CA1153758A - Gripping apparatus - Google Patents
Gripping apparatusInfo
- Publication number
- CA1153758A CA1153758A CA000374254A CA374254A CA1153758A CA 1153758 A CA1153758 A CA 1153758A CA 000374254 A CA000374254 A CA 000374254A CA 374254 A CA374254 A CA 374254A CA 1153758 A CA1153758 A CA 1153758A
- Authority
- CA
- Canada
- Prior art keywords
- jaw
- lug
- gripping
- jaws
- urge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
ABSTRACT
GRIPPING APPARATUS
A gripping apparatus (200) having a jaw (202), a body (201) and a floating interfacing assembly (203) having a curved surface (212, 213) bearing against an opposing surface or groove (210, 211), the interfacing assembly (203) being operable to generate a proportional gripping force in response to an axial force upon a cylinder to be gripped. The jaw (202) is not connected to the body (201).
The interfacing assembly (203) is operable to permit a transverse displacement of the jaw (202).
GRIPPING APPARATUS
A gripping apparatus (200) having a jaw (202), a body (201) and a floating interfacing assembly (203) having a curved surface (212, 213) bearing against an opposing surface or groove (210, 211), the interfacing assembly (203) being operable to generate a proportional gripping force in response to an axial force upon a cylinder to be gripped. The jaw (202) is not connected to the body (201).
The interfacing assembly (203) is operable to permit a transverse displacement of the jaw (202).
Description
1~537~i~
GPMA:005 GRIPPING APPARATUS
This invention relates generally to an apparatus for S gripping a member. The member may conveniently be in the form of a cylinder, pipe or tube. More particularlyr this invention concerns an apparatus having a plurality of jaws adapted for gripping a cylinder, pipel tube or other mem-ber. The jaws are in operative association with a body such that the radial gripping counterforce exerted by the jaws upon the member, cylinder, pipe or tube is propor-tional to an axial force upon the cylinder tending to urge the cylinder in an axial direction with respect to the body. If the cylinder, pipe or tube attempts to move axially with respect to the body, an interfacing assembly urges the jaws~into grippin~ engagement with the cylinder.
In a hydrostatic testing apparatusl it is necessary to grip a pipe or tube to be hydrostatically tested with sufficient force to sealingly engage the apparatus upon the pipe. It is necessary that the hydrostatic testing apparatus grip the pipe with sufficient force to reduce or minimize the danger of the pipe slipping out of the testing apparatusO
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In the past, it has been common to grip a pipe or cylinder with hydraulic rams and threaded devices to slips which apply an outside force to hold a hydrostatic testing device or cap onto the pipe. Such devices must be tight-ened to the pipe under substantially zero internal pres-sure conditions because the slips must be firmly engaged before the pipe can be pressurized. Tigh~ening during pressurization of the pipe is impractical and dangerous~
During zero pressure conditions there is no internal fluid pressure to offset the clamping pressure or gripping force.
Thus, such devices must necessarily stress the outer wall of the pipe while there is little or no internal pressure to offset the pipe gripping force. If the initial gripping force is inadequate, the hydrostatic testing cap will slip off during internal pressurization of the pipe. If the initial gripping force is excessive, the pipe may be deformed or weakened. For pressure testing, the jaws or slips of such devices must be initially tightened to a holding force sufficient to withstand test pressure before the pipe is pressurized.
In prior art jacking systems for offshore oil drilling platforms, it has been common to grip platform legs with shear pins, slips or hydraulic rams. Such hydraulic rams shear pins or slips had to be manually set. The gripping force upon the platform leg was not necessarily related to the weight of the platform deck. Oftentimes, a drilling platform becomes unleveled such that the forces upon other _- platform legs may increase substantially. Existing devices for leveling a platEorm ~equire the gripping means to be released from a platform leg before leveling forces can be applied. Releasing the gripping means from one platform leg in order to permit leveling necessarily increases the danger of the platforr,1 sliding down the platform leg and l~LS375;8 creating stress upon the remaining platform legs. Rele~s-ing the gripper means for leveling purposes creates a danger of platform system failure.
-In addition, if one jacking device Eailed, the stress upon the remaining platform legs could increase substan-tially. The failure of jacking systems presents a serious hazard to offshore drilling operations. When the stress upon prior art jacking devices increases, there is no mechanism to assure that the gripping ~orce upon the plat-form leg will also increase in response to such stresses.
Prior art jacking systems are also unsatisfactory in that many such systems require that shear pin holes be aligned or that gears be meshed. Thus, the platform may not be jacked and leveled by moving the platform any desired distance. The platform may be moved only from one pin hole to another.
Prior art blowout preventer devices, used to prevent pipe from being blown out of a hole during drilling operations typically use hydraulic or threaded systems to grip the pipe. Such prior art systems must be set by external gripping forces. Such devices oftentimes cause hoop stresses upon the pipe when engaged. Because the gripping force is not related to the force tending to push the pipe out of the hole, the pipe must be gripped wi~h an adequate force to prevent a blowout regardless Qf the existence of any downhole pressure. Thus, under substan-tially zero downhole pressure conditions, the pipe tends to be overstressed. Moreover, existing systems may be slow to engage. Prior art blowout preventer devices require manual setting and are not automatic or self-engaging.
1 lS37~
If a large downhole pressure suddenly de~elops, there is no mechanism in such prior art blowout preventer devices to automatically set or increase the gripping force~
Thus, such prior art devices are ineffective to prevent a blowout unless they have previously been set upon the pipe with sufficient force to withstand the sudden increase and in downhole pressure. Such prior art blowout preventers must also be released in order to permit the withdraw of casing, coupling or upset portions on the drill string.
Prior art hanging systems for pipe, tubing and casing, such as systems employed to prevent pipe from being dropped down into a hole during workover and drilling operations, commonly referred to as "hangers", and systems used to grip pipe going in and out of a well, commonly referred to as "elevators" or "snubbers", re~uired that an expensive derrick be constructed at the drill site in order to permit operation of the hanging device. Such prior art devices typically employ slips that must be manually reset. In order to pass casing, coupling or upset portions of the pipe or drill string, such prior art devices require that the slips be released and expanded to permit the pipe and casing to be passed. While the slips are released for the passage of the casing, the safety hanging device is inoperative. Thus, during such periods, the pipe or drill string is exposed to the risk of being dropped into the hole.
The adverse economic consequences and delays encoun-tered when drill pipe or other devices are dropped into ahole and the difficulty of retrieving the pipe or such devices requires that a safety hanging apparatus be available to guard against dripping th epipe at all times during drilling operations.
~S37S8 In addition, many prior art hanging devices, includ-ing snubbers, elevators and hangers, cannot take upward pressure upon the pipe without impairing their operation.
While prior art arrangements have exhibited a degree of utility in gripping a pipe, cylinder or tube, room for significant improvement remains. The problems enumerated in the foregoing are not intended to be exhaustive, but rather are among many which tend to impair the effective-ness of previously known devices for gripping cylinders or pipes. Other noteworthy problems may also exist; however, those presented above should be sufficient to demonstrate that the prior arrangements appearing in the art have not been altogether satisfactory.
SUMMARY OF A PREFERRED
EMBODIMENT OF THE INVENTION
Recognizing the need for an improved apparatus for gripping a cylinder or pipe for hydrostatic ~esting for jacking operations upon offshore drilling platforms for gripping drill pipe to prevent a blowout and for gripping drill pipe, tubing and casing in safety hanging systems and other wellhead workover applications, it is, therefore, ~a general intent in disclosing the present invention to provide a novel apparatus for gripping a cylinder, pipe or tube, which minimizes or reduces the problems of the type previously noted. The present invention has further useful application in gripping a pipe, tube or cylinder for other purposes.
It will be appreciated, however, that the invention can also have application in gripping members which are not necessarily circular in section or cylindrical in shape. In this event the gripping jaws of this invention -h-would be provided with friction surfaces which general~y conform to the outer surface configuration of the member to be gripped. The invention has, however, for the sake of convenience generally been described herein with reference to the gripping of cylindrical members of circular cross-section.
~ feature of the cylinder gripping apparatus resides in the abili~y to permit the cylinder, pipe or tube to move in one direction with respect to a body, and to pre-vent the cylinder from moving in a second opposite direc-tion with respect to the body. A correlated feature resides in the ability of the cylinder gripping apparatus to grip the pipe with a force which is proportional to the axial force upon the pipe tending to move the pipe with respect to the body. In an application as a blowout pre-venter, the cylinder gripping apparatus includes the more detailed feature of increasing its grip upon the pipe in response to an increase in downhole pressure tending to force the pipe out of the well. Thus, a sudden increase in downhole pressure will result in a sudden increase in the gripping force upon the pipe.
A feature resides in the provision of floating lugs which allow jaws to grip a cylinder, pipe or tube with a proportional gripping force which opposes rotational move-ment of the cylinder.
~ In an application as a snubber, the invention includes the feature of back-to-back gripping apparatus which grip pipe in both axial directions while tubing is installed or removed. One set of back-to-back apparatus reciprocates axially to jack the tubing in or out of the well. During this operation, the tubing is secured at all times in both 3~ axial directions. The gripping means of the present l~LS~
invention has the additional feature of incorporating lugs which will not only grip the pipe axially but will grip the pipe with a force proportional to a rotational torque for making up or unscrewing joints or pipe.
Of independent significance, the gripping apparatus includes an interfacing assembly which is more economical to construct and operate. A more detailed feature resides in the utilization of force translation lugs to interface the jaw with the cylinder. The utilization of such force translation lugs renders the cylinder gripping apparatus inexpensive to construct and simple to operate.
Yet another feature of the cylinder gripping apparatus is the provision for an interfacing assembly which permits the jaw to be easily aligned with the cylinder, even when the cylinder is not axially centered within the body. The interfacing assembly permits radial, axial and transverse movement of the jaw with respect to the body in order to permit the jaw to correctly align itself upon the cylinder.
In an application as a drilling platform jacking apparatus, the cylinder gripping apparatus includes the related feature o~ providing a jacking apparatus which increases its grip upon the platform leg in response to increased pressures generated by unleveling of the plat-form deck or the failure of a jacking apparatus upon another leg of the platform. This feature reduces the incidence of failure of the jacking apparatus.
A cylinder gripping apparatus according to a presently preferred embodiment of the invention intended to substan-tially incorporate the foregoing features includes a jaw adapted for gripping a cylinder, a body adapted to axially receive the cylinder, and an interfacing assembly. The ~5~5i 3 interfacing assembly is interposed between the jaw and the body and is adapted to urge the jaw into gripping engage-ment with the cylinder when the cylinder is ~rged in a first direction with respect to the body. The interfacing assembly is adapted to~allow the jaw to release from the cy,linder when the cylinder is moved in a second direction with respect to the body.
The interfacing assembly is adapted to provide a radial gripping force in response to an axial force upon the cylinder which is proportional to that axial force.
The interfacing assembly is adapted to permit radial, axial and transverse movement of the jaw with respect to the body in order to permit the jaw to align itself upon the cylinder when the cylinder is not perfectly centered within the axis of the body or when the cylinder is deformed.
The interfacing assembly may comprise a force trans-lation lug which is engageably within bearing grooves uponthe jaw and the body.
The interfacing assembly may also comprise a plurality of generally cylindrical rollers interposed between the jaw and the body. In this embodiment, the body has an inclined side wall. The rollers are operable to facilitate the movement of the jaw relative to the body along the inclined side wall of the body in order to urge the jaw into grip ping engagement with the cylinder. Channels adapted to 3n receive the cylindrical rollers may be formed either in the jaw or in the side wall of the body.
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g The interfacing assembly may alternatively comprise a cam arm pivotally attached to the body having a generally arcuate cam surface. The jaw may have a groove adapted to receive the cam surface of the cam arm. The can arm is operable to urge the jaw into engagement with a cylinder when the cam arm is rotated with respect to the body.
~~ Employed as a platform jacking apparatus, the cylinder gripping apparatus may employ two sets of jaws. One set of the jaws is operable to grip the platform leg while the other set is released Actuating means or hydraulic cylin-ders are connected to one set of the jaws to provide a means for jacking the platform deck up upon the platform leg.
Examples of the more important features of this inven-tion have thus been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will also form the subject of the claims appended hereto. Other features of the present invention will become apparent with reference to the following detailed descrip-tion of a presently preerred embodiment thereof in connec-tion with the accompanying drawings, wherein like reference numerals have been applied to like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
~ IGURE 1 depicts a side view of an embodiment of a cylinder gripping apparatus constructed in accordance with the present invention.
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- 1 o -FIGURE 2 shows a cutaway end view of the cylinder gripping apparatus depicted in FIGURE 1.
FIGURE 3 shows a side view of an alternative embodi-ment of the cylinder gripping apparatus.
Similar to FIGURE 3, FIGURE 4 shows a side view of the embodiment illustrated in FIGURE 3 depicting the retainers or stays.
FIGURE 5 illustrates a partially cutaway end view of the embodiment depicted in FIGURE 4.
FIGURE 6 is a side view of an alternative embodiment of the cylinder gripping apparatus.
FIGURE 7 is a side view of yet another alternative embodiment of the cylinder gripping apparatus.
FIGURE 8 illustrates a side view of an alternative embodiment of the cylinder gripping apparatus.
FIGURE 9 deplcts a partially cutaway side view of an embodiment of the cylinder gripping apparatus employed as a safety hanging apparatus for a pipe.
FIGURE 10 shows an enlarged side view of the force translation lug and the bearing groove in the body.
FIGURE 11 illustrates a cutaway bottom view of the apparatus shown in FIGURE 10.
FIGURE 12 shows a partially cutaway bottom view of the apparatus illustrated in FIGURE 9O
~ ~5~7S8 -1 1~
J FIGURE 13 depicts an embodiment of the cylinder grip- `
ping apparatus employed as a drilling platform jacking apparatus.
DETAILED DESCRIPTION OF A
PREFERRED EMBODIMENT OF THE INVENTION
~~ Turning now to the drawings in Figure 1I there is depicted a side view of a portion of a cylinder gripping apparatus 200. The cylinder gripping apparatus 200 com-prises a body 201, a jaw 202 and an interfecting assembly 203. The body 201 is only partially shown in Figure 1.
