Long life rotary gate valve for aircraft vacuum toilet system

• US 6,325,356 B1
• Filed: 05/05/1997
• Issued: 12/04/2001
• Est. Priority Date: 05/05/1997
• Status: Expired due to Term

• Current Assignee: MAG Aerospace Industries LLC (Safran SA)
• Original Assignee: MAG Aerospace Industries Incorporated (Safran SA)
• Inventors: Rozenblatt, Mike M.
• Primary Examiner(s): Rivell, John
• Assistant Examiner(s): Schoenfeld, Meredith H.
• Application Number:
  US08/851,145
• Time in Patent Office: 1,674 Days
• Field of Search: 251/298, 251/299, 251/300, 251/301, 251/302
• US Class Current: 251/302
• CPC Class Codes: B64D 11/02 Toilet fittings of general application A47K
• CPC Class Codes: Y02T 50/40 Weight reduction

Abstract

A light weight gate valve and method for a aircraft vacuum toilet system. The valve resists jamming due to scale buildup, thereby reducing maintenance costs associated with repair or cleaning. The gate valve is intended for mounting between two portions of a sewer pipe connected between a waste receiving bowl and a waste reservoir. More particularly, the gate valve includes a housing having an internal valve chamber with an inlet opening opposing an outlet opening. A slice-of-pie shaped rotary gate is mounted within the chamber of the housing for rotation about a predetermined axis to selectively allow fluid communication between the inlet and outlet of the housing for flushing of the toilet. The gate has opposing side surfaces, each of which opposes an associated sidewall of the chamber enclosing the gate. The distance between each the side surface of the gate and its associated sidewall of the chamber is from 0.050 inch to 0.120 inch. While this separation is small enough to prevent most foreign objects from becoming wedges between the disk and the housing, this separation is sufficient to significantly reduce valve maintenance due to scale build-up on the sides of the gate. Other detailed features offer associated advantages.

Claims

1. A rotary gate valve for a vacuum toilet system in a vehicle, the valve intended for mounting between two portions of a sewer pipe connected between a waste receiving bowl and a waste reservoir, interior regions of the valve being subject to a build-up of scale-like deposits from the waste during extended use, the gate valve comprising:

a housing having two sidewalls fixedly connected to a peripheral wall, said walls cooperatively defining the sides of an cylindrical internal valve chamber having a central axis with an inlet opening opposing an outlet opening, said openings positioned between the center of said chamber and said peripheral wall, said inlet opening connected to the portion of the sewer pipe in fluid communication with the waste receiving bowl and said outlet opening connected to the portion of the sewer pipe in fluid communication with the waste reservoir, said sidewalls of said housing located in opposed, parallel relation; and

a plate-like gate configured as a segment of a circle having an opening sized to correspond to said inlet and outlet openings and a peripheral edge in sliding relation with said peripheral wall and leading and trailing edges, said gate mounted between the interior sidewalls for rotation about said central axis between open and closed positions which allow and prevent fluid communication between the inlet and outlet of said housing in aligned and obscured positions of said inlet and outlet openings relative to said opening in said gate, respectively;

two aligned O-ring seals extending peripherally around said inlet and outlet openings in sealing contact with said gate on opposite sides thereof;

wherein said leading and trailing edges are shaped to cut through the deposits on said sidewalls and wherein the rotation of said gate is limited so that said leading and trailing edges do not traverse said inlet and outlet openings to avoid damaging said seals; and

wherein said sidewalls, in a region within and surrounding said seals are sufficiently proximate to said gate to support said seals for sealing action against said gate, said sidewalls, elsewhere in said chamber, being spaced at a relatively greater distance from said gate on both sides thereof to provide a space in which deposits displaced by said leading and trailing edges can be accommodated thereby extending the period for which the valve can operate before becoming obstructed.

2. A rotary gate valve for a vacuum toilet system in a vehicle as defined in claim 1,

wherein the spacing distance in the region extending inside said seals is in the range of 0.0035 to 0.006 inches; and wherein said relatively greater distance is in the range of 0.050 to 0.120 inches.