Flexible joint

A flexible joint for the connecting and sealing of tubular sections that includes a flexible pad having inner and outer surfaces. A contoured portion extends around the inner surface of the pad. The flexible joint further includes a first tubular section having a raised portion. The raised portion engages the contoured portion on the inner surface of the pad. A second tubular section includes a housing. The housing has exterior and interior surfaces. The interior surface of the housing engages the outer surface of the pad for retaining the pad in a sealing relationship with the first tubular section.

FIELD OF INVENTION 
The present invention is directed generally to a flexible joint for the 
sealing of tubular sections. More specifically, the invention is directed 
to a flexible joint having a flexible pad positioned between aligned 
tubular sections to provide a flexible, sealed connection. 
BACKGROUND OF THE INVENTION 
Flexible joints are used for the joining of tubing in, for example 
automobile fluid conveying systems. The flexible joints must be capable of 
bending, twisting and moving axially in response to forces on the tubing. 
The flexible joints must also preferably provide sound and vibration 
dampening. The present invention meets the above requirements and also 
provides a relatively inexpensive and easy to manufacture flexible joint. 
SUMMARY OF THE INVENTION 
The present invention is directed to a flexible joint for the connecting 
and sealing of tubular sections. The flexible joint includes a flexible 
pad having inner and outer surfaces. A contoured portion extends around 
the inner surface of the pad. The flexible joint further includes a first 
tubular section having an annular raised portion. The raised portion 
engages the contoured portion on the inner surface of the pad. A second 
tubular section includes an annular housing. The housing has exterior and 
interior surfaces. The interior surface of the housing engages the outer 
surface of the pad for retaining the pad in a sealing relationship with 
the first tubular section. 
The primary object of the present invention is to provide a flexible joint 
for tubing that can move in response to forces on such tubing while 
providing a superior seal. 
An important object of the invention is to provide a flexible joint that is 
inexpensive and easy to manufacture. 
Other objects and advantages will become apparent as the invention is 
described hereinafter in detail with reference being made to the 
accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, the preferred embodiments of the present 
invention are shown. Referring to FIG. 1, the flexible joint of the 
present invention is indicated by reference number 10. The flexible joint 
10 includes a first tubular section 12 and a second tubular section 14. In 
the FIG. 1 embodiment, the first tubular section 12 is in communication 
with an automobile air conditioning compressor 16. However, it will be 
appreciated by those skilled in the art that the flexible joint of the 
present invention can be used in many automotive and nonautomotive fluid 
conveying systems depending on the application. At least two flexible 
joints are usually required to provide the necessary degrees of freedom to 
insure proper alignment of the several tubular sections in a system. 
A first embodiment of the present invention is shown in FIG. 2. The 
flexible joint 10 of this embodiment includes a first tubular section 12 
and a second tubular section 14. The flexible joint further includes a 
flexible pad 20. 
Still referring to FIG. 2, the flexible pad 20 includes an outer surface 22 
and an inner surface 24, both of which extend along an axis A in a 
generally circular configuration. The flexible pad 20 further includes a 
first side 26 and a second side 28. A centerline C divides the flexible 
pad 20 into substantially equal parts. The flexible pad 20 has an 
indentation or contour portion 30 extending around the inner surface 24 of 
the pad 20. The contour portion 30 can be an annular groove. The contour 
portion 30 may have various configurations and still fall within the 
present invention. For example, the contour portion 30 may have a 
spherical configuration. In the present embodiment, the groove 30 extends 
around the inner surface 24 of the flexible pad 20 between the centerline 
C of the pad and the second side 28 of the pad. However, the groove 30 can 
also be located between the centerline C of the pad and the first side 26 
depending on application. 
The flexible pad 20 can be made of any suitable material depending on the 
application. It has been found that elastomeric materials are especially 
suitable for most applications. Examples of suitable elastomeric materials 
include synthetic rubber, natural rubber, neoprene or a urethane material. 
The use of an elastomeric material in the construction of the flexible pad 
20 allows the pad to provide sound and vibration damping. 
Still referring to FIG. 2, a first tubular section 12 is shown. The first 
tubular section 12 is formed of a wall 40 extending along an axis A to an 
open end 42. The wall 40 has a cylindrical outer surface 44. A raised 
portion 46 or lip is formed on the outer surface 44. The raised portion 46 
is integral with the outer surface 44. The raised portion 46 and contour 
portion 30 can be a variety of geometric shapes. It has been found that 
circular, spherical and oblong shapes are preferred. 
