IMPROVEMENTS IN METERS FOR MEASURING FLUIDS, AND IN PACKINGS AND COUNTING APPARATUS TO BE USED THEREWITH, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO ENGINES FOR OBTAINING MOTIVE POWER FROM FLUIDS UNDER PRESSURE, AND TO OTHER PURPOSES." PROVISIONAL SPECIFICATION
Year: 1870

page_text: LETTERS PATENT to Henry Law, Civil Engineer, of No. 15, Essex
Street, Strand, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN METERS FOR MEASURING FLUIDS, AND IN PACKINGS AND
COUNTING APPARATUS TO BE USED THEREWITH, PARTS OF WHICH IMPROVEMENTS
ARE APPLICABLE TO ENGINES FOR OBTAINING MOTIVE POWER FROM FLUIDS
UNDER PRESSURE, AND TO OTHER PURPOSES."
PROVISIONAL SPECIFICATION left by the said Henry Law at the
Office of the Commissioners of Patents, with his Petition, on the
18th May 1870.
I, HENRY LAW, Civil Engineer, of No. 15, Essex Street, Strand, in
the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN METERS FOR MEASURING FLUIDS, AND IN
PACKINGS AND COUNTING APPARATUS TO BE USED THEREWITH, PARTS OF WHICH
IMPROVEMENTS ARE APPLICABLE TO ENGINES FOR OBTAINING MOTIVE POWER
FROM FLUIDS UNDER PRESSURE, AND TO OTHER PURPOSES," to be as follows:-
The improved meter consists of two pistons working in two cylinders,
which pistons give motion to two cranks fixed at right angles to each

page_text: other at opposite extremities of the same shaft. The fluid to be
measured is admitted successively to the upper and lower extremities of
the cylinders by a rotary valve upon the crank shaft. The pressure of
the fluid gives motion to the pistons, causing the crank shaft to revolve
continuously in one direction, and the quantity of fluid which passes
is registered by a counting apparatus which exhibits the number of
revolutions made by the crank shaft.
The first part of my Invention consists in casting the two cylinders in
which the pistons move in one piece, and in dividing the space between
them by a partition, so as to form the passages to convey the fluid to
the lower ends of the cylinders; and, further, in so forming the caps or
covers of the cylinders, that one shall contain the valve ports and
passages to convey the fluid to either extremity of each cylinder, and
that the other shall contain the moving valve by means of which these
ports are successively opened and closed, and that both shall form the
bearings for carrying the crank shaft, and that they shall contain recessed
spaces sufficient to allow of the free revolution of the cranks within
them. By the arrangement here described I obtain great simplicity in
construction, there being only three separate parts to form the entire
shell of the meter, and the surfaces to be faced being each in one
plane.
The second part of my Invention consists in so arranging the rotary
valve that although carried round by the crank shaft which passes
through its center it is free to adapt itself to the face containing the
ports against which it revolves, and always to remain in contact there-
with, notwithstanding that the axis of the shaft may not be truly per-
pendicular to the face of the valve; furthermore I so arrange the con-
nection between the crank shaft and the rotary valve that I am able to
adjust the relative positions of the valve and cranks with the utmost
accuracy, and so to ensure the ports being opened and closed at the
precise instant required.
The third part of my Invention consists in a mode of adjusting the
quantity of fluid discharged by each revolution of the meter, so as to
insure the utmost accuracy, notwithstanding any want of exactness in
the diameters of the cylinders or in the lengths of the cranks; and this
I effect by making the pin of one of the cranks to which the connecting
links of one of the pistons is attached capable of adjustment, so as to
increase or lessen the radius of the crank, and as a consequence the

