CN211166143U - Safety structure of pencil sharpener - Google Patents

Abstract

A safety structure of a pencil sharpener comprises a shell, a motor arranged in the shell, a knife rest cover detachably connected with the shell, a starting device capable of starting the motor to run, and an electric loop connecting the starting device and the motor, wherein at least one safety mechanism capable of being linked with the knife rest cover is arranged on the electric loop; when the tool rest cover is installed in place on the shell, the electric circuit is communicated, and the motor can start to move; when the tool rest cover is separated from the shell, the electric circuit is disconnected, and the motor cannot run. When the tool rest cover is detached, the electric circuit is disconnected certainly, the situation that the electric circuit is not disconnected in advance due to negligence when a user detaches the tool rest cover is prevented, and the tool rest cover has the advantage of high safety; in addition, when the tool rest cover is disassembled and assembled, the electric circuit is correspondingly disconnected and communicated at the same time, and the electric circuit is disconnected and communicated without extra operation steps, so that the tool rest cover has the advantages of convenience and quickness.

Description

Safety structure of pencil sharpener

Technical Field

The utility model relates to a cut a ware technical field, especially relate to a safety structure of cutting a ware.

Background

The pencil sharpener cuts through the hob so that the pencil lead has certain thickness. The pencil sharpener comprises a hob head for mounting the hob and a hob head cover covering the hob head.

After the pencil sharpener is used for a period of time, the cutting edge of the hob is easy to reduce in sharpness due to abrasion, and the cutting speed and the smoothness of the pencil are affected. For this reason, it is desirable to design a sharpener that facilitates removal of the holder cover to facilitate replacement of worn roller cutters in the holder cover. For example, chinese utility model patent application No. CN201721868654.1 (publication No. CN208428859U) discloses an electric pencil sharpener, which comprises a pencil holder, a pencil holder cover, a base and a scrap barrel; the knife rest is arranged on the base, the knife rest cover covers the knife rest, and the lower end of the knife rest cover is connected with the upper end of the base through a buckle; the scrap barrel is sleeved outside the knife rest cover. The connection structure between the tool rest cover and the base of the electric pencil sharpener is simple, the electric pencil sharpener is convenient to disassemble and assemble, and the hob cutter is also very convenient to replace.

In addition, a starting device for starting the motor is arranged on the tool rest cover, the starting device is connected with the motor through an electric loop, when the starting device is communicated with the electric loop of the motor, the motor is started, and the motor drives the hob rest to rotate. When the hob needs to be replaced, the hob head cover needs to be detached first, but the above patent does not relate to a safety mechanism related to the hob head cover, if the hob head cover is detached carelessly without breaking an electric circuit in advance, when the hob head cover is detached, a motor still operates, and the hob head still drives the hob to rotate, so that the safety of a user is threatened. Therefore, the structure of the pencil sharpener can be further optimized.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that to prior art's current situation, a safety structure of the ware of cutting that motor shut down when ensureing to pull down the knife rest cover is provided.

The utility model provides a technical scheme that above-mentioned technical problem adopted does: the utility model provides a safety structure of ware cuts, includes the casing, sets up the motor in the casing, can dismantle the knife rest cover of being connected, can start motor operation starting drive, the electric circuit of connecting starting drive and motor with the casing, its characterized in that: at least one safety mechanism which can be linked with the tool rest cover is arranged on the electric circuit; when the tool rest cover is installed in place on the shell, the electric circuit is communicated, and the motor can be started to run; when the tool holder cover is separated from the housing, the electrical circuit is broken and the motor cannot operate.

The safety mechanism may have various configurations, and preferably, the electrical circuit includes at least one wire, each wire including a first length of wire electrically connected to the starting device and a second length of wire electrically connected to the motor, the safety mechanism includes a resilient metal portion provided on one of the first length of wire and the second length of wire and a metal contact portion provided on the other of the first length of wire and the second length of wire, the resilient metal portion and the metal contact portion contacting each other to connect the electrical circuit when the cartridge cover is in place on the housing. The safety mechanism may also be a position sensor that senses the position of the tool holder housing.

