What is claimed:
1. A pump-off control system for use in conjunction with an electric motor driven beam pumping unit including a polished rod attached by a wire-line carrier and hangar assembly to a horse head of the beam and to a down hole sucker rod pump comprising:
(a) an electrical power source;
(b) an interlocking pair of normally open relays wherein the first relay of said pair must be closed before the second relay of said pair can close;
(c) a first electrical circuit connected to the power source for energizing the first relay after a pre-determined time delay;
(d) a control device attached to the polished rod as a component of said first electrical circuit, the control device momentarily de-energizing the first relay upon incurring fluid pound.
(e) a second electrical circuit connected to the power source for energizing the second relay when the first relay is energized; and
(f) a motor controller connected to the power source for starting and stopping the electric motor, the motor controller starting the electric motor in response to the second relay being energized and stopping the electric motor in response to the second relay being de-energized.
2. A pump-off control system for use in conjunction with an electric motor driven beam pumping unit including a polished rod attached by a wire-line carrier and hangar assembly to a horse head of the beam and a down hole sucker rod pump comprising:
(a) an electrical power source;
(b) an electrical power circuit coupling the power source to the electric motor for supplying power to the electric motor; and
(c) an electric motor control circuit for connecting and disconnecting the power circuit to the electric motor including a control device secured to the polished rod maintaining the power circuit coupled to the electric motor until the polished rod encounters fluid pound, causing the control device to disconnect the power source from the electric motor for a preset time delay period.
3. The control device of claim 1 comprising:
(a) an insulating sleeve member closed at one end by a removable insulating cap;
(b) a metallic member secured in the other end of the sleeve member and attached to the polished rod for movement with the polished rod;
(c) a metallic cylinder slideably retained within the insulating sleeve member having a metal plug at one end, said metal plug normally abutting said metallic member and making electrical contact therewith interruptible upon encountering fluid pound force; and
(d) an electrical conductor connected to the metal plug and extending through the cap.
4. The control device of claim 3 wherein the metal plug in Babbitt.
5. The control device of claim 3 wherein the insulating sleeve member is plastic.
6. A pump-off control system for use in conjunction with an electric motor driven beam pumping unit including a polished rod attached by a wire-line carrier and hangar assembly to a horse head of the beam and to a down hole sucker rod pump comprising:
(a) an electrical power source;
(b) a first electrical circuit connected to the power source for energizing the first relay after a predetermined time delay;
(c) a control device attached to the polished rod as a component of said first electrical circuit, the control device momentarily de-energizing the first relay upon incurring fluid pound.
(d) a second electrical circuit connected to the power source for energizing a second relay only while the first relay is energized; and
(e) a motor controller connected to the power source for starting and stopping the electric motor, the motor controller starting the electric motor in response to the second relay being energized and stopping the electric motor in response to the second relay being de-energized.
7. The control device of claim 6 comprising:
(a) plastic sleeve;
(b) a metal plug secured in one end of plastic sleeve and the other end secured to the polished rod;
(c) a metal member slideably retained in the plastic sleeve resting upon the metal plug; and
(d) the metal member and the metal plug forming an electrical contact interruptible upon occurrence of fluid pound.
8. The control device of claim 7 wherein the metal plug includes Babbitt metal.
9. The control device of claim 7 wherein the metal member includes at least one stackable weight.
10. The control device of claim 7 wherein the plastic sleeve is polyvinyl chloride.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A digital camera comprising:
a solid-state electronic imaging device that continuously images a subject in a predetermined period and outputs image data representing a subject image in the predetermined period;
an imaging lens arranged so as to be movable ahead of a light receiving surface of said solid-state electronic imaging device;
an auxiliary light emission control device that controls an auxiliary light emitting device such that auxiliary light is irradiated onto the subject at a rate of once per a plurality of times of imaging in said solid-state electronic imaging device;
an imaging lens positioning device that images the subject onto which the auxiliary light has been irradiated under the control of said auxiliary light emission control device, to position said imaging lens at a focusing position on the basis of the image data outputted from said solid-state electronic imaging device; and
a recording control device that images the subject when the auxiliary light is not irradiated by said auxiliary light emission control device, to record on a recording medium the image data outputted from said solid-state electronic imaging device.
2. The digital camera according to claim 1, wherein said imaging lens positioning device images the subject onto which the auxiliary light has been irradiated under the control of said auxiliary light emission control device, to position said imaging lens at the focusing position on the basis of a part of the image data outputted from said solid-state electronic imaging device.
