Improvements in Means for Obtaining Adhesion between Wheel Tyres and Brake Blooks or Rails, also applicable to Friction Clutches.
Year: 1891

page_text: Date of Application, 5th Oct., 1891
Complete Specification Left, 30th June, 1892-Accepted, 30th July, 1892
PROVISIONAL SPECIFICATION.
Improvements in Means for Obtaining Adhesion between Wheel
Tyres and Brake Blooks or Rails, also applicable to Friction
Clutches.
I BENJAMIN WILLCOX of 47 Lincoln's Inn Fields in the County of Middlesex,
Patent Agent, do hereby declare the nature of this invention, which has been
communicated to me from abroad by Armand de Bovet of 47 Rue Taitbout, Paris in
the Republic of France, Engineer, to be as follows :-
This invention relates to means for creating adhesion between two pieces of
magnetisable and demagnetisable metal and utilising the adhesion so produced in
working brakes or preventing slipping of wheels or in working friction clutches.
The invention is more particularly applicable to railway brakes. The means for
producing the adhesion between the two pieces of metal may consist in arranging
one of the pieces so as to form an electro-magnet and closing the magnetic circuit
between the poles of this electro-magnet by means of the other piece which produces
a short magnetic circuit. The two pieces may be of any suitable shape and the
electric current which may be derived from a primary or secondary battery or
dynamo machine or other suitable source is under the control of the operator who
can regulate the current passing in the coils of the electro magnets by means of a
rheostat or regulating apparatus.
By means of the arrangements employed according to this invention it is rendered
possible to produce, between two surfaces in contact, a resistance to a sliding motion
considerably greater than has heretofore been found possible, and with a relatively
small expenditure of electricity a bar of iron weighing 12 kilogrammes per metre
for example placed vertically so as to form a tangent to a pulley so arranged that
the flanges or sides of the groove form the poles of an electro-magnet supplied
with a current from a dynamo, will not slip under a weight of less than 320 kilo
grammes with a current of such strength that a weight of 875 kilogrammes is
required to pull off the same bar in a radial direction.
In carrying out this invention when applied to a railway brake, the brake shoe
being arranged to act as an electro-magnet is suspended from the under frame by a
link or hanger in such a manner that when the current is cut off the shoe is
automatically moved out of contact with the wheel by the action of a spring or
gravity for example and rests against an adjustable stop by which it is supported
with the poles in close proximity to the wheel so that the passage of a relatively
weak current in the coils placed on the yoke or bar connecting the two poles which
form the wearing surface of the shoe is sufficient to create sufficient attraction to
bring the brake into action.
The hanger on which the shoe is suspended is preferably of non-magnetic metal
and the two poles of the electro magnet may be separated by a piece of brass or
other non-magnetic material.
The poles may be so arranged that the magnetic flow takes place in the direction
of the movement of the wheel tyre. that is to say parallel with the plane in which
the wheel revolves or transversely to the direction of motion of the tyre that is to
say transversely to the said plane of revolution.
It is advantageous to make the acting surfaces or poles of the magnet of good
wearing metal and a maximum of good effect is obtained when the coils are supplied™
with a current sufficient for producing magnetic saturation of one of the two parts,
in contact that is to say the legs or poles of the brake shoe or the part of the
wheel forming the ar:nature. The adhesion diminishes in proportion as the
intensity of the current falls below that which produces the maximum effect.

page_text: These brakes are easily controlled by simply regulating the current and admit
of being readily fitted to vehicles of ordinary-construction.
It is evident that similar results may be obtained by magnetising the wheel or
tyre in place of magnetising the brake shoe. In this case the tyre is divided into
two parts by a ring or washer of non-magnetic material and the coils are arranged
in the body of the wheel. The brake shoe may be constituted simply by a block
of metal suspended in proximity to the tyre so as to be capable of forming a short
circuit between the two parts of the latter.
This arrangement involves a special construction of the wheels but presents the
advantage of enabling the adhesion of locomotive wheels to the rails to be greatly
increased.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agents.
COMPLETE SPECIFICATION.