As best shown in Figure 2, the jaw 202 has a friction surface 204 adapted for gripping a cylinder 205. The fric-tion surface 204 may comprise serrations, teeth, a smooth friction surface, or other conventional friction surfaces.
With reference to Figure 1, the interfacing assembly 203 may comprise floating force translation lugs 206. The intlerfacing assembly also comprises a resilient member, elastic member or spring 207. The elastic mernber 207 is connected to the jaw 202 at a firs-t spring anchor point 208. The elastic member 207 i5 connected to the body 201 at a second spring anchor point 209.
The floating force translation lugs 206 are floating in the sense that the lugs 206 are unconnected to either the body 201 or the jaw 202. The lugs 206 fit into first bearing grooves or sockets 210 formed in the jaw 202. The other end of the lugs 206 fit into second bearing grooves or sockets 211.
As shown in Figure 2, the lug 206 has a first arcuate end or curved end 212 and a second arcuate or curved end :~ ~S~7S13 213. The first arcuate end 212 is adapted to fit into the first bearing groove 210. Similarly, the second arcuate end 213 is adapted to fit into the second bearing groove 211.
As best shown in the side view depicted in Figure 1, the forced translation lugs 206 are anyularly disposed between the body 201 and the jaw 202. The first bearing groove 210 has a first arcuate or curved bearing surface 214 which tapers to a sloped forward surface 215. The sloped forward surface 215 allows the lug 206 to rotate in a first sense inside the first bearing groove 210. In Figure 1, the first sense of rotation is clockwise with respect to the jaw 202.
Similarly, the second bearing groove 211 comprises a second arcuate or curved bearing surface 216 which tapers to a sloped or planar rearward surface 217. The sloped rearward surface 217 permits the lug 206 to rotate in a first sense with respect to the body 201.
The lugs 206 are floating and~thus unconnected to the body 201 or the jaw 202. Therefore, it is desirable to provide a means for compressively engaging the jaw 202 toward the body 211 in order to hold the lugs 206 within the first and second bearing grooves 210 and 211. In the present instance, this is essentially accomplished by the elastic member 207. When the jaw 202 is not engaged against a cylinder 205, the elastic member 207 tends to urge the jaw 202 toward the body 201, thus holding the lugs 206 in engagement within the first and second bearing grooves 210 and 211.
~l S7~17~
It will be appreciated that some actuating means may be provided to ~rge the jaw 202 into initial engagement with the cylinder 205. When the jaw 202 is engaged against a cylinder 205 and an axial force urges the cylinder 205 in a forward direction, or to the right in Figure 1, then the lugs 206 will tend to rotate in a second sense, or counterclockwise in Figure 1. The tendency of the lugs 206 to rotate in a second sense will tend to urge the jaw 202 into gripping engagement with the cylinder 205. The gripping force between the jaw 202 and the cylinder 205 will be proportional to the axial force exerted upon the cylinder 205. Thus, the force transla-tion lugs 206 provide a radial coun`terforce in response to the axial force upon the cylinder.
When the cylinder 205 is not perfectly axially aligned with respect to the body 201, it is desirable to permit the jaw 202 to move in a direction transverse to the axis of the body 201. As best shown in Figure 2, it is desira-ble to allow the jaw 202 to move transversely, i.e., tothe left or right, in order to allow the friction surface 204 to engage the cylinder 205. The curved end~ 212 and 213 cooperate with the first opposing face 218 of the jaw 202 and the second opposing face 219 of the body 201 to permit a transverse displacement of the jaw 202 from an initial axially aligned position to a displaced position either to the right or to the left of Figure 2. Thus, the floating lug 206 permits the friction surface 204 of the jaw 202 to engage the cylinder 205 even when the cylinder 205 is not preferably axially aligned within the body 201.
Thus, the floating nature of the lug 206 which is interposed between the jaw 202 and the body 201 permits movement between the jaw 202 and the body 201 with at least three degrees of freedom~ That is, the j~w 202 may LS37S;13 14~
move axially, radially and transversely with respect to the body 201. These degrees of freedom of movement that are permitted the jaw 202 with respect to the body 201 - facilitate the effective engagement of the jaw 202 against the cylinder 205 even for imperfectly aligned cylinders 205.
In some applications, such as a wellhead snubber apparatus, it may be desirable to grip a pipe, tube or cylinder 205 to prevent rotation of the pipe, tube or cylinder 205 about the axis o~ the body 201. As shown in Figure 2, the floating lug 206 may be positioned in offset position 400 (shown as a broken line). In the offset position 400, the lug 206 will tend to oppose clockwise rotation of the pipe 205. The gripping force of the jaw 202 upon the pipe 205 will be proportional to the clockwise torque upon thepipe 205. Similarly, counterclockwise rotation of the pipe 205 may be prevented by a jaw 202 with the lug 206 offset in an opposite directlon, or to the right in Figure 2 (not shown).
It will be appreciated that a second cylinder gripping apparatus 200 may be connected to the same pipe 205 as a ~irst gripping apparatus 200 with a set of lugs 206 offset in an opposite direction in order to prevent both clockwise and counterclockwise rotation of the same pipe 205.
Turning now to Figure 3, another embodiment of the interfacing assembly 203 is shown. The interfacing assem-bly 203 comprises floating lugs 220 interposed between the body 201 and the jaw 202. The floating lugs 220 may be fabricated differently from the lugs 206 illustrated in Figures 1 and 2. ~s best shown in Figure 5, the lug 220 has a first curved or arcuate end 221 and a second curved or arcuate end 222. The first curved end 221 is wider ~.S~)758 than the second curved end 222. The first curved end 221 may be substantially the same width as the jaw 202~ As best shown in Figure 5, the first bearing groove 210 may extend across substantially the entire width of the jaw 202.
s The first end 221 of the lug 220 may be held within the first bearing groove 210 by a set of first stays or retaining means 223. The first stays 223 are fixedly held against the jaw 202 by fastening means 224. Faster.ing means 224 may comprise a bolt, screw, pin, or other con-ventional fastening mechanisms.
Similarly, the second end 222 of the lug 220 may be held within the second bearing groove 211 by a set of second stays or retaining means 225. The second stays 225 are fixedly held against the body 201 by fastening means 226. Fastening means 226 may comprise a bolt, screw, pin, or other conventional fastening mechanisms.
Fastening means 224 and 226 are connected to the jaw 202 and the body 201, respectively. The first and second stays 223 and 225 are not connected to the lug 220. This can best be seen with reference to Figure 4. The first and second stays 223 and 225 are adapted to cover at least a portion of the cross-sectional area of the first and second bearing surfaces or grooves 210 and 211 in the jaw 202 and the body 201, respectively. The first and second stays 223 and 225 are adapted to laterally retain the lug 220 within the first and second bearing grooves 210 and 211 r while leaving the lugs 220 free to rotatively pivot within the bearing grooves 210 and 2110 The stays 223 and 225 may be omitted, as shown in Figure 3, and are not essential for the operation of the cylinder gripping apparatus.
~1 ~537~8 Thus, as shown in Figure 3, the first and second curved ends 221 and 222 of the lug 220 cooperate with first and second opposing faces 218 and 219 of the jaw 202 and the body 201, respectively, to permit a transverse displacement of the cylinder 205 from an initial axially aligned position to a displaced position. This degree of freedom of movement of the ~aw 202 in the transverse direc-tion permits the jaw 202 to more evenly engage the cylinder 205 when the cylinder 205 is not perfectly axially aligned within the body 201.
As shown in Figure 3, the opposing face 218 of the jaw 202 has a curved surface or bearing groove 210 adapted to receive the curved end 221 of the floating lug 220.
An elastic member 207 tends to urge the jaw 202 toward the body 201 in order to hold the lugs 220 into engagement within the first and second curved surfaces 210 and 211~
A compression member or spring 227 tends to urge the jaw 202 into engagement with the cylinder 205. As shown in Figure 3, the compression member 227 is interposed between the front of the body 201 and the jaw 202.
Actuatiny means 228 is connected to the lug 220 for rotationally pivoting the lug 220. Actuating means 228 may comprise a handle. Actuating means 228 may be used to rotationally pivot the lug 220 in a first sense, or clockwise as shown in Figure 3, to permit the jaw 202 to disengage the cylinder 205.
It will be noted that the elastic member 207 tends to urge the jaw 202 radially outwardly with respect to the body 201, thus urging the lugs 22n into operative engage-ment with the ~irst and second bearing grooves 2~0 and ~S37~8 211. When the cylinder 205 is removed from the body 201, the elastic member 207 tends to hold the jaw 202 and the body 201 into engagement with the lu~s 220.
As shown in Figure 4, the first bearing groove 210 comprises a first curved or arcuate bearing surfaces 214 ~hich tapers to a sloped or planar forward surface 215.
Similarly, the second bearing groove 211 comprises a second curved or arcuate bearing surface 216 which slopes to a planar or sloped rearward surface 217.
It will be appreciated that a floating force trans-lation by 206 may be constructed with a first arcuate, curved or spherical end 212 as shown in Figures 1 and 2, and with a second end fashioned in accordance with the embodiment described above with reference to Figures 3, 4 and 5.
Referring to Figure 6, a side view of another embodi-ment of the present invention is illustrated. The inter-facing assembly 203 is interposed between the sidewall of the body 201 and the jaw 202. In the present instance, the interfacing assembly 203 has curved or arcuate sur-faces 229 which engage an opposing face 230 of the side-wall of the body 201. The curved or circular surfaces 229 form the outer surEace of generally cylindrical or circular rollers 231. In a preferred embodiment, the rollers 231 are formed in the shape of cylindrical rods.
The rollers 231 are adapted to fit within channels 234 in the jaw 202. The channels 234 are formed transversely along the inner surface 235 of the jaw 202. As shown in Figure 6, the inner surface 235 of the jaw 202 is inclined or sloped. Similarly, the opposing face 229 of the side-wall of the body 201 is similarly sloped or inclined.
~i;37.~8 The rollers 231 are floating, and are thus ~ncon-nected to either the jaw 202 or the body 201. The elas-tic member 207 tends to urge the jaw 202 radially out-wardly toward the sidewall of the body 201. Thus, the S elastic member 207 tends to hold the rollers 231 in the channels 234.
-The rollers 231 facilitate the movement of the jaw 202 along the planar sloped opposing face 230 of the body 201. The rollers 231 are operable to facilitate the move-ment of the jaw 202 relative to the body 201 along the inclined inner surface 230.
The inclined inner surface 230 is adapted to urge the jaw 202 into engagement with the outer surface of the cylinder 205 when the jaw 202 is urged rearwardlyr or to the right in Figure 6, with respect to the body 201. A
compression memberr resilient member or spring 227 is adapted to urge the jaw 202 rearwardly with respect to the body 201.
Actuating means 232 is pivotally connected to the body 201 at a pivot point 233. Actuating means 232 may comprise a handle, in a preferred embodiment. Actuating means 232 is a~apted to urge the jaw 202 generally for-wardly, but that is to the left in Figure 6, with respect to the body 201~ Thus, actuating means 232 may be used to disengage the jaw 202 from the cylinder 205.
The rollers 231 may be confined to the channels 234 by stays 225 (not shown).
~537~ii8 ,g Because the rollers 231 are floating, the jaw 202 is permitted to move transversely with respect to the body 201. This transverse movement of the jaw 202 permits the jaw to grip the cylinder 205 even when the cylinder 205 is not axially centered within the body 201. Thus, the curved surface of the rollers 231 is cooperable with the opposing face 230 of the body 201 to permit a transverse displacement of the jaw 202 from an initial axially aligned positioned to a displaced position.
It will be appreciated that the channels 234 are pref-erably generally cylindrically shaped in substantial correspondence with the shape of the rollers 231. A first boss, finger or projection 236 limits the transverse movement of the jaw 202 with respect to the body 201. The boss 236 prevents the jaw 202 from completely slipping out of the cylinder gripping apparatus 200. Similarly, a second boss, finger or projection 237 is formed UpGn the rear of the jaw 202.
Figure 7 illustrates an alternative embodiment of the interfacing assembly 203 interposed between the jaw 202 and the body 201.
In the present instance, generally cylindrical roller 238 have curved, arcuate or generally round surfaces 239 which are cooperable with an opposing planar inclined face 240 of the jaw 202 to permit movement of the jaw 202 with respect to the body 201. The rollers 238 fit within generally cylindrically shaped channels 241 formed trans-versely along the inclined or sloped inner surface 230 of the sidewall of the body 201. The rollers 238 permit the jaw 202 to move transversely with respect to the body 201 in a manner similar to the interfacing assembly described with reference to Figure 6.
~l ~S37~
In other respects the interfacing assembly 203 depicted in Figure 7 is constructed and operated similar to the interfacing assembly 203 described with reference to Figure 6.
Turning now to Figure 8, the interfacing assembly - ~F- 203 is interposed between the body 201 and the jaw 202.
In the present instance, the interfacing assembly 203 has a curved surface 242 which interfaces with an opposing face 243 of the jaw 202. The opposing face 234 of the jaw 202 is located generally opposite to the friction surface 204 of the jaw 202.
The opposing face 234 of the jaw 202 has a curved surface or groove 244 formed in a position generally in correspondence with the curved surface 242 of the inter-facing assembly 203. The curved surface 242 of the interfacing assembly 203 is cooperable with the opposing face 234 of the jaw 202 to permit the jaw 202 to move not only radially and axially with respect to the body 201, but also transversely with respect to the body 201. Thus, if the cylinder 205 is not axially centered within the body 201, the curved surface 242 will permit the jaw 202 to move from an initial axially centered position to a displaced position in correspondence with the uncentered or displaced position of the cylinder 205. Thus, the interfacing assembly 203 permits the jaw 202 to be dis-placed transversely with respect to the body 201 in order to more effectively engage the cylinder 205 when the cylinder 205 is deformed or uncentered within the body 201.
. The interfacing assembly 203 further comprises a cam arm or force translation arm 245 which may be pivotally 35 connected to the body 201 at a second pivot point 246.
~s~
The cam arm 245 is operable to urge the jaw 202 into engagement with the outer surface of the cylinder 205 when the cam arm 245 is rotated in a second sense, or counter-clockwise in Figure 8, with respect to the b~dy 201.
