US3054354A

US3054354A - By-pass valve assembly for pumps of the positive displacement type

Info

Publication number: US3054354A
Application number: US72120A
Authority: US
Inventors: Albert J Granberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-11-28
Filing date: 1960-11-28
Publication date: 1962-09-18
Anticipated expiration: 1979-09-18

Description

p 8, 1962 A. J. GRANBERG 3,054,354

' BY-PASS VALVE ASSEMBLY FOR PUMPS OF THE POSITIVE DISPLACEMENT TYPE Filed Nov. 28, 1960 IN V EN TOR.

ALBERT J- GRANBERG BY United States Patent Dfiice 3,54,354 Patented Sept. 18, 1962 3,054,354 Elf-PASS VALVE ASSEMBLY FGR PUMPS (PF THE PDSHTIVE DEPLACEMENT TYPE Albert J. Granberg, 6691 Rockwell St, Oakland, Calif. Filed Nov. 28, 1960, Ser. No. 72,120 Claims. (Cl. 10342) My invention relates to pumps of the positive displacement type, and more particularly to a by-pass valve assembly for such pump.

Among the objects of my invention are:

(1) To provide a new and improved by-pass valve assembly for a pump of the positive displacement type;

(2) To provide a novel and improved by-pass valve assembly for a pump of the positive displacement type, whereby pump idling pressure will be minimized;

(3) To provide a novel and improved by-pass valve assembly for a pump of the positive displacement type, which by-pass valve assembly is adjustable to provide control for the operating discharge pressures of the P p;

(4) To provide a novel and improved by-pass valve assembly for a pump of the positive displacement type, which by-pass valve assembly may be adjusted to enable the pump to satisfy the requirements of a particular installation.

Additional objects of my invention will be brought out in the following description of a preferred embodiment of the same, taken in conjunction with the accompanying drawings wherein the positive displacement type pump illustrated, is of the type illustrated and described in my earlier patent for Pump Valve, No, 2,260,805 or" October 28, 1941, though the invention is applicable to positive displacement type pumps of other designs and construction.

FIG. 1 is a view in section along the longitudinal axis, while FIG. 2 is a sectional view in plane 2-2 of FIG. 1.

The particular pump illustrated involves a pump casing 1 which is preferably formed into half sections to facilitate machining of a spherical inner surface 3 therein. A driving head 5 having the shape of a spherical segment is positioned within the chamber and has, extending outwardly therefrom, a drive shaft '7. This drive shaft is journalled in a casing bearing 9 close to the pump chamber, and this casing bearing is prolonged to terminate in a stufiing box assembly, comprising a pressure closure 11 forced against packing 13 by pressure bolts 15. The shaft continues beyond the stuifing box and I prefer to steady the outer end in an outboard bearing 17 mounted on a bracket 19.

Extending inwardly into the pump chamber from the driving head 5 is a pump chamber partition 21 attached to a discoidal piston 23 by hinges 25. In like manner, a second pump chamber partition 27 is attached to the discoidal piston 23 by similar hinges, and this second partition extends across the discoidal piston at right angles to the first partition. This second partition 27 is attached to a driven head 29, also having the shape of a spherical segment, and extending from this latter spherical segment is a stub shaft 31.

This stub shaft 31 has its free end supported in a bearing 33 at an angle to the main drive shaft 7, the

bearing in turn extending through an opening in the pump casing and supported in cap 37 covering said opening and constituting a housing for the bearing.

A single inlet port 39 to the pump chamber is provided diametrically opposite a single output port 41, the first connecting with a chamber 42 at intake pressure, while the latter or output port 41 connects with a chamber 44 of high or discharge pressure, these chambers being separated by a partition 45.

The rim of the piston 23 has a uniform width and presents a bearing surface around the disc, which of necessity is a spherical surface so that the disc may both oscillate and rotate within the spherical pump chamber. Four portions of the periphery deviate to form semicircular valve faces 53, each alternate surface extending in the opposite direction so that as the piston is rotated, each port 39 and 41 is opened to its associated chamber.

The semi-circular divergences of the discoidal piston allow the placing of hinge pins 51 in the hinges 25 at right angles to each other, to hingedly couple the piston to both the drive head 5 and driven head 28. Thus, the device may be easily assembled and disassembled when the split casing is separated by taking out the screws 55 holding the casing assembled.

