Abstract:
A fitting assembly for fluid and vapor connection comprising a first tube, a second tube and a ring. The first tube has a male member at the end of the first tube and a radially enlarged upset formed at a distance from the end of the first tube. The second tube has a hollow female body formed at the end of the second tube. The male member is received in the female body. The ring surrounds the female body. The ring has an axial bore with an innermost diameter smaller than the outermost diameter of the female body for deforming the female body radially inward. The innermost diameter of the axial bore is smaller than at least a portion of the upset of the first tube.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to fluid and vapor line systems which include fittings, and more particularly, to a fitting having an axially movable swaging ring. 
     For the automotive and other industries, fittings are commonly used to connect metal tubes and pipes to each other to provide a fluid or vapor connection. 
     One type of fittings often used is a ring having a conical bore for securing a male member formed at the end of a first tube inserted into a radially enlarged female body formed at the end of a second tube. For this type of fitting, the ring is loosely and slidably mounted on the first tube. The ring is mounted such that the enlarged diameter portion of the conical bore is directed toward the male member. To provide the fluid or vapor connection, the male member is first inserted into the female body. The ring is then slid along the first tube toward the female body and swaged over the female body with the male member inserted within. The swaging of the ring over the female body crushes the female body radially inward and creates a sealing surface between the female body and the male member. Once the ring is swaged over the female body, it retains the male member within the female body. The ring constantly applies a radially inward force to the female body. The female body reacts by applying a radially inward force to the male member. This radially inward force by the female body onto the male member prevents the male member from withdrawing from the female body, thus securing the male member within the female body. This type of fitting is prevalent in the art, and has proven effective in many fluid or vapor line applications. 
     Nevertheless, such fittings have occasionally been prone to failure. During insertion of the male member into the female body, the male member may not have been inserted sufficiently into the female body. Thus, when the ring is swaged over the female body, there is not sufficient surface between the crushed female body and the relational male member to form an effective sealing surface. Furthermore, if the male member has not been inserted sufficiently into the female body, upon swaging the ring over the female body the ring can bypass the portion of the female body overlaying the male member. Should such a situation occur, there is no radially inward force applied by the female body onto the male member, thus allowing the male member to be easily withdrawn from the female body. 
     While the swaging of the ring over the female body creates a sealing surface between the female body and the male member, the surface is still prone to leak should a gap develop between the female body and the male member. 
     One solution disclosed in prior art references is to apply a bonding agent onto the male member just prior to insertion of the male member into the female member. Examples of such bonding agents include solder and anaerobic. After insertion of the male member into the female body, the bonding agent bonds the outer surface of the male member to the inner surface of the female body. The bonding agent thus fills any gaps developed between the female body and the male member. However, the bonding agent must be applied just prior to insertion of the male member into the female body. Should the bonding agent be applied in advance, contaminants will adhere to the outer surface of the bonding agent. This lack of ability to apply the bonding agent in advance increases complexity and labor for the final assembly manufacturer&#39;s assembly plant. 
     Another disadvantage of this type of fitting is the need to install the ring onto the tube forming the male member just prior to the insertion of the male member into the female body. Since the ring is loosely and slidably mounted, the ring can slide off the end of the male member or up the tube away from the male member, thus preassembly of the ring onto the tube is not feasible. This lack of feasibility for preassembly of the ring increases complexity and labor for the final assembly manufacturer&#39;s assembly plant. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a fitting assembly for fluid and vapor connection comprising a first tube, a second tube and a ring. The first tube has a male member at the end of the first tube and a radially enlarged upset formed at a distance from the end of the first tube. The second tube has a hollow female body formed at the end of the second tube. The male member is received in the female body. The ring surrounds the female body. The ring has an axial bore with an innermost diameter smaller than the outermost diameter of the female body for deforming the female body radially inward. The innermost diameter of the axial bore is smaller than at least a portion of the upset of the first tube. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view of a first embodiment of a fitting assembly prior to assembly. 
     FIG. 2 is a partial section view of the fitting assembly of FIG. 1 after a ring is preassembled onto an upset and a male member is inserted into a female body. 
     FIG. 3 is a partial sectional view of the fitting assembly of FIG. 1 after the ring is swaged over the female body. 
     FIG. 4 is a sectional view of a second embodiment of a fitting assembly prior to assembly. 
     FIG. 5 is a partial sectional view of the fitting assembly of FIG. 4 after a ring is swaged over a female body. 
     FIG. 6 is a sectional view of a third embodiment of a fitting assembly prior to assembly. 
     FIG. 7 is a partial sectional view of the fitting assembly of FIG. 6 after a ring is swaged over a female body. 
     FIG. 8 is a sectional view of a fourth embodiment of a fitting assembly prior to assembly. 
     FIG. 9 is a partial sectional view of the fitting assembly of FIG. 8 after a ring is swaged over a female body. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1-3 illustrate a first embodiment of a fitting assembly of the present invention. The fitting assembly  10  comprises a male member  12 , a female body  14  and a ring  16 . 
