Disc stack connector

A wiring system for modular structures, such as prefabricated panels, which utilizes a novel disc stack connector. The connector comprises a stack of alternating conductive and insulative discs which are held in place by a rod traversing a central aperture in each disc. A primary supply cable may be attached to the disc stack connector, allowing parallel connections to secondary cables. Connector heads on the cables have several prongs for engaging the conductive discs. In the preferred embodiment, the conductive discs are smaller than the insulative discs, and one insulative disc is made larger to provide keying with a slot in the connector heads (i.e., the heads are polarized). The connector and cables are located out of sight within the raceways of the prefabricated panels.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention generally relates to electrical connectors for wiring 
systems, and more particularly to the distribution of power to, and the 
interconnection of, electrical outlets and switches in modular structures, 
such as prefabricated wall panels. 
2. Description of the Prior Art 
Construction and design of interior office spaces has become simplified 
through the use of modular structures, such as prefabricated wall panels. 
Such panels are comprised of two outer layers defining an internal space 
which may be left hollow, or filled with thermal insulation, soundproofing 
material, etc., and often include means for locking adjacent panels 
together, affording structural integrity to the completed office 
construction. 
In the past, these panels have been provided (integrally or detachably) 
with electrical devices such as lighting fixtures and standard electrical 
receptacles. Provision must therefore be made to deliver power to such 
devices and distribute the electricity to the entire array of 
interconnected panels. Several variations of wiring systems for modular 
structures exist, some of which are disclosed in the following patents: 
______________________________________ 
U. S. Pat. No. Applicant(s) 
______________________________________ 
U. S. Pat. No. 2,608,634 
C. Abbott 
U. S. Pat. No. 4,135,775 
R. Driscoll 
U. S. Pat. No. 4,203,639 
VandenHoek et al. 
U. S. Pat. No. 4,235,495 
Propst et al. 
U. S. Pat. No. 4,241,965 
Wilson et al. 
U. S. Pat. No. 4,277,123 
Haworth et al. 
U. S. Pat. No. 4,295,697 
P. Grime 
U. S. Pat. No. 4,367,370 
Wilson et al. 
U. S. Pat. No. 4,370,008 
Haworth et al. 
U. S. Pat. No. 4,377,724 
Wilson 
U. S. Pat. No. 4,437,716 
G. Cooper 
U. S. Pat. No. 4,596,098 
Finkbeiner et al. 
U. S. Pat. No. 4,716,698 
Wilson et al. 
U. S. Pat. No. Re 31,733 
Haworth et al. 
______________________________________ 
These patents present many alternatives in supplying power to prefabricated 
panels, but they nonetheless suffer significant disadvantages. For 
example, most of these systems rely on specialized terminal blocks, power 
tracks, receptacles, etc. which are not compatible with alternative 
systems. This means that, once a particular system has been selected and 
installed, the user is thereafter committed to that same system in any 
future expansions. The cost of these systems is necessarily increased due 
to the extra expense associated with the manufacture of the specialized 
components, even though many optional features are never utilized in 
practice. 
Another disadvantage relates to the manner in which prior art systems 
serially connect the electrical devices to the power supply. This results 
in a chain of multiple connections leading to any given device, increasing 
the chances that no power will be delivered at all due to a single faulty 
connection in the chain. A longer current path also means more power loss. 
Moreover, in some systems this leads to the wasteful and convoluted 
overlap of supply cables (see, e.g., U.S. Pat. No. 4,135,775, FIG. 4a). It 
would be preferable to connect the power circuit in parallel to adjacent 
panels; such an arrangement has, however, been difficult to accomplish due 
to the limited number of connections that may be made at prior art 
terminal blocks. 
Finally, prior art wiring systems do not allow sufficient variability in 
the placement of connectors along the panels. On the contrary, several of 
the foregoing patents rigidly specify the location of the terminal block, 
e.g., as being fixedly attached to one end of the panel. This unduly 
complicates, and limits use of, such systems. It would, therefore, be 
desirable and advantageous to devise a system for providing electrical 
connections to modular structures incorporating a connector which is 
simple to use and install, and which allows more flexibility in placement. 
The connector should reduce the number of overall junctions in the power 
supply chain, and yet provide a reliable means for supplying multiple 
power connections in parallel. It should also facilitate expansion of 
circuits and easily adapt to alternative wiring systems. 
SUMMARY OF THE INVENTION 
The foregoing advantages are achieved in an electrical connector having a 
plurality of conductive disc members, and a plurality of insulative disc 
members in spaced relation with, and interposed between, the conductive 
disc members. The preferred embodiment comprises five or more circular 
metal discs and six or more insulative discs separating and surrounding 
the conductive discs. The insulators are also circular and have a larger 
diameter than the conductors, minimizing the possibility of accidental 
connections which could result in short circuits or shock hazards. 
