Abstract:
A breakaway coupling for a fuel supply hose includes a male valve body interfitting with a female valve body for defining a fuel passage, and the valve bodies enclose axially movable spring biased poppet valve members. The valve bodies are connected by a permanent magnetic coupling system which provides 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. In one embodiment, the coupling system includes an annular strike member surrounding the fuel passage and a mating annular magnet member supporting a plurality of circumferentially spaced permanent magnets of rare earth materials. In another embodiment, the valve bodies define a vapor return passage with a poppet valve member and disposed either radially outboard or inboard of the fuel passage. The magnetic coupling system also simplifies reconnecting the valve bodies.

Description:
RELATED APPLICATION 
   This application is a continuation of application Ser. No. 11/445,417, filed Jun. 1, 2006, now U.S. Pat. No. 7,252,112. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to a breakaway coupling for a flexible fuel supply hose and of the general type disclosed in U.S. Pat. No. 4,691,941 and in U.S. Pat. Nos. 4,763,683, 5,433,247 and 6,899,131 which issued to the assignee of the present invention and the disclosures of which are herein incorporated by reference. The breakaway coupling may be constructed for a coaxial hose as disclosed in the patents 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 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 discussed in above-mentioned U.S. Pat. No. 4,691,941, the coupling separates when the hose receives a substantial axial tension force, for example, between 200 and 400 pounds. Upon separation, the internal valve members move to their closed positions to prevent the release of fuel from the coupling components and attached hoses. 
   The female and male coupler bodies are releasably retained together by various means, for example, by a spring biased annular cam pressing against circumferentially spaced balls, as disclosed in above-mentioned U.S. Pat. No. 4,691,941, or by one or more shear pins, as disclosed in above-mentioned U.S. Pat. No. 4,763,683 or by the use of an annular coil spring, such as disclosed in above-mentioned U.S. Pat. Nos. 5,433,247 and 6,899,131. While the use of shear pins is the least expensive means for releasably connecting the coupler bodies, trained repair personnel and significant time is required to replace the shear pins after the coupler bodies have been separated. Since the use of the circumferentially spaced balls and a spring biased cam ring results in an expensive connection of the coupler bodies, the use of an annular coil spring has been adopted to reduce the cost of the releasable connection of the coupler bodies and to permit reconnecting the coupler bodies. However, the use of annular coil springs results in variation in the tension force required to separate or pull the coupler bodies apart. In addition, the annular coil spring connection also requires a significant axial compression force to rejoin or reconnect the coupler bodies. It has also been determined that the hydraulic line shock or hammer effect produced in the fuel supply lines or hoses during shut off of the fuel supply by the dispensing nozzles results in wear of the shear pins and coil springs. This wear reduces the tension force required to separate the coupler bodies and thus requires periodic maintenance or replacement of the pins or springs. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to an improved breakaway coupling for a flexible fuel supply hose and of the general type described above. The breakaway coupling of the invention provides for separating the coupler bodies with a substantially uniform and constant tension force which may be selected and which greatly simplifies the reconnection or recoupling of the coupler bodies. A coupling constructed in accordance with the invention may also be used with a flexible fuel supply hose with a single fuel passage or with a coaxial fuel supply hose with a vapor return passage which may surround the fuel passage or be located within the fuel passage in order to accommodate a vapor assist fuel dispensing nozzle or a balance-type fuel dispensing nozzle. 
   In accordance with illustrated embodiments of the invention, a tubular male coupler body and a tubular female coupler body of a breakaway coupling are each provided with internal spring bias poppet valve members for closing the fuel supply passage and any vapor return passage upon separation of the coupler bodies. The coupler bodies are releasably connected in a coupled position by a coupling system including a permanent magnet system which mounts on one coupler body around the fuel supply passage and mates with a strike member which mounts on the other coupler body around the fuel supply passage. 
   In the illustrated embodiment, the magnet system includes circumferentially spaced magnets formed of rare earth materials, and the magnets are slightly spaced from the annular strike member when the coupler members are connected. Both the magnet system and the strike member are protected after separation of the coupler bodies by interfitting annular protective or cylindrical semi-rigid covers or sleeves. The magnetic coupling system of the invention also provides for conveniently reconnecting or recoupling the coupler 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 axial section of a breakaway coupling constructed in accordance with the invention and having a fuel supply passage; 
       FIG. 2  is a radial section of the coupling, taken generally on the line  2 - 2  of  FIG. 1 ; 
       FIG. 3  is an end view of the coupling, taken generally on the line  3 - 3  of  FIG. 1 , the opposite end view being substantially the same; 
       FIG. 4  is an axial section of another embodiment of a co-axial breakaway coupling constructed in accordance with the invention and having both a fuel supply passage and a vapor return passage; 
       FIG. 5  is a radial section of the coupling, taken generally on the line  5 - 5  of  FIG. 4 ; and 
       FIG. 6  is an end view of the coupling, taken generally on the line  6 - 6  of  FIG. 4 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  illustrates a breakaway hose coupling  10  which includes a tubular male coupler body or body member  12  and a tubular female coupler body or body member  14  which are formed of a metal such as aluminum and have corresponding hexagonal outer end surfaces  16  and  18 , respectively. As shown in  FIG. 1 , the body members  12  and  14  are in their coupled or connected position and are partially surrounded by interfitting annular or cylindrical sleeves or covers  20  and  22  molded of a semi-rigid plastics material such as nylon. The male cover  20  has an end portion  23  which mounts on the body member  12  against an annular shoulder, and the cover  22  has an end portion  24  which mounts on a cylindrical surface of the body member  14 . The inner cover  20  has an external groove which carries a resilient sealing or O-ring  27  which forms a fluid-tight seal between the covers  20  and  22 . The body member  14  has an external groove which receives a resilient sealing or O-ring  29  which forms a fluid-tight seal between the body member  14  and the outer cover  22  which is secured by a spring retaining ring. 
