US 3459873 A
Description (OCR text may contain errors)
5,1959 L.A. HARRIS ET 3,459,873 I SHIELDED CONNECTOR FOR MOVABLE LINES Filed Feb. 16, 1967 If'rvervtor-si Lawrence A.Hd.r-r-'is Arthur N. De Tom mdSI,
.b d. M
y Their Attorney.
United States Patent 3,459,873 SHIELDED CONNECTOR FOR MGVABLE LINES Lawrence A. Harris, Schenectady, and Arthur N. De Tommasi, Newtonville, N.Y., assigncrs to General Electric Company, a corporation of New York Filed Feb. 16, 1967, Ser. No. 616,687 Int. Cl. H02g 15/18 US. Cl. 17486 3 Claims ABSTRACT OF THE DISCLOSURE To provide a shielded flexible connection for two coaxial lines, two conductive balls with diametrical aper tures are inserted over each of the two coaxial lines, a wire is connected between the inner conductors of each of the two coaxial lines, conductive tubular members form a socket for each of the conductive balls and are engaged with screw threads to shield the connecting wire, and a tubular insulator within the tubular members encircles the 'wire and separates the conductive balls.
This invention relates to a shielded connector for shielded conductors, and more particularly, to a shielded connector allowing angular displacement of the axes of shielded conductors.
In many electronic vacuum systems utilized in experimental and industrial apparatus, it is necessary to shield various conductors. These conductors may require shielding for one of two reasons. First, very small currents carried by the wires are subject to serious disturbances caused by stray electrons or ions within the system striking the wires. Second, those wires of the systems which are at a high electrical potential may create fields which would seriously impair the desired characteristics of the phenomenon occurring within the vacuum system.
Not only is it necessary that the wires be shielded, but it is equally necessary that all connections between the Wires be shielded. While a conventional coaxial line satisfies the requirement of the shielded wire, the requirement of the shielded connector is somewhat more ditficult since the connection itself should retain some degree of flexibility to accommodate the connection of shielded conductors with angularly displaced axes.
In addition, the shielded wire and connectors must withstand rather high temperatures within the vacuum system without giving off contaminating vapors. Of course, contaminating vapors within the vacuum system would also greatly impair the desired characteristics of the phenomenon within the systems. In the art, this ability to withstand the high temperatures of the vacuum system without giving cit contaminating gases is termed bakeability. Commercially available flexible coaxial cables have organic insulation which is not bakable. The need for bakeability restricts the materials to metals and inoganic insulators such as glass or ceramic which are inflexible.
In the prior art, the desired characteristics of flexibility and bakeability of shielded electrical connections have achieved by utilizing a series of hollow insulating beads inside a copper braid. While this method was effective to some degree, the braid was generally undesirable since the shielding was not complete and the many fine wires in the copper braid were difiicult to control.
Although various ball and socket arrangements have been utilized for connecting coaxial cables for RF transmission, many are expensive and/or not easily disconnected.
Accordingly, it is an object of this invention to provide a flexible connection between inflexible sections of a shielded conductor.
It is another object of this invention to provide a flexible connection having a high degree of bakeability.
It is still a further object of this invention to provide a shielded connector which is simplified and may be readily disconnected or adjusted.
Briefly, in accordance with one form of this invention, there is provided a shielded connector which allows for angular displacement of the axes between a first shielded conductor comprising inner and outer conductors and a second shielded conductor comprising inner and outer conductors. The shielded connector comprises conductive balls with apertures through which the shielded conductors are inserted making electrical contact therewith and a flexible conductive member electrically connecting the inner conductors of the shielded conductors. The conductive balls are separated by a tubular inorganic insulator member and enclosed therewith in a conductive tubular enclosure forming sockets for and making electrical contact with the conductive balls.
The specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention. The invention may also be understood from the following description taken in connection with the accompanying drawings in which:
FIGURE 1 is a partial cross-sectional view of a shielded conductor;
FIGURE 2 is an end view of a tubular insulator contained therein; and
FIGURE 3 is an end view of an alternative tubular insulator.
As shown in FIGURE 1, a first shielded conductor 10 comprising a first inner conductor 11, a first rigid insulator 12, and a first outer conductor 13 are electrically connected to a second shielded conductor 14 comprising a second inner conductor 15, a second rigid insulator 16, and a second outer conductor 17. Effectively, the first shielded conductor 10 and the second shielded conductor 14 are coaxial lines electrically connected by a shielded connector 18.
In order to provide the necessary flexibility in the electrical connection, the shielded connector 18 utilizes two ball and socket electrical connections comprising a first metal conductive ball 19 contained within a socket formed by a tapered portion of a first metallic tubular member 20 of a conductive enclosure and a second conductive or metal ball 21 and a socket formed by a tapered portion of a second metallic tubular member 22 of the conductive enclosure. The first conductive ball 19 and the second conductive ball 21 have diametrical apertures through which the shielded conductors 10 and 14 respectively pass. In this manner, electrical contact is made between the outer conductor 13 which shields the inner conductor 11 and the shielding ball and socket arrangement comprising the conductive ball 19 and the tubular member 20. Similarly, an electrical connection is made between the outer conductor 17 shielding the inner conductor 15 and the ball and socket combination comprising the conductive ball 21 and the tubular member 22.
