US2610027A - Split knocker-head jar and safety unit - Google Patents

Description

% dim-" 13 f 3 3 m 4 6 w w x e J J B K E WAGGENER SPLIT KNOCKER-HEAD JAR AND SAFETY UNIT Sept. 9, 1952 Patented Sept. 9, 1952 SPLIT KNOCKER-HEAD'JAR AND SAFETY UNIT Kenneth E. WaggenenBrea, Calif.

Application August 6, 1949, Serial No.108,893 it 4 Claims.

This invention'is a combined up-bumping jar and safetyjoint for deep well tool strings.

Heretofore it has been necessary to unscrew the upper or hammer bowl assembly from a lower c'rmandrel assembly when the bowlfor housing is to be pulled or elevated froma well hole after the hammer has been repeatedly rib-jarred on the head or mandrel of the assembly, or following such other operations as a given ja tool may be employed for. Such unscrewing function risks the unscrewing of an assembled string of drill pipe sections atone or moreother joints in the string connected to the effectivetool at its foot.

Therefore, apurpose of this invention is to provide a simple, practical, substantial reliable and highlyrefficient housing and mandrel unit which is readily made up, or as readily disconnected, as to the housing and the mandrel, without risk of unscrewing a jointing screw in an attached tool string. And, in this connection, a purposeis to provide a jarrin housingand an anvil mandrel on which latter there is a rigid head which is peripherally interrupted by axially directed gaps so that the head may be regarded as split for the ifree passage upwardly ofa complementary hammer which is rigidly combined with the inner face or the housing. A 1 w A capacity of the unit is that when the housing is to be pulled from the mandrel it is only necessary to lower the tool string and at the :same time exert a left-hand torque whereby to slightlyturn the housing and hammer over into register with the passage gaps in the head, whereupon thehousing is free to be elevated from the mandrel.

Further, there is provided in the invention a means for closely predetermining a desired hammer impact or jar to be delivered to the mandrel, and also jar repeating capacity.

The drawing is a partial axial section of the unit.

Attachable to the lower end of a tool string S Kdotted lines) is a top sub 2 screwed at 3 into the ripper end of a housing 4 whose lower end has an :aflixed set of bore-face keys 5. These keys shift longitudinally along guide ribs 5r which are rigid onthe lower portion of a substantial mandrel 6 having a joint pin tip for attachment to a subjacent tool or other apparatus not shown.

Such ribs are circumferentially spaced at d to snugly fit the keys 5 when the housing is in its lowest position for positive right-hand or lefthand drive of the mandrel (by operation of its suspending string S during use of the safety joint). In the vertically shifted position of the housing each key 5 lies snugly between a near face g of a rib anda short laterally, adjacent abutment lug Ba of. the mandrel so that a right or left hand drive of the, mandrel may still be had.

In; .order to permit the housing to be safely freed from the mandrel the lugs 6a (in suitable number) are spaced vertically above a respective shoulder 6e to form. an escapement'passageway W of L-shape and leading out from the top edge of the respective rib 6r, This enables the escape of the drivin keys 5 and safe freeing of the bowl from the mandrel-without unthreading at any joint.-

A further features resides in the provision of a split head or anvil flange 1 rigid with the mandrel 6 and spa ed longitudinally above the set of ribs fir a snfiicient distance to provide for free reciprocation of a set of segments forming a split or eircumferentially interrupted hammer .8 rigid with the housing and on its inner face. This pgrmits the longitudinal passa e of. the hammer as to the mandrel as th housing is lowered or is elevated and worksthekeys Sin the respective passageways. l p y g In normal operation the hammer 8 is snapped upagainst the anvil flange for jarring effect, and by rotatingthehonsing the hammerturns to register with the slgts pf the mandrel and is then readily elevated with a by th h stin wh n it is to he pulled frrom the weliho'lel It is ,desired that the jar impact may be de; livered with a positive and predetermined force and. also. that-t J r ay be e e ted t while the tool is the hole. Means ar provided to effect these tunctions and as here embodied the mandrel has a. reduced topjstemifis surrounded by a collar l0 having upwardly pro jecting inwardly pressing spring leaves (or dogs) l0). On the tips of the leaves rests a trip ring I I camming the leaves inwardly under the foot edge I21 of a core l2 screwed at [3 onto the mandrel stem 6s. The said foot edge m is bevelled to have an out-thrust camming effect on. the eneased tips of thes i e rs ardr s gesta wi effectively push the ring 14 upward so that the tips of the expanded leaves will slide up along the core l2.

