Patent Application
20060180335
The invention relates to the field of electrical connectors, and, more particularly, to electrical insulator boots used in electrical connectors for electrical distribution systems 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 an elongate bus 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 to receive a fastener to secure the electrical conductor within the upper end of the post. U.S. Pat. No. 6,347,966, for example, discloses such a connector and a method for securing the posts to the bus portion.
An insulating coating is provided on the lower portion of the posts and bus of the connector. In addition, EPDM insulating boots or rockets may be used to provide waterproof seals to the insulating outer jacket of the wire or cable. These boots include an insulating tube having a lower end to be received onto the connector post. The upper end or end cap includes a series of progressively smaller diameter step or ring portions. An installer selects at which ring to cut the boot cap so that the resulting opening is properly sized for the diameter of electrical cable or wire to be received therein. U.S. Pat. No. 5,533,912 discloses a similar arrangement; however, the insulating boot with a stepped shape is positioned within a receiving port in an inverted configuration.
Unfortunately, water ingress, particularly where the boot is intended to seal against the jacket of the cable end, may result in corrosion and failure of the connector. When properly installed, such boots do not permit water ingress. Unfortunately, if improperly installed the seal provided by the boot may not be sufficient to keep water out. Accordingly, water may enter and degrade the electrical connection resulting in premature failure of the connector.
There is also a trend to require less highly skilled craftsman to install the connectors as a cost savings measure for utilities and their subcontractors. Instances of improper installation are more likely to occur as training and skill levels are reduced, and while at the same time greater production rates are required. For example, an improperly trained installer may cut the boot at a ring that is too large to correctly seal. Of course, the larger the ring, the less insertion force required to position the cable through the boot. Months or years after installation, water may penetrate the area of the seal and cause connector failure.
Other electrical connector insulator boots are described in U.S. Pat. No. 2,932,965 to Raila et al.; U.S. Pat. No. 3,740,692 to Filhaber; and U.S. Pat. No. 4,283,597 to Cooper, Jr. Unfortunately, these also may fail to provide proper sealing and/or accommodate different sized cable ends.
In view of the foregoing background, it is therefore an object of the present invention to provide an electrical connector and insulating boot that is more easily installed and with an increased margin for error during installation.
This and other objects, features and advantages in accordance with the present invention are provided by an electrical connector for at least one electrical cable end comprising a conductor and an insulating jacket thereover. The electrical connector may comprise a conductive body having at least one conductor receiving passageway therein to receive the conductor of the at least one cable end. The conductive body may also have at least one fastener receiving passageway intersecting the at least one conductor receiving passageway, and at least one fastener may be positioned in the at least one fastener receiving passageway for securing the conductor. The connector may also include at least one insulating boot associated with the at least one conductor receiving passageway. The insulating boot in one class of embodiments may comprise an insulating tube, and at least one rupturable seal closing the insulating tube and rupturing upon initial insertion of the cable end therethrough. In addition, the at least one rupturable seal may also be compliant to accommodate different sized cable ends and form a seal with adjacent portions of the insulating jacket.
The at least one rupturable seal may comprise a layer having a plurality of radially oriented lines of weakness therein. Alternately or additionally, the at least one rupturable seal may comprise a layer having a plurality of successive concentric rings of weakness therein. The at least one rupturable seal may also additionally or alternately comprise a layer being puncturable and having a percentage elongation to yield of not less than about 300 percent, for example. The at least one rupturable seal may be, for example, more compliant than the insulating tube. The insulating boot may comprise a thermoplastic elastomer in some embodiments.
The insulating boot may further comprise an elastic body contained within the insulating tube for urging the at least one rupturable seal radially inward, in some embodiments. The insulating boot further may also comprise a sealant material and/or a lubricant within the insulating tube. The insulating tube may also include a series of gripping rings on an interior proximal end thereof.
