CN209737657U - Safety knife - Google Patents

Abstract

The utility model discloses a safety knife belongs to hand tool technical field, and aim at overcomes safety knife's blade needs the release to push away the defect that the button could be retrieved. The safety knife comprises a knife shell, a knife rest and a blade, wherein a driving frame capable of sliding forwards and backwards is arranged in the knife shell, the knife rest can be arranged on the driving frame in a front-back sliding mode, the blade is arranged on the knife rest, an inlet and an outlet for the blade to stretch are formed in the front end of the knife shell, a reset elastic piece is connected to the knife rest, the driving frame is connected with a driving structure, a safety mechanism capable of limiting the knife rest on the driving frame is arranged in the knife shell, the safety mechanism can enable the knife rest to be limited after the blade stretches out the inlet and the outlet, and the limit of the knife rest is. The utility model discloses safety knife can let the blade retract automatically before release drive structure when safety knife finishes using, avoids forgetting the potential safety hazard that release drive structure exists and the risk of damaging the blade when the user, has increased the security that safety knife used.

Description

Safety knife

Technical Field

The utility model belongs to the technical field of hand tool, a safety knife that blade can contract automatically is related to.

Background

The existing telescopic hand knife which is provided with a sliding knife rest in an outer frame, a knife blade is arranged on the knife rest, the front and back of the knife rest slide to drive the knife blade to extend out of the outer frame and retract into the outer frame, a plurality of gears are mostly arranged on the outer frame, and when the knife rest is positioned at each gear, the length of the knife blade extending out of the outer frame is different. However, the blade of the hand knife with the structure can not automatically retract after extending out, the blade is often forgotten to retract into the outer frame after being used, the blade extends out of the outer frame, potential safety hazards such as scratch and stab are easily caused, and the extending blade (particularly the blade edge) is collided, is easily damaged such as rolled edge and gap and is discarded, so that waste is caused.

In order to solve the problems of the existing telescopic hand knife, a safety knife with a blade capable of automatically retracting to the inside of an outer frame appears on the market. For example, the invention patent of a gear safety knife 201110364694.3 disclosed in the chinese patent document includes an outer frame, a knife holder, and a knife blade, wherein the knife holder is slidably disposed in the outer frame forward and backward, the knife blade is mounted on the knife holder, an inlet and an outlet for the knife blade to extend and retract are provided at the front end of the outer frame, a return elastic member for applying an elastic force to the knife holder into the outer frame is connected to the knife holder, a gear slider capable of sliding forward and backward and positioned at a gear is provided in the outer frame, the knife holder is independently slidable forward to push the knife blade out of the outer frame by separating the knife holder from the gear slider and automatically retract into the outer frame depending on the elastic force of the return elastic member, when the push button is released, the knife blade retracts into the outer frame by pushing the corresponding push button with a hand. This achieves the function of automatically retracting the blade after the push button is released at the end of use of the safety knife. However, the blade can be retracted into the outer frame only after the push button is released, and the blade cannot be retracted into the outer frame when the user forgets to release the push button, so that the blade still has great potential safety hazard and risk of damaging the blade.

Disclosure of Invention

The utility model discloses problem to prior art existence provides a safety knife, and aim at overcomes safety knife's blade needs the release to push away the defect that the button could be retrieved.

The utility model discloses a realize like this:

A safety knife comprises a knife shell, a knife rest and a knife blade, and is characterized in that a driving frame capable of sliding back and forth is arranged in the knife shell, the tool rest is assembled on the driving frame in a sliding way back and forth, the blade is arranged on the tool rest, the front end of the knife shell is provided with an inlet and an outlet for the blade to stretch, the knife rest is connected with a reset elastic piece which applies elastic force to the knife rest to the interior of the knife shell, the driving frame is connected with a driving structure for pushing the driving frame, a safety mechanism is arranged in the knife shell, when the blade is positioned in the knife shell, the safety mechanism limits the knife rest on the driving frame so that the driving frame drives the knife rest to slide forwards in the knife shell, the safety mechanism can release the limit of the knife rest when the blade is pulled by the pulling force greater than the reset elastic piece after the blade extends out of the inlet and the outlet so as to pull the blade back into the knife shell by the reset elastic piece.

