Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02222884 1998-02-10
DESCRIPTION OF THE INVENTION
METHOD 1ND OPP4RATUS FOR ELECTRONIC4LLY MONITORING
eIR BRAKE-STROKE
The invention is a method and apparatus for electronically
monitoring air brake-stroke travel and adjustment on air
brake equipped motor vehicles and trailers, which alerts
the operator if/when any brake is out of adjustment.
DRAWING # 1 shows a preferred rectangular shaped enclosure
1 which is suitably fixed to an adjustable slotted angle
shaped bracket ~, and of which is secured to an air brake
chamber bolt ~. The bolt 3 provides the necessary negative
(-) D C (direct current) grounding means to activate (open)
and close electronic circuit functions. The enclosure 1
also serves as an integral grounding component of the
electronic signal warning system.
Within the rectangular enclosure 1 is a metallic torsion
spring 8 suitably positioned, however, isolated and insulated
from the enclosure 1 by non-conductive materials ~. 11n
electrically conductive wire lead 10 connects the torsion
spring a to a negative (-) ground wire lead of a electronic
monitoring gauge 11 or other compatible electronic signalling
device. The torque lever 12 of the torsion spring d normally
rests against a metallic contactor pin 13 which serves as a
"closed electrical circuit" grounding means. The electronic
circuitry normally maintains a "closed circuit" atatus.
The suitable wired electronic monitoring gauge 11 contains
L.E.D.'s 14 (light emitting diodes). One L.E.D, is positioned
under each r~beel as displayed on the monitoring gauge 11 and
each L.E.D, is visible through each transparent wheel overlay
on the gauge face. Each L.E.D. 14 is electronically linked
to a corresponding torsion spring switch assembly located
within each enclosure 1. The monitoring gauge 11 is mounted
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CA 02222884 1998-02-10
inside the cab of a vehicle, or, as a variation, an elec-
tronically activated warning buzzer, horn and/or warning
lights) is mounted to the framework of a vehicle or trailer.
Each electronic warning device is audible and vis~.ble from
the operators seated driving position) Any standard D C
(direct current) power supply provides the electrical means
to operate the electronic warning system.
A non-conductive pin ~ is fixed into a two-piece collar 5
and is secured by a jamnut 6. The non-conductive pin 4
protrudes outwardly at a right angle away from the two-piece
collar 5. The two-piece collar assembly 4, 5 and 6 is
adjustably secured to an air brake chamber push rod ?. The
non-conductive pin 4 of the two-piece collar assembly remains
fixed at a preset distance from the torsion spring torque
lever 12.
While brakes are in proper adjustment, the air brake chamber
20 push rod ~ travel distance is limited due to proper slack
adjustment of the slack adjuster land due to the resistance
of the brake shoes pressing against the wheel drum. However,
when any brake is out of adjustment due to improper slack
adjustment, the push rod 'T has little or no resistance, which
allows excessive push rod travel when the operator applies
the brakes. During such a brake application, as the push rod
7 continues to travel outwards and away from the air brake
chamber 20, the brake will become out of adjustment. During
a normal brake application, when push rod travel distance
exceeds the allowable preset travel tolerance between the
non-conductive pin ~ and the torsion spring torque lever 12,
the non-conductive pin 4 pushes against the torque lever 12,
which, in turn, causes the "normally closed" electrical cir-
cuit between the contactor pin 4 and the torque lever 12 to
open. As the "normally closed" electrical circuit opens,
the monitoring device activates and displays a warning light
or signal, alerting the operator that a brake is out of
adjustment.
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CA 02222884 1998-02-10
An insulated metallic bolt 16 or an optional non-conductive
bolt 16 is utilized to adjust and maintain adequate torsion
sp ring tension and thus holds the torque lever 12 firmly
against the grounded metallic contactor pin 13 and thereby
assures a "normally closed " electronic circuit.
A cap 1? seals the uppermost end of the rectangular shaped
enclosure 1. A slotted lower cap 18 permits the torque
lever 12 to travel back and forth within the slot.
A lubricating nipple 19 is utilized to fill the entire inner
cavity of the enclosure 1 with grease. The grease prevents
contaminants and moisture from entering the enclosure 1 as
well as providing lubrication for inner components.
DRAWING # 2 is a variation of the original design. It shows
a similar electronic enclosure 1 complete with switching means.
However, for certain air brake chamber mounting applications,
the two-piece collar 5 is positioned and fixed onto the push-
rod T in close proximity to the push rod clevis jamnut 21
instead of being fixed near the air brake chamber 20. A non-
conductive eye bolt 22 replaces the non-conductive pin ~.
The lowermost end of the torsion spring torque lever 12 is
circular in shape. An adjustable cable, chain or strap 23
attaches to the torque lever 12 and to the eye bolt 22 of the
two-piece collar assembly. This arrangement provides the
means necessary to "pull" (instead of push, as described in
Drawing #1) the "normally closed" circuit contactor pin 13
and the torque Sever 12 apart, thus creating an "open"
circuit position when a brakes) is out of adjustment. This
action activates a corresponding L.E.D. 14 warning light
within the suitably wired electronic monitoring gauge 11, or
alternatively, activates any other compatible electronic
warning device, thus alerting the operator.
Another variation described in Drawing # 2 is to attach the
cable, chain or strap 23 to a breck~t 24, or to an extended
slack adjuster clevis pin t3, or other suitable auxiliary
mounting means.
1997 wilhelm K. Sellin
