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EP-4304811-B1 - KNIFE SHARPENING DEVICE AND METHOD

EP4304811B1EP 4304811 B1EP4304811 B1EP 4304811B1EP-4304811-B1

Inventors

  • MILLER, ERIC ARTHUR
  • LAVINS, Nathaniel R.
  • ANTHONY, JOSHUA D.
  • Soto, Orlando
  • RICHARDSON, ROSS

Dates

Publication Date
20260506
Application Date
20220309

Claims (14)

  1. A knife sharpener device, comprising: a support structure (116) configured to hold a knife (110) having a handle and a blade (110b) extending therefrom; and a carriage assembly (124) mounted on the support structure (116) and having a pivotal arm (130) carrying a sharpening element (128) configured to sharpen a cutting edge (110c) of the blade (110b), wherein the carriage assembly (124) is movable in a first direction within a guide track (134) in the support structure (116) to move the pivotal arm (130) in a first track (138) that causes the sharpening element (128) to apply a force to the cutting edge (110c) of the blade (110b) of the knife (110) held by the support structure (116), and wherein the carriage assembly (124) is movable in a second direction opposite the first direction within the guide track (134); characterised in that a pawl (140) is mounted to the support structure (116), the pawl (140) being configured to move the pivotal arm (130) into a second, return track (144) in the support structure (116) when the carriage assembly (124) switches from moving in the first direction to moving in the second, opposite direction; the second track (144) being spaced from the first track (138) such that the sharpening element (128) is maintained a predetermined distance apart from the cutting edge (110c) of the blade (110b) while the carriage assembly (124) is moving in the second direction.
  2. The knife sharpener device of claim 1, wherein the sharpening element (128) is spring-biased toward the cutting edge (110c) of the blade (110b) to provide a constant force to the cutting edge (110c) of the blade (110b) when the carriage assembly (124) is moved in the first direction.
  3. The knife sharpener device of claim 1, wherein the support structure (116) includes a clamping assembly (146) configured to maintain the knife (110) in a fixed position.
  4. The knife sharpener device of claim 3, wherein the clamping assembly (146) includes a pair of jaws (148a, 148b) configured to engage a portion of the knife (110).
  5. The knife sharpener device of claim 4, further comprising a release mechanism (158) configured to at least partially separate the jaws (148a, 148b) to allow the knife (110) to be removed from the clamping assembly (146).
  6. The knife sharpener device of claim 1, wherein the carriage assembly (124) is configured to automatically advance along the guide track (134) in the first direction.
  7. The knife sharpener device of claim 6, further comprising a constant-force spring (314) coupled to the carriage assembly (304) and configured to automatically advance the carriage assembly (304) along the guide track (308) in the first direction.
  8. The knife sharpener device of claim 7, further comprising a secondary carriage (316) movably disposed in a housing (302), the secondary carriage (316) being configured to engage the carriage assembly (304) and move the carriage assembly (304) in the second direction against the force of the spring (314).
  9. The knife sharpener device of claim 8, wherein the secondary carriage (316) is configured to automatically release the carriage assembly (304) when the secondary carriage (316) reaches a predetermined position.
  10. The knife sharpener device of claim 1, wherein the carriage assembly (124) includes a handle (136) coupled thereto and extending from the support structure (116) to allow a user to move the carriage assembly (124) relative to the support structure (116).
  11. The knife sharpening device of claim 1, wherein the carriage assembly (124) travels in the guide track from a position adjacent to the handle to a position beyond a tip of the blade when the carriage assembly (124) is moved in the first direction, and once the carriage assembly (124) is beyond the tip of the blade a ratchet mechanism (504, 514) prevents the carriage assembly (124) from moving in the second opposite direction until the carriage assembly (124) reaches a predetermined position.
  12. A method for sharpening a knife (110), comprising: inserting a knife (110) into a clamping assembly (146) of a support structure (116) such that the clamping assembly (146) engages the knife (110) to maintain a blade (110b) of the knife (110) in a fixed position; a carriage (126) being mounted on the support structure (116), an arm (130) being pivotably coupled to the carriage (126), the arm (130) carrying a sharpening element (128); causing the carriage (126) to travel in a first direction along a guide track (134) in the support structure to move the arm (130) in a first track (138) in the support structure (116), the sharpening element (128) being biased toward a cutting edge (110c) of the blade (110b) such that the sharpening element (128) travels along the cutting edge (110c) of the blade (110b) to sharpen the blade (110b) as the carriage (126) moves along the guide track (134) in the first direction; and causing the carriage (126) to travel in a second, opposite direction in the guide track (134); characterised in that a pawl (140) mounted on the support structure (116) moves the arm (130) into a second, return track (144) in the support structure (116) when the carriage (126) switches from moving in the first direction to moving in the second, opposite direction, the second, return track (144) being spaced from the first track (138) such that the sharpening element (128) is spaced apart from the cutting edge (110c) of the blade (110b) as the carriage (126) moves along the guide track (134) in the second, opposite direction along a length of the cutting edge (110c) of the blade (110b).
