Electrical transition fitting

An electrical transition fitting for enabling electrical wires contained in multiple cables to be extended through an electrical conduit, or into a panel box. The fitting has a lower body member having a first member dimensioned for receipt of an electrical conduit or passage through a knockout hole of a panel box, and a second member with a slot at a second end, an upper body member having at least three bores formed therein, the bores for receipt of the cables, the upper body member having a plate at a first end, the plate dimensioned for contact with a perimeter of the second member and having a tab for receipt in the slot, and a hole for receipt of a fastener to secure the upper body member to the lower body member and plastic insulators and inner locking devices for installation in the bores.

TECHNICAL FIELD

The present invention is directed to an electrical transition fitting for enabling electrical wires contained in more than two metal clad or armored clad cables to be combined and passed through an electrical conduit or into to an electrical panel box or the like.

BACKGROUND OF THE INVENTION

The present invention is directed to an electrical transition fitting that can be used in residential, commercial and industrial applications. As disclosed in applicant's U.S. Pat. No. 7,402,752, various electrical conduits, such as electrical metallic tubing (EMT) and cables, such as metal clad (MC) or armored clad (AC), which contain electrical wires with insulated conductors must be interconnected, for example, to a primary power supply in a suitable power distribution outlet box, junction box, panel box or other enclosure where metal clad or armored clad cable is used.

In some applications, it is desirable to allow passage of electrical wires from multiple metal clad or armored clad cables to a single electrical conduit where the conduit may then be connected to an electrical panel box or the like or for other purposes. In other applications, it is desirable to combine the electrical wires of multiple MC or AC cables for passage into a panel box directly through a single knockout hole in the panel box or the like.

There have been many duplex electrical connectors and electrical transition couplings for allowing two AC or MC cables to be combined in a single fitting to allow the electrical wires to pass either into a single electrical conduit (such as an EMT) or to pass into a panel box or the like through a single knockout hole in the panel box.

Although some electrical transition fittings have provided for more than two cables to be combined to allow wires to pass out of a single end thereof, none are believed to combine the features as disclosed in the present application which provide for easy and secure attachment of multiple MC or AC cables for combining and passing the electrical wires thereof through an electrical conduit or into a panel box or the like.

SUMMARY OF THE INVENTION

The present invention relates to an electrical transition fitting for enabling electrical wires contained in N metal clad or armored clad cables to be combined and extended through an electrical conduit or into an electrical panel box or the like, comprising a lower body member having a first member with an open first end dimensioned for receipt of an electrical conduit or for passage through a knockout hole in a panel box or the like, and a second member integrally connected at a first open end to an open second end of the first member, said second member having an open second end with a perimeter greater than a perimeter of the first open end of the second member, the open second end also having at least one slot formed therein, an upper body member having an extended region with N bores formed therein, the bores for receipt of a metal clad or armored clad cable, the upper body member having a plate at a first end, the plate dimensioned for contact with the perimeter of the second open end of the second member of the lower body member, the plate having openings formed therein at least in partial alignment with the bores, the plate including a hole formed therein, the hole for receipt of a fastener so as to secure and electrically bond the upper body member to the open second end of the lower body member, the plate also having at least one tab dimensioned for receipt in the at least one slot of the second end of the second member, N plastic insulators each dimensioned for snap in installation in one of the N bores at the first end of the upper body member, and N inner locking devices each dimensioned for press-in installation in one of the N bores at a second end of the upper body member and further configured to capture a metal clad or armored clad cable, where N is an integer greater than two.

Another embodiment of the present invention is the electrical transition fitting as described above, wherein the second member of the lower body member has a region that forms a flat surface so as to facilitate installation of the electrical transition fitting adjacent a flat surface.

Another embodiment of the present invention is the electrical transition fitting as described above, wherein the at least one slot is formed in a rim segment on the second end of the second member of the lower body member.

A further embodiment of the present invention is the electrical transition fitting as described above, wherein the at least one slot is formed in a rim segment on the second end of the second member of the lower body member.

