Abstract: The invention relates to an apparatus for adjusting the length of dough strands, comprising a receiving gutter, V-shaped in cross-section, whose walls are defined by elements which engage a dough strand placed in the gutter at regularly spaced apart locations along the length of the dough strand and can exert axial forces thereon. According to the invention, the elements which define the walls of the receiving gutter and engage the dough strands are formed by rolling members arranged with interspaces and adapted to be driven progressively and selectively from the middle (X--X) of the gutter in either direction, and support members which convey the strands transversely of the gutter are arranged between the rolling members. The mutual arrangement of the gutter and of the support members is variable, at least as to the relative level.

Abstract: The hydraulic system comprises a 4/4-way valve, which is adapted to control the velocity of the mold-closing operation and the fluid pressure during said mold-closing movement and to assume three consecutive control positions, in each of which fluid pressure is applied to a stationary piston of an advance-retract cylinder from a first cylinder chamber, which is nearer to the mold. One of said control positions is a differential control position, in which pressure fluid displaced from the second cylinder chamber of said advance-retract cylinder, which second chamber is remote from the mold, is supplied to a pressure conduit through a branch passage, which includes a non-return valve. The differential control position is preceded and succeeded by a transitional control position, in which the pressure fluid displaced from the second cylinder chamber is returned through the 4/4-way valve to a reservoir.

Abstract: A decorative emblem is formed having a front surface and an opposite back surface. A mold is placed against the back surface. Cavities in the mold are sized and shaped to conform to a desired shape of a locator lug. Flowable plastic is injected into the cavity and sets against the back surface of the emblem.

Abstract: A method is described in which the operative condition of the cooling sections of a slot die for making flat films of thermoplastic material, or of an annular die of a blow molding extruder for making tubular films from synthetic thermoplastics, is tested. The cooling sections are provided with lines for supplying and discharging cooling air and the lines for supplying cooling air are connected, as required, to a central cooling air feed line, which is under superatmospheric pressure, by solenoid valves controlled by an electronic computer. In one embodiment of the invention, a testing program is performed in which the cooling air feed line is disconnected by a shut-off valve from the branch lines leading to respective solenoid valves when the latter are closed.

Abstract: An improved sterolithography system for generating a three-dimensional object from object defining information, the information defining the object being structurally specified to reduce curl, stress and distortion in the ultimately formed object is described. A stereolithographic distortion known as curl is reduced by the system, and several techniques to eliminate or reduce curl are utilized by the system, including dashed line, bent line, secondary structure, rivets, and multi-pass techniques.

Abstract: A device is provided for precision tipping catheters with repeatable accuracy. The device includes a die, a thermal heater for the die, a clamping pad for holding an untipped catheter in an aligned position, a lead screw for moving the catheter into and out of the die a precise distance, and a forced air cooler for cooling the tipped catheter. Preferably, the lead screw is rotated by a stepping motor.

Abstract: A single continuous dough sheet is conveyed by a conveyor up an incline to a dough tension and drive system. In the system, the dough sheet passes around a lower drive roller, around an intermediate drive roller, and around an upper drive roller. The dough sheet extends at a downward angle to an idler roller which directs the dough sheet generally vertically downward in a flat condition. A wishbone pushing element having a rounded V-shape forms the first face of the dough sheet into a generally V-shape having two wings. The wings of the V-shape are then guided by an aligning element such as laterally spaced rollers which roll on the opposite face of the wings to form a folded, two-ply continuous dough sheet.

Abstract: A continuous vacuum processing apparatus has a vacuum processing chamber and at least one auxiliary vacuum chamber connected to at least one of the upstream and downstream ends of the vacuum processing chamber as viewed in the direction of flow of a material to be processed. The apparatus further has a slit-type seal device provided in the auxiliary vacuum chamber and capable of conveying the material to be processed while sealing the vacuum processing chamber from exterior of the vacuum processing chamber. The seal device is provided with a guide member for guiding the material. Independent tensioning devices are provided in the vacuum processing chamber and the auxiliary vacuum chamber and capable of independently applying tensions to the portions of the material in the vacuum processing chamber and auxiliary vacuum chamber, so that a material which is not resistant to heat can be processed without being damaged.

