Apparatus for connecting tubulars using a top drive

Information

  • Patent Grant
  • 7451826
  • Patent Number
    7,451,826
  • Date Filed
    Tuesday, August 15, 2006
    17 years ago
  • Date Issued
    Tuesday, November 18, 2008
    15 years ago
Abstract
An apparatus for facilitating the connection of tubulars using a top drive, said apparatus comprising a motor (4, 4′) for rotating a tool (30) for drivingly engaging a tubular, and means (3) for connecting said motor (4, 4′) to said top drive, the apparatus being such that, in use, said motor (4, 4′) can rotate one tubular with respect to another to connect said tubular.
Description
BACKGROUND OF THE INVENTION
Field of the Invention

This invention relates to an apparatus for facilitating the connection of tubulars using a top drive and is more particularly, but not exclusively, intended for facilitating the connection of a section or stand of casing to a string of casing.


SUMMARY OF THE INVENTION

In the construction of oil or gas wells it is usually necessary to line the borehole with a string of tubulars known as a casing. Because of the length of the casing required, sections or stands of say two sections of casing are progressively added to the string as it is lowered into the well from a drilling platform. In particular, when it is desired to add a section or stand of casing the string is usually restrained from falling into the well by applying the slips of a spider located in the floor of the drilling platform. The new section or stand of casing is then moved from a rack to the well centre above the spider. The threaded pin of the section or stand of casing to be connected is then located over the threaded box of the casing in the well and the connection is made up by rotation there between. An elevator is then connected to the top of the new section or stand and the whole casing string lifted slightly to enable the slips of the spider to be released. The whole casing string is then lowered until the top of the section is adjacent the spider whereupon the slips of the spider are re-applied, the elevator disconnected and the process repeated.


It is common practice to use a power tong to torque the connection up to a predetermined torque in order to make the connection. The power tong is located on a platform, either on rails, or hung from a derrick on a chain. However, it has recently been proposed to use a top drive for making such connection. The normal use of such a top drive may be the driving of a drill string.


A problem associated with using a top drive for rotating tubulars in order to obtain a connection between tubulars is that some top drives are not specifically designed for rotating tubulars are not able to rotate at the correct speed or have non standard rotors.


According to the present invention there is provided an apparatus for facilitating the connection of tubulars using a top drive, said apparatus comprising a motor for rotating a tool for drivingly engaging a tubular, and means for connecting said motor to said top drive, the apparatus being such that, in use, said motor can rotate one tubular with respect to another to connect said tubulars.


Other features of the invention are set out in Claims 2 et seq.





BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention and in order to show how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawings, in which:



FIG. 1 is a front perspective view of an apparatus in accordance with the present invention; and



FIG. 2 is a rear perspective view of the apparatus of FIG. 1 in use.





DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1 there is shown an apparatus which is generally identified by reference numeral 1.


The apparatus 1 comprises a connecting tubular 2, a suspension unit 3 and a hydraulic motor 4 and 4′. The hydraulic motor 4,4′ has a stator 5 and a rotor 6 and is driven by a supply of pressurised hydraulic fluid (the fluid supply lines are not illustrated in the Figures). The suspension unit 3 suspends the hydraulic motor 4,4′ from the connecting tubular 2.


The suspension unit 3 comprises a plate 7 which is fixed to the connecting tubular 2 by a collar 8. The plate 7 has two projections 9 and 10 which have holes 11 and 12 for accommodating axles 13 and 14, which arc rotationally disposed therein. The axles 13 and 14 are integral with a rigid body 15. A slider 16 is arranged on runners 17 and (not shown) on the rigid body 15. Arms 18 and 19 are connected at one end to the slider 16 via spherical bearings 20 and at the other end to each side of the stator 5 via spherical bearings 21 and 21′. The arms 18 and 19 are provided with lugs 22 and 22′ to which one end of a piston and cylinder 23, 24 is attached and are movable thereabout. The other end of each piston and cylinder 23, 24 is attached to lugs 25, 26 respectively and is movable thereabout. A mud pipe 27 is provided between the plate 7 and the stator 5 for carrying mud to the inside of a tubular therebelow. The mud pipe 27 comprises curved outer surfaces at both ends (not shown) which are located in corresponding recesses in cylindrical sections 28, 29, thus allowing a ball and socket type movement between the plate 7 and the stator 5.


