Abstract:
A power source is provided for a machine. The power source includes an engine and an engine fuel system of the type that generates fuel vapor containing hydrocarbon material.

Description:
[0001]     This application claims priority under 35 U.S.C § 119(e) to U.S. Provisional Application No. 60/731,205, filed Oct. 28, 2005, which is expressly incorporated by reference herein. 
     
    
     BACKGROUND  
       [0002]     The present disclosure relates to an engine fuel system for outdoor tools such as lawn mowers, and particularly to a fuel vapor venting system for a fuel tank associated with a small internal combustion engine. More particularly, the present disclosure relates to a carbon canister in a fuel vapor venting system.  
         [0003]     Engine fuel systems include valves associated with a fuel tank and configured to vent pressurized or displaced fuel vapor from the vapor space in the fuel tank to a separate charcoal canister. The canister is designed to capture and store hydrocarbons entrained in fuel vapors that are displaced and generated in the fuel tank.  
       SUMMARY  
       [0004]     A fuel vapor recovery apparatus comprises a carbon canister, a check valve assembly adapted to be coupled to a vacuum source, and a vapor conduit adapted to be coupled to a vapor space in a fuel tank. The fuel vapor recovery apparatus is included in a power source associated with a small internal combustion engine.  
         [0005]     Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     The detailed description particularly refers to the accompanying figures in which:  
         [0007]      FIG. 1  is a perspective view of a lawn mower including a fuel vapor recovery apparatus in accordance with a first embodiment of the present disclosure and a fuel tank associated with a small internal combustion engine;  
         [0008]      FIG. 2  is an enlarged perspective view of a power source included in the lawn mower of  FIG. 1  showing a fuel vapor recovery apparatus comprising a carbon canister, a “one-way” check valve assembly adapted to be coupled to a vacuum source associated with a carburetor, and a T-shaped vapor conduit arranged to interconnect the carbon canister and the check valve assembly and to mate with a vapor line coupled to a rollover valve associated with the fuel tank;  
         [0009]      FIG. 3A  is an enlarged perspective view of an illustrative embodiment of the fuel vapor recovery apparatus of  FIGS. 1 and 2 , with portions broken away, showing (in series) a cylindrical carbon canister, a T-shaped conduit, and a “one-way” check valve assembly;  
         [0010]      FIG. 3B  is a “left-side” elevation view of the fuel vapor recovery apparatus of  FIG. 3A , with portions broken away, showing a first filter backing plate lying in front of a first filter located in an interior region formed in the carbon canister;  
         [0011]      FIG. 4  is a portion of an enlarged sectional view taken along line  5 - 5  of  FIG. 3A  showing various components included in an illustrative embodiment of the fuel vapor recovery apparatus of  FIGS. 3A and 3B ;  
         [0012]      FIG. 5  is an enlarged sectional view taken along line  5 - 5  of  FIG. 3A  showing a spring-biased valve included in the check valve assembly in a normal channel-closing position to block flow of fuel vapor extant in the carbon canister through a channel to the engine while the engine is off and showing flow of vented fuel vapor from the fuel tank through the T-shaped vapor conduit to cause hydrocarbons associated with the vented fuel vapor to be captured by a carbon bed in the carbon canister and showing cleaned vapor discharged from the canister to the atmosphere;  
         [0013]      FIG. 6  is a sectional view similar to  FIG. 5  showing “purging” of the carbon bed in the canister by means of a purge vacuum applied through an opened channel in the check valve assembly and through the T-shaped vapor conduit to the carbon bed when the engine is running to cause atmospheric air to be drawn through the carbon bed to produce a first stream of fuel vapor (laden with hydrocarbons released from the carbon bed) that mixes with a second stream of fuel vapor discharged from the fuel tank into the T-shaped vapor conduit to produce a fuel vapor mixture that passes through the opened channel in the check valve assembly to the engine (for combustion therein) while the spring-biased valve is moved (by the purge vacuum) to a temporary channel-opening position;  
         [0014]      FIG. 7  is a perspective view of an electricity generator including a fuel vapor recovery apparatus in accordance with a second embodiment of the present disclosure and a fuel tank associated with a small internal combustion engine;  