Preferably, safety mechanism includes latch hook and unblock elastic component, the one end at the latch hook is fixed to the one end of unblock elastic component, the other end of unblock elastic component is fixed on the carriage, have on the sword shell can the carriage is extruded when retracting the unblock elastic component makes the income locking portion of the spacing knife rest rear end of latch hook, the place ahead of going into the locking portion has the confession the space of stepping down that unblock elastic component kick-backs, when unblock elastic component was located the space of stepping down, its elasticity can make the skew knife rest of latch hook.

Preferably, the lower end of the tool rest is provided with a folded edge, a first convex edge is arranged in the tool shell, the first convex edge is located below the folded edge and is provided with a first slit which penetrates through the first convex edge from top to bottom, the lock hook penetrates through the first slit and is hooked on the folded edge when the safety mechanism is in a limiting state, and the unlocking elastic piece is fixed on the first convex edge.

Preferably, the rear end of knife rest has the second chimb, the second slit that the side direction runs through has on the driving frame, the latch hook passes the second slit and is in the safety mechanism is in when spacing hook is in on the second chimb, the unblock elastic component is fixed the driving frame dorsad one side of knife rest.

Preferably, the driving frame is provided with a concave part for the locking hook to avoid the tool rest.

Preferably, the latch hook hooks or abuts against the tool holder.

Preferably, the unlocking elastic piece is a spring piece or a spring.

preferably, the knife housing comprises a first housing and a second housing, the driving frame is located between the first housing and the second housing, the knife rest is located between the driving frame and the second housing, the knife blade is located between the knife rest and the second housing, and the second housing is provided with a convex part for preventing the knife rest from being excessively returned.

Preferably, the knife shell is provided with a knife storage cavity for containing the spare blade, a cavity cover is arranged at the opening of the knife storage cavity, one end of the cavity cover is hinged to the knife shell, and the other end of the cavity cover is clamped to the knife shell.

Preferably, the blade is provided with a limiting groove, the blade holder is provided with a limiting part embedded into the limiting groove, the blade holder is provided with a bending part protruding out of the blade, the bending part is provided with a first inclined plane deviated to the front, a convex block is arranged in the blade shell, and the convex block is provided with a second inclined plane deviated to the rear and corresponding to the first inclined plane.

Preferably, the upper section of the tool rest is provided with two strip-shaped grooves which are parallel to each other, an elastic part is formed between the two strip-shaped grooves, and the limiting part and the bending part are located on the elastic part.

Preferably, the sword shell is equipped with the dog in import and export one end department, have the protruding stop part backward on the dog, first through-hole and second through-hole have respectively on the both sides wall of sword shell, the both ends of dog are worn out respectively first through-hole and second through-hole, a terminal surface of dog has horizontal first caulking groove, the second caulking groove has on the sword shell, first caulking groove and second caulking groove form a column cavity jointly, be equipped with first spring in the column cavity, first spring part is located first caulking groove and part is located the second caulking groove.

Preferably, be equipped with the gear slider on the inner wall of sword shell, be equipped with the smooth button of gear on the outer wall of sword shell, rectangular hole has on the sword shell, the gear slider with fixed connection can be dismantled to the smooth button of gear, the gear slider can reciprocate along rectangular hole along with the smooth button of gear, the medial surface of gear slider has the gear post, the gear portion that has locking part and echelonment on the drive frame, on the slip path of gear slider, the gear post can with locking part or gear portion support and lean on.

Preferably, the gear sliding block is provided with a semi-cylindrical limiting column, the cutter shell is provided with a plurality of arc-shaped grooves matched with the limiting column, and when the gear sliding block is at different gears, the limiting column is clamped in different corresponding arc-shaped grooves.

Preferably, a return spring is arranged between the driving frame and the knife shell, one end of the return spring is fixed on the driving frame, and the other end of the return spring is fixed on the knife shell.