The intake or low pressure chamber 42 of the casing 1 has an internally threaded pipe connecting opening 59, in its rear Wall for a rear pipe connection 61 and a similar opening 63 in its side Wall for a similar pipe connection 65. Similarly, the discharge or high pressure chamber 44 has in its rear wall, a similar pipe connecting opening 67 for a pipe connection 68, and in its side wall, a pipe connecting opening 69, a pipe connection '71 to this latter opening being shown. If only one inlet opening and only one outlet opening are utilized to the exclusion of the others, the other remaining openings can be capped or plugged;

Chambers 42 and 44 are each further provided with an opening 75, 77 respectively in the ceiling thereof, and a hollow ganged cap 79 supported upon the common upper surface of the chambers and bolted thereto, serves to provide a passageway flow interconnecting the two chambers and associated pipe connections.

To this point, the pump structure corresponds to that of my earlier cited patent.

The present invention resides primarily in a new and improved by-pass valve assembly 81 which is located in the interconnecting passageway where it may be exposed to the pump pressure developed in that chamber 44 connecting with the discharge of the pump and designated the region of high or discharge pressure.

At the high pressure end of the interconnecting passageway is a valve seat 87, while in the passageway, there is provided a partition 89 dividing the passayeway into a pair of

chambers

93, 95, the first 93, connecting with the high pressure chamber 44 and forming a valve housing, while the other chamber connects with the lower pressure chamber 42. This partition provides a connecting opening 101 between the two chambers adjacent the aforementioned valve seat 87, and a valve opening 193 connecting the upper ends of both

chambers

93, 95. In the valve chamber 93 is a main valve 107 adapted to seat upon the valve seat 87. This valve includes a broad circular base 109 and an upwardly extending 7 opening 103 in the partition may be closed. Due to the fact that the under side of the main valve 1ti7 presents a greater exposure area to the liquid pressure bearing thereagainst than the combined exposed upper surfaces of the valve, the valve in the absence of other forces would, under normal conditions, be urged to move upwardly from its valve seat. This however, is precluded by the presence of a loading spring 119 disposed within the hollow valve stem 111 and held under adjustable compression by an adjusting screw 121 in the roof of the valve chamber, bearing against a spring cap 123.

The loading of this spring is made sufficient to overcome the differential liquid pressure to which the valve would normally be exposed when the valve opening 103 in the partition is closed and the pump is discharging. However, when such valve opening is exposed to relieve the back pressure of the liquid against the upper surfaces of the main valve 107, the spring loading by itself is insufficient to hold the main valve seated.

The blocking of the valve opening 103 in the partition wall, which in turn determines the existence or release of the liquid back pressure on the main valve 107, is the function of a partition valve 127 supported for operation by a valve stem-129 which slidably fits a cylindrical passageway 131 cast in the wall of the valve assembly cap, such passageway being closed at its exposed end by a threaded plug 133. Operations of the partition valve 127 are under control of a pressure responsive gate 137 extending transversely of the chamber 95 with its lower end substantially blocking the flow connection 1611 between the two chambers through the lower end of the partition. Thisgate is pivotally supported by a transverse pin 141 anchored in the opposing walls of the valve'assembly cap 79, the edge of: the gate above the pivotal pin support, extending into a transverse notch 145 formed in the valve stem 129 of the partition valve 127 to transmit gate movements to the valve in efiecting operation of such valve.

The lowermost position of the gate 137, which represents not only its substantially blocking position of flow through the lower end of the partition, but also determines the closed position of the partition valve 127, is determined by engagement of the gate with the partition 89, the gate for this purpose being bent or angled toward the partition and provided with a transverse rib or button 14? to function as a stop.

The gate is normally spring loaded in the direction of its substantially blocking position, whereby a certain pressure against the gate will be required in order to swing the gate to effect opening of the partition valve. Toward this end, a pin 151 with a threaded head 153 adjnstably supported in a hollow internally threaded boss 155, extends through an opening formed in the gate, and a light spring 159 surrounding the pin and in compression between the threaded head of the pin and a plate 161 covering the opening in the gate, serves to maintain the gate under spring loading, the degree of spring pressure exerted thereby being adjustable through adjustment of the pin in its supporting boss.

In the operation of the by-pass valve assembly, during functioning of the pump, the spring loading on the main valve is such' as to hold the main valve seated during normal operating discharge pressures of the pump.

When however, the nozzle associated with the discharge hose through which the pump may be discharging liquid, is shut off, the responsive build up of pressure against the underside of the main valve will exceed the liquid back pressure on the main valve plus that of the loading spring and the main valve under such conditions, will be lifted off its seat to expose the gate 137 to flow impact from the liquid at high pressure.

This flow impact will cause the gate to Swing to a more open position and cause unseating of the partition valve 127, whereby the liquid back pressure on the main valve will be released and the main valve will pop open to full open position, since the only back pressure against the main valve under these conditions, is that attributable only to the spring loading.

