Paper knife and folding knife with same

Abstract

The paper knife comprises a first knife handle and a first blade, the first knife handle is provided with a sliding groove and an outer shell, a sliding seat is arranged in the sliding groove in a sliding fit mode, the first blade is arranged between the sliding seat and the outer shell, the sliding seat is provided with an elastic piece, the free end of the elastic piece is provided with a protruding block, and the protruding block is arranged in the sliding groove. A clamping opening is formed in the lower side wall of the first blade, a first receding groove is formed in the bottom of the sliding groove, the elastic piece enables the protruding block to be matched with the clamping opening in the natural state, and the protruding block can be disengaged from the clamping opening when the free end of the elastic piece is pressed to deform towards the first receding groove. Compared with a blade replacement operation mode of an existing paper knife, the whole blade replacement operation process of the paper knife does not need to screw a screw, the first blade can be replaced only by pressing the protruding block of the elastic piece to be separated from the bayonet, replacement operation is very convenient and fast, and operation time is saved.

Description

Technical Field

[0001] This utility model belongs to the technical field of manual cutting tools, specifically relating to a paper cutter and a folding knife with the paper cutter. Background Technology

[0002] Existing paper cutter structures generally include a handle and a blade. A groove runs along the outer side of the handle, and a housing is located on the side of the handle corresponding to the groove. The four corners of the housing are threaded to the handle via screws. The blade slides within the groove, corresponding to the inner side of the housing. A button is connected to the blade, extending beyond the housing. Pushing the button moves the blade to an extended position outside the groove and to a retracted position inside the groove. In use, pushing the button moves the blade to the extended position for cutting paper; when not in use, pushing the button moves the blade to the retracted position, preventing cuts. This design is convenient and safe to carry.

[0003] However, the aforementioned paper cutter still has shortcomings: after a period of use, the blade becomes dull and inconvenient to use, requiring replacement. However, replacing the blade requires first unscrewing the screws at the four corners of the outer casing to disassemble it before the blade can be replaced. Furthermore, after replacing the blade, the screws must be tightened again to reassemble the casing, making the blade replacement process very cumbersome. Utility Model Content

[0004] In view of the shortcomings of the prior art, one of the objectives of this utility model is to provide a paper cutter with a convenient blade replacement.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a paper cutter, including a first handle and a first blade. The outer side of the first handle is provided with a groove that passes through its rear end face. A slide block is slidably fitted in the groove. The first handle is provided with a shell on the side corresponding to the groove. The first blade is placed between the slide block and the shell. The slide block is provided with a spring piece. The free end of the spring piece is provided with a protrusion. The shell is provided with a clearance groove corresponding to the free end of the spring piece. The lower side wall of the first blade is provided with a locking slot. The bottom of the groove is provided with a first clearance groove. In its natural state, the spring piece will cause the protrusion to engage with the locking slot. At this time, the slide block can drive the rear end of the first blade to slide to the extended state outside the groove and the retracted state inside the groove. When the first blade is slid to the extended state, the spring piece and the first clearance groove are aligned. At this time, pressing the free end of the spring piece to deform it towards the first clearance groove will cause the protrusion to disengage from the locking slot.

[0006] In the above solution, a latch is provided on the lower side of the first blade, and a protrusion is provided on the free end of the spring piece. In its natural state, the spring piece will cause the protrusion to engage with the latch, thereby connecting the slide block and the first blade. The outer shell is provided with a clearance groove, which provides space for the free end of the spring piece, ensuring that the user can operate the free end of the spring piece to push the slide block to slide, so that the slide block can drive the first blade to slide to the extended and retracted state, and can also pass through the clearance groove to press the free end of the spring piece to deform inward. The bottom of the groove restricts the inward deformation of the free end of the spring piece, so that the protrusion of the spring piece cannot disengage from the latch of the first blade, ensuring the connection stability between the slide block and the first blade. When the first blade needs to be replaced, it can be slid to the extended position, aligning the spring with the first clearance groove. The first clearance groove then creates space for the free end of the spring to deform inward, allowing the free end of the spring to be pressed towards the first clearance groove and placed within it. This causes the protrusion of the spring to disengage from the latch, allowing the old first blade to be pulled backward and disengaged from the slide. The new first blade is then inserted into the slide, aligning its latch with the protrusion. Finally, the free end of the spring is released, allowing the protrusion to engage with the latch of the new first blade, thus completing the replacement of the first blade. The blade replacement operation is convenient and saves time.

