JPH0612088U - Mechanical pencil detent mechanism - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] When the tip of the brush is facing upward, it prevents the return of the lead to the lead storage part and enables the smooth lead-out.
Pupencil core detent mechanism. [Structure] Normally, the core 1 is released while maintaining the expanded state, and a core feeding chuck 2 is provided for gripping and fixing the core 1 during a feeding operation of the lead 1. A radial guide groove 55 is provided between the lead feeding chuck 2 and the lead storage portion 16 that houses the spare lead 1. A plurality of balls 51 fitted in the guide groove 55 so as to freely move, and the ball 51 of the guide groove 55 during writing.
And a taper portion 50 that guides the ball 51 of the guide groove 55 toward the center and tightens the core 1 with the tip of the writing brush facing upward.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention provides a part of the touch-fing type mechanical pencil, and when the tip of the brush retreats with the wear of the lead and the tip is separated from the surface of the paper, the tip of the tip advances again and the lead is extended when the tip advances. Like an automatic feeding type mechanical pencil with such a structure, the lead is normally maintained by keeping the expanded state and the lead is provided with a lead-out chuck that holds and fixes the lead during the lead-out operation. -The present invention relates to a core detent mechanism for a sharp pencil, which is provided on the sharp pencil to improve the usability of the sharp pencil.

[0002]

[Prior art]

 In the case of the conventional general touch-finger type mechanical pencil and automatic type mechanical pencil, a knock body is installed at the rear end of the barrel, and the finger-feeding is performed only when the lead is gripped by the lead-feeding chuck. The core can be extended by moving the body and the tip of the writing brush forward and backward. In other cases, for example, when extending the second and subsequent cores that follow the core during writing, or when extending a completely new core, the knock body It is necessary to press the to open the lead-out chuck, and to hold the lead by the lead-out chuck. Also, when returning the lead to the shaft after writing, it is also necessary to press the knock body to open the lead-out chuck. However, there was a complaint that the operation was extremely troublesome. Therefore, the applicant of the present invention not only pays out the lead being drawn while being held by the lead feeding chuck, but also feeds out the lead after the second lead following the lead being written, and the feeding of a completely new lead. Since it can be operated by the body, knocking operation is not required. Therefore, in order to simplify the operation and improve the usability, the expanded state is usually maintained and the core is released. In the previous application (Japanese Patent Application No. 4-14410), a finger-feeding type mechanical pencil provided with a lead feeding chuck that grips and fixes a lead during a feeding operation was proposed.

[0003]

[Problems to be solved by the device]

 By the way, if the lead-out chuck is normally kept in the expanded state, the second lead will return to the lead storage part when the writing tip part is facing upward, and the lead will be fed again even if the writing tip part is facing down. There may be a delay in inserting the inside of the chuck, and a state in which the second lead is not supplied to the rear end of the first lead may cause a trouble that the lead cannot be smoothly fed out. Therefore, an object of the present invention is to prevent the lead from returning to the lead storage portion when the writing tip is directed upward so that the tip of the second lead is always in contact with the rear end of the first lead. The purpose of the present invention is to provide a core detent mechanism for a sharp pencil that allows the core to be smoothly fed out when placed.

[0004]

[Means for Solving the Problems]

 In order to achieve the above object, the lead detent mechanism of the mechanical pencil of the present invention normally maintains the expanded state to release the lead 1, and holds the lead 1 when the lead 1 is extended. In a sharpening pencil having a lead feeding chuck 2 that is fixed by fixing the lead feeding chuck 2, a radial radial guide groove 55 is provided between the lead feeding chuck 2 and a lead storage portion 16 that accommodates a spare lead 1. , A plurality of balls 51 which are fitted in the guide grooves 55 so as to be free to move, and the balls 51 of the guide grooves 55 are guided to the outside and separated from the core 1 in a state in which the tip of the writing tool is downward as in writing. And a taper portion 50 for guiding the ball 51 of the guide groove 55 toward the center and tightening the core 1 with the writing tip portion facing upward.