The utility model provides a safety knife owing to set up safety mechanism, can let the blade retract automatically before the release drive structure when safety knife finishes using, avoids forgetting the potential safety hazard that the release drive structure exists and the risk of damaging the blade when the user, has increased the security that safety knife used.

Drawings

Fig. 1 is a schematic external structural view of the first embodiment.

Fig. 2 is an exploded view of the first embodiment.

Fig. 3 is a schematic structural view of a tool holder according to a first embodiment.

FIG. 4 is a schematic structural view of the first embodiment before pushing out the blade.

Fig. 5 is a partial enlarged view of B in fig. 4.

FIG. 6 is a schematic structural view of the first embodiment after the blade is pushed out.

Fig. 7 is a partial enlarged view of C in fig. 6.

Fig. 8 is a schematic structural diagram illustrating a shift principle according to an embodiment.

Fig. 9 is a schematic view of a shackle disengaged from a toolholder during use in accordance with one embodiment.

Fig. 10 is a sectional view a-a of fig. 1.

FIG. 11 is a schematic structural diagram illustrating a blade changing state according to an embodiment.

Fig. 12 is a partial structural diagram according to a first embodiment.

Fig. 13 is a schematic structural diagram of a second housing according to the first embodiment.

Fig. 14 is a schematic structural view of a knife storage cavity in the first embodiment.

Fig. 15 is a schematic view of the assembly relationship of the driving frame, the tool post and the blade in the second embodiment.

Fig. 16 is a schematic view of a first angle perspective of the assembled relationship of the driving frame, the tool post and the blade in the second embodiment.

Fig. 17 is a second perspective view of the assembled relationship of the drive carriage, tool post and blade of the second embodiment.

Fig. 18 is a schematic structural view of a safety mechanism according to a second embodiment.

Fig. 19 is an assembly structure diagram of a safety mechanism in the third embodiment.

Reference is made to the accompanying drawings in which: 100. the cutter comprises a cutter shell, 110, a first shell, 111, a locking part, 112, a limiting sheet, 113, a cavity cover, 114, a shell cover, 115, a cutter taking groove, 116, a cutter storage cavity, 117, a first convex edge, 118, a concave part, 120, a second shell, 121, a convex part, 130, an inlet and an outlet, 140, a convex block, 141, a second inclined surface, 150, a stop block, 151, a blocking part, 152, a first embedded groove, 160, a first through hole, 170, a second through hole, 180, a first spring, 190, a second embedded groove, 200, a driving frame, 210, a driving structure, 211, a driving part, 212, a driving push button, 300, a cutter rest, 310, a reset elastic part, 320, a limiting part, 330, 340, a folded edge, 350, a second convex edge, 360, a strip-shaped groove, 370, an elastic part, 331, a first inclined surface, 400, a cutter blade, 410, a limiting groove, 500, a safety mechanism, 510, a locking hook, an unlocking elastic part, 610, a gear slide block, a sliding block and a gear column, 612. the gear comprises a limiting column, 613, an arc-shaped groove, 620, a gear sliding button, 630, a long hole, 640, a locking part and 650, and a gear part.

Detailed Description

The following detailed description is made of specific embodiments of the present invention with reference to the accompanying drawings, so as to make the technical solution of the present invention easier to understand and master. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

The front and rear of the present embodiment are referred to fig. 1, which is the left and right of fig. 1.

This embodiment provides a safety knife, as shown in fig. 1-19, comprising a knife housing 100, a drive carriage 200, a knife holder 300, and a blade 400. The knife housing 100 includes a first housing 110 and a second housing 120, and the first housing 110 and the second housing 120 are buckled to form the knife housing 100. The drive carriage 200 is slidably disposed back and forth within the tool housing 100, the tool holder 300 is slidably disposed back and forth on the drive carriage 200 between the drive carriage 200 and the second housing 120, and the blade 400 is mounted on the tool holder 300 between the tool holder 300 and the second housing 120. The blade holder 300 is connected to a return spring member 310 for applying a spring force to the blade holder 300 into the blade case 100, and the return spring member 310 used in the present embodiment is a spring. The driving rack 200 is connected to a driving structure 210 for pushing the driving rack 200, the driving structure 210 may be a pushing type or a pressing type, and the embodiment employs the pushing type. Referring to fig. 9, the driving structure 210 includes a driving portion 211 fixed on the upper end of the driving frame 200, the driving portion 211 may be integrated with the driving frame 200, and the driving portion 211 passes through the cutter housing 100 and is connected to a driving push button 212.

