Abstract: A metalworking fluid central system through which aqueous cutting fluid recirculates through a plurality of machine tools is provided with an in-line fluid condition monitor which produces real-time fluid composition data for use in controlling the condition of the fluid. Four sensors simultaneously measure temperature, pH, dissolved oxygen and conductivity at hourly intervals and the data is stored in a computer module linked to the monitor. A plurality of diversely located plants are similarly equipped. A computer at a remotely located central monitoring facility selectively connects to the computer modules at the various plants through modems and a telephone system to collect the data daily. The data is analyzed at the central facility and dimensions are made manually and automatically to add components to the fluid at the respective plants or to take other corrective action.

Abstract: To maintain tension on a fiber tow as it travels between a spool of the tow and a fiber placement head in a computer controlled fiber placement machine, closed tension loop servo control tow velocity feed forward is provided to control spool rotation so as to not only provide closed loop tension control but to also cause rotation in anticipation of expected tow movement such as due to tow payout upon commanded movements of the fiber placement head. Gain scheduling based on spool radius is also provided. Additionally, a compliant roller is provided to reduce tension dips and spikes from disturbances on the tow, and an inner velocity loop is included with the closed tension loop to provide more effective control of tow tension. The servo control is reconfigurable into an open or pseudo-closed loop mode with a safety low power supply to slowly reel-up slack tow after tow threading, for example, and to otherwise maintain low tension on the tow to hold it in the machine while allowing servicing thereof.

Abstract: A method and apparatus are disclosed for reducing the cross-coupled movement in a member of a CNC machine caused by movement in another member of the machine through the structural dynamics of the machine. The method includes receiving the discrete position commands for a member oriented in one axis of movement for the machine, transforming the discrete position commands to attenuate frequency components that contribute to the movement coupled through the structural dynamics of the machine, and generating velocity commands from the transformed discrete position commands to control the servos that drive the members. The discrete position command transform is preferably a second order filter that implements the transfer functions of a digital notch filter and digital low pass filter. The second order filter that transforms the discrete position commands is implemented in a digital computer by state variable difference equations.

Abstract: A proximity switch mounting plate is rotatable about a center point and releasably-clamped to a mounting surface of a device. The cylindrical proximity switch is attached to the mounting plate at a location spaced outwardly from the center point, and the detection end of the switch extends to a moving member within the device. Rotation of the mounting plate around its center point adjusts the radial position of the detection end of the switch.

Abstract: A method and apparatus are provided for servo control of injection molding machine devices. A signal processor periodically produces analogue control signals for controlling machine mechanisms at a first loop closure interval and periodically produces digital control signals for controlling energization of machine heaters at a second loop closure interval. Values of analogue and digital control signals are determined according to control algorithms relating set point values and measured parameter values. Calculation of values of analogue control signals includes calculation of a first command value according to a first control algorithm, calculation of a second command value according to a second control algorithm and selection of the lesser of the first and second command values. Compensation for "cold" thermocouple junctions created at the connection of remote temperature sensing thermocouple leads and the signal processor interface circuits is provided.

Abstract: An extrusion blow molding machine including an extruder and an extrusion die head, the extruder and extrusion die head carried on a carriage member. The carriage member is movable linearly along an extruder support frame of generally rectangular configuration, the extruder support frame extending laterally outwardly beyond a supporting mold clamp support frame that is adapted to support a movable blow mold. The carriage is shiftable in a horizontal direction so that the extrusion head can be selectively positioned above the blow mold when in an operating position, and can be shifted laterally outwardly in one direction to be positioned beyond the mold clamp support frame when in an inoperative position, to provide convenient access to the extrusion head from below for purposes of maintenance, cleaning, and the like.

