CA1085377A - Casing tong - Google Patents
Casing tongInfo
- Publication number
- CA1085377A CA1085377A CA305,047A CA305047A CA1085377A CA 1085377 A CA1085377 A CA 1085377A CA 305047 A CA305047 A CA 305047A CA 1085377 A CA1085377 A CA 1085377A
- Authority
- CA
- Canada
- Prior art keywords
- lever arm
- gear rim
- gripping
- radially recessed
- housing
- 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.)
- Expired
Links
- 238000006243 chemical reaction Methods 0.000 abstract description 5
- 230000002093 peripheral effect Effects 0.000 description 6
- 230000000717 retained effect Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
- E21B19/16—Connecting or disconnecting pipe couplings or joints
- E21B19/161—Connecting or disconnecting pipe couplings or joints using a wrench or a spinner adapted to engage a circular section of pipe
- E21B19/164—Connecting or disconnecting pipe couplings or joints using a wrench or a spinner adapted to engage a circular section of pipe motor actuated
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27C—PLANING, DRILLING, MILLING, TURNING OR UNIVERSAL MACHINES FOR WOOD OR SIMILAR MATERIAL
- B27C7/00—Wood-turning machines; Equipment therefor
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mechanical Engineering (AREA)
- Mining & Mineral Resources (AREA)
- Forests & Forestry (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- Physics & Mathematics (AREA)
- Wood Science & Technology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Placing Or Removing Of Piles Or Sheet Piles, Or Accessories Thereof (AREA)
- Earth Drilling (AREA)
- Drilling And Boring (AREA)
- Drilling Tools (AREA)
Abstract
ABSTRACT
There is provided an improved casing tong wherein a novel cam and guide roller arrangement allows unilateral application of the clamping or gripping force by one jaw, while the second jaw serves only as a reaction element, and wherein the clamping face of the cams is provided with a steeper slope to allow a rapid increase in clamping force and a virtually radial approach of the jaws to the casing.
There is provided an improved casing tong wherein a novel cam and guide roller arrangement allows unilateral application of the clamping or gripping force by one jaw, while the second jaw serves only as a reaction element, and wherein the clamping face of the cams is provided with a steeper slope to allow a rapid increase in clamping force and a virtually radial approach of the jaws to the casing.
Description
`~ 1085377 The present invention relate~ to a casing tong, in particular a tong for turning borehole casings, which comprises an enclosure with an axial opening and a radially recessed portion adapted to the casing outside diameter as well as a gear rim inside said enclosure which i~ rotatable under the action of a drive means, said gear rim being provided with a corresponding radially recessed portion and with cams having associated gripping jaws which are universally movably arranged on suitable holding elements, The use of oasing tongs of the type described above requires high gripping or clamping forces to sorew pipes into and/or out of engagement with one another. Tongs that have been used in the past employ very flat curvatures of the cams which convert the peripheral forces of the drive means into gripping or clamping force. Besides the existence of substantially radial forces which are very unfavourable to the tong and which may result in undesired expansion thereof, there is another drawback involved in that the magnitude of forces would cause sub~tantial penetration oi the blades into the casing pipe material 90 that after elimination of contaot forces said blades are prevented from clearing the pipe wall by turning the gear rim in the opposite direction. A reversal of the direction of rotation after screwing would force the pipe to rotate to the opposite direction so that the screwed joint i~ loo~ened again. Even more difficult is to separate the clamping blades from the pipe or casing after an un~crewing operation. The pressure applied to the ca~ing wall by the gripping or clamping jaws i9 increased
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108~;377 until the unscrewing process has been initiated. A~ter complete separation of the oa~in~ pipe from it~ ~onnector it is very difficult and may even be impossible to detac~
the gripping jaws from the unscrewed casing section by reversing the direction o~ rotation, since there is no longer any countertorque. Trials with steeper cams ~howed that the contact force~ were too low. A makeshift was therefore adopted in practice in that unscrewing was done in two 6teps of which the first was to initiate the unscrewing operation and was stopped immediately on having achieved such initiation ~or refitting the tong, and the second was to carry out the remainder of the unscrewing operation with reduced gripping or clamping forces involved, ~he bite of the tong bladee into the casing pipe material is all the heavier, the flatter are the cams oi the gear rim, the reasons being that as the tongs grip there i9 simultaneously a con~iderable peripheral distance being traversed which entails a tangentially directed cut into - the ca~ing pipe material. The application oi high forces by flat cams moreover results in a resilient deiormation of the mating parts, i,e, of olamping jaw guide rollers and cams. This resilient deformation partioularly contributes to the fact that separating the clamping blades on termination of a working cycle is extremely di~iicult.
