Pencil feeding mechanism for pencil sharpener

Abstract

The utility model relates to a pencil feeding mechanism for a pencil sharpener. The pencil feeding mechanism comprises a front cover, a pencil rubbing wheel, a pencil clamping disc, a wheel shifting disc and a rear cover. Wherein the front cover is provided with a rib-plate-shaped first supporting part, the pen clamping disc is provided with a cylindrical barrel-shaped main body, a rib-plate-shaped second supporting part is arranged in the barrel-shaped main body, a groove for roughly receiving the end part of each pen rubbing wheel is formed in the second supporting part, and the first supporting part and the second supporting part are matched with each other to clamp the pen rubbing wheels together. And a pencil feeding gear positioned on the pencil rubbing wheel is meshed with a poking wheel disc positioned between the pencil clamping disc and the rear cover. The front cover, the pen clamping disc and the rear cover are connected through a plurality of connecting parts located on the front cover, the pen clamping disc and the rear cover respectively. A pencil enters the pencil sharpener through the first pencil inlet hole of the front cover, the second pencil inlet hole defined by the pencil rubbing wheel, the center hole of the dial wheel disc and the third pencil inlet hole of the rear cover so as to carry out the subsequent pencil sharpening step. The pencil sharpener comprising the pencil feeding mechanism is simple in structure, small in size and more convenient to carry.

Description

Technical Field

[0001] This utility model relates to the field of stationery technology, and more specifically, to a pen feeding mechanism for a pencil sharpener. Background Technology

[0002] Pencil sharpeners, as tools for cutting pencils, are safe and quick, especially automatic pencil sharpeners, which are particularly popular among students. A typical pencil sharpener includes a housing, a clamping mechanism, a feeding mechanism, and a sharpening mechanism. The pencil first passes through the clamping and feeding mechanisms, then enters the sharpening mechanism. Once the pencil reaches the desired position, it is clamped by the clamping mechanism, and the sharpening mechanism cuts the pencil tip.

[0003] To broaden its application and enable the cutting of various types of pencils, patent application CN202420524807.4 discloses an adjustable pencil feed device, comprising an adaptive adjuster, three adjusting springs, and adjusting mating parts. The adaptive adjuster has a disc-shaped body with three circumferential openings on this body that substantially receive the ends of the adjusting springs, and three axial levers extending along the pencil feed centerline Y to the pencil-gripping wheel. The adjusting mating parts can partially engage with the circumferential openings of the adjusting parts, forming accommodating spaces for the adjusting springs. This allows for automatic adjustment of the size and shape of the clamping space to apply a uniform and fitting clamping force to pencils of different diameters and shapes, resulting in more reliable and stable pencil feed. However, to accommodate pencils of different diameters and shapes, the pencil sharpener containing this feed device is relatively large and inconvenient to carry. For students, who generally use 8mm diameter pencils, a simple and portable pencil sharpener is needed.

[0004] In short, there is a technical need in this field to provide a solution that can take into account the versatility, portability, ease of operation, and simple and cost-effective manufacturing of pencil sharpeners. Utility Model Content

[0005] Therefore, the technical problem to be solved by this utility model is to overcome the defects of the prior art, which is that the diameter of the pencil feeding mechanism can be adjusted according to the pencil being cut, resulting in a complex structure of the pencil sharpener components containing it, which complicates the processing and manufacturing and increases the cost, as well as the defects of the large size and inconvenience of carrying.

[0006] To overcome one or more of the above-mentioned defects, this utility model provides a pencil feeding mechanism for a pencil sharpener. It is primarily suitable for pencils with a diameter of approximately 8mm, has a small size, and is convenient for students and other users to carry.

[0007] According to one aspect of the present invention, a pencil sharpener feeding mechanism is provided, comprising a front cover, a plurality of pencil-rubbing wheels, a pencil-clamping disc, a dial disc, and a rear cover, wherein the front cover comprises a plurality of first support portions evenly distributed along the circumferential direction, a centrally arranged first pencil-feeding hole, a plurality of first positioning holes evenly distributed along the circumferential direction, and a plurality of first connecting portions evenly distributed along the circumferential direction, wherein the first pencil-feeding hole is designed to be generally circular and has a diameter of 8 to 10 millimeters.