Referring to FIG. 2, the apparatus 1 is suspended from a top drive (not shown) via connecting shaft 2. A tool 30 for engaging with a tubular is suspended from beneath the rotor 6 of the hydraulic motor 4. Such a tool may be arranged to be inserted into the upper end of the tubular, with gripping elements of the tool being radially displaceable for engagement with the inner wall of the tubular so as to secure the tubular to the tool.


In use, a tubular (not shown) to be connected to a tubular string held in a spider (not shown) is located over the tool 30. The tool 30 grips the tubular. The apparatus 1 and the tubular are lowered by moving the top drive so that the tubular is in close proximity with the tubular string held in the spider. However, due to amongst other things manufacturing tolerances in the tubulars, the tubular often does not align perfectly with the tubular held in the spider. The suspension unit 3 allows minor vertical and horizontal movements to be made by using alignment pistons 31 and 32 for horizontal movements, and piston and cylinders 23 and 24 for vertical movements. The alignment piston 31 acts between the rigid body 15 and the plate 7. The alignment piston 32 acts between the slider 16 and the arm 19. The alignment pistons 31 and 32 and pistons and cylinders 23, 25 are actuated by hydraulic or pneumatic means and controlled from a remote control device.


The piston and cylinders 23, 24 are hydraulically operable. It is envisaged however, that the piston and cylinders 23, 24 may be of the pneumatic compensating type, i.e. their internal pressure may be adjusted to compensate for the weight of the tubular so that movement of the tubular may be conducted with minimal force. This can conveniently be achieved by introducing pneumatic fluid into the piston and cylinder 23, 24 and adjusting the pressure therein.


Once the tubulars are aligned, the hydraulic motor 4 and 4′ rotate the tubular via 15 gearing in the stator 5 thereby making up the severed connection. During connection the compensating piston and cylinders 23, 24 expand to accommodate the movement of the upper tubular. The alignment pistons 31 and 32 can then be used to move the top of the tubular into alignment with the top drive. If necessary, final torquing can be conducted by the top drive at this stage, via rotation of the pipe 27, and the main elevator can also be swung onto and connected to the tubular prior to releasing the slips in the spider and lowering the casing string. It will be appreciated that the suspension unit 3 effectively provides an adapter for connecting a top drive to the tubular engaging tool 30.

