Machining method employing cutting or grinding by conductive grindstone

Claim 2

A machining method of cutting or grinding a work piece by use of a rotating partially conductive disc grindstone and dressing the grindstone, comprising the steps of: (a) providing a disc grindstone for machining formed by a non-conductive grinding disc having a conductive element exposed at portions of the peripheral surface of the non-conductive grinding disc; (b) providing an electrode comprising a disc-like partially conductive grindstone close to the peripheral surface of said disc grindstone for machining and spaced therefrom; and (c) applying a dressing voltage between said electrode and said grindstone for machining while supplying a working liquid directly to a space between said electrode and said grindstone, dressing of said grindstone being accomplished by a process of at least one of electrical discharge and electrolytic melting, simultaneously with machining of said work piece by said grindstone.

Claim 3

A machining method as defined in claim 1 wherein for dressing a smoothed D.C. voltage is applied between said electrode and said grindstone for machining.

Claim 4

A machining method as defined in claim 1 wherein for dressing an intermittent voltage is applied between said electrode and said grindstone for machining.

Claim 5

A machining method as defined in claim 1 wherein for dressing a smoothed D.C. voltage and an intermittent voltage are simultaneously applied between said electrode and said grindstone for machining.

Claim 6

A machining apparatus for cutting or grinding a work piece by use of a partially conductive grindstone and for dressing the grindstone comprising: a rotating partially conductive disc grindstone for machining a work piece formed by a non-conductive grindstone disc having a conductive element exposed at portions of the peripheral surface of the non-conductive grindstone disc, a dressing electrode comprising a disc-like partially conductive grindstone provided close to the peripheral surface of said partially conductive disc grindstone for machining, means for supplying a working liquid to a space between said dressing electrode and said grindstone for machining, and a power source for applying a dressing voltage between said electrode and said machining grindstone such that dressing of said grindstone is accomplished, simultaneously with machining said workpiece by said grindstone, by a process of at least one of electrical discharge and electrolytic melting.

Claim 7

A machining apparatus for cutting or grinding a work piece by use of a partially conductive grindstone and for dressing the grindstone comprising: a rotating partially conductive disc grindstone for machining a work piece formed by a non-conductive grindstone disc having a conductive element exposed at portions of the peripheral surface of the non-conductive grindstone disc, a dressing electrode comprising a disc-like partially conductive grindstone provided close to the peripheral surface of said partially conductive disc grindstone for machining, means for supplying a working liquid to a space between said dressing electrode and said grindstone for machining, and a power source for applying a dressing voltage between said electrode and said machining grindstone such that dressing of said grindstone is accomplished, simultaneously with machining said workpiece by said grindstone, by a process of at least one of electrical discharge and electrolytic melting.

Claim 8

A machining apparatus as defined in claim 5 wherein for dressing a smoothed D.C. voltage is applied between said electrode and said grindstone for machining

Claim 9

A machining apparatus as defined in claim 5 wherein for dressing an intermittent voltage is applied between said electrode and said grindstone for machining.

Claim 10

A machining apparatus as defined in claim 5 wherein for dressing a smoothed D.C. voltage and an intermittent voltage are applied between said electrode and said grindstone for machining.