US 3558800 A
Description (OCR text may contain errors)
References Cited UNITED STATES PATENTS 2,621,228 12/1952 Tompers...................... 174/77X 3,087,606 l74/87UX generally to the field of type used to maintain isted configuration, and is general type specific cona joint which ambient atmosphere,
Benedict L. Wallis 445 East 68th St., New York, N.Y. 10021; Michael Gold, 80 Oak Drive, Roslyn, N.Y. l 1576 3 Feb. 3, 1970 Patented Jan. 26, 1971 Substitute for application Ser. No. 579,084, t- 3 12 6, qwab d Inventors AppLNo.  Filed 1 CONSTRUCTION 2 Claims, 5 Drawing Figs.
54 smuuc PIGTAIL CONNECTOR United States Patent r t a SEALING PIGTAIL CONNECTOR CONSTRUCTION This application is a substitute for application Ser. No. 579,084 filed Sept. l 3. 1966, now abandoned.
In many electrical applications it is desirable to form a con ductive electrical joint which will be impervious to the presence of moisture, whereby corrosion and oxidation will not affect the conductive ability of the interconnected conductors at the joint. This is particularly important in marine installations, and in other areas where a high concentration of moisture is always present. Since the pigtail interconnection is formed by stripping the wires to be interconnected of their protective insulation prior to twisting the same, and the connector which engages the pigtail is open at one end to permit the insertion of the same, the possibility of circulation of moisture-carrying air to the joint has, in prior constructions, caused a substantial amount of corrosion.
In addition to the above problem, many pigtail connector constructions are incapable of sustaining ajoint in such condition that it will be free from the deleterious affects of vibration, so that with continued use of the equipment upon which the pigtail connector is installed, the electrical interconnection is loosened with a corresponding loss in conductivity. It is to be understood that it is not necessary that the mechanical interconnection be broken, it is sufficient that it is loosened with a corresponding increase in electrical resistivity.
The application by manual means of a sealing composition surrounding the conductor at the pigtail connector has been possible, and it is known in the prior art to employ various tarry or waxy compositions for this purpose. Such compositions, however, upon aging lose their adhesion to the electrical wires thus exposing the wire joint to the surrounding atmosphere with subsequent onset of corrosion, loosening of the connection, increase in electrical resistance and possible failure.
It is therefore among the principal objects of the present invention to provide an improved means for placing a sealant in the area of the pigtail, in such manner that a minimum of manual effort is required.
Another object of the invention lies in the provision of an improved pigtail connector construction incorporating selfsealing means therein which may be manually actuated upon the threading of the connector upon a pigtail, and which will confine the resin to the desired areas during the period in which the same is setting in situ.
A further object of the invention lies in the provision of an improved pigtail connector construction incorporating a multicavity reservoir capable of containing resin and hardener in separated condition, and having means for expelling the resin and hardener into contact with each other, and subsequently around the joint to be protected.
Yet another object of the invention lies in the provision of an improved construction of the class described, in which the cost of fabrication may be of a reasonably low order, with consequent wide sale, distribution and use.
A feature of the disclosed embodiment lies in the fact that the same may be constructed almost entirely from injection molded synthetic resinous materials which may be conveniently manually assembled.
These objects and features, as well as other incidental ends and advantages, will more fully appear in the progress of the following disclosure, and be pointed out in the appended claims.
In the drawing, to which reference will be made in the specification, similar reference characters have been employed to designate corresponding parts throughout the several views.
FIG. 1 is an exploded longitudinal sectional view of an embodiment of the invention.
FIG. 2 is a longitudinal sectional view of the embodiment in assembled condition, and with a wire pigtail engaged thereby, following'which plunger means comprising an element of the embodiment has been actuated to surround the joint with curable epoxy resinous material.
FIG. 3 is an end elevational view of the plunger element as seen from the upper portion of FIG. 1.
FIG. 4 is an end elevational view of the reservoir element from a similar viewpoint.
FIG. 5 is an end elevational view of the strainer element from a similar viewpoint.
In accordance with the invention, the device, generally indicated by reference character 10, comprises broadly: a connector element 11, a reservoir element l2, a plunger clement 13, and a strainer element 14. As mentioned above, all of the above elements are at least partially fabricated from suitable synthetic resinous material to relatively close tolerances, to prevent leakage of the epoxy sealant materials employed.
The connector element 11 is of a type known in the prior art, and includes a hollow shell member 16 and a metallic spiral insert 17. The shell member 16 is bounded by an end surface 18, a tapered frustoconical surface 19, and an end surface 20 leading to a conically-shaped recess 21. The recess 21 communicates with a threaded recess 22 which engages the spiral insert 17, as best seen in FIG. 2 in the drawing.
