage chamber in a direction orthogonal to the central axis.

In the mechanical pencil according to the present invention,
A dimension of the evacuation space in a direction perpendicular to the central axis may be smaller than 1/2 of a dimension of the storage chamber in the direction perpendicular to the central axis.

In the mechanical pencil according to the present invention,
A central axis of the evacuation space may coincide with a central axis of the storage chamber.

In the mechanical pencil according to the present invention,
a connection member connected to the rear end of the storage chamber;
a pipe member connected to the connection member from behind,
A space inside the pipe member may form at least part of the evacuation space.

In the mechanical pencil according to the present invention,
A rear end of the evacuation space may be closed.

According to the present invention, it is possible to suppress the occurrence of lead clogging in a mechanical pencil.

FIG. 1 is a longitudinal sectional view showing a mechanical pencil according to the present invention. 2 is an enlarged view of a connection member of the mechanical pencil of FIG. 1. FIG. FIG. 3 is a cross-sectional view corresponding to line III-III of FIG. FIG. 4 is a perspective view showing a connecting member. FIG. 5 is a cross-sectional view showing a connecting member. FIG. 6 is a diagram showing how writing is performed using a mechanical pencil.

An embodiment of the present invention will be described below with reference to the drawings. In the drawings attached to this specification, for the convenience of illustration and ease of understanding, the scale, length-to-width ratio, etc. are appropriately changed and exaggerated from those of the real thing.

In addition, terms such as "parallel", "perpendicular", "identical", length and angle values, etc. that specify shapes and geometric conditions and their degrees used in this specification are strictly It shall be interpreted to include the extent to which similar functions can be expected without being bound by the meaning.

In this specification, the direction in which the central axis A of the mechanical pencil extends (longitudinal direction, vertical direction in a vertical cross-sectional view) is the axial direction da, the direction orthogonal to the axial direction da is the radial direction dr, and the circumference around the central axis A The direction along is defined as the circumferential direction dc. In addition, along the axial direction da, the side that approaches a writing surface such as a paper surface when writing is defined as the front side, and the side that is separated from the writing surface is defined as the rear side.

FIG. 1 is a longitudinal sectional view showing a mechanical pencil 10 according to the invention. The mechanical pencil 10 includes a barrel 20 and a core drawing unit 30. - 特許庁The barrel 20 includes a barrel main body 22, a tip member 24 located in front of the barrel main body 22, a sleeve 25 attached to the front end of the tip member 24, and connecting the barrel main body 22 and the tip member 24 to each other. and a connecting member 26 . A clip 28 is provided on the outer surface of the rear portion of the barrel body 22 . The barrel main body 22 has a cylindrical shape extending in the axial direction da along the central axis A of the mechanical pencil 10 . Therefore, the central axis of the barrel body 22 coincides with the central axis A of the mechanical pencil 10 . At least a part of the core pulling-out unit 30 is arranged inside the barrel main body 22 . The tip member 24 is a member forming the tip portion of the mechanical pencil 10 . The tip member 24 has a substantially conical shape, and its outer diameter decreases toward the front. A female threaded portion formed on the inner surface of the front end of the barrel main body 22 is screwed into a male threaded portion formed on the outer surface of the rear end of the connecting member 26, whereby the barrel main body 22 and the connecting member 26 are connected to each other. . Further, the tip member 24 and the connecting member 26 are connected to each other by screwing the female threaded portion formed on the inner surface of the rear end of the tip member 24 into the male threaded portion formed on the outer surface of the front end of the connecting member 26. . Thereby, the barrel main body 22 and the tip member 24 are connected to each other via the connecting member 26 . Sleeve 25 is fixed relative to tip member 24 . The writing lead 80 drawn forward by the lead drawing unit 30 passes through the sleeve 25 and protrudes from the front end of the sleeve 25 .

The lead drawing unit 30 has a mechanism for drawing out the writing lead 80 forward by the user's operation. The core pulling-out unit 30 of this embodiment includes a first core pipe 32, a second core pipe 34, a cap 38, a connecting member 40, a pipe member 50, a chuck 61, an elastic member 62, and a receiving member. It includes member 63 , fastener 64 and lead holder 65 .

Both the first core pipe 32 and the second core pipe 34 are members that accommodate the writing core 80 . The first lead pipe 32 forms a first accommodation chamber (accommodation chamber) C1 in which the writing lead 80 can be accommodated. The second core pipe 34 is positioned behind the first core pipe 32 . The second lead pipe 34 forms a second storage chamber C2 that can accommodate the writing lead 80 . Therefore, the second storage chamber C2 is positioned behind the first storage chamber C1. The connection member 40 connects the first core pipe 32 and the second core pipe 34 to each other. Therefore, the connecting member 40, which connects the first storage chamber C1 and the second storage chamber C2, allows the writing lead 80 to pass from the second storage chamber C2 toward the first storage chamber C1. It has a possible passageway 42 . Details of the connection member 40 will be described later. In this embodiment, the first core pipe 32, the second core pipe 34, and the connecting member 40 also have the function of transmitting the pressing force from the cap 38 to the chuck 61 when the user presses the cap 38 forward. The first core pipe 32 and the second core pipe 34 are made of resin, for example.

