Patent Application
20060148336
The present invention relates to the field of electrical components, and, more particularly, to an electrical connector for connecting together a plurality of cable ends, and associated methods.
Underground and submersible junction bus connectors are widely used in electrical power distribution systems. One type of such connector is offered under the designation SWEETHEART® by Homac Mfg. Company of Ormond Beach, Fla., the assignee of the present invention. The SWEETHEART® connector is a cast or welded aluminum connector including a bus, or bar, portion and a series of tubular posts extending outwardly from the bus portion. The posts have an open upper end to receive one or more electrical conductors. A threaded bore is provided in the sidewall of the post, and which receives a fastener to secure the electrical conductor within the upper end of the post. An insulating coating is provided on the lower portion of the posts and bus of the connector. In addition, EPDM insulating sleeves may be used to provide waterproof seals for the posts. U.S. Pat. Ser. Nos. 6,347,966; 6,345,438 and 6,262,567 disclose various embodiments of such bus and post connectors.
Homac also manufacturers a RAB series of “Flood Seal”® Rubberized Aluminum Bar connectors suitable for direct burial, handhole or pedestal applications. The RAB connector includes a generally rectangular aluminum body having a plurality of spaced apart cable-receiving passageways therein. These cable-receiving passageways are blind holes, that is, they extend inward, but do not extend fully through the connector body. The blind hole is useful to provide sealing at the lower end of the connector body for the later molding of the rubber insulating cover.
The connector body also has a fastener-receiving passageway intersecting each cable-receiving opening. A fastener is provided in each fastener receiving passageway. Each fastener comprises a blunt end for bluntly contacting a corresponding insulation-free cable end. In particular, the blunt end may be a ball bottom screw end that helps break up aluminum oxides of the insulation-free cable end to ensure better electrical contact.
As the name states, the RAB connector includes a rubber insulating cover over the connector body. The insulating cover includes integrally molded inlets for both the cable-receiving openings and fastener-receiving openings. An insulating boot, such as a cable size adaptor or Rocket may be provided for the cable-receiving inlet, and a sealing cap may be received over the screw in the fastener-receiving inlet. Unfortunately, with less experienced labor crews, it is possible that a cable end may not be fully seated in its blind hole. Thus, even if the fastener initially presses partially against the cable end, this connection may work lose as the RAB connector is subsequently repositioned.
U.S. Pat. Ser. No. 6,688,921 to Borgstrom et al. discloses a connector similar to the Homac RAB series connector. In place of EPDM, the patent uses a thermoplastic elastomer (TPE) that combines the properties of thermoplastic with the performance characteristics of a thermoset rubber. The use of TPE enables the molding to further form sealing plugs and cable size adaptors attached to the cover with respective tethers. The connector also includes blind cable-receiving passageways, and is thus also susceptible to less reliable connections if the cable ends are not fully seated.
Michaud Electrical Equipment of France offered an insulation displacing connector (IDC) including a generally rectangular connector body, and transverse cable-receiving and fastener-receiving passageways. More particularly, the connector body included a backwall having a pattern of sharp ridges thereon to pierce the insulation on the cable end as the end of the fastener engages and presses against the cable end from the opposite side. To be sure the cable end is fully pressed onto the sharp ridges, a plastic viewing window is provided opposite the inlet of the cable-receiving passageway. Accordingly, an installer can view the cable end to be sure the insulation has been pierced. The window is adjacent the rubber cover. Unfortunately, the Michaud IDC device is likely to leak at the window since the seal is only a mechanical seal. In addition, insulation. displacement technology may not be suitable for larger cable sizes with thicker insulation coverings.
The Borgstrom et al. ′921 patent discloses an integrally formed tether or strap between a removable fastener inlet closure cap and a fastener inlet. The tether is relatively narrow and weak, thereby discouraging gripping of the tether to facilitate positioning of the cap. Moreover, the integrally formed tether requires a fairly complicated and expensive mold so that it can be formed along with the insulating cover and other components as described in the patent.
In view of the foregoing background, it is therefore an object of the present invention to provide an electrical connector that is craft-friendly for installation, and readily manufactured.
