WO2008077013A2

WO2008077013A2 - Connection of tubes for air conditioning and seal adapted thereto

Info

Publication number: WO2008077013A2
Application number: PCT/US2007/087879
Authority: WO
Inventors: Robert J. Dubiel; Frank M. Levanduski; William V. Blevins, Jr.; Nikhil Baxi
Original assignee: Parker-Hannifin Corporation
Priority date: 2006-12-18
Filing date: 2007-12-18
Publication date: 2008-06-26
Also published as: WO2008077013A3

Abstract

A fitting for connecting a male and female tube (52, 54). According to one aspect, a fitting is provided having a one-piece seal (30) that radially seals both the male and female tubes and axially seals the female tube (54). According to another aspect, a fitting (50) is provided having a body with a seal element bonded to the body and surrounding at least a portion of a bore through the body. The seal (30) is configured to seal both radially and axially. Assembly of the fittings is simplified by one-piece seal elements (30) and the elimination of the need to roll form an annular retention groove in the male tube.

Description

AIR CONDITIONING CONNECTOR SEAL

Related Applications

This application claims the benefit of U.S. Provisional Application No. 60/870,450 filed December 18, 2006, and U.S. Provisional Application No. 60/954,405 filed August 7, 2007, both of which are hereby incorporated herein by reference in their entireties.

Field of the Invention The present invention relates generally to fluid fittings. More particularly, the invention relates to fittings for connecting conduits that carry refrigerant material in an automobile air conditioning system.

Background of the Invention It is common to conduct refrigerant in automobile and other air conditioning systems in flexible hoses or metallic tubes. Often the flexible hoses are fitted with ends that include metallic tube portions. The tube portions are adapted to be connected to various components that are parts of the air conditioning system. Such components may include a condenser, compressor, expansion valve, accumulator or receiver/dryer.

Various types of fittings have been developed for connecting the tube portions to each other and/or to the various components of the system. One such type of fitting is a two-piece seal fitting generally indicated by reference numeral 2 in Fig. 1. This fitting 2 includes a male block 10 through which a male tube 12 extends. The male tube 12 has an annular recess 13 formed therein in which an O-ring 14 is retained. A female tube 16 is configured to be telescoped over the end of the male tube 12. An axial seal member 18 supported by the male block seals the axial end face (flange) of the female tube 16 while the O- ring 12 radially seals the male tube 12 and female tube 16. A female block 20 engages a flange on female tube 16 and prevents withdrawal of the female tube 16 from the fitting 2. The male and female blocks are secured together with bolt 22 and nut 24 n position against the male block 10. To assemble the fitting 2 of Fig. 1 , typically the end of the male tube 12 is press fit through the block 10, such as by tapping or pounding the end of the tube 12. Using a roll-forming tool, the annular groove 13 is formed in the male tube 12 into which the O-ring 14 is installed. The female tube 16 then is telescoped over the male tube 12. Finally, female block 20 is secured to male block 10 with bolt 22, which is first threaded into female tube 16, and nut 24.

Although the fitting 2 of Fig. 1 is suitable for some applications, it will be appreciated that the several steps involved in forming the connection (e.g., press-fitting the male tube, forming the annular groove, etc.) during assembly of an air conditioning system can be tedious and time consuming.

Summary of the Invention

The present invention provides a fitting that is easily assembled and does not require forming an annular groove in the male tube. According to one aspect, a fitting is provided having a one-piece seal that radially seals both the male and female tubes and axially seals the female tube. According to another aspect, a fitting is provided having a body with a seal element bonded to the body and surrounding at least a portion of a bore through the body. The seal is configured to seal both radially and axially. Assembly of the fittings is simplified by the one-piece seal designs and the elimination of the need to roll form an annular retention groove in the male tube.

Accordingly, a seal for a fitting assembly used to connect a male tube to a female tube in a refrigeration system comprises a carrier and a seal element supported by the carrier. The seal element includes a tubular portion extending axially from an opening in the carrier through which a male tube can be inserted. The tubular portion has a radially outwardly protruding sealing bead on an outer surface thereof spaced apart axially from the carrier whereby when the tubular portion is positioned between the male tube and a mating female tube, the radially outwardly protruding sealing bead seals an inner diameter of the female tube.

