CA2517773A1 - Pipe alignment apparatus - Google Patents

Abstract

An alignment apparatus for mounting on a drilling rig and having a head with jaw members for movement into a pipe engaging position to thereby contact an upper portion of a pipe on a circumference of the pipe opposite to the head so as to hold the pipe in alignment with the well head. The head includes a V-block for engagement of the pipe for engagement with the circumference of the pipe at the side of the pipe adjacent the head. The head includes a control structure for providing individual settings of the jaw members, each setting being an optimum setting for a particular pipe size over an extended range of pipe sizes. The V-block also has means for setting its position at individual predetermined positions for optimum positioning in relation to each individual optimum setting of the jaw members.

Description

PIPE ALIGNMENT APPARATUS
FIELD OF THE INVENTION
This invention relates to an alignment apparatus for mounting on a well rig for supporting an upper portion of a drill pipe above a well head.
BACKGROUND OF THE INVENTION
In various operations at a well site, it is necessary to support a length of pipe above a well head, such as when adding a section of pipe to a drill string, and in thus supporting the section of pipe it is important to align the section of pipe with the drill string by ensuring the upper portion of the pipe is positioned exactly above the well head.
Numerous types of such pipe alignment devices, which are usually supported by the existing drilling rig, have been developed. An example of the prior art structure is shown in U.S. Patent No. 5,609,457, March 11, 1997, which is owned by the applicant.
Many of the prior art devices do not require proper mechanisms to easily 1 S achieve the setting up of the apparatus to hold the pipe accurately in a completely aligned position. While others include features which achieve good alignment, such devices often are of rather complicated structure making these more costly to produce, and in some cases are more subject to damage and/or are expensive to maintain.
SUMMARY OF THE PRESENT INVENTION
It is an object of the present invention to provide an alignment apparatus which is of relative simply construction and thus less expensive to produce and maintain, while at the same time provide for accurate initial set-up over the well head as well as providing for accurate setting for the optimum selection for each pipe size over a large range of sizes.
According to the present invention the pipe aligning of the present invention includes a pipe engaging head and a support structure for attachment to a structural member of the well rig and supporting the head above the well head. The head includes a framework with connecting means for attaching the head to the supporting structure outward from the structural member of said well rig, and a pair of jaw members having outer ends extending outwardly from the framework and into a pipe contacting area. Pivot pins connect the jaw members to the framework for pivoting about transversely spaced vertical axes, and pipe contact members, one each carried at an outer end of each jaw member, provide engagement points with the outer circumferential surface of the pipe on a side thereof remote from the framework of the head. Motor means pivot the jaw members from an open position to a closed pipe engaging position, and control means are present for individual settings of the pipe engaging position of the jaw members in the closed position, each setting being an optimum setting for a particular pipe size over an extended range of pipe sizes. A
pipe contacting means is included which has a pipe engaging member for engaging the outer circumference of the pipe on a side juxtaposed the head, and includes a carriage mounting the pipe contacting means above the head and being movable longitudinally relative to the head. Adjustment means is included for setting the position of the carriage at individual predetermined positions for optimum position of the pipe contacting members in relation to each individual optimum setting of the jaw members for the extended range of pipe sizes.
In a specific embodiment of the invention, each of the jaw members has a tail portion extending from the pivot pin into the framework of the head, and the motor means includes a double acting, fluid operated, piston and cylinder unit. A
piston rod of the piston in the unit is pivotally connected at an outer free end to the tail portion of one of the jaw members, and the cylinder of the unit is connected at an outer end thereof to the tail portion of the other of the jaw members, so that on expansion of the unit, the pipe contact members of the jaw members are pivoted toward the pipe engaging position.
More specifically a movement co-ordinating link is pivotally connected at one end to one of the jaw members at a point outward of the pivot pin of the one jaw member and is connected at its opposite end to the tail portion of the other of the jaw l0 members at a point on the tail member a distance from the pivot pin of the other jaw member.
The distance between the pivot connection of the link to the jaw members and the pivot pin of the one jaw member and the distance between the pivot connection of the link to the other jaw member and the pivot pin of the other jaw member are preferably equal, whereby the pivot movements of the two jaws toward the pipe engaging position are uniform.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a rear perspective view as seen from above the pipe alignment apparatus when mounted on a cross member of a drilling rig;
Figure 2 is a front perspective view as seen from above the same pipe alignment apparatus but in which the mounting portion of the apparatus is supported in an alternative manner on the cross member;
Figure 3 is an enlarged perspective view of the head of the pipe alignment apparatus of Figure 1 as seen from above at a different angle;
Figure 4 is a simplified side view of the head shown in Fig. 3;
Figure 5 is a cross sectional view through the head as seen from the line 5--5 of Fig. 4;
Figure 6 is a cross sectional view through the head as seen from the line 6--6 of Fig. 4;
Figure 7 is an enlarged top view of one of the jaws of the head;
Figure 8 is an enlarged cross sectional view as viewed from the line 8--8 of Figure 7 for the purpose of illustrating the connector of a pipe engaging riser to the outer end of the jaw;
Figure 9 is a top perspective view of an extendible arm structure as seen from the front with the head removed for sake of simplicity;
Figure 10 is a side view of the arm structure of Fig. 9, illustrating an extension drive system in hidden lines;
Figure 1 I is a top view of the arm structure of Fig. 9, again showing the drive system by hidden lines;
Figures 12a, and 12B illustrate a pair of decals which are attached to the head to illustrate settings of jaw closure;

