US 3740692 A
A rugged and compact electrical cable connector assembly for direct burial applications using a limited number of components which can be readily assembled into numerous configurations to provide stable electrical connections for a range of cables and tap lines.
Description (OCR text may contain errors)
United States Patent 11 1 Filhaber June 19, 1973 1 UNDERGROUND DISTRIBUTION CONNECTOR ASSEMBLY  Inventor: llmar J. Filhaber, Poughkeepsie,
 Assignee: Fargo Mfg. Company, Inc.,
 Filed: May 10, 1972  Appl. No.1 252,321
 US. Cl 339/19, 174/72 R, 339/198 N,
339/242  Int. Cl H0lr 31/08, H011 11/32  Field of Search 339/198 .1, 198 N,
339/109 R, 242, 22 B, 19; 174/72 R, 84 S, 88 S  References Cited UNITED STATES PATENTS 3,519,981 7/1970 Koletsos 339/242 1/1972 Polidori 339/19 3, 33,147 3,577,114 5 1971 Hawkins 339 242 x 3,546,364 12/1970 ONeel 339/242 x Primary Examiner-Joseph l-l. McGlynn Assistant Examiner-William F. Pate, lIl Attorney-David S.v Kane, Daniel H Kane, Philip T. Dalsimer et a1.
 ABSTRACT A rugged and compact electrical cable connector assembly for direct burial applications using a limited number of components which can be readily assembled into numerous configurations to provide stable electrical connections for a range of cables and tap lines.
15 Claims, 10 Drawing Figures PAIENIEB J n 1 18- UNDERGROUND DISTRIBUTION CONNECTOR ASSEMBLY BACKGROUND OF THE INVENTION It has become highly desirable for a number of reasons to bury electrical transmission lines underground. Connector assemblies for such underground applications must be designed with this end use in view. In direct burial applications where the connection of electrical wires is made and left without benefit of enclosure in a vault, the connector used must be moisture proof and provision must be made for sealing.
Additionally, the design should be such that a variety of sizes of cables and tap lines can be accommodated with a minimum of installation effort and without special tools. The connector must be designed so that taps can be made by tap lines and cables added and withdrawn after the original installation.
Additionally, it is important that the connector be sufficiently flexible so as to accommodate a variety of sizes of cable and at the same time relatively economical of manufacture having a minimum number of parts.
SUMMARY OF 'THE INVENTION A connector for electrically and mechanically connecting cables and tap lines including in combination an elongated base member formed of an electrically conductive material and having a plurality of transverse parallel groovesprovided in one face thereof, a plurality of individual pressure pads with each having a groove formed therein, screw means for attaching each of said pressure pads to said base with the groove therein overlying and facing a respective groove of said pressure pad for receipt of a cable end therebetween, a moisture proof container in which said base member and said pressure pads are disposed, bolt means of said screw means disposed on the outside of said container with the remainder of the screw means projecting therethrough, first sealing means between each of said bolt means and said container, tap line attachment means formed on certain of the bolt means for electrically and mechanically connecting a tap line thereto, openings in said container aligned with respective grooves of said basev member for passage of cables therethrough and second sealing means formed on said container at said openings.
DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a connector constructed in accordance with the teachings of this invention with the container and container cover shown which are used in direct burial applications;
FIG. 2 is an exploded perspective viewof the base and pressure pad which is shown in FIG. 1 but from the remaining side thereof as is seen in FIG. 1;
FIG. 3 is a perspective view of the connector shown in FIG. 1 but in fully assembled condition with cables illustrated extending therefrom;
FIG. 4 is a longitudinal sectional view taken along the line 44 in the direction of the arrows in FIG. 3;
FIG. 5 is a transverse sectional view taken along the line 55 in the direction of the arrows in FIG. 4 illustrating cables extending from the connector through the sealing cones of the container cover;
FIG. 6 is a transverse sectional view taken along the line 6-6 in the direction of the arrows in FIG. 4 illus- LII trating the tap bolts which are utilized for attaching tap lines to the connector;
FIG. 7 is a transverse sectional view taken along the line 7--7 in the direction of the arrows in FIG. 6;
FIG. 8 is a perspective view of the connector base with a bus bar attached thereto;
FIG. 9 is a perspective view of the connector base with a stud-to-spade adapter mounted thereon; and
FIG. 10 is a transverse partially sectional, partially exploded view of connector, casing, cable, cable sealing cone, tap line, tap bolts and tap line seal which are utilized in the practice of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT The distribution connector which is the subject of this invention consists of elongated base 20, a plurality of pressure pads such as pad 21 shown in FIG. 1, screw 22 for fastening the pressure pad in position, adapter 23, moisture proof container body 24 and moisture proof container cover 25 vulcanized thereto.