It is an objeat of the present invention, therefore, to provide a oasing tong of the type described above wherein the gripping or clamping Jaws thereof can be readily freed irom the casing pipes after both a screw-ing and an unsorewine operation, In particular, the ioroe~ prêvailing between the cams and the guide rollers 108~7 moving along the curved faces thereof are minimized so that the material will not be exposed to ~uch loads as would entail resilient deformation.
According to the present invention thi~ problem is solved in that lever means to increase the clamping or gripping force are used between the clamping or gripping jaws and the holding elements thereof and that each cam iB provided with a shallow-curve centering face and a substantially steeper-curve clamping face, Contact force~ can be very advantageously increased in that the clamping or gripping force is applied unilaterally, i,e, via one clamping or gripping jaw at a time while the opposite jaw only serves as reaction element. This permits the clamping face to be provided with an even steeper slope so that there is a rapid increase of clamp-ing force and the gripping jaws engage into the casing materials in a virtually radial orientation. It is for this purpose that the centering face is subdivided into a shallow-slope centering portion and a circular concen-trically extsnding retainer portion. ~he lever means are provided in the form of one-armed lever~ to simplify construction, They are pivoted to the outer extremities of a substantially semicircular gripping jaw carrier and on their iree ends carry guide rollers adapted to move along the curved ¢entering and clamping face~ of the cams, with the pivot attachment of said gripping jaws to the lever~ being dispo~ed between the pivotal axes of the guide rollere and the pivotal axes of the lever mean~ at the extremitiee of the gripping jaw carrier, It ha~ ~urprisingly been found that steeper cams, the u~ of which i~ pr~ctic~ble due to provision of ~orce-increasing lever arms and introduction o~ clamping force via only one of the gripping jaws, permit to disengage the tong from the casing without difficulties even in the absence of countertorque. No resilient deformation can be caused of the cams and guide rollers due specifically to the use o~ steeper clamping faces, Another advantage is that the gripping jaw blades traverse only very minor peripheral distances on the cn~ing ~o that the casing or pipe material undergoes deformation to only a negligible degree only, ~he necessary clamping or gripping force leads to no further casing or pipe deiormation~
. Another essential advantage is that the steeper-curve clamping faces suppress development of a radial force of such magnitude as might bend or force the tong open, A considerable portion of the driving force remains :
tangential so as to protect the gear rim from deflection, The gripping or olamping force proper is accommodated by the carrier directly holding the gripping jaws and thus - kept away from the gear rim, Fitting and removal of conventional radially-retractable tong~ i9 difficult and time wasting, The tong must be forced against the casing until ~he jaws have concentric-qlly gripped or engaged the casing, Due to provision of a short centering curved face which then changes over into a holding or retaining curved face, the gripping jaws are ad~usted into centering position after a minor rotational movement of the gear rim, This means that the tong automatically keep~ to the casing, though in .
the absence of any driving contact therewith, so that the casing is still freely movable to a minor degree in the tong. It is no longer possible after screwed engagement for the tong to come off the casing since, following their release, the gripping jaws of the tong initially remain in centering position, which means that the tong arrests the casing in said position and the jaw blades are only disengaged out of contact with the casing material. ~ue to the fact that the cams are disposed in a symmetrically opposed relation and engage the guide rollers of the lever means in such a way that the guide rollers of none lever moves on the centering curved face, and the guide roller of the lever opposite thereto necessarily moves on the clamping face, the peripheral force is converted into clamping force via only one of the levers during the clamping operation. The force of reaction is applied as backup force by the opposite gripping jaw and the associated clamping lever. This permits the use of an optimal, i.e. substantially steep, clamping face which results in a substantially radial clamping force of the gripping jaws as desired. By reversing the direction of rotation of the tong, the gripping jaws can easily be released from the pipe without the necessity of applying a countertorque.
