US2760510A - Volume control valve - Google Patents

Description

Aug. 28, 1956 W- D. TRETHEWEY VOLUME CONTROL VALVE 2 Sheets-Sheet 1 Filed Sept. 17, 1953 INVEN TOR William D. Tre fhewey ATTORNFY Aug. 28, 1956 w. D. TRETH EWEY 2,760,510

VOLUME CONTROL VALVE Filed Sept. 1'7, 1953 2 Sheets-Sheet 2 INVENTOR.

William D. Tre fhewey ATTORNEY- VOLUME CONTROL VALVE William D. Trethewey, Douglas, Wyo.

Application September 17, 1953, Serial No. 380,779

7 Claims. (Cl. 137-99) This invention relates to valves and more particularly to hydraulic valves adapted to divide a stream of fluid for operating two or more hydraulic motors simultaneously, and independently of motor load or fluid pressure. Preferably, such valves divide a stream of fluid from a single hydraulic pump into two streams of predetermined flow for operating, for example, a pair of hydraulic cylinder hoists simultaneously, when one has a heavy load and the other has a lighter or no load.

In the use of hydraulic equipment it is frequently necessary to utilize two hydraulic motors and to operate the two from a single source of power. For example, a bulldozer blade, where hydraulic pressure is used to control the blade, usually two hydraulic cylinders raise and lower the blade. The two cylinders are operated by hydraulic fluid pressurized by a single fluid pump. Equipment, including the bulldozer blade, loaders, hay rakes, truck hoists, etc. which have two or more hydraulic cylinders operating from a single source of fluid under pressure, generally have no means of individual control of the cylinders. Both cylinders operate under straight line pressure from the source of power. If one cylinder has more of a load than the other cylinder, it will be the last to move as the fluid will take the least line of resistance. That is, the cylinder under the least load moves first. For instance, if one side of a loader shovel has a lighter load than the other, the cylinder on the light side will get more fluid and will operate faster, further unbalancing the load.

According to the present invention, there is provided a valve which will supply a predetermined amount of fluid into each of two streams from a single source of fluid under pressure. The valve will divide the fluid into two equal fractions of the original stream regardless of the pressure against which each of the streams are forced. The single stream of fluid will be divided into the two equal fractions regardless of the volume of flow or the viscosity of the liquid.

It is an object, therefore, of the present invention to provide a simple device for accurately dividing a stream of fluid into two equal fractions.

It is another object of the invention to provide a de vice to accurately divide a stream of fluid into two equal fractions regardless of the pressure against which the divided streams are forced.

It is a further object of the invention to provide a device to accurately divide a stream of fluid into two equal fractions regardless of the rate of flow of fluid through the valve.

It is still another object of the invention to provide a device which is a volume control device operating on the flow of fluid only, independent of inlet or outlet pressure.

It is yet another object of the invention to provide a valve which supplies an open hydraulic line from the pump to the hydraulic motor.

These and other objects and advantages of the present invention may be more readily understood by referring nited States Patent '0 Patented Aug. 28, 1956 ice to the following description and appended drawings, in which:

.Fig. l is atop plan view of a valve according to the invention;

Fig. 2 is a side elevation in partial section, of the device of Fig. 1;

Fig. 3 is a sectional side elevation of a modified device according to the present invention; and

Fig. 4 is a top plan view of the device of Fig. 3.

The volume control valve, illustrated in Figs. 1 and 2, has a body 10 enclosing a balance arm 12. The body is closed by a removable closure 14 extending across one side of the body. A partition 16 substantially divides the body into a pair of hollow chambers, including a right chamber 18 and a left chamber 20. The balance arm 12 extends into each of the chambers, and a circular midsection 22, acting as a seal and a bearing for the balance arm, separates the two chambers. A cup 24 is secured to each end of the balance arm, and an inlet jet 26 is directed into eachcup. The jet assembly comprises an extension 27 passing through a retaining nut 28. A lock nut 29 engaged with a retaining nut and releasably secures an outer extension 30 for moving the jet extension 27 inwardly and outwardly in relation to the cup. The extension 30 provides means for adjusting the depth of penetration of the jet 26 into the cup. A fluid inlet 31 is attached to the retaining nut 28 communicating with the jet 26 and provides an inlet means for fluid under pressure, from a common source to each of the jets.

