Knife

Abstract

The present invention relates to a retractable knife (2) comprising a handle (4) and a blade (6) movably mounted to the handle (4). An actuator (14) is movably mounted to the handle (4), and the actuator (14) operably engages a cam (42) or rod, the cam / rod (42) being rotatable into abutment with a linkage mechanism (34) operably engaging the blade (6), such that movement of the actuator (14) causes the blade (6) to move between a retracted position in which the blade (6) is partially received within the handle (4) and an extended position in which the blade (6) is extended from the handle (4).

Description

Technical Field

[0001] The present disclosure relates to a knife, and in particular but not limited to a craft knife. Background Art

[0002] A craft knife can be used to cut paper or card. Typically, a craft knife includes a handle and a blade. The blade can be replaced, for example, when the blade becomes dull. Such knives have an exposed blade, which can be dangerous to children and / or can cause the blade to become dull. A safety craft knife may include a frangible blade that is slidably contained within a housing so that the blade can be retracted when not in use.

[0003] The inventors have identified a number of problems with prior art devices. Safety blades are often not ergonomic and can be difficult for children and the like to handle. Blades can also be limited in shape to provide a breakable form. Changing blades for non-retractable craft knives can also be complicated and therefore difficult for, for example, children.

[0004] The present disclosure is directed to overcoming or ameliorating one or more of the above-mentioned problems. Summary of the invention

[0005] According to a first aspect, there is provided a retractable knife comprising: a handle; a blade movably mounted to the handle; an actuator movably mounted to the handle, wherein the actuator operably engages a cam or a rod, the cam / rod being rotatable into abutment with a linkage mechanism operably engaging the blade, such that movement of the actuator causes the blade to move between a retracted position in which the blade is partially contained within the handle and an extended position in which the blade extends from the handle.

[0006] The linkage mechanism includes a movable shaft or rod. The shaft / rod may extend along the axial length of the handle. The linkage mechanism may be received within a core of the handle. The core may include a channel or hollow portion to receive the linkage mechanism. The channel may be elongated (e.g., extending along the axial length of the handle). The core may form a portion of the handle (e.g., its outer surface). The core may be covered by a shield / housing to form a portion of the handle. The actuator may move in a linear manner. The blade may move in a linear manner (e.g., between an extended position and a retracted position).

[0007] The blade may be mounted to a blade holder to together define a cartridge. The blade / cartridge may be removable / detachable. The cartridge may be mounted to and / or fixed within a handle.

[0008] The linkage mechanism may abut or engage the barrel, for example, to drive its extension.

[0009] The blade may be biased toward the retracted position by a biasing member, such as a spring. The biasing member may be operably disposed between the handle and the barrel. The spring may engage a head or edge of the barrel. The biasing member may be operably disposed between the linkage and a core configured to receive the linkage. The linkage may include an edge or flange to engage the biasing member.

[0010] A portion of the handle may be removable from the knife. The removable portion may allow removal of the blade / blade cartridge.

[0011] The handle may include a core that receives the linkage mechanism. The removable portion of the handle may be removably attached to the core. The handle may include two shell parts, and one of the two shell parts may be separable from the other shell part. The shell parts may be connected by threads and / or bayonet attachment.

[0012] The cam may be mounted to the core. The actuator may be mounted to the core. The cam may be snap-fit ​​to the core.

[0013] The blade may be loosely retained within the knife. The blade may be retained within a channel or hollow in the knife (e.g., in the handle). The blade may be loosely engaged with the linkage (i.e., not rigidly fixed to the linkage). The blade may be rotatable about an axis defined by the axial length of the handle (i.e., the position of the blade or blade barrel is axially fixed, but rotation thereof is permitted).

[0014] The blade may be attached / connected to the linkage. The blade may be removably attached to the linkage. The blade or blade cartridge may include a snap fit with the linkage. One of the linkage and the blade may include a head portion and a neck portion. The other of the linkage and the blade may include a groove and a constriction configured to provide a snap fit with the neck portion.

