IMPROVEMENTS IN THE CONSTRUCTION OF RAILWAY BRAKES
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Adolfo Cozza at the Office of the
Commissioners of Patents on the 1st January 1878.
"
ADOLFO COZZA, of Orvietto, in the Kingdom of Italy, but at present residing at
Queen Street Place, in the City of London. IMPROVEMENTS IN THE CONSTRUCTION
OF RAILWAY BRAKES."
This Invention relates to a novel arrangement of continuous chain break, which
may be set in action either by the engine driver in front of the train or by the
guard at the rear end of the train.
The power for maintaining the break pressure being obtained from the steam in
the boiler, and the action of the breaks being initiated by the power derived from
the rotation of a wheel axle of the tender or break van. The break chain is
connected at its opposite ends with a chain barrel, forming part of a frictional
driving apparatus. These chain barrels are mounted on transverse shafts at the
opposite ends of the train, and fitted to the ends of these transverse shafts are chain
pullies, which are connected by endless chains to similar pullies keyed on the axle
of an adjacent pair of running wheels. The barrel shafts are mounted on sliding
bearings, the thrusting outwards of which brings the endless chain to tension, and
causes them to transmit rotary motion from the wheel axle to the barrels of their
respective transverse shafts.
The tender, or it may be the engine, is fitted with a steam cylinder, which is
capable of being brought into communication with the engine and boiler by means
of a five-way cock and pipes leading therefrom. This cylinder is fitted with a
piston, the rod of which is linked to a rock lever that has its fulcrum in the framing.
Jointed to this rock lever, at about the middle of its length, is a rod that is jointed
to the arm of a transverse rock shaft mounted in the framing, and through this
connection of the pistons with the rock shaft an axial motion is given to the latter.
A pair of short arms on the opposite ends of this rock shaft serve by means of links
connected with the chain barrel shaft to thrust that shaft outwards and bring the
endless chain before mentioned to tension. This will take place when steam is
admitted by the five-way cock to the top of the piston. As the endless chains are
Price 2d1

page_text: brought to tension they will, through the friction pulley on the axle of the running
wheels, set the chain barrel rotating and cause it to wind up the break chain, and
thereby put the breaks in action. So long as the pressure of the steam is upon the
top of the piston, the breaks will be maintained in action, but on reversing the five-
way cock the steam will be directed to the under side of the piston, which, being
raised, will cause the endless chain to slacken and stop their further action on the
break chain barrel, thus releasing the breaks from action.
Fitted to the rock shaft before mentioned is a crank lever, carrying at its lower.
end a guide pulley, under which, as one of a series of pendant guide pullies, the
break chain passes on its way from the break van to the chain barrel at the forward
end of the train. The upper end of this crank lever is connected with a steam-cock,
the turning of which will admit steam into the top of the piston, and thereby apply
the breaks. This arrangement is for the purpose of enabling the guard, as well as
the engine driver, to slacken or stop the train.
I have said that the guard's van is fitted with a frictional driving apparatus
similar to that provided for the engine driver. This is however put in action by
means of a hand lever which brings the endless chains to tension in order to set the
break chain barrel in action. So soon as the break chain is tightened up, the crank
lever on the rock shaft will be caused to open the steamway to the top of the
piston, and thereby apply the breaks as before mentioned. When this is effected,
the guard will move back his lever, and lock it in its normal position.
The breaks I propose to support above their respective wheels by means of links
and rods standing out from bell-crank levers.
These crank levers connect by means of a rod at their lower end with swinging
arms pendent below the carriages and carrying guide pullies.
The break chain is led along the train from end to end thereof over fixed guide
pulleys in a serpentine direction. When therefore the break chain is wound up
from either end of the train the tension put upon it will lift the swinging arms
which carry the pendent pulleys, and thereby draw down the breaks upon the
wheels; the slackening of the break chain will allow the swinging arms to drop,
and thereby raise the breaks out of contact with the wheels.
In order to provide for the putting on of the breaks of the several carriages in
the event of the break chain being severed by reason of the severance of the train,
certain of the swinging arms which carry the pendant break chain guide pulleys
are provided with a means of gripping the chain and securing the loose ends thereof
against the pull of the friction apparatus at either end of the train, and thereby
ensuring the break action in the several parts of the train.
The gripping surfaces of these swinging arms are kept out of action by tho
tension of the break chain; but as soon as it becomes slack by severance the clip
will fall and grip the chain firmly, thereby holding the breaks which have been
thrown into action by the undue strain put on the break chain firmly in contact
with the wheels.