U.S. patent number 3,871,613 [Application Number 05/389,705] was granted by the patent office on 1975-03-18 for non-rotating ram rod locking assembly for blowout preventer.
Invention is credited to Robert K. LeRouax.
United States Patent |
3,871,613 |
LeRouax |
March 18, 1975 |
NON-ROTATING RAM ROD LOCKING ASSEMBLY FOR BLOWOUT PREVENTER
Abstract
A non-rotating ram rod locking assembly for a blowout preventer
having a new and improved means for locking the ram in its sealing
position, and means for preventing rotation of the ram rod itself
during actuation of the locking assembly.
Inventors: |
LeRouax; Robert K. (Houston,
TX) |
Family
ID: |
26874577 |
Appl.
No.: |
05/389,705 |
Filed: |
August 20, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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178713 |
Sep 8, 1971 |
3791616 |
Feb 12, 1974 |
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Current U.S.
Class: |
251/1.3;
251/110 |
Current CPC
Class: |
E21B
33/062 (20130101) |
Current International
Class: |
E21B
33/06 (20060101); E21B 33/03 (20060101); E21b
033/06 () |
Field of
Search: |
;251/1,89,110,111,112
;277/73,126,127,129 ;92/13.6 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schwadron; Martin P.
Assistant Examiner: Gerard; Richard
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of co-pending application Ser. No.
178,713, filed Sept. 8, 1971, now U.S. Pat. No. 3,791,616 issued
Feb. 12, 1974.
Claims
I claim:
1. A locking assembly for a blowout preventer ram, comprising:
a blowout preventer body having a lateral opening for movement of a
ram therein;
a blowout preventer ram bonnet having a ram recess therein aligned
with said lateral opening in said body;
a blowout preventer ram adapted to move in and relative to said ram
recess and said lateral opening for moving from a retracted
position to a sealing position;
a ram rod having connection with said ram and having a hollow
bore;
a piston cylinder mounted with said bonnet;
a piston disposed in said cylinder and having connection with said
ram rod;
fixed guide means engaging said ram rod for preventing rotation of
said ram rod;
a rotatable locking element mounted on said cylinder and adapted to
extend into said cylinder for locking said piston in its inward
position for thereby locking said ram in its sealing position;
said rotatable locking element having a rotatable stem
therewith;
said rotatable stem extending into said cylinder and into the
hollow bore of said ram for rotation and longitudinal movement
relative thereto; and
means for rotating said locking element and said stem therewith to
move said stem longitudinally and move said locking element from a
retracted position to a locking position.
2. The structure set forth in claim 1, wherein said guide means
includes:
a guide plate mounted in said ram recess of said bonnet and having
at least one guide surface; and
a connector button on said ram having a guide surface engageable
with said guide surface on said guide plate for preventing rotation
of said button and said ram rod therewith relative to said guide
plate.
3. The structure set forth in claim 2, wherein:
said ram has a channel formed therein for receiving said guide
plate; and
said channel and said guide plate have co-acting surfaces in
engagement with each other to prevent said ram from rotating
relative to said ram rod.
4. The structure set forth in claim 1, wherein said guide means
includes:
a guide plate mounted in said ram recess of said bonnet and having
a pocket with guide walls on each side thereof; and
a connector button on said ram rod having a guide surface on each
side thereof in sliding engagement with said guide walls.
5. The structure set forth in claim 1, including:
a connector button on said ram rod having means co-acting with said
ram for preventing rotation of said ram relative to said ram
rod.
6. The structure set forth in claim 1, wherein said guide means
includes:
co-acting guide surfaces on said preventer body and said ram rod
for preventing rotation of said ram rod while permitting relative
movement of said ram to and from said retracted and sealing
positions.
Description
BACKGROUND OF THE INVENTION
The field of this invention relates to blowout preventers, and
parts thereof.
In U.S. Pat. No. 2,752,119, a blowout preventer is disclosed
wherein the preventer ram is prevented from rotating by preventing
the piston to which the ram is connected from rotating, with a
rigid connection between the rod and the ram. Such construction
thus places a limitation on the construction of the piston and/or
its locking means therewith so that such piston does not rotate in
its cylinder. Since it is difficult to maintain a fluid seal if the
piston is not round, such prior construction as shown in U.S. Pat.
No. 2,752,119 shows a locking assembly disposed eccentrically
relative to the piston which is disadvantageous since it introduces
a couple acting on the ram rod and/or seals and/or the ram
therewith.
SUMMARY OF THE INVENTION
The present invention relates to a locking assembly for a blowout
preventer ram wherein the ram may be locked in its sealing position
by a rotating locking assembly, but means are provided for
preventing rotation of the ram rod itself to thereby prevent
transmission of such rotation of the locking assembly to the ram.
