U.S. patent number 3,818,282 [Application Number 05/325,871] was granted by the patent office on 1974-06-18 for electrical panel board with ground and neutral plug-in buses.
This patent grant is currently assigned to I-T-E Imperial Corporation. Invention is credited to Aldon L. Buxton, Leonard Donnerstag, Carl E. Gryctko.
United States Patent |
3,818,282 |
Buxton , et al. |
June 18, 1974 |
ELECTRICAL PANEL BOARD WITH GROUND AND NEUTRAL PLUG-IN BUSES
Abstract
A very flexible electric service panel for temporary hookups is
constructed to receive plug-in circuit breakers for direct wiring,
as well as four prong receptacle type plug-in power outlet fittings
for making cord set connections. The power outlet fitting is
constructed by utilizing a hook-like member to mechanically hold a
subassembly and a receptacle together as a unitary structure. The
subassembly consists of two single pole circuit breakers stacked
side by side. The receptacle is adjacent to the load end of the
subassembly and electrically connected to the load terminals of the
breakers. Plug-in type neutral and grounding connectors at the rear
of the receptacle engage forwardly extending legs of neutral and
ground busses in the service panel, as plug-in line terminals of
the breakers engage energized stabs in the service panel.
Inventors: |
Buxton; Aldon L. (Stone
Mountain, GA), Donnerstag; Leonard (Atlanta, GA),
Gryctko; Carl E. (Haddon Heights, NJ) |
Assignee: |
I-T-E Imperial Corporation
(Philadelphia, PA)
|
Family
ID: |
26877427 |
Appl.
No.: |
05/325,871 |
Filed: |
January 22, 1973 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
181696 |
Sep 20, 1971 |
|
|
|
|
Current U.S.
Class: |
361/627; 439/654;
439/721 |
Current CPC
Class: |
H02B
1/50 (20130101) |
Current International
Class: |
H02B
1/00 (20060101); H02B 1/50 (20060101); H02b
001/20 () |
Field of
Search: |
;317/104,105,107,108,111,112,118-120 ;200/168R ;339/198M,198N |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schaefer; Robert K.
Assistant Examiner: Tolin; Gerald P.
Attorney, Agent or Firm: Ostrolenk, Faber, Gerb &
Soffen
Parent Case Text
This is a continuation of application Ser. No. 181,696, filed Sept.
20, 1971, now abandoned.
Claims
The embodiments of the invention in which an exclusive privilege or
property is claimed are defined as follows:
1. An electric panel including an enclosure and within said
enclosure an elongated neutral bus, an elonaged grounding bus, and
conductor means defining hot contact points; within said enclosure,
said contact points being electrically insulated from said buses
said buses being transversely spaced and parallel to each other
with said contact points positioned to one side of said buses; said
conductor means and said buses being operatively positioned so that
said contact points are engageable by line terminals of receptacle
type power outlet fittings having plug-in type neutral and ground
terminals engageable with the neutral and ground buses,
respectively; one of said buses being positioned between the other
of said buses and said contact points; each of the buses being
generally of L-shaped cross-section with a forwardly extending leg
thereof engageable by plug-in type terminals of receptacle type
power outlet fittings having at least three prong engaging contact
elements.
2. An electric panel as set forth in claim 1 in which the hot
contact points are disposed in a row parallel to and transversely
spaced with respect to said buses.
3. An electric panel as set forth in claim 2 in which the hot
contact points are alternately phased and are engageable by plug-in
type line terminals of a receptacle type power outlet fitting.
4. An electric panel as set forth in claim 3 including a mounting
ledge within said enclosure extending parallel to said buses and
positioned between said hot contact points and said buses; said
mounting ledge having a forward surface provided with securing
formations for mechanical securement of receptacle type power
outlet fittings.
5. An electric panel as set forth in claim 1 including a mounting
ledge within said enclosure extending parallel to said buses and
positioned between said hot contact points and said buses; said
mounting ledge having a forward surface provided with securing
formations for mechanical securement of receptacle type power
outlet fittings.
6. An electric panel as set forth in claim 5 including a meter
socket positioned on the side of said contact points remote from
said mounting ledge; said meter socket having terminals
electrically connected to said conductor elements.
7. An electric panel as set forth in claim 5 in which the mounting
ledge is provided with first and second forwardly extending
mounting hooks for mechanically engaging a circuit breaker whose
width spans at least four consecutive ones of said contact points
said mounting hooks being positioned between said securing
formations.