The pipe member 50 is a member that forms a retraction space S in which the writing lead 80 in the first accommodation chamber (accommodation chamber) C1 can be retracted. The pipe member 50 is attached to the rear portion of the connecting member 40 . Therefore, the pipe member 50 is positioned behind the first core pipe 32 . In addition, the pipe member 50 is positioned behind the first accommodation chamber (accommodation chamber) C1. In the example shown in FIG. 1, the pipe member 50 is positioned inside the second core pipe 34 . That is, the pipe member 50 is positioned inside the second storage chamber C2. Details of the pipe member 50 will be described later.

The mechanical pencil 10 of the present embodiment is configured such that the occurrence of lead clogging is suppressed by limiting the number of writing leads 80 accommodated in the first accommodation chamber C1. On the other hand, it is possible to accommodate a large number of writing leads 80 in the mechanical pencil 10 by further having the second accommodation chamber C2 capable of accommodating the writing leads 80 therein. Further, the mechanical pencil 10 of the present embodiment connects the first storage chamber C1 and the second storage chamber C2, and the writing lead 80 can pass from the second storage chamber C2 toward the first storage chamber C1. By having the connection member 40 having a possible passage, when the number of the writing lead 80 accommodated in the first accommodation chamber C1 is reduced, the writing lead 80 accommodated in the second accommodation chamber C2 does not pass through the first accommodation chamber C2. It is configured to be able to move to C1.

Further, the mechanical pencil 10 of the present embodiment retracts when retracting the writing lead 80 that protrudes greatly from the tip of the mechanical pencil 10, or when inserting the writing lead 80 while retracting it from the tip side of the mechanical pencil 10. The space S is configured to allow the other writing lead 81 pushed backward by the retracted writing lead 80 to retreat backward.

An eraser 36 is detachably attached to the rear end of the second core pipe 34 . Note that the eraser 36 can be omitted. The cap 38 is a member attached to the rear end portion of the second core pipe 34 to cover the rear end of the second core pipe 34 . If the mechanical pencil 10 has an eraser 36 attached to the rear end of the second core pipe 34 , the cap 38 also functions as a cover for the eraser 36 . In this embodiment, the cap 38 is also a knock body that is pushed forward by the user when the writing lead 80 is extended. In the example shown in FIG. 1, removing the cap 38 from the second core pipe 34 enables the eraser 36 to be used. Also, by removing the cap 38 and the eraser 36 from the second lead pipe 34 , the user can replenish the writing lead 80 inside the second lead pipe 34 .

The chuck 61 is a member that grips the writing lead 80 . The chuck 61 can move forward and backward integrally with the first core pipe 32 . In the example shown in FIG. 1 , the rear end of the chuck 61 is inserted into the front end of the first core pipe 32 , thereby fixing the chuck 61 to the first core pipe 32 .

An elastic member 62 is arranged in front of the first core pipe 32 . The resilient member 62 is, for example, a coil spring. A receiving member 63 is arranged in front of the elastic member 62 , and the elastic member 62 is arranged in a compressed state between the front end portion of the first core pipe 32 and the receiving member 63 . The receiving member 63 is a member that receives the elastic force of the elastic member 62 , is pushed forward by the elastic force of the elastic member 62 , and abuts on a step formed on the inner surface of the tip member 24 . The fastener 64 is an annular component positioned radially outward with respect to the front portion of the chuck 61 . The rearward movement of the fastener 64 is restricted by the rear end portion of the fastener 64 coming into contact with the receiving member 63 . The lead holder 65 is arranged in front of the chuck 61 and is a member that contacts the outer surface of the writing lead 80 to hold the writing lead 80 . The lead holder 65 is made of an elastic member such as rubber, and suppresses the writing lead 80 from moving in the axial direction da when the writing lead 80 is not gripped by the chuck 61 .

When the writing lead 80 is drawn out by the lead drawing unit 30, the user presses the cap 38 forward. As a result, the second core pipe 34 , the connecting member 40 , the first core pipe 32 and the chuck 61 move forward against the elastic force of the elastic member 62 . The outer surface of the front portion of the chuck 61 abuts against the fastener 64 from the inside when the cap 38 is not pushed forward. Therefore, the front portion of the chuck 61 is prevented from opening radially outward. Thereby, the front portion of the chuck 61 grips the writing lead 80 . When the chuck 61 moves forward together with the fastener 64, the writing lead 80 gripped by the chuck 61 moves forward. When the chuck 61 moves further forward, the fastener 64 comes into contact with the inner stage of the tip member 24 and the front portion of the chuck 61 moves forward with respect to the fastener 64 . As a result, the front portion of the chuck 61 opens outward and the writing lead 80 gripped by the front portion of the chuck 61 is released. At this time, the writing lead 80 is held by the lead holder 65 .

