INDICATING & REGISTERING AT A DISTANCE THE SPEED OF STEAM AND OTHER ENGINES-VENTILATING MACHINES & AIR CURRENTS
Year: 1884

page_text: HENRY HALL Rainhill-Prescot Mining Engineer do hereby declare the nature
of my invention for INDICATING & REGISTERING AT A DISTANCE THE SPEED OF
STEAM AND OTHER ENGINES-VENTILATING MACHINES & AIR CURRENTS to be as
follows:-
That by gearing a small exhausting Fan to the Engine, the speed of which it is
desired to indicate at a distance, a partial vacuum is set up in a chamber. This
chamber is connected by closed pipes with a (U shaped) water gauge fixed in the
Office of the Works or other convenient place and by means of the varying height
of one leg of water above the other in the water gauge accordingly as the Engine
and consequently the Fan is driven faster or slower and causing more or less
vacuum I am enabled to exhibit at a distance the comparative speed of the Engine.
And I also actually count at a distance the strokes of the said Engine by
means of a small valve on the said closed pipes which valve is so arranged and
geared to the said engine that at every stroke of the engine or every 10th or other
convenient number of strokes the said valve is opened by the engine and outside
air admitted into the pipes destroying the vacuum for a second or two and causing
the water gauge to fall to zero at each admission of outside air or each opening of
the valve, and thus by counting the number of times the water-gauge falls to zero
in a certain period of time I am able to say what is the actual speed at which the
engine is being driven.
I indicate the speed of Ventilating Machines by the same method except that
advantage is taken of the partial vacuum set up directly by the Ventilating Machine
itself without adding a special Fan for the purpose.
1 indicate the speed of Air-Currents by taking advantage of the vacuum set up
by the current itself, the variation of this vacuum and consequently of the speed of
the current being shown by a water-gauge as already described.
The registration of the indications in each case. being done by an ordinary
Indicating Machine worked by clock-work and floats which exhibits the varying
pressures on a diagram and the precise time they occurred.

page_text: I HENRY HALL Mining Engineer Rainhill, Prescot do hereby declare the naturo
of my invention for INDICATING AND REGISTERING AT A DISTANCE THE SPEED
OF STEAM & OTHER ENGINES, VENTILATING MACHINES & AIR CURRENTS and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
That by means of a small Fan geared to the Engine or Machine, the speed of
which it is required to indicate and register, and driven by it at a high speed a
certain amount of vacuum or exhaustion can be set up in a line of closed pipes
reaching from the outlet of the said Fan to an ordinary indicating machine
consisting of a U shaped tube containing water one leg of the tube being closed
and the other has a float inserted and is open to the atmosphere, this float carries a
marking pencil which moves over a dial moved by clockwork the line of pipes
having one end inserted into the closed chamber of the U shaped tube has the
effect of altering the level of the water on which the float rests according to the
amount of vacuum set up by the speed at which the said small Fan is travelling.
The amount of vacuum set up in the line of pipes and consequently the rise and
fall of the float and movement of the marking pencil is constantly proportional to
and dependent on the speed at which the tips of the vanes of the Fan are travelling
and this speed of the Fan being due and dependent on the speed at which the
Engine to be indicated and registered is driven, the line marked by the pencil on
the dial will show any deviation from the regular speed of the Engine and the
hour it occurred, the hours of the day being marked on the revolving dial.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed 1 declare that what
I claim is
An Invention for indicating and registering at a distance the speed of steam and
other ongines, ventilating machines and air currents by gearing a small Fan to the
Engine &c. to be driven by it at a high speed, by which means a partial vacuum is
set up in a line of airtight pipes connected with the outlet of the said Fan and the
closed side of the U shaped tube of the registering machine described.
" 1000