US2495669A

US2495669A - Fluid apparatus

Info

Publication number: US2495669A
Application number: US776453A
Authority: US
Inventors: Cannon Earl
Original assignee: American Steel Foundries
Current assignee: American Steel Foundries
Priority date: 1947-09-27
Filing date: 1947-09-27
Publication date: 1950-01-24
Anticipated expiration: 1967-01-24

Description

E. CANNON FLUID APPARATUS Filed Sept. 2'7. 19417 QN mvw M W WA mi :wl mm wmV/ 4 MRI, ,Qm W mm Q\ m MN W Jam 2% WLW atented Jan. 24, 1950 FLUID APPARATUS Earl Cannon, Downers Grove, 111., assignor to American Steel Foundries, Chicago, 111., a corporation of New Jersey 1 Application September 27, 1947, Serial No. 776,453

7 Claims.

This invention relates t hydraulic systems for supplying hydraulic fluid under pressure and more particularly to a novel system for supplying a non-lubricating fluid under an adjustable predetermined pressure value as, for example,

to a vessel to be tested under pressure.

Testing apparatus of the above type may be utilized to test large water vessels at pressures varying from five hundred to three thousand or more pounds per square inch with th pressure adjustable in small increments such as two hundred pounds per square inch. In a system of this type wherein the adjustable pressure is maintained by a relief valve adapted to discharge the pressure fluid at a predetermined value, rapid wearing of the valve seat not only increases maintenance costs but produces undesirable variations in pressure while the apparatus is in use.

It has been found that the use of accumulators to provide the adjustable pressure in a system of this type is undesirable inasmuch as the accumulators are bulky and expensive.

Accordingly, a general object of the present invention is to provide means in a system, such as above-described, for deliverin the fluid under an adjustable predetermined pressure without utilizing an accumulator and without blowing the non-lubricating hydraulic fluid through a relief valve.

Another object of the invention is to provide a novel pressure interchanger device whereby the desired adjustable pressure on the non-lubricating hydraulic fluid may be maintained by an hydraulic system containing a lubricating fluid, such as oil.

Still another object of the invention is to provide novel means for automatically charging the pressure interchanger with non-lubricating fluid when the volume thereof in the interchanger device reaches a predetermined minimum value.

The foregoing and other objects and advantages of the invention will become apparent from a consideration of the following specification and the accompanying drawing wherein the single figure is a flow diagram of a novel hydraulic system embodyin the invention, in combination with an electrical diagram illustrating the actuating circuits for the hydraulic system.

Describing the invention in detail, the interchanger device, generally designated l, comprises an oil cylinder 2 and a water cylinder 4 preferably maintained in fixed relationship by bolts 6 connected to ears or lugs 8 on the cylinder 2 and to ears or lugs It on the cylinder 4.

An oil ram l2 reciprocates within the cylinder 2 and is operatively connected to a relatively small diameter Water ram l4 reciprocal within the cylinder 4. It will be understood that by means of this arrangement, a given pressure in the cylinder 2 develops a relatively great pressure within the .cylinder 4 for a purpose hereinafter described in detail. Thus the interchanger device is, in effect, an intensifier wherein the relatively large diameter ram I2 is eiiective to develop relatively great pressure within the cylinder 4.

The cylinder 4 is charged by a water pump I6 operated by a motor Hi, the suction side of the pump being connected to a low pressure supply line H and the discharge side of the pump being connected to a high pressure supply line 20 connected to the cylinder 4 through a conventional selector valve 22 adapted in the closed or discharge position thereof to direct fluid from the pump It to a discharge line 24. In the open or delivery position thereof the valve 22 is operable to deliver pressure fluid from the pump 16 to the cylinder 4 through a one-way check valve 28. The line 20 is also connected to a vessel 30 adapted to be tested under the pressure of the water in the system and is preferably connected to a low pressure water supply line 32 equipped with a shut off valve 34 whereby the vessel 30 may be filled with water from the line 32 before the system is put into operation, as hereinafter described.

The motor I8 also operates an oil pump 35 having its suction side connected by a pipe 36 to a reservoir 38 of hydraulic fluid, such as oil, having lubricating qualities. The discharge side of the pump 35 is connected to an oil supply line 40 which is connected to the cylinder 2 and is preferably provided with a surge tank 42 equipped with a conventional stop cock 43.

The hydraulic pressure in the oil line 40 is maintained at an adjustable predetermined value by a relief valve diagrammatically illustrated as comprising a casing 44 with a port 46 communicating with a cylindrical chamber 48 containing a complementary piston 49 in slidable fluidtight engagement therewith. The piston is provided with a small port 50 affording communication between the portions of the chamber 48 at opposite sides of the piston, and the piston is connected to a hollow stem 52 operable in its closed position to close the port 46. The stem is yieldingly urged to its closed position by a sprin 54.

