US2789870A - Drill pipe protector - Google Patents

Description

April 3, 1957 J. w. E. HANES 2,789,870

DRILL PIPE PROTECTOR Filed Feb. 5, 1.954 2 Sheets-Sheet 1 r o I,

'W A T INVENTOR.

- 1M5 E H B 2 J7 4 wave April 23, 1957 J. w. E. HANES I 2,789,870

DRILL PIPE PROTECTOR" Filed Feb. 5. 1954 2 She'ets-Sheet 2 uvwszvrm ANES,

r v DRILL PIPE PROTECTOR James W. E. Hanes, Ventura, 'Calif., assignor, by mesne 1 assignments, to Borg-Warner Corporation, Chicago,

Ill.-, .a corporation of Illinois Application February 5," 1954, Serial No. 408,450

13 Claims. (Cl. 308-4) The present invention relates to drill pipe protectors, and more particularly to protectors composed primarily of rubber, orrubber-like materials, that are capable of being clamped around drill pipe sections.

'An object of the present invention is to provide a drill pipe' protector of the longitudinally split type capable of being placed laterally on and around drill pipe and of being locked in position on the drill pipe, in which the lock parts can be made thinner and more economically, not only eifecting monetary savings, but also presenting a greater thickness of rubber over the region of the lock to provide-greater wear and useful life in the protector.

Another objectof the invention is to provide a drill pipe protector of the longitudinally split type, in which the. lock portion is fabricated from stampings, instead of forgings, riveted, or otherwise secured together, thereby minimizing,'if not eliminating entirely, machine work on the parts.

A further object of the invention is to provide a drill pipe protector of the longitudinally splittype having metallic bands embedded therein for drawing and clamping the protector around the pipe, in which stabilizing bars employed for holding the band in longitudinally spaced relation constitute part of the lock for securing the protector on the pipe, thereby contributingto the provision of a thinner lock with a greater rubber thickness around the region of the lock.

Yet another object of the invention is to provide a drill pipe protector of the longitudinally split type, in which the longitudinal rubber edges of the protector at the split are supported and pressed together while the protector is on the pipe, in order to eliminate the tendency of these edges to be torn while the protector is in service.

Still a further object of the invention is to provide a drill pipe protector of the longitudinally split type having stabilizing bars therein that serve to hold reinforcing and clamping bands in spaced relation, the bars forming part of the lock for securing the protector on the pipe, and

' also serving to support and press together the rubber longitudinal edges of the protector at its split region.

This invention possesses many other advantages and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form'is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not tobe taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a side elevation of a drill pipe protector clamped around a drill pipe section, with parts broken away to disclose the interior construction;

Fig. 2 is a cross-section taken along the line 2-2 on Fig. 1; k p r Fig. 3 is an enlarged side elevation'of a portion of the "ice clamping and lock mechanism, with the encasing rubber sleeve removed;

Fig. 4 is an enlarged cross-section taken along the line 4-4 on Fig. 3;

Fig. 5 is an enlarged cross-section taken along the line 55 on Fig. 3;

Fig. 6 is an elevational view of one of the lock members as seen from the interior of the protector;

Fig. 7 is an isometric projection of a portion of the clamping and lock device.

The protector A is adapted to be placed around and clamped to a drill pipe section B, and is also releasable and removable therefrom. The protector is formed of an annular collar or sleeve 10 made of rubber, or rubberlike material, having an inside diameter corresponding to the external diameter of the drill pipe section B. The rubber collar has tapered end portions 11 to facilitate movement of the drill pipe longitudinally within a well casing (not shown), and to minimize the tendency of the protector to be damaged while in use.

