Abstract: Apparatus for the sprueless injection molding of parts from polymers. The apparatus includes an injection mold having a part-forming cavity, and an injection nozzle having a front end cooperating with the mold. A selectively operated closing valve is disposed in the nozzle, the valve having a movable valve member with a valve seat thereon cooperating with a valve seat on the nozzle body. A gate channel or passage is disposed between the valve seat on the body of the nozzle and the inlet opening of the mold cavity. The movable valve member has an elongated forward end portion which is telescoped within the gate passage, the forward end portion sealingly engaging the wall of the gate passage when the valve member is in its forward, closed position, the forward end surface of the elongated forward end portion of the valve member facing the mold cavity lying substantially flush with the wall of the mold when the valve member is in its forward, valve-closed position.

Abstract: An apparatus for nitriding metal materials and ferroalloys under pressure in which a melting furnace is positioned above a pulverizing chamber and connected thereto, with an intake chamber, provided with a pulverizer, disposed in between with a dust-catching cyclone having a suction collector being connected to the upper portion of the pulverizing chamber. An exchange hopper is connected to an outlet formed in the lower portion of the pulverizing chamber and feeds into an inlet end of a pipe furnace which in turn, feeds into an intermediate hopper. An end hopper is positioned beneath the intermediate hopper and connected thereto and feeds into a briquetting installation. Separate pipe conduit systems are connected to the various elements of the apparatus for supplying pressurized nitrogen thereto or for the evacuation thereof.

Abstract: An apparatus for the casting of metals and other materials under pressure in which the molten metal is introduced into a cylinder which is pressurized by a piston through an intervening pneumatic cushion to drive the molten metal into the mold. When the mold is filled with the metal, the piston increases the pressure further so as to maintain the pressure during solidification. Advantageously, the cylinder from which the molten metal is driven, is connected by a further cylinder to a hot chamber in which the melt is prepared, the connection between the two cylinders being at the bottom thereof and the entire assembly being mounted on a tiltable frame.

Abstract: An induction crucible furnace for the smelting of materials comprises a crucible which is surrounded by the induction coils and yoke which are mounted upon an intermediate vessel or shell closed by a cover overlying a mass of insulating material interposed between the crucible and inductor and the shell. The intermediate shell has an outwardly extending support flange by which it is mounted on an outward flange of the outer housing with clearance, the clearance likewise being filled with insulating material through openings formed in the flange of the intermediate shell inwardly of the wall of the housing. The flange of the latter projects beyond the flange of the intermediate member and a cover is connected to the housing flange to hermetically seal the system.

Abstract: A casting apparatus for low-pressure or counterpressure casting of nonferrous metals comprises a casting mold which is fed with the melt by a siphon tube opening upwardly into the mold and communicating with an intermediate crucible for molten metal. The siphon tube has an elbow lying above the level of the molten metal in the intermediate crucible which is connected to a main crucible by a conduit whose inlet into the intermediate crucible can be blocked by a bell. Gas from an inert-gas supply can be applied under pressure to the crucible and the elbow.

Abstract: A lockable gas cap assembly includes an inner hollow shell adapted to be threadedly connected to the filler tube of a vehicle gas tank and an outer shell which coaxially surrounds the inner shell for removably retaining it for normal relative rotation with respect thereto. A two-part, key-operated locking member is likewise releasably secured within the outer sleeve, a front hollow portion of the locking member exhibiting a radial slot that is aligned with an inwardly cusped periphery of an aperture in the inner sleeve when such inner sleeve is likewise retained within the outer sleeve. A rear tumbler portion of the locking member has a forward projection with a recess or flat thereon, the recess being moved into registration with the slot in the hollow body when the key is operated.

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: An improved technique of pulsed-arc welding is described for applying, to a consumable welding electrode, a DC welding current on which is superimposed a cyclic, high-amplitude pulse component. The pulse-generating circuit includes a capacitor chargeable during the existence of the arc, such capacitor having a normally disabled discharge path including a first thyristor. Such thyristor is energized at a rate of 200-1,000 Hz from a trigger generator, which in turn is energized during the existence of the arc. The discharge pulses from the capacitor are coupled to the welding electrode via a pulse transformer whose secondary winding is isolated from the DC source via a blocking diode. The pulse-generating circuit is so designed that the pulses have a duration in the range of 0.5 .times. 10.sup.-.sup.4 to 5 .times. 10.sup.-.sup.4 sec., a front edge steepness greater than 8 .times. 10.sup.6 amps/sec.

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.