Glass container forming machine control

Abstract: A cyclical machine for forming at least one glass container each machine cycle comprising a plurality of controllers for controlling regulators and/or profiled motion actuators, at least one displaceable structure, controllers controlling the operation of all the other controllers, each of the controllers including repetitive sequencer and operable in any of a plurality of states, the one controller determines the critical time when each of the states should begin, and instructs each of the other controllers to begin any of the states at the associated determined critical time.

Description: The present invention relates to machines which form glass containers from discrete gobs of molten glass. One such machine is referred to as an I.S. (individual section) machine which has a plurality of identical sections each having a number of mechanisms (takeout, invert, plungers, pusher etc...). The operation of the machine is carried out by operating motion actuators which can be profiled as in the case of servo motors or non-profiled as in the case of a simple pneumatic cylinder and by operating regulators such as valves which distribute high and low pressure air to supply process air, electric devices and analog or digital signals. The operation of these actuators and regulators is controlled by a controller which has a repetitive sequencing device. US-A-4685947 discloses an I.S. machine and a control system therefor. The machine comprises a plurality of mechanisms which are operated by peripherals, that is to say profiled and non profiled regulators and actuators and a plurality of mechanism controllers each controlling at least one of the peripherals. Each of the mechanism controllers includes repetitive sequencing means and a library of machine states or profiles in which the peripherals can be operated. The control system also comprises a section controller which instructs the mechanism controllers to begin operating in a selected machine state at the appropriate time, and a machine controller which supplies mechanism specific timing set up information to the mechanism controllers. Such a control system comprises a hierarchy of controllers and is inherently expensive. It is one of the objects of the present invention to provide a simpler control system for controlling the operation of a machine for forming glass containers. The invention provides a machine for forming glass containers comprising: a plurality of peripherals, which periferals are the operated profiled motion actuators and the regulators of the machine, which regulators are non-profiled actuators such as solenoid valves, and a plurality of controllers, each controlling at least one of said peripherals and each including, a repetitive sequencing means, a library of machine states in which said controlled peripherals can be operated, and means for carrying out an instruction for beginning operation in any one of said plurality of machine states, characterised in that one of said controllers controls the operation of said plurality of controllers and includes means for determining the critical time when each of said machine states should begin, and means for beginning operation in a selected machine state and for instructing each of said other controllers to begin operation in said selected machine state at the determined critical time for said selected machine state. Other objects and advantages of the present invention will become apparent from the following portion of this specification and from the accompanying drawings which illustrate in accordance with the mandate of the patent statutes a presently preferred embodiment incorporating the principles of the invention. Referring to the drawings: Figure 1 is a schematic representation illustrating the control of an individual section of an I.S. machine made in accordance with the teachings of the present invention; Figure 2 is a schematic representation illustrating the controllers shown in Figure 1; Figure 3 is a logic diagram illustrating the operation of the section controller shown in Figure 1; and Figures 4A and 4B show a logic diagram illustrating the operation of a motion controller shown in Figure 1. As shown in Figure 1, an individual section of an I.S. machine has a number of mechanisms, each of which has one or more structures which are displaced by a profiled motion actuator (stepper, electric servo, hydraulic servo, pneumatic servo, etc.) during each cycle of the section. Where the machine (for purposes herein a section will be treated as a machine) is operating in the press and blow configuration, for example, plungers (one or more) will be raised into gobs of molten glass contained within a blank mold to force the gobs to fill the molds and to simultaneously define an initial dimple in the gobs. This may be done with a single motion actuator or with a motion actuator for each plunger. An invert will take the thereby formed parisons from the blank mold to a blow mold where they will be blown into the final containers and a takeout will remove the containers from the blow mold and deposit them on a dead plate. A pusher has advanceable fingers which are supported on a plate which can be rotated through an angle to displace containers from the dead plate to a moving conveyor. Each of these movements can be carried out by a profiled motion actuator which is controlled by a controller. High pressure and low pressure air is utilized in a variety of ways in the section. For example, air is used to cool the molds and to cool the ware over the dead plate. These air lines are controlled by regulators such as valves (non-profiled actuators such as solenoid valves) which may be operated by an associated controller. Such valves can also control non-profiled actuators like pneumatic cylinders. Other regulators can also be controlled. For example, a regulator could be an electric device or analog or digital signals. For convenience, the operated profiled motion actuators and the regulators (a non-profiled actuator such as a solenoid valve, for example) will collectively be referred to as peripherals (auxiliary devices). A plurality of controllers are used with one controller controlling all of these motion controllers. All controllers (Figure 2) have a repetitive sequencer which controls the time in a section cycle in degrees or milliseconds when actions are to occur, a cycle speed algorithm for determining the speed and adjusting the phase of the repetitive sequencer, a library of states in which the controlled mechanisms can be operated (a state, for example, could be, normal stop which would bring all motion actuators to a halt after glass has been removed from the section, normal running, cold molds/cold blanks which would mean that specific motion actuators would operate at different angles than for normal operations (angles that could be forwarded to the controllers by the controller which is in control of all the controllers), or any of the other well known machine states), diagnostics for identifying malfunctions, etc., and a maintenance stop which when initiated by any controller will prevent displacement of all the controlled displaceable structures of the entire section by disengaging the motive force. (Watchdog timer logic can be used to remove power to the outputs). A controller may control the displacement of one or more profiled motion actuators, and may have a library of selectable motion profiles for each profiled motion actuator (or can define such based on provided parameters). As shown in figure 1, the controllers for the invert and takeout control one profiled motion actuator, whereas the controller for the pusher controls two profile motion actuators. The controller may also just control the operation of regulators. The controller in the preferred embodiment which controls all the controllers is the controller that is only controlling regulators. This controller can also determine critical times which are the times when it is best to shift to given states. Not every controller has to operate differently in each state. For example, the pusher can operate the same for normal operation and for cold molds/cold blanks. Accordingly, when this controller advises all the controllers to shift to the cold molds/cold blanks mode the controller for the pusher will know that these two states for the pusher are the same and will continue to operate unchanged. The controllers are synchronized with a sync signal issued by the once/machine cycle pulse generator and distributed on the sync signal line. Before the controllers can operate in a selected state the controller that controls all the controllers will verify that each controller is operational (Figure 3) by first sending a high level signal on a parallel distribution transition signal line (T.S.) to each controller. The controller that is in control of all the controllers inquires via the local area network (LAN) whether this high level signal was sensed by each motion controller. When the controller diagnostics (Figure 4) determine that a high level signal has been sensed it advises the controller in control via the LAN network and the procedure is repeated with a low level signal. The controller in control will then advise each controller to go into a selected state (N) on the rising edge of a transition signal which will be distributed on the transition signal line (T.S.). If a controller is in maintenance stop or for any other reason can not go into that state the diagnostics will advise the controller in control accordingly. If it is possible for the controller to go to state N it will so inform the controller in control which can then, if it has received the same information from all the controllers, raise the transition signal. When the critical time is reached the controller in control raises the transition signal to the controllers and the controller in control and all the other controllers begin operating in that state. The controller diagnostics will also determine when some action in the cycle of operation of that controller has not occurred, etc... For example, referring again to Figure 4, each controller not only can displace its associated structures but it has diagnostics which can determine whether the mechanism has malfunctioned and, if so, whether the malfunction is the type of malfunction requiring an immediate maintenance stop or only requiring that the machine be brought to a normal stop. Where the error does not require either stop it can be signalled to the operator for corrective action. As can be seen from Figure 1, the maintenance stop line (M.S.) is drawn as a bidirectional circuit interconnecting all the controllers. This conveys the fact that a maintenance stop for the entire section can be instituted by any controller. When a controller has determined that the section should come to a normal stop it can communicate via a one-way normal stop line (N.S.) to the controller in control. Basic two-way communication between the controllers is, as has already been discussed, carried out on the local area network (LAN). While a single control controls all the controllers in the preferred embodiment, it would be possible for this responsibility to be shared with other controllers so long as at any given time only one controller is in charge of all the controllers.