The rubber portion 10 of the protective collar device is preferably made of one piece, being provided with a longitudinal split 12 extending completely through its side wall to provide confronting generallyradial faces 13, 14 at the split that are to be pressed together when the protector is mounted on the drill pipe section. By providing the split 12, the protector A can be opened and closed transversely with respect to the drill pipe section on which it is mounted, to enable the protector to be readily placed upon and removed from the drill pipe section. When the protector is placed around the drill pipe and closed, the opposing faces i3, 14 at the split portion abut one another, and are held firmly in such abutting relation for the purpose of providing a circum- 'ferentially continuous external rubber surface engageable with the inner wall of the well casing (not shown), and also to provide a circumferentially continuous internal rubber surface embracing and clamped upon the drill pipe section. I

To secure the split rubber protective collar 10 in appropriate position around and upon the drill pipe, a plurality of flexible metal bands 15 are embedded in the rubber sleeve or collar. These bands are preferably longitudinally spaced from one another and are also spaced longitudinally inward from the upper and lower ends of the rubber collar 10. Each band is split and has a lock device secured to each of its end portions on opposite sides of the split. These devices may be fabricated from stampings to effect economy in their manufacture. Thus, an inner arcuate lock member 16 is secured to one end of a band, as by means of a plurality of rivets 17. This inner arcuate lock member is adapted to be placed in overlapping relation with an outer arcuate lock member or tongue 18 secured to the other end of the band, as through the use of rivets 19. The outer lock member is receivable within a recess or arcuate slot 20 formed between the inner lock member 16 and an outer lock portion 21 secured to the band 15 and the inner member by the rivets 17. As disclosed, the outer member 21 has an inner step portion 22 clamped between the inner lock member 16 and the band 15 by the rivets, the outer member having an outwardly directed intermediate web 23, forming an end of the arcuate slot 20, which merges into an outer step portion 24 spaced radially outward from the inner arcuate lock member 16 by a'sutficient distance to accommodate the outer tongue 1'8.

Each band 15 and the rubber collar 10 can be contracted and clamped around and to the drill pipe B by a rotatable cam type of lock device. This device includes a member 25 rotatably mounted in the outer tongue 18 and having a cam or eccentric pin 26 received within an opening 27 in the inner arcuate lock member 16. This opening is generally ovate or elliptical in shape, with the greater dimension of the opening extending vertically. The cam lock member 25 has its eccentric pin 26 receivable Within this opening, the locking member itself being rotatable within a circular or cylindrical bore 23 of the outer tongue 18. Endwise movement of the lock member 25 relative to this tongue along the axis of the lock member is prevented by an inner flange 29 on the lock member received Within a counter-bore 3 d in the tongue and engaging an inner shoulder 31 provided by the base of this counterbore. Such engagement of the flange 29 with the shoulder 31 prevents lateral outward movement of the eccentric member 25 with respect to the tongue '18. Inward movement of the eccentric member with respect to the tongue is prevented by an outer retainer ring 32 forced into a circumferential groove 33 in the outer portion-of the eccentric member 25 and engaging the outer surface 34 of the tongue.

The ring 32 is made of a comparatively malleable metal, its inner diameter originally being greater than the outside diameter of the cam member 25, enabling it to be moved over the latter and then pressed into the peripheral groove 33, with its outwardly extending portion slidably engaging the outer surface 34 of the arcuate lock member or tongue 18. In view of the assembly of the retainer ring 32 in the cam member groove 33 and its engagement with the outer surface 34 of the tongue, inward axial movement of the cam member 25 is prevented, whereas the flange 29 engages the shoulder 31 at the inner end of the counterbore 30 to prevent outward, movement of the cam lock member. This locking member 25 is therefore confined for rotary movement only Within the tongue 18.

The rubber collar is provided with opposed recesses 41) on opposite sides of its split portion 12 to provide access to the eccentric or cam locking members 25, and also to enable the split end portions 13, 14 of the collar to be drawn together without interference from the lock members. Similarly, the outer step 24, Which is spaced from the inner arcuate lock member 16, is provided with an arcuate recess 41 adapted to receive a portion of each lock member 25 when the collar has been fully clamped around the drill pipe. The recesses just referred to allow a suitable tool (not shown), such as a wrench, to fit Within a polygonal or non-circular socket 42 formed in each cam locking member 25. When the latter is rotated, through use of the wrench or other tool, to draw the opposed ends of each band and the locking elements 18, 16, 21 toward each other, the cam locking member and its outer retainer ring 32 are received within the arcuate recess or notch 41 provided in the outer step 24, as described above.

