Patent ID: 6270084
Filing Date: 2001-08-07
Classification: B23B,Y10T

Abstract:
A pneumatic chuck assembly comprising a chuck body, a plurality of chuck jaws supported on said chuck body for movement between open and closed positions, means for defining a pressure chamber, a piston supported within said pressure chamber for movement in one and an opposite direction within said pressure chamber, chuck jaw actuating means coupled to said piston and to said chuck jaws for moving said chuck jaws between said open and closed positions in response to movement of said piston, spring biasing means for applying mechanical pressure to said piston and normally urging said piston in said one direction to urge said chuck jaws toward and maintain said chuck jaws in said closed position, said chuck jaws in said closed position being operative to exert clamping pressure upon a workpiece to secure the workpiece to said chuck body, and a pneumatic control system including manually adjustable regulating means for introducing opposing air under pressure into said pressure chamber to act upon said piston in opposition to said biasing means to overcome said mechanical pressure applied to said piston by said spring biasing means, incrementally reducing the pressure of the opposing air under pressure until the pressure of the opposing air under pressure reaches zero, changing the direction of flow of air under pressure into said pressure chamber when the pressure of the opposing air reaches zero to cause assisting air under pressure to enter said chamber and act in consort with said spring biasing means, and incrementally increasing the pressure of said assisting air under pressure until the pressure of the assisting air under pressure equals the mechanical pressure applied to said piston by said spring biasing means.