Carburetor

Claim 2

An internal combustion engine carburetor comprising a mixture conduit, an air valve disposed in said mixture conduit, means controlling said air valve to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream from said air valve during engine operation, a fuel bowl containing fuel up to a cerTain level therein, a fuel vapor passage opening from said fuel bowl above said level, said fuel vapor passage having a first branch extending to said mixture conduit and a second branch, valve means disposed in said vapor passage for alternatively directing the flow of fuel vapor through said first and second branches, said valve means including a diaphragm responsive to the pressure in said region to position said valve means for directing the flow of fuel vapor from said fuel bowl through said first branch to said mixture conduit during engine operation and for directing the flow of fuel vapor from said fuel bowl through said second branch when the engine is not operating.

Claim 3

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said conduit, means controlling said air valve to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and opening into said region whereby the subatmospheric pressure therein may purge fuel vapor from said device into said region for delivery to the engine when the engine is operating, a fuel bowl containing fuel up to a certain level, a vent passage opening from said fuel bowl above said level, said vent passage having a first branch extending to said mixture conduit for delivering fuel vapor from said fuel bowl to the engine when the engine is operating and a second branch extending to said purge passage for delivering fuel vapor from said fuel bowl to said fuel vapor storage device when the engine is not operating, valve means disposed in said passage, means biasing said valve means to prevent the flow of fuel vapor through said first branch and to permit the flow of fuel vapor through said second branch, said valve means including a diaphragm responsive to the subatmospheric pressure maintained in said region during engine operation to overcome said biasing means to permit the flow of fuel vapor through said first branch and to prevent the flow of fuel vapor through said second branch during engine operation.

Claim 4

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said conduit, means controlling said air valve to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and opening into said region whereby the subatmospheric pressure therein may purge fuel vapor from said device into said region for delivery to the engine when the engine is operating, a fuel bowl containing fuel up to a certain level, a vent passage opening from said fuel bowl above said level, said vent passage having a first branch extending to said mixture conduit for delivering fuel vapor from said fuel bowl to the engine when the engine is operating and a second branch extending to said purge passage for delivering fuel vapor from said fuel bowl to said fuel vapor storage device when the engine is not operating, valve means disposed in said passage, means biasing said valve means to prevent the flow of fuel vapor through said first branch and to permit the flow of fuel vapor through said second branch, said valve means including a diaphragm responsive to the subatmospheric pressure maintained in said region during engine operation to overcome said biasing means to permit the flow of fuel vapor through said first branch and to prevent the flow of fuel vapor through said second branch during engine operation.

Claim 5

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said mixture conduit, means controlling said carburetor to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and extending to said mixture conduit, a fuel bowl containing fuel up to a certain level, a cover member secured over said fuel bowl, lower, intermediate and upper members secured to said cover member, vent passage extending from said fuel bowl through said cover member and said lower member to a vent chamber defined between said lower and intermediate members, a first branch passage extending from said vent chamber to a valve chamber defined between said lower and cover members, said purge passage extending through said valve chamber and having a portion disposed coaxially with said branch passage, a diaphragm clamped between said intermediate and upper members, a second branch passage extending from said vent chamber to a chamber defined between said diaphragm and said intermediate member, means equalizing the pressure in said last mentioned chamber with the pressure in said mixture conduit upstream of said air valve, a valve seat formed about said second branch passage and engaged by said diaphragm to prevent flow therethrough, valve seats formed in said valve chamber about said first branch passage and said purge passage, a valve stem secured to said diaphragm and extending through said branch passages into said valve chamber, a valve disc mounted on said valve stem and disposed in said valve chamber for alternative engagement with said valve seats formed therein, means biasing said diaphragm into engagement with said second branch passage valve seat and said valve disc with said purge passage valve seat, and a signal passage extending from said mixture conduit region to a chamber defined between said diaphragm and said upper member whereby during engine operation the bias of said biasing means is overcome and said diaphragm is disengaged from said second branch passage valve seat and said valve disc is disengaged from said purge passage valve seat and engaged with said first branch passage valve seat.

