US3091179A

US3091179A - Well pumping operation control system

Info

Publication number: US3091179A
Application number: US95837A
Authority: US
Inventors: Echols Wilford Ray
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-03-15
Filing date: 1961-03-15
Publication date: 1963-05-28
Anticipated expiration: 1980-05-28

Description

May 28, 1963 w. R. ECHOLS WELL PUMPING OPERATION CONTROL SYSTEM 2 Sheets-Sheet 1 Filed March 1 1961 lOu HQ Q

f S n Mo or INVENTOR WI LFORD RAY ECHOLS BY QM/w w 601% ATTORNEYS.

y 1963 w. R. ECHOLS 3,091,179

WELL PUMPING OPERATION CONTROL SYSTEM Filed March 15, 1961 2 Sheets-Sheet 2 INVENTOR WILFORD RAY ECHOLS ATTORNEYS.

ates

This invention relates to systems for controlling the operation of well pumping installations, and more particularly to systems for automatically controlling the operation of a well pump in accordance with the availability of fluid, for example oil, in the sub-surface well bore or cavity.

in many wells, particularly during the later stages of the exploitation of oil wells, the rate of flow of fluid from the underground strata into the bore or cavity eventually becomes so low as not to keep the bore or cavity sufficiently filled to enable the pump to maintain a pumped fluid delivery rate which is etficient and economical and conducive to optimum production from the well. When the in-flow of fluid from the well cavity falls off to this extent, the well is said to be pumped off or pumped dry. In the past, the extraction of fluids from wells inclined to be readily pumped ofif has been continued by intermittent operation of the pumping installation, which may he eftected or controlled either automatically or manually at intervals. -It has also previously been proposed to stop the pumping operation automatically when the delivery of pumped fluid ceases or diminishes significantly; and it has further been proposed to provide well pumping installations both with mechanisms for automatically stopping the pumps in response to cessation of fluid delivery, and mechanisms for automatically restarting the pumps at predetermined times, irrespective of the times of stopping of the pumps. Such arrangements have the inherent disadvantage of being susceptible to restarting the pumps automatically, and it might be said indiscriminately, without ensuring a certain period of nonoperation of the pumps, following the automatic stopping of the pumps, sufficient to enable the well bore or cavity to become re-filled.

An object of the present invention is to provide a well pump control system including means for automatically stopping the pump motor in response to cessation or significant diminution of the delivery of pumped fluid and for maintaining the pump inoperative for a rest period of certain and predetermined extent, and for then restarting the pump but only after the well has beein rested for the complete, certain and prededtermined period of nonoperation of the pump, thus ensuring that sufiicient time will elapse, following the stopping of the pump, for the well bore or cavity to become filled, or substantially so, before the next operation of the pump.

Another object of the invention is to provide a system of the character stated including means for automatically effecting operation of the pump for a testing period of relatively short duration at the end of the predetermined and certain rest period, for automatically again placing the pump under the control of the fluid delivery in the event fluid delivery is resumed and for automatically stopping the pump at the end of the short testing period in the event normal pump delivery is not resumed during the testing period.

Another object of the invention is to provide a control system of the kind stated, including means for limiting the total period of operation of the pump to a predetermined number of hours, including hours of pump operation during fluid delivery and any testing operation time, cumulatively and in sequence.

A further object of the invention is to provide a new and improved arrangement for controlling the operation of the pump in dependence upon continued fluid delivery,

3,691,179 Patented May 28, 1963 even with the pulsating flow usually characteristic of reciprocating deep well pumps.

A further object of the invention is to provide a system for performing the various controlling functions outlined above and which may be adjusted or conditioned selectively for being adapted to operate differently according to different conditions and requirements, as, for example, operating the pump under manual control, and/ or with or without the total period of operation control.

Other objects of the invention will become apparent from a reading of the following description of a preferred embodiment, the appended claims and the accompanying drawings, in which:

FIGURE 1 is a somewhat schematic elevational view of a well pump installation, itself of generally conventional character;

FIGURE "2 is an electrical circuit diagram of the control system, certain control mechanism components being shown schematically;

FIGURE 3 is a top plan view of a check valve switch, shown in elevation in FIGURE 2;

FIGURE 4 is a schematic view of a predetermined hour counter device for limiting the total number of hours of operation of the pump, either while delivering pumped fluid or while operating during the rest period; and

FEGURE 5 is a schematic view of an oil cycle timer which controls the maintaining of the pump inoperative during a rest period and the operation of the pump during the abbreviated test period.

General Arrangement A control system embodying the invention is illustrated as being arranged to control the operation of a deep well pumping installation, itself of generally conventional kind, shown somewhat schematically in FIGURE 1. A well pump, represented by a conventional sucker rod string P is operable by a prime mover or driving motor M which drives a crank 1 through a reduction gear mechanism RG, the crank being connected by a pitman 2 to a walking beam 3 pivoted at 4 on a standard 5. The sucker rod string is connected to the walking beam, as by a flexible connecting member 6. Fluid elevated by the pump P is delivered through a conduit 7 interposed in which is a check valve 8 arranged to permit fluid to flow only in the direction of the arrow, that is away from the pump.

The motor M may be of any suitable kind, electrically powered, or otherwise powered and eelctrically controlled for being started and stopped. In the illustrative installa tion, the pump is of the deep well lift type characterized in operation by delivering a pulsating flow of pumped fluid. In one of its aspects, the invention is particularly adapted for use in connection with pumping installations of this type in which the fluid is delivered in a series of flow pulses. However, control systems embodying the invention may be used for controlling pumps of the substantially constant delivery type as well as pumps delivering intermittently, that is with a somewhat pulsating flow.

In the normal operation and controlling of a well installation in accordance with the invention, the pump may be continued in operation indefinitely in response to predetermined flow of pumped fluid through the delivery conduit 7, provided the run-in of fluid into the cavity at the bottom of the well continues to be high enough to maintain a substantially undiminished supply of fluid to be pumped, so that the rate of delivery by the pump will be maintained at a substantially predetermined average flow, with either substantially continuous or pulsating fiow. However, the invention contemplates automatically limiting the overall operating time of the pump to a predetermined total number of hours under the control of a predetermined hour counter generally designated HQ in FIGURES 2 and 4.