page_text: length of stroke of the piston without taking the meter to pieces or
disturbing any of the moving parts.
The fourth part of my Invention consists in so constructing and
arranging the parts that air is prevented from being imprisoned within
the cylinders so as to interfere with the accurate measurement of the
fluid. I effect this object by making the lower surface of the pistons
perfectly flush, so as to leave no hollow within which air can be retained;
and I so form the ports at the lower extremities of the cylinders that
the lower margin of the piston shall when at its lowest point be some-
what below the highest point of the port, by which means any air
within the cylinders would immediately escape, and pass away through
the discharge pipe, owing to its levity as compared with the fluid to be
measured. To allow of the escape of the air which would be contained
within the upper part of the cylinder covers I form a small hole for its
escape at the highest point of each, which hole may be closed with a
plug, or a cock, or a self-acting valve so constructed as to allow air to
escape, but to close so soon as the denser fluid reaches it.
The fifth part of my Invention consists in a substitute for stuffing
boxes or packings to prevent leakage where the revolving crank shaft
and the index shaft pass through the partitions of the cylinder covers.
Upon the side of the partition exposed to the greater pressure I form a
raised surface or boss forming a margin or disc round the revolving shaft,
and this surface is made perfectly true, smooth, and perpendicular to the
axis of the shaft; upon the shaft and in contact with this boss I place a
metallic washer or disc, having the surface presented to the boss perfectly
smooth and true, and behind this metallic washer I place a washer of
mineralised india-rubber or other suitable elastic material bearing against
a projecting flange or fixed collar upon the revolving shaft, the elastic
washer being sufficiently compressed to insure the metallic washer or
disc being kept in close contact with the boss. A spring may be
substituted for the elastic washer, and in place of having a raised surface
or boss upon the partition through which the revolving shaft passės a
second washer or disc may be used, an elastic washer being interposed
between it and the partition to form a tight joint. Where the pressure
is alternately greater upon opposite sides of the partition smooth surfaces
or discs to revolve in contact must be formed one on the shaft and the
other on the partition on each side of the partition, but the elastic washer

page_text: is only required upon one side. By the arrangement here proposed
the rubbing surfaces are entirely metallic, and, the necessity of re-
packing the stuffing boxes from time to time will be avoided.
This
part of my Invention is not only applicable to meters, but to all other
machines in which a revolving shaft passes through a partition requiring
a different pressure to be maintained on its opposite sides without
leakage.
The sixth part of my Invention is an improvement in the counting
apparatus for registering the number of strokes which the meter has
made, and is applicable to the apparatus for registering the number of
strokes or revolutions of every class of machinery and tell-tales. In
place of having a train of wheels and pinions on separate axes, moving
separate indices with fixed dials, I provide the requisite number of
wheels of the same size and form, and having an equal number of
notches upon their circumferences. I attach to each wheel a separate
dial, and I then place the several wheels one in advance of the other
upon the same fixed axis, so regulating the sizes of the dials by putting
the largest behind and allowing each one to be decreased in diameter
sufficiently to render visible the divisions and numbers upon the margins
of the dials behind it. I move these several dials by means of a spring
detent, so arranged that each stroke or revolution of the machine shall
push the detent forwards and backwards the space of one of the notches
upon the circumferences of the wheels. The part of the detent which
bears against the circumferences of the notched wheels is divided into as
many parts as there are wheels to be moved, and the wheels and detent
are so formed in relation to each other; that the reciprocating motion of
the detent moves the wheels with which it is in contact always in the
same direction through the space of one notch for every stroke of the
detent. It is so arranged, however, that only the first part of the detent
is always in contact with the wheel attached to the front dial, so that
this wheel moves the space of a notch for each stroke that the detent
makes. The second part of the detent is however upheld from contact
with the second notched wheel by bearing upon a smooth rim attached
to the first wheel; at one point of this rim, corresponding with the zero
point of the first dial, is a break or notch which allows the second part
of the detent to fall into contact with, and so to actuate for one stroke,
the second wheel, but it is then again lifted out of contact, so that in