The eccentric cam or pin 26 has opposed flat sides 43, 44 which are interconnected by curved convex surfaces 45. Similarly, the sides 46, 47 of the opening 27 in the inner arcuate lock member 16 are also preferably flat and vertical, the bottom 48 of the opening interconnecting these sides preferably being curved in concave fashion, while the upper end of the opening is defined by a curved corner pocket 49 merging into one of the flat sides 46 of the opening, and conforming to the curvature of the pin 26. The other side 47 of the opening merges into an arcuate corner 50 running into the upper straight side 51 of the opening, Which, in turn, runs into the corner 49.

Originally, each band 15 is in open position, with the pins 26 disposed out of their companion openings '27. The protector A is spread apart, as permitted by the fact that it is longitudinally split, and placed laterally around the drill pipe 13, whereupon its opposed faces 13, 14 are moved toward each other and the eccentric pins 26 placed within their companion ovate openings 27. At this time, one side 44 of each eccentric pin will engage one flat side 46 of the opening 27 in the inner arcuate lock member 16. A suitable Wrench (not shown) is then placed in the polygonal socket 42 in the cam member 25 and the latter rotated in a clockwise direction, as seen in 'Figs. 1 and 3, and in a counter-clockwise direction, as seen in Fig. 6, which causes each cam to shift its associated inner arcuate lock member 16 and the outer lock portion 21 secured thereto over the tongue 18, the latter being received within the recess 20 defined between the inner arcuate lock member 16 and the outer step 24. Rotation of the cam can continue until the side 44 of the pin engages the fiat side 47 of the opening 27, with the upper curved end 45 of the pin disposed in the corner pocket 50, as shown most clearly in Fig. 6. When in this position, the center of the pin 26 and axis of the cam 25 lie in the central plane of the band normal to the axis of the collar 10, there being substantially no components of force passing to one side of the axis of the lock member that can inadvertently release it from its locking position.

When the parts are in the locked position, each band 1.5 and the rubber collar 10 have been fully contracted around the drill pipe B, the rubber collar being under compression upon the latter to insure that it is held immovably thereon during operation of the drill pipe in the Well casing and well bore. At this time, the opposed faces 13, 14 of the rubber collar abut one another firmly, the only openings present being the arcuate recesses 40 in the rubber collar provided for the cam locking members 25. The rubber protector material is circumferentially continuous, both externally and internally of the collar. Any tendency for each band 15 and the collar 10 to expand is resisted by each cam device 25, 27, since the latter provides a self-locking arrangement.

As mentioned above, it is desirable to provide a plurality of longitudinally spaced band members and attached locking mechanisms, each combination being a duplicate of the other and being operated in exactly the same manner. Each band 15 may have holes 60 therethrough into which the rubber material can flow during the molding of the device, to securely and firmly anchor the bands to the rubber collar. In addition, the rubber collar 10 may also have circumferentially spaced recesses 61 therein, formed as a result of parts of the mold extending into the mold cavity, for the purpose of holding the bands in appropriate position during the molding operation.

In order to hold the bands 15 in proper longitudinally spaced relation, to reinforce the entire structure, to prevent separation of the opposed faces 13, 14 from each other, and to facilitate the fabrication of the lock portion of the apparatus, a plurality, such as a pair, of longitudinally extending stabilizing bars or straps 52, 53 are provided, there preferably being one bar disposed on each side of the split portion 12 of the rubber collar 10. The bars 52, 53 may be of substantially equal length, extending longitudinally beyond the bands 15, but terminating substantially inward from the upper and lower ends of the rubber collar 10. One of the stabilizer bars 53 is disposed across the outer surfaces of the outer tongues 18, and is secured thereto by the rivets 19 securing each tongue to a band 15. This stabilizing bar 53 is curved to conform to the curvature of the tongues 18 and is pnovided with an inwardly directed longitudinal stiffening flange 54 at its outer end adjacent the radial face 13 of the rubber collar, this inwardly directed stiffening flange being disposed slightly inwardly from this face, in order to be embedded within the rubber material of the collar. T o avoid interference with the rotation of the cam members 25 in the tongues 18, the stabilizing bar 53 is provided with arcuate recesses 55 to receive the outer p'ortions [of the cam members 25 and the retainer ring 32, the curved edges of the recesses 55 being disposed only slightly away from the periphery of the retainer rings 32.

