Abstract: Disclosed is a hydraulically controlled extruder injection molding unit which includes a measured value pick-up for the position of the piston rod of the working cylinder and/or of the injection piston. A pressure control valve which can be switched on is provided in the line leading to the surge chamber of the working cylinder for the piston. A proportionally controlled pressure valve is provided in the line to the other surge chamber, the value being controlled as a function of dropping control values when switching from subsequent pressure to dynamic pressure until the measured value pick-up emits an output signal. The then existing instantaneous value of the dynamic pressure is then added to the preselected dynamic pressure. Consequently, the dynamic pressure phase takes place under a corrected dynamic pressure.

Abstract: A mold closing unit of an injection molding machine has a hydraulic traveling cylinder and a hydraulic mold closure retention cylinder for the movable mold clamping plate. One-half of a divided injection mold is clamped on the plate and defines with a fixed mold die a mold cavity having a larger volume at the commencement of the mold charge than at the termination of the mold charge. A threaded spindle is engaged with the movable mold clamping plate through a spindle nut, and the spindle is freely rotatable in the stationary mold clamping plate and is connected with a stepping motor. A 4/2-way valve is arranged in the hydraulic supply line leading to the traveling cylinder, and its valve body is axially shiftable on the spindle. The stepping motor is controlled depending on a specified pressure and/or speed pattern as a function of the distance between the mold halves or the mold clamping plates.

Abstract: An injection molding apparatus having movable die operated by a piston and cylinder, includes a hydraulic circuit having a supply line for closing and opening the movable die. A branch line from the supply line leads into a die locking chamber defined between the piston and cylinder, and a first multi-directional control valve is provided for control of the closing mechanism. A second multi-directional valve is located in the branch line for feeding hydraulic fluid into the die locking chamber as sensed by a pressure sensor in the supply line. A threaded spindle meshes with a support for the movable die which feeds back the rate of travel and pressure exerted by the movable die to a stepping motor which varies the spindle rotation in accordance with the rate and the pressure.

Abstract: A mold closing unit of an injection molding machine has a threaded spindle which is engaged with the movable mold clamping plate of the machine via a spindle nut. The spindle is attached to the stationary mold clamping plate of the machine in a freely pivotable manner, and is connected with a stepping motor by means of a coupling. The stepping motor is controlled depending on a specified speed pattern as a function of the distance between the mold halves of the mold clamping plates. The valve body of a 4/2-way valve engages the spindle for relative axial movement and controls the hydraulic operating medium for the mold closing unit. A switch is arranged in the casing of the valve which can be triggered by the coupling and which actuates, for example, an indication system when a mold closure security error occurs.

Abstract: A mold closing unit has a multi-way valve in a hydraulic supply line leading to a hydraulic traveling cylinder which is controlled as a function of a speed pattern specified for the movable mold clamping plate. The valve body of this multi-way valve is arranged on an elongated, threaded rotatable spindle in an axially movable manner. The spindle is connected with a stepping motor which is controlled as a function of the speed pattern. As soon as the movable mold clamping plate has reached a predetermined distance from the stationary mold clamping plate, the stepping motor is switched to a higher number of steps per revolution and the mold is closed below the creep rate.

Abstract: A plastification and injection device for an injection molding machine includes a plunger rod on the pressurized piston coupled to a spindle on which the valve body of a directional control valve is guided axially. The spindle is axially rotatable and is coupled to a stepping motor controlled in accordance with the injection pressure and/or the injection rate. The shaft of a hydromotor driving the plastification and injection screw is guided by means of another directional control valve, the valve body of which is guided so as to slide axially on the shaft. And, this shaft is further coupled to another stepping motor. This, upon completion of the plastification process, the direction of rotation of the hydromotor is reversed in order to close the backflow and, because of the interaction of the other stepping motor and the other directional control valve, the screw moves axially by a predetermined amount to close the backflow.

Abstract: A cut-off process for an injection molding machine for forming two-layer, directly laminated footwear soles and includes a pressure transmission pin which is guided in a passageway constructed as a through-hole between the mold cavity and the outer surface of the mold. The pressure transmission pin is preloaded by a spring in the direction of the mold cavity so that it can be depressed or actuated under injection pressure. When the injection pressure is relieved and the molded piece shrinks, the pressure transmission pin will be moved back by the spring to its initial position, thereby releasing a switch for a new switching operation for the next, second, injecting operation.

Abstract: During the emission-spectroscopical testing of metallic samples by means of unipolar discharges, material is precipitated onto the counterelectrode material which leads to faulty test results. According to the invention, at the start of the pre-spark period half waves of the unipolar discharge are replaced by oscillating discharges, wherein two parallel-connected discharge capacitors and two series-connected discharge resistors, one discharge capacitor and one discharge resistor can be shunted and the shunting is canceled out after a prespecified period of time, starting with the pre-spark period.

