# US 5,707,521 A · Filter element having a nonwoven layer and a permeable shrink tube

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,707,521 A
- Document ID: US5707521A
- Status: Granted
- Kind: A
- Application number: 08/631,329
- Filed: 1996-04-12
- Granted: 1998-01-13
- Earliest claimed: 1995-04-13
- Assignees: Filterwerk Mann & Hummel GmbH
- Inventors: Hans Erdmannsdoerfer; Bruno Sommer
- Web page: https://patentgrep.com/patent/US5707521A

## CPC

- B01D 46/64: arranged concentrically or coaxially
- B01D 46/0005: {Mounting of filtering elements within casings, housings or frames (B01D46/2422 takes precedence)}
- B01D 46/24: Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
- B01D 2265/06: Details of supporting structures for filtering material, e.g. cores
- B01D 2275/10: Multiple layers
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)

## Abstract

A filter element having a first tube 2 and a second tube 3, the outer circumferential surface of the first tube 2 being surrounded by a nonwoven layer 4, and the second tube 3 surrounding the first tube 2. On the outer periphery of the second tube 3 there is a yarn and/or paper winding 5, and a shrink tube 6 presses the yarn and/or paper winding 5 against the second tube.

## Claims

### Claim 1

A filter element comprising a first permeable tube, a nonwoven layer supported on the outer periphery of said first permeable tube, a second permeable tube surrounding said first tube and nonwoven layer, a winding supported on the outer periphery of said second tube, said winding comprising at least one winding structure selected from the group consisting of (1) a yarn winding and (2) at least two layers of filter paper, and a permeable shrink tube surrounding said winding and holding said winding on said second tube; wherein the nonwoven layer has a greater axial length than the first permeable tube and is axially compressed when the filter element is installed in a filter.

### Claim 2 (depends on 1)

A filter element according to claim 1, further comprising a lid attached at one axial end of said first and second tubes to close the tube ends.

### Claim 3 (depends on 1)

A filter element according to claim 1, further comprising a mounting flange at one axial end of said first and second tubes.

### Claim 4 (depends on 1)

A filter element according to claim 1, wherein the first tube is permeable in a radial direction.

### Claim 5 (depends on 1)

A filter element according to claim 1, wherein the second tube is permeable in a radial direction.

### Claim 6 (depends on 1)

A filter element according to claim 1, wherein the winding is a yarn winding of yarn made from fibers selected from the group consisting of glass fibers and synthetic resin microfibers.

### Claim 7 (depends on 1)

A filter element according to claim 1, wherein the winding is a paper winding formed of at least two layers of gas permeable paper.

### Claim 8 (depends on 1)

A filter element according to claim 1, wherein the nonwoven layer comprises a polyester fleece.

### Claim 9 (depends on 1)

A filter element according to claim 1, wherein at least one of said first and second tubes has radially impermeable areas adjacent its axial ends.