# US 9,435,110 B2 · Back-pressure safeguard

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- Number: US 9,435,110 B2
- Document ID: US9435110B2
- Status: Granted
- Kind: B2
- Application number: 14/291,046
- Filed: 2012-11-29
- Published: 2014-10-02
- Granted: 2016-09-06
- Earliest claimed: 2011-12-01
- Assignees: Lasso Technik AG
- Applicants: Lasso Technik AG
- Inventors: Daniel Rohrer; Roger Waser
- Web page: https://patentgrep.com/patent/US9435110B2

## CPC

- E03F 7/04: Valves for preventing return flow {(in gullies, drains or the like E03F5/042)}
- F16K 15/145: {the closure elements being shaped as a solids of revolution, e.g. cylindrical or conical}
- F16K 15/147: {the closure elements having specially formed slits or being of an elongated easily collapsible form}
- Y10T 137/788: Having expansible port
- E03F: SEWERS; CESSPOOLS
- F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)}
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The backflow prevention device consists of a funnel-shaped membrane and a clamping device for mounting in a pipe. The clamping device consists of a spread member expanding the membrane to the pipe cross section and pressing it against the pipe wall, and a support member supporting the spread member against the pipe wall.

## Claims

### Claim 1

A backflow prevention device consisting of an elastomeric element to be arranged in an interior of a pipe and a clamping device for securing the elastomeric element in the pipe,
the elastomeric element having a shape of a conical bag with an open end to be arranged in the pipe toward the backflow, and a closed end,
the clamping device comprising
a support portion arranged radially outside the open end of the elastomeric element and being supported by the pipe and
a spread portion being supported by the support portion and being arranged inside the open end, the spread portion comprising a screw mechanism to increase a circumference of the clamping device, thereby pressing a respective portion of the elastomeric element towards the pipe.

### Claim 2 (depends on 1)

The backflow prevention device according to claim 1 further comprising a sealing lip at the open end of the elastomeric element.

### Claim 3 (depends on 1)

The backflow preventing device according to claim 1 wherein the elastomeric element has a shoulder behind the clamping device which serves as a stopper.

### Claim 4 (depends on 1)

The backflow preventing device according to claim 1 wherein the spread portion comprises bows angularly inclined against each other and a screwing mechanism changing the distance between the bows thereby causing an increase or decrease of the circumference of the clamping device.

### Claim 5 (depends on 4)

The backflow preventing device according to claim 4 wherein the screwing mechanism comprises thread blocks and a clamping screw with right and left handed threads extending through the thread blocks for moving the thread blocks toward or away from each other.

### Claim 6 (depends on 1)

A clamping device for the backflow prevention device according to claim 1 comprising an expandable spread portion and a support portion supporting the spread portion against a pipe wall.

### Claim 7 (depends on 6)

The clamping device according to claim 6 wherein the spread portion comprises inclined bows and a spreading mechanism moving the bows apart from each other and thereby expanding the circumference of the clamping device.