Abstract: A fluid flow control valve system to be used to control a hydraulic lifting mechanism used on elevators and the like. The valve system includes an inlet conduit from the pump and an inlet-outlet to and from a jack connected together by a conduit with a one-way valve operable in the direction from the pump to the jack, a first by-pass chamber connected to the pump side of the one-way valve and a second by-pass chamber connected to the jack side of said one-way valve, outlets to the pump sump from each by-pass chamber, and a movable gate control mechanism for controlling the exit of pressurized fluid from the first by-pass chamber or the second by-pass chamber through the outlets to the pump sump. Hydraulic fluid from the pump when the first chamber is sealed, passes through the one-way check valve. When the second chamber is also sealed, the fluid will provide pressure to a jack to lift a load. With the first chamber gate opened at least a portion or all of the fluid passes back to the sump.

Abstract: A hydraulic elevator is employed having the usual call buttons at the respective floors and selector buttons for all floors located in the elevator cab. When a button is pushed to select a floor to which the cab is to travel, up or down, as the case may be, the cab starts moving slowly in the selected direction. During initial movement a cam on the cab triggers components in an electric circuit which, by motivating hydraulic valving causes the cab initially to accelerate to a selected rate of travel after which travel proceeds at the selected rate to a slow down point. At that point another component is triggered and the valving causes the cab to decelerate for a selected interval of travel, after which the cab moves slowly to the level to which it was called.The invention here disclosed is one of a balanced electric bridge circuit which is made constantly sensitive to the rate of travel of the cab by use of a stationary tape extending for the full height of the vertical hoist way.

Abstract: When a Hydraulically operated valve is used to control the operation of a hydraulic elevator, it is required to do so in a manner such that as the elevator cab approaches a floor level in either direction, it is first decelerated through a transition cycle and after that moved slowly a short distance through a creeping cycle to the floor level where it stops. In the up direction, an extra heavy load cuts the transistion time and adds objectionably to the time needed for up leveling. The compensating valve of the invention is interposed in the hydraulic line of the operating valve which normally is depended on to cause deceleration for transition, replacing the deceleration valve. A plunger in the compensating valve is shifted by an increase in hydraulic pressure resulting from an extra heavy load.

Abstract: A hydraulic valve assembly for operating a hydraulic elevator is simplified in its construction by positioning the check valve for the up level control in axial alignment with the bypass valve in the same valve housing mutually guided on a central valve stem. Pressure for actuating the bypass valve is controlled by a direct acting valve element structurally mounted on the valve element of the up leveling check valve.

Abstract: When a Hydraulically operated valve is used to control the operation of a hydraulic elevator, it is required to do so in a manner such that as the elevator cab approaches a floor level in either direction, it is first decelerated through a transition cycle and after that moved slowly a short distance through a creeping cycle to the floor level where it stops. In the up direction, an extra heavy load cuts the transistion time and adds objectionably to the time needed for up leveling. The compensating valve of the invention is interposed in the hydraulic line of the operating valve which normally is depended on to cause deceleration for transition, replacing the deceleration valve. A plunger in the compensating valve is shifted by an increase in hydraulic pressure resulting from an extra heavy load.