US3894780A

US3894780A - Drill pipe protector having tapered latch

Info

Publication number: US3894780A
Application number: US409428A
Authority: US
Inventors: Dallas N Broussard
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-06-19
Filing date: 1973-10-25
Publication date: 1975-07-15
Anticipated expiration: 1992-07-15

Abstract

A drill pipe protector adapted to fit in encircling relation about a joint of rotating drill pipe and to prevent the external surfaces of the drill pipe from becoming worn by rubbing against the walls of a bore within which the drill pipe is rotated. The drill pipe protector comprises a generally cylindrical structural element that is hinged to enable the device to be assembled to the drill pipe and includes a body of molded yieldable material that encapsulates the structural element and extends beyond the surfaces of the drill pipe for contact with the wall of the bore within which the drill pipe is rotated. For the purpose of locking the pipe protector device to the drill pipe, the structural element is provided with a pair of tapered flanges defining elongated diverging cam surfaces each having transverse locking depressions. A latch element is provided having opposed tapered diverging tab elements that are adapted to be received in camming engagement with the cam surfaces and are controllable moved toward or away from one another to cause controlled compression of the yieldable material against the drill pipe upon movement of the latch element relative to the tabs. At least one locking projection is carried by the latch element and is received within the locking depressions to lock the latch element in the latching position thereof.

Description

United States Patent [191 Broussard [451 July 15,1975

[ DRILL PIPE PROTECTOR HAVING TAPERED LATCH Dallas N. Broussard, 204 Diane St., Houma, La. 70360 [22] Filed: on. 25, 1973v [21] App]. No.: 409,428

Related U.S. Application Data [63] Continuation-impart of Ser. No. 263,878, June,

19, 1972, abandoned.

[76] lnventor:

Primary E.\'aminer-Charles .l. Myhre Assistant E.ranziner--R. l-l. Lazarus 5 7 ABSTRACT A drill pipe protector adapted to fit in encircling relation about a joint of rotating drill pipe and to prevent the external surfaces of the drill pipe from becoming worn by rubbing against the walls of a bore within which the drill pipe is rotated. The drill pipe protector comprises a generally cylindrical structural element that is hinged to enable the device to be assembled to the drill pipe and includes a body of molded yieldable material that encapsulates the structural element and extends beyond the surfaces of the drill pipe for contact with the wall of the bore within which the drill pipe is rotated. For the purpose of locking the pipe protector device to the drill pipe, the structural element is provided with a pair of tapered flanges defining elongated diverging cam surfaces each having transverse locking depressions. A latch element is provided having opposed tapered diverging tab elements that are adapted to be received in camming engagement with the cam surfaces and are controllable moved toward or away from one another to cause controlled compression of the yieldable material against the drill pipe upon movement of the latch element relative to the tabs. At least one locking projection is carried by the latch element and is received within the locking depressions to lock the latch element in the latching position thereof.

9 Claims, 6 Drawing Figures DRILL PIPE PROTECTOR HAVING TAPERED LATCH This is a continuation-in-part of application Ser. No. 263,878, filed June 19, 1972, and is now abandoned.

FIELD OF THE INVENTION The present invention relates generally to pipe protector members utilized to prevent wear on the external surfaces of drill pipe and more specifically to a pipe protector structure including novel latching means for locking the pipe protector in encircling relation about a section of drill pipe and controllably compressing yieldable material of the pipe protector to control frictional engagement of the yieldable material and the drill pipe.

BACKGROUND OF THE INVENTION In the drilling of oil, gas and water wells by the rotary method, the well bore or hole in the earth surface is typically formed by means of a drill bit which is secured on the end of what is generally termed a drill string. The drill string is formed of a plurality of drill pipe sections that are connected by couplings which are male and female threaded elements that may be threaded together to secure the drill pipe section into an integral drill string unit.

As the well bore is progressively deepened by drilling operations, additional pipe sections are added to the drill string at the earths surface so that the drill bit or cutting tool at the lower end of the drill string will be maintained in proper engagement with the bottom of the well bore until the well bore is drilled to the desired depth. During the drilling operations, the drill string will be rotated and simultaneously lowered in controlled manner to transmit rotational movement to the drill bit at the bottom of the hole and to maintain predetermined pressure on the drill bit to insure straight and efficient drilling of the well bore.

The sections of drill pipe are not considered expendable items in the drilling of wells. The drill pipes may be used over and over to drill other wells and therefore it is desirable to minimize the amount of wear to which the drill pipes may be subjected during drilling.

In drilling deep bore holes in the earth, such as in drilling to reach a deep production formations, the bore holes are typically of such depth that the metal drill string carrying the drill bit will tend to whip laterally into abrasive engagement with the metal casing lining the bore hole or with the wall structure of the bore hole itself. If the drill pipe is allowed to whip against the casing or well bore wall during drilling operations, the abrasion resulting will erode the exterior surfaces of the drill string to the point that replacement of the drill string will be necessary within a short period of time.

