GB1603754A - Concerning a cyclically operating container forming machine - Google Patents

Abstract

The control device serves to increase the efficiency of a machine, which is subdivided into individual sections, for producing objects from glass. Each section has a shaping device (14). Each shaping device is assigned a section computer (13) which produces control signals for the shaping device (14) every working cycle of the machine as a function of a control program stored in a storage device (16) and of time switching values. The relative position of each working step within the working cycle is defined by a switch-on time and a switch-off time. These switching time values are stored in the section computer (13). The difference between the switch-on time value and switch-off time value is the dwell time available for carrying out the respective work step. This dwell time can be changed with the aid of a control console (21) by manual displacement of one or of both switching time values. The section computer (13) is programmed in such a way that it automatically prevents a change in the dwell time if a negative dwell time which is in practice not possible were to be produced by this change. <IMAGE>

Description

(54) IMPROVEMENTS CONCERNING A CYCLICALLY OPERATING CONTAINER FORMING MACHINE (71) We, OWENS-ILLINOIS, INC., a Corporation organized under the laws of the State of Ohio, of Toledo, State of Ohio, United States of America, (Assignee of ERIC ROBERT ZABOR), do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates generally to machines operating on regular cycles including a series of predetermined steps, and particularly individual section glassware forming machines.

The individual section or IS glassware forming machine is well known and includes a plurality of sections each having means for forming glassware articles in a timed, predetermined sequence of steps. Typically, the sections are fed from a single source of molten glass which forms gobs of the molten glass which gobs are distributed to the individual sections in an ordered sequence. The sections are operated in synchronism at a relative Dhase difference such that one section is receiving a gob while another section is delivering a finished glassware article to a conpeyor and one or more other sections are performing various ones of the intermediate forming steps.

The forming means in each section are typically operated from pneumatic motors or actuators. In early prior art machines, the pneumatic motors were controlled by a valve block which in turn was controlled by a timing drum for each section driven from a line shaft which synchronized all parts of the machine. One of the limitations of the timing drum was the difficulty of adjusting the timing during the operation of the machine. One solution to this problem was to replace all the timing drums with an electronic control means. The electronic control means included a master unit which was responsive to a clock pulse generator and a reset pulse generator driven by the line shaft. The master unit generated reset signals to an individual control circuit for each of the individual sections to synchronize the operation of the individual circuits.Each individual circuit included a pulse counter responsive to the clock pulse and the master unit generated reset pulse for counting the degrees of the section cycle. Each individual circuit included forty-eight, three decade thumb-wheel switches for setting the degrees of rotation of the machine thereon.

Thus, each particular function of the glass ware forming cycle was controlled by one of the thumb-wheel switches. Such a control system is disclosed in U.S. Patent No.

3,762,907.

The previously described electronic control system utilized discrete components in its counter and gating circuitry. In a later prior art control apparatus, a digital computer with a memory and associated program storage was utilized. Not only did such a control circuit provide a means for automatically changing the timing values of the functions without the manual resetting of thumb-wheel switches, but such a circuit also provided a means for programming events, groups of related func tions, in accordance with certain boundary event timings. The computer generated con trol signals through an interface circuit to actuate solenoid controlled valve blocks. Such a control system is disclosed in U.S. Patent No. 3,905,793.

According to the present invention there is provided a cyclically operated container forming machine comprising means for forming containers in a cyclic series of predetermined forming steps in response to a plurality of on and off control signals issued by a control means of the machine, the control means comprising means which store a control program defining the series of predetermined forming steps and which store on and off timing values defining a dwell time during which a container forming means is actuated in use; means which generate on or off control signals for each of said on and off timing values respectively in accordance with the control program; means controllable by a human operator, which generate a signal representing a desired change, as determined by the operator, in a selected one of said on and off timing values, wherein the control signal generating means is responsive to said desired change signal to effect the desired change in said selected timing value if a dwell time reversal (as hereinbelow defined) would not occur as a result of the desired change and to prevent the desired change if a dwell time reversal would occur as a result of the desired change.

The machine may be a glass forming machine and particularly an IS machine. In this case, each individual section of the machine constitutes a said container forming means and said store means stores a control program defining the series of predetennined steps for each section, and on and off timing values defining the dwell time during which each section is to be actuated in use.

In a preferred embodiment of the invention employing a plurality of individual container forming sections, the control means has a machine supervisory computer connected to a plurality of individual section computers, one for each of the individual sections of the machine. The machine supervisory computer loads the individual section computers with the control programmes and timing data for forming a particular container. Each individual section computer then generates the control signals required to actuate the various forming mechanisms of the associated section to perform forming functions. A section operator.

console is provided at each section to enable the machine operator to change the on and off timing values for any of the forming functions. The section operator console is connected to the individual section computer which reads the timing change value and replaces the corresponding previous timing data with the new data.