         [0015]      FIG. 8  is an enlarged perspective view of a power source included in the electricity generator of  FIG. 7  showing a fuel vapor recovery apparatus comprising a carbon canister, a “one-way” check valve assembly adapted to be coupled to a vacuum source associated with a carburetor, and a vapor conduit arranged to mate with a vapor line coupled to a rollover valve associated with the fuel tank;  
         [0016]      FIG. 9  is an enlarged perspective view of an illustrative embodiment of the fuel vapor recovery apparatus of  FIGS. 7 and 8 , with portions broken away, showing a cylindrical carbon canister, a “one-way” check valve assembly coupled to a first end of the carbon canister, and a vapor conduit coupled to the first end of the carbon canister;  
         [0017]      FIG. 10  is a “left-side” end elevation view of the fuel vapor recovery apparatus of  FIG. 9 , with portions broken away, showing the vapor conduit below the check valve assembly on the first end of the carbon canister;  
         [0018]      FIG. 11  is an enlarged sectional view taken along line  11 - 11  of  FIG. 10  showing a spring-biased valve included in the check valve assembly in a normal channel-closing position to block flow of fuel vapor extant in the carbon canister through a channel in the check valve assembly to the engine while the engine is off and showing flow of vented fuel vapor from the fuel tank through the vapor conduit to cause hydrocarbons associated with the vented fuel vapor to be captured by a carbon bed in the carbon canister and showing cleaned vapor discharged from the canister to the atmosphere;  
         [0019]      FIG. 12  is a sectional view similar to  FIG. 11  showing “purging” of the carbon bed in the canister by means of a purge vacuum applied through an opened channel in the check valve assembly and the vapor conduit to the carbon bed when the engine is running to cause atmospheric air to be drawn through the carbon bed to produce a stream of fuel vapor (laden with hydrocarbons released from the carbon bed) that passes through the opened channel in the check valve assembly to the engine (for combustion therein) while the spring-biased valve is moved (by the purge vacuum) to a temporary channel-opening position;  
         [0020]      FIG. 13  is a perspective view of another illustrative embodiment of a fuel vapor recovery apparatus suitable for use in the environment of  FIGS. 1 and 2  or  FIGS. 7 and 8 ;  
         [0021]      FIG. 14  is a view similar to  FIG. 13  showing removal of a filter unit comprising a filter cap and a fresh-air foam filter retained in an interior region of the filter cap from a housing;  
         [0022]      FIG. 15  is a side elevation view of the fuel vapor recovery apparatus of  FIG. 13 ;  
         [0023]      FIG. 16  is a left-end elevation of the fuel vapor recovery apparatus of  FIG. 13 ; and  
         [0024]      FIG. 17  is an enlarged sectional view taken along line  17 - 17  of  FIG. 16  showing a carbon canister housing containing a carbon bed, a filter unit coupled to a left-end of the housing, and a “two-way” vapor conductor coupled to the right-end of the housing and formed to include a vapor tube adapted to be coupled to a fuel tank and a vacuum tube adapted to be coupled to an engine intake associated with an engine and configured to contain a vacuum-actuated check valve. 
     
    
     DETAILED DESCRIPTION  
       [0025]     A fuel vapor recovery apparatus  10  in accordance with a first embodiment of the present disclosure is included in a lawn mower  12  as shown, for example, in  FIG. 1  and in a power source  14  included in lawn mower  12  as suggested in  FIG. 2 . A fuel vapor recovery apparatus  110  in accordance with another embodiment of the present disclosure is included in an electricity generator  112  as shown, for example, in  FIG. 7  and in a power source  114  included in electricity generator  112  as suggested in  FIG. 8 . Fuel vapor recovery apparatus  10  is shown in more detail in  FIGS. 3-6  while fuel vapor recovery apparatus  110  is shown in more detail in  FIGS. 9-12 . An alternative fuel vapor recovery apparatus  210  is shown, for example, in  FIGS. 13-17 .  
         [0026]     Lawn mower  12  includes a deck  16  supporting and covering blades (not shown), wheels  18  rotatable on axles coupled to deck  16 , a push handle  20  coupled to deck  16 , and power source  14  comprising a small internal combustion engine  22 , a fuel tank  24  provided with a filler neck closed by fuel cap  25 , a carburetor  26 , an air filter  28 , and a shroud  30  covering a portion of fuel vapor recovery apparatus  10  and lying above deck  16  a shown, for example, in  FIG. 1 . Shroud  30  can be configured to cover engine  22  and fuel tank  24 . It is within the scope of this disclosure to include fuel vapor recovery apparatus  10  in a power source associated with other outdoor tools and/or associated with other small internal combustion engines.  
