초록 ▼

A fixed air circulation system for the cab enclosure of an off-highway vehicle is disclosed. Fresh air is introduced into the cab through a fresh air inlet having a fresh air filter therein. The air inlet leads, through a manifold or fresh air duct, to the inside of the operator's compartment. When

A fixed air circulation system for the cab enclosure of an off-highway vehicle is disclosed. Fresh air is introduced into the cab through a fresh air inlet having a fresh air filter therein. The air inlet leads, through a manifold or fresh air duct, to the inside of the operator's compartment. When a cab door is opened, a bypass valve to the conduit is opened. When the door is closed, the air pulse created in the cab is effective, through the bypass valve or normal openings with the blower off, to dislodge dust and dirt from the filter.

대표청구항 ▼

Having thus described the invention, what is claimed is: 1. A fixed air circulation system for an off-highway vehicle having a cab body, a generally dust-tight operator's enclosure and work station within said cab body, and a cab door pivotally mounted on said cab body and adapted to open and close

Having thus described the invention, what is claimed is: 1. A fixed air circulation system for an off-highway vehicle having a cab body, a generally dust-tight operator's enclosure and work station within said cab body, and a cab door pivotally mounted on said cab body and adapted to open and close said operator's enclosure permit ingress thereto and egress therefrom, said circulation system comprising: a distribution plenum for distributing a combination of fresh air and recirculated air into said operator's enclosure; a heating and air conditioning core housing; a fresh air inlet port through said cab body; a fresh air filter arranged such that air passing through said inlet port also passes through said filter; a blower in air flow communication with said plenum and said core housing, said blower, core housing, fresh air inlet port and air filter arranged such that said blower causes fresh air to flow through said fresh air inlet port and air filter along a first air flow path through said core housing into said plenum and thence into said operator's enclosure; a second air flow path extending directly from said fresh air inlet port, through said air filter, into said cab enclosure; a bypass valve between said fresh air inlet port and said operator's enclosure, said fresh air bypass valve having a closed position allowing air to flow along said first air flow path and not along said second air flow path, and an opened position allowing air to flow along both said first and second air flow paths; and a purge control connected to said fresh air bypass valve and said cab door such that said fresh air bypass valve is activated to said opened position when said cab door is opened, and activated to said closed position when said cab door is closed. 2. The air circulation system of claim 1, further including: a time delay device to delay the time period between closure of said cab door and turning on of said blower. 3. The air circulation system of claim 1, wherein: said purge control is also connected to said blower such that said blower is inactivated when said cab door is opened, and activated when said cab door is closed; whereby closing of the cab door creates an air pressure pulse within the operator's enclosure, causing a reverse air flow along said second air flow path outwardly through said air filter and fresh air inlet port. 4. The air circulation system of claim 3, wherein: said first air flow path includes a main air conduit having a first end in air flow communication with said core housing and an opposite second end in air flow communication with a fresh air duct which is in air flow communication with said air filter; an air recirculation opening between said main air conduit and said operator's enclosure; and said blower is a recirculation blower and is arranged in said first air flow path such that it pulls air from outside said cab through said fresh air inlet port and said air filter, through said fresh air duct and said main air conduit, through said core housing, and pushes the air conditioned by said core housing through said plenum and into said operator's enclosure, at the same time, air from inside the operator's enclosure is pulled through said air recirculation opening, the amount depending upon the size of the opening, and added to the fresh air being pulled through said fresh air inlet port. 5. The air circulation system of claim 4, further including: a pressurizer blower between said fresh air duct and said main air conduit; said fresh air bypass valve is connected to said fresh air duct such that in its closed position air does not flow from said fresh air duct to said operator's enclosure, and in its open position air does flow from said operator's enclosure to said fresh air duct; and said purge control is an electro-mechanical actuator connected to said fresh air bypass valve, actuated by electrical pulses generated by the opening and closing of said door. 6. The air circulation system of claim 5, wherein: said purge control is also connected to said pressurizer blower such that said blower and said pressurizer blower may be selectively activated or inactivated