Tube testing connector

A tube testing connector having a body member with an axial bore therethrough and a stem slidably disposed within said bore for internal sealing of open ended thin wall deformable tubing which employs a wide elastomer seal which provides for a more liquid tight seal. A relief groove is provided at the rear end of the stem which allows pressure within the connector to be vented rearwardly as the relief groove moves axially beyond an O-ring from a sealing position to a non-sealing position allowing venting of the tube prior to removal.

BACKGROUND OF THE INVENTION 
This invention relates to connectors for temporarily sealing the end of 
tubes and conduits and pressurizing the tubes for testing to be sure that 
the tubing does not leak. Recently, to increase the surface area of copper 
tubing used in the refrigeration industry, a "Rifle ID" feature has been 
included. This feature involves a knurling operation which is performed on 
the inner diameter of the tubing. Problems have been encountered with the 
sealing devices used when pressure testing the components that utilize 
this copper tubing. Previous devices have utilized an O-ring seal which 
provides inadequate sealing at high pressures and minimal seal life, due 
to the high internal pressure and the grooved inner diameter. Sealing on 
the outer diameter of the copper tubing has provided unsatisfactory 
results because the OD of the tube is not controlled to a sufficient 
tolerance to allow for consistent sealing. 
SUMMARY OF THE INVENTION 
The tube testing connector of the present invention provides a wide 
elastomer seal which results in more sealing area, thereby increasing the 
effectiveness of the seal between the connector and the tube being tested. 
A relief groove is provided in the tube connector which provides an 
exhaust passage for pressurized gas within the tubing prior to removal of 
the tube testing connector. This allows for removal of the tube connector 
after the system is depressurized, thus extending the life of the seal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention is directed to a tube testing connector 2 which 
provides for a more satisfactory seal when pressure testing thin wall 
deformable tubing having a "Rifle ID" feature, and provides for an 
extended seal life. Generally, as shown in FIG. 1, the tube testing 
connector 2 has a body 4 which includes an axial bore 6 extending 
throughout its entire length. The body 4 has a shoulder portion 8 and a 
terminal portion 10. The terminal portion 10 is adapted for insertion into 
a tube 12. The bore 6 is enlarged at the shoulder portion 8 of the body 4 
and its function will hereinafter become apparent. A stem 16 is shiftably 
disposed within the bore 6 between the unsealed position illustrated in 
FIG. 1 and the sealed position illustrated in FIG. 2. The stem 16 includes 
a threaded first end 18 and an enlarged second end 20 which projects 
beyond the shoulder portion 8 of body 4. The stem 16 is in close tolerance 
relationship with the bore 6 at the terminal portion 10 of the body 4. A 
passage means 24 is formed between the bore 6 and the stem 16, at the 
shoulder portion 8 of the body 4. The stem 16 is provided with a 
longitudinal groove or channelway 26 which extends substantially from a 
point immediately below a portion of the passage means 24 to the threaded 
first end 18 of the stem 16 as seen in FIG. 3. The channelway 26 provides 
a passage for pressurized gas to flow into the tubing. 
A handle 30 is pivotally attached to the enlarged second end 20 of the stem 
16 by a pin 32. The handle 30 has a first end 34 and a second end 36. A 
cam washer 38 is disposed between the first end 34 of the handle 30 and 
the shoulder portion 8 of the body 4, which provides a camming surface for 
handle 30 when it is pivoted through an arc of 90.degree. as will 
hereinafter become apparent. A counterbore 40 is defined in the left end 
of body 4 adjacent the cam washer 38 in communication with bore 6. A 
sealing member such as an O-ring 42 is disposed in the counter bore 40 to 
seal the left end of bore 6 adjacent the enlarged second end 20 of the 
stem 16 in fluid tight relationship. 
A wide elastomer seal 46, an actuating ring 48 and a spacer member 50 are 
disposed about the first end 18 of the stem 16. The elastomer seal 46 has 
a wall thickness to length ratio of approximately 1 to 3. The seal 46 is 
preferably made from chloroprene rubber which is sold under the trade name 
"Neoprene" by E. I. du Pont although other elastomers may be substituted 
if they are compatible with the test fluid and other test conditions. 
