IMPROVEMENTS IN CONTINUOUS BRAKES
Year: 1884

page_text: I HARRY RYLANCE HAIGH of 3 Arboretum Square Derby in the County of
Derby Engineer do hereby declare the nature of my invention for IMPROVEMENTS
IN CONTINUOUS BRAKES and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement:-
My invention consists in an improved form and arrangement of a valve or
valves, applicable in particular to that form of Automatic continuous brake
described and shown in Patent Specifications N° 946 of 1878 and No 593 of 1879
(and now commonly called or known as the "Clayton-two minute leak off break")
and is for preventing this particular form of brake from wholly leaking off when
not required, without destroying the principal advantages claimed for that form and
arrangement of brake, which are, that by means of the small hole admitting air
into the reservoir gradually after the brake on the train is applied, the vacuum
therein is thereby reduced, and the pressure of the brakes upon the wheels decreases
as the train approaches the stopping place.
This advantage of that brake is obvious, for it is well known that after a brake
has been applied with full force at high speed the friction of the brake blocks upon
the wheels increases rapidly as the speed of the train decreases; and this gradual
reduction of pressure on the brake blocks greatly diminishes the jerking and
unpleasantness felt towards the end of rapid stops, and also prevents the skidding
of the wheels which is a great advantage-Also the reduction of vacuum which
by means of the leak hole takes place in the reservoir and pulling on side of the
piston during the time the brake is applied and the train is stopping, enables the
engine driver to take the brake off again quickly and easily, as he has only to raise
a vacuum on the pulling off side of the piston equal to the reduced vacuum
remaining on the pulling on side.
My improved form and description of valve, combined with the form and
arrangement of the continuous brake apparatus shown and described in the Patent
Specifications above referred to, I have invented for the purpose and with the object
of preserving and maintaining the advantages mentioned in the above paragraph,
and also to accomplish the great advantage of preventing that form and description
of brake from leaking off altogether when not required to do so, as my improvement
will allow the pressure to leak away or reduce say from 20 inches of vacuum down
to 14 or 12 inches, and then cease; and retain that amount in the reservoir and on
the pulling on side of the piston, which, in case a passenger train became separated,
will be sufficient to hold it on any incline for any length of time.
In order to make my improvements fully understood I will now describe them
as shown in the accompanying drawing Fig : 1.

page_text: The valve casing A has within it the flexible diaphragm B which is firmly
secured at the edge by the protective covering C being screwed tightly upon it;
the stem d with the ball D at the top forms a valve and is attached to the
diaphragm B with screw nuts and washer as shown; the spring F is for the purpose
of closing the valve D and is made of sufficient strength and adjusted to resist the
atmospheric pressure on the diaphragm when acting against 12 or 14 inches of
vacuum (or whatever amount may be found most desirable) inside the casing A;
the hole g and the passage G lead to the reservoir or vacuum chamber and to the
'pulling on side of the brake piston; the passage H leads to a hole through the
cylinder cover thence to the pulling off side of the brake piston and the train pipe;
the ball I is an ordinary vertical ball valve; E is a small leakage hole between
passage H and passage J; the bottom end of the stem & when the valve D is seated
enters the hole K in the cover C for the purpose of protecting the diaphragm from
any possible injury.
I fix the valve casing A to the underside of the brake cylinder cover as shown
in Fig 2 with the passage H under the hole through the said cover, and with the
passage G under the hole into the reservoir; and the action of the arrangement is as
follows; the engine driver by the use of the ejector on the engine exhausts the air
along the train pipe from the bottom side of the brake piston and through the ball
valve I and passage G from the reservoir or vacuum chamber and pulling on side
of the brake piston, also by the hole g from L inside the casing A; and when the
vacuum in the reservoir and on both sides of the brake piston and in the casing A
is 20 inches, the atmospheric pressure on the diaphragm B overpowers the spring F,
lifts and opens the valve D which remains open until after the brake has been
applied, but when the brake is applied, which is done by the engine driver letting
in air to the underside of piston, the ball valve I remains seated, but air
immediately begins to leak through the small hole E and the opened valve D into
the space L, and thence through the hole y and passage G into the reservoir, and
continues to reduce the vacuum therein until it comes down to 14 or 12 inches
when the power of the spring F overbalancing the then pressure of the atmosphere
on the diaphragm B closes the valve D and prevents any further leakage taking
place thus preserving the remaining 12 or 14 inches of vacuum in the reservoir
which will be ample for subsequent applications of the brake, or for holding a train
on any incline in case of its accidental separation.
Having now particularly described and ascertained the nature form arrangement
and purpose of my said Invention and in what manner the same is or may be
applied to and combined with that form of automatic continuous brake which
I have referred to in this Specification I declare that what I claim is
1st The particular form device and arrangement and combination of valve or
valves substantially as described and shown in Fig 1 of the accompanying
drawing.
2nd The particular form device and valve arrangement substantially as described
and shown in Fig 1 of the accompanying drawing applied to and combined
with those continuous brakes arrangements substantially as set forth in
Patent Specification No 593 of 1879 referring in particular to Figs 4 and 5
of the drawing accompanying that Patent Specification.
D
1 L
1004