when said cab door is opened and closed, whereby closing of the cab door creates an air pressure pulse within the operator's enclosure, causing a reverse air flow along said second air flow path outwardly through said air filter and fresh air inlet port. 7. The air circulation system of claim 1, wherein: said first air flow path includes a main air conduit having a first end in air flow communication with said core housing and an opposing second end in air flow communication with a fresh air duct which is in air flow communication with said air filter; an air recirculation opening between said main air conduit and said operator's enclosure; and said blower is a recirculation blower and is arranged in said first air flow path such that it pulls air from outside said cab through said inlet port and said air filter, through said fresh air duct and said main air conduit, through said core housing, and pushes the air conditioned by said core housing through said plenum and into said operator's enclosure, at the same time, air from inside the operator's enclosure is pulled through said air recirculation opening, the amount depending upon the size of the opening, and added to the fresh air being pulled through said fresh air inlet port. 8. The air circulation system of claim 7, wherein: said purge control also connected to said blower such that said blower is inactivated when said cab door is opened, and activated when said cab door is closed; whereby closing of the cab door creates an air pressure pulse within the operator's enclosure, causing a reverse air flow along said second air flow path outwardly through said air filter and fresh air inlet port. 9. The air circulation system of claim 8, further including: a pressurizer blower between said fresh air duct and said main air conduit; said fresh air bypass valve is connected to said fresh air duct such that in its closed position air does not flow from said fresh air duct to operator's enclosure, and in its open position air does flow from said fresh air duct to said operator's enclosure; and said purge control is an electro-mechanical actuator connected to said fresh air bypass valve, actuated by electrical pulses generated by the opening and closing of said door. 10. The air circulation system of claim 9, wherein: said purge control is also connected to said pressurizer blower such that said blower and said pressurizer blower may be selectively activated or inactivated when said cab door is opened and closed, whereby closing of the cab door creates an air pressure pulse within the operator's enclosure, causing a reverse air flow along said second air flow path outwardly through said air filter and fresh air inlet port. 11. In a fixed air circulation system for an off-highway vehicle having a cab body, a generally dust-tight operator's enclosure and work station within said cab body, and a cab door pivotally mounted on said cab body and adapted to open and close said operator's enclosure to permit ingress thereto and egress therefrom, a distribution plenum for distributing a combination of fresh air and recirculated air into said operator's enclosure; a heating and air conditioning core housing; a fresh air inlet port through said cab body; a fresh air filter adjacent said fresh air inlet port, arranged such that air passing through said fresh air inlet port also passes through said filter, the improvement comprising: a pressurizer blower between a fresh air duct and a main air conduit; a blower in air flow communication with said plenum and said core housing, said blower, core housing, fresh air inlet port and air filter arranged such that said blower causes fresh air to flow through said fresh air inlet port and air filter along a first air flow path through said core housing into said plenum and thence into said operator's enclosure; a second air flow path extending directly from said fresh air inlet port, through said air filter, into said cab enclosure; a purge control also connected to said blower and said pressurizer blower such that said blower and said pressurizer blower are inactivated when said cab door is opened, and activated when said cab door is closed; whereby closing of the cab door creates an air pressure pulse within the operator's enclosure, causing a reverse air flow along said second air flow path outwardly through said air filter and fresh air inlet port; and a bypass valve between said fresh air inlet port and said operator's enclosure, said fresh air bypass valve having a closed position allowing air to flow along said first flow path and not along said second air flow path, and an opened position allowing air to flow along both said first and second air flow paths, said bypass valve being connected to said fresh air duct such that in its closed position air does not flow from said operator's enclosure to said fresh air duct, and in its open position air does flow from said operator's enclosure to said fresh air duct. 12. The air circulation system of claim 11, further including: a time delay device to delay the time period between closure of said cab door and the turning on of said blower. 