eases Another stabilizing bar 52 is provided on the other side of the split collar 10. This stabilizing bar is also availed of to form a portion of the Keck mechanism. The base 22 of the stabilizing bar is curved to conform to the outer surfaces of the inner arcuate lock members 16, the bar being secured to and between the bands 15 and the inner arcuate lock members 16 by the rivets 17. From the base portion, the stabilizing bar has the outwlardly directed intermediate web 23 which merges into the outer step portion 24 of the bar, which lies substantially on the same circle as the main portion of the other stabilizing bar 53, being spaced from the inner arcuate lock members 16 a suflicient distance to snugly receive the tongues 18 at the regions where the outer step members 24 overlie the inner arcuate lock members 16, in the manner described above. The stabilizing bar also has an inwardly directed stiffening flange 56 embedded in the rubber collar adjacent the radial face 14 of the collar, this stiffening flange being disposed circumferentially away from its companion face 14 about the same distance as the stiffening flange 54 of the other stabilizer bar'53. By Way of example, the stiffening flanges S4, 56 may be disposed about one-quarter of an inch away from the radial faces 13, 14 'of the rubber collar or sleeve 10.

At the regions of the inner arcu'ate lock members 16, the stabilizer bar 52 does not have any stiffening flange portions. Instead, such flange portions, in effect, are extended transversely, being placed in alignment with the outer step 24 itself, in order to form a deeper recess 20 between each outer step and the inner 'arcuate lock members 16. It is this portion which has the arcuate recess 41 for receiving the retainer ring 32 and the rotatable cam member 25 itself, when the latter has been turned to its locked position securely clamping the protector around the drill pipe. I

When the protective device A has been placed about the drill pipe B and locked in position, the stiffening flanges 54, 56 urge the opposed radial faces 13, 14 snugly against each other, which holds them in compression and tends to prevent their outward movement beyond the peripheral confines of the main portion of the rubber material, that might result in their tearing, or other destruction. In addition, the stiffening flanges 54, 56 tend to prevent the radial outward movement of the marginal portions of the rubber protective collar onropposite sides of the rubber collar split 12, insuring that the rubber collar retains, in effect, a circumferentially continuous surface capable of effectively protecting the drill pipe as the latter is rotated in the well bore and surface casing, and also when it is moved longitudinally therein.

As above stated, the stiffening flanges 54, 56 are disposed slightly inwardly from their companion faces 13, 14, which reinfiorces the marginal portions of the rubber protective collar on opposite sides of the split 12. The spacing of each flange 54 or 56 from its companion face 13 or 14 is much less than the radial thickness of the rubber collar 10, as is evident from the drawings, being only about one-seuenth of the radial rubber thickness in the specific example of the invention disclosed. If the ' fianges 54, 56 are to efiectively reinforce the marginal portions of the rubber protective collar on opposite sides of the split 12, the spacing of each flange from its companion fiace 13 or 14 should be no more than the thickness of the rubber radially inwardly or outwardly of the straps 53, 52, which means that the spacing should be no more than about one-half of the radial thickness of the rubber collar 10.