The operating mechanism of the locking assembly is located in
alignment with the longitudinal axis of the ram rod to prevent the
creation of a couple acting on the rods and/or seals and/or ram.
The locking assembly may have a rising stem or a non-rising stem,
and may utilize the bore of the ram rod for the threaded portion of
the locking assembly in either form because of the alignment of the
operating mechanism of the locking assembly with the ram rod,
whereby the extension or projection of the locking assembly from
the piston cylinder is minimized.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a vertical sectional view, partly in elevation,
illustrating one form of the locking assembly of this invention in
a typical blowout preventer;
FIG. 2 is a sectional view taken on line 2--2 of FIG. 1;
FIG. 3 is a view of the left hand portion of the apparatus shown in
FIG. 1, but showing the locking assembly in the locked
position;
FIG. 4 is a view similar to FIG. 1, but showing a modified form of
the assembly, wherein the stem is of the non-rising type; and
FIG. 5 is a view of the left hand portion of the apparatus
illustrated in FIG. 4 to show such apparatus in the locked
position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings, the letter A designates generally a blowout
preventer which includes a conventional blowout preventer body B, a
blowout preventer head or bonnet H, a ram R, and means C for moving
the ram R from a closed or sealing position (FIG. 1) to an open
position (not shown) and vice versa. A locking assembly, generally
designated with the letter L is operably mounted with a ram rod 10
which in turn is connected to the ram R, preferably using a
connector button 11, as will be more fully explained.
Considering the invention more in detail, the blowout preventer
body B is provided with a longitudinally or vertically extending
bore or opening 12 of conventional construction through which well
pipe, wire line or well tools may pass in the known manner. The
body B also has a laterally extending ram opening 14 for receiving
the ram R and for forming a fluid seal therewith in any suitable
manner. The ram opening 14 is in alignment with a ram cavity or
recess 15 formed in the bonnet or head H.
The bonnet H is releasably connected to the body B by releasable
bolts 13 or other suitable connecting means which extend through
the bonnet H and into the body B. The head or bonnet H may be
mounted with an known type of support so that it either swings
arcuately with respect to the body B after the bolts 13 are
released from the body B so as to expose the ram R when the ram R
is in the retracted position (not shown) within the ram cavity or
recess 15. Alternatively, the head or bonnet H may move outwardly
on any suitable supports (not shown) after the bolts 13 are
released. It will also be understood that only one half of the
blowout preventer is illustrated in FIG. 1; the other half is a
duplicate of the portion which is illustrated.
It will also be understood that the ram R coacts with a
corresponding ram R for closing off the bore 12 through the blowout
preventer body B. For this purpose, the ram R has a resilient
sealing member 16 with rigid plates 16a and 16b thereabove. The
resilient portion 16 is preferably formed of synthetic or natural
rubber so that it is yieldable when it engages the corresponding
resilient portion on the other ram which is not shown. It will also
be understood that the ram R may have a suitable curvature for
sealing around the external surface of a pipe or pipe joint, as is
well understood. Similarly, the ram R has a seal element 17 which
engages the bore 14 of the preventer body B in a known manner to
prevent the fluid pressure within the bore 12 from passing around
the ram R.
The moving means C which is utilized for moving the ram R may be
hydraulic, mechanical, manual or of any other suitable type. As
illustrated in the drawings, such power means C includes a cylinder
20 which is connected by bolts (not shown) or any other suitable
securing means to the head or bonnet H in any known manner so that
under normal operating conditions, the cylinder 20 moves with the
head or bonnet H. A cylinder liner 21 is suitably mounted within
the cylinder 20 in the preferred form of the invention, with a
piston 22 movable within such liner 21 in the known manner. The
piston 22 is moved inwardly or in a right hand direction as viewed
in FIG. 1 by hydraulic fluid or any other fluid pressure introduced
through a fluid pressure line 23 into an annular space 21a between
the liner 21 and the cylinder 20 in the known manner. It will be
understood that the fluid pressure line 23 is only partially
illustrated and it connects with a suitable source of fluid
pressure.
For moving the piston 22 outwardly or in a direction to the left as
viewed in FIG. 1, the fluid pressure is introduced through a line
25, a portion of which is illustrated in the drawings and which is
suitably connected to a source of hydraulic fluid or other fluid
under pressure in the known manner.
