Improvements in and relating to Brake Mechanism for Railway Vehicles.
Year: 1893

page_text: Date of Application, 11th July, 1893
Complete Specification Left, 11th Apr., 1894-Accepted, 30th June, 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to Brake Mechanism for Railway
Vehicles.
I, WOLFGANG SCHMID of The Centralbahnhof, München in the Empire of
Germany, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to brakes for railway cars and locomotives and is especially
designed as an improvement in the railway-brake set forth and claimed in my
Letters Patent of the United Kingdom, No. 18237, dated December 13, 1888,
although it may be applied to brakes of other descriptions.
The object of the said invention is to simplify the mechanism set forth in said
Patent and to substitute, for the brake-rope or cord, the agency of compressed air
or the suction of rarefied or exhausted air.
The railway-brake constructed under the said Patent No. 18237 has hitherto
been controlled by a brake-cord or rope, the said cord being wound upon a windlass,
whereby all the brakes of the system were made inoperative, or unwound therefrom
or loosened to operate the brakes.
This mode of operation by means of a brake-cord was, however, only adapted
for short trains, and the present invention, therefore, consists in providing the
brake set forth in the above British Patent, and other mechanical brakes, such as
gravity-brakes, buffer-brakes and the like, with a controlling mechanism actuated
by pneumatic pressure through the agency of compressed air, gas, or suction air or
gas, or both combined. And the said invention consists in such other features,
means and combinations of parts as will be hereinafter described.
One of the principal features of my invention consists in two air-pots or receivers
provided with diaphragm-pistons, that is to say, pistons mounted on flexible or
elastic diaphragms or membranes arranged one in each air-pot.
These air-pots each consist of two conical or flaring sections connected by bolts
or screws passing through the continuous peripheral flanges. A flexible or elastic
diaphragm or membrane of india-rubber, leather or other air-tight material, is
clamped between the two flanges of each air-pot, and upon opposite sides of each
diaphragm are mounted two piston-halves, which are secured to a common piston-
rod, the piston-rod being guided in the necks or thimbles of the air-pots. The two
piston-halves are clamped together air-tight and it will thus be seen that a
complete isolation of the two bodies of air on either side of the piston is secured,
while, at the same time, all frictional resistance to the movement of the piston is
avoided.
When compressed air is employed as the brake-controlling agency, air-pot No. 1
is employed. As soon as compressed air is admitted into the air-pot on the left
side of the piston, the said piston is forced to the right. The air-pot- is provided
with an air-steering valve consisting of a casing, a piston and a slide. The bottom
of the casing is provided with an air-inlet. This steering-valve has the important
office of permitting the complete escape of compressed air from the air-pot as soon
as the excess of pneumatic pressure in the air-pipe and the main air-conduit of
the entire train is diminished by as much as from one-fourth to one-half of an
atmosphere. The purpose of this steering-valve is to enable brakes of the
character set forth in Patent No. 18237 of 1888 to be applied to trains equipped

page_text: with Westinghouse and other air-brakes, and the manner of controlling these
brakes by the engineer is precisely the same for both.
When compressed air is admitted through the inlet of the casing, the piston and
the slide are pushed forward. This causes an air-duct to be opened and the air
enters this air-duct, having first opened a valve, which is pressed against the valve
seat with a slight pressure. From the air-duct, the air enters the chamber and
thence passes through a second air-duct to the air-pot where the excess of pressure
urges the diaphragm-piston forward until it reaches the other end of the air-pot, in
which position it is held by the excess of pressure, whereby the brake, preferably
of the construction set forth in my aforesaid Patent No. 18237 of 1888 is applied
to and held against the wheel.
In order to set the brake into action, the excess of pressure in the air-pipes must
be reduced from one-fourth to one-half atmosphere. The valve closes immediately,
and the excess of pressure in chamber causes the piston with the slide to be forced
backwards until it bears against the lid of the chamber.
