CN215850494U - Full-automatic pencil sharpener - Google Patents

Abstract

The utility model discloses a full-automatic pencil sharpener which comprises a pencil feeding mechanism, a knife rest assembly and a power device, wherein the power device is respectively in transmission electric connection with the pencil feeding mechanism and the knife rest assembly, the knife rest assembly is positioned below the pencil feeding mechanism, the pencil feeding mechanism comprises a support, a pair of pencil feeding wheel assemblies and a transmission gear, the pencil feeding wheel assemblies are in transmission connection with the transmission gear, the pencil feeding wheel assemblies comprise a rubber wheel and a pencil feeding gear shaft, the pencil feeding gear shaft is rotatably arranged on the support, one side of the rubber wheel is tightly matched with the pencil feeding gear shaft to form a friction force area, the other side of the rubber wheel is in clearance fit with the pencil feeding gear shaft to form a clamping force area, and the friction force area and the clamping force area are distributed in a staggered mode. Therefore, the pencil clamping force and the pencil feeding force can be simultaneously considered by setting the friction force area for controlling the pencil to pass in and out and the clamping force area for preventing the pencil from rotating at different positions.

Description

Full-automatic pencil sharpener

Technical Field

The utility model relates to the technical field of pencil sharpeners, in particular to a full-automatic pencil sharpener.

Background

At present, the electric pencil sharpener is more and more popular, the pencil sharpening is completed through automatic pencil feeding, pencil sharpening and pencil discharging, the electric pencil sharpener utilizes a power device to realize the rotation of rubber wheels, the two rubber wheels are respectively positioned at two sides of a pencil to be sharpened, the steering directions of the two rubber wheels are opposite, the pencil can move upwards or downwards under the rotation of the two rubber wheels, and a friction force area for controlling the pencil to pass in and out and a clamping force area for preventing the pencil from rotating are in the same position. The tool rest assembly is arranged below the rubber wheels, so that the pencil can be cut, when the steering directions of the two rubber wheels respectively rotate towards one side of the pencil, namely the rubber wheels rotate towards the inner side, the pencil to be cut moves downwards, and when the pencil to be cut is positioned in the working area of the tool rest assembly, the cutting work can be finished; after cutting, the turning directions of the two rubber wheels rotate towards the outer side of the pencil respectively, the pencil moves upwards, and then the pencil is taken away from the working area of the tool rest assembly, so that the cutting process does not need to be manually participated.

However, the existing electric pencil sharpener has the following defects: (1) due to the sliding friction force, the rubber wheel and the transmission gear rotate asynchronously, the speed of the rubber wheel is low, if the clamping force is too large, the transmission gear is blocked, if the clamping force is small, the rotating force caused by the cutting process is difficult to overcome when the pencil is cut, the pencil is difficult to accurately feed and withdraw, and the clamping force and the pencil feeding force of the pencil cannot be simultaneously considered; (2) the pencil feeding force is easily influenced by pencil scraps, the pencil scraps only contain pencil lead powder as long as the composition of the pencil scraps, the main composition of the pencil lead powder is graphite, the graphite has a lubricating effect, and when the graphite powder falls on the friction working surface of the pencil feeding rubber wheel, the rubber wheel loses the friction force and is not wear-resistant; (3) for soft pencils, the pencil feeding force degree is smaller, and for hard pencils, the pencil feeding force degree is larger, so that the pencil feeding device cannot be simultaneously applied to the soft pencils and the hard pencils; (4) the service life of the pen entering mechanism is short, once graphite dust falls into the friction surface of the rubber wheel, the rotation and the slipping are easily caused, the pen feeding force is lost, and the conventional service life is about 1000-2000 times; (5) if there is no clearance completely between rubber wheel and the transmission shaft, though can prevent falling into of graphite dust, but will lead to rubber wheel and drive gear synchronous rotation, send a power degree inhomogeneous, can influence the centre gripping dynamics size along with the pencil of different diameters, influence and send a power degree size, if small, can lead to cutting a time overlength, if big then can lead to transmission system to damage.