When the user releases the pressure on the cap 38, the cap 38, the second core pipe 34, the connecting member 40, the first core pipe 32, and the chuck 61 move rearward due to the resilient force of the resilient member 62. . As a result, the front portion of the chuck 61 moves inside the fastener 64 and contacts the fastener 64 to grip the writing lead 80 . At this time, since the writing lead 80 is held by the lead holder 65, the writing lead 80 is restrained from moving backward. By repeating this, the writing lead 80 is drawn forward, and the front end of the writing lead 80 passes through the sleeve 25 and protrudes forward from the front end of the sleeve 25 .

Details of the connection member 40 and the pipe member 50 will be described with reference to FIGS. 2 to 5. FIG. 2 is an enlarged view of the connecting member 40, FIG. 3 is a cross-sectional view of the mechanical pencil 10 corresponding to line III-III in FIG. 2, and FIG. 4 shows the connecting member 40. 5 is a cross-sectional view showing the connecting member 40. FIG.

The connection member 40 is a member that connects the first storage chamber C1 and the second storage chamber C2. The connection member 40 has a passage 42 through which the writing lead 80 can pass from the second storage chamber C2 toward the first storage chamber C1. The connecting member 40 is made of resin, for example. In particular, in order for the writing lead 80 to pass through the passage 42 smoothly, the connecting member 40 is preferably made of a material having a highly slippery surface. For example, a polyacetal resin or the like can be used as a material having a highly slippery surface.

The connection member 40 has a main body portion 44 and a rear projection portion 46 that projects rearward from the main body portion 44 . The body portion 44 and the rear projection portion 46 each have a hollow, substantially cylindrical shape. The outer diameter of the rear protruding portion 46 is smaller than the outer diameter of the body portion 44 . The body portion 44 and the rear projection portion 46 each have a through hole extending in the axial direction da, and the through hole of the body portion 44 and the through hole of the rear projection portion 46 communicate with each other.

The body portion 44 includes a first contact portion 44a that contacts the first core pipe 32 and receives the first core pipe 32, and a second contact portion that contacts the second core pipe 34 and receives the second core pipe 34. 44b and . The first contact portion 44a is a surface of a stepped portion provided on the inner surface of the through hole of the main body portion 44 and facing forward. The rear end of the first core pipe 32 is inserted from the front into the through hole of the body portion 44 and comes into contact with the first contact portion 44a. Thereby, the first core pipe 32 and the connecting member 40 are fixed to each other. The second contact portion 44b is a surface of the outer surface of the body portion 44 that faces rearward. In the illustrated example, the second contact portion 44b is located at the rear end of the body portion 44. As shown in FIG. In addition, the second contact portion 44b is located outside the rear projecting portion 46 in the radial direction dr. The front end of the second core pipe 34 is attached to the outside of the rear projecting portion 46 from the rear and contacts the second contact portion 44b. Thereby, the second core pipe 34 and the connecting member 40 are fixed to each other.

An inner inclined surface 44 c is provided at the rear portion of the inner surface of the through hole of the body portion 44 . The inner inclined surface 44c extends in a direction inclined with respect to both the axial direction da and the radial direction dr. The inner inclined surface 44c extends toward the center axis A toward the rear. A rear end of the inner inclined surface 44c is connected to the internal space of the rear protrusion 46 . The inner inclined surface 44c also serves as a guide surface that guides the writing lead 80 when the writing lead 80 in the first storage chamber C1 retreats toward the evacuation space S.

The rear projecting portion 46 has a third contact portion 46 a that receives the pipe member 50 . The third contact portion 46a is a rear facing surface of a stepped portion provided on the inner surface of the through hole of the rear projection portion 46. As shown in FIG. The front end of the pipe member 50 is inserted from the rear into the through hole of the rear projecting portion 46 and comes into contact with the third contact portion 46a. Thereby, the pipe member 50 and the connecting member 40 are fixed to each other.

