IMPROVEMENTS IN VALVES FOR BREAK APPARATUS WORKED BY FLUID PRESSURE
Year: 1879

page_text: LETTERS PATENT to George Westinghouse, junior, of No. 20, Southampton
Buildings, in the County of Middlesex, for the Invention of "IMPROVEMENTS
IN VALVES FOR BREAK APPARATUS WORKED BY FLUID PRESSURE."
Sealed the 26th August 1870 and dated the 14th June 1870
PROVISIONAL SPECIFICATION left by the said George Westinghouse at the
Office of the Commissioners of Patents on the 14th June 1879.
"
GEORGE WESTINGHOUSE, junior, of No. 20, Southampton Buildings, in the County
of Middlesex. IMPROVEMENTS IN VALVES FOR BREAK APPARATUS WORKED BY
FLUID PRESSURE.'
In the Specifications of Patents granted to me for break apparatus worked by
fluid pressure, I have described certain forms of valves whereby the pressure is
brought into and out of action on the break pistons, and auxiliary reservoirs
connected to the break cylinders become charged. My present Invention relates
to an improved construction of such valves which is of the following character:-
The valve casing has four passages into it, one from the pipe communicating
throughout the train, which I will term the supply passage; one to the auxiliary
reservoir, which I will term the reservoir passage; one to the break cylinder,
which I will term the cylinder passage; and one to the outer air, which I will
term the exhaust passage. The supply passage opens into a cup chamber where
moisture or grit is collected; above this chamber and communicating with it is a
cylindrical compartment fitted with a piston having a rod extending upwards.
There is a notch at the upper part of the cylindrical compartment, such that when
the piston is at the upper part of its stroke fluid can leak through this notch to
the space above the piston. The upper side of the piston is formed as a valve to
seat on a seating above, and at the edge of this valve is a notch permitting a
passage of fluid when the valve is seated. As there are a number of valves for the
several break apparatus throughout the train, and it is of advantage that these
should be equally supplied, the notching of the valve above described regulates
the passage
of fluid to each apparatus independently of any irregularity of leakage
past the piston of the valve. The piston rod has on one side a long notch in which
is fitted a D slide free to move some distance within the notch, and this D slide is

