U.S. patent number 3,894,781 [Application Number 05/483,095] was granted by the patent office on 1975-07-15 for connector plug for power distribution track.
This patent grant is currently assigned to Lightolier Incorporated. Invention is credited to Anthony C. Donato.
United States Patent |
3,894,781 |
Donato |
July 15, 1975 |
Connector plug for power distribution track
Abstract
The present invention relates to a connector plug attachment for
use with a power distribution track of the type having an open
channel housing insulated conductive conduits. The connector is
characterized by the ability to be electrically and mechanically
coupled to the track by a single operation, notably a rotation of
elements of the connector plug relative to the track. The plug
includes a pair of wings or flanges for rotation into mechanically
locked engagement with portions of the track and a pair of contact
portions rotatable into electrically coupled relation with the
conduits of the track, a lost motion coupling being interposed
between the flanges and contacts whereby, upon rotation of a single
drive or locking element on the plug, the contacts and flanges are
appropriately positioned to secure the desired mechanical and
electrical coupling.
Inventors: |
Donato; Anthony C. (Westfield,
NJ) |
Assignee: |
Lightolier Incorporated (Jersey
City, NJ)
|
Family
ID: |
23918641 |
Appl.
No.: |
05/483,095 |
Filed: |
June 26, 1974 |
Current U.S.
Class: |
439/121;
439/314 |
Current CPC
Class: |
H01R
25/142 (20130101) |
Current International
Class: |
H01R
25/14 (20060101); H01R 25/00 (20060101); H01r
009/00 (); H01r 013/60 () |
Field of
Search: |
;339/21R,21S,22R,22B,75R-88R,188C,189R,190 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lake; Roy
Assistant Examiner: Abrams; Neil
Attorney, Agent or Firm: Colvin; Arthur B.
Claims
I claim:
1. As an article of manufacture, a connector plug adapted in a
single operation to be mechanically and electrically attached to a
power distribution track of the type including spaced parallel
conduits disposed within a downwardly open channel having parallel
side walls and opposed flanges, comprising a housing including a
stop portion adapted to engage the outer face of said flange, key
means on said housing for locking said housing against rotation
relative to said track, a plug member rotatably mounted in said
housing including projecting contact portions adapted to enter into
said channel and engage the conduits of said track responsive to
rotation of said plug member, a sleeve surrounding said plug member
and rotatable relative to said housing and said plug member, lock
flange means on said sleeve for engaging behind and locking said
housing to said flanges responsive to rotation of said sleeve
relative to said housing, torque drive means rotatably mounted on
said housing in driving connection with said plug for rotating said
plug through an angle corresponding with the angle of rotation of
said drive means, and lost motion coupling means on said sleeve
adapted to engage said drive means for coupling the sleeve and
drive means for conjoint rotation following predetermined relative
rotation between said plug and sleeve, whereby rotation of said
drive means rotates said locking flanges through a first arc into
mechanically coupled relation with said flanges of said track, and
said plug through a second and greater arc electrically to connect
said contact portions and said conduits.
2. Apparatus in accordance with claim 1 wherein said lost motion
coupling means comprises an arcuate slot in said sleeve, and said
drive means includes a finger keyed to said plug and extending
outwardly through said slot.
3. Apparatus in accordance with claim 2 wherein said drive means
includes a barrel rotatably mounted on said housing and surrounding
said sleeve and said plug, said finger being fixed to said barrel
and said plug.
4. Apparatus in accordance with claim 1 wherein said lock flange
means includes inner end portions fixed to said sleeve and distal
portions spaced radially from said sleeve, the spacing between said
distal portions exceeding the distance between said side walls of
said channel, whereby the engagement of said ends against said
channel walls limits the permitted extent of rotation of said
sleeve relative to said housing.
5. Apparatus in accordance with claim 4 wherein said lost motion
coupling means comprises an arcuate slot in said sleeve, said drive
means includes a finger keyed to said plug and extending through
said slot, the spacing of said distal portions of said lock flanges
being coordinated with the angular extent of said slot and the
distance between said side walls of said channel to permit said
plug member to rotate a maximum of about 90.degree. when said lock
flanges are disposed within said channel.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a plug member, and more
particularly to a plug member adapted to be connected to a power
distribution track. More particularly, the invention is in the
field of plug members for use in power distribution tracks of the
types illustrated, for example, in U.S. Pat. Nos. 2,346,074 and
3,286,052, such tracks comprising generally an elongated aluminum
or like metallic extrusion in the form of a channel having a slot
or opening, the channel containing recessed electric conduits.
