US2295630A - Overshot grapple - Google Patents

Description

D'ept. l5, 1942. G. w. BOWEN OVERSHOT GRAPPLE Filed Oct, 18, 1940 3mm GEogE//V Bows/v Patented Sept. 15, 1942 UNITED STATES I PATENT OFFICE OVERSHOT GRAPPLE George W. Bowen, Houston, Tex.

Application October 18, 1940, Serial No. 361,729

y(Cl. 294-102) 2 Claims.

This invention relates to a grapple and has particular relation to an overshot type of grapple specially designed for engaging with and pulling pump sucker rods .and like objects from wells.

Pump sucker rods are made up of sections connected by large couplings. These couplings are composed of very hard material and the conventional type of grapple will not take hold of the coupling with a suii'ciently secure grip to permit the removal of a stuck rod that has been broken oif in the well.

It is an object of the present invention to provide a novel type of overshot grapple which will securely engage either the enlarged coupling of the rod, or the rod itself and which may be designed to simultaneously engage both the coupling and the rod above the coupling and which will securely grip the same to permit the sucker rod to be pulled.

It is another object of the invention to provide a grapple of the character described which embodies one or more tubular bodies, or bowls, each having a helical downwardly and inwardly tapering inside face with a helical gripping jaw mounted on each face and whose outer side conforms to the shape of the corresponding face and whose inner side is toothed to engage the rod or the coupling thereof,'said jaw being unattached to, and iloating freely in, its bowl.

It is a further object of the invention to provide an overshot grapple of the character above specified embodying means whereby the inside diameter of the jaw may be slightly expanded, upon appropriate manipulation of the tool whereby the tool may be released from the engaged object.

With the above and other objects in view the invention has particular relation to certain novel features of construction, arrangement of parts and use, examples of which are given in this specification and illustrated in the accompanying drawing, wherein:

Figure 1 shows a longitudinal, sectional view of a form of the tool adapted to simultaneously engage both the coupling and the rod itself.

Figure 2 shows a cross-sectional View taken on the line 2--2 of Figure 1.

Figure 3 shows a cross-sectional view taken on the line 3-3 of Figure 1.

Figure 4 shows a longitudinal, sectional view of an embodiment of the invention adapted to engage the rod only, and

Figure 5 shows a longitudinal, sectional View of a form of the tool adapted to engage the coupling only.

Referring now more particularly to the drawing wherein like numerals of reference designate the same parts in each of the iigures, the numeral I designates a tubular connecting nipple whose upper end is attached to an operating string 2 which extends to the ground surface. The lower end of the nipple I has an inside bowl 3 whose inner wall is formed with a helical, downwardly and inwardly tapering, inside face 4 extending to the lower end thereof. On this face there is a helical gripping jaw 5 whose outer side tapers downwardly to conform to the shape of and to lit closely on the face 4 and whose inner side is toothed to effectively engage and grip the sucker rod 6 or other similar object.

In the form shown in Figure 4 there is a guide 1 screwed onto the lower end of the nipple I and whose lower end isv flared as shown. This form of the grapple is specially designed for engaging with a section of the rod should the rod become broken at a point distant from the cupling.

As is well known pump sucker rods are made up of sections whose connected ends are similar and are connected by means of couplings such as 8. 'I'he couplings are of somewhat greater diameter than that of the rod sections and are usually formed of very hard material so that the conventional type of overshot heretofore used will not take hold of them securely. The type of grapple shown in Figure 1 as well as that shown in Figure 5 have been found to be very effective in taking hold of and securely gripping this sucker rod coupling. The form shown in Figure 5 has been adapted specially for engaging the sucker rod coupling alone. It comprises the nipple Ia which, as is noted, may be formed solid. Screwed onto the lower end of this nipple there is the tubular sleeve-like bowl 9 which is provided with a helical, downwardly and inwardly taper-- ing, inside face I0 and on this face there is a helical gripping jaw II whose outer side tapers downwardly to conform to the shape of and to fit closely on the face I0 and whose inner side is toothed to effectively engage and grip the coupling 8.

Attached to the lower end of the bowl 9 there is a tubular guide I2 whose lower end is down- 'wardly and outwardly flared so as to guide the tool over the coupling.

