Note: Descriptions are shown in the official language in which they were submitted.
3~
The field of the invention is optics, measuring and testing wlth
optical pyrometers. The lnventlon is particularly concerned with a device
for detecting overheated components of moving railroad cars, in particular
the spotting of hot bearings and/or wheel rims or brakesO
The state of the art may be ascertained by reference to United
States Patents 3,454,758 and 3,998,549-
It is known from the above prior art to mount infrared detectorsnear the rails of a railroad track and to project by means of suitable
optics part of the infrared heat radiation from the bearings of the passing
railroad cars onto the detector. The detectors deliver an electrical
signal proportional to the bearing heat, and the magnitude of this signal
allows spotting overheated passing bearings, that is, when they are
running hot. Electrical amplifiers and electronic switching means are
connected for that purpose afte. the detector, containing a set of thres-
hold switches. The threshold switches respond to specific signal strengths
and thus report hot bearings.
Moreover, rail switch means are also provided at the tracks,
which are actuated by the passing wheels and only activate the overall
detection circuit when a wheel is passing by.
It is furthermore known to use such detection systems in the
same manner to spot ho. bralces or wheel rims. However, the systems of
this kind known to date suffer from the drawback that two separate
devices m~lst be used to spot overheated bearings and overheated brakes,
or wheel rims, and these two sets are spatially located at wholly
different places on the rail. 'l'he drawback is that most of the need is
for the detectors and their subsequent electronic circuitry in a redundant
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manner, and most of all the drawback is that the measurements of the
bearing on one hand and of the brake or wheel rim on the other never takes
..
place at the same wheel, rather, due to the separate spatial arrangement,
the measurements always take place at different wheels.
Having in mind the limitations of the prior art, it is an object
of a broad aspect of the present invention to provide~a system for detec-
ting overheated components of moving railroad cars which detects both an
inadmissible temperature rise in the axle bearings and a temperature rise
in the brake shoes or the wheel ri~s, and this at the same wheel, and for
1~ which the expenditure in electronic components is substantially reduced.
According to an aspect of the present invention, the analyzing
electronics contain threshold value switches for spotting both an
increased bearing temperature as well as an increased wheel rim tempera-
ture, i.e., brake shoe temperature, and that the detector for the bearing
temperature and the detector for the wheel rim temperature are construc-
tively combined in a common housing.
By a broad aspect of this invention, an improvement is provided
in a detection device for spotting overheated components at the wheel
frame of a railroad car moving on a rail, the detection device including
detector means operatively associated with the rail to sense infrared
radiation and including subsequent analyzing electronic circuitry, rail
switch means mounted at the rail to activate the detector means and the
circuitry at the ti.me a wheel passes by, the circuitry containing threshold
value switches transmitting a detector signal to a memory display only
when the signal is the analogue of an inadmissibly high temperature,
wherei.n the detector means are mounted below the bearing of the wheel
30~
passing by and the measuring axis of the detector means extends approxi-
mately vertically upward and parallel to the plane of the wheel passing
by, the improvement whereby the detector means comprises: a first detector
for sensing a bearing temperature; and a second detector for sensing a
wheel rim temperature, the first, bearlng temperature detector and the
second, wheel rim temperature detector being constructively combined in
a common housing; and a single rail switch means provided for actuating
the first, bearing temperature detector and said second, wheel rim
temperature detector.
Accordingly, the overall concept of an aspect of the present
invention is to combine the detectors for the bearing temperature and for
the brake shoe or wheel rim temperature in such a particular spatial
manner that both will always measure the same wheel, and will make use
of the required analyzing electronics twice, this electronics containing
separate threshold value switches for the bearing temperature and for the
brake shoe or wheel rim temperature.
This is possible because these two temperatures are far apart.
The bearing temperature is already inadmissibly high ~hen exceeding the
ambient by 100C, whereas brake shoe or wheel rim overheating becomes
excessive only when they are 250C. above the ambient. These so-called
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even numbers" however, do not represent precise values, and are cited
merely to indicate the order of magnitude in the temperatu~e differences.