A dwell value is associated with each machine function and indicates that portion of a machine cycle between the on and off timing values during which the particular machine function is performed. For the purpose of this specification, a dwell reversal is defined as being that condition when either the on value is moved past the off value or the off value is moved past the on value for a particular machine function. A dwell reversal of a machine function could result in mechanism collisions and disrupt the forming cycle.

None of the prior art devices included means for preventing a dwell reversal. In accordance with an embodiment of the present invention, when an operator desires to change a timing value, the respective individual section computer automatically prevents a dwell reversal from occurring and thus eliminates the problems associated with a dwell reversal.

It is an aim of the present invention to increase the efficiency of the container forming machines by preventing dwell reversal of mechanism timing values.

The invention is described further, by way of example, with reference to the accompanying drawings, wherein: Fig. 1 is a simplified block diagram of an individual section glassware forming machine and a control system therefor to which the present invention is applicable; Fig. 2 is a more detailed block diagram of the control system and one of the individual sections of Fig. 1; Figs. 3 through 8 are simplified flow diagrams which are representative of a portion of the programs run by the machine supervisory computer of Fig. 2; and Figs. 9 through 12 are simplified flow diagrams which are representative of a portion of the programs run by the individual section computer of Fig. 2.

There is shown in Fig. 1 a block diagram of an individual section glassware forming machine and control therefor to which the present invention is applicable. A machine supervisory computer 11 receives a train of timing pulses from a timing pulse generator 12 to establish the timing for the machine cycle. The generator 12 typically can be a shaft encoder or pulse generator.

The machine supervisory computer 11 is connected to a plurality of individual section computers 13, one through N, each of which is connected to an associated one of a plurality of individual sections 14, one through N, of the glassware forming machine. Initially, the machine supervisory computer 11 loads each individual section computer 13 with a control program and timing data for controlling the associated individual section. Thereafter, each individual section computer 13 generates control signals, in response to the control program and timing pulses from the timing pulse generator 12, to a valve block (not shown) in the associated individual section 14 to control the glassware forming cycle.The machine supervisory computer 11 periodically receives current timing data from each of the individual section computers 13 which data can be stored for use the next time that particular type of glassware is to be formed or in the event that one of the individual sections is shut down for any reason.

Fig. 2 is a more detailed block diagram of the control system and one of the individual sections of Fig. 1. The timing pulse generator 12 generates a train of timing pulses to the machine supervisory computer (MSC) 11 and the individual section computer (ISC) 13. An input/output device 15 and a data storage device 16 are both connected to the machine supervisory computer 11 by a pair of bidirectional lines. The machine supervisory computer 11 and the individual section computer 13 typically can be LSI-1 1 computers, the input/output device 15 typically can be a LA36 DECwriter teleprinter and the data storage device typically can be a RXV11 Floppy Disk Drive all manufactured by the Digital Equipment Corporation of Maynard, Massachusetts.

The timing pulse generator 12 generates a clock signal to the MSC 11 and the ISC 13 which signal provides a reference for timing the machine cycle and the sequence of steps to be performed by the ISC. Typically, machine timing is expressed in degrees and a machine cycle is 3600 in length. Thus, 360 clock pulses or some multiple thereof comprise one machine cycle. The cycle for each individual section is also 360" but the cycles for all of the sections can be offset from the start of the machine cycle by a different number of degrees to compensate for the difference in gob delivery time to each section. The timing pulse generator also generates a reset signal after 360" of clock pulses which reset signal is utilized by the MSC and the ISC to define the end and beginning of successive machine cycles.

The MSC 11 is used to load the control programs and timing data into the ISC 13 from the data storage device 16. An operator uses the I/O device 15 to select the particular timing data which is to be loaded into the ISC.

It should be noted that each ISC has a separate set of timing data for the particular individual section which it controls.

The ISC 13 generates control signals to a valve block 17 through a section operator console discussed below. The valve block is connected to a plurality of glassware forming mechanisms 18 for actuating the forming mechanisms in a predetermined timed sequence of steps to form the articles of glassware. The valves in the valve block 17 are actuated by solenoids (not shown) which are controlled by signals generated by the ISC 13 in accordance with the control programs and timing data which are currently stored in the ISC.

The valve block 17 and the glassware forming mechanisms 18 together comprise the individual section 14.

There is also shown in Fig. 2 a blank sensor 19 which generates a signal upon the detection of a gob at the mold in an individual section. The blank sensor 19 includes a blank detector circuit (not shown) for generating the signal to the ISC 13 which signal is utilized to adjust the timing of that individual section to the presence of the gob rather than to a position related distribution time as was done in the prior art. The blank sensor 19 and the blank detector circuit are the subject matter of United States Patent Application Serial No. in the name of Homer F. Peters and assigned to the assignee of the present invention.

A section operator console (SOC) 21 is connected to the ISC 13 and the valve block 17 and is used by the operator to make adjustments to the mechanism timing. The actuation of a particular valve may be either advanced or retarded by the operator with the use of the SOC 21. The SOC 21 may also be used to vary the section offset value and the reject synchronization value as will be discussed. The SOC 21 can be provided with a display (not shown) which enables the operator to check the current timing value for a particular machine function.

