US1170294A - Casing-spear. - Google Patents

Description

W J. LOUDEN.

CASING SPEAR.

APPLICATIONIFILED 1uLY27.1915.

Patented Feb. 1, 1916."

'lllll llll\\\ 2 A QEL UNI

FATE}? opt on.

CASING-SPEAK.

Specification of Letters Patent.

Patented Feb. 1, 1916.

Application filed July 27, 1915. Serial No. 42,174.

adapting the spear to casings of different;

diameters and avoiding the present usual practice of provldlng a different spear for each size. The improved spear is .quite as effective for one size as another, and by increasing its range a marked economy in an expensive type of well tool is effected.

The invention is embodied in improved means for adjustably maintaining the slips at the desired elevation, also improved means for accomplishing such adjustment.

In the accompanying drawings, Figure 1 is an elevation of the improved spear. Figs. 2 and 3 are vertical longitudinal sectional views of the same taken at right angles to each other. Fig. 4 is a cross-section on line 4.4: of Fig. 2. Fig. 5 is a cross-section, enlarged, on line 5-5 of Fig. 3. Fig. 6 is a sectional detail of the adjustable slip-holding means.

Referring to the drawings, 2 designates the body of the spear having axial bore 3 extending upwardly from its lower end, the bore being closed by plug 1. At opposite sides of the body are the downwardly cliverging slipways 5, each provided with a central longitudinal groove 6 of dove-tail section. 7 are the wedging slips of usual construction in this type of tools which are slidable on ways 5, the inner faces of the slips formed with holding ribs 6' complementary with and fitting the. grooves 6. The outer faces of the slips are serrated at 7 for securing a biting hold on theinterior of the casing to be elevated. The upper ends of ways 5 terminate in shoulders 8 which overhang theslips, and above these shoulders the body is provided with wrench hold 9. Projecting from the upper-end of the body is the usual coupling pin 10. i In the preferred construction the entire body, in-

cluding wrench hold 9 and pin 10, is a single ways 5 with the ends of the key entered loosely in slots 14: of slips 7. Interposed between the lower extremity of stem 11 and plug 4 is the expansible coiled spring 15 which opposes depression of the stem and slips and when the stem is released operates to raise the latter and the slips to the upper portions of ways 5, thereby contracting or drawingin the slips andreleasing their hold on the casing.

When setting the slips it is desirable to retain them at such .elevation on the ways as will causetheir serrated faces 7 to just clear the inner face of the casing on the downward movement but'which' will impinge the casing on the slightest upward movement, the sloping under faces of serrations 7 and their horizontal or abrupt upper facesproducing this ratchet-like effect. For thus accurately holding the slips for each different size casing, stem 11 is provided with the vertical series of horizontal toothlike serrations 16 whichare preferably continuous around the stem excepting for the interruption caused by vertical rack 17 at one side thereof. A. horizontal opening 18 in one side of body 2 is adapted to accommodate the latch-like bolt 19 having its outer extremity accessible for pressing the latch inwardly into engagement with the stem in opposition to spring 20 which holds the latch normally out of engagement with the stem. The preferred form of serrations and latch deviceare illustrated in detail in Fig. 6, each serration having a sloping under .surface and a top surface that is slightly dished at 16. so that it will provide a secure hold for the. curved and beveled extremity 19 of latch 19, said extremitybeing slightly hooked as shown to more securely engage the dished serration. The" machine work incident to producing serrations 16 is not increased by reason of the fact that they are extended almost entirely around the stem as they are simply turned up in a lathe, and by thus forming them the latch device need not be located in the body with exact precision. I

