US2875982A

US2875982A - Drive clamp

Info

Publication number: US2875982A
Authority: US
Publication date: 1959-03-03
Anticipated expiration: 1976-03-03

Description

March 3, 1959 E. l. UNGLESYBY DRIVE CLAMP Filed Sept. 8, 1955 IN VEN TOR.

ELMER UNGLESBY ATTORNEYS United Sta -fit DRIVE CLAMP Elmer I. Unglesby, New Carlisle, Ohio Application September 8, 1955, Serial No. 533,050

g 3 Claims. (Cl. 255-1) This application relates to drive clamps for driving well casings.

In drilling a well with a reciprocating type drill, it is customary to suspend the drill from a walking beam and to rock the walking beam to successively raise and drop the drill, thereby cutting a well bore in the ground due to the crushing and cutting action of the drill. It is customary to line the well bore as the drilling takes place with sections of well casing, which are pieces of pipe having an internal diameter sufficiently greater than the diameter of the drill in its associated drill string to permit reciprocation of the drill within the casing. As the drilling progresses, sections of casing are driven into the bore hole to line the bore hole as it is cut. The process might be simply described as a series of steps of alternately drilling and driving casing.

To drive the easing into the bore hole a drive clamp is fastened to the drill bit or to a link in the drill string above the drill bit. This drive clamp extends laterally of the drill string for a distance greater than the diameter of the casing, and thus provides an abutment for striking the top of the casing and driving it into the borev hole as the drill string is reciprocated within the casing. Every time it is desired to stop drilling operations and drive additional sections of casing it is necessary for a workman to climb the supporting tower of the walking beam and attach the drive clamp to the drill. This task requires the workman to operate at a height which may be as great as thirty or forty feet, and at this height .to reach out and attach the clamp about a diametrically reduced portion of the drill string. Obviously this is a risky job and the attachment of the drive. clamp should be simplified in every way possible to permit the workmen to attach the clamp quickly and easily.

Accordingly, it is the primary object of this invention to provide a drive clamp of relatively simple and rugged construction which is capable of rapid and easy attachment to a drilling rig.

Another object of the invention is to provide such a drive clamp wherein a pair of jaws are hinged together for open and closing movement, and wherein each of the jaws has a recessed portion complementary to the recessed portion in the other jaw to provide a passage throughthe closed clamp for clamping around a reduced portion on the drill string.

An additional object of the invention is to provide such a drill clamp with a releasable locking means which may be readily engaged to lock the jaws in the closed position of the clamp thereby to retain the clamp on the drill.

Another object of the invention is to provide in such a drive clamp complementary notches in the sides of the jaws facing each other, which notches provide a passage of non-circular cross section through the clamp for clamping around a similarly non-circular portion of the drill. 7

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims.

f ice In the drawing- Fig. l is a, view partly in elevation and partly in section showing an assembled drill string including the drive clamp of the invention engaging a well casing pipe;

Fig. 2 is a perspective view of the drive clamp of .Fig. 1 in its closed position;

Fig. 3 is a perspective view of the drive clampv in its open position;

Fig. 4 is a section on an enlarged scale taken on line 4-4 of Fig. l", and

Fig. 5 is an enlarged detailed section showing; the tapered locking pin in locking position.

Referring to the drawing, which illustrates a preferred embodiment of the present invention, and particularly to Fig. 1, the drill string includes a cable extended around a suitable pulley 12 carried on a walking beam (not shown). One end of cable 10 is clamped to a socket 13 which is in turn coupled to a set of jars 14. The jars are connected in the usual manner to a link 15 of the drill string, at the lower end of which is carried a bit 18. The well bore cut by bit 18 is shown as lined with a suitable casing pipe 20, sections of which are coupled together in the usual manner and driven into the bore. To drive the casing 20 a drive clamp indicated generally at is attached to the drill string, and reciprocation of the drill string causes clamp 25 to strike repeated blows ,upon the top of casing 29 and drive it into the bore. For example, the clamp is reciprocated between the dotted line. and full line positions in Fig. l to hammer on the top of casing 20. Once the casing has been fully driven into the bore clamp 25 is removed from the drill string and further drilling of the well bore is commenced and continued until it is necessary to drive additional casing, at which time the drill string is pulled up from the well and clamp 25 is again attached to drive the next length of casing.

