Abstract:
A breakaway coupling for a fuel supply hose includes a male tubular valve body interfitting with or female tubular valve body and defining a fuel supply passage, and the valve bodies enclose axially moveable spring biased valve members. The valve bodies are connected by releasable connecting means which provide for moving the valve bodies from a connected position to a disconnected position in response to a substantial axial tension force on the valve bodies. The valve bodies have cooperating peripherally extending and opposing cam surfaces effective to move the valve bodies from the connected position to the disconnected position in response to relative rotation of the valve bodies and cam surfaces. The valve bodies may also define a vapor return passage with an axially movable valve member and disposed either radially outboard or inboard of the fuel supply passage.

Description:
RELATED APPLICATION 
   This application is a continuation-in-part of application Ser. No. 10/853,876, filed May 26, 2004, U.S. Pat. No. 6,899,131. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to a breakaway hose coupling for a flexible fuel supply hose and of the general type disclosed in U.S. Pat. No. 4,763,683 and No. 5,433,247 which issued to the assignee of the present invention and the disclosure of which is herein incorporated by reference. The breakaway coupling may be for a coaxial hose as disclosed in the patent with a fuel supply passage and a vapor return passage both of which have axially moveable valve members for closing the passages in the event the coupling is separated. The present invention also relates to a breakaway coupling having a single fuel supply passage with axially moveable valve members for closing the fuel supply passage in the male and female coupling bodies in the event of separation of the coupling. 
   In a breakaway hose coupling having a single fuel supply passage or coaxial fuel supply and vapor return passages, the breakaway hose coupling protects the fuel dispensing equipment from forces which may damage the equipment when separation of the coupling occurs. For example, when a vehicle driver inadvertently forgets to remove the fuel dispensing nozzle from the fuel tank inlet tube and drives away, as disclosed in U.S. Pat. No. 4,691,941, the coupling separates when the hose receives an axial tension force, for example, between 300 to 350 pounds. Upon separation, internal valve members move to their closed positions to prevent the release of fuel from the coupling components and attached hoses. 
   It has been found desirable to provide for separating the breakaway coupling by the operator of the fueling station or by inspection personnel in order to perform periodic inspection and maintenance on the breakaway coupling to insure continued proper operation of the coupling. One form of manual separation of the breakaway hose coupling is disclosed in U.S. Pat. No. 6,182,695. This patent discloses the use of a cup-like tool having a lever actuated cam and which mounts on the coupling after one of the hoses has been removed by threadably engaging one of the coupling members. The tool applies an axial tension force to the coupling to produce separation of the coupling members. After the coupling is inspected and parts are replaced, if necessary, the tool is used for reassembling the coupling, after which the hose is reattached so that the use of the coupling may be continued. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to an improved breakaway coupling for a flexible fuel supply hose and of the type described above. The breakaway coupling of the invention provides for conveniently and quickly separating the coupling without removing a hose from the coupling and with the use of conventional hand tools or wrenches. This separation of the coupling permits a person to perform regular or periodic inspection and maintenance of the breakaway coupling to assure proper and continued operation of the coupling including free movement of the internal valve members. The means for manual separation of the coupling components does not add substantial cost to the manufacture of the coupling nor does it add any significant weight or size to the coupling. 
   In accordance with embodiments of the invention, a tubular male and female components or valve bodies of a breakaway coupling are provided with axially opposing and peripherally extending cam surfaces. The cam surfaces are effective to exert a substantial axial separating force on the tubular coupling components or valve bodies in response to relative rotation of the valve bodies using conventional tools such as a pair of open end wrenches. The cam surfaces may be formed on integral parts of the valve bodies or may be formed on cylindrical sleeves or collars threadably connected to the valve bodies. Preferably, a resilient cylindrical sleeve is attached to the male valve body and surrounds the cam surfaces and junction of the valve bodies. 
