US2384420A

US2384420A - Pump control means

Info

Publication number: US2384420A
Application number: US453709A
Authority: US
Inventors: Donald G Griswold
Original assignee: Clayton Manufacturing Co
Current assignee: Clayton Manufacturing Co
Priority date: 1942-08-05
Filing date: 1942-08-05
Publication date: 1945-09-04
Anticipated expiration: 1962-09-04

Description

Sept 4, 1945. D. G. GRlsWoLD PUMP CONTROL MEANS Filed Aug. 5, `1942 arranged exteriorly of the main valve I. The valve stem I2 projects outwardly of the cover 3 and carries a roller I3 adapted to engage the movable contact element |.1 of the micro switch llas said stem moves upward. The movable Vass-1,4910

. ranged in the drain conduit 33 and is adapted contact |1 is arranged to engage a stationary contact I3 of the micro switchA I5 to complete a circuit to a holding coil I3.' the function of which will be described more. fully later.

The opening and closing of the main valve I is controlled by a pilot valve P. which in turn is actuated'by a solenoid mechanism generally cludes a housing 2l containing a chamber 2| adapted to receive operating fluid under pressure. In the present construction, the chamber 2| is connected with both the inlet chamber I3 and the outlet chamber of the main valve I. Thus, a conduit'22 extends from the inlet chamber I3 to a pipe T 23, and a conduit 24 connects the outlet chamber II with said pipe T. A conduit 25 connects the stem of the T 23 with the pressure chamber 2|. Acheck valve 231s arranged in the conduit 22 and a check valve 21 is arranged in the conduit 24. The check valves 25 andy21, as will be obvious from the drawing. vare arranged so that fluid can ilow through the

conduits

22 and 24 in only one direction, namely, toward the pressure chamber 2 I. An adjustable needle valve 23 is arranged in the conduit 2l to control the rate at which iluid can pass into the chamber 2| and thus control the rate at which the main valve I can gradually close.

The connection of the pressure chamber 2| with both the inlet and outlet chambers III and II, respectively, assures the availability of operating fluid under pressure for closing'the valve I when the pump 2 is idle as well as when the pump is operating. When the pump 2 is in operation the higher pressure will prevail in the lnlet chamber In, whereas, when the pump is stopped the higher pressure will be in the outlet chamber so that the conduit arrangement. 22-24-25 assures the supply of operating nid to the pilot valve from whichever chamber contains the higher pressure. In either event the area of the diaphragm subject to the pressure of the operating iiuid is greater than that exposed to the fluid in the body 1 of the valve I so that said valve will always close when ldesired.

The pilot valve P also includes a base 3l secured to the housing 23 in any conventional manner. The base 3|) serves as a closure for the lower side of the pressure chamber 2l and also provides a seat for a pilot disc 3| received in said chamber. The pilot disc 3| is shown in plan in Fig. 2 and in cross-section in Fig. 3, and has a straight pressure port 32 and a U-shaped exhaust port 33 arranged upon an angle of 60 relatlve to each other. Obviously, more than one pressure port andfexhaust port can be used i! desired. A pilot valve shaft 34 is diagrammatically shown connected with the pilot disc 3| for turning said pilot disc.

One of the legs of the U-shaped port 33 is arranged axially of the pilot disc 3| and communicates with a drain passage 35 (Fig. 2) in the base 30. The other leg of said U-shaped port 33 communicates with a passage 36 which is connected by conduit 31 with the main diaphragm chamber 38 of the valve I. A drain conduit 39 is connected with the passageway 35 and serves to conduct spent operating fluid fromthe pilot valve P. An adjustable needle valve 40 isl arvindicated by th'e letter S. The pilot valve P into be regulated to control the rate of dow oi spent operating iluid from the diaphragm chamber 3l and thus control the rate at which the main valve can gradually open.

The solenoid mechanism B for actuating the pilot valve P includes the usual coil 4l and armature 43. One end ofthe armature 43 is pivotally connected to a link 41 by a pin 43. The link 41 is also pivotally connectedto a crank 4l by a rod 43 which has a portion 3l projecting through suitable openings in both the link and the crank, The rod 49 also has a portion Il projecting through an opening in one'end of an arm 32. the opposite end o1' said arm being nxedlyv secured to the pilot shaft 34, so that upon actuation of the arm 52, rotary movement will be transmitted through the pilot shaft 34 to the pilot disc 3|.