This causes the slide first to cover the duct No. 2 whereupon the recess of the
said slide registers with two further ducts Nos. 3 and 4. The compressed air hence
escapes from the air-pot through the duct No. 3 into the recess of the slide and
thence through the duct No. 4 provided with an outlet at right angles, into the
open air. As soon as the excess of pressure has escaped from the air-pot, the
piston returns to its first position, whereby the worm-wheel brake is caused
to act.
The operation when applying suction or exhaust air is as follows:-
The air-pot No. 2 is connected with the suction air pipe or exhaust pipe which
extends through the entire train to the locomotive. By an air-suction device or
air exhaust on the locomotive, a vacuum is produced throughout this exhaust pipe
and in all the air-pots communicating therewith. The pistons are thereby drawn
to the right and the worm-wheel brakes are kept from operating as long as the said
pistons remain to the right. As soon, however, as the vacuum is destroyed, the
piston recedes and the worm-wheel brake is allowed to act.
The arrangement thus described results in an automatic action of the vacuum.
The vacuum may, however, be applied also to a non-automatic system. In the
latter case, the worm-wheel brake must be held out of action by a weight and it is
caused to operate when a vacuum is generated.
The compressed-air and exhaust-air arrangements are both simultaneously
combined with the worm-wheel brake in the following manner :-
The common piston-rod connecting both pistons is provided at an intermediate
point with an opening for the reception of one end of a lever, keyed or fastened on
a shaft. Upon the same shaft is fastened a second lever, No. 2, provided with a
counterweight, and also a lever No. 3 connected by a connecting-rod with a hanger
or rocking arm, pivoted or journaled in a bearing. The rocking arm carries a
friction roller, and it serves to either cause the said friction roller to engage with
an axle roller or to hold it away from the said axle roller, thereby either causing
the brake to act or to remain inactive.
A farther lever, No. 4, is fixed to the shaft, which lever is connected by link with
another lever, No. 5, which, in turn, is connected at its upper end with a brake-rod
and a chain. The other end of the brake-chain is secured to the chain-drum or
windlass in the interior of the worm-wheel cylinder by a pin or bolt, thereby
enabling the chain to be wound upon the drum when the brake is to be applied.
The worm-wheel cylinder of the present application consists of a cylindrical
casing having a bottom cast thereto, and may contain precisely the same mechanism
as shown in the said Patent. Upon the shaft, passing vertically through the
cylinder, is secured or keyed a worm-wheel. There is a chain-drum loose upon said
shaft, and is provided at top and bottom with annular and concentric ribs which are
adapted to fit exactly into two corresponding annular grooved parts. These three
parts are firmly pressed together by means of a lever and rod and counterweight,
and hence form a powerfully acting friction clutch. When, therefore, the shaft is

page_text: rotated by the worm-wheel, the chain-drum is caused to rotate also, and winds up
the brake-chain, whereby the brake is applied.
When the pressure of the counterweight is relieved and the chain-drum and
grooved parts of the clutch are separated somewhat, the chain-drum is revolved
back to its original position by the tension of the chain, and hence the brake is
opened. The raising and lowering of the counterweight is effected by the shaft
and a clutch coupling.
The power for operating the brake is derived from the rotating axle of the car
or other vehicle, the rotation of the same being transferred to a shaft by means of
wedge-shaped friction-rolls. This shaft is connected with an endless screw by a
universal joint, the endless screw meshing with and rotating the worm wheel.
The manipulation of this mechanical brake is effected by a very small quantity
of compressed or exhaust air, and the source of power costs nothing, being derived
from the car wheels.
Supposing the piston of the compressed air-pot No. 1, be standing to the left,
the brake is then applied, inasmuch as the wedge-shaped friction-rolls are in engage-
ment, whereby the power of the revolving axle of the car or other vehicle is
transmitted to the brake-chain. The air-pot No. 1 is then empty of air in this
position of the parts.