Abstract: A high gain and high torsional stiffness servo axis drive system for machine tools is described as providing improved stability. This system includes a servo motor mounted on a base and connected to a C-Axis spindle drive arrangement via a toothed drive belt. A first by-damper is attached to the spindle drive pulley and tuned for damping torsional oscillations of the servo output shaft, belt, and spindle when the system is not fitted with a workpiece. An independent second damper is attached to the driving pulley of the servo motor and tuned for damping torsional oscillations of the entire servo drive system when the system is loaded with a workpiece. The resulting servo axis drive system features improved stiffness and can be adapted to a variety of predetermined loading conditions by convenient retuning of the second damper. At least the second damper is provided as a combination of a damper mass ring attached to the servo motor pulley by a plurality of viscoelastic damping elements.

Abstract: Extruder barrel temperature control apparatus in the form of a plurality of axially spaced tubular shells positioned in end-to-end relationship on the outer surface of a tubular extruder barrel. Each of the shells includes individual resistance heater elements embedded in the shell wall for providing heat to maintain a desired shell temperature. Each shell includes two groups of outwardly extending cooling fins, each group axially spaced from the other, and each group of fins has an associated air blower positioned below the fins and supported by an outer casing surrounding the extruder barrel. The outer casing includes an internal shroud to confine the cooling air flow so it is directed over and along the cooling fins. The heating elements and the blower motors are connected with a suitable control system for providing and maintaining a desired temperature level at the barrel inner surface. Six such shells defining six respective heating and cooling zones are disclosed.

Abstract: An injection molding machine clamping system in which a stepped bar is provided between the movable and stationary platens, and blocking apparatus is carried by one of the platens to block movement of the stepped bar upon the happening of certain conditions. The stepped bar is slidably carried in a bushing in the other mold platen, the bushing preferably being made from an ultra-high molecular weight polyethylene material to reduce wear, to eliminate the need for lubricants, and also to reduce the intermittent clicking noise that results when the notched bar is moved axially through a bore.

Abstract: A quill feed and spindle drive assembly has a bore formed along a longitudinal axis of a housing. A nut, rotatably mounted to the housing, carries a threaded quill which reciprocates along the axis through the housing. An elongate rotatable spindle passes through the bore and carries a tool at an outer end. The threaded quill is preferably a hollow screw, within which the spindle is mounted, and the quill and spindle are coextensive and linearly moved in unison along the axis. The quill provides both radial and axial thrust support, and forms a longitudinal guideway for the tool.

Abstract: A clamping system for traversing and clamping molds in a molding machine, the clamping system including a toggle-type clamp arrangement defined by a plurality of pivotally connected links. A movable crosshead is connected with one end of the toggle and is carried on a crosshead guide, and a ball screw is rotatably secured to the movable crosshead to extend in the direction opposite from the molds and through a stationary platen. A ball nut rotatably carried by the stationary platen is in engagement with the ball screw and is drivingly connected with a first motor to axially move the ball screw to provide between the molds a clamping force sufficient to resist separation of the molds during high pressure injection of molding material. A second motor is drivingly coupled with the ball screw and is movable therewith in an axial direction. The second motor is adapted to rotate the ball screw for rapid traverse movement of the movable crosshead to rapidly bring the molds into and out of contact.

Abstract: An apparatus and method for controlling brushless DC motors are provided. Velocity loop control is performed digitally to produce current commands at a high frequency loop closure interval. Commutation of field coil current is controlled in response to current commutation pattern control signals produced in response to measured relative position of the motor rotor and motor stator and a velocity average over a number of loop closure intervals. Switch control signals to control transistor switches providing current from a DC power source to the motor terminals are produced in response to the current commands, measured motor current and the commutation pattern control signals. The velocity loop control implements a selected transfer function relating velocity, the motor torque constant, and the moment of inertia of the motor and associated load. Facilities are provided for periodically adjusting velocity loop transfer function gain factors and the effective moment of inertia in response to input signals.