The crank 43* is pivotally mounted at one end upon a pin 53. A lug I4 projects laterally from the crank 4l* and.is adapted to engage a stop pin 55 to limit the clockwise movement of the crank 43 about the pin I3. 'I'he crank 43l also has a. longitudinal extension 53, which is connected to one end of a return tension spring 51. 'I'he spring 51 is -arranged so as to hold the lug 54 in engagement with the stop pin 5I when the solenoid coil 4l is 'de-energized. The

supplying current to the circuit.

pilot disc 3| is shown 1n the position corresponding to the de-energized condition oi the solenoid S, namely, with the pressure port 32 communicating with the passage 33 to maintain the main valve I in its closed position.

'I'he stroke of the amature 44 is such as to the

ports

32 and 33 are alternately connected with the passage 38 to successively eiIect closing and opening ofthe main valve I. When more than one set of pilot ports 32-33 is used. a corresponding number of passages 33 will be needed, all connected with the conduit 31.

The motor 8, the micro switch Il, the holding coil I9, and the solenoid coil 45, all previously referred to, are interconnected in an electrical circuit which will now be described. The numerals and 3| indicate two main leads for I'he lead 4I is connected to one side ot the holding coil I3,

. which forms an element of a double contact relay 62. The relay 52 includes a ilrst movable contact 63 adapted to engage a stationary contact 34 and a second movable contact 45 adapted to engage a stationary contact .53. The other side of the relay coil I3 is connected with a stationary contact 31 of a main switch 33 having

movable contacts

33 and 10. The other main lead 3| is connected at 1| with the movable contact 65 oi the4 relay 32 and is also connected with the stationary contact 1l of the switch I3 by a line 12. 'I'he switch 33 has a second stationary contact 13 which is connected by a line 14 with one side of the solenoid coil 45. The other side of said solenoid coil is connected by a line 15 with the lead Il. g

One side of the micro switch I5 is connected by a line 18 with the main lead 6| and the other side of said micro switch is connected with th'e movable contact 53 of th'e relay 62 by a line 11.

The motor 5 is controlled by an electrically operated switch 18 including three movable contacts 19, three stationary contacts 30, an armature 8|, and a coil 32 for eecting actuation of other side of said coil is connected by a, line the armature. One side of the coil 82 is'connested with the main lead 60 by a line 83 and the 83 with the stationary contact 'G8 of the relay S2. Current is supplied to the motor 10 through three lines indicated at 8d. It will be apparent that wh'en the coil 82 is energized, the armature 8| will cause engagement of the movable contacts 'I9 with the stationary contacts BD so that the circuit to the motor 6 will be completed.

The operation of the aforedescribed control apparatus is as follows: The main switch t8 is preferably manually operated, although it will be understood that it may be controlled by a-oat, (not shown), or any other suitable mechanism. The closing of the main switch 68 will complete the circuit to the solenoid S, for actuating the pilot valve P, and to the coil t2, for effecting actuation of the motor control switch lt. Simultaneously, the circuit will be completed to the relay et and its holding coil i9.

The circuit to the solenoid S will be completed as ollows: Current from the main lead ei will idow through the line l, across the contacts et and 'lil of the switch tu, through line i@ to one side or the solenoid coil 35, through said coil and back through the line l5 to th'e other main lead Likewise, the circuit to the holding coil it is completed through the mainlead t l, line l2, con- @l and lil or the switch tu, and line des tc one side of the holding coil it, the other side of coil being directly connected with the lead @t course, energization of the relay holding coil i@ obviously will complete the circu to the motor control switch it, as follows: Current ironri the main leadei will ow through the reiay contacts e5 and et and line 233B to one side of the coii 32, and from the other side or the coil il@ bach to the other main lead te through the iine is wiil be apparent from the foregoing, several functions occur simultaneously upon closing of the main switch' te. Thus, energization of the eolennid coil iii will actuate the pilot valve P so that the arm engages the stop 52e with the resuit that the exhaust port 33 is positioned to interccnnect the passageways and te to permit the exhaust of spent operating fluid from the diachamber of the main valve through the drain iine This will allow the main valve i te open at a, gradual rate controlled by the adiustment of the needle valve dil. The circuit to motor switch l having been completed simultaneously with the actuation of the solencid S, the motor d is started and the centrifugal pump 2 begins to pump water or other liquid into the pipe line d. However, inasmuch as the main vaive il only begins to open shortly, after the.