As long as the writing lead 80 can pass from the second storage chamber C2 toward the first storage chamber C1, the specific shape and dimensions of the passage 42 are not particularly limited. In this embodiment, the passageway 42 includes a hole 44d provided in the body portion 44 and a groove 46b provided in the rear projection portion 46. As shown in FIG. The hole 44d is a through hole that connects the inner surface of the body portion 44 and the groove 46b. In the particularly illustrated example, hole 44d connects inner inclined surface 44c of body portion 44 and groove 46b. The groove 46b is provided on the outer surface of the rear projection 46. As shown in FIG. The groove 46b extends parallel to the axial direction da. The passage 42 is configured as a passage extending parallel to the axial direction da as a whole. Therefore, the writing lead 80 can move in the passage 42 in a direction parallel to the axial direction da. The minimum dimension of passage 42 in the direction orthogonal to axial direction da is larger than the diameter of writing lead 80 to be accommodated in mechanical pencil 10 . For example, when the diameter of the writing lead 80 to be accommodated in the mechanical pencil 10 is 0.57 mm, the minimum dimension of the passage 42 in the direction orthogonal to the axial direction da is set to be larger than 0.57 mm. Designed. The dimensions of passage 42 may be designed to allow only one writing lead 80 to pass through, or may be designed to allow multiple writing leads 80 to pass through at the same time.

In the present embodiment, the passage 42 is positioned with a deviation from the central axis A of the mechanical pencil 10 in the radial direction dr. In this case, when the passage 42 is positioned vertically downward with respect to the central axis A (see FIG. 6), the writing lead 80 accommodated in the second storage chamber C2 is pulled out of the passage 42 by the action of gravity. It becomes easier to be guided toward. Therefore, the writing lead 80 can be smoothly moved from the second storage chamber C2 toward the first storage chamber C1.

Also, in this embodiment, the passage 42 is located on the opposite side of the clip 28 with respect to the central axis A of the mechanical pencil 10 . When writing with the mechanical pencil 10, the user often holds the mechanical pencil 10 with the clip 28 facing upward. In this case, the passage 42 located on the side opposite to the clip 28 with respect to the center axis A is located vertically below the center axis A (see FIG. 6). Therefore, even if the user is not conscious of positioning the passage 42 downward with respect to the central axis A, the passage 42 can be aligned with the central axis A simply by gripping the mechanical pencil 10 with the clip 28 facing upward. It can be located below A.

The connecting member 40 may have guide portions 44 e , 46 c , 46 d that guide the writing lead 80 to the passage 42 . The rear protrusion 46 has a first inclined surface 46c and a second inclined surface 46d. The first inclined surface 46 c extends from the bottom surface 46 b 1 of the groove 46 b in a direction inclined with respect to both the bottom surface 46 b 1 and the rear end surface 46 e of the rear protrusion 46 . The first inclined surface 46c connects the bottom surface 46b1 and the rear end surface 46e. In the illustrated example, the first inclined surface 46c intersects the through hole of the rear projection 46, and the straight line extending the straight line connecting the rear end surface 46e and the first inclined surface 46c is the mechanical pencil 10. It intersects the central axis A. The first inclined surface 46c extends forward as the distance from the central axis A increases. When the front end of the writing lead 80 accommodated in the second accommodation chamber C2 comes into contact with the first inclined surface 46c, the front end of the writing lead 80 is guided by the first inclined surface 46c and can move into the passage 42. . That is, the first inclined surface 46 c functions as a guide portion that guides the writing lead 80 toward the passage 42 .

The second inclined surface 46d extends from the rear end of the side surface 46b2 of the groove 46b in a direction inclined with respect to the side surface 46b2. The groove 46b has a pair of opposing side surfaces 46b2. The connecting member 40 has two second inclined surfaces 46d respectively corresponding to the pair of side surfaces 46b2. A second inclined surface 46d connected to one side surface 46b2 of the pair of side surfaces 46b2 extends rearward away from the other side surface 46b2. The second inclined surface 46d connected to the other side surface 46b2 extends away from the one side surface 46b2 toward the rear. When the front end of the writing lead 80 accommodated in the second accommodation chamber C2 comes into contact with the second inclined surface 46d, the front end of the writing lead 80 is guided by the second inclined surface 46d and can move into the passage 42. . That is, the second inclined surface 46 d functions as a guide portion that guides the writing lead 80 toward the passage 42 . The first inclined surface 46c and the second inclined surface 46d may be flat or curved.

A groove 44 e extending in the radial direction dr is formed in the rear end surface of the body portion 44 . The groove 44 e communicates with the passage 42 . In particular, groove 44e communicates with hole 44d and with groove 46b. If the connecting member 40 has such a groove 44e, the front end of the writing lead 80 accommodated in the second accommodation chamber C2 fits into this groove 44e. A writing lead 80 whose front end is located within groove 44e can move to passageway 42 along groove 44e. That is, the groove 44 e functions as a guide portion that guides the writing lead 80 whose front end is positioned within the groove 44 e toward the passage 42 .