Abstract: In a double-belt press for the manufacture of wood chip boards and the like having a width less than the nominal working width of the double-belt press, the forming belts are held in contact with the support structure so as to ensure heat transfer in the edge portion of the pressing zone extending beyond the edge of the filling which produces the boards to the region near the edge of the pressing zone. In this edge portion, an edge filling composed of unbonded particles is compressed on a compressible rotating belt.

Abstract: The invention relates to apparatus for controlling equipment for treating rubber and or plastic strand-form products produced by an extruder and/or calender, such equipment having at least one conveyor. The apparatus has a feeler roll carried by at least one arm on a rotatable shaft and engageable with the strand-form product at the end of a conveyor or between two conveyors of the treating equipment. On one end of the shaft there is a cam disc the position of which is sensed by an inductive pick-up to produce a signal indicative of the angular position of the shaft. The shaft is rotatable to vary the position of the feeler roll, by a pneumatic servo motor actuating a rack meshing with a gear wheel fixed on the shaft. The servo motor is controlled by a control circuit which receives the position indicating signal.

Abstract: A transfer and molding apparatus for transferring an image or pattern from an elongate transfer film to a molded article. The transferring and molding apparatus includes a film feed-out mechanism for feeding the transfer film wound around a supply drum and introducing the transfer film between a stationary mold member and a movable mold member and a film take-up mechanism for taking up the transfer film positioned between the stationary mold member and the movable mold member onto a take-up drum. A longitudinal direction feeding device has a controlling motor for feeding the transfer film in a longitudinal direction thereof from the film feed-out mechanism toward the film take-up mechanism by a predetermined length during each molding cycle, and a longitudinal direction sensor for detects a position setting mark on the transfer film.

Abstract: An apparatus and a proces for the manufacture, by the extrusion method, of roof covering plates having at their underside a transverse flange shaped thereto. At a filling station cavities in the pallets corresponding to the transverse flange, are first filled with a hardenable plastic material such as fresh concrete, and said material is then compacted at at least one compacting station. Thereafter, a continuous layer of the material is deposited at a depositing station. The material is finally processed to roof covering plates.

Abstract: A molding apparatus transfers plural molds in succession through a temperature elevating step, an injection molding step, pressurized cooling step and a molded article removing step. The apparatus is provided with plural cooling presses for the pressurized cooling step and so constructed as to prevent the stagnation in the transfer of the molds according to the molding conditions and the number of molds.

Abstract: In a process for mass producing optical storage sheets, an elongate film of a liquid crystalline material is fed lengthwise along a path through an aligning gate. The aligning gate applies to successive areas of the film a field which aligns the molecules. The field may be an electric field and/or a shear field. An aligning layer, such as a surfactant layer may also be used for alignment of the film areas. The aligned film may then be cut into pieces for use as microfiches or microfilms. The film material is preferably a liquid crystal polymer material.

Abstract: A rotary pelleting machine comprises a housing, a drive shaft, a matrix disc connected with the drive shaft and guiding upper plungers and lower plungers, a unit for controlling position of the plungers during rotation of the matrix disc. The unit includes a cam ring provided for controlling the upper plungers. The cam ring is supported rotatably relative to the housing and the drive shaft. Also a unit for measuring a torque of the cam disc is provided.

Abstract: A plastics molding machine is provided with a control architecture which includes a dedicated programmed logic controller, a real time analog signal processor, an operator interface station, and a general purpose open architecture digital computer. The computer accepts data entered by an operator from a keyboard on the operator station panel, displays information to the operator, performs analysis of process monitoring and control data, and generates commands to the controller. The controller simultaneously controls the real time digital and analog functions of the machine. The analog functions are controlled in response to analog signals from the controller by performing real time closed loop servo control of analog and other machine functions.