[0005]

[Action]

 When the tip of the brush is downward, the ball 51 is guided to the outside of the guide groove 55 by the taper portion 50 and separated from the core 1, so that the core 1 can be inserted freely, and the core storage 16 can be used to extract the core. The core 1 is smoothly inserted into the inside of the 2. When the tip of the writing brush is facing upward, the ball 51 is moved toward the center of the guide groove 55 by the taper portion 50 to tighten the lead 1, so that the lead 1 from the lead feeding chuck 2 to the lead storage portion 16 is removed. The return will be blocked.

[0006]

【Example】

 Hereinafter, the illustrated embodiment will be described in detail. The outer periphery of the front shaft 3 is covered with an outer cover 38 made of elastic rubber or resin rubber. A chuck set 13 described later is housed inside the front shaft 3. A base 9 is screwed to the front end of the front shaft 3, while a rear shaft 47 is screwed to the rear end of the front shaft 3 (in the drawing, the lower side indicates the front and the upper side indicates the rear). As shown, an eraser stopper 64 holding an eraser 65 is fitted on the rear end of the rear shaft 47, and a cover 63 is attached to the outer peripheral portion of the eraser stopper 64.

First, the rear shaft 47 has an inner space as a lead storage portion 16, and has a partition wall 15 which has a small hole 14 at the front end portion through which only one lead can pass and a rear surface of which is a serpentine shape. A tubular portion 72 is provided further forward of the partition wall 15, and as shown in FIGS. 3 and 4, a rib 73 is provided at a rear end portion of the tubular portion 72 at a predetermined circumferential position by a taper portion. 50 are provided. A core detent member 56 is fitted inside the tubular portion 72. The core detent member 56 has radial guide grooves 55 in the radial direction at the portions corresponding to the taper portion 50 of the ribs 73, and the ball 51 can be freely moved inside the guide groove 55. It is inserted. The ball 51, the guide groove 55, and the taper portion 50 constitute the core detent mechanism 54 of the present invention. That is, when the brush tip portion is facing downward, the ball 51 is guided to the outside of the guide groove 55 by the taper portion 50 to separate from the lead 1 and release the lead 1, so that the lead 1 is moved forward from the lead storage portion 16. However, when the tip of the brush is facing upward, the ball 51 moves toward the center of the guide groove 55 by the taper portion 50 and tightens the lead 1, so that the lead 1 passes backward. Is blocked. A cylindrical portion 81 is provided at the front end of the lead detent member 56 so as to be slidably inserted into the rear end of the lead feeding chuck 2 described later.

Next, the chuck set 13 housed inside the front shaft 3 has a taper portion 18 on the inner surface of the front end and is movable in the front-rear direction with respect to the front shaft 3, and a chuck case 5 inside the chuck case 5. Of the lead-out chuck 2, the pull-in spring 4 for urging the lead-out chuck 2 to the rear, and the ball 21 fitted into the recess 20 formed on the outer surface of the lead gripping portion 19 of the lead-out chuck 2. A stopper 27 that is fixed to the front end of the chuck case 5 to prevent the ball 21 from coming off, a slide body 7 that is attached to the front end of the lead-out chuck 2 and is movable in the front-rear direction, and a spring that is more elastic than the retracting spring 4. It is composed of an expansion spring 6 that has a strong force and urges the sliding body 7 forward, and a locking cylinder 60 that is fixed to the chuck case 5 and accommodates the sliding body 7 therein. The chuck set 13 is urged forward by a return spring 8 interposed between a flange portion 39 provided on the outer surface of the chuck case 5 and the front end of the rear shaft 47. The return spring 8 has a stronger elastic force than the expansion spring 6.

As shown in FIG. 5, the lead-out chuck 2 is formed by joining two symmetrical parts into a tubular shape, and a ring 33 is fitted to the rear end thereof to be integrated. The lead feeding chuck 2 has a tubular portion 23 in front of the lead gripping portion 19, and a hole 24 is provided in the tubular portion 23. The lead feeding chuck 2 exerts a sufficient lead fixing force capable of withstanding the force pushing the lead 1 backward, but when pulling the lead 1 forward, it is more than the lead fixing force of the tip lead gripping chuck 10 described later. Is possible with a small force.

