Note: Descriptions are shown in the official language in which they were submitted.
CA 02603470 2007-09-19
BRAKE STROKE INDICATOR
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority date of U.S.
Application No. 11/655,339 as filed on January 19, 2007.
BACKGROUND OF THE INVENTION
The present invention relates in general to vehicular
braking systems, and more particularly to a brake stroke
indicator, which visually warns drivers of faulty brake
operation.
Faulty vehicle braking systems can cause serious accidents.
One factor contributing to faulty brakes is the wear of
brake parts, which increases the amount of effort required
by an operator to effectively brake. If brake wear is
extreme, it may result in complete loss of braking power.
To determine whether a braking system is working properly
and whether wear is within limit, brake stroke indicators
are used to indicate the stroke of the brake push rod.
Several types of brake stroke indicating systems have been
developed in art. U.S. Pat. No. 5,913,385 to Thibodeau
discloses a visual brake stroke indicator for determining
brake stroke condition on a vehicle braking system. The
indicator comprises a bracket having an elongated member
having at one end an attachment portion located generally
at a right angle radius to the elongated member, a
continuous slot extending along the length of the elongated
member, and a second bracket detachably mounted to the
continuous slot along the elongated member. The bracket is
1
CA 02603470 2007-09-19
mounted to a chamber mounting bracket which supports a
brake chamber having a clevis assembly connected to a brake
arm. The elongated member runs parallel to the clevis
assembly. The second bracket has a base and two extending
members from the base.
U.S. Pat. No. 5,358,076 to Lucas discloses an indicator
unit for a vehicle air brake system which includes a brake
rod mounted for movement between a non-braking first
position and a predetermined safe maximum braking second
position. A pivotally mounted slack adjuster is connected
to the brake rod and is responsive to the movement of the
rod. An indicator unit is provided which has a first
section mounted on the connection between the rod and
adjuster, a second section retained in a predetermined
alignment with the rod, and a third section angularly
disposed relative to the second section. The unit third
section is provided with angularly disposed, exposed, first
and second reference marks. When the rod is in the first
position, the first reference mark is aligned with a
predetermined first segment of the adjuster. When the rod
is in the second position, the second reference mark is
aligned with the predetermined segment of the adjuster. The
alignment of the second reference mark with the adjuster
segment is indicative that the rod has traversed 80%, or
the limit, of its safe braking stroke and thus indicates
adjustment of the brake system is warranted.
U.S. Pat. No. 5,320,198 to Hoyt discloses an air brake
stroke length adjustment gauge for indicating the setting
and linear stroke movement of a brake rod of a brake
assembly. Reference indicators are provided on both the
2
CA 02603470 2007-09-19
brake-rod's clevis and on the arm of the brake's slack
adjuster member. The indicators cooperate, by their
relative movement, showing brake rod travel and adjustment
as a visual indication by the relative movement by the
reference indicator of the linearly-moving clevis with
respect to the angular rotation of the reference indicator
on the rotating-slack adjuster arm.
However, the installing location, structure and over-stroke
indicating means of the brake stroke indicator of the
present invention are different. Moreover, the brake stroke
indicator of the present invention is completely concealed
and can only be seen in case of an over-stroke or out of
adjustment condition. This and other features of the
present invention will become better understood with
reference to the appended Summary, Description, and Claims.
BRIEF DESCRIPTION OF THE INVENTION
The present invention is a brake stroke indicator which
visually indicates the over stroke and out of adjustment of
the push rod. The indicator comprises a L shaped indicator
member which is connected to the push rod clevis pin and
the slack adjuster, and a concealing means for concealing
the indicator member when the push rod stroke is within
safe operational limit. The L shaped member includes a
first section with holes for mounting it on the clevis pin
and a second section disposed at an angle substantially 90
degrees with the first section. The indicator member moves
with the clevis pin and oscillates as the push rod is
reciprocating. The second section of the indicator having a
highly reflective color surface, shows up out of the
3
CA 02603470 2007-09-19
concealing means when the push rod moves beyond its safe
operational limits.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an unassembled view of the brake stroke indicator
in accordance with the present invention.
FIG. 2 is the assembled view of the brake stroke indicator
showing the indicator behind the concealing means, when the
push rod reciprocates within safe limits.
FIG. 3 is the assembled view of the brake stroke indicator,
showing the indicator out of the concealing portion, when
the push rod is over stroked or out of adjustment.