   Other features and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an elevational view of an assembled and connected breakaway coupling constructed in accordance with the invention; 
       FIG. 2  is an elevational view similar to  FIG. 1  but with the protective cylindrical cover removed; 
       FIG. 3  is an axial section of the assembled and connected coupling components, taken generally on a line  3 — 3  of  FIG. 1 ; 
       FIG. 4  is an axial section of the coupling components shown in  FIGS. 1–3  and with the components disconnected; 
       FIG. 5  is an end view of the assembled coupling taken generally on the line  5 — 5  of  FIG. 2 ; 
       FIG. 6  is an elevational view similar to  FIG. 2  and showing a modification of a coupling constructed in accordance with the invention; 
       FIG. 7  is an axial section similar to  FIG. 3  and taken generally on the line  7 — 7  of  FIG. 6 ; 
       FIG. 8  is an axial section similar to  FIG. 7  and showing an assembled co-axial balanced-type breakaway coupling constructed in accordance with another embodiment of the invention; and 
       FIG. 9  is a section similar to  FIG. 8  and showing an assembled co-axial inverted-type breakaway coupling constructed in accordance with another embodiment of the invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  illustrates a breakaway hose coupling  10  constructed in accordance with the invention and which includes a tubular male valve fitting or body  12  and a tubular female valve fitting or body  14  which are formed of a metal such as aluminum and have corresponding hexagonal outer end surfaces  16  and  18 , respectively. As shown in  FIGS. 1 and 3 , the valve bodies  12  and  14  are shown in their coupled or connected position and are partially surrounded by a resilient and cylindrical sleeve or cover  20  which has an internal circumferential bead  22  which snap-fits into a mating external groove  23  within the valve body  16 . 
   Referring to  FIG. 3 , the female valve body  14  defines an internal fuel supply passage  25  and has an end portion with internal threads  27  for receiving a fitting on the end of a short fuel supply hose (not shown) extending from a fuel pump or dispenser. A valve element or member  32  is supported for axial movement within the center of the passage  25  by a valve stem  33  slidably supported by a center cross portion  34  of a washer  36  ( FIG. 5 ) secured within the valve body  14  by a retaining ring  39 . The valve member  32  carries a resilient sealing ring  42  which is normally urged toward a tapered or frusto-conical surface or valve seat  44  by a compression spring  46 . The valve member  32  has an axially projecting center pin  48  which has a tapered or conical end surface  51 . The valve body  14  defines a cylindrical bore  53  and a cylindrical end portion  54  having external threads and defines an annular or cylindrical counterbore or cavity  56 . The cavity  56  confines an annular latch spring  58 , for example, in the form of a canted coil spring as disclosed in U.S. Pat. No. 4,655,462. The valve body  14  also defines a slightly larger diameter counterbore or cavity  61  is connected to the counterbore  56  by a tapered or frusto-conical surface  62 . 
   The male valve body  12  has internal threads  66  for receiving a fitting on the end of a flexible fuel supply hose (not shown) which extends to a fuel dispensing nozzle (not shown). The valve body  12  includes a cylindrical intermediate portion  68  which seats within the end portion  54  of the valve body  14  and carries a pair of external resilient sealing rings  71  to form a fluid-tight seal with the end portion  54  of the valve body  14 . The valve body  12  has a cylindrical inner end portion  73  which slides into the bore  53  and carries a resilient external sealing ring  74  to form a second fluid-tight seal between the valve bodies  12  and  14 . An annular external seat  77  is formed on the valve body  12  and normally retains the latch spring  58 . A tapered or frusto-conical surface  79  extends from the seat  77  to the cylindrical outer surface of the body end portion  73 . 
   The valve body  12  also supports a valve element or member  82  which includes a guide stem  84  supported for sliding movement within the center hole of another circular washer  36  in the same manner as the guide stem  34  of the valve member  32  is supported for sliding movement. The washer  36  is retained by a spring retaining washer  39 , and the valve member  82  carries a resilient sealing ring  86  which is adapted to seat on a tapered or frusto-conical surface  88  formed within the valve body  12 . The valve member  82  also has a tubular inner end portion  93  with a tapered or frusto-conical seat  94  which receives the tapered end surface  51  of the valve member  32 . A compression spring  96  extends from the center portion of the washer  36  into a counterbore within the valve member  82  and cooperates with the compression spring  46  to center the valve members  32  and  82  in their open positions ( FIG. 3 ) when the valve bodies  12  and  14  are coupled or connected together. 