The elastic metal part may have various structures, and preferably, the elastic metal part is an elastic metal thimble including a needle tube electrically connected to a corresponding lead in the electric circuit, a needle head movable relative to the needle tube and electrically connected to the metal contact part, and a return spring connecting the needle tube and the needle head, the return spring being capable of supporting the needle head so that the needle head always has a tendency to be close to the metal contact part. The elastic metal part can also adopt an elastic sheet.

The metal contact part can be arranged at different positions, preferably, in order to fix the metal contact part conveniently, the elastic metal thimble is arranged on the first section of conducting wire and outside the shell, a through hole for accommodating the metal contact part is formed in the shell, one end of the metal contact part is electrically connected with the second section of conducting wire in the shell, and the other end of the metal contact part is electrically connected with the elastic metal thimble outside the shell when the tool rest cover is installed in place. The metal contact part is accommodated in the through hole of the shell, so that the metal contact part is limited and is not easy to shake.

Preferably, the electric circuit comprises two conducting wires, each conducting wire comprises a first conducting wire electrically connected with the starting device and a second conducting wire electrically connected with the motor, and correspondingly, the number of the elastic metal thimble and the number of the metal contact part are two. Compared with the scheme with an elastic metal thimble and a metal contact part, when the installation position of the tool rest cover is slightly deviated, the electric circuit can be communicated; through setting up two elastic metal thimbles and two metal contact portions, there are two contact points like this, when having guaranteed that the knife rest cover installation targets in place, two elastic metal thimbles and two metal contact portions contact each other.

In order to shield the first section of conducting wire, the novel tool rest further comprises a shielding plate arranged on the tool rest cover, and the rear part of the first section of conducting wire and the elastic metal part are arranged on the inner side of the shielding plate. Therefore, the rear part of the first section of wire and the elastic metal part are not easy to see from the outside, and the wire is neat and attractive and compact in structure.

The starting device can have various structures, preferably, the starting device comprises a moving block and a touch switch connected with the moving block, the touch switch is connected with the motor through the two conducting wires, and the pen to be cut pushes the moving block to move outwards to trigger the touch switch, so that the motor is started. The activation device may also be a position sensor that senses the position of the pen.

The touch switch can have various structures, and preferably comprises a metal elastic sheet connected with the moving block and metal contact pieces arranged at intervals with the metal elastic sheet, wherein the metal elastic sheet is electrically connected with one of the conducting wires, the metal contact pieces are electrically connected with the other conducting wire, and the pen to be cut pushes the moving block to move outwards so as to enable the metal elastic sheet to be in contact with the metal contact pieces to conduct electricity, so that the motor is started. The touch switch can also adopt a toggle switch and the like.

As the improvement, still including setting up reduction gear box and the hob head of setting in the knife rest cover in the casing, reduction gear box's input links to each other with the motor, and reduction gear box's output links to each other and can drive the hob head and rotate with the hob head, and the second section wire links to each other with reduction gear box's outer wall. In this way, the hob head can obtain the appropriate torque and rotation speed.

The detachable connection of the housing and the tool holder cover can have various structures, and the housing and the tool holder cover are connected through a first buckle structure. The shell and the tool rest cover can also be detachably connected by adopting an adhesive buckle.

The first fastener can be in various structures, and preferably, one of the shell and the tool holder cover is provided with a clamping block, and the other of the shell and the tool holder cover is provided with a clamping groove, and the clamping block can extend into the clamping groove to connect the shell and the tool holder cover.

Compared with the prior art, the utility model has the advantages of: the safety mechanism capable of being linked with the tool rest cover is arranged on the electric circuit, when the tool rest cover is installed on the shell in place, the electric circuit is communicated, the motor can start to move, when the tool rest cover is separated from the shell, the electric circuit is disconnected, the motor cannot run, and therefore when the tool rest cover is detached, the electric circuit is disconnected certainly, the situation that a user does not disconnect the electric circuit in advance due to negligence when the tool rest cover is detached is prevented, and the safety mechanism has the advantage of high safety; in addition, when the tool rest cover is disassembled and assembled, the electric circuit is correspondingly disconnected and communicated at the same time, and the electric circuit is disconnected and communicated without extra operation steps, so that the tool rest cover has the advantages of convenience and quickness.