The discs are disposed generally parallel to one another, and are united by 
a longitudinal member which extends through a central aperture in each 
disc. The central member has a free end and a base, the base including an 
integral mounting plate which may conveniently be mounted at any point 
along a raceway or column in a prefabricated wall panel. Means are 
provided at the free end to secure the discs to the longitudinal member. 
By providing 360.degree. access to a central power tap, a multitude of 
cables may be connected in parallel, each having a narrow connector head 
which engages a plurality of the discs. Such a construction combines 
flexibility and efficiency in the distribution of power to electrical 
devices incorporated into the panel architecture.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference now to the figures, and in particular with reference to FIG. 
1, there is depicted a modular structure 10 comprised of a plurality of 
interconnected, prefabricated panels 12 forming walls or partitions which 
subdivide a room or office space. Panels 12 are attached to one another by 
means of connecting posts or columns 14, and include raceway structures 16 
which typically have detachable closures 18. Modular structure 10 further 
includes electrical devices such as a lighting fixture 20 and outlets 22, 
e.g., standard 3-pole receptacles. 
Panels 12 are known in the art, and generally comprise two outer layers 
defining an internal space which may be left hollow, or filled with 
thermal insulation, soundproofing material, etc. Panels 12 may be of any 
desired dimensions (i.e., height and length) depending upon the type of 
partitioning to be effected. Attachment means are provided within columns 
14, such as hooks 24 formed integrally with the side walls of column 14, 
which engage slots in the end walls of panels 12 (see FIG. 2). Alternative 
attachment means are discussed in detail in U.S. Pat. Nos. 3,841,042; 
4,235,495; 4,241,965; 4,370,008; 4,437,716; 4,596,098; and 4,716,698. 
Referring now to FIG. 2, electrical power is typically delivered to the 
panel arrangement by a wiring system traversing raceways 16. In the 
present invention, the wiring system employs a disc stack connector 26 to 
deliver power to the various electrical devices incorporated into modular 
structure 10. Disc stack connector 26 is generally comprised of a 
plurality of conductive elements 28, which are separated by a plurality of 
insulative elements 30. In other words, the insulative discs 30 are in 
spaced relation with, and interposed between, the conductive discs 28. As 
used herein, the term "disc" refers to any generally circular, planar 
member, although polygonal plates would also be included, provided they 
allow for essentially continuous access along a curve of at least 
270.degree., and preferably 360.degree.. 
Discs 28 and 30 are disposed generally parallel to one another, and are 
united by a rod member 34 which extends longitudinally through a central 
aperture in each disc (see FIG. 3). Rod member 34 may take the form of a 
bolt, screw, spring pin, etc., although it is preferably a (steel) rivet 
rod having a free end 36 and a base 38. Base 38 is attached to a mounting 
plate 40 which may be mounted at any point along raceway 16 or within 
column 14, using fastening means such as screws 42. Mounting plate 40 
further includes a standoff 44. Means are also provided at free end 36 to 
secure the discs to rod member 34. If a rivet rod is used for member 34, 
then the securing means is a rivet cap. If a bolt were used instead, then 
the securing means might comprise a locknut. Other means may be devised 
for supporting the discs in the stack construction. 
In the preferred embodiment, disc stack connector 26 comprises five 
conductive discs and six insulative discs. Five conductive discs are 
provided inasmuch as the power supply for a panel structure commonly 
employs five separate conductive paths: one for ground, one for a neutral 
line, and three "hot" lines for 3-phase voltage. Of course, more or less 
discs could be used, depending upon the intended application. In this 
regard, the number of conductive (and insulative) discs could be varied, 
even after installation, provided that detachable means are used to secure 
the discs to rod member 34. 
Discs 28 may be formed from any conductive (metallic) material, preferably 
a tin-plated copper alloy with a thickness of about one millimeter. Discs 
30 may be formed from any insulative material, preferably an engineering 
thermoplastic polymer such as polyester. Insulators 30 should have a 
larger diameter than conductors 28 (i.e, conductors 28 are recessed), to 
reduce shock hazards and the chances of accidental connections which could 
result in a short circuit. A typical outer diameter for insulative discs 
30 is about 25 millimeters. 
The central portions of insulators 30 are thickened on each side to form 
spacers 32 which create a clearance space around conductive discs 28 
(e.g., a clearance of about 5 millimeters on either side of each 
conductive disc). It will further be appreciated that a short circuit 
might occur between adjacent conductive discs if rod member 34 is also 
conductive. In order to avoid such an event, each conductor 28 is 
preferably isolated from rod member 34 by an annular rim or bushing 33 
integral with spacer 32 on insulator 30 which extends into the aperture in 
conductive disc 28. In such an embodiment, the apertures in conductive 
discs 28 are accordingly larger than the apertures in insulative discs 30. 
