Abstract:
A safety fuel tank and filler cap apparatus is disclosed for use with a powered implement such as a lawnmower, tiller, weed trimmer or the like. The apparatus includes switch members mounted on the fuel cap and tank that disallow engine operation when the filler cap is separated from the tank such as during refueling.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part of U.S. Ser. No. 09/267,877, filed Mar. 11, 1999. 
     INVENTOR: Charles Brister, a U.S. citizen of 505 Ellis Road, Amite, La. 70422. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     REFERENCE TO A &#34;MICROFICHE APPENDIX&#34; 
     Not applicable 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to small internal combustion engines of the type that are used to power lawn mowers, tillers, lawn vacuums, weed trimmers, snow blowers, water blasters and the like. Even more particularly, the present invention relates to an improved safety fuel tank and filler cap apparatus that automatically disables the magnetoelectric generator when a fuel filler cap portion of the apparatus is separated from a fuel filler flange such as when the fuel filler cap inadvertently disconnects from the fuel tank or is removed for filling the fuel tank. 
     2. General Background of the Invention 
     Every year, fires cause serious and sometimes fatal bodily injury to operators of small yard and garden implements such as lawn mowers, lawn vacuums, weed trimmers and the like. One of the most common problems is associated with the attempt by individuals to add gasoline to a lawn mower or like engine that is still running. Sometimes, an implement gradually loosens the gas filler cap because of vibration. If the user is not paying close attention to the gas tank and its filler cap, gasoline can begin to leak when the cap is loosened. This problem is especially acute with rear drive type implements such as go-karts, riding lawn mowers wherein the gasoline tank may be behind the operator or underneath a seat or hood preventing the user from seeing it. Many tractor style riding lawnmowers have such a hidden fuel tank and filler cap. 
     Many of these implements are operated by adolescent children that are not warned sufficiently by their parents about the danger of filling tanks with gasoline when the implement or vehicle is hot from operation. 
     Even adults sometimes have a bad habit of smoking when operating such an implement, so that if the cap loosens, the operator does not notice the escape of fumes if the engine keeps running. 
     Generators are often filled when running because the user does not want to interrupt the flow of electricity. 
     All of these situations are hazardous if the engine continues to run when the filler cap is removed. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides and improved safety fuel tank and filler cap apparatus for supplying fuel to an internal combustion engine that can be started with a magnetoelectric generator. 
     The apparatus includes an exposed fuel tank having a fill opening, a fuel filler flange surrounded by an adjoining fuel tank outer surface, the flange extending a short distance from the filler opening in the fuel tank wall. 
     A filler cap fits the fuel filler flange to form a closure of the tank at the fill opening, the filler tank and adjoining fuel tank outer surface being configured to enable a user to grip and turn the fuel filler cap. 
     A switch is interfaced between the fuel tank and filler cap that disables the magnetoelectric generator when the filler cap is removed from the fuel filler tank. This construction prevents the user from filling the fuel tank with gasoline when the engine is running. 
     The switch can be a magnetic switch, a photoelectric switch, or a mechanical switch such as a button switch , toggle switch, rocker switch, as examples. 
     The mechanical switch can be a switch that moves between operating and disabled positions, the switch including a moving member that shifts positions when the fuel filler cap is separated from the fuel filler flange. 
     The switch can include a magnetic switch member mounted in the fuel tank and another magnetic switch member mounted on the filler cap. 
     The switch can include a switch member mounted on the filler cap the does not interfere with the sealing of the fuel filler flange with the filler cap, being spaced from the threads or bayonet connectors that join the cap and tank. 
     The filler cap can have a top, an annular skirt with internal threads, and wherein the switch member is mounted on the annular skirt in between the threads and the top. Such internal threads form a threaded engaged connection with external threads on the fuel filler flange. 
     The fuel fuller cap preferably has a top, an annular skirt with a threaded portion thereon, and an unthreaded outer surface and wherein the switch member is mounted on the annular skirt. The switch member can be mounted on an unthreaded portion of the filler cap. 