The SOC 21 is provided with a rotarytype function switch (not shown) for selecting the particular machine function for timing adjustments. An on/off switch (not switch) is provided on the SOC 21 form aking adjustment in either the on timing value or the off timing value of the selected machine function. The SOC 21 is also provided with a spring-return type "sooner" switch (not shown) for advancing the timing value toward the beginning of the cycle and a spring-return type "later" switch (not shown) for retarding the timing value. If an operator desires to change a timing value, he first selects the particular machine function on the function switch and then selects whether he desires to change the on or off timing value on the on/off switch.Next, he depresses the sooner switch if he desires to advance the timing or the later switch if he desires to retard the timing. As long as the operator continues to depress either the sooner switch or the later switch, the ISC will automatically respectively decrement or increment the timing value one degree at a time. When the timing value reaches the desired value, the operator releases the depressed switch. It should be noted that the section does not have to be in the off condition for timing adjustments, as the mechanism timing values can be changed when the section is in the operating condition.

As was previously discussed, each machine function has an on timing value and an off timing value. The dwell value of a machine function indicates that portion of a machine cycle between the on value and the off value during which the particular machine function is on. Thus, if a machine cycle consists of 360 , a dwell value of 0 indicates that the function is continuously off while - a dwell value of 359" indicates that the function is continuously on. If an operator desires to change a timing value of a function, the timing value must not be changed so that an on value is moved past an off value or an off value is moved past an on value. This type of dwell value change causes a dwell reversal and could result in mechanism collisions which would disrupt the forming cycle.As required by the present invention, the respective ISC will not permit the dwell value of a machine function to switch from 0" to 3590 or from 3590 to 00.

The SOC 21 is also used to control the operating condition of the individual section.

When the individual section is on, it is designated to be in the "run" condition and, when the section is off, it is designated to be in the "safe" condition. If the section is in the safe condition, the operator can switch to a manual mode wherein the solenoids of the valve block 17 can be individually controlled by a plurality of switches (not shown) which are provided in the SOC 21.

Although the SOC 21 is provided with start and stop controls, the SOC 21 is located on one side of the machine and is only easily accessible to the operator when the operator is on that side. A remote start and stop station 22 is provided and is typically mounted on the side opposite the corresponding SOC Thus, the start and stop controls are easily accessible to the operator from both sides of the machine.

A bottle reject control panel 23 includes a plurality of switches (not shown) each of which corresponds to a particular cavity of the mold in each individual section. If an operator desires to reject a particular article of glassware, he actuates the corresponding switch on the panel 23. The MSC 11 periodically scans the panel 23 to see if any switches have been actuated. When the MSC 11 senses an actuated switch, the MSC will compare the reject synchronization value corresponding to the section of the rejected glassware with the current machine position. If these two values are equal, a reject signal will be supplied to a bottle reject station 24 such that the appropriate bottle(s) will be rejected.

As was previously discussed with respect to the valve timing, the operator can utilize the SOC 21 to adjust the reject synchronization value for the individual section such that a glassware article from a selected cavity of the mold is rejected when it arrives at the reject station 24. The reject synchronization valve is stored in the ISC as a position in the machine cycle. At a predetermined interval, typically every one minute, the MSC reads the reject synchronization values from the ISC's and stores them. Each time there is a one degree change in machine position, the MSC compares the new machines position with the reject synchronization values and generates the reject signal when they correspond.

Communications between the ISC 13 and the MSC 11 and between the MSC 11 and the I/O device 15 can be achieved utilizing model DLV11 serial input/output interface boards (not shown). Input and output control for the ISC 13 to the SOC 21 and the valve block 17 and for the MSC 11 to the control panel 23 and the reject station 24 can be provided by utilizing model DRV11 parallel input/output interface boards (not shown). If a floppy disk drive is used as the data storage device 16, an RXVl 1 floppy drive controller (not shown) can be used to control data transfers between the MSC and the floppy disk drive. The DLVI1, DRVll and RXVll are all manufactured by the Digital Equipment Corporation of Maynard, Massachusetts.

As previously mentioned, the machine supervisory computer 11 and the individual section computer 13 can be LSI 11 computers. This particular type of computer features hardware priority interrupts. As will be discussed, other features of this computer are an automatic power failure restart and user control of external task scheduling.