[0007] Furthermore, the free end of the aforementioned spring is also equipped with a button, which is located below the corresponding slot in the clearance groove. The button can slide along the clearance groove, and pushing the button can drive the slide block to slide, making the operation more convenient.

[0008] Furthermore, when the first blade is slid to the retracted state, the front end of the button abuts against the front end of the clearance groove. At this time, the front end of the clearance groove will block the button from sliding forward, thereby preventing the first blade from sliding further in the retracted direction and positioning the first blade in the retracted state. When the first blade is slid to the extended state, the rear end of the button abuts against the rear end of the clearance groove. At this time, the rear end of the clearance groove will block the button from sliding further backward, thereby preventing the first blade from sliding further in the extended direction and positioning the first blade in the extended state.

[0009] Furthermore, the slide block is provided with a front stop on the front side and an upper stop on the upper side of the slide block. The front stop abuts against the front side of the first blade, so that the front stop will prevent the first blade from sliding forward relative to the slide block. The upper stop abuts against the upper side of the first blade, so that the upper stop will prevent the first blade from sliding upward relative to the slide block. At the same time, under the cooperation of the protrusion and the locking block, the protrusion will prevent the first blade from sliding forward, backward and downward relative to the slide block, thereby ensuring the assembly stability of the first blade and the slide block.

[0010] Furthermore, the aforementioned spring is formed by two fracture openings on the side wall of the slide, which simplifies the manufacturing process of the spring and makes the spring and the slide form an integral structure, making the structure more stable. The four corners of the aforementioned outer shell are respectively connected to the outer thread of the first tool holder by screws, which facilitates the disassembly and assembly of the outer shell and ensures the installation stability of the outer shell.

[0011] Furthermore, the bottom of the aforementioned slide groove is also provided with a second clearance groove, and the inner side of the outer shell is provided with a first locking groove. The thickness of the aforementioned protrusion is greater than the thickness of the latch. When the first blade is slid to the retracted state, the spring is located in the position of the second clearance groove, so that the second clearance groove can make room for the free end of the spring to deform inward. At this time, the spring in its natural state will cause the protrusion to cooperate with both the latch and the first locking groove, so that the slide block cannot slide forward or backward under the cooperation of the protrusion and the first locking groove of the outer shell, thus preventing the button from being pushed to slide and locking the first blade in the retracted state. When the free end of the spring is pressed to deform towards the second clearance groove, so that the free end of the spring is placed in the second clearance groove, the protrusion will disengage from the first locking groove. At this time, the locking of the first blade in the retracted state can be released, so that the button can be pushed to drive the first blade to slide in the extended direction.

[0012] Furthermore, the inner side of the aforementioned outer casing is also provided with a second locking groove. When the first blade is slid to the extended state, the spring is located in the second clearance groove position, so that the second clearance groove can make room for the free end of the spring to deform inward. At this time, the spring in its natural state will cause the protrusion to cooperate with the bayonet and the second locking groove at the same time, thereby locking the first blade in the extended state. When the free end of the spring is pressed to deform towards the second clearance groove, so that the free end of the spring is placed in the second clearance groove, the protrusion will disengage from the second locking groove. At this time, the locking of the first blade in the extended state can be released, so that the button can be pushed to drive the first blade to slide in the retracted direction.

[0013] Furthermore, the aforementioned first clearance groove is located at the bottom of the second clearance groove, so that when the first blade slides to the extended state, the protrusion at the free end of the spring can not only deform inward and be placed in the second clearance groove to disengage from the second locking groove, but also deform inward and be placed in the first clearance groove to disengage from the latch. The bottom of the second clearance groove, corresponding to the free end of the spring, is also provided with a transverse groove. The transverse groove extends along the sliding direction of the first blade. The first clearance groove is a vertical groove structure intersecting the transverse groove, and the first clearance groove and the transverse groove are interconnected. The transverse groove provides more space for the free end of the spring, ensuring that the protrusion at the free end of the spring can deform inward and disengage from both locking grooves.

[0014] Furthermore, the aforementioned second clearance groove is a transverse groove structure extending along the sliding direction of the first blade, so that the second clearance groove and the free end of the spring piece are aligned in both the retracted and extended states of the first blade. The aforementioned first clearance groove is a vertical groove structure intersecting with the second clearance groove, and the first clearance groove and the second clearance groove are interconnected, so that when the first blade slides to the extended state, the protrusion at the free end of the spring piece can not only deform inward and be placed in the second clearance groove to disengage from the second locking groove, but also deform inward and be placed in the first clearance groove to disengage from the latch.