The lock members 16, 18 can be made of stampings, and the stabilizing bars 52, 53 of sheet metal of proper thickness to provide the necessary stiifness, in order to resist deformation under operating conditions encountered in the well bore, and to hold the parts appropriately related to each. other in the manner described above. It is not necessary to utilize forgings or similar relatively complex parts that require subsequent machining in producing the lock mechanism. 'histead, the lock mechanism is formed of stamped and shaped parts which have substanti'al strength, and which are much thinner in radial dimensions than has heretofore been supplied. As a result of this construction, the amount of rubber material disposed over the lock portions of the device is much thicker than could heretofore be provided, which gives the protector a longer eflFective life, inasmuch as a much greater extent of wear of the rubber collar 10 is necessary befiore there would be any tendency for metallic elements to engage the wall of the surface well casing, during operation of the drill pipe therein. Inaddition to these ad vantages, the use of the stabilizer bars 52, 53 as described, and the employment of Ia portion of at least one of the bars 52 as pant ot the lock mechanism itself, reduces the cost 'of the apparatus considerably, since lighter weight material is used and the number of parts is decreased. The radial stiffening flanges 54, 56 of the stabilizer bars not only prevent radial outward movement of the marginal portions of the collar on opposite sides of the split 12, but they also cause the opposed faces 13, 14 of the rubber collar, on opposite sides of the split 12, to be pressed firmly together when the collar is clamped on the drill pipe B, all of which eliminates the tendency of the edges of the protector on opposite sides of the split to be torn.

The inventor claims:

1. Ina drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally at one side thereof; a split, flexible band embedded in said member between its inner and outer walls and extending circumferentially therearound; inner and outer individual lock members separate from each other and overlapping the inner surfiace of and secured to one end of said band on one side of the band split and having portions spaced from each other to form a slot; a tongue overlapping the outer surface of and secured to the other end of said band on the other side of said band split; and coengagin'g means on said tongue and one of said lock members for positioning said tongue in said slot while drawing the ends of said band and collar member circumferentially toward each other to contract said band and collar member and to hold said band and collar member in such contracted relation.

rate from said inner lock member and secured to said end portion and having a first portion extending circumferentiallyof said collar member and a second portion extending circumferentially of said collar member and outwardly oflset from said first portion; said second portion being spaced outwardly from said inner lock member to fiorm a slot therewith; a tongue externally of and secured to the other end portion of said band on the other side of said band split; and coengageable means on said tongue and inner lock member for shifting said tongue in said slot While drawing the ends of said band and collar member circumferentially toward each other to contract said band and collar member and to hold said band and collar member in such contracted relation.

3. In a drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally atone side thereof; a split, flexible bian d embedded in said member between its inner and outer walls and extending circumferentially therearound; an inner lock member within and secured to one end portion of said band at one side of the band split; an outer lock member separate fromsaid inner lock member and secured to said end portion and having a first portion extending circumferentially of said-collar member and a second portion extending circumferentially 'of said collar member'a'nd outwardly offset from said first pontion; said second portion being spaced outwardly from said inner lock member to form a slot therewith; a tongue externally of and secured to the other end portion of said band on the other side of said band split; and cam means rotatably mounted in said tongue and engageable with said inner lock mem her in an opening therein for shifting said tongue in said slot while drawing the ends of said band and collar member circumferentially toward each other to contract said band and collar member and to hold said band and collar member in such contracted relation; said outer lock mem ber having a recess receiving said cam means when said band and collar member are in contracted relation.

4. In a drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally at one side and having opposed faces on opposite sides of the split; a plurality of split, flexible metallic bands extending circurnferentially of and disposed within said collar member and longitudinally spaced from each other, the ends of each band being separated at the split portion of the collar; straps, extending longitudinally of the collar member, connecting the bands in axially spaced relation, said straps having longitudinal flanges closely !adjacent said opposed faces and disposed generally radially of said collar mernher; and a lock member adjustably connected to one end 'of each of the bands and detnchably connected to the other end of the corresponding band in such manner as to tightly clamp the collar member around a drill pipe and to cause said flanges to tightly press said opposed faces against each other; said collar member having an opening at each lock member permitting access to each of said lock members; at least one of said flanges lying in a plane intersecting said opening.