page_text: pressed by a light spring against a cylindrical facing through which there are ports
to the cylinder and exhaust passages. In the body of the D slide there is a longi-
tudinal passage having a side opening towards the port face, and in this passage is
a valve attached to the piston rod so as to move with it. On the opposite side of
the compartment containing. the D slide is the reservoir passage. The valve casing
is preferably made of cast iron lined in the working parts with hard brass, gun
metal, or other material not liable to rust. The operation of this valve arrange-
ment is as follows:-When the communicating pipe is charged with fluid under
pressure the piston is pressed up, seating its valve, and moving up the D slide so as
to bring the cylinder and exhaust passages into communication by the D cavity of
the slide. In this condition a portion of the fluid from the supply passage leaks
through the notches past the piston and its valve into the upper compartment of
the valve box, and thence by the reservoir passage to charge the auxiliary reservoir,
whilst at the same time fluid passes out from the break cylinder as exhaust, and
the breaks are taken off. When the pressure in the communicating pipe is some-
what reduced, the piston being subject to the greater pressure in the auxiliary
reservoir descends past the notch in the cylinder, and by its farther descent moves
the D slide downwards closing the communication from the cylinder to the exhaust,
and at the same time opening the valve in the D slide. In this condition fluid can
pass by the passage in the D slide from the auxiliary reservoir to the break
cylinder, putting on the breaks gently. When the pressure in the auxiliary
reservoir is thus reduced to a little below that in the communicating pipe, the
piston moves a little up, closing the valve in the D slide, and so preventing further
passage of fluid from the reservoir to the cylinder. In this condition the breaking
power can be very delicately regulated by slight changes of pressure in the com-
municating pipe. When the pressure in the pipe is considerably and rapidly
reduced, the piston descends rapidly, moving down the D slide to its lowest position
so as to uncover the cylinder port, whereby fluid is freely admitted from the
auxiliary reservoir to the break cylinder, causing the breaks to be applied with
full force. I have above described the valve apparatus as applied when compressed
air or other elastic fluid is employed to work the breaks. When rarefied air is
employed, the valves are similarly arranged in an inverted condition. When
water or incompressible fluid is employed, a like arrangement of valves is applied
in connection with a loaded accumulator which takes the place of the auxiliary
reservoir.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Westinghouse in the Great Seal Patent Office on the 29th
October 1879.
GEORGE WESTINGHOUSE, Junior, of No. 20, Southampton Buildings, in the
County of Middlesex. "IMPROVEMENTS IN VALVES FOR BREAK APPARATUS
WORKED BY FLUID PRESSURE."
In the Specifications of Patents granted to me for break apparatus worked by
fluid pressure, I have described certain arrangements of valves whereby the
pressure is brought into and out of action on the break pistons, and auxiliary
reservoirs connected to the break cylinders become charged. My present Invention
relates to an improved valve apparatus for this purpose, whereby I am enabled not
only to apply the breaks with full force when required, but also to moderate their
force so as to regulate the speed of trains on inclines, or in other conditions where
partial breaking is necessary. I will describe my improved apparatus with
reference to the accompanying Drawing, which represents a vertical section of the
valve box and valves. The valvebox A may be made of cast iron lined in its
working parts with brass or other metal not subject to rust. The lower part B
constitutes a receptacle for moisture or grit. Into this receptacle there is a passage
C connected to the pipe which communicates throughout the train, and from the
receptacle B there is a free passage into a cylindrical compartment D which is
fitted with a piston E. The upper side of the piston is formed as a conical valve,
which when the piston rises seats itself on a coned seating F formed in the cover
above. A notch d is cut at the upper part of the cylinder D in such a position
that when the piston E is at the upper end of the cylinder, fluid can leak past the
notch & into the space above the piston; from this space it can leak by a notch f
cut on the edge of the piston valve into the upper part of the valve box, and flow
thence by a passage G to the auxiliary reservoir. As the notches f on the several
valves throughout the train can be made very nearly equal, the charging of the
several auxiliary reservoirs is equalised notwithstanding that there may be irregu-
larities of leakage past the edges of the pistons E, or through the notches d. The
piston E has a rod H extending upwards, and guided in the upper part of the
valve box. One side of this rod is notched out, and in the notch is a slide K,
which has certain freedom of movement in the notch. It is pressed by a spring k
against the cylindrical face of the valve box in which are two ports, the one L
leading to the break cylinder, and the other M opening to the outer air. In a hole
in the body of the slide K. there is fitted a rod N, which at its upper end is reduced
in diameter and coned as a valve, and at its lower end is attached by a pin n to
the piston rod H. The upper valve end of this rod N fits a seating in a passage O
leading to the face of the slide. When the valve N is unseated there is passage for
fluid through a hole o under the valve seating past the valve N to the passage O.
The operation of this valve arrangement is as follows:-When the pipe communi-
cating throughout the train is charged with compressed air, the piston E is forced
up to the top of the cylindrical space D. Air leaks past the piston by the notch d,
and past the seating F by the notch f, and flows by the passage G to the auxiliary
reservoir. At the same time the slide K is raised, so that the cavity in its face
makes communication between the ports L and M, and air issues from the break
cylinder, relieving the pressure therein so that the breaks are taken off. When
the pressure in the communicating pipe is somewhat reduced, the piston E is forced
downwards by the greater pressure of the air in the auxiliary reservoir. The
slide K being thus drawn down closes the communication between L and M, and the
valve N becoming unseated, air from the reservoir flows by the passages o and O
into the break cylinder, until the pressure above the piston E becomes a little less
than that below it, whereupon the piston E moves a little upwards, closing the
passage O by seating the valve N. In this condition the breaking power can be

page_text: very delicately regulated by slight change of pressure in the communicating pipe.
When the pressure in the communicating pipe is considerably and rapidly reduced,
the piston E descends rapidly moving down the slide K so as to uncover the port L,
whereby air from the auxiliary reservoir flows freely into the break cylinder,
causing the breaks to be applied with full force.
The valve apparatus above described as being applied to breaks worked by
compressed air is obviously applicable when other fluid under pressure is employed
to work the breaks. When water or other liquid is used a loaded accumulator is
employed intead of the auxiliary reservoir, as may be readily understood. Some-
times instead of working the breaks by compressed air, they are worked by the
pressure of the atmosphere acting against rarefied air, in which case there is a
partial vacuum maintained in the auxiliary reservoir and usually in the communi-
cating pipe. A like valve arrangement with suitable invertions is applicable to
breaks worked in this manner.
Having thus described the nature of my Invention and in what manner the
same is to be performed, I claim,―
The construction of valves for governing the operation of breaks worked by
fluid pressure, as herein described with reference to the accompanying Drawing.
In witness whereof, I, the said George Westinghouse, junior, have hereunto set
iny hand and seal, this Twenty-seventh day of September, in the year of our
Lord One thousand eight hundred and seventy nine.
GEO WESTINGHOUSE JB (L.S.)