Note: Descriptions are shown in the official language in which they were submitted.
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description
PLUG-IN INSTRU~FNTATION SYSTEM
Technical Field
This invention relates to vehicle instrumentation
systems, and more particularly, to a system which permits
instruments or gauges to be readily and interchangeably
installed and serviced.
background Art
Manufacturers of motorized vehicles, particularly
truck manufacturers, offer a relatively large number of
optional instruments for sale to their customers in addition
to standard instruments, such as speedometers and odometers,
which are sold with every vehicle. These optional instru-
ments monitor a wide variety of system conditions and func-
tions. For example, electrical gauges and mechanical gauges
(such as vacuum and pressure gauges) can be used to monitor
the temperature and pressure of the various fluid systems
within the vehicle. Additionally, electrical gauges can be
used to monitor various conditions within the electrical
system of the vehicle. eased on individual interests and
needs, a customer wily normally select several of these
instruments when Purchasing a motorized vehicle, such as a
truck cab.
Each electrical qauge normally requires that three
connections be made before it is operable. Two electrical
2~ connections are required to provide power to the gauge. A
ground wire and a lead wire normally connect the qauge to
the vehicle's electrical system. The third required connec-
tion is the signal or transducer connection. In the case of
an electrical gauge, the signal connection is made by con-
necting a wire carrying an input signal to a terminal on thegauqe.
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Each vacuum or pressure qauge normal]y requires
only a signal connection to be operable. hose coupled to
the appropriate part of the vehicle for determining pres-
sure, is secured to the rear of the gauge to provide the
necessary signal connection.
Existing instrumentation systems for motorized
vehicle gauges rely, for the most part, on mounting each
gauge at a predesignated location on the vehicle dashboard
and thereafter making the connections necessary for each
gauge. As gauges are preferably mounted as close to one
another as possible to facilitate easy reading of the guages
by the vehicle operator, a "bird's nest" of wires and hoses
inevitably develops behind the dashboard, making installa-
tion and maintenance difficult.
One effort to minimize this "bird's nest" of
wiring is shown in the patent to Henssl U.S. Patent Jo.
3,02~,4~7. The Henss patent discloses an instrumentation
system in which measuring instruments are mounted to a dash-
board in conventional fashion. A backplate engages the rear
of the instruments to provide all necessary electrical con-
nections as well as bulbs which project into the rear of the
instruments to provide illumination. Although the system
disclosed in Henss reduces the "bird's nest" of wires which
would otherwise accumulate behind the instruments, several
~5 difficulties remain with such a system. Each instrument or
gauge in the Henss system is dedicated to a particular loca-
tion. For this reason, the ~enss system is not well suited
to permit a customer to select from a large variety of
gauges. Another drawback of the Henss system is that it is
not we]l suited to accommodate vacuum and pressure gauges
interchangeably with electrical gauges. Additionally,
removal of a gauge for maintenance or replacement requires
that the backplate be removed and the instrument discon-
nected. Similarly, replacement of light bulbs in the Henss
system also requires that the entire backplate be removed.
As the backplate is mounted behind the dashboard, removal of
the backplate and alignment of the backplate for reinstalla-
tion can be inconvenient and time-consuming.
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Disclosure of Invention
It is an object of this invention to provide an
instrumentation system which permits gauges installed there-
in to be interchangeably mounted
It is another object of this invention to provide
an instrumentation system which permits gauzes mounted
therein to be readily replaced with either the same or a
different type of gauge.
It is another object of this invention to provide
an instrumentation system that will permit either electrical
gauges or mechanical gauges, such as vacuum or pressure
gauges, to be mounted in a given location.
It is another object of this invention to provide
an instrumentation system that will minimize assembly and
installation time by reducing the number of connections to
be made when assemblinq or installing the system.
It is another object of this invention to provide
an instrumentation system having individual bulbs for
illuminating the individual instruments wherein the bulbs
may be readily replaced without removing or disconnecting
the gauge.
It is another object ox this invention to provide
such an instrumentation system wherein all such illuminating
bulbs may be dimmed simultaneously.