pump 2 has started, the pipe line i will be maintained under pressure so that no surging can take place therein. The gradual opening of the main valve i will increase the rate at which water can iiow through said valve, but the difference between the volume permitted to ilow through said valve while opening and the capacity of the pump is taken care oi by slippage in said pump in the case of a centrifugal "pump, or through a relief valve in the case of a positive displacement pump. Continued pumping will gradually effect flexing of the diaphragm 9 upwardly and force the spent operating fluid out of the diaphragm chamber 3%, eventually effecting full opening o1" the main valve. The upward ilexing of the diaphragm Q necessarily results in an upward movement of the valve stem i2 so that the roller I6 engages the movable contact I1 of the micro switch I5 causing said contact to engage the stationary contact IB and thus complete a. second circuit to the holding coill I9 of the relay 82. The completion of this circuit has no eiect upon the circuits already completed. The roller I6 Land movable contact l1 are preferably arranged so that the micro switch' l5 is closed upon only a. very slight upward movement of the valve stem l2, after the'valve I starts to open. Hence, the

micro switch' l5 remains closed so long as the valve i is open, and said switch will open only when the main valve is about to completely close and cut oi th'e flow between the chambers lil and il.'

When it is desired ,to close the main valve' l, this can be eiected by opening the switch 88, which will interrupt the circuit to the solenoid S and return the pilot disc 3| to its initial position under the action of the return spring 51. This will align the pressure. port 32 with the passage te `(see Fig. l) so that operating fluid under pressure can flow from the chamber tl through the conduit 3l into the "diaphragm chamber te and effect gradual closing of the valve i, or in other words, downward flexing of the diaphragm t with its incidental downward movement of the valve stem i2. It will be recalled that the micro switch le is closed and remains closed until the main 'valve i h'as substantially completely closed. This means that the holding coil 62 will remain energized and continue the maintenance oi the circuit to the motor control switch lil, notwithstanding the fact that the main switch 'd8 has been opened. Thus, the micro switch IE5-remains closed, after opening of the switch dii, and com pletes the circuit to the switch 'it as follows: Current will flow from the line 6I across th'e relay contacts e5 and t@ to one side of the coil S2 and from the other side of said coil through the line t5 to the other main lead itil. When th'e main valve i has almost completely closed the stem i2 will have moved downwardly a sufiicient distance to permit the contact' il of the micro switch l5 to disengage the contact i8, and thus eiect opening ci th'e micro switch i5.. The opening of the micro switch i5 will, of course, break the circuit to the motor control switch-'lt so that the circuit to the motor t will now be interrupted and the pump 2 will stop. Here again, it will be noted that the pump h'as continued to operate against a gradual restriction of flow due to the closing action of the main valve l and that the pump 2 will continue to operate against such resistance until the said main valve has substantially completely closed, any slippage necessary to prevent excessive pressure in the line being automatically taken care ofv byth'e pump. In this manner all surging is avoided during the shutting down'oi the pump and the system operates quietly, free from vibrations and shocks.

The present invention, in addition to preventing line surges during` both the starting and shutting down of the pump 2, affords th'e addiseconds after the solenoid S has been actuated `to permit opening of the main valve I. In this manner, the main valve I will be conditioned for opening slightly before the pump 2 starts. The

Vadvantage of th'is is that water can ilow back through the valve while it is slightly open and prime the pump in installations where such priming is necessary, or in installations where it is highly desirable to wet th'e pump bearings before the pump is actually started.

It will be apparent that the principle of start- 'ing the pump and gradually opening the valve with the starting oi' the pump, and the gradual closing of th'e valve just prior to the stopping oi' the pump, may be eil'ected by various other circuits, devices, and mechanisms diierent from that disclosed herein. Accordingly, it willl be understood that the present invention is not limited to the particular circuits and apparatus disclosed herein, and that various alterations and changes may be made therein without departing from the spirit of the invention or the scope of the annexed claims.

Iclaim:

l. In combination, a pump; means for driving said pump; a valve upon the discharge side of said pump arranged to have iluid pumped thereth'rough by said pump: and control means operatively connected with said pump driving means and valvearranged to allow said valve to start opening before said pump driving means starts to drive said pump.

2. The combination defined in claim 1, in which the drive means for the pump is an electric motor and the control means includes a delayed action relay for delaying operation ot the pump drive means until after the valve has started to open.

3. In combination, a pump; means i'or driving said pump; a valve upon th'e discharge side oi said pump arranged to have fluid pumped therethrough by said pump; and control means operatively connected with said pump driving means and valve arranged to allow said valve to start opening before said pump starts, and to start closing of said valve while said pump is running and to stop said pump as said valve is about to completely close.

4. Control means for a motor driven pump,

` and a valve arranged on the discharge side of said pump, comprising: means for. substantially simultaneously effecting starting of said pump and permitting the opening of said main valve, including a circuit containing electrically operated pilot valve means' for controlling the opening of said main valve means including an electrically operated switch for completing a circuit to said motor; and means including a main switch connected in circuit with said electrically operated pilot valve means and said electrically operated switch for simultaneously completing the circuit to said electrically operated pilot valve means and said electrically operated n iotor switch.

