摘要:
A thermal expansion compensation support (40) and method are used in a hot runner injection mold for maintaining liquid-tight relationships between parts that define a flow passageway. The support includes an annular housing (56) having an recess (64) that receives a spring (68), such as a Belleville washer, and a cover (70) that overlies the recess (64) in the housing (56). The housing (56) and the cover (70) are spring biased from each other to maintain a pressure force on the surfaces that are in contact with the outer faces of the cover (70) and housing (56). The support (40) imparts a holding force on the parts of the machine that define the molding material flow passageway to prevent leakage. The method involves holding the parts together at a first holding force level for an initial portion of a warm-up temperature range and holding the parts together at a second holding force level for the remainder of the temperature range.
摘要:
A flow nozzle (10) that conveys plastic melt from an injection unit of a molding machine to a mold cavity (72) has an improved, removable seal design. The nozzle body (12) is designed to threadedly receive a nozzle tip (24) that includes an outlet (30) that communicates with the mold cavity. A thin-wall, cylindrical seal ring (40) includes a compression portion that is received between the nozzle body and nozzle tip and is compressed to create a seal between these two elements when the tip is assembled to the nozzle body. The seal ring further includes a sealing portion (50) that encircles the nozzle tip and has an outer diameter slightly larger than the outer diameter of the nozzle body.
摘要:
A pressurized-fluid-operated actuator has multiple piston surfaces for providing increased output force. The actuator includes a stationary cylinder that contains a movable cylinder having multiple inner chambers separated by stationary inner pistons. The inner chambers are in fluid communication with extension and retraction ports provided in the stationary cylinder wall. Introduction of pressurized fluid into one port causes the fluid pressure to act on 'n' piston surface(s) to retract the movable cylinder. Introduction of pressurized fluid into the other port causes the fluid pressure to act on 'n + 1' piston surfaces to provide an increased output force without increasing the diameters of the cylinders and without increasing the pressure of the fluid.