     The present invention also teaches and provides a powered implement that has a frame, an internal combustion engine mounted on the frame that includes a magnetoelectric generator for starting the engine, and including an exposed fuel tank having a fill opening, a fuel filler flange surrounded by an adjoining fuel tank outer surface, the flange extending a short distance from the filler opening in the fuel tank wall and wherein a filler cap fits the fuel filler flange to form a closure of the tank at the fuel opening. 
     The filler cap and adjoining fuel tank outer surface are configured to enable a user to grip and turn the fuel filler cap. A switch is interfaced between the fuel tank and filler cap that disables the magnetoelectric generator when the filler cap is removed from the fuel filler flange, the switch including switch portions mounted respectively on the fuel tank and on the fuel filler cap. 
     The implement can be for example a lawn mower, go-kart, garden tractor, lawn vacuum, snow blower, tiller, chain saw, weed trimmer, hedge clipper, or log splitter. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein: 
     FIG. 1 is a perspective view of the preferred embodiment of the apparatus of the present invention; 
     FIG. 1A is perspective view of the preferred embodiment of the apparatus of the present invention used with an auxiliary tank; 
     FIG. 1B is a perspective view of the preferred embodiment of the apparatus of the present invention showing a powered implement in the form of a weed trimmer; 
     FIG. 2 is a partial sectional elevational view of the preferred embodiment of the apparatus of the present invention; 
     FIGS. 3A-3B are schematic diagrams of the preferred embodiment of the apparatus of the present invention shown in engine operating (FIG. 3A) and engine disabled (FIG. 3B) positions; 
     FIG. 4 is a side elevational view of a second embodiment of the apparatus of the present invention; 
     FIGS. 5A-5B are schematic sectional elevational views of the second embodiment of the apparatus of the present invention showing the switch in engine operating (FIG. 5A) and engine disabled (FIG. 5B) positions respectively; 
     FIG. 6 is an elevational view of a third embodiment of the apparatus of the present invention; 
     FIG. 7 is a perspective view of the third embodiment of the apparatus of the present invention; 
     FIG. 8 is a perspective view of a fourth embodiment of the apparatus of the present invention; 
     FIG. 9 is a partial perspective view of the fourth embodiment of the apparatus of the present invention; 
     FIG. 10 is an exploded perspective view of the fourth embodiment of the apparatus of the present invention; 
     FIG. 11 is a sectional elevational, exploded view of the fourth embodiment of the apparatus of the present invention; 
     FIGS. 12A, 12B, 12C are upper perspective, bottom perspective and bottom views respectively of a filler cap construction having a bayonet type mount and that can be used with the embodiments of FIGS. 1-11; 
     FIGS. 13A, 13B, 13C are upper perspective, bottom perspective, and bottom views respectively of another filler cap construction having a bayonet mount and that can be used with the embodiment of FIGS. 1-11; 
     FIGS. 14-15 are perspective view of a hinged filler cap construction that can be used with the embodiment of FIGS. 1-11, showing closed and open positions respectively of the filler cap; 
     FIG. 16 is a perspective exploded view of a fifth embodiment of the apparatus of the present invention; 
     FIG. 17 is a fragmentary plan view of the fifth embodiment of the apparatus of the present invention showing a micro switch type switch arrangement; 
     FIG. 18 is a fragmentary plan view of the fifth embodiment of the apparatus of the present invention shown with a plunger switch type switch arrangement; 
     FIG. 19 is a fragmentary plan view of the fifth embodiment of the apparatus of the present invention shown with a magnetic switch proximity switch or optical switch arrangement; 
     FIGS. 20A-20B are schematic wiring diagrams of the fifth embodiment of the apparatus of the present invention showing respectively in ignition system on and ignition system off wiring diagrams; and 
     FIGS. 21A-21B are alternate circuit drawings showing an ignition system for the present invention in respective &#34;on&#34; and &#34;off&#34; positions. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1, 1A and 1B show the preferred embodiment of the apparatus of the present invention designated generally by the numeral 10 in FIGS. 1, 1A and 1B. 