[0015] The blade cartridge may include a first portion for holding the blade. The blade cartridge may include a second portion for defining the neck portion. The first portion and the second portion may be connected by a snap fit.

[0016] The actuator may include a cap. The cap may be located at the end of the handle opposite the blade. The cap may be spherical and / or may protrude outwardly from the lateral width of the handle. The cam and / or rod may be completely contained within the cap / actuator.

[0017] The cam may include a rod. A portion of the rod is received in a groove on the actuator. The rod may include a head portion. The head portion may be rotatably received in the groove. The cam may include an eccentric surface configured to engage the linkage mechanism.

[0018] A bearing may be disposed between the blade or blade cartridge and the handle to facilitate movement therebetween. The bearing may include a sleeve. A biasing member may be disposed between the bearing and the handle.

[0019] The actuator may move in a first direction and the blade in an opposite second direction. During actuation, the actuator may move a first distance and the blade may move a shorter second distance. The cam / rod may provide a non-uniform transmission ratio. The first distance may be between 1.5 and 2.5 times the second distance.

[0020] The blade may comprise a ceramic material.The knife may comprise a craft knife.

[0021] A portion of the handle may include a high friction surface. The high friction surface may include a rubber coating. The high friction surface may be provided on a removable portion of the handle, such as a handle shield.

[0022] According to another aspect, a retractable knife is provided, comprising: a handle; a blade movably mounted to the handle; an actuator movably mounted to the handle, the actuator being configured to move the blade between a retracted position in which the blade is partially contained within the handle and an extended position in which the blade extends from the handle; wherein the blade is mounted to a blade holder to define a cartridge, and wherein the cartridge is removably mounted to the handle.

[0023] A retractable knife comprises: a handle; a blade movably mounted to the handle; an actuator movably mounted to the handle, the actuator being configured to move the blade between a retracted position in which the blade is partially contained within the handle and an extended position in which the blade extends from the handle; wherein the blade is mounted to a blade holder to define a barrel, and wherein the barrel is rotatably mounted to the handle so that the barrel can rotate about an axis defined by an axial length of the handle.

[0024] Where practicable, any aspect of the invention may be combined with any other aspect of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] With reference to the accompanying drawings, embodiments of the present invention are described below by way of example only:

[0026] Figure 1 An exploded view of a first embodiment of a craft knife is shown;

[0027] Figure 2 A side view of a first embodiment of a craft knife is shown;

[0028] Figure 3 shows a cross-sectional side view of a first embodiment of a craft knife in a retracted state;

[0029] Figure 4shows a cross-sectional side view of a first embodiment of a craft knife in an extended state;

[0030] Figure 5 An exploded view of a second embodiment of a craft knife is shown;

[0031] Figure 6 shows a side view of a second embodiment of a craft knife;

[0032] Figure 7 showing a cross-sectional side view of a second embodiment of a craft knife in a retracted state;

[0033] Figure 8 A cross-sectional side view of a second embodiment of a craft knife is shown in an extended state;

[0034] Fig. 9 An exploded view of a third embodiment of a craft knife is shown;

[0035] Fig.10 shows a side view of a third embodiment of a craft knife;

[0036] Fig.11 shows a cross-sectional side view of a third embodiment of a craft knife in a retracted state;

[0037] Fig.12 shows a cross-sectional side view of a third embodiment of a craft knife in an extended state;

[0038] Fig.13 An exploded view of a fourth embodiment of a craft knife is shown;

[0039] Fig.14 shows a side view of a fourth embodiment of a craft knife;

[0040] Fig.15 shows a cross-sectional side view of a fourth embodiment of a craft knife in a retracted state;

[0041] Fig.16 A cross-sectional side view of a fourth embodiment of a craft knife is shown in an extended position. DETAILED DESCRIPTION

[0042] Figures 1 to 4 2 or cutter is shown. The knife 2 comprises a craft knife for cutting, in particular, paper, card, cardboard, felt, plastic, etc. It will be appreciated that the exact use of the knife is irrelevant to the present invention. The knife 2 comprises a handle 4 portion. The handle 4 allows a user to hold the knife 2 during use. The handle 4 may be ergonomically shaped. The handle 2 comprises a polymeric material, such as acrylonitrile butadiene styrene (ABS). The handle 4 comprises a generally elongated / tubular form.