     The male member  12  is formed at the end of a first hollow and rigid tube  18  which forms a part of a fluid line system. The tube  18  may lead to a component in a fluid line system, or may itself be a portion of a component in a fluid line system. Formed at a given distance from the distal end  20  of the male member  12  is a radially enlarged upset  22 . The upset  22  is situated between the male member  12  and the remaining portion of the first tube  18 . 
     The female body  14  is formed at the end of a second hollow and rigid tube  24  which forms the other part of a fluid line system. The female body  14  is enlarged radially in relation to the remaining portion of the second tube  24 . The length of the female body  14  is slightly longer than the length of the male member  12 . The inner diameter D 1  of the female body  14  is slightly larger than the outer diameter D 2  of the male member  12 . The inner diameter D 1  of the female body  14  is smaller than the outer diameter D 3  of the upset  22  of the first tube  18 . 
     The ring  16  has a generally cylindrical outer surface  32 . The ring  16  has an axial bore  34  extending axially inward from an entrance  36 . The entrance  36  is defined by a first conical surface  38 . The first conical surface  38  acts as a lead-in surface to facilitate the swaging of the ring  16  over the female body  14 . Axially inward from the first conical surface  38  is a first cylindrical surface  40 . The diameter D 4  of the first cylindrical surface  40  is sized such that the first cylindrical surface  40  will crush the female body  14  radially inward, but will not crush the male member  12 . Therefore, the diameter D 4  of the first cylindrical surface  40  is smaller than the outer diameter D 5  of the female body  14 , but larger than the outer diameter D 2  of the male member  12  plus twice the wall thickness T 1  of the female body  14 . Axially inward from the first cylindrical surface  40  is a second conical surface  48 . The second conical surface  48  acts as a lead-in surface to a second cylindrical surface  50 . The diameter D 6  of the second cylindrical surface  50  is sized such that the second cylindrical surface  50  will crush both the female body  14  and the male member  12  radially inward. Therefore, the diameter D 6  of the second cylindrical surface  50  is smaller than the outer diameter D 2  of the male member  12  plus twice the wall thickness T 1  of the female body  14 . 
     The diameter D 6  of the second cylindrical surface  50  also sized to be slightly smaller than a portion of the upset  22  of the first tube  18 , thus creating an interference fit between the second cylindrical surface  50  and a portion of the upset  22 . The upset  22  as illustrated in FIGS. 1-3 has a cylindrical surface. However, it should be noted that the upset can have a further radially enlarged surface in which only the further radially enlarged surface of the upset creates an interference fit with the second cylindrical surface. The upset can also have a conical surface such that a portion of the conical upset creates an interference fit with the second cylindrical surface. 
     The first embodiment of a fitting assembly  10  functions as follows. The ring  16  is preassembled onto the upset  22  of the first tube  18 . The ring  16  is slid axially onto the upset  22  such that the first conical surface  38  is directed toward the distal end  20  of the male member  12 . Since a portion of the upset  22  creates an interference fit with the second cylindrical surface  50  of the ring  16 , the ring is retained on the upset  22 . This preassembly can be performed prior to the components of the fitting assembly arriving at the final assembly manufacturer&#39;s assembly plant, thus reducing the complexity and labor required at the assembly plant. 
     To connect the fitting assembly  10 , the male member  12  is first inserted into the female body  14  until the terminal end  54  of the female body  14  abuts the upset  22  of the male member  12 . Hence, the upset  22  does not only serve as a retainer for the ring  16  during preassembly, but the upset  22  also serves as a positive stop during the insertion of the male member  12  into the female body  14 . The upset  22  allows for consistency in the amount of male member  12  inserted into the female body  14 . 
     After the male member  12  is fully inserted into the female body  14 , the ring  16  is slid axially toward the female body  14 . As the ring is slid over the female body  14 , the first conical surface  38  contacts the terminal end  54  of the female body  14 . Thereafter, the trailing end  56  of the first conical surface  38  and the first cylindrical surface  40  apply a radially inward force, crushing the female body  14  radially inward, thus creating a sealing surface between the inner surface of the female body  14  and the outer surface of the male member  12 . Once the second conical surface  48  contacts the terminal end  54  of the female body  14 , the second conical surface  48  and the second cylindrical surface  50  further apply a greater radially inward force, crushing both the female body  14  and the male member  12 . The crushed female body  14  and male member  12 , along with the constant radially inward force applied by the ring  16 , prevents the withdrawal of the male member  12  from the female body  14 . 
     FIGS. 4 and 5 illustrate a second embodiment of a fitting assembly  100  of the present invention. The second embodiment is the same as the first, but includes an additional sealing layer  102  surrounding a male member  104 . The sealing layer  102  is a thin layer of polymeric material bonded to the male member  104 , but is not bonded to a female body  106 . Since the sealing layer does not have any adhesion characteristic on the outer surface, the concern of contaminants attaching to the sealing layer has been eliminated, thus the sealing layer can to be applied to the male member well before the male member  104  is inserted into the female body  106 . 