Improvements in Means for Obtaining Adhesion between Wheel
Tyres and Brake Blocks or Rails, also applicable to Friction
Clutches.
I, BENJAMIN WILLCOX of 47 Lincoln's Inn Fields, in the County of Middlesex,
Patent Agent do hereby declare the nature of this invention (which has been com-
municated to me from abroad by Armand de Bovet, of 47 Rue Taitbout, Paris, in
the Republic of France, Engineer) and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:-
This invention relates to means for creating adhesion between two pieces of iron,
or other metal such as steel, provided it be magnetisable and demagnetisable and
utilising the adhesion so produced in working brakes, or preventing slipping of
wheels, or in working friction clutches; as hereinafter set forth.
The invention is more particularly applicable to railway brakes and friction
clutches. The means for producing the adhesion between two pieces of iron, for
example, may consist in arranging one of the pieces so as to form an electro magnet
and closing the magnetic circuit between the poles of this electro-magnet by means
of the other piece which produces a short magnetic circuit. The two pieces may
be of any suitable shape and the electric current (which may be derived from a
primary, or secondary, battery, or dynamo machine, or other suitable source) is
under the control of the operator who can regulate the current passing in the coils
of the electro-magnets by means of a rheostat or regulating apparatus.
And in order that the said invention may be fully understood I shall now proceed
more particularly to describe the same and for that purpose shall refer to the
several figures on the annexed sheets of. drawings.
Figure 1 of the accompanying drawings illustrates in elevation and Figure 2 in
plan a railway brake arranged according to this invention.
Figure 3 illustrates in elevation, Figure 4 in plan and 4ª in plan partly in
horizontal section a modified arrangement.
Figures 5 and 6 illustrate another modification in elevation and in vertical section
respectively.
Figures 7, 8 and 9 illustrate in elevations at right angles to each other and in
longitudinal section a clutch, or shaft coupling as hereinafter explained.
In the arrangement of railway brake illustrated in Figures 1 and 2, the brake
shoe 1 is arranged to act as an electro magnet being wound with a coil of wire 5 on
the yoke or bar connecting the two poles 10, 11, the magnetic circuit of which is
closed by the wheel tyre 2 the said poles forming the wearing surface of the shoe.
In this arrangement the shoe 1 is suspended from a pin 4 on the under frame 3 by
a forked link, or hanger, 8 in such a manner that when no electric current flows in

page_text: -the coils 5 the shoe-1 moves-out of contact with. the wheel 2-either automatically
by gravity or otherwise for instance by the aid of a spring 6. An .adjustable
stop 7 limits the movement of the shoe and maintains the magnetic, poles 10, 1ị
sufficiently near to the wheel to allow of the passage of a relatively weak current
in the coils 5 creating sufficient attraction to bring the brake into action.
"The hanger 8 on which the shoe is suspended is preferably of dia-magnetic
metal and the two poles 10 and 11 of the electro-magnet may be separated by a
piece of brass, or other dia-magnetic, material as shewn at 9. In the arrangement
illustrated in Figures 1 and 2 the brake is so arranged that the magnetic. flow
between the poles 10, 11 takes place in the direction of the movement of the wheel
tyre 2.
Figures 3, 4, and 44, illustrate a brake generally similar to that shewn in
Figures 1 and 2 but in which the magnetic flow between the poles 10, 11 takes
place in a direction at right angles to the direction of motion of the tyre 2.
This arrangement will be readily understood without further description by
referring to the drawing in which the same numerals of reference indicate the same
parts as in Figures 1 and 2. The arrangement of the poles and separating block 9
is represented most clearly in the sectioned part of Figure 4ª.
My foreign correspondent states that it is advantageous to make the acting
surfaces or poles of the magnet of steel in order to obtain a stronger magnetic field
and that the best effect is obtained when the coils are supplied with a current
sufficient for producing magnetic saturation of one of the parts in contact that is
to say either the legs or poles of the brake shoe or the part of the wheel forming
the armature.
