U.S. patent number 3,805,927 [Application Number 05/295,214] was granted by the patent office on 1974-04-23 for electromagnetic rail brake for railroad vehicles.
This patent grant is currently assigned to Knorr-Bremse GmbH. Invention is credited to Gunter Tolksdorf.
United States Patent |
3,805,927 |
Tolksdorf |
April 23, 1974 |
ELECTROMAGNETIC RAIL BRAKE FOR RAILROAD VEHICLES
Abstract
An electromagnetic rail brake for railroad vehicles travelling
on rails equipped with inductive signal control and having sensors
located laterally and below the top surface of a rail has a rod of
ferromagnetic material attached thereto with the rod extending the
length of the magnet pole pieces. The rod is positioned laterally
and downwardly with respect to the faces of the pole pieces toward
the sensors. In this position, the rod is a conductor for any stray
magnetic fields emanating from the rail brake or the sensors.
Inventors: |
Tolksdorf; Gunter (Hagen,
DT) |
Assignee: |
Knorr-Bremse GmbH (Munich,
DT)
|
Family
ID: |
5825168 |
Appl.
No.: |
05/295,214 |
Filed: |
October 5, 1972 |
Foreign Application Priority Data
|
|
|
|
|
Nov 15, 1971 [DT] |
|
|
2156657 |
|
Current U.S.
Class: |
188/165;
335/304 |
Current CPC
Class: |
B61H
7/08 (20130101); B60L 2200/26 (20130101) |
Current International
Class: |
B61H
7/08 (20060101); B61H 7/00 (20060101); B60t
013/74 () |
Field of
Search: |
;303/3 ;310/93 ;335/304
;188/165 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Reger; Duane A.
Attorney, Agent or Firm: Jaskiewicz; Edmund M.
Claims
What is claimed is:
1. An electromagnetic rail brake for railroad vehicles travelling
on rails equipped with inductive signal control and having sensors
located laterally and below the top surface of a rail, comprising
magnet means positioned immediately above the rail top surface, a
rod of ferromagnetic material attached to the rail brake and
extending the length of the magnet means, said rod being positioned
laterally and downwardly from said magnet means toward the sensors
whereby the rod is a conductor for any stray magnetic fields
emanating from the rail brake or the sensors.
2. An electromagnetic rail brake as claimed in claim 1 wherein said
rod has a straight central portion along the length of the magnet
means and both ends are bent upwardly and obliquely to
approximately the centers of the end surfaces of the magnet
means.
3. An electromagnetic rail brake as claimed in claim 2 and
comprising a plate mounted on each end of said magnet means, the
bent ends of said rod being attached rigidly to said end
plates.
4. An electromagnetic rail brake as claimed in claim 3 wherein said
plates are adjustably mounted thereon.
5. An electromagnetic rail brake as claimed in claim 3 wherein said
end plates are each parallel to the respective ends of the magnet
means.
6. An electromagnetic rail brake as claimed in claim 1 wherein said
rod has a rectangular cross-section, the central portion of the rod
being disposed such that the shorter dimension edges are
horizontal.
7. An electromagnetic rail brake as claimed in claim 1 wherein said
rod has a circular or trapezoidal cross-section.
Description
The present invention relates to an electromagnetic rail brake for
railroad vehicles travelling on rails equipped with inductive
signal control and having sensors located laterally and below the
top surface of a rail, more particularly, to the elimination of
interference between any stray magnetic fields emanating from the
rail brake or the sensors.
In the railway signalling art, it has been known to employ an
inductive signal control system which includes a number of sensors
arranged laterally and below the top surface of a rail. When
railroad vehicles having electromagnetic rail brakes travel on
rails equipped with inductive signal control, false control systems
may be emitted in the event the sensors are actuated by a variation
in their magnetic field during the passage of railroad vehicles.
Such a signal would indicate the passage of the railroad vehicle
and possibly its direction of travel. It is known that under such
circumstances a sensor has released a signal indicating a false
direction of travel of a passing railroad vehicle whose
electromagnetic rail brake was switched on at that time. Such
erroneous indications are particularly frequent in those situations
where the rail brake magnet of the electromagnetic rail brake
consisted of an eddy-current brake magnet. The use of shields for
the sensors has not been particularly satisfactory since such a
shielding arrangement becomes very costly when the number of
sensors employed in a rail system are considered.
It is therefore the principal object of the present invention to
provide a novel and improved electromagnetic rail brake for
railroad vehicles travelling on rails equipped with inductive
signal control and having sensors located laterally and below the
top surface of a rail.
It is another object of the present invention to provide such an
electromagnetic rail brake which cannot induce the emission of
false signals in the sensors of the inductive signal control.
The objects of the present invention are attained and the
disadvantages of the prior art as discussed above are eliminated by
the electromagnetic rail brake of the present invention. According
to one aspect of the present invention there is disclosed an
electromagnetic rail brake for railroad vehicles travelling on
rails equipped with inductive signal control and having sensors
located laterally and below the top surface of a rail. The rail
brake has a magnetic means positioned immediately above the rail
top surface. A rod of ferromagnetic material is attached to the
rail brake and extends the length of the magnet means. The rod is
positioned laterally and downwardly from the magnetic means toward
the sensors so that the rod is a conductor for any stray magnetic
fields emanating from the rail brake or the sensors.