This and other objects, features and advantages in accordance with the invention are provided by an electrical connector for a plurality of electrical cables comprising a respective removable fastener inlet closure cap for each tubular fastener inlets, and a respective flexible tether having a proximal end removably connected adjacent a corresponding tubular fastener inlet and a distal end integrally molded with a corresponding removable fastener inlet closure cap. More particularly, the connector may include an electrically conductive body having a plurality of spaced apart cable-receiving passageways for receiving respective electrical cable ends therein, with each cable-receiving passageway having a cable inlet opening. The electrically conductive body may also have at least one respective fastener-receiving passageway intersecting each of the cable-receiving passageways. A respective fastener may be provided in each of the fastener-receiving passageways. The connector may also include an insulating cover on the electrically conductive body and comprising a respective integrally molded tubular fastener inlet aligned with each of the fastener-receiving openings.
Each of the flexible tethers may comprise a flexible elongate base. In addition, the flexible elongate base may have enlarged width distal and proximal ends, and a reduced width medial portion therebetween. The proximal end of the flexible elongate base may also have a ring shape defining an opening to be removably positioned surrounding a corresponding one of the tubular fastener inlets.
Each of the removable fastener inlet closure caps may include a cylindrical plug having a closed end extending outwardly from a distal end of the flexible elongate base. The removable boot closure cap may further comprise a gripping member extending within the cylindrical plug and beyond the enlarged width distal end of the flexible elongate member. The removable fastener inlet closure cap may further comprise at least one outer peripheral friction rib integrally molded with a corresponding cylindrical plug. Moreover, the flexible elongate member, cylindrical plug, and gripping member may be integrally formed as a monolithic unit.
The insulating cover may comprise an integrally molded respective tubular cable inlet aligned with each of the cable inlet openings. The electrical connector may also include a respective insulating boot received in each of the tubular cable inlets. Each cable-receiving passageway may have a respective cable end viewing opening opposite each cable inlet opening. In these embodiments, the connector may also include a respective electrically insulating transparent viewing window positioned adjacent each of the cable end viewing openings. The insulating cover may have a respective window opening therein aligned with each of the transparent viewing windows.
The insulating cover may comprise a thermoplastic elastomer (TPE). Additionally or alternately, each removable fastener closure cap and associated tether may comprise TPE. The electrically conductive body may have a generally rectangular shape, and may comprise aluminum, for example.
Another aspect of the invention relates to a method for making an electrical connector for a plurality of electrical cables. The method may include forming an electrically conductive body to have a plurality of spaced apart cable-receiving passageways for receiving respective electrical cable ends therein. Each cable-receiving passageway may have a cable inlet opening. The conductive body may also be formed to have at least one respective fastener-receiving passageway intersecting each of the cable-receiving passageways.
The method may further comprise forming an insulating cover on the electrically conductive body, and comprising a respective integrally molded tubular fastener inlet aligned with each of the fastener-receiving openings. The method may also include forming a respective flexible tether and cap assembly with the tether having a proximal end to be removably connected adjacent a corresponding tubular fastener inlet and a distal end integrally molded with a corresponding removable fastener inlet closure cap. The method may also include removably connecting each proximal end on a respective tubular fastener inlet, and positioning each removable fastener inlet closure cap in a respective tubular fastener inlet.
The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime notation is used in alternate embodiments to indicate similar elements.
Referring now initially to
The electrically conductive body 21 also has a plurality of spaced apart cable-receiving passageways 26 for receiving respective insulation-free electrical cable ends 31 therein.
Each cable-receiving passageway 26 has a cable inlet opening 27 and the cable end viewing opening 23 opposite the cable inlet opening. The electrically conductive body 21 also illustratively has a respective fastener-receiving passageway 32 intersecting each cable-receiving passageway 26 (
Each electrically insulating transparent viewing window 24 may be positioned adjacent a respective cable end viewing opening 23. The windows 24 thereby provide a cover and permit visual confirmation of proper placement of the insulation-free electrical cable end 31 within a corresponding one of the cable-receiving passageways 26. By transparent is meant that proper positioning of the cable end 31 is visible therethrough. Accordingly, although the window 24 can be fully transparent, transparent is also meant to include partially transparent or translucent where proper seating of the cable end is still viewable.
