U.S. patent number 3,564,280 [Application Number 04/799,406] was granted by the patent office on 1971-02-16 for plex-path circumferential energy control and distribution system.
This patent grant is currently assigned to Essex International, Inc.. Invention is credited to Bay E. Estes, III, Ralph G. Nedbal, Peter W. Sognefest.
| United States Patent |
3,564,280 |
| Sognefest , et al. |
February 16, 1971 |
PLEX-PATH CIRCUMFERENTIAL ENERGY CONTROL AND DISTRIBUTION
SYSTEM
Abstract
The invention comprises an electrical-fluidic control system
adapted to control essentially every function of a vehicle. In a
preferred embodiment, the invention comprises a single harness
formed of electrical and fluidic transmission paths, respectively
connected to sources of electrical and fluid power, control means
for applying coded control signals to an electrical signal
transmission path, and receiving means connected to the electrical
signal and power transmission paths for receiving said coded
electrical signals to selectively activate electrical and fluidic
switching means to operate desired load devices for performing
selected vehicle functions.
|
Inventors: |
Sognefest; Peter W. (Glenshaw,
PA), Nedbal; Ralph G. (Pittsburgh, PA), Estes, III; Bay
E. (Murrysville, PA) |
|
Assignee: |
Essex International, Inc.
(N/A)
|
| Family
ID: |
25175829 |
| Appl.
No.: |
04/799,406 |
| Filed: |
February 14, 1969 |
| Current U.S.
Class: |
307/155;
340/12.32; 307/10.1 |
| Current CPC
Class: |
F15C
1/003 (20130101); B60R 16/0315 (20130101) |
| Current International
Class: |
F15C
1/00 (20060101); B60R 16/02 (20060101); H02g
003/00 () |
| Field of
Search: |
;307/10,38,40,42,140,149,155 ;340/147,163 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Macon; Robert S.
Assistant Examiner: Hohauser; H. J.
Claims
We claim:
1. An electrical-fluidic control system comprising, in
combination:
a source of electrical power;
a source of fluidic power;
a harness for selectively connecting electrical and fluidic power
to desired load devices, said harness comprising a fluid
transmission path connected to said source of fluidic power,
electrical power and signal transmission paths connected to said
source of electrical power, control means for applying control
signals to said electrical signal transmission path, and receiving
means connected to said electrical power and signal transmission
paths for receiving said control signals to selectively activate
electrical and fluidic switching means to operate desired load
devices.
2. An electrical-fluidic control system in accordance with claim 1
wherein said harness comprises: an air tube for carrying compressed
air from said fluidic power source, and a plurality of electrical
conductors for carrying said electrical power and said control
signals.
3. An electrical-fluidic control system in accordance with claim 1
wherein said harness is located in the automotive vehicle and said
control and receiving means are positioned in modules connected to
said harness at various locations around said automotive
vehicles.
4. An electrical-fluidic control system in accordance with claim 3
wherein some of said receiving means are connected to control
electrical load devices to perform electrically operated functions
when actuated and some of said receiving means are connected to
control fluidic load devices to perform fluidically operated
functions when actuated.
5. An electrical-fluidic control system in accordance with claim 1
wherein said control means applies coded signals to said electrical
signal transmission path to actuate desired ones of said receiving
means and said receiving means are set to respond to particularly
coded signals to selectively activate electrical and fluidic
switching means to operate their associated load devices.
6. An electrical-fluidic control system comprising, in
combination:
a source of electrical power;
a source of fluidic power;
a harness for selectively connecting electrical and fluidic power
to desired load devices, said harness comprising a fluid
transmission path connected to said source of fluidic power,
electrical power and signal transmission paths connected to said
source of electrical power, control means for applying control
signals to said electrical signal transmission path, said control
signals including timing signals and function selection signals,
and receiving means connected to said electrical power and signal
transmission paths for receiving said control signals to
selectively activate electrical and fluidic switching means to
operate desired load devices.
7. An electrical-fluidic control system comprising, in
combination:
a source of electrical power;
a source of fluidic power;
a harness for selectively connecting electrical and fluidic power
to desired load devices, said harness comprising a fluid
transmission path connected to said source of fluidic power, an
electrical power transmission path connected to said source of
electrical power, a timing signal transmission path and an
information signal transmission path, control means for applying
control signals to said electrical timing and information signal
transmission paths, and receiving means connected to said
electrical power and signal transmission paths for receiving said
control signals to selectively activate electrical and fluidic
switching means to operate desired load devices.