As to the order of unit pressures involved and apt to be encountered in a pump and pump system, with which the present invention is concerned, it might be pointed out that with normal discharge pressures of the pump running on the order of pounds per square inch, the pressure at idling, that is with the hose nozzle shut off, will drop to about 20 or 30 pounds per square inch, while the pressure developed on the discharge side of the pump, promptly upon closing of the nozzle, will increase to a value well above the normal 100 pounds discharge pressure.

If one starts with the pump in operation and dis charging liquid through an open nozzle, the main valve will be seated, as well as the partition valve, inasmuch as the gate will not be exposed to pressures on the discharge side of the pump with the main valve seated. These conditions will prevail while the pump is operating at pressures within its normal pumping range.

Upon shutting off of the nozzle at the end of the hose line through which the pump might be discharging, the responsive build-up of pressure on the discharge side of the pump will reach a value sufficient to unseat the main valve and expose the gate to resulting high pressure, whereupon, the partition valve Will open, relieving the liquid back pressure against the main valve and leaving the spring 119 as the only acting force opposing the opening pressure against the main valve, whereupon the main valve will pop open to its maximum open position and the pressure on the discharge side of the pump, which is now fully exposed to the intake or low pressure side of the pump, will drop to an idling pressure of the order of 20 to 30 pounds, depending on the setting of the main valve spring.

Upon again opening the nozzle for discharge of liquid through the hose line, the pressure on the discharge side of the pump will momentarily drop sufliciently to enable the main valve spring to seat the main valve, and by thus cutting off the liquid pressure against the gate, bring about a closing of the partition valve. Under these conditions, liquid back pressure can again develop behind the main valve, and in conjunction with the spring loading on the main valve, permit of normal discharge pressures building up in the pump without unseating the main valve. Upon again closing off the nozzle, the resulting increase in pressure on the discharge side of the pump will unseat the main valve to again reduce the pump to a condition of idling at the low idling pressures referred to.

Differences in hose line characteristics, such as length of hose and diameter, willcall for different spring calibrations in the by-pass valve assembly to achieve desired pump discharge and pump idling pressures. The provision of adjustments in spring pressure of either the main valve spring or the gate associated spring, will enable one to adjust conditions within the by-pass valve assembly to realize such uniformity in pump operation.

Inasmuch as the structure of the pump is symmetrical with respect to the vertical plane through the longitudinal axis of the pump, the by-pas's valve assembly can be reversed if an installation calls for rotation of the pump piston in the reverse direction, in which case, what has been designated as the intake and discharge sides of the pump will be'reversed.

From the foregoing description of my invention in its preferred form, it will be apparent that the same fulfills all the objects of my invention, and while I have illustrated and described the same in its preferred form and in considerable detail, I do not desire to be limited in my protection to such details as illustrated and described except as may be necessitated by the appended claims.

I claim:

1. In a positive displacement pump of the type having a region of high or discharge pressure and a region of lower or intake pressure, a by-pass passageway connecting said region of high pressure with said region of lower pressure, said passageway including a valve seat at the high pressure end thereof and a partition in said passageway dividing the same into a pair of chambers, one connecting with said region of high pressure and forming a main valve housing, while the other chamber connects with said region of lower pressure, said partition having a connecting opening between the two chambers adjacent the lower end thereof, and a valve passageway connecting the upper ends of said chambers, a spring loaded valve in said valve chamber and normally biased by said spring loading toward said valve seat, said spring loaded valve having a leak passage thereby providing fluid coupling between said region of high pressure and the upper end of said valve chamber, and valve means normally closing said valve passageway and responsive to impact of fluid flow through said partition connecting opening during opening of said main valve, to unblock said valve passageway, said main valve spring loading exerting a pressure against said main valve sufficient in conjunction with liquid back pressure on said main valve during closure of said valve passageway, to effect seating of said mairr valve against normal pumping pressures of said pump but insufficient to efiect seating against sudden discharge pressure increase arising from blocking of pump discharge.

2. In a positive displacement pump of the type having a region of high or discharge pressure and a region of lower or intake pressure, a by-pass passageway connecting said region of high pressure with said region of lower pressure, said passageway including a valve seat at the high pressure end thereof and a partition in said passageway dividing the same into a pair of chambers, one connecting with said region of high pressure and forming a main valve housing, while the other chamber connects with said region of lower pressure, said partition having a connecting opening between the two chambers adjacent the lower end thereof and a valve opening connecting the upper ends of said chambers, a spring loaded valve in said valve chamber and normally biased by said spring loading toward said valve seat to close said connecting opening, said spring loaded valve having a leak passage thereby providing fluid coupling between said region of high pressure and the upper end of said valve chamber, and valve means normally closing said partition valve opening and including a valve actuating gate in the flow path of any liquid flow through said partition connecting opening in the open condition of said main valve, said main valve spring exerting a pressure against said main valve sutlicient in conjunction with liquid back pressure on said main valve during closure of said partition valve, to efiect seating of said main valve against normal pumping pressures of said pump but insufficient to effect seating against sudden discharge pressure increase arising from blocking of pump discharge.

