Abstract: An indexing system for the rotary work changer of a machining center for supporting and interchanging work-holder pallets between the machining zone and the load/unload zone of the machining center.

Abstract: A lightweight structure for the base of a co-ordinate measuring machine is formed of a triangulated space frame arrangement using carbon fibre reinforced plastics bars (30) having a near zero coefficient of thermal expansion. The frame arrangement may be covered by a skin extending across one or more faces of the frame members to form a closed structure.

Abstract: A servomotor-driven U-axis tool member rotation device for a boring and facing head is affixed to a machine by a bracket, and has a torque coupling slidable on the servomotor shaft. A cover is mounted to a pivot shaft on the bracket, and is rotated by the servomotor to selectively cover and uncover the torque coupling. The cover pivot shaft has a driven gear, and the torque coupling has a driving gear. When a U-axis head is disengaged from the torque coupling and machine spindle, the gears are held in mesh by a biasing spring applied to the torque coupling, and the cover may be rotated. When a U-axis head engages the torque coupling, the biasing spring is overcome and the gears are forced out of mesh; at this time, the servomotor may rotate the input tool member of the U-axis head to position its tool, while the cover remains stationary in the open position.

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 damping means 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 visoelastic damping elements.

Abstract: To maintain alignment of a band of fiber tows as it travels between a source of such tows and a fiber placement head in a computer controlled fiber placement machine, a pair of redirect rollers are provided, at least one of which is automatically and drivingly swivelled by an amount related to commanded movement of the fiber placement head relative the source of tows so as to maintain alignment of the fiber band between the source and the fiber placement head such that a vector normal the fiber band and across the width thereof is parallel the longitudinal axis of rotation of the redirect roller as the fiber band passes thereover.

Abstract: A control for an injection molding machine is provided including: a processor module producing set point signals in response to detection of coincidence of, selectably, analogue input signals, binary status signals, and elapsed time signals; and, a signal processing module for periodically producing control signals in response to the set point signals, measured parameter signals and control algorithms relating set point values and measured parameter values. A DC output interface module is provided including a plurality of DC output interface circuits for applying binary control signals to machine devices. The DC output interface circuits include self-latching over-current protection including means for sensing a latched condition thereof to produce an over-current fault indicating signal available to the processor module. The processor module includes an expansion bus for connection of the signal processing module and the DC output interface module.

Abstract: A method and apparatus for machine member motion control are provided which reduce position path errors in sampled data motion control systems. Position commands defining locations of a moveable machine member are periodically produced at a predetermined interval as is conventional in sampled data motion control. Intermediate position commands are produced at a predetermined sub-interval less than the predetermined interval in response to a parametric function relating member position and time, the parametric function being continuous through positions defined by the position commands. The intermediate position coordinates are computed as the sum of products of coefficients and coordinates of selected member position commands. To reduce processing time, the coefficients are computed and stored in advance of execution of motion for recall as motion progresses.

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 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: 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.