US2293916A - Air balanced pumping unit and pressure regulation thereof - Google Patents

Description

1 E. w. PATTERSON 2,293,916

AIR BALANCED PUMPING UNIT AND :PRES SURE REGULATION THEREOF Filed Aug. 3, 1940 fl'QaJ'W-PQZZEI'SOIL INVENTOR ATTORNEY Patented Aug. 25, 1942 "warren STATES 'PATE AIR. BALANCED PUIWPING UNIT AND PRES- SURE REGULATION THEREOF Edgar W. Patterson, Long- Beach, Calif., assignor of one-half to Charles M. OLeary, Jr., Los An- I geles, Calif.

Application August 3, 1940, Serial No. 350,282

8 Claims. (01. 230-30) The present invention relates generally to air balanced pumping units, and is especially conc'erned with the pressure regulation thereof, its

primary object being the provision of a system of regulation by which to steadily maintain a predetermined set pressure in the air reservoir through the employment of means unaffected'in the desired operation thereof by the fluctuations of pressure in said reservoir necessarily incident to normal operation of the unit.

More particularly, the invention has to do with the type of air balanced pumping unit such as disclosed in my Patent Number 2,148,638, granted February 28, 1939, wherein air is supplied, by a reciprocating compressor actuated by the walking beam of the unit, to a reservoir for pressure which is in open communication with the working chamber of a balance cylinder so arranged that it opposes downward rocking movement of the walking beam and, in such movement, stores up energy which assists in the upward rocking movement of the beam. Since the reservoir, as above stated, is necessarily in open communication with the working chamber of the balance cylinder, it follows that it is subject to alternate rise and fall of pressure therein as the walking beam respectively lowers and rises.

It is the purpose of the present invention to 1 provide simple, effective means for maintaining in-the reservoir a predetermined and desired low pressure, the operation and function of which means will not be affected in any manner by the rise and fall of pressure in the reservoir during normal operation, and which means readily responds to manual regulation for setting the desired pressure and automatic pressure control in its subsequent functioning.

A further object of theinvention is the provision of an efflcient pressure regulating system for the above purposes, which will be substantially fool-proof in its adjustments for diiferent pressures, and in which, for this purpose, no valves need be adjusted and the set pressure is always plainly visible.

A still further object of the invention is the provision of a pressure regulating system in which, in spite of .the fluctuating reservoir pressure, its lowest point will be determined and controlled at all times by means which remain stationary except when pressure is to be supplied to the reservoir, so that for long periods its parts not be subject to wear nor disarrangement through the influence of such fluctuations.

With the above general objects in mind, other and further objects of the invention, as well as.

its operating and functional advantages, will clearly appear in the course of the following description detailing one way of carrying the invention into practical effect.

' Carefully bearing the foregoing'in mind, the

invention will be better understood and more thoroughly appreciated from the following description and by reference to the accompanying drawing, forming a part of this specification, and wherein,

Figure 1 is a side elevational view, partly broken away to better show certain parts, of an air balanced pumping unit embodying the present invention.

Figure 2 is a vertical sectional view through the compressor, showing its adjustable beam conon line 5-5 of Figure 2, and showing a slight modification.

Figure 6 is an' enlarged view showing the regulator in-central vertical section.

Figure 7 is a top plan view of the pressur regulator. I i o Figure 8 is a side elevation of the regulator of Figure 6. v

Figure 9 is a detail side view of the inner adjusting sleeve of the regulator.

Figure 10 is a detail transverse sectional view taken substantially on line I0l0 of Figure 9, and,

Figure 11 is a detail sectional and view of the valve of Figure 6.

Referring nowto these figures, and particularly to Figure 1, the present invention has been enlarged "illustrated in connection with an air balanced said working chamber and the air reservoir 20.

The beam lliis shown as actuated in its up and down swinging movements on a bearing atop the Samson post 22, by pitmans 23, from crank discs 4 side of pitman 23 with respect .to the balance cylinder l5.

The working chamber 3| of the compressor is, as best seen in Figure 2, below its piston 21, and

take pipe 32 and an outlet pipe 33, the former being open to atmosphere and provided with a check valve 34 opening toward the compressor, and the latter extending to the reservoir 20, as clearly seen by a comparison of Figures 1 and 3, and having therein two spaced apart check valves 35 and 36, both opening in a direction away from the compressoran'd toward the reservoir, for a purpose which will presently appear.

The compressor outlet pipe 33, which is the reservoir feed pipe, is also preferably provided with a pressure indicator 31 whose dial will always respond to, and plainly show, the pressure in the reservoir as it rises and falls with the low-- ering and rising movements of the beam l6 and balance cylinder IS, the lowest pressure being when the balance cylinder and the beam are at the top of their stroke. It is for this reason that the pressure indicator 31 is placed between the reservoir and the second check valve 36.

