JPH0624983U - mechanical pencil - Google Patents

Abstract

(57) [Summary] [Purpose] It is possible to provide a mechanical pencil suitable for children and examinees of lower grades who frequently write and erase. [Structure] A core case 11 having a chuck 14 fixed to the tip is housed in the front shaft 1 so that the core can be moved axially, and a chuck spring 16 that elastically springs the chuck rearward is attached. A weight 17 which is fitted to the core case and is capable of axial shifting by its own weight is provided between the two, and a cap 20 having a spiral groove 21 in the inner hole and a slit 25 are provided to enable rotation in the cap inner hole. The fixed inner cylinder 24 and the return spring 45 allow the inner cylinder to move only in the axial direction at least within a certain forward range, and are fixed so as to prevent the backward movement at the most advanced position. A joining cylinder 34 which is detachably attached to the rear end of the shaft, and an eraser holder 31 having a protrusion 32 on the side surface and an eraser 33 fixed to the rear end allow the protrusion to be fitted into the slit and the spiral groove in the inner cylinder. Eraser A mechanical pencil characterized by its body.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a mechanical pencil for children of lower grades and for taking an examination.

[0002]

[Prior art]

 Conventionally, a mechanical pencil in which the rear shaft is rotated with respect to the front shaft to extend a large-diameter eraser from the rear end of the rear shaft, and the rear end of the rear shaft is knocked against the front shaft to extend the lead. It has been known. This product has the trouble of frequently knocking the rear end as the core wears out. Further, when knocking, the eraser that is in a protruding state may be cumbersome to be housed in the rear shaft. (If you knock in the protruding state, your fingers may become dirty, or the oil on your fingers may transfer to the end surface of the eraser, making erasability worse.)

[0003]

[Problems to be solved by the device]

 An object of the present invention is to solve the problems of the conventional example and to provide a mechanical pencil which is convenient for children of lower grades and for taking an examination.

[0004]

[Means for Solving the Problems]

 The mechanical pencil of the present invention, which was devised to achieve the above object, is a chuck spring that elastically stores a core case with a chuck fixed to the tip in a tip shaft so that the chuck can be moved backward with a weak force. The core case is fitted between the tip of the core case and the ring fixed to the rear end circumferential groove, and a weight that can move the axis by its own weight is placed on the core case. It is a convenient sharp pencil that is detachably attached. The eraser feed-out body has a cap with a spiral groove in the inner hole, an inner cylinder with a slit that is rotatably fixed in the inner hole of the cap, and an inner cylinder with at least a fixed amount through the elastic return spring. It is movable only in the axial direction within the range of forward movement, and is fixed so that it can be appropriately retracted at the most advanced position, and has a joining cylinder that is detachably attached to the rear end of the front shaft and a protrusion on the side surface. An eraser holder with an eraser fixed to the rear end is constructed by fitting a protrusion into a slit and a spiral groove in the inner cylinder, and is provided so that the axial movement of the inner cylinder interlocks with the lead case and the chuck. There is. As described above, by swinging the shaft, the chuck moves axially by the inertial force of the weight and the core is drawn out, and by rotating the cap with respect to the front shaft, the eraser can be retracted from the rear end. . Therefore, since the lead can be extended without knocking the rear end, there is no need to bother with the eraser frequently. Further, when the cap is held at the most advanced position with respect to the leading shaft, the gripping of the lead by the chuck is released, so there is no inconvenience that the lead swings out when carried.

[0005]

【Example】

 1 and 2 show a first embodiment of the present invention. First, a tip pipe 9 that allows a core to be inserted is fixed to the tip of the mouthpiece 7, and a holding chuck 10 made of rubber or the like that allows the core to be inserted by appropriately frictionally engaging is fixed to the tip of the inner hole. Further, a screw portion (female screw) having a step portion 8 at the tip is provided behind the inner hole of the mouthpiece 7.

The front shaft 1 is provided with a shaft portion 2 provided with a screw portion 5 (male screw) at the tip of a cylindrical body, and the shaft portion 2 is provided with a hole having a front stage portion 6, and the hole is rearward. It communicates with the inner hole of the cylinder. Further, a step portion 3 is provided at the tip of the inner hole portion, and the rear end inner wall of the inner hole portion is formed with a joint cylinder 34, which will be described later, and a projection 4 that locks and prevents disengagement. There is.

The chuck 14 is fitted by engaging the fastener 15 with the head in the hole of the shaft portion 2 of the front shaft, and the core case 11 is inserted into the inner hole of the front shaft 1 to insert the core. The rear end of the chuck 14 is fixed to the front end of the case 11. At that time, a chuck spring 16 is urged between the step portion 3 at the tip of the inner hole and the flange portion 12 provided at substantially the tip of the lead case 11. The chuck spring 16 springs the chuck 14 rearward with an appropriate weak force. Further, the lead case 11 is a cylindrical body having a lead storage portion through which the lead can be inserted into the chuck 14, and a peripheral groove 18 is formed on the outer periphery near the rear end. Further, a cushioning material 13 such as rubber is fixed to the outer periphery of the lead case 11 at the rear end of the collar portion 12, and a weight 17 is fitted to the rear side. Then, the ring 19 is fixed to the circumferential groove 18. Although the ring 19 is elastically deformed and fixed to the circumferential groove 18, a split portion 19 'is appropriately formed to facilitate the deformation. The weight 17 can be axially moved between the cushioning member 13 and the ring 19 by its own weight.

