Attenuating foam insert and method for manufacture

• US 20050126845A1
• Filed: 12/10/2004
• Published: 06/16/2005
• Est. Priority Date: 12/10/2003
• Status: Abandoned Application

• Current Assignee: Michael A. Vaudrey, William R. Saunders, Yu Du
• Original Assignee: Michael A. Vaudrey, William R. Saunders, Yu Du
• Inventors: Du, Yu, Saunders, William R., Vaudrey, Michael A.
• Application Number:
  US11/009,744
• Publication Number:
  US 20050126845A1
• Time in Patent Office: Days
• US Class Current: 181/129
• CPC Class Codes: A61F 11/14 external, e.g. earcaps or earmuffs

Abstract

A shaped acoustic foam insert for use in improving the performance of circumaural hearing protectors is described. A foam block having a cross-section and shape is adapted to occupy the entire interior volume of an earcup of a circumaural hearing protector. The insert has no folds or open acoustic cavities. The surface of the insert that faces the ear of the user of the circumaural hearing protector comprises a curvilinear groove. The groove has no sharp angles and accommodates the average human pinna. A system and method of manufacturing the attenuating foam insert are provided.

Claims

1. A shaped acoustic foam insert for use in an earcup of a circumaural hearing protector comprising:

a cross-section and shape adapted to occupy the entire interior volume of the earcup, the insert having no folds or open acoustic cavities, and

a curvilinear groove cut in a surface facing an ear of a user of the circumaural hearing protector, wherein the curvilinear groove accommodates the average human pinna and has no sharp angles.

2. The shaped acoustic foam insert as in claim 1, wherein the shaped acoustic foam insert is formed from a solid piece of acoustic foam.

3. The shaped acoustic foam insert as in claim 1, wherein the shaped acoustic foam insert is formed from open cell foam.

4. The shaped acoustic foam insert as in claim 1, wherein the shaped acoustic foam insert is formed from closed cell foam.

5. The shaped acoustic foam insert as in claim 1, wherein the shaped acoustic foam insert is shaped to accommodate a specific earcup shape.

6. A system for manufacturing a shaped acoustic foam insert for use in an earcup of a circumaural hearing protector comprising:

a top assembly comprising a rectangular top plate circumscribed by four side plates, wherein the top plate comprises an opening that is the same size as the opening in the circumaural earcup;

a bottom fixture having an opening of sufficient size to receive a foam block, wherein the opening in the top plate and the opening in the bottom plate are adjustable relative to each other;

a bottom plate situated under the bottom fixture and adapted to retain the foam block;

means to align the top plate and the bottom fixture and to lock the alignment in place; and

means to compress the top plate and bottom fixture to expose a portion of the foam block for removal.

7. The system of claim 6 wherein the acoustic foam block is cut to a prescribed thickness through a process known as skiving.

8. The system of claim 6 wherein the acoustic foam block is cut to have rounded corners to fit the shape of the earcup.

9. A method of manufacturing a shaped acoustic foam insert for use in an earcup of a circumaural hearing protector comprising:

cutting a foam block to completely fill the earcup; and

forming in a surface of the foam block facing an ear of a user of the circumaural hearing protector a curvilinear groove that accommodates the average human pinna and has no sharp angles.

10. The shaped foam as in claim 9, wherein the foam block is formed from open cell foam.

11. The method of manufacturing a shaped acoustic foam insert as in claim 9, wherein the foam block is formed from closed cell foam.

12. The method of manufacturing a shaped acoustic foam insert as in claim 9, wherein the foam block is shaped to accommodate a specific earcup shape.

13. The method of manufacturing a shaped acoustic foam insert as in claim 9, wherein the foam block is a solid piece of acoustic foam.