The plug is intended to be mechanically and electrically coupled at
virtually any point along the length of the track, it being
understood that the plug may support a lighting fixture or may be
used to provide an outlet for a tool or other electrical
appliance.
2. The Prior Art
The concept of providing elongated power distribution tracks and
plugs connectible at any desired position therealong is known, for
example, in the above noted patents. Typically, tracks of the sort
referred to are secured along the ceiling structure of a room,
although, of course, they may be otherwise located.
As will be evident, where the power distribution track is
positioned in a relatively inaccessible location, such as a
ceiling, a user desirous of effecting connection to the track, must
of necessity climb a ladder, chair, or like support to gain access
to the track. In accordance with the two above noted patents, plug
apparatuses are described which are structurally and functionally
efficient for their intended purpose in that excellent mechanical
and electrical connections to the track may be effected.
The plug fixtures of both of the noted patents, however, require
substantial amounts of manipulation for actually completing the
coupling between the plug and track, such manipulation including,
for example, the carrying out of sequential operations and/or
operations requiring two hands for their satisfactory
performance.
SUMMARY
The present invention may be summarized as directed to an improved
plug adapted for mechanical and electrical connection to a power
distribution track by simplified, one-hand operation facilitating
the task of a user who is required to climb a ladder, stand on a
chair or otherwise be perched in an unstable position to gain
access to the track.
The plug apparatus comprises a housing including a stop portion or
plate adapted to engage against the flanges leading to the interior
of the power distribution channel. The housing includes a barrel
member which may be rotated after appropriate positioning of the
housing to drive a pair of locking wings or flanges through a
predetermined angular arc, to effect mechanical engagement of the
locking flanges and the track flanges.
An insulated plug member carrying contact portions is rotatably
mounted within the barrel and is directly connected to the barrel
or drive means, such that rotation of the barrel is likewise
communicated to the plug.
A lost motion coupling is interposed between the barrel and the
locking flanges, whereby the plug carrying the contacts may be
rotated a greater arcuate distance than the locking flanges. It
will thus be perceived that both operations, viz. mechanical
coupling of the housing to the track and electrical coupling of the
contacts carried by the plug to the conduits within the track are
accomplished by a single rotary movement applied to the barrel or
drive means.
With the foregoing in mind, it is an object of the invention to
provide an improved plug assembly for attachment to a power
distribution track, the plug assembly being characterized by the
fact that both electrical and mechanical couplings are accomplished
responsive to a simple rotary movement of a single part of the
plug.
A further object of the invention is the provision of an improved
plug assembly of the type described including a barrel rotatably
mounted on the housing of the plug, rotation of the barrel being
effective simultaneously to engage mechanical locking flanges of
the plug with flanges of the track, securely to connect the parts,
and electrically connect contact portions of the plug and the
conduits in the track.
According to the invention, these objects are accomplished by the
arrangement and combination of elements hereinafter described and
particularly recited in the claims.
In the drawings, in which are shown one or more of the various
possible embodiments of the several features of the invention:
FIG. 1 is a fragmentary perspective view of a track section and
portions of the plug assembly;
FIG. 2 is a plan view taken in the direction of the arrows 2--2 of
FIG. 1;
FIG. 3 is a side elevational view of a lighting fixture supported
on a track section;
FIG. 4 is a magnified horizontal section taken on the line 4--4 of
FIG. 3;
FIG. 5 is a vertical section taken on the line 5--5 of FIG. 4;
FIG. 6 is a vertical section taken on the line 6--6 of FIG. 4;
FIG. 7 is a horizontal section taken on the line 7--7 of FIG.
5.
Referring now to FIG. 1, there is shown at 10 a track section of a
type known per se, and consisting essentially of an elongated
aluminum extrusion including side walls 11, 12, and a horizontal
web 13. An opposed pair of inturned flanges 14, 15 terminate in
spaced relation defining therebetween a downwardly open slot S.