Following upon the above discussion, the invention provides in one broad aspect an apparatus for rotating a tubular member, comprising a housing having a radially recessed opening for receiving the tubular member; a latch for closing off the radially recessed opening during operation of the apparatus, said latch being pivotally secured to the housing on one side of the radially recessed opening; a latch power means for actuating the latch connected to the latch; guide discs mounted within the housing, said guide discs having a radially recessed opening for receiving the tubular member corresponding to the radially recessed opening of the housing; a gear rim mounted inside said radially recessed opening in said housing and rotatable under the action of a drive means, said gear rim having an interior wall and a -~ - 6 -B
- . : . . : . . :
. .
.
radially recessed opening for receiving the tubular member corresponding to the radially recessed openings of the housing and of the guide discs; a power drive means for driving the gear rim, said power drive means being secured to the exterior of the housing; a first and a second multi-faceted cam mounted within the gear rim in axially staggered positions with respect to the axis of the apparatus; a substantially crescent-shaped carrier member mounted within the gear rim, and having a first end and a second end, said carrier member being rotatable within the gear rim and along the cams; a first lever arm pivotally secured to the first end of the carrier member; a second lever arm pivotally secured to the second end of the carrier member; a first gripping jaw for gripping the tubular member, said jaw pivotally secured to the first lever arm; a second gripping jaw for gripping the tubular member, said jaw pivotally secured to the second lever arm; a :~
first guide roller rotatably mounted to the first lever arm so that it moves on the faces of the first multi-faceted cam for actuating the first gripping jaw; and a second guide roller rotatably mounted to the :~
second lever arm so that it moves on the faces of the second multi-faceted cam for actuating the second gripping jaw.
In a further embodimene, the multi-faceted cams are disposed on substantially opposite sides of the axis of the apparatus, said cams having three faces formed on the surface thereof, a centering face, a holding face, and a clamping face, the holding face being shaped in the form of a circular arc oriented concentrically to the axis of the apparatus, the centering face sloping gently away from one end of the holding face to the edge of the radially recessed opening of the gear rim, and the clamping face sloping abruptly from the other end of holding face to the interior wall of the gear rim, said cams being axially staggered with respect to the gear rim and the axis of the apparatus and disposed symmetrically with respect to the axis of the apparatus.
I~
- 6a -~, .
s ,~, : ,,,,. ' .. :, . .. ~ . .. . . : ..
853~7 An embodiment of the present invention given by way of example is hereinafter described with reference to the accompanying schematic drawings in which:
Fig. 1 is a plan view of the casing tong;
Fig. 2 shows the gripping jaws with jaw carrier and gear rim with cam means in neutral B ~: ~
position, the top half of the figure showing the tong during introduction o-f the casing, and the bottom half show-ing the ca~ing already swung into position between the gripping jaws;
Fig. 3 shows a centered casing;
Fig. 4 shows a casing clamped in place between the gripping jaws; and Fig. 5 also shows a casing clamped in place, but turned in opposite direction.
The plan view of the complete apparatus seen in Fig.
1 shows an enclosure 1 with holding and guide disks 2 to afford guiding action and to retain a gear rim 5 (Figs. 2 to 5) disposed therein to operate gripping jaws
108~;377 until the unscrewing process has been initiated. A~ter complete separation of the oa~in~ pipe from it~ ~onnector it is very difficult and may even be impossible to detac~
the gripping jaws from the unscrewed casing section by reversing the direction o~ rotation, since there is no longer any countertorque. Trials with steeper cams ~howed that the contact force~ were too low. A makeshift was therefore adopted in practice in that unscrewing was done in two 6teps of which the first was to initiate the unscrewing operation and was stopped immediately on having achieved such initiation ~or refitting the tong, and the second was to carry out the remainder of the unscrewing operation with reduced gripping or clamping forces involved, ~he bite of the tong bladee into the casing pipe material is all the heavier, the flatter are the cams oi the gear rim, the reasons being that as the tongs grip there i9 simultaneously a con~iderable peripheral distance being traversed which entails a tangentially directed cut into - the ca~ing pipe material. The application oi high forces by flat cams moreover results in a resilient deiormation of the mating parts, i,e, of olamping jaw guide rollers and cams. This resilient deformation partioularly contributes to the fact that separating the clamping blades on termination of a working cycle is extremely di~iicult.
