Improved Method and Means for Retarding Vehicles.
Year: 1891

page_text: Date of Application, 12th May, 1891-Accepted, 13th June, 1891
COMPLETE SPECIFICATION.
Improved Method and Means for Retarding Vehicles.
A communication from ELIAS ELKAN RIES, residing at Baltimore, 430, South
Broadway, in the State of Maryland, United States of America, Electrician.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E., do hereby declare the nature of this invention and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement:-
This invention has reference to the method of and apparatus for slowing up and
stopping a travelling vehicle or train, wherein both the friction between the wheels
and brake-shoes and the frictional adhesion between the rails and wheels, are
utilized.
When a train is running at full speed, and it is desired to rapidly reduce the
speed, or stop the train, this is ordinarily done by applying the brakes with
sufficient force to lock the wheels against rotation. While this may be done with
the desired rapidity, the car or train will, for this reason, not at the same time
stop or slow down to the desired extent, since it is carried along by its momentum
a considerable distance, notwithstanding the fact that the wheels are locked against
rotation. In such case, the wheels will slide or skid over the rails, until the
momentum of the train is consumed by the friction between the wheels and
rails.
The time which thus elapses between the moment when the brakes are applied
and the moment when the car or train comes to a standstill, is comparatively long,
and it is difficult for the engineer to estimate with any degree of accuracy, the
point where the brakes must be applied, if it is desired to stop the train at a given
station. In the case of an emergency stop, necessitated by a danger signal ahead,
or by other causes, the train is ordinarily carried a considerable distance beyond
the point at which the brakes are applied, and the skidding movement of the
wheels causes injury to the rolling stock and also to the track.
All this is avoided by this improved method of and apparatus for slowing up or
stopping cars and trains, and the fundamental idea which underlies the invention
is this:-
It is found that if the frictional adhesion between the wheels and the track can.
be controlled in such manner that it may be increased at the time or immediately
after the wheels are locked by the brakes, the momentum of the car or train will
be speedily consumed by this increased friction, and the train will stop without
skidding to any considerable extent, within an exceedingly short time after the
brakes have been applied.
The invention therefore consists essentially in retarding or stopping the rotation
of one or more wheels of a travelling vehicle or train by the application of a
braking agency, and either simultaneously, or immediately after it, increasing the
friction between the said wheels and the surface upon which they travel.
The invention as defined by the above statement, may assume a variety of forms,
some of which are hereinafter shown and described, and others will readily
suggest themselves to those skilled in the art. My correspondent therefore
wishes it to be understood that he does not confine himself to the special forms
shown and described, nor in fact, to any particular details of construction, so long
as the fundamental principle of the invention is adhered to.
In the accompanying drawings are shown three separate and independent
organizations of apparatus, each embodying this invention, and each capable of
various modifications, as will be readily understood.

page_text: Referring to the drawings :—
Figure 1 is a plan view partly in section, partly in diagram, of a railway car
truck equipped with one form of this invention and showing conventionally an
exciting source of electricity, and the circuits and electrical connections constituting
auxiliary parts of this form of the invention.
Figure 2 is a view in side elevation partly in diagram of Figure 1.
Figures 3 and 4 are views in side elevation, of a steam locomotive and its
tender, the former being provided with certain apparatus comprising two other'
forms which this invention may assume.
Like numerals of reference designate like or corresponding parts in the several
views of the drawings.
Referring now more particularly to Figures 1 and 2 the car there shown is
arranged to be propelled by an electric motor of any approved type, which may
derive current from any convenient or available source, the conductors from which
latter may be overhead or underground, or the source of current may be a storage
battery carried upon the vehicle.
I indicates the car-truck frame, 22 the wheels; 33 the axles and 44 are bars
supported on the car-axles and themselves supporting an electric motor 7. This
motor 7 is supported by the side bars 4 4 centrally between the front and rear
axles, with its armature-shaft at right angles to the axles, and geared at each end
to the latter. For each axle there are two magnetizing coils 5 6 5' 6' which are
preferably secured to the inner faces of the side-bars 4 4 but are loose on the
axles and between the inner ends of these magnetizing coils there is a space for the
accommodation upon the axles of a mitre-gear 10 with which a nitre pinion
carried by the armature-shaft meshes.