SUMMERY OF THE UTILITY MODEL

An object of the present invention is to provide a full-automatic pencil sharpener, which overcomes the disadvantages of the prior art, and can simultaneously take account of the clamping force and the pencil feeding force of the pencil by setting the friction force area for controlling the pencil to enter and exit and the clamping force area for preventing the pencil from rotating at different positions.

Another object of the present invention is to provide a full-automatic pencil sharpener, which effectively seals the friction area for controlling the pencil to enter and exit, so as to effectively prevent the pencil scraps from falling into the tight matching surface, ensure constant friction force for feeding the pencil, and prolong the service life of the pencil feeding mechanism.

In order to achieve the above purposes, the technical scheme adopted by the utility model is as follows: the utility model provides a full-automatic ware of cutting is including going into a mechanism, knife rest assembly and power device, power device can drive ground electricity respectively connect go into a mechanism with knife rest assembly, knife rest assembly is located go into the below of a mechanism, it includes support, a pair of pen wheel subassembly and drive gear to go into a mechanism, but go into pen wheel subassembly and connect with driving drive gear, it includes the rubber wheel and goes into the pen gear axle to go into the pen wheel subassembly, go into the pen gear axle rotationally install in the support, one side of rubber wheel with it closely cooperates and forms the frictional force region to go into the pen gear axle, the opposite side of rubber wheel with it forms the clamping-force region to go into pen gear axle clearance fit, the frictional force region with clamping-force region dislocation distribution.

Preferably, the rubber wheel is provided with a first friction portion, a second friction portion and a clamping concave surface, the first friction portion and the second friction portion are respectively located on the inner side of the rubber wheel, the clamping concave surface is arranged on the outer side of the rubber wheel, the first friction portion is tightly matched with the pen-entering gear shaft, the second friction portion is located under the clamping concave surface, and the second friction portion is in clearance fit with the pen-entering gear shaft.

Preferably, the first friction portion has a friction coefficient equal to or greater than that of the second friction portion.

Preferably, the inner diameter of the first friction part is smaller than that of the second friction part, so that the first friction part is tightly matched with the pen input gear shaft, and a gap is formed between the second friction part and the pen input gear shaft.

Preferably, the pen wheel entering assembly further comprises a rubber wheel shaft sleeve, the rubber wheel shaft sleeve is arranged between the second friction portion and the pen gear entering shaft, the second friction portion is fixedly connected to the outer wall of the rubber wheel shaft sleeve, and the pen gear entering shaft is in clearance fit with the inner wall of the rubber wheel shaft sleeve.

Preferably, a frictional force between the first friction portion of the rubber wheel and the input gear shaft is greater than a frictional force between the rubber wheel sleeve and the input gear shaft.

Preferably, the rubber wheel is made of soft rubber, the rubber wheel sleeve and the pen input gear shaft are made of hard plastic or metal, and the rubber wheel is made of one of silica gel, rubber, TPR, TPE, TPU, TPEE and HTPR.

Preferably, the friction area and the clamping area at most partially overlap, and the boundary of the friction area at most extends beyond 1/3 of the clamping area.

Preferably, the rubber wheel is provided with a first positioning surface, the first positioning surface is positioned on the side surface of the rubber wheel, the rubber wheel shaft sleeve is provided with a second positioning surface, the second positioning surface is abutted against the first positioning surface,

preferably, the pen input gear shaft is provided with a first shaft section, a second shaft section and a third positioning surface, the second shaft section is connected with the first shaft section and the third positioning surface, the outer diameter of the first shaft section is smaller than that of the second shaft section, the rubber wheel is connected with the second shaft section, the third positioning surface is opposite to the second positioning surface, and the third positioning surface can limit the axial movement of the second positioning surface.

Drawings

FIG. 1 is a perspective view of a fully automatic sharpener provided in accordance with an embodiment of the present invention;

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;

FIG. 4 is a side view of a pen-entry mechanism provided in accordance with an embodiment of the present invention;

FIG. 5 is a cross-sectional view taken along line B-B of FIG. 4;

FIG. 6 is a cross-sectional view taken along line C-C of FIG. 5;

FIG. 7 is a perspective view of a rubber wheel provided in accordance with an embodiment of the present invention;

FIG. 8 is a cross-sectional view of the rubber wheel of FIG. 7;

fig. 9 is a structural perspective view of a rubber wheel hub provided in accordance with an embodiment of the present invention;

FIG. 10 is a cross-sectional view of the rubber hub of FIG. 9;

FIG. 11 is a perspective view of a structure of a stylus input shaft provided in accordance with an embodiment of the present invention;

FIG. 12 is a cross-sectional view of the input shaft of FIG. 11;

FIG. 13 is a perspective view of a structure of a pen wheel assembly provided in accordance with an embodiment of the present invention;

FIG. 14 is a cross-sectional view of the pen wheel assembly according to FIG. 13.