Abstract: An apparatus and a method for forming a three-dimensional article with photosetting or thermosetting material on the basis of a three-dimensional information on the article by means of an ink jet method. The material is jetted from at least one ink jet head to a stage and laminated thereon. The laminated material is exposed to light by a light source to be cured. In this process, a jetting direction of the material from the ink jet head to the stage and/or a jetting amount of the material jetted from the ink jet head is changed in accordance with the information by a control unit, thereby forming a solid article having a desired three-dimensional shape.

Abstract: A device for continuously measuring and correcting a tackiness of a sheet of rubber material including a feeding unit for continuously feeding an unvulcanized rubber sheet along a flat support surface and a rotatable roller in contact with the unvulcanized rubber sheet, whereby the roller is rotated by the movement of the unvulcanized rubber sheet, and entrained in the sheet feed direction due to a tackiness of the unvulcanized rubber sheet. A load cell is connected to the roller via a linkage, for measuring a resistance to the rolling of the roller, i.e., a change of a position of the roller entrained in the sheet feed direction.

Abstract: A loading elevator for a multi-platen press is provided with a pusher which simultaneously transfers a number of transport plates loaded with stampings to the press. After press operations are completed, the plates are unloaded by an extractor to an unloading elevator. The pushing and the unloading of the plates are automatic, with sensors provided to halt the loading and unloading in the event of excessive resistance to the movement of any one of the plates. A plurality of sensors are provided in the pusher and in the extractor, one sensor there for each of the plates. Each sensor is connected to halt the operation on recognition by the sensor that an express resistance exists and if desired to provide a signal that the halting has taken place.

Abstract: Method and apparatus for automatically controlling the operation of a rotary extruder, including using a pressure transducer (38, 40, 42) communicating with the annular space (50) between the barrel (12) and rotor (14) to monitor the hydraulic pressure of the melted polymer, using a microprocessor-based controller (62) to compare the measured pressure with a predetermined set point, and thereafter selectively controlling the speed of a feed drive motor (56) or melt drive motor (60) to maintain the melt pressure within a desired range while holding the extruder rotor speed constant.

Abstract: The present invention is an improvement upon a known apparatus for polymerization of a body from dental plastic material by irradiation of the body with radiation of a selected wave length in the range between about 350 nm and about 550 nm. To achieve a desired degree of polymerziation of the dental plastic, a specific amount of radiation must be applied to the body. In order to achieve reproducible irradiation results in spite of fluctuations in supply voltage, alterations in lamp characteristics, burn out of one or more lamps, shifting of spectral outputs, replacement of defective or superannuated lamps, soiling of lamps and reflector surfaces and/or changes of operating temperatures in the irradiation area, a supplemental detection system in provided.

Abstract: An optimum molding condition setting system for an injection molding machine comprises a molten material flow analysis component for analyzing resin flow, resin cooling and the structure/stength of molded products by using a designed mold model and also comprises an analysis result evaluation component for determining an initial molding condition and its permissible range in accordance with the analysis results. The initial molding condition is set into the injection molding machine and a test shot is carried out in order to check for a deficiency of a molded product. If a deficiency of the molded product is detected, a data of the deficiency is entered into a molding defect elimination component. After performing a convenient data processing based on the entered data, a cause of the molding defect can be inferred and a measure for the cause can be obtained with high efficiency and accuracy.

Abstract: An apparatus for manufacturing a multielement sintered material is provided, more particularly an appartus of the automated type which weighs and mixes predetermined amounts of powdery elements, molds the mixed elements and then sinters them.

