Propelling pencil
By setting a lead core planer on the push cap of the automatic pencil, and using the spiral coordination structure of the rotating shaft and the propulsion rod to achieve closed collection of lead chips, the problem of falling contamination of lead chips in existing automatic pencils is solved, and the pen experience is improved.
Patent Information
- Application Number
- CN202421595092.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-05
- Publication Date
- 2025-04-25
- Estimated Expiration
- 2034-07-05
AI Technical Summary
After the existing automatic pencils have cut the refill core with the lead core planer, granular graphite chips will fall, contaminating the hands and paper, and the remaining graphite chips will easily fall when using the pencil.
An automatic pencil is designed, and the lead core planer is set on the push cap, and the spiral matching structure between the rotating shaft and the propulsion rod is made to make the lead core planer open when used. It is automatically closed after the planing is completed, and the lead chips are collected in the chip storage cavity.
It effectively prevents lead chips from falling during the planing process, avoids contamination of hands and paper, and prevents leakage of lead chips when using pencils, improving the pen experience.
Smart Images
Figure CN222793090U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of stationery, and in particular relates to a mechanical pencil. Background Art
[0002] Automatic pencils, also known as mechanical pencils or automatic pencils, are a type of pencil, which is characterized by pushing out or retracting the lead by pressing a mechanism at the end of the pencil, rather than sharpening the pencil to extend the graphite lead to a suitable distance like a traditional wooden pencil. However, when the lead of the automatic pencil is blunt, it is still necessary to use a lead sharpener to sharpen the lead. At present, in order to facilitate sharpening the lead, the automatic pencil will be equipped with a lead sharpener at the end of the automatic pencil. However, after the lead sharpener installed on the automatic pencil sharpens the lead, granular graphite chips generated by sharpening the lead will fall off, contaminating hands and paper, and will also cause harm after being inhaled by the human body. Moreover, the lead sharpener on the automatic pencil opens outward, so that not only the graphite chips remaining after use are also easy to fall out when the pencil is used, so in order to avoid the shortcomings existing in the prior art, it is necessary to improve the prior art. Utility Model Content
[0003] The utility model aims to provide an automatic pencil, which can conveniently sharpen the lead core, and after sharpening the lead core, no granular graphite chips will fall off to pollute paper, and the residual graphite chips will not fall out when the pencil is used.
[0004] In order to solve the above technical problems, the technical solutions adopted by the utility model are as follows:
[0005] A mechanical pencil, comprising a pen holder, a pen tip, a lead tube, a spring and a push cap; the push cap comprises a push cap shell, a push rod, a rotating shaft, a lead planer and a cap head; the front end of the push rod can be slidably inserted into the rear end of the pen holder and fixedly connected to the lead tube, the rear end of the push rod is provided with an axial hole, and the hole wall of the axial hole is provided with a spiral groove; the front end of the push cap shell is sleeved on the rear end of the push rod; the front end periphery of the rotating shaft is provided with a spiral convex rib matching with the spiral groove, the rear end of the rotating shaft is extended with a shaft rod, the interior of the push cap shell is provided with a shaft rod hole matching with the shaft rod, the shaft rod passes through the shaft rod hole and is fixedly connected to the lead planer; the cap head is connected A chip storage chamber is connected to the rear end of the push cap shell and enclosed with the push cap shell to form; the lead planer is arranged in the chip storage chamber; a lead core plug hole is arranged on the cap head; in the process of the rotating shaft being pulled out from the shaft hole, the rotating shaft performs a positive rotational motion under the cooperation of the spiral rib and the spiral groove, thereby driving the planing hole of the lead planer to rotate to face the lead core plug hole; in the process of the rotating shaft being inserted into the shaft hole, the rotating shaft performs a reverse rotational motion under the cooperation of the spiral rib and the spiral groove, thereby driving the planing hole of the lead planer to be separated from the lead core plug hole, and the lead core plug hole is blocked by the end face of the lead planer.
[0006] As a preferred solution of the utility model, the cap head is provided with an external thread connection portion, and the cap shell is provided with an internal thread threadedly connected to the external thread connection portion.