The web 13, side walls 11 and 12, and flanges 14, 15 define a
generally C-shaped, downwardly open channel within which is mounted
an appropriately configurated vinyl or like insulating member 16
carrying conduits 17 and 18 connected to the electrical mains.
The plug assembly 19 consists essentially of a housing including a
stop plate or portion 20 adapted to lie against the flanges 14, 15,
and a barrel or drive portion 21, in torque transmitting connection
with locking flanges 22 for mechanically coupling the plug to the
flanges 14, 15 of the track assembly, and contact ears 23, 23 for
effecting electrical coupling to the conduits 17, 18. The plate 20,
which preferably has a cork or like insulating cushioning layer 24
on its track-adjacent face, is provided with a keying flange 25
adapted to ride within the slot S between flangers 14, 15, to
prevent relative rotation of the plate and the track.
Preferably the stop plate 20 may include a longitudinally
extending, polarizing groove 26 adapted to receive a complemental
polarizing rib 27 formed on the flange 14, whereby the plug may be
received within the channel of the track only in a desired and
properly polarized orientation.
The plug may include a grounding spring 28, adapted to be received
within the channel to ground the plug to the track 10, which is
itself at ground potential.
As best seen from FIGS. 5 and 6, the barrel or drive portion 21,
which is essentially cylindrical, is rotatably mounted on a
vertical cylindrical boss 29 extending downwardly from the plate
20, the plate and boss being preferably of integral die cast
construction.
The locking flanges 22 extend radially outwardly from the upper end
of a sleeve member 30, the main body of which is cylindrical in
horizontal section, the sleeve member riding within the boss 29
forming part of the housing.
A generally cylindrical insulating plug or stem 31 is rotatably
mounted within the sleeve 30, the stem preferably including an
insulating plastic shield member 32, the upper end of which shield
is frictionally received on depending skirt 33 at the lower end of
the plug 31. The stem or plug 31 is provided with a pair of
vertically extending slots 34, 34, within which slots are received
L-shaped conductor members 35, 35, the uppermost end portions of
which are bent outwardly and define the contact ears 23.
It will be appreciated that as thus far described, the drive or
barrel member 21 may be rotated about the boss 29, sleeve 30
carrying locking flanges 22 is free to rotate within the boss, and
the contact supporting stem 31 is likewise free to rotate relative
to the sleeve 30, boss 29 and barrel 21. Driving connection between
the barrel 21, sleeve 30 and stem 31 is provided by a transversely
directed drive screw 36.
The inner end 37 of the screw 36 is received in a complementally
threaded aperture 38 formed in the stem 31. The head of the screw
36 lies within a circular aperture 39 formed in the barrel. It will
thus be seen that when the barrel 21 is rotated, as by manipulation
of the driver lever 40 projecting from the barrel, the rotary
movement is communicated through the screw 36 to the stem 31.
The boss 29 is provided with an arcuate slot 41, of an angular
extent of just over about 90.degree.. Since the screw 36 passes
through such slot, it will be observed that the total rotary
movement which may be imparted to the barrel and hence to the plug
is limited to about 90.degree.. The screw 36 passes through a
further arcuate slot 42 in the sleeve 30. The angular extent of the
arcuate slot 42 is substantially less than 90.degree., being in the
order of about 70.degree..
When the plug assembly 19 is in position for insertion (FIGS. 1 and
2), the contact ears 23 and locking flanges 22 are substantially in
alignment, as are the trailing edges of the arcuate slot 41 in the
boss 29 and 42 of the sleeve 30. Since the angular extent of the
arcuate slot 42 is, as noted, about 20.degree. less than that of
the slot 41, it will be apparent that initial rotation of the
barrel 21 in an anti-clockwise direction (when viewed in the
orientation of FIGS. 1 and 2) will be accompanied by a concomitant
anti-clockwise rotation of the contacts 23 carried by the stem 31
since the screw 36 directly couples the stem and barrel. Since the
screw 36 passes freely through the slot 42 in the sleeve 30, no
movement of the sleeve 30 is experienced until the barrel has been
rotated through about 70.degree., at which point the lead end of
the screw 36 will engage against the terminal or trailing end of
the slot 42, at which point the screw picks up the sleeve and
imparts rotary movement thereto (see FIG. 7).