Next, the evacuation space S will be explained. When retracting the writing lead 80 that protrudes greatly from the tip of the mechanical pencil 10, or when inserting the writing lead 80 while retracting it from the tip side of the mechanical pencil 10, the rear end of the retracted writing lead 80 and the first storage chamber (Accommodation chamber) There is a possibility that another writing lead 81 may be caught between it and the rear end portion of C1, and the other writing lead 81 may break. The broken writing lead 81 moves to the front portion of the first storage chamber C1 during writing. In this case, when the writing lead 80 in use is worn out, the broken writing lead 81 may prevent the other writing lead 80 from moving forward, causing so-called lead clogging. In order to suppress the occurrence of such lead clogging, in the present embodiment, the mechanical pencil 10 is provided with a retraction space S in which the other writing lead 81 pushed backward by the retracted writing lead 80 can be retracted. . Note that FIG. 1 shows an example in which another writing lead 81 is positioned behind the writing lead 80 gripped by the chuck 61 and used for writing.

In this embodiment, the mechanical pencil 10 has a pipe member 50 connected to the connecting member 40 from behind. The space inside the pipe member 50 forms at least part of the evacuation space S. As shown in FIG. The evacuation space S may be configured to include only the space inside the pipe member 50 . Also, the evacuation space S may be configured to include the space inside the pipe member 50 and the space inside the connecting member 40 . The retraction space S is located behind the first storage chamber C1 and allows the writing lead 80 in the first storage chamber (accommodation chamber) C1 to retract. The pipe member 50 is inserted from the rear into the through hole of the rear projecting portion 46 . The front end of the pipe member 50 is in contact with the third contact portion 46a of the rear projecting portion 46. As shown in FIG. The pipe member 50 is a tubular member extending in a direction parallel to the central axis A of the mechanical pencil 10 . The pipe member 50 is made of resin or metal, for example.

The evacuation space S communicates with the first storage chamber C1. In this embodiment, the central axis of the evacuation space S is aligned with the central axis of the first storage chamber C1. The central axis of the first storage chamber C1 coincides with the central axis A of the mechanical pencil 10. As shown in FIG. Also, the central axis of the retraction space S coincides with the central axis A of the mechanical pencil 10 . Since the central axis of the retraction space S coincides with the central axis of the first storage chamber C1, the writing lead 80 is pushed backward along the central axis of the first storage chamber C1 by being pushed by the rear end of the writing lead 80. The other writing lead 81 can be appropriately retracted. In addition, as described above, the main body portion 44 of the connecting member 40 has the inner inclined surface 44c. Therefore, the rear end of the other writing lead 81 that is pushed backward by the rear end of the writing lead 80 that has retreated can be guided by the inner inclined surface 44c toward the retreat space S. As shown in FIG.

The dimension of the evacuation space S in the direction orthogonal to the central axis is smaller than the dimension of the first storage chamber C1 in the direction orthogonal to the central axis. Here, the dimension in the direction perpendicular to the central axis refers to the smallest dimension among dimensions measured so as to pass through the central axis in a cross section perpendicular to the central axis of the member. When the evacuation space S and the first accommodation chamber C1 are cylindrical spaces, the dimensions of the evacuation space S and the first accommodation chamber C1 in the direction perpendicular to the central axis are the same as the evacuation space S and the first accommodation chamber C1, respectively. is the diameter of In this embodiment, the inner diameter of the pipe member 50 is smaller than the inner diameter of the first storage chamber C1. As a result, the dimension of the evacuation space S in the direction perpendicular to the central axis is smaller than the dimension of the first storage chamber C1 in the direction perpendicular to the central axis. In this case, the volume occupied by the evacuation space S can be reduced. Therefore, the space inside the mechanical pencil 10 can be effectively used. Further, when the mechanical pencil 10 has the passage 42, it is also possible to arrange the evacuation space S and the passage 42 side by side in a direction perpendicular to the central axis. The dimension of the evacuation space S in the direction orthogonal to the central axis may be smaller than 1/2 of the dimension of the first storage chamber C1 in the direction orthogonal to the central axis. In this case, the volume occupied by the evacuation space S can be further reduced. Therefore, the space inside the mechanical pencil 10 can be used more effectively.

The dimension of the retraction space S in the direction orthogonal to the central axis is larger than the diameter of the writing lead 80 to be housed in the mechanical pencil 10 . For example, when the diameter of the writing lead 80 to be housed in the mechanical pencil 10 is 0.57 mm, the dimension of the retraction space S in the direction perpendicular to the central axis is designed to be larger than 0.57 mm. be done. Also, the dimension of the retraction space S in the direction orthogonal to the central axis may be smaller than twice the diameter of the writing lead 80 to be housed in the mechanical pencil 10 . For example, when the diameter of the writing lead 80 to be accommodated in the mechanical pencil 10 is 0.57 mm, the dimension of the retraction space S in the direction orthogonal to the central axis is designed to be smaller than 1.14 mm. may be In this case, only one writing lead 80 can enter the evacuation space S.

