Drilling latch apparatus

Wire line drilling apparatus having an axial extending central axis and being movable inwardly through a drill string to seat on a drill string landing shoulder and latchingly engage a drill string latch seat, comprising an axially extending latch body having an outer end portion, an inner end portion and a shoulder seatable on the landing shoulder, a drilling tool mounted to the latch body to extend axially inwardly thereof, an axially extending latch retractor having an outer overshot coupling portion and an inner latch mounting portion that includes means defining an inwardly opening chamber, the retractor having an axially extending central axis, a latch assembly for releasably retaining the latch body in the drill string and having at least an axial outer end portion located in the chamber for free rotation about the retractor central axis relative to the retractor and the latch body and free floating axial movement relative to the retractor, the latch assembly including first and second latches pivotally movable at least predominantly transverse between latch seated and latch retracted positions and having axial outer end portions in the chamber and axial opposite inner end portions for removably engaging the latch seat, and connecting means within the chamber and mounted to the latch outer end portions for mounting the latches for pivotal movement about at least one transverse pivot axis between the latch positions, and means for mounting the retractor to the latch body for limited axial movement relative thereto, the the chamber defining means including means for moving the latches to the latch retracted positions as the retractor is moved axially outwardly relative to the latch body.

Wire line drilling apparatus having a central axis and being movable inwardly through the drill string to seat on a drill string landing shoulder and latchingly engage a drill string latch seat, comprising an axially extending latch body having an outer end portion, an inner end portion and a shoulder seatable on the landing shoulder, a drilling tool mounted to the latch body to extend axially inwardly thereof, an axially extending latch retractor having an outer overshot coupling portion and an inner latch mounting portion that includes means defining a latch chamber, the retractor having an axially extending central axis, limiting means for mounting the retractor to the latch body to extend outwardly of the latch body and for limited axial movement relative to the latch body, and a latch assembly at least in part located in the chamber, the latch assembly including first and second latches pivotally movable at least predominantly transversely between latch seated and latch retracted positions and having first end portions in the chamber and second end portions for removably engaging the latch seat, and a rigid transverse link in the chamber and having a first transverse end portion and a second transverse end portion radially opposite the central axis from the link first end portion, said link being movable relative to the latch body, a first transverse pivot having a first pivot axis for mounting the first latch first end portion to the link first end portion for pivotal movement about the first pivot axis and a second transverse pivot having a second pivot axis parallel to the first pivot axis for mounting the second latch first end portion to the link second end portion for pivotal movement about the second pivot axis, the pivots mounting the latches for pivotal movement between the latch positions, the retractor having means for moving the latches to the latch retracted positions as the retractor is moved axially outwardly relative to the latch body.

For wire line drilling apparatus, an axially elongated wire line latch body having axial inner and outer ends, the latch body having a tubular retractor mounting portion opening axially outwardly, a latch retractor axially movably extended into the tubular portion and having an overshot coupling portion for retracting the latch body and a latch chamber axially inwardly or the overshot coupling portion, the latch body and retractor having a central axis, a latch assembly at least in part retained in the retractor chamber, the latch assembly including a first and a second latch pivotally movable between a latch seat engaging position for blocking removal of the latch body and a retracted position permitting axial withdrawal movement of the latch body, and connecting means for attaching the latch retractor to the latch body for limited axial movement relative thereto between a latch seating position and a latch retracting position and in moving to the latch retracting positions retracting the latches, the latches each having a laterally extending latch seat engaging lateral section extendable radially outwardly of the latch body and a latch leg joined to the latch seat engaging section to extend axially away from the latch seat engaging section, a transverse link mounted in the chamber for axial movement relative to the retractor as the retractor is axially moved outwardly relative to the latch body and having a first end portion radially spaced from the central axis and a second end portion radially spaced from the central axis and diametrically opposite the central axis from the link first end portion, a first transverse pivot having a first transverse pivot axis and mounted to the first latch leg axially remote from the first latch section, mounted to the link first end portion for axial movement with the link and mounting the first latch for pivotal movement about the first pivot axis between the latch assembly positions, and a second transverse pivot having a second transverse pivot axis, mounted to the second latch leg axially remote from the second latch section and to the link second end portion to move axially with the link and mounting the second latch for pivotal movement about the second pivot axis between the latch assembly positions.

