FIELD OF THE INVENTION
This invention relates to an electrical power distribution system and, more particularly, to such a system having selectively movable convenience outlets.
BACKGROUND OF THE INVENTION
The distribution of electrical power in a household, commercial establishment or business has until now been handled in one of two ways. Either individual electrical convenience outlets have been located in fixed positions within a structure and then been wired in place, or else a long strip outlet has been used permitting a plug to be inserted anywhere along the strip outlet.
Both approaches have certain inherent limitations. The fixed position system permits very little flexibility. A change in power distribution, due to changing needs, typically necessitates structural changes and rewiring. By comparison, the long strip outlet is relatively flexible since a plug may be inserted anywhere along its length. However, this system poses a significant safety hazard due to electrical shock because the power carrying strip contact is relatively exposed.
This relative exposure exists, in any outlet permitting direct insertion of a plug to establish contact, since a foreign object could also be directly inserted. However, the strip outlet system represents significantly more of a hazard since direct access is not restricted to a relatively small area, but is present in a long, open access slot. The long, open slot permits a great variety of objects to be inserted, most of which would not fit into the openings of other systems. For example, an infant could readily insert a coin, toy, belt buckle or similar common object into the long open slot, thereby incurring serious injury or death.
Due to the necessity of providing substantial physical separation between contacts to insure electrical isolation, strip outlets have until now been restricted to two-conductor systems, thereby excluding use of a separate safety ground as a third conductor.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the present invention, the hazard of inadvertent interconnection with live contacts in a strip conductor arrangement is avoided by eliminating all direct access to those conductors. Access to those conductors is available only to an adapter of special geometry. The adapter includes a convenience outlet with conventional contacts directly accessible to an ordinary plug. The outlet contacts, in turn, interconnect with the otherwise inaccessible strip conductors when the adapter is properly positioned.
In a preferred embodiment, a generally U- or C-shaped slideway member is secured to a wall, open face out, for receiving adapters. The open face of the member is substantially shielded by a baffle extending virtually the length of the member. The strip conductors are housed within the member, but behind the baffle to prevent inadvertent contact with the conductors through the open face.
The adapter is also generally U- or C-shaped, but oriented substantially perpendicular to the orientation of the slideway member. The relative geometries are such that the baffle of the member extends into the open face of the adapter. One leg of the adapter is thereby substantially enclosed by the member and that leg includes contacts for interconnecting with the strip conductors. The other leg of the adapter includes a conventional convenience outlet interconnecting with those contacts.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view, partially exploded and cut-away, of a power distribution system in accordance with this invention, and
FIGS. 2 and 3 are cross-sectional views of portions of FIG. 1 taken respectively along lines 2-2' and 3-3', and showing the mating of an adapter with the slideway member of the system of FIG. 1 in accordance with this invention.
DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT
FIG. 1 shows a perspective view of a strip conductor arrangement 10 in accordance with this invention. The arrangement comprises an elongated C-shaped slideway member 11 having a mounting surface 12 and an elongated open front face 13. As viewed in FIGS. 1 and 2, an elongated baffle 14 extends downward across open face 13, but spaced rearward of that face. Baffle 14 thereby divides the interior area of member 11 into an inner chamber 17 and an outer chamber 18. Baffle 14 includes a front shielding wall 20 and a rear access wall 21. Included within access wall 21 are electrical strip conductors 22, 23, and 24.
Communication between inner chamber 17 and outer chamber 18 is possible only through the narrow separation 25 between baffle 14 and the lower wall of element 11. As a result, conductors 22, 23 and 24 are not accessible through the open face 13. Rather, access to conductors 22, 23 and 24 is possible only from inner chamber 17. Thus, the narrow separation 25 and the shielding wall 20 prevent inadvertent and hazardous contact with conductors 22, 23 and 24.
Although inadvertent contact with conductors 22, 23 and 24 is prevented by the geometry of member 11, intended contact with the conductors is readily accomplished through use of a special type adapter 30. As can be seen, particularly in the broken-away portion to the left of FIG. 1, adapter 30 has a generally U-shaped geometry. The geometry of adapter 30 is such that it readily mates with the geometry of member 11. Thus, a contact leg 31 of adapter 30 fits into inner chamber 17 of member 11 and an outlet leg 32 of the adapter fits into open face 18 of the member. A reduced portion 33 can be seen to correspond to separation 25. Projecting into the void above portion 33 from the face of contact leg 31 are contacts 35, 36 and 37 for mating respectively with conductors 22, 23 and 24 in member 11.