Seals which have been utilized effectively have the following sizes: (a) 
0.35" OD.times.0.22" ID.times.0.19" long, and (b) 0.29" OD.times.0.16" 
ID.times.0.19" long. The ring 48 and the spacer 50 encircle the stem 16 
and move with it. The elastomer seal 46 abuts the terminal portion 10 of 
the body 4. The actuating ring 48 has a narrow end 51 and an inclined 
surface 52. A retaining ring 56 is disposed on the inclined surface 52 of 
the actuating ring 48 between the elastomer seal 46 and the spacer member 
50. The spacer member 50 has a projecting portion 58 which provide the 
means whereby the retaining ring 56 is urged up the inclined surface 52 of 
the actuating ring 48 into an anchoring or locking position. A stop nut 62 
and washer 64 are secured to the threaded first end 18 of the stem 16 so 
as to retain the elastomer seal 46, actuating ring 48, retaining ring 56 
and spacer member 50 in the relative positions shown in FIG. 1. 
A resilient stop member 66 is located on the outer periphery of the 
terminal portion 10 of the body 4 adjacent the shoulder portion 8. Upon 
insertion of the connector 2 into a tube 12, the stop member 66 engages 
the inner periphery of the end of tube 12 and forms a gap 68, between the 
tube 12 and the shoulder portion 8 of the body 4 thereby preventing the 
tube 12 from abutting the shoulder portion 8 of the body 4 and being 
damaged. 
A fluid inlet port 70 is located in the shoulder portion 8 of the body 4, 
and is in communication with the passage 24. This inlet port 70 is adapted 
to receive pressurized fluid from a pressure source (not shown). A 
pressure releif groove 72 is formed in the stem 16 at the second end 20 to 
provide for venting of the pressurized gas. 
In operation, the tube testing connector 2 is inserted into a tube 12 for 
testing with the handle 30 in the unlocked, unsealed position as shown in 
FIG. 1. Once fully inserted so that the tube end firmly engages the stop 
member 66, the handle 30 is rotated counterclockwise through an arc of 
90.degree. to a locked and sealed position as shown in FIG. 2. When the 
handle 30 is rotated, the stem 16 is pulled to the left, as viewed in FIG. 
2, thereby moving the actuating ring 48 to the left, causing the 
compression of the elastomer seal 46 thereby increasing its outer diameter 
and forcing the same into sealing engagement with the internal wall of the 
tube 12 to form a tight seal. At the same time, the spacer member 50 is 
also moved to the left and the projecting portion 58 acts upon the 
retaining ring 56 to drive it up the inclined surface 52 of the actuating 
ring 48. This causes the retaining ring 56 to also engage the internal 
wall of the deformable tube 12 to form an internal groove and an external 
bead to anchor the tube testing connector 2 securely in place within the 
tube 12. In the unsealed position of FIG. 1, the relief groove 72 has 
portions lying on either side of the seal 42. In the sealed position of 
FIG. 2, the relief groove 72 is shifted entirely to the left of the O-ring 
42 which seals against the escape of gas. Thus, a pressure tight seal is 
formed at the end of the tube 12 where the tube testing connector 2 is 
attached. Normally a pressurized gas is used for testing the tubing but 
other pressurized fluid including pressurized liquids can also be used. 
Pressurized fluid is introduced into the connector via the inlet port 70. 
The fluid flows through the passage 24, through the longitudinal groove 26 
in the stem 16 and into the tube 12 to be pressure tested. 
When the test has been completed, the opposite sequence of steps is 
followed. As the handle 30 is returned to its non-sealing position of FIG. 
1, a portion of the relief groove 72 passes the O-ring 42 as shown in FIG. 
1 and provides for a release of the pressure which has built up inside the 
tube 12. The elastomer seal 46, actuating ring 48, retaining ring 56 and 
spacer member 50 return to the non-sealing position shown in FIG. 1. This 
thereby allows for an easier removal of the tube testing connector 2 and 
less wear on the O-ring 42 and elastomer seal 46. 
Various features of the invention have been particularly shown and 
described in connection with the illustrated embodiments of the invention, 
however, it must be understood that these particular arrangements merely 
illustrate, and that the invention is to be given its fullest 
interpretation within the terms of the appended claims.