More specifically, the tubular portion of the seal element can be generally cylindrical and configured such that a female tube can be telescoped over the tubular portion. The seal element can include an outer annular axial seal portion extending radially outward from the tubular portion for sealing an axial end face of the female tube when telescoped over the tubular portion of the seal element. The seal element can also include an inner annular axial seal portion extending radially inward from the tubular portion and spaced axially from the carrier for sealing an axial end face of the male tube when inserted into the tubular portion of the seal element. The carrier can have an annular support flange projecting from the carrier surrounding the opening for providing radial support to of a proximal portion the seal element. The tubular portion can also include first and second axially spaced-apart radial seal beads on radially inner and/or outer surfaces thereof. The carrier can be made of a thermoplastic material with the seal element being overmolded thereon.

The seal can be included in a fitting assembly comprising first and second fitting block halves, a male tube and a female tube. The male tube is supported by the first fitting block half and extends through a bore in the first fitting block half such that an end of the male tube protrudes from the bore. The male tube also has a radially outward protruding bead spaced axially from the protruding end of the tube trapped in a counterbore of the first fitting half preventing withdrawal of the male tube from the fitting assembly. The female tube is telescoped over the protruding end of the male tube, and is supported by the second fitting block half which is secured to the first fitting block half with a fastener. An end of the female tube extends through a bore in the second fitting block half and has thereon a radially outward protruding flange trapped in a counterbore of the second fitting block half preventing withdrawal of the female tube from the fitting assembly. The seal is radially interposed between the male and female tube for radially sealing an outside diameter of the male tube to an inside diameter of the female tube.

According to another aspect a seal for a fitting assembly used to connect a male tube to a female tube in a refrigeration system comprises a carrier and a seal element supported by the carrier. The seal element includes a tubular portion extending axially from an opening in the carrier through which a male tube can be inserted, the tubular portion having concentric radially outer and inner surfaces. The carrier has an annular support flange projecting from the carrier surrounding the opening for providing radial support to a proximal portion of the seal element.

The carrier can be made of a thermoplastic material, and the seal element can be an elastomeric material overmolded on the carrier. The seal element can have an outer annular axial seal portion extending radially outward from the tubular portion for sealing an axial end face of the female tube. The seal element can also or alternatively have an inner annular axial seal portion extending radially inward from the tubular portion and spaced apart axially from the carrier for sealing an axial end face of the male tube.

According to another aspect of the invention, a fitting block for a fitting assembly used to connect lines of a refrigeration system comprises a body having a bore extending therethrough, and a seal element bonded to the body and surrounding at least a portion of the bore, the seal element having a radially inner seal portion for sealing a circumferential surface of a first tube, and an axial seal portion for sealing an axial end face of a second tube. The body can be made of a thermoplastic material, and the seal element can be overmolded on the body. The seal element can be located in a counterbore in the block.

Further features of the invention will become apparent from the following detailed description when considered in conjunction with the drawings.

Brief Description of the Drawings Fig. 1 is an assembly view of a conventional fitting. Fig. 2 is a cross-sectional view of an exemplary seal in accordance with the invention.

Fig. 3 is a top view of the seal of Fig. 2.

Fig. 4 is a cross-sectional view of a partially assembled exemplary fitting in accordance with the invention including the seal of Figs. 2 and 3.

Fig. 5 is cross-sectional view of the fitting of Fig. 5 assembled. Fig. 6 is a cross-sectional view of another exemplary seal in accordance with the invention. Fig. 7 is a cross-sectional view of another exemplary fitting in accordance with the invention.

Detailed Description Referring now to the drawings in detail, and initially to Figs. 2 and 3, an exemplary seal 30 in accordance with the invention is illustrated. As will be appreciated, and as described in detail below in connection with Fig. 4, the seal 30 is used in a fitting for sealing a joint between a male and female tube.

The seal 30 includes a carrier 32 and an overmolded elastomeric seal element 34. The carrier 32, which can be thermoplastic, includes a mount hole through which a fastener, such as a bolt, can extend for securing the seal within the fitting, as will be described. An annular support flange 36 projects from the carrier 32 and surrounds an opening 38 in the carrier 32 through which a tube can extend. The annular support flange 36 is generally provided to support the elastomeric seal element 34 and can also serve as an interlock structure for interlocking with overmolded seal element.

The elastomeric seal element 34, which can be a rubber seal, surrounds opening 38 in the carrier 32 and includes a generally tubular portion that is configured to receive an end of a male tube therein. A radially inwardly extending shoulder 40 limits the extent to which the male tube can be inserted into the seal element 34 and is configured to seal an axial end face of the male tube when inserted therein. A pair of seal beads 42 on the inner surface the seal element 34 are provided for sealing against a radially outer surface of the male tube when inserted therein.