[0007] As a preferred embodiment of the utility model, a radially protruding calibration block is provided on the outer side of one end of the lead core planer close to the cap head, and a radially protruding calibration strip is provided on the inner wall of the cap head, the calibration strip being radially protruding and extending in the axial direction, and the calibration strip can circumferentially abut against the calibration block during the threaded connection process between the cap head and the press cap shell; the external threaded connection portion is provided with at least two pitches.
[0008] As a preferred solution of the utility model, the outer periphery of the push rod is provided with a first limiting rib which is radially protruding and extends axially, the inner wall of the pen shaft is provided with a first limiting groove which cooperates with the front section of the first limiting rib, and the inner wall of the button cap shell is provided with a second limiting groove which cooperates with the rear section of the first limiting rib.
[0009] As a preferred solution of the utility model, a second limiting rib that is radially protruding and circumferentially surrounding is provided between the front side section of the first limiting rib and the rear side section of the first limiting rib, and the outer diameter of the rear end face of the pen shaft and the outer diameter of the front end face of the button cap shell are consistent with the outer diameter of the second limiting rib.
[0010] As a preferred solution of the utility model, the outer periphery of the front end of the push rod is provided with a third limiting rib which is radially protruding and circumferentially surrounding, and the inner wall of the rear end of the pen shaft is provided with a plurality of first limiting blocks which are radially protruding and circumferentially distributed, and the front end surface of the first limiting block abuts against the rear end surface of the third limiting rib and forms an axial limiting structure for preventing the push rod from separating from the pen shaft; the outer diameter of the third limiting rib is smaller than the outer diameter of the first limiting rib.
[0011] As a preferred solution of the utility model, the middle outer periphery of the push rod is provided with a fourth limiting rib which is radially protruding and circumferentially surrounding, and the front end inner wall of the push cap shell is provided with a plurality of second limiting protrusions which are radially protruding and circumferentially distributed, and the rear end surface of the second limiting protrusion is abutted against the front end surface of the fourth limiting rib to form an axial limiting structure for preventing the push cap shell from separating from the push rod; the outer diameter of the fourth limiting rib is smaller than the outer diameter of the first limiting rib.
[0012] As a preferred solution of the utility model, the pen head is threadedly connected to the pen holder.
[0013] As a preferred solution of the utility model, the front end of the push rod is provided with a first connecting hole for the lead core tube to be inserted.
[0014] As a preferred solution of the utility model, the portion where the shaft rod is connected to the lead planer is a regular hexagonal prism, and the lead planer is provided with a second connecting hole which is interference fit with the regular hexagonal prism.
[0015] Compared with the prior art, the mechanical pencil provided by the utility model has the following beneficial effects:
[0016] The automatic pencil of the utility model is designed with a lead planer on the push cap, so that the user can take out the lead planer at any time to plan the lead; and because the lead planer is arranged in a chip storage cavity formed by the cap head and the push cap shell, the lead chips will not fall and contaminate the hands and objects during the lead planing process; furthermore, through the design of the rotating shaft and the push rod, the spiral matching structure of the spiral convex rib and the spiral groove is utilized, so that when the push cap shell is connected to the push rod with the rotating shaft, the lead planer is in a closed state and cannot be used, and when the push cap shell is separated from the push rod with the rotating shaft, the lead planer is in an open state for use, and thus such a design can effectively ensure that the lead chips in the chip storage cavity will not leak during the use of the pen, and there is no need to clean the lead chips in time, thereby improving the user's pen-using experience. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solution of the embodiment of the utility model, the drawings of the embodiment will be briefly introduced below.