8. A method for controlling electrical and fluidic operated devices
comprising the steps of connecting an electrical power source, a
fluidic power source, a control signal source and signal receiving
means to a common harness having fluid transmission and electrical
transmission paths, applying coded control signals to said
electrical signal transmission path, to select desired ones of said
signal receiving means and causing the selected signal receiving
means to be actuated to apply electrical and fluidic power from the
harness to their associated load devices for operating the same.
Description
BACKGROUND OF THE INVENTION
The electrical wiring systems in many modern vehicles, such as
automobiles, have been developed over the years in a brute force
fashion wherein an increase in the number of power operated devices
used in the vehicle has been achieved primarily by the expedient of
adding more wires and switches to the existing electrical harness.
Manifestly, this approach, with its large number of connections and
its high complexity, has not resulted in the most efficient and
reliable type of system.
Furthermore, such present systems are difficult to diagnose when a
failure does result. At the same time the replacement of parts
often is made more difficult because of the great number of wires
present in the system. Those skilled in the art know that a
substantial percentage of the problems arising in automobiles today
are due to electrical system failures.
SUMMARY OF THE INVENTION
The present invention therefore has as its principal object the
provision of an improved control system for vehicles which
overcomes the defects of prior electrical harnesses and which is
characterized by better assembly procedure, high system
reliability, simple trouble diagnosis and simple replacement
procedures.
In a preferred embodiment, the invention takes the form of a
harness which advantageously may be positioned around the vehicle
and to which logic, control and display modules may be connected
for controlling every function of the vehicle, such as lighting,
comfort, transmission, ignition, power assist, air-fuel, and the
like. The harness comprises electrical and fluidic transmission
paths for transmitting control signals, timing signals, electrical
power and fluid power between the power sources, the control logic
and the receiving modules to effect the desired automotive
functions.
The harness can be formed of a single fluid supply tube formed of
electrically conductive material or it may comprise a plurality of
electrical wires in combination with one or more fluid supply
tubes, the basic requirement being that the harness must be capable
of providing both electrical and fluidic transmission paths within
the vehicle. In a preferred exemplary embodiment, as disclosed in
greater detail herein, a four path harness is utilized, with three
electrical wires and one air supply tube. Two of the wires carry
electrical timing and control signal information, the third wire
carries electrical power, and the air tube carries fluidic power.
All timed sequential information is transmitted over two of the
wires to all of the sending and all of the receiving modules
connected to the harness. When the correct code is recognized by
the receiver module or modules to be selected, the load devices
associated with the selected modules are activated to perform the
desired function. Each receiver module has an integrated circuit
with an associated electric power amplifier or a fluidic amplifier
or an electrical relay or any combination of them. The integrated
circuit selected by the coded signal permits the electric power or
the fluidic power from the harness to be applied to the load
device. The electric power can be utilized to provide electric
energy to various electrical loads, such as electric motors or
lights, and the fluidic power can be utilized to actuate fluidic
loads, such as hydraulic power servos in the transmission and mode
selection doors in the comfort system.
The various objects, advantages and features of the invention are
more clearly set forth in the detailed description of the preferred
embodiment which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
In a detailed description which follows, reference will be made to
the drawings in which:
FIG. 1. is a pictorial view of the invention as embodied in an
automotive vehicle;
FIG. 2 is a schematic circuit diagram showing a preferred
embodiment of harness connected to the various power control and
receiver modules in accordance with the invention;
FIG. 3 is a schematic circuit diagram of a typical sender
module;
FIG. 4 is a schematic diagram of a typical receiver module;
FIG. 5 illustrates several typical electrical and fluidic interface
and load circuits; and
FIG. 6 illustrates a typical reset signal generator in accordance
with a preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and more particularly to FIG. 1,
there is illustrated automotive vehicle embodying an exemplary form
of the inventive electric-fluidic control system. Those skilled in
the art will appreciate that the term fluidics as used herein
includes moving part fluid operated devices as well as nonmoving
part devices, sometimes called flueric devices.
The vehicle 10 has a harness 11 positioned about its periphery or
circumference such that various power, control and receiver modules
may be connected thereto at any desired location on the automobile.
Thus, the power module 12 incorporating the sources of electrical
and fluidic power can be located beneath the hood of the vehicle
for connection to the harness 11. Advantageously, in one embodiment
of the invention, the electrical power source may comprise a 12
volt battery and the fluidic power source may comprise a compressor
capable of delivering air at a pressure of 12 lbs. p.s.i.g.
