Browse Prior Art Database

Floating Seal

IP.com Disclosure Number: IPCOM000037499D
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Colby, RS: AUTHOR

Abstract

Particulate seals that must operate at very small clearances from a moving surface present several design difficulties. The operating clearance must be smaller than the smallest particle that must be restrained. This dimension may be less than the size of the surface irregularities or the "runout" of the moving surface. Therefore, the seal needs to be flexible, have low inertia and possess control means to restore the operating clearance after the disturbance passes.

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Floating Seal

Particulate seals that must operate at very small clearances from a moving surface present several design difficulties. The operating clearance must be smaller than the smallest particle that must be restrained. This dimension may be less than the size of the surface irregularities or the "runout" of the moving surface. Therefore, the seal needs to be flexible, have low inertia and possess control means to restore the operating clearance after the disturbance passes.

The design problem described above is often met in magnetic brush developers in electrophotographic printers and copiers. There "carrier beads" and toner particles must be retained within the developer while a moving photoconductor surface passes through it.

The seal design shown in the attached figure is a plastic or metal sheet, supported above the moving surface by low pressure air. The stiffness or spring loading of the sheet is balanced against the air pressure to set the desired operating clearance. The low inertia of the sheet enables it to follow irregularity or runout of the moving surface. Vacuum or other collection means can be provided for removal of particles as the seal intercepts them.

Disclosed anonymously.

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