The leaf collar [0 is normally lodged on a bore bench 4b of the housing 4 and is constantly pressed downward by a suitable or preferred spring here being a stack [4 of dished spring rings setting on the ring II. The upper end of the spring stack (which surrounds the core 12) reacts on a gland l5 screwed into the lower end trolling leaves 10 and hold them under the tripping wedge cam I21, while the collar I is butted on the bench 4?). Therefore, when there is set up a certain tension in the tool string and the attached housing 4 the tripping cam 12f will push the tips of the dogging leaves outward freeing the collar upward just as the load of the preset spring stack is overcome. The released collar will ride up along the core [2 and concurrently the housing hammer will be snapped up to the anvil flange by effort of the tensioned tool string 8;. this operation taking place as the housing keys slide along their guide ribs. Repeat jar is had by merelylowering the housing to again set the dogging leaves under the core cam 12].

Rotating torque can be put on the mandrel when the keys are in their upper or lower positions as to the guiding ribs.

When the housing is to be elevated and pulled from the mandrel, as is sometimes desired, leftdrive torque on the string will turn the keys into the escape passageways of the ribs and then housing elevation will entirely clear the split hammer and the therewith alined keys out of the said windows.

What is claimed is:

- l. A combined up-stroke jar and safety joint unit comprising a'mandrel having a peripheral flange circumferentially split to form longitudinal slots from top to bottom and constituting an anvil, and a housing rotative on the mandrel and having an internal hammer flange split complementally to the said anvil flange to be passed along each other for attachment or detachment and facilitate assembly or disassembly of the housing and the mandrel, and including bore face keys fixed on the housing and in alinement with and below parts of the hammer flange, and ribs fixed on the mandrel and forming guides for the longitudinal shift of the'housing" keys and the hammer flange toward or from the mandrel flange; the ribs having guide passageways for withdrawal of the keys by and with the housing and said hammer flange between said mandrel slots; the anvil striking hammer flange parts being wider than the said alined keys to give long wear life.

2. In a safety joint assembly for deep well-hole tools, a mandrel having an external anvil flange which is interrupted circumferentially by longitudinal slots and having circumferentially spaced guide ribs below and alined with parts of said flange and form escapement passageways alined with said flange slots, an elongate housing enclosing the mandrel and having keys fixed on its bore face and movable along the mandrel and turnable into said passageways, and an annularly interrupted hammer flange rigidly fixed on the inner face of the housing located above 7 and in alinement with and which hammer flange includes jarring portions les in Width than the width of said slots and being'movable through said slots when the keys are alined therewith;

parts of the spaces between the ribs being longi- J tudinally alined below the slots in the interrupted anvil flanges.

3. A well tool saiety joint assembly including a housing whose lower end is provided with internal, afiixed, circumferentially spaced hammer segments and with aiflxed keys alined with and below said segments, and a cylindrical mandrel member slidably mounted within said housing and provided with affixed, external circumferential anvil segments whose lower faces are engageable with and by said hammer segments, the circumferential spaces between the anvil segments being greater in width than the width of the hammer segments so that the housing may be lowered onto or pulled from the mandrel, and guide members on the mandrel mounted below said anvil segments and cooperating with the said keys to lead the hammer segments to the anvil segments for jar effect or for escape from the mandrel.

4. The assembly of claim 3; and spring latch means mounted in the housing and engaging and yieldably locking the mandrel in the housing in open position of the hammer segments from the anvil segments.

KENNETH E. WAGGENER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,158,406 Collett et a1 May 16, 1939 2,199,969 Hamm May 7, 1940 2,309,866 Reed Feb. 2, 1943 2,354,709 Shaffer Aug. 1, 1944

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