Extending radially from the wider end of the surface 19 is an annular rib 23 which serves as interconnecting means cooperating with the reservoir element 12.
The spiral insert 17 may be formed of copper wire, and includes an outer or larger end 24 as well as an inner end 25, the overall length of the same as measured along its principal axis being preferably slightly shorter than the recess 22, as best seen in FIG. 1.
The reservoir element 12 is best seen in FIGS. 1 and 4, and includes an outer cylindrical wall 28, an inner cylindrical wall 29, a pair of axially arranged planar septums 30 and 31, as well as first and second coplanar walls 32 and 33. There are thus formed first and second chambers 34 and 35, each having a lower opening at 36 and 37 (FIG. 4) through which epoxy resin and corresponding hardener (not shown) may be forced to a lower portion 38 enclosed by the wall 28. The lower edge 39 of the wall 28 includes an inwardly extending bead 40 forming a recess 41 in which the above mentioned annular rib 23 is positioned when the device is assembled (FIG. 2). To facilitate engagement, the bead 40 is preferably provided with a tapered surface 42.
The plunger element 13 is slidably positioned within the reservoir element 12, and includes first and second plunger members 46 and 47, respectively, each having an outer wall 48, an inner wall 49 and a lower wall 50 forming slots 51 for clearance with the septums 30 and 31. An annular bead 52 contacts the upper edge of the wall 28, as seen in FIG. 2, when the plunger element is fully seated within the reservoir element.
Disposed centrally of the inner walls 49 is a cup-shaped member 54, including a cylindrical sidewall 55 and a thin lower wall 56 having a centrally disposed opening 57 coaxially disposed with a centrally disposed opening 58 in the reservoir element 12. As the lower wall 56 is preferably as little as .003 inches thick, it will readily flex upon the entry ofa conductor, and if necessary, rupture to the proper degree to allow passage thereof.
The strainer element 14 is positioned within the recess 21 prior to assembly of the device, and serves to provide a solid area in which the mixing of the epoxy resin and hardener may take place. As best seen in FIG. 1, it includes a cylindrical wall member 60 having a centrally disposed bore 61 therein. An upper annular member 62 is formed integrally therewith, and includes a radially extending wall 63 meeting an axially extending cylindrical wall 64 to fomr a trough with the wall member 60. A transverse opening 65 extends through the wall member 60, preferably in the area of an axially extending opening 66.
Referring to FIG. 2, there is illustrated the appearance of the device after installation. A plurality of conductors 69 have been stripped of insulation at the ends thereof and twisted to form a pigtail, following which they are inserted within the connector element 11 to be threadedly engaged by the spiral insert 17. Following this, the plunger element 13, which has been previously engaged to a limited degree within the reservoir element 12 is depressed, forcing epoxy resin and hardener from the chambers 34 and 35 through the openings 36 and 37 wherein streams of each component flow through the axially extending opening 66 into the space between the tapered surface of the recess 21 and the outer surface of the wall member 60. Mixed resin 71 then flows through the opening 65 to flow downwardly and upwardly to completely enclose the end 70 of the conductor 69. and where sufficient resin is present to flow upwardly through the bore 61 up to the point where the insu lated portion of the conductors is contacted. Since the mixed resin is relatively thick. and the pigtail connector securely engaged, the interconnected conductors may be left in this condition until the resin has cured to establish a hermetic seal about the exposed portions of the conductor.
It may thus be seen that we have invented novel structure accomplishing the following results:
I. intimate contact of resin and wire.
2. Adhesion of resin to wire.
3. Total encapsulation of wire joint.
4. Enclosure and exclusion from ambient atmosphere.
5. A vibration-proof joint.
We wish it to be understood that we do not consider the invention limited to the precise details of structure shown and set forth in this specification, for obvious modifications will occur to those skilled in the art to which the invention pertains.
I. Improved-sealing wire pigtail connector construction comprising: a shell member having a conductor-receiving cavity therein and defining an opening leading to said cavity, a reservoir element connected to said shell member and having a through opening communicating with said cavity for the passage of a conductor therethrough, a plunger element slidably moveable into said reservoir element, said reservoir element defining first and second fluid-containing compartments, a two-phase fluid sealant maintained in separated con dition within said fluid-containing compartments, relative movement of said plunger element into said reservoir element serving to vary the effective size of said first and second compartments, whereby said sealant, contained in said compartments is expelled into said cavity to be mixed and activated thereat.
2. Structure in accordance with claim 1, including strainer means disposed between said opening to said cavity and said reservoir element, for providing an intermixing function to fluids passing from said two compartments upon being injected into said cavity.