| 摘要 |
<p>Safety device for a stretching machine of the brake type comprising a negative brake which can be selectively activated and de-activated so as to constrain and respectively allow the rotation of at least one capstan which supports cables, a pumping device connected to the negative brake and configured to de-activate the latter during the normal use of the stretching machine, putting a working fluid under pressure, pressure energy accumulation means of said working fluid, and a maximum pressure valve configured to regulate the working pressure of a hydraulic motor for controlling the twisting torque applied to the capstan. The device also comprises a motorized drive device connected to the maximum pressure valve and provided to selectively regulate the action of the latter on the hydraulic motor, even in a breakdown condition of at least the pumping device, in order to maintain the working pressure of the hydraulic motor and to maintain the negative brake de-activated by the intervention of the pressure energy accumulation means.</p> |