A still further embodiment of the present invention is the electrical transition fitting as described above, wherein the first member of the lower body member includes a threaded bore passing therethrough dimensioned for receipt of a fastener so as to secure an electrical conduit to said first member.

Another embodiment of the present invention is the electrical transition fitting as described above, wherein the first member of the lower body member has an inner rim that acts as a stop to an electrical conduit positioned within the first member.

Another embodiment of the present invention is the electrical transition fitting as described above, wherein each inner locking device comprises a pair of arms extending inwardly from an inner surface of the inner locking device, the arms configured to secure and electrically bond to an outer surface of a metal clad or armored clad cable.

A further embodiment of the present invention is the electrical transition fitting as described above, wherein the second member of the lower body member has a generally frustoconical shape.

A further embodiment of the present invention is the electrical transition fitting as described above, wherein N=3.

A still further embodiment of the present invention is the electrical transition fitting as described above, wherein the second member of the lower body member has a region that forms a flat surface so as to facilitate installation of the electrical transition fitting adjacent a flat surface.

Another embodiment of the present invention is the electrical transition fitting as described above, wherein the plate of the upper body member has N openings with inwardly extending rims each rim positioned about one of the N bores and wherein each plastic insulator has a radially extending rim at one end and radially projecting flexible fingers so as to capture the insulator between said radially extending rim, one of the N inwardly extending rims, and said radially projecting fingers.

Another embodiment of the present invention is the electrical transition fitting as described above, wherein the first member of the lower body member includes threads positioned on the outer surface thereof to secure installation of the electrical transition fitting through a knockout hole of an electrical panel box or the like by securement of a locknut thereto.

A further embodiment of the present invention is the electrical transition fitting as described above, wherein each of the N plastic insulators has an inner end that acts as a stop to a metal clad or armored clad cable when inserted into a bore of the electrical transition fitting.

A still further embodiment of the present invention is the electrical transition fitting as described above, wherein the first member of the lower body member has an inner rim that acts as a stop to an electrical conduit positioned within the first member.

DETAILED DESCRIPTION

As best seen inFIG. 1, an electrical transition fitting50according to an embodiment of the present invention has a lower body member52and an upper body member54which are configured for attachment to each other. The lower body portion includes in this embodiment a first member56and a second member58connected to the first member56. The first member has an open first end61dimensioned for receipt of an electrical conduit104(seeFIGS. 1 and 15).

The upper body member has an extended region59having three bores60formed therein, as well as a plate62at a first end71for attachment of the upper body member to the lower body member. The plate has opening73formed therein at least in partial alignment with bores60formed in extended region59of the upper body member so as to allow electrical wires in the bores to pass through the plate. As seen inFIGS. 1,4,6-8and10, plate62includes at least one tab64configured for insertion within a corresponding slot66formed in an open second end68of the second member58. Each slot can be formed in a rim segment67of second end68of second member58. In this way, upper body member54can be easily positioned on lower body member52by sliding tabs64in slots66. The slot and tab configuration assist in alignment of the upper body member to the lower body member.

Also located at the open second end68of second member58is a threaded bore70formed in a boss72of the second member. As seen inFIG. 10, this boss may be finger-like in shape. Fastener74passes through a hole76in plate62as best seen inFIG. 10. The fastener provides not only securement of the lower body member to the upper body member, but also provides for electrical bonding of the two members to each other.

As best seen inFIG. 2, the electrical transition fitting50also includes plastic insulators78each for snap-in insertion in one of the bores60. The plastic inserts are preferably fabricated from nylon and provide a passageway80for the passage of insulated electrical wires82emanating from a metal clad or armored clad cable84as best seen inFIG. 19. The passageway thereby facilitates the prevention of chaffing of the insulation86formed around conductors88of each electrical wire82. As seen inFIGS. 13,14and19each plastic insulator includes projections79that are finger-like and depressible so as to snap into bore60so as to secure the insulation between rim83of extended region59and flange85formed on an end of insulator78. Each plastic insulator has an inner end87opposite flange85that can act as a physical stop to an end89of MC/AC cable84.