The ram rod 10 is of a special construction and it includes a
reduced diameter portion 10a with an annular shoulder 10b for
receiving and confining the piston 22 thereon. A notch 10c is
formed in the ram rod 10 for receiving a split retaining ring 26
therein to secure the piston 22 to the ram rod 10. A retainer ring
27 which is in the form of a complete solid ring is secured to the
piston 22 by a plurality of attaching means such as screws 27a so
as to prevent the split ring 26 from inadvertently becoming
released.
The ram rod extends through an opening 15a in the head or bonnet H
and in which a plurality of seals 30, 31 and 32 are disposed for
sealing engagement with the external surface of the ram rod 10. It
will be understood that the particular sealing arrangement between
the ram rod 10 and the seal or seals in the opening 15a may be
varied within the scope of those skilled in the art.
The ram rod is hollow and is thus provided with a hollow bore 10d.
A plug 10e is welded near the forward end of the bore 10d to seal
such bore 10d and prevent fluid flow therethrough. The forward
portion of the bore 10d is threaded at 10f to receive threads 11a
which are a part of the connector button 11 and which serve to join
the connector 11 directly to the ram rod 10. It is also desirable
to have one or more welds 11b between the ram rod 10 and the
connector button shaft as illustrated in FIG. 1.
The connector button 11 is preferably of a square or rectangular
shape as best seen in FIG. 2 whereas the shaft 11c therewith is
preferably round and of a smaller dimension. The shaft 11 fits
within a reduced width slot 35 which is formed to the left of a
larger button receiving slot 36 as viewed in FIG. 1. Preferably,
the side walls 36a of the slot 36 are substantially vertical and
are adapted to be engaged by the side surfaces 11d of the button 11
(FIG. 2). Such construction prevents the ram R from rotating
relative to the button 11 and thus relative to the ram rod 10,
which is desirable when the ram R has been moved to an exposed
position out of the blowout preventer body B. Such construction
would also be desirable if the ram R is round since it would assure
alignment of the seals and the proper setting of the ram R in the
sealing position.
A guide plate 40 is mounted in the bonnet recess or cavity 15 so as
to be between the ram rod 10 and the bonnet H. Preferably, the
guide plate 40 is connected by connecting screws 41 or any other
suitable securing means so that such guide plate 40 moves with the
bonnet H when it is moved to an open position after the bolts 13
have been released, as previously explained.
The guide plate 40 has a guide recess 40a with guide walls 40b
formed on each side thereof which are in engagement with the side
guide surfaces 11d of the connector button 11 so as to prevent
relative rotation of the connector button with respect to such
guide plate 40.
The guide plate 40 also extends upwardly into a recess 43 formed in
the lower portion of the ram R, in the preferred form of the
invention so that there is a coaction between guide surfaces 40c at
each side of the guide plate 40 and adjacent slide walls 43a in the
recess 43. The coaction between the surfaces 40c and 43a guides the
ram R as it moves inwardly and outwardly with respect to the guide
plate 40 to prevent cocking or misalignment of the ram R. The
coaction between such surfaces 40c and 43a could be omitted and the
purposes of the invention heretofore described would still be
accomplished.
The locking assembly L includes a rotatable stem 50 which extends
into the cylinder 20 and has a threaded portion 51 therewith which
engages with internal threads 10g within the hollow bore 10d of the
ram rod 10. The stem 50 has a stop flange 52 disposed outwardly of
the threaded locking sleeve portion 51 which is adapted to abut the
end of the ram rod 10 when the stem 50 is in the telescoped
position with the threaded portion 51 internally of the bore 10d.
Also, the flange 52 is adapted to engage a stop surface 20a (FIG.
3) when the stem 50 has been moved to the locking position with the
threaded portion 51 extended with respect to the ram rod 10 (FIG.
3). The flange 52 preferably has an anti-friction ring 52a
therewith for abutment with the stop surface 20a.
The stem 50 extends through an opening 20b in the cylinder 20 and
suitable seal 55 and wiper 56 are employed for engagement with the
external surface of the stem 50. The stem 50 projects outwardly
from the cylinder 20 and preferably a guard extension 57 is
provided on the cylinder 20 for protecting the stem 50. Wrench
flats 50a are provided on the stem 50 to facilitate engagement with
a wrench so as to rotate the stem 50 and thereby rotate the threads
51 relative to the threads 10g. The form of the invention shown in
FIGS. 1 and 3, insofar as the locking mechanism L is concerned, is
known as the rising stem type in view of the longitudinal travel of
the stem 50 relative to the cylinder 20.
