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:
Nov. 21, 1978
Filed:
Jul. 25, 1977
Robert L Huntt, Damascus, MD (US);
Trans-Tech, Inc., Gaithersburg, MD (US);
Abstract
An assembly including a ceramic insert and a surrounding dielectric filler in a ferrite or garnet toroid is disclosed, wherein a void is provided into which the dielectric filler can expand, such as by the formation of a temporary layer of liner material on an outer surface of the ceramic insert, or on the liner surface of the toroid, or on both. The ceramic insert is inserted into the toroid, and then the void between the ceramic insert and the toroid is filled with a dielectric heat-curable composition. Then the filled assembly is heated to an elevated temperature to burn out said liner. The liner material burns at a temperature of about 100.degree. F to a temperature which is at least 20.degree. F below the curing temperature of the dielectric heat-curable composition, and preferably the liner burns at a temperature below about 300.degree. F, to leave essentially no ash adversely affecting the resulting assembly. The dielectric composition is then cured, and the space left in the assembly by burning out the liner permits relative expansion and/or contraction of the insert, the toroid and the filler so the residual stresses in the final assembly are low. The assembly of the present invention is highly suitable for use in the production of phase shifters having a toroidal arrangement, where it is desired to eliminate any air gaps between the toroid and the ceramic insert, while avoiding or minimizing residual stresses in the final toroid assembly.