Abstract: A nickel-free corrosion-resistant steel which consists by weight of:Carbon .ltoreq. 0.08%Silicon .ltoreq. 0.9%Chromium = 18.05 to 22%Manganese = 6.0 to 10.5%Nitrogen = 0.40 to 1.10%Sulfur .ltoreq. 0.025%Phosphorus .ltoreq. 0.035%Copper .ltoreq. 3% and the remainder iron.

Abstract: A method of injection molding foamed articles wherein, after the mold is closed and while the mold is held closed, a gas counterpressure is generated within the mold cavity against which a portion of the foamable resin is injected under a pressure which prevents foaming. Thereafter, a shape-forming element adapted to be retracted to be flush with a wall of the mold cavity in the final phase thereof, is advanced to force the nonfoamed material, still against the gas counterpressure, into the remainder of the cavity. After a skin has formed, on the mass within the mold cavity the latter element is retracted to permit foaming, preferably after foaming has been initiated by allowing a portion of the foamable mass to recede into the injection cylinder during the inception of the foaming process.

Abstract: An injection molding machine in which a support on a base carries oppositely facing stationary mold portions which, when joined by movable mold portions, form a pair of mold cavities, one of which can be injected with a moldable material having a long solidification time, while the other contains a previously injected article which is solidifying and can be released as soon as the injection of the first cavity is completed. One of the movable mold portions is connected to a movable plate in a fixed spaced relationship, with a wedge-type locking mechanism between the plate and the other movable mold portion for the locking of both mold cavities simultaneously with a single locking mechanism.

Abstract: An apparatus for casting a molten material in which the mold is received in one chamber and the molten material is received in another chamber, the two chambers being subject to different pressures so that a tube connecting them can deliver the molten material from the second chamber to the first under a pressure differential. Signal-producing apparatus connected to the mold chambers produce signals representing the two pressures and the pressure differential, the signal-producing apparatus being connected to differentiating apparatus whose output produces time derivatives of the pressures and pressure differential. The time derivatives can be used to control the pressures via a comparator to which a reference value or set point signal is applied thereby varying the rate of filling of the mold in accordance with a predetermined program.

Abstract: A system for the die stamping of a fluid comprises a male die member which s forced into a die cavity to compress and spread the fluid material therein. A piston in this die member is advanced after the die member is arrested by a shoulder of the female die member to compress gas ahead of this piston and increase the pressure at selected locations along the face of the male member at which cavities are provided to communicate this gas pressure to the fluid.

Abstract: A method of controlling the rate of filling of a casting mold wherein a pressure P.sub.1 is applied to a chamber containing a crucible holding the molten material to be cast, a pressure P.sub.2 is provided in a chamber containing the mold, the mold is connected with the crucible by a tube conveying the molten material to the mold, and the molten material is displaced through the tube by a pressure differential .DELTA.p equal to P.sub.1 -P.sub.2, which comprises detecting the time derivatives dP.sub.2 /dt and d.DELTA.P/dt of the pressure in the chamber containing the mold and the pressure differential, respectively. The rate of variation of the pressure in the chamber of the mold is monitored to regulate the process while one of the other derivatives is compared with a set point value to control one of the pressures as a function of time to vary the rate of filling of the mold in accordance with a predetermined program.

Abstract: A method of and apparatus for the molding of foamed thermoplastic bodies with integral skins wherein, for each mold operation after the first, a portion of previously foamed material produced by expansion in the mold cavity, is temporarily accumulated behind a body of unfoamed thermoplastic and the foamed and unfoamed material are then forced into the mold cavity and permitted to expand therein.

Abstract: An apparatus for the production of articles with a compact smooth skin and a cellular core from polymer materials, which contain blowing agents, by injection molding or extrusion wherein the apparatus contains an electric heating element within a channel through which the polymeric material is passed.