Elastic members or springs 247 are connected to the jaw 202 at first spring anchor points 248 and are connected to the body 201 at second spring anchor points 249. The elastic members 247 tend to urge the jaw 202 radially outwardly with respect to the body 201. Thus, the elastic members 247 tend to urge the ~aw 202 into .
engagement with the generally arcuate cam surface 242 of l:
the cam arm 245.
In the present instance the jaw 202 has a forward alignment lip 250 and a rear alignment lip 251. The alignment lips 250 and 251 are connected to the forward l:
and rear edges of the jaw 202 respectively, as shown in Figure 27. The alignment lips 250 and 251 operate to disengage the entire jaw 202 from the cylinder 205 in the event that either the forward or rear end of the jaw 202 does not initially disengage from the cylinder 205. If the cam arm 245 is rotated in a first sense, or clockwise in Figure 8, with respect to the body 201, the jaw 202 will be urged radially outwardly from the cylinder 205 by the elastic members 247. In the event that the rear portion of the jaw 202 does not initially disengage from the cylinder 205, the forward align~ent lip 250 will contact the inner surface 219 of the body 201. Thus, further rotation of the cam arm 245 in a first sense with respect to the body 201 will cause the jaw 202 to pivot about the point where the forward alignment lip 250 contacts the inner surface 210 of the body 201 and will cause the rear portion of the jaw 202 to disengage from the cylinder 205.
~5375Z3 In the present instance, the cam arm 245 has actua-tion means or a handle 252 connected to it~ An elastic member or spring 253 may be connected between the handle 252 and the body 201. The elastic member 253 will tend to urge the cam arm 245 to rota~e in a second sense with respect to the body 201 and thus urge the jaw 202 into engagement with the cylinder 205.
It will be appreciated that the interfacing assem-blies 203 illustrated in Figures 3, 6, 7 and 8 are adapted to provide a radial counterforce in response to an axial force upon the cylinder. If an axial force is exerted upon the cylinder 205 when the jaw 202 is in engagement with the cylinder 205, and the cylinder 205 is urged to the right in Figures 3, 6, 7 and 8~ the interfacing assemblies 203 will provide a radial counterforce or gripping force which is proportional to the axial ~orce exerted upon the cylinder 205.
It will also be appreciated that, similar to Figure 8, the inter~acing assembly 203 illustrated in Figures 1,
GPMA:005 GRIPPING APPARATUS
This invention relates generally to an apparatus for S gripping a member. The member may conveniently be in the form of a cylinder, pipe or tube. More particularlyr this invention concerns an apparatus having a plurality of jaws adapted for gripping a cylinder, pipel tube or other mem-ber. The jaws are in operative association with a body such that the radial gripping counterforce exerted by the jaws upon the member, cylinder, pipe or tube is propor-tional to an axial force upon the cylinder tending to urge the cylinder in an axial direction with respect to the body. If the cylinder, pipe or tube attempts to move axially with respect to the body, an interfacing assembly urges the jaws~into grippin~ engagement with the cylinder.
In a hydrostatic testing apparatusl it is necessary to grip a pipe or tube to be hydrostatically tested with sufficient force to sealingly engage the apparatus upon the pipe. It is necessary that the hydrostatic testing apparatus grip the pipe with sufficient force to reduce or minimize the danger of the pipe slipping out of the testing apparatusO
~L~S37~
In the past, it has been common to grip a pipe or cylinder with hydraulic rams and threaded devices to slips which apply an outside force to hold a hydrostatic testing device or cap onto the pipe. Such devices must be tight-ened to the pipe under substantially zero internal pres-sure conditions because the slips must be firmly engaged before the pipe can be pressurized. Tigh~ening during pressurization of the pipe is impractical and dangerous~
During zero pressure conditions there is no internal fluid pressure to offset the clamping pressure or gripping force.
Thus, such devices must necessarily stress the outer wall of the pipe while there is little or no internal pressure to offset the pipe gripping force. If the initial gripping force is inadequate, the hydrostatic testing cap will slip off during internal pressurization of the pipe. If the initial gripping force is excessive, the pipe may be deformed or weakened. For pressure testing, the jaws or slips of such devices must be initially tightened to a holding force sufficient to withstand test pressure before the pipe is pressurized.
In prior art jacking systems for offshore oil drilling platforms, it has been common to grip platform legs with shear pins, slips or hydraulic rams. Such hydraulic rams shear pins or slips had to be manually set. The gripping force upon the platform leg was not necessarily related to the weight of the platform deck. Oftentimes, a drilling platform becomes unleveled such that the forces upon other _- platform legs may increase substantially. Existing devices for leveling a platEorm ~equire the gripping means to be released from a platform leg before leveling forces can be applied. Releasing the gripping means from one platform leg in order to permit leveling necessarily increases the danger of the platforr,1 sliding down the platform leg and l~LS375;8 creating stress upon the remaining platform legs. Rele~s-ing the gripper means for leveling purposes creates a danger of platform system failure.
-In addition, if one jacking device Eailed, the stress upon the remaining platform legs could increase substan-tially. The failure of jacking systems presents a serious hazard to offshore drilling operations. When the stress upon prior art jacking devices increases, there is no mechanism to assure that the gripping ~orce upon the plat-form leg will also increase in response to such stresses.
Prior art jacking systems are also unsatisfactory in that many such systems require that shear pin holes be aligned or that gears be meshed. Thus, the platform may not be jacked and leveled by moving the platform any desired distance. The platform may be moved only from one pin hole to another.
Prior art blowout preventer devices, used to prevent pipe from being blown out of a hole during drilling operations typically use hydraulic or threaded systems to grip the pipe. Such prior art systems must be set by external gripping forces. Such devices oftentimes cause hoop stresses upon the pipe when engaged. Because the gripping force is not related to the force tending to push the pipe out of the hole, the pipe must be gripped wi~h an adequate force to prevent a blowout regardless Qf the existence of any downhole pressure. Thus, under substan-tially zero downhole pressure conditions, the pipe tends to be overstressed. Moreover, existing systems may be slow to engage. Prior art blowout preventer devices require manual setting and are not automatic or self-engaging.
1 lS37~
If a large downhole pressure suddenly de~elops, there is no mechanism in such prior art blowout preventer devices to automatically set or increase the gripping force~
Thus, such prior art devices are ineffective to prevent a blowout unless they have previously been set upon the pipe with sufficient force to withstand the sudden increase and in downhole pressure. Such prior art blowout preventers must also be released in order to permit the withdraw of casing, coupling or upset portions on the drill string.
Prior art hanging systems for pipe, tubing and casing, such as systems employed to prevent pipe from being dropped down into a hole during workover and drilling operations, commonly referred to as "hangers", and systems used to grip pipe going in and out of a well, commonly referred to as "elevators" or "snubbers", re~uired that an expensive derrick be constructed at the drill site in order to permit operation of the hanging device. Such prior art devices typically employ slips that must be manually reset. In order to pass casing, coupling or upset portions of the pipe or drill string, such prior art devices require that the slips be released and expanded to permit the pipe and casing to be passed. While the slips are released for the passage of the casing, the safety hanging device is inoperative. Thus, during such periods, the pipe or drill string is exposed to the risk of being dropped into the hole.
The adverse economic consequences and delays encoun-tered when drill pipe or other devices are dropped into ahole and the difficulty of retrieving the pipe or such devices requires that a safety hanging apparatus be available to guard against dripping th epipe at all times during drilling operations.
~S37S8 In addition, many prior art hanging devices, includ-ing snubbers, elevators and hangers, cannot take upward pressure upon the pipe without impairing their operation.
While prior art arrangements have exhibited a degree of utility in gripping a pipe, cylinder or tube, room for significant improvement remains. The problems enumerated in the foregoing are not intended to be exhaustive, but rather are among many which tend to impair the effective-ness of previously known devices for gripping cylinders or pipes. Other noteworthy problems may also exist; however, those presented above should be sufficient to demonstrate that the prior arrangements appearing in the art have not been altogether satisfactory.
SUMMARY OF A PREFERRED
EMBODIMENT OF THE INVENTION
Recognizing the need for an improved apparatus for gripping a cylinder or pipe for hydrostatic ~esting for jacking operations upon offshore drilling platforms for gripping drill pipe to prevent a blowout and for gripping drill pipe, tubing and casing in safety hanging systems and other wellhead workover applications, it is, therefore, ~a general intent in disclosing the present invention to provide a novel apparatus for gripping a cylinder, pipe or tube, which minimizes or reduces the problems of the type previously noted. The present invention has further useful application in gripping a pipe, tube or cylinder for other purposes.
It will be appreciated, however, that the invention can also have application in gripping members which are not necessarily circular in section or cylindrical in shape. In this event the gripping jaws of this invention -h-would be provided with friction surfaces which general~y conform to the outer surface configuration of the member to be gripped. The invention has, however, for the sake of convenience generally been described herein with reference to the gripping of cylindrical members of circular cross-section.
~ feature of the cylinder gripping apparatus resides in the abili~y to permit the cylinder, pipe or tube to move in one direction with respect to a body, and to pre-vent the cylinder from moving in a second opposite direc-tion with respect to the body. A correlated feature resides in the ability of the cylinder gripping apparatus to grip the pipe with a force which is proportional to the axial force upon the pipe tending to move the pipe with respect to the body. In an application as a blowout pre-venter, the cylinder gripping apparatus includes the more detailed feature of increasing its grip upon the pipe in response to an increase in downhole pressure tending to force the pipe out of the well. Thus, a sudden increase in downhole pressure will result in a sudden increase in the gripping force upon the pipe.
A feature resides in the provision of floating lugs which allow jaws to grip a cylinder, pipe or tube with a proportional gripping force which opposes rotational move-ment of the cylinder.
~ In an application as a snubber, the invention includes the feature of back-to-back gripping apparatus which grip pipe in both axial directions while tubing is installed or removed. One set of back-to-back apparatus reciprocates axially to jack the tubing in or out of the well. During this operation, the tubing is secured at all times in both 3~ axial directions. The gripping means of the present l~LS~
invention has the additional feature of incorporating lugs which will not only grip the pipe axially but will grip the pipe with a force proportional to a rotational torque for making up or unscrewing joints or pipe.
Of independent significance, the gripping apparatus includes an interfacing assembly which is more economical to construct and operate. A more detailed feature resides in the utilization of force translation lugs to interface the jaw with the cylinder. The utilization of such force translation lugs renders the cylinder gripping apparatus inexpensive to construct and simple to operate.
Yet another feature of the cylinder gripping apparatus is the provision for an interfacing assembly which permits the jaw to be easily aligned with the cylinder, even when the cylinder is not axially centered within the body. The interfacing assembly permits radial, axial and transverse movement of the jaw with respect to the body in order to permit the jaw to correctly align itself upon the cylinder.
In an application as a drilling platform jacking apparatus, the cylinder gripping apparatus includes the related feature o~ providing a jacking apparatus which increases its grip upon the platform leg in response to increased pressures generated by unleveling of the plat-form deck or the failure of a jacking apparatus upon another leg of the platform. This feature reduces the incidence of failure of the jacking apparatus.
A cylinder gripping apparatus according to a presently preferred embodiment of the invention intended to substan-tially incorporate the foregoing features includes a jaw adapted for gripping a cylinder, a body adapted to axially receive the cylinder, and an interfacing assembly. The ~5~5i 3 interfacing assembly is interposed between the jaw and the body and is adapted to urge the jaw into gripping engage-ment with the cylinder when the cylinder is ~rged in a first direction with respect to the body. The interfacing assembly is adapted to~allow the jaw to release from the cy,linder when the cylinder is moved in a second direction with respect to the body.
The interfacing assembly is adapted to provide a radial gripping force in response to an axial force upon the cylinder which is proportional to that axial force.
The interfacing assembly is adapted to permit radial, axial and transverse movement of the jaw with respect to the body in order to permit the jaw to align itself upon the cylinder when the cylinder is not perfectly centered within the axis of the body or when the cylinder is deformed.
The interfacing assembly may comprise a force trans-lation lug which is engageably within bearing grooves uponthe jaw and the body.
The interfacing assembly may also comprise a plurality of generally cylindrical rollers interposed between the jaw and the body. In this embodiment, the body has an inclined side wall. The rollers are operable to facilitate the movement of the jaw relative to the body along the inclined side wall of the body in order to urge the jaw into grip ping engagement with the cylinder. Channels adapted to 3n receive the cylindrical rollers may be formed either in the jaw or in the side wall of the body.
~5~3~75~
g The interfacing assembly may alternatively comprise a cam arm pivotally attached to the body having a generally arcuate cam surface. The jaw may have a groove adapted to receive the cam surface of the cam arm. The can arm is operable to urge the jaw into engagement with a cylinder when the cam arm is rotated with respect to the body.
~~ Employed as a platform jacking apparatus, the cylinder gripping apparatus may employ two sets of jaws. One set of the jaws is operable to grip the platform leg while the other set is released Actuating means or hydraulic cylin-ders are connected to one set of the jaws to provide a means for jacking the platform deck up upon the platform leg.
Examples of the more important features of this inven-tion have thus been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will also form the subject of the claims appended hereto. Other features of the present invention will become apparent with reference to the following detailed descrip-tion of a presently preerred embodiment thereof in connec-tion with the accompanying drawings, wherein like reference numerals have been applied to like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
~ IGURE 1 depicts a side view of an embodiment of a cylinder gripping apparatus constructed in accordance with the present invention.
~l53~75~
- 1 o -FIGURE 2 shows a cutaway end view of the cylinder gripping apparatus depicted in FIGURE 1.
FIGURE 3 shows a side view of an alternative embodi-ment of the cylinder gripping apparatus.
Similar to FIGURE 3, FIGURE 4 shows a side view of the embodiment illustrated in FIGURE 3 depicting the retainers or stays.
FIGURE 5 illustrates a partially cutaway end view of the embodiment depicted in FIGURE 4.
FIGURE 6 is a side view of an alternative embodiment of the cylinder gripping apparatus.
FIGURE 7 is a side view of yet another alternative embodiment of the cylinder gripping apparatus.
FIGURE 8 illustrates a side view of an alternative embodiment of the cylinder gripping apparatus.