In the event the run-in of fluid into the well cavity does not keep up with the pumping of fluid from the cavity with resulting diminution of the rate of fluid delivery by the pump, the control system, operating through the check valve 8 and a control relay, generally designated CR in FIGURE 2, responds to stop the pump driving motor M and to maintain the motor inoperative for a predetermined rest period, for example approximately four hours. The extent of the rest period is predeterminable by an off cycle timer generally designated OCT in FIG-

URES

2 and 5. When the rest period for which the OE cycle timer has been set has expired, the off cycle timer automatically re-starts the motor M and causes it to operate for a test period, of say five minutes, and in any case less than the period of operation of the off cycle timer. If the well cavity has been sufliciently refilled with fluid during the four hour rest period, the test period operation of the motor under the control of the off cycle timer will cause the pump again to deliver fluid through the check valve 8, so that controlling of the motor and continued operation thereof will be resumed under the control of the check valve 8 and the control relay CR. However, if the well cavity has not been refilled during the rest period with the result that fluid will not be discharged by the pump while operating during the five minute test period under the control of the ofl cycle timer, the latter will stop the pump motor M automatically shortly after the end of the test period. In that case, the otf cycle timer will continue to operate throughout a further rest period of approximately four hours, at the end of which a further testing under the control of the off cycle timer OCT will be effected. The rest period of approximately four hours and the testing period of five minutes would be suited for many operating situations, but where conditions vary, as for example as to the size and depth of the well and the relative degree of exhaustion of fluid in the underground strata, it may be desirable to change the extents of the rest period and testing interval. It is, however, very impotrant that the pump should not be started by a timing or any other mechanism until after the lapsing of a predetermined period of time following the stopping of the pump in response to cessation or significant diminution of the rate of fluid delivery by the pump.

Main Pump Power and Control Circuits Several of the broader aspects of the invention, the timing of some of the operational phases and the genoral inter-relationship of some of the control system components having been outlined, the representative embodimerit of the invention will be described in greater detail. The pump motor M is powered by three wire 230 volt A.C. power

source comprising conductors

9, 10 and 11. The conductor 11 is directly connected to one of the three motor terminals, and the

conductors

9 and 10 are connected to the other two motorterminals respectively through relays 12 and 13 and other conductors 9a and 10a. In FIGURE 2, three relays 12 and '13 are shown as being separate with their coils connected in series for the purpose of diagrammatic illustration, but in practice it may be preferred to use a single double pole single throw relay having a single energizing coil. In any event, the relay switch arms or poles 12 and 13 are biased to open position and are closed simultaneously. For convenience in description, the motor control relay will here inafter be referred to generally as the relay 14 having an energizing coil or winding 14a.

A control circuit for energizing the relay coil 14:: includes a manually operable double pole single throw master switch 16, a predetermined hour counter switch generally designated .17, forming part of the hour counter HC, a manually operable double pole double throw selector switch 18 settable at the left in FIGURE 2 for effecting constant running of the motor M without being controlled by the control system and being settable at the right as shown in FIGURE 2 for conditioning the system for automatic control, a manually operable starting switch '19, and, of course, appropriateconductors or wiring to be described and traced hereinafter. In the most usual types of operation, the selector 7 switch is closed to the right, as in FIGURE 2. so as to condition the system for automatic operation, and the starter switch 19 is temporarily closed. Closing of the starting switch 19 will complete a circuit through the relay coil 14a. This circuit, beginning with the power source conductor 10, includes a conductor 20, the upper pole of the closed master switch '16, a fuse 21, a condnctor 22, the hour counter switch 17, a conductor 23, the lower pole of the selector switch -18, a conductor 24-, a conductor 25, a conductor 26, the temporarily closed starting switch 19*, a conductor 27, a conductor 28, the upper pole of the selector switch 18, a condoctor 29, the relay coil winding 14a itself, a conductor 30, a conductor 31, the lower pole of the closed master switch 16, and a conductor 32 leading to the power conductor 11. Energizing of the relay coil 14a and closing of the relay 14 will start the pump motor M. The motor M will then operate under the control of the switch 19 which is held closed only long enough for the pump to begin to deliver fluid through the conduit 7 and check valve 8 at a normal or predetermined rate, or average rate in the case of a pulsating delivery. As soon 'as'such' a normal or average rate of delivery has been established, the relay coil 14a will be energized by an automatic control circuit including a check valve switch CVS and the control relay CR so that the starter switch 19 may be opened and the pump continued in operation by the automatic control system as long as the predetermined delivery of fluid is maintained.

The check valve switch CVS may be of any suitable form adapted to be closed in response to opening of the check valve. In the form shown, the check valve 8 includes a flapper element 33 fixed on a shaft 34 pivotally mounted in a valve housing 35 and projecting outwardly through a high pressure packing gland 36 and thence into an explosion proof switch housing 37. Mounted on the shaft 34 within the housing 37 are a biasing weight 38 and a mercury switch 39. The arrangement is such that the weight 38 and the mass of the flapper element 33 tend to 'hold the flapper in closed position with the switch 39 correspondingly positioned to be in open or circuit breaking condition. A predetermined delivery of fluid through the check valve will swing the flapper 33 clockwise and so tip the switch 39 to aclosed or circuit making position.

Closing of the check valve switch in this manner will complete a circuit for actuating the control relay CR in a manner to close a circuit through the motor relay winding 14a. In the illustrative embodiment, the control relay CR comprises an armature and contact arm element 40 pivoted or otherwise tiltably supportedtat 41 and having two

contacts

42 and 43 respectively on its left and right sides as shown in FIGURE 2. The arm 40 is biased toward the right, as viewed in FIGURE '2, by a spring '44, tending to bring the arm contact 43 into engagement with a fixed contact 45. A coil 46 is adapted, when energized, to pull the arm 40 to the left against the bias of the spring 44 for bringing the arm contact '42 into engagement with a fixed contact 47.

7 When the check valve switch CVS is closed, a circuit is completed through the control relay coil 46. .Beginning with the power supply conductor 10, this circuit includes the conductor '20, the upper pole of the master switch 16, the fuse 21, the conductor 22, the hour counter switch 17, the conductor 23, the lower pole of the selector switch 13, the conductor 24, a conductor 48, the mercury switch 39, a conductor 49, a conductor 50, in-

cluding resistors

51, 51 and a rectifier 52, the relay coil 46 itself, a conductor 53, the conductors 31 and 32, the lower pole of the master switch 16, and the supply line conductor 11.

