US 3252056 A
Abstract available in
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Description (OCR text may contain errors)
May 17, 1966 PQESL 3,252,056
ELECTRICAL DISTRIBUTION SYSTEM Filed July 1, 1963 3 Sheets-Sheet 1 CONDUCT! vs I.AvEes LAYER rlvvavfwe y 1966 .1. 1 .v POESL 3,252,056
ELECTRICAL DISTRIBUTION SYSTEM Filed July 1, 1965 5 Sheets-Sheet 2 FIG. 2
JaH/V Poes 3 Sheets-Sheet 5 Filed July 1, 1963 \\\Q\ mm m w k m mmfifi O a L mw O0 91H 8 WM? 3 \\\n .5 m 8 Q 1 0w 854m United States Patent 8 Claims. 61. 317-112 This invention relates to an electrical distribution system and more particularly to a plug board system.
In laboratories, in industry or institutions of higher learning, it is often desirable to supply a variety of voltages to any given service outlet. This is often accomplished by the use of plug boards which include a number of plugging cords connected from the source of the required voltages to the receptacles of the plug board. The receptacles are protected by circuit breakers or fuses which in turn are connected to a single or group of service outlets. 4
One disadvantage of the known plug boards is that a large number of cords is required thus complicating the tracing of circuits. A further problem arises in maintaining polarities and phase sequence.
A still further disadvantage is that persons using the system tend to use cords having a lower current carrying capacity than the circuit protection devices, thereby creating a fire hazard.
Other disadvantages of -known systems include the unsightly appearance created by the large number of cords and the considerable time required to set up such systems.
A feature of the present invention resides in the pro-.
vision of a greater number of circuits in the same area required by the conventional plug board.
A further feature is the ease with which the plug board of the present invention can accommodate two, three, four or six-wire circuits.
A still further feature is the provision of a plug which provides complete safety during insertion of the plug, since no electrical contact is made until the plug is fully inserted.
The above advantages may be gained and the disadvantages overcome through the use of the present invention.
Accordingly, the present invention consists of an electrical distribution system comprising a sandwich type panel including electrically conductive layers, and elec trically insulating layers arranged alternately therewith, said conductive layers and insulating layers having a plurality of sets of aligned apertures and at least one elongated plug adapted to be inserted into an aligned set of apertures, said plug including means to contact a selected one of said conductive layers to. thereby complete an electrical circuit. I v 1 In the drawings which illustrate an embodiment of the invention:
FIG. 1 is a perspective view of a section of a plug board in accordance with this invention showing plugs partially inserted;
plug board of FIG. 5 is a transverse sectional view taken along the section 5-5 of FIG. 3, and
FIG. 6 is an end elevational view of a plug as shown in FIG. 3.
Referring now in detail to the drawings shown in FIGS. 1 and 2 is a plug board 10 comprising a facing' ice panel 11 of sheet steel or other suitable rigid material, a receiving board 25, layers of electrical insulating material 13, 14, 15, 16, 17 and 18 alternately arranged with electrically conductive layers 20, 21, 22, 23 and 24 therebetween and held together by a frame (not shown).
The facing panel 11 has spaced apertures 12 arranged in horizontal and vertical rows. As will be apparent hereinafter, horizontal rows of 12 apertures and vertical rows of 17 apertures provide a convenient arrangement to accommodate either 102 two-wire circuits or 68 three-wire circuits or 51 four-wire circuits or 34 six-wire circuits. The panel 11 may, desired, be folded around at the edges, and include a channel iron base 11' or other suitable mounting means.
Behind the panel 11 are layers 13, 14, 15, 16, 17 and 18 of electrical insulating material alternately arranged with electrically conductive layers 20, 21, 22, 23 and 24 of copper or other suitably conductive metal. The layer 13 immediately behind the panel is an insulating layer.
The insulating and conductive layers together form a sandwich type panel which is provided with a plurality of apertures 28 extending therethrough, similarly arranged and in alignment with apertures 12 in the panel 11. Apertures 28 are of the same diameter as apertures 12 in the panel 11.
superposed on the layer 18 of insulating material'is the receiving board 25 which forms the rear faceof the sandwich panel. The receiving board 25 includes a plurality of apertures 26 similarly arranged and in alignment with apertures 12 in the panel 11. The board 25 consists of insulative material. Each of the apertures 26 in the board 25 is provided with a connector pin 27 of brass or other electrically conductive metal. The connector pins 27 extend through the board 25 into the apertures 28 and are secured to the board 25 by any suitable means such .each other. The bus bars in all of the layers are oriented in the same direction and each of the bars of each layer coincides with a vertical row of apertures 12 in the panel 11. A
It will be apparent that each of the conductive layers may also comprise an electrically conductive plate rather than a plurality of bus bars.