[0043] The blade 6 is disposed at the first end 8 of the handle 4. The blade 6 may include a scalpel-type blade (i.e., its apex / tip includes an acute angle). The blade 6 is held / fixed to a blade holder 10. The blade 6 and the blade holder 10 may together define a barrel 12. The barrel may be replaceable to allow replacement of the blade 6. The barrel 12 provides a simple means of replacing the blade 6 without directly handling the blade 6. The blade 6 may include a thickness between 0.4 mm and 0.8 mm. The blade 6 may include a ceramic material. The blade may include zirconium oxide. The blade 6 may include hardened steel.

[0044] The actuator 14 is disposed at the second end 16 of the handle 4 (i.e., at the end of the handle 2 opposite the blade 6). The actuator 14 is movably mounted to the handle 4. The actuator 14 is movable along the axial length of the handle 4 (i.e., toward / away from the blade 6). The actuator 14 is mounted to the core 18. The actuator 14 includes an inner portion 20 that is configured to be movably mounted to the core 18 during use. The inner portion 20 is generally elongated. The inner portion 20 is hollow to receive the core 18. The inner surface of the inner portion 20 includes a shape similar to the outer surface of the core 18 to provide a close fit with the core. The core 18 includes a retaining protrusion 22 that is configured to be received by a corresponding groove 24 in the inner portion 20 (at Figure 1 The projection 22 can slide along the slot 24 during use to allow the actuator 14 to move while retaining the actuator 14 on the handle 4. Figure 1 Only a single protrusion 22 is shown in FIG, but another protrusion 22 is provided on the opposite side of the core 18. Additionally or alternatively, the protrusion is provided on the inner part 20 and is received in a groove located on the core 18. The inner part 20 may be snap-fit ​​onto the core 18.

[0045] The shield 25 is mounted to the inner portion 20. The shield 25 covers the inner portion 20. For example, the shield 25 covers the slot 24 to prevent interference therewith. The shield 25 can be snap-fit ​​and / or adhered to the inner portion 20. The actuator 14 protrudes outward from the side of the handle 4 (i.e., includes a larger portion than the handle 4). This allows the user to more easily grasp the actuator 14. The actuator 14 can include a round or spherical shape.

[0046] The core 18 extends along the inside of the handle 4. The handle shield 26 is configured to at least partially cover / enclose the core 18. The handle shield 26 includes a tight fit with the core 18. The handle shield 26 is removable from the core 18. This allows access to the barrel 12 to allow it to be replaced. For example, the handle shield 26 and the core 18 include threads 28 to allow them to be attached / detached. It will be appreciated that any suitable attachment mechanism may be provided, such as an interference fit, a snap fit (e.g., one of the handle shield 26 and the core 18 includes a protrusion that is configured to snap into a groove located on the other of the handle shield 26 and the core 18), a notch and resilient pawl arrangement, a latch, etc.

[0047] The core 18 includes a wide portion 30. The wide portion 30 is disposed adjacent to the actuator 14. The wide portion is similar to the width of the handle 4 (e.g., greater than 80% of the width of the handle). The core 18 includes a narrow portion 32. The narrow portion 32 is disposed toward the blade 6. The narrow portion is less than 60% of the width of the handle 4. The narrow portion 32 allows the thread 28 to be provided. The handle shield 26 includes a greater wall thickness in the portion covering the narrow portion 32 to ensure that the handle 4 has sufficient rigidity. The thread 28 is disposed on the narrow portion 32 to allow it to be accommodated within the shield 26.