The seal element 34 is also configured such that a female tube can be telescoped over the tubular portion. A pair of radial seal beads 44 on the outer surface of the seal element 34 are provided for sealing against a radially inner surface of the female tube when telescoped over the seal element 34. An axial seal bead 46 is provided for sealing an axial end face of the female tube when telescoped over the seal element 34. Turning now to Figs. 4 and 5, the seal 30 is illustrated in an exemplary fitting 50 for connecting a male tube 52 to a female tube 54. The fitting 50 includes male block 56, seal 30, and female block 58 which are secured together via bolt 60 and nut 62. The male and female blocks 56 and 58 can be made of a thermoplastic material or, more typically, aluminum.

As mentioned above, male tube 52 is inserted into the tubular portion of the seal 30, while the female tube 54 is telescoped over the tubular portion of the seal 30. The annular support flange 36 of the carrier 32 generally supports the tubular portion during the telescoping of the female tube 54 to prevent deformation of the seal element 34. The male tube 52 and female tube 54 are secured relative to each other via the male and female blocks 56 and 58, which each engage a shoulder on a respective tube. Bolt 60 and nut 62 are then tightened to secure the fitting 50 and thereby ensure a tight sealing joint between male tube 52 and female tube 54.

It will be appreciated that the fitting 50 in Figs. 4 and 5, which does not have a separate O-ring as in the conventional fitting of Fig. 1 , does not require the extra steps of roll forming a groove in the male tube 52 and installing an O- ring therein. Further, the fitting 50 effectively reduces the number of parts as compared to the fitting of Fig. 1. Accordingly, assembly of the fitting 50 can be more efficient.

As mentioned above, the annular support flange 36 of the carrier 32 is generally provided for supporting the seal element 34 when the female tube 54 is telescoped over the tubular portion. Such support can be desired particularly when friction and/or interference between the female tube 54 and the seal element 34 would otherwise cause the tubular portion to collapse or otherwise deform thereby preventing proper installation of the fitting 50.

Turning to Fig. 6, a seal 30 is illustrated without the annular support flange 36. In this embodiment, the seal element 34 of the seal is composed of a material having sufficiently low friction such that the female tube 54 can be installed (e.g., telescoped) over the seal 30 without the tubular portion of the seal member 34 collapsing or otherwise deforming in an unfavorable manner. In this regard, certain lubricating fillers can be included in the seal compound to achieve a seal material having a suitable friction coefficient. The seal 30 of Fig. 6 is otherwise identical to the seal 30 shown in Figs. 2-5, and is used in the fitting 50 in the same manner. Turning now to Fig. 7, another exemplary fitting in accordance with the invention is illustrated. The fitting 70 includes a male seal block 72 and female block 74 for connecting male tube 52 to female tube 54. In this embodiment, the seal (or seals) is formed as part of male seal block 72 and, as such, the assembly of a separate seal element is avoided.

Male seal block 72 has a thermoplastic body (carrier) 76 with an opening 78 through which male tube 52 is press fit. In general, the male tube is secured to the male seal block by interference, although a retention bead and retainer plate could also be provided. A resilient seal material is overmolded or otherwise bonded in an inner counterbore 80 surrounding the opening 78 thereby forming seal element 82.

Seal element 80 has a radially inner side having a pair of radial seal beads 84 configured to seal radially against the outer diameter of the male tube 52. An axial seal bead 86 is configured to seal against an axial end face of the female tube, which in the illustrated embodiment is a radially outwardly extending flange 88.

Male seal block 72 also has an outer counterbore 90 in which resilient seal material is overmolded or otherwise bonded to provide a secondary seal element 92. The secondary seal element 92 has an undercut region 94 in which a kink 96 on the male tube 52 resides when the male tube 52 is fully inserted into the male seal block 72. The secondary seal material adjacent the undercut region 92 generally operates to retain the male tube 52 in the male seal block 72 during assembly.

To assemble the fitting 70, male tube 52 is press fit through bore 78 in the seal block 72. This can be done by, for example, pounding an end of male tube 52. As mentioned, the interference between the male tube 52 and male seal block 72 generally secures the male tube in the fitting 70. An additional retainer plate (not shown) could also be provided for securing male tube 52 to the seal block 72. As will be appreciated, the end of the male tube 52 protrudes from the male seal block 72 when fully inserted therein. Female tube 54 is telescoped over the protruding end of the male tube 52 such that flange 88 of the female tube engages the seal element 82. Flange 88 is captured in counterbore 97 in female block 74 thereby preventing removal of the female tube 54 from the fitting 70. Bolt 98 and nut 99 are used to secure the male seal block 72 and female block 74 together. In this embodiment, since the seal element is formed as part of the male seal block 72, no separate assembly of the seal is needed. As such, this embodiment both eliminates the need to roll form a groove in the male tube 52 and the need to separately handle a seal member. Thus, the fitting 70 can be more quickly and easily installed. Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a "means") used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.