         [0027]     As suggested, for example, in  FIG. 2 , fuel vapor recovery apparatus  10  includes a carbon canister  32 , a check valve assembly  34 , and a three-legged vapor conductor  35  arranged to interconnect carbon canister  32  and check valve assembly  34  in fluid communication. Three-legged vapor conductor  35  is T-shaped in the illustrated embodiment. Three-legged vapor conductor  35  is also arranged to mate with a vapor line  38  coupled to, for example, a rollover valve  40  associated with fuel tank  24 . In an illustrative embodiment, fuel vapor recovery apparatus  10  comprises a “three-way” vapor conductor  36  comprising three-legged vapor conductor  35  and check valve assembly  34 .  
         [0028]     Rollover valve  40  regulates flow of fuel vapor and liquid fuel from an interior region of fuel tank  24  to fuel vapor recovery apparatus  10  via vapor line  38 . Rollover valve  40  is configured to block discharge of fuel vapor and liquid fuel from fuel tank  24  to fuel vapor recovery apparatus  10  whenever rollover valve  40  is “inverted” or at least tilted a selected number of degrees from its normal upright position to minimize any chance that carbon granules stored in carbon canister  32  will be exposed to liquid fuel during a lawn mower “roll-over” situation.  
         [0029]     Canister  32  has a housing  42  containing a carbon bed  44  as suggested in  FIGS. 5 and 6  and is sized to fit into a canister-receiving cavity provided under shroud  30  in power source  14  as suggested in  FIG. 1 . Housing  42  is formed to include an interior region  400  containing carbon bed  44 , an atmosphere orifice  401  opening into interior region  400 , and a tank-and-engine orifice  402  opening into interior region  400  as suggested in  FIGS. 5 and 6 .  
         [0030]     In an illustrative embodiment, housing  42  includes a cylindrical sleeve  423  interposed between first and second end closures  411 ,  412  as suggested in  FIGS. 3A and 5 . It is within the scope of this disclosure to provide sleeve  423  with any suitable length and shape and form end closures  411 ,  412  to mate with sleeve  423 . One end of sleeve  423  is formed to include atmosphere orifice  401  and another end of sleeve  423  is formed to include tank-and-engine orifice  402 .  
         [0031]     Canister  32  is configured to allow both fuel tank fuel vapor and atmospheric air to pass through carbon bed  44 . Canister  32  is configured to “clean” fuel vapor  46  vented from fuel tank  24  during, for example, a fuel tank fuel vapor venting cycle that takes place during tank refueling as suggested diagrammatically in  FIG. 5 . Canister  32  is “cleaned” or “purged” using a vacuum provided by engine intake  48  (e.g., carburetor  26 ) during a carbon bed cleaning cycle that takes place when engine  22  is running as suggested diagrammatically in  FIG. 6 .  
         [0032]     In use, when engine  22  is off during fuel tank refueling, hydrocarbon material (not shown) entrained in fuel vapor  46  discharged from fuel tank  24  and passed through carbon bed  44  is captured or stored (e.g., adsorbed) on charcoal granules included in carbon bed  44  as that fuel vapor  46  is passed through carbon bed  44 . A stream of cleaned vapor  50  is discharged from canister  32  to the atmosphere  52  through atmosphere orifice  401  during a vapor-cleaning process as suggested diagrammatically in  FIG. 5 .  
         [0033]     When engine  22  is running, a purge vacuum  94  is applied to carbon bed  44  in housing  42  of canister  32  through tank-and-engine orifice  402  as suggested in  FIG. 6 . Atmospheric air  97  is drawn into housing  42  through atmospheric orifice  401  and passes through carbon bed  44  to purge hydrocarbon material from carbon bed  44  and discharge it as fuel vapor stream  101  from housing  42  through tank-and-engine orifice  402  as suggested in  FIG. 6 .  
         [0034]     First end closure  411  comprises a first end cap  421  in an illustrative embodiment as suggested in  FIGS. 5 and 6 . Second end closure  412  comprises a second end cap  422  and a three-way vapor conduit  36  coupled to second end cap  422  as suggested in  FIGS. 4-6 . In the illustrated embodiment, three-way vapor conduit  36  includes a first tube section  361  formed to include a housing channel  361   h , a second tube section  362  formed to include a tank channel  362   t , and a third tube section  363  formed to include a vacuum channel  363   v  as suggested in  FIGS. 4-6 . Housing channel  361   h , tank channel  362   t , and vacuum channel  363   v  merge with one another in fluid communication at a junction “J” located inside three-way vapor conduit  36  as shown, for example, in  FIGS. 4-6 .  