Abstract: An injection control method for an electrically-operated injection molding machine is provided, which is capable of sharply increasing the injection speed of a low-priced electric injection molding machine. A command pulse train is supplied to a servo circuit for an injection servomotor whereby substantial rotary motion of the injection servomotor is initially prevented, as a result of the fact that the torque limit value (Ts) is set at a value sufficient to establish equilibrium between the output torque of the injection servomotor and the resin pressure acting on the injection screw. The error between the target rotational position of the injection servomotor and an actual rotational position thereof then is allowed to increase until it reaches a feed stop positional error (Fs).

Abstract: A method and apparatus for manufacturing fiber preforms includes a relatively small motor which is able to power a large fan because the fan is kept in a partial vacuum condition. A duct connects a fan housing to a vacuum box which has an air flow opening therein of relatively narrow width. A shuttle member is horizontally translatable above the vacuum box on a support bed and the shuttle member is divided into air flow channels by baffle plates. Only a small number of air flow channels can pass above the air flow opening at a single time and this serves to keep low pressure in the vacuum box. In addition, a vortex gate is provided in the duct between the fan housing and the vacuum box and serves to restrict air flow through the duct when the pressure within the duct drops below a certain level.

Abstract: A method for positioning an operating unit of an electrically-operated injection molding machine at a predetermined operating position in an optimum manner, by using widths of positive-side and negative-side regions of an allowable positioning zone which are set independently of one another in accordance with the operating direction of the operating unit and the function to be achieved by the operating unit. Positioning of a screw at an injection-end position is completed when the actual screw position (PA) is equal to or less than the sum of a target injection-end position (PS) and the positive-side region width (W1), which is set to "0", and is equal to or larger than the value obtained by substracting the negative-side region width (W2) from the target position (PS), so that the screw is positioned at the target injection-end position or a screw-moving position which slightly exceeds the target position by a permissible distance, to thereby actually control an amount of shot.

Abstract: An apparatus for forming a zoned distribution of particulate material within a fibrous web includes a conveying mechanism for providing a gas entrained supply of the particulate material and a segregating mechanism for centrifugally directing at least a portion of the particulate material into an accumulation region of the apparatus. A transferring mechanism selectively directs particulate material from the accumulation region into a delivery gas stream to provide an intermittent flow volume of a selected quantity of particulate material from the accumulation region through a delivery conduit and into a web forming chamber. A fiberizing mechanism provides a flow of a selected fibrous material into the web forming chamber, and a directing mechanism controls the intermittent flow of particulate material from the delivery conduit into the forming chamber.

Abstract: A method and an apparatus for controlling the back pressure of a motor-driven injection molding machine, capable of achieving an optimum plasticized state of a molten resin by continuously and smoothly varying a screw receding speed during metering.

Abstract: The quality that is good or bad of an injection molded product is judged. The temperature T of a metal mold, of a resin in the mold cavity, barrel or nozzle of an injection molding machine is measured at a time t elapsed after comencement of a pressure holding step of the injection molding machine. The present P of resin in the mold cavity or barrel or nozzle is measured at the time t, and a time function A=f(t) is calculated using the temperature T and the pressure P, where A represents a calculating parameter T/P, P/T, T.times.P, T+P or T.+-.P. This is compared with a reference time function Ao=f(t) of a shot in which satisfactory products can be obtained, with a time function An=f(t) of another shot.

Abstract: A method and device for directing and controlling the operation of an injection molding machine having sensors which provide actual values during machine operation, the machine having actuators forming and executing control orders received from the sensors. The sensors and actuators are serially connected via a closed loop control cable such that all information is available in successive words. The sensors and/or actuators deliver their information jointly and in dependence on the status of the program. The actuators jointly execute their control orders in corresponding numbers. The actuators and sensors are coupled through interface couplers to the closed loop or stub cable.