The base 20is a substantially rectangular elongated member which in the preferred embodiment is an aluminum extrusion provided with transverse parallel cable receiving grooves 26, 27, 28 and 29 in face 30 thereof. The grooves are alike and each has a V base channel formed by walls such as 26a and 26b in groove 26 with upper side walls 260 and 26d extending respectively therefrom in planes forming a larger angle therebetween than that formed by the planes of walls 26a and 16b. The number of these grooves in the base can be varied from the four shown in base 20 to more or less. A pressure pad 21 also formed of a conducting material is provided for cooperation with each of the grooves. Each of the pressure pads has a groove formed therein such as the groove 31 in pad 21. Groove 31 has a single channel formed by walls 31a and 31b which form an angle of magnitude in the range of the angle formed by walls 26a and 26b. Screw means consisting of screws of the type screw 22 are provided for attaching each of the pressure pads to the base with the groove in the pressure pad overlying and facing a respective groove of the pressure pad for receipt of a cable end therebetween. Hence, in the Figs. the pressure pad 21 is provided with groove 31 for cooperation with groove 26 of the base 20 whereby small diameter cables disposed within groove 26 and maintained therein by pressure pad 21 will be embraced by walls 26a and 26b of groove 26 and walls 310 and 31b of groove 31. Larger diameter cables will be embraced by walls 260 and 26d of groove 26 as well as walls 31a and 31b of groove 31. Hence, the grooves in the unit are useful for a variety of cables having different diameters. In order to allow the attachment by screw 22, flanges 32 and 33 are provided on pressure pad 31 and each of these flanges has a threaded insert formed therein. Flange 32 is provided with threaded insert 32a and flange 33 is provided with threaded insert 33a for receipt of the end 22a of screw 22 which is threaded. Two screws 22 would be utilized to attach pressure pad 21 to base 20. The groove in the pressure pad and in the base are so designed that they will allow conductor sizes of a wide range to be connected without change of pressure pad or additional fitting. As will appear below, it is merely necessary'to skin the conductor or cable end and thereafter tighten the two bolts controlling that pressure pad in order to make the connection.
Tongue and groove attachments are provided at the ends of base to allow for the joining and satisfactory current interchange at the joining of several base members in tandem. They furthermore allow base members to be joined without any loss of position of the adjacent cable termination area or groove. Hence, groove 34 is provided in base 20 for receipt of a tongue such as tongue in base 20 from another base member thereby joining base member 20 in tandem with an additional base member. Adapter 23 with hole 23a for passage of screw 22 therethrough, is provided for use in groove 34 to enable the proper usage of the screw 22.
The base member 20 and pressure pads are disposed within moisture proofcontainer 24 which is formed of anysuitable material such as rubber. Holes are provided in the container 24 in alignment with the threaded inserts of the pressure pads in the assembly for passage of screws 22 therethrough for engagement of the threaded portion 22a .of each screw with its respective threaded insert. In the Figs. the holes in container 24 are each identified by the numeral 35 and surrounded by an outwardly projecting turret 36. The holes in base 20 through which the screws are passed are identified in the Figs. by the numeral 37. The bolts 22 are designed to allow for conventional fastener operation by allowing a metal-to-metal fastener thrust while retaining the insulation integrity of the head and I dished out sealing washer. In the Pigs. the numeral 22a as mentioned above, identifies the threaded portion of the bolt. The numeral 22b identifies the unthreaded portion of the shank. The numeral 22c identifies the metal shank with a portion not encapsulated. The numeral 22d indicates the encapsulated insulated head which allows for torque transmittal. This also provides hex corners resulting in a cam action when excess turning torque is applied. The bolt cannot be destroyed through the application of excessive torque since, if a destructive torque is applied to the head, the head merely cams out from under the wrench and once the strain has been removed, it restores itself to its normal state thereby retaining its functionality. With the castellation additional material supports the head and keeps it from shearing. The washer is identified by the numeral 22e. I
Sealing means is provided between each bolt 22 and the container. The sealing means is provided by a number of features each of which individually provides a seal and which together provide an extremely superior sealing effect.