[0008] The pen holder includes multiple second supports that pair with multiple first supports to jointly support multiple pen feed rollers. Each second support has a groove for supporting the pen feed rollers, a second positioning hole, a support surface for supporting the second support and the second positioning hole, a second connecting portion configured to form a shape fit with the first connecting portion, and a third connecting portion. Multiple pen feed rollers together form a generally circular second pen feed hole, the diameter of which is no greater than 8 mm. The rear cover includes a third pen feed hole, a third positioning hole, and a fourth connecting portion configured to form a shape fit with the third connecting portion, thereby clamping the pen holder between the pen holder and the rear cover. The pen feed mechanism has a thickness in the range of 2 to 3 cm.

[0009] Therefore, compared with the prior art, the pencil feeding mechanism of the pencil sharpener provided by this utility model is not only compatible with common pencils on the market, allowing them to be stably pushed into the pencil sharpener, but also stably clamps the pencil after it has been pushed into the desired position with a small footprint. At the same time, because the adjustment mechanism is significantly simplified, it provides better ease of operation and reduced manufacturing and assembly difficulty, while also significantly reducing production costs and consumer purchase costs.

[0010] As a preferred aspect of the present invention, the pen-rubbing wheel includes a pen-clamping shaft, which is designed as a stepped shaft including a first journal, a second journal, and a third journal, wherein the diameter of the third journal located in the middle region of the pen-clamping shaft is greater than the diameter of the first journal and the second journal located at its two ends.

[0011] As a preferred aspect of the present invention, the pencil-gripping wheel further includes a pencil-feeding gear arranged sequentially on the pencil-clamping shaft, a pencil-clamping wheel for forming a force-transmitting engagement with the pencil inserted into the pencil-feeding mechanism, and a thrust stop.

[0012] As a preferred aspect of the present invention, the rear side of the dial has a flange and is designed to be generally cylindrical, wherein the outer diameter of the flange is equal to or slightly smaller than the third pen inlet hole of the rear cover, so that the flange can be connected to the rear cover.

[0013] As a preferred aspect of the present invention, the front cover, the pen holder, and the rear cover are sequentially connected to each other via a first connecting portion, a second connecting portion, a third connecting portion, and a fourth connecting portion respectively arranged thereon, wherein these connections are designed as snap-fit ​​connections.

[0014] As a preferred aspect of this utility model, the first positioning hole, the second positioning hole, and the third positioning hole are substantially coaxially aligned along the assembly direction of the pen feeding mechanism.

[0015] As a preferred aspect of this utility model, a washer is arranged on the side where the pen feed gear contacts the pen clamping wheel, so that there is a predetermined gap between the pen feed gear and the pen clamping wheel.

[0016] As a preferred aspect of the present invention, a gasket is arranged around the third pen inlet hole on the front surface of the rear cover.

[0017] As a preferred aspect of this utility model, a support rib is also arranged on the side of the support surface facing the rear cover inside the pen holder.

[0018] As a preferred aspect of this invention, the volume of the pen feeding mechanism is designed to be 30 to 32 cubic centimeters. Attached Figure Description

[0019] The subject matter of this utility model will now be described in more detail with reference to the embodiments shown in the accompanying drawings.

[0020] Figure 1 An exploded view of the pencil feeding mechanism of a pencil sharpener according to the present invention is shown;

[0021] Figure 2 A perspective view of the overall shape of the pencil feed mechanism of the pencil sharpener according to the present invention after assembly is shown.

[0022] Figure 3 A perspective view of the front cover of the pencil feed mechanism of the pencil sharpener according to the present invention is shown;

[0023] Figure 4 A front view of the pencil feeding mechanism of a pencil sharpener with a removable front cover according to the present invention is shown;

[0024] Figure 5 A perspective view of a single brush wheel of the brush feed mechanism of the pencil sharpener according to the present invention is shown;

[0025] Figure 6 A perspective view of a pen clip shaft according to the present invention, with only the pen feed gear installed;

[0026] Figure 7 A perspective view of the pen-feeding mechanism of the pencil sharpener according to the present invention is shown, with the pen clamp facing the front cover.