3. In a positive displacement pump of the type having a region of high or discharge pressure and a region of lower or intake pressure, a by-pass passageway connecting said region of high pressure with said region of lower pressure, said passageway including a valve seat at the high pressure end thereof and a partition in said passageway dividing the same into a pair of chambers, one connecting with said region of high pressure and forming a main valve housing, while the other chamber connects 6. with said region oflower pressure, said partition having a connectnig opening between the two chambers adjacent the lower end thereof and a valve opening connecting the upper ends of said chambers, a spring loaded valve in said valve chamber and normally biased by said spring loading toward said valve seat, said spring loaded valve having a leak passage thereby providing fluid coupling between said region of high pressure and the upper end of said valve chamber, and valve means normally closing said partition valve opening, said valve means including a valve for said partition valve opening and a valve actuating gate normally substantially blocking said partition connecting opening during seating of said main valve, said main valve spring loading exerting a pressure against said main valve sufiicient in conjunction with liquid back pressure on said main during closure of said partition valve, to effect seating of said main valve against normal pumping pressures of said pump but insuflicient to effect seating against sudden discharge pressure increase arising from blocking of pump discharge, said valve actuating gate in response to resulting unseating of said main valve and exposure to impact of liquid at higher than normal pump discharge pressure, opening said partition valve to relieve liquid back pressure on said main valve and permit idling of said pump at lower than normal pump discharge pressures.

4. In a positive displacement pump of the type having a region of high or discharge pressure and a region of lower or intake pressure, a by-pass passageway connecting said region of high pressure with said region of lower pressure, said passageway including a valve seat at the high pressure end thereof and a partition in said passageway dividing the same into a pair of chambers, one connecting with said region of high pressure and forming a main valve housing, while the other chamber connects with said region of lower pressure, said partition having a connecting opening between the two chambers adjacent said valve seat and a valve opening connecting the upper ends of said chambers, a spring loaded valve in said valve chamber and normally biased by said spring loading toward said valve seat to block flow to said connecting opening, said spring loaded valve having a leak opening therethrough providing fluid coupling between said region of high pressure and the upper end of said valve chamber, and valve means normally closing said partition valve opening in opposition to pressure from said main valve chamber, said valve means including a valve for said partition valve opening and a valve actuating gate normally substantially blocking said partition connecting opening during seating of said main valve, said main valve spring exerting a pressure against said main valve sufiicient in conjunction with liquid back pressure on said main valve during closure of said partition valve, to effect seating of said main valve against normal pumping pressures of said pump but insufficient to efiect seating against sudden discharge pressure increase arising from blocking of pump discharge, said valve actuating gate in response to resulting unseating of said main valve and exposure to impact of liquid at higher than normal pump discharge pressure, opening said partition valve to relieve liquid back pressure on said main valve and permit idling of said pump at lower than normal pump discharge pressures.

5. A by-pass valve assembly comprising a cap adapted to couple the high or discharge pressure region of a pump to the low or intake region and define a passageway connecting said region of high pressure with said region of lower pressure, said passageway adapted to terminate at a valve seat at the high pressure end thereof, and including a partition in said passageway dividing the same into a pair of chambers, one adapted to connect with said region of high pressure and forming a main valve housing, while the other chamber is adapted to connect with said region of lower pressure, said partition having a connecting opening between the two chambers adjacent the 7 lower end thereof and a valve opening connecting the upper ends of said chambers, a spring loaded valve in said valvechamber and normally biased by said spring loading toward said valve seat, said spring loaded valve having a leak passage thereby providing fluid coupling between both sides of said main valve, and valve means normally closing said partition valve opening in opposition to pressure from said main valve chamber and including a valve actuating gate responsive to flow of fluid through said partition connecting opening to open said partition valve means, said main valve spring loading exerting a pressure againstsaid main valve sufiicient in 8, conjunction With liquid back pressure on said main valve during closure of said partition valve, to effect seating of said main valve against normal pumping pressures of a pump When included therein, but insufiicient to effect seating against sudden discharge pressure increase arising from blocking of pump discharge.

References (Cited in the file of this patent UNITED STATES PATENTS Granberg Oct. 28, 1941 2,737,966 I Lucien Mar. 13, 1956