It is further noted that when the brake shoe or the wheel rim
temperature is measuredl t~e wheel rim temperature is actually the signi-
ficant one. Such an increased wheel rim temperature may arise on the one
hand because the brake shoes are draggin~ on the wheel, but also because
because the wheel blocked by the brake shoes is dragging on the rail. The
heating taking place in this way by dragglng is by far the stronger, and
after a few kilometers of dragging may result in detachment of the heat
shrunlc mounted wheel rim and hence in derailing the train.
The above overall concept for solving the problem can be imple-
mented by two different specific solutions. These so~utions differ in the
manner in which the measurement beam axis extends in relation to the plane
of the passing wheelg namely either ~n a slanted manner or parallel to it.
In other words, this means that the detector either is arran~ed in a first
embodiment vertlcally underneath the bearing passing over it (parallel
measurement axis) or that the detector is arranged in a second embodîment
as much to the side ne~t to the rail that the measurement axis is oblique
to the wheel.
In the second embodiment, the measurement a~is is directed at
the wheel center and when a wheel passes by, then the measurement axis is
crossed in time sequence first by a brake shoe, then an axle bearing and
then the second brake shoe. Therefore, the same detector can always be
used to measure both the brake shoe temperature and the bearing tempera-
ture. However~ thls detec~or and its subsequent electronics must be
sequentially activated twice; first for the front brake shoe and then for
t~e axle bearing. (~le second brake shoe need not be measured as its
temyerature is essentiall~ equal to that of the 'irst). Rail switch means,
for instance magnetlc switches, are required for this double activation,
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which are arranged at th~ track offset from each other and are sequentially
switched by the wheel passing by.
In the first embodiment, the measurement axis is directed verti-
cal]y upward and only the bearing passing over the detector is sensed.
This detector does not "see" either the brake shoes or the wheel rim.
Therefore, a special detector is needed to measure the wheel rim tempera-
ture, which can be mounted together with the axle detector in the same
or at the same housing. The measuring axle oE the wheel rim temperature
detector, however, is specifically directed at the wheel rim, and on that
site which rests on the wall vertically underneath the axle bearing.
Accordinglyl the measurements of the temperatures of the bearing
and of the wheel rim take place in this first embodiment at the same time.
Th~refore, this solution allows using the same rail switch means which
simultaneously activate the two detectors. Thus, while the second embodi-
ment employs the same detector but different rail switch means, the first
embodiment employs the same rail switch means but different detectors.
In the accompanying drawings,
Figure 1 is a schematic of a device of one embodiment of the
present invention sr~nn;ng the axle bearing vertically from below~ and com-
prising two detectors and one rail switch;
Figure 2 is a schematic of a device of a second embodiment of
the present invention with oblique sc~nnlnp, of the axle bea-ling, comprising
one detector and two rail swltches; and
Figure 3 is the device of Figure 2 seen in elevation along the
dlrection of line A-A of Figure 2.
. With particular reference to Figure 1, the wheel of a railroad
car is designatecl as 1 and runs on a rail 2. The wheel is borne by an
axle 3 supported in a bearing 4 in turn supported by a frame 5.
A device for spotting overheating of the bearing 4 and of the
3~
wheel rim of the wheel 1 is located to ~he side of the rail 2. This device
consists of the infrared detectors 6 and 7. The detector 6 is provided
- -Eor sensing the bearing 4 and the ~ensor 7 is provided for sensing the
wheel rim 1. However, both detectors are mounted in a co~mon housing ~.
The sensing of the bearing 4 takes place vertically from below. To that
end a deflection mirror 10* is arranged in the measuring a~is 6a in addi-
tion to the conventional optical components 9 for the purpose of deflecting
the measuring axis or the incident infrared rays by 90. The detector 7
on the other hand measures in the horizontal d~rection directly level with
the wheel rim.
The two detec~ors 6 and 7 are followed by electronic components
which are used in common for the two circuîts and are mounted in the
schematically ~ndicated housing 11. These circuits, however contain in
separate manner the threshold value switches for the bearing temperature
(SSL) and those for the wheel rim temperature (SST). The r~ nlng elec
tronic components consist of, for instance, amplifiers, means for analog
signal processing, axle counters, etc. as disclosed in United States P
Patent 3,998,5~9. Separate memory displays with display means 12, 13 are
provided.
