Improvements in Electromagnetic Rail Brakes.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Electromagnetic Rail Brakes.
I, ADOLF WILDE, of Bei dem Hühnerposten 19/20, Hamburg, in the Empire
of Germany, Manufacturer, do hereby declare the nature of this invention to
be as follows:-
This invention relates to electromagnetic waggon brakes of the class in which
the electromagnets act directly upon the rails.
In brakes of this kind as hitherto constructed, the magnets are suspended ver-
tically above the rails upon springs so that in order that they may act upon the
rails it is necessary to overcome the resistance of the springs, whilst upon the
interruption of the current the brakes are again drawn upwards and maintained
suspended.
This method of suspending the brakes by means of springs, however, presents
numerous defects. In the first place the power necessary to overcome the resis-
tance of the springs amounts in the aggregate to a considerable consumption of
current. In addition to this, springs are always an unreliable method of sus-
pension and one in which the strength readily changes, whilst the alteration and
adjustment of the force of the spring for a given resistance can only be effected
approximately and with the expenditure of a large amount of time.
adjustment is frequently rendered necessary owing to the wear of the pole pieces.
Springs also invariably offer the same resistance whatever the strength of the
electromagnetic current which is employed may be, so that the action of the
brakes is not at all uniform and bears no proportion to the magnetic force.
Such
These defects which are inherent to the suspension of the electromagnets
upon springs are obviated by means of this invention in the following manner:
The magnets are carried by two-armed levers, in such a manner that the
magnet is arranged upon one of the arms of the lever, whilst upon the other is
provided a sliding weight which counteracts the weight of the magnet so that
no loss of power takes place and the whole of the magnetic force is available for
acting upon the rails.
By means of the sliding weight, the resistance for any desired strength of the
magnetic current may be readily and speedily adjusted; the travel of the arm
of the levers which is provided with the counter weight may be limited both in
the upward and downward directions by means of adjustable stops, so that the
distance of the pole pieces from the rails may be adjusted in accordance with
the strength of the current.
Dated this 2nd dox of Aroust 1899

page_text: improvements in Electromagnetic Rail Brakes.
I, ADOLF WILDE, of 19 and 20, Bei dem Hühnerposten, Hamburg, in the
Empire of Germany, Manufacturer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
This invention relates to electromagnetic waggon or car brakes of the class
in which the electromagnets act directly against or upon the rails.
In brakes of this kind as hitherto constructed, the magnets are suspended ver-
tically above the rails by means of springs, so that in order that they may act
against the rails, it is necessary to overcome the resistance of the springs, whilst
upon the interruption of the current, or opening of the circuit respectively, the
brakes are again drawn upwards and maintained suspended by the said springs
a certain distance above the rails.
This method of suspending the brakes by means of springs, however, presents
numerous defects. In the first place the power necessary to overcome the resist-
ance of the springs amounts in the aggregate to a considerable consumption of
current, and in the second place, concussions of the supporting points of the
springs produce bounding or vibratory motions of the brakes suspended from
the lower ends of such springs. In addition to this, springs are always an unre-
liable method of suspension and one in which the strength readily changes,
whilst the alteration and adjustment of the force of the spring for a given resist-
ance can only be effected approximately and with the expenditure of a large
amount of time. Such adjustment is frequently rendered necessary owing to the
wear of the pole pieces or brake shoes of the brakes. Springs also invariably
offer the same resistance whatever the strength of the electromagnetic current
which is employed may be, so that a large amount of current is by all means
necessary for energizing the electromagnets of the brakes, in order to overcome
the resistance of the springs and to move or shift the brakes from the normally
elevated position above the roadway down into contact with the rails.
action of the brakes therefore bears no proportion to the magnetic force, and it
is impossible in spring suspended brakes to change or alter the efficiency of the
brakes according to demand.
The
These defects which are inherent to the suspension of the electromagnets by
springs are obviated by means of this invention in the following manner:
The electromagnets are carried by double armed levers, in such a manner that
the magnets are suspended from one of the arms of the lever, whilst upon the
other is provided an adjustable sliding weight which counteracts the weight of
the magnets so that only a very small loss of power, if any, takes place and
nearly the whole of the magnetic force is available for the braking operation.
By means of the sliding weight, the resistance for any desired strength of the
magnetic current may be readily and speedily adjusted; the travel or amplitude
of the arm of the levers which is provided with the counter weight may be limited
both in the upward and downward directions by means of adjustable stops, so
that the distance of the pole pieces from the rails may be adjusted in accordance
with the strength of the current.
In comparison with spring suspended brakes, brakes carried by weighted levers
which counteract the weight of the brakes, warrant the advantage, first, that
a small amount of electric current is sufficient, and able to throw the brakes
down, and second, that by vertical concussions of the supporting points of the
suspension levers no dead motion of the brake system takes place

page_text: In order that my invention may be more fully understood by one skilled in
the art to which it appertains, I shall now proceed to describe the same in detail
and for that purpose reference is made to the accompanying sheet of drawing on
which I have represented a diagrammatic longitudinal elevation of the inner side
of a car frame equipped with my improved multipolar electromagnet brakes
suspended by weighted levers.
.
According to the example shown, the car frame is provided with main brakes
between the car wheels, and with auxiliary brakes in front and in the rear of the
said car wheels. Each brake is constructed in the well known manner shown
on the drawing in connection with the main brake only, and is composed of a
conductive core a, in two parts, suitably insulated from each other at a¹, and
connected by an insulating muff a², and of conductive spools carrying the wire
coils b', and brake shoes or pole pieces between, and at the outer ends of the
said spools, the coils being wound and interconnected to form a multipolar
electro-magnet with alternative positive and negative poles. The construction
arrangement and action of such electromagnet rail brakes are, however, well
known and need therefore no further explanation.
The brakes are pivotally suspended with their outer pole shoes c¹ by means of
links d from sliding bolts e adapted to raise and lower in suitable guideways or
guide irons attached to the frame work of the car. The sliding bolts e are
supported by double armed rock-levers g pivoted at gl to the frame work of the
car in any suitable manner. The opposite arms of these supporting or rock
levers are provided with sliding weights which are so adjusted as to slightly
overbalance the weight of the brakes suspended from the said levers g. In order
to adjust the distance of the pole pieces or brake shoes above or from the rails,
and to limit the upward and downward oscillation or rocking motion of the sup-
porting levers suitable adjustable stops i may be provided above and below and
in the path of the said levers as this is evident from the drawing without any
further description.
The suspension levers 9 are arranged in the longitudinal direction of the car
frame, that is to say, in a parallel direction to the brakes but they may also be
arranged in a transverse direction to the car frame i.e. at right angles to the
brakes. This latter construction is, for the saving of space, preferred for the
suspension of the auxiliary brakes in front and the rear of the car wheels. The
sliding bolts e of each auxiliary brake are in this case coupled or connected with
each other by means of a connecting bar
which is pivoted the supporting arm of the
suitable manner.
having at its inner side a lug / to
weighted lever g fulcrumed in any
The free and adjoining ends of the levers may be provided with slots g² and
connected by a pin m passing through the said slots 2, in order to secure a
uniform and contemporary movement or swinging of the suspension levers g.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. In electromagnetic rail brakes the suspension of the electromagnets proper
by means of double armed levers fulcrumed to the framework of the car and
provided with adjustable weights, substantially as and for the purpose set forth.
2. The improved electromagnet rail brake constructed, arranged and operating,
substantially as hereinbefore set forth.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.