         [0035]     As suggested in  FIGS. 4-6 , second end closure  412  is coupled to housing  42  to close tank-and-engine orifice  402 . Second end closure  412  is formed to include a passageway  412   p  arranged to provide vapor/vacuum means for conducting inbound fuel vapor  46  from fuel tank  24  into interior region  400  of housing  42  and outbound fuel vapor  101  from interior region  400  of housing  42  to an engine intake  48  coupled to an engine  22  associated with fuel tank  24  as suggested in  FIGS. 4-6 . In the illustrated embodiment, shown in  FIG. 4 , second end cap  422  is formed to include an aperture  364  defining a “first portion” of vapor/vacuum means  412   p . Housing channel  361   h  defines a “second portion” of vapor/vacuum means  412   p . Tank channel  362   t  defines a “third portion” of vapor/vacuum means  412   p . Vacuum channel  363   v  defines a “fourth portion” of vapor/vacuum means  412   p . In an illustrative embodiment shown, for example, in  FIG. 4 , first tube section  361  of three-way vapor conduit  36  terminates at a tank hose mount adapted to mate with a tank hose or vapor line  38  configured to conduct fuel vapor  46  between fuel tank  24  and tank channel  362   t . As also shown in  FIG. 4 , third tube section  363  of three-way vapor conduit  36  terminates at a vacuum hose mount adapted to mate with a vacuum hose or purge line  86  configured to conduct vacuum between vacuum channel  363   v  and engine intake  48 .  
         [0036]     As suggested in  FIG. 4 , third tube section  363  of three-way vapor conduit  36  includes a first portion  363   a  coupled to first and second tube sections  361 ,  362  and a second portion  363   b  coupled to first portion  363   a . Second portion  363   b  is formed to include the vacuum hose mount as suggested in  FIG. 4 . In the illustrated embodiment, second end cap  422 , first tube section  361 , second tube section  362 , and first portion  363   a  of third tube section  363  cooperate to define a monolithic element  90  made of a plastics material.  
         [0037]     First end cap  421  of housing  42  is formed to include apertures  56  arranged to communicate with atmosphere  52  as suggested in  FIGS. 2, 5 , and  6 . Interposed in series between carbon bed  44  and first end cap  421  is a porous first filter  58  and a first filter locator  60  comprising a filter backing plate  62  and a cylinder-shaped plate support  64  as shown, for example, in  FIG. 5 . Filter backing plate  62  is cross-shaped and is formed to include a central aperture  63  and four surrounding apertures as suggested in  FIGS. 4 and 5 . Further, interposed in series between carbon bed  44  and second end cap  421  is a porous second filter  66 , a second filter locator  68  comprising a second filter backing plate  70  and a cylinder-shaped plate support  72 , and a locator-biasing spring  74  surrounded, at least in part, by cylinder-shaped plate support  72  as suggested in  FIG. 5 . In an illustrative embodiment, second filter backing plate  70  has a shape similar to that of first filter backing plate  62 .  
         [0038]     Locator-biasing spring  74  is used to move second filter locator  68  inside housing  42  toward first filter locator  60  to compact carbon granules included in carbon bed  44  to govern the density of carbon granules in carbon bed  44 . In the illustrated embodiment, an inner portion of locator-biasing spring  74  engages second filter backing plate  70  of second filter locator  68  and an outer portion of locator-biasing spring  74  engages an interior wall  75  of second end cap  422  and mates with a spring retainer  76  on that interior wall  75  as suggested in  FIGS. 5 and 6 . In the illustrated embodiment, locator-biasing spring  68  is a helical compression spring.  
         [0039]     In the illustrated embodiment, third tube section  363  of three-way vapor conduit  36  is configured to include check valve assembly  34 . Check valve assembly  34  includes a base  78 , a cover  80 , a valve  82 , and a valve-control spring  84  as shown, for example, in  FIGS. 5 and 6 . Base  78  is formed to include a valve housing  781  and a housing tube  782  adapted to mate to a downstream portion of a vacuum purge line  86 . Cover  80  is formed to include a cover plate  801  adapted to mate with first portion  363   a  of third tube section  363  and with valve housing  781 . First portion  363   a  of third tube section  363  is formed to include an annular valve seat  88 . Valve  82  includes a seal plate  821 , a valve stem  822  coupled to seal plate  821  and arranged to extend away from cover  80 , and an annular seal  823  mounted on seal plate  821  and arranged to mate with an annular valve seat  88  provided on cover  80  to provide a sealed connection between valve  82  and cover  80  upon movement of valve  82  to a channel-closing position as shown, for example, in  FIG. 5 .  
