The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 26, 1989
Filed:
Mar. 21, 1988
Robert W Harmon, Centralia, MO (US);
A. B. Chance Company, Centralia, MO (US);
Abstract
An improved, integrally cast, synthetic resin insulator (22) especially adapted for use in an electrical cutout device (20) is provided which can be readily fabricated and gives greatly enhanced beam strength and arc track resistance characteristics. The preferred insulator (22) is cast using an epoxy resin such as bisphenol A filled with a relatively large quantity of glass beads and hydrated alumina. The filler fraction contributes to lowered viscosity, deaerability and improved settling properties while the resin is in an uncured state, and moreover enhances the arc track resistance and mechanical strength of the resin system after curing. The preferred insulator (22) is cast to present a longitudinal bow giving the insulator (22) an arcuate central axis. Further, the periphery of the insulator (22) is formed with a series of superposed, generally oval-shaped in cross-section, outwardly flaring skirts (30) interconnected by smooth transition regions (32) free of stress-inducing sharp corners. By virtue of the oval-shaped skirts (32), the insulator (22) has a greater effective width than thickness, thus maximizing the beam strength of the insulator (22).