US3081123A - Bit grab - Google Patents

Description

C- O. STEED March 12, 19 63 BIT GRAB Filed May 9, 1960 m m p f 2 2 E- 4 m M h! v a ll 3 a w m H MW w m w. m. a H 6r w c HA PL 5 9: s TEED IN V EN TOR threaded connection (pin) itself has broken off.

United States Patent() 3,081,123 BIT GRAB Charles 0. Steed, 47 Andrews Highway, Odessa, Tex.

0 Filed May 9, 1960, Ser. No. 27,889

3 Claims. (Cl. 294-8629) This invention pertains to fishing tools and more particularly to a tool specially designed to grapple drill bits from within oil wells.

A problem exists in the drilling of oil Wells with the occasional loss of a bit within the hole. This may be because the bit with the threaded connection has totally come off as illustrated in FIG. 1 or it may be that She ne of the means to fish these out of the prior practice is to lower an explosive charge down within the bit, detonate the charge thereby destroying the bit, then fishing the pieces out with magnetic means.

An object of this invention is to provide a fishing tool specially designed to remove drill bit-s from oil wells.

Another object of this invention is to provide a tool which has jets for washing debris away from tools so that said tool may engage the bit easily.

Further objects are to achieve the above with a device that is sturdy, compact, durable, simple, and reliable, yet inexpensive and easy to manufacture.

The specific nature of the invention as well as other objects, uses, and advantages thereof will clearly appear from the following description and from the accompanying. drawing, in which:

FIG. 1 is an elevational view of a tool according to this invention just above such a bit it is designed to remove.

FIG. 2 is a top view of the tool.

FIG. 3 is an axial sectional view of the tool taken on line 3-3 of FIG. 2.

FIG. 4 is a partial sectional view at a larger scale taken on line 44 of FIG. 3.

As may be seen in the drawings, one of the principal features of a tool according to this invention is the cylindrical barrel which forms the body thereof.

Attached to the outside of the barrel are three pairs of ribs 12. The ribs extend axially of the barrel on the outside thereof. They are arranged in pairs, so that a slot is formed by each pair. Bolt 14 about midway of the ribs, extends across the slot between each pair of ribs. Each bolt is normal to the slot, therefore parallel to a tangent of the cylindrical barrel 10.

An arm 16 is within each of the slots. Bolt 14 extends through a holein the arm thus pivoting the arm to the ribs. The arm has a lower foot portion 18 which extends below the body of the barrel. The shank end 20 is above bolt 14. Two holes are in the barrel through the slot radially of the barrel. Cups 22 are attached by welding or otherwise to the barrel and extending therein. A spring 24 is within each cup. These compression springs push against the shank of the arm causing the arm 16 to rotate about the bolt 14. This causes the shanks 20 collectively to extend outward and thefoot portions 18 collectively to contract.

On the extreme lower end of the foot of each arm there is a earn surface 26. When the tool passes over a bit, the cam surfaces 26 will cause the lower portion of the arms to rotate about bolt 14, compressing the springs 24, enlarging the opening between the claws 28. When the foot portion passes over the largest diameter of the bit, the springs will cause claws 28 to rotate about bolt 14, toward the axis of the barrel. This will cause contraction of the opening between the claws 2'8 and will firmly secure the tool to the bit. I have found most of these bits are in the upright position.

3,081,123 Patented Mar. 12, 1963 The barrel 10 is attached to sub 30. The top of the sub is threaded, thus making it adapted to attach to the same string of drill stem to which the bit was previously attached. It is therefore possible to circulate fluid through the tool. The attachment of the sub to the barrel is by threading or any other convenient means.

The bit may be imbedded in debris such as mud. In such instances it is desirable to provide means for removing or loosening said debris. One method is to weld or attach a plate 32 transverse the barrel therein. The plate has axial nozzle 34 therethrough. The nozzle is directed downward so that fluid passing through drill stem (not shown) and sub will be directed in a jet With great force upon the bit, cleaning debris away from it.

