U.S. patent number RE29,376 [Application Number 05/637,079] was granted by the patent office on 1977-08-30 for welded sleeve fitting.
This patent grant is currently assigned to Imperial-Eastman Corporation. Invention is credited to Jan A. Hiszpanski.
United States Patent |
RE29,376 |
Hiszpanski |
August 30, 1977 |
Welded sleeve fitting
Abstract
A fitting for use with metal tubes adapted for critical
applications such as involving high pressure and/or elevated
temperatures for heavy external loads. The fitting includes a
sleeve which is sealingly welded to the tube end and defines an
improved cooperative nut and sleeve structure whereby the nut may
be threadedly withdrawn from the body notwithstanding the
projection of the sealing weld sufficiently from the tube to
prevent complete withdrawal of the nut from the sleeve.
Inventors: |
Hiszpanski; Jan A. (Chicago,
IL) |
Assignee: |
Imperial-Eastman Corporation
(Chicago, IL)
|
Family
ID: |
26923546 |
Appl.
No.: |
05/637,079 |
Filed: |
December 2, 1975 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
229707 |
Feb 28, 1972 |
03751077 |
Aug 7, 1973 |
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Current U.S.
Class: |
285/148.9;
285/332; 285/386; 285/288.1 |
Current CPC
Class: |
F16L
19/0206 (20130101); F16L 19/0225 (20130101); F16L
19/0231 (20130101) |
Current International
Class: |
F16L
19/02 (20060101); F16L 055/00 () |
Field of
Search: |
;285/169,286,332,386,354,12,31,32 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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562,012 |
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Aug 1958 |
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CA |
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731,198 |
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May 1932 |
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FR |
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1,104,282 |
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Jun 1955 |
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FR |
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1,321,479 |
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Feb 1963 |
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FR |
|
Primary Examiner: Arola; Dave W.
Attorney, Agent or Firm: Wegner, Stellman, McCord, Wiles
& Wood
Claims
I claim:
1. A tube coupling structure comprising: a body having a port and a
threaded portion coaxially of said port; a tubular sleeve having an
inner end adapted to sealingly engage the body, an annular radially
outer, axially outwardly facing shoulder, and a tubular outer end
extending axially outwardly of said shoulder and terminating in a
distal end; an annular nut having a threaded portion threadedly
connected to the body threaded portion, said nut coaxially
encircling said sleeve and having an inturned flange disposed
axially outwardly of said sleeve shoulder for engaging said
shoulder to urge said sleeve into sealing engagement with said body
as an incident of threaded advance of said nut toward said body; a
tube end extending coaxially inwardly into said sleeve; and an
annular weld between said sleeve distal end and said tube sealingly
connecting the sleeve to the tube end, said weld and said shoulder
having a radial outer dimension greater than the corresponding
radial inner dimension of said nut flange whereby said nut flange
is captured axially movably between said sleeve shoulder and said
weld in the made-up arrangement of the tube coupling, the length of
said sleeve outer end outwardly of said shoulder being preselected
to permit withdrawal of the nut axially outwardly of the axially
inner end of the sleeve thereby to permit separation of said sleeve
and nut from said body with said nut flange maintained radially
outwardly of said sleeve outer end.
2. The tube coupling structure of claim 1 wherein said sleeve
defines an internal tube stop shoulder axially outwardly of said
radially outer shoulder limiting the axially inward positioning of
the tube end in said sleeve outer end.
3. The tube coupling structure of claim 1 wherein said nut flange
is annular.
4. The tube coupling structure of claim 1 wherein the axial length
of said nut is no greater than the axial length of said sleeve.
5. The tube coupling structure of claim 1 wherein the axial length
of said nut is less than the axial length of said sleeve.
6. The tube coupling structure of claim 1 wherein the length of
said sleeve outer end outwardly of said shoulder is sufficient to
permit said nut to be spaced outwardly from said body with said
sleeve inner end engaging said body.
7. The tube coupling structure of claim 1 wherein said nut has an
axial length no greater than the axial length of said sleeve outer
end.
8. The tube coupling structure of claim 1 wherein said nut flange
has an inner diameter only slightly greater than the outer diameter
of said sleeve outer end.
9. The tube coupling structure of claim 1 wherein said body
threaded portion defines a male thread.
10. The tube coupling structure of claim 1 wherein said inner end
of the sleeve defines a convex seating surface and said body
defines a complementary concave seating surface with said sleeve
seating surface projecting into said body to sealingly engage said
body seating surface in the make-up arrangement of the fitting.
.Iadd. 11. The tube coupling structure of claim 1 wherein said
sleeve outer end defines an annular, axially outwardly facing
surface, said tube end being retained in abutment therewith by said
weld. .Iaddend..Iadd. 12. The tube coupling structure of claim 1
wherein said sleeve outer end is defined by a stepped annular end
surface including an axially outwardly facing outer planar portion,
a cylindrical intermediate portion, and an axially outwardly facing
inner planar portion, said tube end axially abutting said end
surface. .Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to tube couplings and in particular to tube
couplings having a sleeve permanently joined to the tube as by
welding.
2. Description of the Prior Art
In one conventional form of tube coupling, the tube end is
sealingly coupled to the fitting body by means of a sleeve attached
to the tube end as by welding. The sleeve, in turn, is sealingly
engaged with the fitting body as a result of a force application
effected by a nut threaded to the body. In welding the sleeve to
the body, a weld bead is formed at the outer end of the sleeve
sealingly joining the sleeve thereat to the tube end which projects
into the sleeve outer end. In the known fittings of this type, a
problem has arisen from time to time in that the weld bead
interferes with the removal of the nut from the body causing
substantial difficulty in disconnecting the tube from the body when
desired.
SUMMARY OF THE INVENTION
The present invention comprehends an improved tube coupling of the
above described welded sleeve type wherein the sleeve is arranged
in a novel manner to permit free withdrawal of the nut from the
body while yet permitting the user to form a substantial weld joint
wherein the weld bend may project substantially outwardly from the
tube to prevent axial outward movement of the nut therebeyond.
More specifically, the invention comprehends the provision of a
tube coupling structure including a body having a port and a
threaded portion coaxially of the port, a tubular sleeve having an
inner end adapted to sealingly engage the body, and annular
radially outer, axially outwardly facing shoulder, and a tubular
outer end extending axially outwardly of the shoulder and
terminating in a distal end, an annular nut having a threaded
portion threadedly connected to the body threaded portion, the nut
coaxially encircling the sleeve and having an inturned flange
disposed axially outwardly of the sleeve shoulder for engaging the
shoulder to urge the sleeve into sealing engagement with the body
as an incident of threaded advance of the nut toward the body; a
tube end extending coaxially inwardly into the sleeve, and an
annular weld between the sleeve distal end and the tube sealingly
connecting the sleeve to the tube end and having a radial outer
dimension greater than the corresponding radial inner dimension of
the nut flange whereby the nut flange is captured axially movably
between the sleeve shoulder and the weld in the made-up arrangement
of the tube coupling, the length of the sleeve outer end outwardly
of the shoulder being preselected to permit withdrawal of the nut
axially outwardly of the axially inner end of the sleeve thereby to
permit separation of the sleeve and nut from the body with the nut
flange maintained radially outwardly of the sleeve outer end.
The sleeve may define a tube stop shoulder within the outer end
thereof for limiting the insertion of the tube end thereinto. The
nut flange may define an inner cylindrical surface having a
diameter only slightly greater than the outer diameter of the
sleeve outer end. The bead may define an outer circumference having
a diameter throughout greater than the inner diameter of the nut
flange.
The length of the sleeve outer end may be sufficient to permit the
nut to be spaced outwardly from the body with the sleeve inner end
engaging the body. In the illustrative embodiment, the axial length
of the nut is no greater than the axial length of the sleeve outer
end. The sealing surface of the sleeve inner end may comprise a
convex, frustoconical surface received in a complementary concave
frustoconical recess in the body. The length of the sleeve outer
end may be preselected to permit the separation of the threaded
means of the nut and body with the sleeve seating surface received
in the concave seating surface of the body.
BRIEF DESCRIPTION OF THE DRAWING
Other features and advantages of the invention will be apparent
from the following description taken in connection with the
accompanying drawing wherein:
FIG. 1 is a side elevational view of a tube coupling structure
embodying the invention;
FIG. 2 is a diametric section thereof; and
FIG. 3 is a diametric section illustrating the arrangement thereof
upon disconnection of the tube end from the body.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the exemplary embodiment of the invention as disclosed in the
drawing, a tube coupling structure generally designated 10 is shown
to comprise a tube coupling 11 having sealingly secured thereto a
tube end 12. The tube coupling 11 includes a sleeve 13, a nut 14,
and a body 15. The sleeve is sealingly connected to the tube 12 by
a weld 16 at the outer end of the sleeve.
As shown in FIGS. 2 and 3, body 15 may comprise a tubular fitting
body having an axial bore 17 opening at the outer end into an
enlarged recess 18 defined by a frustoconical outwardly widening
seating surface 19. The body may define an outer thread 20 for
coupling the body to another element as desired, and an inner
thread 21 for threaded engagement with the nut 14. A plurality of
flats 22 may be provided on a mid-portion of the body for
cooperation with a suitable tool, such as a wrench, in making up
the fitting.
Nut 14 comprises a tubular element having an inner female thread 23
and an axially outer inturned flange 24 defining a cylindrical
inner surface 25.
Sleeve 13 herein comprises a tubular element having a through bore
26 provided with a radially enlarged outer portion 27 defining at
its inner end a stop shoulder 28 for limiting the insertion of tube
end 12 into the sleeve. At its inner end, the sleeve defines a
frustoconical inwardly narrowing seating surface 29 adapted to have
sealing engagement with the seating surface 19 of the body in the
made-up arrangement of the fitting. The sleeve further defines a
collar portion 30 defining an axially outwardly facing shoulder 31
adapted to be engaged by the nut flange 24 as an incident of
threaded advancement of the nut on the body thread 21 as during
make-up of the fitting.
The sleeve further defines a tubular outer end 32 extending axially
outwardly of the plane of shoulder 31 and terminating in a distal
end 33.
Weld 16 may comprise a conventional weld defined by a bead of
suitable weld material fused to the distal end 33 of the sleeve and
to the outer surface of the tube 12 to define a sealed connection
of the tube to the sleeve.
As shown, the weld bead may extend radially outwardly beyond the
outer circumference of sleeve end 33 and as best seen in FIG. 3,
may have an outer dimension greater than the diameter of nut flange
surface 25 whereby the nut is maintained captive on the sleeve in
the made-up arrangement of the sleeve and tube end.
As indicated briefly above, the invention comprehends providing an
outer end 32 of the sleeve having an axial length preselected to
permit withdrawal of the nut axially outwardly of the axially inner
end of the sleeve, thereby to permit separation of the sleeve and
nut assembly from the body notwithstanding the maintenance of the
nut flange radially outwardly of the sleeve outer end portion 32,
as shown in FIG. 3. In the illustrated embodiment, the axial length
of the nut is made to be no greater than the axial length of the
sleeve 13, and more specifically, as shown in FIG. 3, may be no
greater than the axial length of sleeve outer end 32.
The diameter of nut flange surface 25 may be made only slightly
greater than the outer diameter of sleeve end portion 32 as there
is no need for the nut to be withdrawn axially beyond the weld bead
16 in order to permit disconnection of the tube end from the
fitting body 15, as illustrated in FIG. 3. Thus, the present
fitting permits make-up and disassembly of the joint in the normal
manner notwithstanding the provision of a relatively large weld
bead 16 assuring positive sealed connection of the sleeve to the
tube. Thus, the coupling 10 is adapted for critical applications
involving high pressure, elevated temperature, heavy external
loads, and the need for high reliability in maintaining the sealed
connection such as required in nuclear industry, power plant,
chemical plant, shipyard, pressure testing, etc. applications. The
invention comprehends the use of the disclosed structure in a wide
range of coupling sizes as desired.
The application of the weld 16 may be effected by the user and the
use of the relatively long sleeve end 32 provides improved
facilitated make-up of the fitting in spacing the point of welding
substantially from the seating surface 29, thereby effectively
minimizing possibility of deformation of the seating surface as
from the heat of welding as may occur in the conventional fittings
where the weld is made relatively close to the seat end of the
sleeve.
In use of the fitting, the user need merely insert the tube end 12
into the sleeve end bore portion 27 into abutment with shoulder 28
with nut 14 installed about the sleeve. The sleeve is then
sealingly joined to the tube by the application of the weld 16. The
tube end may then be coupled to a suitable male coupling element,
such as body 15, having a suitable cooperating threaded portion for
use with the nut 14. The axial length of sleeve end portion 32
permits free movement of the nut on the sleeve, notwithstanding the
fact that the nut is effectively captured between shoulder 31 and
weld bead 16, to permit facilitated make-up and disconnection of
the fitting. In connecting the tube to the body, the user threads
the nut on body threads 21 suitably to urge nut flange 24 against
sleeve shoulder 31 and resultingly seal sleeve seating surface 29
sealingly against body seating surface 19, thereby to complete the
sealed make-up of the coupling.
In disconnecting the joint, the user may threadedly withdraw the
nut sufficiently to completely disengage the nut from the thread 21
whereupon the seating surface portion 29 may be withdrawn axially
from the body recess 18 as desired.
The foregoing disclosure of specific embodiments is illustrative of
the broad inventive concepts comprehended by the invention.
* * * * *