초록 ▼

In a control system of the type having a hydraulic cylinder, a piston slidable in the cylinder and dividing the interior thereof into a first and a second pressure chamber, a pressure fluid reservoir, a pump, conduits having a valve interposed therein which is electronically controlled and connects

In a control system of the type having a hydraulic cylinder, a piston slidable in the cylinder and dividing the interior thereof into a first and a second pressure chamber, a pressure fluid reservoir, a pump, conduits having a valve interposed therein which is electronically controlled and connects the second chamber with the reservoir or pump, respectively, or block the second chamber, and an auxiliary device for operating the system in the event the electronic control for the valve malfunctions, the invention provides a movable member extending into the second chamber; subdividing means located in the second chamber intermediate the movable member and the piston and subdividing the second chamber into a first and a second compartment, the movable member being operable to shift the subdividing means in the second chamber; and valve means controlling communication between the compartments and of the same with the first chamber, the valve means forming with the piston and with the movable member a follow-up control.

대표청구항 ▼

In a follow-up control system, a combination comprising: A. means for changing the position of a movable element during operation of the control system, including a hydraulic cylinder having an interior for accommodating fluid; a piston mounted for movement relative to said cylinder, said piston hav

In a follow-up control system, a combination comprising: A. means for changing the position of a movable element during operation of the control system, including a hydraulic cylinder having an interior for accommodating fluid; a piston mounted for movement relative to said cylinder, said piston having a leading portion which divides the interior of said cylinder into a first and a second chamber, and a trailing portion adapted to be coupled to the element to be moved; means for pumping fluid; means for receiving fluid; conduit means defining a fluid flow path intermediate said pumping means and one of said chambers, and another fluid flow path intermediate said receiving means and the other of said chambers; and means for moving said piston relative to said cylinder, including switching means having a multi-position valving member movable in said flow paths for directing fluid flow, and electronic control means for moving said valving member between one position in which said chambers are respectively connected to said pumping means and said receiving means for moving said piston in one direction, and another position in which said chambers are respectively oppositely connected to said pumping means and said receiving means for moving said piston in an opposite direction; and B. safety override means for adjusting the position of the movable element in the event of malfunction of said electronic control means, including means associated with said piston for subdividing said second chamber into a first and a second compartment said first compartment being defined in part by said piston; valve means having a valve element mounted on said piston for movement relative thereto between a first position in which said compartments are in communication with each other, and a second position in which said first chamber communicates with said first compartment; a pressure-responsive movable member having a contact side facing said valve element, and an opposite side; means for biasing said valving member of said switching means in the event of malfunction of said electronic control means to said one position in which said piston is moved in said one direction until said valve element mounted thereon overlies said contact side; and actuating means at said opposite side of said pressure-responsive member for moving said contact side of the latter into force-transmitting engagement with said valve element so as to move the latter from said first position towards said second position in which fluid from said first chamber enters said first compartment so as to move said piston in direction opposite to said one direction, whereby the position of the movable element is adjusted despite failure of said electronic control means.