It is an objeat of the present invention, therefore, to provide a oasing tong of the type described above wherein the gripping or clamping Jaws thereof can be readily freed irom the casing pipes after both a screw-ing and an unsorewine operation, In particular, the ioroe~ prêvailing between the cams and the guide rollers 108~7 moving along the curved faces thereof are minimized so that the material will not be exposed to ~uch loads as would entail resilient deformation.
According to the present invention thi~ problem is solved in that lever means to increase the clamping or gripping force are used between the clamping or gripping jaws and the holding elements thereof and that each cam iB provided with a shallow-curve centering face and a substantially steeper-curve clamping face, Contact force~ can be very advantageously increased in that the clamping or gripping force is applied unilaterally, i,e, via one clamping or gripping jaw at a time while the opposite jaw only serves as reaction element. This permits the clamping face to be provided with an even steeper slope so that there is a rapid increase of clamp-ing force and the gripping jaws engage into the casing materials in a virtually radial orientation. It is for this purpose that the centering face is subdivided into a shallow-slope centering portion and a circular concen-trically extsnding retainer portion. ~he lever means are provided in the form of one-armed lever~ to simplify construction, They are pivoted to the outer extremities of a substantially semicircular gripping jaw carrier and on their iree ends carry guide rollers adapted to move along the curved ¢entering and clamping face~ of the cams, with the pivot attachment of said gripping jaws to the lever~ being dispo~ed between the pivotal axes of the guide rollere and the pivotal axes of the lever mean~ at the extremitiee of the gripping jaw carrier, It ha~ ~urprisingly been found that steeper cams, the u~ of which i~ pr~ctic~ble due to provision of ~orce-increasing lever arms and introduction o~ clamping force via only one of the gripping jaws, permit to disengage the tong from the casing without difficulties even in the absence of countertorque. No resilient deformation can be caused of the cams and guide rollers due specifically to the use o~ steeper clamping faces, Another advantage is that the gripping jaw blades traverse only very minor peripheral distances on the cn~ing ~o that the casing or pipe material undergoes deformation to only a negligible degree only, ~he necessary clamping or gripping force leads to no further casing or pipe deiormation~
. Another essential advantage is that the steeper-curve clamping faces suppress development of a radial force of such magnitude as might bend or force the tong open, A considerable portion of the driving force remains :
tangential so as to protect the gear rim from deflection, The gripping or olamping force proper is accommodated by the carrier directly holding the gripping jaws and thus - kept away from the gear rim, Fitting and removal of conventional radially-retractable tong~ i9 difficult and time wasting, The tong must be forced against the casing until ~he jaws have concentric-qlly gripped or engaged the casing, Due to provision of a short centering curved face which then changes over into a holding or retaining curved face, the gripping jaws are ad~usted into centering position after a minor rotational movement of the gear rim, This means that the tong automatically keep~ to the casing, though in .
the absence of any driving contact therewith, so that the casing is still freely movable to a minor degree in the tong. It is no longer possible after screwed engagement for the tong to come off the casing since, following their release, the gripping jaws of the tong initially remain in centering position, which means that the tong arrests the casing in said position and the jaw blades are only disengaged out of contact with the casing material. ~ue to the fact that the cams are disposed in a symmetrically opposed relation and engage the guide rollers of the lever means in such a way that the guide rollers of none lever moves on the centering curved face, and the guide roller of the lever opposite thereto necessarily moves on the clamping face, the peripheral force is converted into clamping force via only one of the levers during the clamping operation. The force of reaction is applied as backup force by the opposite gripping jaw and the associated clamping lever. This permits the use of an optimal, i.e. substantially steep, clamping face which results in a substantially radial clamping force of the gripping jaws as desired. By reversing the direction of rotation of the tong, the gripping jaws can easily be released from the pipe without the necessity of applying a countertorque.