Claim 6

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said mixture conduit, means controlling said carburetor to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and extending to said mixture conduit, a fuel bowl containing fuel up to a certain level, a cover member secured over said fuel bowl, lower, intermediate and upper members secured to said cover member, vent passage extending from said fuel bowl through said cover member and said lower member to a vent chamber defined between said lower and intermediate members, a first branch passage extending from said vent chamber to a valve chamber defined between said lower and cover members, said purge passage extending through said valve chamber and having a portion disposed coaxially with said branch passage, a diaphragm clamped between said intermediate and upper members, a second branch passage extending from said vent chamber to a chamber defined between said diaphragm and said intermediate member, means equalizing the pressure in said last mentioned chamber with the pressure in said mixture conduit upstream of said air valve, a valve seat formed about said second branch passage and engaged by said diaphragm to prevent flow therethrough, valve seats formed in said valve chamber about said first branch passage and said purge passage, a valve stem secured to said diaphragm and extending through said branch passages into said valve chamber, a valve disc mounted on said valve stem and disposed in said valve chamber for alternative engagement with said valve seats formed therein, means biasing said diaphragm into engagement with said second branch passage valve seat and said valve disc with said purge passage valve seat, and a signal passage extending from said mixture conduit region to a chamber defined between said diaphragm and said upper member whereby during engine operation the bias of said biasing means is overcome and said diaphragm is disengaged from said second branch passage valve seat and said valve disc is disengaged from said purge passage valve seat and engaged with said first branch passage valve seat.

Claim 7

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said mixture conduit and rotatable between closed and open positions, means controlling said carburetor to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and having a port disposed in said mixture conduit adjacent the upstream edge of said air valve when said air valve is in said closed position and traversed by the upstream edge of said air valve as said air valve is rotated from said closed position, whereby the pressure in said mixture conduit may induce a flow of fuel vapor from said storage device through said purge passage to said mixture conduit which may be increased from a minimum when said air valve is in said closed position to a selected value when the upstream edge of said air valve has traversed said port, a fuel bowl containing fuel up to a certain level, a cover member secured over said fuel bowl, lower, intermediate and upper members secured to said cover member, a vent passage extending from said fuel bowl through said cover member and said lower member to a vent chamber defined between said lower and intermediate members, a first branch passage extending from said vent chamber to a valve chamber defined between said lower and cover members, said purge passage extending through said valve chamber and having a portion disposed coaxially with said branch passage, a diaphragm clamped between said intermediate and upper members, a second branch passage extending from said vent chamber to a chamber defined between said diaphragm and said intermediate member, means equalizing the pressure in said last mentioned chamber with the pressure in said mixture conduit upstream of said air valve, a valve seat formed about said second branch passage and engaged by said diaphragm to prevent flow therethrough, valve seats formed in said valve chamber about said first branch passage and said purge passage, a valve stem secured to said diaphragm and extending through said branch passages into said valve chamber, a valve disc mounted on said valve stem and disposed in said valve chamber for alternative engagemnt with said valve seats formed therein, means biasing said diaphragm into engagement with said second branch passage valve seat and said valve disc with said purge passage valve seat, and a signal passage extending from said mixture conduit region to a chamber defined between said diaphragm and said upper member whereby during engine operation the bias of said biasing means is overcome and said diaphragm is disengaged from said second branch passage valve seat and said valve disc is disengaged from said purge passage valve seat and engaged with said first branch passage valve seat.

Claim 8

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said mixture conduit and rotatable between closed and open positions, means controlling said carburetor to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and having a port disposed in said mixture conduit adjacent the upstream edge of said air valve when said air valve is in said closed position and traversed by the upstream edge of said air valve as said air valve is rotated from said closed position, whereby the pressure in said mixture conduit may induce a flow of fuel vapor from said storage device through said purge passage to said mixture conduit which may be increased from a minimum when said air valve is in said closed position to a selected value when the upstream edge of said air valve has traversed said port, a fuel bowl containing fuel up to a certain level, a cover member secured over said fuel bowl, lower, intermediate and upper members secured to said cover member, a vent passage extending from said fuel bowl through said cover member and said lower member to a vent chamber defined between said lower and intermediate members, a first branch passage extending from said vent chamber to a valve chamber defined between said lower and cover members, said purge passage extending through said valve chamber and having a portion disposed coaxially with said branch passage, a diaphragm clamped between said intermediate and upper members, a second branch passage extending from said vent chamber to a chamber defined between said diaphragm and said intermediate member, means equalizing the pressure in said last mentioned chamber with the pressure in said mixture conduit upstream of said air valve, a valve seat formed about said second branch passage and engaged by said diaphragm to prevent flow therethrough, valve seats formed in said valve chamber about said first branch passage and said purge passage, a valve stem secured to said diaphragm and extending through said branch passages into said valve chamber, a valve disc mounted on said valve stem and disposed in said valve chamber for alternative engagemnt with said valve seats formed therein, means biasing said diaphragm into engagement with said second branch passage valve seat and said valve disc with said purge passage valve seat, and a signal passage extending from said mixture conduit region to a chamber defined between said diaphragm and said upper member whereby during engine operation the bias of said biasing means is overcome and said diaphragm is disengaged from said second branch passage valve seat and said valve disc is disengaged from said purge passage valve seat and engaged with said first branch passage valve seat.

