# US 11,304,851 B2 · Push-to-fit earplug with tip cavity

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- Number: US 11,304,851 B2
- Document ID: US11304851B2
- Status: Granted
- Kind: B2
- Application number: 16/643,080
- Filed: 2018-08-30
- Published: 2020-06-25
- Granted: 2022-04-19
- Earliest claimed: 2017-09-01
- Assignees: 3M Innovative Properties Company
- Applicants: 3M Innovative Properties Company
- Inventors: Robert C. Coffin; Matthew V. Stonebraker, Jr.; Jacob H. Ely; Jeff L. Hamer; Kenneth F. Teeters; Ravi Thomas
- Web page: https://patentgrep.com/patent/US11304851B2

## CPC

- A61F 11/08: internal, e.g. earplugs
- A61F 11/085: {including an inner channel}
- A61F 2210/0071: thermoplastic
- A61F 2240/001: Designing or manufacturing processes
- 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 earplug comprises a core and a sound-attenuating body attached to the core, the sound-attenuating body comprising a tip cavity extending proximally from the tip of the sound-attenuating body and comprising a distal opening. The tip cavity side wall includes a plurality of protrusions extending inwardly toward the longitudinal axis of the core. The plurality of protrusions may include from 2 to 12 protrusions. A method of making an earplug includes covering at least a portion of a core with a material including unactivated foaming agent; inserting an end of the core and at least a portion of the material into a mold cavity; and activating the foaming agent to create a sound-attenuating body. The sound-attenuating body has a base, tip, and tip cavity with a plurality of protrusions. The mold cavity may include a boss with a cup and plurality of cut-outs on the cup for forming the protrusions.

## Claims

### Claim 1

An earplug comprising:
a core comprising a proximal end, a distal end, and a major outer surface and a longitudinal axis extending from the proximal end to the distal end;
a sound-attenuating body attached to the major outer surface of the core, the sound-attenuating body comprising a base and a tip, the distal end of the core disposed within the sound-attenuating body and the tip extending distally beyond the distal end of the core; and
a tip cavity of the sound-attenuating body extending proximally from the tip and comprising a distal opening, the tip cavity having a volume defined by a side wall formed by the sound-attenuating body and a bottom at least partially formed by the distal end of the core, the tip cavity side wall comprising a plurality of protrusions extending inwardly toward the longitudinal axis.

### Claim 2 (depends on 1)

The earplug of claim 1, wherein the plurality of protrusions comprises from 2 to 12 protrusions.

### Claim 3 (depends on 1)

The earplug of claim 1, wherein the sound-attenuating body is thermally bonded to at least a portion of the outer major surface of the core; and wherein the earplug is free of adhesives.

### Claim 4 (depends on 1)

The earplug of claim 1, wherein each of the plurality of protrusions has a proximal end that contacts the distal end of the core.

### Claim 5 (depends on 1)

The earplug of claim 1, wherein each of the plurality of protrusions is thermally bonded to the distal end of the core; or
wherein the plurality of protrusions is integrally formed with the sound-attenuating body.

### Claim 6 (depends on 1)

The earplug of claim 1, wherein the plurality of protrusions has a total volume ranging from about 5 to about 60% of a volume of the tip cavity measured without the plurality of protrusions.

### Claim 7 (depends on 1)

The earplug of claim 1, wherein each of the plurality of protrusions extends distally from the bottom of the tip cavity.

### Claim 8 (depends on 1)

The earplug of claim 1, wherein the plurality of protrusions defines pillars, each pillar individually extending in a plane with the longitudinal axis.

### Claim 9 (depends on 1)

The earplug of claim 1, wherein at a plane perpendicular to the longitudinal axis, the tip cavity has a minor radius at an apex of a protrusion and a major radius between adjacent protrusions, wherein the minor radius is from about 15 to about 85% of the major radius.

### Claim 10 (depends on 1)

The earplug of claim 1, wherein the tip cavity has a first major cross dimension at a plane at the distal end of the core and a second major cross dimension at a plane adjacent the distal opening, and wherein the first major cross dimension is greater than the second major cross dimension.

### Claim 11 (depends on 1)

The earplug of claim 1, wherein the distal end of the core comprises a non-planar distal surface.

### Claim 12 (depends on 1)

The earplug of claim 1, wherein the core is constructed of a first material and the sound-attenuating body is constructed of a second material, wherein the first material is different from the second material.

### Claim 13 (depends on 12)

The earplug of claim 12, wherein the first material comprises a thermoplastic; or wherein the second material comprises a thermoplastic, a partial thermoset, a thermoset polymer, or a combination thereof.

### Claim 14 (depends on 1)

The earplug of claim 1, wherein a portion of the distal end of the core is exposed at the bottom of the tip cavity.

### Claim 15 (depends on 1)

The earplug of claim 1, wherein each of the plurality of protrusions has a length extending to the distal opening of the tip cavity.

### Claim 16 (depends on 1)

The earplug of claim 1, wherein the plurality of protrusions is visible through the distal opening of the tip cavity.

### Claim 17

A method of making an earplug, the method comprising:
covering at least a portion of a major outer surface of a core that comprises a first material with a second material that comprises an unactivated foaming agent, the core comprising a proximal end, a distal end, and wherein the major outer surface and a longitudinal axis extending from the proximal end to the distal end;
inserting the distal end of the core and at least a portion of the second material into a mold cavity; and
activating the unactivated foaming agent in the mold cavity to form a sound-attenuating body in the mold cavity that is attached to the major outer surface of the core, the sound-attenuating body comprising:
a base and a tip, the distal end of the core disposed within the sound-attenuating body and the tip extending distally beyond the distal end of the core; and
a tip cavity of the sound-attenuating body extending proximally from the tip and comprising a distal opening, the tip cavity having a volume defined by a side wall formed by the sound-attenuating body and a bottom at least partially formed by the distal end of the core,
the tip cavity side wall comprising a plurality of protrusions extending inwardly toward the longitudinal axis.

### Claim 18 (depends on 17)

The method of claim 17, wherein a boss extends into the mold cavity, wherein the boss is positioned to contact a first end of the core when the first end of the core is inserted into the mold cavity.

### Claim 19 (depends on 17)

The method of claim 17, wherein the method further comprises deforming the first end of the core in the mold cavity.