13. The air circulation system of claim 11, wherein: said first air flow path includes a main air conduit having a first end in air flow communication with said core housing and an opposing second end in air flow communication with a fresh air duct which is in air flow communication with said air filter; an air recirculation opening between said main air conduit and said operator's enclosure; and said blower is a recirculation blower and is arranged in said first air flow path such that it pulls air from outside said cab through said fresh air inlet port and said air filter, through said fresh air duct and said main air conduit, through said core housing, and pushes the air conditioned by said core housing through said plenum and into said operator's enclosure, at the same time, air from inside the operator's enclosure is pulled through said air recirculation opening, the amount depending upon the size of the opening, and added to the fresh air being pulled through said fresh air inlet port. 14. The air circulation system of claim 13, further including: a purge control connected to said fresh air bypass valve and said cab door such that said bypass valve is activated to said opened position when said cab door is opened, and activated to said closed position when said cab door is closed; said purge control being an electro-mechanical actuator connected to said fresh air bypass valve, actuated by electrical pulses generated by the opening and closing of said door. 15. The air circulation system of claim 13, further including: a time delay device to delay the time period between closure of said cab door and turning on of said blower, and an automatic temperature control circuit controlling the components of said air circulation system to maintain the temperature set by the operator. 16. A fixed air circulation system in an off-highway vehicle cab, comprising: a cab body; an operator's enclosure within said cab body; a cab door pivotally mounted on said cab body and adapted to open and close said operator's enclosure to permit ingress thereto and egress therefrom; a distribution plenum for distributing a combination of fresh air and recirculated air into said operator's enclosure; a heating and air conditioning core housing; a fresh air inlet port to said enclosure from outside said body; a fresh air filter adjacent said fresh air inlet port, arranged such that air passing through said fresh air inlet port also passes through said filter; a blower in air flow communication with said plenum and said core housing, said blower, core housing, fresh air inlet port and air filter arranged such that said blower causes fresh air to flow through said fresh air inlet port and air filter along a first air flow path through said core housing into said plenum and thence into said operator's enclosure; a second air flow path extending directly from said fresh air inlet port, through said air filter, into said cab enclosure; a bypass valve between said inlet port and said operator's enclosure, said fresh air bypass valve having a closed position allowing air to flow along said first air flow path and not along said second air flow path, and an opened position allowing air to flow along both said first and second air flow paths; and a purge control connected to said fresh air bypass valve, said blower, and said cab door such that said fresh air bypass valve is activated to said opened position and said blower is inactivated when said cab door is opened, and said fresh air bypass valve is activated to said closed position and said blower is activated when said cab door is closed, whereby closing of the cab door creates an air pressure pulse within the operator's enclosure, causing a reverse air flow along said second air flow path outwardly through said air filter and fresh air inlet port. 17. The air circulation system of claim 16, further including: a time delay device to delay the time period between closure of said cab door and the turning on of said blower. 18. The air circulation system of claim 16, wherein: said first air flow path includes a main air conduit having a first end in air flow communication with said core housing and an opposing second end in air flow communication with a fresh air duct which is in air flow communication with said air filter; an air recirculation opening between said main air conduit and said operator's enclosure; and said blower is a recirculation blower and is arranged in said first air flow path such that it pulls air from outside said cab through said fresh air inlet port and said air filter, through said fresh air duct and said main air conduit, through said core housing, and pushes the air conditioned by said core housing through said plenum and into said operator's enclosure, at the same time, air from inside the operator's enclosure is pulled through said air recirculation opening, the amount depending upon the size of the opening, and added to the fresh air being pulled through said fresh air inlet port. 19. The air circulation system of claim 18, further including: a pressurizer blower between said fresh air duct and said main air conduit; said bypass valve is connected to said fresh air duct such that in its closed position air does not flow from said fresh air duct to operator's enclosure, and in its open position air does flow from said fresh air duct to said operator's enclosure; and said purge control is an electro-mechanical actuator connected to said fresh