5. VIn combination, a pump; means for driving said pump; a iluid pressure operable valve con-y -nected with said pump upon the discharge side thereof; a pilot valve controlling the exhaust and admission ot operating duid to said main valve to eiTect opening and closing of ysaid main valve; and control means operatively connected with said pump'driving means and said pilot valve arranged to actuate said pilot valve to permit opening of said main valve substantially simultaneouslyV with' thev initiation of the drive ot said pump.

6. In combination, a pump; means for driving said pump; a main diaphragm valve connected with said pump upon the discharge side thereof; a pilot valve controlling the exhaust and admission of operating i'iuid to the diaphragm chamber of said main valve to eilect opening and closing of said main valve; means ior controlling the rate of exhaust and admission oi slid operating iluid to determine the rate at which said main valve can operate; and control means operatively connected with said pump driving means and said pilot valve arranged to actuate said `pilot valve to permit opening of said main valve substantially simultaneously with the initiation of the drive of said pump.

7. In combination, a pump; means for driving said pump; a uid pressure operable main valve connected with the discharge of .said pump; a pilot valve controlling the opening and closing oi' said main valve; and control means for said' pump driving means and said pilot valve arranged to actuate said pilot valve to permit opening of said main valve substantially simultaneously with the initiation of the drive oi' said pump, and to effect actuation oi' said pilot valve to cause said main valve to close and to discontinue the drive of said pump at a time when said main valve has substantially completely closed.

8. In combination, a pump; means for driving said pump; a iluid pressure operable main valve connected with the discharge side of said pump; a pilot valve controlling the opening and closing of said main valve; means i'or controlling the rate at whichsaid'main valve can open and close, respectively; and control means for said pump driving means and said pilot valve arranged to actuate said pilot valve to permit opening ol said main valve substantially simultaneously with the initiation of the drive of said pump, and to eil'ect actuation of said pilot valve to cause said main valve to close and to discontinue the drive o! said pump at a time when said main valve-has substantially completely closed.

9. In combination, a motor driven pump; a main valve connected with the discharge side of said pump-and including a reciprocable valve stem; a switch arranged to be operated upon slight upward movement of said valve stem; a motor switch arranged to complete a circuit to the motor for driving said pump; and a holding coil, said valve stem-operated switch being so connected in circuit with said holding coil and motor switch that when said valve stem operated switch is closed said holding coil maintains a circuit to said motor switch until said valve stem reaches substantially its lower limit of movement.

l0. In combination, a pump; means for driving said pump; electrically operated means for controlling said pump drive means; a main valve connected with the discharge side of said pump; a relay coil in circuit with said electrically operswitch. said ated means for controlling said pump drive asssaao pump drive control means remains de-energized means: a pilot valve for controlling the openingl and closing. of said main valve; electrically oper'- ated means for actuating said pilot valve. said last-mentioned means being connected in circuit with said relay coil and pump drive control means; and a main switch in said circuit arranged so that upon closing .thereof said pilot actuating means and relay coil are simultaneously actuated to eilect initiation oi operation of sgild pump drive means and opening of said main v ve.

il. In comtmation. a motor driven pump; an electrically operated switch for controlling the operating of said motor; a main valve connected with the discharge side of said pump and including a reciprocable element movable coincidental with the opening and closing of said main valve; a switch arranged to be closed by said reciprolast mentioned switch and said motor control relay being arranged to complete a circuit to said motor control switch when energized; a pilot valve controlling the opening and closing of said main valve; a solenoid for actuat ing said pilot valve, said solenoid being operably connected in circuit with said reciprocable element-operated switch, relay, and motor switch; and a main switch in said circuit arranged so that upon closing thereof said solenoid and holding coil are simultaneously actuated to eilect opening of said main valve and the starting of said motor. said reciprocable-element operated switch serving to maintain a circuit to said relay after said main switch is opened and until said main valve is nearly completely closed.

