Downhole reciprocating pumps, a non tap tool with a clutch

Abstract

A tool which connects the last sucker rod of a sucker rod string to a downhole pump has a circularly cylindrical cylinder and piston so that the piston slides reciprocally and rotates freely within the cylinder. However, the closed upper end of the cylinder and the upper face of the piston have a cooperable tongue and groove which prevent relative rotational motion of the piston in the cylinder when the tongue is engaged in the groove so that the tool can be disconnected from the pump in response to rotation of the string at the uppermost stroke of the plunger to engage and turn the tongue and groove.

1 . A tool connectable between the last sucker rod of a sucker rod string and a downhole pump comprising:
 a circular cylinder having a closed upper end externally adapted for connection to the last sucker rod of the sucker rod string; and   a circular cylindrical piston reciprocally slidably and rotatively disposed within said cylinder and having a lower portion extending through an opening in a lower end of said cylinder and adapted for connection to the pump, said closed upper end of said cylinder and an upper face of said piston having a cooperable tongue and groove for preventing relative rotational motion of said piston in said cylinder when said tongue is engaged in said groove.   
   
   
       2 . A tool according to  claim 1 , said tongue and groove being of rectangular cross section. 
   
   
       3 . A tool according to  claim 1 , said tongue and groove being diametric in relation to said cylinder and piston. 
   
   
       4 . A tool according to  claim 1 , said groove being wider than said tongue. 
   
   
       5 . A tool connectable between the last sucker rod of a sucker rod string and a downhole pump comprising:
 a cylinder concentric about a vertical longitudinal axis and having an internally threaded upper portion, a smooth middle portion and a lower portion of inner diameter less than an inner diameter of said middle portion so as to form an annular seat at a junction of said cylinder middle and lower portions;   a plunger concentric about said vertical longitudinal axis and having an externally threaded lower portion adapted to be coupled to the pump, a smooth middle portion and a smooth upper portion having a horizontal end face and an outer diameter greater than an outer diameter of said middle portion so as to form an annular stop at a junction of said plunger middle and upper portions, said plunger upper portion being reciprocally slidably and rotatively disposed within said cylinder middle portion and said stop and said seat being cooperable to limit a lowermost travel of said plunger upper portion within said cylinder; and   a pin concentric about said vertical longitudinal axis and having an externally threaded lower portion with a horizontal end face engaged in said internally threaded upper portion of said cylinder, a middle portion of outer diameter greater than an inner diameter of said plunger so as to position said pin end face at the top of said cylinder middle portion when said pin lower portion is fully threaded into said cylinder upper portion and an externally threaded upper portion adapted for engagement with the last sucker rod of the sucker rod string, said pin and plunger end faces being cooperable to limit an uppermost travel of said plunger upper portion within said cylinder with said plunger lower portion extending below said cylinder lower portion, said horizontal end face of said pin having a diametric groove therein and said plunger upper portion horizontal end face having a diametric tongue thereon, said tongue and groove being cooperable to disconnect the tool from the pump in response to rotation of the string to engage and turn said tongue and groove at an uppermost stroke of said plunger.   
   
   
       6 . A tool connectable between the last sucker rod of a sucker rod string and a downhole pump comprising:
 a cylinder having a closed end externally adapted for connection between the last sucker rod of the sucker rod string and the pump and an internal annular seat proximate an open end thereof; and   a piston reciprocally slidably and rotatively disposed within said cylinder and having a portion adapted for connection to the pump extending through said open end of said cylinder, said cylinder seat limiting travel of said piston within said cylinder in one direction of reciprocation of said piston and said closed end of said cylinder limiting travel of said piston within said cylinder in another direction of reciprocation of said piston,   said closed upper end of said cylinder and an upper face of said piston having a tongue and groove cooperable to disconnect the tool from pump in response to rotation of the string to engage and turn said tongue and groove at an uppermost stroke of said plunger.