[0048] A rod or shaft 34 is disposed within the core 18. The shaft 34 is movable (i.e., slidable) within the core 18. The shaft 34 may include a plastic material and / or aluminum. The first end 36 of the shaft 34 is configured to abut / engage the blade barrel 12. The shaft 34 thus provides a linkage mechanism. The knife 2 includes a spring 38 that is configured to bias the barrel 12 to a position in which the blade 6 is received within the handle 4 (see FIG. 1 ). Figure 3 ). The second end 40 of the shaft 34 is configured to engage a cam 42. The cam includes an eccentric surface 44. There, when the cam 42 rotates, the eccentric surface 44 drives the shaft 34 along the core 18 (see Figure 3 and Figure 4 ). When the shaft 34 moves toward the barrel 12, the barrel is pushed out of the handle 4 to expose the blade 6. If the cam 42 is rotated back to the initial position, the shaft 34 is free to retract under the action of the spring 38.

[0049] Cam 42 is mounted to core 18. Core 18 includes a slot 46 that receives cam 42. Cam 42 includes a protrusion 48 on either side that is configured to snap fit into core 18 to provide a rotatable pivot point. Cam 42 includes a rod 50. Rod 50 projects outwardly from cam 42 to enable rotation thereof. Rod 50 is angled relative to the radial direction of cam 42 (i.e., extends in radial and tangential directions). A head portion 52 or protrusion is provided at an end 54 of rod 50. Head portion 52 extends outwardly from the plane of cam 42 (e.g., extends in radial and tangential directions). Figure 14). The head portion 52 extends outwardly from the rod 50 in the plane of the cam 42. Thus, the rod 50 includes a hook shape. The end 54 of the rod 50 (e.g., the head portion 52) is configured to engage the actuator 14. The actuator 14 includes a groove 56 that accommodates the head portion 52. When the actuator 14 moves away from the blade 6, the rod 50 rotates away from the blade 6 accordingly. This rotates the cam 42 so that the eccentric surface 44 engages the shaft 34, thereby extending the blade barrel 12. As the actuator 14 moves away from the blade 6, the head portion 52 abuts a first side or edge 58 of the groove 56. When the actuator 14 moves back toward the blade 6, the head portion 52, the second side or edge 60 of the groove 56 abuts the head portion 52 to rotate the cam 42 back to the blade 6. Figure 3 The structure in .

[0050] The cam 42 and rod 50 are completely contained within the knife 2. In particular, no portion of the cam 42 and rod 50 protrudes from the actuator / cap 14. This helps prevent interference with the operation of the actuation mechanism during use.

[0051] Therefore, the actuator 14 is movable to achieve the movement of the blade 6 / blade cylinder. The actuator 14 is configured to be pulled to extend the blade 6. This provides a safer configuration because it is generally more difficult to accidentally pull the actuator 14 than to push the actuator 14. Therefore, the actuator 14 moves in a first direction to extend the blade 6 in an opposite second direction. In an alternative embodiment, the actuator 14 can be pushed toward the blade 6 to extend the blade 6. For example, when the actuator 14 is set in a position toward the blade 6, the cam surface 44 engages the shaft 34, and when the actuator 14 is displaced away from the blade (for example, the cam surface 44 is set in a position rotated 90 degrees counterclockwise compared to the position shown in this embodiment), the cam surface 44 disengages the shaft 34. The actuator 14 and the blade 6 move in a linear manner.

[0052] The actuator 14 is configured to be pulled a first distance so that the blade cylinder 12 extends a smaller second distance. Therefore, the actuator 14 and the cylinder are connected by a transmission mechanism. The rod 50 and the cam surface 44 effectively provide a transmission mechanism. The effective distance of the rod 50 and the cam surface 44 from the pivot point defines the effective transmission ratio (for example, the longer the rod 50, the more the actuator 14 must move to move the cylinder 12 a certain distance). In the present embodiment, the actuator 14 is configured to move 6 to 10 mm. The blade cylinder 12 is configured to move 1 to 4 mm. In a specific embodiment, the actuator 14 moves 8 mm and the blade cylinder moves 4 mm. The distance moved by the actuator 14 is 1.5 to 2.5 times the distance moved by the blade cylinder.