The safety mechanism 500 for limiting the tool holder 300 to the driving frame 200 is provided in the tool housing 100, and the safety mechanism 500 can release the limitation of the tool holder 300 when the blade 400 is pulled by a pulling force greater than the return elastic member 310 after the blade 400 is extended out of the entrance 130. Specifically, the safety mechanism 500 includes a locking hook 510 and an unlocking elastic member 520, one end of the unlocking elastic member 520 is fixed to one end of the locking hook 510, the other end of the unlocking elastic member 520 is fixed to the driving frame 200, the knife housing 100 is provided with a locking portion 111 capable of pressing the unlocking elastic member 520 to make the locking hook 510 hook or abut against the rear end of the knife holder 300 to realize locking when the driving frame 200 retracts, a portion where the locking hook 510 and the knife holder are connected may be a hook shape to hook the knife holder or a straight strip shape to abut against the knife holder 300 through friction, an abdicating space for rebounding the unlocking elastic member 520 is provided in front of the locking portion 111, the bottom of the knife housing 100 may be provided with a housing cover 114 for covering the abdicating space, and the housing cover 114 may be integrally provided with the. The drive bracket has a recess 118 for the latch hook to clear the tool holder.

This embodiment provides three examples depending on the location of the security mechanism 500 and the unlocking spring 520. In a first embodiment, referring to fig. 1 to 14, the safety mechanism 500 is disposed at the bottom of the safety knife, the unlocking elastic member 520 is a spring, the lower end of the knife holder 300 has a folded edge 340, a first raised edge 117 is disposed in the knife housing, the first raised edge 117 is disposed below the folded edge 340 and has a first slit penetrating vertically, the locking hook 510 passes through the first slit and hooks onto the folded edge 340 when the safety mechanism 500 is in a limiting state, and the unlocking elastic member 520 is fixed on the first raised edge 117. The first convex edge 117 located behind the first slit can apply force to the latch hook 510, so that the elastic sheet is not stressed. In the second embodiment, referring to fig. 15-18, the safety mechanism 500 is disposed at a side portion of the safety knife, the unlocking elastic member 520 is a spring, the rear end of the knife holder 300 has a second flange 350, the driving frame 200 has a second slit extending laterally therethrough, the locking hook 510 passes through the second slit and hooks onto the second flange 350 when the safety mechanism 500 is in the limit state, and the unlocking elastic member 520 is fixed at a side of the driving frame 200 facing away from the knife holder 300. In the third embodiment, referring to fig. 19, the safety mechanism 500 is disposed at the bottom of the safety knife, and the unlocking elastic member 520 is a spring.

The present embodiment will be further described below based on examples. Referring to fig. 13, the second housing 120 has a protrusion 121 for preventing the tool holder 300 from being excessively returned. Fig. 4 and 5 show a state before the blade 400 is pushed out, at this time, the locking portion 111 abuts against the unlocking elastic member 520, the upper hook portion of the locking hook 510 is higher than the bottom of the blade holder 300, the driving push button 212 is pushed, the driving rack 200 is driven to overcome the elastic force of the restoring elastic member 310 to drive the blade holder 300, the blade 400, the locking hook 510 and the unlocking elastic member 520 to move forward, at this time, because the locking hook 510 hooks the blade holder 300, the blade holder 300 cannot move back under the action of the restoring elastic member 310, after the blade 400 is pushed out of the entrance/exit 130, the unlocking elastic member 520 leaves the extrusion of the locking portion 111 and enters the abdicating space (see fig. 6 and 7), at this time, the blade 400 is used to cut an article, the blade 400 is pulled outward during the cutting process by a friction force, when the friction force is greater than the elastic force of the restoring elastic member 310, the blade 400 and the blade holder 300 move forward together, at this time, when the safety knife is used and the friction force disappears, the knife holder 300 moves into the knife housing 100 under the action of the return elastic member 310, so that the blade 400 is automatically retracted into the knife housing 100, and when the knife holder 300 moves to the protrusion 121, the blade is not further retracted, and then the driving push button 212 is pushed back, and the latch-in part 111 presses the unlocking elastic member 520 again to urge the lock hook 510 to move upward and raise the bottom of the knife holder 300 again, so as to return to the initial state shown in fig. 4 and 5.