There are shown in Figs. 3 through 8 simplified flow diagrams of programs utilized in the operation of the machine supervisory computer (MSC) 11. As shown in Fig. 2, the MSC is connected to an input/output device 15 which can be a teleprinter having a keyboard input and a printer output and to a data storage device 16 which can be floppy disk drive. The storage device stores on floppy disks both system data, such as control programs, and job histories which include the timing data for forming each type of glassware article.The MSC 11 can be loaded with various "keyboard" programs from the data storage device 16 which programs allows the machine operator to install, change, list or delete a job history in the storage device or to list a directory of all job histories stored or to uansfer a job history(s) from one floppy disk to another; to set up the machine parameters for a new job; to load a job history into the ISC's from the storage device; to save an active job history by loading it from an ISC into the storage device; to reload an ISC with a control program and timing data from any other ISC or with a test pattern; to display cavity rate and machine speed; and to display or change the number of cycles in which glassware articles are rejected.

The main program for the MSC 11 is shown in the flow diagram of Fig. 3. The program is initiated at a circle "START" and immediately enters a decision point "KEYBOARD PROGRAM REQUEST" to check for any request to run a keyboard program that may have been entered by the machine operator. If there is such a request, the program branches at "YES" to a processing point. The processing point "EXECUTE REQUESTED KEYBOARD PROGRAM" represents a set of instructions directing the MSC to execute the program. The program then returns to the beginning of the main program. If there is no keyboard program request, the main program branches from the decision point at "NO" and returns to the beginning of the program. It should be noted that all of the keyboard programs run on the lowest priority and can be interrupted by any of the programs which are shown in Figs. 4 through 8.

In addition to the keyboard programs initiated with the input/output device 15, the MSC 11 is also responsible for running other programs all of which have a higher priority than the keyboard programs. A clock interrupt program has the highest priority and is shown in the flow diagram of Fig. 4. A clock interrupt is generated each time a timing pulse is received by the MSC 11 from the timing pulse generator 12. If the MSC is running a keyboard program when the clock interrupt is generated, the keyboard program is interrupted and the clock interrupt is serviced before returning to the keyboard program. The clock interrupt program is initiated at a circle labeled "CLOCK INTERRUPT" and theni enters a processing point "INCREMENT MACHINE POSITION COUNT" to update a count total representing the position of the machine in the machine cycle.Next, the program enters a processing point "CHECK STATUS OF REJECT CONTROL SWITCHES BY SECTION" which includes instructions for checking the status of the reject control switches on the reject control panel 23 of Fig. 2 by section. The program enters a decision point "ANY REJECT SWITCHES" to determine if any bottles have been designated for rejection. If any of the reject control switches are actuated, the pro gram branches at "YES" to a decision point "MACHINE = REJECT" wherein the MSC 11 compares the current machine position count total with the reject synchronization value for each individual section. If they are equal, the program branches at "YES" to a processing point "REJECT DESIGNATED BOTTLE(S)" which includes instructions for generating a reject signal to the bottle reject station 24 of Fig. 2 such that the designated bottle will be rejected.The clock interrupt program then returns to the main program at the point the main program was interrupted as is the case when the program branches at "NO" from the "ANY REJECT SWITCHES" decision point when no switches are actuated or when the program branches at "NO" from the "MACHINE = REJECT" decision point when the machine position count total is not equal to the reject synchronization value.

A reset interrupt program has the second highest priority and is shown in Fig. 5. Each time a reset pulse is generated by the timing pulse generator 12, the reset program is initiated at a circle "RESET INTERRUPT".

The program enters a processing function "RESET MACHINE POSITION COUNT TOTAL TO 359" which includes instructions for resetting the machine position counter count total at the end of each machine cycle.

The reset interrupt program then returns to the main program at the point it was interrupted. The next timing pulse will then set the counter to zero and 359 more timing pulses are counted to complete the machine cycle. As the counter accumulates the last timing pulse, the reset pulse is again generated to correct any error which may have occurred in the machine position count total.

As was previously discussed, the operator can change the section timing data utilizing the SOC 21. Approximately every five minutes, the MSC 11 executes a store program shown in Fig. 6 to update the current section timing data for each individual section which is stored on a floppy disk in the data storage device 16. Thus, if the operator has changed the timing data for a section by advancing or retarding the actuation of a valve, that timing change will be stored in the data storage device 16 within no more than five minutes.

The LSI-1 1 computer is provided with a control over external task scheduling. For example, the operator can schedule a program to run at an absolute time of the day, a delta time from a clock unit synchronization or every so many units of time, such as five minutes. Thus, every five minutes, the store program is initiated at a circle "DATA UP DATE INTERRUPT" and enters a processing function "OBTAIN TIMING DATA FROM ISC AND PLACE IN DATA STOR AGE DEVICE". After the current timing data has been stored, the program returns to the main program.

There is shown in Fig. 7 a reject program that is executed by the MSC approximately every one minute to update the reject synchronization values. Thus, if the operator has changed any of these values to achieve a more accurate reject, the change will be stored by the MSC within no more than one minute.

The reject program is initiated at a circle "REJECT UPDATE INTERRUPT" and enters a processing function "OBTAIN RE JECT SYNCHRONIZATIOZN VALUE FROM ISC AND STORE" which includes instructions for reading and storing the current reject synchronization values for each ISC.

