Year: 1887

page_text: Date of Application, 12th Apr., 1887
Complete Left, 11th Jan., 1888
Complete Accepted, 17th Feb., 1888
I, ROBERT WILLIS of 48 Lime Street in the City of London, Merchant and
Commission Agent, do hereby declare the nature of this invention to be as follows:-
The object of this invention is more especially to provide a speed indicator for
indicating the speed of locomotives which can be placed on the weather board in front
of the driver, and which will show at a glance the speed at which the engine is running
and which in addition can without alteration be applied to any engine whether its
wheels be large or small.
To indicate the speed I cause a rapid to and fro movement to be given to a
diaphragm when the engine is running. By this movement of the diaphragm I cause
a rapid to and fro flow of air through an air passage leading from a chamber in rear of
diaphragm. This rapid to and fro flow of air I employ to draw air through a small nozzle
which is made to project into the air passage at right angles to it. From the rear end
of the nozzle I lead a pipe to the interior of a vertical glass or other indicator tube
which dips at its lower end into a bath of liquid-so that when air is drawn through
the nozzle a partial vacuum is formed in the indicator tube and liquid drawn up
it from the liquid bath-thereby indicates the speed as the higher the speed the better
the vacuum that will be obtained.
into
To give this to and fro motion to the diaphragm I attach it at its centre to one
end of a rod the opposite end of which is coupled to a crank or eccentric on a revolving
shaft.
For indicating the speed of a locomotive I drive this shaft by causing a wheel fixed
upon it to be kept bearing against the circumference of one or other of the locomotive
wheels so that it is made to revolve at the same speed as though it were running on
the railway rails and consequently it is immaterial whether the locomotive wheel be
of large or small diameter, and I lead a small pipe from the rear end of the nozzle
above mentioned to the indicator tube which may as above mentioned be placed just
in front of the driver. The pipe need only be of very small diameter its length within
reasonable limits will be immaterial as the only effect of lengthening the tube is
slightly to retard the action of the indicator and not in other respects to alter its
indication.
CA
11007
CARPMAEL & Co.,
Agents for the Applicant.

page_text: I, ROBERT WILLIS of 48 Lime Street in the City of London, Merchant and
Commission Agent 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 :-
The object of this invention is more especially to provide a speed indicator for
indicating the speed of locomotives which can be placed on the weather board in front
of the driver, and which will show at a glance the speed at which the engine is running
and which in addition can without alteration be applied to any engine whether its
wheels be large or small.
To indicate the speed I cause a rapid to and fro movement to be given to a
diaphragm when the engine is running. By this movement of the diaphragm I cause
a rapid to and fro flow of air through an air passage leading from a chamber in
rear of the diaphragm. This rapid to and fro flow of air I employ to draw air through
a small nozzle which is made to project into the air passage at right angles to it. From
the rear end of the nozzle I lead a pipe to the interior of a vertical glass or other
indicator tube which dips at its lower end into a bath of liquid so that when air is
drawn through the nozzle a partial vacuum is formed in the indicator tube and liquid
drawn up into it from the liquid bath thereby indicates the speed as the higher the
speed the better the vacuum that will be obtained.
To give this to and fro motion to the diaphragm I attach it at its centre to one
end of a rod the opposite end of which is coupled to a crank or eccentric on a revolving
shaft.
For indicating the speed of a locomotive I drive this shaft by causing a wheel fixed
upon it to be kept bearing against the circumference of one or other of the locomotive
wheels so that it is made to revolve at the same speed as though it were running on
the railway rails and consequently it is immaterial whether the locomotive wheel be of
large or sinall diameter, and I lead a small pipe from the rear end of the nozzle above
mentioned to the indicator tube which may as above mentioned be placed just in front
of the driver. The pipe need only be of very small diameter its length within reasonable
limits will be immaterial as the only effect of lengthening the tube is slightly to retard
the action of the indicator and not in other respects to alter its indication.
In the drawing hereunto annexed I have shewn apparatus constructed as above
described adapted for being driven by an endless band from any revolving wheel.
Figure 1 is a side elevation and Figure 2 a vertical section of the apparatus.
Figure 3 is a vertical section on a larger scale of the diaphragm chamber and
diaphragm.
A is the diaphragm which passes across the upper part of a cylinder B that forms
the base of the apparatus-Ú a rod passing from the centre of the diaphragm to an

page_text: eccentric on the spindle D-E a band pulley fixed on the spindle and by which the
spindle can be driven from any revolving wheel-F is a chamber above the diaphragm
from this there is an opening into one end of a passage G, the opposite end of the
passage being open to the outer air--H is a small tube at right angles to the passage G
and projecting downwards into it-I is a vertical tube into which the upper end of the
tube H opens and which is itself open at the top-J is a glass tube surrounding the
tube I-its upper end is hermetically closed and its lower end is immersed in a small
cistern K filled with liquid-usually with colored water.
When the spindle D is rotated the partial vacuum caused in the small tube H by
the to and fro movement of the diaphragm produces a corresponding partial vacuum
in the upper part of the glass indicator tube J and liquid is thereby drawn into the
up
lower part of this tube from the cistern K. The height to which it rises depending
upon the vacuum and this depending upon the speed at which the spindle is driven.
To permit of adjustment of the apparatus the small tubo H is carried by a scrow plug
by turning which the lower end of this tube can be set nearer to or further from the
central line of the passage G as may be required. L is a guard tube surrounding
the glass indicator tube J and with a vertical slit in it through which the tube can
be seen.
When the apparatus is to be used for indicating the speed of a locomotive the
spindle, the diaphragm, the chamber F, passage G and small tube H projecting into it
may be separate from the indicator portion of the apparatus and be carried in such a
manner that the periphery of the pulley E can be made to bear against the periphery
of any of the wheels of the locomotive whilst the indicator portion of the apparatus can
be placed on the weather board in front of the driver-and the two parts be connected
by a pipe passing from the outer end of the tube H to the lower end of the vertical
inner tube of the indicator.
The way in which the indicator portion of the apparatus is constructed to indicate
the vacuum produced in the tube H by the to and fro movement of the diaphragm
may be considerably varied the arrangement shewn in the drawing is however very
suitable for the purpose. The indicator apparatus may also if desired be so constructed
as to record the speeds attained at various times as will be well understood.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is :-
1. A speed indicator in which air is alternately drawn and forced along a tubular
passage by a rapid to and fro movement imparted to a diaphragm and a partial vacuum
thereby produced in a tube which projects or opens transversely into the passage and
in which the vacuum obtained is indicated by a suitable indicator substantially as
described.
2. The construction of speed indicators substantially as herein before described and
llustrated in the drawing annexed.
Dated this 11th day of January 1888