[0018] Figure 1 It is a schematic structural diagram of a mechanical pencil according to an embodiment of the utility model;
[0019] Figure 2 It is Figure 1 A magnified view of region A in the structure shown;
[0020] Figure 3 is a cross-sectional view of a mechanical pencil according to an embodiment of the utility model, showing that the rotating shaft and the pushing rod are in a separated state;
[0021] Figure 4 This is an exploded view of the push button cap;
[0022] Figure 5 This is an exploded view of the push button from another perspective;
[0023] Figure 6 It is a schematic diagram of the structure of the rear end of the pen holder;
[0024] Markings in the figure:
[0025] Pen body 1; first limiting groove 11; first limiting protrusion 12; pen tip 2; lead tube 3; clamping head 31; push-button cap 4; cap shell 41; shaft hole 411; internal thread 412; second limiting groove 413; second limiting protrusion 414; push rod 42; shaft hole 421; spiral groove 422; first limiting rib 423; second limiting rib 424; third limiting rib 425; fourth limiting rib 426; first connecting hole 427; rotating shaft 43; spiral rib 431; shaft 432; regular hexagonal prism 433; lead planer 44; planing hole 441; calibration protrusion 442; second connecting hole 443; cap head 45; lead plug hole 451; external threaded connection part 452; calibration rib 453; chip storage chamber 46; lead 5. DETAILED DESCRIPTION
[0026] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.
[0027] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0028] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.
[0029] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.
[0030] Please also read Figures 1 to 6 Now, the automatic pencil provided by the embodiment of the utility model is described.
[0031] like Figures 1 to 6 As shown, a mechanical pencil according to an embodiment of the utility model, taking the existing mechanical pencil structure as an example, mainly comprises a pen body 1, a pen head 2, a lead tube 3, a spring (not shown in the figure) and a push-button cap 4.
[0032] The pen barrel 6 is the main body of the automatic pencil; the pen tip 2 is connected to the front end of the pen barrel 1, and a damping ring for protecting the protruding part of the lead 5 is provided in the pen tip 2, that is, the damping ring is used to slow down the vibration, movement speed and displacement of the lead 5, so that the lead 5 can be written more stably, thereby playing a protective role; the lead tube 3 is arranged inside the pen barrel 1, for storing the lead 5 and allowing the lead 5 to move forward, and a clamp 31 and a locking hoop for releasing and locking the lead 5 are installed at the front end of the lead tube 3; the front end of the spring 4 is against the front end cavity wall of the pen barrel 1, and the rear end of the spring 4 is against the lead tube 3; the push-button cap 4 is arranged at the rear end of the pen barrel 1 and is fixedly connected to the lead tube 3. When the push cap 4 is subjected to the pressing pressure (finger pressure), the elastic force of the spring 4 is overcome to drive the lead tube 3 and the clamp 31 to move forward. At this time, the clamp 31 and the locking hoop fixed at the front end of the pen body 1 move relative to each other, so that the claws of the clamp 31 are freed from the constraint of the locking hoop and open, releasing the lead 5. At the same time, the lead 5 leaves its original position in the lead tube 3 by its own gravity and moves a certain length along the axial direction of the pen head 2 under the control of the damping ring. After the pressing pressure is released, the push cap 4, the lead tube 3 and the clamp 31 return to their original positions under the action of the spring 4, and the lead 5 is locked and positioned again by the clamp 31 and the locking hoop, completing a pulsating core-extracting process.
[0033] Based on the above existing mechanical pencil structure, the core technology of the embodiment of the utility model is to promote the improvement of the button cap, which is as follows:
[0034] The push-button cap 4 comprises a cap shell 41, a push rod 42, a rotating shaft 43, a lead planer 44 and a cap head 45; the front end of the push rod 42 can be slidably inserted into the rear end of the pen barrel 1 and fixedly connected to the lead tube 3, the rear end of the push rod 42 is provided with an axial hole 421, and the hole wall of the axial hole 421 is provided with a spiral groove 422; the front end of the push-button cap shell 41 is sleeved on the rear end of the push rod 42; the outer periphery of the front end of the rotating shaft 43 is provided with a spiral rib 431 that cooperates with the spiral groove 422, and the rotating shaft 43 is provided with a spiral rib 431 that cooperates with the spiral groove 422. A shaft 432 extends from the rear end of the rotating shaft 43, and the outer diameter of the shaft 432 is smaller than the outer diameter of the rotating shaft 43. A shaft hole 411 that matches the shaft hole of the shaft 432 is provided inside the push cap shell 41, and the shaft 432 is fixedly connected to the lead planer 44 through the shaft hole 411; the cap head 45 is connected to the rear end of the push cap shell 41 and is enclosed with the push cap shell 41 to form a chip storage chamber 46; the lead planer 44 is arranged in the chip storage chamber 46; and a lead core socket 451 is provided on the cap head 45.
