Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
182 words
A motor control unit for automatically controlling the torque output of a high slip motor powering a pump jack unit for stroking a downhole pump, said motor including motor starter means connected to motor stater windings and circuit means for altering the electrical configuration of said stater windings, said motor control unit comprising: sensor means for detecting the magnitude of the average current flow through said starter windings during a multiplicity of pump strokes; said stater windings being electrically connected in a first electrical configuration for a relatively lower motor torque output; first overload means responsive to said sensor means for automatically altering the electrical configuration of said motor windings from said first electrical configuration to a second electric configuration when said average current flow exceeds a first preselected value to increase said motor torque output; first timing means for sensing the time period said stater windings are connected in said second electrical configuration and automatically altering said motor stater windings from said second electrical configuration to another electrical configuration to reduce said motor torque output after a preselected period of time.
Claim 2
Dependent Claim
182 words
A motor control unit for automatically controlling the torque output of a high slip motor powering a pump jack unit for stroking a downhole pump, said motor including motor starter means connected to motor stater windings and circuit means for altering the electrical configuration of said stater windings, said motor control unit comprising: sensor means for detecting the magnitude of the average current flow through said starter windings during a multiplicity of pump strokes; said stater windings being electrically connected in a first electrical configuration for a relatively lower motor torque output; first overload means responsive to said sensor means for automatically altering the electrical configuration of said motor windings from said first electrical configuration to a second electric configuration when said average current flow exceeds a first preselected value to increase said motor torque output; first timing means for sensing the time period said stater windings are connected in said second electrical configuration and automatically altering said motor stater windings from said second electrical configuration to another electrical configuration to reduce said motor torque output after a preselected period of time.
Claim 3
Dependent Claim
37 words
A motor control as defined in claim 1, wherein said first electrical configuration is a Y configuration, said second electrical configuration is a Δ configuration, and said another configuration is said Y configuration of a ΔY configuration.
Claim 4
Dependent Claim
34 words
A motor control as defined in claim 1, wherein said first electrical configuration is a Y configuration, said second electrical configuration is a ΔY configuration, and said another electrical configuration is said Y configuration.
Claim 5
Dependent Claim
46 words
A motor control as defined in claim 1, said first overload means further comprising: delay means for shortening the response rate for altering said first electrical configuration as a function of the magnitude of the difference between said first preselected value and said average current flow.
Claim 6
Dependent Claim
27 words
A motor control as defined in claim 4, wherein said delay means is a thermally actuated switch responsive to heat generated by current through said starter windings.
Claim 7
Dependent Claim
108 words
A motor control as defined in claim 1, further comprising: second overload means responsive to said sensor means for automatically altering said electrical configuration of said motor stater windings from said second configuration to a third configuration when said average current exceeds a second preselected value greater than said first preselected value to further increase said motor torque output; second timing means for sensing the time period said stater windings are connected in said third electrical configuration and automatically altering said motor stater windings from said third electrical configuration to said first or second electrical configuration to reduce said motor torque output after a preselected period of time.
Claim 8
Dependent Claim
35 words
A motor control as defined in claim 6, further comprising: third overload means for terminating current to said motor when said average current flow exceeds a third preselected value greater than said second preselected value.
Claim 9
Dependent Claim
43 words
A motor control as defined in claim 6, wherein each of said first and second timing means returns said motor stater windings to a lower torque configuration only after maintaining an electrical configuration during a time period exceeding the multiplicity of pump strokes.
Claim 10
Dependent Claim
34 words
A motor control as defined in claim 6, wherein said first electrical configuration is a Y configuration, said second electrical configuration is a ΔY configuration, and said third electrical configuration is a ΔY configuration.