Improvements in Pneumatic Apparatus, applicable for Controlling Compressed Air Brakes and for Preventing Racing in Steam Engines.
Year: 1893

page_text: The decision of the Comptroller-General, of the 9th day of August 1894, allowed,
, under Section 18 of the Patents, &c. Act, 1883, an Amendment of this
Specification.
Date of Application, 21st Jan., 1893-Accepted, 6th May, 1893
COMPLETE SPECIFICATION (AMENDED).
Improvements in Pneumatic Apparatus, applicable for Controlling
Compressed Air Brakes and for Preventing Racing in Steam
Engines.
A communication by FREDERIK ARNOLD HOLLEMAN, of Oisterwijk, in the
Kingdom of Holland, Gentleman.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool and 6, Bank Street, Man-
chester both in the County of Lancaster & 323, High Holborn in the County of
Middlesex, Civil Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention relates to valves for use in connection with compressed air brakes,
whereby these brakes can be transformed into quick-acting brakes; and a part of
the invention, as will be hereinafter shown, can be applied or made use of in steam
engines to prevent their pistons from bolting or racing in case of breakage of the
engine shaft, or of bad weather on steamers, etcetera.
The invention consists, firstly, in the combination of a controlling and discharge
valve with the main and auxiliary reservoirs, the brake cylinder and their
connections of a compressed air brake, the valves being interposed in those
connections; and, secondly, in the construction of the valves as hereinafter
described and illustrated in the accompanying sheets of drawings-
Figures 1-4 of which show a combination of the controlling and discharge
valve for brakes which operate by means of auxiliary air reservoirs ; and
Figures 5-6, the combination of the discharge valve only with the main air
pipe of all kinds of compressed air brakes.
Figures 1, 3 and 4 are longitudinal sections of the valve casing showing the
valves in different positions.
Figure 2 is a partial end view of the casing.
Figures 1A, 1B, 1C and 1 are sections of parts of the valve.
Figures 5 and 6 are longitudinal sections of the valve casing connected to the
main air pipe, showing the discharge valve in its different positions: and
Figures 54, 5 and 5° are sections and a view of parts of this valve.
In Figures 1, 2, 3 and 4:-
'
A, is the valve casing with covers C and C¹ screwed to it, the bosses A' being
provided for such purpose.
The valve casing A has a diaphragm or divisional piece A' with a wide aperture A³,
(clearly seen in Figure 1) which establishes free communication between the
spaces on both sides of the division A². There are in these spaces reciprocating
valves D and E, which are accurately but freely fitted in brass cylinders or
sleeves B B with which the casing is lined.
The valves have grooves D' E', into which enter loosely screw pins A' A' which

page_text: prevent the valves from moving in a rotary direction, packing rings de are
provided to insure a perfect air-tight fit to the casing.
The valve casing and the brass sleeves B B¹ have openings A', 6', A' and A³, by
means of which the former is connected respectively with the auxiliary air reservoir
through A, with the brake cylinder through b', A', and with the main air pipe
through A. Besides these openings, the valve casing has an opening. A closed by
a screw plug for the reception of small quantities of condensed water, which may be
drained therefrom, when desirable, by removing the said screw-plug; and, to the
further opening A, a valve chamber H is applied which contains a valve H¹
having openings H2 H; this valve H is supported by a very sensitive spring
(Figure 1 shows the valve H' in cross section). In the brass cylinder B is a
groove b, by which communication is established between the main air pipe AB
and auxiliary air reservoir through A in the normal position of the valve D
(Figure 1).
The cover C¹ is traversed by an air-tight valve or pine by means of which the
valve E can be moved inwardly.
In a cut out portion of the valve D, there rests a slide D' having a stud, which
projects in into its periphery and by which the slide D is moved simultaneously
with the valve D. Room is left between the slide D' and the valve D, so that the
slide is pressed down by the pressure of the compressed air and slides air-tight over
the apertures A' b' and a.
The slide D has a groove D³ (seen clearly in Figure 1A) which, during the
normal position of the valve (Figure 1) establishes a constant communication
between the brake cylinder and the open air through A', ' and a (Figures 1
and 1^).
In order to attenuate heavy shocks, the valve D has its interior face covered with
leather. Its movement is limited by the abutment of the division A', and by that
of the cover C; it is regulated by the buffer K and the spring N, which is kept
compressed in the interior of the division A' and by the discharge valve E, the
latter valve being continually pressed towards the cover C₁ with sufficient force
to overcome the friction occasioned by both valves D and E and their slides the
ralne E and its slide E³.
The valve E has a hollow extension E supporting and guiding the buffer K,
which enters it when the spring N is further compressed by the movements of the
valves D and E. The valve E has a cut out portion containing a slide E*, which is
provided with an oblong opening E' (Figure 1°) and in its top with a small
opening E, which establishes some communication between the main air pipe and the
space behind the valve E.
The manner in which the valve operates is as follows:-
When compressed air is admitted to the valve casing from the main air pipe, the
valve D is moved toward the cover C and so brought into its first or normal
position, as shown in Figure 1.
The compressed air now passes through the groove 6 and enters the auxiliary
eylinder reservoir by way of the pipe A At the same time, it passes through A³
and E behind the valve E until the equilibrium in the whole valve casing is
established. Slight differences of pressure in the main air pipe and auxiliary
reservoir are equalised without moving the valves D and E, but, when the pressure
in the main pipe becomes reduced or falls below the pressure in the auxiliary
reservoir, the valve D, by reason of the greater pressure of air in this reservoir,
moves towards the buffer K, thus coming into its second position (Figure 3) cutting
off the communication through the groove b between the main pipe A" and the
auxiliary reservoir, and also the passages A' D' a from the brake cylinder to the
open air.
When the reduction of pressure in the main pipe increases is further reduced, the
spring N is compressed by the valve D, which now uncovers the channel A' ', so
that compressed air of from the reservoir enters the brake cylinder in small
quantities, thus applying the brakes slightly.

