IMPROVEMENTS IN WATER METERS
Year: 1877

page_text: LETTERS PATENT to Gerard Wenzeslaus von Nawrocki, of the Firm of J. Brandt
and G. W. v. Nawrocki, Civil Engineers and Patent Agents, of Berlin, in the
Empire of Germany, for the Invention of "IMPROVEMENTS IN WATER METERS."
A communication from Richard Bredo, residing at M. Gladbach, in Germany,
Chief Engineer.
Sealed the 10th August 1877, and dated the 14th February 1877.
PROVISIONAL SPECIFICATION left by the said Gerard Wenzeslaus von
Nawrocki at the Office of the Commissioners of Patents on the 14th February
1877.
GERARD WENZESLAUS VON NAWROCKI, of the Firm of J. Brandt and G. W. v.
Nawrocki, Civil Engineers and Patent Agents, of Berlin, in the Empire of Germany.
"IMPROVEMENTS IN WATER METERS." A communication from Richard Bredo,
residing at M. Gladbach, in Germany, Chief Engineer.
This Invention relates to an improved rotary water meter.
All water meters in use up to the present time, as is well known, fulfil their
object very imperfectly, and do not answer even the most moderate claims of
science and mechanics.
A water meter, in order to fulfil the object of measuring water under pressure to
and flowing from the same, must in order to gain its introduction into general use,
in towns furnished with waterworks, fulfil the following conditions :-
1°. The apparatus must give with certainty the right results; the exactness of
its action must not be affected by variation of pressure occasioned by difference
of the velocity of the passing water, nor through any certain uncleanliness of the
water.
2º. The water after having passed through the apparatus must have lost only a
small part of its force.
3º. The whole apparatus must not be complicated, and must be of small bulk,
and the cost of the same must be comparatively low.
40. The duration of the apparatus must be for a great length of time.
Bearing in mind the above necessary requirements the above-mentioned improved
rotatory water meter has been invented; it is of a special and new kind of construc-
tion which at the first glance appears remarkable for its simplity, and on account of
its few working parts.

page_text: Figure 1 of the accompanying Drawings shews a sectional view of the improved
apparatus through the line A, B, and Figure 2 of such Drawings shews a sectional
view thereof through the line C, D.
In a cast-iron or other suitable metal casing A is fitted a drum B made of
sheet metal, which drum, so to speak, acts at the same time both as conduit wheel
and turbine.
The water enters the casing in the direction shewn by the arrows, and con-
tinues its passage, as the arrows indicate, through a rectangular opening at the side
of the drum, to the interior of this latter, passing along its interior circumference,
and strikes against the first partition c, pressing against this partition in the
direction in which the drum revolves, and always passing by way of its circum-
ference to the other partitions c, lastly passing through the hollow axis d by h
out of the drum to the discharge. But as the water at the inner circumference or
periphery of the drum always presses against the eight partitions c the force of the
water will cause the drum to revolve, and the working power will be so much
greater by reason of the same qnantity of water being caused to operate repeatedly
and constantly in the normal direction against the partitions c; therefore in this
case the water operates by its own direct action, and not as in the case of other water
meters by reaction.
This apparatus, being also considered from the point of view of its employment as
a prime mover would shew a very high useful result, as the water presses directly
against the buckets or blades, and its operation is utilized over and over again in
such manner that the whole of the theoretical power (excepting a very small
deduction on account of loss from friction) can be utilized, and given off from the
turbine. But at present the question of utilizing the power given off by the flow
of water is not being considered, but only how to take away the smallest possible
amount of this power in causing the drum B to revolve. The greater the scale on
which the apparatus works the more favourable is it for overcoming any sudden
drawbacks or interruptions that may occur from different causes, and so tend to affect
the exactitude of the measurement of the water. The velocity at which the
periphery of the drum travels will correspond and be proportionate to the speed of
the water passing through the same. The quantity of water is easily ascertained
by multiplying the velocity of the flow of the water by its cross sectional area.
The apparatus only requires the speed of the current of water and the number
of revolutions of the drum to be indicated, and this may be effected by con-
necting the apparatus to a mechanical counter of any ordinary and well-known
construction.
The resistances to be overcome in the working of the drum are chiefly the vis
inertia when the apparatus is set in motion, as also in overcoming friction. No
reactionary force can be given out by the water.
When the discharge cock is opened, in order to prevent a too copious outflow of
water before the drum makes a corresponding number of revolutions, the axis of
the drum is fitted with a'conical valve, such axis, together with the drum, resting
on the closed cone when the apparatus is not in operation. When the discharge
cock is opened the water, in proportion to its velocity, raises the cone, and with it
the axis and drum, so that whilst revolving it also dances on the water, whereby
the facility of operation is much increased, and the drum, in consequence of its
small weight and very little friction, quickly attains the same velocity as the water
passing through it.
When the discharge cock is closed the axis of the drum sinks down, thus causing
the conical valve to close and inducing friction, and stopping the operation of the
apparatus.
When the discharge cock is opened only to a very small extent no water will
flow through, as in such case the weight of the drum acts on the conical valve;
therefore the inexactness of operation caused by the setting in motion and the
stoppage of the apparatus is by this means reduced to a minimum.
In short it may be said that the accompanying water meter is very sensitive in

page_text: its operation, and the results given by its measurement of water are in respect to
exacness, such as reach practical limits; it also fulfils the conditions set forth in
paragraphs 1 to 4.
In the accompanying Drawings the drum of the apparatus has a diameter of
180 millimetres, and a circumference of 0.5652 metres. With the water flowing at
a medium velocity of five metres per second the number of revolutions per second
would be =
9.02, which number is certainly not too high for this improved
apparatus with a sectional flow of 25 millimetres.
5
0-5652
=
A suitable bearing is provided on which the axis of the drum can work up and
down, and at the same time by means of a suitable connection communicate with
the counter. The small stuffing box may be removed, providing the mechanism
for counting the revolutions is fitted so as to be pressure proof.
The axis of the drum is carried at G in such manner that it moves with facility,
and is pressure proof, as the hydrostatic pressure is the same on both sides.
All the dimensions of the before-described apparatus have been so designed as to
provide for a flow of water having a cross sectional area of 25 millimetres, but
such dimensions may be varied as circumstances may require.
Any suitable metal may be used in the construction of this improved apparatus,
which may also be made of any convenient dimensions.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Gerard Wenzeslaus von Nawrocki in the Great Seal Patent Office on
the 14th August 1877.
GERARD WENZESLAUS VON NAWROCKI, of the Firm of J. Brandt and G. W: v.
Nawrocki, Civil Engineers and Patent Agents, of Berlin, in the Empire of Germany.
IMPROVEMENTS IN WATER METERS." (A communication from Richard Bredo,
a person resident at M. Gladbach, in Germany, Chief Engineer.)
it
This Invention relates to an improved rotatory water meter.
All water meters in use up to the present time, as is well known, fulfil their
object very imperfectly, and neither do they answer to the most moderate claims of
science and mechanics.
A water meter, in order to fulfil the object of measuring water under pressure to
and flowing from the same, must in order to gain its introduction into general use,
in towns furnished with waterworks, fulfil the following conditions:-
--
1°. The apparatus must give with certainty the right results; the exactness of
its action must not be affected by variation of pressure occasioned by difference of
the velocity of the passing water, nor through any certain uncleanliness of the
water. 1
2º. The water having passed through the apparatus must have lost only a small
part of its force.
3°. The whole apparatus must not be complicated, and must be of small bulk,
and the cost of the same must be comparatively low.
4°. The duration of the apparatus must be for a great length of time.
Bearing in mind the above necessary requirements the above-mentioned im-
proved rotatory water meter has been invented; it is of a special and new kind of
construction, which at the first glance appears remarkable for its simplicity, and on
account of its few working parts.
Figure 1 of the accompanying. Drawings shews a sectional view of the improved
apparatus through the line A, B, and Figure 2 of such Drawings shews a second
sectional view thereof through the line C, D, and Figure 3 and Figure 4 shew an
elevation and plan of the same.
'
In a cast-iron or other suitable metal casing A is fitted a drum B made of sheet