page_text: fact the second wheel is only moved through the space of one notch for
each revolution which the first wheel completes; and in a similar
manner the same relation subsists between all the wheels, so that the
third wheel only moves through the space of one notch for each completo
revolution made by the second wheel, and the fourth wheel only moves
through the space of one notch for each complete revolution of the third
wheel, and so on throughout the series. A fixed index is employed to
show the movements of the several dials.
By the combination of these several improvements I obtain great
simplicity of construction and compactness of form, with very few moving
parts, and perfect accuracy of measurement independent of imperfections
of workmanship.
By prolonging one end of the crank shaft so as to pass through the
cylinder cover to the outer side motive power may be obtained by the
action of any fluid under pressure upon the pistons.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Law in the Great Seal Patent Office on
the 10th November 1870.
!
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, 'HENRY
LAW, Civil Engineer, of No. 18, Adam Street, formerly of No. 15,
Essex Street, both in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of May in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Henry Law, Her special licence, that
I, the said Henry Law, my executors, administrators, and assigns, or
such others as I, the said Henry Law, my executors, administrators,
and assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands
and Isle of Man, an Invention for "IMPROVEMENTS IN METERS FOR MEASURING
FLUIDS, AND IN PACKINGS AND COUNTING APPARATUS TO BE USED THEREWITH,

page_text: PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO ENGINES FOR OBTAINING
MOTIVE POWER FROM FLUIDS UNDER PRESSURE, AND TO OTHER PURPOSES," upon
the condition (amongst others) that I, the said Henry Law, my execu-
tors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Law, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement :-
The improved meter consists of two pistons working in two cylinders,
which pistons give motion to two cranks fixed at right angles to each
other at opposite extremities of the same shaft, the fluid to be measured
is admitted successively to the upper and lower extremities of the
cylinders by a rotary valve upon the crank shaft, the pressure of the
fluid gives motion to the pistons, causing the crank shaft to revolve
continuously in one direction, and the quantity of fluid which passes is
registered by a counting apparatus which exhibits the number of revo-
lutions made by the crank shaft.
The first part of my Invention consists in casting the two cylinders in
which the pistons move in one piece, and in dividing the space between
them by a partition so as to form the passages to convey the fluid to the
lower ends of the cylinders; and further, in so forming the caps or
covers of the cylinders that one shall contain the valve ports and
passages to convey the fluid to either extremity of each cylinder, and
that the other shall contain the moving valve by means of which these
ports are successively opened and closed, and that both shall form the
bearings for carrying the crank shaft, and that they shall contain recessed
spaces sufficient to allow of the free revolution of the cranks within
them.
By the arrangement here described I obtain great simplicity in con-
struction, there being only three separate parts to form the entire shell
of the meter, and the surfaces to be faced being each in one plane.
The second part of my Invention consists in so arranging the rotary
valve that although carried round by the crank shaft which passes

page_text: .
through its center it is free to adapt itself to the face containing the
ports against which it revolves, and always to remain in contact there-
with, notwithstanding that the axis of the shaft may not be truly per-
pendicular to the face of the valve; furthermore I so arrange the
connection between the crank shaft and the rotary valve that I am able
to adjust the relative positions of the valve and cranks with the utmost
accuracy, and so to insure the ports being opened and closed at the
precise instant required.
.
The third part of my Invention consists in a mode of adjusting the
quantity of fluid discharged by each revolution of the meter, so as to
ensure the utmost accuracy, notwithstanding any want of exactness in
the diameters of the cylinders or in the lengths of the cranks, and 'this
I effect by making the pin of one of the cranks to which the connecting
links of one of the pistons is attached capable of adjustment, so as to
increase or lessen the radius of the crank, and as a consequence the
length of stroke of the piston, without taking the meter to pieces or
disturbing any of the moving parts.
The fourth part of my Invention consists in so constructing and
arranging the parts that air is prevented from being imprisoned within
the cylinders so as to interfere with the accurate measurement of the
fluid. I effect this object by making the lower surface of the pistons
perfectly flush, so as to leave no hollow within which air can be retained,
and I so form the ports at the lower extremities of the cylinders that
the lower margin of the piston shall, when at its lowest point, be some-
what below the highest point of the port, by which means any air within
the cylinders would immediately escape and pass away through the
discharge pipe owing to its levity as compared with the fluid to be
measured. To allow of the escape of the air which would be contained
within the upper part of the cylinder covers I form a small hole for
its escape at the highest point of each, which hole may be closed with
a plug, or a cock, or a self-acting valve, so constructed as to allow air
to escape but to close so soon as the denser fluid reaches it.
The fifth part of my Invention consists in a substitute for stuffing
boxes or packings to prevent leakage where the revolving crank shaft
and the index shaft pass through the partitions of the cylinder covers.
Upon the side of the partition exposed to the greater pressure I form a
raised surface or boss forming a margin or disc round the revolving,

