Automatic control valve system for hydraulic motor

Claim 2

A control valve system for connecting first, second and third hydraulic motors in series, in parallel, or in series-parallel with one another in a pump fluid circuit, each of which motors has first and second ports, one for connection with either one of the high or low pressure sides of the pump fluid circuit while the other is connected to the other side of the pump fluid circuit and which motors are reversible upon reversal of the direction of flow of pump fluid, comprising: a first fluid conduit adapted to be connected to one side of the fluid circuit and to the first port of the first motor, a second fluid conduit adapted to be connected to the second port of the first motor, a third fluid conduit adapted to be connected to the first port of the second motor, a fourth fluid conduit adapted to be connected to the second port of the second motor, a fifth fluid conduit adapted to be connected to the first port of the third motor, and a sixth fluid conduit adapted to be connected to the other side of the fluid circuit and to the second port of the third motor, first and second valve means each having first and second pump fluid ports and first and second service ports, the first and second pump fluid ports of both valve means being respectfully connected to the first and second fluid conduits, the first service ports of the first and second valve means being respectfully connected to second and fourth fluid conduits and the second service ports of the first and second valve means being respectfully connected to the third and fifth fluid conduit, each of said valve means being shiftable between three positions, in the first of which the service ports thereof are connected together and fluid flow from the pump fluid ports to the service ports is substantially blocked, in the second and third of which positions the first service and first pump fluid ports are connected together and the second service and second pump fluid ports are connected together and means for shifting said first and second valve means between said positions.

Claim 3

The control valve system recited in claim 1, wherein said valve means are of the spool valve type reciprocating in valve bores, and wherein in the first position thereof they are centered and in the second and third positions thereof the spools are disposed towards respectively opposite ends of the bores, spring means for normally centering the valve means, and pilot valve means associated with the opposite ends of the bores for controlling relative fluid pressures therein, whereby to shift the valve means to said second and third positions by differential fluid pressures in the bore ends.

Claim 4

The combination claimed in claim 2, at least some of said pilot valve means being responsive to differential pressures prevailing at the pump fluid ports.

Claim 5

The control valve system recited in claim 2, at least one of said pilot valve means being externally controllable.

Claim 6

The control valve system recited in claim 1, wherein said valve means are of the spool type which, in the shifting of the valve from position to position could normally block fluid flow to or from at least one service port but for a transitional mode bypass system, said bypass system comprising pressure-responsive check valves and means providing fluid connections past the check valves from pump fluid ports to a service port in response to differential pressure in thE service ports.

Claim 7

A control valve system for connecting first, second and third hydraulic motors in series, in parallel, or in a series-parallel with one another in a pump fluid circuit, each of which motors has first and second ports, one for connection with either one of the high or low pressure sides of the pump fluid circuit while the other is connected to the other side of the pump fluid circuit and which motors are reversible upon reversal of the direction of flow of pump fluid, comprising: a first fluid conduit adapted to be connected to one side of the fluid circuit and to the first port of the first motor, a second fluid conduit adapted to be connected to the second port of the first motor, a third fluid conduit adapted to be connected to the first port of the second motor, a fourth fluid conduit adapted to be connected to the second port of the second motor, a fifth fluid conduit adapted to be connected to the first port of the third motor, and a sixth fluid conduit adapted to be connected to the other side of the fluid circuit and to the second port of the third motor, first and second spool valve chambers each having first and second pump fluid ports and first and second service ports, the first and second pump fluid ports of both valve chambers being respectfully connected to the first and second fluid conduits, the first service ports of the first and second valve chambers being respectfully connected to second and fourth fluid conduits and the second service ports of the first and second valve means being respectfully connected to the third and fifth fluid conduit means, first and second spool valves reciprocable in said chambers respectively between three positions, in the first of which the service ports thereof are connected together and fluid flow from the pump fluid ports to the service ports is substantially blocked, in the second and third of which positions the first service and first pump fluid ports are connected together and the second service and second pump fluid ports are connected together, and means for shifting said first and second spool valves between said positions.