The embodiment illustrated comprises five conductive layers, however, a greater or lesser number of conductive layers may be employed in accordance with the requirements of the user.
The five conductive layers are adapted to be connected to various voltage supplies. All the bus bars of a selected layer may be connected to one side of the voltage supply or pairs of bus bars in a selected conductive layer may be connected to a common voltage supply to provide a twowire circuit as illustrated in FIG. 1. Each of the connector pins 27 receives a wire 29 for connection to service outlets (not shown). A plug 30 for use with the plug board 10 is shown in detail in FIGS. 3 to 6. The plug 30 includes a housing 31, of insulative material and an integral elongated tubular member 32 extending therefrom. The diameter-of the tubular member is slightly less than the diameter of the apertures 12 in the panel 11. The tubular member 32 and the apertures 12,.as illustrated, are substantially circular in cross section, however, they may be of any suitable cross sectional configuration such as square, oval or the like.
The housing 31 defines a rectangular switch receiving vided with hard rubber plugs 65 box 33 having integral opposite side walls 34, end wall 35, a top wall 36 and a bottom wall 37 The tubular member 32 is integral with end wall 35 and communicates with the interior of the box 33 through an aperture 38 in the end wall 35.
The box 33 is adapted to receive a conventional circuit breaker 41 of the type know as a mini-breaker. The circuit breaker 41 may also automatically protect the circuit from overload. A plate 42 having a handle portion 39 integral therewith and projecting from one face thereof and a circuit breaker 41 secured to and projecting from the other face is secured to the box 33 by screws 43, thereby closing the open end 40 of the box 33 and mounting the switch within the the circuit breaker 41 extends through a suitable opening in the plate 42.
An inner tubular member 45 of brass or similar electrically conductive metal is positioned within the tubular member 32, and extends from the end wall 35 to a point adjacent the tip of the tubular member. For the purpose of describing this invention, the metal parts are described as being of brass, however, other suitable electrically conductive material such as copper, or the like, may be used. Similarly, insulative material can include plastic, hard rubber or the like.
Pairs of diametrically opposed tapped holes 50, 51, 52,
53 and 54 are provlded in the inner tubular member 45. Similarly pairs of holes 56A, 56B, 56C and 56B are provided in the tubular member 32, and are in communication with respective pairs of the holes 50 to 54 inclusive.
A tubular brass insert 46, in the tip of the tubular member 32 is separated from the inner tubular member 45 by an insulating sleeve 47. An annular enlargement or ring 61 is provided on the exterior of the tubular member 32 and is formed integral therewith. The ring 61 is spaced from the tip of tubular member 32, and the outside diameter of the ring is slightly less than that of holes 28. An aperture 62, extending through the ring 61 and the tubular member 32, matches a tapped 'hole- 63 in the brass insert 46 and is adapted to receive and engage a headless brass screw 64 to retain the insert 46 in the tubular member 32. For insulating purposes the aperture 62 is proat both ends of the brass screw 64.
A brass contact ring 48 having diametrically opposed holes 49 therein is positioned concentrically on the tubular member 32, and may be slid axially therealong to any one of the tapped holes 50 to 54 in the inner tubular member 45, and secured in position by a brass screw 55 inserted through aperture 49 in the contact ring 48, and through a hole 56A in the tubular member 32 to engage one of the tapped holes 50 to 54. A second brass screw 55 is similarly secured in the diametrically opposed holes, provided in the contact ring the tubular member and the inner tubular member.
In order to ensure that the ring 48 makes good electrical contact with, for example, the conductive bar 20, the inside diameter of the ring 48 is slightly larger than the outside diameter of the tubular member 32. Thus, screws 55 pull the ring 48 into a substantially oval cross-section, thereby providing resiliency. The outside diameter of the ring 48 and the diameter of the holes 28 are such that the ring 48 fits tightly in any of the holes 28, but upon deformation will pass therethrough.