Following upon the above discussion, the invention provides in one broad aspect an apparatus for rotating a tubular member, comprising a housing having a radially recessed opening for receiving the tubular member; a latch for closing off the radially recessed opening during operation of the apparatus, said latch being pivotally secured to the housing on one side of the radially recessed opening; a latch power means for actuating the latch connected to the latch; guide discs mounted within the housing, said guide discs having a radially recessed opening for receiving the tubular member corresponding to the radially recessed opening of the housing; a gear rim mounted inside said radially recessed opening in said housing and rotatable under the action of a drive means, said gear rim having an interior wall and a -~ - 6 -B
- . : . . : . . :
. .
.
radially recessed opening for receiving the tubular member corresponding to the radially recessed openings of the housing and of the guide discs; a power drive means for driving the gear rim, said power drive means being secured to the exterior of the housing; a first and a second multi-faceted cam mounted within the gear rim in axially staggered positions with respect to the axis of the apparatus; a substantially crescent-shaped carrier member mounted within the gear rim, and having a first end and a second end, said carrier member being rotatable within the gear rim and along the cams; a first lever arm pivotally secured to the first end of the carrier member; a second lever arm pivotally secured to the second end of the carrier member; a first gripping jaw for gripping the tubular member, said jaw pivotally secured to the first lever arm; a second gripping jaw for gripping the tubular member, said jaw pivotally secured to the second lever arm; a :~
first guide roller rotatably mounted to the first lever arm so that it moves on the faces of the first multi-faceted cam for actuating the first gripping jaw; and a second guide roller rotatably mounted to the :~
second lever arm so that it moves on the faces of the second multi-faceted cam for actuating the second gripping jaw.
In a further embodimene, the multi-faceted cams are disposed on substantially opposite sides of the axis of the apparatus, said cams having three faces formed on the surface thereof, a centering face, a holding face, and a clamping face, the holding face being shaped in the form of a circular arc oriented concentrically to the axis of the apparatus, the centering face sloping gently away from one end of the holding face to the edge of the radially recessed opening of the gear rim, and the clamping face sloping abruptly from the other end of holding face to the interior wall of the gear rim, said cams being axially staggered with respect to the gear rim and the axis of the apparatus and disposed symmetrically with respect to the axis of the apparatus.
I~
- 6a -~, .
s ,~, : ,,,,. ' .. :, . .. ~ . .. . . : ..
853~7 An embodiment of the present invention given by way of example is hereinafter described with reference to the accompanying schematic drawings in which:
Fig. 1 is a plan view of the casing tong;
Fig. 2 shows the gripping jaws with jaw carrier and gear rim with cam means in neutral B ~: ~
position, the top half of the figure showing the tong during introduction o-f the casing, and the bottom half show-ing the ca~ing already swung into position between the gripping jaws;
Fig. 3 shows a centered casing;
Fig. 4 shows a casing clamped in place between the gripping jaws; and Fig. 5 also shows a casing clamped in place, but turned in opposite direction.
The plan view of the complete apparatus seen in Fig.
1 shows an enclosure 1 with holding and guide disks 2 to afford guiding action and to retain a gear rim 5 (Figs. 2 to 5) disposed therein to operate gripping jaws
3 and 4. These gripping jaws 3 and 4 encompass a casing 6 to be centered and to be screw connected or di~connected to and/or from extension means, A radially reces~ed position 7 permits the tong to be pluced aroun~
the casing 6 and/or to remove it therefrom after the ôperation has been completed. This reoessed position 7 is closed off by means of a latch type flap 8 which is mechanically, hydraulically or pneumatically operable with a means 9 and which connects the enclosure portions separated by said rece~s 7 in a positive and form-fitting manner, A hydraulic drive means 10 i8 used to operate the gear rim (not ~hown) in Fig, 1, Identical parts are raferred to by identical refer-enca numerals in the figures, The gear rim 5 carries cams 12 and 13 which are disposed in a symmetrical relation to the centerline of the recessed portion 11.