         [0040]     As suggested in  FIGS. 4-6 , valve  82  is located in a part  92  of vacuum channel  363   v  formed in second portion  363   b  of third tube section  363 . Valve-control spring  84  is located in vacuum channel  363   v  and arranged to yieldably urge valve  82  to a normally closed channel-closing position mating with annular valve seat  88  as suggested in  FIGS. 4 and 5 . In this position, flow of fuel vapor from housing channel  361   h  and tank channel  362   t  into the part  92  of vacuum channel  363   v  formed in second portion  363   b  of third tube section  363  is blocked. Valve-control spring  84  yields as suggested in  FIG. 6  to allow valve  82  to move to a temporarily opened channel-opening position unmating from annular valve seat  88  to allow flow of fuel vapor from housing channel  361   h  into the part  92  of vacuum channel  363   v  formed in second portion  363   b  of third tube section  363 .  
         [0041]     During a tank-venting situation shown diagrammatically in  FIG. 5 , vented fuel vapor  46  is discharged from fuel tank  24  and flows through vapor line  38  and first and second tube sections  361 ,  362  of three-way vapor conduit  36  into carbon bed  44  in canister  32 . Hydrocarbons (not shown) associated with vented fuel vapor  46  are captured by carbon bed  44  and cleaned vapor  50  is discharged from canister  32  through apertures  56  formed in first end cap  421  to atmosphere  52 . During this fuel vapor-cleaning event, valve-control spring  84  urges valve  82  to mate with valve seat  88  on cover  80  as shown, for example, in  FIG. 6  to assume a normal channel-closing position in valve housing  781  to block flow of fuel vapor extant in canister  32  and three-way vapor conduit  36  through a channel  92  formed in base  78  to engine  22 .  
         [0042]     Later on, when engine  22  is running, a purge vacuum  94  (generated using any suitable means) is applied to housing tube  782  via vapor purge line  86  to purge hydrocarbon material (not shown) from carbon bed  44  in canister  32 . Application of purge vacuum  94  to channel  92  in valve housing  781  causes valve  82  to move away from valve seat  88  and against valve-control spring  84  to compress valve-control spring  84  as suggested in  FIG. 6  to move valve  82  away from mating engagement with cover  80  to a “temporary” channel-opening position. Purge vacuum  94  is thus exposed to vapor in canister  32  and three-way vapor conduit  36 . This causes atmospheric air  97  to be drawn into and through carbon bed  44  to produce a first stream  101  of fuel vapor (laden with hydrocarbons released from carbon bed  44 ) that mixes with a second stream  102  of fuel vapor discharged from fuel tank  24  into three-way vapor conduit  36  to produce a fuel vapor mixture  103  that passes through opened channel  92  in check valve assembly  34  and flows to engine  22  for combustion therein.  
         [0043]     Electricity generator  112  includes a floor  116  covered by a shell  117  formed to include a pair of grip handles  115  and configured to support an electrical outlet  118  coupled to power source  114  included in electricity generator  112  as suggested in  FIG. 7 . Electricity generator  112  burns gasoline or other fuel to produce electricity that is accessed through electrical outlet  118 . Power source  114  comprises a small internal combustion engine  122 , a fuel tank  124  provided with a filler neck closed by fuel cap  125 , and a carburetor  126  as shown, for example, in  FIGS. 7 and 8 . At least a portion of shell  117  covers fuel vapor recovery apparatus  110  as suggested in  FIG. 7 . It is within the scope of this disclosure to include fuel vapor recovery apparatus  110  in a power source associated with other outdoor tools and/or associated with other small internal combustion engines.  
         [0044]     As suggested, for example, in  FIG. 8 , fuel vapor recovery apparatus  110  includes a carbon canister  132 , a check valve assembly  134 , and a vapor conduit  136  arranged to mate with a vapor line  138  coupled to a rollover valve  140  associated with fuel tank  124 . Rollover valve  140  regulates flow of fuel vapor and liquid fuel from an interior region of fuel tank  124  to fuel vapor recovery apparatus  110  via vapor line  138 . Rollover valve  140  is configured to block discharge of fuel vapor and liquid fuel from fuel tank  124  to fuel vapor recovery apparatus  110  whenever rollover valve  140  is “inverted” or at least tilted a selected number of degrees from its normal upright position to minimize any chance that carbon granules stored in carbon canister  132  will be exposed to liquid fuel during a lawn mower “roll-over” situation.  