Claims
  • 1. A method of facilitating making of a connection between an upper tubular and a lower tubular, comprising: engaging the upper tubular with a tubular engagement tool attached to a suspension unit;engaging a lower end of the upper tubular with an upper end of the lower tubular;rotating the upper tubular via the tubular engagement tool, thereby threading the tubulars to form the connection;torquing the connection via the tubular engagement tool; andcompensating for movement of the upper tubular with the suspension unit during the threading.
  • 2. The method of claim 1, wherein the upper tubular is rotated using a motor mounted on the suspension unit.
  • 3. The method of claim 2, further comprising rotating the upper tubular using a top drive.
  • 4. The method of claim 1, further comprising adjusting the suspension unit to move the upper tubular in at least two planes.
  • 5. The method of claim 1, wherein compensating for movement of the upper tubular comprises pneumatically compensating via at least one piston and cylinder arrangement.
  • 6. The method of claim 1, wherein compensating for movement of the upper tubular comprises compensating via at least one piston and cylinder arrangement.
  • 7. The method of claim 1, wherein the tubular engagement tool includes at least one gripping element displaceable in a radial direction for engagement with a wall of the upper tubular during engaging the upper tubular.
  • 8. The method of claim 1, further comprising rotating the upper tubular using a top drive.
  • 9. A method of facilitating making of a connection between an upper tubular and a lower tubular, comprising: engaging the upper tubular with a gripping assembly having at least one radially displaceable element for gripping the upper tubular, wherein the gripping assembly is connected to a suspension unit;compensating for weight of the upper tubular to accommodate movement of the upper tubular while engaged by the gripping assembly;engaging a lower end of the upper tubular with an upper end of the lower tubular to form the connection therebetween; anddelivering torque to the upper tubular via the gripping assembly.
  • 10. The method of claim 9, wherein the torque is generated from a motor mounted to the suspension unit.
  • 11. The method of claim 9, wherein engaging the lower end of the upper tubular with the upper end of the lower tubular includes rotating the upper tubular, thereby threading the tubulars together.
  • 12. The method of claim 11, further comprising compensating for movement of the upper tubular with the suspension unit during the threading.
  • 13. The method of claim 9, further comprising adjusting the suspension unit to move the upper tubular in at least two planes.
  • 14. The method of claim 9, wherein compensating for weight of the upper tubular comprises compensating via at least one piston and cylinder arrangement.
  • 15. The method of claim 9, wherein compensating for weight of the upper tubular is pneumatic.
  • 16. An apparatus for making a connection between an upper tubular and a lower tubular, comprising: a tubular engagement tool for gripping the upper tubular, wherein the tubular engagement tool includes at least one gripping element displaceable in a radial direction for engagement with a wall of the upper tubular in an engaged position; anda suspension unit connected to the tubular engagement tool, the suspension unit having a motor for rotating the tubular engagement tool and a compensation portion, wherein, with the tubular engagement tool in the engaged position, the upper tubular is rotatable by the motor and is, relative to the lower tubular, movable along with the tubular engagement tool by operation of the compensation portion to compensate for movement of the upper tubular during making of the connection to the lower tubular.
  • 17. The apparatus of claim 16, further comprising a top drive connected to the suspension unit.
  • 18. The apparatus of claim 17, wherein the top drive is capable of rotating the tubular engagement tool.
  • 19. The apparatus of claim 16, wherein the suspension unit is adapted to move the tubular engagement tool in the axial direction to compensate for movement of the upper tubular during make up.
  • 20. The apparatus of claim 16, wherein the suspension unit is adapted to move the upper tubular in at least two planes.
  • 21. The apparatus of claim 16, wherein the compensation portion comprises at least one piston and cylinder arrangement.
  • 22. The apparatus of claim 16, further comprising a mud pipe for carrying mud to the tubulars.
  • 23. The apparatus of claim 16, wherein the at least one gripping element is displaceable for engagement with an inner wall of the upper tubular in the engaged position.
Priority Claims (1)
Number Date Country Kind
9818360.1 Aug 1998 GB national
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 10/801,289, filed Mar. 16, 2004, now U.S. Pat. No. 7,090,021, which claims benefit of U.S. patent application Ser. No. 09/762,606, filed May 21, 2001, now U.S. Pat. No. 6,705,405, which is the National Stage of International Application No. PCT/GB99/02708, filed Aug. 16, 1999, which claims benefit of Great Britain Patent Application No. GB9818360.1, filed Aug. 24, 1998. Each of the aforementioned related patent applications is herein incorporated by reference.