[0015] Another objective of this invention is to provide a folding knife with the aforementioned paper cutter.

[0016] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a folding knife, including a second handle, a second blade, and a paper cutter as described above. The second handle is disposed opposite to the first handle. The second blade is hinged at the front end between the two handles. The second blade can rotate relative to the two handles to open and fold between the two handles. A sliding groove is provided on the side of the first handle that is away from the second handle.

[0017] In the above solution, by combining the first and second handles of the paper cutter to form the handle of the folding knife, the folding knife of this invention has two blades. The first blade is suitable for cutting paper, while the second blade is thicker and can be used for cutting hard objects, thus offering more versatility. Furthermore, this folding knife also features the convenient replacement of the first blade of the paper cutter, and when not in use, the first blade can be retracted, and the second blade can be folded up, making it convenient and safe to carry.

[0018] Furthermore, the aforementioned second blade is hinged to the two handles via a connecting assembly, which includes a female pin and a male pin. The female pin passes through the first handle, the second blade, and the second handle in sequence and is connected to the male pin, so that the second blade can rotate around the female pin to open and fold between the two handles.

[0019] Compared to existing paper cutters, the blade replacement operation of this utility model's paper cutter eliminates the need for screwing. Simply pressing a button disengages the protrusion from the latch, allowing for easy replacement of the first blade. This streamlined process saves time. Furthermore, the two locking grooves secure the first blade in both extended and retracted states, ensuring structural stability. Additionally, this folding knife, by employing the aforementioned paper cutter design, allows for the use of two blades simultaneously. It can be used for both paper cutting and cutting hard objects, offering greater versatility. It also retains the convenient first blade replacement feature of the existing paper cutter. When not in use, the first blade retracts, and the second blade folds away, making it convenient and safe to carry. Attached Figure Description

[0020] Figure 1 This is an exploded structural diagram of the paper cutter of Embodiments 1 and 2 of this utility model.

[0021] Figure 2 This is a schematic diagram of the paper cutter in Embodiments 1 and 2 of this utility model, showing the first blade in the extended state.

[0022] Figure 3 This is a schematic diagram of the paper cutter of Embodiments 1 and 2 of this utility model, with the first blade in the extended state (the structure of the outer shell is omitted in the figure).

[0023] Figure 4 This is a schematic diagram of the paper cutter in Embodiments 1 and 2 of this utility model, where the first blade is in a retracted state.

[0024] Figure 5 for Figure 4 Sectional view of AA.

[0025] Figure 6 This is a schematic diagram of the outer shell structure of the paper cutter in Embodiments 1 and 2 of this utility model.

[0026] Figure 7 This is a schematic diagram of the structure of the folding knife according to Embodiment 3 of this utility model.

[0027] Figure 8 This is an exploded structural diagram of the folding knife according to Embodiment 3 of this utility model. Detailed Implementation

[0028] The accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0029] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "long," and "short" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0030] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0031] Example 1

[0032] like Figure 1-4 As shown, this embodiment provides a paper cutter, including a first handle 1 and a first blade 2. The left side of the first handle 1 has a groove 10 that extends through its rear end. A slide block 3 is slidably fitted in the groove 10. The left side of the first handle 1 is provided with a housing 4 corresponding to the position of the groove 10. The four corners of the housing 4 are respectively connected to the left side of the first handle 1 by screws 44. This facilitates the disassembly and assembly of the housing 4 and ensures the installation stability of the housing 4.

[0033] The first blade 2 is positioned between the slide block 3 and the outer casing 4. The slide block 3 is provided with a spring piece 31, which is formed by two fracture openings 30 on the side wall of the slide block 3. This simplifies the manufacturing process of the spring piece 31 and makes the upper end of the spring piece 31 and the slide block 3 form an integral structure, making the structure more stable. The lower end of the spring piece 31 is a free end, which is provided with a protrusion 311. The outer casing 4 is provided with a relief groove 41 corresponding to the free end of the spring piece 31. The lower side wall of the first blade 2 is provided with a retaining slot 21. The free end of the spring piece 31 is also provided with a button 312, which is located in the relief groove 41 below the retaining slot. The button 312 can slide along the relief groove 41. By pushing the button 312, the slide block 3 can be driven to slide along the slide groove 10, making the operation more convenient.

