Crane overload safety device

Claim 2

An overload safety device designed for variable-reach cranes, said device comprising: a load pick-up; a reach pick-up; load sensing means incorporated in said load pick-up; reach sensing means incorporated in said reach pick-up; a converter incorporated in said load pick-up and adapted to change the mechanical movement of said load sensing means into electrical signals; a converter incorporated in said reach pick-up and adapted to change the mechanical movement of said reach sensing means into electrical signals; a load pick-up converter screen mounted on said load sensing means; load pick-up converter cores mounted on said load sensing means; primary and secondary coils fitted in said cores and positioned so that there is a gap formed therebetween for said screen to freely move therein when load change takes place; a sine-wave generator circuit in which said primary coils are inserted theRein; a detector being connected to said secondary coils, said secondary coils being wound differentially; a comparison circuit the input of which is connected to the outputs of said load and reach pick-ups; an overload warning device connected to one of the outputs of said comparison circuit; and crane actuating arrangements connected to another output of said comparison circuit.

Claim 3

An overload safety device designed for variable-reach cranes, said device comprising; a load pick-up; a reach pick-up; load sensing means incorporated in said load pick-up; reach sensing means incorporated in said reach pickup; a converter incorporated in said load pick-up and adapted to change the mechanical movement of said load sensing means into electrical signals; a converter incorporated in said reach pick-up and adapted to change the mechanical movement of said reach sensing means into electrical signals; a reach pick-up converter screen mounted on said reach sensing means; reach pick-up converter cores mounted on said reach sensing means; primary and secondary coils fitted in said cores and positioned so that there is a gap formed therebetween for said screen to freely move therein when reach change takes place; a sine-wave generator circuit in which said primary coils are inserted therein; a detector being connected to said secondary coils, said secondary coils being wound differentially; a comparison circuit the input of which is connected to the outputs of said load and reach pick-ups; an overload warning device connected to one of the outputs of said comparison circuit; and crane actuating arrangements connected to another output of said comparison circuit.

Claim 4

An overload safety device designed for variable-reach cranes, said device comprising; a load pick-up; a reach pick-up; load sensing means incorporated in said load pick-up; reach sensing means incorporated in said reach pickup; a converter incorporated in said load pick-up and adapted to change the mechanical movement of said load sensing means into electrical signals; a converter incorporated in said reach pick-up and adapted to change the mechanical movement of said reach sensing means into electrical signals; a reach pick-up converter screen mounted on said reach sensing means; reach pick-up converter cores mounted on said reach sensing means; primary and secondary coils fitted in said cores and positioned so that there is a gap formed therebetween for said screen to freely move therein when reach change takes place; a sine-wave generator circuit in which said primary coils are inserted therein; a detector being connected to said secondary coils, said secondary coils being wound differentially; a comparison circuit the input of which is connected to the outputs of said load and reach pick-ups; an overload warning device connected to one of the outputs of said comparison circuit; and crane actuating arrangements connected to another output of said comparison circuit.

Claim 5

An overload safety device as claimed in claim 2, in which there is additionally provided a kinematic connection between said screen and a boom operating mechanism and a kinematic connection between said cores and another crane boom operating mechanism.

Claim 6

An overload safety device designed for variable-reach cranes, said device comprising: a load pick-up; a reach pick-up; a load sensing means incorporated in said load pick-up; reach sensing means incorporated in said reach pick-up; a converter incorporated in said load pick-up and adapted to change the mechanical movement of said load sensing means into electrical signals; a converter incorporated in said reach pick-up and adapted to change the mechanical movement of said reach sensing means into electrical signals; a load pick-up converter screen mounted on said load sensing means; a reach pick-up converter screen mounted on said reach sensing means; load pick-up converter cores mounted on said load sensing means; reach pick-up converter cores mounted on said reach sensing means; primary and secondary coils fitted in said load pick-up converter cores and positioned so that there is a gap formed therebetween for said load pick-up converter screen to freely move therein when load change takes place; a sine-wave generator circuit in which said primary coils fitted in said load pick-up converter cores are inserted therein; a detector being connected to said secondary coils fitted in said load pick-up converter cores, said secondary coils being wound differentially; primary and secondary coils fitted in said reach pick-up converter cores and positioned so that there is a gap formed therebetween for said reach pick-up converter screen to freely move therein when reach change takes place; a sine-wave generator circuit in which said primary coils fitted in said reach pick-up converter cores are inserted therein; a detector being connected to said secondary coils fitted in said reach pick-up converter cores, said secondary coils being wound differentially; a comparison circuit the input of which is connected to the outputs of said load and reach pick-ups; an overload warning device connected to one of the inputs of the comparison circuit; and crane actuating arrangements connected to another output of said comparison circuit.

