GB1045018A - Vacuum chucking - Google Patents

Abstract

1,045,018. Vacuum work-holders. DUNHAM TOOL CO. Inc. March 18, 1964, No. 11500/64. Heading B3D. A vacuum work-holder comprises a housing 11 having vacuum channel means 15, and a flat porous block 20 having its bottom surface supported by the housing and in direct communication with the channel means, the top surface of the block being exposed to the ambient atmosphere. A sheet 38 of non-porous film material may be placed over the top surface and a workpiece W thereon to increase the effect of the vacuum. The housing 11 is supported on walls 12 and has its top surface formed with a groove 13 containing an 0-type sealing ring 26 and a network 14 of interconnected canals 15 forming the vacuum channel means. The canals are separated by bars 16 which form the upper surface of the housing and support the porous block 20 which may be of stainless steel. The block is retained on the upper surface of the housing by a frame 21 which also compresses the 0-ring 26. In operation, a workpiece W is placed on the block 20 and both are covered by the non-porous film material 38, such as vinylidene chloride, which is retained in position by a frame 39. Suction is applied to the channel means 15 and block 20 by a vacuum pump connected at 30 to the network 14, the suction being controlled by an adjustable release valve 35 and indicated on a gauge 33 and acting to pull the workpiece and film against the block. When the top surface of the workpiece is to be machined, an initial cut is made to remove the film covering the top surface of the workpiece, the remaining film then being drawn by the suction more closely to the block to resist any tendency of the workpiece to slide.