Cuno, Inc.

3m Innovative Properties Company

C Thomas Paul

John L Pulek

William A Larsen

Clifford L Schorr

Francis J Swiatek

Art Artinyan

John A Corey

Thomas J Hamlin

Richard D Sale

Scott D Wofsy

A fluid filtration unit having two or more filter medium layers and/or zones, at least one of the layers/zones having a different particle retention capability disposed on each side of a non-filtering separator element. The filter medium are presently preferably positioned such that each succeedingly distal filter layer or zone from the separator has a decreased particle retention capability than each proceeding filter layer or zone. The filter medium layer most proximal to the separator element may be separated from the separator by a support material for supporting such filter medium element and preventing collapsing of the medium into any separator conduit. At least one of the medium elements is formed from a material which swells in size due to fluid absorption with the various zones and the separator being operatively connected by a new and innovative edge seal. The new and innovative edge seal is presently preferably formed from a thermoplastic material having a modulus of elasticity which is sufficient to permit radial expansion of the edge seal when the unit medium swells in size.

Graded particle-size retention filter medium for fluid filtration unit with improved edge seal

A filter is disclosed that includes a cylindrical filter element having a longitudinal axis, an outer periphery, an inner periphery, and a plurality of longitudinal pleats arranged in a spiral configuration in close proximity to one another. Each of the pleats has a pair of legs, and the legs of each pleat are joined to one another at a root. The roots of adjacent pleats are radially spaced from one another about the inner periphery of the filter element.

Spiral pleated filter cartridges

A spiral wound filter element is disclosed which includes alternating layers of filter medium and diffusion medium wrapped about a cylindrical core defining a central axis of the filter element. The alternating layers extend from a radially innermost layer of the filter element to a radially outermost layer of the filter element, the diffusion medium is defined by a continuous lengthwise sheet of mesh material, and the filter medium is defined by at least one sheet of filter material arranged along the length of the continuous sheet of mesh material. The alternating layers of filter medium and diffusion medium define three distinct radially disposed layered filtering sections surrounding the cylindrical core, and include a first filtering section having radially outer prequalifying layers, a second filtering section having middle prequalifying layers and a third filtering section having radially inner qualifying layers. The radially outer prequalifying layers and the middle prequalifying layers define about two-thirds of the radial distance from the radially outermost layer of the filter element to the radially innermost layer of the filter element.

Filter and method of filtering a fluid

A method is disclosed for forming a filter cartridge which includes the steps of providing a cylindrical filter element having a plurality of radially extending longitudinal pleats, engaging an outer periphery of the cylindrical filter element along a substantial portion of the length thereof, and simultaneously moving the plurality of radially extending longitudinal pleats into a laid-over spiraled configuration along the entire length of the cylindrical filter element to form a spiral pleated filter element. An apparatus is also disclosed for effectuating the disclosed method.

Apparatus for forming spiral pleated filter cartridges

Apparatus and method for forming spiral pleated filter cartridges

Growing community of inventors

Madison, CT, United States of America

C Thomas Paul