1. A tandem press shuttle area isolation gate system, comprising:
at least two presses arranged such that an exit side of a preceding press is adjacent to an entry side of a subsequent press, with a shuttle area therebetween;
press envelope safety gates for preventing access to a work envelope of each press via opposing die transfer sides thereof while said presses are in operation;
shuttle area safety gates for preventing access to shuttle areas between presses while said presses are in operation; and
transfer area safety gates for preventing access to said work envelope of each press via said exit side or said entry side thereof while a die change is taking place, said transfer area safety gates maintained in a normally open position during press operation;
wherein, the use of said transfer area safety gates allows workers to safely enter said shuttle areas concurrently with a die change due to the isolation of said press work envelopes from said shuttle areas.
2. The tandem press shuttle area isolation gate system of claim 1, wherein said transfer area safety gates are maintained in a normally open position that is above said exit sides and entry sides of said presses.
3. The tandem press shuttle area isolation gate system of claim 1, wherein said transfer area safety gates are maintained in a normally open position that is horizontally offset from said exit sides and entry sides of said presses.
4. The tandem press shuttle area isolation gate system of claim 1, wherein at least certain ones of said transfer area safety gates are designed to accommodate component transfer equipment when in a closed position.
5. The tandem press shuttle area isolation gate system of claim 1, wherein at least certain ones of said transfer area safety gates are comprised of more than one individual gate.
6. The tandem press shuttle area isolation gate system of claim 1, wherein operation of said transfer area safety gates is interlocked with an automatic die change control system.
7. The tandem press shuttle area isolation gate system of claim 1, further comprising a lockout means that prevents said transfer area safety gates from being returned to their normally open positions while a worker remains in one or more of said shuttle areas.
8. The tandem press shuttle area isolation gate system of claim 1, wherein said transfer area safety gates are adapted to operate as a group.
9. The tandem press shuttle area isolation gate system of claim 1, wherein said transfer area safety gates are adapted to operate independently of one another.
10. The tandem press shuttle area isolation gate system of claim 1, wherein said press envelope safety gates and said shuttle area safety gates are in a normally closed position during press operation.
11. A tandem press line shuttle area isolation gate system, comprising:
a line of presses arranged such that an exit side of a preceding press is adjacent to an entry side of a subsequent press, with a shuttle area therebetween;
a press envelope safety gate preventing access to a work envelope of each press along a first die transfer side thereof, said press envelope safety gate normally closed during press operation;
a press envelope safety gate preventing access to a work envelope of each press along a second die transfer side thereof, said press envelope safety gate normally closed during press operation;
a shuttle area safety gate preventing access to each shuttle area between adjacent presses along said first die transfer side thereof, said shuttle area safety gate normally closed during press operation;
a shuttle area safety gate preventing access to each shuttle area between adjacent presses along said second die transfer side thereof, said shuttle area safety gate normally closed during press operation;
a transfer area safety gate preventing access to said work envelope of each press via an associated shuttle area located along said exit side thereof, said shuttle area safety gate normally open during press operation;
a transfer area safety gate preventing access to said work envelope of each press via an associated shuttle area located along said entry side thereof, said shuttle area safety gate normally open during press operation; and
an automatic die change system designed to transfer new dies into said presses through one of said die transfer sides thereof while simultaneously transferring old dies out of said presses through the other of said die transfer sides thereof;
wherein, by closing said transfer area safety gates and opening said press envelope safety gates and said shuttle area safety gates, workers can safely enter said shuttle areas concurrently with a die change due to the isolation of said press work envelopes from said shuttle areas.
12. The tandem press line shuttle area isolation gate system of claim 11, wherein each transfer area safety gate is maintained in a normally open position that is above said exit sides and entry sides of said presses.
13. The tandem press line shuttle area isolation gate system of claim 11, wherein each transfer area safety gate is maintained in a normally open position that is horizontally offset from said exit sides and entry sides of said presses.
14. The tandem press line shuttle area isolation gate system of claim 11, wherein at least one transfer area safety gate is designed to accommodate component transfer equipment when in a closed position.
15. The tandem press line shuttle area isolation gate system of claim 11, wherein at least one transfer area safety gate is comprised of more than one individual gate.
16. The tandem press line shuttle area isolation gate system of claim 11, wherein operation of each transfer area safety gate is interlocked with an automatic die change control system.