   The body members  16  and  18  define an internal fuel supply passage  35  and have outer end portions within internal threads  37  for receiving threaded fittings, for example, on the end of a short fuel supply hose (not shown) extending from a fuel pump or dispenser and on a fuel supply hose (not shown) extending to a fuel dispensing nozzle. A valve member  42  is supported for axial movement within the center of the fuel supply passage  35  by a guide stem  43  slidably supported within a center hole  44  ( FIG. 3 ) formed within a cylindrical disk or washer  46  having circumferentially spaced openings or holes  47  ( FIG. 3 ). The disk or washer  46  is retained within the body  16  and passage  35  by a spring retaining ring  49 . The valve member  42  is constructed as disclosed in above-mentioned U.S. Pat. No. 6,899,131 and has tapered surfaces extending from an annular groove which receives a resilient sealing or O-ring  52  for engaging a tapered valve seat  54  formed within the valve body  12 . The valve member  42  also has a tubular inner end portion  56  with a tapered inner end surface  57 . A compression coil spring  59  extends within an annular groove within the valve member  42  and engages the supporting disk or washer  46  for normally urging the valve member  42  to a closed position where the sealing ring  52  engages the tapered valve seat  54 . 
   The body member  14  also supports an internal valve member  62  constructed and supported as disclosed also in above-mentioned U.S. Pat. No. 6,899,131. That is, the valve member  62  is supported for axial movement within the center of the fuel passage  35  by a guide stem  63  slidably supported within the center hole  44  of another circular disk or washer  46  having circumferentially spaced holes  47  and secured by another retaining ring  49 . The valve member  62  also carries a resilient sealing ring  52  and has an inner center pin portion  64  with a tapered end surface mating with the tapered seat  57 . Another compression coil spring  59  extends within an annular groove within the valve member  62  and engages the disk or washer  46  for normally urging the valve member  62  to a closed position where the sealing ring  52  engages a tapered valve seat  73  formed within the body member  14 . Preferably, the valve members  42  and  62  are molded of a rigid plastics material such as an acetal and are normally retained in their retracted open positions ( FIG. 1 ) when the body members  12  and  14  are connected together. The operation of the valve members  42  and  62  from open positions ( FIG. 1 ) to closed positions in response to separation of the body members  12  and  14 , is the same as disclosed in above-mentioned U.S. Pat. No. 6,899,131. 
   In accordance with the present invention, the body members  12  and  14  are releasably connected together by a magnetic coupling system  80  which is illustrated in one form by an annular permanent magnetic member  82  and an annular strike member  84  both of which are formed of a plated ferrous material or steel. The members  82  and  84  are secured to their corresponding body members  12  and  14  by internal threads  86  and  87 , and the annular strike member  84  has a pair of diametrically opposed and axially extending small holes (now shown) for threadably connecting the strike member  84  to the body member  12  after the end portion  23  of the tubular protective cover  20  is mounted on the body member  12 . 
   As shown in  FIG. 2 , the annular magnetic member  82  has a plurality of circumferentially spaced arcuate permanent magnets  95  which are recessed within an annular groove  96  formed within the member  82 . The arcuate permanent magnets  95  are retained within the groove  96  by an encapsulating film of adhesive or potting and bonding material, for example, as sold under the trademark LOCTITE. Preferably, the magnets  95  are formed of a rare earth material such as neodymium iron boron, and the magnets  95  are arranged with common poles on the inside diameter and common poles on the outside diameter, with small gaps between the magnets. As shown in  FIG. 1 , the annular groove  96  which receives the magnets  95  does not extend completely through the annular member  82 , and the outer edge faces of the arcuate magnets  95  are slightly recessed from the end surface or face of the annular member  82 . The recess is preferably on the order of 0.005″ to 0.007″. 
   The magnetic attraction between the permanent magnet member  82  and the strike member  84  provides for an attraction of substantial force requiring a tension force greater than 100 pounds to separate or pull the body members  12  and  14  apart. Preferably, the attraction force requires over 200 pounds and on the order of about 240 pounds of tension force to separate the body members  12  and  14 . After the body members  12  and  14  have been separated as a result of the axial tension force, it is apparent that the magnetic coupling system  80  provides for conveniently reconnecting the body members with only a small force to overcome the forces exerted by the springs  59  and the O-ring friction when the body member  12  is inserted into the body member  14 . The magnetic attraction then pulls the body members together. The force required to separate the body members may be selected by increasing or decreasing the small recess space between the outer ends of the magnets  95  and the end surface of the member  82  and/or increasing or decreasing the thickness of the wall at the bottom of the groove which receives the magnets  95  or by perforating the bottom wall. 