[0027] Figure 8 A perspective view of the pen-feeding mechanism of the pencil sharpener according to the present invention is shown, with the pen clamp facing the rear cover.

[0028] Figure 9 A perspective view of the pen feeding mechanism of a pencil sharpener with a removed front cover and a clip plate according to the present invention is shown.

[0029] Figure 10 A perspective view and a side view of the dial of the pencil feed mechanism of the pencil sharpener according to the present invention are shown.

[0030] Figure 11 A perspective view of the rear cover of the pencil feed mechanism of the pencil sharpener according to the present invention is shown.

[0031] Explanation of reference numerals in the attached figures

[0032] 10-Pen feeding mechanism; 11-Front cover; 12-Pen rolling wheel; 13-Pen clamping disc; 14-Dial disc; 15-Rear cover; 111-First support part; 112-First connecting part; 113-First pen feeding hole; 114-First positioning hole; 121-Pen clamping shaft; 122-Pen feeding gear; 123-Pen clamping wheel; 124-Thrust part; 125-Second pen feeding hole; 131-Second support part; 132-Groove; 133-Second positioning hole; 134-Second connecting part; 135-Third connecting part; 136-Supporting surface; 137-Supporting rib; 141-Dial disc teeth; 142-Flange; 151-Fourth connecting part; 152-Third positioning hole; 153-Third pen feeding hole; 1211-First journal; 1212-Second journal; 1213-Third journal. Detailed Implementation

[0033] An exemplary embodiment of the pencil-feeding mechanism of a pencil sharpener according to the present invention will now be described in detail with reference to the accompanying drawings. The drawings are provided to illustrate multiple embodiments of the present invention; however, the drawings are not necessarily drawn to the dimensions of the specific embodiments, and certain features may be enlarged, removed, or partially cut to better illustrate and explain the disclosure of the present invention. Some components in the drawings may be repositioned according to actual needs without affecting the technical effect. The phrase "in the drawings" or similar expressions appearing in the specification do not necessarily refer to all drawings or examples.

[0034] Certain directional terms used in the description of the accompanying drawings below, such as “inner,” “outer,” “upper,” “lower,” and other directional terms, shall be understood to have their normal meaning and refer to those directions involved when normally viewing the drawings. Unless otherwise specified, the directional terms used in this specification are generally in accordance with the conventional directions understood by those skilled in the art.

[0035] The terms “first,” “first,” “second,” “second,” and similar terms used in this utility model do not indicate any order, quantity, or importance, but are used to distinguish one component from other components.

[0036] In this document, the term “approximately” means that the parameters or values ​​used need not be implemented precisely, and deviations or variations (which include, for example, tolerances, measurement errors, measurement accuracy limitations, and other factors known to those skilled in the art) may occur in an aggregate that does not impede the desired effect provided by the described features.

[0037] like Figure 1 The diagram shows an exploded view of the pencil-feeding mechanism 10 of the present invention. The pencil-feeding mechanism 10 shown here includes at least a front cover 11, a plurality of pencil-rolling wheels 12, a pencil-clamping disc 13, a dial disc 14, and a rear cover 15. Figure 2 This is a perspective view showing the overall shape of the pencil feed mechanism 10 of the pencil sharpener according to the present invention after assembly, where the pencil feed mechanism 10 is along... Figure 2 The thickness in the front-to-back direction is approximately 2 to 2.5 centimeters. The front cover 11, the pen clamping plate 13, and the rear cover 15 constitute the outer shell of the pencil sharpener feeding mechanism 10. The pencil grinding wheel 12 is placed in the pen clamping plate 13, and the dial 14 is clamped between the pen clamping plate 13 and the rear cover 15.

