Patent GB-1048934-A (GB)
Title: Improvements in or relating to diamond trueing, dressing and forming tools for grinding wheels and to a method of producing such wheels by electrolytic deposition
Inventor: CANTRELL JOHN
IPC: C25D1/00
Filed: 1962-04-12
Abstract: <FORM:1048934/C4-C5/1> <FORM:1048934/C4-C5/2> A diamond trueing, dressing, or forming tool is formed by providing a bed of diamond particles in contact with an accurate former, electrolytically tacking a single layer of diamond particles directly on to the former by depositing a layer of soft metal so as to cover partially the diamond particle layer, bonding and completely covering the layer of diamond particles by a second electro-deposited layer, and removing at least the former and the soft metal tacking layer.  Typically in producing a trueing tool for a thread grinding wheel an aluminium former 10, which is of the form required for the thread grinding wheel, is connected as cathode in a bath 15 of copper sulphate in a sleeve 12 embracing the former which is supported on a porous ceramic tile 11, and its central opening is filled with diamond grit 14 into which an anode rod 13 is centrally introduced.  When a thin deposit 18, e.g. 2 mils. thick, of copper, has been formed, the former with its adhering single layer of particles is then electroplated with nickel, e.g. to a thickness of 1/8 inch, and a steel centre piece 20 is then located in the central opening and the annular space between the nickel and the steel centre is filled with a metal powder-loaded epoxy resin cement.  When this has hardened, the bore of the steel centre is enlarged to the required size concentrically with the periphery of the former, and the former is removed by machining and dissolving in caustic soda, whereafter a dilute hydrochloric acid treatment removes the copper layer, and some of the nickel if desired, to reveal the diamond particles 17. By an analogous method starting from a former having a size and shape to which a grinding tool is to be trued, a trueing tool for a flute grinding wheel may be produced (Fig. 8, not shown). Instead of aluminium, the formers may be of other alkali soluble metals, a metal of low melting point, or a metallized plastic material.ALSO:<PICT:1048934/C6-C7/1> <PICT:1048934/C6-C7/2> A diamond trueing, dressing or forming tool is formed by providing a bed of diamond particles in contact with an accurate former, electrolytically tacking a single layer of diamond particles directly on to the former by depositing a layer of soft metal so as to cover partially the diamond particle layer, bonding and completely covering the layer of diamond particles by a second electrodeposited layer, and removing at least the former and the soft metal tacking layer.  Typically in producing a trueing tool for a thread grinding wheel an aluminium former 10, which is of the form required for the thread grinding wheel, is connected as cathode in a bath 15 of copper sulphate in a sleeve 12 embracing the former which is supported on a porous ceramic tile 11, and its central opening is filled with diamond grit 14 into which an anode rod 13 is cetrally introduced. When a thin deposit 18, e.g. 2 mils thick, of copper has been formed, the former with its adhering single layer of particles is then electro plated with nickel, e.g. to a thickness of 1/8 inch, and a steel centre piece 20 is then located in the central opening and the annular space between the nickel and steel centre is filled with a metal powder-loaded epoxy resin cement.  When this has hardened, the bore of the steel centre is enlarged to the required size concentrically with the periphery of the former, and the former is removed by machining and dissolving in caustic soda, whereafter a dilute hydrochloric acid treatment removes the copper layer, and some of the nickel if desired, to reveal the diamond particles 17.  By an analogous method starting from a former having a size and shape to which a grinding tool is to be tried, a trueing tool for a flute grinding wheel may be produced (Fig. 8 not shown).  Instead of aluminium, the formers may be of other alkali soluble metals, a metal of low melting point or a metallized plastic material.