     FIGS. 4-6  illustrate another embodiment or modification of the breakaway coupling as described above in  FIGS. 1-3  and which has similar components as the breakaway coupling  10 . Accordingly, the similar components are identified with the same reference numbers but with the addition of prime marks. The breakaway coupling  10 ′ is of the inverted type, that is, has a center vapor return passage  105  surrounded by an annular fuel passage  110 . The coupling  10 ′ includes a male body member  12 ′ and female body member  14 ′. The body member  12 ′ supports a concentric inner tube  114  having peripherally spaced positioning spokes or ribs  116  ( FIG. 6 ) engaging a shoulder within the valve body  12 ′ and secured by a retaining ring  117 . The inner tube  114  supports an axially slidable tubular valve member  120  which carries a resilient sealing O-ring  123 . A compression coil spring  126  urges the valve member  120  towards a closed position where sealing ring  123  engages the annular tapered valve seat  54 ′. The inner tube  114  also supports an inner tubular wire coil  129  having an axially extending straight end portion or pin  131  within the center of the tube  114 . 
   The coupler body member  14 ′ also supports a center tube  142  which has radially outwardly projecting spokes or ribs  143  engaging a shoulder within the body member  14 ′ and retained by another spring-type retaining ring  117 . The center tube  142  also supports an axially slidable valve member  120  which carries a resilient O-ring seal  123  for engaging the annular tapered valve seat  73 ′ within the body member  14 ′. Another compression spring  126  urges the valve member  120  towards its closed position, and the two valve members  120  have opposing end surfaces which engage at  146  to hold the valve members  120  in their open positions when the body members  12 ′ and  14 ′ are coupled together, as shown in  FIG. 4 . The center tube  142  has a cylindrical inner end portion  152  which projects into the inner end portion of the center tube  114  and also forms an annular tapered inner valve seat  154 . 
   A valve member  156  has a center hole which normally receives the inner end portion of the pin  131  and carries a resilient O-ring seal  157  for engaging the valve seat  154 . A tapered compression wire spring  159  urges the valve member  156  towards its closed position. Thus when the coupler body members  12 ′ and  14 ′ are separated, the valve members  120  move to their closed positions to close the fuel supply passage  110  in both body members, and the valve member  156  moves to its closed position for closing the inner vapor return passage  105  within the coupler body member  14 ′. Thus the operation of the valve members within the coupler bodies  12 ′ and  14 ′ is substantially the same as disclosed in-connection with FIG. 9 of applicant&#39;s U.S. patent application No. 2005-0263193-A1, published Dec. 1, 2005 and assigned to the assignee of the present invention. The full disclosure of this published patent application is herein incorporated by reference, and the manual rotational separation of the breakaway hose coupling as disclosed in that application may also be incorporated in the hose coupling of the present invention. 
   The coupler bodies  12 ′ and  14 ′ are releasably connected together by the same magnetic coupling system  80  as described above in connection with  FIGS. 1-3 . Accordingly, the same reference numbers are used in  FIGS. 4-6  to identify the same components of the magnetic coupling system  80  as described above in connection with  FIGS. 1-3 . As apparent, the magnetic coupling system  80  may also be used for releasably connecting the tubular coupler bodies of a breakaway coupling of the balanced type, for example, as disclosed in above-mentioned U.S. Pat. No. 4,763,683. In this type of coupling, the fuel vapor within a motor vehicle fuel tank is displaced by the incoming fuel and is directed back to the fuel dispensing pump or dispenser through an annular outer vapor passage surrounding the inner fuel supply passage both within the coupling and each connected co-axial hose. 
   From the drawings and the above description, it is apparent that a breakaway hose coupling constructed in accordance with the invention, provides desirable features and advantages. For example, the magnetic coupling system  80  provides for releasably securing the tubular coupler bodies together with substantial force so that over 100 pounds and preferably over 200 pounds of axial tension force is required to separate the coupler bodies. This coupling force remains substantially constant over time and is not subjected to wear. The magnetic coupling system also provides for conveniently and quickly reconnecting coupling body members together with only a small axial force required to overcome the forces exerted by the compression springs on the valve members and the friction produced by the resilient O-rings between the coupling members and between the cover members. It is also apparent that when the coupler bodies are separated, the surrounding cover  22  protects the magnet member  80 , and the cover  20  protects the strike member  84  as well as the tubular inner portion of the male coupler body. While the arcuate rare earth magnets  95  provide the desired substantial magnetic attraction force while minimizing the overall diameter, it is apparent that other forms of permanent magnets may be used, for example, as known in the art of permanent magnets formed of rare earth materials. 
   While the forms of coupling 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.