As shown in FIG. 7, the locking cylinder 60 has an appropriate slit 66 formed on the front side surface thereof, a circumferential groove 29 formed on the outer surface of the front end thereof, and the elastic O-ring 28 is formed in the groove 29. Is fitted. A taper portion 67 is provided on the inner surface of the front end opening of the locking cylinder 60, and a step portion 32 is provided at the rear end position of the taper portion 67. The locking cylinder 60 is capable of elastically appropriately expanding the stepped portion 32 by abutting the tapered portion 67 on the circumferential projection 68 provided on the inner surface portion of the front shaft 3. Further, the forward movement of the locking cylinder 60 is simultaneously restricted by the protrusion 68 of the front shaft 3. A step 70 is provided on the inner surface of the locking cylinder 60.

As shown in FIG. 6, the sliding body 7 is provided with a projecting piece 25 at the rear end, and the projecting piece 25 is inserted into the hole 24 of the cylindrical portion 23 of the above-mentioned lead-out chuck 2 and locked. is doing. The sliding body 7 is urged forward by the expanding spring 6 which has a stronger elastic force than the retracting spring 4 which urges the lead-out chuck 2 backward. Therefore, the lead-out chuck 2 is pulled out forward by the projecting piece 25, and the lead-out chuck 2 is in the normally expanded state. The sliding body 7 is prevented from coming off by the step portion 70 of the locking cylinder 60. At the front end of the sliding body 7, there is provided a tubular portion 30 including a large diameter portion 30a and a slightly thin small diameter portion 30b. The tube portion 30 passes through the front end opening of the locking tube 60 and projects forward.

The base 9 screwed to the front end of the front shaft 3 accommodates a tip core gripping chuck 10 inside the front end thereof so as to be movable in the front-rear direction. The tip core gripping chuck 10 is biased rearward by a tip retracting spring 37. Further, a tightening ring 43 for fastening the head of the tip core gripping chuck 10 is fixed to the front end of the mouthpiece 9, and an elastic ring 42 is fixed to the shaft portion on the rear side of the head of the tip core gripping chuck 10. As a result, when the tip lead gripping chuck 10 is moved forward, a force for frictionally holding the lead is appropriately applied. The tip core gripping chuck 10 exerts a sufficient core fixing force to withstand the writing pressure, that is, the force of pushing the core 1 backward, but when the above-mentioned core feeding chuck 2 feeds the core 1. In this case, the core 1 is easily passed forward.

Inside the mouthpiece 9, behind the tip core gripping chuck 10, a feeler feeding body 12 is movably arranged in the front and rear directions. The finger-feeding body 12 is housed inside the mouthpiece 9, a central tube portion 35, an arm piece portion 36 penetrating a notch 34 provided in the mouthpiece 9, and a finger-touch operation portion 11 exposed on the outer peripheral portion of the mouthpiece 9. The arm piece 36 can move back and forth in the notch 34 without any restriction. A front half portion of a guide pipe 41, to which a fixing ring 40 is fixed to a substantially central outer peripheral portion, penetrates and is fixed inside the central tubular portion 35 of the finger feeding body 12. The front end of the guide pipe 41 is tightly fitted in the rear end of the tip core gripping chuck 10 in a slidable manner. The fixed ring 40 fixed to the guide pipe 41 is located inside the reinforcing ring 46 fixed to the inner surface of the rear end of the mouthpiece 9, and the rear half of the guide pipe 41 is inside the tubular portion 30 of the sliding body 7. It is tightly fitted in a slidable state. The reinforcing ring 46 is attached to prevent elastic deformation of the threaded portion at the rear end of the mouthpiece 9 due to the notch 34. The fixed ring 40 has its front end abutting on the rear end of the central tubular portion 35 of the finger feeding body 12, and its rear end abutting on the front end of the tubular portion 30 of the sliding body 7. The central tubular portion 35 of the touch-feeding body 12, the fixed ring 40, and the small-diameter portion 30b of the tubular portion 30 of the sliding body 7 are slidably fitted in the reinforcing ring 46 closely. .