Abstract: Extrusion of a tubular parison for blow molding is controlled according to a program of set point data defining parison wall thicknesses and extrusion rates. Progress of purge of plasticized material from an accumulator through a variable annular gap is measured. Parison profile set point signals defining wall section thickness at points correlated with progress of purge of the accumulator are produced in response to the measured progress. Purge velocity set point signals defining purge velocities correlated to selected profile points are produced in response to progress of purge of the accumulator. Variation of the annular gap is controlled in response to the parison profile set point signals and velocity of purge of the accumulator is controlled in response to the purge velocity set point signals.

Abstract: A cover assembly for a machine tool having a base supporting a workhead and a second machine part such as a spindle housing, headstock or tool turret, and wherein a rotatable workpiece changing mechanism is provided in conjunction with the workhead. The cover assembly includes an external housing member which encloses the workhead and the second machine part and permits movement of the second machine part therewithin. The external housing member further includes a workpiece exchange opening and a workpiece exchange shield which is reciprocable between a first position which effectively closes the opening, and a second position which allows unencumbered rotation of the workpiece changing mechanism. The shield is reciprocable in parallel with the workpiece changing mechanism to obviate added machine idle time. An internal housing substantially encloses the second machine part within the external housing, and is mounted for movement with the second machine part.

Abstract: An alignment system and method wherein a machine module is aligned with and secured to a machine base. A plate is loosely held on the module by screws, and the base and plate have mating pin holes. A pin is inserted through the mating pin holes, and the plate moves to find its aligned position. The screws are then tightened to fix the plate on the module, and the pin is removed. Subsequent realignment can be easily accomplished by reinsertion of the alignment pin to insure registration between the preset plate and base pin holes.

Abstract: A close clamp cycle for an injection molding machine in which a toggle locking motion is executed using a plurality of velocities to permit faster clamp operation while maintaining control of the clamp to bring it quietly to its final position without damage to the machine.

Abstract: An extruder screw mixing head that is adapted to be carried by an extruder screw at a downstream portion of the screw for improved distributive mixing. The mixing head includes a central body that tapers and diverges in a downstream direction to provide a progressively diminishing flow channel in an axial direction of the mixing head. Four equally spaced flights of equal pitch are provided on the outer periphery of the mixing head, and each flight has a series of peripheral recesses that are spaced from each other along the flights and that permit flow of plasticated material between adjacent flow channels defined by the spaced flights to improve homogeneity of the material. The recesses are so configured that their respective leading and trailing edges are aligned to define circumferential angles with the longitudinal axis of the mixing head, so that the inter-channel flow areas of the recesses increase in a direction toward the outlet of the extruder barrel.

Abstract: A method for making vitreous bonded grinding wheels having a porosity of from 20 to 55% by volume is provided that reduces or prevent shrinkage. The method includes a step of mixing unclad, non-abrasive, non-metallic, particulate, inorganic solid shrinkage control agent with the abrasive grain, vitreous matrix precursor and other ingredients for producing the wheel. Non-abrasive hexagonal boron nitride is a preferred shrinkage control agent and may be used in amounts ranging for 1 to 10% by volume based on the volume of the grinding wheel. Reduced shrinkage of wheels made by the method over comparable wheels made without the shrinkage control agent is obtained.

Abstract: A radiant heating control system for a computerized tape laying machine is described in which the radiant heater is controlled so as to reliably heat thermoplastic composite tape to a processing temperature above the melting point of the thermoplastic matrix irrespective of velocity or change in velocity of the tape as it travels from a spool of tape to a tape application point for application to a layup tool or the like.

Abstract: An articulated axis workslide assembly having a bridge plate with an upper surface and first and second bridge keyways. The bridge keyways are oriented precisely parallel to one another and a first longitudinal axis, and first and second bridge keys are slidably mounted in respective bridge keyways for reciprocation parallel to the first axis. There is a combination swivel/slide member having a lower surface, a slide keyway and a pivot hole, and a slide key is slidably mounted in the slide keyway. The swivel/slide is slidably and pivotally connected and supported with its lower surface facing the upper surface of the bridge member along a single interface plane. Such connection is preferably provided in part through pivotal connection of the slide key to the first bridge key, and through the slide pivot hole to the second bridge key.