The rear end of the evacuation space S may be open or closed. When the rear end of the retraction space S is open, the writing lead 80 stored in the first storage chamber C1 can be taken out through the retraction space S to the outside. Further, when the rear end of the evacuation space S is closed, when the user replenishes the writing lead 80 in the second storage chamber C2, the writing lead 80 to be replenished enters the evacuation space S by mistake. can be prevented.

Next, the operation of the mechanical pencil 10 of this embodiment will be described. FIG. 6 is a diagram showing how the mechanical pencil 10 is used for writing.

The user removes the cap 38 and the eraser 36 from the second lead pipe 34 and replenishes the writing lead 80 inside the second lead pipe 34 . After that, the eraser 36 and the cap 38 are attached to the second core pipe 34 .

As shown in FIG. 6, when writing on a writing surface 90 such as paper, the user normally aligns the center axis A with respect to both the writing surface 90 and the vertical direction. A mechanical pencil 10 is held. 6, the writing surface 90 extends horizontally, and gravity acts downward in FIG. That is, the vertical direction in FIG. 6 is the vertical direction. When the user holds the mechanical pencil 10 so that the passage 42 is positioned vertically downward with respect to the central axis A, the writing lead 80 accommodated in the second storage chamber C2 is pushed into the passage 42 by the action of gravity. guided towards. Specifically, in the example shown in FIG. 6, the passageway 42 is located on the opposite side of the clip 28 with respect to the central axis A of the mechanical pencil 10 . When writing with the mechanical pencil 10, the user often holds the mechanical pencil 10 with the clip 28 facing upward. In this case, the passage 42 located on the side opposite to the clip 28 with respect to the center axis A is located below the center axis A.

The writing lead 80 guided to the passage 42 moves through the passage 42 into the first storage chamber C1 by the action of gravity. The dimensions of the first storage chamber C1 are designed to limit the number of writing leads 80 that can be stored in the first storage chamber C1. As a result, when the writing lead 80 in use is consumed, it is possible to prevent the many writing leads 80 accommodated in the first accommodation chamber C1 from hindering each other from moving forward. Therefore, it is possible to effectively suppress the occurrence of lead clogging in the first storage chamber C1.

Moreover, in the mechanical pencil 10 of this embodiment, a large number of writing leads 80 can be accommodated in the second accommodation chamber C2. As a result, the number of times of replenishing the writing lead 80 into the mechanical pencil 10 can be reduced.

When retracting the writing lead 80 that protrudes greatly from the tip of the mechanical pencil 10, or when inserting the writing lead 80 while retracting it from the tip side of the mechanical pencil 10, the other writing lead 81 is pushed backward by the retracted writing lead 80. , the other writing lead 81 that has been pressed can be retracted into the retraction space S. As shown in FIG. As a result, another writing lead 81 is sandwiched between the rear end of the retracted writing lead 80 and any member in the accommodation chamber, for example, the rear end of the first accommodation chamber C1, and the other writing lead 81 You can prevent it from breaking. Therefore, it is possible to effectively prevent the broken writing lead 81 from moving to the front portion of the first storage chamber C1 during writing and causing lead clogging due to the writing lead 81 .

The mechanical pencil 10 of the present embodiment includes a first storage chamber C1 that can store the writing lead 80, a second storage chamber C2 that is located behind the first storage chamber C1 and can store the writing lead 80, and a second storage chamber C2 that can store the writing lead 80. a connection member 40 that connects the first storage chamber C1 and the second storage chamber C2 and has a passage 42 through which the writing lead 80 can pass from the second storage chamber C2 toward the first storage chamber C1; Prepare.

In conventional mechanical pencils, it has not been possible to accommodate a large number of writing leads in the mechanical pencil. Therefore, even if the writing lead is not replenished for a short period of time, the writing lead contained in the mechanical pencil may be used up, and the mechanical pencil may become unusable in important situations. This problem has sometimes been a serious problem for users of mechanical pencils. Moreover, in order to avoid such problems, it is necessary to carry a spare lead housed in a separate case together with the mechanical pencil, which sometimes causes inconvenience to the user.

According to the mechanical pencil 10 of this embodiment, a large number of writing leads 80 can be accommodated in the second accommodation chamber C2 while limiting the number of writing leads 80 accommodated in the first accommodation chamber C1. . Therefore, it is possible to reduce the number of times of refilling the writing lead 80 into the mechanical pencil 10 while suppressing the occurrence of lead clogging. Above all, in the mechanical pencil 10 of the present embodiment, even if the writing lead 80 is not frequently replenished, the writing lead 80 contained in the mechanical pencil 10 is prevented from being used up. Therefore, it is possible to reduce the possibility that the mechanical pencil 10 cannot be used in an important situation. This allows the user to use the mechanical pencil 10 with peace of mind. In addition, the user does not have to carry the spare lead housed in a separate case, which reduces the burden on the user.