page_text: As soon as the pressure in the reservoir has been nearly reduced to a pressure
equal to that in the main pipe, the valve D will move back to its second position
(Figure 3) under the influence of the spring N, so that no more air can then enter
the brake cylinder nor escape from it.
By repeating thus the admission of small quantities of compressed air to the
brake cylinder, the brakes. can be applied gradually with any desired amount
of force.
When it is desired to put on the brakes with more speed and energy, the pressure
in the main pipe must be steadily reduced, the valve D will then be moved further
to the right and-comes in into its extreme or third position (Figure 4). The oblong
aperture A is then fully uncovered, and the brake-cylinder-entirely-filled-with
compressed-air-operating the brakes with full force allowing compressed air from the
auxiliary reservoir to enter freely into the brake cylinder until the pressure in A equals
that in the main pipe, when the valve D is again brought into its second position
(Figure 3) by the spring N.
During these operations, the discharge valve E remains inactive in its place, as
the pressure of the small quantity of air behind the valve E is easily reduced
through the passage E³, in the same degree as the pressure in the main pipe is
gradually diminished so that the valve E will not move. When, on the contrary,
the pressure in the main pipe is suddenly reduced, the compressed air behind the
valve E cannot escape in time through the small passage E³, so that both valves
are then suddenly moved towards each other (Figure 4).
The valve D allows air from the reservoir to enter freely into the brake cylinder,
and by the valve E the wide opening Et is brought into connection with A10, allowing
air of from the main pipe to escape in into the open air through A8, A³ E A10, thus
effecting, a speedy discharge of the main air pipe throughout its entire length and.
an accelerated operation of all brakes.
-
The compressed air, which escapes from the main pipe into the open air, may
also be conducted into the brake cylinder.
For that purpose, the valve chamber H, heretofore hereinbefore described, is
screwed on A10. The compressed air passes from A10 through the oblong
openings H3 and by the pipe H³ to the brake cylinder, where it contributes to the
operation of the brakes. A return of compressed air from the filled brake cylinder
to the partially emptied main pipe is prevented by the valve H'.
The automatic operation of the compressed air brakes is greatly increased in case
of accidents by means of the pin or valve c, when the last 2 or 3 millimetres of
traverse of the pressed in buffers of the carriage are used to move a lever in the
direction of the arrow X (Figures 4, 5 and 6). By means of such a lever, the
pin c, being pressed in the opposite direction, moves the valve E inwardly, thus
effecting a sudden discharge of the main pipe through A E A and applying
all brakes with full force before impending shooks-arrive collision of the carriages
takes place.
The manner in which the discharge valve operates for all kinds of brakes, so as
to transform them into quick acting brakes by effecting an accelerated discharge
of the main pipe throughout its entire length, is illustrated in Figures 5-6.
The valve casing A has no controlling valve and is connected to the main air
pipe P by a single connection A⁹.
The same letters of reference indicate the same parts in this valve as in the
combined controlling and discharge valve (of Figures 1-4). V is a vessel to
enlarge the space behind the valve, it has a cock v to draw off the condensed water.
The buffer K is formed in this valve of an abutment of the cover C, by which
the movement of the valve E is limited, the spring N presses it against the said
valve towards the cover (1
The slide E3 is a long one. Figure 5 is a plan view, and Figure 5 a cross
section on the line Y Z of it and of the valve casing A.
Figure 5 is a cross section of the valve H¹ showing the location of the oblong
openings Hand of the pipe H³ to the brake cylinder.

