IMPROVEMENTS IN WATER METERS, ALSO APPLICABLE TO WATER PRESSURE ENGINES
Year: 1879

page_text: LETTERS PATENT to Henry Davey, Civil Engineer, of Hyde Lodge, Clarendon
Road, Leeds, in the County of York, for the Invention of "IMPROVEMENTS
IN WATER METERS, ALSO APPLICABLE TO WATER PRESSURE ENGINES."
Sealed the 18th April 1879, and dated the 28th January 1879.
PROVISIONAL SPECIFICATION left by the said Henry Davey at the Office
of the Commissioners of Patents on the 28th January 1879.
HENRY DAVEY, Civil Engineer, of Hyde Lodge, Clarendon Road, Leeds, in the
County of York. "IMPROVEMENTS IN WATER METERS, ALSO APPLICABLE TO
WATER PRESSURE ENGINES."
My Invention relates to that description of apparatus for measuring water or
other liquids in which the liquid enters a cylinder alternately on opposite sides of a
piston which is moved alternately in opposite directions by the pressure of the
entering liquid, at the same time expelling the liquid that had previously entered
it, such meters being known as "positive or "piston" meters.
According to my present Invention I construct such meters as follows:-A
cylinder having side apertures for the inlet and outlet of the liquid situated
diametrically opposite each other at the middle of its length, contains a piston
having two side cavities corresponding to the said inlet and outlet ports, and of
such a length that they remain in communication with the ports during the entire
stroke of the piston. The piston has a central transverse cylindrical chamber with
diametrically opposite side openings communicating with the before mentioned side
cavities, and other diametrically opposite openings communicating respectively with
each end of the cylinder. In the said chamber is fitted a cylindrical plug valve
capable of partial rotation therein and having passages so formed that when turned
into one position it establishes a communication between the side inlet port of the
cylinder and the one end thereof by the before mentioned ports in the piston, while
at the same time it establishes a communication between the side outlet port and
the other end of the cylinder, so that the liquid to be measured passes from the
inlet port through the piston to the one end of the cylinder, and at the same time
escapes from the other end of the cylinder through the piston to the discharge port.
On the said plug being turned into another position the above described com-
munications are reversed so that the liquid flows into that end of the cylinder from

page_text: which it had previously been discharged and escapes from the other end, and such
reversal of the position of the plug valve is effected at the end of each stroke of
the piston by connecting-the-plug-valve-by-a-rod to a crank situated in an extension
at one end of the cylinder so that as the piston moves to and fro the connecting
rod is made to turn the crank, and is thereby made to impart the requisite
reciprocating-motion-to-the-plug valve. In order to insure the regularity of working
of the meter, two such above described-cylinders-with-their-pistons-are-provided_
side by side, the two cranks being fixed on one and the same spindle at right angles
to each other. For registering the motion of the pistons on a counter-the-pin-of-
the one crank is made to rotate an arm on a spindle having a worm in gear with a
worm wheel which is made to actuate any suitable known form of counter or
registering mechanism.
According to another arrangement the piston has in its transverse cylindrical
chamber a piston valve capable of sliding to and fro but not rotating therein.
The
piston valve has a side aperture communicating with the supply cavity of the piston,
and it has ports on the opposite side so formed as when in one position to establish
a communication between the discharge port of the cylinder and a passage leading
through the piston to the one end of the cylinder, while at the same time a com-
munication is established between the supply port and a second passage leading
through the piston to the other end of the cylinder. On the position of the piston
valve in the piston chamber being reversed, the above communications between the
supply and discharge ports and the two ends of the cylinder are reversed, and such
reversal is effected at or near the end of each stroke as follows: The piston slide
has two passages, one communicating with each end of the cylindrical chamber,
such passages having ports that are governed by a subsidiary slide carried by the
piston slide. This subsidiary slide has a rod attached to it which projects somewhat
through each enu of the main piston, so that as this approaches each end stroke the
rod of the subsidiary slide comes in contact with the closed end of the meter cylinder,
whereby the subsidiary slide will be shifted so as to uncover one of the subsidiary
ports and thus put the one end of the cylindrical chamber of the piston in com-
munication with the supply while the other end is put in communication with the
exhaust. By this means the fluid pressure at one end of the piston chamber is
caused to move the piston valve so as to reverse the communications as before
described. The subsidiary ports and their slide are made of diagonal form so that
when the subsidiary slide has been moved so as just to open its ports the piston
slide in commencing its motion by the liquid pressure thus admitted to one end.
thereof will cause the ports to open fully, and thus the reversal of the communica-
tions will be effected with precision and at a uniform speed, no matter how slow the
main piston may travel. The extent of the stroke of the piston valve is always
the same and is limited by stops in the chamber of the main piston. The stroke of
the latter may be variable, that is, the reversal of its motion may commence before
it has arrived at the extreme end-of-its-stroke, and -in-order. to register correctly_
the quantity of water delivered at each stroke the motion of the piston is com-
municated to the counter by forming a toothed rack on the side of the latter in
gear with a pinion which is situated in a recess in the cylinder and has a spindle
which imparts motion to the counter by a pawl and ratchet wheel. Thus whatever
may be the extent of stroke of the meter piston, the ratchet wheel will only be
moved to a proportionate extent and will effect a corresponding registration on the
counter.
I prefer to make the toothed wheel in the cylinder of such a size that it performs
only one revolution during the full stroke of the piston, and I make its teeth at
varying distances from its centre, as in an elliptical wheel, the rack being made of
a correspondingly curved form. By this means for a given extent of travel of the
piston towards the end of its stroke the toothed wheel, and consequently also the
ratchet of the counter, will be moved through a less number of teeth than at the
middle part of the stroke. The object of this arrangement is that when the piston
is performing its minimum stroke stroke it shall register such minimum displacement,

