Warning system for load handling equipment

Claim 2

A warning system for producing a warning signal indicating a condition of failure or approach to failure of load handling equipment, comprising: memory means for storing digital data pertaining to discrete operating parameters of said load handling equipment; selection means for selecting portions of the stored digital data from within said memory means in dependence upon at least one operating condition of said equipment; digital to analog conversion means for converting said selected digital data from within said memory means into analog signals; means for generating analog signals representing at least two further operating conditions of said load handling equipment; at least two comparator means for receiving and comparing said analog signals converted from selected digital data from said memory means with said generated analog signals representing at least two further operating conditions and producing, without interpolation between discrete values of said stored digital data, a warning signal when the compared signals reach a predetermined relation.

Claim 3

A warning system for load handling equipment as claimed in claim 1, additionally comprising: said load handling equipment including a crane having a cab mounted boom lifted by cables; said means for generating analog signals including load cell means for measuring the load to be lifted by the boom, one of said further operating conditions thus including said load; a back hitch pin assembly connecting said crane cable to said crane cab; and a pin within said back hitch pin assembly housing said load cell, whereby said warning system may be installed within said crane by changing pins within said back hitch pin assembly and connecting said warning system thereto without connecting externally from said cab.

Claim 4

A warning system for load handling equipment as claimed in claim 1, additionally comprising: means for generating fixed signals for said analog signals representing said at least one operating condition and for said analog signals representing said at least two further operating conditions of said load handling equipment; and switching means for connecting said fixed signals to said warning system including said memory means for establishing a predetermined test sequence to test said warning system including said memory means thereof.

Claim 5

A warning system for load handling equipment, comprising: memory means for storing data peculiar to said equipment; selection means for selecting portions of the stored data from within said memory means and presenting said stored data as sequential sets of output data; first holding and converting means for receiving one set of sequentially presented output data; first sensing means for sensing one equipment parameter; comparing means to which said first holding and converting means and said first sensing means are connected being connected to said selection means for presenting an output signal thereto when said one set of sequentially presented output data reaches a predetermined proportion of said one equipment parameter; second holding and converting means for receiving a second set of sequentially presented output data from said memory means after said output signal is presented to said selection means; second sensing means for sensing a second equipment parameter; compraing means to which said second holding and converting means and said second sensing means are connected for generating an output warning signal when said second set of sequentially presented output data reaches a predetermined proportion of said second equipment parameter.

Claim 6

A warning system for load handling equipment, comprising: memory means for storing data peculiar to said equipment; selection means for selecting portions of the stored data from within said memory means and presenting said stored data as sequential sets of output data; first holding and converting means for receiving one set of sequentially presented output data; first sensing means for sensing one equipment parameter; comparing means to which said first holding and converting means and said first sensing means are connected being connected to said selection means for presenting an output signal thereto when said one set of sequentially presented output data reaches a predetermined proportion of said one equipment parameter; second holding and converting means for receiving a second set of sequentially presented output data from said memory means after said output signal is presented to said selection means; second sensing means for sensing a second equipment parameter; compraing means to which said second holding and converting means and said second sensing means are connected for generating an output warning signal when said second set of sequentially presented output data reaches a predetermined proportion of said second equipment parameter.

Claim 7

A warning system for load handling equipment such as a crane, comprising: memory means for storing data peculiar to said crane including stored data for first and second crane parameters; sensing means for selecting portions of the stored data within said memory means to reflect present operating conditions of said crane; logic means for selecting the remaining portions of the stored data within said memory means to selectively provide said data as output data; first converting means connected to said logic and memory means for converting said output data into a signal representing possible values of said first crane parameter; first parameter measuring means for generating a first parameter signal; comparing means connected to said logic means for comparing the signals from said first converting means and said first parameter measuring means and for applying an output signal to said logic means as said compared signals approach each other; second converting means connected to said logic and memory means for converting said output data into a signal representing maximum values of said seconD crane parameter as said output signal from said last mentioned comparing means is received by said logic means; second parameter measuring means for generating a signal representing said second crane parameter; and comparing and warning means for comparing said signal representing maximum values of said second crane parameter with said signal representing said second crane parameter and for generating a warning as said second crane parameter signal approaches said maximum value of said second crane parameter signal.

