IMPROVEMENTS IN COMMUNICATING FROM ONE PART OF A RAILWAY TRAIN TO ANOTHER
Year: 1853

page_text: nov yover COLCCIE LIVE
time prescribed by the Act.)
PROVISIONAL SPECIFICATION left by William Frederick Green-
field at the Office of the Commissioners of Patents, with his
Petition, on the 16th November 1853.
I, WILLIAM FREDERICK GREENFIELD, of Ipswich, in the County of
Suffolk, Clerk, Master of Arts, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN COMMUNICATING FROM ONE PART OF A
RAILWAY TRAIN TO ANOTHER " to be as follows:-
A. THE OBJECTS PROPOSED.
1. To enable the guard to convey a signal to the driver.
2. To enable one guard to convey a signal to another.
3. To afford a self-acting means of signalling such an accident as
the running off the line or uncoupling of a carriage.
B. THE MEANS PROPOSED.
The signal, a gong or other noisy instrument, placed on the tender
(or engine), with a spring tongue to be touched by a toothed wheel set
in motion-by a rod running the length of the tender, and having at its

page_text: other extremity a cylinder firmly fixed, and another loosely attached to
the former by a screw thread, and capable of revolving easily upon the
rod. Round these cylinders are coiled two ropes, the ends passing
downwards on opposite sides; that on the loose cylinder being so placed
that its tension, if the other fast cylinder be desired to turn in the
opposite direction, may unloose the screw and cause the loose cylinder
o revolve in the opposite direction to the fixed cylinder (of course, if
there be tension only on one cylinder the two will move together).
The ropes (or chains) from these cylinders pass under two pullies, and
thence to ropes (or chains) depending from similar cylinders at t e end
of a rod which runs the length of the adjoining carriage. The pullies
are fixed to plates (heavy), which rest on a frame formed of two racks
placed in a plane perpendicular to the end of the carriage. A wheel is
placed between the racks, having its lower circumference toothed, and
firmly fixed to a cylinder (or cone), whose diameter (or smallest
diameter) is that of the wheel. Round this cylinder (or cone) is coiled
a rope (or chain), the end of which is joined to that of another on a
similar cylinder (or cone) at the end of the adjoining carriage, the racks
and plates being here also similar. The same kind of apparatus is to be
at each end of every carriage. The rods may be placed inside or outside
the carriages, provided they are so placed that they will revolve easily.
It is best that the whole apparatus be placed in the middle of the end
of the carriages. In the case of trucks the rod may be placed at the
bottom of one side, the rest being in the centre, and the motion
communicated by a belt or rope from the cylinder over the pullies to
that at the end of the rod.
C. THE METHOD OF ACTION.
Suppose the carriages to have the distance between them increased
by being put in motion, going up an incline or other cause, the toothed
wheels being set in motion by the ropes on the cylinders move the
racks upwards, so letting loose from the pullies a length of rope equal
to the circumference through which the cylinder revolves, that is, equal
to the length of rope uncoiled from the cylinder. Thus no action on
the rods takes place, and no signal consequently is nossed.

page_text: Suppose the carriages have the distance between them diminished,
the racks descend by their own weight, and turning the cylinder, so
recoil the rope which was uncoiled in the ascent.
If the carriages separate to a greater distance than a circumference
of the cylinder (each having revolved through half a circumference),
which should be the greatest distance to which they may be allowed
without danger to separate, the wheels still revolving will allow the
rack to descend with it, thus causing a tension on the ropes coiled round
the upper cylinders and turning them, and with them the others along
both directions of the train. Thus a spontaneous signal will be given.
It is manifest that if any of the upper cylinders be turned a signal will
be passed, and that too instantaneously, because the ropes are always
in gear.