page_text: plus the constant displacement produced by the piston valve, while when the piston
performs an increased stroke it shall only register in addition to such combined
minimum displacement the further displacement due to the increased stroke of the
piston. It will be evident that both the above described constructions of fluid
meters are equally applicable as water pressure engines. For this purpose in the
first described arrangement the crank shaft actuated by the pistons may serve as
the means of transmitting the power of the engine, while in the last described
arrangement either the toothed wheel actuated by the piston rack may transmit the
power, or the piston may have a piston rod passing through a stuffing box on the
cylinder and transmit the power through a connecting rod and crank or other
suitable mechanism.

page_text: -WATER-PRESSURE ENGINES.
My Invention relates to that description of apparatus for measuring-water-or-
other liquids, in which the liquid enters a cylinder alternately on opposite sides of
a piston which is moved alternately in opposite directions by the pressure of the
entering liquid, at the same time expelling the liquid that had previously entered
it, such meters being known as "positive" or "piston" meters. -
According to my present Invention I construct such meters as follows:-A
cylinder having side apertures for the inlet and outlet of the liquid situated diame-
trically opposite each other at the middle of its length contains a piston having two
side cavities corresponding to the said inlet and outlet ports, and of such a length
that they remain in communication with the ports during the entire stroke of the
piston. The piston has a central transverse cylindrical chamber with diametrically
opposite side openings communicating with the before mentioned side cavities, and
other diametrically opposite openings communicating respectively with each end of
the cylinder. In the said chamber is fitted a cylindrical plug valve capable of
partial rotation therein, and having passages so formed that when turned into one
position it establishes a communication between the side inlet port of the cylinder
and the one end thereof by the before mentioned ports in the piston, while at the
same time it establishes a communication between the side outlet port and the other
end of the cylinder, so that the liquid to be measured passes from the inlet port
through the piston to the one end of the cylinder, and at the same time escapes
from the other end of the cylinder through the piston to the discharge port. On
the said plug being turned into another position the above described communica-
tions are reversed, so that the liquid flows into that end of the cylinder from which
it had previously been discharged, and escapes from the other end; and such reversal
of the position of the plug valve is effected at the end of each stroke of the piston
by connecting the plug valve by a rod to a crank situated in an extension at one
end of the cylinder, so that as the piston moves to and fro the connecting rod is
made to turn the crank, and is thereby made to impart the requisite reciprocating
motion to the plug valve. In order to insure the regularity of working of the
meter two such above described cylinders with their pistons are provided side by
side, the two cranks being fixed on one and the same spindle at right angles to each
other. For registering the notion of the pistons on a counter the pin of the one
crank is made to rotate an arm on a spindle having a worm in gear with a worm
wheel, which is made to actuate-any-suitable-known-form-of-counter or registering
mechanism. According to another arrangement the piston has in its transverse
cylindrical chamber a piston valve capable of sliding to and fro, but not rotating
therein. The piston valve has a side aperture communicating with the supply cavity
of the piston, and it has ports on the opposite side so formed as when in one posi-
tion to establish a communication between the discharge port of the cylinder and a
passage leading through the piston to the one end of the cylinder, while at the same
time a communication is established between the supply port and a second passage
leading through the piston to the other end of the cylinder. On the position of the
piston valve in the piston chamber being reversed, the above communication
between the supply and discharge ports and the two ends of the cylinder are
reversed, and such reversal is effected at or near the end of each stroke as follows:-
The piston slide has two passages, one communicating with each end of the cylin-
drical chamber, such passages having ports that are governed by a subsidiary slide