The reject program then returns to the main program. The stored values are utilized in the comparison with the machine position pertormed at the decision point "MACHINE = REJECT" of Fig. 4.

If a power failure occurs, the volatile register contents of the MSC and the ISCs will be lost. There is shown in Fig. 8 a flow diagram which indicates the steps taken by the MSC after a power failure recovery. If the MSC is a LSI-11, it can be programmed to execute a restart program which is initiated at a circle "START" Next a process function "RESTORE CONTROL PROGRAM AND JOB HISTORY TO EACH ISC" restores the ISC memory with the control programs and timing data with which they were loaded before the power failure. There the restart program returns to the main program.

There are shown in Figs. 9 through 12 flow diagrams which are representative of the operation of an ISC. The main program is shown in Fig. 9. After ISC memory has been restored by the MSC, the ISC performs several control program initialization tasks such as setting the machine position counter to 359.

The main program is initiated at a circle "START" and enters a processing function "DISABLE INTERRUPTS AND PER FORM INITIALIZATION TASKS". Next, the program enters a subprogram "FUNC TION TIMING CHANGE' which includes instructions for checking the SOC 21 to determine if the operator has requested a change in the timing data, the section offset value or the reject synchronization value. A more detailed flow diagram of this program is shown in Fig. 12. Any requested changes are stored in the ISC memory to be sent through the MSC to the data storage device when the store program of Fig. 6 is executed by the MSC Next, the ISC main program enters a pro cessing function "ENABLE INTERRUPTS" which includes instructions to enable the ISC to respond to the timing and reset pulses generated by the timing pulse generator 12.

The program then enters a decision point "COMMUNICATION REQUEST BY MSC". If the MSC has requested to either transmit data to or receive data from the ISC, the program branches at "YES" to a process ing function "TRANSMIT OR RECEIVE DATA" which includes the required instructions for communication between the MSC and the ISC The program then returns to the processing function "CHECK SOC FOR TIMING CHANGES AND STORE ANY NEW VALUES" and continues to loop. If the MSC has not requested communication, the program branches from the decision point "COMMUNICATION REQUEST BY MSC" at "NO" to return to the processing function "CHECK SOC There is shown in Fig. 10 a flow diagram of the clock interrupt program for the ISC.

Each time a timing pulse is received from the timing pulse generator 12 and the main program has enabled the clock and reset inter rupts, the ISC initiates a clock interrupt since the clock interrupt program has a higher pri ority. The clock interrupt program is initiated at a circle "CLOCK INTERRUPT" and enters a decision point "IGNORE INTER RUPT" which checks for a direction to ignore the clock interrupt. As will be discussed below, a late occurring reset pulse will require that at least one clock interrupt be ignored such that the program branches at "YES" and returns to the main program.If the clock interrupt is not to be ignored, the program branches at "NO" and enters a processing function "INCREMENT MACHINE POSI TION CONT" which includes instructions for updating a count total representing the position of the machine in the machine cycle.

As discussed above, this count total is conveniently zero to 359 representing 360 degrees in a machine cycle. This corresponds to one rotation of the prior art timing drum which utilized cams to operate the valves which actuated the glassware forming means, the position of the cams being defined in degrees.

Next, the program enters a processing function "SUBTRACT SECTION OFFSET" which includes instructions for subtracting the section offset value, if any, from the machine position count total to obtain a count total representing the instantaneous position of the individual section in the machine cycle which count the total enter is stored.

Next, the program enters a processing func tion "CHECK SOC STATUS a processing CHANGE SWITCHES" which includes instructions for checking the status of the start and stop switches on the SOC 21 and the remote panel 22 to determine if the operator has requested a change in the status of the machine. The program enters a decision point "RUN" to check if the section is in the run condition forming glassware articles. If the section is not running, the program branches at "NO" to a decision point "START ACTUATED" to check whether either of the start switches has been actuated as determined by the "CHECK SOC STATUS CHANGE SWIT CHES" processing function. If neither start switch has been actuated, the clock interrupt program branches at "NO" to a decision point "REPEAT CLOCK INTERRUPT".As will be discussed below, an early occurring reset pulse will require at least one extra clock interrupt such that the program branches at "YES" back to the "INCREMENT MA CHINE POSITION COUNT" processing function. If the clock interrupt is not to be repeated, the program branches at "NO" to return to the main program to await the next timing pulse. If either start switch has been actuated, the program branches at "YES" back to the "START" circle of the main program to start the section.

If the section is running, the program branches from "RUN" at "YES" to a decision point "STOP ACTUATED" to check whether either of the stop switches has been actuated as determined by the "CHECK SOC STATUS CHANGE SWITCHES" processing function. If either stop switch has been actuated, the program branches at "YES" to a processing function "STOP SECTION" which includes instructions for stopping the operation of the section.

