Hydraulically operated bridge crane

In a crane construction wherein two transversely spaced rails are spanned by a travelling bridge with end-support means riding said rails, and a hoist trolley and hook movably supported for guided movement along said bridge, the improvement wherein hydraulic-accumulator means including upper and lower parallel closed elongate horizontal cylinders are in fluid communication and are carried by said bridge, said cylinders being rigidly spaced from each other and connected at their ends to said end-support means to thereby contribute structural intergrity to said bridge, a traction cylinder and piston carried by said bridge within a fraction of said span, an elongate horizontal piston/cylinder having a gas connection at one end to said closed horizontal cylinders, hydraulic-circuit means comprising a reversibly controllable hydraulic-power intergrator connecting the other end of piston/cylinder to the tail end of said traction cylinder, and hook-suspension cabling connected to said piston via sheave means mounted to said trolley and to the one end of said bridge which faces the tail end of said traction cylinder.

In a crane construction wherein two transversely spaced longitudinal rails are spanned by a travelling bridge with end-support means riding said rails, and a hoist trolley and hook movably supported for guided movement along said bridge, the improvement wherein said bridge is an elongate structure of high sectional moment of inertia in essentially a single vertical plane of symmetry, hydraulic-accumulator means including upper and lower closed elongate horizontal cylinders in fluid intercommunication and having positional symmetry with respect to said plane, said cylinders being rigidly spaced from each other and connected at their ends to said end-support means to thereby contribute to said high sectional moment of inertia, traction-cylinder and piston means carried by said bridge within a first fraction of said span, a reversibly controllable hydraulic-power integrator connecting said accumulator means to the tail end of said traction cylinder, and hook-suspension cabling connected to said piston via sheave means mounted to said trolley and to the one end of said bridge which faces the tail end of said traction cylinder.

As an article of manufacture, an elongate travelling bridge with end-support means for riding spaced parallel horizontal rails to be spanned by said bridge, said bridge comprising spaced upper and lower closed elongate cylinders defining substantially the full bridge span, hydraulic-accumulator means having a gas-pressurized volume, said cylinders having fluid communication and coating to define substantially the entire gas-pressure volume of said hydraulic-accumulator means, means rigidly connecting said cylinders to each other and defining their spacing, the end-support means being rigidly connected to the respective ends of said cylinders, a traction cylinder and piston carried by said bridge within a first fraction of said span, the tail end of said piston having externally accessible means of cable connection, an elongate piston/cylinder having a gas connection at one end to one of said upper and lower cylinders, and hydraulic-circuit means comprising a reversibly controllable hydraulic power integrator connecting the other end of said piston/cylinder to the tail end of said traction cylinder.