page_text: carried by the piston slide. This subsidiary slide has a rod attached to it, which
projects somewhat through each end of the main piston, so that as this approaches
each end stroke, the rod of the subsidiary slide comes in contact with the closed end
of the meter-cylinder, whereby the subsidiary slide will be shifted so as to uncover
one of the subsidiary ports, and thus put the one end of the cylindrical chamber of
the piston in communication with the supply, while the other end is put in commu-
nication with the exhaust. By this means the fluid pressure at one end of the
piston chamber is caused to move the piston valve so as to reverse the communica-
tions, as before described. The subsidiary ports and their slide are made of
diagonal form, so that when the subsidiary slide has been moved so as just to open
its ports, the piston slide in commencing its motion by the liquid pressure thus
admitted to one end thereof will cause the ports to open fully, and thus the reversal
of the communications will be effected with precision and at a uniform speed, no
matter how slow the main piston may travel. The extent of the stroke of the piston
valve is always the same, and is limited by stops in the chamber of the main piston.
The stroke of the latter may be variable, that is, the reversal of its motion may com-
mence before it has arrived at the extreme end of its stroke, and in order to register
correctly the quantity of water delivered at each stroke the motion of the piston is
communicated to the counter by forming a toothed rack on the side of the latter in
gear with a pinion which is situated in a recess in the cylinder, and has a spindle
which imparts motion to the counter by a pawl and ratchet wheel. Thus whatever
may be the extent of stroke of the meter piston, the ratchet wheel will only be
moved to a proportionate extent, and will effect a corresponding registration on the
counter.
I prefer to make the toothed wheel in the cylinder of such a size that it per-
forms only one revolution during the full stroke of the piston, and I make its teeth
at varying distances from its centre, as in an elliptical wheel, the rack being made
of a correspondingly curved form; by this means, for a given extent of travel of the
piston towards the end of its stroke, the toothed wheel, and consequently also the
ratchet of the counter, will be moved through a less number of teeth than at
the middle part of the stroke. The object of this arrangement is that when the
piston is performing its minimum stroke it shall register such minimum displace-
ment plus the constant displacement produced by the piston valve, while when the
piston performs an increased stroke it shall only register in addition to such com-
bined minimum displacement the further displacement due to the increased stroke
of the piston. It will be evident that both the above described constructions of
fluid meters are equally applicable as water pressure engines. For this purpose in
the first described arrangement the crank shaft actuated by the pistons may serve
as the means of transmitting the power of the engine, while in the last described
arrangement either the toothed wheel actuated by the piston rack may transmit the
power, or the piston may have a piston rod passing through a stuffing box on the
cylinder, and transmit the power through a connecting rod and crank or other
suitable mechanism.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a side elevation of a water meter of the form first described above;
Fig. 2 is a longitudinal section; Fig. 3, a transverse section through one of the
cylinders; Fig. 4, a sectional plan taken through the cylinders; and Fig. 5, a
sectional plan taken on the level of the crank shaft. The two cylinders A1, A2, have
ports a, a, at their opposite sides, communicating respectively with supply and
discharge chambers in the casing, having the inlets and outlets B1 and B2. The
pistons C, C, which work with suitable packing in the cylinders are made with
cavities c¹, c², on their opposite sides, facing respectively the cylinder ports a¹, a²,
and of such length that during the whole stroke of the piston there is communi-