Abstract: Described herein is an interlock system for an isostatic press machine of the type including a high pressure container having upper and lower closure plugs releasably received in upper and lower openings to be used for loading and unloading work therethrough, and a holder frame for supporting the axial force of the container in an isostatic pressing phase of the press operation, the holder frame being pivotally supported at one side thereof for swinging movements about a vertical axis into and out of a holding position in engagement with the high pressure container, wherein the interlock system is provided with a lock mechanism constantly urged to lock the holder frame in the holding position, and a control means adapted to control the lock mechanism to maintain the lock on the holder frame when the internal pressure of the high pressure container is higher than a predetermined level and to release the lock when lower than the predetermined level.

Abstract: A carrier for the injecting unit of the injecting machine is adapted to be transferred to different operating positions for forming moldings having sprues in different arrangements. The frame is adapted to be driven by a control device, which has a screw drive and a displacement-measuring device and is adapted to be fixed in its operating positions. The control device has detachably been inserted into retaining openings of the injection molding machine by an axial installing movement in a direction which is transverse to the injection axis. As a result, the injection molding machine can be delivered by the manufacturer in different versions, inclusive of a more expensive version in which the transfer movement of the injecting unit to the various operating positions can be program-controlled, and a less expensive version, which does not permit of a program-control of the transfer movement. The machine can be converted from one version to the other with a minimum of work.

Abstract: In an apparatus for the reaction injection molding of a shaped article from a polymerizable flowable resin-forming composition, once such composition has attained a predetermined increased level of viscosity as measured in situ within the mold cavity, an amount of pressure is applied to the polymerizing composition which is sufficient to maintain any entrapped gas(es) dissolved therein and/or to prevent the composition from pulling away from mold cavity surfaces.

Abstract: An extrusion head for processing rubber or thermoplastic plastics material including a housing flange-mountable on a screw extrusion device. The head further including an inlet region for receiving material from the extrusion device and for receiving the downstream end of the screw, the inlet leading into a flow channel portion and a nozzle outlet which receives the material from the flow channel for extrusion in the form of a shaped profile. A sealable air discharge device is disposed in the flow channel portion to remove air bubbles, particularly that which is formed during the start up phase of the extrusion downstream of the downstream end of the screw.

Abstract: A mold clamping system for molding articles by injecting a flowable material into a mold cavity defined by a pair of movable mold sections. The machine includes an hydraulically operated mold clamping system, and a separate hydraulic fluid reservoir for the hydraulic cylinder that provides the clamping force for holding together the mold sections during high pressure injection of molding material into the mold. The separate reservoir along with a lower, main reservoir permits a reduction of the overall height of the molding machine. The clamping system reservoir includes a level sensor, and a comparator is provided to compare the actual fluid level within the clamping system reservoir with the expected level based upon the position of the clamping ram, as sensed by a position transducer, to control the operation of an overflow valve when the actual fluid level is greater than the expected level.

Abstract: Device which serves to atomize a solid or liquid medium with the aid of a standing ultrasonic wave that is generated between two ultrasonic transmitters. This allows one to tune the standing ultrasonic wave automatically when the temperature of the medium or other process parameters should change.

Abstract: A pellet mill comprises a perforated annular pellet die having an axis of rotation and first and second ends; and a die carrier rotatable about an axis of rotation and having an annular recess for receiving the first end of the annular pellet die. Fixing devices are secured to the first end of the die and cooperating fixing devices are provided in the annular recess in the die carrier. The fixing devices and the cooperating fixing devices have a first position relative to one another permitting insertion of the first end into the annular recess by relative axial movement of the die and die carrier and a second relative position permitting the transmission of force between the fixing devices and the cooperating fixing devices to draw the die towards the die carrier into a clamped position. Various different devices are provided for generating the force. In addition centering devices are provided which are effective on drawing of the die towards the die carrier to center the die relative to the die carrier.

