# US 8,540,221 B2 · Air spring

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- Number: US 8,540,221 B2
- Document ID: US8540221B2
- Status: Granted
- Kind: B2
- Application number: 13/063,848
- Filed: 2009-08-27
- Published: 2011-07-14
- Granted: 2013-09-24
- Earliest claimed: 2008-09-16
- Assignees: Bridgestone Corporation
- Applicants: Isao Watanabe
- Inventors: Isao Watanabe
- Web page: https://patentgrep.com/patent/US8540221B2

## CPC

- F16F 9/38: Covers for protection or appearance
- F16F 9/0454: {characterised by the assembling method or by the mounting arrangement, e.g. mounting of the membrane (F16F9/0409, F16F9/0445 take precedence)}
- F16F 9/05: the flexible wall being of the rolling diaphragm type
- F16J 3/02: Diaphragms
- F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS

## Abstract

The opposite side of a connecting intermediate section 32A of a diaphragm 32 to that of a first end section 32B extends from the connecting intermediate section 32A as a second end section 32C side that folds back towards the tube outside in an inside out reversed state. The diameter of the second end portion 32C is set larger than the diameter of the connecting intermediate section 32A. The second end portion 32C is fitted over an end on a chamber member 22 side of an outer tube member 60 and fixed with press contact against the outer tube member 60 by a band 72.

## Claims

### Claim 1

An air spring for disposing between a first moving body and a second moving body that move relative to each other, the air spring comprising:
a chamber member attached at the first moving body side;
a piston member attached at the second moving body side;
an outer tube member of cylindrical shape of larger diameter than that of the piston member; and
a diaphragm of cylindrical shape of larger diameter than that of the piston member, inserted inside the tube of the outer tube member, connected to the chamber member and the piston member such that a chamber enclosure is configured inside and with the external periphery of the diaphragm attached to an intermediate section of an inner wall at the chamber member side of the outer tube member, wherein,
a connecting intermediate section of the diaphragm on the chamber member side is connected to the chamber member, and a first end section disposed on the piston member side of the diaphragm is connected to the piston member,
the first end section side of the diaphragm is folded back towards the tube inside in an inside out reversed state,
a second end section side of the diaphragm extends from the connecting intermediate section and is folded back towards the tube outside in an inside out reversed state, and
the second end section of the diaphragm is connected to the outer periphery of the outer tube member.

### Claim 2 (depends on 1)

The air spring of claim 1, wherein the second end section of the diaphragm is set with a larger diameter than the connecting intermediate section.

### Claim 3 (depends on 2)

The air spring of claim 2, wherein reinforcement material is incorporated in the diaphragm spanning from the connecting intermediate section to the first end section.

### Claim 4 (depends on 1)

The air spring of claim 1, wherein reinforcement material is incorporated in the diaphragm spanning from the connecting intermediate section to the first end section.