Pencil extender
By using the sliding fit between the inner and outer tubes and the cap design of the pencil extender, the problem of difficulty in holding the pencil caused by its shortened length is solved. This allows for adjustable and fixed pencil length and integration with the eraser, improving the comfort and convenience of writing and drawing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2026-04-03
AI Technical Summary
Pencils become difficult to hold due to shortening in length, affecting writing comfort and precise control. Existing extenders are complicated to operate, and erasers are inconvenient to use.
Design a pencil extender, including an inner tube, an outer tube, an elastic reset component, and an eraser. Through the sliding fit between the inner and outer tubes and the design of the eraser cap, the pencil length can be adjusted and fixed, and the eraser function is integrated to simplify the operation steps.
Significantly increases the effective length of the pencil, improves grip comfort and writing experience, simplifies operation, extends eraser life, and prevents erasers from becoming loose or falling off.
Smart Images
Figure CN224075326U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of school supplies technology, and in particular to a pencil extender. Background Technology
[0002] In daily writing and drawing, pencils, due to their inherent length limitations, gradually shorten after a period of use. As the pencil length decreases, the user's grip and control significantly decline. This change not only affects writing comfort but may also lead to hand fatigue and reduced writing quality. This is especially true for drawing or design work that requires fine manipulation, where shorter pencils make precise control more difficult. Utility Model Content
[0003] The main purpose of this invention is to provide a pencil extender, which aims to solve the problem of difficulty in holding a pencil due to its shortened length during use.
[0004] To achieve the above objectives, this utility model proposes a pencil extender, which includes:
[0005] eraser;
[0006] The inner tube includes a tube body and a movable retaining plate. The two ends of the tube body are respectively a first end and a second end. The first end is provided with a first groove and a first protrusion is provided on the outer wall of the first end. The second end is provided with a slot. The top of the slot is connected to the movable retaining plate. The movable retaining plate is arranged facing the central axis of the tube body and has an intermittent movable retaining groove formed on the top of the movable retaining plate. A limiting platform is provided on the outer wall of the movable retaining plate, and a second protrusion is provided on the outer wall of the tube body.
[0007] The outer tube is sleeved on the outer wall of the tube body and coaxially arranged with the tube body. The outer tube is slidably engaged with the tube body. The two opposite ends of the outer tube are the third end and the fourth end. The inner wall of the third end can abut against the first protrusion. The fourth end is provided with an opening for the movable plate to pass through. The limiting platform can abut against the fourth end. The inner wall of the outer tube is provided with a limiting groove.
[0008] An elastic reset member is sleeved on the outer wall of the inner tube, and both ends of the elastic reset member abut against the second boss and the groove wall of the limiting groove, respectively.
[0009] A leather cap, wherein a second groove is provided on the leather cap, and the leather cap is detachably connected to the second end so that the first groove and the second groove can communicate to form a receiving groove, the receiving groove being used to receive the rubber.
[0010] In one embodiment, the cap includes a connecting portion and a pressing portion. The connecting portion is provided with a second groove. One end of the connecting portion is detachably connected to the second end, and the other end of the connecting portion extends through the third end to the outside of the outer tube and is connected to the cap.
[0011] In one embodiment, a third protrusion is provided on the inner wall of the connecting part, and a snap-fit groove is provided on the outer wall of the first end to engage with the third protrusion.
[0012] In one embodiment, the number of active cards is at least two.
[0013] In one embodiment, the number of active cards is three.
[0014] In one embodiment, the limiting groove is disposed near the fourth end.
[0015] In one embodiment, a gripping portion is provided on the outer wall of the outer tube, and the number of gripping portions is multiple, with the multiple gripping portions arranged at intervals along the outer wall of the outer tube.
[0016] In one embodiment, the size of the outer tube is gradually reduced from the third end toward the fourth end.
[0017] In one embodiment, the resilient reset member includes a spring.