When the mercury switch 39 is closed and the relay coil 46 is therefore energized, the contacts 4-2 and 47 will be held closed upon one another and this will maintain the motor relay coil 14a energized through a circuit to be described later; and it is, of course, necessary for the motor control relay .14 to be held steadily closed during normal operation. Since the check valve flapper 33 will oscillate when the pumped fluid is delivered in a pulsating stream, the mercury switch 39 will be alternately opened and closed, even during normal pumping operations. In order to hold the control relay in its FIGURE 2 position, that is, so as not to permit the spring 44 to move the arm 40 to the right when the mercury switch 39 is momentarily opened, means are provided for maintaining the control relay coil 46 energized when the switch 39 is open during the brief intervals between successive fluid delivery pulses. As shown in FIGURE 2, electrical capacitor means 54 are connected in shunt across the relay coil .6, more specifically between the

conductors

50 and 53, the connection of the capacitor means to the conductor 54 being between the rectifier 52 and the relay coil 46. The arrangement is such that during each period of operation when the mercury switch 39 is closed for energizing the coil 46, the capacitor means 54 will be charged by direct current applied thereto through the rectifier 52. During each recurrent opening of the mercury switch 39, the capacitor means 54 will discharge through the relay coil 46 to maintain the latter energized until the next closing of the switch 39. The interval during which the discharging of the capacitor means 54 will maintain the relay coil 46 energized depends of course upon the capacity of the means 54-. This may readily be determined and fixed by the use of a plurality of capacitors each having sufiicient capacity to deliver enough charge to the relay coil 46 to maintain the latter energized for a period of say ten seconds. By employing additional capacitor units, for example three as shown, the system is adapted for maintaining the relay coil 46 efiectively energized for periods determined by the pump operating speed and hence the frequency of delivery pulses. Normally, three capacitors together having the capacity to maintain the relay coil 46 effectively energized for thirty seconds will be suificient, and in many cases a lesser total capacity may be sufiicient. The etfective capacity may also be determined by employing a single and adjustable capacitor unit.

With the control relay contacts 42 and 47 being held closed upon one another during normal pump operation, the motor relay coil 14a will be maintained energized automatically after opening of the starter switch 19. The circuit for maintaining the coil 14:; energized, beginning with the line conductor 10, includes the conductor 20, the upper pole of the master switch 16, the fuse 21 and conductor 22, the hour counter switch 17 and conductor 23, the lower pole of the selector switch 18, the conductors 24- and 48, the relay arm 49 and contacts 42 and 47, the conductor 28, the upper pole of the selector switch 18, the conductor 29, the coil 14a itself,

conductors

39, 31 and 32 and the lower pole of the master switch 16, the conductor 32 leading to the line conductor 11.

As long as the pump continues to deliver fluid at a predetermined rate, the control relay will be maintained in the position with its contacts 42 and 47 closed upon each other, the motor control relay coil 14a will be maintained energized and the motor M will continue to run. If the delivery of fluid should fall below the predetermined rate, either due to stopping of the motor for some unforeseen reason or exhaustion of fluid in the well cavity, the mercury switch 39 will remain open for so long that the discharging of the capacitors 5 1-, which is of short duration,

will be unable to maintain the relay coil 46 energized. When the coil 46 has been tie-energized, the biasing spring 4-4 will pull the relay arm 4i to the right so as to separate the contacts 42 and 47 and to close the contact 43 upon the contact 45. Separation or opening of the contacts 42 and 4'7 will dc-energize the motor relay coil 14a, thus stopping the motor M.

Of} Cycle Timer As previously stated, when delivery of pumped fluid at a predetermined average rate ceases, as for example in the event the well is pumped oif, the control relay coil 46 is de-energized and the relay arm 40 is pulled to the right by the spring 44 so as to open the contacts 42 and 47 and thus de-energize the motor relay coil 14a and stop the pump motor. This operation, including the movement of the relay arm 40 to the right with resultant engagement of the

contacts

43 and 45, will bring about a rest period which has been assumed to be approximately four hours, determined by operation of the olf cycle timer OCT. The oii cycle timer is shown schematically in FIGURES 2 and 5 as including a normally inoperative substantially constant speed motor, which may be a synchronous electrical motor transmitting drive through a reduction gear 56 to a shaft 57 on which are mounted a timer motor control cam disk 58 and a test period operation control cam disk 59. The timer motor control cam disk 58 is formed with a lobe fill which extends a peripheral distance equivalent to seven minutes of the four hours required for the disk to make one complete revolution, the remainder of the disk periphery being equivalent to three hours and fiftytnree minutes. The test operation control cam disk 59 is formed with a lobe 61 which is of a peripheral extent equivalent to five minutes of the four hour period reuired for a complete revolution of the cam disk 59, the remainder of the periphery being equivalent to three hours and fifty-five minutes. The cam lobes 66 and 61 are located with their central portions in registry, so that the leading end of the lobe 69 in the direction of rotation indicated by the arrow is one minute in advance of the leading end of the lobe 61, and the trailing end of the lobe ea trails the trailing end of the lobe 61 by one minute.

FIGURE 5 illustrates the relative positions of the parts just after normal pumping delivery has stopped and the arm 40 of the control relay CR has been pulled to the right and the contact 43 has engaged the contact 45. At this instant, the timer motor cam lobe is disposed just beyond a cam follower 62 on a movable switch arm 63 provided with a contact 64 adjacent to but disengaged from a relatively fixed contact as. The contacts 64, 6S constitute a timer motor switch, closing of which will start the timer motor 55 for initiating a rest period of definite extent followed by a test period under the control of the cam disk 59 as will be described hereinafter.

Closing of the

control relay contacts

43 and 45 incident to stopping of the pump motor will complete a circuit to the timer motor 55 resulting in driving the

cam disks

58 and 59. Since the cam lobe ll will be moved away from the follower 62 for a period of three hours and fifty-three minutes, the synchronous motor 55 must be energized through a circuit independent of the

timer motor switch

64, 65. This circuit includes, beginning with the line conductor lit the conductor 2%, the upper pole of the master switch 16, the fuse 21, the conductor 22, the hour counter switch 17, the conductor 23, the lower pole of the selector switch 18, the conductors 2.4 and 48, the relay arm 4%, the

closed contacts

43 and 45, a conductor 66, a conductor 67, the timer motor 55, a conductor 68, the conductors 31 and 32, the lower pole of the master switch 16, and the line conductor 11.