The two coils 5 6 51 61 on each axle are connected by a looped conductor 11.
The terminal of magnetizing coil .5 is connected by a conductor 12 with a switch-
arm 13 at the pivot 29 of the latter; while the terminal of the magnetizing coil 61
is similarly connected by a conductor 121 with the pivot 291 of the switch-arm 131.
The terminals of the magnetizing coils and 5 are connected by a conductor 14.
and the coils are so wound that if a current passes through all of them in series
cach axle will be magnetized like a straight bar electro-magnet of which the wheels
are the polar extensions; but the two axles will be oppositely polarized, so that
the wheels on the same side of the car will represent opposite poles; so that there
will be a complete magnetic circuit including two axles, the wheels thereon and the
track rails between the wheels, each track rail constituting an armature for the
opposite poles of two electro-magnets.
The source of current for energizing the magnetizing coils 5 6 is represented in
the drawing as a battery 32 which may be carried on the car but it will be under-
stood that my correspondent is not confined to the use of such battery since any
other source of current whether carried on the car or located at the station may be
used. Conductors 33 33' from the poles of the source of current terminate in
contact plates 31 31¹ with which the switch-arms 13 13¹ can be moved in contact as
indicated in dotted lines. When contact is thus made the current from the battery
will traverse the magnetizing coils on the axles as follows:-
From one terminal of the battery by conductor 33' terminal 31 switch-arm 131
pivot 29 and conductor 12¹ to and through the coil 6¹ loop 11 coil 5' connection 14
and then by coil 6 loop 11 coil 5 conductor 12 pivot 29 switch-arm 13 contact
plate 31 and conductor 33 to the other pole of the battery.
To the truck frame I are secured brackets 21" 21" one pair for each set of wheels
and to each bracket is pivotted a pendulum bar 25. To the free ends of each pair
of pendulum bars is secured a soft iron core 17 extending between and through
said bars and furnished at their ends with brake-shoes 23 of magnetic material
preferably iron and upon the core 17 is placed the magnetizing coil 16 which like
the coils 5 6 5 61 has a protecting shield 15 on its outer surface.
From each pendulum bar 25 near its pivotal point extends an arm 25" under the
bracket 21 and an adjusting screw 27 passing through that arm and impinging on

page_text: the undersic of the Dracker S
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and this backward movement is produced by a spring 27" connecting at one end
with the pendulum bar and at the other end with a downwardly projecting arm 26
of the bracket. The tension of this spring may be adjusted in the ordinary
manner. In the normal condition of the apparatus this spring acts to withdraw the
brake-shoes from the wheels to a distance determined by the adjusting stop screw 27.
The brakes are applied by passing a current in the manner herein before described
through the magnetizing coils 565 6', whereby the wheels become the poles of
electro-magnets of which the axles are the cores; in which case each pair of
brake-shoes together with the core 17 becomes the armature of the electro-magnet
constituted by an axle and its wheels; or instead of passing the current through
coils 5 6 5 6 it may be passed through the coils 16 16 thus making the core 17
with its attached brake-shoes the electro-magnet and the corresponding axle with
its wheels the armature; or a current may be passed both through the coils 5 6 5' 6'
and the coils 16 16' in such manner that each wheel will have a brake-shoe of
opposite magnetic polarity opposed to it.
A brake is released either by discontinuing the current in the coils and allowing
the springs 27" to withdraw the brake-shoes or by passing the currents through the
axle coils and through the brake coils in such directions as to give to each brake-
shoe the same polarity which resides in the wheel in connection with which it
operates whereby the brake-shoes are repelled from the wheels thus assisting the
springs 27.
The brake coils 16 16' are connected in series and their terminals are arranged
in operative relation to the switch-levers 13 13 as follows:
One terminal of one coil is connected with one terminal of the other by the con-
ductor 21; the other terminal of coil 16 is extended by the conductor 18 to within
the sweep of the switch-arms 13 131 and the other terminal of coil 16' is also
extended to within the sweep of these switch-arms by the conductor 18. Near
these switch-arms each conductor 18 18' is formed into two branches terminating
at contacts within the sweep of the switch-arms. The conductor 18 thus
terminates in the contacts 19 19" and the conductor 18' in the contacts 20 20ª.
