Precision means for sharpening and creation of microblades along cutting edges

Abstract

A knife-edge conditioning apparatus comprises at least one precision angled knife guide with one face of the knife blade maintained in sustained sliding or rolling contact and which guides the elongated edge of the blade into sustained contact with the hardened surface of an object and positions the plane of the adjacent edge facet at a precise predetermined angle relative to the contact plane of the hardened surface made of a material of equal or greater hardness than the metal of the knife blade without any tendency to abrade as the blade face is moved along the guide with its elongated edge in sustained contact with the hardened surface.

1 . In a multi-stage assembly for modifying the physical structure of an elongated edge of a knife blade which has two faces that at their extremity each have a facet that intersects to form the elongated edge, said assembly having at least one stage which includes structure for sharpening the edge by removing material from at least one of the facets, and said assembly including a further stage, the improvement being in that said further stage is an edge conditioning stage which has at least one precision knife guide with a planar knife face contacting surface along which the face of the blade can be stroked with the elongated edge of the blade in sustained moving contact with a hardened surface of an object at a location of contact adjacent to and at an angle to said guide surface, and said hardened surface being substantially free of abrasive particles and free of sharp edges characteristic of abrading, skiving and metal removing tools.  
   
   
       2 . The assembly of  claim 1  where said structure for sharpening the edge in said at least one stage is motor driven, and said object in said edge conditioning stage is non-motor-driven.  
   
   
       3 . The assembly of  claim 1  where said at least one stage includes a sharpening stage having a sharpening member with an abrasive surface and a finishing stage having a finishing member with an abrasive surface, and said abrasive surface of said sharpening member being more coarse than said abrasive surface of said finishing member.  
   
   
       4 . The assembly of  claim 3  where said conditioning stage is located between said sharpening stage and said finishing stage, said object in said conditioning stage being non-motor-driven, and each of said sharpening member and said finishing member being rotatably motor driven.  
   
   
       5 . The assembly of  claim 1  where said at least one stage is a skiving stage having at least one skiving surface for skiving the facet.  
   
   
       6 . The assembly of  claim 1  where said hardened surface is of non-planar shape to maintain sustained contact with and locally stress and fracture the edge of the blade at the location of contact with said hardened surface on repeated stroking to create a microscopic serration along the edge.  
   
   
       7 . The assembly of  claim 1  where said hardened surface has an arcuate shape at the location of contact.  
   
   
       8 . The assembly of  claim 1  where said precision knife guide has an elongated flat surface which comprises said planar knife face contacting surface.  
   
   
       9 . The assembly of  claim 1  where said object has said hardened surface at two opposite locations, and one of said knife guides being disposed at each of said two opposite locations.  
   
   
       10 . The assembly of  claim 1  where said hardened surface is the surface of a stationary object.  
   
   
       11 . The assembly of  claim 1  where said hardened surface is the surface of a rotatable cylindrical object.  
   
   
       12 . The assembly of  claim 11  where a braking mechanism prevents rotation of said rotatable cylindrical object unless a torque is applied to said cylindrical object in excess of that applied by said braking mechanism.  
   
   
       13 . The assembly of  claim 1  where said object is adjustable in order that different areas of said hardened surface of said object can be selected as the location of contact.  
   
   
       14 . The assembly of  claim 1  where said hardened surface of said object is serially grooved with a plurality of grooves at the location of contact, and said grooves being oriented angularly to cross the elongated edge as the edge is moved across said grooved hardened surface.  
   
   
       15 . The assembly of  claim 1  where said hardened surface has a hardness above Rockwell C-60.  
   
   
       16 . The assembly of  claim 1  where there are at least two linearly aligned of said objects each having said hardened surface, and said knife guide having said planar knife face contacting surface for use with said at least two objects.  
   
   
       17 . The assembly of  claim 1  where there are two of said knife guides which are parallel to each other with said object between said knife guides.  
   
   
       18 . The assembly of  claim 1  where said object is mounted on a support member, said knife guide being pivotally mounted to said support member, and adjusting structure controlling the angle of orientation of said knife guide.  
   
   
       19 . The assembly of  claim 1  where said knife guide comprises at least two aligned rods or rollers which define an extended guide plane, and said extended guide plane being said knife face contacting surface.  
   
   
       20 . The assembly of  claim 1  where said hardened surface has a surface roughness no greater than 10 microns.  
   