8. An electric panel as set forth in claim 7 in which the mounting
hooks are spaced apart by a distance sufficient to permit a
receptacle type power outlet fitting for a plug having at least
three prongs, to be secured to the forward surface of said mounting
ledge in a position between said mounting hooks.
9. An electric panel as set forth in claim 8 in which the forward
surface of the mounting ledge is long enough to secure at least
three receptacle type power outlet fittings for a plug having at
least three prongs positioned side-by-side.
10. An electric panel as set forth in claim 7 in which each of the
L-shaped cross-section with a forwardly extending leg engageable by
plug-in type terminals of a receptacle type power outlet fitting
having at least three prong engaging contact elements; each of said
contact points comprising a forwardly extending sheet-like stab
disposed in a plane transverse to said legs of said buses.
11. An electric panel as set forth in claim 7 in which each of the
L-shaped cross-section with a forwardly extending leg engageable by
plug-in type terminals of a receptacle type power outlet fitting
having at least three prong engaging contact elements; each of said
forwardly extending legs having notches in line with said mounting
hooks.
12. An electric panel as set forth in claim 10 in which the
mounting hooks are spaced apart by a distance sufficient to permit
a receptacle type power outlet fitting, for a plug having at least
three prongs, to be secured to the forward surface of said mounting
ledge in a position between said mounting hooks.
13. An electric panel as set forth in claim 10 in which the hot
contact points are disposed in a row parallel to and transversely
spaced with respect to said buses.
Description
In recent years local regulatory agencies have become more active
in setting standards for electric service equipment for temporary
hookups as required for boat docks, marinas, trailer parks, and
mobile home parks. In particular, such a temporary service panel
must be flexible enough so as to readily connect thereto either by
utilization of plugs or by direct wiring.
Typically, the equipment in a trailer or mobile home park is called
upon as the hookup point for basic electric service requirements in
a single phase four-wire system, including a neutral and an
equipment ground. For 40 or 50 ampere service the park equipment
must accept either a cord set or direct wiring; for 100 ampere
service either two 50 ampere cord sets or direct wiring; for 150
ampere service, three 50 ampere cord sets or direct wiring; and for
200 ampere service, direct wiring only. Thus, the park equipment
must provide seven alternative service connections. To make matters
even more difficult, the park equipment must be factory wired so
that only extremely limited field modification may take place, and
in particular there is a prohibition against field wiring between
receptacles and circuit breakers to achieve interchangeability.
The most flexible prior art approach appears to be one in which
plug-in units were provided. Each of these units comprised a
relatively large mounting plate carrying circuit breakers and
receptacles. These plug-in units were relatively bulky and
expensive. In addition, these prior art devices were difficult to
manufacture to reasonable dimensional tolerances because of size.
Quite often these plug-in units did not operate properly, in that
poor connections were made resulting in a floating neutral and/or
poor ground integrity especially when screw pressure was used to
make connections by forcing abutting steel parts together.
In accordance with the instant invention the trailer or mobile home
park is provided with panels having bussing so arranged that
plug-in type circuit breaker units of the desired combination may
readily be mounted. For direct wiring conventional circuit breakers
are mounted in the panel and for cord sets power outlet fittings
are mounted in the panel. Each of these power outlet fittings
consists of an assembly of two conventional single pole circuit
breakers and a receptacle for receiving a four-prong plug. Each of
these single pole units is provided with a plug-in type line
terminal and the receptacle section is provided with plug-in type
neutral and ground terminals.
Accordingly, a primary object of the instant invention is to
provide novel flexible electrical service equipment for temporary
service requirements.
Another object is to provide a novel construction for a panel that
may be used for direct wiring or cord sets.
Still another object is to provide a novel construction for a panel
which mounts receptacle type power outlet fittings.
A further object is to provide a novel construction for a panel
that mounts four prong receptacle plug-in type power outlet
fittings.
These objects as well as other objects of this invention will
become readily apparent after reading the following description of
the accompanying drawings in which:
FIG. 1 is a front elevation of a four-prong receptacle type power
outlet fitting constructed in accordance with teachings of the
instant invention.
FIG. 2 is a side elevation of the power outlet fitting looking in
the direction of arrows 2--2 of FIG. 1.
