US2505073A - Grab tool - Google Patents

Description

April 25, 1950 w. N. suTLlFF 2,505,073

I I GRAB Toot.

Filed March 8, 1949 131311 Eff-2 WAYN E N. SuTLl FF.

A BY @im ATToRNEY.

are slightly bevelled and bear against lock balls 31 which are mounted within upwardly and outwardly inclined pockets 33. These pockets are closed at their outer ends by threaded plugs 39 and accommodate helical springs 40 which are interposed between the plugs 39 and the lock balls 31.

In the form of the invention shown in Fig. 2 of the drawing a tubing 4I is provided. A plurality of friction springs 42 are mounted to reciprocate within the central .bore of the tubing 4I. These are carried upon a sleeve 43 which reciprocates upon a mandrel 44. The mandrel 44 is formed with a reduced cylindrical portion 45 upon its upper end and a threaded box 46 at its lower end. The upper end of 'the cylindrical portion 45 is externally threaded and receives a nut 41 which is housed within a bumper sleeve 48. The upper end of the bumper sleeve is provided with a sub or other suitable connection 49. The body member 44 carries a plurality of latch fingers 50 which are mounted upon the sleeve 43 and temporarily hold the friction spring fingers 42 in their innermost position. The nut 41 has a central bore which receives the bumper sleeve 48. This sleeve is formed with a central opening 5I through which the reduced portion 45 of the member 44 reciprocates.

Mounted upon the lower end of the mandrel 44 is a body member 52 which is formed with a pin 53 extending within the box 45. The body member reeiprocates within the sleeve 43 and extends beyond the lower end thereof. Mounted upon the body member 52 is a plurality of spring grab fingers 54. These grab lingers have straight portions which lie in longitudinal grooves in the body member 52 and arcuate free portions 55 which act as grab ngers and may t around the valve 1call 56 which is mounted upon the valve seat 51. It is obvious that by this arrangement the grab fingers 54 will be forced around the ball 56 and will draw itself inwardly to grip the ball while wedging it olf of its seat 51 and to a holding position, as indicated by dotted lines in Fig. 2.

In' operation of the device shown in Fig. 1 of thedrawing the mandrel I5 is either mounted on the sub II, which is attached to a stem, or to a cable not shown in the drawing. In any event the sub il is suspended in the well and the entire structure is lowered. It is obvious that at this time the head I6 and the grab elements I9 and 23 are in their retracted position within the housing 21. At this time the ends 23 of the lever extensions 22 will be drawn upwardly against the tapered cone face 24 and the fingers 26 will be drawn together. The trip ring 32 is also slipped upwardly on the housing 21, so that the shoulders on the enlarged portion 3l of the housing and the shoulders of the trip ring will limit downward movement of the trip ring. At this time the tapered faces 36 of the housing 21 will be retracted and the lock balls 31 will be forced downwardly by the Springs 46 into the path of travel of the inclined faces 36 so that the trip ring will be held in its uppermost position temporarily. The entire grab structure is lowered into the well until the legs 35 rest upon the lower end of the well bore. At this time the housing 21 will dispose its weight downwardly and will be held against movement relative to the legs by the lock balls 31. Attention is directed to the fact that the lock balls are mounted lower end of the housing bears against the lock balls. In View of this inclined position of the bores 3S the lock balls will move downwardly by gravity and obstruct the downward movement of the housing. At the same time the member il will move downwardly and will relieve the mandrel I5. This will permit the mandrel I5 and the nut I3 to move downwardly carrying the member I6 and the grab arms. The portions 26 of the grab arms will then move downwardly into the space between the legs 35 to encounter an object to be grappled. At this time the spring 25 and the expander I6 will tend to act upon the arm 22 and swing the grab arms 26 outwardly in the space defined by the legs 35. When it is desired to grasp or grapple an object which is to be retrieved, the member II is moved down further until the stop-weight 29 is encountered. This will impose weight upon the housing 21 and will cause it to act against the lock balls 31 forcing them rearwardly and upwardly in a nonlocking position and permitting the lower end of the housing 21 to pass downwardly between the legs 35. At this time there will be a tendency for the arms 26 to swing inwardly in the direction of the arrow -aas shown in Fig. l. When it is desired to draw the arms 26 together, the member II is lifted until the nut I3 is engaged after which the mandrel I5 is lifted. This will raise the portion I6 and pull the arms 26 into the housing 21. By the action the arms 26 will grasp an objectrto be retrieved from the bottom of the well bore.