[0018] In one embodiment, the first end is provided with a demolding hole communicating with the first groove.
[0019] In this embodiment of the invention, the inner tube, as the core component of the pencil extender, provides the functions of fixing and sliding the pencil. The outer tube is sleeved outside the inner tube, providing protection and gripping functions, and allowing the inner tube to slide inside it. The upper end of the tube body is the first end, and the lower end is the second end. The upper end of the outer tube is the third end, and the lower end is the fourth end. A first protrusion provided at the first end of the inner tube can abut against the inner wall of the third end of the outer tube, thereby limiting the maximum downward travel of the inner tube relative to the outer tube. A limiting platform provided on the movable plate of the inner tube can abut against the fourth end, thereby limiting the maximum upward travel of the inner tube relative to the outer tube, ensuring that the inner tube will not slide out of the outer tube. The movable plate on the inner tube forms... The movable slot can hold the pencil, thereby extending its length and improving grip comfort, thus addressing the difficulty of holding the pencil due to its shortened length during use. The elastic reset element provides a restoring force to the inner tube, allowing it to automatically return to its initial position when no external force is applied. The elastic reset element is fitted onto the outer wall of the inner tube, with its two ends abutting against the second protrusion on the inner tube and the groove wall of the limiting groove on the outer tube, ensuring stable transmission of the restoring force. The eraser provides erasing functionality, allowing users to easily make corrections while writing or drawing. The eraser is placed in its receiving slot, and because the cap is detachably connected to the inner tube, it ensures the eraser remains in the correct position, preventing the eraser from slipping. In case of loosening or falling off during use, the cap effectively protects the eraser from dust, dirt, and other external contaminants, extending its lifespan. Furthermore, users can easily operate the pencil extender by pressing the cap, such as adjusting the pencil's extension length or locking the position. This design simplifies operation and improves ease of use. Initially, the pencil extender is stationary, with the movable locking plate inside the outer tube, not protruding from the opening. The elastic reset element is in a natural or slightly compressed state, providing a certain tension. When clamping the pencil, the user presses the cap to slide the tube body towards the fourth end, allowing the tube to... The movable plate on the main body gradually protrudes from the opening of the outer tube. When it is fully extended from the opening, the intermittent movable slot is no longer restricted by the inner wall of the opening. The diameter of the movable slot expands, forming a ready state for clamping the pencil. The user inserts the pencil into the movable slot. When the pencil reaches the appropriate position, the user releases the cap. The elastic reset component recovers part or all of its deformation, causing the tube body to slide towards the third end. This forces the movable plate to retract into the inner part of the outer tube. The movable plate returns to its original shape, and the groove wall of the movable slot presses the pencil inward, ensuring that the pencil is firmly clamped and will not loosen or shift. At this time, the pencil is fixed in the pencil extender, extending the length of the pencil, and the user can use it normally.This utility model embodiment significantly increases the effective length of the pencil by employing a sliding fit between the inner and outer tubes and a cap design, ensuring that the user can always hold the pencil comfortably, reducing hand fatigue, and improving the user's writing and drawing experience. The design of the movable card plate and elastic reset component provides a simple and reliable clamping method, allowing users to easily insert or remove the pencil without complicated tools or steps, improving operational convenience and user experience. The integrated eraser function allows users to easily erase at any time, avoiding the hassle of finding an extra eraser, thus enhancing the overall practicality, multifunctionality, and ease of use of the product. Furthermore, the connection method between the various components of the pencil extender is simple and reliable, facilitating disassembly and maintenance. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the structure of an embodiment of the pencil extender of this utility model;
[0022] Figure 2 for Figure 1 AA sectional view;
[0023] Figure 3 This is a schematic diagram of the structure of an embodiment of the inner tube of the pencil extender of this utility model;
[0024] Figure 4 This is a schematic diagram of the structure of an embodiment of the outer tube of the pencil extender of this utility model.
