# US 4,674,134 A · Earmuff having sealing ring including liquid and foam plastic layers

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- Number: US 4,674,134 A
- Document ID: US4674134A
- Status: Granted
- Kind: A
- Application number: 06/843,511
- Filed: 1986-03-25
- Granted: 1987-06-23
- Earliest claimed: 1985-03-25
- Assignees: Bilsom AB
- Inventors: Tord R. Lundin
- Web page: https://patentgrep.com/patent/US4674134A

## CPC

- A61F 11/14: external, e.g. earcaps or earmuffs
- A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C)

## Abstract

An earmuff (10) has a sealing ring (20) with an outer liquid layer (38) and a foamed plastics layer (36) thereinunder. The liquid layer is arranged as a separate, annular, sheath-equipped liquid ring (38) the sheath (40) of which can move freely relative the sheath (30,32) of the sealing ring (20).

## Claims

### Claim 1

Earmuff apparatus particularly suited for a hearing protector, comprising two earmuffs mounted on a headband, said earmuff being adapted to be placed over an ear to engage against the head around the ear and including a pliable sealing ring provided with a first sheath, the sealing ring including within the first sheath a liquid layer and an annular foamed plastic layer, said liquid layer atop said foamed plastic layer so that upon applying the earmuff to the head of the user the liquid layer is nearer to the head than said foamed plastic layer said liquid layer enclosed in a second annular sheath separate of said first sheath, whereby said liquid layer is substantially freely movable relative to said first sheath.

### Claim 2 (depends on 1)

The earmuff apparatus as claimed in claim 1, wherein the foamed plastic layer lies freely inside the first sheath of the sealing ring, whereby said liquid layer and said foamed plastic layer may yield independently.

### Claim 3 (depends on 1)

The earmuff apparatus as claimed in claim 1, wherein the first sheath of the sealing ring is perforated so that air can flow into and out of the sealing ring.

### Claim 4 (depends on 1)

The earmuff apparatus as claimed in claim 1, wherein the liquid layer and the foamed plastic layer have generally planar radial surfaces.

### Claim 5 (depends on 4)

The earmuff apparatus as claimed in claim 4, wherein the liquid and foamed plastic layers each have a generally rectangular cross section.

### Claim 6 (depends on 4)

The earmuff as claimed in claim 4, wherein the liquid and foamed plastic layers are coextensive with each other along a radial plane.

### Claim 7

Sealing ring suitable for use in an earmuff of an ear protector, said sealing ring including a first sheath and a yieldable material arranged in the first sheath, said yieldable material including a liquid layer and a foamed plastic layer, said liquid layer located atop said foamed plastics layer so that upon applying the earmuff to the head of a user, said liquid layer is nearer to the head than the foamed plastic layer;
the liquid layer being enclosed in a second annular sheath which is separate of the first sheath so as to be unfixed relative to the first sheath, the foamed plastic layer separate of the first sheath of the sealing ring.

### Claim 8 (depends on 2)

The earmuff apparatus as claimed in claim 2, wherein the first sheath of the sealing ring is perforated so that air can flow into and out of the sealing ring.

### Claim 9 (depends on 2)

The earmuff apparatus as claimed in claim 2, wherein the liquid layer and the foamed plastic layer have generally planar radial surfaces.

### Claim 10 (depends on 3)

The earmuff apparatus as claimed in claim 3, wherein the liquid layer and the foamed plastic layer have generally planar radial surfaces.

### Claim 11 (depends on 5)

The earmuff apparatus as claimed in claim 5, wherein the liquid and foamed plastic layers are coextensive with each other on a radial plane.