Claim 9

An internal combustion engine carburetor comprising a mixture conduit, an air valve disposed in said mixture conduit, means controlling said air valve to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream from said air valve during engine operation, a fuel bowl containing fuel up to a certain level therein, a fuel vapor passage opening from said fuel bowl above said level, said fuel vapor passage having a first branch extending to said mixture conduit and a second branch Extending to a fuel vapor storage device, valve means disposed in said vapor passage for controlling the flow of fuel vapor through said second branch, said valve means including a diaphragm responsive to the pressure in said region to position said valve means for restricting the flow of fuel vapor from said fuel bowl through said second branch during engine operation and for permitting the flow of fuel vapor from said fuel bowl through said second branch when the engine is not operating.

Claim 10

An internal combustion engine carburetor comprising a mixture conduit, an air valve disposed in said mixture conduit, means controlling said air valve to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream from said air valve during engine operation, a fuel bowl containing fuel up to a certain level therein, a fuel vapor passage opening from said fuel bowl above said level, said fuel vapor passage having a first branch extending to said mixture conduit and a second branch Extending to a fuel vapor storage device, valve means disposed in said vapor passage for controlling the flow of fuel vapor through said second branch, said valve means including a diaphragm responsive to the pressure in said region to position said valve means for restricting the flow of fuel vapor from said fuel bowl through said second branch during engine operation and for permitting the flow of fuel vapor from said fuel bowl through said second branch when the engine is not operating.

Claim 11

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said conduit, means controlling said air valve to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and opening into said region whereby the subatmospheric pressure therein may purge fuel vapor from said device into said region for delivery to the engine when the engine is operating, a fuel bowl containing fuel up to a certain level, a vent passage opening from said fuel bowl above said level, said vent passage having a first branch extending to said mixture conduit for delivering fuel vapor from said fuel bowl to the engine when the engine is operating and a second branch extending to said purge passage for delivering fuel vapor from said fuel bowl to said fuel vapor storage device when the engine is not operating, valve means disposed in said second branch, means biasing said valve means to permit the flow of fuel vapor through said second branch, said valve means including a diaphragm responsive to the subatmospheric pressure maintained in said region during engine operation to overcome said biasing means to restrict the flow of fuel vapor through said second branch during engine operation.

Claim 12

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said conduit, means controlling said air valve to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and opening into said region whereby the subatmospheric pressure therein may purge fuel vapor from said device into said region for delivery to the engine when the engine is operating, a fuel bowl containing fuel up to a certain level, a vent passage opening from said fuel bowl above said level, said vent passage having a first branch extending to said mixture conduit for delivering fuel vapor from said fuel bowl to the engine when the engine is operating and a second branch extending to said purge passage for delivering fuel vapor from said fuel bowl to said fuel vapor storage device when the engine is not operating, valve means disposed in said second branch, means biasing said valve means to permit the flow of fuel vapor through said second branch, said valve means including a diaphragm responsive to the subatmospheric pressure maintained in said region during engine operation to overcome said biasing means to restrict the flow of fuel vapor through said second branch during engine operation.

Claim 13

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said mixture conduit, means controlling said carburetor to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and extending to said mixture conduit, a fuel bowl containing fuel up to a certain level, a cover member secured over said fuel bowl, lower and upper members secured to said cover member, a vent passage extending from said fuel bowl through said cover member and said lower member to a vent chamber defined between said lower and upper members, a branch passage extending from said vent chamber to a valve chamber defined between said lower and cover members, said purge passage extending through said valve chamber and having a portion disposed coaxially with said branch passage, a diaphragm clamped between said lower and upper members, valve seats formed in said valve chamber about said branch passage and said purge passage, a valve stem secured to said diaphragm and extending through said branch passage into said valve chamber, a valve disc mounted on said valve stem and disposed in said valve chamber for alternative engagement with said valve seats formed therein, means biasing said valve disc into engagement with said purge passage valve seat, and a signal passage extending from said mixture conduit region to a chamber defined between said diaphragm and said upper member whereby during engine operation the bias of said biasing means is overcome and said valve disc is disengaged from said purge passage valve seat and engaged with said branch passage valve seat.