[0025] Explanation of icon numbers:
[0026] 100. Pencil extender; 1. Eraser; 2. Inner tube; 21. Tube body; 211. First end; 2111. First groove; 2112. First boss; 2113. Snap-fit groove; 2114. Demolding hole; 212. Second end; 2121. Slot; 213. Second boss; 22. Movable retaining plate; 221. Movable retaining groove; 222. Limiting platform; 3. Outer tube; 31. Third end; 32. Fourth end; 321. Opening; 33. Limiting groove; 34. Grip part; 4. Elastic reset part; 5. Leather cap; 51. Connecting part; 511. Second groove; 512. Third boss; 52. Pressing part; 6. Receiving groove.
[0027] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.
[0029] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, and back), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.
[0030] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0031] In daily writing and drawing, pencils, due to their inherent length limitations, gradually shorten after a period of use. As the pencil length decreases, the user's grip and control significantly decline. This change not only affects writing comfort but may also lead to hand fatigue and reduced writing quality. This is especially true for drawing or design work that requires fine manipulation, where shorter pencils make precise control more difficult.
[0032] After careful research, the applicant discovered that some pencil extenders already exist on the market to address the problem of pencils being too short. However, these existing extenders typically use screws or other complex methods to secure the pencil, which not only increases the difficulty of operation but also affects the user experience. Furthermore, when a pencil becomes too short, it usually means that the eraser at its end is unusable or has completely disappeared, meaning that users must find an extra eraser when they need to erase, further reducing the convenience and efficiency of use.
[0033] The main purpose of this invention is to propose a pencil extender to solve the problem of difficulty in holding a pencil due to its shortened length during use.
[0034] Please see Figure 1 , Figure 2 and Figure 4 In one embodiment of this utility model, the pencil extender 100 includes an eraser 1, an inner tube 2, an outer tube 3, an elastic reset member 4, and a cap 5. The inner tube 2 includes a tube body 21 and a movable retaining plate 22. The two ends of the tube body 21 are respectively a first end 211 and a second end 212. The first end 211 is provided with a first groove 2111, and the outer wall of the first end 211 is provided with a first boss 2112. The second end 212 is provided with a slot 2121, the top of which is connected to the movable retaining plate 22. The movable retaining plate 22 is positioned facing the central axis of the tube body 21, and an intermittent movable retaining groove 221 is formed on the top of the movable retaining plate 22. A limiting platform 222 is provided on the outer wall of the movable retaining plate 22, and a second boss 213 is provided on the outer wall of the tube body 21. The outer tube 3... The outer tube 3 is sleeved on the outer wall of the tube body 21 and coaxially arranged with the tube body 21. The outer tube 3 and the tube body 21 are slidably fitted. The two ends of the outer tube 3 are respectively the third end 31 and the fourth end 32. The inner wall of the third end 31 can abut against the first boss 2112. The fourth end 32 is provided with an opening 321 for the movable plate 22 to pass through. The limiting platform 222 can abut against the fourth end 32. The inner wall of the outer tube 3 is provided with a limiting groove 33. The elastic reset member 4 is sleeved on the outer wall of the inner tube 2, and the two ends of the elastic reset member 4 abut against the second boss 213 and the groove wall of the limiting groove 33, respectively. The cap 5 is provided with a second groove 511. The cap 5 and the second end 212 are detachably connected so that the first groove 2111 and the second groove 511 can communicate to form a receiving groove 6. The receiving groove 6 is used to receive the rubber 1.