The insulating cover 25 on the electrically conductive body 21 also has respective window openings 35 therein aligned with the transparent viewing windows 24. The insulating cover 25 may preferably comprise TPE in some embodiments thereby forming an integrally molded bond with adjacent portions of the transparent viewing windows 24 as will be appreciated by those skilled in the art.
With particular reference to
The mounting flange 37 is illustratively overlapped by adjacent portions of the insulating cover as shown perhaps best in
The insulating cover 25 also illustratively includes an integrally molded respective tubular cable inlet aligned 41 with each of the cable inlet openings 27. The electrical connector may further include a respective insulating boot 45 received in each of the tubular cable inlets 41 as will be described in greater detail below.
The insulating cover 25 also illustratively comprises an integrally molded respective tubular fastener inlet 51 aligned with each of the fastener-receiving passageways 32 (
Referring now additionally to
A respective removable boot closure cap 57 is illustratively included for the open outer end 56 of the insulating boot 45. The insulating boot 45 also includes an integrally molded tether 58 connecting the removable boot closure cap 57 to the tubular sidewall 55. Accordingly, the removable boot closure cap 57 is readily available if needed for use, and is readily formed along with the other components of the insulating boot 45 during manufacturing. For example, the insulating boot 45 may be molded from TPE material, although other materials may also be used.
The removable boot closure cap 57 includes a flange 62, and a hollow cylindrical plug 63 having a closed end 64 extending from the flange. Of course, the plug 63 could be solid in other embodiments. The removable boot closure cap 57 also illustratively includes a gripping member or tab 66 extending within the hollow cylindrical plug 63 and beyond the flange 62. The gripping member 66 facilitates manual grasping or grasping using a suitable tool to permit removal or insertion of the boot closure cap 57. As will be appreciated by those skilled in the art, the flange 62, hollow cylindrical plug 63, and gripping member 66 may be integrally formed as a monolithic unit with the tether 58 and the tubular sidewall 55. The removable boot closure cap 57 can be inserted for an environmental seal to permit the boot 45 to be used even after it has been cut to receive a cable end 51, and the cable thereafter removed.
Referring now additionally to
As shown in the illustrated embodiment, the flexible tether 70 may comprise a flexible elongate base with enlarged width distal and proximal ends 70a, 70b and a reduced width medial portion 70c therebetween. The proximal end 70a of the flexible elongate base illustratively has a ring shape defining an opening 71 to be removably positioned surrounding a corresponding one of the tubular fastener inlets 51. Other configurations are also possible; however, the ring shape permits slight elastic expansion to secure the ring around the outside of the fastener inlet as will be appreciated by those skilled in the art.
The removable fastener inlet closure cap 53 includes a flange provided by the enlarged width distal end 70b of the base, and a hollow cylindrical plug 73 having a closed end 74 extending from the flange. In other embodiments, the plug 73 could be solid, for example. The removable fastener inlet closure cap 53 also illustratively includes a gripping member or tab 76 extending within the hollow cylindrical plug 73 and beyond the enlarged width distal eng 70b.The gripping member 76 facilitates manual grasping or grasping using a suitable tool to permit removal or insertion of the fastener inlet closure cap 53. The cylindrical plug 73 also includes an integrally molded peripheral friction rib 78 in the illustrated embodiment. As will be appreciated by those skilled in the art, the cylindrical plug 73, and gripping member 76 may be integrally formed as a monolithic unit with the tether 70. As will be appreciated by those skilled in the art, because of its relative large size and ruggedness, the tether 70 itself may be grasped and used to manipulate the fastener inlet closure cap 53.
The flexible tether 70 and removable fastener inlet closure cap 53 may be molded separately and thereafter installed on the fastener inlet 51 of the cover, in contrast to the similar tether and cap disclosed in U.S. Pat. Ser. No. 6,688,921 to Borgstrom et al. as discussed in the Background of the Invention section. In the Borgstrom et al. patent, the tether, its associated cap and an insulating boot are all molded simultaneously with the insulation cover. This may make molding more difficult and complicated as compared to the separate tether and cap, and separate insulating boot described herein. The separate tether and cap, and separate insulating boot may permit different materials and/or properties to be provided for these components as will also be appreciated by those skilled in the art.