Drawings

FIG. 1 is a schematic view of an embodiment of the present invention applied to a pencil sharpener;

FIG. 2 is a schematic view from another angle of FIG. 1;

FIG. 3 is an exploded view of FIG. 1;

FIG. 4 is a schematic view of the second housing of FIG. 3;

FIG. 5 is a cross-sectional view of the bottom portion of FIG. 3 taken along the line A-A;

FIG. 6 is another exploded view of FIG. 1;

FIG. 7 is a schematic view of FIG. 1 with the crumb cartridge and housing removed;

FIG. 8 is a schematic view of FIG. 7 with the tool holder cover, end caps, roller cutters and hob holder removed;

FIG. 9 is yet another exploded view of FIG. 1;

FIG. 10 is a schematic view of the intermediate portion of FIG. 9 with the mounting base removed;

FIG. 11 is a schematic view of a scrap barrel according to an embodiment of the present invention;

FIG. 12 is a partially exploded view of the second snap feature;

FIG. 13 is yet another exploded view of FIG. 1;

FIG. 14 is a schematic view from another angle of FIG. 13;

FIG. 15 is a schematic view of the dial of FIG. 1;

FIG. 16 is a schematic view from another angle of FIG. 15;

FIG. 17 is a schematic view of the connecting socket of FIG. 1;

FIG. 18 is a schematic view from another angle of FIG. 17;

FIG. 19 is a longitudinal cross-sectional view of FIG. 1;

fig. 20 is a schematic view of the connecting sleeve in fig. 1;

fig. 21 is a schematic view from another angle of fig. 20.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

As shown in fig. 3-7 and fig. 13-14, the safety structure of the pencil sharpener of the embodiment of the present invention is applied to the pencil sharpener. The safety structure of the pencil sharpener of the embodiment comprises a shell 1 and a waste chip barrel 200 connected with the shell 1, wherein a motor 20 and a reduction gear box 40 are arranged in the shell 1, a hob cutter 5 is arranged in the waste chip barrel 200, a hob head 2 used for mounting the hob cutter 5, a hob head cover 7 covered outside the hob head 2, a shielding plate 9 arranged on the hob head cover 7, a starting device 400 arranged at a position close to the hob head cover 7, an electric circuit for connecting the starting device 400 and the motor 20, and two safety mechanisms which are arranged on the electric circuit and can be linked with the hob head cover 7. When the tool rest cover 7 is mounted in place on the housing 1, the electrical circuit is connected and the motor 20 can be started to operate; when the blade holder cover 7 is separated from the housing 1, the electric circuit is broken and the motor 20 cannot operate.

Wherein the electrical circuit comprises two wires 8, each wire 8 comprising a first length of wire 8a (fig. 3, 5) electrically connected to the starting device 400 and a second length of wire 8b (fig. 7, 8, 13) electrically connected to the motor 20.

Referring to fig. 8, 13 and 14, the starting device 400 includes a moving block 400a and a touch switch connected to the moving block 400a, the touch switch is connected to the motor 20 through the two wires 8, and the pen to be cut pushes the moving block 400a to move outward to trigger the touch switch, so as to start the motor 20. Specifically, the touch switch includes a metal spring 400b connected to the moving block 400a and a metal contact piece 400c spaced from the metal spring 400b, the metal spring 400b is electrically connected to one of the conductive wires 8, the metal contact piece 400c is electrically connected to the other conductive wire 8, and the pen to be cut pushes the moving block 400a to move outward, so that the metal spring 400b and the metal contact piece 400c are in contact conduction, thereby starting the motor 20.

Accordingly, there are two safety mechanisms, which are respectively disposed on the corresponding first and second sections of wire 8a and 8 b. Each safety mechanism includes a resilient metal portion provided on the first length of wire 8a and a metal contact portion 82 provided on the second length of wire 8b, the resilient metal portion and the metal contact portion 82 contacting each other to make the electrical circuit communicate while the cartridge cover 7 is in place on the housing 1. Referring to fig. 4, the elastic metal portion is an elastic metal thimble 81 in the present embodiment, and the present embodiment has two elastic metal thimbles 81 and two metal contact portions 82 in total, so that there are two contact points, and the two elastic metal thimbles 81 and the two metal contact portions 82 contact each other while the tool rest cover 7 is mounted in place. The elastic metal thimble 81 includes a needle tube 811 electrically connected to the corresponding lead wire 8a in the electric circuit, a needle 812 movable relative to the needle tube 811 and electrically connected to the metal contact 82, and a return spring 813 connecting the needle tube 811 and the needle 812, and the return spring 813 is capable of supporting the needle 812 so that the needle 812 always tends to approach the metal contact 82.