page_text: shaft, and this surface is made perfectly true, smooth, and perpendicular
to the axis of the shaft. Upon the shaft and in contact with this boss
I place a metallic washer or disc having the surface presented to the
boss perfectly smooth and true, and behind this metallic washer I place
a washer of mineralized india-rubber or other suitable elastic material
bearing against a projecting flange or fixed collar upon the revolving
shaft, the elastic washer being sufficiently compressed to insure the
metallic washer or disc being kept in close contact with the boss. A
spring may be substituted for the elastic washer. In place of having a
raised surface or boss upon the partition through which the revolving
shaft passes a second washer or disc may be used, an elastic washer
being interposed between it and the partition to form a tight joint.
Where the pressure is alternately greater upon opposite sides of the
partition smooth surfaces or discs to revolve in contact must be formed,
one on the shaft and the other on the partition, on each side of the
partition, but the elastic washer is only required upon one side. By the
arrangement here proposed the rubbing surfaces are entirely metallic,
and the necessity of repacking the stuffing boxes from time to time will
be avoided. This part of my Invention is not only applicable to meters,
but to all other machines in which a revolving shaft passes through
a partition requiring a different pressure to be maintained on its opposite
sides without leakage.
The sixth part of my Invention is an improvement in the counting
apparatus for registering the number of strokes which the meter has
made, and is applicable to the apparatus for registering the number of
strokes or revolutions of every class of machinery or tell-tales. In place
of having a train of wheels and pinions on separate axes moving separate
indices with fixed dials I provide the requisite number of wheels of the
same size and form and having an equal number of notches upon their
circumferences. I attach to each wheel a separate dial, and I then place
the several wheels one in advance of the other upon the same fixed axis,
so regulating the sizes of the dials by putting the largest behind and
allowing each one to be decreased in diameter sufficiently to render
visible the divisions and numbers upon the margins of the dials behind
it. I move these several dials by means of a spring detent so arranged
that each stroke or revolution of the machine shall push the detent
forwards and backwards the space of one of the notches upon the
circumferences of the wheels. The part of the detent which bears

page_text: against the circumference of the notched wheels is divided into as many
parts as there are wheels to be moved, and the wheels and detents are
so formed in relation to each other that the reciprocating motion of the
detent, always in the same direction, moves the wheels with which it is
in contact through the space of one notch for every stroke of the detent.
It is so arranged, however, that only the first part of the detent is always
in contact with the wheel attached to the front dial, so that this wheel
moves the space of a notch for each stroke that the detent makes. The
second part of the detent is however upheld from contact with the
second notched wheel by bearing upon a smooth rim attached to the first
wheel. At one point of this rim corresponding with the zero point of
the first dial is a break or notch which allows the second part of the
detent to fall into contact with and so to actuate for one stroke the second
wheel, but it is then again lifted out of contact, so that in fact the
second wheel is only moved through the space of one notch for each
revolution which the first wheel completes, and in a similar manner
the same relation subsists between all the wheels, so that the third wheel
only moves through the space of one notch for each complete revolution
made by the second wheel, and the fourth wheel only moves through
the space of one notch for each complete revolution of the third wheel,
and so on throughout the series. A fixed index is employed to shew the
movements of the several dials.
1
By the combination of these several improvements I obtain great
simplicity of construction and compactness of form with very few
moving parts, and perfect accuracy of measurement independent of
imperfections of workmanship. By prolonging one side of the crank
shaft so as to pass through the cylinder cover to the outer side motive
power may be obtained by the action of any fluid under pressure upon
the pistons.
And in order to make the nature of my said Invention more perfectly
understood, I have prepared the Drawings hereunto annexed.
The general form and construction of the meter is shewn in Figs. 1, 2,
& 3, Drawing No. 1; & in Figs. 7, 9, 11, 12, & 13, Drawing No. 2:
The two pistons J, J, work in two cylinders K, K, giving motion by
means of the connecting rods L, L, to the two cranks M & N fixed at
right angles to each other at opposite extremities of the crank shaft O.
The two cylinders are cast in one piece K, and the space between them
is divided by the partition a so as to form two passages b and c wbich