[0035] When the cap shell 41 is pulled out of the push rod 42 with the rotating shaft 43, that is, in the process of the rotating shaft 43 being pulled out of the shaft hole 421, the rotating shaft 43 performs positive rotational motion under the cooperation of the spiral rib 431 and the spiral groove 422, thereby driving the planing hole 441 of the lead planer 44 to rotate to face the lead plug hole 451, at which time the lead that has leaked out of the pen tip 2 can be inserted into the lead planer 44 for planing, and the planed lead chips will enter the chip storage chamber 46; after the lead planing is completed, when the cap shell 41 is pulled out with the rotating shaft 43, the lead that has leaked out of the pen tip 2 can be inserted into the lead planer 44 for planing, and the planed lead chips will enter the chip storage chamber 46. When the rotating shaft 43 is inserted back onto the pushing rod 42, that is, when the rotating shaft 43 is inserted into the shaft hole 421, the rotating shaft 43 performs reverse rotation under the cooperation of the spiral rib 431 and the spiral groove 422, thereby driving the planing hole 441 of the lead planer 44 to be separated from the lead plug hole 451, and the lead plug hole 451 is blocked by the end surface of the lead planer 44. At this time, the planed lead scraps can be temporarily stored in the closed scrap storage chamber 46, so that the leakage of lead scraps will not cause contamination to hands and objects. When the lead scraps need to be poured out from the scrap storage chamber 46, the scrap storage chamber 46 can be opened by removing the cap head 45 to realize the operation of dumping the lead scraps.
[0036] Therefore, according to the mechanical pencil of the embodiment of the utility model, by designing the lead planer 44 on the push-button cap 4, it is convenient for the user to take out the lead planer 44 to plan the lead at any time; and because the lead planer 44 is arranged in the chip storage chamber 46 formed by the cap head 45 and the push-button cap shell 41, the lead chips will not fall and contaminate the hands and objects during the lead planing process; in addition, through the design of the rotating shaft 43 and the push rod 42, the spiral matching structure of the spiral rib 431 and the spiral groove 422 is utilized, so that when the push-button cap shell 41 is connected to the push rod 42 with the rotating shaft 43, the lead planer 44 is in a closed state and cannot be used, and when the push-button cap shell 41 is separated from the push rod 42 with the rotating shaft 43, the lead planer 44 is in an open state for use, and such a design can effectively ensure that the lead chips in the chip storage chamber 46 will not leak during the use of the pen, and there is no need to clean the lead chips in time, thereby improving the user's pen-using experience.
[0037] Exemplarily, the cap head 45 is provided with an external threaded connection portion 452, and the cap shell 41 is provided with an internal thread 412 threadedly connected to the external threaded connection portion 452. Furthermore, considering that after the cap head 45 is disassembled, it is easy to touch the lead planer 44 to cause it to rotate and shift, resulting in the end surface of the lead planer 44 after the rotating shaft 43 and the push rod 42 are reconnected. The lead plug hole 451 cannot be automatically blocked, and the planing hole 441 of the lead planer 44 cannot be rotated to face the lead plug hole 451 after the rotating shaft 43 and the push rod 42 are separated next time. Therefore, in order to ensure that the reassembled lead planer 44 can be used normally, the lead planer 44 is close to the cap head 45. A calibration protrusion 442 is provided on the side in a radially protruding manner, and a calibration convex strip 453 is provided on the inner wall of the cap head 45 in a radially protruding manner and extending in the axial direction. The calibration convex strip 453 can be circumferentially abutted against the calibration protrusion 442 during the threaded connection process between the cap head 45 and the press cap shell 41, so that the lead planer 44 is automatically reset to the planing hole 441 and the lead core plug hole 451 when the cap head 45 is reinstalled, thereby ensuring that the correct assembly can be achieved when the press cap shell 41 is connected with the rotating shaft 43 and the push rod 42 next time. In this embodiment, the external thread connection part 452 is provided with at least two pitches, so that the cap head 45 can rotate more than 360 degrees when connected and fixed on the press cap shell 41, ensuring that the calibration convex strip 453 can effectively move to the calibration protrusion 442 to achieve the position calibration of the lead planer 44.