It further will be appreciated as the description of the invention
proceeds that it is not intended to limit the use of the system to
any particular number of electrical or fluid operated load devices
and that the illustrative load devices shown in FIG. 1 and
described herein are intended to be merely exemplary of the great
utility and flexibility of the invention. Thus, other modules which
may be connected to the harness 11, as illustrated in FIG. 1,
include two head light modules 13 and 17, the two parking and turn
signal lights 14 and 16, and the horn 15, all located in their
normal positions at the front of the vehicle. The harness also is
shown as connected to the front side light module 18 at one fender,
the window 19 and door lock 20 modules at the side door locations,
the rear side light module 21 and the fuel sensor module 29 at a
rear fender location. At the rear of the automobile are the brake
light and turn signal modules 22 and 26, the rear taillight modules
23 and 25 and the trunk lock module 24. In addition, for purposes
of illustration, FIG. 1 shows the windshield wiper 27 and the
comfort module 28 connected to the harness 11 at a position forward
of the dashboard, and a display module 30 together with a control
or sender module 31 connected to the harness 11 at the dashboard
location. Manifestly, as the explanation of the invention proceeds,
it will become clear that any desired number of electrically
operated or fluid operated load devices may be controlled from the
common harness 11 in accordance with the principles and teachings
of the invention.
FIG. 2 illustrates the manner in which the modules may be connected
to a common harness 11. In this example, the harness 11 is formed
of an electrical supply line 32, an air supply tube 33, and
electrical signal or information line 34 and an electrical clock or
timing line 35.
A source of electrical power 36, such as a 12 volt battery or the
like, is connected between ground (the chassis of the car is the
ground of the system) and electrical supply line 32. Thus, the
latter carries the electrical power to all other modules which may
be connected to the line 32 around the harness path.
A source of compressed air 37 is connected to the air supply tube
33 so that the compressed air can be supplied to any of the fluidic
operated devices connected to the tube 33, is such devices are
selected for actuation by the coded signals transmitted over the
signal line 34. In a preferred embodiment, the compressed air
source may take the form of a one horsepower compressor capable of
supplying compressed air at a pressure of 12 p.s.i. but clearly any
other fluid power source, either positive or negative, may be
utilized.
A clock or timing module 42 is connected between the electrical
supply line 32 and ground, and its output is supplied to the clock
line 35 by means of the connector 43. The purpose of the clock
module 42 is to supply timing pulses to all of the modules
connected to the harness 11 so that their operations will all be
synchronized from a common clock source. Advantageously, in a
preferred embodiment of the invention, the clock module 42
comprises an oscillator or pulse generator of any suitable
construction which is capable of providing output timing pulses at
a frequency of 100,000 cycles per second.
FIG. 6 illustrates a schematic diagram of a reset signal generator
38 which supplies a coded signal through connection line 41 to
signal line 34 for the purpose of resetting all sending and
receiving modules. In this illustrative embodiment, the reset
signal generator consists of a 4-bit binary counter, formed of
trigger flip-flop stages 101, 102, 103 and 104, the AND gate 105
and the line amplifier 106. The free-running (i.e., not reset)
binary counter of flip-flops 101, 102, 103 and 104 is triggered by
the clock signal on line 35 through line 40. The AND gate 105 is
connected to the one state outputs of all flip-flops in the counter
except the lowest order flip-flop 101. The AND gate 105 is enabled
for two consecutive clock states (or clock cycles) which in this
case is time count 14 and 15.
Amplifier 106 transmits a signal onto signal line 34 through line
41 during these two consecutive clock states. This
two-consecutive-clock-state signal forms the coded reset signal to
be received by all sending and receiving units of the system. It
should be noted that there must never be another similar signal for
two consecutive clock states transmitted on the signal line 34
during a countercycle (in this illustrative case 16 clock states)
since another such signal would look like a reset code to all the
senders and receivers causing all to become reset without
completing a whole countercycle.
Another module illustrated in FIG. 2 of the drawing, and described
in greater detail below, is the sender module 44. The latter is
connected to a suitable controller 45 which may take the form of a
sensor, a computer, an operator, or any combination of the same.