The unused tapped holes 51 to 54 are plugged with hard rubber inserts 60 for insulating purposes. The positions of the tapped holes 50 to 54 correspond to the positions of the conductive plates in the sandwich.
A terminal 57 of the circuit breaker is electrically connected to the brass inner tubular member 45 by a short length of wire 57'. A second terminal 58 is electrically connected to the brass insert 46 in the tip of the tubular member 32 by a suitable length of insulated wire extending through the inner tubular member 45.
A color-coded voltage supply identification plate 59 is .secured to the handle ,59 of the plug 30.
box. A switch actuating arm 44 of In operation, when conductor plates 20 to 24 have been electrically connected to suitable supplies of various voltages and electrical connections made between the connector pins and the service outlets, the plug 30 is inserted in one of the apertures 12 in the panel 11. When fully inserted, the tubular brass insert 46 will receive an end portion of the connector pin 27 to thereby make electrical contact. The contact ring 48, as illustrated, will contact conductive layer 20 in the plug board 10.
A second identical plug (not shown) having a contact ring secured thereon, at a position to cont-act one of the conductive layers 21 to 24 to obtain the desired potential difference between that layer and the previously contacted layer 20, is inserted in the plug board 16. The circuit breakers 41 being closed, a two-wire circuit is thus formed between the supply and the service outlets.
Alternatively, a second identical plug 30, as shown in FIG. 1 having a contact ring secured at the appropriate position to contact conductive layer 20', is inserted in the plug board 10 thereby connecting layer 26 to the connector pin 27, which is in turn connected to the service outlet. The circuit breakers 41 of the two plugs 30 and 30' being closed, a two-wire circuit is thus formed between the supply and the service outlets.
1. In an electrical distribution system a sandwich type panel of electrically conductive layers and insulating layers alternately arranged therewith, an outer layer of said sandwich being of insulating material, and having connector pins mounted thereon, apertures extending through said sandwich panel in alignment with said pins, an elongated plug for insertion in a selected one of said apertures and having an electrical contact thereon selectively axially movable therealong to contact a selected one of said conductive layers, an electrically conductive tip on said plug adapted to contact a connector pin and means whereby said contact means and said tip are in electrical contact.
2. An electrical distribution system, as claimed in claim 1, wherein said electrically conductive layers comprise rows of bars electrically insulated from each other.
3. An electrical distribution system, as claimed in claim 1, wherein each said electrically conductive layer is a plate.
4. An electrical distribution system, as claimed in claim 1, wherein said ring is insulated from said tip and said tip is connected to said ring through circuit protective means on said plug.
5. An electrical distribution system comprising:
(a) a plug board comprising electrically conductive and insulating layers arranged alternately thereby to form a sandwich type panel, said layers having a plurality of aligned apertures each of said conductive layers being adapted to be connected to a service outletg (b) said service outlet electrically connected to.said
(c) a plurality of potential sources selectively connected to said conductive layers of said plug board and (d) a plug including a metal ring thereon axially movable therealong to contact selected conductive layers and to connect said selected layer to said service outlet.
6. An electrical distribution system as defined in claim 5 and including further plug means adapted to electrically connect together selected conductive layers.
7. In an electricaldistribution system a sandwich type panel comprising electrically conductive layers, and electrically insulating layers arranged alternately therewith,
said conductive layers and insulating layers having a plurality of sets of aligned apertures and at least one elongated plug insertable into axially aligned apertures, said plug including an electrical contact selectively axially movable along said plug to contact a selected one of said conductive layers thereby to complete an electrical circuit.
8. In an electrical distribution system a sandwich type panel comprising electrically conductive layers arranged alternately therewith, said conductive layers and insulating layers having a plurality of sets of aligned apertures and at least one elongated plug insertable into axially aligned apertures, said plug having a metal ring mounted thereon for axial movement therealong to contact a selected one of said conductive layers thereby to complete an electrical circuit.
References Cited by the Examiner UNITED STATES PATENTS 233,081 10/1880 Dowd 3171 12 255,056 3/1882 Vail 317-112 1,235,515 7/1917 Chrisman 317-112 2,006,436 7/1935 Bowers 317l12 3,049,645 8/1962 Skippan 33918 KATHLEEN H. CLAFFY, Primary Examiner. JOHN F. BURNS, Examiner. J. G. COBB, Assistant Examiner.