The outlet leg 32 of adapter 30 includes an outward surface having a conventional electrical convenience outlet or receptacle configuration. Thus, through openings in the receptacle face, a conventional three-conductor plug (not shown) may be inserted. Contacts 35, 36 and 37 connect to receptacle ends 39, 40 and 41, respectively, which are positioned within the openings in the receptacle face. Electrical continuity may therefore be established from conductors 22, 23 and 24 to contacts 35, 36 and 37, thence through receptacle ends 39, 40 and 41, respectively, to the individual conductors of such an inserted plug.
FIG. 2 shows a cross-sectional view of an adapter 30 in mating relationship with elements 11 and 14 taken along line 2-2' in FIG. 1. As can be seen, the electrical continuity beginning at the juncture of conductor 23 and contact 36 extends through receptacle end 40 to the safety ground conductor 50 of a conventional plug. As FIG. 3 shows, the electrical continuity beginning at the juncture of conductor 24 and contact 37 extends through receptacle end 41 to the power conductor 49 of a conventional plug (remainder of plug not shown). FIG. 3 is a cross-sectional view of adapter 30 taken along line 3-3' in FIG. 1.
Thus it can be seen that although contact with the "live" conductors 22, 23 and 24 is virtually impossible from the front of the power distribution arrangement, adapter 30 makes ready contact with the conductors and with an inserted plug. Once adapter 30 is positioned in the desired location along member 11, a locking screw 57 is tightened against baffle 14 as shown in FIG. 2. Screw 57 not only locks adapter 30 in the desired location to prevent any unwanted movement along member 11, but it also insures intimate electrical contact between conductors 22, 23, and 24 of member 11 and contacts 35, 36 and 37 of adapter 30, respectively.
As shown in the center of FIG. 1, a feed-in connector box 44 is provided for the incoming electrical leads 46. Connector box 44 is fitted with a "quick-connect" contact configuration so that sections of slideway member 11 may be snapped into either end of the box. In this way, the electricity is distributed to the strip conductors 22, 23 and 24 from the incoming leads 46. Feed-in connector box 44 is also arranged to permit the adapters 30 to be inserted around baffle 14 and thence positioned at the desired location along the length of member 11.
Feed-in connector box 44 is fitted with a cover 45 for installation after the desired number of adapters 30 have been inserted, yet the cover may be readily removed for addition or subtraction of adapters as the demands on the system change. The specific configuration of the interior of box 44 has not been shown since that is of an engineering nature and is not central to the invention. Those skilled in the art could devise a number of arrangements suitable for these purposes, the specific arrangement chosen being a factor of materials, available manufacturing methods, and economics.
Since the strip conductor arrangement 10 could be used in a wide variety of applications, it is advantageous to make the system as flexible as possible. Towards that end, an end cap 60 has been shown at the right side of FIG. 1 for use where the end of member 11 would be otherwise exposed. This provides an aesthetic and functional closure to the end of member 11. Similarly, although member 11 is shown to include a decorative skirt 59, the skirt could just as easily be a separate piece for use only where a "baseboard" appearance is desired. Also, although connector box 44 is shown as a straight junction device between lengths of member 11, connector boxes having a corner turning configuration, either "inside" or "outside," could also be used. A connector box could also be used with only a single section of member 11.
No attempt has been made to indicate the full range of variations possible using this invention. Since a wide variety of environments exist in which the system could be utilized, such an exhaustive explanation would be needlessly involved. Any designer of ordinary skill will see how easily this invention may be adapted for use with frame construction, wet wall construction, masonery wall construction, in metal partitions, for renovations, etc. A variety of decorative trims might also be considered for installations where that would be advantageous.
Although a variety of materials and manufacturing methods are applicable to this arrangement, slideway member 11 is probably most advantageously manufactured from an extrusion. The extruded material could be entirely an insulating material, such as plastic, or a combination of a material such as aluminum with an insulating core. In the later arrangement, slideway member 11 would be fabricated from aluminum or other conducting material while all or part of baffle 14 is fabricated from insulating material to simultaneously provide electrical isolation between the strip conductors 22, 23 and 24 and to provide shock hazard shielding from the front opening in the slideway member.
Adapter 30 is perhaps most advantageously made from an insulating material, such as plastic, to form insulation protection from the conducting elements housed within it. As can be seen, an arrangement in accordance with the invention is entirely shock proof. As a further safety feature, a three-conductor system, including a local ground, is shown to provide additional precaution against the hazard of electrical shock.
What has been described above is merely illustrative of the principles of this invention. No attempt has been made to present an exhaustive list of the variety of possible modifications. Therefore, various modifications can be devised by those skilled in the art in accordance with the principles disclosed without departing from the spirit and scope of this invention as encompassed in the following claims.