These and other objects of the invention, which
will be apparent to those skilled in the art as the inven-
tion is more fully described below, are obtained by provid-
ing an instrumentation housing which is preferably pivotally
mounted in the vehicle dashboard such that the entire hous-
ing can swing outwardly away from the dashboard. The hous-
ing includes a front instrument panel and a rear circuit
board plate with a predetermined number of standardized
(equal size and shape) holes placed at corresponding loca-
tions in the panel and plate. Gauges shaped to conform to
the standardized holes may be interchangeably mounted in
the system from the front of the instrumentation panel.
When the gauges are inserted into the housing, a mounting
pin positioned on the back of each gauge snaps into a
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corresponding bracket member mounted on a circuit board on
the back side of the circuit board plate. At the same time,
the ground and lead terminals of each electrical gauge are
fitted wi-thin corresponding female terminals on the circuit
board. The circuit hoard ties the ground and lead terminals
of each electrical gauge to a common location, thus requir-
ing only a single ground and lead connection between the
vehicle power source and the instrumentation system.
The circuit board also includes means for mounting
bulbs on the rear of the circuit board such that the bulbs
project through apertures in the circuit board plate to the
front side of the circuit board plate. The back side of
each gauge preferably includes an aperture positioned corre-
sponding to each bulb location to permit the bulb to extend
within the gauge to provide illurnination of the gauge. The
circuit board also provides ground and lead connections
to each bulb location so that all bulbs are on a common
circuit, which may include a dimming unit.
Brief Description of the Drawings
Fig. 1 is an isometric view of the instrumentation
system of this invention showing the front side of the
instrumention system secured to a vehicle dash in solid line
and the rear of the system when it is pivoted outwardly for
access in phantom lines.
Fig 2 is an exploded isometric view illustrating
the relationship of the components of the instrumentation
system.
Fig. 2A is a side elevational view of the pivotal
mounting.
Best Mode for Carrying Out the Invention
Fig. 2 illustrates a preferred embodiment of the
plug-in instrumentation system of this invention. A housing
10 includes a front instrument panel 20 having a plurality
of apertures 22 of uniform size and shape for receiving
either electrical gauges 12 or mechanical gauges 12', each
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of which has exterior dimensions shaped to conform to the
instrumentation plate apertures.
A circuit hoard plate 30 is positioned behind the
front instrument panel 20 a distance corresponding to the
depth of the gauges 12,12'. Mounted on the rear face of the
circuit board plate 30 is circuit board 40.
Projecting from the rear of each electrical gauge
12 are lead and ground terminals 16 and a mounting pin 18.
Mechanical gauges 12' may also include a dummy terminal 16'
to enhance securing and alignment of the gauge 12' within
the housing 10. Additionally, gauges 12,12' include signal
terminals 19,19' which project outwardly from the rear of
each gauge. On mechanical gauges 12', the signal terminal
19' comprises a hose mounting which receives either a pres-
sure or vacuum hose (not shown) communicating with another
part of the vehicle. When electrical gauges 12 are inserted
through apertures 22 from the front side of the front in-
strument panel 20, the lead and ground connectors 16 and
signal terminals 19 of each gauge preferably project through
aperture 32 positioned in the circuit board plate. Similar-
ly, when mechanical gauges are so inserted, dummy terminals
19' preferably project through aperture 32. A separate
aperture 38 is provided for mounting pins 18. As illustrat-
ed in Fig. 2, the front instrument plate apertures 22 are
preferably shaped to include slots 24, which receive align-
ing ribs 14 positioned on gauges 12,12' to ensure that the
gauges 12, 12' are properly aligned relative to apertures 32
as well as apertures, terminals and brackets on the circuit
board 40, as discussed below.
When gauges 12,12' are mounted within the housing
10, ground and lead terminals 16 and dummy terminals 16'
extend through apertures 32 and through correspondingly
placed apertures in the circuit board 40 into female termi-
nals 46, as required by the gauge type. The female termi-
nals 46 for each gauge location are electrically coupled to
gauge plugs 56 by the circuit board 40. The gauges 12,12'
are held in place by mounting pin 18 which extends through
aperture 38 in circuit board plate 30 and is held in place
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by aperture and bracket combination 48 of the circuit board
40.
Siqnal terminals 19,19' of each gauge 12,12'
extend through aperture 32 and a corresponding aperture 49
in the circuit board 40, preferably Jo the back side of the
housing 10 to permit signal wires (not shown) or pressure or
vacuum hoses (not shown) rom the monitored systems to be
connected to the gauges 12,12'.