Abstract: An injection molding machine includes a main structure formed of a pedestal including a top cover, a mold clamping unit supported on the pedestal; and an injecting unit supported on the pedestal. The injection molding machine further includes a control cabinet situated in the rear zone of the main structure; an input unit situated in an operator's control zone of the main structure. The input unit includes a data display device and an input keyboard. A cable connects the input unit with the control cabinet. To a bracket arrangement on the pedestal there is pivotally mounted a swivel arm swingable in a horizontal plane about a vertical axis. The input unit is secured to the swivel arm at a top side thereof such that the data display device is approximately at eye-level height. The input unit has, dependent upon pivotal positions of the swivel arm, a working position situated externally of the area occupied by the main structure and a position of rest within such area.

Abstract: A process for filling the edge joints of insulating glass by introducing a sealing compound into the edge joint from at least one filling nozzle moved along the edge joint. The depth of the edge joint is detected, and the velocity at which the filling nozzle is moved along the edge joint is slowed down in case of a deeper edge joint and increased in case of a less deep edge joint. The amount of sealing compound conveyed through the filling nozzle per unit time is detected, and the velocity with which the filling nozzle is moved along the edge joint is reduced in case of a reduced delivery output and increased in case of an increased delivery output.

Abstract: Apparatus for applying marking to the outside surface of an outer jacket of a cable assembly including a cable having flat cable sections and sections where the conductors are not held. The apparatus includes a supply station for providing a length of the cable, a take up station for taking up the completed cable assembly, and a driver for moving the cable toward the take up station. The apparatus also includes a flat cable section detector adjacent the supply station for marking a flat cable section with an implant, and an extruder positioned downstream of the flat cable section detector for providing the outer jacket about the cable and the implant. The apparatus further includes an implant detector disposed downstream of the extruder for detecting the passage of the implant, and a printer located between the implant detector and the take up station and which is responsive to the implant detector for marking the location of a flat cable section on the outside surface of the outer jacket.

Abstract: An apparatus for the extraction of melt samples, particularly from continuously operating plastics processing plants, has a test sample mould which is connected to a melt channel via a transfer channel. There are provided a shutoff device and a device for transferring the melt into the mould. In the transfer channel there is arranged a suction piston which sucks the melt out of the melt channel into the transfer channel which in this case is opened simultaneously. In addition, there is provided a pressure piston for injecting this melt into the moulding chamber. An apparatus of particularly simple construction is created in this way and permits extraction of melt samples without the melt coming into contact with the atmosphere, no dead spaces at all being created at the same time in the melt channel during the time when no melt samples are extracted.

Abstract: A system for distributing wax or a similar substance in semi-solid form is provided which includes a liquid wax supply system, a wax conditioning system including a heat exchanger which cools the wax to a semi-solid state and an accumulator for storing conditioned wax until needed, and a die press or similar work station which receives semi-solid wax from the accumulator in a continuous stream or flow. Such a system allows a lost wax die press to operate without need to manually open and reload the press with wax. An automated control system according to the invention allows die press reloading to occur automatically when needed, and operates the wax conditioning system as needed to maintain a supply of wax in the accumulator. Wax tunneling problems are avoided by means of a piston disposed in the heat exchanger which is movably interposed between hot liquid wax entering the heat exchanger and cooler, semi-solid wax leaving the heat exchanger.

Abstract: A device to detect the loss of a continuous spun web of plexifilament fibers exiting a forwarding apparatus depends on the manner in which the filaments oscillate in a cross machine direction prior to depositing onto a collecting surface. The loss of these fibers, due to hang up in the filament forwarding device, can cause multiple position spinning machine loss due to the knock down of nearby spinning positions or wrap the sheet on forwarding rolls. The hang up in the forwarding device is referred to as a blow-up. This invention detects the instant a blow-up occurs through the loss of electrostatic charge due to the absence of the oscillating swath at the sensor. When the instant charge is lost at the sensor, a signal indicates a blow-up has occurred.

