Improved Contrivances for Closing Railway-carriage Doors by Means of Compressed Air or Vacuum.
Year: 1890

page_text: Date of Application, 11th Sept., 1890
Complete Specification Left, 8th Dec., 1890-Accepted, 10th Jan., 1891
PROVISIONAL SPECIFICATION.
Improved Contrivances for Closing Railway-carriage Doors by
Means of Compressed Air or Vacuum.
We, EDWARD THUNDERBOLT at present residing at No. 31 Forest Street
Collingwood near Melbourne in the Colony of Victoria Engineer and JAMES
FULTON of Trenery Crescent Abbotsford near Melbourne aforesaid Engineer, do
hereby declare the nature of this invention to be as follows:-
The essential feature of this invention is the employment of what we call a "door-
closing cylinder," which is mounted upon the framework of the carriage in any
convenient position, and is provided with a sliding piston having a piston rod.
The end of a length of chain or rod is secured to the end of said piston rod,
and said chain or rod is connected by lengths of chain to each of the doors of
the carriage.
The said "door-closing cylinder" is in communication through an air pipe with
a compressed air reservoir connected with a pump worked by the engine or van axle.
This said air "reservoir" is fixed in some convenient position on the guard's van,
and said compressed air pipe is preferably arranged on the van door frame, and is
fitted with a three-way valve whereby the guard may at will either release or apply
the air pressure to the door closing cylinder, thus enabling him to close or release
all the doors under his control without leaving the van.
We provide an adjustable safety valve on the air reservoir, in order to regulate
the amount of pressure employed therein and thereby the rapidity with which the
doors can be closed, thus ensuring that passengers will not be injured by being
crushed by the doors, and at the same time all objectionable slamming of the doors
will be avoided. It will be obvious that the pressure in the door-closing cylinder
can, if desired, be maintained while the train is in motion.
Instead of employing compressed air for operating our improved door-closing
contrivances, we may reverse the door-closing cylinder and piston, and work on
what is known as the " vacuum principle," that is, we may connect said cylinder
to a vacuum pump, and cause the atmospheric pressure to close the doors.
Dated this Fifth day of August One thousand eight hundred and ninety.
COMPLETE SPECIFICATION.
Improved Contrivances for Closing Railway-carriage Doors by
Means of Compressed Air or Vacuum.
We, EDWARD THUNDERBOLT, at present residing at No. 31 Forest Street,
Collingwood, near Melbourne, in the Colony of Victoria, Engineer, and JAMES
FULTON, of Trenery Crescent, Abbotsford, near Melbourne aforesaid, 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 been devised for the purpose of providing some simple and
inexpensive means whereby the whole of the doors in a railway train can be
simultaneously closed and kept so by the mere turning of a cock, and by which
they can be simultaneously and instantly released by the opening of a valve.
We accomplish this by means of air pressure acting on a piston in a cylinder, the
rod of which piston is connected by suitable intermediate gear with a series of
lever arms, one for each door, which lever arms are simultaneously operated so as
Pine 8d1