If, now, compressed air having a tension of one atmosphere is admitted through
the inlet pipe, the piston is thrust to the right, the requisite lever, being also
moved to the right, causes the friction rolls to become disengaged. At the same time,
the clutch coupling causes the counterweight to be raised somewhat, whereby the
brake-chain is again unwound and the brake released. During the motion of the
vehicle, the atmospheric pressure in the air-pot No. 1 is at least one atmosphere.
When the engineer desires to apply the brake, he reduces the pressure in the air-
pipe, whereby the air is exhausted from the air-pot and the brakes are brought into
operation.
The above describes a compressed-air brake-applying device, as it operates when
using an air-escape valve. This air-escape valve is necessary when it is desired to
employ worm-wheel brakes with a simple air brake device, and at the same time a
rapid application of the brakes is desired. For long freight trains, however, the
too rapid application of brakes is injurious and often results in the separation of
the trains in braking.
The compressed-air brakes are, moreover, unsuitable to freight trains on account
of the great number of complex valves, pistons and slides which require continuous
examination, repairs, lubricating and taking apart of the pistons and slides. When
the revision of these parts has been discontinued for only three months, the action of
the compressed air-brakes becomes so uncertain that separation of trains of only
ten cars may occur. Inasmuch as the freight cars in great number continuously
become "vagrants," which may run for years on every possible strange road, it is
impossible to employ thereon any complicated brake arrangement.
For freight trains, my invention, therefore, contemplates the use of a compressed-
air brake-applying device embracing only the air-pot No. 1, with diaphragm and
omitting the air-escape valve, the air-pot being connected with the air-pipe,
thereby eliminating the valves, slides and pistons connected therewith. Under this
arrangement, an excess of pressure of one atmosphere is employed, and no air
escapes by reason of leaks in the pistons and valves, as is the case in the compressed
air-brake.
D
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.

page_text: COMPLETE SPECIFICATION..
Improvements in and relating to Brake Mechanism for Railway
Vehicles..
I, WOLFGANG SCHMID of The Centralbahnhof, München in the Empire of
Germany, 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 brakes for railway cars and locomotives and is especially
designed as an improvement in the railway-brake set forth and claimed in my
Letters Patent of the United Kingdom, No. 18237, dated December 13, 1888,
although it may be applied to brakes of other descriptions..
The object of the said invention is to simplify the mechanism set forth in said
Patent and to substitute, for the brake-rope or cord, the agency of compressed
air or the suction of rarefied or exhausted air.
The railway-brake constructed under the said Patent No. 18237 has hitherto been
controlled by a brake-cord or rope, the said cord being wound upon a windlass,
whereby all the brakes of the system were made inoperative, or unwound therefrom
or loosened to operate the brakes.
This mode of operation by means of a brake-cord was, however, only adapted for
short trains, and the present invention, therefore, consists in providing the brake
set forth in the above British Patent, and other mechanical brakes, such as gravity-
brakes, buffer-brakes and the like, with a controlling mechanism actuated by
pneumatic pressure through the agency of compressed air, gas, or suction air or gas,
or both combined. And the said invention consists in such other features, means
and combinations of parts as will be hereinafter described.
In the accompanying drawings :-
Figure 1 represents a side elevation, partly in section, of so much of a brake
mechanism as is necessary to illustrate the preferred embodiment of my invention,
Figure 2, a plan view thereof,
Figures 3 and 4, detail views to be hereinafter explained.
One of the principal features of my invention consists in two air-pots or receivers
provided with diaphragm-pistons, that is to say, pistons mounted on flexible or
elastic diaphragms or membranes arranged one in each air-pot.
