Abstract: A hydraulic cylinder is provided which allows for a mount plate, or the like, to be moved between three positions. The mount plate can be positively positioned in any one of three different positions by appropriately supplying or removing pressurized hydraulic fluid to hydraulic fluid ports on the cylinder. The provision of appropriate positive stops corresponding to each desired position avoids the necessity for complex and/or expensive hydraulic control mechanisms. The cylinder is believed to be particularly suited for performing piercing operations, involving a negative pierce, in hydro-forming operations.

Abstract: A piercing device for hydro-formed members comprises a punch having a cutting surface and a guide bore, a support member having a guide post complementary in shape to the guide bore and drive passages, and a drive member having two arms forming U-shaped members. The arms of the drive member extend through the drive passages of the support member to transfer a force between a ram and the punch.

Abstract: A hydraulic cylinder is provided which allows for a mount plate, or the like, to be moved between three positions. The mount plate can be positively positioned in any one of three different positions by appropriately supplying or removing pressurized hydraulic fluid to hydraulic fluid ports on the cylinder. The provision of appropriate positive stops corresponding to each desired position avoids the necessity for complex and/or expensive hydraulic control mechanisms. The cylinder is believed to be particularly suited for performing piercing operations, involving a negative pierce, in hydro-forming operations.

Abstract: A piercing device and method is provided which can be used to form apertures in formed members. In particular, it is believed that the present invention is particularly suited for forming apertures in hydro-formed members. The piercing device of the present invention advantageously occupies relatively little volume, allowing multiple piercing devices to be located within relatively small volumes about a hydro-forming die, or the like. The device and method can be used to perform complete pierces, wherein the slug is removed from the formed member, or to perform partial pierces, wherein the slug is maintained captive in place until removed by a subsequent manufacturing operation. The present invention also provides for a negative pierce to be achieved, during the hydro-forming process, prior to the pierce operation being performed. This negative pierce results in a reduction in the force required to perform the pierce operation and thus permits the use of a smaller hydraulic ram, or the like.