In the state shown in FIGS. 1 and 8, when the tip of the lead 1 during writing is worn and the lead 1 is extended by a necessary amount, first touch the finger operation part 11 with the fingertip and gently pull it back. The finger extending body 12 is retracted. When the touching finger feeding body 12 is retracted, the sliding body 7 is also pushed and retracts. When the sliding body 7 retreats, the lead-out chuck 2 which is free from the projecting piece 25 of the sliding body 7 is retracted by the retracting spring 4, and the ball gripping portion 19 is closed by tightening the ball 21 that slides on the taper portion 18. To hold. At this time, the chuck set 13 is prevented from moving backward by the force of the return spring 8. When the sliding body 7 retreats by α as shown in FIG. 9, the large-diameter portion 30a of the tubular portion 30 of the sliding body 7 pulls out the step portion 32 of the locking tube 60, and the step portion 32 of the locking tube 60. Reduces the inner diameter slightly, so that the front end edge 31 of the large diameter portion 30a of the sliding body 7 is locked to the rear end edge 74 of the step portion 32 of the locking cylinder 60. When the touching finger feeding body 12 is further retracted, the rear end of the projecting piece 25 of the sliding body 7 contacts the front end of the stopper 27 to retract the chuck set 13. At that time, since the lead 1 is held and fixed by the tip lead gripping chuck 10, the lead gripping portion 19 of the lead feeding chuck 2 slides on the outer surface of the lead 1 and moves to the rearward position, so that the lead 1 moves forward. It will be pulled out. When the finger feed body 12 is retracted to an appropriate position and then the finger is released, the chuck set 13 and the finger feed body 12 are moved forward by the force of the return spring 8. At this time, since the front end edge 31 of the large-diameter portion 30a of the sliding body 7 is locked to the rear end edge 74 of the step portion 32 of the locking cylinder 60, the sliding body 7 maintains the retracted state with respect to the locking cylinder 60. Therefore, the lead-out chuck 2 is not pulled out forward by the protrusion 25 of the sliding body 7 and is not opened, but is moved forward while keeping the state of gripping the lead 1, so that the lead 1 is fed out forward. When the taper portion 67 of the locking cylinder 60 of the chuck set 13 moves forward until it comes into contact with the protrusion 68 of the front shaft 3, the step portion 32 of the locking cylinder 60 elastically expands, and the sliding body 7 is thickened. Since the locked state between the front end edge 31 of the diameter portion 30a and the rear end edge 74 of the step portion 32 of the locking cylinder 60 is released, the large diameter portion 30a of the sliding body 7 becomes the step portion 32 of the locking cylinder 60. While moving forward while being inserted into the inside, the projecting piece 25 of the sliding body 7 again pulls the lead-out chuck 2 forward to form an expanded state, and returns to the state of FIG.

When the lead 1 during writing is exhausted and the front end of the second lead 1 that follows is advanced to the position immediately after the lead gripping portion 19 of the lead-out chuck 2, the finger-feeder 12 is retracted, As described above, when the sliding body 7 retreats to grip the second core 1, and the tongue feeding body 12 further retracts to retract the chuck set 13, in this case, the second core 1 moves to the above-mentioned position. As described above, since the lead is not fixed by the tip core gripping chuck 10, the lead 1 is conveyed backward by the lead feeding chuck 2, but the touching finger feeding body 12 is further retracted to the rear end of the lead feeding chuck 2. Is brought into contact with the chuck receiver 17 provided at the front end of the rear shaft 47, and when the finger feed body 12 is further retracted to the limit as shown in FIG. 10, the lead feed chuck 2 is not retracted and the chuck case 5 is moved. Only retreat and the lead-out chuck 2 moves relatively The core 1 is released by expanding and expanding. Therefore, the second core 1 advances by free fall, and its front end contacts the rear end of the first core 1. In this state, when the finger is released from the touching finger feeding body 12, the chuck case 5 moves forward by the force of the return spring 8 and the lead feeding chuck 2 moves forward while holding the second lead 1. Therefore, even if the first lead 1 is consumed up to a length that cannot be gripped by the lead feeding chuck 2, it is pushed out by the second lead 1 and fed out. Further, even if the first lead 1 is consumed to a length that cannot be grasped by the lead feeding chuck 2, it can be written because it is grasped by the tip core grasping chuck 10 and used until it is pushed out from the tip core grasping chuck 10. You can

When there is no lead 1 in the shaft and it is desired to quickly hold the newly refilled lead 1 by the tip core gripping chuck 10 to start writing, or when the writing is completed and the tip core gripping chuck 10 is When it is desired to immerse the core 1 protruding from the front end, the tip core gripping chuck 10 is pushed forward by lightly moving the touching finger feeding body 12 forward with the fingertip, and the tip core gripping chuck 10 is released from the tightening ring 43 to release the core. The grip chuck 10 may be expanded. Since the lead feeding chuck 2 is normally expanded, the lead 1 of the lead storage portion 16 reaches the tip lead gripping chuck 10 immediately by free fall. Further, when the lead 1 is to be retracted into the shaft, the front end of the lead 1 may be pressed against the front surface of the lead 1 with the front end of the lead 1 held against the paper surface, etc.

