Mechanism for positioning and restricting crane control levers to prevent dangerous load condition

Claim 2

A mechanism for positioning and restraining manual control levers on a crane or the like, comprising opposing members movable toward and away from each other between mechanism active and inactive positions relative to said control levers, control lever contact elements on said members engageable with said control levers in said mechanism active position and returning the levers automatically to a neutral position and restraining said levers against movement in directions which would produce a dangerous load condition on a crane, an actuator means for said mechanism, a control means for said actuator means responding to the operation of a safe load sensing means, and a support means for gang mounting said control levers pivotally on a common pivot axis, said levers having crank extensions extending between said opposing members, and said contact elements on the members being aligned with the crank extensions and contacting the latter when the members move toward each other in said mechanism active position.

Claim 3

The structure of claim 1, and fixed stop means extending between said members and being aligned with certain of the contact elements on the members, whereby such contact elements will engage opposite sides of the fixed stop means in said mechanism active position.

Claim 4

The structure of claim 1, and said contact elements comprising laterally spaced adjustable screw contacts on each of the members disposed for engagement with one side of the crank extensions of particular control levers in said gang.

Claim 5

The structure of claim 1, and additional control linkage means connected with said crank extensions of said levers and adapted to operate control valves in a crane hydraulic system to thereby regulate basis crane movements.

Claim 6

The structure of claim 1, and a floor member forming a part of a crane cab or the like, said support means for said gang of control levers comprising a support shaft for the pivotal mounting of said levers above the floor member, said members having said contact elements disposed beneath the floor member, support arms for said members having pivotal connections with said shaft above the floor member, and said floor member having slots receiving said crank extensions and arms.

Claim 7

A mechanism for positioning and restraining manual control levers on a crane or the like, comprising opposing members movable toward and away from each other between mechanism active and inactive positions relative to said control levers, control lever contact elements on said members engageable with said control levers in said mechanism active position and returning the levers automatically to a neutral position and restraining said levers against movement in directions which would produce a dangerous load condition on a crane, an actuator means for said mechanism, a control means for said actuator means responding to the operation of a safe load sensing means, and a fixed support shaft, a gang of said control levers pivotally mounted on said support shaft and having crank extensions disposed between said opposing members and being aligned with said contact elements on the members, supporting arms for the members pivotally secured to said support shaft, said actuator means comprising an extensible and retractable device, one relatively movable part of said device having a connection with one of said members and the other relatively movable part of said device having a connection with the other member in such a way that the extension and retraction of the device causes simultaneous movements of the members toward and away from each other.

Claim 8

A mechanism for positioning and restraining manual control levers on a crane or the like, comprising opposing members movable toward and away from each other between mechanism active and inactive positions relative to said control levers, control lever contact elements on said members engageable with said control levers in said mechanism active position and returning the levers automatically to a neutral position and restraining said levers against movement in directions which would produce a dangerous load condition on a crane, an actuator means for said mechanism, a control means for said actuator means responding to the operation of a safe load sensing means, and a fixed support shaft, a gang of said control levers pivotally mounted on said support shaft and having crank extensions disposed between said opposing members and being aligned with said contact elements on the members, supporting arms for the members pivotally secured to said support shaft, said actuator means comprising an extensible and retractable device, one relatively movable part of said device having a connection with one of said members and the other relatively movable part of said device having a connection with the other member in such a way that the extension and retraction of the device causes simultaneous movements of the members toward and away from each other.

Claim 9

The structure of claim 6, and fixed stop means for said members when the members are shifted by said device toward each other to said mechanism active position.

Claim 10

The structure of claim 6, and said device comprising a cylinder-piston unit with the piston rod of said unit connected to one of said members, and an actuating linkage interconneCting the cylinder of said device to said other member.

Claim 11

The structure of claim 8, and said actuating linkage comprising a crank arm having a fixed pivot between its ends, one end of said crank arm pivotally connected to said cylinder and supporting the cylinder, and a connecting rod pivotally attached to the other end of the crank arm and extending to and connecting with the member with which the piston rod of said unit is connected.

Claim 12

The structure of claim 8, and a biasing spring in the cylinder of said unit bearing on the piston of the unit and causing the unit to normally maintain the mechanism in said active position relative to said control levers.

Claim 13

In a crane or the like, a gang of manual control levers arranged in side-by-side spaced relationship for convenient manipulation by an operator, a common support shaft for said gang of levers of which they are all pivotally mounted, a pair of opposing elongated bar members spanning said gang of levers transversely thereof and in parallel relation to said shaft, one bar member of the pair disposed on each side of the gang of levers in unattached relationship thereto, said bar members being movable in unison toward and away from each other and toward and away from opposite sides of the gang of levers, a common actuator means for said pair of bar members causing them to move in unison between inactive separated positions relative to the gang of control levers and active engaging positions relative to the gang of control levers, and an automatic control means for said common actuator means responding to the operation of a safe load sensing means on a crane or the like.

Claim 14

In a crane or the like, a gang of manual control levers arranged in side-by-side spaced relationship for convenient manipulation by an operator, a common support shaft for said gang of levers of which they are all pivotally mounted, a pair of opposing elongated bar members spanning said gang of levers transversely thereof and in parallel relation to said shaft, one bar member of the pair disposed on each side of the gang of levers in unattached relationship thereto, said bar members being movable in unison toward and away from each other and toward and away from opposite sides of the gang of levers, a common actuator means for said pair of bar members causing them to move in unison between inactive separated positions relative to the gang of control levers and active engaging positions relative to the gang of control levers, and an automatic control means for said common actuator means responding to the operation of a safe load sensing means on a crane or the like.

Claim 15

The structure of claim 11, and said actuator means being resiliently biased in said active engaging position.

Claim 16

The structure of claim 11, and plural spaced individual control lever contact elements on said bar members engageable with selected control levers to return the same to neutral positions and to restrain selected control levers from movement in directions which would produce a dangerous load condition on a crane or the like.

Claim 17

The structure of claim 12, and said actuator means comprising an extensible and retractable mechanical actuator, and a linkage having connections with said mechanical actuator and said bar members and operable to move said bar members in unison.

Claim 18

The structure of claim 14, and said actuator means comprising a cylinder-piston unit having a fluid inlet and outlet on one side of the piston of said unit, said biasing means comprising a spring engaging the other side of the piston and opposing movement of the piston in response to fluid pressure on said one side thereof.

Claim 19

The structure of claim 15, and said control means comprising a valve, and a fluid conduit leading from the valve to said inlet and outlet of the cylinder-piston unit.

Claim 20

The structure of claim 16, and said valve being a solenoid-operated valve, and a relay electrically connected with the solenoid of said valve and also connected with said safe load sensing means and responding to an electrical signal from said sensing means.