   In accordance with the present invention, diametrically opposite cam surfaces  102  ( FIGS. 2 and 3 ) are formed on the male valve body  12 , and opposing and mating diametrically opposite cam surfaces  104  are formed on the female valve body  14 . In the embodiment shown in  FIGS. 2–4 , the cam surfaces  102  are formed on the end of a tubular or cylindrical sleeve or collar  106  which is connected to the valve body  12  by mating threads  108  ( FIG. 3 ). The cam surfaces  104  are formed on the end of a tubular or cylindrical sleeve or collar  110  which is rigidly connected to the valve body  14  by mating threads  112 . Diametrically opposite V-shaped gaps  114  are defined between the cam surfaces  102  and  104  to provide for assembling the valve bodies  12  and  14 . 
   When the valve bodies  12  and  14  are separated ( FIG. 4 ), the latch spring  58  is rolled or shifted to the right ( FIG. 3 ) until the spring  58  expands outwardly into the large annular cavity  61 . The valve body  12  is then inserted into the valve body  14  until the cam surfaces  102  engage the cam surfaces  104 . The valve bodies  12  and  14  are then pulled axially apart by the width of the gap  114  so that the latch spring  58  rolls inwardly due to pressure exerted by the annular surface  77  until the latch spring is confined within the annular recess  56 , as shown in  FIG. 3 . In this position, the latch spring  58  secures the valve bodies  12  and  14  together in their normal connected and operating position. As mentioned above, a substantial axial tension force, such as 300 pounds to 350 pounds, is required to separate the valve bodies  12  and  14  back to the disconnected positions shown in  FIG. 4 . 
   When it is desired to separate the valve bodies  12  and  14  for inspection and/or replacement of internal parts or components, such as the springs and O-ring seals, a pair of wrenches, such as open end wrenches, are inserted onto the hex surfaces  16  and  18 , and torque is applied so that the valve bodies  12  and  14  are rotated relative to each other. This causes the cam surfaces  102  and  104  to exert the necessary substantial axial tension force on the valve bodies so that the valve body  12  collapses the latch spring  58  radially until the valve bodies  12  and  14  are free to separate when the valve members  32  and  82  move to their closed positions, as shown in  FIG. 4 . As also shown in  FIG. 4 , when the valve bodies  12  and  14  separate, the protective resilient cover  20  remains with the male valve body  12  to provide protection for the tubular end portion  73  of the valve body  12 . 
   A modification of the breakaway coupling is shown in  FIGS. 6 and 7 . In this embodiment, a breakaway coupling  10 ′ has the same components as the breakaway coupling  10  described above in connection with  FIGS. 1–5 , and accordingly, the components are identified with the same reference numbers but with the addition of prime marks. The primary difference in the embodiment disclosed in  FIGS. 6 and 7  is that the diametrically opposite cam surfaces  102 ′ and the opposing diametrically opposite cam surfaces  104 ′ are formed as integral parts of the corresponding valve bodies  12 ′ and  14 ′. Preferably, the valve bodies  12 ′ and  14 ′ are machined from a metal such as aluminum using an automatic machining tool center. Thus, the integral cam surfaces  102 ′ and  104 ′ may be easily formed on the valve bodies by appropriate programming of the machining tool center. 
   Referring to  FIG. 8 , a breakaway coupling  120  is of the balanced-type, for example, as disclosed in above mentioned U.S. Pat. No. 4,763,683, and wherein the fuel vapor within a motor vehicle fuel tank is displaced by the incoming fuel and is directed back to the fuel dispenser pump through an outer passage within a co-axial hose. In this embodiment, the coupling  120  includes a male valve member or body  122  which couples with a female valve member or body  124 . The valve body  122  includes a fitting  126  which has internal threads for receiving a co-axial hose (not shown), a hexagonal outer surface  127  and a center fuel supply passage  128  surrounded by circumferentially spaced and axially extending vapor return passages  132 . The fitting  126  is threaded into a tubular fitting extension  136  which has circumferentially spaced spacing ribs and a tubular portion  138  with a peripherally extending groove receiving the latch spring  58 ′ and also has a tapered annular valve seat  141 . 