Figure 13 is an enlarged side view of the V-block member illustrating its mounting in more detail and further showing a decal mounted on it to provide a guide for the setting of the V-block member, and Figure 14 is an enlarged view of a portion of the pipe alignment apparatus and showing in more detail the manner in which it is adjustably mounted on the cross members of the rig.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the Figures of drawings, wherein the reference numbers correspond to those utilized herein, the pipe alignment apparatus 20 is shown in Figure 1 attached to a cross member 21 of an overall drilling rig (not shown) by way of an adjustable clamping means 22. The apparatus 20 provides a pipe clamping head 23 for holding an upper end portion of a drill pipe (not shown) in axial alignment with the well head centre (not shown), the head 23 including a pair of movable jaws 24a and 24b having pipe engaging members 25 and a movable V-block 26 which also has pipe engaging surfaces 27,27. The head 23 is releasably attached to the outer end of an extendible framework 30 attached at an inner end for pivoting in relation to the clamping means 22 by a tilting device 31.
The clamping head 23, which is shown in more detail in Figures 3 to 6, has an outer, main housing or framework 32 having outer side panels 35,35 provided with openings 33 for receiving screw members (not shown) to attach the head 23 between outer ends of parallel arms 34,34 of the extendible framework 30 (Figs. 9 -11). The framework 32 includes top and bottom panels 36,37, between which the jaws 24a and 25b are pivotally mounted on a pair of transversely spaced pins 40, 40 extending between and carried by top and bottom panels 36,37. The outer ends of the jaws 24a, 24b to which pipe engaging members 25,25 are attached extend through an open forward end of the framework 32. As best seen in Figure 5, the two jaws 24,24b have rearwardly extended tail portions 41a, 41b projecting inwardly into the framework 32 behind their pivot pins 40,40. The tail portion 41a terminates in an additional tail extension 42 which will be further described hereinafter. Each of the tail portions 41a,41b have bores therein equally spaced from the axes of the pins 40,40 for receiving connection pins 43,43. The pins are received in a bore in the outer end of the piston rod 44 of an extendible fluid piston and cylinder type motor 46, and the bore at the outer end of the cylinder of the motor 46, respectively. The motor 46 is shown in its most extended condition in Fig. 5 so that the outer ends of the jaws 24a, 24b are pivoted to their most closed position.
Each of jaws 24a, 24b are provided with bores for receiving pins 47,47 which also pass through bores in a movement equalizing cross-link 50. The pin receiving bore in the jaw 24a is located outboard of its pivot pin 40, and the pin receiving pin for jaw 24b is located inboard of its pivot pin 40 in the tail portion 41b.
However, the spacings of the pins 47,47 are equal in distance from the axis of their respective pivot pins 40,40. It may be noted, that the cross-link 50 has a curvature so that its mid-portion does not extend to any extent across the space between the jaws 24a,24b forward of the housing or framework 32 of the head 23.
As will become apparent from the description below, the head 23 has been designed to function with a wide variety of pipe sizes, in the embodiment illustrated, to accommodate at least twelve different pipe sizes, from 2 3/8 to 20 inches.
Accordingly, it is important in the travel of the pipe engaging parts 25,25 of the jaw, the movement of the jaws be completely controlled towards the closed position.
In the embodiment of the closure mechanisms just described, wherein the control of pressurized fluid into the motor for expanding the cylinder may be done by an operator at the rig floor, the movement of the two jaws toward the closed position as the motor expands is completely synchronized by the link connection shown.