Although the above-mentioned embodiment relates to a finger-feed-out type sharp pencil, the present idea is that when the tip of the brush retreats with the wear of the lead and the tip of the brush is separated from the surface of the paper, the tip of the brush again. Of course, it can also be configured as an automatic feeding type mechanical pencil having a structure in which the body moves forward and the core is extended when moving forward.

[0018]

[Effect of device]

 The present invention is as described above, and it is arranged between the lead feeding chuck 2 and the lead storage portion 16, and when the writing tip portion faces downward, the ball 51 is guided by the taper portion 50 into the guide groove 5. Although the lead 1 is free to be inserted by being guided to the outside of the lead 5 and separated from the lead 1, the ball 51 is moved by the taper portion 50 toward the center of the guide groove 55 when the writing tip portion is directed upward. Since the passage of the lead 1 is blocked by tightening the lead 1, the lead 1 is moved from the lead-out chuck 2 to the lead-storing portion 16 even if the tip of the writing brush is turned upward with the lead-out chuck 2 expanded. Since the second core 1 can always be supplied to the rear end of the first core 1 without returning, there is an effect that the feeding of the core 1 can be made extremely smooth.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a front half of a sharp pencil.

FIG. 2 is a vertical cross-sectional view of the rear half of the sharp pencil.

FIG. 3 is an enlarged vertical sectional view showing a core detent mechanism.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is an exploded perspective view of a lead feeding chuck.

FIG. 6 is a perspective view of a sliding body.

FIG. 7 is an exploded perspective view of a locking cylinder.

FIG. 8 is a partially enlarged vertical cross-sectional view of a state in which a finger-feeding body is not retracted.

FIG. 9 is a partially enlarged vertical cross-sectional view showing a state in which the finger-feeding body is retracted to lock the front end edge of the large-diameter portion of the sliding body cylinder portion to the rear end edge of the step portion of the locking cylinder.

FIG. 10 is a partially enlarged vertical cross-sectional view of the state where the finger-feeding body is retracted to the maximum.

FIG. 11 is a view just before the engagement state between the front end edge of the large-diameter portion of the sliding body cylinder portion and the rear end edge of the step portion of the engagement cylinder is released in the process of returning the retracted finger-feeding body to the front. It is a partial expanded longitudinal cross-sectional view showing a state.

[Explanation of symbols]

 1 core 2 core feeding chuck 3 front shaft 4 retracting spring 5 chuck case 6 expansion spring 7 sliding body 8 return spring 9 mouthpiece 10 tip core gripping chuck 10 11 touching finger operating part 12 touching finger feeding body 13 chuck set 14 Small hole 15 Partition wall 16 Core storage part 17 Chuck receiver 21 Ball 25 Projecting piece 27 Stopper 28 O-ring 30 Tube part 30a Large diameter part 30b Small diameter part 32 Step part 35 Center tube part 36 Arm piece part 37 Retracting spring 38 Outer jacket 40 Fixing ring 41 Guide pipe 46 Reinforcement ring 47 Rear shaft 50 Tapered portion 51 Ball 54 Core detent mechanism 55 Guide groove 56 Core detent member 60 Locking cylinder 68 Projection 73 Rib

Claims (1)

[Scope of utility model registration request] 1. A sharp pencil provided with a lead-out chuck 2 which normally maintains an expanded state to release the lead 1, and which holds and fixes the lead 1 when the lead 1 is fed out. A radial radial guide groove 55 is provided between the feeding chuck 2 and the lead storage portion 16 for accommodating the spare lead 1, and a plurality of balls 51 fitted in the guide groove 55 so as to be freely movable. When writing, the ball 51 of the guide groove 55 is guided outward so as to be separated from the core 1 when the writing tip is downward, and the ball of the guide groove 55 is raised when the writing tip is upward. A core detent mechanism for a sharp pencil, which comprises a taper portion 50 for guiding 51 toward the center to tighten the core 1.