The shell 1 is provided with a containing cavity, the shell 1 comprises a first shell 11 and an L type second shell 12 which are connected, two elastic metal thimbles 81 are arranged on a corresponding first section of lead 81a and are positioned outside the L type second shell 12, a through hole 1b for containing a metal contact part 82 is arranged on the L type second shell 12, one end of the metal contact part 82 is electrically connected with a second section of lead 81b in the shell 1, and the other end of the metal contact part 82 is electrically connected with the elastic metal thimbles 81 outside the shell 1 when the tool rest cover 7 is installed in place.

Referring to fig. 3 and 5, the shielding plate 9 is disposed on the blade holder cover 7, and the first-stage conducting wire 81a and the elastic metal thimble 81 are disposed inside the shielding plate 9.

The reduction gear box 40 is arranged in the shell 1 (specifically in the first shell 11), the input end of the reduction gear box 40 is connected with the motor 20, the output end of the reduction gear box 40 is connected with the hob head 2 and can drive the hob head 2 to rotate, and the second section of lead 8b is connected with the outer wall of the reduction gear box 40.

The blade holder cover 7 is detachably connected with the housing 1, and referring to fig. 3, in this embodiment, the housing 1 (specifically, the L-shaped second housing 12) and the blade holder cover 7 are connected with the blade holder cover 7 through a first snap structure, specifically, the blade holder cover 7 has a latch 71, the housing 1 has a latch slot 1a, and the latch 71 can extend into the latch slot 1a to connect the housing 1 with the blade holder cover 7.

In addition, referring to fig. 1 to 21, the pencil sharpener applied to the safety structure in the embodiment further includes a pencil lead thickness adjusting mechanism, a rotary connecting structure 10, a third spring 90, a connecting sleeve 60, an indicator light 70, a circuit board 80, a safety switch 100, a mounting seat 101, a second fastening structure 300, an automatic pencil feeding device 500, and an end cap 600.

The refill thickness adjusting mechanism comprises a trigger rod 3, a connecting seat 6 and a dial 4. The hob head 2 has a pencil sharpening hole 21 and an opening 23 below the pencil sharpening hole 21, and the wall of the pencil sharpening hole 21 close to the hob 5 has a pencil sharpening mouth 22.

The trigger rod 3 comprises a first section of rod body 31 and a second section of rod body 32 which are abutted, the first section of rod body 31 is inserted into the opening 23 of the hob head 2, and the second section of rod body 32 is matched with the connecting seat 6 to act; the first end (located on the first section rod body 31) of the trigger rod 3 is inserted into the opening 23 of the hob head 2 and can move axially in the opening 23, and the second end (located on the second section rod body 32) of the trigger rod 3 cooperates with the connecting seat 6.

The connecting seat 6 comprises an abutting part 61 and a microswitch 62, the abutting part 61 can be a connecting block with smooth end, the microswitch 62 is used for controlling the operation of the hob 5, and the microswitch 62 is matched with the second end of the trigger rod 3 to act; the connecting base 6 has a first through hole 63 and a groove 64 communicated with the first through hole 63, the micro switch 62 is accommodated in the groove 64, and the trigger rod 3 passes through the first through hole 63 and then cooperates with the micro switch 62 in the groove 64.

The dial 4 includes a stroke guide block 43, a first stopper 41, and a second stopper 42; the stroke guide block 43 is in contact fit with the abutting part 61 of the connecting seat 6, the thickness of the stroke guide block 43 is gradually reduced from top to bottom, and the thickness of the stroke guide block 43 can be gradually increased from top to bottom in other embodiments; when the dial 4 is rotated, the abutting portion 61 can slide on the stroke guide block 43, and accordingly the first end 3a of the trigger lever 3 is moved closer to or away from the pencil sharpening hole 21; the first stopper 41 is adjacent to the uppermost end of the stroke guide 43 of the dial 4 and can abut against the abutting portion 61 of the connecting seat 6, and the second stopper 42 is adjacent to the lowermost end of the stroke guide 43 of the dial 4 and can abut against the abutting portion 61 of the connecting seat 6.