page_text: Figure 5 shows the normal position of this valve, when however the pressure, in
the main pipe P is suddenly reduced, the valve will move to the left by the
pressure of the compressed air behind the valve and in the vessel V and then
uncovers A10, so that compressed air of from the main pipe escapes into the open air
through A E A 10 or to the brake cylinder by the pipe H³, where it contributes to
the operation of the brakes as heretofore hereinbefore mentioned. The valve returns
in a few moments to its normal position, Figure 5, thus allowing the brakes to be
released each time.
Brakes can thus be operated in the ordinary manner with any desired amount of
force without any risk being incurred that they will operate suddenly with full
force against the intention of the driver.
The action of the pin or valve c is the same as heretofore hereinbefore described.
According to the foregoing description of the valve, it will be seen-
a. That, in opposition to other kinds of controlling valves for compressed air
brakes, the quick operation of this valve is not dependent on the quantity of
compressed air from the main pipe :
b. That it operates only in extraordinary circumstances, when the pressure in the
main pipe is intentionally suddenly reduced :
c. That such an involuntary sudden application of the brakes with full force can
only take place on using the heretofore hereinbefore ḍescribed discharge valve in
case of accidents:
d. That the accelerated operation of all kinds of compressed air brakes is
obtained in a simple and cheap way by means of the single discharge valve adapted
to the main pipe without needing any alteration of them or without interrupting
the free communication of the brake cylinder with the auxiliary air reservoir and
the main pipe in the combined valve:
e. That it is able to increase in a high degree the automatic operation of the
brakes in case of accidents.
When the invention is to be applied or made use of in steam engines to prevent
the pistons from bolting or racing, the discharge valve only is employed.
Figure 7 is a longitudinal section of the valve; Figure 7 a vertical horizontal
cross section on the line 1-2 of Figure 7, and Figure 7B a horizontal vertical
section on the line 3-4 of Figure 7, which is a part of the discharge valve showing
location of the valve and the slide located in it.
The valve casing A with covers C and C¹ is connected with one end of
the steam cylinder through A8 and through A10 with the exhaust, it contains the
reciprocating valve E which is accurately but freely fitted in it. This recipro-
cating valve has a groove E into which enters loosely a screw pin A which
prevents the valve from moving in a rotary direction, a packing-ring e is also
provided.
In a cut-out portion at the bottom of the valve rests a slide E³, which covers
in the normal position of the valve the opening A to the exhaust and is
provided with an oblong opening E. In its top the valve has an opening E',
which establishes a communication between the spaces in the valve casing A on
both sides of it.
It has also a valve E capable of opening only in the direction of the cover C
and its the movement of which is limited by a stop E7 fixed to the valve E
(Figures 7 and 7B).
In its normal position, the valve E is pushed against the abutment
cover C by the spring N located in the abutment C³ of the cover C.
of the
Within the spring N is located a buffer K to limit the stroke of the
valve E. The discharge valve so constructed is applied at both ends of the
steam engine,
At each stroke of the engine the end of the discharge valve in the direction
of C is filled with steam through A8 and the valve E®. This steam expands
through E in the same degree as the steam in the engine, so that the valve E
remains inactive, whilst the engine works normally, but as soon as the piston

page_text: commences to bolt or race, the valve E is moved to the left by the pressure of the
excess steam in the end of the discharge valve at C¹ and uncovers the exhaust
port A10, so that steam can escape out of the engine through A8, E', A10, and the
accelerated movement of the piston is prevented.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is :-
1. A discharge valve for compressed air brakes which when the pressure is
suddenly reduced opens the main air pipe and when steadily reduced holds it closed
so that the brakes will be applied in the ordinary manner without any risk of an
involuntary quick and strong action of the brakes substantially in the manner
hereinbefore set forth.
2. In combination with a discharge valve of the kind hereinbefore set forth,.
a controlling valve for brakes which operate by means of auxiliary air reser-
voirs substantially as hereinbefore described and illustrated in the accompanying
drawing.
3. The combination of the discharge valve of the kind hereinbefore set forth.
with the buffers of the carriage substantially as and for the purposes hereinbefore
set forth.
4. In a valve of the kind hereinbefore described, the application of
(a) a groove b in the brass cylinder or sleeve B as and for the purposes set.
forth.
(b) a slide D in the valve D acting as set forth.
5. In a valve of the kind hereinbefore set forth the application to its discharge
portion, of a slide E' and the valve chamber H with its adjuncts as and for the
purpose set forth.
6. The exact construction of the combined controlling and discharge valve
described and illustrated with reference to Figures 1-4 inclusive.
7. The exact construction of the discharge valve described and illustrated with
reference to Figures 5-6 inclusive.
8. The construction of the discharge valves herein before set forth, for the
purpose of preventing the pistons of steam engines from bolting or racing.
Dated this 20th day of January 1893.
WM. P. THOMPSON & Co.,
Agents for the Applicant.