Air brake system with line pressure loss protection

In an air brake system for a vehicle which has air-controlled brakes and a compressed air source, the combination comprising:

• brake control means for receiving said compressed air and for selectively applying said compressed air to said brakes and for selectively releasing said compressed air from said brakes,
• first and second compressed air reservoirs each having an air outlet port communicated with said brake control means,
• first air supply passage means for transmitting compressed air from said source to said first reservoir,
• second air supply passage means for transmitting compressed air from said source to said second reservoir, and
• air delivery control means, connected between said compressed air source and said first and second air supply passage means, for closing the flow path from said source to either of said air supply passage means in response to air leakage therein, wherein said air delivery control means includes a shuttle valve having an air inlet communicated with said compressed air source and having first and second air outlets and having a movable valve member which is shiftable from a first position at which said inlet is communicated with both of said outlets to a second position at which said inlet is communicated only with said first outlet and which is shiftable to a third position at which said inlet is communicated only with said second outlet, said shuttle valve having means for biasing said valve member toward said first position thereof, and further includes pilot means for shifting said valve member of said shuttle valve to said second position thereof in response to a pressure drop in said second air supply passage means and for shifting said valve member to said third position thereof in response to a pressure drop in said first air supply passage means.

In an air brake system for a vehicle which has air-controlled brakes and a compressed air source, wherein said compressed air source is a compressor of the form having an air pressure-controlled governor, the combination comprising:

• brake control means for receiving said compressed air and for selectively applying said compressed air to said brakes and for selectively releasing said compressed air from said brakes,
• first and second compressed air reservoirs each having an air outlet port communicated with said brake control means,
• first air supply passage means for transmitting compressed air from said source to said first reservoir,
• second air supply passage means for transmitting compressed air from said source to said second reservoir, and
• air delivery control means, connected between said compressed air source and said first and second air supply passage means, for closing the flow path from said source to either of said air supply passage means in response to air leakage therein,
• a branched flow signal conduit connected between said governor and each of said reservoirs, and
• a pair of check valves each being disposed in a separate branch of said conduit and having means for blocking air flow from said reservoirs to said governor except when the pressure in at least one of said reservoirs exceeds a predetermined value.

In an air brake system for a vehicle which has air-controlled brakes and a compressed air source, the combination comprising:

• brake control means for receiving said compressed air and for selectively applying said compressed air to said brakes and for selectively releasing said compressed air from said brakes,
• first and second compressed air reservoirs each having an air outlet port communicated with said brake control means,
• first air supply passage means for transmitting compressed air from said source to said first reservoir,
• second air supply passage means for transmitting compressed air from said source to said second reservoir, and
• air delivery control means, connected between said compressed air source and said first and second air supply passage means, for closing the flow path from said source to either of said air supply passage means in response to air leakage therein, wherein said air delivery control means comprises a pair of air fuses each being disposed in a separate one of the flow paths between said source and said brake control means, each of said air fuses having means for closing said flow path when air flow therethrough reaches a predetermined velocity.

In an air brake system for a vehicle which has air-controlled brakes and a compressed air source, the combination comprising:

• brake control means for receiving said compressed air and for selectively applying said compressed air to said brakes and for selectively releasing said compressed air from said brakes, wherein said brake control means has at least two separate compressed air-receiving ports each communicating with a one-way flow valve,
• first and second compressed air reservoirs each having an air outlet port communicated with said brake control means,
• a pair of separate air conduits each communicating said outlet port of a separate one of said reservoirs with a separate one of said air-receiving ports,
• first air supply passage means for transmitting compressed air from said source to said first reservoir,
• second air supply passage means for transmitting compressed air from said source to said second reservoir, and
• air delivery control means, connected between said compressed air source and said first and second air supply passage means, for closing the flow path from said source to either of said air supply passage means in response to air leakage therein.