Patent ID: 7093433

Claim:
Laying apparatus for cables, lines, or conductors, the laying apparatus having a hydraulic circuit comprising: a variable delivery feed pump for pumping oil through the hydraulic circuit, a motor, hydraulically connected to said feed pump, and able to drive laying means for laying said cables, lines, or conductors, detection means for measuring the pressure of the oil inside said hydraulic circuit and comparing the measured pressure with a pre-determined pressure value, at least one command member of said feed pump which controls delivery of said feed pump, and valve means connected to said detection means and able to modify operation of said hydraulic circuit by acting on said at least one command member of said feed pump which controls delivery of the feed pump to reduce the hydraulic delivery of said feed pump in the event that the pressure measured exceeds said pre-determined pressure value; wherein said detection means and said valve means are of the hydraulic type, and said valve means comprises a valve able to be selectively activated to act on the at least one command member of said feed pump to vary the hydraulic delivery of said feed pump; an actuator, wherein said at least one command member is mechanically connected to said actuator kept in an intermediate position of balance by counteracting elastic means for balancing said actuator arranged inside respective containing chambers; wherein said actuator comprises a hydraulic actuator, at least one of said containing chambers is connected to said valve means, and the activation of said valve means determines the axial displacement of said hydraulic actuator for inverting the direction of pumping or reducing the hydraulic delivery of the feed pump; a distributor valve connected to said containing chambers that axially displaces the actuator in accordance with a manual command, wherein said valve means predominates over said distributor valve in affecting the displacement of the actuator.