# US 4,399,832 A · Air gap assembly

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- Number: US 4,399,832 A
- Document ID: US4399832A
- Status: Granted
- Kind: A
- Application number: 06/265,470
- Filed: 1981-05-20
- Granted: 1983-08-23
- Earliest claimed: 1981-05-20
- Assignees: The Mundo Corporation
- Inventors: Robert A. Appleby
- Web page: https://patentgrep.com/patent/US4399832A

## CPC

- E03C 1/102: {using an air gap device}
- Y10T 137/3185: Air vent in liquid flow line
- Y10T 137/6977: Escutcheon type support
- E03C: DOMESTIC PLUMBING INSTALLATIONS FOR FRESH WATER OR WASTE WATER (not connected to either water-supply main or to waste pipe A47K; devices of the kind used in the ground E03B, E03F); SINKS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Air gap assembly for preventing backflow from a waste line to a dishwasher or other appliance connected to the line. The assembly comprises a vertically extending hollow body, an inlet tube extending upwardly within the body, an outlet tube connected to the body, an air vent in the body in proximity to the upper portion of the inlet tube, and a deflector cap mounted on the body above the inlet tube. Water entering the device through the inlet tube is deflected in a downward direction toward the outlet tube without leakage through the air vents, and the air vents prevent syphoning action which might otherwise produce undesired backflow from the waste line to the appliance connected to the inlet tube.

## Claims

### Claim 1

In an air gap assembly for preventing backflow from a waste line to an appliance which discharges into the waste line: a vertically extending generally cylindrical hollow body, an inlet tube for connection to the discharge outlet of the appliance extending upwardly within the body and communicating with the interior of the body through the upper portion of said tube, and outlet tube communicating with the interior of the body for connection to the waste line, a pair of diametrically opposed air vents in the body in proximity to the upper portion of the inlet tube, a deflector cap mounted on the body above the inlet tube with a depending skirt interposed between the upper portion of the tube and the air vents, said skirt extending downwardly within the body to a level below the air vents, and a pair of hooks projecting outwardly from opposite sides of the deflector cap in locking engagement with the diametrically opposed air vents for securing the deflector cap to the body.

### Claim 2 (depends on 1)

The air gap assembly of claim 1 further including a pair of nuts threadedly mounted on the body for securing the assembly to the deck portion of a sink, a seal member mounted on the body between the nuts for sealing engagement with the upper surface of the deck portion of the sink, and a friction ring mounted on the body below the seal member for engagement with the lower surface of the deck portion.

### Claim 3 (depends on 1)

The air gap assembly of claim 1 further including a nut threadedly mounted on the body for securing the assembly to a sink deck, a cover removably mounted on the upper portion of the body, and retainer means releasably securing the cover on the body.

### Claim 4 (depends on 3)

The air gap assembly of claim 3 wherein the retainer means includes a plurality of nubs projecting outwardly from the nut, and a flange projecting inwardly within the cover.

### Claim 5 (depends on 1)

The air gap assembly of claim 1 wherein the inlet tube is provided with a plurality of externally projecting ribs for engagement with a hose by which said tube is connected to the discharge of the appliance.