Apparatus for Connecting And Disconnecting a Downhole Assembly

In a production well, a system for delivering production fluid through a string of tubing, said string of tubing extending from the surface to a downhole assembly, said downhole assembly including a pump for moving said fluid from a downhole deposit in said well to the surface;

• a drive rod string inside said tubing string, said drive rod string extending from the surface to the downhole assembly and depending from a source of rotational motive power located at the surface;
• an overshot assembly;
• said overshot assembly including a female overshot assembly fixedly attached to the downhole end of said drive rod string, said overshot assembly consisting of a longitudinally extending tubular receptacle, open at the downhole end, with a noncircular contour on the inside surface of said tubular receptacle;
• a receiver shaft extending upwardly from said downhole assembly, said shaft being so dimensioned as to fit into the tubular receptacle of female overshot assembly and mate with said noncircular contour of the inside surface of said receptacle, whereby rotation of said drive rod string and overshot assembly causes rotation of said receiver shaft;
• a drive shaft within said downhole assembly rotationally connected to said receiver shaft and extending to the rotational input of the pump of the downhole assembly, such that rotation of the receiver shaft by the drive rod string causes rotation of said pump to move fluid in said well to the surface.