In some embodiments, the at least one rupturable seal comprises a first rupturable seal at a distal end of the insulating tube, and a second rupturable seal at a medial portion of the insulating tube. For example, the first rupturable seal may comprise a first rupturable seal connected to the distal end of the insulating tube. The second rupturable seal may comprise a second rupturable seal integrally molded with the insulating tube. In these embodiments, the insulating boot may further comprise a sealant material between the first and second rupturable seals.
The electrical connector in other embodiments may comprise a conductive body having at least one conductor receiving passageway therein to receive the conductor of the at least one cable end, and at least one insulating boot associated with the at least one conductor receiving passageway. The insulating boot may include an insulating tube having a proximal end to be positioned adjacent the conductive body, a distal end opposite the proximal end, and a medial portion between the proximal and distal ends. In addition, the insulating boot may include a first seal at the distal end of the insulating tube that is penetrable upon insertion of the cable end therethrough, and a second seal at the medial portion of the insulating tube that is penetrable upon insertion of the cable end therethrough. The first and second seals may also be compliant to accommodate different sized cable ends and form respective seals with adjacent portions of the cable end.
Another aspect of the invention is directed to an insulating boot for an electrical connector comprising a conductive body having at least one conductor receiving passageway therein to receive a conductor of at least one cable end. The insulating boot may include an insulating tube having a proximal end to be positioned adjacent the conductive body, a distal end opposite the proximal end, and a medial portion between the proximal and distal ends. A first seal may be at the distal end of the insulating tube that is penetrable upon insertion of the cable end therethrough, and a second seal may be at the medial portion of the insulating tube that is penetrable upon insertion of the cable end therethrough. The first and second seals may be compliant to accommodate different sized cable ends and form respective seals with adjacent portions of the cable end.
In some embodiments, the first seal may be connected to the distal end of the insulating tube and be penetrable upon insertion of the cable end therethrough, and wherein the first seal is more compliant than the insulating tube. In addition, the second seal may be integrally formed with the insulating tube at the medial portion thereof and be penetrable upon insertion of the cable end therethrough. A sealant material may be provided within the insulating tube between the first and second seals.
In still other embodiments, the insulating boot may include an insulating tube, and at least one rupturable seal closing the insulating tube and rupturing upon initial insertion of the cable end therethrough. In these embodiments, the at least one rupturable seal may have a percentage elongation to yield of not less than about 300 percent to thereby be compliant to accommodate different sized cable ends and form a seal with adjacent portions of the cable end.
Another aspect of the invention relates to a method for making an electrical connector for at least one electrical cable end comprising a conductor and an insulating jacket thereover. The method may include forming a conductive body having at least one conductor receiving passageway therein to receive the conductor of the at least one cable end, the conductive body also having at least one fastener receiving passageway intersecting the at least one conductor receiving passageway. The method may also include providing at least one fastener positioned in the at least one fastener receiving passageway for securing the conductor within the at least one conductor-receiving passageway. Moreover, the method may also include forming at least one insulating boot associated with the at least one conductor receiving passageway by forming an insulating tube, and at least one rupturable seal closing the insulating tube and rupturing upon initial insertion of the cable end therethrough. The at least one rupturable seal may also be compliant to accommodate different sized cable ends and form a seal with adjacent portions of the insulating jacket.
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 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 and multiple prime notation are used to indicate similar elements in alternate embodiments.
Referring initially to
For clarity of explanation, only the upper end of the insulating boot 20 is shown in
In the illustrated embodiment, the boot 20 includes a tubular insulating sidewall 21 or insulating tube ending in a tapered or conical end cap 22 that defines a rupturable seal. By rupturable is meant having a continuous surface prior to initial penetration.
The end cap seal 22 illustratively contains a body of sealant material 23 and can advantageously receive a wire or cable of different widths therethrough, yet provide a tight and moisture resistant seal therewith. The sealant material 23 may be a mastic or moisture barrier gel that will adhere to the cable 25 and adjacent boot portions to form a water resistant seal as will be appreciated by those skilled in the art. Since the cable 25 is typically inserted through the end cap seal 22 and then the boot 20 is slid forward along the cable, this action will likely spread the layer of sealant material 23 to be positioned between the cable and the adjacent boot portions.