FIGURE 9 deplcts a partially cutaway side view of an embodiment of the cylinder gripping apparatus employed as a safety hanging apparatus for a pipe.
FIGURE 10 shows an enlarged side view of the force translation lug and the bearing groove in the body.
FIGURE 11 illustrates a cutaway bottom view of the apparatus shown in FIGURE 10.
FIGURE 12 shows a partially cutaway bottom view of the apparatus illustrated in FIGURE 9O
~ ~5~7S8 -1 1~
J FIGURE 13 depicts an embodiment of the cylinder grip- `
ping apparatus employed as a drilling platform jacking apparatus.
DETAILED DESCRIPTION OF A
PREFERRED EMBODIMENT OF THE INVENTION
~~ Turning now to the drawings in Figure 1I there is depicted a side view of a portion of a cylinder gripping apparatus 200. The cylinder gripping apparatus 200 com-prises a body 201, a jaw 202 and an interfecting assembly 203. The body 201 is only partially shown in Figure 1.
As best shown in Figure 2, the jaw 202 has a friction surface 204 adapted for gripping a cylinder 205. The fric-tion surface 204 may comprise serrations, teeth, a smooth friction surface, or other conventional friction surfaces.
With reference to Figure 1, the interfacing assembly 203 may comprise floating force translation lugs 206. The intlerfacing assembly also comprises a resilient member, elastic member or spring 207. The elastic mernber 207 is connected to the jaw 202 at a firs-t spring anchor point 208. The elastic member 207 i5 connected to the body 201 at a second spring anchor point 209.
The floating force translation lugs 206 are floating in the sense that the lugs 206 are unconnected to either the body 201 or the jaw 202. The lugs 206 fit into first bearing grooves or sockets 210 formed in the jaw 202. The other end of the lugs 206 fit into second bearing grooves or sockets 211.
As shown in Figure 2, the lug 206 has a first arcuate end or curved end 212 and a second arcuate or curved end :~ ~S~7S13 213. The first arcuate end 212 is adapted to fit into the first bearing groove 210. Similarly, the second arcuate end 213 is adapted to fit into the second bearing groove 211.
As best shown in the side view depicted in Figure 1, the forced translation lugs 206 are anyularly disposed between the body 201 and the jaw 202. The first bearing groove 210 has a first arcuate or curved bearing surface 214 which tapers to a sloped forward surface 215. The sloped forward surface 215 allows the lug 206 to rotate in a first sense inside the first bearing groove 210. In Figure 1, the first sense of rotation is clockwise with respect to the jaw 202.
Similarly, the second bearing groove 211 comprises a second arcuate or curved bearing surface 216 which tapers to a sloped or planar rearward surface 217. The sloped rearward surface 217 permits the lug 206 to rotate in a first sense with respect to the body 201.
The lugs 206 are floating and~thus unconnected to the body 201 or the jaw 202. Therefore, it is desirable to provide a means for compressively engaging the jaw 202 toward the body 211 in order to hold the lugs 206 within the first and second bearing grooves 210 and 211. In the present instance, this is essentially accomplished by the elastic member 207. When the jaw 202 is not engaged against a cylinder 205, the elastic member 207 tends to urge the jaw 202 toward the body 201, thus holding the lugs 206 in engagement within the first and second bearing grooves 210 and 211.
~l S7~17~
It will be appreciated that some actuating means may be provided to ~rge the jaw 202 into initial engagement with the cylinder 205. When the jaw 202 is engaged against a cylinder 205 and an axial force urges the cylinder 205 in a forward direction, or to the right in Figure 1, then the lugs 206 will tend to rotate in a second sense, or counterclockwise in Figure 1. The tendency of the lugs 206 to rotate in a second sense will tend to urge the jaw 202 into gripping engagement with the cylinder 205. The gripping force between the jaw 202 and the cylinder 205 will be proportional to the axial force exerted upon the cylinder 205. Thus, the force transla-tion lugs 206 provide a radial coun`terforce in response to the axial force upon the cylinder.
When the cylinder 205 is not perfectly axially aligned with respect to the body 201, it is desirable to permit the jaw 202 to move in a direction transverse to the axis of the body 201. As best shown in Figure 2, it is desira-ble to allow the jaw 202 to move transversely, i.e., tothe left or right, in order to allow the friction surface 204 to engage the cylinder 205. The curved end~ 212 and 213 cooperate with the first opposing face 218 of the jaw 202 and the second opposing face 219 of the body 201 to permit a transverse displacement of the jaw 202 from an initial axially aligned position to a displaced position either to the right or to the left of Figure 2. Thus, the floating lug 206 permits the friction surface 204 of the jaw 202 to engage the cylinder 205 even when the cylinder 205 is not preferably axially aligned within the body 201.
Thus, the floating nature of the lug 206 which is interposed between the jaw 202 and the body 201 permits movement between the jaw 202 and the body 201 with at least three degrees of freedom~ That is, the j~w 202 may LS37S;13 14~
move axially, radially and transversely with respect to the body 201. These degrees of freedom of movement that are permitted the jaw 202 with respect to the body 201 - facilitate the effective engagement of the jaw 202 against the cylinder 205 even for imperfectly aligned cylinders 205.
In some applications, such as a wellhead snubber apparatus, it may be desirable to grip a pipe, tube or cylinder 205 to prevent rotation of the pipe, tube or cylinder 205 about the axis o~ the body 201. As shown in Figure 2, the floating lug 206 may be positioned in offset position 400 (shown as a broken line). In the offset position 400, the lug 206 will tend to oppose clockwise rotation of the pipe 205. The gripping force of the jaw 202 upon the pipe 205 will be proportional to the clockwise torque upon thepipe 205. Similarly, counterclockwise rotation of the pipe 205 may be prevented by a jaw 202 with the lug 206 offset in an opposite directlon, or to the right in Figure 2 (not shown).
It will be appreciated that a second cylinder gripping apparatus 200 may be connected to the same pipe 205 as a ~irst gripping apparatus 200 with a set of lugs 206 offset in an opposite direction in order to prevent both clockwise and counterclockwise rotation of the same pipe 205.
Turning now to Figure 3, another embodiment of the interfacing assembly 203 is shown. The interfacing assem-bly 203 comprises floating lugs 220 interposed between the body 201 and the jaw 202. The floating lugs 220 may be fabricated differently from the lugs 206 illustrated in Figures 1 and 2. ~s best shown in Figure 5, the lug 220 has a first curved or arcuate end 221 and a second curved or arcuate end 222. The first curved end 221 is wider ~.S~)758 than the second curved end 222. The first curved end 221 may be substantially the same width as the jaw 202~ As best shown in Figure 5, the first bearing groove 210 may extend across substantially the entire width of the jaw 202.
s The first end 221 of the lug 220 may be held within the first bearing groove 210 by a set of first stays or retaining means 223. The first stays 223 are fixedly held against the jaw 202 by fastening means 224. Faster.ing means 224 may comprise a bolt, screw, pin, or other con-ventional fastening mechanisms.
Similarly, the second end 222 of the lug 220 may be held within the second bearing groove 211 by a set of second stays or retaining means 225. The second stays 225 are fixedly held against the body 201 by fastening means 226. Fastening means 226 may comprise a bolt, screw, pin, or other conventional fastening mechanisms.
Fastening means 224 and 226 are connected to the jaw 202 and the body 201, respectively. The first and second stays 223 and 225 are not connected to the lug 220. This can best be seen with reference to Figure 4. The first and second stays 223 and 225 are adapted to cover at least a portion of the cross-sectional area of the first and second bearing surfaces or grooves 210 and 211 in the jaw 202 and the body 201, respectively. The first and second stays 223 and 225 are adapted to laterally retain the lug 220 within the first and second bearing grooves 210 and 211 r while leaving the lugs 220 free to rotatively pivot within the bearing grooves 210 and 2110 The stays 223 and 225 may be omitted, as shown in Figure 3, and are not essential for the operation of the cylinder gripping apparatus.
~1 ~537~8 Thus, as shown in Figure 3, the first and second curved ends 221 and 222 of the lug 220 cooperate with first and second opposing faces 218 and 219 of the jaw 202 and the body 201, respectively, to permit a transverse displacement of the cylinder 205 from an initial axially aligned position to a displaced position. This degree of freedom of movement of the ~aw 202 in the transverse direc-tion permits the jaw 202 to more evenly engage the cylinder 205 when the cylinder 205 is not perfectly axially aligned within the body 201.
As shown in Figure 3, the opposing face 218 of the jaw 202 has a curved surface or bearing groove 210 adapted to receive the curved end 221 of the floating lug 220.
An elastic member 207 tends to urge the jaw 202 toward the body 201 in order to hold the lugs 220 into engagement within the first and second curved surfaces 210 and 211~
A compression member or spring 227 tends to urge the jaw 202 into engagement with the cylinder 205. As shown in Figure 3, the compression member 227 is interposed between the front of the body 201 and the jaw 202.
Actuatiny means 228 is connected to the lug 220 for rotationally pivoting the lug 220. Actuating means 228 may comprise a handle. Actuating means 228 may be used to rotationally pivot the lug 220 in a first sense, or clockwise as shown in Figure 3, to permit the jaw 202 to disengage the cylinder 205.
It will be noted that the elastic member 207 tends to urge the jaw 202 radially outwardly with respect to the body 201, thus urging the lugs 22n into operative engage-ment with the ~irst and second bearing grooves 2~0 and ~S37~8 211. When the cylinder 205 is removed from the body 201, the elastic member 207 tends to hold the jaw 202 and the body 201 into engagement with the lu~s 220.
As shown in Figure 4, the first bearing groove 210 comprises a first curved or arcuate bearing surfaces 214 ~hich tapers to a sloped or planar forward surface 215.
Similarly, the second bearing groove 211 comprises a second curved or arcuate bearing surface 216 which slopes to a planar or sloped rearward surface 217.
It will be appreciated that a floating force trans-lation by 206 may be constructed with a first arcuate, curved or spherical end 212 as shown in Figures 1 and 2, and with a second end fashioned in accordance with the embodiment described above with reference to Figures 3, 4 and 5.
Referring to Figure 6, a side view of another embodi-ment of the present invention is illustrated. The inter-facing assembly 203 is interposed between the sidewall of the body 201 and the jaw 202. In the present instance, the interfacing assembly 203 has curved or arcuate sur-faces 229 which engage an opposing face 230 of the side-wall of the body 201. The curved or circular surfaces 229 form the outer surEace of generally cylindrical or circular rollers 231. In a preferred embodiment, the rollers 231 are formed in the shape of cylindrical rods.
The rollers 231 are adapted to fit within channels 234 in the jaw 202. The channels 234 are formed transversely along the inner surface 235 of the jaw 202. As shown in Figure 6, the inner surface 235 of the jaw 202 is inclined or sloped. Similarly, the opposing face 229 of the side-wall of the body 201 is similarly sloped or inclined.
~i;37.~8 The rollers 231 are floating, and are thus ~ncon-nected to either the jaw 202 or the body 201. The elas-tic member 207 tends to urge the jaw 202 radially out-wardly toward the sidewall of the body 201. Thus, the S elastic member 207 tends to hold the rollers 231 in the channels 234.
-The rollers 231 facilitate the movement of the jaw 202 along the planar sloped opposing face 230 of the body 201. The rollers 231 are operable to facilitate the move-ment of the jaw 202 relative to the body 201 along the inclined inner surface 230.
The inclined inner surface 230 is adapted to urge the jaw 202 into engagement with the outer surface of the cylinder 205 when the jaw 202 is urged rearwardlyr or to the right in Figure 6, with respect to the body 201. A
compression memberr resilient member or spring 227 is adapted to urge the jaw 202 rearwardly with respect to the body 201.
Actuating means 232 is pivotally connected to the body 201 at a pivot point 233. Actuating means 232 may comprise a handle, in a preferred embodiment. Actuating means 232 is a~apted to urge the jaw 202 generally for-wardly, but that is to the left in Figure 6, with respect to the body 201~ Thus, actuating means 232 may be used to disengage the jaw 202 from the cylinder 205.
The rollers 231 may be confined to the channels 234 by stays 225 (not shown).
~537~ii8 ,g Because the rollers 231 are floating, the jaw 202 is permitted to move transversely with respect to the body 201. This transverse movement of the jaw 202 permits the jaw to grip the cylinder 205 even when the cylinder 205 is not axially centered within the body 201. Thus, the curved surface of the rollers 231 is cooperable with the opposing face 230 of the body 201 to permit a transverse displacement of the jaw 202 from an initial axially aligned positioned to a displaced position.
It will be appreciated that the channels 234 are pref-erably generally cylindrically shaped in substantial correspondence with the shape of the rollers 231. A first boss, finger or projection 236 limits the transverse movement of the jaw 202 with respect to the body 201. The boss 236 prevents the jaw 202 from completely slipping out of the cylinder gripping apparatus 200. Similarly, a second boss, finger or projection 237 is formed UpGn the rear of the jaw 202.
Figure 7 illustrates an alternative embodiment of the interfacing assembly 203 interposed between the jaw 202 and the body 201.
In the present instance, generally cylindrical roller 238 have curved, arcuate or generally round surfaces 239 which are cooperable with an opposing planar inclined face 240 of the jaw 202 to permit movement of the jaw 202 with respect to the body 201. The rollers 238 fit within generally cylindrically shaped channels 241 formed trans-versely along the inclined or sloped inner surface 230 of the sidewall of the body 201. The rollers 238 permit the jaw 202 to move transversely with respect to the body 201 in a manner similar to the interfacing assembly described with reference to Figure 6.
~l ~S37~
In other respects the interfacing assembly 203 depicted in Figure 7 is constructed and operated similar to the interfacing assembly 203 described with reference to Figure 6.
Turning now to Figure 8, the interfacing assembly - ~F- 203 is interposed between the body 201 and the jaw 202.
In the present instance, the interfacing assembly 203 has a curved surface 242 which interfaces with an opposing face 243 of the jaw 202. The opposing face 234 of the jaw 202 is located generally opposite to the friction surface 204 of the jaw 202.
