US1744381A - Slip-releasing means for casing spiders and the like - Google Patents

Description

Jan. 21, 1930. R. H. FOLSOM 1,744,381

SLIP RELEASING MEANS FOR CASING SPIDERS AND THE LIKE- Filed March 25, 1928 INVENTORI Patented Jan. 21, 1930 UNITED STATES PATENT OFFICE ROBERT H. FOLSOM, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO JOHN GRANT, OF LOS ANGE-LES, CALIFORNIA SLIP-RELEASING MEANS FOR CASING SPIDERS AND THE LIKE Application filed March 23, 1928. Serial No. $564,071.

The present invention relates to casing spiders and similar devices employed in oil Well practice and embodying pipe engaging wedges or slips in conjunction with an annular body or ring.

In devices of this class the ring is provided with a tapered bore of decreasing diameter downwardly and the outer surfaces of the slips are correspondingly tapered.

The wedges are segmental in form and are arranged around the pipe or casing between same and the ring so that the weight of the wedges and pipe act to crowd the wedges between the ring and pipe until the latter is fully suspended and held thereby.

W hen it is desired to release the Wedges for further movement of the pipe the usual practice is to lift the pipe slightly. Owing to the usual and practical angle of the said wedges and the bore of the ring, it is often found that the Wedges remain jammed between the pipe and ring with the result that the ring is lifted with the pipe. In such event the common and crude expedient is to strike the ring several blows with a sledge to break the frictional hold beween the ring and wedges.

It is the main object of this invention to provide devices of the class described which will act automatically to release the wedges should they become jammed to the extent that they do not release when the weight of the casing is relieved.

Other objects and advantages of the invention will appear hereinafter.

In carrying out my invention in its application to wedge and ring assemblies, I provide means arranged to move automatically under the wedges whenever the ring is lifted from the surface on which it ordinarily reposes. Thus whenthe pipe and ring is again lowered the entire weight of the pipe comes upon the said means which in turn applies such weight upwardly against the wedges to dislodge them. Said means are so arranged as to hold the wedges in released and inoperative position until such time as the said means are Withdrawn from under the wedges.

In the accompanying drawings I have illustrated one practical embodiment of my in- 50 vention.

In the said drawings:

Figure 1 is a view in vertical section of the embodiment in use as a casing spider.

Figure 2 is a plan view thereof.

Figure 3 is a view in bottom elevation thereof.

Figure 4: is a View in side elevation showing the device in operation just prior to dis lodgment of the wedges.

Figure 5 is a view similar to Figure 1 and showing the arrangement of parts when the wedges have been moved automatically to inoperative position.

In the embodiment illustrated the numeral 8 on the drawings indicates a spider body of ring of usual arrangement and provided with the tapered bore 9 of decreasing diameter downwardly In said bore the slips or wedges 10 are arranged in the usual man nor to suspend oil well casing 11. The ring is provided with the usual radial arms 12 and is shown as spanning an aperture 13 provid ed by a member 1 1. .Member 14: may be a 1'0.-

tary table or any other suitable apertured structure employed in oil well practice with the aperture 18 alined with the bore of the well. into which the casing 11, is to be lowered.

In conformity with a salient feature of the invention each arm 12 is provided with a coextensive channel 15 which intersects the con tral bore 9 of the ring, as at 16. The slips and ring are so proportioned that when the slips are in the normal operative position in which they are shown in Figure 1, the lower ends 10 of the slips are disposed below the supper limits of the channels 15. In each channel a striker 17 is disposed so as to be movable longitudinally of the corresponding channel in a horizontal path. A transvei e pin is provided in each channel and pass 3 thru a horizontal elongated slot in the corresponding striker. Thus each striker is not only secured in the channel for limited longitudinal movement but each striker has limited swinging movement of the corresponding channel. Upright pins 19. one at the outer end of each striker provide for manually moving the striker and each pin limits the swinging movement of the CiOlTQSDOllCllIlQ' striker to the angular position in which the strikers are shown in Figure 4. The strikers may be formed from short lengths of I beam stock or traction rail. The length of each striker is such that its forward end 17 can be moved into close contiguity with the easing and under the corresponding slip or slips. Usual practice requires only three slips whereas I have shown four strikers in order to be assured of at least one striker for each slip regardless of the position of the slips. The channels are deep enough to permit of the ring resting directly on the underlying surface while permitting of unrestricted longitudinal movement of each striker in its channel.

