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US 6,779,503 B2Granted
Automatic engine priming system for rotary mowers
AssigneeTecumseh Products Company
InventorGordon E. Rado
Life of this patent
Estimating the term…
Abstract
A priming system for a carburetor for small internal combustion engines, wherein the priming system is remotely actuated and includes an automatic primer disabling feature operative when the engine is in a warm condition to prevent the supply of an overly rich fuel/air mixture to the engine intake system during warm re-starts, for example.
Claims26
A carburetor, comprising:
- a carburetor body having a throat;
- a movable primer element connected to said carburetor, said primer element and said carburetor defining a variable-volume priming chamber therebetween in which liquid fuel is disposed;
- a thermally-responsive element disposed between said priming chamber and said throat, said thermally-responsive element moveable between a first position corresponding to cold temperatures in which said priming chamber is in fluid communication with said throat and a second position corresponding to warm temperatures in which said thermally-responsive element prevents fluid communication between said priming chamber and said throat;
- said thermally responsive element comprising:
- a movable member movable between said first and second positions;
- and
- a bimetallic element connected to said movable member, said bimetallic element having a cold temperature position corresponding to said movable member being in said first position and a warm temperature position corresponding to said movable member being in said second position;
- whereby when said thermally-responsive element is in said first position, movement of said primer element forces at least a portion of said liquid fuel from said priming chamber into said throat.
5 more elements
A carburetor, comprising:
- a carburetor body having a throat;
- a movable primer element connected to said carburetor body and defining a variable volume priming chamber therebetween in which liquid fuel is disposed;
- and
- thermally-responsive means disposed within said priming chamber for allowing passage of fuel from said priming chamber into said throat at cold temperatures upon movement of said primer element, and for preventing passage of fuel from said priming chamber into said throat at warm temperatures;
- said thermally-responsive means comprising:
- a movable member;
- and
- a bimetallic element connected to said movable member, said bimetallic element positioning said movable member in a first position at cold temperatures to allow passage of fuel from said priming chamber into said carburetor throat upon movement of said primer element, said bimetallic element positioning said movable member in a second position at warm temperatures in which said movable member prevents passage of fuel from said priming chamber into said carburetor throat.
5 more elements
An internal combustion engine, comprising:
- an engine housing;
- a carburetor attached to said engine housing, said carburetor having a throat;
- a movable primer element connected to said carburetor, said primer element and said carburetor defining a variable volume priming chamber therebetween in which liquid fuel is disposed;
- and
- a thermally-responsive element disposed between said priming chamber and said throat, said thermally-responsive element movable between a first position corresponding to cold engine temperatures in which said priming chamber is in fluid communication with said throat and a second position corresponding to warm engine temperatures in which said movable member prevents fluid communication between said priming chamber and said throat;
- said thermally responsive element comprising:
- a movable member having an aperture therein, said movable member movable between said first and second positions;
- and
- a bimetallic element connected to said movable member, said bimetallic element having a cold temperature position corresponding to said movable member being in said first position and a warm temperature position corresponding to said movable member being in said second position;
- whereby when said thermally-responsive element is in said first position, movement of said primer element forces at least a portion of said liquid fuel from said priming chamber into said throat, and when said thermally-responsive element is in said second position, flow of fuel from said priming chamber to said throat is blocked.
7 more elements
A method of operating an implement having an internal combustion engine having a carburetor, comprising the steps of:
- depressing a primer element to reduce the volume of a priming chamber in which liquid fuel is disposed;
- thereby forcing at least a portion of the liquid fuel from the priming chamber into a throat of the carburetor to prime the carburetor;
- starting the engine;
- and
- automatically disabling priming of the carburetor when the engine reaches a warm operating temperature by heating a thermally-responsive sensor element mechanically linked to a movable member to position the movable member in blocking relation with the passage of fuel from the priming chamber into the throat of the carburetor.
2 more elements
A carburetor, comprising:
- a carburetor body having a throat;
- a movable primer element connected to said carburetor body, said primer element and said carburetor body defining a variable-volume priming chamber therebetween in which liquid fuel is disposed;
- and
- a thermally-responsive sensor element connected to said carburetor body, said sensor element mechanically linked to a movable member disposed between said priming chamber and said throat, said sensor element positioning said movable member in a first position corresponding to cold temperatures in which said priming chamber is in fluid communication with said throat, and positioning said movable member in a second position corresponding to warm temperatures in which said movable member prevents fluid communication between said priming chamber and said throat;
- whereby when said movable member is in said first position, movement of said primer element forces at least a portion of said liquid fuel from said priming chamber into said throat.
2 more elements
Dependencies are inferred from the claim text.