Note: Descriptions are shown in the official language in which they were submitted.
1056483
BACKGROUND OF THE INVENTION
In many types of electrical systems and notably in motor
vehicles, there is little standardization of signals. A prime
example of the lack of standardization is the fact that many
motor vehicles use an external (to the item being controlled~
signal source such as switches in the grou~dc~cIrcuit while
others use switches in the "hot" (+12V) circuit. In some cases,
for convenience, a single vehicle may have both switched hot and
ground signals. Without limiting the generality of the present
invention, all references hereinafter will be to a motor vehicle
system, it being understood that the invention as claimed will
find use in many other applications.
It is often desirable to have a universal control or other
electrical system which can be used in motor vehicles ~egardless
of the nature of the signals available therein. Such universal-
ity has not been found in the known prior art and various compro-
mises have therefore had to be made. Additionally at least cer-
tain of the prior art devices are not fail safe in the event of
an incorrect connection from an external signal.
It is therefore an object of the invention to provide an
interface means to allow an electronic control system or the like
to be readily used with external signals of differing types, par-
ticularly with "hot" and "ground" signals.
It is another object to provide such a means which is fail
safe in the event of an incorrect connection.
It is a further object of the invention to provide such an
interface in an extremely simple way.
SUMMARY OF THE INVENTION
The above and other objects are provided with a two plug
connector system including interconnection means associated
therewith. A first plug is associated with the control circuit
lOS~4~3
and includes at least two sets of terminals with at least three
terminals per set. One set of terminals is sued for a switched
hot input and the other is used for a switched ground input.
]:n use, an element of the control system is connected to a
pair of terminals on each set thereof on the first plug. A
source of hot signal is connected to the third terminal of the
set used for connection with a switched ground signal. The
third terminal of the other set is connected to ground.
A second plug is associated with the external signal and
includes three terminals which are adapted to mate with either
of the sets of terminals on the first plug. The second plug
includes an interconnecting means between a pair of the terminals
thereof.
In a preferred embodiment, the plugs are polarized so as
to a8sure the correct orientation between the terminals of the '
second plug and the terminals of either set on the first plug.
Additionally, the size and geometry of the first and second
plugs are preferably such that two plugs such as the second
cannot be corrected simultaneously with the first plug.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims which parti-
cularly point out and distinctly claim the present invention it
is believed that the same will be better understood with refer-
ence to the following description taken in conjunction with the
accompanying drawings in which:
Figure 1 is a schematic representation of the invention in
its simplest form; and
Figure 2 is a schematic representation of the invention in
a preferred form showing several features which can be optionally
used therewith.
1056483
- DESCRIPTION OF THE PREFERRED E~MBODIMENT
Referring now to the drawings, Figure 1 illustrates the
present invention schematically in its simplest form. The inter-
facing connector consists essentially of two plugs. The first
plug, designated generally by the numeral 10, is associated with
the control circuit. Said circuit is shown only in part, speci-
fically by the relay 20 which can be connected into any other
elements to initiate, terminate or otherwise modify the control
action.
The first plug 10 includes two sets 11 and 12 of at least
three (3) terminals lla, b and c and 12a, b and c per set. The
terminals lla, b and c and 12a, b and c can be of any desired
type and preferably are female sockets. The size and spacing of
the terminals are not critical to the invention except that each
set 11 and 12 must be substantially identical to allow a single
mating plug ~o fit in either set. Certain sizing and spacing is
preferred, however, as will be discussed in detail in connection
with Figure 2.
A second plug, designated generally by the numeral 30, is
associated with the external switched signal and includes at
least three (3) terminals 31a, b and c of such geometry and
spacing to mate with the terminals of either sets 11 and 12, and
normally will be male jacks.
The connections, internal and external, with the plugs 10
and 30, in combination with the geometry of the devices, provide
the universality of the present invention. As illustrated, term-
inal set 11 is associated with a switched ground input. Prefer-
ably, a suitable designation to such effect is, as illustrated,
provided to assure correct connection. One of the terminals lla
of the first set 11 is adapted for connection to a "hot" source
13 indicated by the "+" sign. As will be recognized other
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1056483
non-grounded sources tnegative and alternating) are also "hot"
in the sense of the present invention. Again, and with refer-
~ d ~
ence to motor vehicle systems, a~ Lhsn 12 volt signal is the
common "hot" and further discussion will be limited thereto.
