Combined air system for starter and brakes

Claim 2

A combined air system for a vehicle having air operated brakes and an air operated engine starter; comprising: a brake reservoir means; means for selectively connecting said brake reservoir with said brakes to effect application and release of the brakes; a separate starter reservoir means; conduit means extending between said starter reservoir and said engine starter; an engine-driven compressor for supplying air under pressure to both of said reservoir means; and limiting valve means interposed between said compressor and the brake reservoir means for limiting the maximum pressure therein to a pressure lower than the maximum pressure permitted in the starter reservoir means.

Claim 3

A combined air system according to claim 1, and further comprising check valve means for isolating said brake and starter reservoirs from each other.

Claim 4

A combined air system according to claim 1, and further comprising: relay valve means interposed in said conduit means and normally preventing communication between said starter reservoir and said engine starter; and starter valve means for selectively directing air pressure from said brake reservoir to said relay valve means for opening the latter means permitting air from the starter reservoir to actuate said starter.

Claim 5

A combined air system according to claim 3, wherein said relay valve means opens only at pressures above a predetermined pressure in said brake reservoir.

Claim 6

A combined air system according to claim 3, and further comprising: protection valve means normally permitting communication between said brake reservoir and said relay valve and movable to a position blocking such communication in response to development of oil pressure above a predetermined level within the engine.

Claim 7

A combined air system for a vehicle having an engine, an air operated starter for the engine, and air operated brakes; comprising: a compressor driven by the engine; a wet tank capable of accepting air under pressure produced by the compressor; separate brake and starter reservoirs communicatively connected to said wet tank; means for selectively connecting said brake reservoir with said brakes to effect application and release of the brakes; conduit means extending between said starter reservoir and said engine starter; check valve means interposed between said starter reservoir and said wet tank for permitting flow of air only from said tank to said starter reservoir; check and limiting valve means interposed between said brake reservoir and said tank for permitting flow of air only from said tank to said brake reservoir and for limiting the maximum pressure in said brake reservoir to a pressure lower than the maximum pressure in said starter reservoir.

Claim 8

A combined air system for a vehicle having an engine, an air operated starter for the engine, and air operated brakes; comprising: a compressor driven by the engine; a wet tank capable of accepting air under pressure produced by the compressor; separate brake and starter reservoirs communicatively connected to said wet tank; means for selectively connecting said brake reservoir with said brakes to effect application and release of the brakes; conduit means extending between said starter reservoir and said engine starter; check valve means interposed between said starter reservoir and said wet tank for permitting flow of air only from said tank to said starter reservoir; check and limiting valve means interposed between said brake reservoir and said tank for permitting flow of air only from said tank to said brake reservoir and for limiting the maximum pressure in said brake reservoir to a pressure lower than the maximum pressure in said starter reservoir.

Claim 9

A combined air system according to claim 6, and further comprising: relay valve means having an air actuator normally blocking communication between the starter reservoir and the starter; starter valve means normally blocking communication between the brake reservoir and said air actuator and manually shiftable to direct air pressure from the brake reservoir to said air actuator to open said relay valve means; whereby air pressure from the starter reservoir is directed to the starter.

Claim 10

A combined air system according to claim 7 and further comprising: a starter protection valve having a hydraulic actuator normally permitting communication between said brake reservoir and said air actuator; means communicating engine oil pressure to said hydraulic actuator; and said hydraulic actuator being responsive to development of a predetermined oil pressure by said engine to shift said starter protection valve to block communication between said brake reservoir and said air actuator; whereby the starter is prevented from being actuated whenever the engine is running.

Claim 11

A combined air system according to claim 7, wherein; said air actuator is effective to shift said relay valve means to its open position only when the air pressure received by the air actuator is above a predetermined level; whereby the engine can be started only when the brake reservoir has sufficient air pressure for subsequent safe operation of the vehicle.

Claim 12

A combined air system according to claim 9, wherein said brake reservoir comprises separate and isolated front and rear brake reservoir means; and further comprising: a low pressure selector valve means for providing fluid communication between one of said front and rear brake reservoir means and said starter valve means; and comparator and shifter means connected to said selector valve means and capable of comparing the pressures in said front and rear brake reservoir means and shifting said selector valve means to communicate the lower pressure in said reservoir means to said starter valve means.