     Suitable polymeric materials for the sealing layer  102  include, but are not limited to, elastomers, fluoropolymers, polyamides, polyesters, polyurethanes, polyvinyl chlorides, polyketones, polyolefins and mixtures thereof. The preferred polymeric material for forming the sealing layer is elastomer. The polymeric material can be applied by being painted onto the male member. A brush is used to coat the male member with the liquid form of the polymeric material onto the male member. A liquid form of the polymer material can also be extruded around the male member through use of an extruder. 
     Alternatively, the polymeric material can be formed into thin strips. A layer of adhesive is applied to one side of the strip. The strip of polymeric material with adhesive applied can be rolled up for storage, similar to a roll of tape. The rolled strip can later be spirally wrapped around the male member to provide a layer of polymeric material surrounding and bonded to the male member. 
     The strip of polymeric material is applied to the portion of the male member  104  radially inward of a swaging ring  108  after the ring  108  has been fully swaged around the female body  106 . 
     The second embodiment of a fitting assembly  100  functions the same as the first embodiment, but provides a sealing layer which fills any gap between the male member  104  and the female body  106 . A layer  102  of polymeric material is pre-applied to the outer surface of the male member  104 . The male member  104  is inserted into the female body  106  until the terminal end  110  of the female body  106  abuts an upset  112  formed axially inward of the male member  104 . The ring  108  is slid over the female body  106 . The trailing end of a first conical surface  114  and a first cylindrical surface  116  apply a radially inward force, crushing the female body  106  radially inward. Located between the male member  104  and the female body  106  is the layer  102  of polymeric material. The radially inward force compresses the layer  102  of polymeric material tightly between the male member  104  and the female body  106  to create an effective seal. 
     A second conical surface  118  and a second cylindrical surface  120  then apply a greater radially inward force, crushing the female body  106  and the male member  104  radially inward to prevent the male member  104  from withdrawing from the female body  106 . 
     FIGS. 6 and 7 illustrate a third embodiment of a fitting assembly  150  of the present invention. The third embodiment is the same as the first, but includes an additional O-ring  152  surrounding a male member  154 . The male member  154  of the third embodiment further has a channel  156  formed between the distal end  158  of the male member and an upset  159  formed axially inward of the male member  154 . 
     Situated in the channel  156  is the elastomeric O-ring  152 . The channel  154  retains the O-ring  152  onto the male member  154  and prevents the O-ring  152  from sliding or rolling axially along the male member  154 . The channel  156  is located in a portion of the male member  154  such that, after a swaging ring  160  is fully swaged around a female body  162 , the portion of the female body  162  radially outward of the channel  156  is crushed radially inward, but the male member  154  is not crushed. Thus, a first cylindrical surface  164  of the ring  160  is located radially outward of the channel  156  after the ring  160  is fully waged around the female body  162 . 
     The third embodiment of a fitting assembly  150  functions the same as the first embodiment, but provides a channel formed on the male member and an O-ring situated in the channel. The O-ring  152  is pre-installed in the channel  156 . The male member  154  is inserted into the female body  162  until the terminal end  166  of the female body  162  abuts the upset  159 . The ring  160  is slid over the female body  162 . The trailing end of a first conical surface  170  and the first cylindrical surface  164  apply a radially inward force crushing the female body  162  radially inward. Located between the channel  156  of the male member  154  and the female body  162  is the O-ring  152 . The radially inward force  152  compresses the O-ring tightly between the channel  156  of the male member  154  and the female body  162  to create an effective seal. A second conical surface  172  and a second cylindrical surface  174  then apply a greater radially inward force, crushing the female body  162  and the male member  154  radially inward to prevent the male member  154  from withdrawing from the female body  162 . 
     FIGS. 8 and 9 illustrate a fourth embodiment of a fitting assembly  200  of the present invention. The fourth embodiment is the same as the third, but includes a second channel  202  adjacent to an upset  204  formed axially inwardly of a male member  206  and a radially outward protrusion  208  at the terminal end  210  of a female body  212 . Upon full insertion of the male member  206  into the female body  212 , the protrusion  208  is directly radially outward of the second channel  202  of the male member  206 . 
     The fourth embodiment of a fitting assembly  200  functions the same as the first, but provides a second channel formed on the male member and a protrusion at the terminal end of the female body. The male member  206  is inserted into the female body  212  until the terminal end  210  of the female body  212  abuts the upset  204 . A ring  214  is slid over the female body  212 . The trailing end of a first conical surface  216  and a first cylindrical surface  220  first apply a radially inward force crushing and deforming the protrusion  208  radially inward toward the second channel  202 . The trailing end  218  of the first conical surface  216  and the first cylindrical surface  220  then apply a radially inward force, crushing the remaining portion of the female body  212  radially inward. A second conical surface  222  and a second cylindrical surface  224  then apply a greater radially inward force, further crushing and deforming the protrusion  208  into the second channel  202  of the male member  206 . The deformed protrusion  208  acts as an abutment surface, preventing the withdrawal of the male member  206  from the female body  212 . Since the second conical surface  222  and the second cylindrical surface  224  do not crush the male member  206  radially inward, less effort is required to swage the ring  214  over the female body  212 . 
     Various features of the present invention have been described with reference to the embodiments shown and described. It should be understood, however, that modifications may be made without departing from the spirit and scope of the invention as represented by the following claims.