A joining cylinder 34, which will be described later, of an eraser feeding member is detachably fixed to the rear end hole of the front shaft 1. A groove 41 is formed on the side surface of the shaft portion 35 on the front side of the joining cylinder 34, and elastically rides over the projection 4 in the rear end hole of the front shaft so as to prevent each other from coming off by an appropriate force. Further, the side surface of the joining cylinder 34 is provided with a shape that is engaged with the rear end hole of the front shaft 1 and is integrated with each other in the rotation direction. Further, as shown in FIG. 2, on the side surface of the shaft portion 36 on the rear side of the joining cylinder 34, there is provided a vertical groove 38 in which an engaging step portion 40 is formed together with an opening having a taper portion 44 at an appropriate position from the rear end side. A lateral groove 39 is provided at a front position (a position where the inner cylinder can be advanced to advance the chuck and advance the chuck to release the grip of the core, which will be described later) in a direction substantially perpendicular to the vertical groove 38. A protrusion 43 is formed on the wall on the rear side of the inlet 39.

By the way, the eraser feeding body is configured by combining the members of the cap 20, the inner cylinder 24, the eraser holder 31, and the joining cylinder 34, and the cap 20 is fitted on the outer periphery of the rear end of the front shaft 1 in the forward direction. An inner hole is provided, and a step portion 22 is formed at the rear end of the inner hole. The side surface has a clip 23, and the spiral groove 21 is formed on the inner surface. The inner cylinder 24 has a hole for inserting the eraser 33 and a crown portion 28 for abutting the rear end surface of the cap 20 at the rear end, and a long slit 25 is formed from the approximate center to the crown portion. There is. Further, a flange 27 is provided on the rear end side surface of the front shaft portion 26, a protrusion 29 is further formed on the front side surface, and a boss portion 42 having a step portion 30 is further formed on the front side. ing.

The eraser feed-out body is configured such that the eraser holder 31 is elastically fitted from the slit 25 of the inner cylinder 24 and the projection 32 provided on the side surface thereof is fitted into the slit, and the inner cylinder 24 is attached to the rear end of the cap 20. The protrusion 32 is inserted into the spiral groove 21 while being inserted into the spiral groove 21, and the collar portion 27 is elastically deformed so as to substantially abut the step portion 22 of the cap 20. The cap 20 is placed between the crown portion 28 and the collar portion 27. Is rotatable with respect to the inner cylinder 24 (having a slight frictional resistance with the inner cylinder) and prevented from coming off. An eraser 33 is fixed to the rear end of the eraser holder 31, and a return spring 45 is attached between the flange portion 37 of the joining cylinder 34 and the step portion 22 of the cap 20 to move the cap 20 and the inner cylinder 24 rearward. In the elastic state, the projection 29 of the inner cylinder 24 is fitted into the vertical groove 38 of the joining cylinder 34 by utilizing the elastic deformation of the shaft portion 36, and the projection 29 is retained and locked by the locking step portion 40. Therefore, the inner cylinder 24 axially shifts with respect to the joining cylinder 34, but they are integrated in the rotation direction. Further, the return spring 45 is biased by a force stronger than that of the chuck spring 16.

In this state, the eraser feeding body is detachably attached to the rear end hole of the front shaft 1. At that time, the boss portion 42 is appropriately fitted in the rear end hole of the core case 11 in a state where the step portion 30 ahead of the shaft portion 26 of the inner cylinder is substantially in contact with the rear end surface of the core case 11. Further, when the cap 20 is rotated with respect to the front shaft 1, the eraser 33 comes in and out from the rear end hole of the crown portion 28.

FIG. 3 and FIG. 4 show a second embodiment of the present invention, which is different from the first embodiment only in the shape of the joining cylinder. The joining cylinder 50 of this example is provided with a slit 53 in which a step portion 52 is formed by providing a tapered portion 55 from the rear end at an appropriate position on the side surface of the rear shaft portion 51, and the step portion 52 is formed on the side wall of the slit 53. A protrusion 54 is formed at an appropriate front position.

[0013]

[Action]

 First, in order to feed the lead, the weight 17 is advanced by grasping the front shaft 1 and swinging it forward in the axial direction, and the inertial force of the weight 17 advances the lead case 11 and the chuck 14 to feed the lead. When returning the core that has protruded too much from the tip pipe 9, when the cap 20 is advanced with respect to the tip shaft 1, the chuck 14 moves forward together with the core case 11 in conjunction with the inner cylinder 24, and the fastener 15 moves from the head of the chuck. When the lead is released, the grip of the lead is released, and at the same time, when the tip of the lead is pressed against the paper surface or the like, the lead returns to the inside of the tip pipe 9. When the cap 20 is rotated with respect to the front shaft 1, the eraser 33 projects from the rear end of the crown portion 28.

