Improvements in Liquid Meters.
Year: 1889

page_text: Date of Application, 8:h Nov., 1889
Complete Specification Left, 8th Aug., 1890-Accepted, 4th Oct., 1890
PROVISIONAL SPECIFICATION.
Improvements in Liquid Meters.
I, JOHN JAMES CLARET, of 61 Templeton Road, West Green Road, Tottenham,
in the County of Middlesex, Engineer, do hereby declare the nature of this invention
to be as follows:-
:-
This invention relates to improvements in that class of liquid meter known as
inferential in which the measurement of the quantity of liquid passing through the
meter is incasured by the revolutions of a fan, paddle wheel or turbine set in rotary
motion by such liquid, and more especially to that variety of such meters in which
the entering liquid is caused to raise a weighted piston, plunger or valve which, as
it rises, uncovers or opens the inlet passages that conduct the liquid to the fan; as
for example in meters of the kind for which a Patent was granted to me dated the
14th February 1888, No. 2243.
I have found that when small quantities of liquid are passing through meters of
this latter kind the measuring fan run faster in proportion than when considerable
quantities are passing so that although a given meter may register correctly, or nearly
so, when the maximum quantity of liquid is passing through it in a given time, it
will register too large a quantity when a smaller quantity is passing, and this error
increases in proportion as the quantity actually passing decreases.
The object of my present invention is to provide incans for correcting or neutral-
izing this tendency to register too fast, when small quantities of liquid are passing.
For this purpose I employ the following arrangements :-
I connect the fan, paddle wheel or turbine of a meter of the kind described and
shown for example in the Specification of my aforesaid Patent, with the piston,
plunger or valve which rises and falls according as the quantity of liquid passeing
increases or decreases, in such manner that the said fan, paddle wheel or turbino with
its spindle, rises and falls with the said piston, plunger or valve.
To the upper end of the fan spindle I secure a worm of peculiar construction which
gives motion to the worm wheel driving the registering train.
This worm is formed of a multiple threaded screw, the lowermost part of which is
alone left complete, the upper parts being cut away circumferentially so as to leave.
only portions of screw threads of various lengths.
It will now be understood that any liquid passing through the meter exerts a
pressure upon the under side of the piston, plunger or valve in the usual way
common to this class of meter causing it to rise in opposition to the action of a weight.
This uncovers the inlet parts more or less and allows the liquid to pass through them,
and to impinge upon the vanes of the fan or turbine, so as to set it in rotary motion.
The greater the quantity of liquid entering the higher the piston, plunger or valve
rises, and the larger the area of the passage ways through the ports become. On the
other hand if the quantity of liquid decreases, the weight draws down the piston, and
the area of the passage ways through the ports is proportionately reduced. When
the maximum quantity of liquid is passing through the meter, the piston is raised to
its highest position and consequently the worm is also similarly raised and the lower
part of its threads, that is the portion which remains complete, comes into gear with
the worm wheel and it will bo obvious that that part of the worm will, so long as the
maximum flow, or thereabouts, is passing, continue to turn the worm wheel during
the whole of each revolution of the fan spindle; that is to say each complete
revolution of the fan spindle and worm will move the worm wheel forward a certain
number of teeth thereby moving forward the registering indices to an extent
corresponding to the quantity of water actually passing or thereabouts. If now
the quantity of liquid passing is reduced so that the meter would, under ordinary

page_text: circumstances, register too fast, the corresponding fall of the piston will allow the fan to
fall also and with it the worm so as to bring a part of the threads of the latter which
have been cut away opposite to tho worm wheel; and it will be obvious that so long
as the worm remains in that position relative to the worm wheel, it will only gear with
the teeth of the latter during a portion of its own revolution, consequently one
complete revolution of the worm will pass a smaller number of teeth of the worm
wheel than when the worm was in a higher position. Thus the comparative accele-
ration of the fan due to the reduction of the quantity of liquid passing is compensated
or neutralized by the reduction of the turning effect of the worm on the worm wheel,
and the consequent and proportional reduction in the movement of the registering
indices. If the quantity of liquid is still further reduced so that the moter would,
under ordinary circumstances, register still faster in proportion, the piston falls still
further and with it the fan and worm so as to bring a part of the threads of the
latter which have been still more cut away opposite to the worm wheel, so that the
worm will act during a smaller portion of its revolution on the worm wheel, and will
therefore turn the latter to a smaller extent for each revolution of the worm, and the
still further comparative acceleration of the fan, dne to the greater reduction of the
quantity passing, is again compensated or neutralized by the proportionate reduction
of the turning effect of the worm on the worm wheel, and the consequent pro-
portionate reduction in the movement of the registering indices and so on for further
reductions of quantity of liquid passing, the degree of accuracy of compensation or
neutralization being dependent upon the number of threads composing the worm.