US Referenced Citations (306)
Number Name Date Kind
179973 Thornton Jul 1876 A
1414207 Reed Apr 1922 A
1418766 Wilson Jun 1922 A
1585069 Youle May 1926 A
1728136 Power Sep 1929 A
1777592 Thomas Oct 1930 A
1805007 Pedley May 1931 A
1825026 Thomas Sep 1931 A
1842638 Wigle Jan 1932 A
1917135 Littell Jul 1933 A
2105885 Hinderliter Jan 1938 A
2128430 Pryor Aug 1938 A
2167338 Murcell Jul 1939 A
2184681 Osmun et al. Dec 1939 A
2214429 Miller Sep 1940 A
2414719 Cloud Jan 1947 A
2522444 Grable Sep 1950 A
2536458 Munsinger Jan 1951 A
2570080 Stone Oct 1951 A
2582987 Hagenbook Jan 1952 A
2595902 Stone May 1952 A
2610690 Beatty Sep 1952 A
2641444 Moon Jun 1953 A
2668689 Cormany Feb 1954 A
2692059 Boiling, Jr. Oct 1954 A
2953406 Young Sep 1960 A
2965177 Bus, Sr. et al. Dec 1960 A
3041901 Knights Jul 1962 A
3087546 Wooley Apr 1963 A
3122811 Gilreath Mar 1964 A
3191683 Alexander Jun 1965 A
3193116 Kenneday et al. Jul 1965 A
3266582 Homanick Aug 1966 A
3305021 Lebourg Feb 1967 A
3321018 McGill May 1967 A
3380528 Timmons Apr 1968 A
3392609 Bartos Jul 1968 A
3477527 Koot Nov 1969 A
3489220 Kinley Jan 1970 A
3518903 Ham et al. Jul 1970 A
3548936 Kilgore et al. Dec 1970 A
3552507 Brown Jan 1971 A
3552508 Brown Jan 1971 A
3552509 Brown Jan 1971 A
3552510 Brown Jan 1971 A
3566505 Martin Mar 1971 A
3570598 Johnson Mar 1971 A
3602302 Kluth Aug 1971 A
3608664 Weiner Sep 1971 A
3635105 Dickmann et al. Jan 1972 A
3638989 Sandquist Feb 1972 A
3662842 Bromell May 1972 A
3680412 Mayer et al. Aug 1972 A
3691825 Dyer Sep 1972 A
3697113 Palauro et al. Oct 1972 A
3700048 Desmoulins Oct 1972 A
3706347 Brown Dec 1972 A
3746330 Taciuk Jul 1973 A
3747675 Brown Jul 1973 A
3766991 Brown Oct 1973 A
3776320 Brown Dec 1973 A
3780883 Brown Dec 1973 A
3808916 Porter et al. May 1974 A
3838613 Wilms Oct 1974 A
3840128 Swoboda, Jr. et al. Oct 1974 A
3848684 West Nov 1974 A
3857450 Guier Dec 1974 A
3871618 Funk Mar 1975 A
3881375 Kelly May 1975 A
3885679 Swoboda, Jr. et al. May 1975 A
3901331 Djurovic Aug 1975 A
3913687 Gyongyosi et al. Oct 1975 A
3915244 Brown Oct 1975 A
3961399 Boyadjieff Jun 1976 A
3964552 Slator Jun 1976 A
3980143 Swartz et al. Sep 1976 A
4054332 Bryan, Jr. Oct 1977 A
4077525 Callegari et al. Mar 1978 A
4100968 Delano Jul 1978 A
4127927 Hauk et al. Dec 1978 A
4142739 Billingsley Mar 1979 A
4202225 Sheldon et al. May 1980 A
4221269 Hudson Sep 1980 A
4257442 Claycomb Mar 1981 A
4262693 Giebeler Apr 1981 A
4274777 Scaggs Jun 1981 A
4274778 Putnam et al. Jun 1981 A
4280380 Eshghy Jul 1981 A
4315553 Stallings Feb 1982 A
4320915 Abbott et al. Mar 1982 A
4401000 Kinzbach Aug 1983 A
4437363 Haynes Mar 1984 A
4440220 McArthur Apr 1984 A