     Safety fuel tank and cap apparatus 10 includes a safety system that disables internal combustion engine E if a user removes the fuel filler cap 19 from cylindrically shaped flange 16 of fuel tank 14. Engine E is a type that includes a magnetoelectric generator 11 that can be operated with an electric starter (not shown) or a pull cord starter rope 12. An electrical circuit is provided for disabling magnetoelectric generator 11 when filler cap 19 is removed from fuel tank 14 as will be described more fully herein. An electrical cable 13 extends between a switch mounted on the upper surface 15 of fuel tank 14 and the magnetoelectric generator or &#34;magneto&#34; 11. 
     The fuel filler cap 19 in FIG. 2 provides an internally threaded portion 23 that interlocks with external thread 17 on cylindrically shaped flange 16. The cylindrically shaped flange 16 surrounds fuel tank opening 18. 
     Filler cap 19 is comprised of a circular top portion 21 and a generally cylindrically shaped annular skirt 20. The top portion 21 is joined to the skirt 20 at annular edge 37. Skirt 20 has an inner annular, generally cylindrically shaped surface 20A and an outer annular generally cylindrically shaped surface 20B. Skirt 20 outer surface 20B can be knurled or ribbed to ease gripping by a user. Inner surface 20B can be threaded (see FIGS. 2, 3A-3B, 5A-5B) or a bayonet mount (see FIGS. 14-15). Handle 22 is positioned on top 21 for enabling a user to remove cap 19 from flange 16 or for engaging cap 19 with flange 16. The cap 19 can include a vent 24 for releasing fumes. 
     The filler cap 19 can be an internally threaded cap as shown in FIGS. 1-11. Alternatively, the filler cap can be a bayonet type cap 19A, 19B as shown in FIGS. 12A, 12B, 12C, 13A, 13B and 13C. Such a bayonet mount type cap 19A, 19B is used on engines such as Honda® and Briggs® for example. 
     A magnet 25 is embedded in the unthreaded upper portion of cap 19 next to top 21 as shown in FIG. 2. Magnet 25 provides an outer end 26 that is positioned next to the annular skirt 20. The inner end 27 of magnet 25 is positioned nearer the center of circular top as show in FIG. 2. 
     A magnetic switch 28 is mounted on upper surface 15 of fuel tank 14 adjacent to cylindrically shaped flange 16. Magnetic switch 19 includes an electrical cable 29 that communicates with electrical cable 13 extending to magneto 11. The electrical cable 13 can include a pair of wire leads 29A, 29B as shown in FIGS. 3A, 3B. 
     In FIG. 3A, the magnet 25 is shown with its outer end 26 positioned next to magnetic switch 28. Spring 33 is overcome by magnet 25 so that it pulls contact plate 34 toward magnet 25 and away from contact points 35, 36. This condition shown in FIG. 3A occurs when the gas filler cap 19 is in a fully closed position. In this closed position, the magnet 25 is generally aligned with the magnetic switch 28 as shown in FIGS. 1, 1A, 1B, 2 and 3A. 
     In FIG. 3B, a user has separated the gas filler cap 19 from cylindrically shaped flange 18 as indicated schematically by arrow 31. In such a situation, the spring 33 forces contact plate 34 into contact with leads 35, 36. Arrows 32 in FIG. 3B indicate schematically the movement of contact plate 34 into contact with points 35, 36. In such a situation, electrical power generated by the magneto is unable to start the engine E. 
     In FIGS. 4, 5A and 5B, there is shown a second embodiment of the apparatus of the present invention designated generally by the numeral 40. Safety fuel tank and cap apparatus 40 includes a cap 41 having a handle 42. Cap 41 can also provide a vent 43. The cap 41 is comprised of a generally cylindrically shaped annular skirt 44 and a circular top 45. 