[0034] The bottom of the aforementioned slide groove 10 is provided with a first clearance groove 101. In its natural state, the free end of the spring piece 31 will cause the protrusion 311 to engage with the slot 21 of the first blade 2, thereby connecting the slide block 3 and the first blade 2. At this time, the slide block 3 can be moved by pushing the button 312, so that the slide block 3 can move the rear end of the first blade 2 to the extended state outside the slide groove 10 and the retracted state inside the slide groove 10.

[0035] The bottom of the groove 10 restricts the inward deformation of the free end of the spring piece 31, preventing the protrusion 311 of the spring piece 31 from dislodging from the latch 21 of the first blade 2, thus ensuring the stability of the connection between the slide block 3 and the first blade 2. When the first blade 2 is slid to the extended state, the spring piece 31 is aligned with the first clearance groove 101, which makes room for the free end of the spring piece 31 to deform inward. At this time, pressing the free end of the spring piece 31 to deform it towards the first clearance groove 101 will place the free end of the spring piece 31 into the first clearance groove 101, allowing the protrusion 311 of the spring piece 31 to dislodge from the latch 21 of the first blade 2.

[0036] When using the paper cutter in this embodiment, if it is necessary to replace the first blade 2, the first blade 2 can be slid to the extended state, and then the button 312 can be pressed to squeeze the free end of the spring piece 31 to deform inward, so that the free end of the spring piece 31 is placed in the first clearance groove 101, thereby causing the protrusion 311 of the spring piece 31 to disengage from the latch 21. At this time, the old first blade 2 can be pulled back to disengage from the slide groove 10, and then the new first blade 2 can be inserted into the slide groove 10, so that the latch 21 of the new first blade 2 is aligned with the protrusion 311. Then the button 312 can be released to make the protrusion 311 of the spring piece 31 engage with the latch 21 of the new first blade 2, thus completing the replacement operation of the first blade 2.

[0037] As an improvement to this embodiment, such as Figure 1 , 3 As shown, the slide block 3 has a front stop 32 on its front side and an upper stop 33 on its upper side. The front stop 32 abuts against the front side of the first blade 2, so that the front stop 32 will prevent the first blade 2 from sliding forward relative to the slide block 3. The upper stop 33 abuts against the upper side of the first blade 2, so that the upper stop 33 will prevent the first blade 2 from sliding upward relative to the slide block 3. At the same time, under the cooperation of the protrusion 311 and the locking block 21, the protrusion 311 will prevent the first blade 2 from sliding forward, backward and downward relative to the slide block 3, thereby ensuring the assembly stability of the first blade 2 and the slide block 3.

[0038] Example 2

[0039] This embodiment is a further improvement on the paper cutter structure of Embodiment 1. The improvement lies in that, as... Figure 1 , 4 As shown in Figure 6, the bottom of the slide groove 10 is also provided with a second clearance groove 102, and the inner side of the outer shell 4 is provided with a first locking groove 42. The thickness of the protrusion 411 is greater than the thickness of the latch 21 of the first blade 2. When the first blade 2 is slid to the retracted state, the spring piece 31 is located in the second clearance groove 102, so that the second clearance groove 102 can make room for the free end of the spring piece 31 to deform inward. At this time, the free end of the spring piece 31 will cause the protrusion 311 to cooperate with the latch 21 and the first locking groove 42 in the natural state. This makes the slide block 3 unable to slide forward and backward under the cooperation of the protrusion 311 and the first locking groove 42 of the outer shell 4, so that the button 312 cannot be pushed to slide further, thereby locking the first blade 2 in the retracted state. When the free end of the spring 31 is pressed, it deforms towards the second relief groove 102, causing the free end of the spring 31 to be placed in the second relief groove 102, which will cause the protrusion 31 to disengage from the first locking groove 42. At this time, the locking of the first blade 2 in the retracted state can be released, so that the button 312 can continue to be pushed to drive the first blade 2 to slide in the extension direction.

[0040] like Figure 2 , 6As shown, the inner side of the outer casing 4 is also provided with a second locking groove 43. When the first blade 2 is slid to the extended state, the spring piece 31 is located in the second clearance groove 102. This means that the second clearance groove 102 can make room for the free end of the spring piece 31 to deform inward in both the retracted and extended states of the first blade 2. At this time, the spring piece 31 will cause the protrusion 311 to cooperate with both the latch 21 and the second locking groove 43 in its natural state, thereby locking the first blade 2 in the extended state. When the free end of the spring piece 31 is pressed and deformed towards the second clearance groove 102, the free end of the spring piece 31 will be placed in the second clearance groove 102, causing the protrusion 311 to disengage from the second locking groove 43. At this time, the locking of the first blade 2 in the extended state can be released, so that the button 312 can be pushed to drive the first blade 2 to slide in the retracted direction.