FIG. 4 is a perspective view of another embodiment of the
brake stroke indicator member.
FIGURES - REFERENCE NUMERALS
10 . . . Brake Stroke Indicator
12 . . . Clevis Pin
14 . . . Push Rod
16 . . . Slack Adjuster
18 . . . First Section of Brake Stroke Indicator
20 ... Second Section of Brake Stroke Indicator
22 . . . First Hole of Brake Stroke Indicator
24 . . . First Connection of Clevis Pin and Slack Adjuster
26 . . . Second Hole of Brake Stroke Indicator
28 . . . Second Connection of Clevis Pin and Slack Adjuster
30 . . . Concealing Portion
4
CA 02603470 2007-09-19
32 . . . Centre of Oscillation of Slack Adjuster
34 . . . Slot on Concealing Portion
100 . . . Second Embodiment of Brake Stroke Indicator
120 . . . First Section of Second Embodiment of Brake
Stroke Indicator
140 . . . Hole on Second Embodiment of Brake Stroke
Indicator
160 . . . Gripping Portion on Second Embodiment of Brake
Stroke Indicator
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, a preferred embodiment of the
brake stroke indicator 10 is illustrated and generally
indicated as 10 in FIGS. 1 through 4. The brake stroke
indicator 10 is mounted on the push rod clevis pin 12 and
visually indicates when the push rod 14 moves beyond its
operational limits.
Referring to FIGS. 1 through 4, the indicator comprises a L
shaped indicator 10 which is connected to the push rod
clevis pin 12 and slack adjuster 16 assembly. The indicator
includes two sections, first section 18 which is used to
mount it on the clevis pin 12 and a second section 20
disposed at an angle substantially 90 degrees with the
first section. The second section 20 has a highly
reflective color surface.
The first section 18 includes two holes, first hole 22 is
used to make a first connection 24 with the clevis pin 12
and slack adjuster 16 assembly and, the second hole 26 to
establish a second connection 28 with the automatic slack
5
CA 02603470 2007-09-19
adjuster 16. As the push rod reciprocates the indicator 10
travels with the clevis pin 12. The second connection 28
with the slack adjuster is movable perpendicular to the
push rod 14 motion. When the indicator 10 moves with the
push rod 14, the second connection 28 with the slack
adjuster prevents the indicator 10 to move in the direction
of push rod and tilts the indicator 10, thereby
facilitating the indicator to oscillate, while the push rod
14 is reciprocating.
Referring to FIGS. 1 through 3, the concealing portion 30
is a plate disposed between the first connection 24 of the
push rod clevis pin and the indicator, and the centre of
oscillation 32 of the slack adjuster. The plate has a slot
34 for connecting it on the first connection 24 of the push
rod clevis pin 12 and the indicator 10. The shape of the
plate is such that it conceals the indicator member 10 when
the push rod is operating within safe operational limits.
The second section 20 of the indicator member shows up out
of the concealing portion 30 when the push rod moves beyond
the specified safe maximum braking position or is out of
adjustment.
Referring to FIG. 4, in another embodiment of the present
invention 100 which is especially meant for use with manual
slack adjusters, the first section 120 of the indicator has
one hole 140 to connect with the slack adjuster and a
gripping portion 160 for mounting the indicator 100 on the
clevis pin 12. The gripping portion is perpendicular to the
first section 120, which has a open slot which will fit on
the clevis pin. The second section is similar to the second
section 20 of the previous embodiment. The location of
6
CA 02603470 2007-09-19
mounting and the operation of the present embodiment 100 is
same as that of the previous embodiment 10.
All features disclosed in this specification, including any
accompanying claims, abstract, and drawings, may be
replaced by alternative features serving the same,
equivalent or similar purpose, unless expressly stated
otherwise. Thus, unless expressly stated otherwise, each
feature disclosed is one example only of a generic series
of equivalent or similar features.
Any element in a claim that does not explicitly state
"means for" performing a specified function, or "step for"
performing a specific function, is not to be interpreted as
a "means" or "step" clause as specified in 35 U.S.C. sctn.
112, paragraph 6. In particular, the use of "step of" in
the claims herein is not intended to invoke the provisions
of 35 U.S.C. sctn. 112, paragraph 6.
Although preferred embodiments of the present invention
have been shown and described, various modifications and
substitutions may be made thereto without departing from
the spirit and scope of the invention. Accordingly, it is
to be understood that the present invention has been
described by way of illustration and not limitation.
7
