US3028183A - Sealed ball joint for electrodes - Google Patents

Description

April 3, 1962 w A. PHILLIPS SEALED BALL JOINT FOR ELECTRODES Filed Nov. 50, 1959 IN VENTOR WE PNE R A. PHILLIPS ATTORNEY tinned States Patent 3,028,183 SEALED BALL JOINT OR ELECTRODES Werner A. Phillips, Chemawa, 0reg., assignor t0 the United tates of America as represented by the Secretary of the Interior Filed Nov. 30, 1959, Ser. No. 856,317 3 Claims. (Cl. 287-87) (Granted under Title 35, US. Code (1952), see. 266) The invention herein described and claimed may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of royalties therein or therefor.

This invention relates to improved ball joints for rod or shaft members extending through a Wall section, whereby the rods may be moved axially and from side to side on one side of the the wall by manipulating the rod portion extending through on the other side. The

Y embodiment shown herein is adapted for providing a vacuum-tight joint for water cooled electrodes in a vacuum are melting furnace. However, the device is not limited to this use but may be employed broadly wherever fluid tight ball joints or stufiing boxes are required.

Briefly, the improved ball joint device consists of a seating member adapted to be fastened to a Wall or panel section of a vacuum chamber. The seating member'has a ground concave spherical inner bearing portion adapted to receive a ball member. Stuffing glands and packing permit rotation of the ball but maintain it in vacuumtight conditions. A shaft extends through a diametrical bore in the hall, said shaft having a stufilng gland and packing to permit axial movement while retaining the vacuum.

In the arc furnaces used heretofore for the test melting of refractory metals, a fixed electrode was provided which allowed-melting of only one test button at a time. After melting, the furnace had to be disassembled to remove the button. By providing a vacuum-tight ball joint, the water cooled electrode may be moved to different stations within the furnace without disturbing the rest of the set-up so that a plurality of test buttons may be formed before opening the furnace.

it is an object of this invention to provide an improved fluid or vacuum-tight ball joint for rods or shafts extending through a wall section.

It is a further object of this invention to provide a novel improved ball joint having separate means for compressing a gasket surrounding the ball, and for retaining the ball against its seat.

These and other objects of the invention will be more apparent on consideration of the accompanying drawing and the following description thereof.

FIG. 1 is a view partly in section of a portion of the vacuum electric furnace, showing the water-cooled electrode passing through the ball joint.

FIG. 2 is an enlarged cross-sectional view of the ball joint and associated electrode structure.

FIG. 3 is a view taken along lines 3-4 of FIG. 2.

Referring to FIG. 1, 1 is a double-walled shell of an electric furnace, with water flowing in the hollow portion for cooling purposes. Fastened to the shell by bolts 2 is the ball joint assembly 3 having a ball member 4. Water-cooled electrode 5 having an internal water inlet pipe 6 and an external water outlet pipe 7, an electrical connection terminal 8, and a tungsten tip 9, passes through ball 4.

As best shown in FIG. 2, ball 4 is seated in housing 10 which has a lower spherical cup-shaped inner surface adapted to receive ball 4, and is fastened to the furnace shell by bolts 2, rings 11 and 12, and sleeves 13. Members 11, 12 and 13, which may be of any suitable insulat- "ice ing material, electrically insulate ball joint assembly 3 from the rest of the furnace structure. 0 rings 15 and 16 fitted into associated grooves in shell 1 and ring 11 respectively, serve as vacuum-tight seals when compressed.

At the upper circumferential portion of'the spherical bearing surface of housing 10, a circumferential shoulder 17 is provided into which a resilient O ring or gasket 1-8 fits snugly. Upper portion 19 of housing 10 is threaded internally, and stufilng gland 20, which is just tangential to, or free of contact with the ball, is threadably engaged therewith, compressing 0 ring 18. Thereby the junction of ball 4 and housing It) is made vacuum-tight. Gland 20 has inner threads which engage corresponding threads on ball nut 21. By tightening pressure nut 21 the ball may be held in any desired position.

The avoidance of any hold-down pressure on the ball due to stufiing gland 20' and the provision of a separate nut 21 to retain the ball are very important features of this invention. In previous ball joints both these functions were performed by a single gland member. This was unsatisfactory because the amount of compression on the O ring 17 which could be achieved by tightening the ball. Separating the O ring compression'and ball retention functionsby providing separate means for each enables a more uniform and greater pressure on the 0 ring and therefore a higher degree of vacuum to be achieved and maintained. p Water-cooled electrode 5 passes through a diametrical opening 22 in ball 4, the upper end of which is enlarged to bore'23, a ledge '24 joining bores 22 and 23. The

latter is internally threaded to receive a gland nut 25. An

nace in vacuum-tight condition.