In the operation or use of the form of the invention illustrated in
the drawing and particularly FIGS. 1-3, the locking mechanism L is
normally in the position illustrated in FIG. 1, with the threaded
portion 51 of the stem 50 telescoped within the bore 10d of the ram
rod 10. It is to be noted that the stem 50 is in alignment with the
ram rod 10 so that the axes of the stem 50 and the rod 10 are
coincidental. This is important for the reasons heretofore
described.
When it is desired to lock the ram R in the sealing position shown
in FIG. 1, the stem 50 is rotated to unthread the threaded portion
51 relative to the threads 10g, thereby causing longitudinal travel
of the stem 50 and threaded portion 51 therewith to the left as
viewed in FIG. 1. The piston 22 is at the inward position shown in
FIG. 1 at that time. Continued rotation of the stem 50 moves it to
the left or outwardly until the stop flange ring 52a engages the
stop surface 20a. At that time, as seen in FIG. 3, the piston 22 is
locked against any movement and therefore the ram R is locked
against any movement. A reverse rotation of the stem 50 will return
it to the telescoped position of FIG. 1 for subsequent normal
operations of the ram R. During such rotation of the stem 50 and
the threaded portion 51, the ram rod 10 is prevented from rotating
due to the interengagement of the guide surfaces 40b and 11d, as
heretofore explained. This assures that the rotation of the locking
assembly L is not transmitted to the ram R, but at the same time,
the present invention accomplishes the location of the stem 50 in
direct alignment with the ram rod 10.
A modified form of the invention is illustrated in FIG. 4 and 5
wherein identical parts to those shown in FIGS. 1-3 have the same
letters and/or numerals. The locking assembly L-1 is modified as
compared to the locking assembly L and it is known as the
non-rising stem type. Thus, the stem 150 in FIGS. 4 and 5 rotates
but it does not move longitudinally. The stem 150 has a plurality
of flat sides, preferably six in number and such flat sides fit
within a similarly flat sided internal bore 151a of a threaded
locking sleeve 151. The threaded locking sleeve 151 is adapted to
telescope within the bore 10d of the ram rod 10 in the same manner
as the threaded portion 51 illustrated in FIG. 1. The threads 151b
are in threaded engagement with threads 10g in the bore of the ram
rod 10. Thus, as the stem 150 is rotated, it rotates the locking
sleeve 151 to cause a threading or unthreading thereof with respect
to the threads 10g, depending upon the direction of rotation of the
stem 150.
The stem 150 projects through the cylinder 20 at the opening 20b
and means are provided for preventing longitudinal travel of the
stem 150. As illustrated in FIG. 4, such means includes a flange
150a which engages a surface 20a in the cylinder 20. A retaining
split ring 150b is disposed at the outer portion of the cylinder 20
for preventing inward travel of the stem 150. As illustrated in
FIG. 4, the outer operating end 150c has a plurality of flat
surfaces for engagement by a wrench. The outer operating end 150c
is a separate piece which is connected to the inner part of the
stem 150 by one or more connecting pins 150d, or by any other
suitable mechanism.
The operation of the form of the invention shown in FIGS. 4 and 5
is similar to that described in connection with FIGS. 1-3. Under
normal operating conditions, the ram R is moved back and forth from
the sealing position shown in FIG. 4 to the open or retracted
position (not shown) wherein the ram R is disposed within the
bonnet cavity 15, as will be well understood. When it is desired to
lock the ram R in the sealing position shown in FIG. 4, the stem
150 is rotated by any suitable means, such as a wrench engaging the
wrench flats 150c so as to cause a rotation of the locking sleeve
151 relative to the threads 10g to move same to the locking
position shown in FIG. 5, wherein the left hand end of the sleeve
151 is in engagement with the flange 150a. In such position, the
ram R is locked in the same manner as described heretofore in
connection with FIG. 3. It also should be noted that the cover 156
shown in FIGS. 4 and 5 may be much shorter than required for the
cover 56 since the stem 150 does not move longitudinally relative
to the cylinder 20.
It will also be understood that by a reverse rotation of the stem
150, the locking sleeve 151 may be returned to its telescoped
position within the bore 10d of the ram rod 10.
Although the guide plate 40 is shown as formed separately from the
preventer body B and the bonnet H, it should be understood that the
guide plate 40 could be omitted and instead the guide surfaces 40b
could be formed in the bottom of the body B alone, or together with
an extension thereof in the bottom of the bonnet B. The advantage
of the separate guide plate 40 as illustrated resides in the
maintenance of alignment of the ram R when returning the bonnet H
to the closed position after replacing the ram R on the button
11.
The foregoing disclosure and description of the invention are
illustrative and explanatory thereof, and various changes in the
size, shape and materials as well as in the details of the
illustrated construction may be made without departing from the
spirit of the invention.
* * * * *