Each o~ said cams i~ provided with a curved centering face 12a and/or 13a, a curved center-position holding face 12b and/or 13b and a curved cla~ping face 12c and/or 13c, Levers 15 and 16 are pivotably secured to a ~ubstantially crescent-shaped carrier i4, The respective pivot points on the gripping jaw carrier 14 are designated by the reference numeral 17. ~he levers 15 and 16 carry guide rollers 18 and 19 at their free ends, and also support the gripping jaws 3 and 4 $itted with clamping or gripping blades 20, Levers 15 and 16 - .
are one-armed levers, which means that the respective pivot point 2i of said gripping jaws ~ and 4 is disposed intermediate the guide rollers 18 and 19 and the respect- ~ ~:
ive pivot 17 of the levers at the gripping jaw carrier 14, ~ :
As can be seen from Figs, 3 to 5, the gripping jaw 3 is functionally as~ociated with oam 13 via guide roller i8, and guide roller 19 can only engage cam 12 because the rollers and their associated cams are axially ~taggered, Fig, 3, $or instance, shows a centering operation via gripping jaw 4, The associated roller 19 initially engaged the center- -ing $ace 12a o~ cam 12, which means it was displaced radially inward until it reached the holding face 12b, ~.
and was retained in this position, By further turning - the gear rim 5 in the direction oi~ the arrow, i,e, clockwi~e, the guide roller 18 o$ gripping jaw 3 i9 moved to the curved olamping $aoe l~c. ~his operation i8 particularly ¢lear from Fig, 4, The oams are hence . in ~uoh relative arrangement that one o$ the gripping , 108~3~7 jaws is always retained in centered position by one of the holding races and thus serves as a reaction element to provide the backpressure or reaction ~orce necessary for the clamping pressure of the opposite gripping jaw to build up. As can be seen from Fig. 5, after reversal the guide roller 18 move~ along the holding face 13b oi cam 13, while guide roller 19 has entered the curved olamping face 12c o~ cam 12 to thereby make the lever 16 exert the required pressure to the gripping jaw 4, iOThe figuree of the drawings show that the curved clamping ~ace~ of cams 12 and 13 are provided with a steep ~lope so that the necassary clamping or gripping iorce is obtained with only minor peripheral movements of the gear rim involved, and with the gripping jaws only having to make ex~remely small peripheral movements during each clamping or gripping oper,ation, This tendency ~-is considerably increased due to provision o~ levers 15 and 16.
the casing 6 and/or to remove it therefrom after the ôperation has been completed. This reoessed position 7 is closed off by means of a latch type flap 8 which is mechanically, hydraulically or pneumatically operable with a means 9 and which connects the enclosure portions separated by said rece~s 7 in a positive and form-fitting manner, A hydraulic drive means 10 i8 used to operate the gear rim (not ~hown) in Fig, 1, Identical parts are raferred to by identical refer-enca numerals in the figures, The gear rim 5 carries cams 12 and 13 which are disposed in a symmetrical relation to the centerline of the recessed portion 11.
Each o~ said cams i~ provided with a curved centering face 12a and/or 13a, a curved center-position holding face 12b and/or 13b and a curved cla~ping face 12c and/or 13c, Levers 15 and 16 are pivotably secured to a ~ubstantially crescent-shaped carrier i4, The respective pivot points on the gripping jaw carrier 14 are designated by the reference numeral 17. ~he levers 15 and 16 carry guide rollers 18 and 19 at their free ends, and also support the gripping jaws 3 and 4 $itted with clamping or gripping blades 20, Levers 15 and 16 - .
are one-armed levers, which means that the respective pivot point 2i of said gripping jaws ~ and 4 is disposed intermediate the guide rollers 18 and 19 and the respect- ~ ~:
ive pivot 17 of the levers at the gripping jaw carrier 14, ~ :
As can be seen from Figs, 3 to 5, the gripping jaw 3 is functionally as~ociated with oam 13 via guide roller i8, and guide roller 19 can only engage cam 12 because the rollers and their associated cams are axially ~taggered, Fig, 3, $or instance, shows a centering operation via gripping jaw 4, The associated roller 19 initially engaged the center- -ing $ace 12a o~ cam 12, which means it was displaced radially inward until it reached the holding face 12b, ~.
