ELECTROHYDRAULIC CONTROL SYSTEM

• US 3,800,962 A
• Filed: 02/04/1971
• Issued: 04/02/1974
• Est. Priority Date: 11/26/1968
• Status: Expired due to Term

• Current Assignee: Hughes Tool Company--Usa
• Original Assignee: John E. Ham
• Inventors: Ham, John E.
• Primary Examiner(s): Geoghegan, Edgar W.
• Application Number:
  US05/112,540
• Time in Patent Office: 1,153 Days
• Field of Search: 60/52VS,DIG.2,476,479 91/42 214/25
• US Class Current: 414/22.71
• CPC Class Codes: E21B 19/14 Racks, ramps, troughs or bins, for holding the lengths of rod singly or connected; Handling between storage place and borehole E21B19/20, E21B19/22 take precedence
• CPC Class Codes: Y10S 60/911 Fluid motor system incorporating electrical system

Abstract

Control and operating systems for well pipe racking apparatus in which a number of vertically spaced racker arms are moved longitudinally to extend and retract the racker arms, as well as laterally relative to the pipe racking finger board, the racker arms having pipe supporting means for moving a length of pipe between the racking finger board and a position disposed over the rotary table of a drilling rig, and in which the control and operating systems include a hydraulic operating system comprising a reversible variable displacement pump for supplying fluid at a selected rate to either of a pair of motors, one of which effects longitudinal movement of one of the racker arms and the other of which effects lateral movement of said one of the racker arms. Such control and operating systems in which a second reversible variable displacement pump is employed to selectively supply fluid to either of a pair of motors for effecting longitudinal movement and lateral movement of the rest of the racker arms. Such control and operating systems in which the control system includes selectively operable control circuits for enabling actuation of an upper and a lower racker arm from the same location or, alternatively, to enable operation of the lower racker arm from said location and operation of the upper arm from another location. Such a control system in which a variable displacement pump is adjusted and caused to operate in reversed directions to displace fluid to the racker arm operating motors at a rate proportional to the extent of movement of a control member.

Claims

1. In well drilling derrick apparatus for vertically racking stands of well pipe within the derrick:

rack means for receiving stands of well pipe and supporting the same in spaced vertical rows at one side of the center of the derrick, racker means for successively moving said stands between positions at the center of the derrick and said rack means, said racker means including a longitudinally extended racker arm, carriage means supporting said racker arm for longitudinal movement in a horizontal plane between projected and retracted positions relative to said rack means and the center of said derrick, means supporting said carriage for lateral movements in said derrick to place stands in and remove stands from said rack means, reversible hydraulic rotary motor means for moving said arm and said carriage means, and electrohydraulic operating means for said motor means for reversing said motor means and for selectively effecting said movements of said arm and said carriage means at a selected rate, said electrohydraulic operating means for said motor means comprising a reversible and variable positive displacement pump, a pair of fluid conduits leading between said pump and said motor means for supplying fluid under pressure to said motor means in opposiTe directions, adjuster means for said pump for regulating the direction and rate of flow of fluid from said pump to said motor means, and means for operating said adjuster means including an operating potentiometer and slave motor means connected to said adjuster means and responsive to said operating potentiometer to vary the direction and rate of flow from said pump, normally closed solenoid valve means in said pair of fluid conduits for blocking flow of fluid through both conduits of said pair of fluid conduits, and circuit means including a switch associated with said means for operating said adjuster means and responsive to the operation thereof for opening said solenoid valve means to allow flow of fluid between said pump and said motor means in either direction through said pair of conduits, said solenoid valve means, when closed, blocking the flow of fluid through said motor to effectively brake the same.