Power press

摘要

This invention relates to a hydraulic force modulator used in a power press to provide a predetermined force with a defined force applied by a ram of the press at defined incremental positions of the ram relative to a stationary part of the press. A moveable plate moves relative to a base plate. A resilient pneumatic bellows has one end sealingly mounted on the moveable plate. The resilient pneumatic bellows has an opposite end sealingly mounted on the base plate. A vessel is connected on one of the plates. A metering cylinder is mounted on the same plate as the vessel and is positioned within the vessel. A piston assembly is mounted in the metering cylinder. A piston rod has one end connected to the piston assembly and the opposite end connected to the other of the plates. The metering cylinder has a plurality of orifices regulate the flow of hydraulic fluid from the metering cylinder into the vessel as the piston assembly moves from a starting position and thereby regulates the force on the piston rod in response to the position of the moveable plate relative to the base plate and thereby co-acts with the defined force applied by the ram.