[0038] In an embodiment of the present invention, the pen feeding mechanism 10 includes a front cover 11 that is generally hollow and cylindrical. As an example, the diameter of the front cover 11 is generally designed to be in the range of 4 to 4.5 centimeters. The front cover includes a first support portion 111 evenly distributed along the circumferential direction, a first connecting portion 112 evenly distributed along the circumferential direction, a centrally located first pen feeding hole 113, and first positioning holes 114 evenly distributed along the circumferential direction, as shown below. Figure 3 As shown. The upper surface of the front cover 11 is a circular plane, with a generally circular first pen inlet hole 113 at its center. This generally circular first pen inlet hole 113 has a size of approximately 8-10 mm and allows the pencil to be cut to enter the pen feeding mechanism 10. A flange extends from the circumference of the back side of the upper surface of the front cover 11, forming the sidewall of the front cover 11. Simultaneously, multiple first connecting portions 112 are evenly distributed on the sidewall of the front cover 11. These portions are recessed radially inward on the sidewall and designed to form a fixed connection with the pen clip 13 located behind them.

[0039] Preferably, the front cover 11 is provided with three first connecting portions 112, which are evenly distributed on the side wall of the front cover 11. The first connecting portions 112 are preferably designed as snap-fit ​​parts. On the back side of the upper surface of the front cover 11, along the direction away from the upper surface, a plurality of cylindrical first positioning holes 114 with through holes in the center extend outwards. The side walls of the first positioning holes 114 are connected to the inner side wall of the front cover 11 and are positioned between two first connecting portions 112. The first positioning holes 114 are designed to be at the same height as the side wall of the front cover 11 and are evenly distributed on the inner side wall of the front cover 11. This snap-fit ​​design, with its even or symmetrical distribution along the circumference, facilitates the simple formation of mating parts in mass production and reduces the workload of workers during assembly and the possibility of misoperation.

[0040] Preferably, the front cover 11 is provided with three first positioning holes 114. The front cover 11 is also provided with a plurality of first support portions 111, each first support portion 111 comprising two symmetrical parts, configured as ribs extending opposite each other from the sidewall of the front cover 11 along a direction at a certain angle to the radial direction. The two rib portions meet near the first pen inlet hole 113, forming a shape resembling a "V". Similarly, each first support portion 111 is located between two first connecting portions 112, evenly distributed on the back side of the upper surface of the front cover 11, and each first support portion 111 surrounds the first positioning hole 114 between itself and the sidewall of the front cover 11. Preferably, the front cover 11 is provided with three first support portions 111, and the height of the ribs of the first support portions 111 is designed to be slightly higher than the height of the sidewall of the front cover 11.

[0041] refer to Figure 4 The diagram shows a front view of the pencil feeding mechanism 10 with the front cover 11 removed. Multiple pencil shaping rollers 12 (shown here as three rollers) are arranged in a pencil clamping disc 13. The pencil to be cut can pass through a second pencil feeding hole 125 surrounded by the multiple pencil shaping rollers 12 and be clamped by the rollers 12. In an embodiment according to the present invention, the pencil shaping rollers 12 include a pencil clamping shaft 121, a pencil feeding gear 122, a pencil clamping wheel 123, and a thrust portion 124, see below. Figure 5 The image shows a perspective view of a single brush roller 12 according to the present invention.

[0042] Figure 6A perspective view of a pen-clamping shaft 121 according to the present invention, equipped only with a pen feed gear 122, is shown. The pen-clamping shaft 121 is a stepped shaft, with the diameter of the journal in the middle section being larger than that of the journals at both ends. The journals at both ends of the pen-clamping shaft 121 are a first journal 1211 and a second journal 112, respectively, with the journal on the side where the pen feed gear 122 is mounted being the first journal 1211 and the journal on the other side being the second journal 1212. The middle journal is a third journal 1213. Thus, a shoulder is formed at the connection between the first journal 1211 or the second journal 1212 and the third journal 1213 to fix the position of the components on the pen-clamping shaft 121. (Refer to...) Figure 6 The pen feed gear 122 is fixed to the pen clamping shaft 121 by a shoulder abutting against the first journal 1211 and the third journal 1213.

