Improvements in or relating to Apparatus for Measuring or Recording the Quantity of Water or other Fluid Passing over a Notch or Sill.
Year: 1893

page_text: Date of Application, 12th May, 1893
Complete Specification Left, 28th Nov., 1893-Accepted, 30th Dec., 1893
PROVISIONAL SPECIFICATION.
Improvements in or relating to Apparatus for Measuring or
Recording the Quantity of Water or other Fluid Passing
over a Notch or Sill.
I, DANIEL LEAN HUTCHISON, 6, Belhaven Terrace, Kelvinside, Glasgow, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
As the quantity of water or other fluid passing over a notch or sill at any
instant may be calculated if the height of the still water or fluid above the notch
or sill be known, then it is possible to construct a cam of such a form that its
coordinates will be proportional to the said height and quantity. In my improved
apparatus a cam of this kind is actuated by a float and a counterpoise weight or by
an equivalent piece of mechanism:-the cam controls a pen or pencil which is
guided in a direction corresponding to the ordinates of the cam-the pen or pencil
draws a curve on a card attached to a revolving drum driven by clockwork or
otherwise this curve will be a continuous record of the quantity of water or other
fluid passing over the notch or sill.
000
COMPLETE SPECIFICATION.
Improvements in or relating to Apparatus for Measuring or
Recording the Quantity of Water or other Fluid Passing
over a Notch or Sill.
I, DANIEL. LEAN HUTCHISON, 6, Belhaven Terrace, Kelvinside, Glasgow,
Civil 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, that is to say:-
My said invention has for its object to produce a continuous record of the
quantity of water or other fluid passing over a notch or sill.
or
In carrying out my invention I cause the continuous record to be traced by a
pen or pencil on a drum turned continuously and uniformly by clockwork
otherwise, the ordinates, parallel to the drum's axis, of the line traced by the pen
or pencil representing on a suitable scale the quantity passing per minute or other
time unit at the time that each point of the line is marked. The movement of the
pen or pencil is derived from the variations in the height of the still water above
the notch or sill, but as the quantity of water passing increases in a greater than
the simple ratio with the height, I interpose a device which suitably modifies the
movement of the pen or pencil and renders it unnecessary to calculate or otherwise
determine the quantities from the heights. I employ a cam to act on the pen or
pencil this cam being moved by means of a cord connected to a float, and being
shaped to move the pen or pencil into positions showing the quantities corresponding
to the various heights of the water. It is convenient to arrange the cam to turn
upon an axis; it can however be arranged to move in a straight or other convenient
direction.
And in order that my said invention and the manner of performing the same may
be properly understood, I hereunto append a sheet of explanatory drawings to he
hereinafter referred to and representing my improved apparatus.
Figure, 1, of the drawings is a front elevation of one modification
apparatus, part of which is shown in side elevation in Figure, 2.
Figure, 33, shows parts of a second modification in front elevation,
of the

page_text: In the modification shown in Figures, 1, and, 2, the apparatus is carried on a
framing, A, placed so that a cord, B, from a float, C, passes directly up to it, the
float being in a compartment in which the water whilst undisturbed is through a
communicating pipe always at the same level as the water which is approaching
and passing over the sill or notch, D. The float cord, B, passes over a pulley, E,
and has attached to its other end a counterpoise, F, the pulley being supported and
arranged to turn about a horizontal axis. The pulley, E, has fixed to its inner
side a cam, G, the edge of which acts on a small roller, H, which is fitted to turn
freely upon a small carriage, or slide, J, and this slide is fitted to move freely up
and down on a pair of vertical guide rods, K, and is partly counterbalanced (if
necessary) by a cord passing over a pulley at the top of the rods, K, to a counter-
poise, L.
A pen or pencil, M. in a holder either fixed to the slide, J, or to the
arbor of the roller, H, has its point in contact with the surface of a vertical drum
or cylinder, P, fixed on a vertical spindle, Q, which is turned at a suitable uniform
rate by clockwork in a casing, R. The pen or pencil, M, may be pressed against
the drum, P, by means of a small weight, N, and a cord, or in any other convenient
way. For receiving the markings of the pen or pencil the drum, P, may have
fresh sheets of paper put on it at suitable intervals.
In the modification shown in Figure, 3, the slide, J, carrying a pen or pencil to
mark on a drum, P, as in the first modification, is moved by a cord, S, which passes
over pulleys, T, and down to a slide, U, moving on vertical guides, V, and carrying
a pulley, W, which is always in contact with the cam, G. The cord, S, passes
round part of the pulley, W, and onto the edge of the cam, G, (which may be
grooved) being fixed at the inner end of the cam, and winding more or less upon the
cam according to the positions the cam is made to take by the rising or lowering of
the float, C.
The shape of the cam, G, in either modification can be determined by geometrical
methods in accordance with formulæ which are well known, and established, being
accepted by civil engineers. The line traced on the drum between any two
points will with the ordinates at those points and a base line, enclose an area which
is measurable (by means of a planimeter for example) and represents the total
quantity of water passing during the interval of time in which the line has
been traced.
By suitably counterbalancing the cam, G, and other parts, by varying the size of
the float, C, and by reducing as much as possible the friction of the working parts
the apparatus may be made very sensitive, and so that the tracing pen or pencil
will show changes of flow practically as soon as they take place.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
In apparatus for measuring or recording the quantity of water or other fluid
passing over a notch or sill, the combination of a float with a cam moved thereby
and shaped to correspond to the quantities of water or other fluid instead of the
simple heights of the float and arranged to move a pen or pencil marking a
uniformly rotating drum, substantially as and for the purposes herein before
'described.
Dated this Twenty-seventh day of Vovember 1902
EDMUND HUNT,
Applicant's Agent.