Referring now to
Each moveable cable seating indicator 100 illustratively includes a mounting flange 101 and a pop-out indicator 103 extending outwardly therefrom, with the mounting flange being overlapped by adjacent portions of the insulating cover 25′. The mounting flange 101 and the pop-out indicator 103 may be integrally formed as a monolithic unit, for example. The pop-out indicator 103 illustratively includes a pleated cylindrical sidewall 104 and a closed end cap 105 connected to the sidewall (
As will be appreciated by those skilled in the art, in this embodiment of the connector 20′ the moveable cable seating indicator 100 need not be formed of a transparent material. For example, each moveable cable seating indicator 100 may comprise TPE, or other material, to form a strong bond with the TPE of the insulating cover 25′. The cable seating indicators 100 may also comprise polypropylene, or other similar materials as will be readily appreciated by those skilled in the art. The moveable cable seating indicator 100 may include carbon black or other materials to provide UV protection as will also be appreciated by those skilled in the art. Those other elements of the connector 20′ not specifically mentioned are similar to elements described above with reference to the embodiment 20 shown in
Returning again to
The method may further include aligning a respective electrically insulating transparent viewing window 24 adjacent each of the cable end viewing openings 23 to provide a cover and to permit visual confirmation of proper placement of the insulation-free electrical cable end 31 within a corresponding one of the cable-receiving passageways 26. In addition, the method may include overmolding an insulating cover 25 on the electrically conductive body 21 and having a respective window opening 35 therein aligned with each of the transparent viewing windows 24. The insulating cover 25 may comprise TPE forming an integrally molded bond with adjacent portions of the electrically insulating transparent viewing windows 24.
Returning again additionally to
The method may also include forming an insulating cover 25 on the electrically conductive body 21 and comprising an integrally molded respective tubular cable inlet 41 aligned with each of the cable inlet openings 27. The method may also comprise positioning a respective insulating boot 45 in each of the tubular cable inlets 41. Moreover, each of the insulating boots 45 may comprise a tubular sidewall 55 having a progressively increasing diameter to an open outer end 56 thereof, a removable boot closure cap 57 for removable positioning in the open outer end of the tubular sidewall, and an integrally molded tether 58 connecting the removable boot closure cap to the tubular sidewall.
Another aspect of the invention relates to a method for making an electrical connector for a plurality of electrical cables as explained with reference again to
The method may further comprise forming an insulating cover 25 on the electrically conductive body 21, and comprising a respective integrally molded tubular fastener inlet 51 aligned with each of the fastener-receiving openings 32. The method may also include forming a respective flexible tether and cap assembly with the tether 70 having a proximal end 70a to be removably connected adjacent a corresponding tubular fastener inlet 51, and a distal end 70b integrally molded with a corresponding removable fastener inlet closure cap 53. The method may also include removably connecting each proximal end 70a on a respective tubular fastener inlet 51, and positioning each removable fastener inlet closure cap 53 in a respective tubular fastener inlet.
Returning again to
The method may further include aligning a respective moveable cable seating indicator window 100 adjacent each of the seating indicator openings 23′ to provide a cover and to permit visual confirmation of proper placement of the insulation-free electrical cable end 31′ within a corresponding one of the cable-receiving passageways 26′ . In addition, the method may include overmolding an insulating cover 25′ on the electrically conductive body 21′ and having a respective opening 35′ therein aligned with each of the moveable seating indicators 100. The insulating cover 25′ may comprise TPE forming an integrally molded bond with adjacent portions of the moveable, electrically insulating, cable seating indicators 100.
Other features and advantages of the present invention may be found in copending patent applications filed concurrently herewith and assigned to the assignee of the present invention and are entitled ELECTRICAL CONNECTOR INCLUDING VIEWING WINDOWS AND ASSOCIATED METHODS, attorney docket 64544; ELECTRICAL CONNECTOR INCLUDING INSULATING BOOTS AND ASSOCIATED METHODS, attorney work docket 64554; and ELECTRICAL CONNECTOR INCLUDING MOVEABLE CABLE SEATING INDICATORS AND ASSOCIATED METHODS, attorney work docket number 64556, the entire disclosures of which are incorporated herein in their entirety by reference. In addition, many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Accordingly, it is understood that the invention is not to be limited to the illustrated embodiments disclosed, and that other modifications and embodiments are intended to be included within the spirit and scope of the appended claims.