12. In combination. a motor driven pump; an electrically operated switch for controlling the operation of said motor; a main valve connected with the discharge ing a reciprocable with the opening and element movable coincidental closing of said main valve; a switch arranged to be closed by said reciprocable element as said mainvalve is opened; a relay operably connected in circuit with the said last-mentioned switch and said motor control switch, said relay being arranged to complete a circuit to said motor control switch when energized; a pilot valve controlling the opening' and closing of said main valve; a solenoid for actuating said pilot valve, said solenoid being operably connected in circuit with said reciprocable element operated switch, relay, and motor switch; and a main switch in said circuit arranged so that upon closing thereof said solenoid and relay are simultaneously actuated to eect opening of said main valve and starting of said motor, said reciprocable cient-operated switch being arranged to maintain a circuit to said motor switch through said relay after said main switch has' been opened to de-energise said solenoid, and thereby effect operation of said pilot valve to rmit opening of said main valve.

i3. In combination, a pump; means for driving said pump; electrically operated means for controlling said pump drive means; a main valve connected with the discharge side of said pump; a relay in circuit with said electrically operated means for controlling said pump drive means; a pilot valve for controlling the opening and closing of said main valve; electrically operated means for actuating said pilot valve; a delayed action relay in the circuit between said relay coil and said pump drive control means, whereby said side of said pump and includwhich said spent for a given time interval alter saidpilot valve actuating means isenergized so that said pilot valve is actuated to permit said main valve to open before said pump is driven: and a main switch arranged in the circuit so that upon closing thereof. said pilot actuating means and relays are simultaneously actuated.

14. In combination. a motor driven centrifugal pump; a main valve connected with said pump upon the discharge side of said pump. said main valvev including an inlet chamber. an outlet chamber, diaphragm operatedmeans for controlling the ow between said chambers. and ay reciprocable valve stem connected with said diaphragm; a pilot valve for controlling said diaphragm valve. said pilot valve including a pressure chamber connected by conduit means with the inlet and outlet chambers. respectively, of said main valve, said conduit means including check valves providing a one-way flow between said chambers in said main valve and the pressure chamber in said pilot valve and also including an adjustable needle valve between said check valves and pressure chamber for limiting the rate at which operating iluid can flow into said pressure chamber; a conduit' connecting said pilot valve with the diaphragm` chamber of said main valve and a drain conduit connecting said pilot valve with the atmosphere: a rotatable pilot disc in said pressure chamber having a through port for admitting operating uid -from said pressure chamber into the diaphragm chamber of said main valve when 'said pilot valve is. in one position, and an exhaust port for exhausting spent operating uid from said main diaphragm chamber through said drain conduit to the atmosphere when said pilot disc is in another position, said drain conduit having adjustable means therein for varying the rate at tluid can drain from said main diaphragm chamber. whereby to allow said main valve to open at a gradual rate; electrically operated means for actuating said pilot disc; electrically operated means for completing a circuit to said pump motor; a holding coil operably connected in circuit with both said electrically operated means; a micro switch arranged to be actuated by said valve stem, said micro switch being arranged so that it closes upon very slight upward movement of' said valve stem corresponding to a slightly open position of the main valve; and a main switch connected in circuit with the micro switch. the holding coil, the electrically operated means vfor said pilot operated means lor completing a circuit to 'said motor, the circuit arrangement being such that when said main switch is closed said electrically operated means for actuating said pilot disc is operated to rotate said pilot disc to permit opening of said main valve; and said electrically oper` ated means for controlling said motor is actuated to complete the circuit to said motor so that said main valve starts to open substantially lsimultaneously with the starting of said pump, said circuit being further arranged so that when said main switch is opened, said electrically' operated means for actuating said pilot disc is deenergized, thereby permitting said pilot disc to return to its initial position and eect closing of said main valve. said micro switch being arranged so that vit now maintains said holding coil energized to continue the circuit to said motor so that said motor drives said pump until said main valve has substantially 'closed and said valve stem has assumed a position permitting said micro switch disc, and the electrically to open and thus interrupt the circuit to said holding coil.

. i5. In combination, a centrifugal pump; an electric motor arranged to drive' said pump; a pressure iiuid operable main valve connected with said pump upon the discharge side of said. pump. said main valve including an inlet chamber, an outlet chamber. a diaphragm for controlling the flow `between said chamber and a reciprocable valve stem connected with said dia- 1 phragm; a pilot valve for controlling said main diaphragm valve, said pilot valve including a pressure chamber connected by conduit means with 'the inlet and outlet chambers, respectively. of said main valve, said conduit means including 1 check valve means providing a one-way ilow between said chambers in said main valve and said pressure chamber in said pilot valve; a conduit connecting said pilot valve with the diaphragm chamber of said main valve: a drain conduit for spent operating tluid connecting said pilot valve with the atmosphere; a rotatable. ported pilot disc in said pressure chamber for controlling the iiow of operating iiuid between said main valve and said pilot valve, whereby said main valve can be closed by iluid from the inlet or outlet chambers thereof depending upon which oi' said chambers is subject to the higher pressure; a circuit lincluding electrically operated means for effect- DoNALD G. Gmswoib.