The two switch-arms 13 131 are joined by a line 36 provided with an insulating
button as indicated in the drawing for operating both switch-arms simultaneously
and by the operation of these switch-armis the method constituting this invention
is practised.
In the position of the switch shown in solid lines in the drawing the circuits to
the brake and axle magnets are both open and the car or train is supposed to run
at full speed the electric motor being fed by a current independent of the
source 32 conventionally shown in the drawing although it is quite practicable to
drive the motor from the same source of current.
If it is now desired to stop the car or train it will be understood that the
propelling power is first withdrawn and simultaneously with this act or immediately
after it, the switch is operated to bring the switch-arms to the positions indicated
in dotted lines that is to say one end of the switch-arm 13 will make contact with
the extended contact plate 31 and the inner end of the same switch-arm will bear
upon the contact 20 while the switch-arm 131 will make contact respectively with
the extended contact plate 31 and with the contact 19. In shifting the switch to
this position the insulated handle or button is pulled upward so that the upper
ends of the switch-arms may clear the contacts 19" and 20"; the switch-arms
being for this purpose made comparatively long and slightly elastic.
While this is the preferable construction and operation it is not really essential
that during this phase of operation contact between the switch-arms and the
contacts 19 and 20" be prevented.
When the switch is turned to the position described the current from the battery
or other source traverses two circuits which branch off at the pivots 29 29' one of
these circuits including the axle magnets as above described and the other circuit
including the brake magnet as follows;

page_text: •
From the positive pole of the battery by conductor 33' contact płatć 31' switch-
arm 13¹ to contact 19 by conductor 18 through the switch magnet 16 then by
conductor 21 to and through switch magnet 16 and by conductor 18 contact 20
switch-arm 13 contact plate 31 back to the other pole of the battery.
The switch-magnets are so wound that when the course of the current is as above
described they will be magnetized so that each brake-shoe has a polarity of unlike
name to that of its corresponding wheel. The brake-shoes will therefore be forcibly
attracted and will lock the wheels against rotation while at the same time the rails
extending between two wheels on one side of the car will form an armature to the
car-axles and the rails on the other side of the track will also form a keeper to the
car-axle magnets. Thus, the car as a whole will be forcibly attracted by the rails
increasing the friction between the wheel and rails to such an extent that the
momentum of the car will be speedily consumed and the skidding of the wheels in a
great measure if not entirely prevented. Thus by a single turn of the switch the
speed of the train is rapidly diminished and the train brought to a stand-still within
a very short time.
It will be seen that during this operation there is a complete magnetic circuit
including one car-axle and its wheels and the brake magnet 16¹; also that there is
another complete magnetic circuit including the other car-axle its wheels and the
brake magnet 16, and finally that there is a third complete magnetic circuit including
the two car-axles, their wheels and the intervening rails.
When the train has nearly stopped the switch is thrown back to the position
shown in solid lines whereby both circuits are opened but during this operation the
insulated handle is not pulled up so as to lift the ends of the switch-arms out of
contact with the contacts 19" and 20" but on the contrary the handle is rather
depressed so as to ensure momentary contact at 19 and 20%. During this momentary
contact the two circuits heretofore described are again closed the current through
the axle magnets flowing in the same direction as before, while the current through
the brake-magnets is now reversed as will be seen at a glance by those skilled in the
art consequently during this phase of operation the brake-shoes will have the same
magnetic polarity which resides in the corresponding wheels, so that the brake-shoes
will be repelled thus assisting the springs 27" as hereinbefore indicated.
The position of the switch last described also serves for another very important
operation. It is now understood that while the switch is in that position the
brake-shoes are repelled and withdrawn by the springs so that the wheels are free
to rotate. Now, the closed magnetic circuit including two axles their wheels and
intervening rails still exists and is highly energized by the passage of the current
through the axle magnets.