Operation of the timer motor 55 through the circuit just traced will eventually bring the cam lobe 60 into engagement with the cam folower 62 for closing the

timer motor switch

64, 65 so as to complete an independent circuit through the timer motor 55 and ensure that the latter will continue to run until the

cam disks

58 and 59 have made a complete rotation and have been returned to the starting positions shown in FIGURE 5. This independent circuit, closed by the

switch

64, 65, includes the line conductor 10, the conductor 29, the upper pole of the master switch 16, the fuse 21'and conductor 22, the closed hour counter switch 17, the conductor 23 and lower pole of the selector switch 18, therconductors 24 and 25, a conductor 69, the

closed switch contacts

64 and 65, the con ductors 66 and 67, the timer motor 55, the

conductors

68, 31 and 32, the lower pole of the master switch 1'6, and the line conductor 11. Thus, with the timer

motor control switch

64, 65 closed, the motor 55 and earns 58 and 59 are certain to be driven through the last seven minutes of the oil? cycle timer cycle to their starting positions, even though the

control relay contacts

43 and 45 may be opened during this last seven minutes due to resumption of pumped fluid delivery in the test period next to be described.

A testing switch means is operable for effecting operation of the driving motor M, irrespective of operation or non-operation of the cut-ofi relay CR, but only after the all cycle timing motor 55 has been operating for a substantial part of and less than its predetermined operating time. Beginning one minute after the

timer motor switch

64, 65 is first closed by the cam lobe 60, the testing cam lobe 61 will engage a cam follower 70 so as to move a contact 71 into engagement with a relatively fixed contact 72 for closing a circuit through the motor control relay coil 14a and thereby operating the pump motor M throughout the test period, Whether the test operation produces fluid delivery or not. This test operation circuit for energizing the'motor control relay coil 14a includes the line conductor 10, the conductor 24) and upper pole of the master switch 16, the'fuse 21 and conductor 22, the closed hour counter switch 17, the conductor 23 and lower pole of the selector switch 18, the

conductors

24, 25 and 69, the

switch contacts

71 and 72, a conductor 73, the conductor 28, the upper pole of the selector switch 18, the conductor 29, the motor control relay coil 14a, the

conductors

30, 31 and 32, the lower pole of the switch 16, and the line conductor 11.

With therelay coil 14a energized, the motor and pump will operate for five minutes under control of the off cycle timer

test operation switch

71, 72, irrespective of whether or not pumped fluid delivery is resumed during the testing period. If pumped fluid delivery has not been resumed at the end of the test period, opening of the

switch contacts

71, 72 incident to travel of the cam lobe 61 beyond the follower 70 will de-energize the motor control relay coil 14a in the testing operation circuit, and stop the motor and pump. If, however, pumped fluid delivery is resumed during the testing period, the check valve switch 39 will be closed in the manner previously described, and the control relay coil 46 will thus be energized so as to attract the relay arm 40 toward the left and close the contacts 42 and 47, thereby re-establishing the main control circuit previously traced for energizing the motor control relay coil 14a. In that event, the relay coil 14:: will be energized by two closed circuits, one controlled by the engaged control relay contacts 42 and 47, and the other controlled by the

test switch contacts

71 and 72. When the

test switch contacts

71 and 72 are opened at the end of the predetermined five minutes test interval, the motor control, relay coil 14a will remain energized under the control of the control relay contacts 42 and 47. If, however, fluid pumping has not been resumed by the end of the testing period, the control relay contacts 42 and 47 will not be engaged, and the opening of the

test switch contacts

71 and 72 before stopping of the timing motor 55, restoring the test switch to its non-operated condition, Will de-energize the motor relay coil 14a and-stopthe motor. In either case, the testing operation effecting means will be disabled and the off cycle timer motor 55 will be continued in operation for one minute following the opening of the

test switch contacts

71 and 72 so that the OE cycle timer mechanism will be returned to its starting position.

If the pumping of fluid has not been resumed at the end of the testing period, the spring 44 will hold the contacts 43 of the control relay CR closed upon the con tact 45, so as to maintain the circuit through the timer motor 55 closed, and initiate a further rest period at the end of which there will be a further test period.

The timing eflected by the oil? cycle timer may be varied, for example by using

interchangeable cam disks

58 and 59 and having different cam lobe extents and/ or by varying the speed of rotation of the cam disks.

Total Operational Period Control The selector switch 18 is optionally settable for imposing the control of the predetermined hour counter HC on the system, as when the switch 18 is at the right as shown in FIGURE '2. With the switch 18 in this position, the hour counter HC restricts the operation of the pump to a predetermined total time, including the time of operation during normal pumped fluid delivery with the control relay CR closed, and including also periods of testing operation when the control relay CR is opened and the pump is operating through the testing circuit which includes the

switch contacts

71 and 72. A simple form of hour counter mechanism operable. in this way is shown schematically in FIGURES 2 and 4 as including a synchronous motor 74 transmitting drive through a reduction gear 75 to a shaft 76 equipped with a worm 77 in mesh with a toothed gear or disk 78. The disk 78 is equipped with a pointer and contact arm 79 which may be set in adjusted position relatively to the disk 78, for example by virtue of a frictional mounting of the arm 79 on the disk 78. The arm 79 may be set in any desired position on an arcuate contact strip 80, the position of the arm being readily determined by reference to an hour scale 81. In operation, the disk 78 and arm- 79 are driven counterclockwise from a selected Starting position until the arm 79 moves off of the contact strip 80 to the zero indication. The hour counter switch previously referred to generally as the switch .17 is constituted by the arm 79 and the strip 80. Since the hour counter switch 17 is included in each of the several control circui-tsipreviously described, opening of the switch 17 will disable the system and stop operation of the pump motor M irrespective of the delivery of fluid from the Well and irrespective of the off cycle timer control which, of course, is disabled by opening of the switch 17.

