AN IMPROVED APPARATUS FOR TRANSMITTING SIGNALS BY PNEUMATIC. PRESSURE
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by James Leetch at the Office
of the Commissioners of Patents, with his Petition, on the 15th
February 1868.
I, JAMES LEETCH, of Birmingham, in the County of Warwick; do
hereby declare the nature of the said Invention for "AN IMPROVED
APPARATUS FOR TRANSMITTING SIGNALS BY PNEUMATIC. PRESSURE," to be as
follows:-
The said Invention relates to signalling apparatus in which whistles
at the points in communication are caused to sound by pneumatic
pressure in tubes connecting the said whistles.
The said Invention consists chiefly in the novel construction of a
joint or coupling for connecting and disconnecting separate lengths or
sections of the said tubes in the employment of a peculiar self-closing
mouth piece, and in the combination of the said joint and mouth piece
with the tubing and other parts of a signalling apparatus.
My improved joint is a short tube of metal, wood, or other material
made of such a diameter that the flexible tubing fits tightly over the
same and formed with a collar or ring over which the end of the tubing

page_text: is drawn. When my improved apparatus is employed for transmitting
signals from one part to another in a railway train I prefer to provide
each carriage with these joints to which pieces of flexible tubing are
attached, the said pieces of tubing being connected when the train is
made up by another joint which is formed with a collar or bead near
each end. This intermediate joint allows the tubes attached to any
two. carriages to be instantly connected or disconnected without the
delay or inconvenience arising from the use of screw couplings or other
similar fastenings for the tubes. When employed to form the commu-
nication between the guard and driver of a train the tubes need only
be provided with mouth pieces upon the engine and guard's van, but
when it is desired to provide means of communication between the
passengers and the guard it will be necessary to furnish at least one
mouth piece for each carriage. These intermediate mouth pieces must
be so formed and arranged that one will not at any time prevent the
communication between the other mouth pieces and the guard's whistle..
For this purpose I construct each of such mouth pieces with a hinged
valve, which by means of a spring or other suitable device is rendered
self-closing when the mouth piece is not being used. Each carriage
is preferably furnished with a metal tube which is of the proper length
to extend a little beyond the ends of the carriage, each extremity of
the said tube being provided with my improved joint or coupling.
The collar or bead on the said joint is preferably made semicircular
in its outline, so that the flexible tube can be readily drawn over the
same without being injured by any sharp or square corners.
A part
of the joint outside of the said collar is made taper to allow it to be
readily inserted into the end of the flexible tubing. The portions of
india-rubber or other flexible tubing attached to the ends of the metal
tube on each carriage are made of convenient length to adapt themselves
to the play of the buffers. The portions of flexible tubing are intended
to remain permanently connected with the metal tubes but if required
may easily be removed from the same. The joint which connects the
two portions of the flexible tubing between the carriages forms the
coupling for connecting and disconnecting the said flexible tubing
when the carriages are coupled or uncoupled. By the use of this
intermediate joint, which renders it unnecessary to remove the flexible
tubing from any carriage in detaching the same from a train, the
possibility of finding a carriage unprovided with a connecting tube is
prevented.

page_text: Instead of forming the communication between the two ends of the
train by means of alternate portions of metallic and flexible tubing
I sometimes use a tube formed entirely of india-rubber, gutta percha,
or other flexible substance. In this case I make such tube of sufficient
length for the greatest number of carriages for which it will be used,
and when the train consists of a less number of carriages the extra
length of tubing may be coiled up in the guard's van. To effect the
communication between the passengers and guard I provide the tube
with branch pieces extending into the different compartments of the
carriages, each of these branch pieces being furnished with one of my
improved self-closing mouth pieces. The valve for closing the aperture.
of the mouth piece is made to fit air-tight over the same, and is hinged
at one side of the mouth piece, the spring being so formed and arranged
as to allow the said valve to be readily opened when required but to
close immediately when released.