Plastic vacuum component with groove for seal

In a plastic vacuum-component for use in a vacuum system, said vacuum-component comprising at least one main body-portion having a first end-portion, a second end-portion, an outer surface, an inner surface, and a hollow, interior volume bounded by said inner surface, at least said first end-portion defining an opening into said hollow, interior volume, said first end-portion being capable of vacuum-sealed connection to a mating part of a vacuum system, the improvement comprising:

• said first end-portion of said vacuum-component comprising groove means comprising an annular groove formed in, and extending about, a portion of the outer surface of said first end-portion in which may be received an elastomeric sealing for sealing the connection of said first end-portion with a mating part of a vacuum system;
• said groove means comprising a first, interior, vertical, annular wall having an upper end and a lower end;
• a second, intermediate, annular wall having a first end and a second end, said first end of said second wall being connected to, and forming an acute angle with, said lower end of said first wall;
• said groove of said groove means being located between said first and second walls;
• and a third, exterior, sloping, annular wall having an interior end and an exterior, said interior end being connected to said second end of said second wall and forming an acute angle with respect to said second end of said, intermediate wall, said third wall extending in a direction from said second wall opposite to the direction that said second wall extends from said first wall.

An elastomeric, sealing ring for use with an end of a plastic vacuum-component for coupling the end of the plastic vacuum-component to a mating part of a vacuum system, comprising:

• an interior-facing annular portion and an exterior-facing annular portion;
• said interior-facing annular portion comprising a first, interior, annular wall-surface having an upper end and a lower end;
• and a second, intermediate, annular wall-surface having a first end and a second end, said first end of said second, annular wall-surface being connected to, and forming an acute angle with, said lower end of said first, annular wall-surface;
• said exterior-facing annular portion comprising a third, exterior, sloping annular wall-surface having an interior end and an exterior end;
• and a fourth, exterior-facing, annular wall-surface having an upper end and a lower end, which is used for abutment against a portion of a mating part of a vacuum system;
• said interior end of said third wall-surface being connected to said second end of said second wall surface;
• said fourth, exterior-facing annular wall-surface of said elastomeric ring forming an acute angle with respect a vertical plane, so that, when the vacuum-component is emplaced in a vacuum system, said fourth annular wall-surface is drawn into a contact against a mating surface in stages in order to prevent virtual gas leaks;
• said upper end thereof lying in a vertical plane spaced farther away from said interior-facing annular portion of said elastomeric ring than a vertical plane in which lies said lower end thereof.