Micropore International Limited

Ceramaspeed Limited

Zortech International Limited

Joseph A McWilliams

Ali Paybarah

James D Jackson

Derek E Morgan

John T Hughes

An electrical resistance heating element is made from an electrical resistance material having the following composition in weight percent:

Method of manufacturing an electrical resistance heating means

An electrical heating element for a radiant electric heater takes the form of an elongate electrically conductive strip for partial embedding edgewise in a base of thermal and electrical insulation material. The strip is composed of an elongate continuous portion and an elongate discontinuous portion integral with the continuous portion. The discontinuous portion is intended for embedding in the base and is provided with a plurality of discontinuities so that in operation of the heater current flow in the discontinuous portion is reduced or eliminated.

Method of manufacturing a radiant electric heater

A radiant electric heater is made by providing a base of microporous thermal and electrical insulation material having formed in a surface thereof at least one groove. The groove includes transverse webs of the microporous insulation material spaced apart along the length of the groove. An elongate electrically conductive strip is provided to serve as a heating element and is located edgewise into the groove and is urged into the webs so as to embed and secure the conductive strip in the webs.

Radiant electric heater

A layer of compacted powdery microporous material is formed in a container of substantially air-impervious material by providing at least one air outlet region in the container together with barrier means which is adapted and arranged to substantially prevent passage therethrough of microporous material during compaction thereof, whilst permitting permeation of air displaced therefrom during such compaction. Also provided in the container is means to enable the displaced air permeating at least part of the barrier means during compaction of the microporous material to flow laterally of the direction of movement of a press tool between at least part of the barrier means and the base of the container toward the at least one air outlet region so as to be displaced from the container therethrough.

Method of forming compacted layer

A radiant electric heater having an electric heating element in the form of an elongate electrically conductive strip supported on edge and partially embedded in a layer of microporous thermal and electrical insulation material in a support dish is manufactured by placing an elongate electrically conductive strip on edge in a groove in a press tool, such that a portion of the strip protrudes from the groove, the groove being formed of a pattern corresponding to that required for a heating element in the heater. A predetermined quantity of powdery microporous thermal and electrical insulation material is arranged between the press tool and a support dish of the heater, and the insulation material is compressed into the support dish with the press tool, the material being compacted to form a layer of a desired density and simultaneously compacted against the portion of the strip protruding from the groove, to secure the strip on edge in partial embedment in the layer of the insulation material.

An electrical heating element for a radiant electric heater takes the form of an elongate electrically conductive strip adapted for edgewise mounting on a base of thermal and electrical insulation material. The strip includes an elongate continuous portion and a discontinuous portion integral, and preferably coplanar, with the continuous portion, the discontinuous portion including a plurality of mounting tabs extending in a direction away from the continuous portion at spaced-apart locations, for securement to or in the base. Provided in each tab is at least one aperture such as a hole or slot or slit, so that thermal conduction into the tabs from the continuous portion is reduced or minimized and also variation in electric current density along the continuous portion of the strip is reduced or minimized when the strip is electrically connected for operation in a radiant electric heater.

Electrical heating element, its manufacture and use

A radiant electric heater is manufactured by a method which involves providing a base of microporous thermal and electrical insulation material having a substantially continuous surface, and providing a heating element in the form of an elongate electrically conductive strip. The strip is urged edgewise into the continuous surface of the base of microporous thermal and electrical insulation material so as to embed and support the strip edgewise in the insulation material along substantially the entire length of the strip to a depth corresponding to at least part of the height of the strip.

A wound coil which is rotating about its axis is cut and severed against a stationary member by moving a rotatable cutting blade incorporating a circular cutting edge towards the rotating coil and the stationary member such that the cutting blade rotates about the axis of the arcuate cutting edge against the wound coil, becomes inserted between adjacent turns of the wound coil and cuts the wire forming the coil against the support. Once the coil has been cut, the cutting blade is moved away from the coil. A roller is provided to limit movement of the cutting edge of the cutting blade in the axial direction of the coil.

Apparatus for cutting wound coils

Electrical heating element and heater incorporating same

A radiant electric heater is manufactured by a method which involves providing a base of microporous thermal and electrical insulation material having at least one groove formed in a surface thereof, and providing an elongate electrically conductive strip to serve as a heating element. The elongate electrically conductive strip is located edgewise into the groove and surface pressure is applied to the base of microporous insulation material in a region adjacent to the strip to deform the base and to urge microporous material of the base into contact with the strip so as to secure the strip in the groove.

A close wound coil is formed by a sequence of steps including supplying a wire to be formed into a coil onto a rotating mandrel by means of a guide wheel and urging the wire against the mandrel by means of a pressure wheel so as to form a coil. The formed coil is allowed to free itself from engagement with the mandrel from a point immediately following that at which the wire is urged against the mandrel by the pressure wheel to the end of the mandrel so that the formed coil, although carried by the mandrel, is unrestrained relative to the mandrel.

Coil winding method and apparatus

Vibrations that arise during the winding of a coil of wire onto a rotating mandrel are damped by surrounding the coil with a tube such that the tube is spaced from the coil and by supplying fluid to the tube. The tube extends in the axial direction of the coil along at least a part of its length and, due to the spacing between the tube and the coil, conducts fluid such as water in a confined manner towards at least one end of the tube and releases the fluid from the end of the tube, for example in a region of the coil adjacent to and/or remote from the winding of the coil.

Coil winding method and apparatus for dampening vibrations

Infra-red heater

A method of manufacturing a microporous thermally insulating body comprises mixing together a finely divided microporous insulating material such as silica aerogel or pyrogenic silica and a solid ammonia-generating compound in particulate form, and compressing the mixture to form a thermally insulating body. The ammonia-generating compound is dispersed evenly throughout the insulating material and may comprise, for example, ammonium carbonate, ammonium acetate or urea. Preferably, the ammonia-generating compound comprises a mixture of about one third by weight of ammonium carbonate and about two thirds by weight of ammonium bicarbonate together with a small proportion of magnesium oxide.

Method of manufacturing a microporous thermally insulating roof

An infra-red heater (1) for a glass ceramic top cooker includes a dish containing a base layer of thermal insulating material. A peripheral wall of thermal insulating material extends around the periphery of the base layer and at least one infra-red lamp (3) extends across the base layer. A ballast device (5) is electrically connected in series with the infra-red lamp, for example in the form of a coil of bare resistance wire, and serves to reduce inrush current to the lamp. A thermal cut-out device (7) cuts off the supply of power to the infra-red lamp and to the ballast device (5) if the temperature of the glass ceramic cooking surface becomes excessive. The coil of bare resistance wire preferably has an electrical resistance which is approximately half the electrical resistance of the infra-red lamp at its operating temperature. The use of a ballast device (5) enables the infra-red lamp (3) to be used in conjunction with a cyclic energy regulator (9).

Growing community of inventors

Droitwich, United Kingdom

Joseph A McWilliams