[0035] In this embodiment of the invention, the inner tube 2, as the core component of the pencil extender 100, provides the functions of fixing and sliding the pencil. The outer tube 3 is sleeved on the outside of the inner tube 2, providing protection and gripping functions, and allowing the inner tube 2 to slide inside it. Figure 2As shown, the upper end of the tube body 21 is the first end 211, and the lower end is the second end 212. The upper end of the outer tube 3 is the third end 31, and the lower end is the fourth end 32. The first protrusion 2112 provided at the first end 211 of the inner tube 2 can abut against the inner wall of the third end 31 of the outer tube 3, thereby limiting the maximum downward travel of the inner tube 2 relative to the outer tube 3. The limiting platform 222 provided on the movable plate 22 of the inner tube 2 can abut against the fourth end 32, thereby limiting the maximum upward travel of the inner tube 2 relative to the outer tube 3, ensuring that the inner tube 2 will not slip out of the outer tube 3. The movable slot 221 formed by the movable plate 22 on the inner tube 2 can hold the pencil, thereby extending the length of the pencil and improving the comfort of gripping the pencil, thus improving the pencil's performance. The problem of difficulty in gripping due to the shortened length during use is addressed. The elastic reset element 4 provides a reset force to the inner tube 2, allowing it to automatically return to its initial position when no external force is applied. The elastic reset element 4 is fitted onto the outer wall of the inner tube 2, with its two ends abutting against the second protrusion 213 on the inner tube 2 and the groove wall of the limiting groove 33 on the outer tube 3, respectively, ensuring stable transmission of the reset force. The eraser 1 provides an erasing function, allowing users to easily make corrections during writing or drawing. The eraser 1 is placed in the receiving groove 6. Because the cap 5 is detachably connected to the inner tube 2, it ensures that the eraser 1 remains in the correct position, preventing it from loosening or falling off during use. Furthermore, the cap 5 reduces the entry of external contaminants into the receiving groove 6. This design effectively protects the eraser 1 from external contaminants such as dust and dirt, extending its lifespan. Additionally, users can easily operate the pencil extender 100 by pressing the cap 5, for example, adjusting the pencil's extension length or locking its position. This design simplifies operation and improves ease of use. Initially, the pencil extender 100 is stationary, with the movable locking plate 22 inside the outer tube 3, not extending out of the opening 321. The elastic reset member 4 is in a natural or slightly compressed state, providing a certain tension. When holding the pencil, the user presses the cap 5 to slide the tube body 21 towards the fourth end 32, causing the movable locking plate 22 on the tube body 21 to gradually emerge from the opening 321 of the outer tube 3. When the pencil is fully extended from the opening 321, the intermittent movable slot 221 is no longer restricted by the inner wall of the opening 321. The diameter of the movable slot 221 expands, forming a ready state for clamping the pencil. The user inserts the pencil into the movable slot 221. When the pencil reaches the appropriate position, the user releases the cap 5. The elastic reset member 4 recovers part or all of its deformation, causing the tube body 21 to slide towards the third end 31. This forces the movable plate 22 to retract into the outer tube 3. The movable plate 22 returns to its original shape, and the groove wall of the movable slot 221 presses the pencil inward, ensuring that the pencil is firmly clamped and will not loosen or shift. At this time, the pencil is fixed in the pencil extender 100, extending the length of the pencil, and the user can use it normally.
[0036] The technical solution of this utility model significantly increases the effective length of the pencil by adopting the sliding cooperation of the inner tube 2 and the outer tube 3 and the design of the cap 5, ensuring that the user can always hold the pencil comfortably, reducing hand fatigue, and improving the user's writing and drawing experience. By adopting the design of the movable card plate 22 and the elastic reset member 4, a simple and reliable clamping method is provided, allowing the user to easily insert or remove the pencil without complicated tools or steps, improving the convenience of operation and user experience. By adopting the eraser 1, the eraser function is integrated, allowing the user to perform erasing operations at any time, avoiding the trouble of finding an extra eraser, improving the overall practicality, multifunctionality and ease of use of the product. Moreover, the connection method between the components of the pencil extender 100 is simple and reliable, making it easy to disassemble and maintain.