The second terminal set, 12, is associated with the switched
"hot" input signal and is so designated by the "+" symbol. The
terminal 12a, which geometrically corresponds to terminal lla of
the first set, is adapted for connection to a ground source 14.
The remaining two terminals of sets 11 and 12 are joined by
interconnection means 15 and 16. Interconnection means 15 joins
corresponding terminals llb and 12b and means 16 joins corres-
ponding terminals llc and 12c. An interconnecting means 32 is
also provided on the plug 30 and join terminal 31a, which
connects with either of terminals lla or 12a, with one of the
other two terminals (31b as illustrated) on plug 30. Intercon-
necting means, orJumper, 32 may conveniently be thought of as a
programming means to provide the requisite circuit interconnec-
tions when plugs 10 and 30 are connected.
Terminal pairs llb, 12b and llc, 12c are also adapted for
connection to an element of the control circuit, here illus-
trated as relay 20. The embodiment of Figure 1 is suited for
use only with polarity insensitive devices such as relay 20.
The operation of the embodiment of Figure 1 is as follows.
When a switched ground signal is to be utilized, the second plug
30 is inserted in the set of terminals so noted; i.eO, set 11.
Closure o~ ~he switch in the external ground signal circuit
provides a current path from hot source 13 through jumper 32
and relay 20 to ground thereby enexgizing the relay. Similarly,
a closure of a switch in a switched hot circuit will, upon proper
connection of the plugs 10 and 30, allow current to flow from the
switched hot signal lead through jumper 16 relay 20, jumper 15
1056483
~ and jumper 32 to ground source 14. It should be noted that
should the plug 30 inadvertently be connected improperly that
there will be no energization of relay 20 as no voltage differ-
ential can be applied thereacross.
While the embodiment of Figure 1 is satisfactory in some
applications, the embodiment of Figure 2 provides, in a simple
manner, a number of additional features which are useful, indi-
vidually or in combination, and therefore are preferred. Ele-
ments common between the embodiment of Figures 1 and 2 are
similarly numbered in the two figuresO
The embodiment of Figure 2, unlike that of Figure 1, can
interface with a polarity sensitive element, designated gener-
ally by the numeral 40, in the control circuit. One example of
such an element is an electronic power supply which can be used
to power the remainder of the control circuit. Many examples
of such power supplies and other polarity sensitive devices are
known in the art and therefore not described in more detail here-
inafter.
The ability to accommodate polarity sensitive devices results
from providing interconnecting means in the form of jumpers 17 and
18 between terminal llb and 12c and 12b and llc respectively; i.e.,
between opposite ones of the pairs of the terminals of the first
and second sets. As will be observed, when the second plug 30 is
associated with a switched ground and therefore connected to the
upper set 11 of terminals, terminal llb and the positive side of
the element 40 is connected to positive source 13 through jumper
32. The switched ground is inserted in terminal 11 and thereby
connected to the ground connection of the element 40. With a
switched hot signal the plug 30 is inserted in the lower set 12
of terminals on the first plug. When so connected, the switched
hot is connected to the positive side of element 40 via jumper 17.
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'~ 056483
The ground source 14 is connected to the ground side of the ele-
ment 40 through jumpers 32 and 18.
Again, as with the configuration of Figure 1 it will be seen
that an incorrect connection cannot lead to inadvertent imposition
of a voltage across the element 40.
The embodiment of Figure 2 also includes provision in the
form of terminals lld and 12d on the first plug and 31d on the
second plug to ground the shield of a shielded lead. The termi-
nals lld and 12d are connected to ground for this purpose. Qther
such terminals can be provided for any desired additional con-
nections.
As will be noted, terminals lld, 12d and 31d are spaced
from the adjacent terminals by a different amount from the spac-
ing between the othex terminals. Such an arrangement provides a
keying effect and prevents incorrect connection between the second
plug and the terminals within the sets thereof on the first plug.
Many other keying means, e.g., terminals of different sizes,
shapes and orientations are well known in the art and suitable
for use herewith.
A final feature of the embodiment of Figure 2 is the provi-
sion of means to avoid inadvertent energization of the element 40,
by the connection of a plug 30 to each of the sets 11, 12 of term-
inals on the first plug. In most applications, this result is
most readily, and therefore preferably, provided by placing the
sets 11, 12 of terminals close together in relation to the size of
the second plug. By such an arrangement there is insufficient
room to plug two plugs 30 in at the same time to the two sets of
terminals 11, 12.
Many other variations will occur to those skilled in the art
with reference to the foregoing description of the preferred
embodiments.