     An appendage 46 extends radially outwardly of skirt 41 as shown in FIGS. 4, 5A and 5B. The appendage 46 has an under surface 47 that engages switch button 53 of button switch 48. The button switch 48 is shown in FIG. 5A in an operating position wherein appendage 46 holds the button 53 in a lowermost position that spaces contact plate 52 away from contacts 49, 50. When the cap 41 is removed as shown in FIG. 5B from cylindrically shaped filler flange 16 as shown by arrow 54 in FIG. 5, the spring 51 moves switch button 53 upwardly so that contact plate 52 engages contacts 49, 50 as shown by arrow 55 in FIG. 5B. In such a situation, the magneto 11 will not start the engine E. 
     FIGS. 6 and 7 show a third embodiment of the apparatus of the present invention designated generally by the numeral 56 in FIG. 7. Safety fuel tank and cap apparatus 56 features a filler cap 57 that is threadably engagable with annular skirt 16 as with the embodiments of FIGS. 1-5. Annular skirt 58 connects to a circular top 59 having handle 60. Switch 61 is mounted on the upper surface 15 of tank 14 as shown in FIGS. 6 and 7. The switch 61 includes a switch housing 62 that carries an electric eye 63. Such a switch 61 is commercially available. Arrow 64 in FIG. 7 indicates the communication between electric eye 63 and reflector 65 contained in opening 66 surrounded by annular rib 67. In the embodiment of FIG. 6 and 7, the electric eye is emitting a light source that reflects off reflector 65 and which is interrupted when cap 57 is removed from flange 16 so that the electrical cable 53 communicating with magneto 11 closes a circuit that prevents operation of magneto 11 to start engine E. 
     FIGS. 8-11 show a fourth embodiment of the apparatus of the present invention designated generally by the numeral 68 in FIG. 8. Safety fuel tank and cap apparatus 68 includes a micro switch 69 having a switch arm 70 that includes a ring 71. The ring 71 surrounds opening 72 that fits over flange 16 and filler cap 74 as shown in FIGS. 8-11. The ring 71 attaches to micro switch 69 with beam 73. Such a micro switch 69 is commercially available. 
     Filler cap 74 has a circular to 75 and a cylindrically shaped annular skirt 77. Handle 77 enables cap 74 to be able to be manipulated and turned such as when it is removed from or engaged with cylindrically shaped flange 16. A shroud 78 is provided for covering the combination of the micro switch 69 and its arm 70 as shown in FIGS. 10 and 11. The shroud 78 communicates with cover 79 that can be bolted over the shroud 78 using a plurality of bolts 80. Arrow 81 in FIG. 11 shows how the micro switch 69 is closed when the cap 74 is threaded upon flange 16 as indicated schematically by arrow 81 in FIG. 11. In such a situation, the lower annular edge 84 of cap 74 engages ring 71 of switch arm 70 forcing it downwardly and operating switch 69 to deactivating magneto 11 via electrical cable 73. 
     FIG. 1A shows the apparatus 10 of the present invention attached to an auxiliary fuel tank 14 having a fuel line 82. In FIG. 1B, a powered implement is shown in the form of a weed trimmer that includes a frame 85 that supports an internal combustion engine E having fuel tank 14 and filler cap 18 with magnetic switch 28. 
     Filler cap 19A in FIGS. 12A, 12B and 12C is a Honda® type cap that can have a circular top 38, annular skirt 39 with generally cylindrically shaped outer surface 88, and annular edge 89 at the interface between top 38 and skirt 39. Cap 19 includes bayonet mount projections 86, 87 that interlock with a bayonet type flange (not shown on tank 15). Cap 19A can have gasket 95. Such an interlocking arrangement between projections 86, 87 and bayonet type flange on a fuel tank is known in the art (see for example small (e.g. 5 hp) engines sold under the marks Briggs®, Honda®, and Kawasaki®. 