[0037] Please see Figure 1 and Figure 2 In one embodiment, the cap 5 includes a connecting part 51 and a pressing part 52. The connecting part 51 has a second groove 511. One end of the connecting part 51 is detachably connected to the second end 212, and the other end of the connecting part 51 extends through the third end 31 to the outside of the outer tube 3 and connects to the cap 5. Specifically, the cap 5 is an important component of the pencil extender 100, primarily performing two functions: it connects with the first groove 2111 of the inner tube 2 via the second groove 511 on the connecting part 51 to form a receiving groove 6 for holding the eraser 1; and through the design of the pressing part 52, the user can press... The pressing part 52 drives the inner tube 2 to slide relative to the outer tube 3, thereby precisely adjusting the extension length of the pencil to meet different writing or drawing needs. The design of the connecting part 51 enhances the connection strength between the cap 5 and the outer tube 3, preventing loosening or detachment. One end of the connecting part 51 is detachably connected to the second end 212 of the inner tube 2, making it convenient to use or replace the eraser 1. The other end of the connecting part 51 passes through the third end 31 of the outer tube 3 and extends to the outside of the outer tube 3, so that the pressing part 52 can always be kept outside the outer tube 3. Users can easily operate without additional tools, improving the overall ease of use.
[0038] Please see Figure 2 and Figure 3In one embodiment, a third protrusion 512 is provided on the inner wall of the connecting part 51, and a snap-fit groove 2113 is provided on the outer wall of the first end 211 to engage with the third protrusion 512. Specifically, the snap-fit between the third protrusion 512 and the snap-fit groove 2113 significantly enhances the connection strength between the cap 5 and the inner tube 2, preventing loosening or detachment during use, ensuring the tightness and reliability of the connection. The snap-fit design allows users to easily disassemble and install the cap 5 without additional tools, greatly facilitating the use or replacement of the rubber 1. The snap-fit design is simple and intuitive; users only need to gently push in or pull out to complete the operation, improving the user's operating experience, reducing complex disassembly and assembly steps, and enhancing the ease of use of the product.
[0039] According to one embodiment of the present invention, an internal thread is provided on the inner wall of the connecting part 51, and an external thread is provided on the outer wall of the second end 212 of the inner tube 2. The user can tighten or loosen the connecting part 51 and the second end 212 of the inner tube 2 by rotating the leather cap 5, thereby realizing the detachable connection between the connecting part 51 and the second end 212 of the inner tube 2.
[0040] According to another embodiment of the present invention, a first magnet is embedded in the inner wall of the connecting part 51, and a second magnet with opposite polarity is embedded in the outer wall of the second end 212 of the inner tube 2. When the connecting part 51 approaches the second end 212 of the inner tube 2, the attraction between the magnets will automatically attract the two together, thereby realizing the detachable connection between the connecting part 51 and the second end 212 of the inner tube 2.
[0041] Please see Figure 3 In one embodiment, the number of movable clamping plates 22 is at least two. Specifically, at least two movable clamping plates 22 are distributed at intervals on the top of the slots 2121 of the inner tube 2 to form a multi-point clamping structure. When the pencil is inserted, the at least two movable clamping plates 22 work together to ensure that the pencil is firmly fixed and prevents it from loosening or slipping out. Moreover, the at least two movable clamping plates 22 can flexibly adjust the clamping range to support pencils of various diameters, thereby enhancing the versatility of the product, meeting the needs of a wider range of users, and thus improving market competitiveness.
[0042] Please see Figure 3 In one embodiment, the number of movable clamping plates 22 is three. Specifically, in this embodiment, the three movable clamping plates 22 are distributed at equal angles on the top of the slot 2121 of the inner tube 2 to form a triangular clamping structure. Utilizing the principle of geometric stability, a more uniform clamping force can be provided to ensure that the pencil is firmly fixed without shifting or shaking. The design of three movable clamping plates 22 has a higher elasticity and can better adapt to pencils of different diameters. Compared with a larger number of movable clamping plates 22, the design structure of three movable clamping plates 22 is simpler, easier to manufacture and assemble, and reduces production costs and time.