Operation of the hour counter switch 17 is dependent upon rotation of the disk 78 and arm 79 by the synchronous motor 74. The circuit for operating the hour counter motor 74 during pumped fluid delivery includes the line conductor 16, the conductor 20, the top pole of the master switch 16, the fuse 21 and conductor 22, the hour counter switch 17, the conductor 23 and lower pole of the selector switch 18, the conductors '24 and 48, the relay arm 40, the contacts 42 and 47 and conductor 28, the top pole of the selector switch 18, the conductor 29, a conductor 82, the top pole of a double pole double throw switch 83 which is closed at the left as shown in FIGURE 2, a conductor 84, the hour counter motor 74, a conductor 8-5, the

conductors

68, 31 and 32, the switch 16, and the line conductor 11. This circuit maintains the hour counter motor 74 in operation when the pump is delivering fluid and the control relay contacts 42 and 47 are engaged.

nevertheless be operated through an independent circuit during all test periods effected by closing of the test switches 71, 72 whether pumping of fluid is resumed during the test period or not. This independent circuit includes the line conductor 10, the conductor 20, the top pole of the master switch 16, the fuse 21 and conductor 22, the hour control switch 17 and conductor 23, the lower pole of the selector switch 18,

conductors

24, 25 and 69, the closed

test switch contacts

71 and 72, the

conductors

73 and 28, the top pole of the selector switch 18,

conductors

29 and 82, the top pole of the switch 83, the conductor 84, the hour counter motor 74 itself, conductors S5, 68, 31 and 32, the lower pole of the master switch 16, and line conductor 11.

Since the hour counter motor 74 will operate whenever the pump motor is running, either during normal delivery of pumped fluid or during testing operations, the hour counter HC will limit the total accumulative time of operation of the motor M to the total of any separate periods of operation, either under pumped fluid delivery control or 011 cycle timer control.

If desired, the hour counter HC control may be disabled so that the pump will operate indefinitely as long as it delivers fluid. In order to condition the system for this optional operation, the double pole double throw switch 83 is closed upon its contacts at the right in FIG- URE 2 so as to shunt the hour counter switch 17. The shunt circuit will be provided by a conductor 86 leading from the conductor 22 through the lower pole of the switch 83 to a conductor 87 connected to the conductor 23.

Optional Manual Control Completely manually controlled operation may be obtained by setting the switch 83 to the right, and setting the selector switch 18 to the left. With the switches 18 and 83 so positioned, the relay coil 14a will be energized by a circuit including the line conductor 10, the conductor 20, the top pole of the master switch 16, the fuse 21 and

conductors

22 and 86, the lower pole of the switch 83, the conductors 87 and 23, the lower pole of the selector switch 18, a conductor 83, the conductor 29 and relay coil 14a, the conductors 3t 31 and '32, the lower pole of the master switch 16, and the line conductor 11.

'A further alternative operation for which the system may be readily conditioned is that of running the pump motor M for a predetermined number of hours without being subject to the control by pumped fluid delivery or the off cycle timer. For etfecting such an operation, the switch 83 is set to the left as shown in FIGURE 2, and the switch 18 is also set to the left, oppositely from the position shown in FIGURE 2. The hour timer switch 17 will be set according to the time of operation required. With' the

switches

17, 18 and 83 so positioned, a circuit for energizing the pump relay coil 14a will include the line conductor 10, the conductor 20, the top pole of the master switch 16, the fuse 21 and conductor 22, the hour control switch 17, the conductor 23, the lower pole of the selector switch 18,

conductors

88 and 29, the pump relay coil 14aitself, the

conductors

30, 31 and 32, the lower pole of the master switch 16, and the conductor 11.

The circuit just traced will maintain the pump in operation until the hour counter switch 17 is opened. In order that the switch 17 may be opened at the conclusion of a desired fixed period of pump operation, the hour counter motor 74 must operate. The circuit for operating the motor 74 throughout the fixed period of pump operation includes the line conductor 19, the conductor 26, the top pole of the master switch 16, the fuse 21 and conductor 22, the hour counter switch 17, the conductor 23, the lower pole of the selector switch 18 which is positioned at the left,

conductors

88, 29 and 82, the top pole of the switch 83, the conductor 84, the timer motor 74 itself,

conductors

85, 68, 31 and 32, the lower pole of the master switch 16, and the line conductor 11. When this circuit is broken by opening of the hour counter switch 17, the timer motor 74 will stop as will the pump motor M.

The operating conditions current in the several circuits are indicated, for example, by pilot lights 89 lighted when the pump control relay 14a is closed, 90' when the control relay coil 46 is energized through the check valve switch 39, and 91 when the OE cycle timer motor is in operation.

Summary of Operation The several modes of operation to which a system embodying the invention may be adapted have been explained in the foregoing description of the system. A rsum of the several modes of operation may, however, be of assistance.

Under normal operating conditions, that is when the pump is delivering fluid at a predetermined average rate, the master switch 16 is closed, the switch 83 is closed to the left, the selector switch 18 is closed to the right, and the hour counter arm 79 is closed on the contact strip 80 at a point dependent upon the required number of total hours of operation of the pump. Starting of the pump will be effected by closing the starter switch 19, which will energize the pump relay coil 14a through a circuit independent of the control relay CR and the 011 cycle timer. As soon as the pump starts to deliver fluid, the control relay contacts 42 and 47 will be engaged so as to maintain the pump control relay 14a energized through a circuit independent of the starting switch 19, which may be opened as soon as fluid delivery begins.

If fluid delivery ceases or falls below a predetermined rate, cut-off means including the control relay contacts 42 and 47 will be operated, thereby de-energizing the pump control relay coil 14a and stopping the pump. Coincidentally with the stopping of the pump, the off cycle timer motor will begin to run in response to closing of the

control relay contacts

43 and 45. At the end of a rest period, the oflE cycle timer will automatically energize the motor control relay coil 14a for a predetermined interval to re-start the motor M and etfect a test operation of the pump. If, during the rest period, suflicient fluid has seeped through the well cavity to enable the pump to deliver during the test period, the control relay CR will again be operated to maintain the pump in operation as long as fluid is delivered. If, however, pumping is not resumed during the test period, the off cycle timer will de-energize the pump relay coil 14a at the end of the test period and a further rest period will ensue.

When the system is conditioned for normal operation as explained immediately above, the hour counter HC will limit the total accumulated periods of operation of the pump to a pre-selected number of hours. If it is desired to eliminate the predetermined total hour control, the switch 83 is set to the right so as to shunt the hour control switch 17.

For operating the pump under completely manual control, the switch 83 is set to the right and the selector switch 18 is set to the left, causing the mot-or control relay coil 14a to be energized independently of Whether or not fluid is being pumped.

For effecting manual controlling, modified by being limited to a predetermined number of hours of operation, the switch 83 is set to the left, the hour control switch '17 is set for the desired period of operation, and the selector switch 18 is set to the left, that is oppositely to its FIGURE 2 position.