It is customary to prevent abrasive metal-to-metal engagement between the drill string and the well casing or the wall of the well bore by means of a protector device secured about the drill string. Such protector devices are variously called drill pipe protectors or wear preventors. They typically comprise a sleeve or ring that is split on one side for attachment to the drill string. The sleeve may include an inner reinforcing member, usually composed of relatively rigid metal, and inner and outer layers of yieldable material, such as rubber or any one of a number of commercially available synthetic rubber-like elastomeric materials. It is typically the practice in the industry to mold the rubber or synthetic rubber material about the rigid reinforcing member thereby defining a yieldable inner wall of material for engagement with the drill pipe and defining wear preventing surfaces that extend beyond the outer peripheries of the drill pipe for engagement with the inner wall structure of the well casing or the wall structure of the formation in which the well bore is being drilled.

It is desirable that pipe protectors, applied to pipes for the purpose of preventing wear, be applied to the pipes in such manner that the protector device is secured about the pipe structure in sufficiently tight manner that a non-slip relation is developed between the pipe protector and the pipe. The pipe protector will generally be applied to the pipe structure with sufficient tightness that the inner layer of elastomeric rubber-like material will be compressed to an extent creating necessary frictional engagement with the outer periphery of the pipe and the pipe encircling band of reinforcing material, which may also be referred to as a structural element, will be placed in tension.

Drill pipe protector devices are typically secured in frictional engagement around the pipe sections of the drill string by means of a latching or retaining mechanism. It is customary to employ a separate tool or tensioning device to contract the jaws of the pipe protector device about a drill pipe. After the jaws have been properly contracted, a pin, key or other latching device, may be placed in assembly with the jaws to retain the jaws closed and thereby retain the pipe protector device in immovable, but releasable assembly with the section of drill pipe.

In view of the facts that latch devices may become separated from a wear preventer mechanism during operation of the well drilling mechanism and can cause expensive repair or fishing operations to retrieve the latch devices from the well, it is desirable that such latch devices be provided with a positive locking device that prevents inadvertent separation of the latch devices during use.

In view of the fact that most drill pipe is rather accurately dimensioned, it is generally necessary that the drill pipe protectors be also accurately dimensioned to allow the drill pipe protectors to be placed in proper frictional assembly with the drill pipe. The band-like pipe encircling structural element and the molded elastomeric rubber-lil e body of yieldable material must also be quite precisely dimensioned to enable optimum frictional engagement to exist when the pipe protectors are applied to the drill pipe. Precision manufacture of drill pipe protectors in this manner obviously increases the cost of production of the drill pipe sections and thereby decreases the commercial feasibility thereof. It is desirable that drill pipe protectors be capable of production by utilization of low cost production methods and yet be capable of proper assembly with sections of drill pipe to establish the desired degree of frictional engagement.

It is therefore a primary object of the present invention to provide a novel drill pipe protector structure that may be manufactured simply and efficiently to wide manufacturing tolerance levels and yet be capable of optimum assembly to drill pipe sections.

It is another object of the present invention to provide a novel drill pipe protector structure incorporating molded elastomeric material that is capable of cold flowing to an optimum degree upon assembly of the pipe protector to a section of drill pipe.

It is an even further object of the present invention to provide a novel drill pipe protector incorporating a latching mechanism to maintain the pipe protector in assembly with a section of drill pipe, which latch assembly may be adjusted as desired to control the degree of compression of elastomeric material in contact with the outer periphery of the drill pipe.

It is also an object of the prevent invention to provide a locking means for positively retaining the latch assembly in the latched position thereof.

Among the several objects of the present invention is noted the contemplation of a novel drill pipe protector structure incorporating a latch mechanism including an interrelated cam system enabling the drill pipe protector to be secured to the drill pipe in a manner compensating for difference in size of the drill protector structure or the drill pipe caused by rather wide manufacturing tolerances allowed during manufacture of the pipe protector and drill pipe.

It is an even further object of the present invention to provide a novel drill pipe protector structure incorporating a hinged structural band or structural element for easy application of the pipe protector in encircling position about a section of drill pipe and further incorporating a latch mechanism enabling the sections of the structural element to be drawn together as tightly as necessary to accomplish optimum frictional engagement between the pipe protector and the drill pipe about which the pipe protector is assembled.

Another object of the present invention contemplates the provision of a novel pipe protector structure that is of simple nature, is reliable in use and is low in cost.

Other and further objects, advantages and features of the present invention will become obvious upon an understanding of the illustrative embodiment about to be described and various advantages, not referred to herein, will occur to one skilled in the art upon employment of the invention in practice.

SUMMARY OF THE INVENTION The present invention concerns a pipe protector structure comprising a pipe encircling relatively rigid structural element comprising two generally semicylindrical sections that are hinged together along one side, thereby allowing the sections to open in jaw-like manner, to allow the pipe protector to be applied in encircling manner to a drill pipe. Elastomeric material, such as rubber or any one ofa number of commercially available synthetic rubber-like materials, is molded or otherwise formed in encapsulating relation about the sections of the structuralelement and defines a resilient, generally cylindrical internal portion disposed for engagement with the outer periphery of a section of drill pipe. The body of elastomeric material may define a plurality of longitudinally disposed ribs equally spaced about the body structure which ribs extend beyond the pipe structure sufficiently to prevent contact between any part of the drill pipe structure and the internal wall defined by a well casing or well bore within which the drill pipe may be rotated.