[0043] like Figure 5 As shown, the inner diameter of the pen-clamping wheel 123 is equal to or slightly larger than the diameter of the third journal 1213. One end of the pen-clamping wheel 123 abuts against one end of the pen-feeding gear 122 and is fixed in the region of the third journal 1213. Simultaneously, a thrust member 124 is mounted on the second journal, fixing the pen-clamping wheel 123 to the third journal 1213. Preferably, on the side where the pen-feeding gear 122 contacts the pen-clamping wheel 123, an annular groove (not shown in the figure) for placing a washer is arranged. Its diameter is larger than the diameter of the third journal 1213 but smaller than the outer diameter of the pen-clamping wheel 123. The washer arranged on the pen-feeding gear 122 creates a certain gap between the pen-clamping wheel 123 and the pen-feeding gear 122. Because the material of the pen-clamping wheel 123 has a certain elasticity, such as rubber, this gap allows the pen-clamping wheel 123 to deform to a certain extent during the pen-feeding step to adapt to the shape of the pencil, thereby clamping the pencil. Furthermore, this allows the second pencil inlet hole 125, enclosed by the plurality of pencil feed rollers 12, to adapt to variations in the outer diameter of the inserted pencil within a certain range, thereby allowing a pencil with a diameter of approximately 8 mm, generally circular or nearly circular, to be inserted through the second pencil inlet hole 125 and held in a force-engaged manner. As a result, with the subsequent rotation of the pencil feed gear 122 about the dial 14 (see, for example, see...), Figure 9 It causes the pencil to be fed toward the pencil sharpening mechanism located in front of the pencil feeding mechanism 10 by applying a force to the pencil located therebetween.

[0044] See Figure 7The diagram shows a perspective view of the pen-feeding mechanism 10 according to the present invention, with the pen holder 13 facing the front cover 11. Here, the aforementioned pen-rubbing wheel 12 can be internally housed within the pen holder 13, and the pen holder 13 is correspondingly connected to the front cover 11. The pen holder 13 has a shape similar to the front cover 11, and is generally cylindrical. On the side wall of the pen holder 13, corresponding to the first connecting portion 112 of the front cover 11, a corresponding number of second connecting portions 134 are arranged for connecting to the first connecting portions 112, thereby connecting and fixing the front cover 11 to the pen holder 13. Preferably, the second connecting portions 134 are designed as recesses corresponding to the snap-fit ​​first connecting portions 112. The side of the pen holder 13 corresponding to the front cover 11 is defined as the front side, and the side corresponding to the rear cover 15 is defined as the rear side. A third connecting part 135 is arranged on the side wall of the pen holder 13, aligned with the second connecting part 134 along its axial direction, and located at one end of the rear side wall of the pen holder 13. It is designed to connect with the back cover 15.

[0045] See Figure 8 The diagram shows a perspective view of the pen holder 13 of the pen feeding mechanism 10 according to the present invention, facing the rear cover 15. Similar to the front cover 11, the pen holder 13 also has a second support portion 131 corresponding to the front cover 11 to jointly support the plurality of brush rollers, and a second positioning hole 133. On the inner side wall of the pen holder 13, between the second connecting portion 134 and the third connecting portion 135, a support surface 136 extends circumferentially inward in the axial direction to increase the strength of the pen holder 13 and prevent deformation during use. The support surface 136 extends only unevenly into the inner side wall of the pen holder 13, forming an irregular hole in the middle, so that after the brush roller 12 is placed inside the pen holder 13, the pen feeding gear 122 can mesh with the dial 14. The second support portion 131 is V-shaped and evenly distributed on the inner side wall of the pen holder 13. Each second support portion 131 consists of two ribs, each rib having a groove 132 for supporting the brush roller 12. The height of the second support portion 131 is slightly less than the distance between the support surface 136 and the front end face of the side wall of the pen holder 13, allowing it to engage with the slightly protruding first support portion 111 of the front cover 11. The hole inside the second positioning hole 133 is a stepped hole. Each second support portion 131, together with the support surface 136 and the side wall of the pen holder 13, surrounds the second positioning hole 133.

[0046] Preferably, the support surface 136 between the second positioning hole 133 and the second support portion 131 has a greater thickness, forming a boss in this area compared to other areas of the support surface 136. This strengthens the support surface 136 and prevents the pencil holder 13 from breaking or being damaged when the pencil is pushed in. To this end, support ribs 137 are evenly arranged on the side of the support surface 136 facing the rear cover. These ribs are arranged radially between the support surface 136 and the sidewall, further strengthening the support surface 136. The cross-section of the support ribs 137 radially along the pencil holder 13 can be of any shape; in this embodiment, the cross-section of the support ribs 137 is rectangular.