page_text: cylindrical plugs D1, D2, which can turn as in bearings in the pistons, and which
are connected by rods E1, E2, to cranks at right angles, or nearly so, to each other
on a shaft F, which works in a middle bearing in the upper part of the casing.
Each of the plugs DD is made with-a-central partition, which as the plug is
caused to rock-by the crank movement of the connecting rod alternately opens to
each end of the cylinder ports d'; d, through the casing of the plug communicating
respectively with the piston cavities c', c². One of the cranks by means of a
worm G or other suitable gear works an upright spindle, which gives motion to a
-set-of registering gear and indices of any suitable kind in a glass faced box H at the
top of the casing.
The water to be measured enters by the inlet B¹ to the supply chamber on one
side of the cylinders, and thence by the ports a' into the cavities c¹ of the piston.
From these cavities, according to the position of the diaphragms of the plugs D¹, D³,
as determined by their respective cranks, the water passes by the ports d, either
to the upper or to the lower ends of the cylinders; if to the upper end, as shewn
in Fig. 3, then at the same time there is free passage for water from the lower end
of the cylinder by the port d² to the cavity c², and thence by the port a² to the
discharge chamber and outlet B2; thus the pressure being alternated each stroke
above and below each piston the pistons are caused to move, turning the shaft F
and the counter worked by it, which registers the quantity of water passed through
the apparatus. According to a modified form of the apparatus of which Fig. 6 is a
longitudinal, and Fig. 7 a transverse section; Fig. 8, a sectional plan, and Fig. 9 a
plan of the top, one cylinder A is employed with inlet B¹ and outlet B2. The
piston C has within it a cylindrical cavity, in which works a piston slide valve
governing two ports d', d², one of which communicates by a cavity in the piston C
with one end of the cylinder, the other port communicating in like manner with
the other end of the cylinder. Through a diaphragm extending across the middle
of the inner piston slide D there are oblique ports ¹, ², the one communicating
with one end of the cylindrical cavity in which D works, and the other communi-
cating with the other end of that cavity. The ports, are governed by a
slide K, the rod of which when it is at midstroke extends a little beyond the
piston C each way; on the side of the piston C is a toothed rack L gearing with a
pinion M on an upright spindle, which works a suitable counter H. Water
entering by the inlet B₁ passes to the interior of the piston slide D, and according
as the slide K uncovers the one or the other of the ports k, 2, the water passes to
the one end or the other of the cylindrical cavity in which D works, thus pressing D
towards the opposite end from which through the hollow of the slide K there is
passage to the outlet B². The piston slide Ď being thus pressed towards one end
of the cylindrical cavity uncovers one or other of the ports d', d², thus giving
passage for water to one end of the main cylinder A; while there is free passage
from the other end of A through the middle of the piston slide D to the outlet B³.
The pressure of the water on the one side of the main piston C causes it to make
its stroke, and as it approaches the end of the cylinder the rod of the slide K-meets-
the end cover. The slide K being thus shifted reverses the action of the pressure
on the piston slide D, and that slide being thus shifted reverses the direction of
flow to and from the opposite ends of the cylinder A, causing the piston C to make
its back stroke. As the piston approaches the end of this stroke the slide K
becomes again shifted, reversing the movements of the parts, and thus the action is
repeated. The rack L is preferably made, as shewn, to bulge in the middle, the
pinion M being made suitably eccentric, so as to give the counter gear greatest
velocity while the piston is moving over the middle part of its stroke, and so allow
for the displacement made by the piston slide when the extent of stroke is varied.
It is obvious that in the arrangement described with reference to Figs. 1, 2, 3, 4,
and 5, the crank shaft F may be extended through a stuffing box in the side of the
casing, and may be applied to work machinery, the apparatus acting in that case as
a water pressure engine; also the piston C of the modified apparatus described with

page_text: reference to Figs. 6, 7, 8, and 9, might for the same purpose have a rod passing
through a stuffing box in either end of the cylinder, and connected to a crank
or other part to be moved. In that case in order to have the piston rod central,
the slide K and the facing on which it works might be arranged nearer to one
side.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, I claim,―
First. The construction of a water meter or water pressure engine wherein the
water pressure is alternated on opposite sides of the piston by the reciprocating
movement of a plug caused to turn within the piston by its connection to a revolving
crank, substantially as herein described with reference to Figs. 1, 2, 3, 4, and 5, of
the accompanying Drawings.
Second. The construction of a water meter or water pressure engine wherein the
water pressure is alternated on opposite sides of the piston by the reciprocating
movement of a piston slide caused to slide within the main piston by the pressure
of water alternated on its opposite sides by the movement of a subsidiary slide
effected at each end of the stroke of the main piston, substantially as herein
described with reference to Figs. 6, 7, 8, and 9, of the accompanying Drawings.
In witness whereof, I, the said Henry Davey, have hereunto set my hand
and seal, this Seventh day of July, in the year of our Lord One thousand
eight hundred and seventy nine.
HENRY DAVEY. (L.S.)