page_text: metal, which drum, so to speak, acts at the same time both as conduit wheel and
turbine.
The water enters the casing in the direction shewn by the arrows, and continues
its passage as the arrows indicate through a rectangular opening at the side of the
drum to the interior of this latter, passing along its interior circumference, and
strikes against the first partition c, pressing against this partition in the direction
in which the drum revolves, and always passing by way of its circumference to
the other partitions c, lastly passing through the hollow axis d by h out of the
drum to the discharge; but as the water at the inner circumference or periphery
of the drum always presses against the partition c the force of the water will
cause the drum to revolve, and the working power will be so much greater by
reason of the same quantity of water being caused to operate repeatedly and con-
stantly in the normal direction against the partitions c; therefore in this case the
water operates by its own direct action, and not as in the case of other water meters
by reaction.
This apparatus being also considered from the point of view of its employment as
a prime mover (turbine) would shew a very high useful result, as the water presses
directly against the buckets or blades, and its operation is utilized over and over
again in such manner that the whole of the theoretical power (excepting a very
small deduction on account of loss from friction) can be utilized, and given off
from the turbine; but at present the question of utilizing the power given off by
the flow of water is not being considered, but only how to take away the smallest
possible amount of this power in causing the drum B to revolve. The greater the
scale on which the apparatus works the more favourable is it for overcoming any
sudden drawbacks or interruptions that may occur from different causes, and so
tend to affect the exactitude of the measurement of the water. The velocity at
which the periphery of the drum travels will correspond and be proportionate to
the speed of the water passing through the same. The quantity of water is easily
ascertained by multiplying the velocity of the flow of water by its cross sectional
area.
The apparatus only requires the speed of the current of water and the number
of revolutions of the drum to be indicated, and this may be effected by con-
necting the apparatus to a mechanical counter of any ordinary and well-known
construction.
The resistances to be overcome in the working of the drum are chiefly the vis
inertia when the apparatus is set in motion, as also in overcoming friction. No
reactionary force can be given out by the water.
When the discharge cock is opened, in order to prevent a too copious outflow of
water, before the drum makes a corresponding number of revolutions, the axis of
the drum is fitted with a conical valve, such axis, together with the drum, resting
on the closed cone when the apparatus is, not in operation. When the discharge
cock is opened the water, in proportion to its velocity, raises the cone, and with it
the axis and drum, so that whilst revolving it also dances on the water, whereby
the facility of operation is much increased, and the drum in consequence of its
small weight and very little friction quickly attains the same velocity as the water
passing through it.
When the discharge cock is closed the axis of the drum sinks down, thus causing
the conical valve to close, and inducing friction, and stopping the operation of the
apparatus.
•
When the discharge cock is opened only to a very small extent no water will
flow through, as in such case the weight of the drum acts on the conical valve;
therefore the inexactness of operation caused by the setting in motion and the
stoppage of the apparatus is by this means reduced to a minimum.
In short it may be said that this improved water meter is very sensitive in its
operation, and the results given by its measurement of water are in respect to
exactness such as reach practical limits; it also fulfils the conditions set forth in
naragraphs 1 to 4.

page_text: In the accompanying Drawing the drum of the apparatus has a diameter of
180 millimetres, and a circumference of 0.5652 metres. With the water flowing at
a medium velocity of five metres per second the number of revolutions per second
would be =, =902, which number is certainly not too high for this improved
apparatus with a sectional flow of 25 millimetres.
5
0-5652
A suitable bearing is provided on which the axis of the drum can work up and
down, and at the same time by means of a suitable connection communicate with
the counter. The small stuffing box may be removed, providing the mechanism for
counting the revolutions is fitted so as to be pressure proof.
The axis of the drum is carried in such manner that it moves with facility and
is pressure proof, as the hydrostatic pressure is the same on both sides.
All the dimensions of the accompanying apparatus have been so designed as to
provide for a flow of water having a cross sectional area of 25 millimetres.
Any suitable metal may be used in the construction of my improved apparatus,
which may also be made of any convenient dimensions.
Having now particularly described and ascertained the nature of my said In-
vention, and the manner of carrying the same into effect, I would have it under-
stood that I claim as new,-
The accompanying water meter in all the parts of its construction, but especially
the construction of the drum B, together with the casing A, substantially for the
objects above mentioned.
I also claim the use of the said drum B as a turbine.
In witness whereof, I, the said Gerard Wenzeslaus von Nawrocki, have here-
unto set my hand and seal, this Thirteenth day of August, in the year of our
Lord One thousand eight hundred and seventy-seven.
ལ TIT
AT ATTDAADTYT
G. W VON NAWROCKI.
NAWROCKI. (L.S.)