     FIGS. 13A, 13B and 13C show a Briggs® type cap arrangement. Cap 19B has top 90, annular skirt 91 that joins top 90 at annular edge 92. Projections 92, 93 connect to fuel tank 15 at a filler flange having a bayonet type mount. Cap 19B has gasket 95. 
     In FIGS. 12A, 12B and 12C there can be seen magnetic switch 28 (FIG. 12A) used with cap 19B, the use of a photoelectric switch at opening 66 (FIG. 13B) and the use of appendage 46 (FIG. 12C) for use with button switch 48. In FIGS. 13A, 13B and 13C there can bee seen magnetic switch 28 (FIGS. 12A), opening 66 with reflector 65 as part of a photoelectric switch, and (in FIG. 12C) an appendage 46 for use with button switch 48. 
     FIGS. 12A, 12B, 12C 13A, 13B and 13C illustrate that a bayonet type filler cap and tank flange arrangement could be used with any of the embodiments of FIGS. 1-11. 
     In FIGS. 14 and 15 there is shown a hinged cap arrangement that can be used with any of the embodiments of FIGS. 1-11. Hinge 96 supports spring loaded cap 97 that automatically springs open to the open position of FIG. 14 when spring loaded latch 98 is moved away from cap 97 in the direction of arrow 104. Latch member 98 is pivotally mounted to tank 15 at pivot 99. A pair of sears 100 normally hold cap 97 in the closed position of FIG. 15. When the cap 97 is closed, sears 100 are engaged and latch 98 pushed away in the direction of arrow 104 until cap 97 closes fully at which time sears 100 engage and hold cap 97. This general concept of a cap 97, hinge 96, latch 98 is known and commercially available. 
     Cap 97 has flat top 101, skirt 102 and skirt outer surface 103. 
     Following the teachings of the present invention, cap 97 could carry a magnet 25 that cooperates with switch 28 as in FIGS. 1-3. The cap 97 could carry a projection or appendage 96 as with the embodiment of FIGS. 4, 5A and 5B that cooperates with button switch 48. The cap 97 could also carry reflector 66 in opening 65 for use with photo electric switch 61 as in FIGS. 6-7. 
     Any of the cap constructions shown in FIGS. 12A, 12B, 12C, 13A, 13A, 13B and 13C or 14-15 can be used in combination with the micro switch arrangement of FIGS. 8-11. 
     FIG. 16 shows an alternate embodiment of the apparatus of the present invention designated generally by the numeral 105. In FIG. 16, fuel tank 106 has an upper surface 107 with a fuel filler neck 108. In the embodiment of FIG. 16, a fuel filler neck 112 can be added to the existing fuel filler neck 108 on tank 107. As an option, an adapter 111 can be placed in between the permanent fuel filler neck 108 of tank 107 and the retrofitted fuel filler neck 112. The adapter 111 can be a cylindrically shaped or donut shaped fitment or shim that fits in between the side wall 109 of filler neck 108 and the new filler neck 112. 
     Filler neck 108 has an annular shoulder 110 that surrounds a central opening through which fuel can be added to the tank 107. The new filler neck 112 has a side wall 113 and an upper annular shoulder 114 that carries a pair of spaced apart slots 115, 116. These slots 115, 116 receive projections 86, 87 of the fuel filler cap 38 shown in FIGS. 12A, 12B, 12C or the filler cap 90 shown in FIGS. 13A, 13B, 13C. 
     The switch S in FIG. 16 schematically represents any of the selected switches that are discussed herein with respect to the preferred embodiments of FIGS. 1-15, or any of the switches shown in FIGS. 17-19. Similarly, the projection P in FIG. 16 represents the portion of an overall switch arrangement that is carried at the periphery of a cap 19, 38 or 90, for any of the embodiments of FIGS. 1-15 or 17-21B. In FIG. 17, a micro switch 117 is shown that cooperates with a projection 119 carried by cap 38 at the periphery of cap 38. The micro switch 117 has an arm 118 that is depressed in order to close the switch when the cap 38 is in a fully closed position engaging a fuel filler neck such as 112 or 16. 