A connector or latch device is employed to maintain the jaws of the pipe protector in closed condition when the pipe protector is in assembly with a section of drill pipe. The latch structure may include a pair of tapered flanges, formed integrally with the structural element, which flanges are reverse bent from the structural element to define generally hook-like tab structures and to define diverging tapered cam surfaces. A tapered latch element having an elongated body portion and a pair of integral elongated hook-like cam engaging tab portions, disposed in diverging relation, may be received by the opposed tabs of the structural element for the purpose of locking the tabs as near together as is appropriate to establish an optimum frictional engaging relation between the pipe protector and the drill pipe. The hook-like tab portions of the latch element may define cam engaging surface means that are disposed in diverging relation, corresponding to the diverging relation of the tapered cam surfaces. The cam engaging surfaces allow the latch element to be positioned in various latching positions relative to the tabs of the structural element thereby allowing the tabs to be slightly spaced or to be tightly drawn together as is necessary to establish proper frictional engagement between the pipe protector and the drill pipe.

The latch element may be moved relative to the opposed tabs of the structural sections of the structural element thereby causing the interrelated cam surfaces and the cam engaging surfaces to cause movement of the extremities of the structural element either toward one another or away from one another as is appropriate to adjust the degree of frictional engagement between the yieldable material of the pipe protector structure and the drill pipe.

The opposed tabs may be provided with transverse locking depressions that receive a locking projection on the latch device to positively lock the latch device in the latched position thereof and to prevent the latch device from becoming separated from the pipe protector during use.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the manner in which the above recited advantages and objects of the invention are attained, as well as others, which will become apparent, can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to a specific embodiment thereof which is illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted however that the appended drawings illustrate only a typical embodiment of the invention and therefore are not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

In the drawings:

FIG. 1 is an isometric view of a drill pipe protector constructed in accordance with the present invention and illustrating in broken line the relationship of the drill pipe protector and a drill pipe about which the protector may be disposed in encircling relation.

FIG. 2 is a sectional view in full line taken along line 22 in FIG. 1 and showing, in broken line, the open position of the drill pipe protector for assembly to or removal from a section of drill pipe.

FIG. 3 is an elevational view illustrating the opposed tapered tabs of the structural element in full line with the tab latch element removed and illustrating the tab latch element in broken line.

FIG. 4 is an enlarged fragmentary sectional view of the latching mechanism of FIG. 2 and illustrating the latching mechanism as being drawn into tight assembly by the latch element.

FIG. 5 is an-enlarged section view of the latching mechanism of FIGS. 2 and 3, illustrating the latching mechanism as being adjusted to allow the extremities of the structural element to be spaced as necessary to compensate for manufacturing tolerances and allow proper frictional assembly of the drill pipe protector to a section of drill pipe.

FIG. 6 is a perspective view of the latch device showing the tapered cam engaging tab portions that define internal cam engaging surfaces.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and first to FIGS. 1 and 2, there is shown a drill pipe protector, generally at 10, constructed in accordance with the present invention and shown to be secured in place about a portion of a drill pipe 12 shown in broken line. The drill pipe protector may include a relatively rigid structural core or band for the purpose of adding rigidity to the drill pipe protector structure and to provide sufficient tensile strength to prevent unnecessary yielding of the protector structure while the drill pipe is being rotated in a heavy and corrosive liquid medium, such as drilling mud. The structural core of the drill pipe protector may conveniently take the form illustrated particularly in FIG. 2, where a pair of generally semi-cylindrical

structural sections

14 and 16 are shown to be connected at one side thereof by means of a hinge 18 defined by interrelated hinge elements formed on each structural section. A hinge pin 20 may secure the hinged relationship between the

structural sections

14 and 16 of the structural element.

It is desirable that the pipe protector structure be provided with a body of yieldable material defining the internal periphery thereof for establishing frictional wear resistant engagement with the outer periphery of drill pipe about which the protector may be disposed in encircling relation. It is also desirable that the drill pipe protector provide external surface structure that is capable of engaging the wall structure of the well casing or well bore within which the drill pipe may be rotating to prevent the wall structure of the well bore from eroding the drill pipe. It is even further desirable that the drill pipe protector present an external configuration that allows channeling of drilling fluid past the drill pipe protector to prevent the drill pipe protector from interfering with the flow of the circulating drilling fluid as the well is being drilled. To accomplish these features, the pipe protector structure may be provided with

bodies

22 and 24 of elastomeric material such as rubber or any one of a number of commercially available suitable rubber-like synthetic materials that are yieldable and have abrasion resistant qualities. The

bodies

22 and 24 of elastomeric material may be molded about the

structural sections

14 and 16, respectively, to achieve a permanently fixed or bonded encapsulating relation between the bodies of resilient material and the structural element. If desired, the structural sections may be perforated or otherwise distorted to insure the maintenance of a permanently bonded relation between the elastomeric material and the structural sections.

The elastomeric material may be molded or otherwise applied to the structural sections in such manner that inner portions of the material shown at 26 and 28, respectively, defines opposed generally

cylindrical surfaces

30 and 32 disposed for engagement with opposed cylindrical surfaces of the drill pipe 12. It is desirable that the drill pipe protector be installed in assembly with the drill pipe 12 in such manner that the inner bands or areas of

material

26 and 28 will yield or coldflow slightly and will, conform to the configuration of the drill pipe and establish an optimum frictional engagement with the drill pipe to prevent the drill pipe protector from slipping as the drill pipe is rotated.