The raised portion 46 engages the contour portion 30 on the inner surface 
24 of the flexible pad 20. This engagement maintains the first tubular 
section in proper alignment with the flexible pad 20. The flexible pad 20 
can be molded on the first tubular section 12 and then cured while in 
place or it can be molded and cured and then placed on the first tubular 
section, depending on the application. The pad 20 may be bonded to one or 
both of the tubular sections 12 and 14. 
A second tubular section 14 is also shown in FIG. 2. The second tubular 
section 14 is formed of a wall 50 extending along an axis A to an open end 
52. The wall 50 has a cylindrical outer surface 54. An enlarged housing 58 
is defined by the wall 50 at the open end 52 of the second tubular section 
14. The housing 58 includes an exterior surface 60 and an interior surface 
62. The interior surface 62 engages the outer surface 22 of the flexible 
pad 20 for retaining the pad in a sealing relationship with the first 
tubular section 12. 
A second housing 66 extends over the exterior surface 60 of the housing 58 
to provide additional structural support. The second housing 66 includes 
at least one lip 68 that can be swaged, rolled or otherwise deformed to 
encompass the flexible pad 20 and engage the exterior surface 60 of the 
housing 58. A gap 69 is preferably maintained between the housing 58 or 
the second housing 66 and the outer surface 44 of the first tubular 
section 12 to allow the flexible joint 10 and the tubular sections 12 and 
14 to move as required in response to a force. 
In the present embodiment, a containment element, such as a washer 71 is 
positioned around the first tubular section 12 between the elastomeric 
flexible pad 20 and the second housing 66. The washer 71 tends to retard 
elastomeric material from entering the gap 69. 
The first and second tubular sections 12 and 14, respectively, can be made 
of a variety of materials depending on the application. Examples of 
suitable materials include metal and plastic, with metal being the 
preferred material. 
The flexible pad 20 can be bonded or non-bonded to the first and second 
tubular sections 12 and 14, respectively, depending on the application. If 
the pad is non-bonded, a surface of synthetic resin polymers including a 
tetrafluoroethene homopolymer material, such as TEFLON.RTM., is preferably 
applied to the interior surface 62 of the housing 58 and the raised 
portion 46 of the first tubular section 12 to allow the pad to slide 
without additional lubrication. 
A second embodiment of the invention is shown in FIG. 3. In this 
embodiment, the contoured portion 30 in the inner surface 24 of the 
flexible pad 20 is substantially along the centerline C of the pad. The 
raised portion 46 of the first tubular section 12 engages the contoured 
portion or groove 30 to maintain proper alignment between the first 
tubular section 12 and the flexible pad 20. 
Still referring to FIG. 3, tapered edges 70 and 70' are included on the 
outer surface 22 of the flexible pad 20. The tapered edges 70 and 70' 
define relief areas to allow for the efficient insertion of the flexible 
pad 20 into the housing 58 during assembly of the flexible joint 10. 
A housing lip 72 is included as part of the housing 58. The housing lip 72 
is rolled or bent over the flexible pad 20 during assembly of the flexible 
joint 10. 
A third embodiment of the invention is shown in FIG. 4. In this embodiment, 
the flexible pad 20 has an outer surface 22, an inner surface 24, a first 
side 26 and a second side 28. A contoured portion or groove 30 extends 
around the inner surface 24 of the pad 20. 
A first tubular section 12 including a wall 40 extends around an axis A to 
an open end 42. The wall 40 has a cylindrical outer surface 44. A raised 
annular portion 46 is integral with the outer surface 44. The raised 
portion 46 is received by the groove 30 and is positioned between a first 
portion 76 of the wall 40 and a second portion 78 of the wall 40. The 
first portion 76 engages the inner surface 24 of the flexible pad 20 in 
the area adjacent the first side 26 to support or "stiffen" the pad. This 
makes the pad 20 relatively inflexible depending on the application. The 
raised portion 46 engages the contoured portion 30 on the inner surface 24 
of the pad 20. 
Referring to FIG. 4, a second housing 66 having a lip 68 engages the 
exterior surface 60 of the housing 58. This provides additional structural 
support to the housing 58. 
It should be understood that many changes can be made to the flexible joint 
disclosed in the drawings and still fall within the scope of the following 
claims.