Load moment indicator system
First Claim
1. In a crane having a load bearing cable, a base, a boom pivotally mounted to said base, and a hydraulic cylinder having a cylinder and a piston rod for raising and lowering said boom, a load moment indicator system comprising:
- means for generating a first signal which is indicative of an angle between said boom and said base;
means for generating a second signal which is indicative of a length of said boom;
a strain sensor embedded in said piston rod for generating a third signal which is indicative of the weight of a load which is connected to said load bearing cable;
means for receiving said signals and for determining a maximum load lifting capacity based on said first and second indicative signals; and
means for determining if the weight of said load corresponding to said third signal is greater than a predetermined percentage of said maximum load lifting capacity.
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Accused Products
Abstract
A load moment indicator system for lift equipment, the system including a sensor embedded in a solid portion of the piston rod of the lifting cylinder of the equipment for generating a signal which is indicative of the load being lifted. A stored value representing the maximum load lifting capacity of the lift equipment for a particular load zone is then compared to the actual load signal, and where the actual load approaches or exceeds the maximum load lifting capacity, alarm signals are activated and/or the operating functions creating the overload incapacitated.
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Citations
17 Claims
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1. In a crane having a load bearing cable, a base, a boom pivotally mounted to said base, and a hydraulic cylinder having a cylinder and a piston rod for raising and lowering said boom, a load moment indicator system comprising:
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means for generating a first signal which is indicative of an angle between said boom and said base; means for generating a second signal which is indicative of a length of said boom; a strain sensor embedded in said piston rod for generating a third signal which is indicative of the weight of a load which is connected to said load bearing cable; means for receiving said signals and for determining a maximum load lifting capacity based on said first and second indicative signals; and means for determining if the weight of said load corresponding to said third signal is greater than a predetermined percentage of said maximum load lifting capacity. - View Dependent Claims (2, 3, 4, 5, 6)
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7. In material handling equipment including support means, a lifting member movable relative to said support means, and a hydraulic cylinder assembly including a cylinder and an at least partially solid piston rod for raising and lowering said lifting member, a load moment indicator system comprising:
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a strain sensor embedded in the solid portion of said piston rod for generating a signal indicative of the weight of a load on said lifting member; means for storing a value representing the said signal maximum load lifting capacity of the lifting member; means for comparing said signal with said value to determine if the weight of said load as indicated by said signal exceeds a predetermined percentage of said value representing the maximum load lift capacity; and means for providing an output signal based on said predetermined percentage, said output signal providing an alarm signal and/or disabling said lift member depending on such percentage of maximum load lifting capacity. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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15. In material handling equipment including support means, a lifting member movable relative to said support means, and a cylinder assembly including a fixed housing and an at least partially solid longitudinally movable load member mounted in said housing for raising and lowering said lifting member, a load moment indicator system comprising:
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a strain sensor embedded in the solid portion of said load member for generating a signal indicative of the weight of a load on said lifting member when in a particular position or zone; means for storing a value representing when in such position or zone maximum load lifting capacity of the lifting member; means for comparing said signal with said value to determine if the weight of said load as indicated by said signal exceeds a predetermined percentage of said value representing the maximum load lift capacity; and means for providing an output signal based on said predetermined percentage, said output signal providing an alarm signal and/or disabling the operating functions of said lifting member and/or said load member depending on such percentage of maximum load lifting capacity. - View Dependent Claims (16, 17)
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Specification