Wire line drilling apparatus having a central axis and being fluidly propellable inwardly through a drill string to seat on a drill string landing shoulder and latchingly engage a drill string latch seat when the drilling apparatus is adjacent to the latch seat, comprising an axially extending latch body having an outer end portion, an inner end portion and a shoulder seatable on the landing shoulder, a drilling tool mounted to the latch body to extend axially inwardly thereof, a latch assembly comprising a generally transverse latch pivot having a generally transverse pivot axis and a latch mounted by the latch pivot for pivotal movement about the pivot axis for movement relative to the latch body between a latch seated position seatable in the latch seat to block retraction of the latch body outwardly through the drill string and a retracted position permitting the latch body moving axially through the drill string, retractor means mounted to the latch body for limited axial movement relative to the latch body from a first relative position permitting the latch moving to its latch seated position to a second relative position for moving the latch from the latch seated position to the latch retracted position, the retractor means having an axial outer overshot coupling portion and axial inner portion means for acting in cooperation with the latch body to mount the latch assembly, including the latch pivot, for significant limited axial and transverse movement relative to the retractor means, the latch pivot throughout its entire transverse dimension being transversely and radially spaced from both the retractor means and the latch body, including during the pivotal movement of the latch between the latch positions, annular fluid seal means mounted on one of the latch body and the retractor means axially outwardly of the latch body shoulder to form a fluid seal with the drill string and the one of the latch body and the retractor means on which it is mounted, bypass means axially movable relative to the seal means and defined at least in part by one of the latch body and retractor means for permitting fluid flow axially bypassing the seal means when the latch is in its seated position and the retractor means is in its first position and preventing fluid bypass flow when the retractor means is in its second position, and stop means for cooperating with the bypass means and the latch for retaining the bypass means in a position to block bypass flow while the apparatus is being propelled inwardly and until the latch has moved to its latch seated position and when the latch has moved to its latch seated position, permit the bypass means allowing fluid to bypass the seal means.

Wire line drilling apparatus movable inwardly through a drill string to seat on a drill string landing shoulder and latchingly engage a drill string latch seat, comprising an axially extending latch body having a central axis, an outer end portion, an inner end portion, a shoulder seatable on the landing shoulder, and a fluid bypass channel having an axially extending first bore portion, a first port opening transversely toward the drill string axially outwardly of the shoulder and to the first bore portion, and a second port opening transversely toward the drill string axially inwardly of the shoulder and to the first bore portion axially inwardly of the first port opening to the first bore portion and in axial spaced relationship to the opening of the first port to the first bore portion, an axially extending latch retractor having an outer overshot coupling portion, the retractor having an axially extending central axis, limiting means for mounting the retractor to the latch body to extend outwardly of the latch body and for limited axial movement relative to the latch body, and a latch assembly mounted by at least one of the latch body and the retractor, the latch assembly including a first latch pivotally movable between latch seated and latch retracted positions and having a first end portion and a second end portion for removably engaging the latch seat the latch body having, a second axial extending bore portion having a first end opening to the first latch when the latch is in its retracted position and a second end portion opening to the first bore portion, first valving means extending within the bore for axial movement to control fluid flow through the bypass channel and provide a high pressure signal only after the latch body has seated on the landing shoulder and the latch has latchingly engaged the latch seat, the latch assembly and first valving means having cooperating means for couplingly engaging the first valving means to the latch assembly when the latch is in the latch retracted position to retain the valving means in a position permitting substantial fluid flow through the bypass channel as the latch body moves axially inwardly through the drill string, upon being seated upon the landing shoulder and after the latch moving to its latch seated position, releasing the coupling engagement allowing movement of the first valving means in the bore to a position blocking substantial fluid flow through the bypass channel until an inward direct fluid pressure build up in the bore outwardly of the opening of the second port to the first bore portion to about a preselected level and thence upon the pressure build up to about the preselected level, moving to open the fluid bypass channel to permit substantial fluid flow through said bypass channel, the cooperating means including a valving means head and a latch assembly valving head coupling engaging means for couplingly engaging the valving means head until the latch is in its latch seated position.