The outer periphery of the dial 4 is exposed out of the first shell 11, the L type second shell 12 supports the waste chip barrel 200, the automatic pen feeding and withdrawing device 500 and the starting device 400 are positioned in the waste chip barrel 30, the end cover 600 covers the automatic pen feeding and withdrawing device 500, the starting device 400 is arranged between the automatic pen feeding and withdrawing device 500 and the end cover 600, the right side of the refill thickness adjusting structure penetrates through the shell wall of the L type second shell 12 and then extends into the waste chip barrel 200, the side wall of the waste chip barrel 200 is provided with a contact part 200a, when the waste chip barrel 200 is installed in place, the contact part 200a triggers the safety switch 100 arranged on the installation seat 101 in the first shell 11, and the second buckling structure 300 is used for limiting the waste chip barrel 200.

A rotary connection 10 connects the dial 4 with the housing 1; the middle part of the dial 4 is provided with a second through hole 44, and the hole wall of the second through hole 44 extends inwards in the radial direction to form a first boss 45; specifically, the rotary connection structure 10 includes a first spring 101, a screw 102, a positioning column 103 provided on the inner wall of the housing 1, and a first boss 45 of the dial 4; the dial 4 is sleeved outside the positioning column 103, the screw 102 is inserted into the positioning column 103, one end of the first spring 101 abuts against the first boss 45, and the other end abuts against the screw 102.

The reduction gear box 40 comprises a box body 401 with a containing cavity and a support leg 402 connected with the box body 401, the box body 401 comprises a first box body 401a close to the connecting seat 6 and a second box body 401b close to the hob head 2, a gear transmission mechanism is contained in the containing cavity of the box body 401, an output shaft of the motor 20 penetrates through the side wall of the box body 401 and then is in driving connection with an input end of the gear transmission mechanism located in the box body 401, an output end of the gear transmission mechanism is fixed with the hob head 2 located outside the box body 401 and can drive the hob head 2 to rotate, and the gear transmission mechanism is provided with five-stage gears 30 which are meshed with each other.

The connecting seat 6 is provided with a plug hole 65 extending left and right, the support leg 402 of the reduction gear box 40 penetrates through the plug hole 65, and the connecting seat 6 can move left and right relative to the support leg 402 of the reduction gear box 40 under the action of the refill thickness adjusting mechanism of the pencil sharpener.

The second spring 50 is sleeved outside the trigger rod 3 and close to the second end of the trigger rod 3, one end of the second spring 50 abuts against the connecting seat 6, and the other end abuts against the outer wall of the gear box 40.

The third spring 90 is sleeved outside the trigger rod 3 and is close to the first end of the trigger rod 3; the trigger rod 3 is provided with a second boss 33 extending radially outwards, the output end of the gear transmission mechanism is connected with the hob head 2 through a connecting sleeve 60, the middle part of the connecting sleeve 60 is provided with a third through hole 601, the hole wall of the third through hole 601 extends radially inwards to form a third boss 602, the trigger rod 3 penetrates through the third through hole 601 of the connecting sleeve 60, one end of the third spring 90 abuts against the second boss 33 of the trigger rod 3, and the other end of the third spring abuts against the third boss 602 of the connecting sleeve 60.

An indicator light 70 is connected to the circuit board 80, the indicator light 70 is partially exposed out of the second housing 12, and the indicator light 70 is used for indicating whether the battery is charged or not, whether the pencil sharpener is out of order or not, whether the pencil sharpener is charging or not, and the like.

The second buckle structure 300 comprises a first clamping block 301, a panel 302, a sliding block 303 and a second clamping block 304 positioned at the bottom of the scrap barrel 200, wherein the sliding block 303 positioned at the outer side of the panel 302 sequentially penetrates through the panel 302 and the first clamping block 301, the panel 302 and the sliding block 303 are in up-and-down sliding fit, and when the sliding block 303 moves upwards, the first clamping block 301 can be driven to move upwards, so that the first clamping block 301 and the second clamping block 304 are transversely abutted.

The automatic pen advancing and retreating device 500 may be a conventional device, such as a rubber roller.