FIG. 3 is an end view of the power outlet fitting looking in the
direction of arrows 3--3 of FIG. 2.
FIG. 4 is a rear elevation of the power outlet fitting.
FIG. 5 is a view similar to FIG. 4 with the receptacle section rear
housing part removed.
FIG. 6 is a rear elevation of the front housing part for the
receptacle section.
FIG. 7 is a side elevation of the securing insert number showing
its operative relationship with adjacent portions of the receptacle
section and the single-pole circuit breakers.
FIG. 8 is an exploded perspective showing the main elements of the
power outlet fitting of FIGS. 1-7.
FIG. 9 is a front elevation, with the front covers removed, of an
electrical panel specially adapted for use in trailer parks and
mobile home parks, and capable of utilizing the power outlet
fitting of FIGS. 1-8.
FIG. 10 is a side elevation, with housing portions cut away, of the
electric panel, looking in the direction of arrows 10--10 of FIG.
9.
FIG. 11 is a rear elevation looking in the direction of arrows
11--11 of FIG. 10 with rear portions of the pedestral cut away to
reveal the bussing through which the electric panel of FIGS. 9 and
10 is energized.
FIG. 12 is a view similar to that of FIG. 9 with the upper front
cover in place and a power outlet fitting mounted in the panel with
a cord set connected to the fitting.
FIG. 13 is a view similar to that of FIG. 10 showing the major
elements of FIG. 12.
Now referring to the figures and more particularly to FIGS. 1-8.
Four-prong receptacle type power outlet fitting indicated generally
by reference numeral 20 comprises single pole circuit breakers 21,
22 and four-prong receptacle 23, secured together by means
including hook-like retainer insert 24 (FIGS. 7 and 8) to form a
unitary structure.
Circuit breakers 21 and 22 are stacked side by side with cap 26 and
rivet 27 mechanically tying the handles of both circuit breakers 21
and 22 together for movement in unison. In addition, circuit
breakers 21, 22 have interconnected automatic overload tripping
units, so that a fault condition in one of the circuit breakers 21,
22 will automatically cause tripping of both. This construction is
illustrated in detail in U.S. Pat. No. 2,996,589 issued Aug. 15,
1961 to F.E. Myers for a "Pivoted Bimetal."
Circuit breakers 21, 22 are identical units, each having a plug-in
type line terminal 28, whose jaws are engageable with plate-like
stab 29 of a distribution panel. Circuit breaker 22 is also
provided with load terminal 31 having wire grip 32 which clamps one
end of stiff conductor 33 into firm electrical engagement with load
terminal 31. Similarly, wire grip 34 clamps one end of stiff
conductor 35 into firm electrical engagement with the load terminal
of circuit breaker 22.
Clamp 36 at the other end of conductor 33 clamps blade receiving
jaw-type terminal 37 into firm electrical engagement with the right
end of conductor 33 as viewed in FIG. 8. Similarly, clamp 38
electrically connects jaw-type terminal 39 to the right end of
conductor 35. Jaw-type terminals 41, 42, extending in opposite
directions from the plane of conducting bar 43, are connected to
opposite ends thereof by the respective clamps 44, 45. Similarly,
jaw-type terminals 46, 47 extend in opposite directions from the
plane of conducting bar 48 and are secured to opposite ends thereof
by the respective clamps 51, 52.
The portions of receptacle housing 54, 65 are held together by one
way screws, 76, 87, 87 received by threaded apertures 89, 91, 91 in
forward housing part 54. The latter is provided with four plug
prong receiving openings 55, 56, 57 and 58, aligned with terminals
37, 39, 41, and 46, respectively, so that these terminals will be
engaged by the respective prongs 59, 60, 61 and 62 of four-prong
plug 63 as these prongs are inserted into receptacle section 23 of
power outlet fitting 20.
Rear molded insulating housing part 65 is provided with parallel
transverse slots 66, 67 at the rear thereof. Jaw portions of
terminals 42 and 47 extend into the respective slots 66, 67 from
the interior of housing 54, 55 for reasons which will be
hereinafter explained. Formations 71, 71 extending to the left from
forward housing part 54 are received in complementary recesses 72
at the load end of circuit breakers 21, 22. Similar locating
formations 73, 73 extend to the ledt from rear housing part 65 into
complementary formations 74 at the load end of circuit breakers 21,
22.
