Casting method for encapsulating an electrical component

Patent metadata

Field	Value
Publication number	US-11673298-B2
Application number	US-202217704239-A
Country	US
Kind code	B2
Filing date	Mar 25, 2022
Priority date	Dec 20, 2019
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

A mold for encapsulating an electrical component. The mold includes an encapsulation chamber and an air inlet. The encapsulation chamber is defined by a housing, an open top, and a solid bottom. The housing includes a solid outer wall, a permeable inner wall, and an air chamber between the solid outer wall and the inner wall. The air inlet is configured to introduce a gas into the air chamber. The encapsulation chamber is sized and shaped to receive the electrical component while leaving a gap for the introduction of encapsulant around the electrical component. The encapsulant may be silicone rubber. To remove an encapsulated electrical component, pressurized air may be introduced through the air inlet into the air chamber, passing through the permeable inner wall, separating the outer surface of the encapsulant from the housing, and allowing the combination casting to be removed from the mold.

First claim

The invention claimed is:

1. A cast molding process for encapsulating an electrical component, the cast molding process comprising:
providing a mold, the mold comprising:
an encapsulation chamber defined by:
a housing that comprises a solid outer wall, a permeable inner wall, and an air chamber between the solid outer wall and inner wall,
an open top,
a bottom, and
an air inlet configured to introduce a gas into the air chamber;

positioning an electrical component within the encapsulation chamber;
introducing an encapsulant into the mold between the electrical component and the permeable inner wall;
curing the encapsulant around at least a portion of the electrical component within the mold forming a combination casting;
introducing pressurized gas into the air chamber to pass through the permeable inner wall separating the contact surface of the encapsulant from the mold; and
ejecting the combination casting from the mold, wherein:
the bottom of the mold is openable and closable;
enclosing the bottom of the mold precedes introducing the encapsulant;
opening the bottom of the mold precedes introducing the pressurized gas into the air chamber; and
ejecting the combination casting includes pressing the combination casting from the bottom through the open top end after the bottom is opened.

2. The cast molding process of claim 1 , wherein the electrical component comprises:
a top;
a bottom;
a cylindrical wall;
a first post extending from the top and positioned within the open top end of the mold; and
a second post extending from the bottom and positioned within the bottom end of the mold.

3. The cast molding process of claim 2 , wherein introducing the encapsulant and curing the encapsulant at least partially encapsulate the electrical component in the encapsulant with the top of the electrical component remaining exposed.

4. The cast molding process of claim 2 wherein introducing the encapsulant and curing the encapsulant at least partially encapsulate the electrical component in the encapsulant with the bottom of the electrical component remaining exposed.

5. The cast molding process of claim 2 , wherein introducing the encapsulant and curing the encapsulant at least partially encapsulate the electrical component in the encapsulant with the top and bottom of the electrical component remaining exposed.

6. The cast molding process of claim 1 , wherein the electrical component is a vacuum interrupter.

7. The cast molding process of claim 1 , wherein the encapsulant comprises silicone rubber.

8. The cast molding process of claim 7 , wherein curing the encapsulant comprises forming the combination casting of the silicone rubber at a thickness of about 2 mm to about 5 mm.

9. A cast molding process for encapsulating an electrical component, the cast molding process comprising:
providing a mold, the mold comprising:
an encapsulation chamber defined by:
a housing that comprises a solid outer wall, a permeable inner wall, and an air chamber between the solid outer wall and inner wall,
an open top,
a bottom, and
an air inlet configured to introduce a gas into the air chamber;

positioning an electrical component within the encapsulation chamber;
introducing an encapsulant into the mold between the electrical component and the permeable inner wall;
curing the encapsulant around at least a portion of the electrical component within the mold forming a combination casting;
introducing pressurized gas into the air chamber to pass through the permeable inner wall separating the contact surface of the encapsulant from the mold; and

ejecting the combination casting from the mold, wherein:
the air chamber comprises a plurality of plenum chambers positioned between the solid outer wall and the permeable inner wall;
the air inlet comprises a plurality of apertures, each of which leads to one of the plenum chambers; and
introducing the pressurized gas into the air chamber comprises substantially equalizing pressure in the air chamber by introducing pressurized gas into each of the plenum chambers.

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Campbell Louis G
• Balasubramanian Ganesh Kumar

Classifications

• B29C39/26

  Moulds or cores · CPC title

• B29C39/10

  incorporating preformed parts or layers, e.g. casting around inserts or for coating articles {(coating a surface by casting in general B05D1/30, B29C39/126 takes precedence)} · CPC title

• B29K2995/0065

  Permeability to gases · CPC title

• B29C39/36 Primary

  Removing moulded articles · CPC title

• B29L2031/34

  Electrical apparatus, e.g. sparking plugs or parts thereof · CPC title