Invalidity dossier
US 2589420
Actuator for reciprocating well pumps
Current assignee: Individual
Added 9/21/2026, 10:22:47 AM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 2589420A
Title: Actuator for reciprocating well pumps
Patent number: US 2589420A
Application number: US746094A
Inventors: Edgar W Mong; William O Anderson
Original/current assignee: Individual
Filing date / priority date: 1947-05-05
Publication (grant) date: 1952-03-18
Legal status listed: Expired – Lifetime (anticipated expiration 1969-03-18)
Purpose. The patent addresses actuators for reciprocating well pumps. It aims to provide a simplified, improved and practical construction for operating the reciprocating element of a well pump from an operating mechanism located in a derrick. A stated problem is that a conventional string of sucker rods forms a heavy unit moved down the well by gravity after being lifted, and that rod sections joined by threaded connections are slow, costly and awkward to run into or remove from a well. The invention therefore proposes a pump operating line that is a flexible element—preferably a flexible steel cable, handled by a reel or spool at the derrick—rather than a stiff string of rods. The disclosure also notes the member 20 may alternatively be the usual sucker rod.
Plain-language scope. The described construction includes a return spring, preferably a long helical spring, located in the well adjacent the pump to return or lower the pump's reciprocating element after it has been lifted. A spring abutment is detachably mounted in the lower end portion of the tubing, forming an abutment for the upper end of the spring and removable with the removable pump parts and spring. Mounting means involve a seat member fixed in the tubing and spring fingers on the abutment with lugs cooperating with seats, plus means for releasing the lugs, including a bumper on rod 3 and, in a modified form, a go-devil operating independently of the line.
Source: https://patents.google.com/patent/[US2589420](/patent/US2589420)/en
What the excerpt does not establish. The supplied text is excerpted and partially garbled; it does not provide complete claims, the full specification, drawing details, the exact number/content of claims, or the complete description of the Fig. 6 modification. No litigation, ownership-transfer, validity, or prior-art conclusions are drawn.
Generated 10/1/2026, 10:01:38 PM
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Litigation summary
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
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