[0038] Exemplarily, the outer periphery of the push rod 42 is provided with a first limiting rib 423 which is radially protruding and extends in the axial direction, the inner wall of the pen body 1 is provided with a first limiting groove 11 which cooperates with the front section of the first limiting rib 423, and the inner wall of the push cap shell 41 is provided with a second limiting groove 413 which cooperates with the rear section of the first limiting rib 423. Thus, through the cooperation between the first limiting groove 11 and the front section of the first limiting rib 423, the push rod 42 can be prevented from being driven to rotate coaxially relative to the pen body 1 during the process of connecting or separating with the rotating shaft 43, thereby realizing the circumferential limitation of the push rod 42; through the cooperation between the second limiting groove 413 and the rear section of the first limiting rib 423, the push cap shell 41 can be prevented from being driven to rotate coaxially relative to the push rod 42 during the process of connecting or separating with the rotating shaft 43, thereby realizing the circumferential limitation of the push rod 42.
[0039] Exemplarily, a second limiting rib 424 is provided between the front section of the first limiting rib 423 and the rear section of the first limiting rib 423, which is radially protruding and circumferentially surrounding. The outer diameter of the rear end face of the pen holder 1 and the outer diameter of the front end face of the push cap shell 41 are consistent with the outer diameter of the second limiting rib 424. After assembly, the rear end face of the pen holder 1 is spaced from the front end face of the second limiting rib 424, and the spacing interval is the advancing distance of the push rod 42 during pulsating core ejection; the front end face of the push cap shell 41 is abutted against the rear end face of the second limiting rib 424, so that the push cap shell 41 transmits the pressing pressure to the push rod 42.
[0040] Exemplarily, in order to make the connection between the push rod 42 and the pen body 1 more stable and reliable, the outer periphery of the front end of the push rod 42 is provided with a third limiting rib 425 which is radially protruding and circumferentially surrounding, and the inner wall of the rear end of the pen body 1 is provided with a plurality of first limiting protrusions 12 which are radially protruding and circumferentially distributed, and the front end surface of the first limiting protrusion 12 abuts against the rear end surface of the third limiting rib 425 to form an axial limiting structure for preventing the push rod 42 from separating from the pen body 1; the outer diameter of the third limiting rib 425 is smaller than the outer diameter of the first limiting rib 423.
[0041] Exemplarily, in order to make the connection between the push rod 42 and the push cap shell 41 more stable and reliable, the middle outer periphery of the push rod 42 is provided with a fourth limiting rib 426 which is radially protruding and circumferentially surrounding, and the front end inner wall of the push cap shell 41 is provided with a plurality of second limiting protrusions 414 which are radially protruding and circumferentially distributed, and the rear end face of the second limiting protrusion 414 is abutted against the front end face of the fourth limiting rib 426 to form an axial limiting structure for preventing the push cap shell 41 from separating from the push rod 42; the outer diameter of the fourth limiting rib 426 is smaller than the outer diameter of the first limiting rib 423.
[0042] Illustratively, in order to facilitate assembly, the present embodiment further provides the following specific assembly form: the nib 2 is threadedly connected to the pen barrel 1; the front end of the push rod 42 is provided with a first connecting hole 427 for the lead tube 3 to be plugged in; the portion where the shaft 432 is connected to the lead planer 44 is a regular hexagonal prism 433, and the lead planer 44 is provided with a second connecting hole 443 which is interference fit with the regular hexagonal prism 433.
[0043] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principle of the present invention. These improvements and substitutions should also be regarded as the protection scope of the present invention.
