Abstract: A method and apparatus for absolute position measurement for numerically controlled machines is provided. The invention produces a unique measurement signal for all locations within the range of a movable machine member using two measuring devices. Each measuring device produces a unique measurement signal within a portion of the range of motion that cyclically repeats over the entire range of motion. The measuring devices are so arranged that the measurement signal of one completes no more than one more cycle over the range of motion than the measurement signal of the other. The difference between the two measurement signals is unique for all locations and is used to produce an absolute position signal.

Abstract: An apparatus and method are provided for controlling the motion of a point associated with a function element carried by a machine. The motion describes an oscillatory pattern in a selectable plane through a path between two positions defined by input signals. The oscillatory motion pattern defines cyclic excursions about the path. Motion is effected by iteratively interpolating intermediate positions along the path, computing incremental excursion amplitudes associated with the intermediate position displacements, calculating coordinates of the intermediate position excursions and producing machine actuator control signals to move the machine members to advance the point from its position along the pattern to an intermediate position.

Abstract: A machine operation monitor is provided for detecting malfunctions during execution of a machine cycle of operation irrespective of the activity being performed. Load levels of machine member driving means are periodically sampled and compared against limits computed by the monitor. The limit calculation uses net force or torque measured by storing load level samples during two preparatory executions of the machine cycle of operation. During the first execution a finished workpiece is produced using good tools. During the second execution no workpiece is present. The differences between load level samples taken during these two executions represent the net force required to perform work on the workpiece. The monitor responds to synchronization signals to maintain correspondence between load level samples taken in successive executions of the machine cycle. The monitor also responds to monitor off signals to suspend monitor operation during periods of no activity in the machine cycle.

Abstract: An articulated manipulator and control are provided for producing controlled motion of a function element carried by the manipulator. The motion is defined by input signals specifying with respect to a rectangular coordinate system the positions and path velocities therebetween of a tool centerpoint associated with the function element. The control interpolates intermediate points along a predetermined path between any two positions. The intermediate points are produced in accordance with a fixed period interval and incremental velocity values instantaneously variable with each interval. Continuous functions of acceleration and deceleration are produced to vary the velocity in accordance with the programmed description of motion. Further velocity adjustment is permitted in accordance with unprogrammed variations of a preselected parameter.

Abstract: A releasable tool mount is provided for protecting tools carried by a manipulator from damage by excessive forces acting upon the tools irrespective of the direction of the force. The tool mount comprises a tool mounting plate, a housing for receiving the plate, support pins peripherally disposed upon the plate, receptacle placed within the housing for receiving the support pins and preload devices for exerting forces along the long axis of the support pins to maintain their engagement with the receptacle. Relative forces between the housing and the plate, sufficient to overcome the preload force, effect dislodgment of the pins from their associated receptacles. Fluidic sensing means are provided for detecting dislodgement of any pin from its receptacle.

Abstract: An apparatus and method for controlling the operation of a system are provided. The overall system operation is described by a plurality of mechanism cycles of operation each defined by a sequence of instructions relating sensed conditions of input devices, selectable conditions of output devices and variable values. Instruction signals representing the instructions of the sequences are stored together with mechanism cycle status signals each representing the executability of the associated mechanism cycle. Only instructions associated with cycles for which the status signal represent an executable condition are executed. Instructions for cycles for which the status signals represent a nonexecutable condition are modifiable during execution of the other instruction sequence. The instruction signals include variable name signals associated with unique interface circuits connected to the input and output devices.

Abstract: A grinding machine control is provided having a compensation circuit for providing correction signals to modify the point at which a wheelhead infeed cycle is terminated. The correction signals represent varying infeed offset values produced in response to the number of completed infeed cycles following a grinding wheel sharpening operation. The correction signals are derived from a plurality of empirically determined functions relating the number of completed infeed cycles for a particular combination of workpiece and tooling design to deviations of workpiece diameter from a desired dimension.

Abstract: An article carrier is provided for blow molding equipment which permits relatively simple exchange of the article gripping chuck portion of the carrier. The carrier includes a carrier body, a spindle rotatably supported by the body, an article gripping chuck removeably attached to the spindle and seals between the chuck and the spindle and between the chuck and a preform retained thereby. The chuck is provided with article gripping levers preferably rotatably supported by ball and socket joints. The levers have preform grasping projections at one end and first and second ball ends at the other end. The first ball end mates with the chuck body socket and the second ball end is engaged by a lever actuating ring slidably mounted on the outside of the chuck body.

Abstract: A manipulator and control are provided for moving a function element carried by the manipulator in accordance with programmed input signals defining positions and path velocities therebetween of a tool centerpoint associated with the function element. The path velocity is made susceptible of variation in accordance with unprogrammed variations of a parameter manually or automatically produced. Motion of the tool centerpoint is effected by interpolation of intermediate point along a predetermined path between any two preprogrammed positions. Each intermediate point is displaced from its predecessor by an increment computed in accordance with a fixed increment interval period and an instantaneously variable increment velocity. Incremental velocity values are computed selectively in accordance with a simple function relating the variable parameter and velocity and in accordance with the preprogrammed definition of motion.

