IMPROVEMENTS IN THE MEANS AND APPARATUS FOR WORKING BREAKS ON RAILWAY 5 TRAINS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Edward Tyer at the Office of the
Commissioners of Patents on the 31st July 1877.
EDWARD TYER, of No. 4, Old Street, Finsbury, in the County of Middlesex.
"IMPROVEMENTS IN THE MEANS AND APPARATUS FOR WORKING BREAKS ON RAILWAY
5 TRAINS."
My Invention relates to means and apparatus whereby the oscillations, horizontal
or vertical, or both, of a railway carriage in relation to its wheels and axles are
utilised in accumulating power for the purpose of working the breaks attached to
such carriage. I cause these oscillations to actuate a pump or pumps for the
compression or exhaustion of air or other fluid contained in a reservoir, in such
manner that when it is desired to apply the breaks, there is a store of pressure
ready for their immediate application. For this purpose I mount on the carriage
a lever, one arm of which has a roller nearly bearing on or against one of the wheels
or axles of the carriage, or a collar on the axle, and the other arm works a piston in
the cylinder of a pump, in the bottom of which cylinder is also fitted a second
piston, which in its normal position is pressed inwards against a stop by an adjust-
able spring. I pack both these pistons with cup leathers having their lips turned
in the same direction, so that they act as suction and discharge valves respectively.
The end of the cylinder beyond the second piston communicates with a reservoir on
the carriage, into which reservoir air is compressed by every stroke of the lever
resulting from an oscillation of the carriage, the spring piston forming the bottom
of the pump allowing for variations of stroke due to variations in the oscillation.
I divide this reservoir into two unequal compartiments, the smaller one communi-
cating with the pump, and the larger one communicating with the smaller com-
partment by a passage or passages provided with two valves. One of these valves
is loaded by a weight or spring, and admits air from the smaller compartment into
the larger, when the pressure in the former exceeds the load on the valve. The
other valve which is not loaded admits air from the larger compartment to the
smaller, when the pressure in the latter falls below that in the former.
From the smaller compartment a pipe provided with a three-way cock or valve
leads to the break-working apparatus, which consists of cylinders fitted with pistons
or of extensible vessels, such as bellows or flexible bags constructed and connected
Price 1

page_text: by break gearing to the break blocks in any known manner, so that when com-
munication is opened to the reservoir the breaks are put on.
In the ordinary or normal condition of the three-way cock or valve, these
cylinders or flexible vessels are in free communication with the outer air, and
weights or springs keep the break blocks retracted from the wheels; but when the
three-way cock or valve is shifted, then the communication with the outer air is
closed, and communication is made with the reservoirs, whereupon the compressed
air entering the cylinders or vessels moves the pistons, or distends or contracts the
vessels, and so causes the break blocks to be applied to the wheels. As the air is
always supplied from the smaller compartment of the reservoir, the pressure in this
is rapidly got up by the oscillations of the carriage and pump, so that the breaks
can be applied even when the carriage has travelled only a short distance; but in
the course of a longer travel of the carriage, the larger compartment also becomes
charged, and as it contains a considerable store of the compressed air, it serves to
supply the smaller compartment for effecting a number of successive applications of
the breaks.
There may be more than one cylinder or extensible vessel for working the breaks
on each carriage, and in this case I connect them all by branch pipes with the one
three-way cock or valve.
In order to work simultaneously these cocks or valves on several carriages of the
train, I provide a cord or chain connected from carriage to carriage, and passing
round pullies fixed to weighted arms that work the cocks or valves, so that when
this cord or chain is pulled either forwards or backwards at any point, the several
cocks or valves are shifted so as to put on the breaks of the several carriages; and
when the cord or chain is slacked out these cocks or valves are shifted back to their
normal position by the weighted arms as above described, so as to take off the
breaks. In this manner, by extending the cord or chain throughout the train,
breaks may be applied to all the wheels thereof, by a pull of the communicating
cord or chain from the engine, or from a guard's van, or other part of the train.
In order to provide for keeping the breaks on when a train becomes divided by
accident, I arrange a spring or weighted stop or secondary lever to each of the
weighted arms that work the cocks or valves in connection with a catch, so that
when these arms are subjected to an unusual strain, such as that which will break
a communicating cord or chain on the division of the train, they are moved beyond
their usual distance; or the secondary levers are moved so that the catches engage
the arms and retain them in the position for keeping the breaks applied, notwith-
standing the fracture of the cord or chain.
In the above described apparatus the oscillations are utilised for compressing air.
It may be readily understood, however, that similar apparatus is applicable when
the oscillations are employed to effect the rarefaction of air in a reservoir, the
atmospheric pressure in that case causing the movement which applies the breaks.