For the purpose of providing external structural elements for contact with the wall of a well casing or the wall defined by a well bore and to allow for optimum circulation of drilling fluid past the drill pipe protector. the

bodies

22 and 24 of the elastomeric material may be provided with a plurality of axially disposed ribs such as shown at 34 and 36. The ribs may define contact surfaces such as shown at'38 that extend radially beyond the couplings of the drill pipe. The contact surfaces 38 will ordinarily be disposed in spaced relation with the internal wall of the well casing or well bore while the drill string is rotated during drilling operations. If the drill string should whip as it is rotated, the contact surfaces 38 of the

ribs

34 and 36 will engage the wall structure of the well casing or well bore and will thereby prevent the drill pipe from coming into abrasive contact with the well casing or well bore. Any wear. therefore, that is allowed to occur, will be limited solely to the wear

resistant ribs

34 and 36 of the

elastomeric bodies

22 and 24. If the elastomeric bodies should become worn to the point that abrasive contact between the drill pipe and the wall surfaces of the well casing or well bore may occur it will simply be necessary to replace the wear preventor device at the time the drill string is removed from the well for repair or replacement of the drill bit or for any other reason. Ordinarily it is not expected that replacement of the wear preventors will be necessary during drilling of a single well.

Thespaced ribs

34 and 36 of the yieldable bodies of elastomeric material effectively define a plurality of spaced longitudinal vertically oriented slots or channels 37 through which the drilling fluid may flow during the drilling operation. Moreover, the spaced ribs defined by the slots or channels formed in the elastomeric bodies, effectively create agitation of the drilling fluid as it is circulated past each of the wear preventors, thereby enhancing the ability of the drilling fluid to entrain the drilling cuttings that are created by the bit as the well is being drilled.

When it is desired to place pipe protectors in assembly with the various pipe sections of a drill string, it is desirable that the pipe protectors be longitudinally split to allow the same to be fitted circumferentially about a pipe section intermediate the couplings thereof and it is also desirable that the pipe protectors be provided with a suitable latch mechanism for securing the longitudinally split portion to prevent inadvertent opening thereof during drilling operations. One suitable latch mechanism may conveniently take the form illustrated particularly in FIGS. 3 and 4, where the extremities of each of the

structural sections

14 and 16 of the structural element are shown to include portions bent back upon themselves to define a pair of hook-

like tabs

44 and 46. As illustrated in FIG. 3, the hook-

like tabs

44 and 46 are tapered from a small dimension at the upper extremity thereof to a large dimension at their lower.

extremities and define a pair of diverging cam surfaces 48 and 51. Each of the cam surfaces 48 and 51 maybe,

without departing from the spirit and scope of the pres ent invention.

As indicated above, it is one of the primary objects of the present invention to provide a latching 'mechae nism for drill pipe protectors having a facilityfor adjustably latching the wear preventor to the drillstem in such manner that a particular'degree of compression of the

internal portions

26 and 28; of the

elastomericbodies

22 and 24 may occur to establish an optimum degree of frictional engagement with the drillpipe. It is desirable, therefore,-that the latching mechanism be capableof moving the

opposed extremities

40 and 42 of the structural sections '14 and 16 into, abutment as shown.iri,FlG,.4, if desired, for maximum compression of the.

internal portions

26 and 28 of the elastomeric bQdlfiSrIIqlS alsodesirable that the

extremities

40 and 42 be capable of being secured or firmly latched with the extremities spaced, as shown in FIG. 5, to the degree necessary to obtain proper compression of the

internal portions

26 and 28 of the elastomeric bodies and thereby achieve. optimum frictional engagement between the wear preventor and the outer peripheryof the drill pipe. The latching mechanism therefore is capable of compensating for dimensional differences in the periphery of the drill pipe and dimensional differences of the

inner periphery portions

26 and 28 of the

elastomeric bodies

22 and 24, such as might be caused by manufacturing tolerances.

For the purpose of positively latching the drill pipe protector in assembly with the drill pipe and for controllably compressing the internal portions 26 and of the elastomeric bodies, atapered latch element is illustrated generally at 50 in FIG. 6. The latch element 50 may be providedwith an elongated body portion 52 having a lifting eye 54 defined at the upper portion thereof. Portions of the latch element 50 may be bent back upon themselves to define opposed elongated camingtabs 56. and 58 that are shown to be of tapered configuration, tapering from a small dimension at the upper extremities thereof to a large dimension at their lower extremities. The

camming tabs

56 and 58 may define internal camming surfaces 6.0 and 62, respectively, that. are disposed for cammingengagement with the cam surfaces 48 and 5l defined on the tabs 44.and 46 of the

structural sections

14 and 16.

It should be noted that the

camming tabs

56 and 58 of the latch element include free extremities'that'are spaced to define an elongated slot 64. The. latch element 50 is placed in assembly with the

tabs

44 and 46 of the

structural sections

14 and 16 by lowering the latch element 50 downwardly over the opposed diverging

tabs

44 and 46 causing the inner portions of the tabs to be received through the elongated slot 64.