As is readily apparent in Figures 3 and S, the control means for the arm movement for a selected size of pipe includes a pattern of circular openings S2 in the rear corner of the framework 32 of the head 23 in the area of the additional tail extension 42 of jaw 24a. The pattern of openings S2 are located in aligned relationship in the top and bottom panels 36 and 37 for receiving therethrough a stop pin S3. The outer edge of the additional tail extension 42 has a plurality of curved recesses S4 for engagement with the pin S3, depending on in which one of a different number of selected openings the pin S3 is inserted. This engagement in turn terminates the pivoting of the jaw 24a towards its closed position. This also terminates the closure of the jaw 24b in its associated closed position through link SO
and together terminate the expansion of the motor 46.
In order to assist the operator in preparing the setting of the jaw closure for a different selected diameter pipe, there is provided on the head 23 a decal of the type shown in Fig. 12A. As illustrated there, each pipe size is given a designated letter A
through K. As an example, the letter J is for a pipe of 16-S/8 inch diameter, and in a depiction of the hole pattern the hole in which the pin is to be inserted, it is identified by the same letter, i.e., in the example just indicated, the hole is denoted J
in the depiction of the hole pattern. Insertion of the pin in that hole will automatically stop the movement of the jaws 24a, 24b in a proper position to algin a pipe of 16-S/8 inch diameter.
As previously indicated, there is provided at outer opposed ends of each of the jaws 24a,24b, pipe engaging members 2S for contacting the pipe as the jaws reach a pipe holding, closed position. As most apparent in Figure 8, the pipe engaging members have an open topped cylindrical channel S4, into which a short length of a cylindrical rod SS (see Fig. 2) may be inserted end-wise. This rod provides a pipe contacting member and provides a narrow line of tangential contact with the outer circumferential surface of the pipe. The cylindrical rod 54 is held against endwise displacement by a pair of set screws 58.
In order to change the angle of approach of the contact member to pipe to compensate for the significant difference in pipe diameter, the pipe engaging members 25 are designed to have added thereto supplementary parts or risers 56.
This riser 56 has an inner end 57 shaped to seat on the outer surface of the pipe engaging members 25 once the cylindrical rod 55 has been slid endwise out of the groove 54. The riser 56 is attached by way of bolts 57 which passes through it and is threaded into a threaded bore 60 provided in the pipe engaging members 25 (Fig.B).
The exposed outer edge of the riser also has an open-topped cylindrical groove 54 for reception of the cylindrical rod forming the contact member 55. As shown in Figure 3 and 5, the risers are not installed, as the head is set up to handle large pipe. In Figures 1 and 2 the riser 56 is shown mounted only on jaw 24b, simply for the reason to illustrate the different angles of approach of the pipe contact means provided by the use of the riser 56, when the head is modified to hold smaller pipes.
Regardless of the size of pipe the pipe contact members engage the pipe on the side of the pipe remote from the framework of the head.
The V-block 26 in the present invention is designed to contact the pipe in opposition to the pipe engaging members 25 or risers 56 in a plane displaced above the plane of the pipe engaging members 25 or risers 56, i.e., the contact points of the V-block 26 with the pipe are on the side of the pipe adjacent the head. This arrangement allows the use of an universal V-block which is equally effective for pipes of the wide range of diameter previously indicated without interfering with the jaw operation. The over V-block unit includes a carriage 61 having a generally rectangularly shaped frame 68 having lateral flanges 62 extending lengthwise along lower side edges thereof. Located on opposite sides of the frame 62 is a pair of grooved rollers 63, mounted on vertical axles 59 affixed to the top panel 36 of the framework 32 of the head 23. A pipe contacting member 64 of the V-block 26 includes a pair of leg portions 65,65, which extend from an apex portion affixed to the carriage 61 at a relative angle of approximately 90 degrees. Pipe contacting surfaces are provided on front faces of the leg portions by cylindrical shaped rod members 66 received endwise in open front cylindrical shaped grooves 67, not unlike those described above in relation to pipe engaging members 25 and risers 56.