The system described and shown in the drawings is preferred, but it is intended that the disclosure be illustrative rather than definitive, the invention being defined in the claims.

I claim:

1. A system for controlling the operation of a well ation; cut-oft means including an element movably mounted in said fluid delivery conduit in contact with fluid flowing therethrough and being immediately movable in response to discontinuance of said predetermined flow, and a cut-oft" device positively mechanically connected to said element and being movable simultaneously therewith immediately in response to discontinuance of said predetermined flow for overriding said normal operation eflecting means and stopping said motor immed ately; and means connected to said motor for 'automatte cal-1y re-starting said motor at the end of a definite predetermined period of time following stopping of said motor by said cut-ofl means.

2. A system for controlling the operation of a well pumping installation including a pump, a motor for operating said pump and a pumped fluid delivery conduit, said system comprising normal operation eflectmg means operatively connected to said motor and being responsive to predetermined flow of pumped fluid through said delivery conduit for maintaining said motor in operation; cut-off means including an element movably mounted in said fluid delivery conduit in contact with fluid flowing therethrough and being immediately movable in response to discontinuance of said predetermined flow, and a cutoff device positively mechanically connected to said element and being movable simultaneously therewith immediately in responseto discontinuance of said predetermined flow for overriding said normal operation effecting means and stopping said motor immediately; and testing means operatively connected to said motor for automatically restarting said motor at the end of a definite predetermined period of time following stopping of said motor by said cut-E means and for maintaining said motor operating under control of said testing means for only a predetermined interval at the end of which said motor will be stopped it the predetermined flow of pumped fluid has not been resumed.

3. A system for controlling the operation of a well pumping installation including a pump, a motor for operating said pump and a pumped fluid delivery conduit, said system comprising normal operation effecting means 7 operatively connected to said motor and being responsive to predetermined flow of pumped fluid through said delivery conduit for maintaining said motor in operation; cut-ofi means operatively connected to said motor and being immediately responsive to discontinuance of said predetermined flow for overriding said normal operation eflecting means and stopping said motor immediately; means operatively connected to said motor for automatically re-starting said motor at the end of a definite predetermined period of time following stopping of said motor by said cut-off means; and means operatively connected to said motor and being operable for overriding said normal operation effecting means for limiting the total period of operation of said motor to a preselected aggregate time period.

4. A system for controlling the operation of a well pumping installation including a pump, a motor for operating said pump and a pumped fluid delivery conduit,

said system comprising normal operation effecting means operatively connected to said motor and being responsive to predetermined flow of pumped fluid through said delivery conduit for maintaining said motor in operation; cut-off means operatively connected to said motor and being immediately responsive to discontinuance of said predetermined flow for overriding said normal operation effecting means and stopping said motorimmediately; testing means operatively connected to said motor for automatically re-starting said motor at the end of a definite predetermined period of time following stopping of said motor by said cut-off means and for maintaining said motor operating under control of said testing means for only a predetermined interval at the end of which said motor will be stopped if the predetermined flow of pumped fluid has not been resumed; and means operatively connected to said driving motor and being operable for overriding said normal operation efiecting means and said testing means for limiting the total period of operation of being responsive to predetermined flow of pumped fluid through said delivery conduit for maintaining said driving motor in operation; cut-off means including an element movably mounted in said fluid delivery conduit in contact with fluid flowing therethrough and being immediately movable in response to discontinuance of said predetermined flow, and a cut-01f device positively mechanically connected to said element and being movable simultaneously therewith immediately in response to discontinuance of said predetermined flow for overriding said normal operation effecting means and stopping said driving motor immediately; and an off cycle timer operatively connected to said driving motor for automatically restarting said driving motor at the end of a definite predetermined period of time following stopping of said driving motor by said cut-ofl means and for maintaining said driving motor operating for only a predetermined interval at the end of which said driving motor will be stopped if the predetermined flow of pumped fluid has not been resumed, said olf cycle timer comprising a normally inoperative timing motor, ofi? cycle timer starting means operatively connected to and being operable in response to operation of said cut-ofl means for rendering said timing motor operative, testing operation effecting means operatively connected to said driving motor and said timing motor and being operable in time with said timing motor for eifecting operation of said driving motor, and means operatively connected to and being operable by said timing motor after a predetermined interval of operation thereof for disabling said testing operation elfecting means.

6. A system for controlling the operation of a well pumping installation including a pump, a driving motor for operating said pump and a pumped fluid delivery conduit, said system comprising normal operation effecting means operatively connected to said driving motor and being responsive to predetermined flow of pumped fluid through said delivery conduit for maintaining said driving motor in operation; cut-01f means including an element movably mounted in said fluid delivery conduit in contact with fluid flowing therethrough and being immediately movable in response to discontinuance of said predetermined flow, and a cut-otf device positively mechanically connected to said element and being movable simultaneously therewith immediately in response to discontinuance of said predetermined flow foroverriding'said normal operation effecting means and stopping said driving motor immediately; and an off cycle timer operatively connected to said driving motor for automatically restarting said driving motor at the end of a definite predetermined period of time following stopping of said driving motor by said cut-olf means and for maintaining said driving motor operating for only a predetermined interval at the end of which said driving motor willtbe stopped it the predetermined flow of pumped fluid has not been resumed, said oflf cycle timer comprising a norfinally inoperative timing motor, oif cycle timer starting means operatively connected to and being operable in response to operation of said cut-otf means for rendering said timing motor operative, electrical switch means operatively connected to said driving motor and said timing motor and being operated in time with said timing motor for efiecting operation of said driving motor, and means operatively connected to and being operable by said timing motor after a predetermined interval of operation thereof for restoring said switch means to its non-operated condition for discontinuing the operation of said driving motor under the control of said electrical switch means.

7. A system for controlling the operation of a Well pumping installation including a pump, a driving motor for operating said pump and a pumped fluid delivery conduit, said system comprising normal operation effecting means operatively connected to said driving motor and being responsive to predetermined flow of pump fluid through said delivery conduit for maintaining said driving motor in operation; cut-off means operatively connected to said driving motor and being immediately responsive to discontinuance of said predtermined flow for overriding said normal operation effecting means and stopping said driving motor immediately; and an oflf cycle timer operatively connected to said driving motor for automatically re-starting said driving motor at the end of a definite predetermined period of time following stopping of said driving motor by said cut-oft means and for maintaining said driving motor operating for only a predetermined interval at the end of which said driving motor will be stopped if the predetermined flow of pumped fluid has not been resumed, said all cycle timer comprising a normally inoperative electrical timing motor, a first switch means operatively connected to said said cut-oft means and said timing motor and being operable in response to operation of said cut-off means for starting said timing motor, a second switch means operatively connected to said timing motor and being operable by said timing motor for maintaining said timing motor in operation for a predetermined time, and third electrical switch means operatively connected to said timing motor and said driving motor and being operable by said timing motor for eflecting operation of said driving motor during operation of said timing motor and for a period less than said predetermined time of operation of said timing motor.