The working principle of the pencil sharpener is as follows.

When the scrap cylinder 200 is mounted in place, the contact portion 200a of the scrap cylinder 200 touches the safety switch 100; the sliding block 303 slides upwards, the sliding block 303 drives the first clamping block 301 to move upwards, so that the first clamping block 301 is transversely abutted against the second clamping block 304, and the scrap barrel 200 is limited; putting a pencil into the starting device 400, enabling the moving block 400a to enable the metal contact spring piece 400b and the metal contact piece 400c to be in contact with each other and communicated through the pencil, and enabling the motor 20 to operate; the five-stage gear transmission mechanism is positioned in the box body 401, and after the motor 20 changes the speed according to the gear transmission mechanism through the five-stage gear 30, the hob 5 can reach a proper speed; the motor 20 also drives the automatic pen feeding and withdrawing device 500 to operate; that is, when the contact portion 200a of the waste container 200 touches the safety switch 100 and the pencil is applied to the starting means 400, the motor 20 is started to operate, which has an advantage of high safety.

When cutting stops, the pencil lead touches the trigger rod 3, the trigger rod 3 acts on the microswitch 62, after the motor 20 idles for 1.5-3 seconds, the motor 20 rotates reversely to drive the automatic pencil advancing and retracting device 500 to rotate reversely, and therefore the pencil is sent out; the scrap is poured out through the scrap barrel 200.

When the hob 5 needs to be replaced, the scrap cylinder 200 is opened, and the tool rest cover 7 is rotated and detached; in the process of rotating the blade holder cover 7, the elastic thimble 81 on the first section of conducting wire 8a is gradually separated from the metal contact part 82 on the second section of conducting wire 8b, so that the electric circuit is disconnected when the blade holder cover 7 is detached, and the motor 20 cannot operate, thereby preventing the situation that a user does not disconnect the electric circuit because of negligence, and having better safety. And then, a new hob 5 is replaced, the fixture block 71 of the hob holder cover 7 is aligned to the position between two adjacent clamping grooves 1a, the hob holder cover 7 is rotated, the fixture block 71 on the hob holder cover 7 is clamped into the clamping groove 1a, in the rotating process of the hob holder cover 7, the elastic thimble 81 on the first section of lead 8a and the metal contact part 82 on the second section of lead 8b are gradually close to each other, when the hob holder cover 7 rotates to the position, the elastic thimble 81 on the first section of lead 8a is abutted to the metal contact part on the second section of lead 8b, and thus the first section of lead 8a and the second section of lead 8b are mutually communicated. Therefore, when the tool rest cover 7 is disassembled and assembled, the electric circuit is correspondingly disconnected and communicated at the same time, and the electric circuit is disconnected and communicated without extra operation steps, so that the tool rest cover has the advantages of convenience and quickness.

When the thickness of the pen core needs to be adjusted, the part of the dial plate 4, which is positioned outside the shell, is rotated upwards or downwards, so that different positions of the stroke guide block 43 of the dial plate 4 are abutted against the abutting part 61 of the connecting seat 6, and accordingly, the first end of the trigger rod 3 is close to or far away from the pen sharpening hole 21; when the dial 4 is rotated to enable the position with larger thickness of the stroke guide block 43 to be abutted against the abutting part 61, the trigger rod 3 connected with the connecting seat 6 where the abutting part 61 is located is close to the pencil sharpening hole 21 rightwards, and the pencil lead which is sharpened at the moment is shorter and thicker; when the dial 4 is rotated to make the position with smaller thickness of the stroke guide block 43 abut against the abutting part 61, the trigger rod 3 connected with the connecting seat 6 where the abutting part 61 is located is away from the pen sharpening hole 21 leftwards, and the sharpened pen core is thinner and longer.

Claims (11)

1. The utility model provides a safety structure of sharpener, includes casing (1), sets up motor (20) in casing (1), can dismantle knife rest cover (7) of being connected, starting drive (400) that can starting drive (20) operation, the electric circuit of connecting starting drive (400) and motor (20) with casing (1), its characterized in that: at least one safety mechanism which can be linked with the tool rest cover (7) is arranged on the electric circuit; when the tool rest cover (7) is installed in place on the shell (1), the electric circuit is communicated, and the motor (20) can be started to operate; when the tool holder cover (7) is separated from the shell (1), the electric circuit is disconnected, and the motor (20) cannot operate.