Claims
1. A mechanical pencil, comprising a pen holder, a pen tip, a lead tube, a spring and a push-button cap, characterized in that: The pushing cap comprises a cap shell, a pushing rod, a rotating shaft, a lead planer and a cap head; the front end of the pushing rod can be slidably inserted into the rear end of the pen barrel and fixedly connected with the lead tube, the rear end of the pushing rod is provided with an axial hole, and the hole wall of the axial hole is provided with a spiral groove; the front end of the cap shell is sleeved on the rear end of the pushing rod; the outer periphery of the front end of the rotating shaft is provided with a spiral rib that matches the spiral groove, and the rear end of the rotating shaft extends with a shaft rod, the interior of the cap shell is provided with a shaft rod hole that matches the shaft rod, and the shaft rod passes through the shaft rod hole and is fixedly connected with the lead planer; the cap head is connected to the rear end of the cap shell and encloses the cap shell to form a chip storage cavity; the lead planer is arranged in the chip storage cavity; the cap head is provided with a lead plug hole; When the rotating shaft is pulled out from the shaft hole, the rotating shaft performs positive rotational motion under the cooperation of the spiral rib and the spiral groove, thereby driving the planing hole of the lead core planer to rotate to face the lead core insertion hole; During the process of inserting the rotating shaft into the shaft hole, the rotating shaft performs reverse rotational motion under the cooperation of the spiral rib and the spiral groove, thereby driving the planing hole of the lead core planer to separate from the lead core insertion hole, and the lead core insertion hole is blocked by the end face of the lead core planer.
2. The mechanical pencil according to claim 1, characterized in that: The cap head is provided with an external thread connection portion, and the cap shell is provided with an internal thread threadedly connected to the external thread connection portion.
3. The mechanical pencil according to claim 2, characterized in that: A radially protruding calibration block is provided on the outer side of one end of the lead core planer close to the cap head, and a radially protruding calibration strip is provided on the inner wall of the cap head, which is axially extending and can be circumferentially abutted against the calibration block during the threaded connection between the cap head and the cap shell; the external threaded connection portion is provided with at least two pitches.
4. The mechanical pencil according to claim 1, characterized in that: The outer periphery of the push rod is provided with a first limiting rib which is radially protruding and extends axially, the inner wall of the pen body is provided with a first limiting groove which cooperates with the front side section of the first limiting rib, and the inner wall of the button cap shell is provided with a second limiting groove which cooperates with the rear side section of the first limiting rib.
5. The mechanical pencil according to claim 4, characterized in that: A second limiting rib is provided between the front section of the first limiting rib and the rear section of the first limiting rib, which is radially protruding and circumferentially surrounding. The outer diameter of the rear end face of the pen shaft and the outer diameter of the front end face of the button cap shell are consistent with the outer diameter of the second limiting rib.
6. The mechanical pencil according to claim 4, characterized in that: The outer periphery of the front end of the push rod is provided with a third limiting rib which is radially protruding and circumferentially surrounding, and the inner wall of the rear end of the pen shaft is provided with a plurality of first limiting blocks which are radially protruding and circumferentially distributed, the front end surface of the first limiting block abuts against the rear end surface of the third limiting rib and forms an axial limiting structure for preventing the push rod from separating from the pen shaft; the outer diameter of the third limiting rib is smaller than the outer diameter of the first limiting rib.
7. The mechanical pencil according to claim 4, characterized in that: The middle outer periphery of the push rod is provided with a fourth limiting rib which is radially protruding and circumferentially surrounding, and the front end inner wall of the push cap shell is provided with a plurality of second limiting protrusions which are radially protruding and circumferentially distributed, the rear end surface of the second limiting protrusion abuts against the front end surface of the fourth limiting rib and forms an axial limiting structure for preventing the push cap shell from separating from the push rod; the outer diameter of the fourth limiting rib is smaller than the outer diameter of the first limiting rib.
8. The mechanical pencil according to claim 1, characterized in that: The pen head is threadedly connected to the pen holder.
9. The mechanical pencil according to claim 1, characterized in that: The front end of the push rod is provided with a first connecting hole for the lead core tube to be inserted.
10. The mechanical pencil according to claim 1, characterized in that: The part where the shaft rod is connected to the lead planer is a regular hexagonal prism, and the lead planer is provided with a second connecting hole which is interference-fitted with the regular hexagonal prism.