Air brake system with line pressure loss protection

Claim 2

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 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 while continuing to provide an open flow path from said source to the other of said air supply passage means in order to enable indefinitely continued operation of said air brake system.

Claim 3

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.

Claim 4

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.

Claim 5

The combination defined in claim 2 further comprising a first air fuse connected between said first outlet of said shuttle valve and said first air supply passage means and a second air fuse connected between said second outlet of said shuttle valve and said second air supply passage means.

Claim 6

The combination defined in claim 3 wherein said shuttle valve and said air fuses are disposed at the outlet of said compressed air source of said vehicle.

Claim 7

The combination defined in claim 2 wherein said shuttle valve comprises a body having a bore therein which is closed at each end, said inlet of said shuttle valve being communicated with a central portion of said bore, said first outlet being communicated with a region of said bore between said central portion and one end thereof and said second outlet being communicated with a region of said bore between said central portion thereof and the other end thereof, a valve spool disposed for axial movement within said bore and having a pair of spaced-apart grooves one of which communicates with inlet with said first outlet and the other of which communicates said inlet with said second outlet when said spool is at a centered position in said bore, spring means biasing said valve spool toward said centered position in said bore, and wherein said pilot means comprises means communicating said first air supply passage means with said one end of said valve body bore and communicating said second air supply passage means with said other end of said valve bore.

Claim 8

The combination defined in claim 2 wherein said compressed air source is an air compressor having a compressed air outlet flow path and wherein said shuttle valve is secured adjacent said compressor with said inlet of said shuttle valve being communicated directly with said compressor outlet flow path.

Claim 9

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.

Claim 10

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.

Claim 11

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.

Claim 12

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.

Claim 13

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.

Claim 14

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.

Claim 15

The combination defined in claim 9 wherein said vehicle has first and second separate brakes and wherein said brake control means has a pair of separately actuatable brake control valves each capable of energizing both of said brakes.