4446745 Stone et al. May 1984 A
4449596 Boyadjieff May 1984 A
4472002 Beney et al. Sep 1984 A
4489794 Boyadjieff Dec 1984 A
4492134 Reinhldt et al. Jan 1985 A
4494424 Bates Jan 1985 A
4515045 Gnatchenko et al. May 1985 A
4529045 Boyadjieff et al. Jul 1985 A
4570706 Pugnet Feb 1986 A
4592125 Skene Jun 1986 A
4593584 Neves Jun 1986 A
4593773 Skeie Jun 1986 A
4604724 Shaginian et al. Aug 1986 A
4604818 Inoue Aug 1986 A
4605077 Boyadjieff Aug 1986 A
4613161 Brisco Sep 1986 A
4625796 Boyadjieff Dec 1986 A
4646827 Cobb Mar 1987 A
4649777 Buck Mar 1987 A
4652195 McArthur Mar 1987 A
4667752 Berry et al. May 1987 A
4676312 Mosing et al. Jun 1987 A
4681158 Pennison Jul 1987 A
4681162 Boyd Jul 1987 A
4683962 True Aug 1987 A
4686873 Lang et al. Aug 1987 A
4709599 Buck Dec 1987 A
4709766 Boyadjieff Dec 1987 A
4725179 Woolslayer et al. Feb 1988 A
4735270 Fenyvesi Apr 1988 A
4738145 Vincent et al. Apr 1988 A
4742876 Barthelemy et al. May 1988 A
4759239 Hamilton et al. Jul 1988 A
4762187 Haney Aug 1988 A
4765401 Boyadjieff Aug 1988 A
4765416 Bjerking et al. Aug 1988 A
4773689 Wolters Sep 1988 A
4781359 Matus Nov 1988 A
4791997 Krasnov Dec 1988 A
4793422 Krasnov Dec 1988 A
4800968 Shaw et al. Jan 1989 A
4813493 Shaw et al. Mar 1989 A
4813495 Leach Mar 1989 A
4821814 Willis et al. Apr 1989 A
4832552 Skelly May 1989 A
4836064 Slator Jun 1989 A
4843945 Dinsdale Jul 1989 A
4867236 Haney et al. Sep 1989 A
4875530 Frink et al. Oct 1989 A
4878546 Shaw et al. Nov 1989 A
4899816 Mine Feb 1990 A
4909741 Schasteen et al. Mar 1990 A
4921386 McArthur May 1990 A
4936382 Thomas Jun 1990 A
4962579 Moyer et al. Oct 1990 A
4962819 Bailey et al. Oct 1990 A
4971146 Terrell Nov 1990 A
4997042 Jordan et al. Mar 1991 A
5022472 Bailey et al. Jun 1991 A
5036927 Willis Aug 1991 A
5049020 McArthur Sep 1991 A
5060542 Hauk Oct 1991 A
5062756 McArthur et al. Nov 1991 A
5107940 Berry Apr 1992 A
5111893 Kvello-Aune May 1992 A
RE34063 Vincent et al. Sep 1992 E
5191939 Stokley Mar 1993 A
5207128 Albright May 1993 A
5233742 Gray et al. Aug 1993 A
5245265 Clay Sep 1993 A
5251709 Richardson Oct 1993 A
5255751 Stogner Oct 1993 A
5272925 Henneuse et al. Dec 1993 A
5282653 LaFleur et al. Feb 1994 A
5284210 Helms et al. Feb 1994 A
5294228 Willis et al. Mar 1994 A
5297833 Willis et al. Mar 1994 A
5305839 Kalsi et al. Apr 1994 A
5332043 Ferguson Jul 1994 A
5340182 Busink et al. Aug 1994 A
5351767 Stogner et al. Oct 1994 A
5354150 Canales Oct 1994 A
5368113 Schulze-Beckinghausen Nov 1994 A
5386746 Hauk Feb 1995 A
5388651 Berry Feb 1995 A
5433279 Tessari et al. Jul 1995 A
5461905 Penisson Oct 1995 A
5497840 Hudson Mar 1996 A