The length of thread left intact at each part of the worm should be so regulated
that it is just sufficient to give the amount of motion to the worm wheel that will
move the registering indices a distance corresponding to the quantity of liquid passing
when the particular part of the worm is opposite to the worm wheel.
Dated this 8th day of November 1889.
JOHN JAMES CLARET.
Per W. H. Bock,
115, Cannon Street, London, E.C., Agent.
COMPLETE SPECIFICATION.
Improvements in Liquid Meters.
1, JOHN JAMES CLARET, of 61 Templeton Road West Green Road, Tottenham,
in the County of Middlesex, Engineer, do hereby declare the nature of the said
invention, and in what manner the same is to be performed to be particularly
described and ascertained in and by the following stateinent, reference being had to
the accompanying sheet of drawings, and to the letters and figures marked thereon,
that is to say :—
This invention relates to improvements in that class of liquid meter known as
inferential, in which the measurement of the quantity of liquid passing through the
meter is measured by the revolutions of a fan, paddle wheel or turbine set in rotary
motion by such liquid, and more especially to that variety of such meters in which
the entering liquid is caused to raise a weighted piston, plunger or valve which, as it
rises, uncovers or opens the inlet passages that conduct the liquid to the fan; as for
example in meters of the kind for which a Patent was granted to me in England
dated the 14th February 1888 No. 2243.
I have found that when small quantities of liquid are passing through meters of this
latter kind, the measuring fan runs faster in proportion than when considerable
quantities are passing, so that although a given meter may register correctly or nearly
so, when the maximum quantity of liquid is passing through it in a given time, it will
register too large a quantity when a smaller quantity is passing, and this error
increases in proportion as the quantity actually passing decreases.
The object of my present invention is to provide means for correcting or neutral-
ising this lency to register too fast when small quantities of liquid are passing.

page_text: For this purpose 1 employ the arrangements shown in the accompanying sheet of
drawings in which Figure 1 is a vertical sectional elevation of a meter constructed
with my improvements applied thereto, and Figure 2 is a developement of the
cylindrical surface of the worm G' shown in Figure 1.
A is the body of the meter, B the inlet passage, the outlet passage, D the
measuring fan, paddle wheel or turbine, the spindle E of which passes upwards
through the bottom F of the clockwork chamber G and carries at its upper end a
worm G' which gives motion to the worm wheel G2 that drives the registering train
in the usual way. This worm G' will be more particularly described hereafter. His
a partition in the body A of the meter, separating the inlet passage B from the outlet
passage C. I is a pipe or cylinder screwed into or otherwise secured in the partition H.
The upper end of this pipe or cylinder passes up into the interior of the fan or
turbine D, and is furnished with lateral inlet openings or ports K. L is a piston
fitted to slide easily up and down in the pipe or cylinder I but resting on the seating I¹
when in its lowest position. The piston L is carried on a rod L the lower end of
which carries a weight N.
The arrangements thus far described are practically the same as those described and
shown in the Specification of my aforesaid English Patent, and I have repeated the
description here merely for the purpose of making more easily understood the devices
now to be described.
The fan or turbine D is carried by a cylindrical piece D³ connected to the spindle E
the lower end of which rests and rotates on the toe-piece D³ formed on, or secured to,
the upper end of the piston rod L' which passes up through a guide I secured to the
upper end of the pipe or cylinder I. The fan or turbine D and the worm G¹,
secured on the upper end of its spindle E, being thus connected to the piston L',
follow the up and down movements of the piston L
This worm G is, in the example shown, formed of a three-threaded the cylindrical
surface of which is shown developed in Figure 2. The lowermost one-third of these
threads, marked 3, is alone left complete, the next third higher, narked 2, is cut
away to the extent of one-third, more or less, of its circumference, and the next or
highest third, marked 1, is cut away to the extent of two thirds, more or less, of its
circumference.
When the
It will now be understood that any liquid passing through the meter enters the
chamber A¹ by the passage B, and, passing up the interior of the pipe or cylinder I,
exerts a pressure upon the underside of the piston L which causes the latter to rise in
opposition to the action of the weight N. This uncovers the ports K, more or less,
and allows the liquid to pass through them, and to impinge upon the vanes of the fan
or turbine 1) so as to set it in rotary motion; and then, after escaping at the circum-
ference of the said turbine, the said liquid passes away through the outlet passage C.