[0047] See Figure 9 This image shows a perspective view of the pencil feeding mechanism 10 of a pencil sharpener with the front cover 11 and the clip plate 13 removed. It can be seen that the pencil feed roller 12 engages with the dial plate 14. When a pencil is fed in, the pencil feed roller 12 rotates due to friction from the pencil, causing the dial plate 14 to rotate around its central axis. This allows the pencil feeding mechanism 10 to support the pencil as it is fed into the sharpener, and simultaneously clamps the pencil when it reaches the desired sharpening position. Figure 4 As shown, when the pencil shaping roller 12 is arranged inside the pencil holder 13, a gap is left between the pencil holder shaft 121 and the groove 132 of the second support portion 131. When the diameter of the pencil is larger than the inlet hole formed by the pencil shaping roller 12, when the pencil is pushed in, the pencil shaping roller 12 will move away from the central axis of the pencil holder 13, so that the pencil holder shaft 121 is pressed against the other side of the groove 132, thereby expanding the inlet hole formed by it. Furthermore, there is also a gap between the thrust portion 124 of the pencil shaping roller 12 and the outer surface of the second support portion 131, so that when the pencil is pushed in, the shape of the inlet hole can be adjusted by the movement of the pencil shaping roller 12 and the deformation of the elastic pencil holder 123 to adapt to the shape of the pencil. Preferably, the diameter of the second inlet hole formed by the pencil shaping roller 12 is no greater than 8mm, which is designed to meet the needs of pencils with a diameter of about 8mm that are commonly found in the market.

[0048] See Figure 10 The diagram shows a perspective view and a side view of a dial 14 according to the present invention. The dial 14 has a central through-hole to allow a pencil to pass through and subsequently enter a pencil sharpener. The front surface of the dial 14 has dial teeth 141 for meshing with the feed gear 122 of the pencil trimmer 12. The rear surface of the dial 14 extends circumferentially away from the rear surface of the dial 14 along the central through-hole, forming a flange 142. The flange 142 has a certain wall thickness and is generally cylindrical. Its inner diameter is the diameter of the through-hole of the dial 14, and its outer diameter is designed to be equal to or slightly smaller than the diameter of the third feed hole 153 of the rear cover 15, thereby mates with it.

[0049] According to the perspective view of the rear cover 15 of this utility model, as shown below Figure 11 As shown. The back cover 15 is generally disc-shaped. Similarly, it has third positioning holes 152 distributed around its circumference and a third pen feed hole 153 at its center. The diameter of the third pen feed hole 153 is equal to or slightly larger than the outer diameter of the flange 142 of the aforementioned dial 14, so that the dial 14 is connected to the back cover 15 through the flange 142, and the rear side of the dial 14 abuts against the front side of the back cover 15. A circular groove with a diameter larger than the central hole is arranged around the front side of the back cover 15 for placing a washer, so that there is a certain gap between the dial 14 and the back cover 15, reducing the wear between the dial 14 and the back cover 15 when the pencil is pushed. The back cover 15 also has a plurality of fourth connecting parts 151 arranged on the outer side of its front circumference, which are designed to cooperate with the third connecting part 135 of the pen holder 13 to fix the back cover 15 and the pen holder 13. Similarly, the back cover 15 has multiple positioning holes evenly distributed in the circumference, corresponding to the aforementioned front cover 11 and pen clip 13.

[0050] As described above, the pencil feeding mechanism 10 mainly relies on the deformability of its own components, the tolerance fit between components, and the clearance fit to achieve versatility, without the need for additional adjustment mechanisms, including components such as springs, as in the prior art. This allows the pencil feeding mechanism 10 of the present invention to not only be suitable for commonly available pencils with a diameter of about 8mm, enabling them to be stably pushed into the pencil sharpener, but also to stably hold the pencil after it has been pushed to the desired position with a relatively small footprint. Specifically, the volume of the pencil feeding mechanism 10 according to the present invention is approximately 30 to 32 cubic centimeters, which is about 30% to 35% smaller than the existing pencil feeding mechanisms, which are generally larger than 45 cubic centimeters.

