US1786729A - Pothead for insulated conductors - Google Patents

Description

Dec. '30, 1930. A. o. AUSTIN 1,786,729 POTHEAD FOR INSULATED C-ONDUCTORS Filed Jan. 16, 19 25 as ix I0 INVENTOR 11 m 9 t A TTORNEYS Patented Dec. 30, 1930 UNITED" STATES PATENT, OFFICE ARTHUR O. AUSTIN, OF BABBERTON', OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE'OHIO BRASS COMPANY, OF MANSFIELD, OHIO, A CORPORATION OF NEW JERSEY PO'IHItlAD FOB INSULATED CONDUCTOBS Application filed January 1a, 1925. Serial no. 2,754.

This invention relates to outlet housings commonly known as potheads such as are 'used for the transition of a conductor from an insulated cable to a bus bar or overhead 5. support, and has for its object the provision of a device of the class named in which the exposed portion of the insulating material will be rotected'fromthe atmosphere and supplied with an insulatingliquid or compound and in which flash-over between the conductor and its sheath or other grounded objects will be prevented. I

The invention is exemplified in the combination and arrangements of parts shown in the-accompanying drawing and described in the following specifications and it is more particularly pointed out in the appended claims. i

In the drawing-- Thefigure is an elevation of a pothead construction showing one embodiment of the prese' t invention, parts of the device being sho in vertical section. f

The numeral designates aconductor thereto, the outer surface of the winding being covered by a sheath 12 of lead or other suitable material. The insulation 11 is commonly made up of narrow strips of paper saturated with oil or other insulating compound and wound in layers upon the conductor 10. The outer sheath 12 protects the insulating material and prevents the escape of the insulating liquid with which the material is saturated. .It'will be apparent that at the termination of the sheath 12 and the insulating material 11, it will be necessary to make some provision ,to'protectthe insulating material so as to retain the insulating fluid and prevent entrance of moisture. It will also, be apparent that there will be a concentration of electrostatic lines of force atthe termination of the sheath which would give rise to discharge from the conductor to the sheath unless some provision is made to provide sutficient insulation at this point. In the construction shown in the drawing for taking care of these conditions, a metal tubu lar housing or bell '13 is provided which is tapered inwardly at its lower end to fit closecable having an insulated winding llvapplied' 10 and insulation 11 pass through the opening-in'the lower end of the housing but the sheath 12 is terminated adjacent the end of the housing and is flared outwardly as shown at 14 to provide a circumferential flange. The lockmg collar 15 surrounds the sheath 12 below the flange 14 and is provided with a flange 16 which grips thetflange 14 against the lower end off the housin 13. A gasket 16 is interposed between the housing and the flange 14 to provide a tight joint between the housing and the sheath 12.

Atthe' upper end of the housing 13, there is provided a supporting flange 17 having a gasket 18 thereon, and a ring 19 is secured to the flange 1-7 on top of the gasket 18 by bolts 20. A tubular dlelectrio'member 21 is secured to the interior of the ring'19 by oement 22 or other suitable means so that when the ring 19 is securely fastened tothe flange 17 the parts 13 and21 are united at their adjacent. ends to form a continuous casing. The ring 19 may be provided with a boss 23 having a 0011(11111324: extending therethru to 1y about thev insulation 11. The conductor permit the'interior of the casmg to be supplied with an insulating oil or compound.

The conduit 24.- may be closed by a p ug 25. A reservoir 26 may be provided at the upper end of the housing member 21 for containing a reserve supply of insulating liquid, and'a gauge glassf2Z is provided for indicati the height of liquid in the reservoir 26. emperature changes will vary the amount of the insulating liquid held by the covering 11 for the conductor 10. During warm weather, the insulating liquid will expand and some of it will be forced from the interior of the sheath 12. At lower temperatures, the liquid will contract so that an additional amount will enter the end of the cable. 'For this reason,

