Hydraulic lock refill valve

Claim 2

In a hydraulic device comprising a housing containing a cylinder which is divided into two chambers by a piston mounted on a tubular piston rod and having a first valve therein for controlling the flow of fluid between said chambers, a fluid reservoir, and a second valve selectively placing at least one of said chambers into communication with said fluid reservoir, the improvement comprising: a normally closed third valve so mounted within said tubular piston rod as to cause fluid delivered thereto from a source other than said hydraulic device to be communicated via said tubular piston rod to at least one of said chambers and comprising a valve body, a first seal means in said valve body, a second seal means in said valve body a valve closing means in said valve body having an actuating extension on one end thereof, means for biasing said valve closing means into sealing contact with said first seal means so that said actuating extension extends through and beyond said second seal means without causing sealing contact therewith.

Claim 3

The apparatus of claim 1 including means in said third valve for adjusting the amount of force required to open said first fluid flow controlling valve.

Claim 4

In a hydraulic device, the combination of a tubular member, a pair of end walls in said tubular member forming a cylinder therebetween, a piston mounted for movement within said cylinder, a piston rod fixed to said piston for movement of said piston within said cylinder, a fluid reservoir operatively associated with said tubular member, a check valve mounted within said piston rod for selectively connecting said reservoir and said cylinder, a flow valve means mounted within said piston rod for allowing flow of fluid within said cylinder from one side of said piston to the other when said piston is moved within said cylinder, a fill valve means mounted within said piston rod and having means for receiving a fluid injectioN means, means normally closing said fill valve means against the passage of fluid therethrough, means for opening said fill valve in response to reception of a fluid injection means in said receiving means for injection of fluid from the fluid injection means to said cylinder and for allowing reverse flow of fluid from said cylinder through said fill valve after the fluid injection means stops injecting fluid therethrough and is being withdrawn, and passage means connecting said fill valve means with said cylinder.

Claim 5

In a hydraulic device, the combination of a tubular member, a pair of end walls in said tubular member forming a cylinder therebetween, a piston mounted for movement within said cylinder, a piston rod fixed to said piston for movement of said piston within said cylinder, a fluid reservoir operatively associated with said tubular member, a check valve mounted within said piston rod for selectively connecting said reservoir and said cylinder, a flow valve means mounted within said piston rod for allowing flow of fluid within said cylinder from one side of said piston to the other when said piston is moved within said cylinder, a fill valve means mounted within said piston rod and having means for receiving a fluid injectioN means, means normally closing said fill valve means against the passage of fluid therethrough, means for opening said fill valve in response to reception of a fluid injection means in said receiving means for injection of fluid from the fluid injection means to said cylinder and for allowing reverse flow of fluid from said cylinder through said fill valve after the fluid injection means stops injecting fluid therethrough and is being withdrawn, and passage means connecting said fill valve means with said cylinder.

Claim 6

The device of claim 3 including means in said fill valve means for sealing the latter to a fluid injection means inserted into said receiving means to prevent fluid flow from such an injection means except through said fill valve means.

Claim 7

The device of claim 3 wherein a fluid passage formed within said piston is provided with means for receiving said flow valve which normally closes said fluid passage, said fill valve including means for controlling the force exerted by said flow valve for sealing said fluid passage.

Claim 8

The device of claim 3 wherein said piston rod is a tubular rod, and has formed therein the fluid reservoir, and means for actuating said flow valve to form a temporary communication between said fluid reservoir and said cylinder.