Pilot operated regulator with adjustable minimum delivery pressure

1. A regulator for establishing outlet fluid pressure, the regulator comprising:

a valve body having a fluid pressure inlet in selective fluid communication with a fluid pressure outlet;

a pilot pressure inlet formed in the valve body and in fluid communication with a source of pilot pressure;

valving structure within the valve body for establishing outlet fluid pressure as a function of pilot pressure;

first adjustable structure within the valve body to establish a minimum outlet fluid pressure threshold without regard to pilot pressure; and

second adjustable structure within said valve body, said second adjustable structure including a piston, a first diaphragm separated by a resilient structure to define a pilot chamber in fluid communication with said source of pilot pressure, and a second diaphragm spaced from and connected with said first diaphragm to locate said second diaphragm to affect the condition of the valving structure,

wherein a force applied by said resilient structure establishes outlet fluid pressure offset relative to pilot pressure.

2. The regulator of claim 1 wherein the first adjustable structure is coaxially arranged with the adjustable second adjustable structure.

3. The regulator of claim 1 wherein the second adjustable structure is coaxially arranged with a direction of movement of the valving structure.

4. The regulator of claim 1 further including a resilient mechanism acting on the piston to position the first diaphragm for establishing the minimum outlet fluid pressure threshold without regard to pilot pressure.

5. The regulator of claim 1 wherein the first adjustable structure is coaxially arranged with a direction of movement of the valving structure.

6. The regulator of claim 1 used in a load-based tire inflation system for a heavy-duty vehicle, the heavy-duty vehicle having an air spring suspension system in which fluid pressure in the air spring suspension system varies with a weight of the heavy-duty vehicle and wherein the source of pilot pressure is fluid pressure from the air spring suspension system.

7. The regulator of claim 1 wherein the valving structure comprises a poppet valve arrangement.

8. A load-based tire inflation system comprising:

an air spring generating a pilot pressure as a function of a weight of a heavy-duty vehicle;

a regulator having a fluid pressure inlet in selective fluid communication with a fluid pressure outlet;

a pilot pressure inlet formed in the regulator and in fluid communication with the air spring to communicate the pilot pressure to the regulator;

valving structure within the regulator for establishing outlet fluid pressure as a function of the pilot pressure; and

first adjustable structure within the regulator to establish a minimum outlet fluid pressure threshold without regard to pilot pressure.

9. The regulator of claim 8 further including second adjustable structure within the regulator to establish outlet fluid pressure offset relative to pilot pressure.

10. The regulator of claim 9 wherein the first adjustable structure is coaxially arranged with the adjustable second adjustable structure.

11. The regulator of claim 9 wherein the second adjustable structure is coaxially arranged with a direction of movement of the valving structure.

12. The regulator of claim 9 wherein the second adjustable structure further includes a piston and a first diaphragm separated by resilient structure to define a pilot chamber in fluid communication with the source of pilot pressure, the force applied by the resilient structure establishes outlet fluid pressure offset relative to pilot pressure.

13. The regulator of claim 12 further including a resilient mechanism acting on the piston to position the first diaphragm for establishing the minimum outlet fluid pressure threshold without regard to pilot pressure.

14. The regulator of claim 12 further including a second diaphragm spaced from and connected with the first diaphragm to locate the second diaphragm to affect the condition of the valving structure.

15. The regulator of claim 8 wherein the first adjustable structure is coaxially arranged with a direction of movement of the valving structure.

16. The regulator of claim 8 wherein the valving structure comprises a poppet valve arrangement.

17. A load-based tire inflation system comprising:

a source of fluid pressure;

a tire and wheel assembly operatively mounted to a heavy-duty vehicle and being in selective fluid communication with the source of fluid pressure;

an air spring suspension system having a fluid pressure that is a function of a weight of the heavy-duty vehicle;

a regulator in fluid communication with and located between the source of fluid pressure and the tire and wheel assembly, the regulator also being in fluid communication with the air spring suspension system, the regulator continuously controlling fluid pressure in the tire and wheel assembly; and

adjustable structure within the regulator to establish a minimum fluid pressure delivered to the tire and wheel assembly, the regulator maintaining fluid pressure in the tire and wheel assembly at or above the minimum pressure threshold without regard to the fluid pressure in the air spring suspension system.

18. The load-based tire inflation system of claim 17 further including adjustable offset control within the regulator to vary fluid pressure delivered to the tire and wheel assembly by an amount relative to fluid pressure in the air spring suspension system.

19. A regulator for establishing outlet fluid pressure, the regulator comprising:

a valve body having a fluid pressure inlet in selective fluid communication with a fluid pressure outlet;

a pilot pressure inlet formed in the valve body and in fluid communication with a source of pilot pressure;

valving structure within the valve body for establishing outlet fluid pressure as a function of pilot pressure; and

first adjustable structure within the valve body to establish a minimum outlet fluid pressure threshold without regard to pilot pressure,

wherein said regulator is used in a load-based tire inflation system for a heavy-duty vehicle, the heavy-duty vehicle having an air spring suspension system in which fluid pressure in the air spring suspension system varies with a weight of the heavy-duty vehicle and wherein the source of pilot pressure is fluid pressure from the air spring suspension system.