Improvements in Apparatus for Actuating Railway Brakes by Air Pressure or Vacuum.
Year: 1890

page_text: Date of Application, 23rd May, 1890
• omplete Specification Left, 20th Feb., 1891-Accepted, 4th Apr., 1891
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Actuating Railway Brakes by Air
Pressure or Vacuum.
I, ERNST HARTMANN, of No. 26, Jacobistrasse, in Düsseldorf, Kingdom of
Prussia, German Empire, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention has for its object to enable railway vehicles having brakes of any
known kind to be employed in trains together with vehicles having brake apparatus
worked either by compressed air or by vacuum. For this purpose such first named
vehicles are provided with an additional conduit pipe having at each end of the
vehicle a flexible extension with coupling devices, for coupling the pipe with the
air pressure or vacuum pipes of adjoining vehicles. The connections are provided
with a valve or cock for shutting off the communication. Each such pipe is con-
nected to each end of a double acting air pressure or vacuum cylinder, such
connections being provided with a shut off cock or valve.
The piston rod of each cylinder is connected in any suitable way either directly
or indirectly to the brake apparatus of the vehicle, so that the brakes can be
operated either by the means provided for that purpose on the vehicle or by the
air pressure or vacuum introduced into the said cylinder, so as to act upon the
piston.
Thus in applying this invention to a railway vehicle having that kind of brake
apparatus in which the brakes are put into operation by bringing a friction roller
or drum into frictional contact with a roller or drum fixed upon one of the wheel
axles, so as, by the rotation of the first named friction roller or drum, to wind up a
cord or chain which draws on the brake blocks, I connect the piston rod of the
before mentioned cylinder to the axis of the said moveable friction roller or drum
and I connect the said cylinder at each end by a branch pipe to the said conduit
pipe, and at the middle of the cylinder I provide a passage whereby a communica-
tion can be established between the two ends of the cylinder when the piston is in
the middle position.
The ordinary gear for actuating the friction drum has a slotted connection with
the rod connecting the piston rod with the friction drum, so that the one can operate
independently of the other.
When the brakes are to be operated by air pressure, the branch pipe connecting
the front end of the cylinder with the conduit pipe is open. The air pressure then
enters the front end of the cylinder, forcing back the piston until this arrives at the
middle position, when the air pressure will pass through the before mentioned passage
to the other end of the cylinder, and the piston will then be in equilibrio, holding
the friction drum out of contact.
For applying the brakes, air pressure is allowed to escape from the pipe, and
consequently also from the front end of the cylinder, so that the air pressure at the
back end will now force forward the piston and bring the friction drum in contact.
When the brakes are to be worked by vacuum, the front branch pipe is closed, and
the back one is opened; the vacuum of the pipes will now be communicated to the
back end of the cylinder, causing the piston to move backward to the middle position
as before, whereupon the said passage will communicate the vacuum to the front end
of the cylinder.
On admitting atmospheric air into the pipe for applying the brakes, such air
pressure, acting at the back end of the cylinder against the vacuum existing in the
front end, will force the piston forward, bringing the friction drum in contact as
before.

page_text: Instead of acting on the friction drum directly from the piston rod, the latter may
act upon intermediate gear such as a rack and pinion, &c.
In applying the invention to a vehicle having ordinary screw hand brakes, a
cylinder arranged in the same way as above described in connection with the conduit
pipe, has its piston rod connected by a rod to the brake levers so that on operating
either with air pressure or with vacuum in the same way as before described, the
piston is made to draw or push the brake blocks into action. The connection
between the hand screw brake gear and the brake rods is made a slotted one so that
this can be operated independently of the air pressure or vacuum brake.
Dated this 23rd day of May 1890.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Actuating Railway Brakes by Air
Pressure or Vacuum.
I, ERNST HARTMANN, of No. 26, Jacobistrasse, in Düsseldorf, Kingdom of
Prussia, German Empire, 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 has for its object to enable railway vehicles having brakes of any
known kind to be employed in trains together with vehicles having brake apparatus
worked either by compressed air or by vacuum. For this purpose such first named
vehicles are provided with an additional conduit pipe having at each end of the
vehicle flexible extensions with coupling devices, for coupling the pipe with the air
pressure or vacuum pipes of adjoining vehicles. The connections are provided with
a valve or cock for shutting off the communication. Each such pipe is connected
to each end of a double acting air pressure or vacuum cylinder such connections
being provided with a shut off cock or valve.
The piston rod of each cylinder is connected in any suitable way either directly
or indirectly to the brake apparatus of the vehicle, so that the brakes can be
operated either by the means provided for that purpose on the vehicle or by the
air pressure or vacuum introduced into the said cylinder, so as to act upon the
piston.
On the accompanying drawing the said invention is shewn applied by way of
example to two systems of brake apparatus.
Figs. 1 and 2 shew the application to brake apparatus of known construction in
which the brakes are applied by bringing a friction wheel or drum into frictional
contact with a wheel or drum fixed on one of the wheel axles.
Figs. 3 and 4 shew the same applied to a hand screw brake.
Referring to Fig. 1, the piston 6 of the brake cylinder a is connected by a rod c
with loop d to the rod e of the friction drum brake in such manner that the putting
in and out of action of the latter in the ordinary manner is not interfered with.
The cylinder a is connected at each end by branch pipes provided with cocks f, y,
to the train pipe T. For working the brake apparatus by air pressure, the air is
admitted at the piston is then moved back from the forward position I to the
position I I until the channel h is uncovered thereby, whereupon the air pressure
passes through to behind the piston.
When the brakes are to be applied, the air pressure is discharged from the train
pipe, and the air pressure contained in the space X behind the piston causes a rapid
forward motion of the piston from II to I, the passage H being sufficiently small
to prevent any material escape of pressure into Y.
The friction wheel k is thus brought in contact with the axle drum 1, and causes
the brakes to be applied in the manner well known with such apparatus the piston

page_text: being made to close the channel
and thus keep the brakes applied.
so as to stop the escape of air pressure from X,
On admitting air pressure to the train pipe again, the piston bis again moved
backwards, thereby either taking off or easing the brakes.
When working the arrangement of Fig. 1 by vacuum, the piston b is moved
from I to II by opening the cock g communicating with the vacuum pipe, and
closing the cock f, thereby producing exhaust in X behind the piston.
When the piston uncovers the passage h, the air is also exhausted from Y in front
of the piston. When the brakes are to be applied, air is admitted to the train
pipe in the usual manner and, entering the space X, causes the piston to move
forward from II 'to I, the vacuum in Y assisting the air
pressure.
The friction wheel is again brought in contact with the drum h so as to apply
the brakes, as before.
The reverse action is produced by again exhausting the train pipe.
If a carriage with brake apparatus as described is shunted from a train working
with air pressure brakes to one with vacuum brakes, then cock f is closed and cock g
is opened, as described.
If on the other hand the carriage is transferred from a train with vacuum brakes
to one with air pressure brakes, then g will be closed and f opened.
The stroke of the piston is limited on the one hand by abutting against the
cylinder cover at I on the forward motion, and on the other hand, by the shoulder
of the loop d abutting against the stuffing box.
Fig. 2 shews a modified arrangement of the brake cylinder a, in which the piston
rod c is connected to the rod e of the friction brake wheel by a bell crank lever e¹,
while the ordinary hand or other gear of the brake is made to work the rod and
lever e el through a pinion gearing with a rack on the piston rod.
It will be obvious that the transmission of the motion of the piston b to the
brake wheel may also be effected in various other ways. The cylinder a can, if
required be provided with a branch pipe leading to a cock or valve in any
compartment of the carriage for enabling the brakes to be applied from such
point.
In the arrangement shewn in elevation and sectional plan at Figs. 3 and 4 the
cylinder a with piston passage and cocks and y, is connected to the train
pipe T as before, the piston being in the position shewn when the brakes are off.
The piston rod c is connected directly to the rod d that actuates the brakes by its
connection at 0; 77 is the ordinary gear for actuating the brakes by the hand
screw.
If now a carriage with this brake gear is combined with a train having air
pressure brake apparatus, the cock is opened and f is closed. The compressed
air enters at 9 in the space X and forces the piston forward until this uncovers
the passage, whereupon the air pressure will also pass through this passage to the
space Y. and the piston will then be held in the equilibrium position shewn at
Fig. 4.
For applying the brakes, the air pressure is discharged from the train pipe and
space X, causing the pressure in Y to force the piston backward, thereby closing
passage h, and applying the brakes.
On admitting air pressure again through g, the piston is forced forward and the
brakes are taken off or their pressure is more or less reduced.
If the carriage is coupled with a train having vacuum brakes, cock f is opened
and is closed. The vacuum in the train pipe exhausts the air from Y, and, when
the piston uncovers passage h, also from X.
For applying the brakes air is admitted to the train pipe and to Y thereby
causing the piston to move to the left and both close the passage and apply the
brakes.
On again exhausting the train pipe and space Y, the brakes will be taken off or
their pressure reduced.
The connecting pin i of the piston rod c and brake rod d is made with some play

page_text: in its connections, in order to allow of the brakes being applied by the hand gear
independently of the other gear; or such slotted connections might be made in the
hand gear.
The distance apart of the two openings of the passage is so arranged that
even after some wear of the brake blocks has taken place, causing an increased
stroke of the piston, the rear opening of the passage will not be closed too
soon, so that sufficient air pressure or sufficient vacuum can be produced on
the rear side for effecting the return motion of the piston for taking off the
brakes.
Instead of admitting air pressure by means of cock 9 or vacuum by means of
cock into the cylinder spaces X and Y, so as to cause the piston to exert a pull
for applying the brakes, the cock 9 may be made to admit vacuum to X and the
cock air pressure to Y, so as to cause the piston to exert pressure for applying
the brakes, should this be required.
In order always to have the same brake power with a varying air pressure or
vacuum, means may be provided for connecting the brake rods to the brake lever
at a greater or less distance from the fulcrum; thus the lever may be provided
with a sliding connection or with a series of holes as indicated at Fig. 5, in
which the connecting pin o of the brake rod can be adjusted to various
positions.
A carriage provided with brake apparatus such as above described can be
coupled with carriages having either the same kind or a different kind of air
pressure or vacuum brakes without in any way interfering with the action of the
fatter.
The said brake apparatus acts automatically so that on one or more carriages,
becoming detached, causing a rupture of the train pipe, both parts of the train will
be automatically braked, in the well known manner.
Having thus described the nature of this invention, and in what manner the same
is to be performed, I claim :-
An air pressure or vacuum brake apparatus for actuating any description of
brakes of railway trains, consisting of a cylinder a with piston 6 connected to
the brake gear, and with a by-pass passage h and cocks f, g, connecting each end
of the cylinder with a train pipe, the said parts being arranged and operating
substantially as described with reference to the drawing, whereby a carriage with
such brake apparatus can be coupled to and be operated in conjunction with other
carriages having either the same or a different kind of brake apparatus.
Dated this 20th day of February 1891.
ABEL & IMRAY,
Agents for the Applicant.