One of these sealing features is the provision of an interference fit between the insulated bolt shank 22f and the hole 35 formed in the casing with the insulation at shank 22fchamfered at 22g for entry. A second sealing feature is the provision of a convex annular surface 36a of turret 36 and a concave or dished out surface of washer 22e with the angles of the surface deviation being such as to provide interference thereat. As the electrical connector is tightened, the mismatch results in compression of the rubber and a positive compres sion water seal.
A third sealing feature results in the rolling of the inner portion of the turret-the portion upon which surface 36a is formed-inwardly to thrust against the bolt. A fourth sealing feature is present since as the bolt is screwed in, the flange of the bolt moves up until metal-to-metal contact is made-thereafter any stresses on the unit are transmitted metal-to-metal and not through the bolt head material.
If a bolt is inadvertently removed or two bolts which control the same pressure pad are inadvertently removed, there is no danger since these pressure pads are captive due to the groove design and the design of the enclosure itself. The seal body and the bolt body portions are held together by the process of vulcanizing thereby rendering this assembly a true hermetic seal.
Tap line attachment means are formed on certain of the bolts where a tap line is to be used. In FIG. 10 the use of such tap line attachment means is shown. The head of the screw 38 is provided with a threaded insert 39 and a cylindrical extension 40 of the insulation through which the threaded shaft of tap bolt 41 extends for engagement with the threaded insert 39. Screw 42 is provided to maintain tap line 43 in position. Alligator clip cover 44 is used for insulating purposes having an end thereof indicated by the numeral 44a adjacent the insulated head of screw 38 and a remaining end 44b embracing the insulation of the tap line 43. In certain installations it may be desirable to utilize a hose clamp to hold the cover 44 in position although the hose clamp is not illustrated in FIG. I0. Holes 45 are formed'in container cover 25 to allow passage of cables 46 therethrough for electrical and mechanical connection to the connecton Sealing means are provided at each hole 45. To provide the sealing means an hourglass configured projection 47 is formed integralwith the cover at each hole 45. A cone integral with the projection and attached thereto at the outermost end 48 projects inwardly within projection 47 and is identified by the numeral 49. It has a tear away tip and fluting 51 on its inside. Since the cone is small, it needs to stretch only slightly when a cable is inserted therein and for small diameter cables only the conical portion 49-stretches. In larger diameter cabling the hourglass projection 47 stretches. As hydrostatic pressure on the outside increases, sealing pressure increases forcing the projection 47 against the insulation of cable 46. The fluting acts as dikes tending to ring air out as the cable is passed through and tends to keep the seal from shifting back and forth.
When the conductor is to be installed, the procedure is as follows: The appropriate bolts which are clearly marked on the box are loosened to the fullest extremity. A mechanical stop device on the shank of the bolt which also renders the bolt casually captive can be used. The conductor is skinned to the prescribed strip length and inserted through the hole 45 until it bottoms. Bottoming will become apparent by the mechanism of the casing bulging slightly opposite the conductor when the conductor has been fully inserted. The bolts are then tightened. Prior to the insertion of the cable, the port is sealed. The insertion of the cable destroys the initial seal which prevents the intrusion of foreign agents into the box and makes a new seal for itself around the periphery of the conductor. If at some future date it is required to remove a connector such as in a service termination, the port must be plugged with a stopper. This will render the system watertight without a conductor once the initial seal has been destroyed. If a larger conductor is to be installed replacing a smaller one, this can be done since the seal will still remain active and merely conform itself to the larger conductor.