The increased friction between the wheels and rails therefore may be utilized for
ascending steep grades or for starting the train or both the traction being greatly
increased by the increased friction. The same friction therefore which when the
wheels are locked acts as a braking agency is effective in increasing the traction
when the wheels are free to rotate. I shall therefore hereinafter speak of "traction
friction as meaning the friction between the wheels and rails when the former are
free to rotate and I shall speak of the same friction as "braking friction" when the
wheels are locked against rotation.
::
Referring now to Figure 3 which illustrates another mode of stopping a railway
train in accordance with this invention there is shown an ordinary steam locomotive
equipped with an air-brake 43 connected by a system of levers with the brake-
shoes 44 which operate upon the wheels 45 in the ordinary and well known manner.
The air-brake lever 40 is mounted in the cab of the engineer but its connection with
the air-braking apparatus proper is not illustrated since this is an ordinary and
well known construction. Mounted on the locomotive there is a dynamo electric
generator 35 capable of furnishing an electric current of great volume but of
moderate tension and which dynamo is operated by a separate steam-engine possibly
of the Brotherhood type also mounted on the locomotive and deriving steam directly
from the steam-dome.

page_text: From the commutator brushes of the dynamo extend the circuit wires 37 37¹ the
one extending to the pivot of the brake operating lever 40 which pivot also serves
as a pivot for the electric switch-lever 39 which is in operative relation to the
rheostat 41 having one free terminal and having its other terminal connected by a
5 heavy conductor 38 with the axle of one driving wheel, or with the wheel itself in
any of the ordinary and well known manners preferably by a contact brush; the
other conductor 371 coming from the commutator brush is directly connected with
the axle of the other driving wheel or with the body of the wheel itself.
My correspondent has heretofore invented a method of increasing the friction
between the driving wheels of a vehicle and the track upon which it travels by
passing an electric current of great volume and preferably of low potential between
the two and this invention has been patented March 20 1888 No. 6075.
In this present invention and by means of the equipment indicated in Figure 3
my correspondent makes use of the method of increasing the friction between wheel
and rails by the passage of an electric current therethrough as will presently
appear.
If
As has been stated above, the switch-lever 39 is mounted on the same pivot with
the brake lever 40 so that both may be grasped and operated at the same time.
it is now desired to slow down or stop a train the operator may proceed in two
different ways.
He may either first operate the brake-lever and thus retard or lock
the wheels and then immediately afterwards operate the switch-lever closing the
circuit and rapidly cutting out resistances so as to increase the current or he may
grasp the two levers at the same time and turn them down thus simultaneously
braking the wheels and passing a current of rapidly increasing volume hetween the
wheels and rails. The second mode of operation is the preferred one since in this
manner the current passing between wheels and rails and consequently the friction
opposed to the sliding or skidding of the wheels is increased at the same rate at
which the braking power is applied.
When the brake is not applied but the circuit of the dynamo is closed the
skidding friction becomes at once a traction friction assisting in the ascent of steep
grades in accordance with the invention set forth in the Letters Patent above
referred to.
In Figure 4 the invention is shown as applied to a steam locomotive in a still
different manner. The air-brakes are arranged in the same manner as shown in
Figure 3 but in place of the electro-magnetic and purely electric friction-increasing
devices a sand-box 101 such as is ordinarily used on steam locomotives is there
shown. A. tube 47 extending from the sand-box and opening in front of the traction
wheels discharges sand upon the rails and thereby increases the friction between
the rails and wheels. In this discharge tube 47 there is a valve 46 which is
connected to the system of levers for operating the air-brake by a link 42 in such a
manner that when the brakes are applied the valve 46 is opened gradually and in
the same measure with which the force is applied to the brakes so that by the
time the wheels are locked the discharge of sand will be at its maximum.
will be clear at once that the fundamental idea of the invention is embodied in this
arrangement.
It
Having now particularly described and ascertained the nature of the said
invention as communicated to me by my foreign correspondent, and in what manner
the same is to be performed I declare that what I claim is :-
:-
1. The herein described method of braking a travelling vehicle or train which
consists in retarding the rotation of a wheel or wheels by the application of
mechanical friction and simultaneously increasing the frictional adhesion between
the wheel or wheels and the surface or surfaces upon which the same travel.