In the figure: 1. a pen feeding mechanism; 2. a pencil; 3. a tool holder assembly; 4. a power plant; 101. a friction force region; 102. a clamping force area; 10. a support; 20. a pen wheel assembly; 21. a rubber wheel; 211. a first friction part; 212. a second friction portion; 213. a first positioning surface; 214. clamping the concave surface; 22. a rubber wheel axle sleeve; 221. an outer wall; 222. an inner wall; 223. a second positioning surface; 23. a pen input gear shaft; 231. a first shaft section; 232. a second shaft section; 233. a third positioning surface; 30. a transmission gear; 40. a pen-in switch touch block; 50. a micro switch.

Detailed Description

The present invention is further described below with reference to specific embodiments, and it should be noted that, without conflict, any combination between the embodiments or technical features described below may form a new embodiment.

In the description of the present invention, it should be noted that, for the terms of orientation, such as "central", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., the terms of orientation and positional relationship indicate that the orientation or positional relationship shown in the drawings is based on, and are only for convenience of describing the present invention and simplifying the description, but 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 should not be construed as limiting the specific scope of the present invention.

It is noted that the terms first, second and the like in the description and in the claims of the present application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

The terms "comprises," "comprising," and "having," and any variations thereof, in the description and claims of this application, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It is noted that, as used in this application, the terms "substantially," "about," and the like are used as terms of table approximation and not as terms of table degree, and are intended to account for inherent deviations in measured or calculated values that would be recognized by one of ordinary skill in the art.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be connected through intervening media. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The full-automatic pencil sharpener as shown in fig. 1-14 comprises a pencil feeding mechanism 1, a tool rest assembly 3 and a power device 4, wherein the power device 4 is respectively connected with the pencil feeding mechanism 1 and the tool rest assembly 3 in a driving and electrical manner, the tool rest assembly 3 is located below the pencil feeding mechanism 1, the pencil feeding mechanism 1 comprises a support 10, a pair of pencil feeding wheel assemblies 20 and a transmission gear 30, the pencil feeding wheel assemblies 20 are connected with the transmission gear 30 in a driving manner, the pencil feeding wheel assemblies 20 comprise a rubber wheel 21 and a pencil feeding gear shaft 23, the pencil feeding gear shaft 23 is rotatably mounted on the support 10, one side of the rubber wheel 21 is tightly matched with the pencil feeding gear shaft 23 to form a friction force area 101, the other side of the rubber wheel 21 is in clearance fit with the pencil feeding gear shaft 23 to form a clamping force area 102, the friction area 101 and the clamping force area 102 are distributed in a staggered mode, so that the friction area 101 for controlling the pencil 2 to enter and exit and the clamping force area 102 for preventing the pencil 2 from rotating are arranged at different positions, stress surfaces of the friction area 101 and the clamping force area 102 are not on the same central line, and the clamping force and the pencil feeding force of the pencil 2 are considered simultaneously.

The tool rest assembly 3 is used for rotatably cutting a pencil 2 to be cut, wherein the tool rest assembly 3 is located below the pencil inserting mechanism 1, namely, the tool rest assembly is located below the inner side of the electric pencil sharpener and above the outer side of the electric pencil sharpener relative to the direction in which the pencil 2 enters, and the dislocation distribution means that the friction force area 101 and the clamping force area 102 are at least partially misaligned.