Thus the pipe engaging surface of the pipe contacting member 64 are actually in the form of two diverging narrow lines provided by the exposed outer surface of the cylindrical shaped rods 66, the lines being disposed tangentially relative to the circumference of the pipe to be engaged. The nature of the cylindrical rods 55 or 69 which are received for rotation in their respective open-topped cylindrical grooves therefore provide not only for relatively resistant-free rotation of the pipe within the closed head, but allows lengthwise resistant free movement of the clamped pipe therethrough.
The apparatus includes adjustment means for setting the position of the carriage at individual, predetermined positions for individual optimum positions of the V-block in relation to each individual optimum setting of the jaw members for the extended range of sizes.
In a top plate 70 of the carriage 61 are three openings spaced transversely across the carriage, the three openings containing an internally threaded bushing 71a, 71b or 71c, respectively. In the top panel 36 of the framework 32, there are three rows of series of openings, each row extending in the longitudinal direction on a line underlying one of part of the threading openings of the bushing 71 a, 71 b, or 71 c. The rear end of one line of the series of openings is shown at 72 in Fig. 3. The openings 72 in total being twelve in the example described, one each being provided for establishing a position for each pipe size. A decal as shown in Fig. 12B is located on the top plate 70 so as to provide an indication as to which row provides an associate opening for receiving a pin 73 threaded into one of the corresponding bushing 71a, 71b, 71c. For the sake of this description the screws shown in the decal have been numbered # 1, #2, #3. When the pin 73 is removed the carriage can be moved by hand in the longitudinal direction. A decal 74 is affixed to one side 75 of the carriage 61 and lists the individual pipe sizes for which the carriage can be locked in a set position. On the top plate 36 of the framework 32, adjacent the side of the carriage 61, there is provided a marker 75 (Fig. 3), in order that the carnage, with the pin 73 removed, can be rolled in a longitudinal direction until the size of the pipe shown on the decal is opposite the marker, at which time the pin 74 is turned into place to lock the carriage so as to properly locate the V-block for that size. In the example previously used, the carriage 61 would be positioned so that the size 16-5/8 inch indicated on the decal (Fig. 13) is aligned with the marker 75, at which time the operator may note from the decal of Fig. 12B that the hole in the series of holes at the side of the carriage closest to the marker 75, #1 of this setting, is aligned under bushing 71a. Thus, on threading in the pin 73, the V-block is properly located for handling pipes of 16-5/8 inch diameter.
As previously indicated, the pipe clamping head 23, as described in detail above, is mounted at the outer end of extendible head supporting framework 30, which is supported at its inner end for pivoting about a horizontal axis provided by an axle 76 (Fig. 14). The axle 76 is carned in a supporting base 69 of which the clamping means 21 forms a part. The axle 76 (Fig. 1) extends through openings 77,77 a pair of U-shaped brackets 79,79, each of which receives one of an outer square tubular member 78. Outer extendible parallel arms 34,34, are slidably received one each in the tubular member 78,78. Each of the extendible outer arms 34,34 are provided with a pair of threaded bushings 80,80 which receive bolts which pass through openings 33,33 (Fig. 3) in the side panels 35,35 of the head 23.