   A valve member  144  is similar in construction to the valve member  82 ′ and carries a resilient sealing ring  86 ′ for engaging the valve seat  141 . The valve member  144  has a center valve stem  146  which is supported for axial movement by a frusto-conical washer  148  similar to the washer  36  and having openings spaced around a hub portion. The outer peripheral portion of the washer  148  seats on the end of a tubular portion  151  of the fitting  126 . A compression spring  152  surrounds the stem  146  and urges the valve member  144  towards a closed portion engaging the seat  141 . The fitting extension  136  has peripherally extending cam surfaces  154  with a diametrically opposite V-shaped configuration similar to the cam surfaces  102  described above. 
   The female valve body  124  includes a tubular fitting  156  which defines a continuation of the center fuel supply passage  128  and has a hexagonal outer surface  161  and internal threads  162  for receiving a fitting (not shown) on the end of a relatively short co-axial fuel supply hose such as disclosed in above mentioned U.S. Pat. No. 4,763,683. The fitting  156  also has vapor return passages  132  and is threadably connected to a tubular valve body  168  which defines a tapered annular valve seat  171  extending to a counterbore which receives the tubular portion  138  of the fitting extension  136 . The valve body  168  surrounds a valve member  173  which carries a resilient sealing ring and has a tip portion  174  projecting axially into a bore formed within the valve member  144 . The valve member  173  also has a stem portion  178  which is slidably supported by another conical washer  148  engaging and seated on the inner end of the fitting  156 . Another compression spring  152  surrounds the valve stem  178  and urges the valve member  173  towards a closed position engaging the valve seat  171 . As apparent from  FIG. 8 , when the valve bodies  122  and  124  are pressed axially together, the valve members  144  and  173  move to their open positions compressing the corresponding springs  152 . 
   A tubular housing  180  has a cylindrical outer surface and one end portion attached to the fitting  156 . The opposite end portion of the housing  180  slides onto the fitting  126 , and resilient sealing rings  182  form fluid-tight connections between the housing  180  and the fittings  126  and  156 . The housing  180  cooperates with the concentrically spaced valve bodies  136  and  168  to define a continuation of the vapor return passages  132  within the fittings  126  and  156 . An annular resilient lip seal  188  is confined within the housing  180  between a ring  191  and a ring  193 , and the seal  188  and rings  191  and  193  move axially to open positions ( FIG. 8 ) forming a continuation of the vapor return passage  132  when the valve bodies  122  and  124  are assembled or coupled together. When the valve bodies are separated, the annular lip seal  188  and the rings  191  and  193  move to the left within the housing  180  in response to a force exerted by a compression spring  196 . When the lip seal  188  engages the outer cylindrical surface of the valve body  168 , the vapor return passage  132  is closed simultaneously with the closing of the fuel supply passage  128  by the valve members  144  and  173 . A set of three circumferentially spaced and axially extending pins  198  have end portions secured to the ring  193  and extend within the vapor return passage  132 . The opposite end portions of the pins  198  project between the spacing ribs on the fitting extension  136  and engage the inner end of the fitting  126 . When the valve bodies  122  and  124  are coupled together, the pins  198  shift the rings  191  and  193  and the sealing ring  188  to the open position ( FIG. 8 ) so that the fuel vapor is free to flow through the passage  132  of the coupling  120 . 
   As shown in  FIG. 8 , the inner end of the valve body member  168  has peripherally extending cam surfaces  204  with a diametrically opposite V-shaped configuration mating with the cam surfaces  154 . The cam surfaces  154  and  204  function in the same manner as the cam surfaces  102  and  104  and  102 ′ and  104 ′ described above, that is, to separate the valve bodies  122  and  124  axially in response to relative rotation of the fittings  126  and  156  of the valve bodies, respectively. To protect the valve bodies  122  and  124  and the cam surfaces  154  and  204 , a cylindrical cover sleeve  206  of a resilient plastics material, has one end portion secured to the fitting  126  and remains with the valve body  122  when the valve bodies  122  and  124  are separated. 