The opposing face 234 of the jaw 202 has a curved surface or groove 244 formed in a position generally in correspondence with the curved surface 242 of the inter-facing assembly 203. The curved surface 242 of the interfacing assembly 203 is cooperable with the opposing face 234 of the jaw 202 to permit the jaw 202 to move not only radially and axially with respect to the body 201, but also transversely with respect to the body 201. Thus, if the cylinder 205 is not axially centered within the body 201, the curved surface 242 will permit the jaw 202 to move from an initial axially centered position to a displaced position in correspondence with the uncentered or displaced position of the cylinder 205. Thus, the interfacing assembly 203 permits the jaw 202 to be dis-placed transversely with respect to the body 201 in order to more effectively engage the cylinder 205 when the cylinder 205 is deformed or uncentered within the body 201.
. The interfacing assembly 203 further comprises a cam arm or force translation arm 245 which may be pivotally 35 connected to the body 201 at a second pivot point 246.
~s~
The cam arm 245 is operable to urge the jaw 202 into engagement with the outer surface of the cylinder 205 when the cam arm 245 is rotated in a second sense, or counter-clockwise in Figure 8, with respect to the b~dy 201.
Elastic members or springs 247 are connected to the jaw 202 at first spring anchor points 248 and are connected to the body 201 at second spring anchor points 249. The elastic members 247 tend to urge the jaw 202 radially outwardly with respect to the body 201. Thus, the elastic members 247 tend to urge the ~aw 202 into .
engagement with the generally arcuate cam surface 242 of l:
the cam arm 245.
In the present instance the jaw 202 has a forward alignment lip 250 and a rear alignment lip 251. The alignment lips 250 and 251 are connected to the forward l:
and rear edges of the jaw 202 respectively, as shown in Figure 27. The alignment lips 250 and 251 operate to disengage the entire jaw 202 from the cylinder 205 in the event that either the forward or rear end of the jaw 202 does not initially disengage from the cylinder 205. If the cam arm 245 is rotated in a first sense, or clockwise in Figure 8, with respect to the body 201, the jaw 202 will be urged radially outwardly from the cylinder 205 by the elastic members 247. In the event that the rear portion of the jaw 202 does not initially disengage from the cylinder 205, the forward align~ent lip 250 will contact the inner surface 219 of the body 201. Thus, further rotation of the cam arm 245 in a first sense with respect to the body 201 will cause the jaw 202 to pivot about the point where the forward alignment lip 250 contacts the inner surface 210 of the body 201 and will cause the rear portion of the jaw 202 to disengage from the cylinder 205.
~5375Z3 In the present instance, the cam arm 245 has actua-tion means or a handle 252 connected to it~ An elastic member or spring 253 may be connected between the handle 252 and the body 201. The elastic member 253 will tend to urge the cam arm 245 to rota~e in a second sense with respect to the body 201 and thus urge the jaw 202 into engagement with the cylinder 205.
It will be appreciated that the interfacing assem-blies 203 illustrated in Figures 3, 6, 7 and 8 are adapted to provide a radial counterforce in response to an axial force upon the cylinder. If an axial force is exerted upon the cylinder 205 when the jaw 202 is in engagement with the cylinder 205, and the cylinder 205 is urged to the right in Figures 3, 6, 7 and 8~ the interfacing assemblies 203 will provide a radial counterforce or gripping force which is proportional to the axial ~orce exerted upon the cylinder 205.
It will also be appreciated that, similar to Figure 8, the inter~acing assembly 203 illustrated in Figures 1,
2, 3, 4 and 5 ~ay be pivotally connected at one end to either the jaw 202 or the body 201.
In Figure 9, an embodiment of the present cylinder gripping apparatus is shown for use in connection with a safety hanger or blowout preventer apparatus for use in connection with drilling operations. The embodiment illustrated in Figure 9 may also have utility as a snubber~
In Figure 9, an embodiment of the present cylinder gripping apparatus is shown for use in connection with a safety hanger or blowout preventer apparatus for use in connection with drilling operations. The embodiment illustrated in Figure 9 may also have utility as a snubber~
3~
As illustrated in Figure 9, the body 201 has an upper cylinder, pipe or tube passageway or opening 254 and a lower pipe, tube or cylinder passageway or opening 255.
The body 201 is adapted to axially receive the pipe, tube or cylinder 205. The jaws 202 have a ~riction surface 204 adapted to grip the drill pipe 205.
~53758 In the present instance, the interfacing assembly 203 comprises angularly disposed floating force translation lugs or arms 256. The lug 256 is floating because it is unconnected to the body 201 or the jaw 202. The lug 256 has a ~irst curved surface or arcuate surface 257 on one end and a second curved or arcuate surface 258 on the other end. The first curved end 257 is adapted to fit ~ithin a first bearing groove 259. Similarly, the second curved end 258 is ~dapted to fit within a second bearing groove 260. The bearing grooves 259 and 260 are constructed similar to the bearing grooves 211 and 214 illustrated in Figures 3, 4 and 5. For example, as best shown in Figure 10, the second bearing groove 260 comprises a second curved or arcuate bearing surface 261 which tapers to a generally planar or inclined surface 262.
As best shown in Figure 10, the lug 256 is floating in the sense that it is not connected to the body 201.
First and second retaining means or stays 265 and 266 are connected or fastened to the jaw 202 and the body 201 respectively. The stays 265 and 266 retain the lugs 256 when the pipe 205 is withdrawn from the body 201, as will be more fully described below.
Referring-to Figure 10, the stay 266 has an aperture or opening 263. The aperture 263 is adapted to receive a projection or pin 264 connected to the lug 256. As best shown in Figure 11, the pin 264 is connected to the lug 256 and extends through the aperture 263 in the stay 255.
When the jaw 202 engages the pipe 205, the lug 256 engages the grooves 259 and 260. When the lug 256 is engaged with the grooves 259 and 260, the pin 264 does not contact the stay 266. As best shown in Figure 10, the aperture 263 is larger than the pin 264. Thus, the lug 256 is essentially 7~S8 2~-floating. The pin 264 cooperates with the stay 266 to retain the lug 256 when the pipe 205 is withdrawn from the body 201.
As best shown in Figures 10 and 11, the sta~ 266 is connected to the body 201 by fastening means 267. Fasten-ing means 267 may comprise a bolt, screw, pin or other conventional fastening mechanisms. Referring to Figure 9, the first stay 265 is similarly connected to the jaw 202.
In addition, the lug 256 has a corresponding pin 268 which is adapted to fit within an aperture in the first stay 265. It will be appreciated that either end of the lug 256 may be pivotally connected to the body 201 or jaw 202.
The operation of the interfacing assèmbly 203 illus-trated in Figures 9 through 12 and providing a radial counterforce or gripping force upon the pipe 205 in response to an axial force upon the pipe 205 is similar to the inter~acing assemblies 203 described above with reference to Figures 1 through 8.
The interfacing assembly 203 illustrated in Figure 9 further comprises a jaw housing 269. The jaw housing 269 has arm passage openings 270 which permit the lugs 256 to pass through the jaw housing 269. A compression member or spring 271 is provided between the body 201 and the jaw housing 269. The spring 271 tends to urge the jaw housing 269 downward as shown in Figure 9. This tends to urge the jaws 202 into engagement with the pipe 205.
A wiper 272 is provided to remove dirt, grime and other foreign matter from the surface of the pipe 205.
The wiper 272 operates to prevent dirt and other matter upon the surface of the pipe 205 from interfering with the gripping surface 204 of the ~aws 202.
A releaserr jaw releasing cylinder or cylinder means 273 is connected to the body 201. The releaser ~
has a rod 274 shown in Figure 9 in the retracted positio The rod 274 is operable to be extended from the releaser 273 so that it contacts the jaw housing 269 and urges it upward. The releaser 273 is adapted to compress the spring 271 and thus disengage the jaw 202 from the pipe 205.
It will be appreciated that a second similar body 275 may be stacked with the body 201 to provide more than one set of jaws 202 to grip the pipe 205. The pipe 205 is shown in Figure 9 with a casing 276. A second set of jaws provided in the second body 275 would operate to grip the pipe 205 when the casing 276 was passed through the body 201.
Employed as a safety hanger apparatus, the embodiment of the invention illustrated in Figure 9 would permit the drill pipe 205 to be removed from the hole by ~oving it upward. However, if the drill pipe 205 was dropped, the jaws 202 would automatically engage the drill pipe 205 and prevent it from falling into the hole (not shown). I'he jaws 202 are adapted to permit the drill pipe 205 to be moved upwardly~in Figure 9, and are adapted to prevent the drill pipe 205 from being dropped down the hole or for moving downwardly in Figure 9.
It will be appreciated that the embodiment o the invention illustrated in Figure 9 may have useful applica-tion for other types of pipe, tu~es or cylinders. The present invention is not intended to be limited to drill pipe. 5 1 ~53~SB
In the event that it is desired to drill and move the drill pipe 205 downwardly, a similar body 201 may be employed as a blowout preventer by turning ~he body 201 upside down from the position shown in Figure 9. In such a position, the jaws would permit the drill pipe 205 to be drilled down into the hole, but would not allow the drill _ar pipe 205 to be blown out of the hole even in the event of a sudden increase in downhole pressure. The gripping force of the jaws 202 upon the drill pipe 205 will be proportional to the downhole pressure. Thus, the gripping force of the ~aws 202 upon the dril~ pipe 205 will increase in proportion to any increases in the downhole pressure.
Thus, a great safety feature is achieved by the present invention because a sudden increase in downhole pressure will be immediately offset by an increase in the radial counterforce or gripping force of the jaws 202 upon the drill pipe 205.
The releaser 273 is operable to disengage the jaws 202 when it is desired to move the drill pipe 205 in a direction opposite to the direction of movement permitted by the jaws 202.
Figure 13 depicts an embodiment of the cylinder grip-ping apparatus having utility as an offshore drilling plat-form deck jacking apparatus.
Although any of the interfacing assemblies previously described with reference to Figures 1 through 12 may be used to interface jaws with a body, the illustrated embodi-ment of the platform jacking apparatus 277 comprises a first jaw 21, a first arm 22, a first pivot point 23, a second pivot point 2~, a first extension 117, a first guide or synch sleeve 123, a first shoe or fastening means 119, a first actuation means 121, a first shaft 125 and a first fastening means 127.
i3~58 Similarly, a second jaw 58, second arm 57, third pivot point 60, fourth pivot point 59, second extension 118, second guide or synch sleeve 124, second shoe 120, second actuation means 122, second shaft 126 and second fastening means 128 operate in a similar manner.
In the embodiment shown in Figure 13, a third arm ~,~
278 is pivotally connected to the body at a fifth pivot point 279. The third arm 278 is pivotally connected to the first jaw 21 at a sixth pivot point 2800 A fourth arm 281 is pivotally connected to the body 290 at an eighth pivot point 282. The fourth arm 281 is connected to the second jaw 58 at an eighth pivot point 283. The body 290 is connected to a platform 284 in the present instance, the platform 2~4 comprises a conventional offshore drilling platform. The first and second jaws 21 and 58 comprise a first set of jaws which are adapted to grip a platform leg 285. A first compression member or spring 286 is inter-posed between the first jaw 21 and the body 290. The spring 286 is adapted to urge the first jaw 21 into engage-ment with the platform leg 285. A second compression member or spring 287 similarly urges the second jaw 58 into engagement with the platform leg 285. A third jaw 288 and a fourth jaw 289 comprise a second set of jaws adapted to grip the platform leg 285. The second set of jaws 288 and 289 operate in a manner similar to the first set of jaws 21 and 58. The body 290 has a guide sleeve 291 which is adapted to receive a jaw housing 292 which is annularly shaped as sho~n in Figure 32. The jaw housing 292 is adapted to axially receive the platform leg 285.
The body 290 is similarly adapted to axially receive the platform leg 285. The jaw housing 292 is adapted to reciprocally slide within the guide sleeve 291 of the body 290. Actuation means or cylinder means 293 is connected ~ 1~3~
to the body 290. Actuation means 293 has a shaft 294 which is operable to reciprocally extend or retract within actuation means 293. The shaft 294 is connected to the jaw housing 292 The platform 284 may be jacked up the platform leg 285 by allowing the second set of jaws 288 and 289 to engage the platform leg 285 while the shafts 294 are in the retracted position. When the shafts 294 are in the retracted position, the jaw housing 292 will be retracted within the guide sleeve 291 of the body 290. Thus, cylinder means 293 may be used to extend shafts 294 to push the jaw housing 292 downwardly with respect to the body 290. Thus, the body 290 and the platform 284 are raised with respect to the platform leg 285 while the jaw housing 292 remains stationary with respect to the plat-form leg 285.
In Figure 13, the shaft 294 is shown in the fully extended position. The shaft may be e~tended a distance X as shown in Figure 13. Thus, for each motion, the platform 284 may be jacked up a distance X.
When the shaft 294 has reached the fully extended position, the first set of jaws 21 and 58 are allowed to engage the platform leg 285. Thus, the first set of jaws 21 and 58 will hold the platform 284 in position as the shafts 294 and the second set of jaws 288 and 289 are retracted within the guide sleeve 291. It will be appre-ciated that both the first set of jaws 21 and 58 and the second set of jaws 288 and 289 will permit the platform leg 285 to be moved in one direction with respect to the body 290 and the jaw housing 292, but will not permit the platform leg 285 to be moved in an opposite direction with respect to thebody 290 or the jaw housing 292.
37~13 The first and second springs 286 and 287 are adapted to insure that the first set of jaws are urged generally radially inwardly with sufficien~ force to insure that the first set of jaws 21 and 58 maintain contact with the platform leg 285. Thus, if the second set of jaws 28~ and 289 should fail for any.reason, the first set of jaws 21 and 58 would automatically grip the plàtform leg 285 with a gripping force proportional to the weight of the platform 284 or`proportional to the stresses upon the platform leg 285. Similarly, a third and fourth spring or compression member 295 and 296 urge the second set of jaws 288 and 289 into engagement with the platform leg 285.
In the present instance, a plurality of wipers 297 is provided between the jaw housing 292 and the guide sleeve 291 and the platform leg 285. The wipers 297 tend to keep sea water or other unwanted matter from contaminating the interior of the guide sleeve 291. Air vent ports 298 pro-vide fluid communication between the air within the inte-rior of the guide sleeve 291 and the external atmosphere.