5501280 Brisco Mar 1996 A
5501286 Berry Mar 1996 A
5503234 Clanton Apr 1996 A
5535824 Hudson Jul 1996 A
5575344 Wireman Nov 1996 A
5577566 Albright et al. Nov 1996 A
5584343 Coone Dec 1996 A
5588916 Moore Dec 1996 A
5645131 Trevisani Jul 1997 A
5661888 Hanslik Sep 1997 A
5667026 Lorenz et al. Sep 1997 A
5706894 Hawkins, III Jan 1998 A
5711382 Hansen et al. Jan 1998 A
5735348 Hawkins, III Apr 1998 A
5735351 Helms Apr 1998 A
5746276 Stuart May 1998 A
5765638 Taylor Jun 1998 A
5772514 Moore Jun 1998 A
5785132 Richardson et al. Jul 1998 A
5791410 Castille et al. Aug 1998 A
5803191 Mackintosh Sep 1998 A
5806589 Lang Sep 1998 A
5833002 Holcombe Nov 1998 A
5836395 Budde Nov 1998 A
5839330 Stokka Nov 1998 A
5842530 Smith et al. Dec 1998 A
5850877 Albright et al. Dec 1998 A
5890549 Sprehe Apr 1999 A
5909768 Castille et al. Jun 1999 A
5931231 Mock Aug 1999 A
5960881 Allamon et al. Oct 1999 A
5971079 Mullins Oct 1999 A
5971086 Bee et al. Oct 1999 A
6000472 Albright et al. Dec 1999 A
6012529 Mikolajczyk et al. Jan 2000 A
6056060 Abrahamsen et al. May 2000 A
6065550 Gardes May 2000 A
6070500 Dlask et al. Jun 2000 A
6079509 Bee et al. Jun 2000 A
6119772 Pruet Sep 2000 A
6142545 Penman et al. Nov 2000 A
6161617 Gjedebo Dec 2000 A
6170573 Brunet et al. Jan 2001 B1
6173777 Mullins Jan 2001 B1
6199641 Downie et al. Mar 2001 B1
6202764 Ables et al. Mar 2001 B1
6217258 Yamamoto et al. Apr 2001 B1
6227587 Terral May 2001 B1
6237684 Bouligny, Jr. et al. May 2001 B1
6276450 Seneviratne Aug 2001 B1
6279654 Mosing et al. Aug 2001 B1
6309002 Bouligny Oct 2001 B1
6311792 Scott et al. Nov 2001 B1
6315051 Ayling Nov 2001 B1
6334376 Torres Jan 2002 B1
6349764 Adams et al. Feb 2002 B1
6360633 Pietras Mar 2002 B2
6378630 Ritorto et al. Apr 2002 B1
6390190 Mullins May 2002 B2
6412554 Allen et al. Jul 2002 B1
6415862 Mullins Jul 2002 B1
6431626 Bouligny Aug 2002 B1
6443241 Juhasz et al. Sep 2002 B1
6527047 Pietras Mar 2003 B1
6527493 Kamphorst et al. Mar 2003 B1
6536520 Snider et al. Mar 2003 B1
6553825 Boyd Apr 2003 B1
6591471 Hollingsworth et al. Jul 2003 B1
6595288 Mosing et al. Jul 2003 B2
6622796 Pietras Sep 2003 B1
6637526 Juhasz et al. Oct 2003 B2
6651737 Bouligny Nov 2003 B2
6668684 Allen et al. Dec 2003 B2
6668937 Murray Dec 2003 B1
6679333 York et al. Jan 2004 B2
6688394 Ayling Feb 2004 B1
6688398 Pietras Feb 2004 B2
6691801 Juhasz et al. Feb 2004 B2
6725938 Pietras Apr 2004 B1
6725949 Seneviratne Apr 2004 B2
6732822 Slack et al. May 2004 B2
6742584 Appleton Jun 2004 B1
6742596 Haugen Jun 2004 B2
6832656 Fournier, Jr. et al. Dec 2004 B2
6832658 Keast Dec 2004 B2
6840322 Haynes Jan 2005 B2
6892835 Shahin et al. May 2005 B2