Each side of the balance arm has a slide valve for the exhausting of fluid from the chambers through outlets 35. The slide valve provides an outlet 32 in a wall portion 33 of the body which substantially contacts the balance arms adjacent thereto. Each arm has a valve opening 34 offset one half the diameter of the outlet 32 in the body when the balance arm is squarely aligned in the body. In other words, when the balance arm is centered, the outlet holes 34 in the arm 12 cannot be squarely aligned with the outlets 32 in the body portion 33. The offset holes provided for a full open outlet on one side when the outlet on the side is fully closed; when the balance arm is fully tilted one way or the other. Each outlet 35 includes a ball check valve 36 to prevent any back pressure from entering the chambers.

The balance arm has a pin 38 which rotatably secures the arm in position in the body. The circular seal 22, likewise aids in holding the lever in place, and further seals the two compartments from each other while permitting rotation of the arm. The arm will rotate through a small are around the pin 38. The seal 22 provides a rotatable seal between the two chambers to substantially seal the chambers apart.

In operation, the valve is connected to a source of fluid under pressure, for instance hydraulic fluid from a single hydraulic pump. A single conduit from the hydraulic pump is teed to the two inlets 3.1; the lines from the T to the inlets 31 are of equal size. The two outlets 35 are each connected to a fluid motor, for example, two hydraulic cylinders. Each outlet is interconnected to a single hydraulic motor. The fluid under pressure is forced through the conduit, and is divided into two streams into inlets 31, and subsequently into the jets 26. The jets exhaust into the cups, and the pressure of the stream of fluid provides a dynamic force into each of the cups. The force of the streams into the cups determines the status of the balance arm. When first starting the valve, the two chambers fill with fluid, and generally, the outlet which is connected to a motor having the least resistance will exhaust a small amount of fluid before-the other outlet exhausts any fluid. For convenience, the component parts of each chamber will be referred to by the numerical indicia of the chamber. For example, if the outlet to chamber 20 is under no pressure whatever, and the outlet of chamber 18 is subject to a load of ten tons, chamber 20 will exhaust a small amount of fluid first due to the cessation of flow of fluid in chamber 18 as it is operating against the ten ton load, and the full flow goes through the jet of chamber 20. As fluid ceases to flow into chamber 1 3 and the full flow goes through the jet of chamber 20, it forces the balance arm away from it closing the outlet of chamber 20. As outlet of chamber 29 is closed, the outlet of chamber 18 is opened releasing a small amount of fluid, and the flow in chamber 20 stops. As the full fluid flow goes through the jet of chamber 18 it forces the arm away from it closing the outlet of chamber 18, and opening outlet of chamber 20 releasing a small amount of fluid. The cycle repeats continuously, each outlet releasing the same amount of fluid. The movement of the lever arm and the flow changes through the jets are almost instantaneous, so that there is substantially no measurable: difference in the amount of liquid being discharged from the two outlets at any one moment.

The operation of the lever and the outlet valves is controlled purely by the flow of fluid, and is due, in the main, to the force of the jet into its adjacent cup. As both jets are fed from a single source, the force of each jet tends to be substantially equal. The force of the jet against its adjacent cup is, therefore, a function of the distance the two are apart.

Since the operation of the valve is due to the flow of fluid only, it is immaterial what back pressure is applied on either or both outlets. The back pressure may be the same or substantially different, without eflecting the operating of the valve.