Wire line drilling apparatus movable inwardly through a drill spring to seat on a drill string landing shoulder and latchingly engage a drill string latch seat, comprising an axially extending latch body having a central axis, an outer end portion, an inner end portion, a shoulder seatable on the landing shoulder, a fluid bypass channel having an axially extending first bore portion, and a transverse inner, outwardly facing plunger shoulder axially inwardly of the fluid bypass channel, a first port opening transversely toward the drill string axially outwardly of the shoulder and to the first bore portion, and a second port opening transversely toward the drill string axially inwardly of the shoulder and to the first bore portion axially inwardly of the first port opening to the first bore portion and in axial spaced relationship to the opening of the first port to the first bore portion, an axially extending latch retractor having an outer overshot coupling portion, the retractor having an axially extending central axis, limiting means for mounting the retractor to the latch body to extend outwardly of the latch body and for limited axial movement relative to the latch body, and a latch assembly mounted by at least one of the latch body and the retractor, the latch assembly including a first and a second latch pivotally movable between latch seated and latch retracted positions and each having an end portion for engaging the latch seat, a second axial extending bore portion having a first end opening to the first latch when the latch is in its retracted position and a second end portion opening to the first bore portion first valving means extendinq within the bore for axial movement for controlling fluid flow through the bypass channel and provide a high pressure signal only after the latch body has seated on the landing shoulder and both latches have latchingly engaged the latch seat, and thence opening the fluid bypass channel to allow the pressure build up to decrease, the valving means including a first valving portion of reduced transverse dimension, a second end portion of a greater transverse area than the transverse area of the first valving portion and diametrically opposite head portions joined to the first valving portion to extend axially outwardly thereof and transverse outwardly of the first valving portion and each latch having a head receiving recess for receiving one of the head portions therein with the second valving portion axially inwardly of the recess when the latches are in their retracted position and the head portions extend therein, blocking axial inward movement of the valving means until the latches have moved to their latch seated position,

Wire line drilling apparatus having a central axis and being movable inwardly through the drill string to seat on a drill string landing shoulder and latchingly engage a drill string latch seat, comprising an axially extending latch body having an outer end portion, an inner end portion and a shoulder seatable on the landing shoulder, a drilling tool mounted to the latch body to extend axially inwardly thereof, a latch assembly comprising a generally transverse latch pivot having a generally transverse pivot axis and a latch mounted by the latch pivot for pivotal movement about the pivot axis for movement relative to the latch body between a latch seated position seatable in the latch seat to block retraction of the latch body outwardly through the drill string and a retracted position permitting the latch body moving axially through the drill string, and retractor means mounted to the latch body for limited axial movement relative to the latch body for moving the latch from the seated position to the retracted position, the retractor means having an axial outer overshot coupling portion and axial inner portion means for acting in cooperation with the latch body to mount the latch assembly, including the latch pivot, for significant limited axial and transverse movement relative to the retractor means, the latch pivot throughout its entire transverse dimension being transversely spaced from both the retractor means and the latch body, including during the pivotal movement of the latch between the latch positions, the latch body and retractor means having an axially extending central axis, the latch body having a transverse outer, exterior peripheral surface, a maximum diameter portion and a reduced diameter portion extending axially inwardly of the maximum diameter portion and joined to the maximum diameter portion to form an inwardly facing landing shoulder, a fluid bypass channel for conducting fluid between a position axially outwardly of the shoulder and a position axially inwardly of the shoulder to bypass the shoulder, and a bore that has a first bore portion opening to the latch and to the bypass channel, the bypass channel including a second bore portion that is a part of the bore, an outer port opening through the peripheral surface outwardly of the shoulder and to the second bore portion and an inner port opening through the peripheral surface inwardly of the shoulder and to the second bore portion, and first valving means mounted for limited axial movement in at least one of the bore and bypass channel between positions permitting substantial fluid flow through the bypass channel and a position blocking substantial fluid flow through the bypass channel and upon a substantial increase in inwardly acting fluid pressure in the channel, move to a position inwardly of the fluid flow blocking position to allow substantial fluid bypass flow though the channel, the latch and first valving means having cooperating means for forming a coupling engagement with one another to retain the first valving means out of the position blocking substantial fluid flow through the fluid bypass channel of the fluid bypass position until the latch has moved to its latch seated position and upon the latch moving to its latch seated position, releasing the coupling engagement to allow the first valving means moving axially inwardly of the latch, and retractable means retractably extending within the bore to limit the inward movement of the first valving means upon the releasing of the coupling engagement to the position blocking the fluid bypass channel after the releasing of the first valving means, and upon the said build up of fluid pressure, permitting the first valving means moving inwardly to unblock said fluid bypass channel.