Further, a return spring may be provided between the driving frame 200 and the cutter housing 100, and one end of the return spring is fixed to the driving frame 200 and the other end is fixed to the cutter housing 100, so that the driving frame 200 can be automatically retracted into the cutter housing 100 by releasing the driving push button 212 after the cutter frame 300 and the cutter blade 400 are automatically retracted into the cutter housing 100.

Further, referring to fig. 2 and 12, the first housing 110 has a limiting piece 112, a knife storage cavity 116 for accommodating the spare knife 400 is provided between the limiting piece 112 and the second housing 120, the limiting piece 112 has a knife taking groove 115 for facilitating the insertion of a finger, a cavity cover 113 is provided at an opening of the knife storage cavity 116, one end of the cavity cover 113 is hinged to the knife housing 100, and the other end is clamped to the knife housing 100. This allows spare blades 400 to be stored for use as needed.

The blade 400 is provided with a limit groove 410, the tool holder 300 is provided with a limit part 320 embedded in the limit groove 410, the tool holder 300 is provided with a bending part 330 protruding out of the blade 400, the upper section of the tool holder 300 is provided with two strip-shaped grooves 360 parallel to each other, an elastic part 370 is formed between the two strip-shaped grooves 360, the limit part 320 and the bending part 330 are positioned on the elastic part 370, the bending part 330 is provided with a first inclined surface 331 deviated to the front, a convex block 140 is arranged in the tool housing 100, and the convex block 140 is provided with a second inclined surface 141 deviated to the rear and corresponding to the first inclined surface 331. The blade 400 has three positions, when the blade 400 is located in the blade housing 100, the blade 400 is in an initial position (see fig. 4 and 5) in a non-use state, when the blade 400 is pushed out of the use position of the blade housing 100 (see fig. 6 and 7), when the blade 400 is continuously pushed forward to a tool changing position (see fig. 11) where the bent portion 330 and the projection 140 abut against and are staggered, and when the blade 400 is located in the tool changing position, the projection 140 presses the bent portion 330 to separate the limiting portion 320 from the limiting groove 410, so that the blade 400 can be pulled out of the tool holder 300 to realize tool changing.

Referring to fig. 6 and 11, the cutter housing 100 is provided with a stopper 150 at one end of the inlet and outlet 130, the stopper 150 is provided with a stopper 151 protruding rearward, two side walls of the cutter housing 100 are respectively provided with a first through hole 160 and a second through hole 170, two ends of the stopper 150 respectively penetrate through the first through hole 160 and the second through hole 170, one end surface of the stopper 150 is provided with a first transverse caulking groove 152, the cutter housing is provided with a second caulking groove 190, the first caulking groove 152 and the second caulking groove 190 together form a cylindrical cavity, the cylindrical cavity is internally provided with a first spring 180, and the first spring 180 is partially located in the first caulking groove 152 and partially located in the second caulking groove 190. When the front end of the driving part 211 abuts against the blocking part 151, the blade 400 is in the maximum extension amount in the use state, the stopper 150 is pushed to one side to enable the blocking part 151 to avoid the driving part 211, the driving frame 200 can be further pushed forward to enable the blade 400 to enter a tool changing position, after tool changing is completed, the driving part 211 is pushed backward, and the stopper 150 is restored under the action of the first spring 180.