The greater the quantity of liquid entering at B the higher the piston L rises, and the
larger the area of the passage ways through the ports K become. On the other hand,
if the quantity of liquid decreases, the weight Ñ draws down the piston L, and the
area of the passage ways through the ports K is proportionally reduced.
maximum quantity of liquid is passing through the meter, the piston L is raised to its
highest position, and consequently the worm G is also similarly raised, and the lower
part of its threads, that is the portion which remains completo, and is marked 3 in
Figure 2, comes into gear with the worm wheel G³, and it will be obvious that that
part of the worm G₁ will, so long as the maximum flow, or thereabouts, is passing,
continue to turn the worm wheel G' during the whole of each revolution of the fan
spindle E; that is to say each complete revolution of the spindle E and worm G¹ will
move the worm wheel G forward three teeth, thereby moving forward the registering
indices to an extent corresponding to the quantity of water actually passing, or there-
abouts. If now the quantity of liquid passing is reduced so that the meter would,
under ordinary circumstances, register too fast, the corresponding fall of the piston L
will allow the fan D to fall also and with it the worm G¹ so as to bring that part of
the threads of the latter, marked 2, and which have been cut away to the extent of
one third, more or less, opposite to the worm wheel G²; and it will be obvious that so

page_text: long as the worm G¹ remains in that position, relative to the worm wheel G³, it will
only gear with the teath of the latter during about two thirds of its own revolution,
consequently one complete revolution of the worm G will only pass two teeth of the
worm wheel G instead of three as before. Thus the comparative acceleration of the
fan D, due to the reduction of the quantity of liquid passing is compensated or
neutralized by the reduction of the turning effect of the worm G' on the worm
wheel G, and the consequent and proportional reduction in the movement of the
registering indices. If the quantity of liquid is still further reduced so that the move-
ment would, under ordinary circumstances, register still fuster in proportion, the
piston L falls still further and with it the fun D and worm G so as to bring that third
part of the threads of the latter, marked I, and which have been cut away to the oxtent
of two thirds, more or less, opposite to the worm wheel G2, so that the worm will only
act during about one-third of its revolution on the worm wheel G2 and will therefore
only turn the latter to the extent of about one tooth for each revolution of the worm
instead of two as in the last case; and the still further comparative acceleration of
the fan D, due to the greater reduction of the quantity passing is again compensated
or neutralized by the proportionate reduction of the turning effect of the worm G' on
the worm wheel G2, and the consequent proportionate reduction in the movement of
the registering indices.
I have described the worm G' as consisting of a triple-threaded screw divided into
three parts, each about one third less in length circumferentially than the one below
it; but it will be understood that the worm may be made as a screw of two, four, five,
six or any other number of threads, divided into a corresponding number of parts,
each part less in length circumferentially than the one below it, and that the greator
the number of threads, the greater the accuracy attainable; because the difference of
the effect of one part of the scrow threads on the worm wheel as compared with that
of the part next to it is less the greater the number of threads, but the number of
threads and therefore the number of different lengths of threads, in a given worm, is
practically limited by considerations:-Firstly, of the height to which the fan can be
lifted, secondly of the size of the worm wheel G³, which has to be smaller in propor-
tion as the number of threads increase, in order to prevent it from being acted on by
a longer length of throad than is intended, and thirdly, of the pitch of the teeth of the
worm wheel G which has to be made smallor the greater the number of threads
employed, so that when the worm is formed of a screw with numerous threads, the
teeth of the worm wheel become too small for practical use. Figure 3 shows the
developement of a four-threaded worm with parts cut away so as to give threads of
four different lengths.
The length of thread left intact at each part of the worm G' should be so regulated
that it is just sufficient to give the amount of motion to the worm wheel G' that will
move the registering indices a distance corresponding to the quantity of liquid passing
when the particular part of the worm is opposite to the worm wheel.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
In a liquid meter in which a piston or other part is caused to rise and fall in pro-
portion to the quantity of liquid passing through such metor, the combination with
such rising and falling piston or other part, of a multiple-threaded worm having parts
thereof cut away or removed so as to present portions of the worm threads of different
lengths to the worm wheel driving the registering gear, according as the quantity of
liquid passing is greater or less, substantially as hereinbefore described, and illustrated
in the drawings and for the purpose set forth.
Dated this 8th do. A
1000