Outer ends of the outer tubular members 78,78 are interconnected by a cross member 81, and their inner ends are connected by a cross member 82. A
transverse, input drive shaft 83 passes through outer ends of the outer tubular members 78,78, and have affixed thereto within the tubular members bevel gears 84,84 which drivingly mesh with bevel gears 85,85 affixed to shafts 86,86, the latter of which extend to outer ends located within the inner ends of extendible arms 34,34.
The shafts 86,86 are threaded and received thereon drive nuts 87,87 (Figs 10 & 11) which are fixed in relation to the extendible arms 34,34. Accordingly, upon rotation of the drive shaft 83, shafts 86,86 are rotated by way of mating bevel gears 84,85;
84,85 and due to the interaction between threaded shafts 86,86 and the internally threaded drive nuts 87,87 the extendible arms are pushed outwardly to a more extended position, or retracted into the members 78,78, thus extending or retracting the position of the head 23.
As indicated in Figs. 1 and 14, for example, the drive shaft 83 has a hex head 90 in order that the amount of extension can be varied by a wrench or ratchet in centering the head properly over the well. Normally in the arrangement shown, and particularly when making significant changes in the extension arms 34,34, an air wrench would be utilized in positioning the head. Alternatively, the apparatus may be fitted with a driven motor which might be remotely controlled so as to be able to achieve the adjustment from a position at the rig floor.
The supporting base 69 of the pipe alignment apparatus 20 includes an L-shaped frame member 91, which has a length greater than the spacing of tubular members 78,78. In the mounting shown in Figs. 1 & 14 this L-shaped member has a horizontal flange 92 which overlies the top of the box-shaped structural member 21 of the rig. Extending upwardly from the horizontal flange of the L-shaped frame member, as mounted in Figs. 1 and 14, are a pair of supporting flanges 89,89, near opposite ends of the L-shaped frame member. It is in this pair of flanges 89,89, in which axle 76, which provides the pivot axis for the extendible head supporting framework 30, is mounted so that the framework 30 can pivot relative to the support base 69.
Depending on the structural characteristics of the rig, in some circumstances it is desirable to invert the supporting members of the apparatus 20, as illustrated in Fig. 2, as opposed to that shown in Figure 1. In this situation the mounting of the head 23 is reversed by removing the bolts from threaded bushings 80 and replacing the head in an upright position in relation to the rig as can be seen from Fig. 2. With this mounting, the L-shaped frame member of the supporting base 69 is reversed to underlie the bottom of the cross member 21 of the rig. The back or vertical flange of the L-shaped frame member remains against the outside surface of the cross member 21 of the rig.
Along the outer or face edges of flanges, there are provided a series of holes which receive the threaded outer ends of rods 94 which are pivotally connected to a corner bracket 95 to form a number of clamps making up clamping means 22. As is apparent from Figures l, 2 and 14, as nuts are threaded onto the outer ends of the two rods of each clamp 96, the corner bracket of each clamp 96 is pulled tightly against the corner of the cross member 21 which is diagonally opposite to the corner of the cross member provided at the intersections of flanges 92 and 93 of the L-shaped frame member 91. In the illustrated embodiment a pair of clamps 96 is provided at opposite ends of the frame member 91.
At one end of the frame member 92 and slightly spaced therefrom is a separate clamp unit 97 which forms an anchor clamp, and has a short bracket 100 of the same cross sectional shape as the frame member 92. Otherwise the same structure of the clamp for this separate clamp unit 97 which is clamped directly onto the cross member 21,21 has an upwardly extending flange 101 formed thereon with an aperture through the flange for receiving a thread rod 102. The rod 102 is connected at its opposite end to the flange 89 of the L-shaped frame member 91. Disposed on opposite sides of the flange 101 of the separate clamp unit 97 are nuts 103,103 which are threaded onto the threaded rod 102.
Thus, in order to make fine laterally adjustments to the overall alignment apparatus 20, all of the individual clamps 96,96 are loosened slightly, and the nut 103 of separate clamp unit 97 on one side of the flange 89 is loosened and the other nut 103 is tightened which provides a pull or a push force through threaded rod 102 to the flange 89 of the L-shaped frame member 91 thus pulling the entire apparatus toward, or pushing it away from the tight separate clamp unit 97. After the proper sideways adjustment is made each of the individual clamps 96 are re-tightened to maintain the apparatus fixed to the cross member 21 of the rig.
The U-shaped brackets 79,79 of the supporting base 69 extends outwardly beyond the pivot axis of the head support framework 30 provided by axle 76. At the extended ends of the U shaped brackets there are provided cross pins 105.
Affixed at upper ends (Figs. 1 & 14) to the vertical flange 93 of the L-shaped frame member 91 are legs 106,106. At lower ends of the legs 106 ,106 there are provided cross pins 107,107. A double acting piston on cylinder type motors 108 is connected between each set of cross pins 105,107 (only one such motor being illustrated in the drawings). When the motors 108,108 are in an extending condition the head remains in a lowered, horizontal operative position, with abutment stops 110, which are fixed to the lower surfaces of the outer tubular members 78,78 resting on the horizontal flange 92 of the L-shaped frame member 91. As is readily apparent from Figs. l and 14, when fluid activated motors 108 are contracted from the extended condition shown, a downward pull is exerted on the rear extended portions of the brackets 79,79 to swing the head supporting framework 30 and the head 23 supported thereby to a raised, upright position completely freeing the area above the well head (not shown).

