Pleated paper filter

In a filter, an elongated permeable filter element providing a lengthwise extending annular array of normally stable pleats, each being resiliently flexible in a direction generally circumferential of the filter element, and flexibly collapsible means successively extending from pleat to pleat and being secured to each pleat and interconnecting the pleats in a selectively collapsible ganged relationship to enable circumferential collapse of any particular ganged pleat towards an adjacent ganged pleat and to provide concurrent circumferential flexing movement of a plurality of successively adjacent ganged pleats when said particular ganged pleat undergoes circumferential collapse, with each of said plurality of successively adjacent ganged pleats thereafter resiliently restoring to act collectively through said flexible means in returning the collapsed pleat, said means including tension transmitting flexible netting circumferentially encircling said filter element in widely distributed, multiple point fixedly intersecting contact with outer extremities of the ganged pleats.

In a filter, an elongated permeable filter element providing a lengthwise extending annular array of normally stable circumferentially distributed pleats, each being resiliently flexible in a generally circumferential direction about said filter element, and tension transmitting flexibly collapsible foraminous means secured to each pleat and extending circumferentially of the filter element and interconnecting the circumferentially distributed individual pleats thereof in a selectively collapsible ganged relationship to enable circumferential collapse of any particular ganged pleat towards an adjacent ganged pleat and to provide concurrent circumferential flexing movement of a plurality of successively adjacent ganged pleats when said particular one thereof undergoes circumferential collapse to enable said successively adjacent ones, in subsequently restoring, to return the collapsed one.

In a filter, an elongated permeable filter element providing a lengthwise extending annular array of normally stable pleats, each being resiliently flexible in a direction generally circumferential of the filter element, tension transmitting flexibly collapsible netting circumferentially encircling said filter element in widely distributed, multiple point, intersecting contact with outer extremities of said pleats, and securing means fixing said netting to the outer extremities of the pleats to connect the pleats in a selectively collapsible ganged relationship to enable circumferential collapse of any particular ganged pleat towards an adjacent ganged pleat and to provide concurrent circumferential flexing movement of a plurality of successively adjacent ganged pleats when said particular ganged pleat undergoes circumferential collapse, with each of said plurality of successively adjacent pleats thereafter resiliently restoring to act collectively through said netting in returning the collapsed pleat.

In a filter, an elongated permeable paper filter element providing a lengthwise extending annular array of normally stable pleats, each being resiliently flexible in a direction generally circumferential of the filter element, flexibly collapsible netting of woven cotton fiber material circumferentially encircling said filter element in widely distributed, multiple point, intersection contact with outer extremities of said pleats, said netting spanning a major fraction of the length of said filter element, and adhesive securing means fixing said netting to the outer extremities of the pleats to establish the netting in tension transmitting relation between adjacent pleats and thereby connect the pleats in a selectively collapsible ganged relationship to enable circumferential collapse of any particular ganged pleat towards an adjacent ganged pleat and to provide concurrent circumferential flexing movement of a plurality of successively adjacent ganged pleats when said particular ganged pleat undergoes circumferential collapse, with each of said plurality of successively adjacent pleats thereafter resiliently restoring to act collectively through said netting in returning the collapsed pleat.

In a filter, an elongated permeable filter element providing a lengthwise extending annular array of normally stable pleats, each being resiliently flexible in a direction generally circumferential of the filter element, and flexibly collapsible foraminous means successively extending from pleat to pleat and being secured to each pleat and interconnecting the pleats in a ganged relationship.