As best seen in Figure 6, the check valve 34 of the compressor intake pipe, is of a type employing a valve member 38, also seen' in Figure -11. This valve member 38 may be depressed, against the tension of its controlling spring, to hold the same away from its seat and in this manner render the valve inactive so that the compressor will take in and discharge air through its intake line, and no air will be fed through the reservoir feed pipe 33. To-control valve 34 in the above manner the invention provides the following.

Mounted on the check valve 34 is a regulator,-

generally indicated at 33,. which functions without regard to the fluctuations of pressure in the reservoir, and has a vertically cylindrical casing 40 in which a vertically shiftable sleeve 41 is slidably mounted. Through the casing and through the otherwise closed lower end of the .with this chamber there communicates an inits lower end will engage and depress the valve member 38 to a position rendering check valve 34 inoperative as such, and permitting air to be both taken'in and discharged through the intake pipe 32.

The effective tension of spring 43 may be trolling spring 43.

sleeve 4|, is a vertically, longitudinally shiftable control stem 42, whose lower end extends through the lower end of casing 40 into the check valve 34 to a point in vertical alignment with the valve member 38.

The upper end of the stem 42 movably projects upwardly through the otherwise closed upper end of the casing 40, and around said stem, within casing 40, is a controlling spring 43 compressed between an upper cross pin 44 of stem 42 and the lower closed end of the sleeve 4|. This spring 43 thus normally presses the stem 42 upwardly to a point where its lower end is above the valve member 38 so as to allow the valve 34 In order that the setting of the spring tension may be quickly and'accurately known at all times, the sleeve 4|, as best seen in Figures 8 and '9, may have thereon vertically aligned gradua tions 50, in pounds pressure, in line with a sight opening 5| through the wall of the casing 40.

As best seen in Figures 1, 3 and 6, a pressure communicating tube 52 opens at one end into the cap 45 of the regulator 33, the other end of said tube opening through the top of, and into, a surge or bufler tank 53 whose lower end is in open communication with the reservoir feed pipe 33 at a point between the two check valves 35 and 36. It is thus the pressure in this tank 33 which forces the controlling stem 42 downwardly through the regulator.

The capacity of the surge or buffer tank 53 is such as to absorb into its relatively quiescent interior each surge of pressure through the reservoir feed pipe 33 in the operation of the compressor. It is, moreover, protected from the fluctuations of' pressure in the reservoir by the check valve 36, andits pressure cannot, of course. return to the compressor by reason of the check valve 35.

It is apparent from the foregoing that during pumping of pressure into the reservoir, the compressor 25 draws air through check valve 34, with,

the controlling stem 42 of the regulator held in its upper positionby the spring 43 adjusted, for example to flfty -pounds. During the filling of the reservoir with the balance cylinder in action, there is a constant rise and fall of reservoir pressure, which corresponds with the strokes of the compressor, but no rise of reservoir pressure above that of a single delivery stroke of the compressor can afl'ect the pressure in the surge or bufl'er tank 53 and, as above stated, the capacity of the latter is such that no sudden rise of its pressure can result from a single stroke of the compressor. In this way the rise of pressure in the surge tank is gradual in the same manner as the rise of the lowest pressure in the reservoir, or in other words that pressure fed thereto by the compressor. when the point is reached where pressure in the surge tank equals fifty pounds, the controlling stem 42 will be forced down and the pumping action of the compressor will cease by reason of the inoperative condition of its intake valve 34. From this point on, during operation of th pumping unit, the several parts of the regulating system are stationary until such time as the pressure in the reservoir falls below that within the surge tank 53, permitting pressure to flow from the latter into the reservoir past the check valve 36, whereupon the spring of the regulator then lifts the stem thereof against the reduced pressure within the surge tank and restores the intake valve 35 of the compressor to operative condition It is plain, as seen in Figure 5, that instead of utilizing the regulator 39 on the check valve '34 of the compressor intake pipe 32, it may be employed on a separate pipe 54 to atmosphere. The result is the same, the working chamber of the compressor being in each instance vented to atmosphere so that itmerely takes in and exhausts airwithout compressing, during all the period of operation of the unit except when pressure must be replenished from time to time in the reservoir.

Having thus fully described the invention, what is claimed is:

1. In a pressure control and supply system, a

reservoir and at the same time adapt the tank vto bleed pressure into the reservoir when pressure in the latter falls below tank pressure, and a pressure connection between the tank and the said regulator for controlling the latter.