Abstract: A separator manufacturing apparatus includes a transfer roller (2) with a plurality of annular shaping grooves (1) having a predetermined shape in cross section which are formed in the outer circumferential surface of the transfer roller in its circumferential direction, a resin feeding device (4) with nozzles (3) feed a hot-melt type resin to the annular shaping grooves (1) of the transfer roller (2), a base paper feeding device (5) to feed a continuous paper (W) at a predetermined speed to the outer circumferential surface of the transfer roller (2) supplied with the resin to thereby form by transfer a plurality of ribs (9) on a surface of the continuous paper (W), and a fault detecting device (6, 36, 46) to detect the shape and /or a dimension of the rib (9) formed by transfer. A resin drop receiving device (53) or an annular shaping groove cleaning device (63) may be provided so that maintenance of the transfer roller (2) can be easy.

Abstract: An automated casting apparatus for use in slip casting is described. A rotatable table assembly is provided for retention of a plurality of plaster molds therein. The table assembly is provided with a clamp member to secure the molds in their relative positions within the table assembly to prevent slippage during rotation. The clamp is controlled by a rotational motor and will apply a predetermined amount of pressure on each of the molds by use of a load detector which will shut down the motor once the predetermined pressure has been attained. Once the molds are securely positioned within the table assembly, the assembly is rotated 90.degree. to its "fill" position where the automatic filler can sequentially fill each of the molds with liquid slurry or slip to a predetermined level whereupon the filled molds are allowed to sit in position for a predetermined setup time which establishes the wall thickness of the castings. The table assembly is then rotated 180.degree.; pouring the excess slip from the molds.

Abstract: Sheet of polyvinyl butyral is extruded, it is subjected to a humidifying and relaxation treatment by maintaining it stretched between rollers, the sheet of polyvinylbutyral is passed through a cold zone, in particular around cooling drums, so as to fix it, the sheet is rolled under a given tension, and prior to fixing the sheet in the cold zone, the sheet is allowed to form at least one free loop.

Abstract: A fishing line, or just a leader, has a core (11) which is coated by plastic material as it is pulled through an extruder (3) and then a quench bath (4) by a variable speed drive device (9). Very fine control can be exerted by laser devices (11, 12) before and after coating, and adjusting a selection of parameters such as drive speed, extrusion rate, pressure and temperature, and cooling. A double coating may be applied or additives mixed in the extruded plastics which will give a desired floating or sinking characteristic.

Abstract: A nozzle touch apparatus in an injection molding machine is provided, which is capable of preventing deformation of a stationary mold half due to a nozzle touch force applied thereto, and of making it possible to use a mold of a type liable to be deformed for production of precise molding products. Springs interposed between a seat plate of the nozzle touch apparatus and a projecting wall of an extruder base generate the nozzle touch force which varies in magnitude as a function of a compressed amount of the springs. Upon a mold lockup state being released, a ball screw is rotatively driven, so that the seat plate, which is integral with a ball nut engaged with the ball screw, retreats from its moved position at the mold lockup state, to reduce the nozzle touch force and prevent deformation of the mold.

Abstract: In a vent type injection molding machine having a screw contained in a heating cylinder, there are provided a plurality axially spaced apart vent openings located at intermediate points of the heating cylinder for venting inside of the heating cylinder to the outside and control means for selectively opening and closing the vent openings in accordance with the position of the screw in the heating cylinder or the pressure of a thermoplastic resin injected by the injection molding machine.

Abstract: A process for casting lenses using male and female mold halves, which includes placing a polymerizable liquid into the female mold, introducing the male mold down into the female mold until the male mold touches the surface of the liquid and then allowing the male mold to fall into the female mold. Also, an apparatus suitable for carrying out the casting process is provided which includes a horizontal support for the female mold, a holder for releasably holding the male mold, a mechanism for moving the holder down towards and into the female mold and a mechanism for detecting contact between the male mold and the surface of the liquid and causing the holder to then release the male mold. The molds are maintained under a predetermined closing pressure during curing by spot welding their flanges together while under that pressure.