Normally the strikers are disposed in the retracted horizontal position in which they are shown in Fig. 1, in which position they are entirely inoperative and bear no part of the weight of the other parts. In Fig. 1 the slips are shown in fully operative position. To release the slips the casing is raised slightly. Fig. 4 shows the casing so raised and in this figure it. is assumed that the slips are jammed to the extent that the casing lifts the slips and ring with it.

\Vhen the ring is so lifted the inner ends of the strikers gravitate downwardly and forwardly as permitted by the elongated slots 20 and the pins 21. Thus the forward ends 17 of each striker become disposed below the cor responding under surface 10 of the slips. The casing is now allowed to descend so that the strikers assume the weight of the casing and become disposed between the member 14 and the slips. Thus the slips are dislodged and forced into the inoperative position in which they are shown in Fig. 5. If, when the casing is raised as explained, the slips are not stuck, the strikers may be manually shifted under the released slips to the position in which they are shown in Fig. 5. In this position the strikers hold the slips against descent so that they are held inoperative dur ing any movement of the casing. IVhen the slips are again to be put in operation it is only necessary to manually retract the strikers to the position shown in Fig. 1.

\Vhile I have shown and described a specific embodiment of my invention I do not limit myself to any specific embodiment or to any specific design or arrangement of parts and may alter the construction and arrangement of parts as I desire without enlarging the scope of my invention, within the appended claims.

I claim 1. In a. device of the class described, a rin pipe engaging means having upward releasing movement in the bore of said ring, and means operable by lifting and subsequent lowering of said ring to release said pipe engagmg means.

2. In a device of the class described a ring having a bore, pipe engaging wedges of friction angularit-y having upward releasing movement in said bore, and means operable by lifting and subsequent lowering of said ring to release said wedges.

3. In a device of the class described, a supporting ring, pipe engaging wedges in said ring having vertical releasing movement witn regard to said ring, and wedge releasing means loosely carried by said ring and disposed to gravitate, when said ring is lifted, below said wedges to project below said ring.

4. In a device of the class described a ring, a supporting member on which said ring is loosely seated, pipe engaging means having upward releasing movement in said ring, and means operable by raising said ring from said member and subsequently returning said ring to said member, to move said pipe engaging means upwardly with regard to said ring.

5. In a device of the class described, :1. ring, a supporting member below said ring, pipe engaging we( of frictional angularity having vertical releasing movement in said ring, and means operable by first raising and subsequently lowering said ring to force said wedges upwardly with regard to said ring and member respectively.

6. In a. device of the class described, a supporting member, a ring seated loosely on said member, pipe engaging wedges in said ring having upward releasing movement with re gard to said ring, and means movable between said member and said wedges on upward movement of said ring with regard to said supporting member, said means preventing return of said ring to said member until said wedges are moved upwardly with regard to said ring.

7. In a device of the class described, a supporting member, a ring loosely seated on said member, pipe engaging wedges in said ring having vertical releasing movement with regard to said ring, and wedge releasing means loosely carried by said ring and disposed to gravitate, when said ring is lifted from said member, between said wedges and said member to prevent return of said ring to said member until said wedges are released by up- 'a rd movement with regard to said rin 8. In a device of the class described, a supporting member, pipe supporting wedges spaced above said member, a wedge supportin g ring resting normally on said member and holding said wedges in such spaced position with regard to said member, and means oper able by lifting of said ring from said member to become disposed between said member and said wedges to limit downward movement of said wedges when said ring is returned to said member.

ROBERT H. FOLSOM.

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