air bypass valve, actuated by electrical pulses generated by the opening and closing of said door. 20. The air circulation system of claim 16, wherein: said first air flow path includes a main air conduit having a first end in air flow communication with said core housing and an opposing second end in air flow communication with a fresh air duct which is in air flow communication with said air filter; an air recirculation opening between said main air conduit and said operator's enclosure; and said blower is a recirculation blower and is arranged in said first air flow path such that it pulls air from outside said cab through said fresh air inlet port and said air filter, through said fresh air duct and said main air conduit, through said core housing, and pushes the air conditioned by said core housing through said plenum and into said operator's enclosure, at the same time, air from inside the operator's enclosure is pulled through said air recirculation opening, the amount depending upon the size of the opening, and added to the fresh air being pulled through said fresh air inlet port. 21. The air circulation system of claim 20, further including: a pressurizer blower between said fresh air duct and said main air conduit; said bypass valve is connected to said fresh air duct such that in its closed position air does not flow from said fresh air duct to operator's enclosure, and in its open position air does flow from said fresh air duct to said operator's enclosure; said purge control is an electro-mechanical actuator connected to said fresh air bypass valve, actuated by electrical pulses generated by the opening and closing of said door; a time delay device to delay the time period between closure of said cab door and turning on of said blower; and an automatic temperature control circuit controlling the components of said air circulation system to maintain the temperature set by the operator. 22. A fixed air circulation system for an off-highway vehicle having a cab body, a generally dust-tight operator's enclosure and work station within said cab body, and a cab door pivotally mounted on said cab body and adapted to open and close said operator's enclosure to permit ingress thereto and egress therefrom, said circulation system comprising: a distribution plenum for distributing a combination of fresh air and recirculated air into said operator's enclosure; a heating and air conditioning core housing; a fresh air inlet port through said cab body; a fresh air filter arranged such that air passing through said inlet port also passes through said filter; a blower in air flow communication with said plenum and said core housing, said blower, core housing, fresh air inlet port and air filter arranged such that said blower causes fresh air to flow through said air fresh air inlet port and air filter along a first air flow path through said core housing into said plenum and thence into said operator's enclosure; an automatic temperature control circuit controlling the components of said air circulation system to maintain the temperature set by the operator, and a time delay device to delay the time period between closure of said cab door and turning on of said blower; a pressurizer blower between a fresh air duct and a main air conduit; and a fresh air bypass valve connected to said fresh air duct such that in its closed position air does not flow from said operator's enclosure to said fresh air duct, and in its open position air does flow from said operator's enclosure to said fresh air duct; and purge control also connected to said blower such that said blower is inactivated when said cab door is opened, and activated when said cab door is closed; whereby closing of the cab door creates an air pressure pulse within the operator's enclosure, causing a reverse air flow along a second air flow path extending outwardly through said air filter and fresh air inlet port. 23. The air circulation system of claim 22, wherein: said first air flow path includes a main air conduit having a first end in air flow communication with said core housing and an opposing second end in air flow communication with a fresh air duct which is in air flow communication with said air filter; an air recirculation opening between said main air conduit and said operator's enclosure; said blower is a recirculation blower and is arranged in said first air flow path such that it pulls air from outside said cab through said fresh air inlet port and said air filter, through said fresh air duct and said main air conduit, through said core housing, and pushes the air conditioned by said core housing through said plenum and into said operator's enclosure, at the same time, air from inside the operator's enclosure is pulled through said air recirculation opening, the amount depending upon the size of the opening, and added to the fresh air being pulled through said fresh air inlet port; and further including: an automatic temperature control circuit controlling the components of said air circulation system to maintain the temperature set by the operator. 