US1876585A - A coepoeatiobt ojt ne w - Google Patents

Description

Sept. 13, 1932. A. o. AUSTIN JOINT FOR CABLES AND OTHER DEVICES Filed May '7', 1929 1V Vii/V TOR Patented Sept. 13, 1932 STATE UNETE ARTHUR O. AUSTIN, 0F NEAR BARBERTC N, OHIO, ASSIGNQR, BY MESNE ASSIGNMENTS TO THE OHIO BRASS COMPANY, OF MANSFIELD, OHIQ, A CQRPOBATION OF NEW JOINT FOR GABLES AND OTEER DEVICES Application filed May '2, 1929. Serial No. 361,204.

This invention relates to joints between metallic and non-metallic parts such as may be used for connecting porcelain sleeves for sectionalizing the outer metal sheath of insulated conductor cables and for other devices where it is desirable to connect metal with porcelain or like material.

The invention has for one of its objects the provision of a joint of this nature which shall be liquid or oil tight and mechanically strong.

Other objects and advantages will appear from the following description.

The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawing and described in the following specification and in the steps of the process described in the specification. The novel features of the invention are more particularly pointed out in the appended claims.

The present application is in part a continuation of application, Serial Number 120,087, filed July 2, 1926.

In the drawing, the figure is an elevation with parts in section showing one embodiment of the invention applied to the metal sheath of an insulated conductor.

In the construction of cable joints, bushings, and other articles, it is frequently desirable to make a joint between metal and porcelain or similar material which will be air or oil tight and which will also provide mechanical strength. While in some cases tightness and mechanical strength are both important, in other, tightness or mechanical strength alone may be essential.

In the form of the invention shown in the drawing, an insulating sleeve or section is inserted in a cable sheath to break up longitudinal currents in the sheath. The porcelain sleeve 12 is interposed between adjacent portions of the cable sheath 13.' The outer surface of the porcelain 12 to be attached to the metal sheath 13 is provided with a metalized surface 14 similar to that described in my prior Patent Number 1,536,749, issued May 5, 1925. As explained in that patent, the surface of the porcelain before firing is covered with a liquid glaze and parof the lead sheath 13. wrapping 18 is to prevent loosenes's of the ticles of unfiredporcelain are distributed over the surface thus treated and adhere to the glaze material. l Vhen the piece is fired the glaze hardens and firmly secures the particles to the surface from which they project forming a roughened or sanded surface. The sanded surface provides a good bond so that a metallic coating may be applied thereto either by electric deposit or by other suitable'coating means such as an air or Shoup gun. If desired the portions to be plated may be given a conducting deposit of silver by the method used in coating mirrors or by any other suitable method which will give a conducting surface so that an electric deposit can be started. The electrical deposit may then be formed of any suitable metal such as copper or zinc. After the deposit is formed, the plated portion may be tinned by using a flux and any suitable metal such as tin or an alloy of tin and lead; the operation being similar to that employed in providing a tinned surface for solder. It is generally preferable to use a substance for this ti-nning operation which will melt readily and which will not damage the porcelain or dielectric'or tend to destroy the metallic film under the surface coating. After the surface of the porcelain has been thus treated.' the lead sheath is removed from a section of the cable and a portion of the sheath 13 is belled or flared outwardly as shown at 15.

The exposed portion of the nsulating covering 16 for the conductor 17 may be given a thin wrapping 18 of flexible insulating material such as cambric or paper, the thickness of the wrapping 18 beingsubstantiallv that The purpose of the sleeve 12 on the insulation 16 when the sleeve is in place. Unless the sleeve 12 is located at a point where the cable is spliced, it will have to be slid into place along the cable and vmust therefore have a sufficiently large opening to receive the cable, including the lead sheath. Both ends of the sleeve 12 are tapered and provided with a metallic coating and one end is inserted beneath the flared end of the sheath 13 until the other end passes the other termination of the lead sheath.