6907934 Kauffman et al. Jun 2005 B2
6938697 Haugen Sep 2005 B2
6976298 Pietras Dec 2005 B1
7004259 Pietras Feb 2006 B2
7028586 Robichaux Apr 2006 B2
7073598 Haugen Jul 2006 B2
7090021 Pietras Aug 2006 B2
7096977 Juhasz et al. Aug 2006 B2
7100698 Kracik et al. Sep 2006 B2
7107875 Haugen et al. Sep 2006 B2
7117938 Hamilton et al. Oct 2006 B2
7140445 Shahin et al. Nov 2006 B2
7188686 Folk et al. Mar 2007 B2
7213656 Pietras May 2007 B2
7325610 Giroux et al. Feb 2008 B2
20010042625 Appleton Nov 2001 A1
20020029878 Victor Mar 2002 A1
20020108748 Keyes Aug 2002 A1
20020170720 Haugen Nov 2002 A1
20030155159 Slack et al. Aug 2003 A1
20030164276 Snider et al. Sep 2003 A1
20030173073 Snider et al. Sep 2003 A1
20030221519 Haugen et al. Dec 2003 A1
20040003490 Shahin et al. Jan 2004 A1
20040069500 Haugen Apr 2004 A1
20040144547 Koithan et al. Jul 2004 A1
20040173358 Haugen Sep 2004 A1
20040216924 Pietras et al. Nov 2004 A1
20040251050 Shahin et al. Dec 2004 A1
20040251055 Shahin et al. Dec 2004 A1
20050000691 Giroux et al. Jan 2005 A1
20050051343 Pietras et al. Mar 2005 A1
20050096846 Koithan et al. May 2005 A1
20050098352 Beierbach et al. May 2005 A1
20060000600 Pietras Jan 2006 A1
20060124353 Juhasz et al. Jun 2006 A1
20060180315 Shahin et al. Aug 2006 A1
20070000668 Christensen Jan 2007 A1
Foreign Referenced Citations (47)
Number Date Country
2 307 386 Nov 2000 CA
3 523 221 Feb 1987 DE
0 087 373 Aug 1983 EP
0 162 000 Nov 1985 EP
0 171 144 Feb 1986 EP
0 285 386 Oct 1988 EP
0 474 481 Mar 1992 EP
0 479 583 Apr 1992 EP
0 525 247 Feb 1993 EP
0 589 823 Mar 1994 EP
1148206 Oct 2001 EP
1 256 691 Nov 2002 EP
1 469 661 Apr 1977 GB
2 053 088 Feb 1981 GB
2 201 912 Sep 1988 GB
2 223 253 Apr 1990 GB
2 224 481 Sep 1990 GB
2 240 799 Aug 1991 GB
2 275 486 Apr 1993 GB
2 345 074 Jun 2000 GB
2 357 530 Jun 2001 GB
2001173349 Jun 2001 JP
WO 90-06418 Jun 1990 WO
WO 92-18743 Oct 1992 WO
WO 93-07358 Apr 1993 WO
WO 95-10686 Apr 1995 WO
WO 96-18799 Jun 1996 WO
WO 97-08418 Mar 1997 WO
WO 98-05844 Feb 1998 WO
WO 98-11322 Mar 1998 WO
WO 98-32948 Jul 1998 WO
WO 99-11902 Mar 1999 WO
WO 99-41485 Aug 1999 WO
WO 99-58810 Nov 1999 WO
WO 00-08293 Feb 2000 WO
WO 00-09853 Feb 2000 WO
WO 00-11309 Mar 2000 WO
WO 00-11310 Mar 2000 WO
WO 00-11311 Mar 2000 WO
WO 00-39429 Jul 2000 WO
WO 00-39430 Jul 2000 WO
WO 00-50730 Aug 2000 WO
WO 01-12946 Feb 2001 WO
WO 01-33033 May 2001 WO
WO 01-94738 Dec 2001 WO
WO 2004-022903 Mar 2004 WO
WO 2005090740 Sep 2005 WO
Related Publications (1)
Number Date Country
20070051519 A1 Mar 2007 US
Continuations (2)
Number Date Country
Parent 10801289 Mar 2004 US
Child 11464575 US
Parent 09762606 US
Child 10801289 US