# US 9,517,674 B2 · Pneumatic control system for a heavy-duty vehicle

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- Number: US 9,517,674 B2
- Document ID: US9517674B2
- Status: Granted
- Kind: B2
- Application number: 14/746,903
- Filed: 2015-06-23
- Published: 2015-12-24
- Granted: 2016-12-13
- Earliest claimed: 2014-06-24
- Assignees: Hendrickson USA, L.L.C.
- Applicants: Hendrickson USA, LLC
- Inventors: Bun-Hiong Chua; Anthony Joseph Bills
- Web page: https://patentgrep.com/patent/US9517674B2

## CPC

- B60G 17/0525: {Height adjusting or levelling valves}
- B60G 11/27: wherein the fluid is a gas
- B60G 17/033: characterised by regulating means acting on more than one spring
- B60G 17/0521: {the spring having a flexible wall}
- B60G 2202/152: Pneumatic spring
- B60G 2300/02: Trucks; Load vehicles
- B60G 2300/04: Trailers
- B60G 2300/042: Semi-trailers
- B60G 2500/202: Height or leveling valve for air-springs
- B60G 2500/2021: Arrangement of valves
- B60G 2500/30: Height or ground clearance
- B60G: VEHICLE SUSPENSION ARRANGEMENTS (air-cushion vehicles B60V; {cycle suspensions B62K25/00})

## Abstract

A pneumatic control system for a heavy-duty vehicle includes an air supply in fluid communication with a height control valve and an air spring. An air lock valve is in fluid communication with the height control valve and the air spring, and is also in fluid communication with a blank cavity. The air lock valve includes an “air lock off” position and an “air lock on” position. When the air lock valve is in the “air lock off” position, fluid flows from the height control valve, through the air lock valve to the air spring. When the air lock valve is in the “air lock on” position, fluid communication between the air spring, the air lock valve and the height control valve is prevented and, instead, fluid flows from the air spring, through the air lock valve to the blank cavity.

## Claims

### Claim 1

A pneumatic control system for a heavy-duty vehicle comprising:
a) an air supply;
b) a height control valve in fluid communication with said air supply and at least one air spring;
c) an air lock valve in fluid communication with said height control valve and said at least one air spring, said air lock valve being in fluid communication with a blank cavity, the air lock valve having an “air lock off” position and an “air lock on” position;
d) whereby, when said air lock valve is in said “air lock off” position, fluid flow is established between the height control valve, the air lock valve and the at least one air spring, and when the air lock valve is in said “air lock on” position, fluid flow is established between said at least one air spring, said air lock valve and said blank cavity, and fluid flow is prevented between said height control valve, the air lock valve and the at least one air spring.

### Claim 2 (depends on 1)

The pneumatic control system for a heavy-duty vehicle of claim 1, wherein said air supply comprises an air tank.

### Claim 3 (depends on 1)

The pneumatic control system for a heavy-duty vehicle of claim 1, wherein said height control valve is a three-way valve including a control arm, wherein the position of the arm controls the operation of the height control valve.

### Claim 4 (depends on 1)

The pneumatic control system for a heavy-duty vehicle of claim 1, wherein said air lock valve is a three way two position valve.

### Claim 5 (depends on 4)

The pneumatic control system for a heavy-duty vehicle of claim 4, wherein said air lock valve further comprises a first air passage and an alternate air passage, whereby when said air lock valve is in said “air lock off” position fluid flows between the height control valve and the air spring via said first air passage, and when said air lock valve is in said “air lock on” position fluid flows between the air spring and the blank cavity via the alternate air passage.

### Claim 6 (depends on 1)

The pneumatic control system for a heavy-duty vehicle of claim 1, further comprising a means for actuating said air lock valve.

### Claim 7 (depends on 6)

The pneumatic control system for a heavy-duty vehicle of claim 6, said means for actuating said air lock valve being a manual switch.

### Claim 8 (depends on 6)

The pneumatic control system for a heavy-duty vehicle of claim 6, said means for actuating said air lock valve being an automated means that simultaneously actuates the air lock valve while actuating another process.

### Claim 9 (depends on 1)

The pneumatic control system for a heavy-duty vehicle of claim 1, wherein said height control valve is also in fluid communication with atmosphere.

### Claim 10 (depends on 1)

The pneumatic control system for a heavy-duty vehicle of claim 1, wherein said blank cavity is positioned separately from said height control valve.

### Claim 11 (depends on 1)

The pneumatic control system for a heavy-duty vehicle of claim 1, said blank cavity being integrated into said height control valve.

### Claim 12 (depends on 1)

The pneumatic control system for a heavy-duty vehicle of claim 1, wherein said air lock valve is also in fluid communication with atmosphere, and said air lock valve further comprises a “dump” position, whereby when the air lock valve is in said “dump” position, fluid flows from said at least one air spring to atmosphere.

### Claim 13 (depends on 12)

The pneumatic control system for a heavy-duty vehicle of claim 12, wherein said air lock valve is a four-way, three-position valve.

### Claim 14 (depends on 1)

The pneumatic control system for a heavy-duty vehicle of claim 1, wherein said at least one air spring comprises a pair of air springs.

### Claim 15 (depends on 6)

The pneumatic control system for a heavy-duty vehicle of claim 6, said means for actuating said air lock valve being automatic.