         [0045]     Canister  132  has a housing  142  containing a carbon bed  144  as suggested in  FIGS. 11 and 12  and is sized to fit into a canister-receiving cavity provided under shell  117  as suggested in  FIG. 7 . Housing  142  is formed to include an interior region  500  containing carbon bed  144 , an atmosphere orifice  501  opening into interior region  500 , and a tank-and-engine orifice  502  opening into interior region  500  as suggested in  FIGS. 11 and 12 . In an illustrative embodiment, housing  142  includes a cylindrical sleeve  1423  interposed between first and second end closures  1411 ,  1412  as suggested in  FIGS. 9 and 11 . It is within the scope of this disclosure to provide sleeve  1423  with any suitable length and shape and form end caps  1421 ,  1422  to mate with sleeve  1423 . One end of sleeve  1423  is formed to include atmosphere orifice  501  and another end of sleeve  1423  is formed to include tank-and-engine orifice  502 .  
         [0046]     Canister  132  is configured to allow both fuel tank fuel vapor and atmospheric air to pass through carbon bed  144 . Canister  132  is configured to “clean” fuel vapor  46  vented from fuel tank  124  during, for example, a fuel tank fuel vapor venting cycle that takes place during tank refueling as suggested diagrammatically in  FIG. 11 . Canister  132  is “cleaned” or “purged using a vacuum provided by engine intake  148  (e.g., carburetor  126 ) during a carbon bed cleaning cycle that takes place when engine  122  is running as suggested diagrammatically in  FIG. 12 .  
         [0047]     In use, when engine  22  is off during fuel tank refueling, hydrocarbon material (not shown) entrained in fuel vapor  46  discharged from fuel tank  124  and passed through carbon bed  144  is captured or stored (e.g., adsorbed) on charcoal granules included in carbon bed  144  as that fuel vapor  46  passes through carbon bed  144 . A stream of cleaned vapor  50  is discharged from canister  132  to the atmosphere  52  through atmosphere orifice  501  during a vapor-cleaning process as suggested diagrammatically in  FIG. 11 .  
         [0048]     First end cap  1411  comprises a first end cap  1421  in an illustrative embodiment as suggested in  FIGS. 11 and 12 . Second end closure  1412  comprises a second end cap  1422 , a vapor conduit  503 , coupled to second end cap  1422 , and a separate vacuum conduit  504  coupled to second end cap  1422  as suggested in  FIGS. 11 and 12 .  
         [0049]     Vapor conduit  503  is configured to define vapor means for conducting inbound fuel vapor from a fuel tank  104  into interior region  500  of housing  142  to reach carbon bed  144  located in interior region  500  of housing  142  so that hydrocarbons associated with the inbound fuel vapor are captured by carbon bed  144 . Vacuum conduit  504  is configured to define vacuum means for conducting outbound fuel vapor from interior region  500  of housing  142  toward an engine intake  148  coupled to an engine  122  associated with fuel tank  124  so that hydrocarbons released by carbon bed  144  and entrained in the outbound fuel vapor are burned in engine  122  after discharge from interior region  500  of housing  142 .  
         [0050]     Second end cap  1422  is coupled to housing  142  to close tank-and-engine orifice  502  and is formed to include a vapor aperture  503   a  defining a first portion of the vapor means and a vacuum aperture  504   a  defining a first portion of the vacuum means. A vapor tube  505  is coupled to second end cap  1422  at vapor aperture  503   a  and is formed to include a tank channel  503   t  defining a second portion of the vapor means. A base  78  is coupled to second end cap  1422  at vacuum aperture  504   a  and formed to include a vacuum channel  504   v  defining a second portion of the vacuum means.  
         [0051]     First end cap  1421  of housing  142  is formed to include apertures  156  arranged to communicate with atmosphere  52  as suggested in  FIGS. 11 and 12 . Interposed in series between carbon bed  144  and first end cap  1421  is a porous first filter  158  and a first filter locator  160  comprising a filter backing plate  162  and a cylinder-shaped plate support  164  as shown, for example, in  FIG. 11 . Filter backing plate  162  is formed to include apertures  163  as suggested in  FIGS. 11 and 6 . Further, interposed in series between carbon bed  144  and second end cap  1421  is a porous second filter  166 , a second filter locator  168  comprising a second filter backing plate  170  and a cylinder-shaped plate support  172 , and a locator-biasing spring  174  surrounded, at least in part, by cylinder-shaped plate support  172  as suggested in  FIG. 11 .  
