Knife sharpening apparatus and method
View Patent ↗An apparatus and method for its use employ a magnet assembly to securely hold a knife by its blade. Along with a carriage and angle adjustment assembly that set and control the sharpening angle of the knife relative to a sharpening surface, the apparatus provides for sharpening of knives such as double hollow ground reed scraping knives, and bevel reed scraping knives.
1 . An apparatus for holding a knife for sharpening, the knife having a blade with a first and second sides extending from a spine along a back surface of the blade and meeting at a linear cutting edge, the apparatus comprising:
a magnet assembly for securely holding the knife only by magnetic attachment to the blade of the knife, said magnetic attachment occurring only along the first side of the knife blade and adjacent spine thereof, without further means to hold the knife;
a carriage for reciprocal movement above a flat sharpening surface parallel to a longitudinal axis of the flat sharpening surface; and
an angle adjustment assembly, pivotally connecting the magnet assembly to the carriage, the angle adjustment assembly further establishing, at a pivot point, a first angular relationship between the magnet assembly and the carriage, and wherein the angle adjustment assembly further incudes a releasable lock at the pivot point to lock a sharpening angle after adjustment;
wherein the carriage includes:
two wheels;
one axle rotatably coupled to and separating the wheels, where each of the wheels is positioned to roll along opposite sides of the flat sharpening surface; and
a sliding bearing, located on the axle, permitting both rotation of the bearing about the axle, thereby establishing a second angular relationship, and linear translation of the bearing over at least a portion of the length of the axle, thereby enabling the knife blade to be translated between tip and heel as drawn along the flat sharpening surface while maintaining the sharpening angle,
where the adjustment of the sharpening angle between the second side of the knife blade and the flat sharpening surface is achieved as a combination of the first angular relationship and the second angular relationship, and thereby enables adjustment of the sharpening angle along the linear cutting edge to a minimum of at least 0 degrees.
2 . The apparatus according to claim 1 , wherein said releasable lock includes a threaded member passing through the pivot point of said carriage and angle adjustment assembly, said threaded member having a head on one end and a threaded retaining member on an opposite end, wherein the head and threaded retaining member are threadably tightened in a manner to create a friction force between said carriage and angle adjustment assembly suitable for locking said carriage to the angle adjustment assembly.
3 . The apparatus according to claim 2 , wherein said releasable lock includes at least one component selected from the group consisting of: a quick-release clamping cam handle, a hex nut, a wing-nut, a locknut, a washer, a lock-washer and a single-wing nut.
4 . The apparatus according to claim 1 , wherein the angle adjustment assembly includes:
a plate operatively attached to the magnet assembly, the plate extending upward to provide a top edge suitable for use as a handle to move the sharpening apparatus; and
a connecting bracket, attached to the plate and pivotally attached to the carriage.
5 . The apparatus according to claim 1 , wherein
the angle adjustment assembly includes a plate operatively attached to the magnet assembly, the plate extending upward to provide a top edge suitable for use as a handle to move the sharpening apparatus, and a connecting bracket attached to the plate;
the carriage includes a backbone extending therefrom; and
said releasable lock pivotally attaches the connecting bracket to the backbone of the carriage.
6 . An apparatus for holding a knife for sharpening, the knife having a blade with first and second sides extending from a spine along a back surface of the blade and meeting at a linear cutting edge, the apparatus comprising:
a carriage for reciprocal movement above the flat sharpening surface and parallel with the flat sharpening surface;
a magnet assembly for securely holding the knife only by magnetic attachment to the blade of the knife, said magnetic attachment occurring only along the first side of the knife blade and adjacent spine thereof, without further means to hold the knife; and
an angle adjustment assembly, operatively connecting the magnet assembly to the carriage, the angle adjustment assembly enabling the adjustment of a sharpening angle, between the second side of the knife blade that is to be sharpened and a flat sharpening surface, to a minimum of 0 degrees, and
a releasable lock assembly, pivotally connecting the angle adjustment assembly and the carriage and locking the sharpening angle;
wherein the carriage further includes:
two wheels;
one axle rotatably coupled to and separating the wheels, where each of the wheels is positioned to roll along opposite sides of the flat sharpening surface; and
a sliding bearing, located on the axle, permitting both rotation of the axle relative to the bearing and linear translation of the bearing over at least a portion of the length of the axle, thereby enabling the knife blade to be translated between tip and heel as drawn along the flat sharpening surface while maintaining the sharpening angle along the linear cutting edge.
7 . The apparatus according to claim 6 , wherein said releasable lock assembly includes a threaded member passing through the pivot point of said carriage and angle adjustment assembly, said threaded member having a head on one end and a threaded retaining member on an opposite end, wherein the head and threaded retaining member are threadably tightened in a manner to create a friction force between said carriage and angle adjustment assembly suitable for locking said carriage to the angle adjustment assembly.
8 . The apparatus according to claim 7 , wherein said releasable lock includes at least one component selected from the group consisting of: a quick-release clamping cam handle, a hex nut, a wing-nut, a locknut, a washer, a lock-washer and a single-wing nut.
9 . The apparatus according to claim 6 , wherein the angle adjustment assembly includes:
a plate operatively attached to the magnet assembly, the plate extending upward to provide a top edge suitable for use as a handle to move the sharpening apparatus; and
a connecting bracket, attached to the plate and pivotally attached to the carriage.
10 . The apparatus according to claim 6 , wherein
the angle adjustment assembly includes a plate operatively attached to the magnet assembly, the plate extending upward to provide a top edge suitable for use as a handle to move the sharpening apparatus, and a connecting bracket attached to the plate;
the carriage includes a backbone extending therefrom; and
said releasable lock pivotally attaches the connecting bracket to the backbone of the carriage.