Hydraulic control

Claim 1

A device for controlling the operation of an external member, said device comprising the following: a cylinder, for containing fluid, said cylinder containing a movable piston therein, said piston being joined to a piston rod which rod extends at least partially without said cylinder; first fluid conduit means linking one end of said cylinder with said cylinder''s other end, said first conduit means including spaced first and second one way check valves, said check valves each restricting fluid flow in opposite directions to each other; second fluid conduit means, communicatingly connected in parallel to said first fluid conduit means, and across said first and second check valves, said second fluid conduit means including spaced first and second flow regulating valves; means for fluid communication between said first and second conduit means, said communication means extending from intermediate said flow regulating valves to intermediate said check valves; and third fluid conduit means communicatingly connected in parallel to said second fluid conduit means, said third means including spaced first and second means for removably blocking fluid flow through said second and third fluid conduit means, and an auxiliary pump in said third conduit means in communication with both of said fluid blocking means, whereby upon said pump being operated, one of said blocking means acts to block said second conduit means and permit pumped fluid in said third conduit means to flow to said cylinder via a portion of said second and first conduit means.

Claim 2

A device for controlling the operation of an external member, said device comprising the following: a cylinder, for containing fluid, said cylinder containing a movable piston therein, said piston being joined to a piston rod which rod extends at least partially without said cylinder; first fluid conduit means linking one end of said cylinder with said cylinder''s other end, said first conduit means including spaced first and second one way check valves, said check valves each restricting fluid flow in opposite directions to each other; second fluid conduit means, communicatingly connected in parallel to said first fluid conduit means, and across said first and second check valves, said second fluid conduit means including spaced first and second flow regulating valves; means for fluid communication between said first and second conduit means, said communication means extending from intermediate said flow regulating valves to intermediate said check valves; and third fluid conduit means communicatingly connected in parallel to said second fluid conduit means, said third means including spaced first and second means for removably blocking fluid flow through said second and third fluid conduit means, and an auxiliary pump in said third conduit means in communication with both of said fluid blocking means, whereby upon said pump being operated, one of said blocking means acts to block said second conduit means and permit pumped fluid in said third conduit means to flow to said cylinder via a portion of said second and first conduit means.