Alternatively, rod member 34 may be constructed of an insulative material. 
Two cables 46 are also illustrated in FIG. 2, having connector heads 48 
proximate disc stack connector 26. Each connector head 48 includes five 
pairs of prongs 50 for engaging the periphery of conductive discs 28, 
prongs 50 also being connected to five separate conductors within cables 
46. The distal ends of cables 46 may be provided with similar connector 
heads. Connector heads 48 and/or disc stack connector 26 may optionally be 
mechanically polarized to preclude miswiring. As shown in FIG. 2, a keying 
(insulative) disc 30a has a diameter greater than the diameter of the 
remaining insulative discs 30, and each connector head 48 has a 
corresponding slot 52. In this manner, connector head 48 may be 
operatively attached to disc stack connector 26 only if properly oriented. 
Latching means may also be provided to secure connector heads 48 to disc 
stack connector 26. 
As those skilled in the art will appreciate, cables 46 may be wired to 
provide different operating circuits for adjacent panels. For example, 
most electrical devices which are attached to or incorporated in modular 
structure 10 operate on 120 volt power, meaning that only one of the three 
hot lines is necessary. Therefore, different connector heads 48 (each 
having only three pairs of prongs 50) could tap into the three different 
hot lines by selective placement of the prongs on the connector heads. 
This minimizes the chances of an overload on any one circuit. Similar 
concepts are disclosed in U.S. Pat. Nos. 4,203,639; 4,367,370; and 
4,377,724. 
Turning now to FIG. 4, one end of a primary supply cable 46a is connected 
(directly or indirectly) to a power source (not shown), with the second 
end being connected to disc stack connector 26 at a four-way panel 
intersection. Disc stack connector 26, in turn, delivers the power to the 
other three cables 46 attached thereto. In FIG. 4, it can be seen that 
connector heads 48 are relatively narrow, allowing connection of several 
such connector heads to disc stack connector 26. Although cables 46 are 
shown extending through raceways 16, they may also be placed within 
columns 14, e.g., to deliver power to light fixture 20. 
The improved flexibility and efficiency in the use of the present invention 
may best be understood with reference to FIG. 5, to which attention is now 
directed. In an exemplary setting, primary cable 46a, having plug means 54 
for attachment to the external power source, enters raceway 16 of the 
first panel 12a. No receptacles have been provided in panel 12a, so cable 
46a passes therethrough to the first disc stack connector 26a in column 
14a, a "T" intersection. Disc stack connector 14a also receives secondary 
cables 46b and 46c which pass through panels 12b and 12c, respectively. 
Cable 46b continues through another column 14b into panel 12d (an "L" 
intersection), and delivers power to a terminal block 22a. Since panel 12d 
is a "dead end," no additional connector is needed in column 14b. 
Returning to cable 46c, that cable conveys the power further to another 
disc stack connector 26b in column 14c. There, panels 12c, 12e and 12f 
form a "Y" intersection. Connector 26b accordingly distributes power to 
cables 46d and 46e which are respectively connected to terminal blocks 22b 
and 22c. The cables may be provided in a variety of standard lengths, or 
could be assembled as needed. In the latter case, cables 46 may be the 
flat ribbon type, and connector heads 48 may conveniently comprise a 
clam-shell type body having a plurality of metallic elements therein which 
pierce the ribbon cable and contact the internal conductors. Connectors of 
this construction are conventionally known as insulation displacement 
connectors. 
The modular structure shown in FIG. 5 could easily be modified as required. 
Additional cables could be attached to connectors 26a and 26b, including 
cables which travel upwardly to distribute power to lighting fixtures. 
Columns 14a-14c may further accommodate power supply cables which are 
provided within the ceiling. Finally, if the specifications of the modular 
structure require a large number of connections at each connector 26, then 
the discs (both insulative and conductive) would be enlarged, thereby 
increasing the circumference and the number of connector heads which may 
be attached. 
Although the invention has been described with reference to specific 
embodiments, this description is not meant to be construed in a limiting 
sense. Various modifications of the disclosed embodiment, as well as 
alternative embodiments of the invention, will become apparent to persons 
skilled in the art upon reference to the description of the invention. For 
example, while the present invention is considerably useful in supplying 
power to prefabricated wall panels, it clearly has broader application in 
providing electrical connections to any type of wiring network. It is 
therefore contemplated that the appended claims will cover such 
modifications that fall within the true scope of the invention.