A plurality of second wipers 299 is provided betweenthe body 290 and the platform leg 285.
In the illustrated embodiment, the first and third arms 22 and 278 are pivotally connected to a first spline or rib 300 formed from the body 290. Similarly, the second and fourth arms 57 adn 281 may be pivotally con-nected to a second spline or rib 301 formed from the body 290~
The actuation means 121 and 122 may also comprise a first releaser operable to release the first set of jaws 21 and 58 from engagement with the platform leg 285.
Similarly, actuation means 302 and 304 may comprise a 1.~537S~3 second releaser operable to release t~le second set of jaws 288 and 289 from engagement with the platform leg 285.
The second releaser 302 and 304 is operable to disengage the second set of jaws 288 and 289 to permit the retraction of the jaw housing 292 within the guide sleeve 291.
The platform 284 may be lowered, ~also by synchronized operation of first and second releasers 121 and 122, and 302 and 304, in a manner generally opposite to that described above with reference to jacking the platform 284 up.
It will be appreciated that the cylinder gripping apparatus described above may find utility in any applica~
tion where it is desirable to grip a cylinder, rod pipe or tube to keep the cylinder, rod pipe or tube from going in an unwanted direction. The cylinder gripping apparatus may be employed with utility to hold the end of a pipe to be forged during the process of upsetting tubing. Alter-natively, the cylinder gripping apparatus may find utilityin holding tubing during the process of belling where a mandrel is inserted and welded to a pipe or tube. Simi-larly, any operation that requires a pipe, tube or cylinder to be held or gripped where large axial forces tend to urge the pipe, tube or cylinder in an unwanted direction.
SUMMARY OF ADVANTAGES OF THE INVENTION
It will be appreciated that in constructing a cylin-der gripping apparatus according to t~e present invention,certain significant advantages are provided.
31 1~i3758 In particular, a cylinder gripping apparatus according to the present invention permits a cylinder, pipe or tube to be held by a gripping force which is proportional to an axial force tending to urge the cylinder, pipe or tube in an unwanted direction. A cylinder gripping apparatus according to the present invention provides an interfacing assembly which dev~lops a radial counterforce or gripping force in response to an axial force upon the cylinder which is proportional to the axial force. Thus, as the axial force tending to urge the cylinder in an unwanted direction increases, the gripping force will increase proportionally in response to the increase axial force.
In addition, a cylinder gripping apparatus according to the present invention provides an interfacing assembly which is more economically constructed and which is adapted to withstand greater forces between the jaw and the body. The elimination of arms which are pivotally connected by pins to the jaw and the body eliminates the requirement that the pins be sufficiently strong to withstand the forces between the arm and the body.
Moreover, the cylinder, pipe or tube need not be perfectly centered within the body. A cylinder gripping apparatus according to the present invention permits the jaw to move transversely with respect to the axis of the body and thereby align into engagement with a cylinder which is deformed or which is not perfectly centered within the body.
A cylinder gripping apparatus according to the present invention includes the further advantage of providing an interfacing assembly which may be used in connection with a hydrostatic testing apparatus for high pressure testing.
The interfacing assembly is adapted to withstand greater forces than the embodiment disclosed in the prior art.
~s~s~
A cylinder gripping apparatus according to the present invention includes the further advantage of providing utility as a snubber, safety hanging apparatus or blowout preventer for use in connection with wellhead operations.
In such an application, the cylinder gripping apparatus provides the advantage of jaws which do not have to be completely released from the pipe in order to pass ~~ couplings. Thus, the risk of dropping the pipe or having a blowout while couplings are being passed is avoided. A
blowout preventer, snubber or safety hanging apparatus constructed according to the present invention will pro-vide a safety feature in that the gripping force generated will be proportional to the axial and Torsional forces upon the pipe.
A cylinder gripping apparatus according to the present invention may employ offset floating lugs which provide the advantage of a gripping force which is also proportional to the rotational forces or torque upon the cylinder, tube of pipe being gripped. The offset floating lugs a~t as tongs to prevent rotation, in addition to gripping the pipe to prevent axial movement.
A platform jacking apparatus constructed in accordance with the present invention will provide a safe method of jacking drilling platforms providing a gripping force upon the platform leg which is proportional to the weight of the drilling platform.
Leveling of a drilling platform is simple and safe. A
jacking distance of a fraction of an inch may be achieved, if desiredl because one set of jaws can grip the platform leg at any point along the leg, while actuation means can be used to slide the platform any desired distance along the platform leg. Gripping is automatic. The jacking ~.~L53~Si~
distance is not constrained by any requirement that shear pin holes be aligned or that gears be meshed. The plat-form may be jacked up or leveled without completely releasing any one of the platform legs.
s Thus, it is apparent that there has been provided in accordance with the invention, a cylinder gripping appara-tus that substantially incorporates the advantages set forth above. Although the present invention has been described in conjunction with specific forms thereof r it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the ~oregoing disclosure. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is to be under-stood that the forms of the invention herewith shown and described are to be taken as the presently preferred embodiment. Various changes may be made in the shape, size and arrangement of parts. For example, equivalent elements or materials may be substituted for those illus-trated and described herein, parts may be reversed, and certain features of the invention may be utilized indepen dently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the invention.
As illustrated in Figure 9, the body 201 has an upper cylinder, pipe or tube passageway or opening 254 and a lower pipe, tube or cylinder passageway or opening 255.
The body 201 is adapted to axially receive the pipe, tube or cylinder 205. The jaws 202 have a ~riction surface 204 adapted to grip the drill pipe 205.
~53758 In the present instance, the interfacing assembly 203 comprises angularly disposed floating force translation lugs or arms 256. The lug 256 is floating because it is unconnected to the body 201 or the jaw 202. The lug 256 has a ~irst curved surface or arcuate surface 257 on one end and a second curved or arcuate surface 258 on the other end. The first curved end 257 is adapted to fit ~ithin a first bearing groove 259. Similarly, the second curved end 258 is ~dapted to fit within a second bearing groove 260. The bearing grooves 259 and 260 are constructed similar to the bearing grooves 211 and 214 illustrated in Figures 3, 4 and 5. For example, as best shown in Figure 10, the second bearing groove 260 comprises a second curved or arcuate bearing surface 261 which tapers to a generally planar or inclined surface 262.
As best shown in Figure 10, the lug 256 is floating in the sense that it is not connected to the body 201.
First and second retaining means or stays 265 and 266 are connected or fastened to the jaw 202 and the body 201 respectively. The stays 265 and 266 retain the lugs 256 when the pipe 205 is withdrawn from the body 201, as will be more fully described below.
Referring-to Figure 10, the stay 266 has an aperture or opening 263. The aperture 263 is adapted to receive a projection or pin 264 connected to the lug 256. As best shown in Figure 11, the pin 264 is connected to the lug 256 and extends through the aperture 263 in the stay 255.
When the jaw 202 engages the pipe 205, the lug 256 engages the grooves 259 and 260. When the lug 256 is engaged with the grooves 259 and 260, the pin 264 does not contact the stay 266. As best shown in Figure 10, the aperture 263 is larger than the pin 264. Thus, the lug 256 is essentially 7~S8 2~-floating. The pin 264 cooperates with the stay 266 to retain the lug 256 when the pipe 205 is withdrawn from the body 201.
As best shown in Figures 10 and 11, the sta~ 266 is connected to the body 201 by fastening means 267. Fasten-ing means 267 may comprise a bolt, screw, pin or other conventional fastening mechanisms. Referring to Figure 9, the first stay 265 is similarly connected to the jaw 202.
In addition, the lug 256 has a corresponding pin 268 which is adapted to fit within an aperture in the first stay 265. It will be appreciated that either end of the lug 256 may be pivotally connected to the body 201 or jaw 202.
The operation of the interfacing assèmbly 203 illus-trated in Figures 9 through 12 and providing a radial counterforce or gripping force upon the pipe 205 in response to an axial force upon the pipe 205 is similar to the inter~acing assemblies 203 described above with reference to Figures 1 through 8.
The interfacing assembly 203 illustrated in Figure 9 further comprises a jaw housing 269. The jaw housing 269 has arm passage openings 270 which permit the lugs 256 to pass through the jaw housing 269. A compression member or spring 271 is provided between the body 201 and the jaw housing 269. The spring 271 tends to urge the jaw housing 269 downward as shown in Figure 9. This tends to urge the jaws 202 into engagement with the pipe 205.
A wiper 272 is provided to remove dirt, grime and other foreign matter from the surface of the pipe 205.
The wiper 272 operates to prevent dirt and other matter upon the surface of the pipe 205 from interfering with the gripping surface 204 of the ~aws 202.
A releaserr jaw releasing cylinder or cylinder means 273 is connected to the body 201. The releaser ~
has a rod 274 shown in Figure 9 in the retracted positio The rod 274 is operable to be extended from the releaser 273 so that it contacts the jaw housing 269 and urges it upward. The releaser 273 is adapted to compress the spring 271 and thus disengage the jaw 202 from the pipe 205.
It will be appreciated that a second similar body 275 may be stacked with the body 201 to provide more than one set of jaws 202 to grip the pipe 205. The pipe 205 is shown in Figure 9 with a casing 276. A second set of jaws provided in the second body 275 would operate to grip the pipe 205 when the casing 276 was passed through the body 201.
Employed as a safety hanger apparatus, the embodiment of the invention illustrated in Figure 9 would permit the drill pipe 205 to be removed from the hole by ~oving it upward. However, if the drill pipe 205 was dropped, the jaws 202 would automatically engage the drill pipe 205 and prevent it from falling into the hole (not shown). I'he jaws 202 are adapted to permit the drill pipe 205 to be moved upwardly~in Figure 9, and are adapted to prevent the drill pipe 205 from being dropped down the hole or for moving downwardly in Figure 9.
It will be appreciated that the embodiment o the invention illustrated in Figure 9 may have useful applica-tion for other types of pipe, tu~es or cylinders. The present invention is not intended to be limited to drill pipe. 5 1 ~53~SB
In the event that it is desired to drill and move the drill pipe 205 downwardly, a similar body 201 may be employed as a blowout preventer by turning ~he body 201 upside down from the position shown in Figure 9. In such a position, the jaws would permit the drill pipe 205 to be drilled down into the hole, but would not allow the drill _ar pipe 205 to be blown out of the hole even in the event of a sudden increase in downhole pressure. The gripping force of the jaws 202 upon the drill pipe 205 will be proportional to the downhole pressure. Thus, the gripping force of the ~aws 202 upon the dril~ pipe 205 will increase in proportion to any increases in the downhole pressure.
Thus, a great safety feature is achieved by the present invention because a sudden increase in downhole pressure will be immediately offset by an increase in the radial counterforce or gripping force of the jaws 202 upon the drill pipe 205.
The releaser 273 is operable to disengage the jaws 202 when it is desired to move the drill pipe 205 in a direction opposite to the direction of movement permitted by the jaws 202.
Figure 13 depicts an embodiment of the cylinder grip-ping apparatus having utility as an offshore drilling plat-form deck jacking apparatus.
Although any of the interfacing assemblies previously described with reference to Figures 1 through 12 may be used to interface jaws with a body, the illustrated embodi-ment of the platform jacking apparatus 277 comprises a first jaw 21, a first arm 22, a first pivot point 23, a second pivot point 2~, a first extension 117, a first guide or synch sleeve 123, a first shoe or fastening means 119, a first actuation means 121, a first shaft 125 and a first fastening means 127.
i3~58 Similarly, a second jaw 58, second arm 57, third pivot point 60, fourth pivot point 59, second extension 118, second guide or synch sleeve 124, second shoe 120, second actuation means 122, second shaft 126 and second fastening means 128 operate in a similar manner.
In the embodiment shown in Figure 13, a third arm ~,~
278 is pivotally connected to the body at a fifth pivot point 279. The third arm 278 is pivotally connected to the first jaw 21 at a sixth pivot point 2800 A fourth arm 281 is pivotally connected to the body 290 at an eighth pivot point 282. The fourth arm 281 is connected to the second jaw 58 at an eighth pivot point 283. The body 290 is connected to a platform 284 in the present instance, the platform 2~4 comprises a conventional offshore drilling platform. The first and second jaws 21 and 58 comprise a first set of jaws which are adapted to grip a platform leg 285. A first compression member or spring 286 is inter-posed between the first jaw 21 and the body 290. The spring 286 is adapted to urge the first jaw 21 into engage-ment with the platform leg 285. A second compression member or spring 287 similarly urges the second jaw 58 into engagement with the platform leg 285. A third jaw 288 and a fourth jaw 289 comprise a second set of jaws adapted to grip the platform leg 285. The second set of jaws 288 and 289 operate in a manner similar to the first set of jaws 21 and 58. The body 290 has a guide sleeve 291 which is adapted to receive a jaw housing 292 which is annularly shaped as sho~n in Figure 32. The jaw housing 292 is adapted to axially receive the platform leg 285.
The body 290 is similarly adapted to axially receive the platform leg 285. The jaw housing 292 is adapted to reciprocally slide within the guide sleeve 291 of the body 290. Actuation means or cylinder means 293 is connected ~ 1~3~
to the body 290. Actuation means 293 has a shaft 294 which is operable to reciprocally extend or retract within actuation means 293. The shaft 294 is connected to the jaw housing 292 The platform 284 may be jacked up the platform leg 285 by allowing the second set of jaws 288 and 289 to engage the platform leg 285 while the shafts 294 are in the retracted position. When the shafts 294 are in the retracted position, the jaw housing 292 will be retracted within the guide sleeve 291 of the body 290. Thus, cylinder means 293 may be used to extend shafts 294 to push the jaw housing 292 downwardly with respect to the body 290. Thus, the body 290 and the platform 284 are raised with respect to the platform leg 285 while the jaw housing 292 remains stationary with respect to the plat-form leg 285.
In Figure 13, the shaft 294 is shown in the fully extended position. The shaft may be e~tended a distance X as shown in Figure 13. Thus, for each motion, the platform 284 may be jacked up a distance X.