Claim 8

A warning system for load handling equipment such as a crane, comprising: memory means for storing data peculiar to said crane including stored data for first and second crane parameters; sensing means for selecting portions of the stored data within said memory means to reflect present operating conditions of said crane; logic means for selecting the remaining portions of the stored data within said memory means to selectively provide said data as output data; first converting means connected to said logic and memory means for converting said output data into a signal representing possible values of said first crane parameter; first parameter measuring means for generating a first parameter signal; comparing means connected to said logic means for comparing the signals from said first converting means and said first parameter measuring means and for applying an output signal to said logic means as said compared signals approach each other; second converting means connected to said logic and memory means for converting said output data into a signal representing maximum values of said seconD crane parameter as said output signal from said last mentioned comparing means is received by said logic means; second parameter measuring means for generating a signal representing said second crane parameter; and comparing and warning means for comparing said signal representing maximum values of said second crane parameter with said signal representing said second crane parameter and for generating a warning as said second crane parameter signal approaches said maximum value of said second crane parameter signal.

Claim 9

A warning system for load handling equipment as claimed in claim 5, wherein: said sensing means includes a first sensor having switching means for providing logic signals to said logic means for enabling portions thereof and disabling other portions thereof and thereby controlling the selection of said stored data from within said memory means; and said sensing means further includes a second sensor having switching means for providing logic signals directly to said memory means for controlling the selection of said stored data from within said memory means.

Claim 10

A warning system for load handling equipment as claimed in claim 6, wherein: said stored data for said first crane parameter is boom angle data; said stored data for said second crand paprameter is maximum boom load data; said first sensor is an extended, retracted sensor for generating a digital signal; and said second sensor is a boom length sensor for generating a plurality of digital signals.

Claim 11

A warning system for load handling equipment as claimed in claim 5, wherein: said memory means includes a read only digital memory; said stored data for first and second crane parameters includes stored digital boom angle data and digital maximum load data; said first crane parameter measuring means includes boom angle measuring means and said second crane parameter measuring means includes load measuring means; said sensing means include means for disabling portions of said read only digital memory depending upon the sensed crane conditions; said first and second converting means connected to said logic and memory means include registers for receiving said stored digital data, and digital to analog converters for generating and applying analog signals to said comparing means and said comparing and warning means; and said comparing means and said comparing and warning means include comparator amplifiers connected for comparing said analog signals and for generating said output signal as the compared analog signals reach a predetermined proportion.

Claim 12

A warning system for load handling equipment as claimed in claim 8, additionally comprising: said comparing and warning means including two comparator amplifiers; a resistive network connecting said two comparator amplifiers to said second converting means and said load measuring means; said warning means further including first and second switching means connected to receive said output signals from said two comparator amplifiers, and first and second indicating means connected to said first and second switching means for providing a first and then a second warning signal as said crane approaches and then reaches a dangerous operating condition.

Claim 13

A warning system for load handling equipment as claimed in claim 9, additionally comprising: a test circuit including a reference potential, resistive network and delay switching means for generating a first reference signal and a delayed second reference signal; and switch means for disconnecting said load measuring means from said two comparator amplifiers and instead connecting said test circuit thereto for providing said first reference signal and said delayed second reference signal to said two comparator amplifiers, whereby said first and second indicating means are respectively energized.

Claim 14

A warning system for load handling equipment as claimed in claim 8 for further indicating the percentage Of safe load being handled by said crane, additionally comprising: third converting means including a digital to analog converter connected to receive said signal representing maximum load from said register within said second converting means; a comparator amplifier connected to receive signals from said third converting means and said load measuring means for comparing said signals; an indicating device connected to receive the output signal from said last mentioned comparator amplifier; and said output from said last mentioned comparator amplifier connected to said third converting means for providing a reference voltage thereto, whereby said indicating device indicates percentage of safe load being handled.

Claim 15

A warning system for load handling equipment as claimed in claim 8 for further indicating the weight of the load being handled by said crane, additionally comprising: said memory means for storing digital data peculiar to said crane further including stored slope data and crane cable tension at zero load data; third and fourth converting means connected to said memory means including registers for repsectively receiving said slope data and said crane cable tension at zero load data and digital to analog converters for generating analog signals representing said slope data and crane cable tension at zero load data; a comparator amplifier connected to receive said crane cable tension at zero load signal from said third digital to analog converter and connected to receive said signal representing the crane load from said load measuring means, the output of said comparator amplifier thereby equalling the difference between said measured crane load and said zero load; said fourth digital to analog converter connected to receive said slope data and connected to receive said output from said last mentioned comparator amplifier as a reference potential, the output signal therefrom thereby represents a value proportional to the load being handled; and indicating means connected to receive said last mentioned output signal for indicating the weight of the load being handled.