When carrying a mechanical pencil, first, in the first embodiment, when the cap 20 is most advanced with respect to the tip shaft 1 and rotated to one side (the cap and the inner cylinder have an appropriate frictional resistance). (In this case, they rotate together.) When the projection 29 provided on the inner cylinder 24 is inserted into the lateral groove 39 and the forward movement is released, the rear end of the projection 29 is the rear wall of the lateral groove 39 as shown in A of FIG. And the cap 20 is in the most advanced position with respect to the front shaft 1. At that time, the chuck 14 also moves to the forward position, and the grip of the lead is released, so that the lead is not drawn out even if shaken. Further, since the protrusion 29 is prevented from rotating by the protrusion 43 of the lateral groove 39, the inner cylinder 24 is prevented from rotating. In order to allow the lead to be drawn out again, the cap 20 is pushed against the front shaft 1 so as to be in the most advanced position and rotated in the opposite direction to insert the projection 29 into the vertical groove 38 from the lateral groove 39. 20 retreats to the state shown in FIG.

Further, in the second embodiment, when the cap 20 is most advanced with respect to the front shaft 1, the projection 29 of the inner cylinder 24 elastically rides over the projection 54 of the slit 53 as shown in FIG. Is locked at the position indicated by B, and the chuck 14 is moved to the advanced position as in the first embodiment, and the grip of the lead is released. When it is possible to extend the lead again, the cap 20 is pulled rearward with respect to the front shaft 1 to release the engagement between the protrusion 29 and the protrusion 54. The locking force between the projection 29 and the projection 54 is within a range where the locking does not come off even if the shaft is normally shaken, and the fastening force between the front shaft 1 and the joining cylinder 50 is the relationship between the projection 29 and the projection 54. It is set stronger than the stopping power.

[0016]

[Effect of device]

 The structure and operation of the mechanical pencil of the present invention are as described above. Since the lead can be extended by simply swinging the writing instrument forward in the axial direction, it is not necessary to knock the rear end each time the lead is extended, unlike the conventional case. Therefore, the hassle of repositioning the shaft and exposing and erasing the eraser is eliminated. Therefore, it is an excellent mechanical pencil for children in lower grades and examinees who frequently write and erase. Further, there is an effect that the core can be set so as not to be drawn out when being carried.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a mechanical pencil according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an axial locking relationship between the inner cylinder and the joining cylinder in the first embodiment.

FIG. 3 is a vertical sectional view of a mechanical pencil according to a second embodiment of the present invention.

FIG. 4 is an explanatory view showing an axial locking relationship between the inner cylinder and the joining cylinder in the second embodiment.

[Explanation of symbols]

 1 Tip Shaft 2 Shaft Part 3 Step Part 4 Projection 5 Screw Part 6 Front Step Part 7 Base 8 Step Part 9 Tip Pipe 10 Holding Chuck 11 Core Case 12 Collar 13 Buffer Material 14 Chuck 15 Fastener 16 Chuck Spring 17 Weight 18 Circumferential Groove 19 ring 19 split part 20 cap 21 spiral groove 22 step part 23 clip 24 inner cylinder 25 slit 26 shaft part 27 collar part 28 crown part 29 protrusion 30 step part 31 eraser holder 32 protrusion 33 eraser 34 joining cylinder 35 shaft part 36 Shaft portion 37 Flange portion 38 Vertical groove 39 Horizontal groove 40 Step portion 41 Groove 42 Boss portion 43 Projection portion 44 Tapered portion 45 Return spring 50 Joining cylinder 51 Shaft portion 52 Step portion 53 Slit 54 Projection portion 55 Tapered portion

Claims (1)

[Scope of utility model registration request] 1. A chuck spring is attached to the tip shaft so that a lead case with a chuck fixed to the tip can be moved axially, and a chuck spring that springs back the chuck with a weak force is attached to the tip of the lead case and the rear end circumferential groove. Between the fixed ring and the core case, a weight that is axially shiftable by its own weight is provided by fitting in the core case.
It is a mechanical pencil with an eraser feeding body detachably attached to the rear end of the front shaft, and the eraser feeding body is
A cap with a spiral groove in the inner hole, an inner cylinder with a slit that is rotatably fixed in the cap inner hole, and an inner cylinder at least in a certain forward range only through the elastic force of the return spring in the axial direction only. It is movable, and is attached to the rearmost end of the front shaft so that it can be properly retracted at the most advanced position and is detachably attached to the front end of the front shaft. The eraser holder is configured by fitting its protrusions into the slits and spiral grooves in the inner cylinder, and is provided so that the axial movement of the inner cylinder interlocks with the core case and the chuck. A mechanical pencil characterized in that the core is extended by axially shifting the chuck by force, and the eraser can be retracted from the rear end by rotating the cap with respect to the front shaft.