Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Background of_the Invention
26 Generally, it is old, as shown by patent No.
~7 3,851,897, to connect and disconnect an underwater wellhead
28 by the use of a hydraulically actuated piston moving locking
29 dogs into a locking relationship ~etween a connector and a
wellhead.
31 The present invention is directed to various
32 Lmprovements in a connector for connecting and disconnecting
34
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two members utilizing an over-the-center toggle rnechanism
which provides a positive mechanical lock of the locking
dogs, provides high preloads by relatively smaller atua-
tor forces due to the high mechanical advantage of the
toggle mechanism, holds the togg],e mechanism in a past
dead center position, and securely supports the act~ating
mechanism in an oil filled cavity.
Summary
The present invention is directed to a connector for
connecting and disconnecting two members in which the first
member includes a locking notch and the second member
includes a double-acting, longitudinally moving piston for
moving locking dogs into and out of the notch in which the
dogs are slideably carried by the second member for trans-
verse movement toward and away from the locking notch.
The novel feature is a locking toggle mechanism comprising
said dogs slideably carried by the second member for trans-
verse moyement toward and away from said second member for
engagement and disengagement with the locking notch, and a
toggle linkage having a first pivot connection connected
to the dogs and a second pivot connection longitudinally
actuated by the piston whereby the longitudinal movement
of the second pivot connection transversely moves said
locking dogs and moves the second pivot connection past
the first pivot connection into a past dead center locking
position.
Another feature of the present inventlon is the pro~
vision of a resi,li~nt load spring acting against the second
pivot connections and toward the first pivot connections
for locking the second pivot connections in a past dead
center position relative to the first pivot connections ,
thereby providing a positive mechanical lock for the dogs
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as well as resulting in high preloadS acting between the
pivot and second member with a relatively small piston
force due to the high mechanical advantage of the togyle
linkage.
Yet a further feature of the present invention is the
provision of a hydraulically actuated connector in which
the second body includes an annular cavity in which a
longitudinally reciprocal carriage is mounted and moved
by the piston and the carriage supports the second pivot
lQ connections and the spring which are transversely movable
on the carriage.
A still further feature is the provision of sealing
means for enclosing the cavity so that it may be oil
filled and a flexible member is provided exposed on one
side to the interior of the cavity and on the second side
to the exterior of the cavity for compensating for a
difference in fluid pressure between the inside and
outside of the body as well as compensating for movement
of the piston and dogs into and out of the cavity.
2Q Other and further objects, features and advantages
will be apparent from the following description of a
presently preferred embodiment of the invention, given for
the purpose of disclosure and taken on conjunction with
the accompanying drawings.
Brief DescEi~tion of_the Drawings
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Flgure 1 is an elevational view, in quarter section,
of the connector of the present invention shown in the
locked position~
Figure 2 is an elevational view, in quarter section,
3Q of the connector of the present invention shown in the
unlocked position, and
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Figure 3 is a cross-sectional vie~w taken along the
line 3-3 of Figure 1.
Description of the Preferred Embodiment
While the present invention is directed to a connector
for connecting and disconnecting two remote underwater
conductors such as a subsea blowout preventer stack or a
subsea Christmas tree to a wellhead of an oil and/or gas
well, the connector is also suitable for use in a remote
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1 subsea pipeline connector, flowline, marine riser connector
2 and other applications.
3 Referring now to the drawings, the reference
4 numeral 10 generally indicates a first tubular meT~er such
as the top of a wellhead having one or more annular locking
6 notches 12 on its exteriox to which a second member of
7 connector, generally indicated by the reference numeral 1~,
8 is connected or disconnected.
9 The connector 14 includes.a tubular body 16 having
an annular cavity 18 therein. The body 16 is adapted to
11 telescope over and seat and seal on member 10.
12 one ar more double acting piston and cylinder
13 assemblies 20 axe provided in the body 16 each with a
14 piston 21 having a piston rod 22 extending into the cavity
lS 18. Hydraulic pressure line 24 supplies hydraulic pressure
16 to on~ side of.the pistons 21, and hydxaulic pressure line
17 26 ap~lies hydraulic pressure to the other side of the
18 pistons 21. An annular carriage 30 is.longitudinally movable
19 in the cavity 18 and is connected to the piston rods 22 and
~ longitudinally reciprocates with the pistons 21. The car-
21 riage 20 bears against the inside of the body .16 for providing
22 a secure supportO
23 A plurality of locking dogs 32 are provided having
24 one end for engaging the locking notches 12 on the first
member 10 and having their second ends extending through
26 seals into the body cavit~ 18. The dogs 32 move transversely
27 in the body 16 for engagement and,disengagement with the
28 locking notch 12.