The line 40 is connected to the chamber 48 at .the. side of the piston 49 whereat the port 46 is disposed, whereupon movement of the stem 52 to its open position relieves pressure within the line 49 through a relief or discharge line 55 connected to the port 46 and the reservoir 38. The portion of the chamber 48 at the side of the piston 49 remote from the port 45 is provided with a port 56 connected to a port 58 of a pressure adjustor valve, generally designated 59, which determines the pressure value at which the relief valve stem 52 opens to accommodate discharge of the hydraulic pressure in the line 40 through the line 55.

The valve 59, as diagrammatically illustrated, comprises a seat element 6|] yieldingly urged to its closed position over the port 58 by a spring 62 which is adjustably compressed by a stem 64 actuated by a cam 55 rotatably mounted within a cylindrical housing 68 containing a spring pressed friction block 59 for holding the cam 66 in any adjusted position thereof to which the cam may be actuated by a handle extending through a slot II in the housing 68.

The valve 59 is connected to the discharge line 55 by a branch line 13 adapted to direct fluid from the port 58 to the line 55 when the valve element 69 opens.

Thus it will be understood that the pressure in the line Ml is effective to open the stem 52 of the relief valve at a predetermined adjustable pressure value within a range, for example, of from five hundred to three thousand pounds per square inch. The maximum pressure value within the line 49 is thus dependent upon the setting of the adjustor valve 59.. It will be understood that the valves are diagrammatically illustrated and any conventional adjustable relief valve mechanism may be utilized.

In operation of the system the vessel 39 to be tested is preferably filled with low pressure water from the line 32, and the adjustor valve 59 is set to maintain a predetermined pressure value in the line 45 and the cylinder 2.

The pumps iii and 35 are actuated by the motor I8 to direct oil and water to the respective lines, 20 and 49. The valve 22 remains in closed or discharge position until an actuator 12 carried by an arm '55 mounted on the ram l2 engages a normall open switch 16 to close the same thereby closin an electrical circuit through a conventional voltage supply l8, one terminal of which is connected at 80 to ground and through a solenoid coil 82 of a normally open double relay, generally designated 84, and through a normally closed switch, generally designated 85, one contact of which is connected at 88 to ground, the other contact of the switch 86 being connected to the coil 82. Energization of the coil 82 closes the normally open relay 84 thereby closing a holding circuit for the coil 82 through contacts 90 and 92. Closing of the relay 84 also closes a circuit through contacts 93 and 94 and through the actuating solenoid coil 96 of the valve 22, one end of said coil being connected at 98 to ground and the other end being connected to the contact 93.

Energization of the coil 96 actuates the valve 22 to its open or operating position at which fluid from the water pump I6 is delivered to the vessel 36 and the cylinder 4 urging the rams l2 and I l to the left, as seen in the drawing, thereby forcing oil in the line 49 through the relief valve and the relief or discharge line 55 into the reservoir 38. It may be noted in this connection that the construction of the relief valve is such that discharge therethrough of the fluid from the cylinder 2 and the pump 35 at the same time does not materially increase the maximum pressure in the line 40.

When the ram l2 has reached its retracted position, at which time, the volume of water in cylinder 4 is at a predetermined maximum value, the actuator 12 opens the normally closed switch 86 thereby breaking all of the above-mentioned electrical circuits whereupon the Valve 22 assumes its closed or discharge position whereat pressure fluid from the pump I5 is discharged through the line 24. Under these conditions, make-up water is supplied to the tested vessel 30 by the cylinder 4 at an adjustable pressure value predetermined by the maximum pressure in the line 59 and the cylinder 2. Preferably the area of the ram I4 is smaller than the ram l2, as above noted, so that a relatively low pressure within the line 40 is effective to maintain a relatively high pressure within the cylinder 4 and the tested vessel 39. Thus, for example, the rams are preferably designed so that a pressure value of two thousand pounds per square inch in the cylinder 2 is efiective to produce a pressure value of three thousand pounds per square inch in the cylinder 4. However, the ram areas may be equal, or either area may be greater, as desired.

As make-up water is supplied from the cylinder t, the ram it gradually moves to its retracted position as the ram I2 advances until the switch 16 is again closed whereupon the above-described cycle is repeated.

It may be noted that the relief valve associated with the line til is not subjected to excessive wearing inasmuch as the hydraulic fluid in this line is preferably a fluid, such as oil, having lubricating qualities.

It is to be understood that I do not wish to be limited by the exact embodiment of the device shown which is merely by way of illustration and not limitation as various and other forms of the device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

I claim:

1. A system of the class described comprising an intensifier with a relatively small chamber, a relatively large chamber, and interconnected ram means reciprocal within respective chambers, a line connected to the small chamber and adapted to supply hydraulic fluid under pressure to an associated hydraulic device, pump means connected to said line for forcing said fluid therethrough, a pressure control line connected to the large chamber, means for continuously delivering a different hydraulic fluid to said control line at an adjustable predetermined pressure value which controls the pressure in said small chamber, the pressure against the ram means in said small chamber exerted by the ram means in said large chamber being at all times less than that deliv ered by said pump means to the small chamber, and means for automatically subjecting the small chamber to the pressure developed by said pump means when the volume of hydraulic fluid in said small chamber reaches a predetermined minimum value and for automatically relieving said small chamber from the pressure developed by said pump means when the volume of hydraulic fluid in the small chamber reaches a predetermined maXimum value.