Lamp assemblies 70 are detachably mounted to the
circuit board 40 at lamp apertures 47. The circuit board 4n
contains a lamp circuit which provides lead and ground con-
nections to all lamp assemblies 70. The lamp circuit is
electrically coupled to the electrical system of the vehicle
via lamp plugs 57. Means for dimming the lamp assemblies
(not shown) may be provided to permit the vehicle operator
to regulate the intensity of illumination. The bulb portion
of the ]amp assembly 70 extends through lamp aperture 47 and
aperture 32 into opening 17 of each gauge 12,12' for illumi-
nation. A washer 77, preferably of foam construction, is
secured to the rear of the circuit board ~0 and circuit
board plate 30 surrounding lamp aperture 47, forming a
closed tunnel between the rear of the circuit board 40 and
the lamp opening 17 through which the bulb portion of the
lamp assembly 70 extends.
When a metal circuit board plate 30 is used, the
circuit board 40 may be simplified by grounding the circuit
board plate 30. The grouncl connection from either the qauge
plugs 56 or the lamp plugs 57 can he electrically coupled to
the circuit board plate 30. The ground connection for the
individual lamp assemblies 70 or gauges 12,12' can then be
completed via a common ground circuit at each gauge loca
tion, the qround circuit being electrically coupled to the
grounded circuit board plate 30. This coupling is prefer-
ably accomplished by connectinq the ground circuit of each
gauge location to the bracket of the bracket and aperture
combination 48, which is preferably riveted to the circuit
board 40 and circuit board plate 30. When this connection
is made, the apertures 32 in the circuit board plate 70,
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through which the lead terminals pass, should be of suffi-
cient size to insure that no contact is made between the
lead terminal and the grounded circuit board plate 30.
The housing assembly 10 preferably additionally
includes cover plate 60, formed of insulating material,
which lsolates the circuit board from direct contact with
other parts of the vehicle. Included within the cover plate
60 are apertures 69, corresponding in location to apertures
49, to permit signal connections to be made, and apertures
67, corresponding in location to lamp apertures 47, which
permit lamp assemblies 70 to be installed and removed from
the circuit board 40 without removing the protective plate
60 and T-opening 66, which permits access to gauge plugs 56
and lamp plugs 57. The protective plate 60 and circuit
board 40 are secured to the circuit board plate 30 by
fasteners 99.
As seen in Fig. 1, the entire assembly illustrated
in Fig. 2 is preferably pivotally mounted within a vehicle
dashboard D. The pivotal mountinq 140 at the bottom of the
housing 10 permit access to the various elements which pro
ject through the rear of the circuit board 40. When the
instrumentation system housing 10 is pivoted outwardly, as
shown in phantom in Fig. 1, lamp assemblies 70 may be read-
ily installed and replaced, signal wires 119 and vacuum or
pressure hoses (not shown) may be readily attached to signal
terminals 19,19', and lead and ground wires 157,156 may be
attached to gauge plugs 56 and lamp plugs 57. A pivotable
housing 10 also facilitates removal of the gauges 12,12' by
permittinq access to the rear of the qau~es 12,12' when the
housing is pivoted outwardly so that pressure may be applied
thereto in order to remove the securing pin 18 from the ap-
erture and bracket combination 48. Fasteners 97 secure the
upper portion of the instrument plate 20 to the dashboard D
of the vehicle to hold the instrumentation housing 10 in an
upriqht position for use.
As seen in Fig. 2A, the pivotal mounting 140 is
preferably comprised of a receptacle 142 shaped to receive a
bottom end 144 of the front instrument panel 20. The bottom
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end 144 is preferably shaped to permit direct insertion of
the housinq 10 into the receptacle 142. Once in the recep-
tacle 142, the housing may pivot as shown in phantom lines
in Fig. 2A. A foam insert 148 may be positioned between
the bottom of the receptacle 142 and the dashboard.
Although the invention has been described here in
reference to a particular embodiment, as illustrated in
Figs 1 and 2, the invention is not limited to this embodi-
ment. Many possible modifications and equivalents will be
apparent to those skilled in the art, and the scope of the
invention is, therefore, not limited to the preferred
embodiment described above.
