Patent · US Expired

Method and apparatus for checking the wall thickness of a layer

US4641525A · kind A · utility

14Cited by
4References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 10, 1985
Grant dateFeb 10, 1987
Priority date
Expiry dateJun 10, 2005

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C2948/9298
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

In a method of checking the insulating sheath on a wire or cable leaving an extruder, the external diameter of the insulating sheath is continuously determined over the whole circumference by means of a first measuring apparatus and the wall thickness of the insulation is continuously detected over the whole circumference by means of a second measuring apparatus. The measured values are supplied to a computer which, inter alia, continuously determines the difference between the maximum and minimum wall thicknesses found (W.sub.max -W.sub.min). Eccentricity and minimum wall thickness of the sheath are calculated from this difference and from the measured external diameter of the insulation and the diameter of the conductor of the wire or cable, and are indicated in a display device. The measurement is thus rendered largely independent of fluctuations in sensitivity of the measuring apparatus for the wall thickness of the insulation. An apparatus for carrying out the method comprises the respective measuring apparatus and a computer for effecting the required calculations.

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