It will typically be necessary to .utilize a tensioning device or clamp that is applied to contract the drill pipe through appropriate openings formed in the

elastomeric bodies

22 and 24. The tensioning device may typically be a pair of tongs that are received in the indentationsand are manipulated manually to place the drill {pipe protector intension aroundf a section of drill pipe When the pipe protector is forcibly applied in encircling relation about the drill pipe bythe tensioning device, the elastomeric material defining the

internal portions

26 and 28 of'the pipe'protectorwill be deformed and frictional contact between the elastomeric body" and the drill pi e will he developed. Simultaneously, the tongs will bring the extremities mend 42 of the

structural sections

14 and 16 int'ojuxtaposition. The opposed diverging tabs '44 and .46.-will either be slightly spaced, as shown in FIGS, or closely abutted, as shown in FIG.. 4, depending upon the degree of deformation that mustoccur inthe inner portions 2 6" and 2 8 of the elastomeric bodies, to compensate for differences in size due to manufacturing tolerances and to achievethe degree of frictional engagement necessary for proper assembly of the drill pipe protector to the drill pipe. After the tabs 44 and46 have been properly positioned, the latch element 50 may be lowered into proper position, thereby bringing the camming tabs 56 and 58'into engagement with

tabs

44 and 46, and causing the internal camming surfaces 60 and 62' of the latchelernent to engage cam surfaces '48 and 51 of the

tabs

44 and 46. The tensioning device then may be removed frorn the

indentations

66 and 68 and the natural spring-like tendency or memory of the' elastomeric material to returnto its original undeformed state, will develop radial forces tending to separate the extremities 40 and '42 of

structural sections

14 and 16. These'radial forces will p'lacethe latch in tension and cause the latch element 50 to maintain its latched engagement with the opposed diverging

tabs

44 and 46. v 5

After assembly of thelatch element 50 in its latched relationship with the opposed diverging

tabs

44 and 46, if it is determined that additional compression of the

inner portions

26 and 28 of the elastomeric bodies is desirable, a bar or other suitable 'device may be inserted into the lifting eye 54 of the latch element and the bar may be struck with a hammer or other suitable instrument, thereby driving the latch element downwardly relative to the

tabs

44 and 46. When'this occurs the cam surfaces 60 and 62 of the latche'lement, interacting with cam surfaces 60 and 62--of the latch eler nent, interacting with cam surfaces 48 and'51 of the opposed tabs, will cause the' tabs to be moved toward one another Wheri this occurs, the

structural sections

14 and 16 of the structural element will be placed in further tension thereby further deforming the elastomeric material from which theinner'portions 2 6 and 28 are composed and further increasing frictional engageprotector body about a section of drill pipe and bring the extremitiesof the structural element into juxaposition in order that the latching mechanism may be se cured. As illustrated in FIGS. 1 and 2, the

structural sections

14 and 16 ofthe structural element of the pipe protector may include a pair of

indentations

66 and 68 that may be engaged by a tensioning device, received ment between the'elastomeric material and the outer periphery of the clrill pipe. Likewise, controlled reduction the degree frictionalengagernent.between the elastomeric bodies and the drill pipem'ay be caused by slight controlled upward movement of the latch ele- 'ment relative to the tabs'44 and '46. A .bar may be ihserted through theliftin'g eye 54' and the bar may be struck from the unde'r side, thereby moving the latch element 50 upwardly relative to' the

tabs

44 and 46.

-When this occurs, the cam surfaces 6 0 a nd 62 'will' allow

tabs

44 and 46 to move further apart thereby de- 2 creasing tensioning of the

structural sections

14 and 16 andhsimultaneously decreasing the degree of compression of the

inner portion

26 and 28 of the elastomeric bodies against the peripheral surface of the drill pipe.

The

opposed tabs

44 and 46 will be disposed in the fully closed position thereof, bringing the

extremities

40 and 42 of

structural sections

14 and 16 into abutment, when the latch element is positioned with the

camming tabs

56 and 58 fully engaged with

tabs

44 and 46. It will not be possible for the latch element 50 to move downwardly to a sufficient degree that it will fall loose from the

opposed tabs

46 and 48. The latch element, therefore, may be disassembled from the opposed tabs only by upward movement of the latch element sufficiently to cause the cam surfaces 60 and 62 to move clear of the opposed tabs.

It is desirable that the latch element be positively se cured or locked in the operative position to prevent it from jarring loose during drilling operations and falling loose in the drill bore. Obviously, a loose latch device can interfere with normal drilling operations and can damage the drilling equipment. Moreover, removal of loose metal objects, such as latches for wear preventers can be extremely time consuming and expensive.

To prevent the latch 50 from separating from the wear preventer structure, the

opposed tabs

44 and 46 may be provided with opposed slots or recesses 47 and 49, respectively, that may receive one or more internal locking projections 65 that positively lock the latch mechanism relative to the opposed tabs. The latch 50 may be urged or driven downwardly until the transverse locking projection 65 is received within the recesses. If further tightening of the wear preventer is desired, the latch may be driven further downwardly and the interengaging cam surfaces of the latch and the tabs will cause the tabs to be drawn toward one another, thus achieving further compression of the elastomeric body against the drill pipe.