17. The tandem press line shuttle area isolation gate system of claim 11, further comprising a lockout means that prevents each transfer area safety gate from being returned to its normally open position while a worker remains in one or more of said shuttle areas.
18. The tandem press line shuttle area isolation gate system of claim 11, wherein said transfer area safety gates are adapted to operate as a group.
19. The tandem press line shuttle area isolation gate system of claim 11, wherein said transfer area safety gates are adapted to operate independently of one another.
20. A method for reducing downtime associated with a changeover of a tandem press line having a plurality of presses arranged such that an exit side of a preceding press is adjacent to an entry side of a subsequent press, with a shuttle area therebetween, said method comprising:
providing press envelope safety gates for preventing access to a work envelope of each press via opposing die transfer sides thereof, said press envelope safety gates normally closed during press operation;
providing shuttle area safety gates for preventing access to said shuttle areas between presses, said shuttle area safety gates normally closed during press operation;
providing transfer area safety gates for preventing access to said work envelope of each press via said exit side or said entry side thereof, said shuttle area safety gates normally open during press operation; and
closing said transfer area safety gates and opening said press envelope safety gates and said shuttle area safety gates during a die change;
whereby, due to isolation of said press work envelopes from said shuttle areas by said transfer area safety gates, workers are able to safely enter said shuttle areas and convert component transfer equipment located therein concurrently with said die change.
21. The method of claim 20, wherein each transfer area safety gate is maintained in a normally open position that is above said exit sides and entry sides of said presses.
22. The method of claim 20, wherein each transfer area safety gate is maintained in a normally open position that is horizontally offset from said exit sides and entry sides of said presses.
23. The method of claim 20, wherein at least one transfer area safety gate is designed to accommodate component transfer equipment when in a closed position.
24. The method of claim 20, wherein at least one transfer area safety gate is comprised of more than one individual gate.
25. The method of claim 20, further comprising interlocking the operation of each transfer area safety gate with an automatic die change control system.
26. The method of claim 20, further comprising following a lockout procedure that prevents each transfer area safety gate from being returned to its normally open position while a worker remains in one or more of said shuttle areas.
27. The method of claim 20, wherein said transfer area safety gates are operated as a group.
28. The method of claim 20, wherein said transfer area safety gates are operated independently of one another.
29. The method of claim 20, wherein movement of dies involved in said die change is prohibited until a signal indicating transfer area safety gate closure is received.
30. The method of claim 20, wherein, during a die change, said press envelope safety and said shuttle area safety gates cannot be opened until a signal indicating transfer area safety gate closure is received.
31. The method of claim 20, further comprising a shuttle area adjacent to an entry side of a first press andor an exit side of a last press in said tandem press line.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for preventing starvations of tasks in a multiple-processing entity system, the method comprising:
examining, during each scheduling iteration, an eligibility of each task data structure out of a group of data structures to be moved from a sorted tasks queue to a ready for execution task;
updating a value, during each scheduling iteration, of a queue starvation watermark value of each task data structure that is not eligible to move to a running tasks queue, until a queue starvation watermark value of a certain task data structure out of the group reaches a queue starvation watermark threshold; and
generating a task starvation indication if during an additional number of scheduling iterations, the certain task data structure is still prevented from being moved to a running tasks queue, wherein the additional number is responsive to a task starvation watermark.
2. The method according to claim 1 comprising sending an interrupt request to at least two processing entities out of the multiple processing entities of the multiple-processing entity system.
3. The method according to claim 1 comprising sending the task starvation indication to at least one processing entity out of the multiple processing entities of the multiple-processing entity system.
4. The method according to claim 1 comprising sending an interrupt request to all multiple processing entities of the multiple-processing entity system in response to the task starvation indication.
5. The method according to claim 1 comprising determining that a task data structure is not eligible to move to a running tasks queue that is associated with a sorted tasks queue if the running tasks queue is full or if at least one pre-requisite to a provision of the task data structure to the associated running tasks queue is not fulfilled.
6. The method according to claim 1 wherein the group of data structures comprises a head of queue task data structure per each sorted tasks queue.
7. The method according to claim 1 comprising sorting task data structures within each unfrozen sorted tasks queue, during each scheduling iterations, according to multiple sorting rules values of each of the task data structures; whereas each sorting rule can be an ascending sorting rule or a descending sorting rule.
