Pump-off control apparatus for a pump jack

Claim 2

A control system for the control of a prime mover of an oil well pump jack apparatus which drives a downhole pump by means of a rod string comprising: control means by which the prime mover is selectively energized and de-energized; first switch means mounted to be moved into a conducting configuration during the pump downstroke; second switch means mounted to be moved into a conducting configuration upon an abnormal movement of the rod string indicative of fluid pounding; circuit means connected to said first and second switch means and to said control means for counting the number of times said second switch means is closed and for causing said control means to de-energize said prime mover after said second switch means has been moved to the closed position a plurality of times; a third switch means, said third switch means being a magnetically actuated switch, a magnet for actuating the last said switch when the magnet is moved into close proximity thereof, said magnet being magnetically attached to structure mounted to said pump jack means so that should a rod string break, the magnet will be forced to move relative to said structure and into proximity of said third switch means, thereby actuating said third switch means; and, circuit means by which actuation of said third switch means causes said prime mover to be de-energized.

Claim 3

In an oil well pump jack apparatus having a prime mover which drives a downhole pump by means of a rod string, wherein the prime mover has a control means by which the prime mover is selectively energized and de-energized; an improved control system for said prime mover comprising: first switch means mounted to be moved into a conducting configuration during the pump downstroke so that cyclic movement of the pump jack causes the switch means to assume a conducting configuration on the downstroke and a non-conducting configuration on the upstroke; second switch means mounted to be moved into a conducting configuration upon an abnormal movement of the rod string indicative of fluid pounding; a source of current; said first switch means being series connected to said second switch means and to the source of current; circuit means forming an electrical pulse storage apparatus for counting the number of times said second switch means is closed; a solenoid actuated switch means having the switch thereof connected to cause said control means to de-energize said prime mover when the solenoid is actuated, said solenoid actuated switch means having the solenoid thereof connected to said circuit means so that when said second switch means has been moved to the closed position a plurality of times said electrical pulse storage apparatus causes the solenoid to be energized, thereby causing the prime mover to be de-energized.

Claim 4

In an oil well pump jack apparatus having a prime mover which drives a downhole pump by means of a rod string, wherein the prime mover has a control means by which the prime mover is selectively energized and de-energized; an improved control system for said prime mover comprising: first switch means mounted to be moved into a conducting configuration during the pump downstroke so that cyclic movement of the pump jack causes the switch means to assume a conducting configuration on the downstroke and a non-conducting configuration on the upstroke; second switch means mounted to be moved into a conducting configuration upon an abnormal movement of the rod string indicative of fluid pounding; a source of current; said first switch means being series connected to said second switch means and to the source of current; circuit means forming an electrical pulse storage apparatus for counting the number of times said second switch means is closed; a solenoid actuated switch means having the switch thereof connected to cause said control means to de-energize said prime mover when the solenoid is actuated, said solenoid actuated switch means having the solenoid thereof connected to said circuit means so that when said second switch means has been moved to the closed position a plurality of times said electrical pulse storage apparatus causes the solenoid to be energized, thereby causing the prime mover to be de-energized.

Claim 5

A control system for the control of a prime mover of an oil well pump jack apparatus which drives a downhole pump by means of a rod string comprising: control means by which the prime mover is selectively energized and de-energized; first switch means, said first switch means being mounted for movement to the pump jack so that cyclic movement of the pump jack causes the switch means to be moved into a conducting configuration during the pump downstroke and moved into a non-conducting configuration during the pump upstroke; second switch means series connected to said first switch means and mounted to be moved into a conducting configuration upon an abnormal movement of the rod string indicative of fluid pounding; circuit means including an electrical pulse storage apparatus connected to said first and second switch means for counting the number of times said second switch means is closed and for causing said control means to de-energize said prime mover after said second switch means has been moved to the closed position a plurality of times.

Claim 6

A control system for the control of a prime mover of an oil well pump jack apparatus which drives a downhole pump by means of a rod string comprising: control means by which the prime mover is selectively energized and de-energized; first switch means, said first switch means being mounted for movement to the pump jack so that cyclic movement of the pump jack causes the switch means to be moved into a conducting configuration during the pump downstroke and moved into a non-conducting configuration during the pump upstroke; second switch means series connected to said first switch means and mounted to be moved into a conducting configuration upon an abnormal movement of the rod string indicative of fluid pounding; circuit means including an electrical pulse storage apparatus connected to said first and second switch means for counting the number of times said second switch means is closed and for causing said control means to de-energize said prime mover after said second switch means has been moved to the closed position a plurality of times.

Claim 7

The control system of claim 3 wherein said second switch means is a magnetically actuated switch; a magnet means resiliently mounted for movement to said pump jack apparatus; said magnet being disposed adjacent to but spaced from said second switch means; said magnet and said second switch means being mounted for movement in relationship with said rod string so that when said magnet is moved relative to said second switch means, said second switch means is moved into the stated conducting configuration.

Claim 8

The control system of claim 3 wherein there is further included a third switch means; circuit means by which said third switch means is connected to de-energize said prime mover when moved from a normal to an alternate position.

Claim 9

The control system of claim 3 wherein said third switch means is a magnetically actuated switch, a magnet for actuating said switch when moved into close proxiMity thereof, said magnet being magnetically attached to structure mounted to said pump jack means so that should a rod string break the magnet will be forced to move relative to the structure and into proximity of said third switch thereby de-energizing said prime mover.