   
       21 . The assembly of  claim 1  including a physical member to contact the knife blade and apply a force to press the blade against said knife guide as the blade is moved along said knife guide with the blade edge in sustained contact with said hardened surface.  
   
   
       22 . The assembly of  claim 1  comprising a set of at least two of said hardened surfaces which are spaced from each other, and one of said precision knife guides adjacent said set of spaced hardened surfaces.  
   
   
       23 . The assembly of  claim 1  where said hardened surface of said object is restrained in a predetermined rest position relative to and adjacent said precision knife guide by a restraining mechanism that applies a restraining force to position said object in said rest position, and said object being displaceable against the force of said mechanism by the force applied by the blade facet contacting said hardened surface of said object.  
   
   
       24 . The assembly of  claim 1  where said object in a rest position can be displaced by an exerting force exerted by the blade edge against said hardened surface of said object against a predetermined restraining force of a resilient structure that upon release of said exerting force repositions said hardened surface to said rest position.  
   
   
       25 . The assembly of  claim 1  where said at least one stage comprises a sharpening stage having at least one disk with an exposed abrasive surface, said disk being mounted on a shaft for rotation, a blade guide surface juxtaposed said disk to guide one face of the blade to bring the blade edge into contact with said abrasive surface of said disk, said blade guide surface being at a predetermined vertical angle A relative to the plane of said abrasive surface of said disk at point of contact with the blade facet, said blade guide surface being in a plane that intersects said abrasive surface, and said conditioning stage knife face contacting surface being at a predetermined angle C relative to the plane of said hardened surface at point of contact of the blade edge.  
   
   
       26 . The assembly of  claim 25  where said at least one stage further includes an edge finishing stage, said finishing stage comprising at least one finishing disk having an exposed abrasive surface, said finishing disk being mounted on a shaft for rotation, a finishing blade guide surface juxtaposed said finishing disk to guide one face of the blade to bring the blade edge into contact with the surface of said finishing disk, and said finishing blade guide surface being in a plane that intersects said finishing disk abrasive surface set at predetermined angle D relative to the plane of the abrasive surface of said finishing disk at point of contact with the blade edge.  
   
   
       27 . The assembly of  claim 26  where the angular difference between angle A and angle C is less than 10 degrees and the angular difference between angle A and D is less than 3 degrees.  
   
   
       28 . The assembly of  claim 26  where each of said sharpening stage disk and said finishing stage disk is rotatably motor driven, and said conditioning stage object being non-motor-driven.  
   
   
       29 . A method for manually modifying the physical structure along an elongated edge of a knife blade which has two faces that at their terminus form two edge facets that intersect to create the elongated edge at the junction of the two facets comprising sharpening the edge by movably contacting the edge with a sharpening member having an abrasive surface in a sharpening stage, then moving the knife blade to a conditioning stage having at least one precision knife guide with a planar knife face contacting surface, providing near the at least one precision knife guide an object having a hardened surface which is substantially free of abrasive particles and free of sharp edges characteristic of abrading, skiving and metal removing tools, the hardened surface having a hardness at least equal to the hardness of the knife blade, repeatedly placing each face of the knife blade against the planar knife face contacting surface of the at least one precision knife guide, maintaining each face alternately in sustained moving contact with the face contacting surface as each facet is stroked against the hardened surface, and maintaining sustained contact between each facet and the hardened surface on repeated stroking to create a microscopic serration along the edge.  
   
   
       30 . The method of  claim 29  where there is a single knife guide in the conditioning stage, and selectively stroking both faces of the blade against the planar face contacting surface of the single knife guide.  
   
   
       31 . The method of  claim 29  where there is a hardened surface at two opposite locations with one of the knife guides in the conditioning stage at each of the two opposite locations, and stroking one of the blade faces against one of the knife guides and the other of the blade faces against the other of the knife guide.  
   
   
       32 . The method of  claim 29  where the sharpening member is mounted on a motor driven shaft, rotating the sharpening member while the sharpening member contacts the blade edge, and the object being non-motor-driven.  
   
   
       33 . The method of  claim 29  including after the blade edge has been conditioned in the conditioning stage the knife blade is moved to a finishing stage having a rotatable finishing member with an abrasive surface which is finer than the abrasive surface of the sharpening member, and rotating the finishing member while in contact with the edge to buff/strop the edge.  
   
   
       34 . The method of  claim 29  the alternating contact is done by sequentially alternating single strokes in each direction.