Claims: A machine for forming glass containers comprising a plurality of peripherals, which peripherals are the operated profiled motion actuators and the regulators of the machine, which regulators are non-profiled actuators such as solenoid valves, and a plurality of controllers, each controlling at least one of said peripherals and each including, repetitive sequencing means, a library of machine states in which said controlled peripherals can be operated, and means for carrying out an instruction for beginning operation in any one of said plurality of machine states, characterized in that one of said controllers controls the operation of said plurality of controllers and includes means for determining the critical time when each of said machine states should begin, and means for beginning operation in a selected machine state and for instructing each of said other controllers to begin operation in said selected machine state at the determined critical time for said selected machine state. A machine for forming glass containers according to claim 1, further characterized by means for synchronizing said controllers. A machine for forming glass containers according to claim 2, characterized in that each of said controllers further comprises maintenance stop means and means for determining that said maintenance stop means should be operated. A machine for forming glass containers according to claim 1, characterized in that said machine is an I.S. machine having a plurality of sections and wherein each section includes said plurality of peripherals and said plurality of controllers. A machine for forming glass containers according to claim 1, characterized in that said one controller further comprises means for signalling each of said other controllers that said one controller is going to instruct said other controllers to switch from one machine state to another machine state and wherein each of said other controllers further comprises means for signalling said one controller that it cannot shift to said another machine state. A machine for forming glass containers according to claim 1, further characterized by means for determining that each of said other controllers is operational. A machine for forming glass containers according to claim 1, further characterized by means for delivering signals issued from said one controller to each of said other controllers and signals issued from any of said other controllers to said one controller, and wherein said instructing means comprises means for issuing a test signal, and wherein each of said other controllers further comprises means for determining that said test signal has been received, and means for issuing an acknowledgment signal acknowledging receipt of said signal. A machine for forming glass containers according to claim 1, characterized in that at least one of said other controllers further comprises means for determining that the machine should shift from one state to another state and means for instructing said one controller to instruct said other controllers to begin operation in said another state. A machine for forming glass containers according to claim 1, characterized in that at least one of said peripherals is a profiled motion actuator and the controller controlling said profiled motion actuator further includes a plurality of profiles.

Inventors: COLLINS GEORGE J, LISKA TIMOTHY J, MCDEVITT JOHN W, NGUYEN CAN, O'CONNOR KEVIN N, PETERSON GEORGE T, COLLINS, GEORGE J., LISKA, TIMOTHY J., MCDEVITT, JOHN W., NGUYEN, CAN, O'CONNOR, KEVIN N., PETERSON, GEORGE T.
Applicants: EMHART GLASS MACH INVEST, EMHART GLASS MACHINERY INVESTMENTS INC.
Application year: 1993
Main classification: C03B9
IPC codes: C03B9, G05B19