Abstract: The determination, through spectrographic analysis, of the C content of iron and steel alloy workpieces via the C 1931.02 line is made using spectrometers having a test head that can be attached to the workpiece. The region of the discharge near the surface of the workpiece is isolated in an argon atmosphere from the light path of the discharge to be imaged onto the grating, so that the two unwanted iron lines, the Fe 1931.4 and the Fe 1930.8 lines, do not occur in the grating spectrum.

Abstract: A breakout warning method and apparatus for a continuous casting installation wherein structure-bound sound, traveling through the area of the ingot mold, is continuously picked up by a sound recorder and checked for the presence of typical frictional noises between the mold and billet. A breakout signal is emitted upon determination that there are no typical frictional noises present.

Abstract: A coal gas supply method converts a carbon carrier in a reactor into a coal gas by the addition of oxygen and feeds the coal gas to fuel consumers. To ensure a continuous fuel supply to the fuel consumers during the coal gasification process, a branch current of the coal gas produced is liquefied and stored. At the same time the oxygen stored in liquid form is drawn from a tank, evaporated and used in the reactor. If there is a breakdown in the coal gasification process, the stored quantity of coal gas is evaporated gradually and fed to the consumers. At the same time, oxygen drawn from an oxygen inlet pipe is liquefied and stored. Instead of coal gas, another fuel gas such as natural gas can also be used.

Abstract: A method of fabricating an insulating joint between a pair of end abutting rail sections of a railroad track includes the suspension of a pair of opposed fishplates at the rail joint at spaced distances outwardly of the rail sides, and simultaneously heating the rail sections and the fishplates to a predetermined temperature for activating a heat-activatable adhesive provided in fabric cuffs which are disposed between the fish surfaces and the fishplates. The fishplates are shifted along guide rods of their support assemblies inwardly toward one another into place against opposed fish surfaces of the rail sections, and are thereafter bolted in place. A device for fabricating the joint includes a box-like hood on which heaters are mounted, or a shear assembly supporting the heaters and being clamped onto the rail head. The heaters may be adjusted to accommodate various rail profiles.

Abstract: An injection mold device for forming an article such as footwear from a plastic material includes a two-part male die such as a boot last, a fabric liner covering the male die, and a split female die surrounding the male die in spaced relation and forming together therewith a mold cavity. Beyond the upper end of the cavity, liner retaining pins on the male die extend outwardly of the peripheral wall thereof for retaining the liner in place during the injection molding operation. One of the pins is mounted for retracting axial movement for disengaging the tip thereof from the liner, and such pin bears against a sloping bearing surface of a first removable male die part which facilitates such retracting movement upon a relative shifting of the parts. The other pins are rigidly mounted in the male die part and project into recesses of the female die having undercuts and grooves extending between the recesses and the mold cavity.

Abstract: A yieldable roof support structure for mine passages and the like includes inner and outer hollow segments attached end-to-end to form a closed or an opened support frame, the segments including separating walls defining chambers associated with the joined together ends so that, upon application of pressure to the chambers, the joined segments are moved apart to facilitate a disassembly of the frame.Alternatively, piston and cylinder units may span the joined ends of the segments for separating them upon the application of external pressure.

Abstract: A transport system for flat metallic materials such as thin, hot-rolled metallic strips in a strip mill includes a roll table and one or more linear drive elements which are positioned between a pair of rollers of the roll table and below the table plane formed thereby to exert a travelling force field on the leading end of the flat metallic material passing thereover which will have a force component directed perpendicularly to the direction of movement of the flat metallic material and thus act to adjust (i.e. center) the positioning of the moving metallic material on the roll table. The linear drive elements may include heat shields and cooling fluid discharge openings.

Abstract: Disclosed is a device comprising a connecting bolt having a gripping profile near one end and a coupling element having a profile adapted to engage the profile of the connecting bolt. The profile of the connecting bolt is a plurality of projecting teeth separated by grooves where the spacing between at least some of the teeth and the depth of at least some of the grooves increases toward the end of the connecting bolt. The profile of the coupling element is a plurality of teeth separated by grooves which generally correspond to the profile of the teeth of the connecting bolt. However, the spacing between at least some of the grooves relative to the teeth on the connecting bolt is slightly greater and becomes increasingly greater from the groove adapted to engage the tooth of the connecting bolt nearest the end of the bolt to the groove adapted to engage the tooth of the connecting bolt furthest from the end of the bolt.

Abstract: A scraper conveyor has a conveyor trough composed of at least two longitudinally adjacent trough sections having respective side walls and juxtaposed terminal faces. A pair of first connecting members is welded to the side walls of one of the sections and recessed longitudinally thereof from the terminal face of the one section. These first connecting members have convex first end faces directed towards the terminal face of the one section, and exposed outer surfaces. A pair of second connecting members is welded to the side walls of the other of the sections and each of these has an end portion projecting beyond the terminal face of the other section. The end portions have second end faces which are each formed with a concave recess in which one of the convex end faces is received, and also exposed outer surfaces.