The modified valve of Figs. 3 and 4 comprises a body having an exterior wall 38 and a common partition 39 segregating the body into a left chamber 40 and a right chamber 41. A doubled-arm pendulum is secured from the top of the chamber and extends through the common partition 39, and comprises a rotatable bar 52 extending into each of the chambers through the partition. A pendulum arm 50 secured to the bar 52 extends downwardly into chamber 40, and a pendulum arm 57 secured to the bar 52 extends into the chamber 41. Each pendulum arm has a cup 42 secured thereto on opposite sides thereof to provide means for balancing forces against the pendulum arm. Extending into each cup 42 is a jet 43 which is secured through a retaining nut 44 by means of a lock nut 45. An extension 46 extending through the lock nut 45 is adapted to move the jet inwardly and outwardly in relation to the cup. An inlet 47 provides a fluid passage from a common fluid source 48. Attached to each arm 1' of the pendulum is an outlet valve. The outlet valve comprises a valve associated with the pendulum arm and intimately associated with an outlet 56 adjacent thereto. A hole 55 in the pendulum arm is slightly oflset from the outlet 56 when the arm is squarely in balance. The pendulum arms 50 and 51 swing with the rotation of bar 52, and the swing moves the'cups slightly to and from the jets.

In operation, the inlet 48 is connected to a hydraulic pump, and the outlets 56 are each interconnected to a hydraulic motor. The initial flow of hydraulic fluid fills the two chambers, if not full, and the outlet which has the least pressure thereon begins to flow fluid first, due to the back pressure against the other outlet. The operation then follows that set out above for the device of Fig. 1. For example, the chamber 40 is connected to a zero pressure outlet, and chamber 41 is connected to a cylinder under a ten ton force, the initial flow of fluid into the filled chambers exhausts a slight amount of fluid from chamber 40, and the flow of the jet in chamber 41 stops due to the valve 41 being closed. As the jet flow in chamber 40 increases,it forces the arm away opening the valve in 41 and closing the valve in 40. The cycle then continuously repeats, providing equal flow of fluid from the valve.

It is obvious that the initial pressure from the hydraulic pump or source of fluid pressure must be greater than the combined forces against which both sides of the valve operate. For example, a hydraulic pump issuing fluid at ten ton pressure will not operate cylinders each operating against a ten ton pressure.

Under normal operating conditions, it is immaterial against what pressure the valve is operating, and it is immaterial what the density of the fluid is. For instance, the valve is equally adaptable to air or gases as with liquids, such as water, oil, etc. The operating force of the valve is the force of the fluid issuing from the jet against the balance arm.

Due to the construction of the valve, the line from the fluid pump to the fluid motor is always open. In any arm position an outlet opening is available, hence the valve provides an automatic safety device to prevent build up of pressure of the pump. However, if one outlet side of the valve is blocked and does not release fluid, the valve will not operate. For example, if one of two hydraulic motors is under a twenty ton load and the fluid motor is capable of producing only five tons, the valve will not operate and will not put fluid into the other outlet. Both outlets must flow or the valve will not work, providing still another safety measure, to prevent motor injury by too much fluid, etc.

In compliance with law, the invention has been illustrated in specific detail, but it is not intended to limit the invention to the precise details so disclosed except insofar as defined by the appended claims.

I claim: I

l. A valve for dividing a stream of fluid under pressure into two predetermined fractions comprising a conduit for fluid under pressure, means for dividing said stream into two parts, means for directing each of said parts through a nozzle, said nozzles being directed into separate chambers, balance means interconnecting said chambers, each chamber having an outlet, each outlet being controlled by a valve interconnected with said balance means, a cup in each chamber being mounted on said balance means, and variable means for directing said nozzles into said cups whereby under the influence of the force of said two parts into said cups fluid is released through each valve in a predetermined fraction of the original stream.

