Patent ID: 8066553
Filing Date: 2011-11-29
Classification: B24B

Abstract:
1. A hydrostatic pad for use in holding a workpiece during grinding of the workpiece by grinding wheels, the hydrostatic pad comprising: a body for holding the workpiece during grinding, the body having a working surface area and a horizontal axis; an opening formed in the body for receiving a first grinding wheel therethrough into engagement with the workpiece, the opening having a peripheral edge defined by the body; at least one pocket formed in the body and being adapted for receiving fluid through the body into the pocket for providing a barrier between the body and the workpiece and for applying pressure to the workpiece during grinding, a total pocket surface area of all pockets in the body being less than said working surface area of the body such that a ratio of the pocket surface area to the working surface area is less than about 0.26; and a free region recessed in the body between the peripheral edge of said opening and the radially opposed one pocket, the pad applying substantially no clamping pressure to the workpiece at the edge of the one pocket, said edge being spaced apart from the peripheral edge of the opening in the body such that the free region is therebetween.