page_text: communicate with the lower ends of the two cylinders. The cap or
cover of the cylinders is formed in two parts, P & Q; the former, P,,
carries the outlet pipe R and contains the valve ports and passages to
convey the fluid to either extremity of each cylinder; the latter carries
the inlet pipe S and contains the valve T. The port & communicates
with the lower end of one of the cylinders, the port e with the upper end
of the same, while the port of communicates with the lower end of the
other cylinder and the port 9 with the upper end of the same, and the
central space / leads to the outlet pipe R, consequently by the rotation
of the valve T the fluid is successively admitted to and discharged from
the alternate ends of each cylinder. The valve is surrounded by a
circular strainer U to keep back any foreign substance which might
impede the action of the meter, and a screw plug V is provided, by the
removal of which the space around the strainer can be cleared out from
time to time without taking to pieces any portion of the meter. The
caps P&Q also form the bearings within which the crank shaft O
revolves, there being in each a recessed space sufficiently capacious to
allow of the rotation of the cranks. The crank shaft O passes through
the rotary valve T, but is in no way attached thereto, being so arranged
as to have sufficient play or movement independent of the shaft to
permit its face always to be in actual contact with the face of the cap P
which contains the ports d, e, f, & g. To give motion to the valve T
I have a carrier W immoveably attached to the crank shaft O; this
carrier has two arms with set screws i, i, and the back of the valve T
has a stud ; which projects between these two set screws. By this
arrangement I am enabled by means of these screws to adjust the
relative positions of the rotary valve T and the cranks M & N with
the utmost accuracy, so as to insure the opening and closing of the
ports d, e, f, & 9, at the precise instant required. It should further be
observed that the stud j is not held between the set screws i, i, but is
perfectly free to allow of the valve always being in contact with the
plate containing the ports. A washer of mineralized india-rubber is
inserted between the valve and the carrier to prevent the fluid finding a
passage between the shaft and the valve. The crank N is of a fixed and
determinate length, but the other crank M is so constructed that the
position of the crank pin 7 can be varied and the length of stroke of the
piston attached to it increased or lessened in order to adjust the quantity
of fluid discharged by each revolution of the meter, so that it may be in
strict accordance with that shown by the registering apparatus. I form