The measurement of the temperatures of the bearing and of the
wheel rim takes place simultaneously, namely when the axle is vertically
above the device, that wheel zone tl,en being measure which at this very
moment is resting on the rail. Therefore, only one rail switch 14 is
required to activate the two detector circuits, this switch turning on
the two circuits when the wheel is in the described position. Still, the
switch may also be arranged elsewhere than where shown9 for instance, on
the same slde as the measuring system. Also, it can be located at the
opposite rail and be switched by the opposite wheel, or it may be offset
by one axle space.
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Figures 2 and 3 show a device with o~lique scanning. The measur--
ing axis 15 in this case slants to the wheel plane. It is easily seen that
in such an arrangement of the measuring axis, first the wheel rim will pass
-through it, then the bearing and then again the wheel rim. '~herefore, the
measurement of the bearing and wheel temperature does not take place at the
same time, as is the case for the embodiment of Figure 19 rather in
sequence. Regarding these time sequence measurements9 only one detectvr
16 is required, to which the infrared radiation is fed by corresponding
optics 17. However~ this detector and its subsequent electronics must be
activated twice and at a spacing corresponding to the wheel radius. Con-
trary to the embodiment shown in Figure 19 two separate rail switches 18
and 19 are required. These switches are shown in Figure 3 as being
located on the opposite rail merely for the sake of clarity in represen-
tation. They are actuated by the wheel la running on the same axle as
wheel 1 and actuate in turn the electronic components of the box 20.
As there are difEerent wheel diameters in the railroad~cars,
the rail switches 18 and 19 must be correspondingly wide to ensure actua-
ting the circuitry at the precise time for practically any wheel diameter
encountered.
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SUPPLEMENTARY DISCLOSURE
The Principal Disclosure provided a device for detecting over-
heated components of moving railroad ca:rs, in particular the spotting of
hot bearings, and/or wheel ri~s or brakes.
By the invention provided by the Principal Disclosure, the
analy~ing electronics contain threshold value switches for spotting both
an increased ~earing temperature as well as an increased wheel rim tem-
perature, i.e., brake shoe temperature. In addition, by such invention,
the detector for the hearing temperature and the detector for the wheel
rim temperature are constructuvely combined in a common housing.
The Principal Disclosure provided an i.mprovement in a detec~ion
device for spotting overheated components at the wheelframe of a railroad
car moving on a rail, the detection device including detector means opera-
tively associated with the rail to sense infrared radiation and including
subsequent analyzing electronic circuitry, rail switch means mounted at
the rail to activate the detector means and the circuitry at the time a
wheel passes by, the circuitry containing thresho].d value switches trans-
mitting a detector signal to a me ry display only when the signal is the
analogue of an inadmissibly high temperature, wherein the detector means
are mounted below the bearing of the wheel passing by and the measuring
axis of the detector means extends approximately vertically upward and
parallel to the plane of the wheel passing by, the improvement whereby the
detector means comprises: a first detector for sensing a bearing temperature;
and a second detector for sensing a wheel rim temperature, -the first, bear-
ing temperature detector and the second, wheel rim temperature detector
be.ing constructively cornbined in a common housing; and a single rail switch
means provided Eor actuatir.g the first, bearing temperature detector and
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the second, wheel rim temperature detector.
While the present invention as taught by the Princi.pal Disclosure
provided a system for detecting overheated components of moving railroad
cars which detected both an inadmissible temperature rise in the axle bear-
ings and a temperature rise in the brake shoes or the wheel rims, and this
at the same wheel, and for which the expenditure in electronic components
is substantially reduced, it would be desirable to provide even greater re-
producibility and reliability in the temperature measurements.
This more desirable aim is now achieved according to the invention
now provided by the present Supplementary Disclosure by spacing the wh~el
rim temperature detector a specified vertical distance from the rail upon
which the wheel, whose wheel rim temperature is to be detected, runs.