24. The air circulation system of claim 22, further including: wherein said purge control is an electro-mechanical actuator connected to said fresh air bypass valve, actuated by electrical pulses generated by the opening and closing of said door. 25. The air circulation system of claim 22, wherein: said first air flow path includes a main air conduit having a first end in air flow communication with said core housing and an opposing second end in air flow communication with a fresh air duct which is in air flow communication with said air filter; an air recirculation opening between said main air conduit and said operator's enclosure; and said blower is a recirculation blower and is arranged in said first air flow path such that it pulls air from outside said cab through said inlet port and said air filter, through said fresh air duct and said main air conduit, through said core housing, and pushes the air conditioned by said core housing through said plenum and into said operator's enclosure, at the same time, air from inside the operator's enclosure is pulled through said air recirculation opening, the amount depending upon the size of the opening, and added to the fresh air being pulled through said fresh air inlet port. 26. In a fixed air circulation system for an off-highway vehicle having a cab body, a generally dust-tight operator's enclosure and work station within said cab body, and a cab door pivotally mounted on said cab body and adapted to open and close said operator's enclosure to permit ingress thereto and egress therefrom, a distribution plenum for distributing a combination of fresh air and recirculated air into said operator's enclosure; a heating and air conditioning core housing; a fresh air inlet port through said cab body; a fresh air filter adjacent said fresh air inlet port, arranged such that air passing through said fresh air inlet port also passes through said filter, the improvement comprising: a blower in air flow communication with said plenum and said core housing, said blower, core housing, fresh air inlet port and air filter arranged such that said blower causes fresh air to flow through said fresh air inlet port and air filter along a first air flow path through said core housing into said plenum and thence into said operator's enclosure; a purge control connected to said door to shut off said blower when said cab door is opened and to turn on said blower when said cab door is closed, and said purge control also connected to said blower such that said blower is inactivated when said cab door is opened, and activated when said cab door is closed; whereby closing of the cab door creates an air pressure pulse within the operator's enclosure, causing a reverse air flow along a second air flow path extending outwardly through said air filter and inlet port; a pressurizer blower between a fresh air duct and a main air conduit; and a bypass valve connected to said fresh air duct such that in its closed position air does not flow from said operator's enclosure to said fresh air duct, and in its open position air does flow from said operator's enclosure to said fresh air duct; and wherein said purge control is an electro-mechanical actuator connected to said air bypass valve, actuated by electrical pulses generated by the opening and closing of said door. 27. The air circulation system of claim 26, further including: a time delay device to delay the time period between closure of said cab door and the turning on of said blower. 28. The air circulation system of claim 26, wherein: said first air flow path includes a main air conduit having a first end in air flow communication with said core housing and an opposing second end in air flow communication with a fresh air duct which is in air flow communication with said air filter; an air recirculation opening between said main air conduit and said operator's enclosure; and said blower is a recirculation blower and is arranged in said first air flow path such that it pulls air from outside said cab through said fresh air inlet port and said air filter, through said fresh air duct and said main air conduit, through said core housing, and pushes the air conditioned by said core housing through said plenum and into said operator's enclosure, at the same time, air from inside the operator's enclosure is pulled through said air recirculation opening, the amount depending upon the size of the opening, and added to the fresh air being pulled through said fresh air inlet port. 29. The air circulation system of claim 26, wherein: said first air flow path includes a main air conduit having a first end in air flow communication with said core housing and an opposing second end in air flow communication with a fresh air duct which is in air flow communication with said air filter; an air recirculation opening is provided between said main air conduit and said operator's enclosure; and said blower is a recirculation blower and is arranged in said first air flow path such that it pulls air from outside said cab through said fresh air inlet port and said air filter, through said fresh air duct and said main air conduit, through said core housing, and pushes the air conditioned by said core housing through said plenum and into said operator's enclosure, at the same time, air from inside the operator's enclosure is pulled through said air recirculation opening in an amount depending upon the size of the opening, and added to the fresh air being pulled through said fresh air inlet port.