When the shaft 294 has reached the fully extended position, the first set of jaws 21 and 58 are allowed to engage the platform leg 285. Thus, the first set of jaws 21 and 58 will hold the platform 284 in position as the shafts 294 and the second set of jaws 288 and 289 are retracted within the guide sleeve 291. It will be appre-ciated that both the first set of jaws 21 and 58 and the second set of jaws 288 and 289 will permit the platform leg 285 to be moved in one direction with respect to the body 290 and the jaw housing 292, but will not permit the platform leg 285 to be moved in an opposite direction with respect to thebody 290 or the jaw housing 292.
37~13 The first and second springs 286 and 287 are adapted to insure that the first set of jaws are urged generally radially inwardly with sufficien~ force to insure that the first set of jaws 21 and 58 maintain contact with the platform leg 285. Thus, if the second set of jaws 28~ and 289 should fail for any.reason, the first set of jaws 21 and 58 would automatically grip the plàtform leg 285 with a gripping force proportional to the weight of the platform 284 or`proportional to the stresses upon the platform leg 285. Similarly, a third and fourth spring or compression member 295 and 296 urge the second set of jaws 288 and 289 into engagement with the platform leg 285.
In the present instance, a plurality of wipers 297 is provided between the jaw housing 292 and the guide sleeve 291 and the platform leg 285. The wipers 297 tend to keep sea water or other unwanted matter from contaminating the interior of the guide sleeve 291. Air vent ports 298 pro-vide fluid communication between the air within the inte-rior of the guide sleeve 291 and the external atmosphere.
A plurality of second wipers 299 is provided betweenthe body 290 and the platform leg 285.
In the illustrated embodiment, the first and third arms 22 and 278 are pivotally connected to a first spline or rib 300 formed from the body 290. Similarly, the second and fourth arms 57 adn 281 may be pivotally con-nected to a second spline or rib 301 formed from the body 290~
The actuation means 121 and 122 may also comprise a first releaser operable to release the first set of jaws 21 and 58 from engagement with the platform leg 285.
Similarly, actuation means 302 and 304 may comprise a 1.~537S~3 second releaser operable to release t~le second set of jaws 288 and 289 from engagement with the platform leg 285.
The second releaser 302 and 304 is operable to disengage the second set of jaws 288 and 289 to permit the retraction of the jaw housing 292 within the guide sleeve 291.
The platform 284 may be lowered, ~also by synchronized operation of first and second releasers 121 and 122, and 302 and 304, in a manner generally opposite to that described above with reference to jacking the platform 284 up.
It will be appreciated that the cylinder gripping apparatus described above may find utility in any applica~
tion where it is desirable to grip a cylinder, rod pipe or tube to keep the cylinder, rod pipe or tube from going in an unwanted direction. The cylinder gripping apparatus may be employed with utility to hold the end of a pipe to be forged during the process of upsetting tubing. Alter-natively, the cylinder gripping apparatus may find utilityin holding tubing during the process of belling where a mandrel is inserted and welded to a pipe or tube. Simi-larly, any operation that requires a pipe, tube or cylinder to be held or gripped where large axial forces tend to urge the pipe, tube or cylinder in an unwanted direction.
SUMMARY OF ADVANTAGES OF THE INVENTION
It will be appreciated that in constructing a cylin-der gripping apparatus according to t~e present invention,certain significant advantages are provided.
31 1~i3758 In particular, a cylinder gripping apparatus according to the present invention permits a cylinder, pipe or tube to be held by a gripping force which is proportional to an axial force tending to urge the cylinder, pipe or tube in an unwanted direction. A cylinder gripping apparatus according to the present invention provides an interfacing assembly which dev~lops a radial counterforce or gripping force in response to an axial force upon the cylinder which is proportional to the axial force. Thus, as the axial force tending to urge the cylinder in an unwanted direction increases, the gripping force will increase proportionally in response to the increase axial force.
In addition, a cylinder gripping apparatus according to the present invention provides an interfacing assembly which is more economically constructed and which is adapted to withstand greater forces between the jaw and the body. The elimination of arms which are pivotally connected by pins to the jaw and the body eliminates the requirement that the pins be sufficiently strong to withstand the forces between the arm and the body.
Moreover, the cylinder, pipe or tube need not be perfectly centered within the body. A cylinder gripping apparatus according to the present invention permits the jaw to move transversely with respect to the axis of the body and thereby align into engagement with a cylinder which is deformed or which is not perfectly centered within the body.
A cylinder gripping apparatus according to the present invention includes the further advantage of providing an interfacing assembly which may be used in connection with a hydrostatic testing apparatus for high pressure testing.
The interfacing assembly is adapted to withstand greater forces than the embodiment disclosed in the prior art.
~s~s~
A cylinder gripping apparatus according to the present invention includes the further advantage of providing utility as a snubber, safety hanging apparatus or blowout preventer for use in connection with wellhead operations.
In such an application, the cylinder gripping apparatus provides the advantage of jaws which do not have to be completely released from the pipe in order to pass ~~ couplings. Thus, the risk of dropping the pipe or having a blowout while couplings are being passed is avoided. A
blowout preventer, snubber or safety hanging apparatus constructed according to the present invention will pro-vide a safety feature in that the gripping force generated will be proportional to the axial and Torsional forces upon the pipe.
A cylinder gripping apparatus according to the present invention may employ offset floating lugs which provide the advantage of a gripping force which is also proportional to the rotational forces or torque upon the cylinder, tube of pipe being gripped. The offset floating lugs a~t as tongs to prevent rotation, in addition to gripping the pipe to prevent axial movement.
A platform jacking apparatus constructed in accordance with the present invention will provide a safe method of jacking drilling platforms providing a gripping force upon the platform leg which is proportional to the weight of the drilling platform.
Leveling of a drilling platform is simple and safe. A
jacking distance of a fraction of an inch may be achieved, if desiredl because one set of jaws can grip the platform leg at any point along the leg, while actuation means can be used to slide the platform any desired distance along the platform leg. Gripping is automatic. The jacking ~.~L53~Si~
distance is not constrained by any requirement that shear pin holes be aligned or that gears be meshed. The plat-form may be jacked up or leveled without completely releasing any one of the platform legs.
s Thus, it is apparent that there has been provided in accordance with the invention, a cylinder gripping appara-tus that substantially incorporates the advantages set forth above. Although the present invention has been described in conjunction with specific forms thereof r it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the ~oregoing disclosure. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is to be under-stood that the forms of the invention herewith shown and described are to be taken as the presently preferred embodiment. Various changes may be made in the shape, size and arrangement of parts. For example, equivalent elements or materials may be substituted for those illus-trated and described herein, parts may be reversed, and certain features of the invention may be utilized indepen dently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the invention.
Claims (26)
1. A member gripping apparatus for gripping a member having a predetermined cross-sectional shape, comprising:
a jaw, said jaw having a friction surface adapted for gripping a member, said friction surface generally conforming to the shape of the member to be gripped;
a body, said body being adapted to axially receive the member, said body having a front and a rear;
an interfacing assembly, said interfacing assembly being interposed between said jaw and said body, said interfacing assembly being adapted to urge said jaw into gripping engagement with the member when said jaw is urged gen-erally rearwardly with respect to said body, said interfacing assembly being adapted to provide a radial counterforce in response to an axial force upon the member, said radial counterforce being proportional to said axial force, said interfacing assembly having a curved surface at one end thereof, said curved surface being cooperable with an opposing face to permit a transverse displacement of said jaw from an initial position to a displaced position.
a jaw, said jaw having a friction surface adapted for gripping a member, said friction surface generally conforming to the shape of the member to be gripped;
a body, said body being adapted to axially receive the member, said body having a front and a rear;
an interfacing assembly, said interfacing assembly being interposed between said jaw and said body, said interfacing assembly being adapted to urge said jaw into gripping engagement with the member when said jaw is urged gen-erally rearwardly with respect to said body, said interfacing assembly being adapted to provide a radial counterforce in response to an axial force upon the member, said radial counterforce being proportional to said axial force, said interfacing assembly having a curved surface at one end thereof, said curved surface being cooperable with an opposing face to permit a transverse displacement of said jaw from an initial position to a displaced position.
2. The apparatus according to Claim 1, wherein said opposing face comprises a planar surface upon said jaw, said planar surface being located upon a side of said jaw generally opposite to said friction surface of said jaw.
3. The apparatus according to Claim 1, wherein said opposing face comprises a curved surface upon said jaw, said curved surface being located upon a side of said jaw generally opposite to said friction surface of said jaw.
4. The apparatus according to Claim 1, wherein said opposing face comprises a curved surface being adapted to receive said end of said interfacing assembly having said curved surface.
5. The apparatus according to Claim 1, wherein said opposing face comprises a planar surface upon said body.
6. A member gripping apparatus, comprising:
a jaw, said jaw having a friction surface adapted for gripping a member, said jaw having a first bearing groove;
a body, said body being adapted to axially receive the member, said body having a side wall, said side wall of said body having a second bearing groove, said body having a front and a rear; and, an angularly disposed floating force translation lug, said lug being engagable in said first and second bearing grooves, said lug being adapted to operatively associate said jaw with said body, said lug being adapted to urge said jaw into gripping engagement with the member when said jaw is urged generally rearwardly with respect to said body, said lug being adapted to permit said jaw to disengage the member when said jaw is urged generally forwardly with respect to said body.
a jaw, said jaw having a friction surface adapted for gripping a member, said jaw having a first bearing groove;
a body, said body being adapted to axially receive the member, said body having a side wall, said side wall of said body having a second bearing groove, said body having a front and a rear; and, an angularly disposed floating force translation lug, said lug being engagable in said first and second bearing grooves, said lug being adapted to operatively associate said jaw with said body, said lug being adapted to urge said jaw into gripping engagement with the member when said jaw is urged generally rearwardly with respect to said body, said lug being adapted to permit said jaw to disengage the member when said jaw is urged generally forwardly with respect to said body.
7. The apparatus according to Claim 6, further comprising:
a first stay connected to said jaw, said first stay being adapted to cover at least a portion of a cross sectional area of said first bearing groove in said jaw, said first stay being adapted to laterally retain said lugs within said first bearing groove while leaving said lugs free to rotatively pivot within said first bearing groove; and, a second stay connected to said side wall of said body, said second stay being adapted to cover at least a portion of a cross sectional area of said second bearing surface in said side wall, said second stay being adapted to lat-erally retain said lugs within said second bearing groove while leaving said lugs free to rotatively pivot within said second bear-ing groove.
a first stay connected to said jaw, said first stay being adapted to cover at least a portion of a cross sectional area of said first bearing groove in said jaw, said first stay being adapted to laterally retain said lugs within said first bearing groove while leaving said lugs free to rotatively pivot within said first bearing groove; and, a second stay connected to said side wall of said body, said second stay being adapted to cover at least a portion of a cross sectional area of said second bearing surface in said side wall, said second stay being adapted to lat-erally retain said lugs within said second bearing groove while leaving said lugs free to rotatively pivot within said second bear-ing groove.
8. The apparatus according to Claim 7, further comprising:
a resilient member disposed against said body, said resilient member being interposed between said body and said jaw, said resilient member being adapted to urge said jaw into engagement with the member.
a resilient member disposed against said body, said resilient member being interposed between said body and said jaw, said resilient member being adapted to urge said jaw into engagement with the member.
9. The apparatus according to Claim 8, further comprising:
actuating means connected to said lug for rotation-ally pivoting said lug whereby said jaw is urged generally forwardly permitting said jaw to disengage the member; and, an elastic member connected between said side wall of said body and said jaw, said elastic member being adapted to urge said jaw radially out-wardly, said elastic member being adapted to urge said lug into operative engagement with said first and second bearing grooves.
actuating means connected to said lug for rotation-ally pivoting said lug whereby said jaw is urged generally forwardly permitting said jaw to disengage the member; and, an elastic member connected between said side wall of said body and said jaw, said elastic member being adapted to urge said jaw radially out-wardly, said elastic member being adapted to urge said lug into operative engagement with said first and second bearing grooves.
10. The apparatus according to Claim 9, wherein:
said first bearing groove comprises a first arcu-ate bearing surface and further comprises a sloped forward surface, said forward sur-face being adapted to permit said lug to rotate in a first sense with respect to said jaw;
said second bearing groove comprises a second arcuate bearing surface and further comprises a sloped rearward surface, said rearward surface being adapted to permit said lug to rotate in a first sense with respect to said sidewall of said body; and, said lug having a first arcuate end and a second arcuate end, said first arcuate end being adapted to substantially contiguously engage said first arcuate bearing surface of said first bearing groove, said second arcuate end being adapted to substantially contiguously engage said second arcuate bearing surface of said second bearing groove, said lug being rotatably engagable against said first and second arcuate bearing surfaces.
said first bearing groove comprises a first arcu-ate bearing surface and further comprises a sloped forward surface, said forward sur-face being adapted to permit said lug to rotate in a first sense with respect to said jaw;
said second bearing groove comprises a second arcuate bearing surface and further comprises a sloped rearward surface, said rearward surface being adapted to permit said lug to rotate in a first sense with respect to said sidewall of said body; and, said lug having a first arcuate end and a second arcuate end, said first arcuate end being adapted to substantially contiguously engage said first arcuate bearing surface of said first bearing groove, said second arcuate end being adapted to substantially contiguously engage said second arcuate bearing surface of said second bearing groove, said lug being rotatably engagable against said first and second arcuate bearing surfaces.
11. Apparatus for capping an open end of a pipe during hydrostatic testing comprising:
a jaw, said jaw having a first bearing groove, said jaw having a friction surface adapted for gripping the pipe;
a body, said body adapted to axially receive a pipe, said body having a second bearing groove; and, a force translation lug, said lug being uncon-nected to said body and said jaw, said lug being disposable against said body and against said jaw, said lug being adapted to rotatively engage within said first and second bearing grooves, said lug being operable to urge said friction surface of said jaw against an outside surface of the pipe when said lug is rotated in a first sense with respect to said body.
a jaw, said jaw having a first bearing groove, said jaw having a friction surface adapted for gripping the pipe;
a body, said body adapted to axially receive a pipe, said body having a second bearing groove; and, a force translation lug, said lug being uncon-nected to said body and said jaw, said lug being disposable against said body and against said jaw, said lug being adapted to rotatively engage within said first and second bearing grooves, said lug being operable to urge said friction surface of said jaw against an outside surface of the pipe when said lug is rotated in a first sense with respect to said body.
