US1345103A - Overshot - Google Patents

Description

J. A. PLANTE.

OVERSHOT.

APPLICATION FILED AUGJB. |919.

1 345, 1 O3 Patented June 29, 1920.

: /f TTORNIS' UNITED STATES PATENT OFFICE.

OVEBSHOT.

Specification of Letters Patent.

Patented June 29, 1920.

Application tiled August 28, 1919. Serial No. 320,542.

To all 'whom z't may concern.'

Be it known that I, JOSEPH A. PLANTE, a citizen of the United States, residing at San Pedro, in the county of Los Angeles and State of California, have invented new and useful Improvements in Overshots, of which the following is a specification'.

My object is to make an improved overshot and my invention consists of the novel features herein shown, described and claimed.

Figure 1 is a fragmentary perspective of an overshot embodying the principles of my invention in use, parts being broken away and shown in section, and parts being omitted.

Fig. 2 is an enlarged longitudinal diametrica] sectional detail of the overshot, the view being taken on the lines 2 2 of Figs.

1 and 3.

Fig. 3 is a horizontal cross section on the line-3 3 of Fig. 2.

Fig. 4 is a perspective of one of the spring dogs.

The overshot consists of the main frame 1, the spring locking dogs 2, the locking sleeve 3, and the fishing bell 4'.

The details ofthe main frame 1 are as follows: A

The head 4 is circular in cross section or end elevation and has a straight outer face 5, an internal bore 6 having a screw-threaded upper end 7, and a reduced lower end 8. The neck portion 9 has a straight outer face 10 concentric to the outer face 5 and smaller in diameter, there being a shoulder 11 between the upper end of the face 10 and the lowerfend of the face 5, and there being an external screw-thread 12 upon the lower end, said screw-thread 12 being smaller in diameter than the face 10.

Longitudinal slots 13, 14 and 15 are formed from the face 10 to the central bore 16, said slots bein evenly spaced apart around the neck. eats 17, 18 and 19 are formed at the lower ends of the slots 13, 14 and 15. The seats are formed from the outer face 10, there being webs 20 at the inner sides of the seats and depressions 21 in the outer faces of the webs.

The details of the spring locking dogs 2 are as follows:

The dogs are made of suitable hard metal and have heads 22 fitting in the seats 17, 18 and 19, lugs 23 fitting in the depressions 21, and spring arms 24 extending from the heads .22 and fitting in the slots 13, 14 and '15, sald spring arms being slightly curved lnwardl'y, and the extreme upper ends 25 of the spring arms 24 are`curved upon their inner faces to substantially t the curvature of the lost pipe or drill stem.

The details of the locking sleeve 3 are as follows:

The annular body 26 fits upon the face l() against the shoulder 11 and extends down- Wardly to the upper end of the screw-thread 12 and has an outer face 27 flush with the outer face 5 and a longitudinal slot 28 in posltlon to uncover the slots and seats 13 17, 14 18, and 15 19 one at a time.

The sleeve 3 is rotated to uncover a slot and seat and then a spring locking do is placed in position and the sleeve rotate to the next slot, and another locking dog is placed in position and the sleeve rotated to the next slot, and another locking dog is placed in position and the sleeve rotated to the next slot, and another locking dog placed in position and then the sleeve is rotated one way or the other to bring the slot 28 out of alinement with the locking dogs thereby holding the locking dogs securely 3 fits closely against the heads 22 so as to 25 of the locking dogs in place. The sleeve the outer faces 29 of throw the upper ends inwardly.

The details of the fishing bell 4.- are as follows:

The body 30 has a` straight outer tace 31 Hush with the outer faee 27 and fits upon the screw-thread 12 against theI lower end of the sleeve 3 and has a hell mouth 32. The form of -fishing bell may be varied to suit the size of the hole being operated upon. The particular bell 4 shown may be unscrewed and a larger bow-l or bell substituted as desired. The bell 1' holds the sleeve securely in place.

In the practical operation the overshot thus constructed is attached to the lower end of an operating stem 33 and lowered into the well hole until the upper end 34 of the lost pipe or drill stem passes inwardly through the bell 1' and into the bore 1G, and then the stem 33 is -still further manipulated until the spring locking dogs 2 pass below the coupling 3 5, then the upper ends 25 of the spring locking dogs 2 will snap inwardly below the eoupliug and the stem 33 may be manipulated to pull the lost pipe 36.

When the spring locking dogs become in- Lured or worn they may be readil removed y manipulating the sleeve 3, an when the dogs have been repaired or a new one substituted they .may be restored to their ope1- ating positions by manipulatin the sleeve 3.

Varlous changes ma be ma e Without departin from the spiritof my invention as claime I claim: An overshot comprising a main frame vadapted to be connected to an operating stem and having a central bore and lon itudinal slots and seats at the bottoms o the slots and a screw-threaded lower end; spring locking dogs having heads fitting in the seats and spring arms extending through the slots; a .locking sleeve rotatably mounted upon the frame and having a slot adapted to uncover the slots and seats in the main frame one at a time so that the spring locking dogs may-be inserted or removed through the slot in the sleeve; and a fishing bell screwed u on the lower end of the main` frame agalnst the sleeve.

In testimony whereof I have signed my name to this specificaton.

i JOS PH A. PLANTE.

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