Also tubes or other passageways 36 are provided from the barrel upstream of the plate. The connection of the top of the tube in opening 42 through the barrels upstream of the plate is by any conventional means. Upstream from the plate and nozzle there will be higher pressure if there is considerable fluid flow through the tool. The lower end 38 of the tubes will discharge upon the bit adjacent to the position of the claws 28. The jet of fluid coming through the tool will clear away debris from this most critical area where the claws engage.

Pads 40 are attached to the extreme lower end of the barrel within the slots so that the foot ends of the arms do not hang against the side of the barrel itself but strike the pads 40.

It will be noted that the foot portions 18 of the arms below the barrel are tapered toward the axis. This is to prevent them from digging into the sides of the open Well causing excessive material to cave into the well. Also it will be noted that the ribs extend above the shank 20' of the arms.

When the tool with the bit is being removed from the well, it is not possible for a projection to strike the shank of the arms causing it to move inwardly and the foot outwardly thus releasing the bit.

It will be understood when I speak of the claw 18 I mean that the bottom of the arm is somewhat L-shaped, however the foot of this L. angles upward. The bottom of this element that angles upward toward the axis is the cam 26. This claw might also be described as a hook or elbow or snag.

It will be apparent that the embodiment shown is only exemplary and that various modifications can be made in construction, materials, and arrangement within the scope of the invention as defined in the appended claims.

I claim as my invention:

1. A grapple for fishing drill bits from oil wells comprising: an upright cylindrical barrel, three pair of ribs extending on the outside of said barrel axially thereof, each of said pair of ribs having a slot therebetween, a bolt extending across from each rib to the rib opposite the slot, an arm extending axially of said barrel in each slot, said bolt extending through a hole in said. arm, a foot portion of said arm extending below the limits of said barrel, a shank end of the arm extending up, a spring for each arm, each spring biasing the shank end of the arm away from the barrel so that the foot portion is biased inward, a cam on the extreme foot end of said arms, a claw above the cam on each foot portion; so that as the grapple is lowered over a bit, the cams spread the arms and fit thereover, and when the grapple is raised the claw engages the bit to lift it with the grapple, and a means for causing a jet of fluid to wash over the bit.

2. The invention as defined in claim 1, wherein said means for causing a fiow of fluid to wash over the bit includes a plate extending transverse the barrel, said plate having a nozzle therein, said nozzle directed axially along References fiterl in the file of this patent the bit. o

3. The invention as defined in claim 2 with the addi- UNITED STATES PATENTD tion of passages connecting to the barrel upstream of the 886,868 Rohen et al. May 5, 1908 plate, said passages extending down along the arms so 5 1,635,622 Henderson July 12, 1927 they direct a stream of fluid along or about the hook 2,090,616 Erwin Aug. 24, 1937 portion of each arm. 2,416,613 Costin Feb. 25, 1947 2,709,617 Lang May 31, 1955

Claims (1)

1. A GRAPPLE FOR FISHING DRILL BITS FROM OIL WELLS COMPRISING: AN UPRIGHT CYLINDRICAL BARREL, THREE PAIR OF RIBS EXTENDING ON THE OUTSIDE OF SAID BARREL AXIALLY THEREOF, EACH OF SAID PAIR OF RIBS HAVING A SLOT THEREBETWEEN, A BOLT EXTENDING ACROSS FROM EACH RIB TO THE RIB OPPOSITE THE SLOT, AN ARM EXTENDING AXIALLY OF SAID BARREL IN EACH SLOT, SAID BOLT EXTENDING THROUGH A HOLE IN SAID ARM, A FOOT PORTION OF SAID ARM EXTENDING BELOW THE LIMITS OF SAID BARREL, A SHANK END OF THE ARM EXTENDING UP, A SPRING FOR EACH ARM, EACH SPRING BIASING THE SHANK END OF THE ARM AWAY FROM THE BARREL SO THAT THE FOOT PORTION IS BIASED INWARD, A CAM ON THE EXTREME FOOT END OF SAID ARMS, A CLAW ABOVE THE CAM ON EACH FOOT PORTION; SO THAT AS THE GRAPPLE IS LOWERED OVER A BIT, THE CAMS SPREAD THE ARMS AND FIT THEREOVER, AND WHEN THE GRAPPLE IS RAISED THE CLAW ENGAGES THE BIT TO LIFT IT WITH THE

Images