Referring to fig. 1, 8, 10 and 13, a gear slider 610 is disposed on an inner wall of the knife housing, a gear slider 620 is disposed on an outer wall of the knife housing, a long hole 630 is disposed on the knife housing, the gear slider 610 and the gear slider 620 are detachably and fixedly connected, the gear slider 610 can move up and down along the long hole 630 along with the gear slider 620, a gear post 611 is disposed on an inner side surface of the gear slider 610, a locking portion 640 and a stepped gear portion 650 are disposed on the driving frame 200, and the gear post 611 can abut against the locking portion 640 or the gear portion 650 on a sliding path of the gear slider 610. The number of the shift posts 611 may be one, and the embodiment employs two shift posts 611, and the upper shift post 611 is used to cooperate with the locking portion 640 for locking the driving rack 200 to prevent the blade 400 from being pushed out. The gear column 611 below is used for cooperating with the gear portion 650, and the gear portion 650 has two steps, can realize two grades, and the gliding gear portion 650 of gear column 611 is not restricted to the below of gear portion 650, for the biggest grade, and the volume that blade 400 can stretch out is the biggest, and when gear slide button 620 slides from bottom to top, be maximum play sword volume shelves, second big play sword volume shelves, minimum play sword volume shelves and locking shelves respectively.

Referring to fig. 2 and 13, the gear slide 610 has a semi-cylindrical limiting post 612, the knife housing 100 has a plurality of arc-shaped grooves 613 matched with the limiting post 612, and when the gear slide 610 is in different gears, the limiting post 612 is clamped in the different corresponding arc-shaped grooves 613. This enables the gear slide 610 not to be out of gear.

Claims (15)

1. A safety knife comprises a knife shell (100), a knife rest (300) and a blade (400), and is characterized in that a driving frame (200) capable of sliding back and forth is arranged in the knife shell (100), the knife rest (300) is assembled on the driving frame (200) capable of sliding back and forth, the blade (400) is installed on the knife rest (300), an inlet and an outlet (130) for the blade (400) to stretch are formed in the front end of the knife shell (100), a reset elastic piece (310) for applying elastic force to the knife rest (300) to the inside of the knife shell (100) is connected to the knife rest (300), the driving frame (200) is connected with a driving structure (210) for pushing the driving frame (200), a safety mechanism (500) is arranged in the knife shell (100), when the blade (400) is positioned in the knife shell (100), the safety mechanism limits the knife rest (300) on the driving frame (200) to drive the knife rest (300) to slide forwards in the knife shell (100), the safety mechanism (500) can release the limit of the knife rest (300) when the blade (400) is pulled by a pulling force larger than the reset elastic piece (310) after the blade (400) extends out of the inlet and outlet (130) so as to pull the blade (400) back into the knife shell (100) by the reset elastic piece (310).

2. The safety knife according to claim 1, wherein the safety mechanism (500) comprises a locking hook (510) and an unlocking elastic member (520), one end of the unlocking elastic member (520) is fixed at one end of the locking hook (510), the other end of the unlocking elastic member (520) is fixed on the driving frame (200), the knife shell (100) is provided with a locking portion (111) which can press the unlocking elastic member (520) to limit the rear end of the locking hook (510) on the knife rest (300) when the driving frame (200) retracts, the front of the locking portion (111) is provided with a yielding space for the unlocking elastic member (520) to rebound, and when the unlocking elastic member is positioned in the yielding space, the elastic force of the unlocking elastic member can enable the locking hook (510) to deviate from the knife rest (300).

3. A safety knife according to claim 2, characterized in that the lower end of the knife holder (300) has a folded edge (340), the knife housing (100) has a first raised edge (117) therein, the first raised edge is located below the folded edge and has a first slit passing therethrough up and down, the locking hook (510) passes through the first slit and hooks onto the folded edge (340) when the safety mechanism is in a limiting state, and the unlocking elastic member (520) is fixed on the first raised edge.