A plurality of inner locking devices90are each positioned through an open second end75of upper body member54in one of the bores60as also seen inFIG. 1. Details of the locking devices are shown inFIGS. 11 and 12and are fully disclosed in U.S. Pat. No. 6,444,907 owned by the present applicant. This patent is hereby incorporated by reference. Each locking device includes a snap-in member92which is resiliently flexible so as to form a secure press fit when inserted into a bore60as best seen inFIG. 19. The locking device also includes a pair of arms94having terminating ends96configured to retain a metal clad or armored clad cable84as seen inFIG. 19. Shoulders91in bores60act as stops for inner locking devices90.

As seen in the figures, includingFIGS. 1 and 10, first member56of the lower body member52includes a hub or boss98with a threaded bore formed therein configured for receipt of a threaded fastener102. As seen inFIG. 15, when an electrical conduit104is inserted into first member56, it can be secured and electrically bonded thereto by tightening fastener102so as to make mechanical and electrical contact with the outer surface of the electrical metallic tubing104.

As best seen inFIGS. 2,6,7,10and20, the second member58of lower body member52preferably includes a region112that defines a flat surface so as to facilitate placement of the electrical transition fitting50along a flat surface114associated with a wall, ceiling, floor or the like. In this manner, the placement of the electrical transition fitting is facilitated in conjunction with such a surface. As seen inFIG. 17, second member57is integrally connected to an open end65of first member56at a first open end63of second member58. The second member has an open second end68with a perimeter greater than a perimeter of first open end63. The second member as seen inFIG. 1can have a generally frustoconical shape.

Furthermore, as seen inFIGS. 17 and 20, first member56of the lower body member52includes an inner rim53at second end65which acts as a stop for an electrical conduit104as it is inserted into the first member56.FIG. 20also shows fastener102making mechanical and electrical bonding connection to the electrical conduit104.

As seen inFIGS. 21 and 22, an alternative embodiment of the electrical transition fitting has a lower body member52where in first member56′ thereof has exterior threads57which are dimensioned for mating with a locknut106so as to secure the electrical transition fitting to an electrical panel box or the like108by passing the first member of the lower body member through a knockout hole110in the panel box or the like. This alternative embodiment allows the desirable properties of the electrical transition fitting to be used in conjunction with a plurality of metal clad or armored clad cables that are combined and to allow the electrical wires thereof to pass into the panel box or the like.

Furthermore,FIGS. 1-22are directed to embodiments of the electrical transition fitting where the upper body member has three bores60. Alternative embodiments may have four or more bores60, such as shown inFIGS. 23-27. Thus, for the three bore embodiment, the bores can be represented by the integer N where N=3 and for the four bore embodiment, N=4. Larger numbers of bores may also be envisioned, although practically it is believed that N=3, 4 or 5 would generally be the more practical embodiments for combining multiple metal clad or armored clad cables to a single electrical conduit or to an electrical panel box.

As seen inFIGS. 23-27, an alternative embodiment of the electrical transition fitting50′ has four bores60for receipt of four MC/AC cables84. The overall configuration of this transition fitting is essentially the same as that shown in the three bore configuration ofFIGS. 1-22and similar elements are shown with the same reference numerals. It is noted that the second member58′ of the lower body member52′ has a generally four-sided configuration with a region112′ as shown inFIG. 24which can act as a flat surface for positioning the electrical transition fitting against a flat surface of a wall or the like.

As also seen in this embodiment and as illustrated inFIG. 25, the upper body member54is secured to the lower body member52by fasteners74into threaded hole70. However, the boss72′ in which the threaded hole is formed is positioned on an outside surface of the second member58′ of the lower body member52′.

FIG. 27shows an alternative embodiment of this four bore configuration which has threads57formed on the first member56′ so as to mate with locknut106.