The purpose of the sender 44 is to transmit coded information
signals throughout the harness 11, by means of the signal line 34,
so that a selected module or modules will be activated to operate
the associated load devices for the performance of a desired
function. Sender module 44 receives its operating power from the
electrical supply line 32 and is synchronized with the remaining
circuits by its connection to the clock line 35 and signal line
34.
As stated above, any number of receiver modules may be connected to
the harness 11 such that they may respond to their uniquely coded
signals for the performance of an electrical or fluidic operated
function. The next module shown in FIG. 2 is representative of the
receiver modules used for providing electrically actuated
functions. Such receiver modules used for providing electrically
actuated functions. Such receiver module 46 is connected to the
electric supply line 32 to receive electrical operating power, to
the signal line 34 to receive the coded information and reset
signals, and to the clock line 35 to receive the timing
signals.
The output of receiver module 46 is provided over the conductor 47
to an electrical load device 48. The latter is connected between
the electrical supply line 32 in the harness 11 and ground. If, for
example, the signals transmitted over the signal line 34 of harness
11 contains the code for which the receiver module 46 has been set,
then the receiver module 46 supplies an output signal over the
connector 47 to turn on the electrical load device 48. Thus, if the
electrical load device 48 were the automobile horn, for example,
the horn would be actuated whenever the properly coded signals
corresponding to the receiver module 46 setting were transmitted
down the signal line path 34.
In a similar manner, a fluidic load device may be selected and
actuated when the sender 44 transmits a properly coded signal down
the signal line path 34. This is illustrated by the receiver module
49 which is connected to receive electrical power from the power
line 32, information and reset signals from the line 34 and timing
signals from the clock line 35. The output of receiver module 49 is
applied by the connector 50 to the fluidic load device 51. The
latter is connected by the tube 52 to receive fluidic power from
the harness air supply tube 33. Thus, if the fluidic load device 51
is a pneumatic trunk lock, for example, and the properly coded
signal was received by the module 49 from the harness signal line
34, receiver module 49 would supply an output signal over the
connector 50 to the fluidic load device 51 to cause the compressed
air in the tube 52 to operate such pneumatic trunk lock.
FIG. 3 illustrates a schematic diagram of a typical sender circuit
which can be attached to the harness 11 to provide coded signal
information so that desired receiver modules can be selected and
operated. As shown in FIG. 3, the sender circuit comprises a binary
counter formed of the flip-flop stages 54, 55, 56 and 57, plus the
reset circuit comprised of flip-flops 107 and 108, the AND gates
and the amplifier. Those skilled in the art are thoroughly familiar
with the various forms which such binary counters can take in
actual practice and, therefore, the binary counter stages are shown
in block form only. Each flip-flop stage of the binary counter is
capable of being switched to either one of two states, such states
representing the digits 0 and 1, respectively. Although the binary
counter illustrated in FIG. 3 comprises four stages, capable of
achieving a count up to 16, it will be understood that a larger or
smaller number of flip-flop stages may be utilized, as desired.
Two J--K flip-flops 107 and 108, and the AND gate 109 comprise the
reset circuit which responds to the reset code generated in the
reset signal generator and transmitted on the signal line 34. The
reset code from signal line 34, which advantageously in this
illustrative embodiment is comprised of a signal for two
consecutive clock states. enters the J input of flip-flop 107
causing flip-flop 107 to be set to a 1 upon the arrival of the next
clock pulse on clock line 35. The output of flip-flop 107 and the
signal from signal line 34 are fed into the AND gate 109. The
output of the AND gate 109 is connected to the J input of flip-flop
108. If flip-flop 107 is set to a 1 and there is a signal on line
34 (the case during the second consecutive signal on the line 34),
flip-flop 108 is set upon the arrival of the next clock pulse. The
output from flip-flop 108 is connected through line 110 to all
reset inputs of counter flip-flops 54, 55, 56 and 57. These counter
flip-flops are reset to zero whenever flip-flop 108 is set to
1.
It will be noted that the J--K flip-flops 107 and 108 are provided
with a K input as well as the J input and the clock T input. As
shown in FIG. 3, the K input is permanently connected to a 1 signal
source. Thus, whenever a 1 is applied to a J input, the flip-flop
changes to a 1 state when a clock pulse is applied to the T input
and changes back to 0 state at the next following clock pulse on
the T input, even if the 1 remains at the J input during the second
clock pulse. It can be seen that the J--K flip-flops are always
reset by changing to a 0 state on the clock pulse following the
clock pulse that set the flip-flop to the 1 state. The operation of
such J--K flip-flops is well known, as described in the publication
entitled USING MRTL I/C FLIP-FLOPS by Motorola Semiconductor
Products Inc. dated Sept. 1966.