[0053] The blade cartridge 12 is loosely retained within a channel 59 within the handle shield 26. This allows the cartridge 12 to be freely extended / retracted. In addition, the cartridge 12 can rotate freely about its axial length. The cartridge includes a head portion 60. The head portion 60 is sized to provide a tight fit with the shield 26 without providing excessive friction. The blade holder 10 includes a shaft portion 62 of reduced width. The shaft portion 62 secures the blade 6 to the cartridge 12. The reduced width further leaves room for the spring 38. The head portion 60 ensures that the cartridge 12 remains restrained within the handle.

[0054] To use the knife 2, the user can first insert (or replace) the blade cartridge. The handle guard 26 is unscrewed from the core 18, and the cartridge 12 is placed therein. The handle guard 26 is screwed back onto the core 18. The user then pulls the actuator 14 to extend the blade 6, and then pushes the actuator 14 back to retract the blade 6. The removable guard 26 allows the blade cartridge 12 to be easily replaced without the use of tools or the like.

[0055] Figures 5 to 8 There is shown a second embodiment of the knife 2. The knife 2 and its operation are substantially the same as the knife 2 of the first embodiment and similar features will not be repeated for the sake of brevity.

[0056] The wide portion 30 of the core 18 is axially shorter than the first embodiment. Therefore, the thread 28 is correspondingly arranged closer to the actuator 14. Therefore, a relatively large portion of the handle shield 26 is removed in use. The shield 26 may include a rubber coating. For example, the shield 26 may include a plastic base (e.g., ABS) with a rubber coating.

[0057] The bearing 64 is disposed between the barrel 12 and the handle shield 26. The bearing 64 includes a sleeve configured to receive the blade holder 10. The bearing 64 includes a protruding edge 66 that is configured to engage the shield 26. The edge 66 is configured to abut against the head portion 60 of the barrel 12 and the spring 38 (i.e., placed between them). The bearing 64 may include a low friction material. The bearing 64 may include stainless steel. The bearing 64 may include a polished surface.

[0058] Figures 9 to 12 A third embodiment of the knife 2 is shown. Again, similar features will not be described in detail. The blade cartridge 12 is removably connected to the shaft 34. The cartridge 12 includes a head portion 66 and a neck portion 68 located between the head portion 66 and the cartridge 12. The first end 36 of the shaft 34 includes a groove 70 configured to receive the head portion 66. The groove 70 is shaped to provide a tight fit with the head portion 66. The groove 70 includes a constriction 72 that is configured to provide a snap-fit ​​connection with the neck (see Fig.10). The constriction 72 comprises a gap / spacing slightly smaller than the width of the neck 68 to provide the snap fit. The head 66 and the neck 68 are rotationally symmetric to allow rotation thereof.

[0059] The handle shield 26 includes two separable parts 26A and 26B. Threads 74 are provided to facilitate connection therebetween. It will be appreciated that any suitable attachment mechanism may be provided. The first part 26A is configured to cover the barrel 12 and / or allow access to the barrel 12. The threads 74 are proximate to the end 36 of the shaft 34. The second part 26B forms the remainder of the handle 4.

[0060] The spring 28 is operably disposed between the shaft 34 and the core 18. The spring 28 is thus displaced from the barrel 12. The shaft 34 includes a flange / rim 76 to retain the spring 28. The spring 28 is disposed between the flange 76 and an end face 78 of a groove 80 in the second portion 26B of the shield. The groove 80 is wider than the width of the shaft 34 to accommodate the spring 28.

[0061] Figures 13 to 15 A fourth embodiment of the knife 2 is shown. Again, similar features will not be repeated for brevity. The two housing parts 26A and 26B are connected by a bayonet connection. The second housing part 26B includes an L-shaped groove 82 to receive a corresponding protrusion 84 on the first housing part 26A (see FIG. Fig.15 and Fig.16 ). The protrusion 84 is inserted axially into the groove 82, and the first housing portion 26A is rotated so that the protrusion 84 is retained in the groove 82. This provides a faster and easier way to remove the first housing portion 26A than the above-mentioned threads.