The friction force area 101 is a friction force area 101 generated by a friction surface between the rubber wheel 21 and the pen input gear shaft 23 when the pencil 2 is fed up and down and withdrawn, and the friction force which can be generated between the rubber wheel 21 and the pen input gear shaft 23 is different, so that the required pen feeding force is also different; the clamping force region 102 is a force-bearing region where the rubber wheels 21 prevent the pencil 2 from rotating to generate a clamping force when the tool rest assembly 3 rotationally cuts the pencil 2, and the clamping force preventing the pencil from rotating is provided by a friction force generated by the outer surfaces of the pair of rubber wheels 21 clamped between the outer surfaces of the pencil 2, and simultaneously provides a feeding force for pushing the pencil 2 downward.

In some embodiments, the rubber wheel 21 is provided with a first friction portion 211, a second friction portion 212 and a clamping concave surface 213, the first friction portion 211 and the second friction portion 212 are respectively located at the inner side of the rubber wheel 21, the clamping concave surface 214 is located at the outer side of the rubber wheel 21, the clamping concave surfaces 214 of the two rubber wheels 21 are oppositely arranged, the outer surface of the rubber wheel 21 is recessed inwards to form an annular clamping concave surface 214, the first friction portion 211 is tightly matched with one side of the pen input gear shaft 23, the second friction portion 212 is located right below the clamping concave surface 214, the second friction portion 212 is in clearance fit with the other side of the pen input gear shaft 23, wherein the tight fit means that the first friction portion 211 of the rubber wheel 21 and the pen input gear shaft 23 cannot relatively rotate, and through the selection of materials and the size of the contacted friction surface, the degree of tightness of the fit between the first friction part 211 and the input gear shaft 23 can be adjusted; the clearance fit means that the friction force between the second friction part 212 and the input gear shaft 23 is small, and compared with the tight fit between the first friction part 211 and the input gear shaft 23, the sliding friction force between the second friction part 212 and the input gear shaft 23 is very small or even negligible, so that only the clamping force on the pencil 2 is generated in the area between the second friction part 212 and the input gear shaft 23, and the friction force area 101 for the pencil 2 to go in and out and the clamping force area 102 for preventing the pencil 2 from rotating are arranged at different positions of the rubber wheel 21.

In some embodiments, the first friction portion 211 and the second friction portion 212 are made of the same or different materials, and the friction coefficient of the first friction portion 211 is equal to or greater than that of the second friction portion 212, for example, the first friction portion 211 is made of a soft rubber material, and the second friction portion 212 is made of a soft rubber material or a hard material.

In some embodiments, the inner diameter of the first friction portion 211 is smaller than the inner diameter of the second friction portion 212, so that the first friction portion 211 and the stylus input shaft 23 are tightly fitted, and a gap is formed between the second friction portion 212 and the stylus input shaft 23, thereby reducing the generation of sliding friction force in the clamping force area 102.

In some embodiments, the pen feeding wheel assembly 20 further includes a rubber wheel sleeve 22, the rubber wheel sleeve 22 is sleeved between the second friction portion 212 and the pen feeding wheel shaft 23, the second friction portion 212 is fixedly connected to an outer wall 221 of the rubber wheel sleeve 22, the pen feeding wheel shaft 23 is in clearance fit with an inner wall 222 of the rubber wheel sleeve 22, and a sliding friction force between the rubber wheel sleeve 22 and the pen feeding wheel shaft 23 is reduced, so that the rubber wheel sleeve 22 and the pen feeding wheel shaft 23 only form a clamping force area 102 for preventing the pencil 2 from rotating, and a friction force area 101 for the pencil 2 to enter and exit is not formed, so that the friction force area 101 and the clamping force area 102 are distributed on the rubber wheel 21 in a staggered manner.

In some embodiments, the friction force between the first friction portion 211 of the rubber wheel 21 and the input shaft 23 is greater than the friction force between the rubber wheel sleeve 22 and the input shaft 23.

In some embodiments, the rubber wheel 21 is made of a soft rubber material with a large friction coefficient, and the material of the rubber wheel 21 is selected from one or more of silicone, rubber, TPR, TPE, TPU, TPEE, and HTPR.

Among these, rubbers include a wide variety of rubbers including, but not limited to, natural rubber, butadiene rubber, styrene-butadiene rubber, ethylbenzene rubber, propylene rubber, or silicone rubber.