page_text: CIUSO
the doors by their pressure or to release them from such pressure, as the
case may be, by the action of the guard or other person in charge of the train.
We provide each carriage with one of these cylinders and pistons, and we connect
each of these cylinders with a main supply pipe which provides the pressure or
vacuum as the case may be, such pressuro or vacuum being produced by any approved
means.
Referring to the accompanying drawings, which are in illustration of our
invention :-
Figure 1 represents a side elevation of the two ends of a railway carriage fitted
with our invention.
Figure 2 is a plan of the said two ends of the said railway carriage, illustrating the
doors at the right hand end thereof closed and those to the left open.
Figure 3 is an elevation of the end of a railway carriage fitted with our improved
contrivances for closing its doors, which latter are shown as open on the right and
closed on the left.
Figures 4 and 5 are respectively a side elevation and a plan of a certain detail
which we will hereinafter describe.
Figures 6 and 7 are respectively a vertical central section and a plan of the upper
end of the door-closing cylinder illustrating the means employed for admitting air
into and out of it, as hereinafter described.
Similar letters of reference indicate the same parts in all the figures.
A represents an air cylinder containing a piston B, whose piston rod b is connected
by chains or rods C, running the whole length of the carriage, and short lengths of
flexible chain D to a series of quadrants E, secured each upon the upper end of a
vertical spindle F from whose lower end projects an arm G whose outer end is pro-
vided with a small india-rubber pad or block H, arranged to bear against the
surface of one of the doors I of the carriage whenever pressure is applied to the
piston B.
The compressed air for operating this piston may be obtained by any suitable
ineaus, such for instance as a reservoir in connection with the brake air pipes, or by
an independent air pump driven from one of the axles of the guard's van, or the said
piston may be operated by a vacuum created by an ejector on the locomotive. The
chains C are secured to a collar upon the piston rod b after having been passed under
sheaves or pulleys e-c on the upper end of the cylinder A. The said chains Care
passed over adjustable pulleys cc on the edge of the roof, and are then preferably
connected to rods (such as are shown at C in Figure 5) arranged to slide lengthwise
of the carriage. The opposite ends of these sliding chains or rods are provided with
counter-balance weights J whose tendency is to always draw the said sliding rods or
chains Cinto their normal positions, and so admit of any of the doors being opened
at will.
In order to regulate the speed at which the air will be enabled to escape from the
upper end of the air cylinder A, and therefore the rate at which the doors can be
closed, we provide a number of small holes a¹ in the upper end of said cylinder, as
shown in Figures 6 and 7, and provide the said holes with small screw plugs a²,
which can be removed at will, an inlet valve a³ being provided to admit the air into
such cylinder freely when it is required to open the doors.
In the event of a vacuum being used instead of a direct pressure the same
contrivances may be used as are hereinbefore described, save and except that the
vacuum must be produced above the piston instead of the pressure being supplied
below it. It will of course be understood that the details of our invention may be
altered or varied without departing from its nature and essence. For instance,
ropes or cords may be substituted for the chains C and so on through the whole
of the apparatus described.
The manner of employing our improved contrivances for closing railway carriage
doors is as follows: Compressed air is admitted into the cylinder A through the
pipe a, by the guard or other official operating a three-way valve arranged in any
convenient position on the train, thereby raising the, piston B and drawing in the

page_text: chains C. By this means a pull will be exerted upon the short lengths of chain or
other flexible material D whereby the quadrants E and projecting arms G will be
drawn inwards, whilst at the same time the said arms will close the doors, and of
course will hold them closed, as illustrated at the right hand side of Figures 1 and 2,
until the pressure in the cylinder is released, when any of the said doors may be
readily opened at will, as illustrated at the left hand side of the said figures.
By this means it will be obvious that it will be impossible for any person to
open a door carelessly before the train is at rest at the platform, neither will people
be liable to fall from a railway carriage whilst the train is in motion. Moreover,
the noise caused by the sudden closing of doors at busy railway stations will be
avoided although at the same time provision is made for closing any of the doors
independently of our contrivances, if desired, whilst the train is standing in a
station, but after the pressure is turned on to the door-closing cylinder, all the
doors will be held closed until the guard or other official again releases the said
doors from such pressure.
Moreover it will be readily understood by all persons skilled in the art to which
our invention relates that it does not necessitate the alteration or interference with
the construction of the rolling stock in any way neither does it injure it, whilst
at the same time it is readily attached to or removed from such rolling stock.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what
we claim is :
First. In contrivances for closing railway carriage doors the combination of hinged
levers G, one for each door, with a piston rod of an air or vacuum cylinder (such
as A) connected by any suitable intermediate gear for the purpose of closing and
keeping closed such doors and for releasing them when required by the action of the
piston rod of such cylinder, substantially as herein described and explained.
Second. In contrivances for closing railway carriage doors the combination with an
air cylinder (such as A) secured upon the end of a railway carriage, and fitted with a
piston (such as B) of chains (such as C-D) connected to quadrants (such as E)
mounted upon spindles whose lower ends are provided with outwardly projecting
arms (such as G) arranged to bear against said doors, substantially as and for the
purposes specified and as illustrated in our drawings.
Dated this Twenty-fifth day of October One thousand eight hundred and ninety.
במדדהד
0
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicants.