U.S. patent application number 10/420476 was filed with the patent office on 2003-10-30 for tube couplings.
This patent application is currently assigned to John Guest International Limited. Invention is credited to Guest, John Derek.
Application Number | 20030201641 10/420476 |
Document ID | / |
Family ID | 9935817 |
Filed Date | 2003-10-30 |
United States Patent
Application |
20030201641 |
Kind Code |
A1 |
Guest, John Derek |
October 30, 2003 |
Tube couplings
Abstract
A tube coupling has a coupling body with a throughway open at
one end to receive an end portion of a tube. A seal encircles the
throughway to seal with the periphery and end of the tube and a cap
is mounted on the body having a tube locking device rotatably
mounted in the cap to engage and hold the tube in the cap. The cap
and body have interengaging means which guide the cap on the body
in an axial direction along the body with rotation of the cap from
a first position in which a tube can be inserted through the cap
and into the seal in the throughway and retained by the locking
device and a second position advanced along the coupling body from
said one end in which the tube end is held positively in engagement
with the seal in the throughway. The locking device engages via a
ring with the coupling body to resist rotation of the locking
device with respect to the body whereby rotation of the cap between
said the first and second positions does not cause the tube to
rotate.
Inventors: |
Guest, John Derek; (Bray,
GB) |
Correspondence
Address: |
WORKMAN NYDEGGER (F/K/A WORKMAN NYDEGGER & SEELEY)
60 EAST SOUTH TEMPLE
1000 EAGLE GATE TOWER
SALT LAKE CITY
UT
84111
US
|
Assignee: |
John Guest International
Limited
|
Family ID: |
9935817 |
Appl. No.: |
10/420476 |
Filed: |
April 22, 2003 |
Current U.S.
Class: |
285/308 |
Current CPC
Class: |
F16L 37/0927 20190801;
F16L 19/086 20130101; F16L 37/0925 20130101 |
Class at
Publication: |
285/308 |
International
Class: |
F16L 037/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 30, 2002 |
GB |
0209897.8 |
Claims
1. A tube coupling comprising a coupling body having a throughway
open at one end to receive an end portion of a tube, a seal
encircling the throughway to seal with the periphery and end of the
tube and a cap mounted on the body having a tube locking device
rotatably mounted therein the cap to engage and hold the tube in
the cap in the axial direction out of the cap, the cap and body
having interengaging means which guide the cap on the body in an
axial direction along the body with rotation of the cap from a
first position in which a tube can be inserted through the cap and
into the seal in the throughway and retained by the locking device
and a second position advanced along the coupling body from the end
thereof in which the tube end is held positively in engagement with
the seal in the throughway, wherein means are provided to resist
rotation of the locking device with respect to the coupling body
whereby rotation of the cap between said the first and second
positions does not cause the tube to rotate.
2. A tube coupling as claimed in claim 1, wherein an annular member
is provided in the cap acting between the coupling body and tube
locking device to resist rotation of the locking device with
respect to the coupling body.
3. A tube coupling as claimed in claim 2, wherein the annular
member and an end of the coupling body have interengaging teeth to
resist rotation of the annular member with respect to the coupling
body.
4. A tube connector as claimed in claim 2, wherein the annular
member and tube locking device have interengaging teeth to resist
rotation of the locking device with respect to the coupling
body.
5. A tube coupling as claimed in claim 2, wherein the annular
member comprises a sleeve which engages in the open end of the
throughway of the coupling body and has an out-turned flange
overlying the end of the coupling body, the end of the coupling
body and side of the flange facing the coupling body having
interengaging teeth to resist rotation of the annular member with
respect to the coupling body and the other side of the flange and
tube locking device having interengaging teeth to resist rotation
of the tube locking device with respect to the coupling body.
6. A tube coupling as claimed in claim 1, wherein the locking
device comprises a collet having an annular head located on the
outer side of the cap and having a plurality of resilient arms
projecting into the cap, the arms having interengaging teeth for
engaging the tube extending through the collet into the coupling
body and the cap having a tapered cam surface converging towards
the open end of the cap remote from the coupling body with which
the arms of the collet are engagable to be pressed inwardly with
outward movement of the collet with respect to the cap to engage
and grip the tube extending through the collet.
7. A tube coupling as claimed in claim 6, wherein the ends of the
arms of the collet projecting into the cap have teeth for
interengaging with the teeth of the annular member for resisting
rotation of the collet with the cap.
Description
BACKGROUND TO THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to tube couplings. It is an object of
the invention to provide a coupling with enhanced sealing for the
tube without voids between the tube and coupling surfaces in which
fluids may be trapped and fester.
[0003] 2. Background of Prior Art
[0004] EP-A-1233225 discloses a tube coupling to receive and hold a
tube comprising a coupling body having a throughway open at one end
to receive a tube. An annular step is formed in the throughway
facing the open end to receive an end of a tube. An end cap is
screwed on to the coupling body for axial movement between forward
and retracted position on the coupling body, the end cap having an
opening for the tube to extend through. A seal is located in the
coupling body between the step and the open end of the body. The
seal has an annular sleeve encircling the throughway and an
out-turned annular flange at one end lying against the annular step
to receive and seal with an end of the tube inserted into the
throughway. A compression device in the throughway is operable to
compress the sleeve around the outer surface of the tube adjacent
said end of the tube as the end cap is screwed on to the coupling
body into the forward position.
SUMMARY OF THE INVENTION
[0005] This invention provides a tube coupling comprising a
coupling body having a throughway open at one end to receive an end
portion of a tube, a seal encircling the throughway to seal with
the periphery and end of the tube and a cap mounted on the body
having a tube locking device rotatably mounted therein the cap to
engage and hold the tube in the cap in the axial direction out of
the cap, the cap and body having interengaging means which guide
the cap on the body in an axial direction along the body with
rotation of the cap from a first position in which a tube can be
inserted through the cap and into the seal in the throughway and
retained by the locking device and a second position advanced along
the coupling body from the end thereof in which the tube end is
held positively in engagement with the seal in the throughway,
wherein means are provided to resist rotation of the locking device
with respect to the coupling body whereby rotation of the cap
between said the first and second positions does not cause the tube
to rotate.
[0006] In a preferred arrangement according to the invention an
annular member is provided in the cap acting between the coupling
body and tube locking device to resist rotation of the locking
device with respect to the coupling body.
[0007] More specifically, the annular member and an end of the
coupling body have interengaging teeth to resist rotation of the
annular member with respect to the coupling body.
[0008] Furthermore, wherein the annular member and the tube locking
device may have interengaging teeth to resist rotation of the
locking device with respect to the coupling body.
[0009] In one particular construction the annular member may
comprise a sleeve which engages in the open end of the throughway
of the coupling body and has an out-turned flange overlying the end
of the coupling body, the end of the coupling body and side of the
flange facing the coupling body having interengaging teeth to
resist rotation of the annular member with respect to the coupling
body and the other side of the flange and tube locking device
having interengaging teeth to resist rotation of the tube locking
device with respect to the coupling body.
[0010] In any of the above arrangements the locking device may
comprise a collet having an annular head located on the outer side
of the cap and having a plurality of resilient arms projecting into
the cap, the arms having interengaging teeth for engaging the tube
extending through the collet into the coupling body and the cap
having a tapered cam surface converging towards the open end of the
cap remote from the coupling body with which the arms of the collet
are engageable to be pressed inwardly with outward movement of the
collet with respect to the cap to engage and grip the tube
extending through the collet.
[0011] In the latter arrangement the ends of the arms of the collet
projecting into the cap may have teeth for interengaging with the
teeth of the annular member for resisting rotation of the collet
with the cap.
[0012] The following is a description of a specific embodiment of
the invention, reference being made to the accompanying drawings in
which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a exploded view of an inline tube coupling having
identical tube connectors at each end thereof;
[0014] FIG. 2 is a cross-sectional view through the coupling of
FIG. 1 with the components of the coupling fully assembled with
tubes, one tube being located in an initial engagement position and
the other being fully engaged;
[0015] FIG. 3 is an enlarged view of part of the coupling of FIG. 2
showing said one tube in the initially engaged position; and
[0016] FIG. 4 is a similar view to FIG. 3 showing the other tube in
the fully engaged position; and
[0017] FIG. 5 is a cut-away perspective view of a modified form of
the connector.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Referring firstly to FIG. 1 of the drawing, there is shown a
double ended inline tube coupling indicated generally at 10 for
connecting together two inline tubes indicated at 11 in FIG. 2.
[0019] The coupling comprises a central cylindrical coupling body
12 having a throughway 13 and an integral annular internal wall 14
located centrally in the throughway with a central aperture 15 for
flow of fluid from tube to tube through the coupling.
[0020] The outer side of the coupling body has an encircling outer
wall 16 formed integrally with the coupling body centrally along
the body. The periphery of the outer wall is formed with four
equally spaced abutments extending across the outer periphery of
the wall and between the abutments the wall has shallow recesses.
The raised abutments provide finger grips to enable the coupling
body to be held against rotation during assembly and disassembly of
tubes with the coupling as described later.
[0021] End caps 20 are engagable over the portions of the coupling
body to either side of the central wall. The end caps are generally
of cylindrical form having an open end 21 to receive an end portion
of the cylindrical body 12 and having a reduced diameter socket 22
at the other end in which a collet 23 is engagable to receive and
lock a tube in the end cap as describe later.
[0022] The open end 21 of the end cap has two shallow lugs 24
formed integrally with the wall of the end cap at diametrically
spaced locations across the end cap. Each end portion of the
cylindrical body 12 has in its outer surface axially extending
grooves 25 formed at diametrically spaced locations around the
coupling body leading towards the central wall 16. The grooves are
dimensioned to receive the lugs 24 on the inner surface of the cap
with a close fit and to guide the cap axially onto the coupling
body.
[0023] Near to the central wall 16 the grooves 25 lead into
helically wound grooves 26 extending a short distance of
approximately one quarter of the circumference around the
cylindrical body. The grooves 26 are dimensioned to receive the
abutments 24 in the cap to allow the cap to rotate and at the same
time to advance axially with respect to the coupling body. The
grooves 26 run out at the wall 16 in a short end section 27
parallel to the wall which terminates with an end stop 28 at the
end of the groove. The side of each groove remote from the wall is
formed with a shallow projection where the groove changes from the
helical portion 26 to the end section 27 to retain the abutment 24
in the parallel section of the groove adjacent the end.
[0024] The axial portion of the groove 25 has a shallow ramp 30
over which the abutment 24 rides immediately before entering the
helically groove section 26. The ramps serve to define a first
position of assembly of the cap 20 on the coupling body and to
retain the cap on the coupling body.
[0025] Thus in assembling the cap 20 on the coupling body, the cap
is initially moved axially onto the coupling body with the
abutments 24 sliding along the groove 25 and snapping over the
ramps 30. Once past the ramps 30, the cap is then rotated along the
helical grooves 26 until it engages in the straight section 27
where it is retained by the projections 29. The arrangement of
grooves on the coupling body and abutments in the cap define a
first position of location of the cap on the coupling body in which
the abutments have just snapped past the ramps in the grooves 25
and a second position in which the cap is rotated through a quarter
turn on the coupling body to bring the abutments 24 into engagement
with the end sections 28 of the grooves and against the end stop
29. To assist in rotating the cap with respect to the coupling
body, the cap has a plurality of axially extending ribs 35 at
spaced locations around its outer surface.
[0026] As indicated earlier, each cap 20 has a reduced diameter
socket 22 at the end remote from the coupling body in which the
collet 23 is located to receive and lock a tube in the cap. Each
collet 23 comprises an annular portion 40 having a plurality of
axially extending spaced resilient arms 41 projecting into the cap
and an out turned head 42. The arms 41 have inturned teeth to
engage and grip a surface of a tube passing through the collet and
have heads 44 at the ends of the arms to engage in an internal
tapered frusto-conical cam surface formed in the tapered portion of
the cap between the main part and reduced diameter socket 21.
Engagement of the heads of the arms with the cam surface causes the
arms to be compressed inwardly with outward movement of the collet
from the cap to press the teeth of the arms firmly into gripping
engagement with the tube and thereby resist withdrawal of a tube
from the coupling body.
[0027] An arrangement of seals is provided in the throughway 12 in
the coupling body to one side of the inner annular wall 11 as
follows. Adjacent the wall there is an annular seal 50 having an
outer sleeve which extends around the throughway and is dimensioned
to receive the end of a tube to be sealed in the coupling body. The
sleeve has a short inner sleeve formed integrally with the outer
sleeve to receive an end face of the tube projecting into the outer
sleeve and form a seal therewith. The sleeve 50 is lodged against
and supported by the inner central wall 11.
[0028] Next to the sleeve 50 there is a ring member 60 one side 61
which abuts the sleeve and the other side of which has an
encircling flange 62 formed with spaced axially facing teeth 64 on
both sides thereof. The ring 60 projects into the open end of the
coupling body 12 and the teeth 63 mesh with corresponding teeth 65
formed on the end face of the coupling body to prevent rotation of
the ring with respect to the coupling body. Likewise the ends of
the arms 41 of the collet are formed with teeth 67 which mesh with
the teeth 64 on the flange 62 so that when the collet is in
engagement with the flange, the cap can be rotated on the coupling
body as described earlier without causing the collet 23 to
rotate.
[0029] As best seen in the left hand part of the coupling of FIG. 2
and the enlarged view of FIG. 3, a tube is assembled in the
coupling body with a cap 20 positioned in the first position
defined above in which the abutments 24 in the cap are snapped over
the ramps in the grooves 25 but the cap is not advanced further on
the coupling body at that stage. The tube to be connected to the
coupling body is aligned with the open end of the cap and is
inserted through the collet 23 in the cap, through the ring 60, and
into the seal 50 in the throughway. The collet automatically grips
and retains the tube to prevent the tube from being withdrawn from
the coupling body.
[0030] The cap 20 is then rotated through the helical path defined
by the grooves 26 to the position shown in the right hand part of
FIG. 2 and in FIG. 4 and in so doing is drawn axially along the
coupling body. The tube held by the collet is forced further into
the throughway in the coupling body and is pressed firmly into the
seal with the end of the tube engaging the inner seal. Ultimately
the abutments 24 in the cap reach the end portions of the groove
and are retained by the shallow projections referred to earlier to
hold the cap in the second position of movement with the end of the
tube held firmly sealed at the end of the tube by the inner seal
and around the outer surface of the tube by the outer seal and
0-ring seal.
[0031] Because the cap 20 rotates independently of the collet and
tube as describe earlier, the tube does not damage the seals in the
coupling body as it is forced into full sealing engagement with the
seals.
[0032] When it is required to detach a tube from the tube coupling,
the cap is rotated in the opposite direction back to the first
position in its movement at the ends of the axial portions of the
groove. The corresponding axial movement of the tube with the cap
slightly releases the engagement of the end of the tube in the seal
and the collet 23 can then be depressed into the cap to release the
gripping engagement of the collet arms with the tube and to allow
the tube to be extracted from the coupling body/cap.
[0033] The arrangement at the other end of the cap is identical and
like parts have been allotted the same reference numerals. It will
be appreciated that the arrangement is equally applicable to single
tube couplings, elbows, T-joints and any other form of a coupling
where a tube is required to be connected to another tube or other
device.
[0034] It will be appreciated that many modifications may be made
to the above described embodiment without departing from the scope
of the invention. For example, an annular spacer and an 0-ring may
be located next to the sleeve in the throughway to receive and
encircle a tube extending into the coupling body. The ring member
60 then abuts the other side of the 0-ring to provide an additional
seal between the tube and coupling body.
[0035] FIG. 5 of the drawings shows a modified arrangement of the
coupling in which ring 60 is omitted and the cap 20 is located on
coupling body 12 by means of a coarse screw-thread indicated at 70.
The teeth 67 on the ends of the arms of the collet engage directly
with the teeth 65 at the end of the coupling body. Thus the
separate ring 60 of the first embodiment is eliminated. The
construction is otherwise the same as that described earlier.
* * * * *