Claims

What is claimed is:

1. A seal for a fitting assembly used to connect a male tube to a female tube in a refrigeration system, comprising a carrier and a seal element supported by the carrier, wherein the seal element includes a tubular portion extending axially from an opening in the carrier through which a male tube can be inserted, the tubular portion having a radially outwardly protruding sealing bead on an outer surface thereof spaced apart axially from the carrier, whereby when the tubular portion is positioned between the male tube and a mating female tube, the radially outwardly protruding sealing bead seals an inner diameter of the female tube.

2. A seal as set forth in claim 1 , wherein the tubular portion of the seal element is generally cylindrical and is configured such that the female tube can be telescoped over the tubular portion.

3. A seal as set forth in any one of claims 1 -2, wherein the seal element has an outer annular axial seal portion extending radially outward from the tubular portion for sealing an axial end face of the female tube when telescoped over the tubular portion of the seal element.

4. A seal as set forth in any one of claims 1-3, wherein the seal element has an inner annular axial seal portion extending radially inward from the tubular portion and spaced axially from the carrier for sealing an axial end face of the male tube when inserted into the tubular portion of the seal element.

5. A seal as set forth in any one of claims 1-4, wherein the carrier has an annular support flange projecting from the carrier surrounding the opening for providing radial support to of a proximal portion the seal element.

6. A seal as set forth in any one of claims 1 -5, wherein the tubular portion includes first and second axially spaced-apart radial seal beads on a radially outer surface thereof.

7. A seal as set forth in any one of claims 1 -6, wherein the tubular portion includes first and second axially spaced-apart radial seal beads on a radially inner surface thereof.

8. A seal as set forth in any one of claims 1-7, wherein the carrier is made of a thermoplastic material, and wherein the seal element is overmolded on the carrier.

9. A fitting assembly including the seal in any one of claims 1-8, comprising first and second fitting block halves, a male tube supported by the first fitting block half, the male tube extending through a bore in the first fitting block half such that an end of the male tube protrudes from the bore, the male tube having a radially outward protruding bead spaced axially from the protruding end of the tube trapped in a counterbore of the first fitting half preventing withdrawal of the male tube from the fitting assembly, a female tube telescoped over the protruding end of the male tube, the female tube supported by the second fitting block half secured to the first fitting block half with a fastener, an end of the female tube extending through a bore in the second fitting block half and having thereon a radially outward protruding flange trapped in a counterbore of the second fitting block half preventing withdrawal of the female tube from the fitting assembly, and the seal of claim 1 radially interposed between the male and female tube for radially sealing an outside diameter of the male tube to an inside diameter of the female tube.

10. A seal for a fitting assembly used to connect a male tube to a female tube in a refrigeration system, the seal comprising a carrier and a seal element supported by the carrier, wherein the seal element includes a tubular portion extending axially from an opening in the carrier through which a male tube can be inserted, the tubular portion having concentric radially outer and inner surfaces, and wherein the carrier has an annular support flange projecting from the carrier surrounding the opening for providing radial support to a proximal portion of the seal element.

11. A seal as set forth in claim 10, wherein the carrier is made of a thermoplastic material, and the seal element is an elastomeric material overmolded on the carrier.

12. A seal as set forth in any one of claims 10-11 , wherein the seal element has an outer annular axial seal portion extending radially outward from the tubular portion for sealing an axial end face of the female tube.

13. A seal as set forth in any one of claims 10-12, wherein the seal element has an inner annular axial seal portion extending radially inward from the tubular portion and spaced apart axially from the carrier for sealing an axial end face of the male tube.

14. A fitting block for a fitting assembly used to connect lines of a refrigeration system comprising: a body having a bore extending therethrough; and a seal element bonded to the body and surrounding at least a portion of the bore, the seal element having a radially inner seal portion for sealing a circumferential surface of a first tube, and an axial seal portion for sealing an axial end face of a second tube.

15. A fitting block as set forth in claim 14, wherein the body is made of a thermoplastic material, and wherein the seal element is overmolded on the body.

16. A fitting block as set forth in any one of claims 14-15, wherein the seal element is located in a counterbore in the block.

17. A fitting block as set forth in any one of claims 14-16, wherein the radially inner seal portion includes first and second axially spaced-apart radial seal beads on a radially inner surface thereof.