     In FIG. 18, a plunger type switch arrangement is shown that includes a plunger type switch 120 having a housing 122 that carries a plunger 121. The plunger 121 closes relative to the housing 122 when it is depressed by projection 119. The projection 119 is carried at the periphery of cap 38 or any of the other fuel filler caps disclosed herein when the cap 38 is in its fully closed position. The switch 120 opens to shut down the engine when the projection 119 is moved away from plunger 121. 
     In FIG. 19, a projection 25 at the periphery of cap 38 can be a portion that cooperates with a magnetic switch, proximity switch, or optical switch, designated generally by the letter S in FIG. 19. 
     In FIGS. 20A and 20B, there is shown a wiring diagram for a ground to shut down arrangement. In FIG. 20A, an ignition system is indicated by the numeral 123 and key switch by the numeral 124. The numeral 125 indicates schematically any other ignition shut down switch. In FIG. 20A, the engine will not run if any switch is closed. Removing the fuel cap 19, 38 or 90 closes the switch S so that the engine will not run. All of the switches are wired and parallel to each other in FIG. 20A. 
     In FIG. 20B, the ignition system is shown in an off position. The fuel cap switch S is closed when the cap 19, 38 or 90 is not secured to the tank, and the engine will not run. The fuel cap system shown in FIG. 20B will work on any type of ignition system/shut off system including magneto type, coil type, negative and positive ground, ground to run and ground to shut down. 
     FIGS. 21A and 21B show other examples of wiring diagrams for &#34;ignition system on&#34; and &#34;ignition system off&#34; configurations respectively. 
     PARTS LIST 
     The following is a list of parts and materials suitable for use in the present invention: 
     
         ______________________________________NUMBER        PART______________________________________10            safety fuel tank and cap apparatus11            magnetoelectric generator12            pull cord starter rope13            electric cable14            fuel tank15            upper surface16            cylindrically shaped flange16A           cylindrically shaped flange17            external thread18            opening19            filler cap19A           filler cap19B           filler cap19C           hinged filler cap20            annular skirt20A           inner annular surface20B           outer annular surface21            top22            handle23            internal thread24            vent25            magnet26            outer end27            inner end28            magnetic switch29A           lead29B           lead30            ground31            arrow32            arrow33            spring34            contact plate35            contact point36            contact point37            annular edge38            circular top39            annular skirt40            safety fuel tank and cap apparatus41            cap42            handle43            vent44            annular skirt45            top46            appendage47            undersurface48            button switch49            contact50            contact51            spring52            contact plate53            switch bottom54            arrow55            arrow56            safety fuel tank and cap apparatus57            filler cap58            annular skirt59            top60            handle61            switch62            switch housing63            electric eye64            arrow65            reflector66            opening67            annular rib68            safety fuel tank and cap apparatus69            micro switch70            switch arm71            ring72            opening73            beam74            filler cap75            top76            annular skirt77            handle78            shroud79            cover80            bolt81            arrow82            fuel line83            weed trimmer84            annular surface85            frame86            laterally extending projection87            laterally extending projection88            outer annular surface89            annular edge90            circular top91            outer annular surface92            annular edge93            laterally extending projection94            laterally extending projection95            gasket seal96            hinge97            spring loaded cap member98            spring loaded latch99            pivot100           sear101           flat top102           skirt103           outer surface104           arrow105           safety fuel tank and cap apparatus106           fuel tank107           upper surface108           fuel filler neck109           side wall110           annular shoulder111           adaptor112           filler neck113           side wall114           annular shoulder115           slot116           slot117           micro switch118           arm119           projection120           plunger type switch121           plunger122           housing123           ignition system124           key switch125           switch126           lead127           groundP             projectionS             switchE             engine______________________________________ 
    
     All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. 
     The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.