According to studies by the inventors of the present invention, in the conventional mechanical pencil, the upper limit of the number of writing leads that can be accommodated in the lead accommodation chamber is about 6 from the viewpoint of suppressing the occurrence of lead clogging. In the mechanical pencil 10 of the present embodiment, even when about 20 writing leads 80 were stored in the second storage chamber C2, the occurrence of lead clogging was sufficiently suppressed. In view of the fact that conventional mechanical pencils were unable to suppress the occurrence of lead clogging while containing such a large number of writing leads, the above-described effects of the present embodiment are extremely remarkable. It can be said.

In the mechanical pencil 10 of the present embodiment, the passage 42 is offset from the central axis A of the mechanical pencil 10 in the radial direction dr.

According to such a mechanical pencil 10, when the passage 42 is positioned vertically downward with respect to the central axis A, the writing lead 80 accommodated in the second accommodation chamber C2 is pushed by the action of gravity. It becomes easier to be guided toward the passage 42 . Therefore, the writing lead 80 can be smoothly moved from the second storage chamber C2 toward the first storage chamber C1.

In the mechanical pencil 10 of this embodiment, the passage 42 includes a hole 44d provided in the connecting member 40. As shown in FIG.

According to such a mechanical pencil 10, the writing lead 80 accommodated in the second accommodation chamber C2 can be smoothly moved toward the first accommodation chamber C1 through the hole 44d.

In the mechanical pencil 10 of this embodiment, the connecting member 40 has a main body portion 44 and a rear projection portion 46 that projects rearward from the main body portion 44, and the passage 42 is provided on the outer surface of the rear projection portion 46. groove 46b.

According to such a mechanical pencil 10, the writing lead 80 accommodated in the second accommodation chamber C2 can smoothly move toward the first accommodation chamber C1 through the groove 46b.

In the mechanical pencil 10 of this embodiment, the connection member 40 has guide portions 44e, 46c, and 46d that guide the writing lead 80 to the passage 42. As shown in FIG.

According to such a mechanical pencil 10, when the front end of the writing lead 80 accommodated in the second accommodation chamber C2 abuts against the guide parts 44e, 46c, 46d, the front end of the writing lead 80 moves toward the guide parts 44e, 46c, 46d. Guided by 46d, it moves into passage 42. Therefore, the writing lead 80 accommodated in the second accommodation chamber C2 can move more smoothly toward the first accommodation chamber C1.

The mechanical pencil 10 of this embodiment has a clip 28 , and the passage 42 is located on the opposite side of the clip 28 with respect to the central axis A of the mechanical pencil 10 .

When writing with the mechanical pencil 10, the user often holds the mechanical pencil 10 with the clip 28 facing upward. In this case, the passage 42 located on the side opposite to the clip 28 with respect to the center axis A is located vertically below the center axis A. As shown in FIG. According to the mechanical pencil 10 of this embodiment, the user holds the mechanical pencil 10 with the clip 28 facing upward without being conscious of positioning the passage 42 downward with respect to the central axis A. The passage 42 can be positioned downward with respect to the center axis A simply by doing so.

The mechanical pencil 10 of this embodiment includes an accommodation chamber C1 that can accommodate the writing lead 80, and a retraction space S that is located behind the accommodation chamber C1 and that allows the writing lead 80 in the accommodation chamber C1 to be retracted. The dimension of the evacuation space S in the direction orthogonal to the central axis A is smaller than the dimension of the accommodation chamber C1 in the direction orthogonal to the central axis A. As shown in FIG.

When retracting the writing lead 80 that protrudes greatly from the tip of the mechanical pencil 10, or when inserting the writing lead 80 while retracting it from the tip side of the mechanical pencil 10, the rear end of the retracted writing lead 80 and the first storage chamber (Accommodation chamber) There is a possibility that another writing lead 81 may be caught between it and the rear end portion of C1, and the other writing lead 81 may break. The broken writing lead 81 moves to the front portion of the first storage chamber C1 during writing. In this case, when the writing lead 80 in use is worn out, the broken writing lead 81 may prevent the other writing lead 80 from moving forward, causing so-called lead clogging.

According to the mechanical pencil 10 of the present embodiment, when retracting the writing lead 80 that protrudes greatly from the tip of the mechanical pencil 10, or when inserting the writing lead 80 while retracting it from the tip side of the mechanical pencil 10, other When the writing lead 81 is pushed backward by the writing lead 80 that has retreated, the other writing lead 81 that has been pushed can be withdrawn into the evacuation space S. As a result, another writing lead 81 is sandwiched between the rear end of the retracted writing lead 80 and any member in the accommodation chamber, for example, the rear end of the first accommodation chamber C1, and the other writing lead 81 You can prevent it from breaking. Therefore, it is possible to effectively prevent the broken writing lead 81 from moving to the front portion of the first storage chamber C1 during writing and causing lead clogging due to the writing lead 81 .