It is also appropriate that the

opposed tabs

44 and 46 be properly disposed in vertical alignment before the latch element 50 is inserted into engaging relation with the opposed tabs. To accomplish this feature, the extremity 40 of the structural element 14 is provided with upper and

lower alignment tabs

70 and 72 that may be received within

alignment indentations

74 and 76 defined by the opposite extremity 42 of the structural element 16. As shown in FIG. 3, the

guide tabs

70 and 72 each include one

side

78 and 80 which are formed at an acute angle with respect to the longitudinal axes of the drill pipe protector body. The side with the acute angle is received in a corresponding and parallel side defined by

indentations

74 and 76 by which the two sides of the latch mechanism are brought into longitudinal alignment.

The guide tabs illustrated in FIG. 3 are shown to be formed on the same side of the latching mechanism, but it will be understood that one guide tab may be formed on one side and the opposite guide tab may be formed on the other side in alternative embodiments of the present invention without departing from the spirit or scope thereof. The guide tabs may take various shapes and forms depending upon the particular application thereof.

In view of the foregoing, it is readily apparent that I have provided a novel drill pipe protector device that incorporates a flange-key connection structure that readily compensates for variations in size of drill pipe or variations in the size of the pipe protector itself, which variations may be caused by differences in size due to manufacturing tolerances. The pipe protector device of my invention provides a flange-key connection structure that may be easily assembled in tightly locked assembly even though tolerance variations of the drill pipe or pipe protector device may exist.

A tapered latch is employed having opposed tapered cam surfaces defined by opposed tapered tabs that cooperate with correspondingly tapered tabs formed on the structural element of the drill pipe protector device and effectively allows controlled variations in tensioning of the structural element and deformation of the elastomeric bodies of the pipe protector through employment of suitable cam surfaces that may be adjusted in simple and efficient manner through the use of simple implements such as hammers and bars. My invention also incorporates a structure that may be easily positioned about a section of drill pipe because of the jawlike configuration thereof that is made possible through the use of a hinge disposed intermediate the extremities of the structural element. The unique drill pipe protector of my invention may be placed into tensioned assembly with the structure of a drill pipe section through the use of any simple commercially available tensioning device, including tongs for urging the free extremities of the pipe protector device into juxtaposition. The latching element may be inserted into proper assembly with the opposed tapered tabs of the structural element after the tensioning device has been utilized to place the extremities of the structural element in the desired assembled position thereof. The cooperating configuration of the locking projections in the latch element and the locking recesses in the tapered opposed diverging tabs of the structural sections effectively secures the latching element into immovable assembly with the tabs and prevents the latching element from vibrating free of the pipe protector device during drilling operations.

It is, therefore, seen that my invention is one well adapted to attain all of the objects and advantages hereinabove set forth, together with other advantages, which will become obvious and inherent from a description of the apparatus itself. It will be understood that certain combinations and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the present invention.

As many possible embodiments may be made of this invention without departing from the spirit or scope thereof, it is to be understood that all matters hereinabove set forth or shown in the accompanying drawings are to be interpreted as illustrative and not in any limiting sense.

What is claimed is:

1. A device for preventing external wear on drill pipe caused by erosive rubbing contact between rotating drill pipe and wall structure defining within which the drill pipe is rotated, said device comprising:

a structural element adapted to be received in encircling relation about the drill pipe, said structural element being defined by opposed generally semicylindrical elements;

hinge means connecting said semicylindrical elements on one side thereof;

the opposite sides of each of said semicylindrical elements being reverse bent and defining opposed tabs, said tabs diverging downwardly and outwardly and defining angularly disposed cam surfaces;

at least one body of yieldable material carried by each of said semicylindrical elements and presenting external surface means extending beyond the outer peripheral surfaces of the drill pipe to prevent contact between said drill pipe and the wall structure defining said bore;

removable latch means engaging said opposed tabs and cooperating with said opposed tabs to lock said device in encircling assembly with said drill pipe with said opposed tabs properly spaced to establish proper frictional engagement between said device and said drill pipe, said latch means comprising an elongated tapered body portion having opposed camming tabs defined thereon, said camming tabs being disposed in angularly oriented spaced relation and engaging said opposed tabs to retain said device in encircling relation with said drill pipe; and

locking means comprising locking recess means and locking projection means, said locking means interengaging to positively lock said latch means relative to said opposed tabs.

2. A device for preventing external wear on drill pipe as recited in claim 1:

the inner portion of said body of yieldable material being deformed upon assembly of said device in encircling relation about said drill pipe; and

said camming tabs being capable of various locked positions relative to the opposed tabs to achieve controlled spacing of the tabs and thereby achieve controlled deformation of the body of yieldable material by the drill pipe.

3. A device for preventing external wear on drill pipe caused by erosive rubbing contact between rotating drill pipe and wall structure defining a bore within which the drill pipe is rotated, said device comprising:

hinge means connecting said semicylindrical elements on one side thereof;

the opposite sides of each of said semicylindrical elements being reverse bent and defining opposed tabs, said tabs diverging downwardly and outwardly and defining angularly disposed cam sur faces;

removable latch means engaging said opposed tabs and cooperating with said opposed tabs to lock said device in encircling assembly with said drill pipe with said opposed tabs properly spaced to establish proper frictional engagement between said device and said drill pipe, said latch means comprising an elongated tapered body portion having opposed camming tabs defined thereon, said camming tabs being disposed in angularly oriented spaced relation and engaging said opposed tabs to retain said device in encircling relation with said drill pipe;

locking recess means being defined in said opposed tabs; and locking projection means being formed on said latch means and being received within said locking recess means to positively lock said latch means relative to said opposed tabs.