With the illustrated clamping means 22, the over all supporting structure can be inverted to the alternative position shown in Fig. 2 wherein the legs 106,106 project upward and on actuation the head supporting framework 30 and the head swing downward to a completely retracted position below the cross member 21 of the rig. Because of the different structural characteristics of the rig, such an alternative mounting option may be necessary.
While various detailed features of the present invention have been illustrated and described, various alternatives which are within the purview of the appending claims will be obvious to those skilled in the art

Claims (13)

1. An apparatus for aligning a pipe with a well head by contacting the pipe about an outer circumferential surface thereof;
said apparatus comprising:
a pipe engaging head, a support structure for attachment to a structural member of the well rig and supporting said head above said well head, said head including a framework with connecting means for attaching said head to said supporting structure outward from said structural member of said well rig, a pair of jaw members having outer ends extending outwardly from said framework and into a pipe contacting area, pivot pins connecting said jaw members to said framework for pivoting about transversely spaced vertical axes, pipe contact members, one each carried at an outer end of each jaw member for providing engagement points with the outer circumferential surface of the pipe on a side thereof remote from said framework of said head, motor means for pivoting said jaw members from an open position to a closed pipe engaging position, control means for individual settings of the pipe engaging position of said jaw members in the closed position, each setting being an optimum setting for a particular pipe size over an extended range of pipe sizes, a pipe contacting means having a pipe engaging member for engaging the outer circumference of the pipe on a side juxtaposed said head, a carriage mounting said pipe contacting means above said head and being movable longitudinally relative to said head, and adjustment means for setting the position of said carriage at individual predetermined positions for optimum position of said pipe contacting members in relation to each individual optimum setting of said jaw members for the extended range of pipe sizes.