3. The digital camera according to claim 1, wherein
the positioning in said imaging lens positioning device is positioning for finely adjusting the position of said imaging lens, further comprising
a brightness determination device that determines whether or not the brightness of the subject is changed by not less than a predetermined level, and
an imaging lens positioning control device that switches the positioning in said imaging lens positioning device into positioning by coarse adjustment in response to the determination by said brightness determination device that the brightness of the subject is changed by not less than the predetermined level, and returns the coarse adjustment to the fine adjustment in response to the positioning of the imaging lens at the focusing position by the coarse adjustment.
4. The digital camera according to claim 3, wherein
said brightness determination device also determines whether the brightness of the subject is so changed as to increase or decrease by not less than the predetermined level, and
said imaging lens positioning control device switches the positioning in said imaging lens positioning device into positioning for coarsely adjusting the position on the NEAR side in response to the determination by said brightness determination device that the brightness of the subject is so changed as to increase by not less than the predetermined level, switches the positioning in said imaging lens positioning device into positioning for coarsely adjusting the position on the FAR side in response to the determination by said brightness determination device that the brightness of the subject is so changed as to decrease by not less than the predetermined level, and returns the coarse adjustment to the fine adjustment in response to the positioning of the imaging lens at the focusing position by the coarse adjustment.
5. The digital camera according to claim 3, wherein
said brightness determination device also detects the amount of change in the brightness by not less than the predetermined level, and
said imaging lens positioning control device decrease the step of adjusting the positioning by said coarse adjustment when the brightness is at not less than the predetermined level and the amount of change in the brightness is small, while increasing the step of adjusting the positioning by said coarse adjustment when the brightness is at not less than the predetermined level and the amount of change in the brightness is large.
6. A digital camera comprising:
a solid-state electronic imaging device that continuously images a subject in a predetermined period and outputs image data representing a subject image in the predetermined period;
an imaging lens arranged so as to be movable ahead of a light receiving surface of said solid-state electronic imaging device;
a first imaging lens positioning device that positions said imaging lens at a focusing position on the basis of the image data outputted from said solid-state electronic imaging device at a rate of once per a plurality of times of imaging in said solid-state electronic imaging device; and
a recording control device that images the subject when the imaging lens is not positioned by said imaging lens positioning device, to record on a recording medium the image data outputted from said solid-state electronic imaging device.
7. The digital camera according to claim 6, wherein
said first imaging lens positioning device finely adjusts said imaging lens to position the imaging lens at the focusing position, and further comprising
a second imaging lens positioning device that coarsely adjusts the imaging lens to position the imaging lens at the focusing position when the positioning of the imaging lens is not finely adjusted by said first imaging lens positioning device.
8. The digital camera according to claim 6, further comprising
an auxiliary light emission control device that controls an auxiliary light emitting device such that auxiliary light is irradiated onto the subject at the time of imaging at a rate of once per a plurality of times of imaging, which corresponds to the time of positioning the imaging lens in said first imaging lens positioning device.
9. In a digital camera comprising a solid-state electronic imaging device that continuously images a subject in a predetermined period and outputs image data representing a subject image in the predetermined period, and an imaging lens arranged so as to be movable ahead of a light receiving surface of said solid-state electronic imaging device,
a method of controlling the digital camera, comprising the steps of:
irradiating auxiliary light onto the subject at a rate of once per a plurality of times of imaging in said solid-state electronic imaging device;
imaging the subject onto which the auxiliary light has been irradiated, to position said imaging lens at a focusing position on the basis of the image data outputted from said solid-state electronic imaging device; and
imaging the subject when the auxiliary light is not irradiated, to record on a recording medium the image data outputted from said solid-state electronic imaging device.
10. In a digital camera comprising a solid-state electronic imaging device that continuously images a subject in a predetermined period and outputs image data representing a subject image in the predetermined period, and an imaging lens arranged so as to be movable ahead of a light receiving surface of said solid-state electronic imaging deice,
a method of controlling the digital camera, comprising the steps of:
positioning said imaging lens at a focusing position on the basis of the image data outputted from said solid-state electronic imaging device at a rate of once per a plurality of times of imaging in said solid-state electronic imaging device; and
imaging the subject when the imaging lens is not positioned, to record on a recording medium the image data outputted from said solid-state electronic imaging device.