After being reset the counter flip-flop stages begin counting clock
pulses received from line 35. The selective outputs of the
flip-flop counter stages are connected to the AND gate 59 along
with a line from switch 61. If switch 61 is closed (those skilled
in the art will appreciate that switch 61 can take the form of some
electrical output from a computer or controller) and there is a
coincidence of inputs to the AND gate 59 from the counter, there
will be an output from the AND gate on line 111 to amplifier 62.
Amplifier 62 transmits the AND gate output to the signal line 34.
In FIG. 3, the output from the AND gate 59 would occur during
counter count 1 (a T 1). Other sending modules may send outputs at
different counter states. Furthermore, it is fully withing the
principles of the invention that there may be several sending
modules at the same counter state, in the event control from more
than one location is desired.
In a manner to be described in greater detail below, the receiver
modules which have been coded to respond to the T 1 signal are
activated to actuate their primary load devices and thereby provide
the desired circuit function. For example, if the automobile head
lights are controlled by a receiver module coded to respond to a T
1 signal, then the closing of the switch 61 in the sender
circuit--either by the automobile driver, the computer, or by a
sensor element such as a photocell--will result in the head lights
being turned on. Although all of the receiver modules are connected
to the harness 11 and will receive the transmitted T 1 signal, only
those modules which have been coded to respond to such signal will
be actuated and the remaining modules will remain inactive.
FIG. 4 illustrates a typical receiver module circuit which is
adapted to be connected to the harness 11 to receive the coded
control signals required for the actuation of the module in order
to effect a desired function. As shown in FIG. 4, the receiver
circuit comprises a reset circuit, a binary counter formed of a
plurality of flip-flop stages and an AND gate in a manner similar
to the typical sender module as shown in FIG. 3 of the drawing.
In addition, an On-Off circuit composed of two J--K flip-flops and
an AND gate is provided to store the face that the module has
received its coded control signal.
The reset circuit comprised of flip-flops 112, 113, and AND gate
114, functions in an identical manner to the reset circuit in FIG.
3 to reset the flip-flops 69, 70, 71 and 72.
The reset circuit is connected to receive the reset signals from
the signal line 34 and timing signals from the clock line 35 so
that the counter will be reset in a cyclic manner in synchronism
with all other send and receive counters.
For purposes of illustration, the binary counter flip-flops
comprise a 4-bit counter with the output lead 74 being connected to
the 1 state output of flip-flop 69 and the output leads 75, 76 and
77 being connected to the 0 state outputs of flip-flops 70, 71 and
72, respectively. Thus, the typical receiver circuit of FIG. 4 is
shown, for purposes of illustration, as a receiver which is
connected to respond only to a T 1 signal pulse on signal line 34,
since there will be an output on all of the output leads 74, 75, 76
and 77 only at the time T 1 in the cycle. Each of these output
leads is connected to AND gate 78 and at the time T 1 only, the AND
gate is permitted to transmit a signal at time T 1 from the signal
line 34. It now is clear that when a T 1 pulse is transmitted on
the signal line 34, and only at this time, the AND gate 78 will
provide an output on line 116, to the J inputs of J--K flip-flops
117 and 118. Flip-flops 117 and 118 will be set to 1 by the
occurrence of a clock pulse (in this case a T 2 clock pulse) is
there is a signal on line 116 during T 1. An ON signal will appear
on line 81 on the output of flip-flop 118 to be used to actuate an
associated load device. Flip-flop 118 will not be reset to 0 unless
there is an input to its K input from the output of AND gate 119.
The AND gate 119 receives its inputs from the reset signal line 115
and from the 0 output of flip-flop 117. Flip-flop 117 receives a
signal from reset line 115 on its K input and is thus reset to
zero, if it were in a 1 state, by the clock pulse that follows the
reset signal. The AND gate 119 would not be enabled during these
times since the flip-flop 117 does not become 0 until after the
reset signal has occurred. (Note that flip-flop 113 and flip-flop
117 change state from 1 to 0 on the same clock pulse. Even though
there is a possibility of AND gate 119 being enabled for an instant
because of differences in switching times in the flip-flops 113 and
117, flip-flop 118 cannot possibly switch since the clock pulse has
already entered its trigger input.) If, however, there is no signal
during T 1 on line 116 and flip-flop 117 does not become set to a 1
state (i.e., it stays in 0 state), AND gate 119 will be enabled
when there is a reset signal on line 115. Flip-flop 118 will then
be reset to 0 on the next clock pulse.
