Ignition interlock and PRNDL indicator powering switch

An ignition interlock with PRNDL powering switch has a mechanism for locking a lock slider in position for prohibiting movement of a gear selector. The mechanism includes a plate for locking the slider in position and a cable for connecting with the gear selector. A sensor is associated with the mechanism and a PRNDL indicator. The sensor senses the position of the lock slider such that upon activation of the sensor, power is applied to the PRNDL indicator, causing a display within the PRNDL indicator to illuminate.

FIELD OF THE INVENTION 
The present invention relates to automotive vehicles and, more 
particularly, to an ignition interlock with a PRNDL powering switch. 
Motor vehicles having automatic transmissions include an indicator which 
provides the driver with a visual indication of the vehicle's transmission 
mode. This indicator is known in the art as a PRNDL (Park, Reverse, 
Neutral, Drive and Low). Ordinarily, the PRNDL indicator is adjacent or 
attached to the gear selector mechanism such that a pointer or the like is 
mechanically coupled to the gear selector so that as the gear selector is 
moved, the pointer moves to the proper letter of the PRNDL indicator. 
In vehicles which have an electronic PRNDL, a sensor is present which 
senses the position of the gear selector and transmits a signal which 
illuminates the proper mode letter on the PRNDL indicator when the gear 
selector is moved into the desired mode. Federal regulations require that 
electronic PRNDL's are powered or illuminated before the driver can move 
the gear selector or shifter from the park position. Thus, electric PRNDL 
must be illuminated so the driver can see what mode the transmission is in 
at starting of the vehicle or immediately thereafter but ordinarily prior 
to or during the unlocking of the ignition switch, when the switch is 
turned to start the vehicle. 
Electronic PRNDL powering systems have been associated with keys entering 
into the vehicle ignition switch. Here, upon the key passing into the 
ignition switch, the key is sensed and a signal is transmitted to 
illuminate the PRNDL indicator. However, these systems have a drawback 
since the sensing device requires power, which power is drawn from the 
vehicle battery. If the keys are left in the vehicle ignition switch for a 
prolonged period of time, the sensor will drain the battery, thus 
prohibiting the driver from starting the vehicle. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to overcome the disadvantages of 
current art devices. The present invention provides an active system which 
is activated upon movement of the ignition interlock locking slide from a 
locking to a use position. The present invention provides an ignition 
interlock with a PRNDL powering switch which is effective and inexpensive 
to manufacture. 
From the following detailed description taken in conjunction with the 
accompanying claims and drawings, other advantages will become apparent to 
those skilled in the art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Turning to FIG. 1, a vehicle cockpit is illustrated and designated with the 
reference numeral 10. An ignition interlock system 12 is coupled to the 
steering column 14. The ignition interlock system includes a cable 16 
which is coupled with the gear selector 18. Also, the ignition interlock 
is associated with the ignition switch 20 which is likewise mounted on the 
steering column 14. 
The ignition interlock 12 includes a housing 22 with a pivot locking plate 
24 and a sensor 26. The housing 22 is secured to the steering column 14 by 
conventional means. The locking plate 24 includes a cut-out or recess 28 
which receives the ignition lock slider 30. When the vehicle ignition 20 
is in a locked position, the lock slider 30 is positioned within the 
recess 28 of the locking plate 24 as seen in phantom in FIG. 2. Thus, the 
gear selector 18 cannot be moved since the plate 24 is unable to move. 
Rotating the ignition switch 20 out of the locked position causes a 
mechanism (not shown) to move the lock slider 30 out of the recess 28, 
allowing the gear selector 18 to be moved into the desired gear mode. A 
spring 32 acts with the cable connection 34 to move the plate to its 
indicated position. 
The sensor 26 may be any type of electronic or mechanical sensor. The 
particular sensor is a micro limit switch having electrical leads 38 
leading to circuitry 40 which is coupled with the PRNDL indicator 42 in 
the dashboard 44. The sensor 26 mechanically senses the movement of the 
lock slider 30 such that as the lock slider 30 is moved out of the cable 
interlock plate recess 28, the switch 26 is activated which, in turn, 
powers the PRNDL indicator, allowing the PRNDL indicator to display the 
current gear mode. As seen in FIG. 3, the switch 26 includes a 
cantilevered arm 46 which is contacted by the slider 30 as it moves from a 
locked to an unlocked position. Thus, upon sensing the lock slider 30 
passing the sensor 26, the PRNDL indicator is powered, causing the 
appropriate display within the PRNDL indicator to illuminate. Accordingly, 
since the lock slider 30 activates the sensor 26 prior to starting the 
vehicle, under the Federal Regulations, illumination occurs prior to the 
starting of the vehicle. 
In operation, a key is inserted into the ignition switch 20. The ignition 
switch 20 is rotated from its locked to an unlocked to a start position. 
As the ignition is turned from the locked to the unlocked position, the 
slider 30 is moved from inside the plate recess 28 and is sensed by the 
switch 26 as it moves out of the recess. As this occurs, a signal is sent 
to the circuitry 40 which, in turn, powers the PRNDL indicator, causing a 
display within the PRNDL indicator to illuminate 42. These steps happen 
very rapidly so that prior to the driver turning the ignition switch into 
the start position, the display within the PRNDL indicator is illuminated 
prior to starting of the vehicle. Thus, the vehicle would be in accordance 
with the desired guidelines. Also, as the slider 30 moves out of the plate 
recess 28, the gear selector 18 can then be moved into the desired gear. 
While the above detailed description describes the preferred embodiment of 
the present invention, the invention is susceptible to modification, 
variation and alteration without deviating from the scope and fair meaning 
of the subjoined claims.