The clock interrupt program then enters the "REPEAT CLOCK INTERRUPT" decision point. If neither stop switch has been actuated, the program branches at "NO" to a processing function "OBTAIN DEGREE VALUE OF NEXT FUNCTION FROM TABLE" which includes instructions for look ing up the degree value of the next glassware forming function to be performed in a table wherein the forming functions are listed in the order they are to be performed in the forming cycle. The program then enters a decision point "POSITION = DEGREE" wherein the instantaneous position count total for the section is compared with the degree value of the next function to be performed. If the values are not equal, the program branches at "NO" to enter the "REPEAT CLOCK INTERRUPT" decision point.If the values are equal, the program branches at "YES" and enters a processing function "PERFORM FUNCTION" which includes instructions for generating a control signal to the solenoid for actuating the proper valve in the valve block 17. Next, the program enters a processing function "POINT TO NEXT FUNC TION IN TABLE" which includes innstructions for shifting to the next function listed in the table such that the degree value for this function is obtained as the program returns to the "OBTAIN DEGREE VALUE OF NEXT FUNCTION FROM TABLE" processing function. Thus, the program will perform all functions having the same degree value before returning to the main program.

A reset interrupt program is shown in Fig.

11. Each time the timing pulse generator 12 generates a reset pulse and the main program has enabled the clock and reset interrupts, the ISC initiates a reset interrupt program which is initiated at a circle "RESET INTER RUPT". The program then enters a processing function "AUTO SYNCHRONIZA- TION" which includes instructions for checking to see if the reset pulse occurred between 359" and 0" of the section cycle and, if it did so occur, no further action is required.

If the reset pulse occurred within a range, for example, 357" through 2", instructions are executed to modify the count of the clock pulses. If the reset pulse was early, on the next clock interrupt the clock interrupt program is cycled as many times as are required to increment the clock pulse count total to place the section in synchronization. If the reset pulse was late, the clock interrupt is ignored as many times as are required to maintain the clock pulse count total to place the section in synchronization. In any of these instances, the reset interrupt program then returns to the main program. If the reset pulse occurs outside of the range, an emergency stop is initiated. The reset interrupt is lower than the clock interrupt in priority.

There is also a line frequency interrupt program which is similar to the reset interrupt program of Fig. 11. An interrupt is generated by each cycle of the alternating current power source for the ISC. Every predetermined number of cycles, the line frequency interrupt program checks the clock pulse count total to determine whether it has been incremented since the last such check. It the clock pulse count total has not been incremented for a predetermined number of these checks, an emergency stop is initiated.

There is shown in Fig. 12 a flow diagram of the ISC sub-program "FUNCTION TIM ING CHANGE" which is entered from the ISC main program of Fig. 9 at a circle "START". As was previously discussed, this subprogram includes instructions for recording any timing data changes requested by the operator. The first step is a decision point "FUNCTION CHANGE REQUEST" which checks the SOC 21 for signals indicatin that the machine operator has requested a change in the timing data, the section offset value or the reject synchronization value. If no function change has been requested, the program branches at "NO" and returns to the main program.

If a function change has been requested, the program branches at "YES" to a decision point "TIMING DATA CHANGE" to check for a requested change in an on or an off value for a selected function. If the machine operator has not requested a timing data change, the program branches at "NO" to a decision point "REJECT OR OIFFSET CHANGE" to determine if the requested change is in one of those two values. If such a change has been requested, the program branches at "YES" to a processing function "RECORD NEW DEGREE VALUE" which includes instructions for either incrementing or decrementing the reject synchronization or offset degree values as required. Since both the reject synchronization and offset degree values are single values, there is no dwell time associated with either and no need to check for a possible dwell reversal.If there is no request to change either value, as in the case of a request without depressing either the sooner or the later switch, the program branches from "REJECT OR OFFSET CHANGE" at "NO" back to the main program.

If the machine operator has requested a change in the timing data, the program branches from "TIMING DATA CHANGE" at "YES" to a processing function "OFF ON = DWELL". This processing function includes instructions for subtracting the on time of the selected machine function from the off time to obtain the dwell time for the function. Then the program enters a decision point "DWELL = 0". If the dwell time value is equal to zero, the program branches at "YES" to a portion of the program which only permits timing changes to expand the dwell time. If the dwell time is greater than zero, the program branches at "NO" to a portion of the program which only permits timing changes to contract the dwell time to a minimum of zero or expand the dwell time to a maximum of 359".

The "YES" branch leads to a decision point "ON OR OFF TIME" to determine if the machine operator has requested a change in the on timing value or the off timing value.