In case the sucker rod becomes broken olf beneath the coupling the type of grapple shown in Figure 4 may be effectively employed but should it becomes broken oi a short distance above the coupling the type of grappling tool shown in Figure 1 may be employed and this type may be assembled by combining the bowl 9, with the jaw II therein, with the nipple I as shown in Figure 4, with the jaw therein, iirst having removed the guide I from said nipple I and substituting an inside guide 'Ia which is screwed into the upper end of the bowl 9 into abutting relation with the lower end of the nipple I.

In each form the operating string 2 above reerred to may consist of the upper portion of the sucker rod which is parted. The selected form of the grapple may be attached to the lower end of the upper section of the sucker rod and lowered over the upper end of the broken off section remaining in the well. If the sucker` rod is broken off immediately beneath the coupling, the form shown in Figure 4 may be employed, but if broken 01T at or a short distance above the coupling the form shown in Figure 5 may be employed.

In some instanceshowever, the rod may` have parted at such distance above the coupling that the form of grapple shownvin Figure 1Y may be employed wherein the lower jaw II- will engage with the coupling BV and the upper jaw 5 will engage with the rod 6 above the coupling and a very secure gripY with the broken off section thus obtained.

As the grapple is lowered over the rod or coupling the jaw will frictionally engage the rod or coupling, as the case may be, and upon anupward pull the tapering face` will cor-act with the corresponding tapered jaw so as to contract the jaw and cause'it to securely grip the object engaged by it.

The lower end of the bowl 3 is provided with an inside abutment I3 and the lower end of the bowl 9 is provided with aninside abutmentY I4'. As shown these abutments consistof longitudinal, dove-tailed splines, or keys. These are positioned to engage against the corresponding lower ends of the respective jaws. Incase it should become desirable to release the grapple from the sucker rod in the well the operating string may be turned to cause the abutmentto engage the opposing lower end of the corresponding jaw and a further turning movement will cause an eX- pansion of the jaw so that by a continued turning; in the same direction and an. upward pull on grapple it will readily release, the. stuck. object.

TheV drawing and descriptionlare illustrative merely and it is not intended to restrict the invention thereby except as deiined by the appended claims.

What I claim is:

1. A sucker rod grapple comprising a tubular bowl which is threaded at both ends and has an inside downwardly and inwardly tapering helical face, a helical jaw on said face whose inner side is toothed to engage an object in the grapple and whose outer side conforms to the taper of, and rests upon, said face to cause contraction of the jaw into engagement with said object upon upward movement of the grapple, said jaw being independent of and unattached to the bowl, said bowlhaving an axial inside dove-tailed slot at the end of the tapering face, a pin in the slot forming an abutment engageable against the end of the jaw whereby upon appropriate turning and upward movement of the grapple the jaw willbe caused to expand to release said object, a guide'threaded intothelower end of the bowl and contacting the pin, a tubular connectingnipple threaded intothe upper end ofthe bowl.

2; A sucker rod grapple comprising a tubular connecting nippleforming anupper bowl, a lower'bowl tlflreadedto the nipple,.each of saidbowls havinganV inside downwardly and inwardlyv tapering, helical facea helical jaw on each'ofi said faces whose inner side is toothed to engage an object in the grapple and, whose outer side conforms to the taper of, and rests upon, said faces to cause; contraction of the; jaw into engagement with saidY object uponupward movement ofthe grapple', the lowerfjaw being substantiallyv twice the diameter of` the upper jaw,v said jawsbeing independent of and unattached to the bowls, an inside guidethreaded into theupper endof the lower bowlbelow and in abutting: relation with the lower end of the nipple, each of saidbowls having ann axial dove-tailed slot atf the. end' of the tapering face,.a pin in each slotA forming an abutment engageable against thev end of the respective. jaw'whereby upon appropriate turning and upward; movement of. the grapple the jaws will be caused to expandand release said object, the pin in the upper bowl slot being retained therein by the inside guide, axlower: guide threaded into therlowerA end of the; lower bowl and positioned to ret'aini the pinw in: the lower bowlslot.

GEORGE W. BOWEN.

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