Blade

Abstract

A blade 1 comprises a strip 2 having a main body portion 4 and an edge portion 6 . Cutting medium 8 in the form of a grit is secured to the strip 2 by braze material. The grit may be diamond, tungsten carbide, cubic boron nitride, a ceramic material, a ceramic-based material or a cermet material. The edge portion 16 is thinner than the main body portion 14.

1 . A blade comprising a strip having a main body portion and an edge portion, and
 cutting medium secured to the strip along the edge portion,   wherein the cutting medium is a grit secured to the strip by brazing.   
   
   
       2 . A blade according to  claim 1 , wherein the edge portion is thinner than the main body portion. 
   
   
       3 . A blade according to  claim 1 , wherein the edge portion meets the main body portion at a step on at least one face of the strip. 
   
   
       4 . A blade according to  claim 3 , wherein the edge portion meets the main body portion at a step on both faces of the strip. 
   
   
       5 . A blade according to  claim 1 , wherein the cutting medium is secured to the strip only on surfaces of the edge portion. 
   
   
       6 . A blade according to  claim 1 , wherein the edge portion has a surface which meets the main body portion at two locations forming a neck between the edge portion and the main body portion, the edge portion having a convex surface between the locations. 
   
   
       7 . A blade according to  claim 6 , wherein the convex surface is a substantially continuous curved surface. 
   
   
       8 . A blade according to  claim 6 , wherein the cutting medium may comprise particles of a size which is less than the radius of curvature of the convex surface. 
   
   
       9 . A blade according to  claim 1 , wherein the edge portion has an edge face and side flanks extending from the edge face to the main body portion, the face and flanks meeting at edges extending along the strip and spaced from the main body portion. 
   
   
       10 . A blade according to  claim 9 , wherein the edge face is concave. 
   
   
       11 . A blade according to  claim 9 , wherein at least one of the flanks is concave. 
   
   
       12 . A blade according to  claim 9 , wherein both flanks are concave. 
   
   
       13 . A blade according to  claim 9 , wherein at least one of the edge face and the flanks is formed to have irregular concavities. 
   
   
       14 . A blade according to  claim 10 , wherein the, or at least one of the concavities, provides a channel receiving braze material. 
   
   
       15 . A blade according to  claim 14 , wherein the cutting medium comprises particles which are sufficiently large to be received within the or a channel and to project out beyond the channel. 
   
   
       16 . A blade according to  claim 1 , wherein the main body has at least one through aperture formed therein. 
   
   
       17 . A blade according to  claim 16 , wherein there are a plurality of through apertures spaced along the strip. 
   
   
       18 . A blade according to  claim 16 , wherein at least part of the circumference of the or an aperture is tapered in thickness to deflect cut material from the aperture. 
   
   
       19 . A blade according to  claim 1 , wherein the cutting medium is selected from the group of diamond, tungsten carbide, cubic boron nitride, a ceramic material, a ceramic-based material and a cermet. 
   
   
       20 . A blade according to  claim 1 , wherein the blade is a reciprocating blade. 
   
   
       21 . A blade according to  claim 1 , wherein the blade is a linear edge blade. 
   
   
       22 . A blade according to  claim 1 , wherein the blade is for a bandsaw, jigsaw, hacksaw, handsaw, reciprocating saw or holesaw. 
   
   
       23 . A method of making a blade, comprising:
 providing a strip having a main body portion and an edge portion;   providing a cutting medium in the form of a grit;   brazing the cutting medium to the strip along the edge portion.   
   
   
       24 . A method according to  claim 23 , wherein the edge portion is thinner than the main body portion. 
   
   
       25 . A method according to  claim 24 , wherein the braze material is applied to the edge before the cutting medium is introduced. 
   
   
       26 . A method according to  claim 25 , wherein the braze material includes adhesive material for holding the braze material to the edge, and to hold the cutting medium prior to brazing. 
   
   
       27 . A method according to  claim 23 , wherein the strip carrying the braze material and the cutting medium is heated to braze the cutting medium to the strip. 
   
   
       28 . A method according to  claim 23 , wherein the strip is provided with an edge portion. 
   
   
       29 . A method according to  claim 28 , wherein the edge portion is thinner than the main body portion. 
   
   
       30 . A method according to  claim 28 , wherein the strip is formed to provide a step on at least one face of the strip, at which the edge portion meets the main body portion. 
   
   
       31 . A method according to  claim 30 , wherein a step is formed on both faces of the strip. 
   
   
       32 . A method according to  claim 28 , wherein the cutting medium is secured to the strip only on surfaces of the edge portion. 
   
   
       33 . A method according to of  claim 28 , wherein the edge portion is formed to have a surface which meets the main body portion at two locations forming a neck between the edge portion and the main body portion, and to have a convex surface between the locations. 
   
   
       34 . A method according to  claim 33 , wherein the convex surface is a substantially continuous curved surface. 
   
   
       35 . A method according to  claim 34 , wherein the cutting medium is provided as particles of a size which is less than the radius of curvature of the convex surface. 
   
   
       36 . A method according to  claim 28 , wherein the edge portion is formed to have an edge face and side flanks extending from the edge face to the main body portion, the face and flanks meeting at edges extending along the strip and spaced from the main body portion. 
   
   
       37 . A method according to  claim 36 , wherein the edge face is formed to be concave. 
   
   
       38 . A method according to  claim 36 , wherein at least one of the flanks is formed to be concave. 
   
   
       39 . A method according to  claim 36 , wherein both flanks are formed to be concave. 
   
   
       40 . A method according to any of  claims 37 , wherein at least one of the edge face and the flanks is formed to have irregular concavities. 
   
   
       41 . A method according to  claim 37 , wherein braze material is provided within a channel provided by at least one of the concavities. 
   
   
       42 . A method according to  claim 37 , wherein the cutting medium is provided as particles which are sufficiently large to be received within the or a channel and to project out beyond the or a channel. 
   
   
       43 . A method according to  claim 23 , wherein at least one through aperture is formed in the main body. 
   
   
       44 . A method according to  claim 23 , wherein a plurality of through apertures, spaced along the strip, are formed in the main body. 
   
   
       45 . A method according to  claim 43 , wherein at least part of the circumference of the or an aperture is formed with a thickness taper to deflect cut material from the aperture. 
   
   
       46 . A method according to  claim 23 , wherein the cutting medium is selected from the group of diamond, tungsten carbide, cubic boron nitride, a ceramic material, a ceramic-based material and a cermet. 
   
   
       47 . A method according to  claim 23 , wherein the blade is formed as a reciprocating blade. 
   
   
       48 . A method according to  claim 23 , wherein the blade is a linear edge blade. 
   
   
       49 . A method according to  claim 23 , wherein the blade is formed for a bandsaw, jigsaw, hacksaw, handsaw, reciprocating saw or holesaw.