A major portion of the mechanical securing of receptacle section 23
to the subassembly of circuit breakers 21, 22 is accomplished by
generally hook or L-shaped retainer insert 24 (FIGS. 4, 7 and 8)
which is fastened to rear housing part 65 by screw 76 which extends
through clearance aperture 77 in enlarged cylindrical portion 83 at
the right end of insert arm 78 through clearance aperture 83a in
rear housing part 65, and is received by threaded aperture 89 in
front housing part 54. The other arm 79 of insert 24 extends into
space 79a between circuit breakers 21, 22 formed by abutting
embossments similar to embossments 81, 82 (FIG. 7). Included
surface 80 of retainer arms 78, 79 is adjacent to embossments 82,
cooperating therewith to prevent receptacle section 23 from being
moved to the right of subassembly 21, 22.
Enlargement 83 and the portion of arm 78 to the right thereof rest
against recessed ledge 84, at the rear of housing part 65,
cooperating therewith to form a dividing wall between gas expansion
chambers 84a, 84b (FIG. 4). These chambers 84a, 84b communicate
with the load end of venting passages 96, 96 (FIG. 2) in the
respective circuit breakers 21, 22 through apertures 97a, 97b,
respectively (FIG. 3), in rear housing part 65. Thus, arcing gases
formed upon separation of movable contact 15 from stationary
contact 16, in circuit breaker 21, travel from arc chute 17 through
passage 96 and aligned aperture 97b into chamber 84b where these
gases expand and are deflected rearward by the curved wall at the
right of chamber 84b.
Screw 92 extends through threaded aperture 93 in forward housing
part 54, through clearance aperture 94 in rear housing part 65 and
clearance aperture 88 in insert leg 78, and is threadably received
in one of the threaded apertures 102 in the forward leg of Z-shaped
mounting ledge 103 of electrical service panel 100 (See FIGS.
9-13).
Now referring more particularly to FIGS. 9-13, panel 100 includes
generally rectangular housing 101 having upper and lower removable
covers 104, 105 at the front thereof. Elongated ground bus 106
extends parallel to and is laterally spaced from transverse circuit
interrupter mounting ledge 103. Screws 107, extending through the
rear leg of ground bus 106, secure the latter flush against the
rear surface of housing 101. The leftmost screw 107 in FIG. 9 also
secures the upper end of grounding strap 108 to bus 106. Terminal
strip 109 and bonding wire 110 are secured to the lower end of
grounding strap 108.
L-shaped neutral bar 111 is positioned below grounding bus 106 and
extends parallel thereto. Molded insulating brackets 112, 113
secured to the rear wall of housing 101 by screws 114 engage
neutral bus 111 at opposite ends thereof to space the latter
forward of rear wall 115 and above grounding strap 108. Neutral
strip 116 and wire grips 117, 118 are mounted to the rear leg of
neutral bus 111 on the forward surface thereof. One end of twisted
neutral strap 109 is connected by screw 121 to neutral bus 111, at
the left thereof, and the other end is connected by screw 122 to
strap 123 (FIG. 11). Screw 124 connects strap 123 to insulating
block 125 positioned adjacent the forward wall of pedestal 130 and
also secures wire grip 126 to strap 123. Another wire grip 127 is
mounted by screw 128 to neutral conductor 119 at a portion thereof
within pedestal 130.
A plurality of screws 128 extend through the rear wall of panel
housing 101 to secure the latter on forward surface 129 of pedestal
130. Neutral conductor 119 as well as hot conductors 132, 133 are
bent over at right angles at points intermediate their ends, with
the horizontal portions of the bends extending between the
interiors of housing 101 and pedestal 130 and in doing so extend
through insulating gasket 134 sandwiched between the rear of
housing 101 and the front of pedestal 130.
Screws 138, 139 secure the pedestal ends of the respective
conductors 132, 133 to the respective straps 136, 137 which are
connected by screws 144, 145, respectively, to insulating block
125. Screws 144, 145 also secure the respective wire grips 142, 143
to straps 136, 137, respectively. Screws 147 secure block 125 to
insulating sheet 148 covering window 149 in the front wall of
pedestal 130.
The ends of conductors 132, 133 within housing 101 are connected by
screws 151 to the respective straps 152, 153 to which plug-in
connectors 154, 155, respectively, of meter block 156 are mounted.