29 A toggle linkage 3~ is provided to translate the
longitudinal motion of each of the piston rods 22 into a
31 txansverse movement o~ one of the locking dogs 32. Each
32 toggle linkage 34 has a first pivot connection connected to
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1 one of the dogs 32 within the cavity 1~. The first pivot
connection may include a pin 36 as well as arcuatc power-
3 bearing surfaces 38. The second pivot connection of each of
4 the toqgle linkages 34 is longitudinally actuated by the
pistons 21 whereby the longitudinal movement of the second
6 pivot connections transversely moves the locking dogs 12.
7 The second pivot connections may include a pin 40 and coacking
8 arcuate power-bearing surfaces 42 between the linkage 34 and
9 a bearing journal 44, which rest on and is carried by the
carriage 30.
11 An annular load spring 46 is supported on the
12 carriage 30 and acts against the second pivot connections
13 and toward the first pivot connections for locking the second
14 pivot connections in a past dead center position relative to
the first pivot connections. The annular spring ring 46 is
16 retained to the carriage 30 by a retainer place 48 and hold-
17 down bolts 50 although the spring 46 and bearing journals 44
18 are transversely movable on the caxriage 30 so that the
19 spring 46, which acts as a large garter spring, flexes
outwardly and inwardly to allow the toggle linkages 34 to
21 snap over dead center into a locked or unlocked position.
22 The cavity 18 includes seals for sealingly en-
23 closing the cavity whereby it may be filled with oil to
24 reduce maintenance of the operating parts and protect the
~5 operating parts from hostile subsea environment. A flexible
26 member such as a rubber bladder 52 may be provided which has
27 one side exposed to thé in~erior of the cavity 18 and a
28 second cide exposed to the exterior of the body 16 for
~9 compensating or a difference in fluid pressure between the
3~ cavity 18 and the outside of the body 16 as well as com-
31 pensating for the movements of the piston rods 22 and dogs
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1 32 into and out of the cavity 18.
2 Referring to Figure 2 with the second member 1~ in
3 position encompassing the first member 10 and in the unlocked
4 position, hydraulic fluid is applied to the bottom side of
the piston 21 through line 26 which forces the piston rods
6 22 and carriage 30 upwardly. The second pivot connections
7 comprising the hearing journals 44 and pins 42 are ~rapped
8 between the carriage 30 and annular load ring 46. As the
9 second pivot connections move upwardly or longitudinally,
they force the toggle linkages 34 to rotate about the first
11 pivot connections which includes the arcuate bearing surfaces
1? 38 and pins 36 to transversely move the locking dogs 32 into
13 the lockihg notches 12 of the first member 10. Furthermore,
14 as the angle between the centerline of the toggle linkages
34 and the centerline of the doys 32 decreases, the ratio of
16 the radial inward force on the dogs 32 to the vertical
17 actuating force on the carriage 30 increases. This mechanical
1~ advantage allows a high clamping force with relatively low
19 actuating forces. Furthermore, the load ring 46 flexes
radially outward to allow the linkage 34 to snap over dead
21 center and then inwardly as the annular ring 46 bottoms out
22 against the body 16 to cre~te a positive past dead center
23 lock to hold the dogs 32 in engagement, as shown in Figure
24 1.
To unlock the connector 14, hydraulic pressure is
26 applied through line 24 moving the pistons 21, piston rods
27 22~ and carriage 30 downwardly. ~he xet~iner plates 48
28 carry the load ring 46 and force the second pivo~ connections
29 . including the bearing journals 44 to move downwardly over
dead center relative to the first pivot connections to
31 unlock the connector 14. Further downward movement of the
32 carriage 30 causes retraction of the dogs 32 by the pins 36
33 ana 42.
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l The presen~ invention, therefore, is ~ell adapted
2 to carry out the objec~s and at~ain the ends and advantages
3 mentioned as well as others inherent therein. While a
4 presently preferred embodiment of the invention has been
given for the purpose of disclosure, numerous changes in the
6 details of construction and arrangement of parts may be
7 provided, without departing from the spirit of the invention
8 and the scope of the appended claims.
What is claimed is:
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