These air-pots a and a¹ represented in longitudinal vertical section in Figure 1,
each consist of two conical or flaring sections connected by bolts or screws passing
through the continuous peripheral flanges as best shown in Figure 4. A flexible or
elastic diaphragm or membrane b, b¹ of indiarubber, leather or other air-tight material,
is clamped between the two flanges of each air-pot, and upon opposite sides of each
diaphragm are mounted two piston-halves c, c', which are secured to a common
piston-rod d, the piston-rod being guided in the necks or thimbles d' of the air-
pots a and a'. The two piston-halves are clamped together air-tight and it will
thus be seen that a complete isolation of the two bodies of air on either side of the
piston is secured, while, at the same time, all frictional resistance to the movement
of the piston is avoided.
When compressed air is employed as the brake-controlling agency, the air-pot a
is employed. As soon as compressed air is admitted into the air-pot a on the left
side of the piston c, which is located to the left in Figure 1, the said piston is forced
to the right. The air-pot a is provided with an air-steering valve consisting of a

page_text: casing e, a piston f and a slide g. The bottom of the casing is provided with an
air-inlet i. This steering-valve has the important office of permitting the complete
escape of compressed air from the air-pot a as soon as the excess of pneumatic
pressure in the air-pipe i and the main air-conduit of the entire train is diminished
by as much as from one-fourth to one-half of an atmosphere. The purpose of this
steering-valve is to enable brakes of the character set forth in Patent No. 18237 of
1888 to be applied to trains equipped with Westinghouse and other air-brakes,
and the manner of controlling these brakes by the engineer is precisely the same
for both.
Figure 4 serves to more clearly illustrate the operation of the air-steering valve.
When compressed air is admitted through the inlet of the casing, the piston f
and the slide g are pushed forward to the position indicated in Figures 1 and 4.
This causes the air-duct 1 to be opened and the air enters this air-duct, having
first opened the valve 2, which is pressed against the valve seat with a slight pressure.
From the air-duct, the air enters the chamber 3 and thence passes through a second
air-duct 4 to the air-pot a where the excess of pressure urges the diaphragm-piston c
forward until it reaches the other end of the air-pot, in which position it is held by
the excess of pressure, whereby the brake, preferably of the construction set forth
in my aforesaid Patent No. 18237 of 1888 is held ready for use.
In order to set the brake into action, the excess of pressure in the air-pipes must
be reduced from one-fourth to one-half atmosphere. The valve 2 closes
immediately, and the excess of pressure in chamber 3 causes the piston f with the
slide y to be forced backwards until it bears against the lid e¹ of the chamber. This
causes the slide g first to cover the duct 4 whereupon the recess of the said slide
registers with two further ducts 5 and 6. The compressed air hence escapes from
the air-pot through the duct 5 into the recess of the slide and thence through the
duct 6 provided with an outlet at right angles, into the open air. As soon as the
excess of pressure has escaped from the air-pot a, the piston e returns to its first
position, whereby the worm-wheel brake is caused to act.
The operation when applying suction or exhaust air is as follows:-
The air-pot a¹ is connected with suction air pipe or exhaust pipe which extends
through the entire train to the locomotive. By an air-suction device or air exhaust
on the locomotive, a vacuum is produced throughout this exhaust pipe and in all the
air-pots al communicating therewith. The pistons c are thereby drawn to the right
and the worm-wheel brakes are kept from operating as long as the said pistons
remain to the right. As soon, however, as the vacuum is destroyed, the piston
recedes and the worm-wheel brake is allowed to act.
The arrangement thus described results in an automatic action of the vacuum.
The vacuum may, however, be applied also to a non-automatic system.
In the latter case, the worm-wheel brake must be held out of action by a weight
and it is caused to operate when a vacuum is generated.
The compressed-air and exhaust-air arrangements are both simultaneously
combined with the worm-wheel brake in the following manner :-
The common piston-rod d connecting pistons c and c¹ is provided at an
intermediate point with an opening for the reception of one end of a lever k, keyed
or fastened on a shaft 1 (see Figures 1 and 2). Upon the same shaft is fastened
a lever m, provided with a counterweight n, and also a lever o connected by a
connecting-rod o' with a hanger or rocking arm o³, pivoted or journaled in a
bearing o. The rocking arm o² carries a friction roller p, and it serves to either
cause the said friction roller to engage with an axle roller q or to hold it away from
the said axle roller, thereby either causing the brake to act or to remain inactive.