   Referring to  FIG. 9 , a breakaway coupling  220  is of the inverted-type, that is, has a center vapor return passage  222  surrounded by a fuel supply passage  224 . The coupling  220  includes a male valve member or body  226  and a female valve member or body  228 , and the valve body  226  includes a stepped tubular portion  232  having a peripherally extending groove  233  which receives the latch spring  58 ′. The tubular portion  232  also has a tapered annular valve seat  236  and supports a concentric inner tube  238  having peripherally spaced positioning ribs  239  engaging the valve body  226  and secured by a retaining ring. The inner tube  238  supports a slidable tubular valve member  242  which carries a resilient sealing ring  243 . A compression spring  246  urges the valve member  242  towards a closed position where the sealing ring  243  engages the valve seat  236 . The inner tube  238  also supports an internal tubular wire coil  248  having an axially extending end portion or pin  249  within the center of the tube  238 . 
   The valve body  228  defines a tapered annular valve seat  252  and has an inner tubular portion  256  which slidably receives inner tubular portion  232  of the valve body  226 . The valve body  228  also supports a center tube  258  having peripherally spaced positioning ribs  259  secured by a retaining ring and having an inner tubular portion  262  defining an annular tapered valve seat  264 . The center tube  258  also supports another tubular valve member  242  which carries a resilient sealing ring  243 , and another compression spring  246  urges the valve member  242  towards a closed position engaging the valve seat  252 . When the valve bodies  226  and  228  are connected or coupled together, the inner opposing ends of the two valve members  242  contact each other at  266 . 
   The center tube  258  also supports an internal conical compression spring  272  which seats on an annular shoulder within the tube  258  and supports a valve member  274 . The valve member  274  carries a resilient sealing ring  276  for engaging the valve seat  264  when the valve bodies  226  and  228  are separated. When the valve bodies are coupled together, the center pin  249  of the coil  248  extends into the valve member  274  and shifts it to an open position ( FIG. 9 ) against the bias of the spring  272 , thereby opening the vapor passage  222 . As also apparent, when the valve bodies  222  and  226  are separated, the valve members  242  shift to their closed positions against the valve seats  236  and  252  in response to the forces exerted by the compression springs  246 . 
   The valve bodies  226  and  228  of the coaxial coupling  220  also has a set of mating and opposing V-shaped cam surfaces  280  and  282 , respectively. The cam surfaces function to separate the valve bodies  226  and  228  and overcome the connection by the latch spring  58 ′ in response to relative rotation of the valve bodies  226  and  228  with the use of wrenches attached to outer end surfaces of the valve bodies. The cam surfaces  280  and  282  are protected by a resilient plastic sleeve  284  which receives the inner portion  256  of the valve body  228  and is attached to the valve body  226 . 
   From the drawings and the above description, it is apparent that a breakaway coupling constructed in accordance with the invention provides desirable features and advantages. As a primary advantage, the breakaway coupling of the invention may be conveniently and quickly inspected for regular or periodic maintenance and to insure proper operation of the internal valve members by simply rotating the valve bodies relative to each other with conventional hand tools or wrenches. In addition, the separation of the valve bodies may be performed without disconnecting any flexible hoses from the valve bodies. Also, the resilient outer tubular sleeve or cover protects the valve bodies and cam surfaces and prevents dust and dirt from entering the gap between the cam surfaces. As described above in connection with  FIGS. 8 and 9 , the opposing cam surfaces may be formed on coaxial breakaway couplings with vapor return passages such as a balanced-type coupling shown in  FIG. 8  or an inverted-type coupling shown in  FIG. 9 . The separation means of the invention also eliminates the need for a specially formed tool as disclosed in above-mentioned U.S. Pat. No. 6,182,695. 
   While the forms of couplings herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of couplings, and that changes may be made therein without departing from the scope and spirit of the invention as defined in the appended claims.