초록 ▼

A hoist system for critical loads incorporates improved safety technology to monitor various possible fault conditions. For example, a command-not-operated function causes braking of the hoist when an encoder detects one of a group of conditions including a lack of load movement when a movement comm

A hoist system for critical loads incorporates improved safety technology to monitor various possible fault conditions. For example, a command-not-operated function causes braking of the hoist when an encoder detects one of a group of conditions including a lack of load movement when a movement command is issued by the operating system, failure of encoder feedback, or failure of a control circuit. An uncommanded motion function also causes braking of the hoist when an encoder detects one of a group of conditions including load movement without a movement command issued by the operating system, or reverse directional movement of the load from a directional movement command input by the operating system.

대표청구항 ▼

What is claimed is: 1. A hoisting system comprising: a hoist for lifting a load; brakes connected to said hoist; an operating system for operating said hoist; and a controller for providing single failure proof operation comprising a command-not-operated function that causes braking of said hoist w

What is claimed is: 1. A hoisting system comprising: a hoist for lifting a load; brakes connected to said hoist; an operating system for operating said hoist; and a controller for providing single failure proof operation comprising a command-not-operated function that causes braking of said hoist when an encoder detects one of a group of conditions consisting essentially of: (1) a lack of load movement when a movement command is issued by said operating system, (2) failure of encoder feedback, or (3) failure of a control circuit. 2. The hoisting system of claim 1, wherein said command-not-operated function further comprises a programmed time delay. 3. The hoisting system of claim 2, wherein said programmed time delay compensates for a time delay caused by at least one of backlash and, hoist drive torque proof testing. 4. The hoisting system of claim 1, wherein said controller further comprises an overspeed function that causes braking of said hoist when an encoder detects one of a group of conditions consisting of; (1) a load movement exceeding a predetermined threshold speed in an upward direction, or (2) a load movement exceeding a predetermined threshold speed in a downward direction. 5. The hoisting system of claim 4, wherein said controller further comprises a differential motion function that causes braking of said hoist when a direction and speed of a load movement does not match a direction and speed of a load movement command issued by said operating system. 6. The hoisting system of claim 5, further comprising; a high speed driveline and a low speed driveline; and wherein said controller further comprises a drive train discontinuity function that causes braking of said hoist when a predetermined ratio difference between said high speed driveline speed and said low speed driveline speed is exceeded. 7. The hoisting system of claim 1, wherein said controller further comprises a differential motion function that causes braking of said hoist when a direction and speed of a load movement does not match a direction and speed of a movement command issued by said operating system. 8. The hoisting system of claim 1, further comprising: a high speed driveline and a low speed driveline; and wherein said controller further comprises a drive train discontinuity function that causes braking of said hoist when a predetermined ratio difference between said high speed driveline speed and said low speed driveline speed is exceeded. 9. The hoisting system of claim 1, wherein said encoder is a quadrature encoder. 10. A hoisting system comprising: a hoist for lifting a load; brakes connected to said hoist; an operating system for operating said hoist; and a controller for providing single failure proof operation comprising: an uncommanded motion function that causes braking of said hoist when an encoder detects one of a group of conditions consisting of; (1) load movement without a movement command issued by said operating system, or (2) reverse directional movement of said load from a directional movement command input by said operating system. 11. The hoisting system of claim 10, wherein said controller further comprises an overspeed function that causes braking of said hoist when an encoder detects one of a group of conditions consisting of: (1) a load movement exceeding a predetermined threshold speed in an upward direction, or (2) a load movement exceeding a predetermined threshold speed in a downward direction. 12. The hoisting system of claim 11, wherein said controller further comprises a differential motion function that causes braking of said hoist when a direction and speed of a load movement does not match a direction and speed of a movement command issued by said operating system. 