' forations 21 through This last named portion of the sheath is then flared outwardly and the sleeve 6 moved back until both ends project beneath flaredportions of the lead sheath 13. The lead sheath 13 is then pressed inwardly until it fits closely about the ends of the sleeve 12 and engages a portion of the metalized surface 14. A helix of reinforcing wire 19 is slid along the cable until it surrounds the overlapping portions of the sheath 13 and sleeve 12 as shown in the drawing. A further reinforcement 20 of sheet metal may be provided enclosing the wire 19. The reinforcing members 19 and 20 may be formed of any suitable metal having sufiicient mechanical strength and a higher coefficient of thermal expansion than the sleeve 12. When the reinforcement 20 is in place, attaching or filling metal 21, in a molten state is poured into the space about the joint and alloys with the coating 14 and the sheath 13 thus forming a perfectly tight joint. A suitable flux may be used to facilitate the union of the attaching metal with the other parts. It is not essential that a molecular union be formed between the attaching metal and the reinforcement but such a union may in some cases be desirable. The parts will be heated by the attaching metal and the member 20 will expand to a greater extent than the sleeve 12 so that when the parts are again cooled the member 20 will exert force on the attaching metal pressing it firmly against the sheath 15 and the coated surface 14. In some instances it may be desirable to use a reinforcing metal having a higher coeflicient of thermal expansion than the attaching metal. In this case if a leadtin solder is used for the filling metal, zinc may be used for the reinforcing member. In some cases it may be found advantageous to add antimony to the attaching metal so that it will contract but little if any in cooling or may even be made to expand, thus insuring complete filling of the space between the member 20 and the surface 14, after the joint has cooled, and permit the reinforcing member to exert the full effect of its contractive force on the joined surfaces. This will overcome any tendency for the joint to work loose. Where an antimony alloy is used for the filling metal, the reinforcement need not be of zinc but other metals such as copper may be used for this member. The reinforcing member 20 may be provided with one or more perwhich the solder is poured into the joint and the sleeve 12 may be perforated as shown at 22 and provided with a filling plug 23 through which the interior of the cable may be vented or supplied with a suitable filling compound. The plug 23 may be cemented in place or the interior of the opening 22 may be roughened and metalized and the tube soldered in position.

It will be apparent that the joint described is equally useful for attaching cables to potheads or other terminal members as well as to sectionalizing insulators.

The metalized surface of the porcelain will permit the solder to form a tight joint with the surface of the porcelain so that there is no danger of leakage. The reinforcement provides mechanical strength to the otherwise comparatively weak solder so that the solder is held firmly against the surface of the porcelain and danger of mechanical rupture of the joint is thus prevented.

It will be apparent that the form of joint described may be used for a great many purposes where it is desirable to connect porcelain or similar material to metal parts.

I claim:

1. The combination with a cable having a conductor, an insulating covering and an outer metal sheath, the end of said sheath be ing flared outwardly, of a dielectric sleeve surrounding said insulating covering and having a tapered portion extending between said sheath and said insulating covering, the outer surface of said tapered portion being roughened and coated with metal, attaching metal for securing said coated surface and sheath together, and a reinforcing member for preventing mechanical separation of the joint between said sheath and dielectric sleeve.

2. The combination with a conductor having an insulating covering and an outer metal sheath, of a porcelain sleeve surrounding said covering at the termination of said sheath, said porcelain sleeve having a tapered portion extending between said insulating covering and metal sheath, said tapered portion being roughened and coated with metal, attaching metal securing said coated surface to said sheath, and a reinforcing member for holding said attaching metal in position and for preventing mechanical separation of said attaching metal from said coated surface.

3. In combination a cable having an outer metal sheath and a porcelain sleeve disposed about said cable adjacent the end of said sheath, said sleeve having a portion of the surface thereof coated with metal, the sheath overlapping said coated portion and connected thereto by solder for forming a physically tight joint, the solder overlapping said sleeve and sheath, and reinforcing means extending about the periphery of said sleeve and sheath and embedded in said solder and acting to hold said solder against said sleev'. and sheath.

In testimony whereof I have signed my name to this specification this 3rd day of May A. D. 1929.

ARTHUR O. AUSTIN.

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