Thus by the invention pro~ided by the present Supplementary
Disclosure, an improvement is provided in a detection device for spotting
overheated components at the wheel frame of a railroad car moving on a rail,
the detection device including detector means operatively associated with
the rail to sense infrared radiation and including subsequent analyzing
electronic circuitry, rail switch means unted at the~rail to activate
the detector means and the circuitry at the time a wheel passes by, the
circuitry containing threshold value switches transmitting a detector sig-
nal to a memory display only when the siynal is the analogue of an inadmis-
sibly high temperature, wherein the detector means are mounted below the
bearing of the wheel passing by and the measuring axis of the detector
means extends approximately vertically upward and parallel to the plane of
the wheel passing by~ the improvement whe_eby the detector means comprises
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first detector for sensing a bearinq temperature; and a second detector for
sensing a wheel rim temperature, the first, bearing tempearture detector
and the second, wheel rim temperature detector being constructively combined
in a common housing; and a single rail switch means provided for actllating
the first, bearing temperature detector and the second, wheel rim temperature
detector; and means spacing the second, wheel rim temperature detector
up to four inches vertically from the top surface of the rail.
By a preferred ~ariant thereof, the vertical distance is two inches.
By another variant thereof, the detector measuring axis is oblique
to the plane of the wheel passing by.
By still another variant thereof, the second, bearing temperature
detector is mounted below the bearing of the wheel passing by and the measur-
ing axis of the second, bearing temperature detector means extends approxi-
mately vertically upward and parallel to the plane of the wheel passing by,
and a single rail switch is provided for actuating the first bearing tempera-
ture detector and the second wheel rim temperature detector.
Thus, it was discovered, and it is now taught by the present Supple-
mentary Disclosure,that an important embodiment of this invention residesin achieving an especially reliable measurement of the rim temperature by
making the measurement, using the second, wheel rim temperatura detector, at
a short vertical distance from the surface of the rail. The best place
would be right adjacent to the rail, but then the measuring spot becomes
too small. Therefore, it is necessary to move a little slight distance
away from the rail, but not too far from the rail.
~ccording to this preferred embodiment of the invention now provided
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by this Supplementary Disclosure, the scanning height between the wheel rim
and the second, wheel rim temperature detector ranges up to a distance of
approximately four inches from the rail surface. The scanning height pre-
ferably ranges at approximately two inches from the rail surface.
In the drawings accompanying the present Supplementary Disclosure:
Figure 4 is a schematic of a de~ice of one embodiment of the present
invention scanning the axlff bearing vertically from below, and comprising
two detectors and one rail switch;
Figure 5 is a schematic of a device of a second embodiment of the
present invention with oblique scanning of the wheel rim axle bearing com-
prising one detector showing the second, wheel rim temperature detector
but omitting the first, bearing temperature detector for clarity,and two
rail switchesi
Figure 6 is a representation of a typical wheel rim temperature scan
along a wheel passing by a detection point; and
Figure 7 is a signal curve of a wheel having rubber tires as the
wheel passes by a detection point.
~ ith particular reference to Figure 4, to the eXtent that Figure
is similar to Figure 1, the same reference numerals used with respect to
Figure 1 will be used now with respect to Figure 4. Thus, the wheel of a
railroad car is designated as 1 and runs on a rail 2. The wheel is borne
by an axle 3 supported in a bearing 4 which is, in turn, supported by a
frame 5.
A de~ice 8 for spotting overheating of the bearing 4 and of the
rim of a wheel 1 is located to the left hand side of the rail 2. This
device 8 consists of inPrared detectors 6 and 7. A first detector 6 is
~rovided for sensing the temperatu~e of the rim 1~ of the wh~el 1. Both
detectors are mounted in a common housing 8a. The sensing of the tempera-
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(
ture of the bearing 4 takes place ver-tically from below.
To that end,a deflection mirror 10 i5 arranged along the measuring axis 6a
in addition to conventional optical components (not shown) for the purpose
of deflecting the rneasuring axis 6a or the incident infrared rays by 90.
on the other hand, the second detector 7 measures the temperature of the rim
la of the wheel 1 in the horizontal direction along measuring axis 6b directly
level with the wheel rim. According to ernbodiments of the invention as now
provided by the present Supplementary Disclosure~the vertical displacement
"y" between the measuring axis 6b and the upper surface of the rail 2
ranges from approximately 2" to approximately 4", with the preferred dis-
placement being 2".