It is evident that similar results may be obtained by magnetising the wheel, or
tyre, in place of magnetising the brake shoe. Figures 5 and 6 illustrate an example.
of this arrangement. In this case the wheel is in two parts 10 and 11 separated by
a ring, or washer, 9 of dia-magnetic material and the coils 5 are arranged in the
body of the wheel. My foreign correspondent states that the brake shoe 12 may
be constituted simply by a block of steel suspended on the hanger 8 in proximity
to the tyre so as to be capable of forming a short circuit between the two parts of
the latter and that this arrangement presents the advantage when applied to
locomotive driving wheels of enabling the adhesion of the driving wheels to the
rails to be greatly increased, and to be regulated as required, the magnetic circuit
being closed by the rail as indicated at 13 in Figure.6.
The same principle of electro-magnetic adhesion may be applied in the
construction of friction clutches or couplings for driving machinery, and an
example of this application is illustrated in Figures 7, 8 and 9. The clutch is
represented in side elevation in Figure 7, in end elevation in Figure 8 and in
longitudinal section in Figure 9 the section being taken on the line A-B Figure 8.
In these Figures the numerals 1 and 2 indicate two shafts which are to be
connected, or disconnected, by means of the electro-magnetic clutch. A disc, or
ring 3 composed of cast iron, or annealed, or soft iron, or other suitable magnetic
material is fixed upon the end of the shaft 1.
A concentric annular cavity 4 is formed in one side of this disc for the reception
of a solenoid, or coil, 5 employed to magnetise the disc 3. The extremities 6 and 7
of the wire forming this coil are connected respectively to two metal rings 8 and 9
placed upon a ring 10 of non-conducting material which insulates the two rings 8
and 9 from one another, and from the disc 3.
The current is conducted to and from the apparatus through these rings by
means of brushes 11 and 12, arranged in contact with the peripheries of the said
rings.
A moveable basin-shaped disc, or sleeve, 13 is fixed on the extremity of the
shaft 2 by keys 14, capable of sliding in grooves 15 formed in the boss of the disc 13
so as to enable the latter to slide longitudinally upon the shaft 2. These movements
of the disc are limited in one direction by a ring, or collar, 16, fixed upon the
shaft 2 by means of a screw and in the other direction by a pair, or pairs of

page_text: Belleville springs 17 (or other equivalent elastic device) bearing against the fixed
ring 18 on the extremity of the shaft 2. The surface of the disc 13 is cut in the
form of a double bevel, or wedge, engaging with a recess 19, of corresponding
shape formed in the disc 3.
When a current is caused to pass in the solenoid 5 the disc 13 is attracted and 5
slides upon the shaft 2, being pressed against the disc 3 with a force in accordance
with the intensity of the current thereby coupling together the shafts 1 and 2.
When the current is cut off from the solenoid 5 the Belleville springs 17 which
were compressed whilst the shafts were coupled together expand and cause the
disc 13 to return to its original position and disconnect the shafts. It is evident 1
that either the electro-magnet or its armature may be movable and that the
apparatus may be worked, either automatically, or by hand in the same way as
ordinary clutches.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I 1
claim is <-
1. A railway, or like, brake, in which the adhesion is produced by the closing in
short circuit of a magnetic field developed in the brake shoe substantially, as
herein before described with reference to Figures 1 to 4ª of the accompanying
drawings.
2. A brake operating by the attraction or adhesion obtained by the closing in
short circuit of a magnetic field produced by the part against which the brake shoe
is applied; substantially as hereinbefore described with reference to Figures 5
and 6 of the accompanying drawings.
3. A locomotive wheel constructed to act as an electro-magnet as set forth, the 2
two magnetised parts of the wheel being placed in short magnetic circuit by contact
with the rails so as to produce an increase of adhesive power capable of being
graduated substantially as hereinbefore described with reference to Figure 6 of the
accompanying drawings.
4. The construction of magnetic clutches or couplings.arranged and operating 3
substantially as hereinbefore described with reference to Figures 7, 8 and 9 of the
accompanying drawings.
Dabad thin 00th an- of T1900