If an on change has been requested, the program branches at "ON" to a decision point "SOONER SWITCH ACTUATED". If the sooner switch is being depressed by the operator, the program branches at "YES" to a portion of the program, beginning with a "DISABLE INTERRUPTS" processing function for changing the timing value since such a change would expand the dwell time from zero. If the sooner switch is not being depressed, then the program branches at "NO" from "SOONER SWITCH ACTUATED" to a processing function "INDICATE CHANGE NOT PERMITTED". This processing function includes instructions for generating a visual indication at the SOC that no change is permitted either because the sooner switch is not depressed or the later switch is depressed and such a change would result in a dwell reversal. The program then returns to the main program.If a change in the off time has been requested, the program branches from "ON OR OFF TIME" at "OFF" to a decision point "LATER SWITCH AC TUATED". If the later switch is being depressed, the program branches at "YES" to the processing function "DISABLE INTER RUPTS" since such a change would expand the dwell time from zero. If the later switch is not being depressed, the program branches at "NO" to the "INDICATE CHANGE NOT PERMITTED" processing function to indicate that no change is permitted either because the later switch is not depressed or the sooner switch is depressed and such a change would result in a dwell reversal. The program then returns to the main program.

If the dwell time is not equal to zero, the program branches at "NO" from "DWELL = 0" to a decision point "DWELL NEGA TIVE" to check the sign of the dwell time.

If the dwell value is negative, indicating that the on value preceeds the change from 359" to 0 in a cycle and the off value follows that change, the program branches at "YES" to a processing function "ADD 3600 TO DWELL" which includes instructions for adding 360 to the dwell time value to obtain the dwell time as a positive value. Then the program enters a decision point "DWELL = 359 '. If the dwell time is already a positive value, the program branches at "NO" from the "DWELL NEGATIVE" decision point to the "DWELL = 359 " decision point.

If the dwell time is not equal to 3590, the.

program branches at "NO" from the "DWELL = 359"' decision point to the "DISABLE INTERRUPTS" processing function since such a dwell time can be either expanded or contracted. If the dwell time is equal to 359', the program branches at "YES" to an "ON OR OFF TIME" decision point to determine if the machine operator has requested a change in the on timing value or the off timing value. If an on change has been requested, the program branches at "ON" to a decision point "LATER SWITCH ACTUATED".If the later switch is being depressed by the operator, the program branches at "YES" to the "DISABLE IN TERRUPTS" processing function since such a change will contract the dwell time from 359". If the later switch is not being depressed, the program branches at "NO" from "LATER SWITCH ACTUATED" to a processing function "INDICATE CHANGE NOT PERMITTED". This processing function includes instructions for generating a visual indication at the SOC that no change is permitted either because the later switch is not depressed or the sooner switch is depressed and such a change would result in a dwell reversal. The program then returns to the main program.

If a change in the off time has been requested, the program branches from "ON OR OFF TIME" at "OFF" to a decision point "SOONER SWITCH ACTUATED". If the sooner switch is being depressed, the program branches at "YES" to the processing function "DISABLE INTERRUPTS" since such a change would contract the dwell time from 359". If the sooner switch is not being depressed, the program branches at "NO" to the "INDICATE CHANGE NOT PER MITTED" processing function to indicate that no change is permitted either because the sooner switch is not depressed or the later switch is depressed and such a change would result in a dwell reversal. The program then returns to the main program.

The processing function "DISABLE IN TERRUPTS" includes instructions for disabling all interrupts to the ISC while the degree value of the on or off time is being changed.

The program then enters a processing function "NEW DEGREE VALUE = OLD DEG REE VALUE +1 " which includes instructions for generating a new degree value for the selected on or off time by incrementing or decrementing the old degree value by one degree as indicated by whether the later switch or the sooner switch respectively is depressed. Next, the program enters a decision point "SECTION POSITION = NEW DEGREE VALUE" which compares the degree value of the present position of the section in the cycle with the new degree value.

If the degree values are equal, the change is not permitted since the ISC may miss generating an on or an off control signal, for example, if the degree value is decremented after the clock interrupt program of Fig. 10 has been executed for the preset section position but before the clock interrupt program has been executed for the next posi tion. Thus, the program branches at "YES" to an "INDICATE CHANGE NOT PER MITTED" processing function which includes instructions for generating a visual indication that the degree value cannot be changed at the present tune. Then the program goes to an "ENABLE INTERRUPTS" processing function.

If the section position does not equal the new degree value, the program branches at "NO" to a "RECORD NEW DEGREE VALUE" processing function which includes instruction for replacing the old degree value stored in the ISC with the new degree value.

This new degree value is then read by the MSC the next time the store program of Fig.

6 is executed. The program then enters the "ENABLE INTERRUPTS" processing function which includes instructions for enabling the interrupts which were disabled before the new degree value was generated. This is the end of the function timing change subprogram and the program returns to the main program.

Copending British Application No. 18365/28 Serial No. 1,603,755 incorporates some of the same drawings used in the present application.