  13. The method of claim 12, wherein the sharpening element (128) applies a constant force to the cutting edge (110c) of the blade (110b).
  14. The method of claim 12, wherein the knife (110) includes a handle with the blade (110b) extending therefrom, and wherein the carriage (510) travels in the guide track (506) from a position adjacent to the handle to a position beyond a tip of the blade (110b) when the carriage (510) is moved in the first direction, and once the carriage (510) is beyond the tip of the blade (110b) a ratchet mechanism (504, 514) prevents the carriage (510) from moving in the second opposite direction until the carriage (510) reaches a predetermined position.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority of U.S. Patent Application No. 17/196,348 filed March 9, 2021, and entitled "Knife Sharpening Systems." FIELD Knife sharpening systems and methods are provided. Document DE102018131332A1 discloses a knife sharpening device and method according to the preamble of claim 1 and 12. BACKGROUND A knife's utility generally depends on the sharpness of the cutting edge of its blade. The cutting edge of most blades, however, eventually becomes dull through repeated use. A wide range of use conditions can contribute, and in some instances accelerate, the dulling of the cutting edge. As a result, in order to maintain an effective cutting edge, and thus prolong the useful life of the knife, the blade must be sharpened periodically. Unfortunately, when purchasing knives, a user typically does not appreciate the need for blade maintenance. Blade maintenance generally involves honing and sharpening of the blade. Honing involves realigning the cutting edge back to its original position by repeatedly passing the cutting edge across a honing rod at an angle. For honing to be effective in maintaining the cutting edge, a user must regularly hone the blade using a proper honing technique (e.g., positioning the blade at a proper angle and applying an appropriate amount of force to the blade as the user passes the blade along the honing rod). Otherwise, the user can damage the cutting edge in such a way that would require replacement and in certain instances, the user can cause injury to themselves. Unfortunately, most users do not know how to properly hone a blade, find it difficult to do so, or simply do not have the time to regularly hone their knives. Further, even with proper honing, the blade will eventually need to be sharpened Sharpening removes material from the blade to produce a new, sharp cutting edge. There are a variety of ways a cutting edge can be sharpened. For example, an end user can send their knives to a professional service for sharpening. However, these services can be expensive and can take long periods of time to sharpen and return the knives. Thus, it is common for a user to purchase an on-demand knife sharpener. A wide variety of on-demand manual and powered knife sharpeners have been developed (e.g., standalone knife sharpeners or knife sharpeners integrated into knife blocks and cutting boards). With many known manual knife sharpeners, the user is required to place the cutting edge of the blade onto the sharpening surface(s) of the sharpener and, while applying a downward force to the blade, the end user moves the blade against the sharpening surface to sharpen the cutting edge. In other instances, the knife can be affixed and the user can manually move a sharpening surface against the blade. While these knife sharpeners are readily available to the user, their effectiveness in sharpening the cutting edge of a blade relies heavily on the user's applied force and the angle at which the sharpening surface is applied to the blade. Unfortunately, most users are unable to apply, or consistently apply, the proper amount of force to the blade and with the sharpening surface at the proper angle. This can result in inconsistent and unrepeatable sharpening of the cutting edge, and in some situations, can cause damage to the cutting edge (e.g., chipping) that could therefore require replacement. Further, when using most knife sharpeners, the user can be exposed to the cutting edge of the blade, and as a result, this can increase the risk for user injury. Powered knife sharpeners are also available, however these can be highly complex and very expensive. Some still require the user to apply a downward force to the blade so that the blade will remain in contact with the sharpening surface as it moves against the blade Other more complex powered knife sharpeners require complicated electronics as well sensing systems that can detect the profile of the blade to allow the sharpening surface to automatically move along the blade. These systems can also be fairly bulky, making storage undesirable. Accordingly, despite existing technologies, there remains a need for improved knife sharpeners that is easy to use and that can consistently and repeatedly sharpen a knife. SUMMARY The invention is defined in the appended independent claim 1 and claim 12. Preferred embodiments are defined in the dependent claims. A knife sharpener device according to the invention is defined in the appended claim 1. The sharpening element can be spring-biased toward the cutting edge of the knife blade to provide a substantially constant force to the cutting edge of the knife blade when the carriage assembly is moved in the first direction. In other aspects, the support structure can include a clamping assembly configured to maintain the knife in a fixed position. The clamping assembly can include a pair of jaws configured to engage a portion of the knife. T