2. A valve for dividing a stream of fluid under pressure into two predetermined fractions comprising a conduit for fluid under pressure, means for dividing said stream into two parts, means for directing each of said parts through a nozzle, said nozzles being directed into separate chambers, lever balance means interconnecting said chambers, each chamber having an outlet, each outlet controlled by a valve, said valves being mounted on said lever balance means, a cup in each chamber mounted on said lever balance means, and means for directing said nozzles into said cups whereby under the influence of the force of said two parts into said cups fluid is released through each valve in two equal fractions of the original stream.

3. A valve for dividing a stream of fluid under pressure into two predetermined fractions comprising a conduit for fluid under pressure, means for dividing said stream into two parts, means for directing each of said parts through a nozzle, said nozzles being directed into separate chambers, pendulum balance means interconnecting said chambers, each chamber having an outlet, each outlet being controlled by a valve mounted on said pendulum balance means, a cup in each chamber mounted on said pendulum balance means, and variable means for directing said nozzles into said cups whereby under the influence of the force of said two parts into said cups fluid is released through each valve in a predetermined fraction of the original stream.

4. A valve for dividing a stream of fluid under pressure into two predetermined fractions comprising a conduit for fluid under pressure, means for dividing said stream into two parts, means for directing each of said parts through a nozzle, said nozzle being directed into separate chambers, balance means interconnecting said chambers, each chamber having an outlet, each outlet being controlled by a valve mounted on said balance means, said valves being constructed and arranged whereby o-ne valve moves from open to closed position and the other moves from closed to open position on pivotal movement of said balance means, there being one balance point where both said valves are partially open an equal amount, a cup in each chamber mounted on said balance means, and means for directing said nozzles into said cups whereby under influence of said two parts into said cups fluid is released through said valves in two equal fractions of the original stream.

5. A valve for dividing a stream of fluid under pressure into two equal fractions comprising conduit means for dividing a single stream of fluid into two smaller streams, each of said smaller streams being directed into a separate chamber, interconnected pivotal balance arm means extending from one chamber into the other chamber, means for directing the force of each said smaller stream against said balance arm means in the corresponding chamber whereby the force of said streams oppose each other on said balance arm means and move said beam toward and away from said directing means, and valve mens in each said chamber interconnected with said balance arm means constructed and arranged with the balance arm in each chamber for opening and closing an outlet for releasing an equal amount of liquid from each chamber under the influence of the forces of said stream against said balance arm.

6. A fluid flow control device comprising two chambers each having an inlet and an outlet, means for supplying a stream of fluid under pressure from a common source to each of said inlets, balance arm means extending into each chamber and having the ends therein each chamber arranged adjacent the inlets to move toward and away from said stream inlet whereby the dynamic force of fluid flowing into the chamber impinges on the balance arm means and tends to cause movement away from the inlets, means interconnecting the balance arm means so that as one recedes from its inlet the other approaches its inlet, and valving means in each ch mber connected with said balance arm means arranged to restrict the outlet of each chamber as said balance arm moves away from its adjacent inlet.

7. A fluid flow control device comprisign two chambers each having an inlet and an outlet, means for supplying a stream of fluid under pressure from a common source to each of said inlets, movable means in each chamber positioned adjacent to and arranged to move away said inlets under the influence of the dynamic force of the stream of fluid entering said chambers, balance arm means interconnecting said movable means so that when one moves away from its inlet and the other approaches its inlet, and valve means in each chamber connected with said balance arm means arranged to restrict the chamber outlet as the movable means moves away from its adjacent inlet and opens the other outlet as the other balance arm moves toward its adjacent inlet, said valve means in each chamber being constructed and arranged so that each is about one half open when the force of the flow of the fluid is evenly balanced on said movable means.

References Cited in the file of this patent UNITED STATES PATENTS 2,414,842 Trexler Ian. 28, 1947 2,478,391 Segerstad Aug. 9, 1949 2,593,185 Renick Apr. 15, 1952 2,624,360 Goddard Ian. 6, 1953 FOREIGN PATENTS 325,753 Great Britain Feb. 17, 1930

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