, The clamp provided by the invention is shown in detail in Figs. 2 and 3, and includes a pair of jaws 3i) and 32 articulated at one end to a hinged bar 33 by suitable hinged pins 34. Jaws and 3.2 are thus arranged for swinging movement about pins 34 between a closed position, shown in Fig. 2, wherein the jaws are closely spaced and substantially parallel to each other, and an .open .position shown in Pig. 3, wherein the jaws diverge with respect to each other from hinge bar 33. The adjacent corners of jaws 3t) and 32 at the hinged ends thereof are relieved, as indicated at 35, to provide for free. swinging movement of the jaws. Thus, in the closed position of the jaws the inner face 36 of jaw 30, and the inner face 38 of jaw 32 are adjacent to each other and may be either abutting or relatively closely spaced apart.

I Each of the

inner faces

36 and 38 is provided with a transverse, preferably fiat-sided, recess shown as'notches 40 and 42, respectively, extending across the inner faces of the jaws. It is to be understood that the particular notched configuration of these recesses shown in the drawing is merely exemplary and they may be of any desirable cross section. Preferably,

recesses

40 and 42 are complementary to each other and are of non-circular configuration in combined cross section.

The other or free ends of jaws .30 and 32 are provided with :

slots

44 and 45 extending longitudinally into the free ends of the jaws. A locking bar 58 is hinged within slot 44 on jaw 30 by a hinged pin 51, and is free to move from the position shown in Fig. 3, wherein bar extends substantially at right angles toface 36 of jaw 30, to a position .extending outwardly from the end of the jaw. The direction of swinging movement of bar 50 is indicated by arrow 52 in .Fig. 3. The free or outer end of bar 50 is receivable within slot 45 on fi w and a o 5. 1s P i d t r u her 5 to e 'tend through the locking bar on the outer face of jaw 32 .to the end of bar 50 by swings the clamp shut about portion 70.

clamp comprising in the closed position of the clamp as shown in Fig. 2, transverse slots 56 are formed in the outer face of jaw 32, across one side of notch 45, and arranged to be aligned with slot 55.

A tapered locking pin 60, having a flat face 61 and a tapered rounded face 62, is provided for retaining locking bar 50 in slot 45. The pin 60 is preferably attached a chain 64 to prevent misplacing of the pin, and more important, to prevent difficulties should a workman lose his grasp on the pin while attaching the clamp to the drill string at a relatively great height. The degree of taper on surface 62 is within the range of self-locking tapers for the material used, and thus when the pin 60 is inserted to lock the clamp, manual force on the pin will be sufiicient to secure it within the slot 55 against accidental loosening. The length of pin 60 is preferably slightly greater than the height or thickness of jaw 32, as will be apparent from inspection of Fig. 5. This provides for a protrusion of the smaller end of the tapered pin below slots 56, and thus the pin may. be knocked loose by tapping its smaller end with a hammer or the like should it become wedged tightly within the slots during use of the clamp.

Jaws

30 and 32 are provided with

handles

65 and 66 for ease of manipulating the clamp. These handles are unnecessary to the operations of the clamp, but they do greatly facilitate the overall ease of attachment and removal of the clamp with respect to' the drill string. To operate the clamp the workman climbs the tower until he reaches the height of the non-circular portion 70 (Fig. 4) of the link 15. With the clamp in its open position, as in Fig. 3, he then grasps handles 65 and 66 and Thus, the

recesses

40 and 42 cooperate to provide a passage through the closed clamp which conforms generally to the cross section of link portion 70. The upper and lower edges of the jaws rest against the

shoulders

71 and 72 on opposite sides of the reduced portion 70, and the clamp is thus fixed upon the drill string so long as it is maintained in its closed position. To lock the clamp it is only necessary to swing bar 50 into slot 45 and firmly insert the pin 60 through

slots

55 and 56.