5. in a drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally at one side and having opposed faces 'on opposite sides of the split; a plurality of split, flexible metallic bands extending circumferentially of and disposed within said collar member and longitudinally spaced from each other, the ends of each band being separated at the split portion of the collar; straps, extending longitudinally of the dollar member, connecting the bands in axially spaced relation, said straps having longitudinal flanges closely adjacent said loppose'd faces and disposed generally radially of said collar member; each of said straps being of a material of substantially uniform thickness; an inner locl; member secured to one end portion of each of said bands at one side of the band split; one of said straps being at said one side of the band split and having a portion at each band spaced outwardly from said inner lock member to form a slot therewith; a tongue secured to the other end pontion of each band at the other side of the band split and adapted to fit within an opposed slot; and coengageable means on each tongue and each inner lock member for shifting said tongue in said opposed slot while drawing the ends of each band and opposed faces toward each other to tightly clamp the collar member around a :drill pipe and. to cause said flanges to tightly press said opposed faces against each other.

6. In a drill pipe protector: an annular collar member 01 pliant, elastic material split substantially longitudinally at one side and having opposed faces on opposite sides of the split; a plurality of split, flexible metallic bands extending circumferentially of and disposed Within said collar member and longitudinally spaced from each other, the ends of each band being separated at the split portion of the collar; straps, extending longitudinally of the collar member, connecting the bands in axially spaced relation, said straps having longitudinal flanges disposed generally radially of said collar member and spaced circumferen ltially from said opposed faces a distance that is no more than one-half the radial thickness of said collar member; a lock member secured to one end portion of each of said bands at one side of the band split; tone of said straps being at said one side of the band split and having a pertion at each band spaced generally radially from said lock member to form a slot therewith; a tongue secured to the other end portion of each band at the other side of the bland split and adapted to fit within an opposed slot; and cocngageable means on each tongue and each lock member for shifting s aid tongue in said opposed slot While drawing the ends or" each band and opposed faces toward each other to tightly clamp the collar member around a :drill pipe and to cause said. flanges to tightly press said opposed faces against each other.

'7. In a drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally at one side and having opposed faces on opposite sides of the split; a plurality of split, flexible metallic bands extending circumferentially of and disposed within said collar member and longitudinally spaced from each other, the ends of each band being separated at the split portion of the collar; straps, extending longitudinally of the collar member, connecting the bands in axially spaced relation, said straps having portions secured to said bands and extending generally circumferentially of said collar member and having longitudinal flanges closely adjacent said opposed faces and disposed generally radially inwardly from said circumferential portions of said straps; a lock member secured to one end portion of each of said bands at one side of the band split; one of said straps being at said one side of the band split and having a portion at each band spaced generally radially from said lock memher to form a slot therewith; a tongue secured to the other end portion of each band at the other side of the band split and adapted to fit within an opposed slot; and coengageable means on each tongue and each lock member for shifting said tongue in said opposed slot while drawing the ends of each band and opposed faces toward each other to tightly clamp the collar member around a drill pipe and to cause said flanges to tightly press said opposed faces against each other.

8. In a drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally at one side; a plurality of split, flexible metallic bands extending circumferentially of and disposed within said collar member and longitudinally spaced from each other, the ends of each band being separated at the split portion of the collar; straps, extending longitudinally of the collar member, connecting the bands in axially spaced relation; each of said straps being of a material of uniform thickness; a lock member secured to one end portion of each of said bands at one side of the band split; one of said straps being at said one side of the band split and having a portion at each end spaced radially from said lock member to form a slot therewith; a tongue secured to the other end portion of each band at the other side of the band split and adapted to fit within an opposed slot; and coengageable means on each tongue and each lock member for shifting said tongue in said opposed slot while drawing the ends of each band toward each other to tightly clamp the collar member around a drill pipe.

9. In a drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally at one side thereof; a split, flexible band embedded in said member between its inner and outer walls and extending circumferentially therearound; an inner lock member of substantially uniform thickness within and secured to one end portion of said band at one side of the band split; a separate sheet metal outer lock member secured to said end portion and having a portion spaced outwardly from said inner lock member to form a slot; a tongue of substantially uniform thickness externally of and secured to the other end portion of said band on the other side of said band split; and coengageable means on said tongue and inner lock member for shifting said tongue in said slot while drawing the ends of said band and collar member circumferentially toward each other to contract said band and collar member and to hold said band and collar member in such contracted relation.