Wire line drilling apparatus having a central axis and being movable inwardly through the drill string to seat on a drill string landing shoulder and latchingly engage a drill string latch seat, comprising an axially extending latch body having an outer end portion, an inner end portion and a shoulder seatable on the landing shoulder, a drilling tool mounted to the latch body to extend axially inwardly thereof, a latch assembly comprising a generally transverse latch pivot having a generally transverse pivot axis and a latch mounted by the latch pivot for pivotal movement about the pivot axis for movement relative to the latch body between a latch seated position seatable in the latch seat to block retraction of the latch outwardly through the drill string and a retracted position permitting the latch body moving axially through the drill string, and retractor means mounted to the latch body for limited axial movement relative to the latch body for moving the latch from the seated position to the retracted position, the retractor means having an axial outer overshot coupling portion and axial inner portion means for acting in cooperation with the latch body to mount the latch assembly, including the latch pivot, for significant limited axial and transverse movement relative to the reactor means, the inner portion means defining a downwardly opening latch assembly chamber including an axially extending retractor tubular portion having the latch pivot located therein, the latch including a latch leg extending within the chamber and having an outer portion mounted to the latch pivot, the latch pivot throughout its entire transverse dimension being transversely spaced from both the retractor means and the latch body, including during the pivotal movement of the latch between the latch positions, the latch body and retractor means having an axially extending central axis, the latch body outer portion comprising an annular, outer tubular end portion opening outwardly and having the inner portion means mounted therein for limited axial movement, and an inner transverse wall, the latch body tubular portion having a latch slot for having the latch extending transversely therethrough, the retractor tubular portion having an axially inner transverse terminal edge axially outwardly of the inner transverse wall and at least in part outwardly of the slot, and the latch having a lateral section joined to the latch leg inwardly of the pivot and the terminal edge and extending through the latch slot in the latch seated position, the latch assembly including a second latch pivot having a second pivot axis substantially parallel to and transversely spaced from the first pivot and a second latch having an outer end portion mounted by the second pivot for pivotal movement of the second latch about the second pivot axis between a latch seated and a latch retracted position and means for mounting the latch pivots and retaining them in transverse spaced relationship, a transverse stop member mounted by one of the latch body and the retractor means for limiting the pivotal movement of the latches toward one another to limit the rotation of the latch assembly relative to the retractor means and axial movement of the retractor means relative to the latch assembly for maintaining the latch assembly at least in part extending into the chamber, the second latch having a latch leg, each latch leg having a radially outer, axially elongated surface diametric opposite the elongated surface of the other latch leg, the retractor means tubular portion having an axially outer, generally circular cylindrical, transverse inner axial wall portion in transverse surrounding relationship to the pivots and diametric opposite, angularly spaced axially inner flanges extending further radially inwardly than the inner axial wall and abuttable against the transversely adjacent leg radial outer surface for moving the latches from their latch seated position to their latch retracted position as the retractor means moves axially outwardly relative to the latch body and arcuate walls sections between the flanges of sufficient angular dimensions to permit the latch assembly axially being moved transversely between the flanges to have the latch legs extended into and the latch pivots located within the chamber when the stop member is removed from the latch body and the retractor, and the retractor is removed from the latch body and the latch assembly is rotated about the retractor means central axis for having the latch pivot angularly adjacent to the arcuate wall sections and transversely between the flanges and then rotated about the retractor means central axis to have the legs in diametric transverse alignment with the flanges.