it is advisable to supply a considerable body .at the same time protects the covering for thezeonductor from exposure to the atmosphere. The metallic member 13 diverges the flaring pothead 13 to the flange 17 which is spaced outwardly a considerable distance from the conductor. The insulating member 28 extends between the covering 11 and the casing member 13 to a point closely adjacent 15 the lower end of the casing member. The

wall of the insulating member beingtapered at its lower end to permit the end to extend well down into the tapered opening between the insulating covering 11 and the member 13. The tubular member 29 is concentric with the member 28 and is spaced outwardly therefrom and secured thereto by rings of cementing material 31. The tubular member 30 is likewise secured to the outer face of the 5 member 29 by cement 32. The entire series of tubular dielectric members is supported from the housing member 13 by a cement zone 33 which connects the outer surface of the tubular member 30 with the inner sur- 30 face of the casing member 13 near the top of this member. A flux control screen 34.

consisting of a sheet metal sleeve surround-- ing tubular member 13 may be supported between the tubular member and the lower 35 edge of the housing member 21 by having its 0 lower edge embedded in the cement 33. In

order to provide anadditional supply of insulating liquid, it may sometimes be advisable to use a supplemental supply reservoir 35 whichmay be connected by a pipe 36 to the interior of the housing member 13. A valve 37 is provided to control the supply of liquid through the pipe 36. The upper end of the conductor 10 1s connected to a conductor rod 38 which extends ,upwardly through the reservoir 26 and isconnected at its upper end with conductors 39 and 40. A spring washer 41 may be interposed between the clamp 42 for the conductor 39 and the stufling box43 at the upper end of the rod 38, within-the pothead and compensates for unequal expansion and contraction between the conductor and the casing due to temperature changes.

' I claimp 1. The combination with a conductor hai inga dielectric covering and an outer metal sheath, of a pothead for said conductor comprising an inverted metallic bell having an opening through its lower end for receiving said conductor, means for securing said sheath to said bell adjacent said opening,

resilient means for supporting the portionof said conductor within said pothead and a tubular dielectric member surrounding said Moreover a series of conductor within said pothead and supported on said bell.

2. The combination with a conductor of a pothead therefor, a reservoir for insulating compound supported by said pothead and resilient means for supporting the portion of said conductor in said pothead.

3. The combination with a conductor having a covering of dielectric material and an outer metal sheath, of a pothead for said conductor comprising a lower metallic bell and an upper dielectric casing member, a reservoir supported on said dielectric casing member and communicating with the interior thereof, means extending through said reser voir for supporting the portion of said conductor within said pothead and a resilient member supported by said reservoir for sustaining said conductor supporting means.

4. The combination with a conductor having a covering of dielectric material and an outer metal sheath, of a pothead for said conductor comprising an inverted flaring metallic bell having an opening through its lower end for receiving said conductor, means for forming a tight joint between said sheath and said bell adjacent the lower end of said bell, a series of concentric tubular insulating members surrounding said conductor within said bell and supported on said bell, a di electric casing member connected with the upper end of said bell to form a closed housing therewith, a reservoir for insulating compound communicating with the upper end of said dielectric casing member, a connector extending through said reservoir and secured to said conductor and means for supporting said connector to said reservoir.

5. In combination, a conductor having an insulating covering and an outer metal sheath, and a terminal housing for said conductor comprising a metallic casin member having an opening at one end rough which said conductor and covering extend into said casing member, said casing member being flared outwardly away from said covering, a complementary casing member of dielectric material having one end thereof arranged in registration with the upper end of said metallic casing member, means for securing the registering ends of said casing members together, a cap supported on the upper end of said dielectric casing member and provided with a terminal for said conductor, and a porcelain tube disposed within said casing members and overlappin the joint between the connected ends of sai casin being tapered and extending into the tapered opening between'said metallic casing member and. said insulating covering.

6. In combination a conductor having a covering of dielectric material, a liquid tight casing of conducting material having an opening through the outer wall thereof members, the lower end of said tube throu h which said conductor and covering extend, a' sheath surrounding said dielectric covering outside of said casing and terminating in an outwardly bent flange at the outer wall of said casing, said flange being day of

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