Claim 7

An overload safety device designed for variable-reach cranes, said device comprising: a load pick-up; a reach pick-up; a load sensing means incorporated in said load pick-up; reach sensing means incorporated in said reach pick-up; a converter incorporated in said load pick-up and adapted to change the mechanical movement of said load sensing means into electrical signals; a converter incorporated in said reach pick-up and adapted to change the mechanical movement of said reach sensing means into electrical signals; a load pick-up converter screen mounted on said load sensing means; a reach pick-up converter screen mounted on said reach sensing means; load pick-up converter cores mounted on said load sensing means; reach pick-up converter cores mounted on said reach sensing means; primary and secondary coils fitted in said load pick-up converter cores and positioned so that there is a gap formed therebetween for said load pick-up converter screen to freely move therein when load change takes place; a sine-wave generator circuit in which said primary coils fitted in said load pick-up converter cores are inserted therein; a detector being connected to said secondary coils fitted in said load pick-up converter cores, said secondary coils being wound differentially; primary and secondary coils fitted in said reach pick-up converter cores and positioned so that there is a gap formed therebetween for said reach pick-up converter screen to freely move therein when reach change takes place; a sine-wave generator circuit in which said primary coils fitted in said reach pick-up converter cores are inserted therein; a detector being connected to said secondary coils fitted in said reach pick-up converter cores, said secondary coils being wound differentially; a comparison circuit the input of which is connected to the outputs of said load and reach pick-ups; an overload warning device connected to one of the inputs of the comparison circuit; and crane actuating arrangements connected to another output of said comparison circuit.

Claim 8

An overload safety device as clAimed in claim 4, in which there is additionally provided a kinematic connection between said screen of said reach pick-up and a boom reach operating mechanism and a kinematic connection between said cores of said reach pick-up and another boom reach operating mechanism.

Claim 9

An overload safety device designed for variable-reach cranes, said device comprising: a load pickup; a reach pick-up; load sensing means incorporated in said load pick-up; a reach sensing means incorporated in said reach pick-up; a converter incorporated in said load pick-up and adapted to change the mechanical movement of said load sensing means into electrical signals; a converter incorporated in said reach pick-up and adapted to change the mechanical movement of said reach sensing means into electrical signals; a screen provided as a common component of said load pick-up converter and said reach pick-up converter and being mounted on said load sensing means; load pick-up converter cores mounted on said load sensing means; reach pick-up converter cores also mounted on said load sensing means; primary and secondary coils fitted in said load pick-up converter cores and in said reach pick-up converter cores, said primary and secondary coils being positioned so that there is a gap formed therebetween for said screen to freely move therein when load and reach changes take place; a sine-wave generator circuit in which said primary coils fitted in said load pick-up converter cores are inserted therein; a detector being connected to said secondary coils fitted in said load pick-up converter cores, said secondary coils being wound differentially; a sine-wave generator circuit in which said primary coils fitted in said reach pick-up converter cores are inserted therein; a detector being wound differentially; a comparison circuit the input of which is connected to the outputs of said load and reach pick-ups; an overload warning device connected to one of the outputs of said comparison circuit; and crane actuating arrangements connected to another output of said comparison circuit.

Claim 10

An overload safety device designed for variable-reach cranes, said device comprising: a load pickup; a reach pick-up; load sensing means incorporated in said load pick-up; a reach sensing means incorporated in said reach pick-up; a converter incorporated in said load pick-up and adapted to change the mechanical movement of said load sensing means into electrical signals; a converter incorporated in said reach pick-up and adapted to change the mechanical movement of said reach sensing means into electrical signals; a screen provided as a common component of said load pick-up converter and said reach pick-up converter and being mounted on said load sensing means; load pick-up converter cores mounted on said load sensing means; reach pick-up converter cores also mounted on said load sensing means; primary and secondary coils fitted in said load pick-up converter cores and in said reach pick-up converter cores, said primary and secondary coils being positioned so that there is a gap formed therebetween for said screen to freely move therein when load and reach changes take place; a sine-wave generator circuit in which said primary coils fitted in said load pick-up converter cores are inserted therein; a detector being connected to said secondary coils fitted in said load pick-up converter cores, said secondary coils being wound differentially; a sine-wave generator circuit in which said primary coils fitted in said reach pick-up converter cores are inserted therein; a detector being wound differentially; a comparison circuit the input of which is connected to the outputs of said load and reach pick-ups; an overload warning device connected to one of the outputs of said comparison circuit; and crane actuating arrangements connected to another output of said comparison circuit.

Claim 11

An overload safety device as claimed in claim 6, in which said converter of said reach pick-up is additionally provided with a movable element which mounts said cores of said reach pick-up and is kinematically connected to said load sensing means, said movable element providing for correlated movement of said cores along the plane of said screen.

Claim 12

An overload safety device as claimed in claim 6, in which there is additionally provided a kinematic connection between said screen and a boom reach operating mechanism and a kinematic connection between said cores of said reach pick-up and another boom reach operating mechanism.