In some embodiments, the rubber hub 22 and the stylus shaft 23 are hard plastic or metal with a low coefficient of friction, including but not limited to nylon, POM plastic (polyoxymethylene), PP (polypropylene), PE (polyethylene), PC (polycarbonate).

In some embodiments, the friction area 101 and the clamping force area 102 at most partially coincide, the first friction portion 211 is partially located below the clamping concave surface 214 of the rubber wheel 21, preferably, the friction area 211 and the clamping force area 102 do not overlap, and the first friction portion 211 is located directly below the non-clamping concave surface of the rubber wheel 21. That is, the friction area 101 is preferably offset from the clamping force area 102, and the boundary of the friction area 101 cannot cross 1/3 of the clamping force area 102, so that the rubber wheel 21 and the transmission gear 30 are not rotated synchronously, and once the friction area 101 and the clamping force area 102 are overlapped too much, the rubber wheel 21 and the transmission gear 30 are rotated synchronously, and the transmission system is damaged.

In some embodiments, the rubber wheel 21 is provided with a first positioning surface 213, the first positioning surface 213 is located at the side of the rubber wheel 21, the rubber wheel sleeve 22 is provided with a second positioning surface 223, the second positioning surface 223 abuts against the first positioning surface 213, so that the axial movement between the rubber wheel 21 and the rubber wheel sleeve 22 is limited, the position of the rubber wheel 21 on the input shaft 23 is maintained, and meanwhile, the step height of the second positioning surface 223 helps to prevent the pen core powder from entering a transverse area and prevent the second friction part 212 of the rubber wheel 21 from slipping with the rubber wheel sleeve 22.

In some embodiments, the pen input gear shaft 23 is provided with a first shaft section 231, a second shaft section 232 and a third positioning surface 233, the second shaft section 232 connects the first shaft section 231 and the third positioning surface 233, the outer diameter of the first shaft section 231 is smaller than the outer diameter of the second shaft section 232, the rubber wheel 21 is connected to the second shaft section 232, the third positioning surface 233 is arranged opposite to the second positioning surface 223, the third positioning surface 233 limits the axial movement of the second positioning surface 223, the second positioning surface 223 and the third positioning surface 233 are in sliding fit, and the third positioning surface 233 provides resistance to the axial movement between the rubber wheel sleeve 22 and the pen input gear shaft 23.

Wherein, the first friction portion 211 of rubber wheel 21 fits all the time go into the second shaft section 232 of pen gear axle 23, because the external diameter of first shaft section 231 is less than second shaft section 232 is convenient for when the equipment, the first friction portion 211 of rubber wheel 21 closely laminate in go into the second shaft 232 section of pen gear axle 23, can carry out effectual sealing, first friction portion 211 with can effectively prevent between the fitting surface between the second shaft section 232 that 2 sweeps of pencil etc. from falling into between the friction stress surface, guarantee to send a frictional force invariable always, the life of going into a mechanism 1 is prolonged manyfold to the adult, can reach 7000 ~ 8000 times on average, effectively solve go into a mechanism 1 short-lived, send a power degree easily to receive the influence of pencil sweeps, the technical problem that does not stand wear and tear. Meanwhile, the friction force area 101 for the pencil 2 to go in and out vertically and the clamping force area 102 for preventing the pencil 2 from rotating are arranged at different positions, so that the pencil 2 is favorably clamped and fed with more proper force.

In some embodiments, the pen inserting mechanism 1 further includes a pen inserting switch contact block 40 and a micro switch 50, the pen inserting switch contact block 40 is detachably connected to the micro switch 50, and the micro switch 50 controls the power device 4 to start to drive the rubber wheels 21 on two sides to rotate in opposite directions.

When the pencil sharpener is used, a pencil 2 is inserted into the full-automatic pencil sharpener, the pencil 2 pushes the pencil inserting switch contact block 40 to move towards the micro switch 50, the pencil inserting switch contact block 40 enables the micro switch 50 to be closed, the power device 4 is started, the transmission gear 30 rotates, the left rubber wheel 21 is driven to rotate anticlockwise or clockwise by the rotation of the pencil inserting gear shaft 23, the right rubber wheel 21 rotates clockwise or anticlockwise, and then the pencil 2 is driven to move downwards or upwards; when pencil 2 through rubber wheel 21 rotate send to with the contact back of knife rest component 3 begins promptly to cut a pencil, rubber wheel 21 provides the revolving force that prevents pencil 2 along self axis direction and with the power of feeding of pencil 2 downward direction, because the regional 101 of frictional force with pencil 2 upper and lower business turn over carries out the setting of different positions with the regional 102 of clamping force that prevents pencil 2 rotation, can compromise pencil 2's clamping force degree and send a power degree simultaneously, satisfy different clamping force degree and send a power degree requirement through the adjustment.