2. The apparatus as defined in claim 1, wherein;
each of said jaw members has a tail portion extending from said pivot pin into said framework of said head, wherein;
said motor means includes a double acting, fluid operated, piston and cylinder unit, and wherein;
a piston rod of the piston in said unit is pivotally connected at an outer free end to said tail portion of one of said jaw members, and the cylinder of said unit is connected at an outer end thereof to the tail portion of the other of said jaw members, whereby on expansion of said unit, said pipe contact members of said jaw members are pivoted toward the pipe engaging position.

3. The apparatus of claim 3 and further comprising a movement co-ordinating link pivotally connected at one end to one of said jaw members at a point outward of said pivot pin of said one jaw member and connected at its opposite end to the tail portion of the other of said jaw members at a point on said tail member a distance from said pivot pin of said other jaw member.

4. The apparatus of claim 3, wherein;
the distance between the pivot connection of the link to the jaw members and the pivot pin of said one jaw member and the distance between the pivot connection of the link to the other jaw member and the pivot pin of said other jaw member are equal, whereby the pivot movements of the two jaws toward the pipe engaging position are uniform.

5. The apparatus of claim 3, wherein said control means includes a stop engaging portion formed on the tail portion of one of said jaw members, and a series of spaced, pin receiving openings formed in said framework of said head, one each of said openings being located for each of said pipe sizes of said extended range, said openings being distributed to achieve engagement of a pin inserted in a selected one of said openings by said stop engaging portion of said tail portion on said one of such jaw members reaching an optimum pipe engaging position for a pipe size corresponding to a selected one of said openings.

6. The apparatus of claim 1, wherein said carriage is mounted on said framework of said head for longitudinal movement relative to said framework toward and away from said pipe contacting area and wherein said pipe contacting means includes a V-shaped block carried by said carriage formed by diverging leg portions facing said pipe contacting area, said leg portions providing separate points for circumferentially spaced contact of the pipe on a side of said pipe juxtaposed said head.

7. The apparatus of claim 6, wherein said V-shaped block provides said separate points of contact in a plane above a plane containing the engagement points provided by the contact members carried by said jaw members.

8. The apparatus of claim 7, wherein in said adjustment means includes carriage locking means for fastening said carriage relative to said framework of said head in each one of said individual optimum settings for each selected pipe of said range of pipe sizes.

9. The apparatus as defined in claim 8, wherein;
said carriage includes at least one opening for receiving a locating bolt member, and wherein said framework of said head includes a series of openings for alignment with said opening a different positions of said carriage in the longitudinal direction of movement of said carriage on said framework of said head, whereby insertion of said bolt member in said opening in said carriage and in an aligned selected one of said openings in said series of openings in said framework, locks said V-shaped block in the selected optimum setting.

10. The apparatus of claim 1, wherein said support means includes a support base for rigid connection to the structural member of said well rig, and a selectively extendible supporting framework connected to said support base at an inner end and carrying said head at an outer end.

11. The apparatus of claim 10, wherein said extendible supporting means is connected to said support base by a pivot connection permitting said extendible supporting means to be selectively swung from an operative position to a substantially vertical position about the structural member to a substantially vertical position, whereby said head is removed from a space above said well head.

12. The apparatus of claim 11, wherein;
a remotely controlled motor means is connected between such extendible support means and said support base for pivoting said head into and out of an operational position in said space above said well head.

13. The apparatus as defined in claim 10, and further comprising;
clamping means for removably attaching said support base to said structural member of said well rig, said clamping means including a plurality of separate releasable clamps, an anchor clamp, and an adjustable connection means between said anchor clamp and said supporting base for selectively applying a force to said support base for moving said support base along said structural member on temporarily releasing said clamping means so as to achieve lateral displacement of said head relative to said well head.