8. A system for controlling the operation of a well pumping installation including a pump, a driving motor for operating said pump and a pumped fluid delivery conduit, said system comprising normal operation effecting means operatively connected to said driving motor and being responsive to predetermined flow of pumped fluid through said delivery conduit for maintaining said driving motor in operation; cut-off means operatively connected to said driving motor and being immediately responsive to discontinuance of said predetermined flow for overriding said normal operation effecting means and stopping said driving motor immediately; and an oil cycle timer operatively connected to said driving motor for automatically re-starting said driving motor at the end of a definite predetermined period of time following stopping of said driving motor by said cut-ofl means and for maintaining said driving motor operating for only a predetermined interval at the end of which said driving motor will be stopped if the predetermined flow of pumped fluid had not been resumed, said ofi cycle timer comprising a normally inoperative electrical timing motor, a first switch means operatively connected to said cut-off means and said timing motor and being operable in response to operation of said cut-off means for starting said timing motor, a second switch means operatively connected to said timing motor and being operable by said timing motor for maintaining said timing motor in operation for a predetermined time, and third electrical switch means operatively connected to said timing motor and said driving motor and being operable by said timing motor only after said timing motor has been operating for a substantial part of and less than its said predetermined operating time for effecting operation of said driving motor irrespective of the operation of said cut-oil means.

9. A system for controlling the operation of a well pumping installation including a pump, a driving motor for operating said pump and a pumped fluid delivery conduit, said system comprising normal operation eflecting means operatively connected to said driving motor and being responsive to predetermined flow of pumped fluid through said delivery conduit for maintaining said driving motor in operation; cut-oif means operatively connected to said driving motor and being immediately responsive to discontinuance of said predetermined flow for overriding said normal operation eflecting means and stopping said driving motor immediately; and an off cycle timer operatively connected to said driving motor for automatically re-starting said driving motor at the end of a definite predetermined period of time following stopping of said driving motor by said cut-off means and for maintaining said driving motor operating for only a predetermined interval at the end of which said driving motor will be stopped if the predetermined flow of pumped fluid has not been resumed, said ofi cycle timer comprising a normally inoperative electrical timing motor, a first switch means operatively connected to said cut-ofli means and said timing motor and being operable in response to operation of said cut-ofi' means for starting said timing motor, a second switch means operatively connected to said timing motor and being operable by said timing motor for maintaining said timing motor in operation for a predetermined time, third electrical switch means operatively connected to said timing motor and said driving motor and being operable by said timing motor after the latter has been operating for the greater part of and less than its said predetermined operating time for re-starting said driving motor irrespective of the operation of said cut-ofi means, and means operatively connected to said timing motor and said third electrical switch means and being operable by said timing motor before stopping thereof for restoring said third electrical switch means to its nonoperated condition.

10. A system for controlling the operation of a well pumping installation including a pump, a driving motor for operating said pump and a pumped fluid delivery con duit, said system comprising normal operation effecting means operatively connected to said driving motor and being responsive to predetermined flow of pumped fluid through said delivery conduit for maintaining said driving motor in operation; cut-off means operatively connected to said driving motor and being immediately responsive to discontinuance of said predetermined flow for overriding said normal operation effecting means and stopping said driving motor immediately; and an oil cycle timer operatively connected to said driving motor for automatically re-starting said driving motor at the end of a definite predetermined period of time following stopping of said driving motor by said cut-oil means and for maintaining said driving motor operating for only .a predetermined interval at the end of which said driving motor will be stopped if the predetermined flow of pumped fluid has not been resumed, said off cycle timer comprising a normally inoperative timing motor, a first switch means operatively connected to said cut-off means and said timing motor and being operable in response to operation of said cut-ofi means for starting said timing motor, a second switch means operatively connected to said timing motor and being operable by said timing motor for discontinuing the operation of said timing motor at the end of a predetermined time of operation of said timing motor, a third switch means operatively connected to said timing motor .and said driving motor and being operable by said timing motor between the operations of said first and second switch means for efiecting operation of said driving motor, and means operatively connected to said timing motor and being operable after operation of said third switch means and before operation of said second switch means for discontinuing the operation of said driving motor under control of said off cycle timer.

11. A system for controlling the operation of a Well pumping installation including a pump, a driving motor for operating said pump and a pumped fluid delivery conduit, said system comprising normal operation efiecting means operatively connected to said driving motor and being responsive to predetermined 'flow of pumped fluid through said delivery conduit for maintaining said driving 'motor in operation; cut-oif means operatively connected to said driving motor and being immediately responsive to discontinuance of said predetermined flow for overriding said normal operation effecting means and stopping 'said driving motor immediately; and off cycle timer operatively connected to said driving motor for automatically re-starting said driving motor at the end of a definite predetermined period of time following stopping of said driving motor by said cut-ofi means and for maintaining said driving motor operating for only a predetermined interval at the end of which said driving motor will be stopped if the predetermined flow of pumped fluid has not been resumed, said ofi cycle timer comprising a normally inoperative timing motor, oft cycle timer starting means operatively connected to and being operable in response to operation of said cut-off means for rendering said timing motor operative, testing operation effecting means operatively connected to said driving motor and said timing motor and being operable in time with said timing motor for efiecting operation of said driving motor, and means operatively connected to and being operable by said timing motor after a predetermined interval of operation thereof for disabling said testing operation effecting means; and means operatively connected to said driving motor and being operable for overriding said normal operation effecting means and said ofl? cycle timer for limiting. to a preselected time period the total period of operation of said driving motor, whether under control of said normal operation effecting means alone, or under control of said normal operation efiecting means and said oif cycle timer in sequence.