page_text: a slotted recess at the outer end of the crank to which is accurately
fitted a sliding block m forming one piece with the crank pin 1; through
the center of the block m passes a screw n securely confined by the
cover plate o, and having a square head to afford the means of turning
the screw by the use of a key introduced through an opening p left for
that purpose at the top of the cover P. By this arrangement if it is
found that the meter discharges either more or less than the intended
quantity of fluid by simply turning the screw n in either direction the
position of the crank pin / can be varied and the length of stroke of the
piston J increased or lessened to the extent required without taking the
meter to pieces or disturbing any of the moving parts, it being only
necessary to unscrew the cap by which the opening p is closed.
The meter is so constructed as to prevent the accumulation of air and
to allow of the escape of the same, the underneath side of the pistons
J, J, being made flush so as to leave no hollow within which the air
can be retained; and to ensure the discharge of the whole of the air
originally contained I form a notch q on the upper margin of each of the
ports communicating with the lower ends of the cylinders, which
notches are carried up above the level reached by the lower margin of the
respective pistons when at the lowest point of their strokes. To allow
of the escape of the air from the cover Q a small plug screw r is inserted
at its upper part, while the same object is effected in the cover P by the
removal of the cap which closes the opening p.
Instead of using stuffing boxes to prevent leakage where the crank
shaft or index shaft passes through the partitions of the covers I employ
metallic discs combined with washers of mineralized india-rubber or other
suitable elastic material. Thus where the crank shaft O passes through
the cover P I employ two metallic discs s, t, and two washers of india-
rubber u,*v.
The surfaces of the discs s, t, in contact with each other
are accurately true and smooth, while the surfaces in contact with the
washers u, v, are left rough. When the shaft O revolves the discs and
the washer u revolve with it, while the disc t and the washer v remain
stationary, the pressure produced by the compression of the washers
& keeping the discs & & & in contact, and preventing any escape of
fluid between them. At the other extremity of the shaft O the surface
of the boss of the crank being formed perfectly true and smooth, only
one disc w and one washer are required, the crank revolving in con-
tact with the disc w which remains stationary. The stationary washers v.
8

page_text: &x should not be in contact with the revolving shaft O, an annular
space being left between them, as shown in the Drawing.
For registering the number of revolutions made by the meter I employ
the following means:-The boss of the carrier W has a screw thread cut
upon it corresponding with the teeth of a small wheel y, the pitch of the
screw and the number of teeth of the wheel being so adjusted as to give
the required ratio between the revolutions of the crank shaft O and of
the wheel y. The wheel y is fixed upon a shaft or axis z moving in
bearings attached to a plate ẞ and having at one end a projecting pin y
set eccentrically so as to act as a crank. In contact with this pin is a
sliding detent 8, shown separately in Fig. 4, Drawing No. 1, having a
transverse slot into which the pin y fits, and it is so arranged that for
each revolution of the wheely and axis z the pin y moves the detent à
backwards and forwards through a space equal to the throw of the pin y,
the detent being constrained to move in a straight line by the guide
screws Є, €. There are two discs & each having the same diameter"
and the same number of notches cut upon their circumferences, the
number shown upon the Drawings being one hundred. The disc ◊ is
attached to another disc μ which is a trifle larger in diameter than 6 and
has only one notch upon its circumference. The disc is also attached
to a disc which has a flat rim divided into one hundred equal parts,
and carrying numbers as shown in Fig. 6, Drawing No. 1. The disc
.is also attached to a similar disc σ also having a rim divided into one
hundred parts, and numbered as shown in the same Figure. The discs
are arranged concentrically as shown in Figs. 12, 13, & 15, Drawing
No. 2 being supported upon the circular frame Y, shown in Fig. 14,
Drawing No. 2. The detent & carries two tongues 1 & 2, the former
bearing against the circumference of the disc 4, and the latter against
the circumferences of the two discs & & μ, the extremities of these
tongues being so formed as to fit the notches upon the circumferences of
the discs, and having sufficient elasticity to allow of their rising. out
of and falling into the notches as the discs revolve. Another detent T
also with two tongues corresponding with and fitting into the notches
on the circumferences of the discs & is fixed to the plate ẞ in
such a position as to prevent the discs moving except in the direction
required.
ทุ