[0051] As a result, the pencil sharpener with the aforementioned feeding mechanism 10 can significantly reduce its overall volume. Specifically, the volume of the pencil sharpener with the feeding mechanism 10 can be reduced to within the range of 300 to 310 cubic centimeters, which is approximately 30% to 35% smaller than the volume of existing pencil sharpeners, which are generally larger than 430 cubic centimeters. This makes it more convenient for students and other users to carry in their daily lives. At the same time, because the adjustment mechanism is significantly simplified, it provides better operability and reduced manufacturing and assembly difficulty, while also significantly reducing production costs and consumer purchase costs.

[0052] While specific embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that many other changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, the appended claims are intended to cover all such changes and modifications within the scope of the present invention.

Claims

1. A lead-in mechanism for a pencil sharpener, comprising a front cover, a plurality of pencil-rolling wheels, a pencil-clamping disc, a dial disc, and a rear cover, characterized in that, the front cover comprises a plurality of first supporting portions uniformly distributed in a circumferential direction, a first lead-in hole centrally arranged, a plurality of first positioning holes uniformly distributed in a circumferential direction, and a plurality of first connecting portions uniformly distributed in a circumferential direction, wherein the first lead-in hole is designed to be substantially circular and has a diameter of 8 to 10 mm; the pencil-clamping disc comprises a plurality of second supporting portions paired with the plurality of first supporting portions to jointly bear the plurality of pencil-rolling wheels, wherein the second supporting portions are provided with grooves for bearing the pencil-rolling wheels, second positioning holes, a supporting surface for bearing the second supporting portions and the second positioning holes, second connecting portions configured to form a form fit with the first connecting portions, and third connecting portions, wherein the plurality of pencil-rolling wheels jointly enclose a second lead-in hole which is substantially circular, and the diameter of the second lead-in hole is not greater than 8 mm; the rear cover comprises a third lead-in hole, third positioning holes, and fourth connecting portions configured to form a form fit with the third connecting portions, so as to clamp the dial disc between the pencil-clamping disc and the rear cover; wherein the lead-in mechanism has a thickness in the range of 2 to 3 cm.

2. The pen advancement mechanism of claim 1, wherein wherein the pencil-rolling wheel comprises a pencil-clamping shaft designed as a stepped shaft comprising a first shaft neck, a second shaft neck, and a third shaft neck, wherein the diameter of the third shaft neck located in the middle region of the pencil-clamping shaft is greater than the diameters of the first shaft neck and the second shaft neck located at both ends thereof.

3. The pen advancement mechanism of claim 2, wherein wherein the pencil-rolling wheel further comprises a lead-in gear, a pencil-rolling wheel for forming a force fit with a pencil inserted into the lead-in mechanism, and a thrust portion arranged in sequence on the pencil-clamping shaft.

4. The pen advancement mechanism of claim 1, wherein wherein the rear side of the dial disc is provided with a flange and is designed as a substantially cylindrical barrel, wherein the outer diameter of the flange is equal to or slightly smaller than the third lead-in hole of the rear cover, so that the flange can be connected with the rear cover in a fit manner.

5. The pen advancement mechanism of claim 1, wherein wherein the front cover, the pencil-clamping disc, and the rear cover are connected with each other in sequence via the first connecting portions, the second connecting portions, the third connecting portions, and the fourth connecting portions arranged thereon respectively, wherein these connections are designed as snap-fit connections.

6. The pen advancement mechanism of claim 1, wherein wherein the first positioning holes, the second positioning holes, and the third positioning holes are substantially coaxially aligned in the assembly direction of the lead-in mechanism.

7. The pen advancement mechanism of claim 3, wherein wherein a gasket is arranged on the side of the lead-in gear in contact with the pencil-rolling wheel, so that a predetermined gap is formed between the lead-in gear and the pencil-rolling wheel.

8. The recharging mechanism of claim 1, wherein wherein a gasket is arranged on the front surface of the rear cover around the third lead-in hole.

9. The pen advancement mechanism of claim 1, wherein the supporting surface in the pencil-clamping disc facing the side of the rear cover is further provided with a supporting rib plate.

10. The pen advancement mechanism of claim 1, wherein wherein the volume of the lead-in mechanism is designed to be 30 to 32 cubic centimeters.

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