         [0052]     Locator-biasing spring  174  is used to move second filter locator  168  inside housing  142  toward first filter locator  160  to compact carbon granules included in carbon bed  144  to govern the density of carbon granules in carbon bed  144 . In the illustrated embodiment, an inner portion of locator-biasing spring  174  engages second filter backing plate  170  of second filter locator  168  and an outer portion of locator-biasing spring  174  engages an interior wall  175  of second end cap  1422  as suggested in  FIGS. 5 and 6 . In the illustrated embodiment, locator-biasing spring  168  is a helical compression spring.  
         [0053]     Check valve assembly  134  comprises a base  178 , a valve  182 , and a valve-control spring  184  as shown, for example, in  FIGS. 11 and 12 . Base  178  is formed to include a valve housing  1781  and a housing tube  1782  adapted to mate to a downstream portion of a vacuum purge line  186 . Valve housing  1781  is coupled to second end cap  1422  at retainer  143 . Valve  182  includes a seal plate  1821 , a valve stem  1822  coupled to seal plate  1821  and arranged to extend away from second end cap  1422 , and an annular seal  1823  mounted on seal plate  1821  and arranged to mate with an annular valve seat  188  provided on second end cap  1422  to provide a sealed connection between valve  182  and second end cap  1422  upon movement of valve  182  to a channel-closing position as shown, for example, in  FIG. 11 .  
         [0054]     Vapor conduit  136  includes a vapor tube arranged to lie in spaced-apart parallel relation to base  178  as suggested in  FIGS. 9-12 . In an illustrative embodiment, a monolithic component  190  made of a plastics material is formed to include vapor conduit  503  and second end cap  1422  as shown, for example, in  FIGS. 5 and 6 .  
         [0055]     Valve  182  is mounted for movement in a first segment  511  of vacuum channel located in valve housing  1781  and a valve control spring  184  located in first segment  511  of vacuum channel  504   v . Valve control spring  184  is arranged yieldably to urge valve  182  to a normally closed channel-closing position mating with an annular valve seat  188  included in base  178  to block flow of fuel vapor from interior region  500  of housing  142  and first segment  511  of the vacuum channel  504   v  into a second segment  512  of vacuum channel  504   v  formed in the housing tube  1782  and to yield to allow flow of fuel vapor from interior region  500  of housing  142  and first segment  511  of vacuum channel  504   v  into second segment  512  of vacuum channel  504   v  formed in housing tube  1782 .  
         [0056]     A distal portion of housing tube  1782  is formed to include a vacuum hose mount adapted to mate with a vacuum hose configured to provide the vacuum purge line. A distal portion of vapor conduit  503  is formed to include a tank hose mount adapted to mate with a tank hose configured to conduct fuel vapor between a fuel tank  124  and vapor conduit  503 .  
         [0057]     During a tank-venting situation shown diagrammatically in  FIG. 11 , vented fuel vapor  46  is discharged from fuel tank  124  and flows through vapor line  138  and vapor conduit  503  into carbon bed  144  in canister  132 . Hydrocarbons (not shown) associated with vented fuel vapor  46  are captured by carbon bed  144  and cleaned vapor  50  is discharged from canister  132  through apertures  156  formed in first end cap  1421  to atmosphere  52 . During this fuel vapor-cleaning event, valve-control spring  184  urges valve  182  to mate with valve seat  188  on second end cap  1422  as shown, for example, in  FIG. 12  to assume a normal channel-closing position in valve housing  1781  to block flow of fuel vapor extant in canister  110  and vapor conduit  504  through a channel  512  formed in base  178  to engine  122 .  
         [0058]     Later on, when engine  122  is running, a purge vacuum  94  (generated using any suitable means) is applied to housing tube  1782  via a vapor purge line  186  to purge hydrocarbon material (not shown) from carbon bed  144  in canister  132 . Application of purge vacuum  94  to channel  512  in valve housing  1781  causes valve  182  to move away from valve seat  188  against valve-control spring  184  to compress valve-control spring  184  as suggested in  FIG. 12  to move valve  182  away from mating engagement with valve seat  188  to a “temporary” channel-opening position. Purge vacuum  94  is thus exposed to vapor in canister  132  and vapor conduit  503 . This causes atmospheric air  97  to be drawn into and through carbon bed  144  to produce a first stream of fuel vapor (laden with hydrocarbons released from carbon bed  144 ) that mixes with a second stream of fuel vapor discharged from fuel tank  124  into vapor conduit  503  to produce a fuel vapor mixture that passes through opened channel  512  in check valve assembly  134  and flows to engine  122  for combustion therein.  