2. A system of the class described comprising a pressure interchanger including spaced chambers and ram means reciprocal therein, a line connected to one of said chambers and adapted to supply hydraulic fluid at a predetermined pressure value to associated means for utilizing said fluid, means connected to said line for forcing an hydraulic fluid therethrough, a pressure control line connected to the other chamber, means for continuously maintaining a diflerent hydraulic fluid at a predetermined pressure in said control line and for automatically exhausting the hydraulic fluid therefrom at a predetermined maximum pressure value lower than that developed by said pump means, and means for automatically subjecting said one chamber to the pressure developed by said pump means when the volume of hydraulic fluid in said one chamber reaches a predetermined minimum value and for automatically rendering said pump means ineffective to develop pressure in said one chamber when the volume of hydraulic fluid therein reaches a predetermined maximum value.

3. A system for supplying hydraulic fluid at a predetermined pressure value comprising a cylinder, a ram therein, means for developing pressure against said ram comprising an hydraulic motor including a cylinder member and a ram member reciprocal therein, one of said members being engaged with said ram, a source of hydraulic pressure fluid connected to the cylinder member, means for automatically discharging the pressure from said source when the pressure in said cylinder member reaches a predetermined maximum. value, a source of hydraulic fluid of a different character connected to said cylinder and adapted to deliver said last-mentioned hydraulic fluid thereto at a pressure value greater than the first-mentioned value, and means for automatically rendering the second-mentioned source ineffective when the volume of the last-mentioned hydraulic fluid in said cylinder reaches a predetermined maximum value.

4. A system for supplying non-lubricating fluid under a predetermined pressure comprising a pair of cylinders, a pair of abutting rams one reciprocal in each cylinder, a source of lubricating fluid under pressure connected to one cylinder, adjustable relief valve means for discharging said lubricating fluid from said source at a predetermined maximum pressure value, means for supplying non-lubricating fluid to the other cylinder under a pressure greater than. said value, means for automatically rendering said last-mentioned means ineffective when the ram in said one cylinder is urged to a predetermined retracted position therein, a line connected to the other cylinder for delivering said non-lubricating fluid therefrom to associated means for utilizing said non- ]ubricating fluid.

5. A system of the class described comprising a pressure interchanger including spaced chambers and interconnected ram means reciprocal within respective chambers, a line connected to one of the chambers and adapted to supply hydraulic fluid therefrom to associated means for utilizing said fluid, a pump, valve means connecting the discharge side of the pump to said one chamber, said valve means being adapted in one position to deliver hydraulic fluid from the pump to said one chamber and being adapted in another position to exhaust the output of said pump, a pressure control line connected to the other chamber, means for continually maintaining a diflerent fluid at a predetermined pressure in said control line and for automatically exhausting the fluid therefrom at a predetermined maximum pressure value lower than that developed by said pump, means for automatically actuating said valve in to said one position thereof when the vole hydraulic fluid in said one chamber reaches a predetermined minimum value, and means for automatically actuating said valve means to said other position thereof when the volume of hydraulic fluid in. said one chamber reaches a predetel mined maximum value.

6. A system of class described comprising a cylinder adaptedto supply fluid to associated means for utilizing the same, a ram in said cylinder. hydraulic motor connected to said ram for advancing the same into said cylinder, a control line connected to said motor, a source of lubricating hydraulic pressure fluid connected to said line, relief valve means in said line for exhausting said fluid from said source at a predetermined maximum pressure value, means for charging the cylinder with a pressure fluid of substantially non-lubricating character at a pressure value greater than said first mentioned Value, said motor being adapted to discharge fluid to said line accommodating movement of said ram from said cylinder when the pressure of the ram against the motor attains said value, and being adapted at other times to receive fluid from said line thereby advancing said ram into said cylinder and means for automatically rendering the second mentioned means ineffective when the volume of fluid in said cylinder reaches a predetermined value.

7. A system of the class described comprising an intensifier having a relatively small chamber, a relatively large chamber and interconnected ram means reciprocal within respective chambers, said small chamber being adapted to supply fluid under pressure to associated means for utilizing said fluid, pump means connected to said small chamber for delivering said fluid thereto, a pressure control line connected to the large chamber, means for continuously delivering pressure fluid to said control line at an adjustable predetermined pressure value, the pressure against the ram' means in said small chamber exerted by the ram means in said large chamber being at all times less than that delivered by said pump means to the small chamber, and means for automatically rendering said pump means ineffective to deliver hydraulic fluid to the small chamber when the volume of fluid therein reaches a predetermined maximum value.

EARL CANNON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number