A further lever ŕ is fixed to the shaft l, which lever is connected by a link
with another lever ², which, in turn, is connected at its upper end with a brake-
rods and a chain t. The other end of the brake-chain t is secured to the chain-drum
or windlass u in the interior of the worm-wheel cylinder, Figure 3, by a pin or
bolt, thereby enabling the chain to be wound upon the drum when the brake is to
be applied.
"

page_text: •
The arrangement of this drum is clearly illustrated in longitudinal section in
Figure 3 of the aforesaid Patent No. 1823788.
worm-
The worm-wheel cylinder shown in Figure 3 of the present application and
which consists of a cylindrical casing having a bottom cast thereto, may contain
precisely the same mechanism as shown in Figure 3 of the said Patent. Upon the
shaft v. passing vertically through the cylinder, is secured or keyed a
wheel. The chain-drum u is loose upon said shaft v, and is provided at top and
bottom with annular and concentric ribs which are adapted to fit exactly into the
corresponding annular grooved parts u¹ and ². These three parts are firmly
pressed together by means of a lever and rod wow and counterweight w
(Figures 1 and 2), and hence form a powerfully acting friction clutch.
When,
therefore, the shaft is rotated by the worm-wheel, the chain-drum is caused to
rotate also, and winds up the brake-chain, whereby the brake is applied.
When the pressure of the counterweight w' is relieved and the parts u, u', and u²
of the clutch are separated somewhat, the part u is revolved back to its original
position by the tension of the chain, and hence the brake is opened. The raising
and lowering of the counterweight w' is effected by the shaft and a clutch coupling.
on the shaft 7 (see Figure 2). .
t
The power for operating the brake is derived from the rotating axle of the car
or other vehicle, the rotation of the same being transferred to the shaft y Fig. 2, by
means of the wedge-shaped friction-rolls and This shaft is connected with an
endless screw by a universal joint, the endless screw meshing with and rotating the
worm wheel v¹.
9.
p.
The manipulation of this mechanical brake is effected by a very small quantity
of compressed or exhaust air, and the source of power costs nothing, being derived
from the car wheels.
Figure 1 represents the piston c of the compressed air-pot a standing to the left,
the brake is then applied, inasmuch as the wedge-shaped friction rolls P and 7 are
in engagement, whereby the power of the revolving axle of the car or other vehicle
is transmitted to the brake-chain t. The air-pot a is empty of air in this position
of the parts.
If, now, compressed air having a tension of one atmosphere is admitted through
the inlet pipe i, the piston c is thrust to the right, the lever k being also moved
to the right, causes the friction rolls p and q to become disengaged. At the same
time, the clutch coupling a fixed to the shaft causes the counterweight w¹ to be
raised somewhat, whereby the brake-chain t is again unwound and the brake released.
During the motion of the vehicle, the atmospheric pressure in the air-pot a is at least
-one atmosphere. When the engineer desires to apply the brake, he reduces the
pressure in the air-pipe whereby the air is exhausted from the air-pot and the
brakes are brought into operation.
The above describes a compressed air-brake applying device, as it operates when
using an air-escape valve. This air escape valve is necessary when it is desired to
employ worm-wheel brakes with a simple air brake device, and at the same time a
rapid application of the brakes is desired. For long freight trains, however, the
too rapid application of brakes is injurious and often results in the separation of the
trains in braking.
The compressed air brakes are, moreover, unsuitable to freight trains on account
of the great number of complex valves, pistons and slides which require continuous
-examination, repairs, lubricating and taking apart of the pistons and slides.
When the revision of these parts has been discontinued for only three months,
the action of the compressed air-brakes_becomes so uncertain that separation
of trains of only ten cars may occur. Inasmuch as the freight cars in great
number continuously become "vagrants," which may run for years on every
possible strange road, it is impossible to employ thereon any complicated brake
:arrangement.