[0043] According to one embodiment of the present invention, the number of movable plates 22 can be four, five or six, and multiple movable plates 22 are arranged at intervals along the top of the slot 2121 of the inner tube 2.
[0044] Please see Figure 2 and Figure 4 In one embodiment, the limiting groove 33 is positioned close to the fourth end 32. Specifically, the positioning groove 33 is positioned close to the fourth end 32, allowing the elastic reset member 4 to be positioned close to the movable retaining plate 22. This ensures a more uniform reset force throughout the sliding process, avoiding sudden changes or unevenness in the reset force. It effectively controls the maximum extension length of the inner tube 2 relative to the outer tube 3, preventing the inner tube 2 from completely sliding out of the outer tube 3. It also ensures that the elastic reset member 4 is always in the best working state throughout the sliding process, improving the sliding stability between the inner tube 2 and the outer tube 3. This allows for precise control of the compression and extension range of the elastic reset member 4, avoiding the problem of poor sliding caused by the offset of the elastic reset member 4.
[0045] Please see Figure 1 and Figure 4 In one embodiment, a grip portion 34 is provided on the outer wall of the outer tube 3. The number of grip portions 34 is multiple, and the multiple grip portions 34 are arranged at intervals along the outer wall of the outer tube 3. Specifically, the specific number of grip portions 34 can be selected according to actual needs to adapt to different users' grip habits and hand shapes, improve the versatility of the product and user experience. This embodiment does not limit this. In this embodiment, there are three grip portions 34. The grip portions 34 can be protrusions, grooves or other ergonomic shapes that can better fit the user's hand shape, ensure that the fingers can get the best support and comfort when placed naturally, and reduce hand fatigue caused by long-term use. The three grip portions 34 are arranged at intervals along the outer wall of the outer tube 3 to ensure that the user can get a good feel in different grip positions. The grip portions 34 can also adopt a textured design or use anti-slip materials to increase friction, thereby preventing the hand from slipping during long-term use and ensuring that the user can firmly hold the pencil extender 100 in various situations. In addition, the grip portions 34 can also be enhanced with different colors, materials or textures to improve the visual effect, improve the appearance design of the product while maintaining functionality, and make it more attractive.
[0046] Please see Figure 4In one embodiment, the outer tube 3 is tapered from the third end 31 toward the fourth end 32. Specifically, the outer tube 3 gradually decreases in size from the third end 31 toward the fourth end 32, conforming to the natural curve of the human hand. This allows it to better fit the natural shape of the user's palm, reducing hand fatigue and providing a more comfortable grip. The portion of the outer tube 3 closer to the fourth end 32 is thinner, making it easier for the user to better control the position of the pencil when fine operations are required. This is particularly suitable for drawing or writing scenarios that require high precision. Furthermore, the tapered shape design gives the product a more streamlined appearance, making it more modern and attractive.
[0047] Please see Figure 2 In one embodiment, the elastic reset member 4 includes a spring; specifically, the elastic properties of the spring enable it to provide a continuous and uniform reset force during compression and extension, ensuring that the inner tube 2 always maintains appropriate tension, thereby enhancing the overall stability and reliability. The spring has the advantages of high strength and fatigue resistance, ensuring that it is not easily damaged during long-term use, thus extending the product's service life. Moreover, the spring has a simple structure, does not require complex installation steps, and is easy to assemble and maintain. The spring's manufacturing process is mature, and the manufacturing cost is relatively low, making it suitable for large-scale production and helping to reduce the overall manufacturing cost.
[0048] According to one embodiment of the present invention, the elastic reset member 4 can be an elastic structural component such as an elastic rubber sleeve or an elastic metal sheet. An elastic rubber sleeve can be made of an elastic rubber material into a ring or cylindrical shape, and the elastic rubber sleeve is fitted onto the outer wall of the inner tube 2. The two ends of the elastic rubber sleeve contact the second protrusion 213 of the inner tube 2 and the limiting groove 33 in the outer tube 3, respectively, thereby providing a reset force. Alternatively, a metal sheet with a certain elasticity, such as a stainless steel sheet or a beryllium copper sheet, can be bent into an arc or spiral shape and fitted onto the outer wall of the inner tube 2. The two ends of the elastic metal sheet contact the second protrusion 213 of the inner tube 2 and the limiting groove 33 in the outer tube 3, respectively, thereby providing a reset force.