The foregoing has described the general principles, principal features, and advantages of the utility model. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are merely illustrative of the principles of the utility model, but that various changes and modifications may be made without departing from the spirit and scope of the utility model, which fall within the scope of the utility model as claimed. The scope of the utility model is defined by the appended claims and equivalents thereof.

Claims (10)

1. The utility model provides a full-automatic ware of cutting, its characterized in that, is including going into a mechanism, knife rest assembly and power device, power device can drive ground electricity respectively connect go into a mechanism with knife rest assembly, knife rest assembly is located go into the below of a mechanism, it includes support, a pair of pen wheel subassembly and drive gear to go into a mechanism, but go into pen wheel subassembly and connect with driving drive gear, go into a wheel subassembly and include the rubber wheel and go into a gear shaft, go into the gear shaft rotationally install in the support, one side of rubber wheel with it closely cooperates and forms the frictional force region to go into the gear shaft, the opposite side of rubber wheel with it forms the clamping-force region to go into gear shaft clearance fit, the frictional force region with clamping-force region dislocation distribution.

2. The full-automatic pencil sharpener according to claim 1, wherein the rubber wheel is provided with a first friction portion, a second friction portion and a clamping concave surface, the first friction portion and the second friction portion are respectively located on the inner side of the rubber wheel, the clamping concave surface is arranged on the outer side of the rubber wheel, the first friction portion is in close fit with the pencil lead-in gear shaft, the second friction portion is located right below the clamping concave surface, and the second friction portion is in clearance fit with the pencil lead-in gear shaft.

3. The full-automatic pencil sharpener of claim 2 wherein the coefficient of friction of said first friction portion is equal to or greater than said second friction portion.

4. The full-automatic sharpener of claim 2, wherein the inner diameter of the first friction portion is smaller than the inner diameter of the second friction portion, such that the first friction portion and the input gear shaft are in close fit, and a gap is formed between the second friction portion and the input gear shaft.

5. The full-automatic pencil sharpener according to claim 2, wherein the pencil feeding wheel assembly further comprises a rubber wheel shaft sleeve, the rubber wheel shaft sleeve is arranged between the second friction portion and the pencil feeding gear shaft, the second friction portion is fixedly connected to the outer wall of the rubber wheel shaft sleeve, and the pencil feeding gear shaft is in clearance fit with the inner wall of the rubber wheel shaft sleeve.

6. The full-automatic sharpener of claim 5, wherein the friction force between the first friction portion of the rubber wheel and the input gear shaft is greater than the friction force between the rubber wheel bushing and the input gear shaft.

7. The automatic pencil sharpener of claim 5 wherein the rubber wheel is made of soft rubber, the rubber wheel sleeve and the input shaft are made of hard plastic or metal, and the rubber wheel is made of one of silicone rubber, TPR, TPE, TPU, TPEE and HTPR.

8. The automatic pencil sharpener of claim 5 wherein said rubber wheel has a first locating surface on a side of said rubber wheel, said rubber wheel sleeve having a second locating surface abutting said first locating surface.

9. The full-automatic pencil sharpener of claim 8, wherein the pencil input gear shaft is provided with a first shaft section, a second shaft section and a third positioning surface, the second shaft section is connected with the first shaft section and the third positioning surface, the outer diameter of the first shaft section is smaller than that of the second shaft section, the rubber wheel is connected with the second shaft section, the third positioning surface is opposite to the second positioning surface, and the third positioning surface can limit the second positioning surface from moving axially.

10. The fully automatic pencil sharpener of any one of claims 1 to 9 wherein said friction area and said clamping area at most partially overlap, said friction area having a boundary that extends at most 1/3 into said clamping area.

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