Production of dielectric insulation layers upon electrical conductors
AssigneeNorthern Telecom Limited
InventorsMichael A. Shannon, John A. McDade
Life of this patent
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Abstract
Providing an electrical conductor with an insulation layer having a layer of dielectric carrier with magnetically permeable particles dispersed within the carrier, in which homogeneity is maintained in a fluid mixture of a fluid carrier and the particles, the conductor is moved vertically through a die means to coat it with a fluid layer of the mixture, the fluid carrier is dried and thickness of the dried insulation layer is controlled. This control is achieved by monitoring the thickness or diameter of the dried layer and, if a variation exists between the monitored and required values, the rate of fluid flow through the die means is adjusted to adjust the monitored values towards that required.
Claims6
A method of providing an electrical conductor with an insulation layer comprising a layer of dielectric carrier and magnetically permeable particles dispersed within the carrier, the method comprising:
- maintaining substantial homogeneity in a fluid mixture of a fluid carrier and a quantity of the magnetically permeable particles;
- moving the conductor through the mixture and vertically through a die means to coat the conductor with a fluid layer of the mixture;
- drying the fluid carrier to form the dried insulation layer with the particles substantially homogeneously dispersed within the dried carrier;
- controlling the thickness of the dried insulation layer by monitoring the thickness or diameter of the dried layer and, if monitored values differ from that required, varying the rate at which the fluid mixture passes through the die means to adjust monitored values towards that desired;
- and
- controlling the quantity of particles dispersed within the carrier by monitoring the quantity of particles by passing the conductor after emergence from the die, concentrically through a magnetic field so as to cause the particles surrounding the conductor to influence the strength of a characteristic of the field and produce signals corresponding to the strength of the influenced characteristic and to the quantity of particles effectively influencing the characteristic, and upon an evaluation of signals differing from that which represents a desired quantity of particles, operating a control means to adjust input of particles or fluid carrier into the mixture to provide the desired quantity of particles in the layer.
Apparatus for providing an electrical conductor with a layer of insulation comprising a dielectric carrier and magnetically permeable particles dispersed within the carrier, the apparatus comprising:
- means to maintain a fluid mixture of carrier and particles in a substantially homogeneous state;
- a die means to coat the conductor with a layer of the fluid mixture;
- means to dry the layer to form the layer of insulation in dried form;
- thickness control means for the dried insulation layer comprising a monitoring means to monitor the thickness or diameter of the dried layer and means to vary the rate at which the fluid mixture passes through the die means and controlled by the monitoring means, if monitored values differ from that required, to adjust the monitored values towards that desired;
- and
- means to control the quantity of particles dispersed within the carrier comprising a means to monitor the quantity of particles surrounding the conductor which includes magnetic field generating means to generate a magnetic field surrounding and concentrically disposed relative to the feedpath of the conductor downstream from the die means so that particles surrounding the conductor influence a characteristic of the field as they pass therethrough, the monitoring means also having a signal producing means to produce signals corresponding to the strength of the influenced characteristic and control means to adjust input of particles or fluid carrier into the mixture to provide the desired quantity of particles in the layer and operable upon produced signals different from that corresponding to the desired quantity of particles.
Dependencies are inferred from the claim text.