In the form of the invention shown in Fig. 2 of the drawing the device is intended to be used for removing the valve ball 56 from its seat 51. In this case the spring members 42 are locked in position by slipping their free ends under the members 5G. The spring members 42 will then engage the tubing 4l and allow the device to be lowered into the tubing until such time as it is desired to encounter the ball 56. The structure is then lifted by suitable supporting means which will act to lift the bumper sleeve 48. This will engage the nut 41 and lift the mandrel 44 until the shoulder formed by its reduced portion 45 strikes the end of the sleeve 43. When this is done the members 50 will be lifted from their locking' engagement with the springs 42 so that upon further lowering the mandrel will move downwardly and the spring fingers 45 will drop over the ball 56 and catch it.

It will thus be seen that the structures here disclosed provide simple means for grappling loose parts in a well bore or a loose valve ball, and insuring that these members will be elevated to the surface of the well, and will act effectively as a grab or shing tool.

While I have shown the preferred form or" my invention as now known to me, it will be understood that various changes may be made in combination, construction and arrangement of parts by those skilled in the art, without departing from the spirit of the invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. A fishing tool comprising a tubular body member, a plurality of grab fingers reciprocably mounted within the tubular member and adapted to be retracted to a non-grabbing position, latch means for supporting the body member above the lower end of the well bore whereby when the weight of the body member is imposed upon the supporting member the latch means will release the body member permitting it to move downwardly, and means acting upon the grab members forcing them into grabbing position when the body member is free to move relative to its support.

2. A fishing tool comprising a cylindrical housing, a plurality of grab lingers, a mandrel free to reciprocate through the housing and providing a pivotal support for the grab fingers, yield- :able means tending to hold the grab lingers in their non-grabbing position, and weighted means acting to positively move the fingers to their grabbing position as controlled by the fishing tool suspension means.

3. A iishing tool comprising a cylindrical housing, a plurality of grab iingers, a mandrel free to reciprocate through the housing and providing a pivotal support for the grab lingers, yieldable means tending to hold the grab fingers in their non-grabbing position, weighted means acting to positively move the fingers to their grabbing position as controlled by the fishing tool suspension means, a supporting member mounted upon said housing to engage the lower end of the well bore and hold the lower end of the housing in spaced relation to the well bore, and latch means temporarily holding the housing and supporting means against movement with each other and acting to release the housing when weight is imposed thereon.

4. A fishing tool comprising a sub structure adapted to be attached to a suspending element, a mandrel relatively movable with said sub structure as the sub is lowered into the well, a

tubular housing through which the mandrel extends vertically and with which it has relative vertical movement, a plurality of grab iingers pivotally mounted at points intermediate their ends to said mandrel and normally disposed within said housing, yieldable means connected to the upper free ends of said grab fingers and acting to swing the lower free ends of said grab fingers outwardly against the housing to limit the outward movement of said grab fingers, and a wedge-shaped member freely mounted upon said mandrel and within the housing, said wedge-shaped member engaging the upper free ends of the grab nger structures to force the lower ends of the grab fingers outwardly.

5. The structure of claim 4 including spacing means into which the housing telescopes, the lower end of said spacing means resting upon the end of the well bore, and latch means acting between the housing and the spacing means tending to hold the spacing means against telescoping movement until the weight of the grab structure is imposed thereon.

WAYNE N. SU'ILIFF.

REFERENCES CITED UNITED STATES PATENTS? Name Date Dodds Feb. 25, 1919 Number

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