Abstract: A machine for high rate production of molecularly oriented thermoplastic bottles is disclosed. The machine is of the reheat-and-blow type. A blow molding station simultaneously blow molds article preforms arranged in matrices by modular article carriers for conveying the preforms and articles through the machine. The carriers are designed to retain the preforms throughout all operations of the machine from a preform load station through a thermal conditioning section, a blow molding station, and to a bottle eject station, thereby eliminating the need for other preform transferring apparatus. The article carriers together with the associated conveying apparatus comprise a sufficiently flexible structure that minor misalignments of the carriers with the blow molding mechanism do not adversely affect bottle production. Both loading of preforms and ejection of finished bottles are accomplished by operation upon matrices of preforms and bottles as defined by the carriers and conveyor lanes.

Abstract: A machine for high rate production of molecularly oriented thermoplastic bottles is disclosed. The machine is of the reheat-and-blow type. A blow molding station simultaneously blow molds article preforms arranged in matrices by modular article carriers for conveying the preforms and articles through the machine. The carriers are designed to retain the performs throughout all operations of the machine from a preform load station through a thermal conditioning section, a blow molding station, and to a bottle eject station, thereby eliminating the need for other preform transferring apparatus. The article carriers together with the associated conveying apparatus comprise a sufficiently flexible structure that minor misalignments of the carriers with the blow molding mechanism do not adversely affect bottle production. Both loading of preforms and ejection of finished bottles are accomplished by operation upon matrices of preforms and bottles as defined by the carriers and conveyor lanes.

Abstract: Apparatus for adjusting the position of a robot arm in response to coordinate data supplied by an external user process control. During the execution of a programmed cycle of operation, a robot control causes the robot arm to move to a predetermined programmed position. In response to a programmed adjust function code, the robot control requests change-of-position information from the user process control. Depending on the actual position of the robot arm, the user process control may transmit a set of adjusted coordinate data to the robot control defining an adjusted position. The robot control moves the robot arm to the adjusted position and proceeds with the programmed cycle of operation.

Abstract: Apparatus for moving a robot arm through a series of nonprogrammed points defining a nonprogrammed path in response to coordinate data supplied by an external device. During the automatic execution of a programmed cycle of operation, a robot control causes the robot arm to move to a predetermined programmed position; and in response to a programmed external path control code, an external path control generator serially provides position data defining the nonprogrammed points. The robot control moves the robot arm through the nonprogrammed points, after which the programmed cycle of operation is continued.

Abstract: Apparatus for controlled dielectric heating a plurality of thermoplastic preforms for blow molding is provided. The apparatus controls the energization of a plurality of electrode pairs by a radio frequency generator. The generator is equipped with a load current limit detector and the electrode energization is enabled selectively for a predetermined time or until a predetermined load current magnitude is reached. The choice of control is determined by the anticipated load as reflected by the number of preforms within the heating station. The generator is further provided with overload detecting means indicative of the occurrence of electrical arcing within the heating station and the apparatus has further means responsive to the arc detector for selectively momentarily or indefinitely deenergizing the electrodes.

Abstract: A dielectric heating section for a blow molding machine is provided. Within the heating section a plurality of heating stations are defined by electrode pairs. At least one electrode of each pair is made recontourable to achieve the desired temperature profile within the wall section of a thermoplastic preform suspended therebetween. The preforms are rotated while supported within the alternating electric field created between the electrodes when the electrodes are energized by a radio frequency signal generator. The preforms are moved from station-to-station to achieve high rate controlled heating of each preform.

Abstract: An apparatus is disclosed for modifying the motion of a tool centerpoint associated with the function element of a robot arm. The motion to be modified is produced during an automatic mode of operation in which the tool centerpoint travels along predetermined paths between programmed points at a programmed velocity. The apparatus is effective to modify the motion during the automatic mode in response to sensed deviations from the predetermined path. Two alternative schemes of modifying the motion are disclosed. A first alternative scheme returns the tool centerpoint to the predetermined path before it reaches the programmed point defining the end of the path. A second alternative scheme produces a new end point offset from the programmed end point and effects motion along offset paths which are translated and rotated from the predetermined paths defined by the programmed points.

Abstract: A machine for high rate production of molecularly oriented thermoplastic bottles is disclosed. The machine is of the reheat-and-blow type. A blow molding station simultaneously blow molds article preforms arranged in matrices by modular article carriers for conveying the preforms and articles through the machine. The carriers are designed to retain the preforms throughout all operations of the machine from a preform load station through a thermal conditioning section, a blow molding station, and to a bottle eject station, thereby eliminating the need for other preform transferring apparatus. The article carriers together with the associated conveying apparatus comprise a sufficiently flexible structure that minor misalignments of the carriers with the blow molding mechanism do not adversely affect bottle production. Both loading of preforms and ejection of finished bottles are accomplished by operation upon matrices of preforms and bottles as defined by the carriers and conveyor lanes.