Any conventional. material of construction suitable for the conditions of service may be employed. Thus, the 0- ring may be made of any suitable elastomer suchnas; noeprene, while the seats, ball and gland members. may be made of brass or steel.

It is obvious that the above described invention is susceptible of much modification and varied uses, and the scope thereof is limited only by the following claims.

I claim:

l. A ball joint for a rod passing through an opening in a plate comprising, a seating member fastened to the late and mounted within the opening, said seating member having a spherical cup-shaped bearing surface, including a central opening and an upper circumferential shoulder, a spherical ball member seated on said cupshaped spherical bearing surface, said ball member having an axial bore including an upper enlarged portion and a ledge at the bottom of the enlarged portion, whereby the rod may be slidably mounted in said ball member through said axial bore, first resilient gasket means mounted in said circumferential shoulder adjacent to the ball member, an apertured first stuffing gland threadably connected to the seating member, said stuffing gland having at most tangential contact with the ball member within the aperture. and an integral portion thereof operably displa-ceable within the seating member to engage the first resilient gasket means and compress it, an aperture'd nut member threadably connected with and located within the aperture of the first stufling gland, said nut member having an integral portion thereof operable for engaging the ball member and exerting a bearing pressure thereon, a second resilient gasket means mounted on the ledge within the axial bore of the ball member, and a second apertured stalling gland adapted to slidably fit over the rod threadably mounted in the axial bore of said ball member, said second stuffing gland land was limited by contact of the gland with the having an integral portion thereof operably displaceable Within the ball member to engage the second resilient gasket to compress it.

2. An improved ball joint sealing structure comprising a seating member having a spherical cup-shaped bearing portion, said seating member having an upper circumferential shoulder, a spherical ball member seated in said cup-shaped bearing portion, resilient gasket means mounted in said circumferential shoulder adjacent the ball member, hollow cylindrical stufling gland means comprising a bearing end face, interiorly a smooth cylindrical surface, an adjusting flange arranged exteriorly on said gland means opposite to said bearing end, and an engageable surface adjacent said smooth surface and said exterior flange, said stuffing gland being adjustably mounted in said seating member to apply the bearing end face thereof to engage the gasket to compress it, the internal diameter of the stufling gland being at least equal to the diameter of the ball member whereby the latter is at most in tangential contact with the said smooth interior surface of the stuffing gland, permitting facile relative movement between the ball member and said smooth surface at any degree of adjustment of the stufling gland with the seating member to compress the gasket, and an adjustable pressure means comprising as parts at opposite ends thereof, a bearing surface portion, and an adjusting flange respectively, and an intermediate portion thcrebetween having interengaging means operable upon the said interior engageable surface of the stufiing gland, whereby said bearing surface portion is displaced relative to the stufiing gland upon adjustment of said flange part and is thereby made operable to contact the ball member above said gasket to force the ball member against the seating member independently of the degree of adjustment of the stufling gland and the pressure applied thereby uPQn the gasket, and wherein one of said adjusting flanges extends out from within the other to facilitate the said independent adjustment.

3. An improved ball joint sealing structure comprising a seating member having a'spherical cup-shaped bearing portion, said seating member having an upper circumferential shoulder, a spherical ball member seated in said a 4 cup-shaped bearing portion, resilient gasket means mounted in said circumferential shoulder adjacent the ball member, hollow cylindrical stufling gland means comprising a bearing end face, an interior smooth cylindrical surface, an adjusting flange arranged exteriorly on said gland means opposite to said bearing end, and an engageable surface adjacent said smooth surface and said exterior flange, said stufiing gland being adjusta-bly mounted in said seating member by means of cooperatively engaging threads in said seating member and on said stufling gland, to apply the bearing end thereof to engage the gasket to compress it, the internal diameter of the stufling gland being at least equal to the diameter of the ball member whereby the latter is at most in tangential contact with the said smooth interior surface of the stuffing gland, permitting facile relative movement between the ball member and said smooth surface at any degree of adjustment of the stufling gland with the seating member to compress the gasket, and an adjustable pressure means comprising a nut means having as integral parts at opposite ends thereof, a bearing surface means, and an adjusting flange, respectively, and an intermediate portion therebetween threadably connected and operable upon the said interior engageable surface of the stuffing gland, whereby said bearing surface means is made operable upon adjustment of said flange part to contact the ball member above said gasket, and exert a bearing pressure thereon to force the ball member against the seating member independently of the degree of adjustment of the stufling gland and the pressure applied thereby upon the gasket, and wherein one of said adjusting flanges extends out from within the other to facilitate the said independent adjustment.

References Cited in the file of this patent UNITED STATES PATENTS 343,769 Levi June 15, 1886 409,277 Curley Aug. 20, 1889 900,603 Silk Oct. 6, 1908 908,414 Mellin Dec. 29, 19-98 909,263 Walters Jan. 12, 1909 1,752,696 Roberts et al. Apr. 1, 1930

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