4. A safety knife according to claim 2, characterized in that the rear end of the knife holder has a second convex edge (350), the driving frame (200) has a second slit extending laterally therethrough, the locking hook (510) passes through the second slit and hooks onto the second convex edge (350) when the safety mechanism is in the limit state, and the unlocking elastic member (520) is fixed on the side of the driving frame (200) facing away from the knife holder (300).

5. A safety knife according to claim 2, characterised in that the drive carriage (200) has a recess (118) for the locking hook (510) to clear the knife carriage.

6. A safety knife according to claim 2, characterized in that the locking hook (510) hooks or abuts against the blade holder (300).

7. A safety knife according to claim 2, wherein the unlocking spring (520) is a leaf spring or a spring.

8. A safety knife according to claim 1, wherein the knife housing (100) comprises a first housing (110) and a second housing (120), the drive carriage (200) is located between the first housing (110) and the second housing (120), the knife carrier (300) is located between the drive carriage (200) and the second housing (120), the knife blade (400) is located between the knife carrier (300) and the second housing (120), and the second housing (120) has a protrusion (121) thereon that prevents over-retraction of the knife carrier (300).

9. The safety knife according to claim 1, characterized in that the knife shell (100) is provided with a knife storage cavity (116) for accommodating the spare knife blade (400), a cavity cover (113) is arranged at the opening of the knife storage cavity (116), one end of the cavity cover (113) is hinged on the knife shell (100), and the other end is clamped on the knife shell (100).

10. The safety knife according to claim 1, wherein the blade (400) is provided with a limiting groove (410), the knife holder (300) is provided with a limiting part (320) embedded in the limiting groove (410), the knife holder (300) is provided with a bending part (330) protruding out of the blade (400), the bending part (330) is provided with a first inclined surface (331) deviated to the front, a convex block (140) is arranged in the knife shell (100), and the convex block (140) is provided with a second inclined surface (141) deviated to the rear and corresponding to the first inclined surface (331).

11. The safety knife according to claim 10, wherein the upper section of the knife holder (300) has two strip-shaped grooves (360) parallel to each other, an elastic part (370) is formed between the two strip-shaped grooves (360), and the limiting part (320) and the bending part (330) are located on the elastic part (370).

12. The safety knife according to claim 10, wherein the knife housing (100) is provided with a stopper (150) at one end of the inlet/outlet (130), the stopper (150) is provided with a stopper portion (151) protruding rearward, two side walls of the knife housing (100) are respectively provided with a first through hole (160) and a second through hole (170), two ends of the stopper (150) respectively penetrate through the first through hole (160) and the second through hole (170), one end surface of the stopper (150) is provided with a first transverse caulking groove (152), the knife housing is provided with a second caulking groove (190), the first caulking groove (152) and the second caulking groove (190) jointly form a cylindrical cavity, a first spring (180) is arranged in the cylindrical cavity, and the first spring (180) is partially located in the first caulking groove (152) and partially located in the second caulking groove (190).

13. The safety knife according to claim 1, characterized in that a gear slide block (610) is arranged on the inner wall of the knife shell, a gear slide button (620) is arranged on the outer wall of the knife shell, a long hole (630) is formed in the knife shell, the gear slide block (610) and the gear slide button (620) are detachably and fixedly connected, the gear slide block (610) can move up and down along the long hole (630) along with the gear slide button (620), a gear column (611) is arranged on the inner side surface of the gear slide block (610), a locking part (640) and a stepped gear part (650) are arranged on the driving frame (200), and the gear column (611) can abut against the locking part (640) or the gear part (650) on the sliding path of the gear slide block (610).

14. A safety knife according to claim 13, wherein the gear slide (610) has a semi-cylindrical stop post (612), the knife housing (100) has a plurality of arcuate grooves (613) matching the stop post (612), and when the gear slide (610) is in different gears, the stop post (612) is locked in the different corresponding arcuate grooves (613).

15. A safety knife according to claim 1, characterised in that a return spring is arranged between the drive carriage (200) and the knife housing (100), one end of the return spring being fixed to the drive carriage (200) and the other end being fixed to the knife housing (100).