This will turn the ON signal on line 81 off. Therefore, the
associated load device will be turned off at this time.
While the construction and operation of the typical modules and
receiver circuits of FIGS. 3 and 4 have been described in
connection with a T 1 signal count, it will be apparent to those
skilled in the art that such sender and receiver circuits may be
coded for other signal codes such that a number or receiver modules
can be connected to the harness 11 for operating their associated
load devices only at desired selected times. In this way, all of
the modules can be connected to a common harness but the coding of
the signals permits the selected actuation of only the desired
modules associated with the functions to be performed.
In accordance with a feature of the present invention, a selection
of a receiver module, in the manner described above, permits the
actuation of an electrically powered or fluid powered load device.
FIG. 5 of the drawing illustrates an exemplary interface for each
of such loads.
In the electrical interface and load, shown in FIG. 5, the output
of the receiver 46, when it is turned on by a properly coded signal
from the signal line 34, is amplified by the amplifier 83 to turn
on the transistor 85 or some other switching device, such as a
relay. Amplifier 83 and transistor 85, each receive electrical
power from the electrical supply line 32 by means of the leads 84,
as does receiver 46. When the transistor 85 is turned on, a circuit
is completed from the electrical supply line 32 to the electrical
load device 48 to actuate the latter and to enable it to perform
its function.
The fluidic interface and load operate in a similar fashion; the
selection of receiver 49 by a properly coded signal from signal
line 34 provides an output through the amplifier 87 to energize the
electric magnet 90. This energization causes the armature 91 to be
moved toward port 110. In doing so, the armature 91 blocks a small
air leak which had existed in the fluid port 110 and switches the
fluidic amplifier comprised of the NOR gates 95 and 96 to provide
pneumatic power to the fluid load device 51.
As shown in FIG. 5b, the fluidic amplifier is connected by the air
tube 97. The illustrated amplifier is comprised of two NOR gates 95
and 96, each of which is connected to the main supply tube 97 for
their respective air supply. NOR gate 96 is connected directly
whereas NOR gate 95, being the lower stage of the amplifier, is
connected by tube 102 through a resistor 101 which decreases the
allowed flow which facilitates a lower power requirement to switch
this stage. The switching pressure for gate 95 is obtained by
tapping off the supply tube 102 with tube 107 through another
resistor 103. This resistor decreases the pressure in the control
tube 107 since the pressure at the control part 104 necessary to
switch the flow from the preferred port 105 to the load actuation
port 106 is only a small percentage of the gate supply pressure
108. The control tube 107 pressure is controlled, however, by the
bleed rate out of port 110, which in turn is controlled by the
position of the electromagnet armature 91.
When the electromagnet is not activated, the armature 91 is in the
uppermost position A, allowing full bleed out of port 110, reducing
the pressure in tube 107 below that needed to switch the flow from
leg 105 to leg 106. When the electromagnet is energized, the
armature is moved to position B, closing down the bleed rate from
port 110, increasing the pressure in tube 107 to that needed to
switch the flow from leg 105 to 106, which is connected to the
control port 109 of the second stage gate 96, which then switches
its output to port 111 to activate the required fluidic load device
51. The latter may take the form of any pneumatically operated
device such as a piston, diaphragm, cylinder or the like and can be
used to actuate primary devices such as the automotive door locks,
hood latches or power servos in the transmission.
In view of the complete description of the inventive
electrical-fluidic control system given above, in conjunction with
the illustrative modules shown in the drawing, those skilled in the
art now will appreciate that a single harness having electrical and
fluid transmission paths can be used to control essentially every
desired function in the automotive system. These principles not
only provide a control system having higher system reliability than
presently existing electrical harnesses but, in addition, greatly
simplify trouble diagnosis since a simple connection can be made at
any point in the harness to permit an external tester to check the
entire system in a relatively short time. Still further, once the
problem is known, a new module can quickly be substituted for the
defective module to permit more effective replacement and repair
procedures.
It will be understood that the various embodiments of the
invention, which have been described, are merely illustrative of an
application of the principles of the present invention. Those
skilled in the art will readily understand that numerous other
embodiments and modifications may be made without departing from
the true spirit and scope of the invention.
* * * * *