[0049] Please see Figure 3 In one embodiment, the first end 211 is provided with a demolding hole 2114 communicating with the first groove 2111. Specifically, the inner tube is made using injection molding. The demolding hole 2114 significantly reduces the demolding difficulty during the injection molding process, reduces the material thickness of the first end 211 of the inner tube 2, makes the mold easier to separate, improves production efficiency, and avoids demolding failure or damage due to excessive material thickness. Furthermore, by reducing the material usage of the inner tube 2, the product becomes lighter and its portability is improved. The shape of the demolding hole 2114 can be circular, elliptical, or other regular shapes. The specific dimensions can be optimized according to the manufacturing process and product requirements. This embodiment does not limit this.
[0050] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.
Claims
1. A pencil extender characterized by, The pencil extender comprises: an eraser; an inner tube, the inner tube comprising a tube body and a movable clamping plate, the tube body having a first end and a second end arranged oppositely, the first end being provided with a first groove, and an outer wall of the first end being provided with a first boss, the second end being provided with a slot, a top of the slot being connected with the movable clamping plate, the movable clamping plate being arranged facing a central axis of the tube body and being formed with spaced movable clamping grooves at a top of the movable clamping plate, a limiting boss being arranged on an outer wall of the movable clamping plate, and a second boss being arranged on an outer wall of the tube body; an outer tube, the outer tube being sleeved on the outer wall of the tube body and being coaxially arranged with the tube body, the outer tube being in sliding fit with the tube body, the outer tube having a third end and a fourth end arranged oppositely, an inner wall of the third end being capable of abutting against the first boss, the fourth end being provided with an opening for the movable clamping plate to pass through, the limiting boss being capable of abutting against the fourth end, and a limiting groove being arranged on an inner wall of the outer tube; a resilient reset member, the resilient reset member being sleeved on an outer wall of the inner tube, and two ends of the resilient reset member being capable of abutting against the second boss and a groove wall of the limiting groove respectively; a leather cap, the leather cap being provided with a second groove, the leather cap being detachably connected with the second end so that the first groove and the second groove are capable of being communicated to form a containing groove, and the containing groove being used for containing the eraser.
2. The pencil extender of claim 1, wherein The leather cap comprises a connecting portion and a pressing portion, the connecting portion being provided with the second groove, one end of the connecting portion being detachably connected with the second end, and the other end of the connecting portion extending out of the outer tube through the third end and being connected with the leather cap.
3. The pencil extender of claim 2, wherein A third boss is arranged on an inner wall of the connecting portion, and a clamping groove capable of clamping and fitting with the third boss is arranged on an outer wall of the first end.
4. The pencil extender of claim 1, wherein The number of the movable clamping plates is at least two.
5. The pencil extender of claim 4, wherein The number of the movable clamping plates is three.
6. A pencil extender according to any one of claims 1 to 5, wherein The limiting groove is arranged close to the fourth end.
7. A pencil extender as claimed in any one of claims 1 to 5, wherein, A gripping portion is arranged on an outer wall of the outer tube, and the number of the gripping portions is multiple, and the multiple gripping portions are arranged at intervals along the outer wall of the outer tube.
8. A pencil extender as claimed in any one of claims 1 to 5, wherein, The outer tube is gradually tapered from the third end to the fourth end.
9. The pencil extender of any one of claims 1 to 5, wherein, The resilient reset member comprises a spring.
10. The pencil extender of any one of claims 1 to 5, wherein, The first end is provided with a demolding hole communicated with the first groove.