DEVICE FOR OPENING OR FOLDING CRANE BOOM HEAD MEMBERS Russian patent published in 2005 - IPC

FIELD: mechanical engineering; tower cranes.

SUBSTANCE: invention relates to tower cranes whose beams consist of several articulated members. Device contains bracket to operate device by crane hoisting wire rope arranged in front part of last main member of boom and furnished with sheave to pass hoisting wire rope at opening or folding of boom head members. Hoisting wire rope is secured to front end of second head member for folding first head member in direction square to main member of boom. Connecting device connecting front part of last main member, first and second head members of boom contains at least one rocker-and-connecting rod system arranged in vertical plane and hinge-connected, respectively, with two head members and with front part of last main member of boom. Rocker-and-connecting rod system contains lever of the first order hinge-connected by its intermediate point with top of first head member of boom, front connecting rod hinge-connected by one end with front point of lever and by other end, with second head member of boom, and rear rocker hinge-connected by one end with rear point of lever and by other end, with front part of last main member of boom. Drive used for opening-folding of boom is made in form of lead screw.

EFFECT: provision of increased speed of folding of boom head members.

6 cl, 7 dwg