Self-lubricating die cylinder

摘要

A press cushion assembly includes a variable volume chamber which is expanded during operation of the press to an open condition and is contracted during operation of the press to a closed condition. During expansion of the variable volume chamber, a flow of lubricating liquid is conducted to the variable volume chamber from a reservoir. At the same time, a flow of gas is also conducted from the reservoir to the variable volume chamber. Upon closing of the press and contraction of the variable volume chamber, a flow of lubricating fluid and gas is conducted from the variable volume chamber back to the reservoir. The cushion assembly may include a manifold plate in which a plurality of piston and cylinder assemblies are mounted. A reservoir disposed in the manifold plate is connected in fluid communication with the piston and cylinder assemblies by a plurality of passages. Check valves may be provided in the passages so that the lubricating fluid can flow in only one direction.