4. In a pressure control and supply system, a

pressure reservoir subject in operation to constant fluctuations between high and low pressures, a constantly operating compressor for feeding pressure into said reservoir whenever low pressure therein falls below a predetermined point, a feed line between the compressor and reservoir, a manually regulated and pressure controlled means for loading and unloading the compressor, a surge or bufier tank connected to the feed line and of a size rendering the same subpressure reservoir subject in operation to constant fluctuations between high and low pressures, a constantly operating compressor for supplying pressure into said reservoir whenever low pressure therein falls below a predetermined point, a feed line from the compressor to the reservoir, a pressure controlled regulator having means for loading and unloading the compressor, a bufier tank connected to receive pressure supplied to the reservoir whenthe compressor is loaded, and of a capacity to'insure gradual rise of pressure therein, a connection between the tank and the reservoir having therein a check valve opening toward the reservoir whereby to protect the tank from high pressures in the reservoir due to pressure fluctuations, while at the same time adapt the tank to bleed pressure into the reservoir when pressure in the latter falls below tank pressure, and a pressure connection between said bufier tank and the regulator for controlling the latter.

ject to gradual rise of pressure therein when the compressor is loaded, a check valve in the feed line between the compressor and bufier tank and a opening toward the latter to prevent bleeding of tank pressure into the compressor when the lat- 2. In a pressure control and supply system, a

said tank having a valved pressure connection.

with the reservoir limiting flow of pressure in a direction from the tank to the reservoir, and a pressure connection between said tank and the ,said regulator for controlling the latter.

3. In a pressure control and supply system, a

pressure reservoir subject in operation to con-' stant fluctuations between high and low pressures, a constantly operating compressor for supplying pressure into said reservoir whenever low pressure therein falls below a predetermined point, a feed line from the compressor to the reservoir, a pressure controlled regulator having means for loading and unloading the compressor, a buffer tank connected to the feed line and of a capacity subjecting'the same to gradual rlse in pressure during several successive strokes of the loaded compressor, a check valve between the said tank and the compressor, preventingbleed= ing of tank pressure into the compressor, a second check valve between the tank and reservoir, opening toward the latter whereby to protect the tank against fluctuating high pressures in the ter is unloaded, a second check valve between the buffer tank and the reservoir opening toward the latter whereby the tank is protected against pressure fluctuations in the reservoir, and at the same time adapted to bleed its pressure into the reservoir when pressure in the latter falls below the predetermined low pressure, whereby the 'low pressure in the tank and reservoir will be the same at all times, and a pressure connection between said tank and the compressor loading and unloading means for controlling the latter.

5. In a pressure regulating system, a pressure controlled, manually adjustable regulator for the loading and unloading of a compressor, said regulator consisting of a casing having a slotted wall and provided also with a sight opening, a sleeve sliclably interfltting said casing having a member outstanding through the slotted wall, and also having a lengthwise series of graduations in pounds pressure, arranged to individually show through the sight opening, a member adjustable on the exterior surface of the casing and engaging said sleeve member to adjust the sleeve lengthwise of, and within, the casing, an axially shiftable operating rod within, and projecting beyond one end of, the casing, a spring connected at one end to the rod and. anchored at its other end on the'sleeve for urging the rod in one direction, a closed cap on the other end of the casing around the other end of the rod, 2. bellows within said cap engaging the latter end of the rod, and a pressure connection for supplying pressure against'the bellows for shifting the rod in the opposite direction.

6. In a pressure regulating system, a pressure controlled, manually adjustable regulator for the loading and unloading of a compressor, said regulator consisting of a casing having a slotted wall and provided also with a sight opening a sleeve slidably interfitting said casing, having a member outstanding through the slotted casing wall, and also having a lengthwise series of graduations in pounds pressure, arranged to individually show through the sight opening, a member adjustable on the exterior surface of the casing and engaging said sleeve member to adjust the sleeve lengthwise of, and within, the casing,

an axially shiftable operating rod within, and projecting beyond one end of, the casing, a spring connected at one end to the rod and anchored at its other end on the sleeve for urging the rod in one direction, and pressure actuated means for urging the rod in the opposite direction.

7. In a pressure regulating system, a pressure controlled and manually adjustable regulator including a lengthwise slotted casing having a sight opening in its wall, an axially shiitable operating rod in the casing and projecting at one end through the respective end 01' the casing, pressure actuated means cooperating with the other in resisting pressure acfiuated movements of the rod, the said spring abutment member including a part elongated lengthwise 01, and within, the casing having thereon graduations in pounds pressure arranged to individually. show through the said sight opening of the casing.

8. In a pressure regulating system, a pressure controlled and manually adjustable regulatorincluding a casing having a sight opening in its wall, an operating rod shiitable axially in the casing and projecting therefrom at one end, pressure actuated means cooperating with the other end of said rod for shitting the latter in one direction, a spring in the casing and in connection at one end with the rod for urging the latter in the opposite direction, a member shittable lengthwise within the casing and forming an adjustable abutment tor the other end oi the spring and having a part thereof elongated lengthwise oi the casing, provided with graduations in pounds pressure arranged thereon to in-' dividually show through the sight opening of the casing, and a member manually adjustable on the exterior of the casing and operatively connected with said spring abutment for shifting the latter to vary the eil'ective tension 0! the spring independent of pressure actuation oi. the rod.

EDGAR W. PATTERSON.

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