Embedded hoist human-machine interface

Abstract

A cable drum receives a length of working cable that is wound in and out from the drum in response to powered rotation of the drum with an uppermost layer of working cable on the drum forming a working surface. A torque sensor in communication with the cable drum measures a torque applied to the cable drum due to tension on the working cable from a load. A drum height gauge is provided for measuring a height of the working surface of the cable on the cable drum. A processor receives the torque value from the torque sensor and the height of the working surface from the drum height gauge and computes a force applied to the length of working cable due to the load based on the torque and height of the working surface. The work performed by the cable may be calculated to assist in determining cable health.

What is claimed is: 
     
         1 . A system comprising:
 a cable drum that receives a length of working cable that is wound in and out from the drum in response to powered rotation of the drum with an uppermost layer of working cable on the drum forming a working surface;   a torque sensor in mechanical communication with the cable drum that measures a torque applied to the cable drum due to tension on the working cable from a load;   a drum height gauge for measuring a height of the working surface of the cable on the cable drum relative to the cable drum;   a processor that receives the torque from the torque sensor and the height of the working surface from the drum height gauge and computes a force applied to the length of working cable due to the load based on the torque and height of the working surface.   
     
     
         2 . The system of  claim 1 , wherein the torque sensor measures the torque applied to a component in a torque path interposing the cable drum and a power source. 
     
     
         3 . The system of  claim 1 , wherein the torque sensor is a magnetic sensor. 
     
     
         4 . The system of  claim 1 , further comprising a display device affixed proximate an end of the drum, the display device providing a numerical readout of the computed force on the working cable. 
     
     
         5 . The device of  claim 1 , wherein the drum height gauge comprises a cable packer assembly with an angle sensor. 
     
     
         6 . The device of  claim 1 , wherein the processor is incorporated into a load moment indicator. 
     
     
         7 . The device of  claim 1 , wherein the processor is incorporated into a drum rotation indicator. 
     
     
         8 . The device of  claim 1 , further comprising:
 an electronic memory associated with the processor;   wherein the processor records into the memory a cumulative amount of work performed by the length of working cable, the work of the length of working cable being defined by the product of the force applied and a distance the load is moved by the length of working cable.   
     
     
         9 . The device of  claim 8 , wherein the electronic memory contains a cumulative work limit associated with the length of working cable and the processor provides an alarm to an operator when the cumulative amount of work performed by the length of working cable passes a predetermined fraction of the cumulative work limit. 
     
     
         10 . A system comprising:
 a powered cable drum that receives a working cable strung onto a boom to lift a load on the boom and that is wound onto the drum such that the load is raised and lowered in response to rotation of the drum;   a torque sensor that is mechanically connected to the cable drum and that measures a torque applied to the cable drum due to tension on the working cable from a load suspended from the boom;   a gauge for measuring a cable height on the cable drum;   a processor that receives the torque from the torque sensor and a cable depth from the gauge and computes a force applied to the length of working cable due to the load based on the torque and the cable depth.   
     
     
         11 . The system of  claim 10 , wherein the processor is in electrical communication with a drum rotation indicator. 
     
     
         12 . The device of  claim 11 , wherein the processor calculates an amount of work performed by the working cable utilizing the computed force and rotation data from the drum rotation indicator. 
     
     
         13 . The device of  claim 12 , further comprising an electronic memory associated with the processor and wherein the processor stores into the memory a cumulative amount of work performed by the length of working cable. 
     
     
         14 . The device of  claim 13 , wherein the electronic memory contains a cumulative work limit associated with the working cable and the processor compares the cumulative work against the work limit and provides a notification when the cumulative work exceeds a predetermined threshold relative to the cumulative work limit. 
     
     
         15 . The device of  claim 10 , wherein the processor comprises a part of a load moment indicator computer. 
     
     
         16 . A device comprising:
 a crane having a boom that suspends a load with a working cable;   a cable drum proximate an opposite end of the boom from the load, the working cable being wound onto the drum such that the load is raised and lowered in response to rotation of the drum;   a torque sensor in mechanical communication with the cable drum so as to determine an amount of torque applied to the cable drum through the working cable;   a drum height gauge that determines the height of working cable wound into the cable drum;   a processor that utilizes the torque and the cable height to determine a force applied to the working cable by the load.   
     
     
         17 . The system of  claim 16 , wherein the processor comprises a component of a load moment indicator computer. 
     
     
         18 . The system of  claim 17 , wherein the processer utilizes data provided by a drum rotation indicator to compute and store into memory a quantity of work performed.