The latter includes insulating mounting sheet 157 to which straps
152, 153, 158, 159 are secured in spaced relationship. Brackets
157a, secured to the rear wall of housing 101 by screws 157b, are
connected by screws 157c to insulating sheet 157 to support the
latter in operative positions spaced forward of housing rear wall
115 and parallel thereto. Housing cover 104 is provided with meter
sealing ring 104a in front of sheet 157.
Plug-in connectors 162, 163 are connected to straps 158, 159 which
are connected by screws 161 to additional straps 164, 165
respectively, connected to conducting sheets 265, 266 from which
the respective stabs 165a, 166a are formed. Conducting sheet 265
also provides stabs 165b-d. Similarly, conducting sheet 266
provides stabs 166b-d. The stabs from these respective conducting
sheets are interleaved and are disposed in a row parallel to
mounting ledge 103 being spaced by rigid insulator 267. Flexible
insulating sheet 268 overlies conducting sheets 265, 266. The
construction of these conducting sheets and the manner in which
stabs 165a-d and 166a-d are maintained in their operative positions
and insulated from one another is described in detail in U.S. Pat.
No. 3,349,292 issued Oct. 24, 1967 to J.F. Meacham for "Load
Center."
Mounting ledge 103 is provided with a pair of spaced mounting hooks
175, 175, in line with stabs 165c and 166b, which are intended to
mount a circuit breaker extending over four adjacent ones of the
stabs 165a-d and 166a-d. Such a circuit breaker is illustrated in
U.S. Pat No. 3,573,415 issued Apr. 6, 1971 to C.E. Gryctko for a
Parallel Pole Circuit Breaker.
The portion of housing 101 containing meter block 156 is separated
from the remainder of housing 101 by transverse insulating sheet
172 which is separately notched to fit over bus elements 119, 164,
165 etc. and is held in operative position by fitting into notches
at the upper end of ledges 173, 174 which extend inward of housing
101 partway along the sides thereof. These ledges 173, 174, in
combination with another ledge 17a extending inwardly of housing
101 along the bottom thereof, support face plate 176 which provides
a dead front over the hot bussing in the region where load
connections are to be made.
When panel 100 is to be used, from one to three power outelt
fittings 20 may be mounting therein. As seen in FIG. 12, one power
outlet fitting 20 is mounted so that the circuit breaker sections
21, 22 engage the leftmost stabs 165a, 166a. The leftmost portion
106a (FIG. 9) of the forwardly extending leg of ground bus 106 is
clamped between the jaws of receptacle section grounding contact 42
(FIG. 13) and the forwardly extending portion 111a at the left of
neutral bus 111 is engaged by the jaws of neutral contact 47 in
receptacle section 23. The prongs of four-prong plug 63 are
inserted into receptacle section 23, and flexible cable 63a
connected to plug 63 extends downward through the leftmost notch
207 in the bottom wall 271 of housing 101. In accordance with
practices well known to the art of distribution panels, all of
those notches in face plate 176 that are not covered by a power
outlet fitting 20 or other circuit interrupter, are covered with
snap-in type dummies to preserve the integrity of the dead front.
It is noted that the spacing between mounting hooks 175, 175 is
sufficient to permit a single power outlet fitting 20 to be mounted
with the line terminals thereof in engagement with stabs 165b and
166c.
For direct wiring, neutral connections are made to wiring devices
116-118 and ground connections are made to terminal strip 109. The
hot wire connections are made to two-pole circuit breakers secured
by one or both of the mounting hooks 175, 175. Such circuit
breakers may be rated up to 100 amps per pole and are of the type
illustrated in the aforesaid U.S. Pat. No. 2,996,589. In ratings
between 100 and 200 amps the circuit breakers are of the type
illustrated in the aforesaid U.S. Pat. No. 3,573,415.
Thus, it is seen that this invention provides a novel construction
for a panel that may be direct wired or may provide means for cord
set hookup utilizing receptacle plug-in type power outlet fittings.
While this invention has been described in connection with a three
wire single phase system, it should now be apparent to those
skilled in the art that teachings of the instant invention may be
utilized for three phase and other multiphase applications.
Although there have been described preferred embodiments of this
novel invention, many variations and modifications will now be
apparent to those skilled in the art. Therefore, this invention is
to be limited not by the specific disclosure herein, but only by
the appending claims.
* * * * *