US1996646A - Insulating packing for electric conductors - Google Patents

Description

April 2, 1935` K, A. JUTHE e-r AL 1,996,646

INSULATING PACKING FOR ELECTRIC CONDUCTORS Filed Dec. 27, 1927 Patented Apr. 2, 1935L PATENT oFFlcE INSULATING PACKING FOR ELECTRIC CONDUCTORS Kristian A. Juthe, Newton, 'andAlbert .Ll-Ianson, Arlington, Mass., assignors to American Electric Furnace Company, a corporation of Massachusetts Application December 2.7, 1927, Serial No. 242,904

1 Claim.

'I'his invention relates to an insulating packing device for electric conductors, and more particularly for electric conductors passing through the walls of a metal container for highly heated and 5 highly compressed air. There are many processes in the industry which call for a supply of heated air under pressure. By this invention, a container is provided for compressed air and a heating element is mounted within the container. For example, an electric resistance unit or group of units may be employed, the units being connected to a suitable source of current through conductors which pass through the wall of the container and are electrically insulated therefrom. It has heretofore been considered impracticable, if not impossible, to pass a conductor through the wall of a pressure tank so as to insulate the conductor from the tank and to preserve the air-tight integrity of the tank, 2o particularly where the problem was aggravated by relatively high temperatures in the tank. By this invention, an efficient mounting device is supplied which successfully resists high temperatures and pressures while holding a conductor passing through the wall of the tank electrically insulated therefrom. Further novel and advantageous features of construction and cornbinations of parts will be apparent to one skilled in the art, from the following description of the 30 apparatus shown on the drawing, of which,-

Figure 1 is an elevation of apparatus embodying the invention, the external wiring connected therewith being diagrammatically shown.

Figure 2 is a plan view of the apparatus. Figure 3 is a sectional detail showing how the binding posts, which pass through the wall of the container, are insulated therefrom.

Referring to the drawing in detail, a suitable tank or container I is provided for compressed air which may be supplied through a supply pipe I I which as shown in Figure 1 may open into the bottom of the container I0. Although the container will operate in any desired position, for convenience of description it will be hereinafter referred to as in an upright position as illustrated in Figure 1. An outlet port is provided, preferably at the top of the container I0, a suitable pipe I3 being connected to the tank at this point. Within the tank I0 we mount one or more heat- 50 ing elements. In order to supply current to the heating elements, suitable terminal posts 20 may be provided, each post passing through an aperture 2| in the shell of the tank which is preferably large enough to permit the post to extend therethrough with clearance all around it. In

order to insulate the post electrically from the tank and at the same time to provide an airtight closure for the aperture 2I by means which will stand upagainst the pressure of highly compressed air at high temperatures within the tank I0, the post may be supported by means such as are illustrated in Figure 3. As shown in this figure, a perforated plate or annulus 22 may be xed to the wall of the tank I0 around the aperture 2I, the plate 22 having an outwardly extending boss 23 and being internally threaded to receive a nipple 24. The nipple 24 is preferably provided with an interior shoulder 25 against which is fitted the radial flange 26 of a bushing 21 made of heat-resisting, electrically insulating material, such as porcelain or lava. The bushing 21 is preferably constructed to fit closely over the post 20. A second bushing 28, which may be similar in construction to the bushing 21, is also fitted on the post 20. This bushing is preferably provided with a radial flange 29 at one end thereof, the flanges 26 and 29 forming end faces of the bushings which are mutually opposed when the bushings are in place within the nipple 24 and on the post 20 as shown in Figure 3. Between the opposed faces of the bushings, We preferably insert a suitable quantity of insulating packing material 30 which is preferably heat resisting. Asbestos is suitable for this purpose. A spacing collar 3I is mounted on the bushing 28 in such a way as to bear at one end against the flange 29. The other end of the collar 3I may be engaged by a cap 32 which as shown is screwthreaded on the outer end of the nipple 24. When the foregoing parts are assembled, the cap 32 is set up on the nipple 24, thus pressing against the collar 2I and the flange 29 so as to compress the packing 30 between the opposing faces of the bushings 21, 28, the bushing being supported against such pressure by the engagement of its ange 26 with the shoulder 25. Thus the post 20 is strongly supported and is in actual contact only with the insulating bushings 21, 28 and the non-conducting packing 3U which also assists in forming an air-tight closure for the aperture 2|. In order to provide a removable external connection for the post 20, the latter may be screwthreaded as at 33 to receive a pair of nuts 34, between which may be clamped the end 35 of a suitable conductor. The nuts 34 may be prevented from contact with the cap 32 by the insertion of an insulating washer 36 against the outer face of the cap.

It is evident that various modications and changes may be made in the speciflc embodiment of the invention herein shown and described without departing from the spirit or scope thereof as defined by the following claim.

We c1aim:- l A device `ior packing and insulating an electrical conductorpassingV through an, aperture inV a metal;wal l,- said device comprisingga pair, of insulating bushings tted on said conductor having radial anges at their mutually adjacent A ends and opposing end faces, a packing of insulating material between saidfaoes', ari-interior 1y shouldered nipple adapted to Vreceive said -1 bushings and packing therein-againstits Shouh KRIsTIAN A. JU'rHE. ALBERT J. HANsoN.

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