Claim 14

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said mixture conduit, means controlling said carburetor to maintain a region of substantially constant subatmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and extending to said mixture conduit, a fuel bowl containing fuel up to a certain level, a cover member secured over said fuel bowl, lower and upper members secured to said cover member, a vent passage extending from said fuel bowl through said cover member and said lower member to a vent chamber defined between said lower and upper members, a branch passage extending from said vent chamber to a valve chamber defined between said lower and cover members, said purge passage extending through said valve chamber and having a portion disposed coaxially with said branch passage, a diaphragm clamped between said lower and upper members, valve seats formed in said valve chamber about said branch passage and said purge passage, a valve stem secured to said diaphragm and extending through said branch passage into said valve chamber, a valve disc mounted on said valve stem and disposed in said valve chamber for alternative engagement with said valve seats formed therein, means biasing said valve disc into engagement with said purge passage valve seat, and a signal passage extending from said mixture conduit region to a chamber defined between said diaphragm and said upper member whereby during engine operation the bias of said biasing means is overcome and said valve disc is disengaged from said purge passage valve seat and engaged with said branch passage valve seat.

Claim 15

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said mixture conduit and rotatable between closed and open positions, means controlling said carburetor to maintain a region of substantially constant subaTmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and having a port disposed in said mixture conduit adjacent the upstream edge of said air valve when said air valve is in said closed position and traversed by the upstream edge of said air valve as said air valve is rotated from said closed position, whereby the pressure in said mixture conduit may induce a flow of fuel vapor from said storage device through said purge passage to said mixture conduit which may be increased from a minimum when said air valve is in said closed position to a selected value when the upstream edge of said air valve has traversed said port, a fuel bowl containing fuel up to a certain level, a cover member secured over said fuel bowl, lower and upper members secured to said cover member, a vent passage extending from said fuel bowl through said cover member and said lower member to a vent chamber defined between said lower and upper members, a branch passage extending from said vent chamber to a valve chamber defined between said lower and cover members, said purge passage extending through said valve chamber and having a portion disposed coaxially with said branch passage, a diaphragm clamped between said lower and upper members, valve seats formed in said valve chamber about said branch passage and said purge passage, a valve stem secured to said diaphragm and extending through said branch passage into said valve chamber, a valve disc mounted on said valve stem and disposed in said valve chamber for alternative engagement with said valve seats formed therein, means biasing said valve disc into engagement with said purge passage valve seat, and a signal passage extending from said mixture conduit region to a chamber defined between said diaphragm and said upper member whereby during engine operation the bias of said biasing means is overcome and said valve disc is disengaged from said purge passage valve seat and engaged with said branch passage valve seat.

Claim 16

For use with an internal combustion engine having a fuel vapor storage device, a carburetor comprising a mixture conduit, an air valve disposed in said mixture conduit and rotatable between closed and open positions, means controlling said carburetor to maintain a region of substantially constant subaTmospheric pressure in said mixture conduit downstream of said air valve during engine operation, a purge passage adapted for connection to said fuel vapor storage device and having a port disposed in said mixture conduit adjacent the upstream edge of said air valve when said air valve is in said closed position and traversed by the upstream edge of said air valve as said air valve is rotated from said closed position, whereby the pressure in said mixture conduit may induce a flow of fuel vapor from said storage device through said purge passage to said mixture conduit which may be increased from a minimum when said air valve is in said closed position to a selected value when the upstream edge of said air valve has traversed said port, a fuel bowl containing fuel up to a certain level, a cover member secured over said fuel bowl, lower and upper members secured to said cover member, a vent passage extending from said fuel bowl through said cover member and said lower member to a vent chamber defined between said lower and upper members, a branch passage extending from said vent chamber to a valve chamber defined between said lower and cover members, said purge passage extending through said valve chamber and having a portion disposed coaxially with said branch passage, a diaphragm clamped between said lower and upper members, valve seats formed in said valve chamber about said branch passage and said purge passage, a valve stem secured to said diaphragm and extending through said branch passage into said valve chamber, a valve disc mounted on said valve stem and disposed in said valve chamber for alternative engagement with said valve seats formed therein, means biasing said valve disc into engagement with said purge passage valve seat, and a signal passage extending from said mixture conduit region to a chamber defined between said diaphragm and said upper member whereby during engine operation the bias of said biasing means is overcome and said valve disc is disengaged from said purge passage valve seat and engaged with said branch passage valve seat.