WHAT WE CLAIM IS: 1. A cyclically operated container forming machine comprising means for forming containers in a cyclic series of predetermined forming steps in response to a plurality of on and off control signals issued by a control means of the machine, the control means comprising means which store a control program defining the series of predetermined forming steps and which store on and off timing values defining a dwell time during which a container forming means is actuated in use; means which generate on or off control signals for each of said on and off timing values respectively in accordance with the control program; means controllable by a human operator, which generate a signal representing a desired change, as determined by the operator, in a selected one of said on and off timing values, wherein the control signal generating means is responsive to said desired change signal to effect the desired change in said selected timing value if a dwell time reversal (as hereinbefore defined) would not occur as a result of the desired change and to prevent the desired change if a dwell time reversal would occur as a result of the desired change.

2. A machine as claimed in claim 1, wherein said timing values are expressed in degrees of a cycle of the machine and wherein said control signal generating means effects the desired change one degree at a time.

3. A machine as claimed in claim 1 or 2, wherein said desired change signal generating means includes manually actuated means for generating a signal representing a container forming means for which it is desired to change one of said on and off timing values, manually actuated means for generating a signal representing a selected one of said on and off timing values and manually actuated means for generating a signal representing whether it is desired to increment or to decrement said selected timing value and wherein said control signal generating means is responsive to said selected forming means signal, said selected on or off timing value signal and said increment or decrement signal for effecting the desired change in said selected timing value.

4. A machine as claimed in claim 3, wherein said means for generating said selected forming means signal includes a manually settable function selection switch, said means for generating said selected on and off timing value signal includes a manually settable on/ off selection switch and said means for generating said increment or decrement signal includes a manually operable later switch and a manually operable sooner switch.

5. A machine as claimed in any of the preceding claims, wherein the machine is constituted as a glass forming machine.

6. A machine as claimed in claim 5, wherein the glass forming machine is an IS glassware forming machine each individual section of which constitutes a said container forming means; and said store means stores a control program defining the series of predetermined steps for each section, and on and off timing values defining the dwell time during which each section is to be actuated in use.

7. A cyclically operated glass forming machine according to claim 6 arranged substantially as herein particularly described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   tion. Thus, the program branches at "YES" to an "INDICATE CHANGE NOT PER MITTED" processing function which includes instructions for generating a visual indication that the degree value cannot be changed at the present tune. Then the program goes to an "ENABLE INTERRUPTS" processing function.

   If the section position does not equal the new degree value, the program branches at "NO" to a "RECORD NEW DEGREE VALUE" processing function which includes instruction for replacing the old degree value stored in the ISC with the new degree value.

   This new degree value is then read by the MSC the next time the store program of Fig.

   6 is executed. The program then enters the "ENABLE INTERRUPTS" processing function which includes instructions for enabling the interrupts which were disabled before the new degree value was generated. This is the end of the function timing change subprogram and the program returns to the main program.

   Copending British Application No. 18365/28 Serial No. 1,603,755 incorporates some of the same drawings used in the present application.

   WHAT WE CLAIM IS: 1. A cyclically operated container forming machine comprising means for forming containers in a cyclic series of predetermined forming steps in response to a plurality of on and off control signals issued by a control means of the machine, the control means comprising means which store a control program defining the series of predetermined forming steps and which store on and off timing values defining a dwell time during which a container forming means is actuated in use; means which generate on or off control signals for each of said on and off timing values respectively in accordance with the control program; means controllable by a human operator, which generate a signal representing a desired change, as determined by the operator, in a selected one of said on and off timing values, wherein the control signal generating means is responsive to said desired change signal to effect the desired change in said selected timing value if a dwell time reversal (as hereinbefore defined) would not occur as a result of the desired change and to prevent the desired change if a dwell time reversal would occur as a result of the desired change.
2. 2. A machine as claimed in claim 1, wherein said timing values are expressed in degrees of a cycle of the machine and wherein said control signal generating means effects the desired change one degree at a time.
3. 3. A machine as claimed in claim 1 or 2, wherein said desired change signal generating means includes manually actuated means for generating a signal representing a container forming means for which it is desired to change one of said on and off timing values, manually actuated means for generating a signal representing a selected one of said on and off timing values and manually actuated means for generating a signal representing whether it is desired to increment or to decrement said selected timing value and wherein said control signal generating means is responsive to said selected forming means signal, said selected on or off timing value signal and said increment or decrement signal for effecting the desired change in said selected timing value.
4. 4. A machine as claimed in claim 3, wherein said means for generating said selected forming means signal includes a manually settable function selection switch, said means for generating said selected on and off timing value signal includes a manually settable on/ off selection switch and said means for generating said increment or decrement signal includes a manually operable later switch and a manually operable sooner switch.
5. 5. A machine as claimed in any of the preceding claims, wherein the machine is constituted as a glass forming machine.
6. 6. A machine as claimed in claim 5, wherein the glass forming machine is an IS glassware forming machine each individual section of which constitutes a said container forming means; and said store means stores a control program defining the series of predetermined steps for each section, and on and off timing values defining the dwell time during which each section is to be actuated in use.
7. 7. A cyclically operated glass forming machine according to claim 6 arranged substantially as herein particularly described with reference to and as illustrated in the accompanying drawings.