         [0059]     As suggested in  FIGS. 13-17 , an alternative fuel vapor recovery apparatus  210  comprises a housing  242  formed to include an interior region  600  containing a carbon bed  244 . Housing  242  is also formed to include an atmosphere orifice  601  opening into interior region  600 , and a tank-and-engine orifice  602  opening into interior region  600  as suggested in  FIG. 17 .  
         [0060]     In an illustrative embodiment, housing  242  includes a cylindrical sleeve  243  interposed between first and second end closures  211 ,  212  as suggested in  FIG. 7 . It is within the scope of this disclosure to provide sleeve  243  with any suitable length and shape and form end closures  211 ,  212  to mate with sleeve  243 . One end of sleeve  243  is formed to include atmospheric orifice  601  and another end of sleeve  243  is formed to include tank-and-engine orifice  602 . Housing  242  and first and second end closures  211 ,  212  cooperate to define a carbon canister  232 .  
         [0061]     First end closure  211  comprises a filter cap  221  formed to include an interior region  219  containing an air filter  220  made, for example, of a porous foam material as suggested in  FIG. 17 . Filter cap  221  is formed to include a port  219  in communication with the atmosphere  252 .  
         [0062]     Second end closure  212  comprises a second end cap  222  and a two-way vapor conduit  236  coupled to second end cap  222  as suggested in  FIGS. 15 and 17 . In the illustrated embodiment, two-way conduit  236  includes a lower tube section  262  formed to include a tank channel  262   t  and an upper tube section  263  formed to include a vacuum channel  263   v  as suggested in  FIG. 17 . A housing channel (or aperture)  261   h  is formed in an end plate  222   e  of second end cap  222 . Housing channel or aperture  261   h , tank channel  262   t , and vacuum channel  263   v  merge with one another in fluid communication at a junction “J” located inside second end closure  212  as shown, for example, in  FIG. 17 .  
         [0063]     As suggested in  FIG. 17 , second end closure  212  is coupled to housing  242  to close tank-and-engine orifice  602 . Second end closure  212  is formed to include a passageway  212   p  arranged to provide vapor/vacuum means for conducting inbound fuel vapor from fuel tank  24  into interior region  600  of housing  242  and outbound fuel vapor from interior region  600  of housing  242  to an engine intake  48  coupled to an engine  22  associated with fuel tank  24  as suggested in  FIG. 17 . In the illustrated embodiment shown in  FIG. 17 , housing channel or aperture  261   h  defines a “first portion” of vapor/vacuum means  212   p , tank channel  262   t  defines a “second portion” thereof, and vacuum channel  263   v  defines a “third portion” thereof.  
         [0064]     In an illustrative embodiment shown, for example, in  FIG. 17  lower tube section  262  of two-way vapor conduit  236  terminates at a tank hose mount adapted to mate with a tank house or vapor line  38  configured to conduct fuel vapor between fuel tank  24  and tank channel  262   t . As also shown in  FIG. 17 , upper tube section  263  of two-way vapor conduit  236  terminates at a vacuum hose mount adapted to make with a vacuum hose or purge line  86  configures to conduct vacuum between vacuum channel  263   v  and engine intake  48 .  
         [0065]     In an illustrative embodiment shown in  FIG. 17 , lower and upper tube sections  262 ,  263  cooperate to define an acute angle  226  therebetween. Included angle  26  is, for example, about 26°.  
         [0066]     It is within the scope of this disclosure to provide a suitable normally closed vacuum-actuated channel-opening valve means  234  in vacuum channel  263   v  as suggested in  FIG. 17 . Such valve means operates in a manner similar to the valve means illustrated in  FIGS. 4-6  or in another suitable manner.  
         [0067]     The components (including carbon bed  244 ) provided inside sleeve  243  of housing  244  are similar to those internal components shown in  FIGS. 4-6 . Moreover, fuel vapor recovery apparatus  210  operates, for example, in a manner similar to fuel vapor recovery apparatus  10  shown, for example, in  FIGS. 4-6 .