4. A device for preventing external wear on drill pipe as recited in claim 3, wherein:

said locking projection means comprises a plurality of locking projections, each being selectively received within said locking recess means depending upon the adjustment position of said latch means relative to said opposed tabs.

5. A device for preventing external wear on drill pipe caused by abrasive contact between rotating drill pipe and structure defining a bore within which the drill pipe is rotated, said device comprising:

an annular structural element adapted to be received in encircling relation about the drill pipe, said structural element being defined by two generally semicylindrical structural sections;

hinge means hingedly connecting said structural sections;

a pair of yieldable bodies of wear resistant material being carried one by each of said structural sections and cooperating to define an internal generally cylindrical portion for frictional engagement with said drill pipe and an external portion for rubbing engagement with the wall structure defining the bore;

each of said structural sections being reverse bent to define hook-like opposed tabs each having cam surfaces disposed in downwardly and outwardly diverging relation;

latch means comprising an elongated tapered body portion having opposed camming tabs formed thereon, said camming tabs being disposed in angularly oriented spaced relation and having cam engaging surface means defined thereon engaging said opposed tabs to lock said device to said drill pipe and causing said cam engaging surface means to engage said cam surfaces and maintain said opposed tabs in controlled spaced relation and to maintain the internal portion of said bodies in controlled deformed engagement with said drill pipe; and

6. A device for preventing external wear on drill pipe as recited in claim 5:

said opposed tabs being tapered and defining diverging cam surfaces;

said elongated camming tabs being downwardly and outwardly tapered and defining opposed tapered cam engaging surfaces corresponding to the angular relation of said cam surfaces; and

said cam engaging surfaces of said camming tabs being capable of establishing various locked position relationships with said diverging cam surfaces upon assembly of said latch means to said structural element to achieve various locked relative positioning of said opposed tabs and thereby achieve controlled compression of said yieldable material against said drill pipe.

7. A device for preventing external wear on drill pipe caused by abrasive contact between rotating drill pipe and structure defining a bore within which the drill pipe is rotated, said device comprising:

hinge means hingedly connecting said structural sections;

each of said structural sections being reverse bent to define opposed tab means each being tapered and defining diverging cam surface means;

latch means comprising an elongated tapered body portion having opposed camming tabs formed thereon, said camming tabs being disposed in angularly oriented spaced relation and having cam engaging surface means defined thereon engaging said opposed tab means to lock said device to said drill pipe and causing said cam engaging surface means to engage said cam surface means and maintain said tab means in controlled spaced relation and to maintain the internal portion of said bodies in controlled deformed engagement with said drill pipe;

locking recess means being formed in said opposed tab means; and

locking projection means being formed on said latch means and interengaging with said locking recess means to establish locking relation therebetween.

8. A device for preventing external wear on drill pipe as recited in claim 7, wherein said locking projection means comprises:

a plurality of projections being defined on said latch means and being selectively engageable within said locking recess means depending upon the relative position of said latch means relative to said opposed tab means 9. A device for preventing external wear on drill pipe as recited in claim 7, wherein said locking recess means comprises:

a pluralityof spaced recesses being defined in each of said opposed tab means and being selectively engageable with said locking projections to establish locking engagement therebetween.

UNITED STATES PATENT OFFICE CERTIFICATE OF' CORRECTION PATENT NO. 3 4 7 DATED July 15, 1975 INVENTOR(S) Dallas N. Broussard it is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8,

Lines

47 and 48, delete the following words: "60 and 62 of the latch element, interacting with cam surfaces" Column 10, line 57, after the word "defining" add a bore before the word "within".

Signed and Scalcd this Arrest:

RUTH C. MASON Arresting Officer C. IARSIIALI. DANN ('mnmissirmtr ufl'arems and Tmdenurks

Claims

1. A device for preventing external wear on drill pipe caused by erosive rubbing contact between rotating drill Pipe and wall structure defining within which the drill pipe is rotated, said device comprising: a structural element adapted to be received in encircling relation about the drill pipe, said structural element being defined by opposed generally semicylindrical elements; hinge means connecting said semicylindrical elements on one side thereof; the opposite sides of each of said semicylindrical elements being reverse bent and defining opposed tabs, said tabs diverging downwardly and outwardly and defining angularly disposed cam surfaces; at least one body of yieldable material carried by each of said semicylindrical elements and presenting external surface means extending beyond the outer peripheral surfaces of the drill pipe to prevent contact between said drill pipe and the wall structure defining said bore; removable latch means engaging said opposed tabs and cooperating with said opposed tabs to lock said device in encircling assembly with said drill pipe with said opposed tabs properly spaced to establish proper frictional engagement between said device and said drill pipe, said latch means comprising an elongated tapered body portion having opposed camming tabs defined thereon, said camming tabs being disposed in angularly oriented spaced relation and engaging said opposed tabs to retain said device in encircling relation with said drill pipe; and locking means comprising locking recess means and locking projection means, said locking means interengaging to positively lock said latch means relative to said opposed tabs.