Claim 8

A control valve system for connecting first, second and third hydraulic motors in series, in parallel, or in a series-parallel with one another in a pump fluid circuit, each of which motors has first and second ports, one for connection with either one of the high or low pressure sides of the pump fluid circuit while the other is connected to the other side of the pump fluid circuit and which motors are reversible upon reversal of the direction of flow of pump fluid, comprising: a first fluid conduit adapted to be connected to one side of the fluid circuit and to the first port of the first motor, a second fluid conduit adapted to be connected to the second port of the first motor, a third fluid conduit adapted to be connected to the first port of the second motor, a fourth fluid conduit adapted to be connected to the second port of the second motor, a fifth fluid conduit adapted to be connected to the first port of the third motor, and a sixth fluid conduit adapted to be connected to the other side of the fluid circuit and to the second port of the third motor, first and second spool valve chambers each having first and second pump fluid ports and first and second service ports, the first and second pump fluid ports of both valve chambers being respectfully connected to the first and second fluid conduits, the first service ports of the first and second valve chambers being respectfully connected to second and fourth fluid conduits and the second service ports of the first and second valve means being respectfully connected to the third and fifth fluid conduit means, first and second spool valves reciprocable in said chambers respectively between three positions, in the first of which the service ports thereof are connected together and fluid flow from the pump fluid ports to the service ports is substantially blocked, in the second and third of which positions the first service and first pump fluid ports are connected together and the second service and second pump fluid ports are connected together, and means for shifting said first and second spool valves between said positions.

Claim 9

The control valve system recited in claim 6, said first and second pump fluid ports being respectively disposed towards opposite ends of said valve chambers and the service ports being disposed relatively towards the center of the pump chamber, spring means for normally biasing the spool valves towards a central position, said spool valves having lands at the opposite ends thereof, and the distances between the lands being slightly less than the distances between the extremities of the pump fluid ports, whereby high pressure fluid from one of the fluid conduits leaks past a land end into one end or the other of each valve chamber, means providing an orifice between opposite ends of each valve chamber, the means for shifting the spool valves between said positions comprising pilot valves associated with the opposite ends of the chambers and operable to relieve the fluid pressure associated chamber end and thereby effect shifting of the spool valves.

Claim 10

The control valve system recited in claim 7, wherein at least one of said pilot valves is responsive to the pressure of fluid flowing through said orifice means.

Claim 11

A control valve system for connecting a plurality of hydraulic motors in series or in parallel with one another in a pump fluid circuit, each of which motors has first and second ports, one for connection with either one of the high or low pressure sides of the pump fluid circuit while the other is connected to the other side of the pump fluid circuit, comprising: a first fluid conduit adapted to be connected to one side of the pump fluid circuit and to the first port of one motor, a second fluid conduit adapted to be connected to the second port of said one motor, a third fluid conduit adapted to be connected to the first port of another motor, a fourth fluid conduit adapTed to be connected to the other side of the pump fluid circuit and to the second port of the other motor, and valve means shiftable between first and second positions for alternatively connecting the second and third fluid conduits together while in the first position or for connecting the third and first fluid conduits together while connecting the second and fourth fluid conduits together while in the second position.

Claim 12

A control valve system for connecting a plurality of hydraulic motors in series or in parallel with one another in a pump fluid circuit, each of which motors has first and second ports, one for connection with either one of the high or low pressure sides of the pump fluid circuit while the other is connected to the other side of the pump fluid circuit, comprising: a first fluid conduit adapted to be connected to one side of the pump fluid circuit and to the first port of one motor, a second fluid conduit adapted to be connected to the second port of said one motor, a third fluid conduit adapted to be connected to the first port of another motor, a fourth fluid conduit adapTed to be connected to the other side of the pump fluid circuit and to the second port of the other motor, and valve means shiftable between first and second positions for alternatively connecting the second and third fluid conduits together while in the first position or for connecting the third and first fluid conduits together while connecting the second and fourth fluid conduits together while in the second position.

Claim 13

The combination claimed on claim 9, said valve means being normally in said first position and being responsive to pressure differential between pressure prevailing in said first and second conduits and shifting from the first to the second position in response to pressure differential above a predetermined norm.