An understanding of the locking action is best appreciated by a
comparison of FIGS. 2 and 4.
In FIG. 2, the contact ears 23 and locking flanges 22 are disclosed
in an aligned position, permitting the same to be inserted into the
interior of the track through the slot S. After insertion,
attachment is effected by rotating the barrel 21, which rotation
may be facilitated by the use of the drive lever 40, such rotation
causing an initial anti-clockwise movement of the contact ears 23,
bringing the same progressively closer to the conduits 17, 18.
The sleeve 30 carrying the locking flanges 22, as noted, remains
essentially stationary during the initial stages of rotation of the
barrel. After about 70.degree. of rotation, the screw 36 reaches
the terminal end of the slot 42 and imparts rotary movement to the
sleeve 30, driving the wings or locking flanges 22 into a tight
frictional engagement over the flanges 14, 15 of the track 10, the
parts now being in the position shown in FIGS. 4 and 7. As a result
of the use of a cork or like resilient and compressible surface 24,
a tight frictional engagement, free of rattles, is obtained between
the plug assembly 19 and the track 10.
Optionally and preferably, the lead edges 22a of the locking
flanges 22 may be beveled or chamfered in an appropriate direction
to facilitate the passing of the flanges 22 of the plug over the
flanges 14, 15 of the track with an appropriate wedging action.
It will be understood that prior to assembling of the plug onto the
track, appropriate electrical connections are made to the
conductors 35 extending from the contacts 23.
It will be further appreciated that a lighting fixture L may be
connected to the plug assembly prior to attachment of the plug
assembly to the track, whereby mounting of a lighting fixture to
the track is accomplished by merely mounting the plug assembly in
the manner above set forth.
As a manner of effecting mounting of the fixture L, the cylindrical
boss 29 may include at its lower end an externally threaded portion
43. A mounting cap 44, having an internally threaded portion 45,
may be threadedly connected to the portion 43. Preferably a clutch
spring 46 is compressed between the opposed shoulders 47 of the
boss and 48 of the cap 44 to provide frictional resistance to
turning between the parts, wear-resistant thrust washers W being
preferably interposed between the spring ends and the shoulders 47,
48 to prevent wear.
The yoke Y of the lighting fixture L is attached to the cap 44, as
by a pair of machine screws 49, 49', extending upwardly through
holes in the yoke into complementally tapped holes 50, 50'.
The outer surface 51 of the boss 29 may include a vertically
extending rib 52, of sufficient length to lie in the path of one of
the lamp supporting screws, e.g., the screw 49 (see FIG. 6) whereby
it will be observed that as a result of the interaction of the
screw and rib, the angular extent through which the cap 44 may be
rotated relative to the remaining assembly is limited. Such
arrangement prevents accidental or inadvertent unthreading of the
lamp L from plug assembly 19, while still permitting a substantial
amount of relative rotation between the parts.
From the foregoing it will be appreciated that there is provided a
novel plug assembly which may be securely electrically and
mechanically attached to a power distribution track by one-hand
operation. A simple rotation of the barrel 21, which is connected
directly to the contact carrying stem 31 and through a lost motion
coupling provided by slot 41 to sleeve 30, completes all of the
operations necessary to effect a connection.
Preferably the arcuate slot 41 in the boss 29 is of sufficiently
great extent that the blocking of rotation of the barrel results
from a bottoming or abutment of the locking flanges 22 against the
walls 11, 12 of the channel rather than impingement of the screw 36
against the terminal end of the slot 41.
It will be further appreciated that, due to the resilient nature of
the material of which the electrical conductors 34, 34 are
fabricated, a secure electrical connection between the contact ears
23, 23 and the conduits 17 and 18 is assured, not-withstanding the
rotated position of the conduits relative to the track may vary by
a few degrees.
As will be apparent to those skilled in the art, variations may be
made in the specific constructions of the illustrated embodiment
without departing from the spirit of the invention and,
accordingly, the invention is to be broadly construed within the
scope of the appended claims.
* * * * *