8. The method according to claim 1 comprising sorting task data structures within each unfrozen sorted tasks queue, during each scheduling iterations, according to multiple sorting rules values of each of the task data structures; whereas each sorting rule is either an ascending sorting rule or a descending sorting rule.
9. The method according to claim 1 comprising receiving sorting rules indicators that indicate, for each sorting rule, whether the sorting rule is an ascending sorting rule or a descending sorting rule.
10. The method according to claim 1 comprising freezing sorted tasks queues other than a sorted tasks queue that stores the certain task data structure.
11. The method according to claim 1 comprising sorting task data structures within each unfrozen sorted tasks queue, during each scheduling iterations, according to hierarchical sorting rules.
12. A system for preventing starvations of tasks, the system comprising:
multiple processing entities, adapted to process tasks; and
a scheduler, adapted to schedule an execution of tasks; wherein the scheduler is further adapted to:
examine, during each scheduling cycle, an eligibility of each task data structure out of a group of data structures to be moved from a sorted tasks queue to a ready for execution task;
update a value, during each scheduling iteration, of a queue starvation watermark value of each task data structure that is not eligible to move to a running tasks queue, until a queue starvation watermark value of a certain task data structure out of the group reaches a queue starvation watermark threshold; and
generate a task starvation indication if during an additional number of scheduling iterations, the certain task data structure is still prevented from being moved to a running tasks queue, wherein the additional number is responsive to a task starvation watermark.
13. The system according to claim 12 wherein the scheduler is adapted to send an interrupt request to at least two processing entities out of the multiple processing entities of the multiple-processing entity system in response to the task starvation indication.
14. The system according to claim 12 wherein the scheduler is adapted to send the task starvation indication to at least one processing entity out of the multiple processing entities of the multiple-processing entity system.
15. The system according to claim 12 wherein the scheduler is adapted to send an interrupt request to all multiple processing entities of the multiple-processing entity system.
16. The system according to claim 12 wherein the scheduler is adapted to determine that a task data structure is not eligible to move to a running tasks queue that is associated with a sorted tasks queue if the running tasks queue is full or if at least one pre-requisite to a provision of the task data structure to the associated running tasks queue is not fulfilled.
17. The system according to claim 12 wherein the group of data structures comprises a head of queue task data structure per each sorted tasks queue.
18. The system according to claim 12 wherein the scheduler is adapted to sort task data structures within each unfrozen sorted tasks queue, during each scheduling iterations, according to multiple sorting rules values of each of the task data structures; whereas each sorting rule can be an ascending sorting rule or a descending sorting rule.
19. The system according to claim 12 wherein the scheduler is adapted to sort task data structures within each unfrozen sorted tasks queue, during each scheduling iterations, according to multiple sorting rules values of each of the task data structures; whereas each sorting rule is either an ascending sorting rule or a descending sorting rule.
20. The system according to claim 12 wherein the scheduler is adapted to sort rules indicators that indicate, for each sorting rule, whether the sorting rule is an ascending sorting rule or a descending sorting rule.
21. The system according to claim 12 wherein the scheduler is adapted to sort task data structures within each unfrozen sorted tasks queue, during each scheduling iterations, according to hierarchical sorting rules.
22. The system according to claim 12 wherein the scheduler is adapted to freeze sorted tasks queues other than a sorted tasks queue that stores the certain task data structure.
23. A computer program product that comprises a computer readable medium that stores instructions for:
examining, during each scheduling iteration, an eligibility of each task data structure out of a group of data structures to be moved from a sorted tasks queue to a ready for execution task;
updating a value, during each scheduling iteration, of a queue starvation watermark value of each task data structure that is not eligible to move to a running tasks queue, until a queue starvation watermark value of a certain task data structure out of the group reaches a queue starvation watermark threshold; and
generating a task starvation indication if during an additional number of scheduling iterations, the certain task data structure is still prevented from being moved to a running tasks queue, wherein the additional number is responsive to a task starvation watermark.
24. The computer program product according to claim 23 comprising instructions for receiving sorting rules indicators that indicate, for each sorting rule, whether the sorting rule is an ascending sorting rule or a descending sorting rule.
25. The computer program product according to claim 23 comprising instructions for sorting task data structures within each unfrozen sorted tasks queue, during each scheduling iterations, according to hierarchical sorting rules.
26. The computer program product according to claim 23 comprising instructions for freezing sorted tasks queues other than a sorted tasks queue that stores the certain task data structure.