and was retained in this position, By further turning - the gear rim 5 in the direction oi~ the arrow, i,e, clockwi~e, the guide roller 18 o$ gripping jaw 3 i9 moved to the curved olamping $aoe l~c. ~his operation i8 particularly ¢lear from Fig, 4, The oams are hence . in ~uoh relative arrangement that one o$ the gripping , 108~3~7 jaws is always retained in centered position by one of the holding races and thus serves as a reaction element to provide the backpressure or reaction ~orce necessary for the clamping pressure of the opposite gripping jaw to build up. As can be seen from Fig. 5, after reversal the guide roller 18 move~ along the holding face 13b oi cam 13, while guide roller 19 has entered the curved olamping face 12c o~ cam 12 to thereby make the lever 16 exert the required pressure to the gripping jaw 4, iOThe figuree of the drawings show that the curved clamping ~ace~ of cams 12 and 13 are provided with a steep ~lope so that the necassary clamping or gripping iorce is obtained with only minor peripheral movements of the gear rim involved, and with the gripping jaws only having to make ex~remely small peripheral movements during each clamping or gripping oper,ation, This tendency ~-is considerably increased due to provision o~ levers 15 and 16.
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An apparatus for rotating a tubular member, comprising, (a) a housing having a radially recessed opening for receiving the tubular member, (b) a latch for closing off the radially recessed opening during operation of the apparatus, said latch being pivotally secured to the housing on one side of the radially recessed opening, (c) a latch power means for actuating the latch connected to the latch, (d) guide discs mounted within the housing, said guide discs having a radially recessed opening for receiving the tubular member corresponding to the radially recessed opening of the housing, (e) a gear rim mounted inside said radially recessed opening in said housing and rotatable under the action of a drive means, said gear rim having an interior wall and a radially recessed opening for receiving the tubular member corresponding to the radially recessed openings of the housing and of the guide discs, (f) a power drive means for driving the gear rim, said power drive means being secured to the exterior of the housing, (g) a first and a second multi-faceted cam mounted within the gear rim in axially staggered positions with respect to the axis of the apparatus, (h) a substantially crescent-shaped carrier member mounted within the gear rim, and having a first end and a second end, said carrier member being rotatable within the gear rim and along the cams, (i) a first lever arm pivotally secured to the first end of the carrier member, (j) a second lever arm pivotally secured to the second end of the carrier member, (k) a first gripping jaw for gripping the tubular member, said jaw pivotally secured to the first lever arm, (l) a second gripping jaw for gripping the tubular member, said jaw pivotally secured to the second lever arm, (m) a first guide roller rotatably mounted to the first lever arm so that it moves on the faces of the first multi-faceted cam for actuating the first gripping jaw, (n) and a second guide roller rotatably mounted to the second lever arm so that it moves on the faces of the second multi-faceted cam for actuating the second gripping jaw.
2. The apparatus of claim 1 wherein each gripping jaw is mounted to its respective lever arm at a point between the point of the securing of the respective lever arm to the carrier member and the lever arm's respective guide roller.
3. The apparatus of claim 1 wherein gripping elements are formed of the face of each gripping jaw.
4. The apparatus of claim 1 wherein the latch power means is a conventional non-electrical power means.
5. The apparatus of claim 1 wherein the power drive means is a conventional hydraulic power means.
6. The apparatus of claim 1 wherein the first and the second multi-faceted cams are disposed on substantially opposite sides of the axis of the apparatus, said cams having three faces formed on the surface thereof, a centering face, a holding face, and a clamping face, the holding face being shaped in the form of a circular arc oriented concentrically to the axis of the apparatus, the centering face sloping gently away from one end of the holding face to the edge of the radially recessed opening of the gear rim, and the clamping face sloping abruptly from the other end of holding face to the interior wall of the gear rim, said cams being axially staggered with respect to the gear rim and the axis of the apparatus and disposed symmetrically with respect to the axis of the apparatus.