13. The hoisting system of claim 12, further comprising; a high speed driveline and a low speed driveline; wherein said controller further comprises a drive train discontinuity function that causes braking of said hoist when a predetermined ratio difference between said high speed driveline speed and said low speed driveline speed is exceeded. 14. The hoisting system of claim 13, wherein said controller further comprises a command-not-operated function that causes braking of said hoist when an encoder detects one of a group of conditions consisting of (1) a lack of load movement when a movement command is issued by said operating system, (2) failure of encoder feedback, or (3) failure of a control circuit. 15. The hoisting system of claim 14, further comprising a programmed time delay before a function is triggered. 16. The hoisting system of claim 15, wherein said programmed time delay compensates for at least one of hoist drive deceleration and, operator reverse plugging. 17. The hoisting system of claim 15, wherein said programmed time delay compensates for at least one of hoist drive deceleration and, operator reverse plugging. 18. The hoisting system of claim 10, wherein said uncommanded motion function further comprises a programmed time delay. 19. The hoisting system of claim 18, wherein said programmed time delay compensates for at least one of hoist drive deceleration and, operator reverse plugging. 20. The hoisting system of claim 10, wherein said encoder is a quadrature encoder. 21. A method of retrofitting a crane assembly with an improved controller, comprising the steps of: providing a controller providing a single failure proof operation comprising a command-not-operated function that causes braking of a hoist when an encoder detects one of a group of conditions consisting off: (1) a lack of load movement when a movement command is issued by said operating system, (2) failure of encoder feedback, or (3) failure of a control circuit. 22. A method of retrofitting a crane assembly with an improved controller, comprising the steps of: providing a controller providing a single failure proof operation comprising an uncommanded motion function that causes braking of a hoist when an encoder detects one of a group of conditions consisting of: (1) load movement without a movement command issued by said operating system, or (2) reverse directional movement of a load from a directional movement command input by said operating system. 23. A method of providing a lift hoisting diagnostic system comprising the steps of: operating an operating system for moving a crane; issuing a command to move a load with said operating system; detecting non-movement of said load with an encoder; transmitting a signal from said encoder to a controller; comparing said command to move with said signal from said encoder; transmitting from said controller a command to a braking system; and braking said crane. 24. The method of providing a lift hoisting diagnostic system of claim 23, further comprising the step of: compensating for a time delay caused by at least one of backlash and, hoist drive torque proof testing. 25. A method for providing a hoisting diagnostic system comprising steps of: detecting movement of a load with an encoder: transmitting a signal from said encoder to a controller; transmitting a signal from an operating system for commanding movement of said load to said controller; comparing said signal from said encoder with said signal from said operating system; transmitting from said controller a command to a braking system; and braking said crane. 26. The method of providing a hoisting diagnostic system of claim 25, further comprising the step of compensating for a time delay due to at least one of hoist drive deceleration and, operator reverse plugging. 27. A hoisting diagnostic apparatus comprising; a controller for providing single failure proof operation comprising; a command-not-operated function that causes braking of a hoist when an encoder detects one of a group of conditions consisting of: (1) a lack of load movement when a movement command is issued by a operating system, (2) failure of encoder feedback, or (3) failure of a control circuit. 28. A hoisting diagnostic apparatus comprising; a controller for providing single failure proof operation comprising: an uncommanded motion function that causes braking of a hoist when an encoder detects one of a group of conditions consisting of: (1) load movement without a movement command issued by an operating system, or (2) reverse directional movement of a load from a directional movement command input by said operating system. 29. A hoisting diagnostic apparatus comprising: a controller for operating a crane comprising: a complex programmable logic device for receiving signals; a processor for interfacing with said complex programmable logic device; and wherein said complex programmable logic device is programmed with encoder counter logic. 30. The hoisting diagnostic apparatus of claim 29, wherein said complex programmable logic device further comprises encoder signal filters. 31. The hoisting diagnostic apparatus of claim 29, wherein said complex programmable logic device further comprises encoder edge decoders. 32. The hoisting diagnostic apparatus of claim 29, wherein said complex programmable logic device further comprises encoder counter control logic.