In the adaptation shown, rack 17 is engaged by pinion 21 located in depression 1 22 diametrically opposite the latch device, the arbor 23 to which the pinion is secured being confined in a suitable passage formed in body 2 and having a head'23 to which a wrench or other turning device may be conveniently applied. By this means the stem may be lowered as desired for setting the slips at the most advantageous elevation for the particular size of casing to be operated upon, and when that position is reached, latch device 19 is projected inwardly in opposition to spring 20 and engages the appropriate serration 16 for holding the stem and slips. Having thus ad'- justed the spear for a casing of particular diameter it is passed downwardly thereinto to a point where it is desired to secure a hold, and with the slips set to justclear the casing on the downward movement, slight upward movement of the spear will cause them to impinge the casing and thereby lower the slips and stem in opposition to spring 15 sufficiently to relax the hold of latch device 19, whereupon the latter is projected outwardly automatically bv spring 20, thereby tripping the spear. The slips may extend downwardly and outwardly as far as may be necessary under the continued upward pull on body 2, the effectiveness of the hold of course increasing with the pulling force exerted on the tool, and the casing is therebv withdrawn unless it has become too solidly fixed in the well. If impractical to loosen it by proper manipulation of the spear, slight downward movement of the latter relaxes the wedging action, and with latch device 19 retracted and out of the way the slips are forced upwardly to shoulders 8, their position being thereby so contracted on the tool body that the spear may be withdrawn without obstruction.

The tool is of simple construction, the bodv being preferably formed of a single forging, and with the range of adjustment as herein provided the spear may be adapted. to casings of various diameters, avoiding the necessity of providing a different spear for each size as is now ordinarily the praotice.

I claim:

1. In a casing spear, the combination of a hollow tool body having downwardly cliverging slipways, slips movable on said ways, a stem movable in the bodv cavity longitudinally of the slipways and. operatively connected to the slips for raising and lowering them, a spring for opposing downward movement of the stem and slips, means mounted in the tool body and operatively connected to the stem for lowering it and the slips in opposition to said spring, and automatically releasable means for main taining the slips in depressed position.

2. The combination of a hollow tool body having downwardly diverging slipways, opposed slips movable on said ways, a stem movable vertically in the body and operatively connected to the slips for holding them elevated, a spring for opposing downward movement of the stem, the stem provided with a vertical series of notches, a latch device carried by the body and adapted to engage one or another of the notches for holding the stem depressed, a spring for opposing movement of the latch device in direction to engage the stem and adapted to disengage the latch device therefrom upon counteracting the upward pressure of the stem-holding spring, the stem provided with a vertical rack, and a pinion mounted on the body and meshing with said rack for lowering the stem in opposition to its hold ing spring.

, 8. The combination of a hollow tool body having downwardly diverging slipways, opposed slips movable on the ways, a stem movable vertically in the body and operatively connected to the slips, the stem formed at one side with a vertical rack and with a vertical series of horizontal tooth-like serrations extending around a portion of the stem not occupied by the rack, the body formed with an externallyopen latchway, a latch device movable in said way with its inner extremity shaped to engage one, or another of said stem serrations for holding the stem depressed, a spring for opposing stem-engaging movement of the latch device and for disengaging said device from the stem, a spring for opposing downward movement of the stem and. for raising the same when the latch device is released, and stem depressing means adapted to cooperate with said ver tical rack.

4. The combination of a hollow tool body having downwardly diverging slipways, opposed slips movable on said ways, a stem movable vertically in the body and operatively connected to the slips, a spring for opposing downward movement of the stem, the stem provided with a vertical rack, a pinion rotatably mounted in the body and meshing with the rack for lowering the stem in opposition to said spring, and an automatically releasable latch device for holding the stem in depression position.

5. In a casing spear, the combination of a tool body having opposite downwardly diverging slipways, slips movable on said ways, the body formed with a cavity and a matically releasable means for maintaining device movable in the cavity and connected the slips in depressed position. 10 to the slips for raising and lowering them, In testimony whereof I affix my signaa spring for opposing downward movement ture in presence of two witnesses.

of said device and for holding it and the WILLIAM J. LOUDEN. slips normally elevated, means mounted in Witnesses:

the body for depressing the slip-holding de- W. A. LOUDEN,

vice in opposition to said spring, and auto SARAH O. LOUDEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C.

Images