page_text: means of the eccentric pin y, causes the detent à to move up and down
once for each revolution through such a space as to carry the discs
through the space of one notch, or in the present case through the one-
hundredth part of a complete revolution, and on the detent à being
drawn down it falls into a fresh notch, the notched wheel being pre-
vented from returning with the moving detent by the fixed detent r.
The tongue of the detent & marked 1 being always in contact with the
disc causes it to advance through the space of one notch, that is,
through one-hundredth part of a revolution for every revolution of the
axis &, but the tongue marked 2 bears against the circumference of the
disc p, and this disc being somewhat larger in diameter than the disc
the tongue is held away from being in contact with the notched disc and
therefore produces no motion therein. The disc is attached to and
carried round with the disce, and having at one point of its circumference
a notch, when this notch arrives in a certain position corresponding with
the zero of the divisions on the rim of the disc it allows the tongue 2 to
fall into gear or contact with the notched disc 4, and so causes that disc to
move through the space of one notch or the hundredth part of a revolu.
tion; on the next downward stroke however of the detent & the tongue 2
passes out of the notch on the disc µ, and so ceases to act any longer
upon the disc until the latter has completed another entire revolution,
and thus the disc 0 and the disc » move through one of the divisions on
the rim of the latter for every revolution of the axis 2, while the discs
and ☛ only move through one of the divisions on the rim of the latter for
every hundred revolutions of the axis s. As shown upon the Drawings,
with two discs each with one hundred notches the apparatus will register
10,000 revolutions of the axis before returning again to the position
from which it started. If, however, a third notched disc be added actuated
by a third tongue on the detent & the apparatus would register 1,000,000
revolutions of before returning to its starting point, and so on for any
additional number of discs.
n
The counting apparatus hitherto described is placed within the cap or
cover Q working in and surrounded by the fluid, the movement of the
rims of the discs and σ being seen through a small window X, there
being a wire a fixed across on its inner surface to which the divisions
on the rims of the discs are referred. This arrangement is especially
adapted for very high pressures as there is no opening whatever in the
cover of the meter through which leakage can take place.

page_text: Figs. 16, 17, 18, 19, and 20, Drawing No. 3, show another arrangement
in which the counting or registering apparatus is placed externally on
the front of the meter, the axis z being carried through the side of the
cover Q. The principle and action are precisely similar to that above
described and the same letters distinguish similar parts; the escape
of the fluid around the axis z where it passes through the side of the
cover Q is prevented by the metallic discs s, t, and india-rubber washers
u, v, as already described in connection with the crank shaft.
By prolonging one end of the crank shaft O, so as to pass through the
cylinder cover Q to the outer side, as shown in Fig. 21, Drawing No. 4,
motive power may be obtained by the action of any fluid under pressure
upon the pistons J, J. The escape of the fluid where the shaft passes
through the cover Q, is prevented by the introduction of the metallic
discs s, t, and the india-rubber washers u, v.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried into effect I would in conclusion observe, that I do not claim
the particular form or configuration of the several parts shewn on the
Drawings, which are to be regarded simply as illustrations of the modes
in which my said Invention may be carried out; but that what I
consider to be novel and original, and therefore claim as my said
Invention is the following:-
Firstly. The general construction and arrangement of meters for
measuring fluids and the applications of the same substantially in the
manner and for the purposes herein-before described and illustrated by
the Drawings.
Secondly. Constructing the shell of the meter in only three pieces,
the two cylinders being cast in one piece, the space between the same
forming passages for the fluid to be measured, and the two cylinder
covers containing the ports, passages, valve, and all the moving parts,
substantially as herein-before described.
Thirdly. The mode of connecting the rotary valve with the crank
shaft, so that the valve shall always be in contact with its face plate,
and that the relative position of the valve and cranks is capable
of accurate adjustment, substantially in the manner herein-before
described.

page_text: Fourthly. So constructing one of the cranks that the length of its
throw is capable of adjustment without taking the meter to pieces, or
disturbing any of the moving parts, substantially in the manner herein-
before described.
Fifthly. So constructing the several parts of the meter in the manner
herein-before described as to prevent the detention of air therein.
Sixthly. The substitution of metallic discs combined with elastic
washers, substantially in the manner herein-before described, in place
of stuffing boxes.
Seventhly. The employment for counting apparatus of a series of
discs on the same axis, actuated by a detent, in such a manner that
each disc moves only through a certain fixed space for every complete
revolution made by the previous disc in the series, substantially in the
manner herein-before described.
In witness whereof, I, the said Henry Law, have hereunto set my
hand and seal, this First day of November One thousand eight
hundred and seventy.