Patent attributes
A vacuum hold-down device comprising a base member (1) and a separate workpiece support (8) which co-operate to define a vacuum chamber. The device further comprises a venturi (15) having an inlet port (7) for connection to a source of pressurized fluid, an outlet (9) for fluid from the venturi, and a fluid connection (19, 5) from a low pressure region of the venturi (15) to the inside of the vacuum chamber, for providing a partial vacuum therein. The partial vacuum will hold the base member (1) and the workpiece support (8) together to maintain a peripheral seal therebetween. The workpiece support (8) is provided with securing means (16) for securing a workpiece (10) thereon. The invention also provides a vacuum hold-down system comprising the base member (1) and a plurality of interchangeable workpiece supports (8).