[0062] The blade cartridge 12 comprises a two-piece structure. The first component 86 comprises a housing that houses the blade 6. The second component 88 comprises a handle portion to be connected to the shaft 34 in use, as previously described. The second component 88 is configured to snap fit into the first component 86. The first component 86 and / or the second component 88 may comprise polyoxymethylene (POM).

[0063] The core 18 includes a pin 90 configured to be received by the housing 26. An adhesive or the like may be provided on the pin to form a secure connection between the core 18 and the housing 26. In other embodiments, the pin is provided on the housing 26, or on both the housing 26 and the core 18.

[0064] The present disclosure provides a simple and effective method of extending or retracting a blade. This is particularly beneficial for children or people with disabilities. The blade is connected in a removable manner, which also allows it to rotate. The blade cartridge allows easy and safe handling of the blade (e.g., replacement of the blade).

Claims

1. A retractable knife comprising: handle; a blade movably mounted to the handle; an actuator movably mounted to the handle, wherein the actuator operably engages a cam or lever that is rotatable into abutment with a linkage that operably engages the blade such that movement of the actuator causes the blade to move between a retracted position in which the blade is partially contained within the handle and an extended position in which the blade is extended from the handle.

2. The retractable knife according to claim 1, wherein: The linkage mechanism includes a movable shaft extending along an axial length of the handle.

3. The retractable knife of claim 1, wherein: The blade is mounted to the blade holder to collectively define a barrel.

4. The retractable knife of claim 2, wherein: The linkage mechanism abuts the barrel.

5. The retractable knife of claim 1, wherein: The blade is biased toward the retracted position by a biasing member.

6. The retractable knife of claim 5, wherein: The biasing member is operably disposed between the handle and the barrel.

7. The retractable knife of claim 5, wherein: The biasing member is operably disposed between the linkage and a core configured to receive the linkage.

8. The retractable knife of claim 1, wherein: A portion of the handle is removable from the retractable knife to allow removal of the blade.

9. The retractable knife of claim 8, wherein: The handle includes a core for receiving the linkage mechanism, and a removable portion of the handle is removably attached to the core.

10. The retractable knife of claim 1, wherein: The handle comprises two housing parts, one of which is separable from the other housing part.

11. The retractable knife of claim 1 , wherein: The blade is rotatable about an axis defined by an axial length of the handle.

12. The retractable knife of claim 1, wherein: The blade is removably attached to the linkage mechanism.

13. The retractable knife of claim 1, wherein: The actuator includes a cap at an end of the handle opposite the blade.

14. The retractable knife of claim 13, wherein: The cap is bulbous and / or projects outwardly from the lateral width of the handle.

15. The retractable knife of claim 13, wherein: The cam and / or rod are completely housed within the cap.

16. The retractable knife of claim 1, wherein: A bearing is disposed between the blade and the handle to facilitate movement between the blade and the handle.

17. The retractable knife of claim 1, wherein: The actuator moves in a first direction and the blade moves in an opposite second direction.

18. The retractable knife of claim 1, wherein: During actuation, the actuator moves a first distance and the blade moves a shorter second distance.

19. A retractable knife comprising: handle; a blade movably mounted to the handle; an actuator movably mounted to the handle, the actuator being configured to move the blade between a retracted position in which the blade is partially received within the handle and an extended position in which the blade is extended from the handle; wherein the blade is mounted to a blade holder to define a cartridge, and wherein the cartridge is removably mounted to the handle.

20. A retractable knife comprising: handle; a blade movably mounted to the handle; an actuator movably mounted to the handle, the actuator being configured to move the blade between a retracted position in which the blade is partially received within the handle and an extended position in which the blade is extended from the handle; wherein the blade is mounted to a blade holder to define a cartridge, and wherein the cartridge is rotatably mounted to the handle such that the cartridge is rotatable about an axis defined by an axial length of the handle.

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