The rod is provided with a straight central portion along the
length of the magnetic means and both ends of the rod are bent
upwardly and obliquely to approximately the centers of the end
surfaces of the magnet means. The bent ends of the rod are rigidly
attached to plates adjustably mounted on the ends of the
magnet.
Other objects and advantages of the present invention will be
apparent upon reference to the accompanying description when taken
in conjunction with the following drawings, which are exemplary,
wherein;
FIG. 1 is a side elevational view of an electromagnetic rail brake
incorporating the present invention;
FIG. 2 is a front and elevational view of the rail brake of FIG. 1;
and
FIG. 3 is a top plan view of the rail brake of FIG. 1.
Proceeding next to the drawings wherein like reference symbols
indicate the same parts throughout the various views a specific
embodiment of the present invention will be described in
detail.
In FIG. 1 there is illustrated a rail brake magnet 1 of a known
structure which is employed in an electromagnetic rail brake as
known in the art. The magnet 1 comprises a plurality of poles 2
which are shaped at their lower ends into pole pieces 3 which are
positioned immediately above the top surface 4 of a rail indicated
at 5 in FIG. 2. When the electromagnetic rail brake is actuated,
the magnet 1 will be moved into contact with the surface 4 of the
rail.
A sensor which is a component of the inductive signal control
system is indicated at 6 in FIG. 2. The sensor 6 is positioned
laterally to and below the rail top surface 4 in such a manner that
the flanges of the wheels of a passing railroad vehicle will
influence or modify a magnetic field originating in the sensor 6.
The sensor 6 may actually comprise a plurality of separate
components positioned closely one following the other parallel to
the longitudinal axis of the rail so that the direction of travel
of the railroad vehicle can be determined from the sequence of
pulses of the signals released by these separate sensor
components.
The rail brake magnet 1 has ends 7 with each end being provided
with two bolts 8 whose axes are in parallel with the longitudinal
direction of the brake magnet 1. A plate 9 having a pair of slots
10 therein is attached to each end 7 of the magnet by means of the
bolts 8 being inserted in the slots 10. The slots 10 permit a
certain vertical adjustment of the end plates 9 with respect to the
rail brake magnet 1. Thus, it is only necessary to loosen slightly
the bolts 8 to enable a vertical adjustment of the end plates.
A rod 11 of a ferromagnetic material has a central portion 12 which
extends along the entire length of the brake magnet 1. The ends of
the rod are bent upwardly and obliquely at 13 and these bent ends
are welded to the end plates 9. The rod 11 has a rectangular
cross-section and the central section 12 of the rod is positioned
such that the shorter dimension edges are substantially horizontal
as can be seen in FIG. 2. As a modification, the rod may also have
a circular cross-section or a trapezoidal cross-section which is
particularly suitable for attaining maximum effect with optimum
utilization of material.
The central portion 12 of the rod is disposed laterally and
downwardly with respect to the pole pieces 3 in the direction of
the sensor 6 as also may be seen in FIG. 2. Thus, when the
electromagnetic brake is actuated, the central section 12 of rod 11
will then be in a position beside the head of rail 5 wherein the
rod can pass closely above the sensors 6 arranged beside the
rail.
During the operation of the electromagnetic rail brake, the central
section 12 of the rod 11 becomes a very good conductor in
comparison with the surrounding atmosphere for any stray magnetic
field emanating laterally from the rail brake magnet 1. Thus, the
stray lines of flux from such a magnetic field will be contained
for the most part within the section 12 of the rod.
In a similar manner, the central section 12 of the rod is a good
conductor for the magnetic field emanating from the sensors 6.
Thus, stray lines of flux from this field are largely concentrated
in the rod section 12. Since the stray magnetic fields of both the
rail brake magnet and the sensor are both largely concentrated in
the rod section 12 these stray fields cannot exert a reciprocal
effect between themselves such that false signals would be released
from the sensor 6. When the sensor 6 is passed by a railroad
vehicle whose electromagnetic brake is actuated, at the most, the
sensor can be induced to release a signal indicating the passage of
the railroad vehicle in the correct direction of travel. On the
other hand, the possibility of sensor 6 being induced by rail brake
magnet 1 to release a signal corresponding to the false direction
of travel is prevented even in those circumstances where the brake
magnet consists of an eddy-current brake magnet comprising a pole
sequence alternating in the longitudinal direction. This is of
particular significance should the sensor 6 be utilized for
controlling a crossing gate along the rail line travelled by the
railroad vehicle. When sensors are used in this manner, it is
apparent that the correct direction of travel of the vehicle be
indicated at all times and that no false signals indicating a wrong
direction of travel be emitted.
Thus it can be seen that the present invention has disclosed an
electromagnetic rail brake which effectively prevents the release
of false signals from sensors of an inductive signal control system
wherein the sensors are positioned adjacent the rails over which
vehicles equipped with the electromagnetic brake are
travelling.
It will be understood that this invention is susceptible to
modification in order to adapt it to different usages and
conditions, and accordingly, it is desired to comprehend such
modifications within this invention as may fall within the scope of
the appended claims.
* * * * *