12. The apparatus according to Claim 11, said body having an interior zone, further comprising:
a purge valve connected to said body; and, a passageway to place said purge valve in fluid communication with the interior zone of said body.
a purge valve connected to said body; and, a passageway to place said purge valve in fluid communication with the interior zone of said body.
13. The apparatus according to Claim 11, further comprising:
a seal axially positioned within said body and adapted to form a hydraulic seal between said body and the pipe to be capped, said seal having a first lip disposable against the inner surface of said body, the seal having a second lip connected to said first lip and adapted to displace toward an outer surface of the pipe to be capped.
a seal axially positioned within said body and adapted to form a hydraulic seal between said body and the pipe to be capped, said seal having a first lip disposable against the inner surface of said body, the seal having a second lip connected to said first lip and adapted to displace toward an outer surface of the pipe to be capped.
14. A member gripping apparatus for gripping a member having a predetermined cross-sectional shape, comprising:
a body, said body being adapted to axially receive a member, said body having a side wall, said side wall having an inclined inner surface;
a jaw, said jaw having a friction surface adapted to grip the member, said friction surface generally conforming to the shape of an outer surface of the member to be gripped;
a plurality of generally cylindrical rollers, said rollers being unconnected to said jaw and said body, said rollers being interposed between said jaw and said body, said rollers being operable to facilitate the movement of said jaw relative to said body along said inclined inner surface, said inclined inner surface being adapted to urge said jaw into engagement with the outer surface of the member when said jaw is urged rearwardly with respect to said body.
a body, said body being adapted to axially receive a member, said body having a side wall, said side wall having an inclined inner surface;
a jaw, said jaw having a friction surface adapted to grip the member, said friction surface generally conforming to the shape of an outer surface of the member to be gripped;
a plurality of generally cylindrical rollers, said rollers being unconnected to said jaw and said body, said rollers being interposed between said jaw and said body, said rollers being operable to facilitate the movement of said jaw relative to said body along said inclined inner surface, said inclined inner surface being adapted to urge said jaw into engagement with the outer surface of the member when said jaw is urged rearwardly with respect to said body.
15. The apparatus according to Claim 14, further comprising:
a plurality of channels formed traversely along said inclined inner surface, said channels being adapted to receive said rollers, said channels being generally cylindrically shaped in substantial correspondence with the shape of said rollers.
a plurality of channels formed traversely along said inclined inner surface, said channels being adapted to receive said rollers, said channels being generally cylindrically shaped in substantial correspondence with the shape of said rollers.
16. The apparatus according to Claim 14, further comprising:
a plurality of channels formed transversely along said jaw upon a surface of said jaw generally opposite said friction surface, said channels being adapted to receive said rollers, said channels being generally cylindrically shaped in substantial correspondence with the shape of said rollers.
a plurality of channels formed transversely along said jaw upon a surface of said jaw generally opposite said friction surface, said channels being adapted to receive said rollers, said channels being generally cylindrically shaped in substantial correspondence with the shape of said rollers.
17. The apparatus according to Claim 15 or Claim 16, further comprising:
a resilient member disposed against said body, said resilient member being adapted to urge said jaw into engagement with the member to be gripped;
actuating means pivotally connected to said body for urging said jaw generally forwardly with respect to said body; and, an elastic member connected between said body and said jaw, said elastic member being adapted to urge said jaw radially outwardly toward said body into operative engagement with said rollers, said elastic member being operable to maintain said rollers within said channels.
a resilient member disposed against said body, said resilient member being adapted to urge said jaw into engagement with the member to be gripped;
actuating means pivotally connected to said body for urging said jaw generally forwardly with respect to said body; and, an elastic member connected between said body and said jaw, said elastic member being adapted to urge said jaw radially outwardly toward said body into operative engagement with said rollers, said elastic member being operable to maintain said rollers within said channels.
18. A bar gripping apparatus for gripping a bar having a predetermined cross-sectional shape, comprising:
a body, said body being adapted to axially re-ceive a bar;
a cam arm pivotally attached to said body, said cam arm having a generally arcuate cam surface; and, a jaw, said jaw having a friction surface adapted for gripping the bar, said friction surface being adapted to conform to the shape of an outer surface of the bar, said jaw having a groove in a surface generally opposite to said friction surface, said groove being adapted to receive said cam arm, said cam arm being operable to urge said jaw into engagement with the outer surface of the bar when said cam arm is rotated with respect to said body.
a body, said body being adapted to axially re-ceive a bar;
a cam arm pivotally attached to said body, said cam arm having a generally arcuate cam surface; and, a jaw, said jaw having a friction surface adapted for gripping the bar, said friction surface being adapted to conform to the shape of an outer surface of the bar, said jaw having a groove in a surface generally opposite to said friction surface, said groove being adapted to receive said cam arm, said cam arm being operable to urge said jaw into engagement with the outer surface of the bar when said cam arm is rotated with respect to said body.
19. The apparatus according to Claim 18, further comprising:
a plurality of elastic members, connected between said body and said jaw, said elastic members being adapted to urge said jaw radially out-ward toward said body, said elastic members being operable to urge said jaw into operative engagement with said cam arm;
a forward alignment lip connected to the forward edge of said jaw; and, a rear alignment lip connected to the rear edge of said jaw.
a plurality of elastic members, connected between said body and said jaw, said elastic members being adapted to urge said jaw radially out-ward toward said body, said elastic members being operable to urge said jaw into operative engagement with said cam arm;
a forward alignment lip connected to the forward edge of said jaw; and, a rear alignment lip connected to the rear edge of said jaw.
20. A member gripping apparatus, comprising:
a jaw, said jaw having a friction surface adapted for gripping a member, said jaw being adapted to dispose against a force translation lug;
a body, said body being adapted to axially receive the member, said body having a side wall, said side wall of said body being adapted to dispose against a force translation lug, said body having a front and a rear; and, an angularly disposed force translation lug, said lug having at least one generally spherical end, said lug being interposed between said body and said jaw, said lug being adapted to urge said jaw into gripping engagement with the member when said jaw is urged generally rearwardly with respect to said body, said spherical end of said lug being adapted to engage in a generally corresponding spherical recess, said spherical end and said spherical recess being operable to permit said jaw to engage the member in generally corresponding alignment with the member.
a jaw, said jaw having a friction surface adapted for gripping a member, said jaw being adapted to dispose against a force translation lug;
a body, said body being adapted to axially receive the member, said body having a side wall, said side wall of said body being adapted to dispose against a force translation lug, said body having a front and a rear; and, an angularly disposed force translation lug, said lug having at least one generally spherical end, said lug being interposed between said body and said jaw, said lug being adapted to urge said jaw into gripping engagement with the member when said jaw is urged generally rearwardly with respect to said body, said spherical end of said lug being adapted to engage in a generally corresponding spherical recess, said spherical end and said spherical recess being operable to permit said jaw to engage the member in generally corresponding alignment with the member.
21. The apparatus according to Claim 20, wherein:
said spherical recess is located upon said side wall of said body; and, said force translation lug is pivotally connected to said jaw.
said spherical recess is located upon said side wall of said body; and, said force translation lug is pivotally connected to said jaw.
22. The apparatus according to Claim 20, wherein:
said spherical recess is located upon said jaw;
and, wherein said force translation lug is pivotally connected to said side wall of said body.
said spherical recess is located upon said jaw;
and, wherein said force translation lug is pivotally connected to said side wall of said body.
23. The apparatus according to Claim 20, wherein:
said force translation lug further comprises a second generally spherical end remote from said first spherical end; and, said spherical recess is located upon said side wall of said body;
and further comprising:
a second spherical recess generally correspond-ing to said second spherical end, said second spherical recess being located upon said jaw, said ends of said force translation lug being adapted to engage said recesses, said force translation lug being operable to permit radial, axial and transverse movement of said jaw with respect to said body.
said force translation lug further comprises a second generally spherical end remote from said first spherical end; and, said spherical recess is located upon said side wall of said body;
and further comprising:
a second spherical recess generally correspond-ing to said second spherical end, said second spherical recess being located upon said jaw, said ends of said force translation lug being adapted to engage said recesses, said force translation lug being operable to permit radial, axial and transverse movement of said jaw with respect to said body.
24. A platform jacking apparatus, comprising:
a body, said body being connectable to a plat-form, said body having a guide sleeve, said body being adapted to axially receive a platform leg, a first set of jaws, said jaws being adapted to grip the platform leg, said jaws being in operative association with said body, said jaws being adapted to provide a first radial counterforce in response to an axial force upon the platform leg, said first radial counterforce being propor-tional to said axial force, a jaw housing, said jaw housing being adapted to axially receive the platform leg, said jaw housing being adapted to coaxially fit within said guide sleeve of said body, said jaw housing being adapted to recipro-cally slide within said guide sleeve, a second set of jaws, said jaws being adapted to grip the platform leg, said jaws being in operative association with said jaw housing, said jaws being adapted to pro-vide a second radial counterforce in re-sponse to said axial force, said second radial counterforce being proportional to said axial force, actuation means connected to said body and disposed against said jaw housing for re-ciprocally moving said jaw housing within said guide sleeve, said actuation means being operable to extend and retract said jaw housing within said guide sleeve;
said first jaws being mutually cooperable with said second jaws and said actuation means to grip the platform leg when said second jaws are disengaged form the platform leg and said jaw housing is being retracted by said actuation means; and said second jaws and said actuation means being mutually cooperable with said first jaws to grip the platform leg when said first jaws are disengaged from the platform leg and said jaw housing is being extended by said actuation means, said actuation means, said second jaws, said jaw housing, and said body being operable to raise the platform when said jaw housing is extended by said actuation means.
a body, said body being connectable to a plat-form, said body having a guide sleeve, said body being adapted to axially receive a platform leg, a first set of jaws, said jaws being adapted to grip the platform leg, said jaws being in operative association with said body, said jaws being adapted to provide a first radial counterforce in response to an axial force upon the platform leg, said first radial counterforce being propor-tional to said axial force, a jaw housing, said jaw housing being adapted to axially receive the platform leg, said jaw housing being adapted to coaxially fit within said guide sleeve of said body, said jaw housing being adapted to recipro-cally slide within said guide sleeve, a second set of jaws, said jaws being adapted to grip the platform leg, said jaws being in operative association with said jaw housing, said jaws being adapted to pro-vide a second radial counterforce in re-sponse to said axial force, said second radial counterforce being proportional to said axial force, actuation means connected to said body and disposed against said jaw housing for re-ciprocally moving said jaw housing within said guide sleeve, said actuation means being operable to extend and retract said jaw housing within said guide sleeve;
said first jaws being mutually cooperable with said second jaws and said actuation means to grip the platform leg when said second jaws are disengaged form the platform leg and said jaw housing is being retracted by said actuation means; and said second jaws and said actuation means being mutually cooperable with said first jaws to grip the platform leg when said first jaws are disengaged from the platform leg and said jaw housing is being extended by said actuation means, said actuation means, said second jaws, said jaw housing, and said body being operable to raise the platform when said jaw housing is extended by said actuation means.
25. The apparatus according to Claim 24, further comprising:
a first releaser, said first releaser being con-nected to said body, said first releaser being in operative association with said first jaws, said first releaser being oper-able to disengage said first jaws from the platform leg to permit said actuation means to extend said jaw housing and raise the platform;
a second releaser, said second releaser being connected to said jaw housing, said second releaser being in operative association with said second jaws, said second releaser being operable to disengage said second jaws from the platform leg to permit said actuation means to retract said jaw housing.
a first releaser, said first releaser being con-nected to said body, said first releaser being in operative association with said first jaws, said first releaser being oper-able to disengage said first jaws from the platform leg to permit said actuation means to extend said jaw housing and raise the platform;
a second releaser, said second releaser being connected to said jaw housing, said second releaser being in operative association with said second jaws, said second releaser being operable to disengage said second jaws from the platform leg to permit said actuation means to retract said jaw housing.
26. Apparatus for gripping a member, comprising a jaw, a body, and an interposed assembly; where:
said jaw has a surface adapted for gripping said member;
said body is adapted to axially receive said member; and said interposed assembly is adapted to operatively associate said jaw with said body to urge said jaw into gripping engagement with said member, when said jaw is moved with respect to said body.
said jaw has a surface adapted for gripping said member;
said body is adapted to axially receive said member; and said interposed assembly is adapted to operatively associate said jaw with said body to urge said jaw into gripping engagement with said member, when said jaw is moved with respect to said body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000374254A CA1153758A (en) | 1981-03-31 | 1981-03-31 | Gripping apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000374254A CA1153758A (en) | 1981-03-31 | 1981-03-31 | Gripping apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1153758A true CA1153758A (en) | 1983-09-13 |
Family
ID=4119587
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000374254A Expired CA1153758A (en) | 1981-03-31 | 1981-03-31 | Gripping apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1153758A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6116118A (en) * | 1998-07-15 | 2000-09-12 | Wesch, Jr.; William E. | Gripping apparatus for power tongs and backup tools |
| CN112027897A (en) * | 2020-09-15 | 2020-12-04 | 四川华神钢构有限责任公司 | Steel box girder rapid hoisting sling and use method thereof |
| CN113830663A (en) * | 2021-11-29 | 2021-12-24 | 山东绅联药业有限公司 | Special hoisting equipment with adjusting capacity |
-
1981
- 1981-03-31 CA CA000374254A patent/CA1153758A/en not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6116118A (en) * | 1998-07-15 | 2000-09-12 | Wesch, Jr.; William E. | Gripping apparatus for power tongs and backup tools |
| CN112027897A (en) * | 2020-09-15 | 2020-12-04 | 四川华神钢构有限责任公司 | Steel box girder rapid hoisting sling and use method thereof |
| CN112027897B (en) * | 2020-09-15 | 2022-09-09 | 四川华神钢构有限责任公司 | Steel box girder rapid hoisting sling and use method thereof |
| CN113830663A (en) * | 2021-11-29 | 2021-12-24 | 山东绅联药业有限公司 | Special hoisting equipment with adjusting capacity |
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |