JPH0574890U - mechanical pencil - Google Patents

Abstract

(57) [Summary] [Purpose] It is possible to provide a mechanical pencil suitable for children and examinees in 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 move axially, and a chuck spring 16 is attached to elastically push the chuck backward with a weak force. A weight 17 which is fitted to the core case and is capable of axial shifting under 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. An inner cylinder 24 fixed to the inner cylinder 24 and an eraser holder 29 having a protrusion 30 on the side surface and an eraser 31 fixed to the rear end constitute an eraser feeding body by fitting the protrusion into the slit and the spiral groove in the inner cylinder. , A mechanical pencil characterized in that an eraser feeding member is detachably attached to the rear end of the front shaft.

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 object has the trouble of frequently knocking the rear end as the core is consumed. 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 that 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 devised to achieve the above object is a chuck spring for elastically retracting the chuck with a weak force to house the lead case with the chuck fixed at the tip inside the tip shaft. The core case is fitted between the front end and the rear end of the core case, and a weight that allows the shaft to move by its own weight is provided.At the rear end of the front shaft, an eraser feeding member is detachably attached. In a mechanical pencil, the eraser feeding body has 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 a protrusion on the side surface. The eraser holder with the eraser fixed to the rear end is constructed by fitting the protrusions into the slits and spiral grooves in the inner cylinder. The key to the front axle. Tsu eraser from the rear end by rotating the flop is Do and retractable, and further mounted to allow a front barrel front barrel forward to a range eraser body from coming off the chuck fasteners in conjunction with the lead case.

[0005]

【Example】

 FIG. 1 shows an 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 appropriately frictionally engaged and inserted is fixed to the tip of the inner hole. . 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 having a screw portion (male screw) at the tip of a cylindrical body, and the shaft portion 2 is provided with a hole having a front step portion 6, and the hole is formed at the rear side. 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 a projection 4 and an engaging groove 5 are formed on the peripheral wall at the rear end of the inner hole portion.

The chuck 14 is fitted by engaging the head portion with the fastener 15 in the hole of the shaft portion 2 of the leading shaft, and the core case 11 is inserted into the inner hole of the leading 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 brim portion 12 provided substantially at the tip of the lead case 11. The chuck spring 16 repels the chuck 14 backward with an appropriate weak force. Further, the lead case 11 is a tubular body provided with a lead storage portion through which the lead can be inserted into the chuck 14, and a flange portion 18 is formed at a rear end thereof with a sliver 19 at an appropriate position. A cushioning material 13 such as rubber is fixed to the outer circumference of the front of the core case 11 by contacting the rear end of the brim portion 12, and a weight 17 is fitted to the rear side by elastic deformation of the flange portion 18. The weight 17 is axially movable between the cushioning material 13 and the flange portion 18 by its own weight.

A joining cylinder 32, which will be described later, of an eraser feeding body is detachably fixed to the rear end of the front shaft 1. A protrusion 36 is formed on the outer periphery of the front end of the joining cylinder 32, and elastically rides over the protrusion 4 of the front end portion of the rear end hole to prevent them from coming off with an appropriate force. Further, a shape is provided on the outer periphery of the joining cylinder so as to be engaged with the engaging groove 5 and to be integrated with each other in the rotational direction. Further, a boss portion 34 having a step portion 35 is formed in the inner hole of the joining cylinder 32, and the boss portion 34 is fitted to the rear end surface of the core case 11 with the step portion 35 in contact with the core case 11. The inner core is prevented from coming off, and the diameter of the flange portion 18 is suppressed so as to prevent the weight from coming off when the weight 17 comes into contact with it.

By the way, the eraser feeding member is configured by combining the members of the cap 20, the inner cylinder 24, the eraser holder 29, and the joining cylinder 32, and the cap 20 is fitted on the outer periphery of the rear end of the front shaft 1 in the forward direction. A step portion 22 that abuts the inner hole and the rear end surface is formed, a clip 23 is provided on the outer peripheral portion of the rear end, and a spiral groove 21 is formed on the inner surface. The inner cylinder 24 has a hole for inserting the eraser 31 and a crown portion 28 that abuts the rear end surface of the cap 20 at the rear end, and a long slit 25 is bored from approximately the center to the crown portion. ing. Further, on the front side, a protrusion 36 that is engaged with the protrusion 4 of the front shaft 1 and the engagement groove 5 and is fixed in the form of a rotation stopper and a joining cylinder 32 having a rotation stopper shape are fixed. That is, the groove 27 is formed on the front outer circumference of the inner cylinder 24, and the projection 33 is formed on the inner circumference of the rear portion of the joining cylinder 32, and they are fixed to each other by elastic deformation. Further, the front outer periphery of the inner cylinder 24 and the outer periphery of the rear portion of the joining cylinder 32 are formed with a rotation stopping shape so that they are integrated in the rotational direction. In the embodiment of the present invention, the inner cylinder 24 and the joint cylinder 32 are provided as separate members, but they may be integrated.

The eraser feeding body is configured such that the eraser holder 29 is elastically fitted from the slit 25 of the inner cylinder 24 and the projection 30 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 30 is inserted into the spiral groove 21 while being inserted, and the joint cylinder 32 is fixed to the front of the inner cylinder 24 by elastic deformation so that the rear end surface of the joint cylinder is substantially brought into contact with the step portion 22 of the cap 20. The cap 20 is rotatable with respect to the inner cylinder 24 between the crown portion 28 and the rear end surface of the joining cylinder 32 and is prevented from coming off. Further, an eraser 31 is fixed to the rear end of the eraser holder 29, and the front portion of the joining cylinder 32 is detachably attached to the rear end hole of the front shaft 1. A gap B38 is formed between the rear end surface of the front shaft 1 and the step portion 22 of the cap 20, and the joining cylinder 32 is axially movable with respect to the front shaft 1 therebetween. As described above, when the cap 20 is rotated with respect to the front shaft 14, the eraser 31 appears and disappears from the rear end hole of the crown portion 28.

[0011]

[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, the cap 20 is advanced by a gap B38 with respect to the tip shaft 1 and the tip of the core is pressed against the paper surface or the like, and the core returns to the inside of the tip pipe 9. The gap B38 is set to be slightly smaller than the gap A37 in which the chuck 14 moves forward and the front end surface of the fastener 15 contacts the step portion 8 of the mouthpiece 7. Further, when the cap 20 is rotated with respect to the front shaft 1, the eraser 31 projects from the rear end of the crown portion 28.

[0012]

[Effect of the device]

 The structure and operation of the mechanical pencil of the present invention are as described above, and the core can be drawn out by simply swinging the writing instrument forward in the axial direction. Therefore, it is an excellent mechanical pencil for children in lower grades and examinees who frequently write and erase.

[Brief description of drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tip shaft 2 Shaft part 3 Step part 4 Protrusion 5 Engagement groove 6 Front step part 7 Base 8 Step part 9 Tip pipe 10 Holding chuck 11 Core case 12 Flange 13 Buffer material 14 Chuck 15 Fastener 16 Chuck spring 17 Weight 18 Flange Part 19 Sleeve 20 Cap 21 Spiral groove 22 Step 23 Clip 24 Inner cylinder 25 Slit 26 Shaft 27 Groove 28 Crown crown 29 Eraser holder 30 Protrusion 31 Eraser 32 Joining cylinder 33 Protrusion 34 Boss 35 Step 36 Protrusion 37 Gap A 38 Gap B

Claims (1)

[Scope of utility model registration request] 1. A chuck spring, which houses a chuck fixedly attached to the tip of the chuck so that the chuck can be moved axially and springs the chuck backward with a weak force, is provided between the tip and the rear end of the lead case. In a mechanical pencil that is fitted to a lead case with a weight that can move the axis by its own weight and an eraser feedout body is detachably attached to the rear end of the front shaft, the eraser feedout body has an inner hole. Inside the inner cylinder, there is a cap with a spiral groove, an inner cylinder with a slit rotatably fixed in the inner hole of the cap, and an eraser holder with a protrusion on the side and an eraser fixed at the rear end. It is configured by fitting the protrusion into the slit and the spiral groove, and by swinging the shaft, the core is extended by axially shifting the chuck by the inertial force of the weight,
By rotating the cap with respect to the front shaft, the eraser can be retracted from the rear end, and the eraser feeding body can be advanced to the extent that the chuck does not come off the fastener in conjunction with the lead case and mounted on the front shaft. A mechanical pencil that is characterized by