The actual connection shielded by the connector 18 comprises a conductive member or Wire 24 connected to the inner conductor 11 and the inner conductor 15 by conventional techniques, as for instance spot welding. The wire 24 spans a gap between the conductive ball 19 and the conductive ball 21, which gap is maintained by a tubular inorganic insulator 25 which abuts the conductive balls 19 and 21 and prevents the inner conductive member 24 from electrically contacting the outer tubular members 20 and 22.
The electrical connection may be mechanically secured by engagement of a male threaded portion 26 of the tubular member 20 and a female threaded portion 27 of the tubular member 22. The threaded engagement of the first tubular member 20 and the second tubular member 22 in combination with the tubular insulator 25 thereby retains the first conductive ball 19 and the second conductive ball 21 in a spaced position. In order to retain the shielded conductor 10 and the shielded conductor 14 within the shielded connector 18 after extending a portion of each conductor through the conductive ball 19 and the conductive ball 21, portions 28 and 29 of the outer conductors 13, 17 respectively, are flared. In order to prevent the shielded conductors 10 and 14 from extending too far within the shielded connector 18, small sleeves 33 and 34 are attached to the outer conductors 13 and 17 respectively, after assembly of the connector is completed. Sleeves 33 and 34 may comprise any suitable metallic material or nonmetallic inorganic material and may be secured to members 13 and 17 in a conventional manner.
Thus, it may be seen that the shielded inner conductor 11 and the shielded inner conductor 15 are electrically connected through a shielded connection provided by the shielded connector 18, and more specifically, by the conductive enclosure provided by the tubular member 20, the tubular member 22, the conductive ball 19, and the conductive ball 21. Yet, in spite of the shielding of the electrical connection as provided by the wire 24, the connection itself obtains the necessary flexibility which may be ascertained by observing the illustrated angular displacement between the axes of the shielded conductor 10 and the shielded conductor 14. The range of angular displacement is limited by interference of the flares 28 and 29 with the insulator 25, or by interference of the sleeves 33 and 34 with the tapered ends of the tubular members 20 and 22, respectively. In order to increase the range of angular displacement the tubular members 20 and 22 have beveled ends 30 and 31, respectively. Of course, the bakeability requirement is readily obtained since the conductive enclosure, the metallic tubular insulator 25, and the wire 24 are not subject to emission of contaminating vapors as an organic enclosure would be.
The precise shape of the insulator 25 may be dictated by the particular assembly technique utilized. When the tubular member 25 is solid as shown in FIGURE 2, the spot welding of the wire 24 to the conductors 11 and 15 can be made after the tubular insulator 25 is inserted intoposition and slid back with the conductive ball 19 along the outer conductor 13. After wire 24 is connected, the ball 19 and insulator 25 are slid toward the flare 28 so that threads 26 and 27 can be engaged. If a slotted tubular insulator 32, as shown in FIGURE 3, is utilized, both spot Welds of the wire 24 may be made before the insulator 25 is placed in position. In either case, the axial positions of the shielded conductor 10 and the shielded conductor 14 must be determined prior to tightening the threaded engagement between the tubular member 20 and the tubular member 22 since the insulator 25 or the insulator 32 serve to retain the conductive ball 19 and the conductive ball 21 in fixed positions after tightening.
It is appreciated that alternative means for attaching the tubular member 20 and the tubular member 22 are available through conventional threaded fastening techniques. It is, of course, not intended to limit the invention to the particular fastening technique shown but rather to disclose one form of inexpensive means for fastening the shielding conductive enclosure.
Although the invention as described has been concerned with provision for a shielded connection between two .4 shielded conductors, the invention is readily adaptable to certain forms of RF transmission. While particular frequencies of RF transmission might be found to be inapplicable due to the discontinuities in the particular ball and socket arrangements, RF transmission at many frequencies can be effected through the shielded connector 18 as shown. Since the intent of the above discussion has been to disclose a low cost shielding connector, there has been no attempt to design around the discontinuities which might impair transmission of particular frequencies.
Although specific embodiments of the invention have been shown and described, it is not desired that the invention be limited to the particular form shown and described, and it is intended by the appended claims to cover all modifications within the spirit and scope of the invention.
What is claimed as new and desired to be secured by Letters Patent of the United States is:
1. A shielded connector for electrically connecting a first shielded conductor comprising a first inner conductor and a first outer conductor with a second shielded conductor comprising a second inner conductor and a second outer conductor comprising:
a first conductive ball with a first aperture therethrough and a second conductive ball with a second aperture therethrough the first shielded conductor being inserted through the first aperture and the second shielded conductor being inserted through the second aperture,
a conductive enclosure enclosing and contacting said first conductive ball and said second conductive ball comprising a pair of interfitting sleeves having inwardly tapered ends engaging the remote outer surfaces of said conductive balls,
an inorganic tubular member positioned within said interfitting sleeves and engaging adjacent outer surfaces of said conductive balls to maintain said balls at a fixed distance,
a flexible conductor connected between said inner conductors, and
adjustable sleeves encircling said shielded conductors for preventing movement of said conductive balls along said outer conductors.
2. The shielded connector of claim 1 in which said interfitting sleeves have a threaded connection and said flexible conductor is folded and has an extended length greater than said fixed distance whereby connection of said flexible conductor to said inner conductors may be made after said inorganic tubular member is placed between said conductive balls.
3. The shielded connector of claim 1 in which said inorganic tubular member has a longitudinall extending slot.
References Cited UNITED STATES PATENTS 1,927,703 9/1933 Glowacki.
FOREIGN PATENTS 545,514 7/1922 France.
DARRELL L. CLAY, Primary Examiner US. 01. X.R, 174 91; 339-7