2. The herein described method of braking a travelling vehicle or train which
consists in retarding the rotation of a wheel or wheels by the application of the
braking agency and simultaneously therewith increasing the frictional adhesión
between the wheels and rails.

page_text: 3. The herein described method of braking a travelling vehicle or train which
consists in retarding the rotation of the wheel or wheels by the application of
mechanical friction, and simultaneously increasing the frictional adhesion between
the wheel or wheels and the rails upon which they travel by the influence of an
electric current.
4. The herein described method of braking a travelling vehicle or train which
consists in retarding the rotation of a wheel or wheels by the application of friction
due to the influence of an electric current and contemporaneously increasing the
frictional adhesion between said wheel or wheels and the rails upon which they travel
by the action of an electric current.
5. The herein described method of braking a travelling vehicle or train which
consists first in applying mechanical friction for the retardation of the rotation of a
wheel or wheels by means of electro-magnetism, and secondly, increasing the
frictional adhesion between the said wheel or wheels and the rails upon which they
travel by the influence of an electric current.
6. The herein described method of braking a travelling vehicle or train which
consists in retarding the rotation of the wheel or wheels by the application of a
certain amount of braking power and increasing the frictional adhesion between said
wheel or wheels and the rails upon which they travel in a degree proportional to the
amount of braking agency required.
7. The method of braking a travelling vehicle or train which consists in retarding
the rotation of the wheels, by the application of mechanical friction and by
increasing the frictional adhesion between the wheels and the rails by the passage
of an electric current from one to the other substantially as described.
8. The herein described method of braking a travelling vehicle or train which
consists in braking the wheels in any ordinary or improved manner, and increasing
the frictional adhesion between the wheel or wheels and the surface or surfaces.
upon which the same travel by the passage therethrough of an electric current,
substantially as described.
9. The herein described method of braking a travelling vehicle or train which
consists in braking the wheels and in passing a traction current between the wheels
and rails in either sequence substantially as described.
10. The herein described method of braking a travelling vehicle or train which
consists in retarding the rotation of the wheel or wheels by the application of a
braking power thereto and in increasing the frictional adhesion between the wheels
and the rails by the passage of an electric current between the same, and proportionate
to the braking power employed, substantially as described.
11. The herein described method of braking a travelling vehicle or train which
consists in electrically increasing the frictional adhesion between the wheels of the
vehicle and the rails and in independently applying a suitable braking agency to
retard the rotation of the wheels while the frictional adhesion is thus increased
substantially as described.
12. The herein described method of braking a travelling vehicle or train which
consists in retarding the rotation of the wheels by the application of a suitable
braking agency, and in electrically increasing the normal frictional adhesion during
the application of such braking agency, and independently thereof so as to diminish
or prevent the skidding of the wheels substantially as described.
13. The herein described method of braking a travelling vehicle or train which
consists in cutting off the propelling power of the same and in simultaneously
therewith increasing the adhesion between the driving wheels and the rails and
applying a suitable force or agency to retard the rotation of the said wheels
substantially as described.
14. The herein described method of braking a travelling vehicle or train which
consists in cutting off the propelling power of the same and in simultaneously
therewith establishing and energizing an electric circuit or circuits to increase the
frictional adhesion between the driving wheels and the rails and to retard the
rotation of said wheels substantially as described.

page_text: 15. The herein described method of braking a travelling vehicle or train which
consists in simultaneously subjecting one or more wheels thereof to the combined
retarding influence of a temporarily increased track and brake friction produced by
the action of an electric current or currents substantially as described.
16. The herein described method of braking a travelling vehicle or train which
consists in checking the momentum of the vehicle or train by the application of a
suitable braking agency or the reversal of the direction of rotation of the driving
wheels thereof and in simultaneously therewith increasing the frictional adhesion
between the driving wheels and rails to an extent proportionate to the braking
power employed substantially as described.
17. The herein described method of braking a travelling vehicle or train which
consists in applying mechanical pressure to prevent the rotation of the wheels and
in braking the vehicle or train by electrically increasing the friction between the
said wheels and the rails substantially as described.
Dated this 12th day of May 1891.
W. P. THOMPSON & BOULT,
Agents for the Applicant.