# US 8,540,222 B2 · Air spring for a heavy-duty vehicle with damping features

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- Number: US 8,540,222 B2
- Document ID: US8540222B2
- Status: Granted
- Kind: B2
- Application number: 13/228,908
- Filed: 2011-09-09
- Published: 2012-03-15
- Granted: 2013-09-24
- Earliest claimed: 2010-09-10
- Assignees: Hendrickson USA, L.L.C.
- Applicants: Andrew J. Westnedge; Michael J. Keeler
- Inventors: Andrew J. Westnedge; Michael J. Keeler
- Web page: https://patentgrep.com/patent/US8540222B2

## CPC

- F16F 9/05: the flexible wall being of the rolling diaphragm type
- B60G 11/27: wherein the fluid is a gas
- B60G 13/10: pneumatic
- B60G 2202/152: Pneumatic spring
- B60G 2206/424: Plunger or top retainer construction for bellows or rolling lobe type air springs
- F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- B60G: VEHICLE SUSPENSION ARRANGEMENTS (air-cushion vehicles B60V; {cycle suspensions B62K25/00})

## Abstract

An air spring for a heavy-duty vehicle axle/suspension system includes a bellows chamber operatively connected to a piston chamber. An opening is disposed between the bellows chamber and the piston chamber in order to allow fluid to communicate between the bellows chamber and the piston chamber. The cross-sectional area of the opening and the volumes of the bellows chamber and the piston chamber are tuned in order to optimize the damping characteristics of the air spring.

## Claims

### Claim 1

An air spring comprising:
a bellows chamber operatively connected to a piston chamber, at least one opening disposed between said bellows chamber and said piston chamber for fluid communication between the bellows chamber and the piston chamber, whereby a ratio of a cross-sectional area of said at least one opening in inches squared to a volume of said piston chamber in inches cubed to a volume of said bellows chamber in inches cubed, is from about 1:600:1200 to about 1:14100:23500, wherein said at least one opening includes a cross-sectional area of from about 0.039 in2 to about 0.13 in2.

### Claim 2 (depends on 1)

The air spring of claim 1, wherein said at least one opening includes a generally circular shape.

### Claim 3 (depends on 1)

The air spring of claim 1, wherein said at least one opening includes a cross-sectional area of about 0.06 in2.

### Claim 4 (depends on 1)

The air spring of claim 1, wherein said piston chamber has a volume of from about 150 in3 to about 550 in3.

### Claim 5 (depends on 1)

The air spring of claim 1, wherein said piston chamber has a volume of about 240 in3.

### Claim 6 (depends on 1)

The air spring of claim 1, wherein said bellows chamber has a volume of from about 305 in3 to about 915 in3.

### Claim 7 (depends on 1)

The air spring of claim 1, wherein said bellows chamber has a volume of about 485 in3.

### Claim 8 (depends on 1)

The air spring of claim 1, wherein said piston chamber further comprises a piston top plate, said at least one opening being formed in said piston top plate.

### Claim 9 (depends on 1)

The air spring of claim 1, further comprising a flapper operatively connected to said at least one opening.

### Claim 10 (depends on 9)

The air spring of claim 9, wherein said flapper is formed with a flapper orifice.

### Claim 11 (depends on 10)

The air spring of claim 10, wherein said flapper orifice includes a cross-sectional area of from about 0.039 in2 to about 0.13 in2.

### Claim 12 (depends on 10)

The air spring of claim 10, wherein said flapper orifice includes a cross-sectional area of about 0.06 in2.

### Claim 13 (depends on 1)

The air spring of claim 1, wherein said air spring is mounted on a heavy-duty axle/suspension system.

### Claim 14 (depends on 9)

The air spring of claim 9, wherein said flapper is formed from metal.

### Claim 15 (depends on 10)

The air spring of claim 10, wherein said flapper orifice includes a generally circular shape.