The attachment and removal of the clamp with respect to the drill string is therefore a simple matter, requiring but a few moments, and with no tightening of screws, bolts or the like being necessary. Thus the workman does not have to carry tools with him and manipulate these tools while retaining his hold on the tower. At the most, should pin 60 become firmly wedged in its locking position, it would be necessary only to rap the bottom of the pin to loosen it and no turning or tighteningof threaded members is operation of the clamp. It is to be understood that such loosening of the pin as described above would be an unusual circumstance, since in the average case the pin would not be so firmly wedged in place as to require striking force to remove it..

required at any time in -Thus, it is seen that the present invention provides a drive clamp which is of rugged yet simple construction, and which is capable of easy and rapid operation for attachment to and removal from a drill string. No tools areneeded for operation of the clamp, and no prolonged tightening operations are required of the workman While he is, manipulating the clamp at a relatively great height.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

l. A drive clamp for attachment to a reciprocating drill string having spaced shoulder. portions thereon, said a pair of jaws hinged together at one 4 end thereof for swinging movement between an open position wherein said jaws are diverging and a closed position wherein said jaws are in substantially parallel side by side relation, the lower surfaces of said jaws being substantially flat and coplanar defining a striking surface for engaging and driving well casing releasable means for locking said jaws in said closed position, said clamp having a transverse passage therein of lesser cross section than said shoulders and of sutficient cross section to encompass the drill string between said shoulders, said passage being provided by complementary recesses in said jaws to provide for attachment and removal of said clamp on the drill string by swinging said jaws to said open position, and the thickness of said clamp about said passage being slightly less than the distance between said shoulders to retain said clamp in closed position against movement relative to the drill string for striking driving well casing through which the drill string itself is freely movable.

2. For use in a well drilling rig having a diametrically reduced portion of relatively short length axially of the drill and adapted for reciprocating drilling action within a tubular well casing, a clamp of greater cross section than the passage of the well casing and adapted to be removably secured around the diametrically reduced portion of the reciprocating drill for movement therewith to drive the well casing into the well bore as drilling progresses, comprising a pair of jaws hinged together at one end for swinging movement between closed and open positions of the clamp, the lower surfaces of said jaws being substantially fiat and coplanar defining a striking surface for engaging and driving well casing each of said jaws having a fiat-sided recess formed transversely thereof, said recesses being complementary to each other to provide a passage through the closed clamp slightly larger than said reduced portion on said drill and smaller than the remainder of said drill, and releasable locking means for retaining said clamp in closed position clamped around said reduced portion and providing for opening of said clamp to facilitate attachment thereof to the drill for driving casing and removal of said clamp from the drill for further drilling of the well.

3. For use in a well drilling rig having a diametrically reduced portion of relatively short length axially of the drill and adapted for reciprocating drilling action within a tubular well casing, a clamp of greater cross section than the passage of the well casing and adapted to be removably secured around the diametrically reduced portion of the reciprocating well drill for movement therewith to drive the well easing into the well bore as drilling progresses, comprising a pair of jaws articulated to a hinge barfor movement toward and away from each other to close and open the clamp, the lower surfaces of said jaws being substantially flat and coplanar defining a striking surface for engaging and driving well casing each of said jaws having a relieved portion formed in the side thereof facing the other said jaw and extending transversely of the jaw, said relieved portions being complementary to each other to provide a passage through said clamp in the closed position of said clamp, said passage being of such cross section as to fit around the reduced portion of the drill and of lesser cross section than the portions of the drill immediately adjacent the reduced portion for retaining said clamp in a longitudinally fixed position on the drill, a locking bar hinged to the free end of one of said jaws, the other said jaw having a slot in the free end thereof for receiving said locking bar, means defining a slot in the free end of said locking bar extending beyond said slot in said other jaw in the closed position of said clamp, a pin receivable in said slot in said locking bar, and means for retaining said pin relative to said free end of said other jaw and within said slot in said locking bar. I

(References on followim page) blows upon I References Cited in the file of this patent UNITED STATES PATENTS Saunders Mar. 17, 1891 Richey Sept. 27, 1898 5 Carpenter Dec. 19, 1899 6 Berg Apr. 15, 1919 Lonergan Feb. 14, 1922 Pringle Jan. 4, 1927 Monroe Aug. 25, 1936 Ekin Jan. 21, 1941 Stanley Oct. 28, 1941