10. In a drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally at one side and having opposed faces on opposite sides of the split; a plurality of split, flexible metallic bands extending circumferentially of and disposed within said collar member and longitudinally spaced from each other, the ends of each band being separated at the split portion of the collar; sheet metal straps, extending longitudinally of the collar member, connecting the bands in axially spaced relation, said straps having longitudinal flanges closely adjacent said opposed faces and disposed generally radially of said collar member; each of said straps being of a material of substantially uniform thickness; an inner lock member of substantially uniform thickness secured to one end portion of each of said bands at one side of the band split; one of said straps being at said one side of the band split and having a portion at each band spaced outwardly from said inner lock member to form a slot therewith; a tongue of substantially uniform thickness secured to the other end portion of each band at the other side of the band split and adapted to fit within an opposed slot; and coengageable means on each tongue and each inner lock member for shifting said tongue in said opposed slot while drawing the ends of each band and opposed faces toward each other to tightly clamp the collar member around a drill pipe and to cause said flanges to tightly press said opposed faces against each other.

11. In a drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally at one side and having opposed faces on opposite sides of the split; a plurality of split, flexible metallic bands extending circumferentially of and disposed within said collar member and longitudinally spaced from each other, the ends of each band being separated at the split portion of the collar; sheet metal straps, extending longitudinally of the collar member, connecting the bands in axially spaced relation, said straps having longitudinal flanges disposed generally radially of said collar member and spaced circumferentially from said opposed faces a distance that is no more than one-half the radial thickness of said collar member; a lock member of substantially uniform thickness secured to one end portion of each of said bands at one side of the band split; one of said straps being at said one side of the band split and having a portion at each band spaced generally radially from said lock member to form a slot therewith; a tongue of substantially uniform thickness secured to the other end portion of each band at the other side of the band split and adapted to fit within an opposed slot; and coengageable means on each tongue and each lock member for shifting said tongue in said opposed slot while drawing the ends of each band and opposed faces toward each other to tightly clamp the collar member around a drill pipe and to cause said flanges to tightly press said opposed faces against each other.

12. In a drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally at one side and having opposed faces on opposite sides of the split; a plurality of split, flexible metallic bands extending circumferentially of and disposed within said collar member and longitudinally spaced from each other, the ends of each band being separated at the split portion of the collar; sheet metal straps, extending longitudinally of the collar member, connecting the bands in axially spaced relation, said straps having portions secured to said bands and extending generally circumferentially of said collar member and having longitudinal flanges closely adjacent said opposed faces and disposed generally radially inwardly from said circumferential portions of said straps; a lock member of substantially uniform thickness secured to one end portion of each of said bands at one side of the band split; one of said straps being at said one side of the band split and having a portion at each band spaced generally radially from a lock member to form a slot therewith; a tongue of substantially uniform thickness secured to the other end portion of each band at the other side of the band split and adapted to fit within an opposed slot; and coengageable means on each tongue and each lock member for shifting said tongue in said opposed slot while drawing the ends of each band and opposed faces toward each other to tightly clamp the collar member around a drill pipe and to cause said flanges to tightly press said opposed faces against each other.

13. In a drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally at one side; a plurality of split, flexible metallic bands extending circumferentially of and disposed within said collar member and longitudinally spaced from each other, the ends of each band being separated at the spit portion of the collar; sheet metal straps, extending longitudinally of the collar member, connecting the bands in axially spaced relation; a lock member of substantially uniform thickness secured to one end portion of each of said bands at one side of the band split; said strap at said one side of the band split having a portion at each end spaced radially from said lock member to form a slot therewith; a tongue of substantially uniform thickness secured to the other end portion of each band at the other side of the band split; and coengageable means on each tongue and each lock member for shifting said tongue in said slot while drawing the ends of said band toward each other to tightly clamp the collar member around a drill pipe.

References Cited in the file of this patent UNITED STATES PATENTS 2,033,592 Skeen Mar. 10, 1936 2,251,428 Smith Aug. 5, 1941 2,636,787 Medearis Apr. 28, 1953 2,657,101 Williams et a1. Oct. 27, 1953

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