The first detector 6 and the second detector 7 are follcwed by electronic
components which are used in common for the two circuits and are mounted
in the schematically indicated housing 11. These circuits, however, contain
the threshold value switches for the bearing temperature (SSL) and those for
the wheel rim ternperature (SST) in a separate manner. The remaining elec-
tronic cornponents consist of, for instance, arnplifiers, means for analog
signal processing, axle counters, etc. as disclosed in United States Patent
No. 3,998,549. Separate memory displays with display means 12, 13 are
also provided.
The measurement of the temperatures of the bearing 4 and of the
rim la of the wheel 1 takes place simultaneously, namely when the axle 3 is
vertically above the device 8, the wheel zone which is then being measured
is that which at that very moment is resting on the rail. Therefore, only
one rail switch 14 i.s required to activate the two detector circuits (SSL)
and (SSR), this swit:ch turning on the two circuits (SSL) and (SSR) when
the wheel 1 is in the described position. On the other hand, the sw:itch 14
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may also be arranged elsewhere than where shown, for instance, on the same
side as the device 8. Furthermore, it can be located at the opposite rai]
and can be switched by the opposite wheel, or it may be offset by one axle
space.
Figure 5 shows a portion of an embodiment of the device 9 of aspects
of the invention now provided by the present Supplementary Disclosure with
oblique scanning from the wheel rim temperature detector. This Figure shows
only the second, wheel rim temperature detector 7. The first, bearing
temperature detector 6 for measuring the temperature of the bearing 4 has
been omitted for clarity. The device 9 includes the second detector 7 with-
in the housing 8a providing a temperature measuring axis 15. To the
extent that parts are the same, the same reference numerals used in Figure 4
will be used herein. The measuring axis 15 for the wheel rim temperature in
this case slants upwardly to the plane of the wheel l, with the measuring
axis 15 intersecting the rim la of the wheel l at an optimum vertical dis-
placement "z" from the rail 2. mis vertical displacement "z" ranges
approximately 4" to approximately 2", with the prefer~ed displacement "z" being
2". It is easily seen that in such an arrangement of th~ measuring axis 15
only the rim la of the wheel l will pass through it. Therefore, the measure-
ment of the temperature of the hearing 4 ~by means of the first detector,
not shcwn) and the temperature of the rim la by the second detector 7 does
not take place at the same time, as in the case for the embodiment of Figure
l, but takes place rather in sequence. Because of these timed, sequence
measurements, only one detector 16 is required in the device 9, to which the
infrared radiation is fed by corresponding optics 17. However, this detec-
tor 16 and its subsequent electronics must be activated twice and at a spac-
ing corresponding to the wheel radius.
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Contrary to the embodiment shown in Figure 4, two separate rail
switches 18 and ],9 are requixed. These switches are shown in Figure 5 as
being located on the opposite rail merely for -the sake of clarity in repre-
sentation. They are actuated by the wheel rim la running on the same axle
3 as the wheel 1 and actuate the electronic components of -the box (not
shown) in turn.
As there are different wheel diameters in railroad cars, the rail
switches 18 and 19 must be corresponding:Ly wide to ensure actuating the
circuitry at the precise time for practically any wheel diameter encountered.
As seen in Figure 6r showing the temperature of the wheel rim only,
temperature peak (1) represents the temperature of the brake at the wheel
remote from the detector; temperature peak (2) represents a ho-t peak
caused by sparks, and this temperature is not evaluated, temperature peak
(3) represents the evaluated temperature peak at the rim of the wheel; and
temperature peak (4) represents the temperature o~ the brake at the wheel
remote from the detector. (5) represents the gate pulse for data evaluation~
In Figure 7, the tire 30 has a safety runnin,g surface 31 and a
safety wheel 32. The wheel 32 runs on a concrete runnin,g track 33. Dotted
line 34 represents the height above the track 33 for scanning the tempera-
ture. This generally ranges between 2" and 4".
A typical temperature scan is as follows:
At A = 90C [194F]
B = 27C [81F~
C = 47C [117F~
D ~ 39C ¦102F~ ~
F represents the gate pulse for data evaluation.
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