[0041] Furthermore, the space freed up by the deformation of the spring piece 31 in the second clearance groove 102 is only sufficient for the protrusion 311 to disengage from the locking groove, but not enough for the protrusion 311 to disengage from the bayonet 21. This ensures the installation stability of the first blade 2 and the slide block 3. The first clearance groove 101 is located at the bottom of the second clearance groove 102, so that when the first blade 2 slides to the extended state, the protrusion 311 at the free end of the spring piece 31 can not only deform inward and be placed in the second clearance groove 102 to disengage from the second locking groove 43, but also deform inward and be placed in the first clearance groove 101 to disengage from the bayonet 21.

[0042] The specific operation is as follows: When the first blade 2 is in the extended state, if it is necessary to unlock the first blade 2 in the extended state, the user can press the button 312 with a little force to release the protrusion 311 from the second locking groove 43, thereby unlocking the first blade 2 and pushing it to slide in the retracting direction; when it is necessary to replace the first blade 2, the user can press the button 312 with a lot of force to release the protrusion 311 from the second locking groove 43 and the bayonet 21 at the same time, so that the first blade 2 is separated from the slide 3, and the first blade 2 can be taken out for replacement.

[0043] As an improvement to this embodiment, for example... Figure 1 As shown, the bottom of the second clearance groove 102 is also provided with a transverse groove 103 corresponding to the free end of the spring piece 31. The transverse groove 103 extends along the sliding direction of the first blade 2. The first clearance groove 101 is a vertical groove structure that intersects with the transverse groove 103, and the first clearance groove 101 and the transverse groove 103 are interconnected. The transverse groove 103 can provide more space for the free end of the spring piece 31, so as to ensure that the protrusion 311 at the free end of the spring piece 31 can deform inward and disengage from the two locking grooves.

[0044] like Figure 4As shown, when the first blade 2 is slid to the retracted state, the front end of the button 312 abuts against the front end of the relief groove 41. At this time, the front end of the relief groove 41 will block the button 312 from sliding forward, thereby preventing the first blade 2 from sliding further in the retracted direction, thus positioning the first blade 2 in the retracted state. This also facilitates the alignment of the protrusion 311 with the first locking groove 42, making it easier for the protrusion 311 to be inserted into the first locking groove 42. Figure 2 As shown, when the first blade 2 is slid to the extended state, the rear end of the button 312 abuts against the rear end of the relief groove 41. At this time, the rear end of the relief groove 41 will block the button 312 from continuing to slide backward, thereby preventing the first blade 2 from continuing to slide in the extended direction, so as to position the first blade 2 in the extended state, and also facilitate the alignment of the protrusion 311 with the second locking groove 43, so that the protrusion 311 can be more easily inserted into the second locking groove 43.

[0045] Example 3

[0046] This embodiment provides a folding knife, such as Figure 7 As shown, it includes a second blade handle 6, a second blade 7, and a paper cutter as described in Embodiment 1 or 2. The second blade handle 6 is disposed opposite to the first blade handle 1. The second blade 2 is hinged to the front end position between the two blade handles. The second blade 7 can rotate and open relative to the two blade handles and fold between the two blade handles. The sliding groove 10 is opened on the side of the first blade handle 1 that is away from the second blade handle 6.

[0047] like Figure 8 As shown, the second blade 7 is hinged to the two handles via a connecting assembly. The connecting assembly includes a female nail 81 and a male nail 82. The female nail 81 passes through the first handle 1, the second blade 7, and the second handle 6 in sequence and is connected to the male nail 82, so that the second blade 7 can rotate around the female nail 81 to open and fold between the two handles, which facilitates the assembly and disassembly of the folding knife.

[0048] This embodiment of the folding knife uses a paper cutter as the handle, similar to that of Embodiment 1 or 2, allowing it to have two blades. The first blade 2 is thinner and suitable for cutting soft materials, such as paper; while the second blade 7 is thicker and suitable for cutting hard materials, making it more versatile. Furthermore, this embodiment also provides the convenience of easily replacing the first blade 2. When not in use, the first blade 2 can be folded away, and the second blade 7 can be folded up, preventing accidental injury from both blades and making it both convenient and safe to carry.