The end cap seal 22 is desirably rupturable along a line of weakness, for example, in some embodiments, to permit positioning of the cable 25 therethrough without requiring careful cutting as in the prior art. The sealant material 23 also forms a barrier to keep water and moisture out of the interior of the boot 20 and away from the electrical connection. The end cap seal 22 is also preferably stretchable or compliant to receive wires or cables 25 of different diameters, for example. For example, the end cap seal 22 may have a percentage of elongation to yield of not less than about 300 percent. This may accommodate different cable sizes of from No. 8 up to 350 kcmil, for example, although other sizes are also possible.
Turning now to
Referring now to
Additional seals may be provided to the inverted boot as shown by the embodiment of
Turning now to
Referring now additionally to
As also shown in
Referring now to
The compressible or elastic body 54 may be provided by a closed cell foam, for example, although other materials are also contemplated by the invention. The boot 50 also illustratively includes an optional sealant material layer 53 positioned beneath the compressible body 54. This sealant material layer 53 may be provided for additional sealing as described above.
Referring now to the eighth embodiment of the boot 60 as shown in
Referring now to
Optional horizontal gripping ribs 97 are formed on the internal surface of the lowermost or proximal end of the boot 70. The end cap seal 92 and intermediate seal 96 may include rings of weakness or other features to permit penetration and sealing as discussed in detail above and as will be appreciated by those skilled in the art. Approximate dimensions for the embodiment of
As can be seen in
A tenth embodiment of the insulating boot 90′ is now explained with additional reference to
Turning now additionally to
As shown in the illustrated embodiment of the boot 110, the interface between the end of the cable jacket 119 and the electrical conductors 118 may be positioned past the intermediate seal 116. In yet other embodiments, the boot 110 may include a sealant material therein, and the interface between the end of the jacket 119 and conductors 118 may be positioned in the sealing chamber defined between the end cap 112 and the intermediate seal 116 as will be appreciated by those skilled in the art.
Referring now to
The end cap or end seal 122 is molded as a separate unit and is inserted into a recess 128 formed in the uppermost end of the sidewall 121. A reduced diameter portion 124 is provided in the illustrated embodiment, but may not be used in other embodiments. In addition, optional gripping ribs 127 are also shown in the illustrated embodiment. The end cap seal 122 and intermediate seal 126 define a sealing chamber therebetween that may contain a sealant material in some embodiments. A cable 125 is installed through the end cap 122 and through the intermediate seal 126 as shown in
As shown in
A method aspect of the invention is for making an electrical connector for at least one electrical cable end comprising a conductor and an insulating jacket thereover. The method may include forming a conductive body having at least one conductor receiving passageway therein to receive the conductor of the at least one cable end, the conductive body also having at least one fastener receiving passageway intersecting the at least one conductor receiving passageway. The method may also include providing at least one fastener positioned in the at least one fastener receiving passageway for securing the conductor within the at least one conductor-receiving passageway. Moreover, the method may also include forming at least one insulating boot associated with the at least one conductor receiving passageway by forming an insulating tube, and at least one rupturable seal closing the insulating tube and rupturing upon initial insertion of the cable end therethrough. The at least one rupturable seal may also be compliant to accommodate different sized cable ends and form a seal with adjacent portions of the insulating jacket.
Other methods are also contemplated by the present invention based upon the connector and/or insulating boots described herein. Indeed, 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. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed, and that other modifications and embodiments are intended to be included within the scope of the appended claims.
This application is based upon prior filed copending provisional application Ser. Nos. 60/448,019 filed Feb. 18, 2003 and 60/499,144 filed Aug. 29, 2003. The entire subject matter of both provisional applications are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60448019 | Feb 2003 | US | |
| 60499144 | Aug 2003 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10781317 | Feb 2004 | US |
| Child | 11380093 | Apr 2006 | US |
