Patent · US Expired

Process for assembling toroids from an intermediate product having a combustible interlayer

US4126723A · kind A · utility

3Cited by
3References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 25, 1977
Grant dateNov 21, 1978
Priority date
Expiry dateJul 25, 1997

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/29
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

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 prese…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.