'12. A system for controlling the operation of a well pumping installation including a pulsating delivery pump, a motor for operating said pump and a pumped fluid delivery conduit, said system comprising means including an electrical relay having a coil and being adapted when said coil is energized to eflect operation of said 'motor and when said coil is dc-energized to stop said motor; :a switch in circuit with said relay coil; means op- :eratively connected to said fluid delivery conduit and to said switch and being responsive to fluid delivery pulses due to pulsating delivery by said pump for closing and opening said switch; and electrical capacitor means in circuit with said switch and said relay coil for storing electrical charges when said switch is closed and for dis charging to said relay coil when said switch is open whereby to maintain said relay coil energized and said 'motor in operation between fluid delivery pulses when said switch is open.

13. A system for controlling the operation of a well pumping installation including a pulsating delivery pump, a motor for operating said pump and a pumped fluid delivery conduit, said system comprising means including an electrical relay having a coil and being adapted when said coil is energized to effect operation of said motor and when said coil is de-energized to stop said motor; an AC. electrical power source; a switch in circuit with said relay coil and said power source; means operatively con nected to said fluid delivery conduit and to said switch and being responsive. to fluid delivery pulses due to pulsating delivery by said pump for closing and opening said switch; a rectifier in said circuit; and electrical capacitor means connected in said circuit between said rectr fier and said relay coil and shunting said relay coil for storing electrical charges when said switch is closed and for discharging to said relay coil when said switch is open whereby to maintain said relay coil energized and said rnotorrin operation between fluid delivery pulses when said switch is open.

14. A system for controlling the operation of a well pumping installation including a pulsating delivery pump,

switch and being responsive to fluid delivery pulses due a to pulsating delivery by said pump for closing and opening said first switch; electrical capacitor means in circuit with said first switch and said relay coil for storing electrical charges when said first switch is closed and vfor discharging to said relay coil when said first switch is open whereby to maintain said relay coil energized and said motor in operation between fluid delivery pulses when said switch is open, said relay coil 'being'de-energized after discharging of said capacitor means therethrough unless said discharging is followed by closing of said first switch before complete discharging of said capacitor means; an oil cycle timer motor; .a second switch operatively connected to said relay coil and to said off cycle timer motor and being operable in response to deenergizing of said relay coil for starting said oif cycle timer motor; a third switch operatively connected to said oflf cycle timer motor and being operable by said ofi cycle timer motor for continuing said ofi cycle timer'motor in operation for a predetermined interval after having been started by operation of said second switch; and V a fourth switch operatively connected to said ofl cycle timer motor and to said relay coil andbeing operable by said ofi cycle timer motor after a predetermined period of operation thereof for energizing said relay coil for a test period ind-ependently of said first switch and said capacitor means and for discontinuing its energizing eifect on said relay coil at the end of said test period.

15. A system for controlling the operation of a well pumping installation including a pulsating delivery pump, a motor for operating said pump and .a pumped fluid delivery conduit, said system comprising means including an electrical relay having a coil and being adapted when said coil is energized to effect operation of said motor and when said coil is dc-energized to stop said motor; a switch in circuit with said relay coil; means operatively connected to said fluid delivery conduit and to said switch and being responsive to fluid delivery pulses due to pulsating delivery by said pump for closing and opening said switch; electrical capacitor means in circuit with said switch and said relay coil for storing electrical charges when said switch is closed and for discharging to said relay coil when said switch is open whereby to rrlaintain said relay coil energized and said motor in operation between fluid delivery pulses when said switch is open, said relay coil being de-energized after discharging of said capacitor means therethrough unless said discharging is [followed by closing of said switch bet-ore complete discharging of said capacitor means; and an off cycle timer operatively connected to said motor and .to said relay coil for automatically re-starting said motor at the end of a definite predetermined period of time following d e-energizing of said relay coil and for maintaining said motor operating for a predetermined test period irrespective of the energized or de-energized condition of said relay coil during said test period.

16. A system for controlling the operation of a well pumping installation including a pump, a motor for operating said pump and a pumped fluid delivery conduit, said system comprising normal operation effecting means operatively connected to said motor and being responsive to predetermined flow of pumped fluid through said 'delivery conduit for maintaining said motor in Opera- 17 ately; testing means operatively connected to said motor operable automatically at the end of a definite predetermined rest period following stopping of said motor by said cut-ofi means, during which rest period said motor and said pump are not operating, for starting said motor; and timing means included in said testing means and being operable at the end of a predetermined interval of test operation of said motor and pump for rendering said testing means inoperative.

References Cited in the file of this patent UNITED STATES PATENTS Tipton Apr. 13, 1943 DeWit Aug. 10, 1943 Smith Dec. 14, 1948 Thomson May 3, 1949 Shanklin Feb. 17, 1953 Long May 3, 1955 McGee Nov. 12, 1957

Claims

1. A SYSTEM FOR CONTROLLING THE OPERATION OF A WELL PUMPING INSTALLATION INCLUDING A PUMP, A MOTOR FOR OPERATING SAID PUMP AND A PUMPED FLUID DELIVERY CONDUIT, SAID SYSTEM COMPRISING NORMAL OPERATION EFFECTING MEANS OPERATIVELY CONNECTED TO SAID MOTOR AND BEING RESPONSIVE TO PREDETERMINED FLOW OF PUMPED FLUID THROUGH SAID DELIVERY CONDUIT FOR MAINTAINING SAID MOTOR IN OPERATION; CUT-OFF MEANS INCLUDING AN ELEMENT MOVABLY MOUNTED IN SAID FLUID DELIVERY CONDUIT IN CONTACT WITH FLUID FLOWING THERETHROUGH AND BEING IMMEDIATELY MOVABLE IN RESPONSE TO DISCONTINUANCE OF SAID PREDETERMINED FLOW, AND A CUT-OFF DEVICE POSITIVELY MECHANICALLY CONNECTED TO SAID ELEMENT AND BEING MOVABLE SIMULTANEOUSLY THEREWITH IMMEDIATELY IN RESPONSE TO DISCONTINUANCE OF SAID PREDETERMINED FLOW FOR OVERRIDING SAID NORMAL OPERATION EFFECTING MEANS AND STOPPING SAID MOTOR IMMEDIATELY; AND MEANS CONNECTED TO SAID MOTOR FOR AUTOMATICALLY RE-STARTING SAID MOTOR AT THE END OF A DEFINITE PREDETERMINED PERIOD OF TIME FOLLOWING STOPPING OF SAID MOTOR BY SAID CUT-OFF MEANS.