Sealing wiring holes in electronic devices

1. An apparatus comprising:

an enclosure having a wall separating a first volume from a second volume;

the wall defining a hole having a diameter and allowing passage between the first volume and the second volume;

a wire passing through the hole; and

a gasket surrounding the wire at the hole,

the gasket comprising:

a first section including a groove between a first flange and a second flange, the groove having an outer diameter matched to the diameter of the hole and the flanges having outer diameters greater than the diameter of the hole,

a second section adjacent the first flange and including a tubular portion having a diameter less than the diameter of the hole, and a tapered section smoothly transitioning from the diameter of the tubular portion to the diameter of the first flange, and

a bore passing through the first and second sections and having an inner diameter matched to the diameter of the wire;

the gasket preventing flow of fluid through the hole between the first volume and the second volume; wherein

the diameter of the bore and the coefficient of friction solely between the gasket and the wire are such that before being positioned in the hole, the force required to pull the wire through the gasket is more than the force required to pull the tapered section and the first flange of the gasket through the hole, and

the diameter of the bore, the outer diameter of the groove, and the coefficient of friction solely between the gasket and the wire are such that when positioned in the hole, the force required to pull the wire through the gasket is less than the force required to pull the second flange of the gasket through the hole.

2. The apparatus of claim 1 wherein the gasket prevents the flow of air through the hole.

3. The apparatus of claim 1 wherein the gasket prevents the flow of water through the hole.

4. The apparatus of claim 1 wherein the gasket has a hardness of 50 Shore A.

5. The apparatus of claim 1 wherein the outer diameter of the groove is greater than the diameter of the hole.

6. The apparatus of claim 1 wherein the enclosure comprises the body of a headphone,

first volume is a back cavity of the headphone containing the back side of an acoustic driver, and

the outer diameter of the groove and the coefficient of friction between the gasket and the side wall of the hole are such that when the gasket is positioned in the hole, the force required to push the second flange of the gasket through the hole is greater than the acoustic pressures produced inside the first volume by operation of the acoustic driver.

7. The apparatus of claim 1 wherein the enclosure comprises the body of an active noise reducing headphone having an acoustic driver, and

the first volume comprises a back cavity containing a first side of the acoustic driver, and

the second volume is open to free space around the headphones.

8. The apparatus of claim 1 wherein the enclosure comprises the body of an active noise reducing headphone having an acoustic driver, and

the first volume comprises a back cavity containing a first side of the acoustic driver, and the second volume comprises a front cavity coupling a second side of the acoustic driver to the ear of a user when the headphones are worn.

9. The apparatus of claim 1 wherein the enclosure comprises the body of an active noise reducing headphone having an acoustic driver, and

the first volume comprises a front cavity coupling a first side of the acoustic driver to the ear of a user when the headphones are worn, and

the second volume is open to free space around the headphones.

10. The apparatus of claim 1 , wherein the enclosure comprises a water-tight case for a mobile electronic device,

the first volume comprises the interior of the case, and

the second volume comprises free space around the case.