Automatic Brake for Railway and similar Vehicles.
Year: 1895

page_text: Date of Application, 16th Feb., 1895-Accepted, 23rd Mar., 1895
COMPLETE SPECIFICATION.
Automatic Brake for Railway and similar Vehicles.
I FREDERICK WILLIAM GOLBY, of 36 Chancery Lane, in the County of
London, Patent Agent, do hereby declare the nature of this invention as com-
municated to me by Marius Groignard and Alexander Parietti, Engineers, both of
123 Avenue d'Arenc, Marseilles, France, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
The automatic brake for railway and similar vehicles which forms the subject of
the present invention is represented in the accompanying drawings:
--
Figure 1 is a plan and Figure 2 is a vertical section of part of the apparatus while
Figure 3 is a sectional elevation of the whole arrangement on a reduced scale,
adapted to a vehicle.
The apparatus consists of a hollow body having two compartments, solidly
constructed, by preference in the form of a cylinder, secured by iron hoops or other
suitable means (see Figure 3) on the floor board of the vehicle; in such a way that
it occupies a horizontal position and parallel to the direction in which the carriage
travels. The interior of this hollow body is partitioned off into three spaces A, B
and C. One of these spaces A. forms a compression cylinder in which travels a
piston D. The piston rod D¹ is jointed by means of the eccentric E, on one of the
axles of the vehicle.
The second space B forms a brake cylinder in which a piston G is situated.
This piston is continually forced inwards by the coil spring H a certain space being
left over which it may travel.
The piston rod G₁ is connected either to the brake rods, or direct to the
brake shoe.
The third space C forms a reservoir for the liquid or other fluid which is
subjected to compression by the piston D.
Water mixed with glycerine is employed by preference, since this mixture freezes
with difficulty and on the other hand forms an excellent lubricant for the working
parts of the apparatus.
The three spaces A B and C are grouped together around a common point T in
such a way that each of them is in communication with the other two by an
entrance and exit.
These openings are controlled by the valves a b and c of which a can only open
towards A, b towards B, and c towards C in such a manner that the fluid
put in motion by the working of the piston D, can only circulate in the
direction c to a to b to c and not in the opposite direction.
The valves a and b are placed in the partition at the inner end of the cylinder A
whilst the valve c is placed in the partition which separates B from C, and outside
the field of action of the brake piston G. The valves a and b can always work
freely, and the following construction and arrangement allows the valve c to work
freely or to be closed at will. The valve c takes by means of the rod c¹ into an
axial hole in the pressure ram K which traverses the upper part of the reservoir C
through a stuffing box and is jointed outside at K' to a lever arm L.
The lever L has its pivot at L' on a pedestal M fixed on the exterior of C. The
free end of the lever L can be controlled from the carriage by any suitable means.
In the example shewn in the drawing (Figure 3) this extremity of the lever is
joined to a piston rod N, the piston of which, in this case, can be controlled in its

page_text: cylinder O by the introduction thereinto of steam or compressed air. The pressure
ram K jointed to L is placed under the influence of a strong coil spring P whose
force of resistance is exactly determined. Another coil spring p placed in the axial
hole in the ram K continually presses the valve c down on to its seating. s is a
screw stopper covering an aperture through which the liquid for compression can be
introduced into the reservoir C.
The action of the apparatus shewn in the drawings is as follows:-While the
brake is inactive, the lever Land also consequently the pressure-ram K, are held
up by steam or air pressure against the pressure exercised by the spring P. The
valve c is thus placed under the sole influence of the small spring p and can work
freely with the other two valves a and b. During the progress of the vehicle - the
piston D is caused by means of the eccentric E to continually work backwards and
forwards. In each of these movements forward it draws the liquid from C by the
valve a and in the backward movement it forces this liquid from A by b into the
brake cylinder B and the free space between the piston G and the valve bis
filled, the liquid flowing from B by valve c and returning to the reservoir C.
Consequently during the motion of the vehicle the liquid performs a continual
circulation. During this time the brake piston G remains unmoved held in place
by the spring H.
If it is necessary now to moderate the speed, the lever L is released, the ram KJ
is thereby lowered and presses the valve c with the proportional force of its
spring on to its seating. The liquid cannot then pass from B to C. The
piston D however continues to work and forces the liquid drawn from Ciuto A
into B and as it cannot escape from B, the brake piston G compresses its spring H and
is pressed outwards and the brake thereby caused to act. It follows that from the
continued pressure exercised by the liquid, a check free from shocks and a pro-
gressive development of the energy of the brake is produced. When the maximum
of pressure is attained and the brake lever cannot advance further, the increasing
pressure of the liquid opens the valve c by pressing back the spring P, the resistance
of which is calculated to this maximum, and this valve c remains open until an
equilibrium of pressure is established and the vehicle stops.
When the vehicle is restarted, the lever L is raised and consequently the ram K,
which produces the disengagement of the valve c from its seating. The brake
piston being released from its counter pressure, returns under the influence of the
spring H to its initial position and thus disengages the brake shoe and the working
of the apparatus cominences afresh. It may be remarked, and is an advantage
arising from this system, that the checking action occurs from the moment of the
clesing of the valve c since the free space at the rear of the brake piston G is con-
tinually filled with compressing liquid. This space B is of smaller dimensions-than
the space A and C whilst C is the largest of the three.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An automatic brake for railway and similar vehicles, characterized by a
pump (A D D') actuated by the motion of the vehicle, a compression pistan G con-
nected to the brake rods or brake shoe and held in position by a spring E, and
a reservoir C to receive the substance compressed of which the compartments A B.C
are grouped around a common point T and connected by valves a b and c of which the
.valve c placed between the brake cylinder B and the reservoir C is allowed to act
freely during the travelling of the carriage, but which when actuated by a system
of brake levers is closed completely, and consequently, while in motion the com-
pressing liquid' is propelled by the pump in a continual circuit in the three
compartments A B and C, but the moment the valve c is closed the said com-
pressing liquid acts immediately and with an increasing power on the brake piston-G
causing the brake to be applied to the wheel, substantially as and for the purpose
hereinbefore described and illustrated in the accompanying drawings.

page_text: 2. A brake of the kind indicated in the preceding claim in which the valve c
placed between the brake cylinder B and the reservoir C forms a safety valve
inasmuch as it works independently of the pressure ram K which, in applying the
brake is lowered by the spring P of a calculated strength in such a way that when
the maximum of pressure is attained in the brake cylinder B it produces an
automatic opening of the valve c substantially as and for the purpose hereinbefore
described and illustrated in the accompanying drawings.
Dated this 16th day of February 1895.
F. W. GOLBY,
36, Chancery Lane, London, W.C.