2. A device for preventing external wear on drill pipe as recited in claim 1: the inner portion of said body of yieldable material being deformed upon assembly of said device in encircling relation about said drill pipe; and said camming tabs being capable of various locked positions relative to the opposed tabs to achieve controlled spacing of the tabs and thereby achieve controlled deformation of the body of yieldable material by the drill pipe.

3. A device for preventing external wear on drill pipe caused by erosive rubbing contact between rotating drill pipe and wall structure defining a bore within which the drill pipe is rotated, said device comprising: a structural element adapted to be received in encircling relation about the drill pipe, said structural element being defined by opposed generally semicylindrical elements; hinge means connecting said semicylindrical elements on one side thereof; the opposite sides of each of said semicylindrical elements being reverse bent and defining opposed tabs, said tabs diverging downwardly and outwardly and defining angularly disposed cam surfaces; at least one body of yieldable material carried by each of said semicylindrical elements and presenting external surface means extending beyond the outer peripheral surfaces of the drill pipe to prevent contact between said drill pipe and the wall structure defining said bore; removable latch means engaging said opposed tabs and cooperating with said opposed tabs to lock said device in encircling assembly with said drill pipe with said opposed tabs properly spaced to establish proper frictional engagement between said device and said drill pipe, said latch means comprising an elongated tapered body portion having opposed camming tabs defined thereon, said camming tabs being disposed in angularly oriented spaced relation and engaging said opposed tabs to retain said device in encircling relation with said drill pipe; locking recess means being defined in said opposed tabs; and locking projection means being formed on said latch means and being received within said locking recess means to positively lock said latch means relative to said opposed tabs.

4. A device for preventing external wear on drill pipe as recited in claim 3, wherein: said locking projection means comprises a plurality of locking projections, each being selectively received within said locking recess meAns depending upon the adjustment position of said latch means relative to said opposed tabs.

5. A device for preventing external wear on drill pipe caused by abrasive contact between rotating drill pipe and structure defining a bore within which the drill pipe is rotated, said device comprising: an annular structural element adapted to be received in encircling relation about the drill pipe, said structural element being defined by two generally semicylindrical structural sections; hinge means hingedly connecting said structural sections; a pair of yieldable bodies of wear resistant material being carried one by each of said structural sections and cooperating to define an internal generally cylindrical portion for frictional engagement with said drill pipe and an external portion for rubbing engagement with the wall structure defining the bore; each of said structural sections being reverse bent to define hook-like opposed tabs each having cam surfaces disposed in downwardly and outwardly diverging relation; latch means comprising an elongated tapered body portion having opposed camming tabs formed thereon, said camming tabs being disposed in angularly oriented spaced relation and having cam engaging surface means defined thereon engaging said opposed tabs to lock said device to said drill pipe and causing said cam engaging surface means to engage said cam surfaces and maintain said opposed tabs in controlled spaced relation and to maintain the internal portion of said bodies in controlled deformed engagement with said drill pipe; and locking means comprising locking recess means and locking projection means, said locking means interengaging to positively lock said latch means relative to said opposed tabs.

6. A device for preventing external wear on drill pipe as recited in claim 5: said opposed tabs being tapered and defining diverging cam surfaces; said elongated camming tabs being downwardly and outwardly tapered and defining opposed tapered cam engaging surfaces corresponding to the angular relation of said cam surfaces; and said cam engaging surfaces of said camming tabs being capable of establishing various locked position relationships with said diverging cam surfaces upon assembly of said latch means to said structural element to achieve various locked relative positioning of said opposed tabs and thereby achieve controlled compression of said yieldable material against said drill pipe.

7. A device for preventing external wear on drill pipe caused by abrasive contact between rotating drill pipe and structure defining a bore within which the drill pipe is rotated, said device comprising: an annular structural element adapted to be received in encircling relation about the drill pipe, said structural element being defined by two generally semicylindrical structural sections; hinge means hingedly connecting said structural sections; a pair of yieldable bodies of wear resistant material being carried one by each of said structural sections and cooperating to define an internal generally cylindrical portion for frictional engagement with said drill pipe and an external portion for rubbing engagement with the wall structure defining the bore; each of said structural sections being reverse bent to define opposed tab means each being tapered and defining diverging cam surface means; latch means comprising an elongated tapered body portion having opposed camming tabs formed thereon, said camming tabs being disposed in angularly oriented spaced relation and having cam engaging surface means defined thereon engaging said opposed tab means to lock said device to said drill pipe and causing said cam engaging surface means to engage said cam surface means and maintain said tab means in controlled spaced relation and to maintain the internal portion of said bodies in controlled deformed engagement with said drill pipe; locking recess means being formed in said opposed tab means; and lOcking projection means being formed on said latch means and interengaging with said locking recess means to establish locking relation therebetween.

8. A device for preventing external wear on drill pipe as recited in claim 7, wherein said locking projection means comprises: a plurality of projections being defined on said latch means and being selectively engageable within said locking recess means depending upon the relative position of said latch means relative to said opposed tab means.

9. A device for preventing external wear on drill pipe as recited in claim 7, wherein said locking recess means comprises: a plurality of spaced recesses being defined in each of said opposed tab means and being selectively engageable with said locking projections to establish locking engagement therebetween.