[0049] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A paper cutter comprising a first handle (1) and a first blade (2), characterized in that The first knife handle (1) has a groove (10) that runs through its rear end face on the outside. A slide seat (3) is slidably fitted in the groove (10). The first knife handle (1) has a shell (4) on the side corresponding to the groove (10). The first blade (2) is placed between the slide seat (3) and the shell (4). The slide block (3) is provided with a spring piece (31), and the free end of the spring piece (31) is provided with a protrusion (311). The outer shell (4) is provided with a relief groove (41) corresponding to the free end of the spring piece (31). The lower side wall of the first blade (2) is provided with a slot (21). The bottom of the slide groove (10) is provided with a first relief groove (101). In its natural state, the spring piece (31) will cause the protrusion (311) to cooperate with the slot (21). At this time, the slide block (3) can drive the rear end of the first blade (2) to slide to the extended state outside the slide groove (10) and the retracted state inside the slide groove (10). When the first blade (2) is slid to the extended state, the spring (31) is aligned with the first relief groove (101). At this time, pressing the free end of the spring (31) and deforming it toward the first relief groove (101) will cause the protrusion (311) to disengage from the bayonet (21).

2. The paper cutter of claim 1, wherein: The free end of the spring (31) is also provided with a button (312). The button (312) is located below the corresponding slot (21) in the clearance groove (41). The button (312) can slide along the clearance groove (41).

3. The paper cutter of claim 2, wherein: When the first blade (2) is slid to the retracted state, the front end of the button (312) abuts against the front end of the clearance groove (41), and when the first blade (2) is slid to the extended state, the rear end of the button (312) abuts against the rear end of the clearance groove (41).

4. The paper cutter of claim 1, wherein: The slide (3) is provided with a front stop (32) on the front side and an upper stop (33) on the upper side. The front stop (32) abuts against the front side of the first blade (2) and the upper stop (33) abuts against the upper side of the first blade (2).

5. The paper cutter of claim 1, wherein: The spring (31) is formed by two fracture openings (30) on the side wall of the slide (3), and the four corners of the outer shell (4) are respectively connected to the outer side of the first knife handle (1) by screws (44).

6. The paper cutter according to any one of claims 1-5, characterized in that: The bottom of the groove (10) is also provided with a second clearance groove (102), and the inner side of the outer shell (4) is provided with a first locking groove (42). The thickness of the protrusion (311) is greater than the thickness of the bayonet (21). When the first blade (2) is slid to the retracted state, the spring (31) is located in the second clearance groove (102). At this time, the spring (31) will make the protrusion (311) cooperate with the bayonet (21) and the first locking groove (42) in the natural state. When the free end of the spring (31) is pressed and deformed in the direction of the second clearance groove (102), the protrusion (311) will disengage from the first locking groove (42).

7. The paper cutter of claim 6, wherein: The inner side of the outer shell (4) is also provided with a second locking groove (43). When the first blade (2) is slid to the extended state, the spring piece (31) is located in the second relief groove (102). At this time, the spring piece (31) will cause the protrusion (311) to cooperate with the bayonet (21) and the second locking groove (43) in the natural state. Pressing the free end of the spring piece (31) will deform it in the direction of the second relief groove (102), causing the protrusion (311) to disengage from the second locking groove (43).

8. The paper cutter of claim 7, wherein: The first clearance groove (101) is located at the bottom of the second clearance groove (102), and the bottom of the second clearance groove (102) is also provided with a transverse groove (103) corresponding to the free end of the spring piece (31). The transverse groove (103) extends along the sliding direction of the first blade (2). The first clearance groove (101) is a vertical groove structure that intersects with the transverse groove (103), and the first clearance groove (101) and the transverse groove (103) are interconnected.

9. A folding knife characterized by The device includes a second handle (6), a second blade (7), and a paper cutter as described in any one of claims 1-8. The second handle (6) is disposed opposite to the first handle (1). The second blade (7) is hinged to the front end between the two handles. The second blade (7) can rotate and open relative to the two handles and fold between the two handles. A groove (10) is provided on the side of the first handle (1) that is away from the second handle (6).

10. The folding knife of claim 9, wherein: The second blade (7) is hinged to the two blade holders via a connecting assembly. The connecting assembly includes a female nail (81) and a male nail (82). The female nail (81) passes through the first blade holder (1), the second blade (7), and the second blade holder (6) in sequence and is connected to the male nail (82).

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