In FIG. 8 a punched bus bar 52 containing two rows of holes 53 is provided in combination with the base 20. This punched bus bar can be affixed by welding and oriented as shown in FIG. 8 or at 90. In FIG. 9 extrusion 54 with tapped opening 55 is brazed onto the base illustrating the flexibility of the system.
It is claimed:
1. A connector for electrically and mechanically connecting cables and tap lines including in combination an elongated base member formed of an electrically conductive material and having a plurality of transverse parallel grooves provided in one face thereof, a plurality of individual pressure pads with each having a groove formed therein, screw means for attaching each of said pressure pads to said base with the groove therein overlying and facing a respective groove of said pressure pad for receipt of a cable end therebetween, a moisture proof container in which said base member and said pressure pads are disposed, head means of said screw means disposed on the outside of said container with the remainder of the screw means projecting.
therethrough, first sealing means between each of said head means and said container, tap line attachment means formed on certain of the head means for electrically and mechanically connecting a tap line thereto, openings in said container aligned with respective grooves of said base member for passage of cables therethrough and second sealing means formed on said container at said openings.
2. A connector in accordance with claim I in which each of the grooves in the face of said base member has a base channel and upper side walls extending respectively therefrom in planes forming a larger angle therebetween than that formed by the planes of the walls of said base channel and the grooves in each of said pressure pads has walls forming an angle of magnitude such that the walls of said base channel cooperate with the walls in the groove of said pressure pad in" connecting small diameter cable while said upper side walls cooperate with the walls in the groove of said pressure pad in connecting large diameter cables.
3'. A connector in accordance with claim 2 in which said base channel and the channel in said pressure pad are V channels.
4. A connector in accordance with claim 1 in which each of said screw means has a head portion and a shank extending therefrom and is encapsulated at said head portion with nonconducting resilient material which extends over said shank with a portion thereof not encapsulated to allow for metal-to-metal contact of said shank and said base member.
5. A connector in accordance with claim 4 in which said head portion is in the form of a hex allowing camming action by movement of said resilient material with respect thereto upon application of excessive torque at said head and return of said resilient material to initial position upon removal of said excessive torque.
6. A connector in accordance with claim 1 in which said tap line attachment means includes a threaded insert in said head means, a tap bolt for connecting a tap line and a cylindrical extension of said resilient material through which the shaft of said tap bolt extends for receipt in said threaded insert.
7. A connector in accordance with claim 1 in which each of said screw means has a head portion and a shank extending therefrom and is encapsulated at said head portion with nonconducting resilient material which extends over said shank and said first sealing means includes the provision of an interference fit between said shank and container at said openings.
8. A connector in accordance with claim 1 in which each of said screw means has a head portion and a concave sealing washer integral therewith with said head portion and said washer encapsulated with nonconducting resilient material, and a convex annular surface surrounding each of said openings with the angle of the surface deviation being such as to provide interference with said respective washer.
9. A connector in accordance with claim 1 in which each of said screw means has a head portion and a shank extending therefrom and is encapsulated at said head portion with nonconducting resilient material which extends over said shank and said container is provided with an annular portion which embraces said shank upon the application of said screw means to roll inwardly to thrust against said shank.
10. A connector in accordance with claim 1 in which each of said second sealing means includes a projection formed integral with said cover and a cone in alignment with said opening attached to said projection at the outer end thereof projecting inwardly within said projection through which said cable extends.
11. A connector in accordance with claim 10 in which the outer surface of said projection is contoured to provide for inward radial movement of said projection upon application of hydrostatic pressure on the outer surface thereof to increase the force of the end of said projection against the insulation of said cable.
12. A connector in accordance with claim 11 in which the outer surface of said projection is contoured in the form of an hourglass.
13. A connector in accordance with claim 10 in which radial fluting is provided on the inner surface of said cone.
14. A connector in accordance with claim 10 in which said cone is provided with a tear-away tip and radial fluting projecting from its inner surface.
15. A connector in accordance with claim 1 in which a tongue is provided at one end of said base member and a groove is provided at the remaining end thereof with each of said tongues formed to be received in said groove of a base member identical to said base member to allow base members to be joined and allow for satisfactory current interchange at the joining without loss of position of any of said grooves.