For freight, trains, my invention, therefore, contemplates the use of a compressed
air brake applying device embracing only the air-pot a with diaphragm and omitting

page_text: the air-escape valve, the air-pot being connected with the air-pipe i, thereby
eliminating the valves, slides and pistons connected therewith. Under this arrange--
ment, an excess of pressure of one atmosphere is employed, and no air escapes by
reason of leaks in the pistons and valves, as is the case in the compressed air-brake.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is-
1. The combination, with a friction brake, of an air controlled brake operating
device, whereby the friction brake is thrown into or out of operation.
2. The combination, with an air pot and a piston, of an elastic diaphragm secured!
to the piston and to the air pot, substantially as set forth.
3. The combination, with an air pot having a thimble, of a piston rod passing
through the thimble, an elastic diaphragm located in the air pot and a pair of
pistons secured one on each side of the diaphragm and attached to the piston rod.
4. The combination, with an air pot having a thimble, an elastic diaphragm.
located in the air pot, a pair of pistons secured to the diaphragm, one on each side
thereof, and a piston rod attached to both pistons, of an air inlet valve communicating
with the air pot, substantially as set forth.
5. The combination, with an air pot, a piston rod opening in one side of the air
pot and a series of air ports in the other side of the air pot, of a piston rod passing
through the piston rod opening, a piston on the end of the piston rod, a slide
valve movable over the ports, a valve rod connected to the valve, a valve operating
piston connected to the valve rod, and means for supplying compressed air above and
below the valve operating piston, substantially as set forth.
6. The combination, with a cylinder having an air inlet at its bottom and a.
by-passage in one side, a valve chest connecting with the cylinder, an air pot.
having a piston rod opening in one side, a series of air inlet ports communicating
with the valve chest, and an air exhaust port communicating with the air, a piston
rod passing through the piston rod opening, a diaphragm in the air pot, and a pair
of pistons secured one on each side of the diaphragm and attached to the piston
rod, of a slide valve movable over the exhaust and inlet ports, a valve operating
piston in the cylinder and connected to the slide valve, and a check valve in the
by-passage, substantially as set forth.
7. The combination, with the car axle, a friction wheel on the axle, a chain
winding drum, a worm wheel attached to the drum, and a worm gear engaging with.
the worm wheel, of a universal joint attached to the worm gear, a swinging lever, a.
shaft journalled in the swinging lever and attached to the universal joint, and a
friction wheel on the shaft and arranged to contact with the friction wheel on the
axle, substantially as set forth.
8. The combination, with a drum shaft, a chain drum loose on the drum shaft,
and a clutch device for locking the drum to the drum shaft, of a clutch lever
connected to the clutch, a friction wheel fixed on the axle, a swinging friction
wheel arranged to contact with the friction wheel on the axle, a shaft, means.
intermediate the shaft and the swinging friction wheel for removing the latter into
or out of contact with the friction wheel on the axle, a counterweighted arm loose
on the shaft and connected to the clutch lever, being provided with a hub having a
stop, and a contact stop fixed on the shaft and arranged to engage the stop on the
arm after the swinging friction wheel has been moved out of contact with the friction
wheel on the axle, substantially as set forth.
9. The combination, with a pair of air pots, a piston in each pot, and a piston.
rod connected to both pistons, of a compressed air pipe communicating with one
side of one air pot, an exhaust pipe communicating with the other side of the
other air pot, and a brake operating device connected to the piston rod, substantially
as set forth.
10. The combination with a pair of air pots, a piston in each pot, a piston rod
connected to both pistons, a compressed air pipe communicating with one side of

page_text: one air pot, an exhaust pipe communicating with the opposite side of the other air
pot and a counterweighted brake operating device connected to the piston rod,
substantially as set forth.
Dated this 10th day of April 1894.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.