2. The safety structure of a sharpener of claim 1, wherein: the electric circuit comprises at least one conducting wire (8), each conducting wire (8) comprises a first conducting wire (8a) electrically connected with the starting device (400) and a second conducting wire (8b) electrically connected with the motor (20), the safety mechanism comprises an elastic metal part arranged on one of the first conducting wire (8a) and the second conducting wire (8b) and a metal contact part (82) arranged on the other of the first conducting wire (8a) and the second conducting wire (8b), and when the tool rest cover (7) is installed in place on the shell (1), the elastic metal part and the metal contact part (82) are contacted with each other to enable the electric circuit to be communicated.

3. The safety structure of a sharpener of claim 2, wherein: the elastic metal part is an elastic metal thimble (81), the elastic metal thimble (81) comprises a needle tube (811) electrically connected with a corresponding wire (8) in the electric circuit, a needle head (812) capable of moving relative to the needle tube (811) and electrically connected with the metal contact part (82), and a return spring (813) connecting the needle tube (811) and the needle head (812), and the return spring (813) can support the needle head (812) to enable the needle head (812) to have a trend of being close to the metal contact part (82) all the time.

4. The safety structure of a sharpener of claim 3, wherein: the elastic metal thimble (81) is arranged on the first section of the conducting wire (8a) and positioned outside the shell (1), a through hole (1b) for accommodating the metal contact part (82) is formed in the shell (1), one end of the metal contact part (82) is electrically connected with the second section of the conducting wire (8b) in the shell (1), and the other end of the metal contact part (82) is electrically connected with the elastic metal thimble (81) outside the shell (1) when the tool rest cover (7) is installed in place.

5. The safety structure of a sharpener of claim 4, wherein: the electric circuit comprises two conducting wires, each conducting wire (8) comprises a first conducting wire (8a) electrically connected with the starting device (400) and a second conducting wire (8b) electrically connected with the motor (20), and correspondingly, two elastic metal thimbles (81) and two metal contact parts (82) are arranged.

6. The safety structure of a sharpener of claim 4, wherein: the wire-cutting machine further comprises a shielding plate (9) arranged on the tool rest cover (7), and the first section of wire (8a) and the elastic metal part are arranged on the inner side of the shielding plate (9).

7. The safety structure of a sharpener of claim 5, wherein: the starting device (400) comprises a moving block (400a) and a touch switch connected with the moving block (400a), the touch switch is connected with the motor (20) through the two conducting wires (8), and the pen to be cut pushes the moving block (400a) to move outwards to trigger the touch switch, so that the motor (20) is started.

8. The safety structure of a sharpener of claim 7, wherein: the touch switch comprises a metal elastic sheet (400b) connected with a moving block (400a) and a metal contact sheet (400c) arranged at an interval with the metal elastic sheet (400b), wherein the metal elastic sheet (400b) is electrically connected with one conducting wire (8), the metal contact sheet (400c) is electrically connected with the other conducting wire (8), a pen to be cut pushes the moving block (400a) to move outwards, so that the metal elastic sheet (400b) is in contact with the metal contact sheet (400c) to conduct electricity, and the motor (20) is started.

9. The safety structure of a sharpener of claim 2, wherein: the motor is characterized by further comprising a reduction gear box (40) arranged in the shell (1) and a hob head (2) arranged in the hob head cover (7), wherein the input end of the reduction gear box (40) is connected with the motor (20), the output end of the reduction gear box (40) is connected with the hob head (2) and can drive the hob head (2) to rotate, and the second section of lead (8b) is connected with the outer wall of the reduction gear box (40).

10. The safety structure of a pencil sharpener according to any one of claims 1-9, wherein: the shell (1) is connected with the knife rest cover (7) through a first buckling structure.

11. The safety structure of a sharpener of claim 10, wherein: one of the shell (1) and the knife rest cover (7) is provided with a clamping block (71), the other one of the shell (1) and the knife rest cover (7) is provided with a clamping groove (1a), and the clamping block (71) can extend into the clamping groove (1a) to connect the shell (1) and the knife rest cover (7).

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