In addition, since the dimension of the evacuation space S in the direction orthogonal to the central axis A is smaller than the dimension of the first storage chamber C1 in the direction orthogonal to the central axis A, the volume occupied by the evacuation space S can be reduced. . Therefore, the space inside the mechanical pencil 10 can be effectively used.

In the mechanical pencil 10 of the present embodiment, the dimension of the retraction space S in the direction orthogonal to the central axis A is smaller than half the dimension of the accommodation chamber C1 in the direction orthogonal to the central axis A.

According to such a mechanical pencil 10, the volume occupied by the evacuation space S can be further reduced. Therefore, the space inside the mechanical pencil 10 can be used more effectively.

In the mechanical pencil 10 of this embodiment, the central axis A of the retraction space S coincides with the central axis A of the storage chamber C1.

According to such a mechanical pencil 10, it is possible to appropriately retract the other writing lead 81 that is pushed by the rear end of the writing lead 80 that has retreated along the center axis of the storage chamber C1 and moves backward.

The mechanical pencil 10 of this embodiment includes a connection member 40 connected to the rear end of the storage chamber C1, and a pipe member 50 connected to the connection member 40 from the rear. At least part of the space S is formed.

According to such a mechanical pencil 10, the evacuation space S can be formed with a simple configuration.

In the mechanical pencil 10 of this embodiment, the rear end of the retraction space S is closed.

According to such a mechanical pencil 10, when the user replenishes the writing lead 80 in the second accommodation chamber C2, the writing lead 80 to be replenished is prevented from erroneously entering the evacuation space S. can be done.

10 mechanical pencil 20 shaft tube 22 shaft tube main body 24 tip member 25 sleeve 26 connecting member 28 clip 30 lead extraction unit 32 first lead pipe 34 second lead pipe 36 eraser 38 cap 40 connecting member 42 passage 44d hole 46b groove 44 body Portion 44a First contact portion 44b Second contact portion 44c Inner inclined surface 44d Hole 44e Groove 46 Rear protrusion 46a Third contact portion 46b Groove 46b1 Bottom surface 46b2 Side surface 46c First inclined surface 46d Second inclined surface 46e Rear end surface 50 Pipe member 61 Chuck 62 Resilient member 63 Receiving member 64 Clamp 65 Lead holder 80 Writing lead 81 Writing lead 90 Writing surface A Center axis C1 First storage chamber C2 Second storage chamber S Retreat space da Axial direction dr Radial direction dc circumferential direction

Claims (11)

a first storage chamber capable of storing a writing lead;
a second storage chamber located behind the first storage chamber and capable of storing a writing lead;
a connection member that connects the first storage chamber and the second storage chamber and has a passage through which the writing lead can pass from the second storage chamber to the first storage chamber. mechanical pencil. 2. The mechanical pencil of claim 1, wherein the passageway is radially offset from the central axis of the mechanical pencil. 3. The mechanical pencil according to claim 1, wherein said passage includes a hole provided in said connecting member. The connection member has a main body and a rear projection that projects rearward from the main body,
The mechanical pencil according to any one of Claims 1 to 3, wherein the passage includes a groove provided on the outer surface of the rear projection. The mechanical pencil according to any one of claims 1 to 4, wherein said connecting member has a guide portion for guiding said writing lead to said passage. having a clip
The mechanical pencil according to any one of claims 1 to 5, wherein the passage is located on the side opposite to the clip with respect to the central axis of the mechanical pencil. a storage chamber capable of storing a writing lead;
a retraction space located behind the storage chamber in which the writing lead in the storage chamber can be retracted;
The mechanical pencil, wherein the dimension of the retraction space in the direction orthogonal to the central axis is smaller than the dimension of the storage chamber in the direction orthogonal to the central axis. 8. The mechanical pencil according to claim 7, wherein the dimension of said retraction space in the direction orthogonal to the central axis is smaller than 1/2 of the dimension of said storage chamber in the direction orthogonal to the central axis. 9. The mechanical pencil according to claim 7, wherein the central axis of said retraction space coincides with the central axis of said storage chamber. a connection member connected to the rear end of the storage chamber;
a pipe member connected to the connection member from behind,
The mechanical pencil according to any one of claims 7 to 9, wherein the space inside the pipe member forms at least part of the retraction space. The mechanical pencil according to any one of claims 7 to 10, wherein the rear end of said retraction space is closed.

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