7. An apparatus for rotating a tubular member, comprising, (a) a housing having a radially recessed opening for receiving the tubular member, (b) a latch for closing off the radially recessed opening during operation of the apparatus, said latch being pivotally secured to the housing on one side of the radially recessed opening, (c) a non-electrical latch power means for operating the latch, said latch power means connected to one side of the latch, (d) guide discs mounted within the housing, each of said guide discs having a radially recessed opening for receiving the tubular member corresponding to the radially recessed opening of the housing, (e) a gear rim mounted inside said radially recessed opening in said housing and rotatable under the action of a drive means, said gear rim having a radially recessed opening for receiving the tubular member corresponding to and substantially aligned with the radially recessed openings of the housing and of the guide discs, said gear rim having an exterior wall and an interior wall, (f) an hydraulic power drive means for driving the gear rim said power drive means being secured to the housing, (g) a first and a second cam disposed on substantially opposite sides of and axially staggered with respect to the axis of the apparatus, each such cam having a holding face, a centering face, and a clamping face, said holding face disposed between the other two faces and shaped in the form of a circular arc and oriented concentrically to the axis of the apparatus, said centering face sloping gently away from one end of the holding face to the inner edge of the radial recessed opening, and said clamping face sloping abruptly from the other end of the holding face to the interior wall of the gear rim, said cams being disposed substantially symmetrically with respect to the axis of the apparatus, (h) a substantially crescent-shaped carrier member rotatably mounted within the gear rim and cams, said carrier member having a first end and a second end, (i) a first lever arm pivotally secured to the first end of the carrier member, (j) a second lever arm pivotally secured to the second end of the carrier member, (k) a first guide roller rotatably mounted to the first lever arm and movable on the faces of the first cam for actuating the first gripping jaw, (l) a second guide roller rotatably mounted to the second lever arm and movable on the faces of the second cam for actuating the second gripping jaw, (m) a first gripping jaw for gripping the tubular member pivotally secured to one end of the first lever arm at a point between the guide roller and the point of the securing of the lever arm to the carrier member, (n) a second gripping jaw for gripping the tubular member pivotally secured to one end of the second lever arm at a point between the guide roller and the point of the securing of the lever arm to the carrier member, (o) gripping elements formed of the surface of each gripping jaw.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2726472A DE2726472C3 (en) | 1977-06-11 | 1977-06-11 | Pipe wrench, in particular for twisting casing pipes for boreholes |
| DEG7718536.5 | 1977-06-11 | ||
| DEP2726472.8 | 1977-06-11 | ||
| DE7718536 | 1977-06-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1085377A true CA1085377A (en) | 1980-09-09 |
Family
ID=25772140
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA305,047A Expired CA1085377A (en) | 1977-06-11 | 1978-06-08 | Casing tong |
Country Status (7)
| Country | Link |
|---|---|
| AU (1) | AU522416B2 (en) |
| BR (1) | BR7803715A (en) |
| CA (1) | CA1085377A (en) |
| GR (1) | GR64993B (en) |
| IN (1) | IN149488B (en) |
| NL (1) | NL189872C (en) |
| NO (1) | NO151254C (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AUPO829097A0 (en) * | 1997-07-29 | 1997-08-21 | Universal Drilling Systems (Aust) Pty Limited | Apparatus for disconnecting drill rods |
-
1978
- 1978-06-02 NO NO78781939A patent/NO151254C/en unknown
- 1978-06-08 CA CA305,047A patent/CA1085377A/en not_active Expired
- 1978-06-09 NL NLAANVRAGE7806271,A patent/NL189872C/en not_active IP Right Cessation
- 1978-06-09 BR BR787803715A patent/BR7803715A/en unknown
- 1978-06-10 GR GR56493A patent/GR64993B/en unknown
- 1978-06-12 AU AU37032/78A patent/AU522416B2/en not_active Expired
- 1978-06-14 IN IN662/CAL/78A patent/IN149488B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| NL189872C (en) | 1993-08-16 |
| GR64993B (en) | 1980-06-11 |
| NO781939L (en) | 1978-12-12 |
| BR7803715A (en) | 1979-01-16 |
| NO151254B (en) | 1984-11-26 |
| NL189872B (en) | 1993-03-16 |
| AU3703278A (en) | 1979-12-20 |
| AU522416B2 (en) | 1982-06-03 |
| IN149488B (en) | 1981-12-26 |
| NL7806271A (en) | 1978-12-13 |
| NO151254C (en) | 1985-03-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |