IMPROVEMENTS IN WATER METERS
Year: 1885

page_text: I, JOHN ROWBOTHAM, of the City of Philadelphia, in the County of Philadelphia,
State of Pennsylvania, United States of America, Mechanical Engineer, do hereby
declare the nature of my invention for "IMPROVEMENTS IN WATER METERS" and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My invention relates in general to a class of water measuring devices to be
applied to pipes, in which the working chamber of a casing, enclosing a drum
provided with two diametrically right-angular rigid sliding vanes, is provided with
two concentric surfaces, of which the upper is a bearing for the peripheral surface
of the drum, and the lower, which is of greater radius than the upper, bounds a
measuring surface,-in which the said concentric surfaces are connected by
eccentric or cam surfaces,-and in which two water ports, respectively forming the
entrance and exit for the water, open into said eccentric surfaces. In meters of the
above class it is a desideratum not only that the water should be caused to pass
through the meter in as nearly as possible a straight line so that its flow be not
retarded by the friction and changes of course incident to long and tortuous
passages, but it is also of prime importance that the vanes during the period of
their sliding over, or being acted upon by, the cam surfaces, should move as freely,
that is to say with as little frictional contact against or straining with respect
either to said cam ways or to their slotted ways or slide bearings in the drum, as is
possible, so that the vane-provided drum may be extremely sensitive under a small
head or pressure of water and, if desired, in connection with a discharge orifice of
small diameter or when supplying a small stream.
It is, moreover, a most essential requirement that the vane-provided drum should
be capable of being rotated backwards or in the opposite direction to that of its
usual rotation, because, in many instances, when the inlet pipe becomes clogged
with matter too large to pass either through it, or through the meter, it becomes
essential to be able to clear said pipe by stream, water, or other pressure applied to
the outlet pipe and exerted backwards through said outlet pipe and through the
meter into the inlet pipe:
Heretofore, however, in meters of the foregoing class in which the drums have
been provided with sliding vanes, the inlet and outlet ports have occupied
relatively such positions that, while the water in passing through the working.

page_text: chamber may have had access at the same time to both sides of both of the acting
extremities of the vanes, so that the said vanes have been under an equilibriated
pressure and the drum acutely sensitive, it yet has been retarded or rendered
sluggish of flow by being caused either to travel completely around the
circumference of the working chamber in a circuitous or spiral course, or else to
travel around said circumference in an arc equal to three fourths of its full extent,
and largely greater than the length of what is in fact the necessary measuring
surface of said chamber; while, so far as my knowledge extends, it never has been
the practice in meters having sliding vanes travelling in contact with the measuring
segment, and in which the ports have been so. introduced to the working chamber
that the water has travelled through it in a short, direct comparatively straight,
and consequently unretarded course, to provide any means for also securing access
of the water to both sides of both the, for the time being, advancing or receding
vanes of the drum during their traverse of the cam surfaces, so that said vanes
may, during such traverse be under an equilibriated pressure and the sensitiveness
of the instrument for accurate measurement be thereby and in consequence thereof
preserved. I have discovered that the admitted advantages, first, of the introduction
to and exit of the water from the working chamber, preferably in the same
straight line, and through a short segmental course throughout the length of and in
contact with the segmental floor of which the vanes travel, and, second, of an equili-
briated pressure of the water upon both sides of both the advancing and retreating
vanes during their traverse of the cam ways,--can both be at the same time and in
the same meter secured by a particular construction and arrangement of the inlet
and outlet ports with respect to a short and direct segmental measuring surface and
to the cam ways of the working chamber, and also by the provision, in conjunction
both with said inlet and outlet ports and with said cam ways, of chambers or
recesses at least co-extensive in length with the length of said cam-ways, and I
have represented in the accompanying drawings and described in this specification
a good form of a convenient embodiment of my said above mentioned improve-
ments, together with certain improvements relating to the structure of the drum
itself, to the shaft upon which the said drum is mounted, and to the vanes with
which it is provided; the particular subject matter which I claim as novel being
hereinafter definitely specified.
In the drawings,
Figure 1 is a front sectional elevation of a meter embodying my improvements,
section being supposed through casing, drum, and vanes, in the plane of the dotted
line 2-2 of Figure 2, and sight being taken in the direction of the arrows on
said line.
In this view the filling piece of the casing is represented as cast with said casing.
Figure 2 is a central vertical side sectional elevation through the entire device
represented in Figure 1, section being supposed in the plane of the dotted
line 1-1 of Figure 1, and sight being taken in the direction of the arrows on said
line. The drum in this view has made an eighth turn beyond the position which it
occupies in Figure 1, so as to bring one vane horizontal, the vertical vane, which is
removed by the section, being indicated in dotted lines."
Figure 3 is a top plan view of my device, the lid of the register box being
supposed removed so as to exhibit the dials, and the driving gearing shown in
detail in Figure 10, which is actuated by the threaded drum journal and actuates
the dial train, being represented in dotted lines. Figure 4 is a central transverse
side sectional elevation through the casing of the working chamber in the plane of
the line 1-1 of Figure 1 and viewed in the direction or its arrows, the drum
and vanes being removed so as to clearly exhibit the recess in the eccentric surface
or cam way presented.
Figure 5 is a sectional front elevation of the left hand half portion of the casing
section being supposed on the line 2-2 of Figure 2, and the drum being
represented in front elevation, while one of its vanes is shown as working upon the
left hand cam way. In this view, as also in Figure 2, the filling piece of the casing

page_text: including the cam ways is represented as applied as a separate member. Figure 6
is a view in perspective of the right-hand half portion of the drum, illustrating
especially the crossing, clearance, and shortened length of the vanes.
Figures 7 and 8 are fragmentary perspective details respectively of the front and
rear sections of the drum, detached from each other. Figure 9 is a perspective view
of the two vanes which I employ, removed from the drum but occupying a position
which they relatively occupy when housed in the drum. Figure 10 is a
fragmentary top plan detail of the worm-provided journal of the drum as engaged
with its worm wheel, showing also the driving gearing of the dial train to which
said wheel imparts motion. Similar letters of reference indicate corresponding
parts. The following is a description of a good construction of my device:-The
casing A is preferably cylindriform as shown in the drawings, and is provided with
an inlet port a and an outlet port a*, preferably in line with each other. One end
of the casing is closed, while the other is provided with a detachable face plate A¹
which preferably screws upon the casing. The casing is provided with a register
box B, containing the registering mechanism, which may be of any suitable
construction, such, for instance, as that represented. The box is preferably cast in
one with the casing. The casing encloses the working chamber of the drum, which
is provided with an upper bearing surface, a lower measuring surface concentric
therewith but of greater radius, and two intermediate eccentric surfaces or cam-
ways, as hereinafter set forth. The drum C is mounted for rotation within the
working chamber of the casing upon two journals, one of which D is provided with
a worm thread d, and has its bearing in a tubular boxing a¹ of the casing, and the
other of which D¹, has its bearing in a boxing a formed in the face plate A¹.
The lower segmental bearing A³, made in the interior of the casing for the ends
of the vanes, is defined by the arc of a circle of which the axis of the drum is the
centre and which extends from line x to line y, as shown in Figure 1. This
bearing A is the measuring surface of the meter. The drum. revolves in contact,
but not severe frictional contact, against an upper segmental bearing surface A³,
which is concentric with the measuring surface A³, but of less radius, and which is
conveniently formed in a filling piece A* either formed in or applied to the casing.
The upper segmental surface A³ extends from line w to line v, as shown in Figure 1.
Intermediate between the upper segmental surface A³ and the lower segmental
Burface A³, and, of course, upon opposite sides of the casing, are two eccentric
surfaces or cam ways A' and A5 which are clear of the drum and respectively
extend from line w to line x, and from line y to line v.
These cam-ways are surfaces against which the ends of the vanes work, as
shown, for instance, in Figure 5, and they are conveniently either formed as a
part of the casing or applied thereto as a part of the filling piece A*.
The ports a and a* open into or cominunicate with the cam ways. R R¹ are
two recesses formed in the cam ways or side walls of the working chamber, and
at least coextensive in length therewith (although they may be longer) and pre-
ferably as shown in Figure 4 of the same breadth as the diameter of the ports.
The office of these recesses is to equalize the pressure of the water upon both
sides of the vanes during their traverse of the eccentric surfaces, by admitting
water to both sides of the acting ends of both the advancing and receding vanes,
and so to lessen the friction and binding of the vanes against their slots in the
drum, and to prevent all lateral pressure on the vanes during their entire sliding
action.
The ports open into or communicate with the recesses. The drum preferably
consists of two castings or sections C C¹, shown in perspective in Figures 7 and 8,
an annular rib c on the section C fitting into a corresponding annular recess c¹ in
the adjoining casting, so that accurate coincidence of the two sections may always
be obtained.
Screws or bolts c* passing through lugs c2, c³, on the respective sections serve to
secure the latter together. Radial slots 8 8' disposed at right angles to each other
in the respective sections, would separate each section of the drum into four parts

page_text: but for the central connecting hubs c. In these slots radial vanes E and F are
fitted snugly, but so as to slide freely. The journals D D¹ are applied to the
respective hubs.. The respective vanes have central slots or notches ef of suitable
width to permit the vanes not only to cross each other but to move a predetermined
distance free of each other. Each vane is in itself rigid, as distinguished from
that class of vanes which are made of two parts with an intermediate spring or
springs to extend them. The drum is, as stated, so mounted that a part of its
periphery will move in contact with the upper segmental bearing A³, while the
ends of its vanes, as they are successively projected from it, will travel in contact
with the lower segmental bearing A³ or measuring surface.
The vanes may, if desired, be each equal in length to the diameter of the
working chamber, but such a construction is attended with the objection that if
any solid matter should get between the end of an advancing vane and the lower
edge of the inlet port the meter would cease to operate. To meet this difficulty,
I prefer to make the vanes, as shown in Figures 1 and 6, somewhat shorter in
length than the diameter of the working chamber, so that if any solid matter
should get in between an advancing blade and the edge of the inlet opening, the
clearance left at the opposite end of the blade will allow the latter to yield lift or
back into its slot, and the drum to continue its rotation, the solid matter being
allowed to pass through the meter and escape without arresting the operation of
the drum. As the vanes are shorter than the diameter of the working chamber,
the eccentric surface A5 can not be relied on entirely to push the vanes outward
at the opposite side to such full extent as to insure their always coming into
contact with the measuring surface A throughout its entire length. This however,
is insured by centrifugal force when the meter is operating at a relatively high
speed, and by gravity when the drum rotates slowly. I therefore always place
the measuring surface below, in order to attain this gravitating action in connection
with shortened vanes.
In order that the meter may continue to work even when its vanes by wear
become shortened at their ends, I make the notches e-and f of the respective vanes
considerably wider than the longitudinal extent of diametric movement of the
vanes, and, preferably, of about double such extent, so that the legs ex f* of the
vanes will not encounter their transverse central portions or bodies, and thereby
prevent the outer end or leg of either vane from coming into contact with the
measuring or eccentric surfaces of the working chamber, all as fully illustrated in
Figures 6 and 9. The box B which is applied to the casing to contain the regis-
tering and indicating contrivances, is provided, conveniently, with a hinged or
removable lid B¹, beneath which is a face b provided with a series of dials b¹ upon
which the indicating hands 62 revolve. A glass or other transparent medium b
is placed over the face b and sealed hermetically to keep the register box B water
tight. Above a base plate 63 and between the latter and the face 6, is contained
a dial train G, which may be a clock work or other gearing of any preferred
description. This train and its connected indicating hands and dials form no part
of my invention. The dial train G is conveniently actuated from a master
spindle g stepped in the box below the train and provided with a spur wheel g¹
engaged by a pinion g² on the shaft g³ of a worm wheel g', the teeth of which are
in removable engagement with the worm d on the drum journal D. The worm
wheel g shaft g³, pinion g' spur wheel g¹ and master spindle g, together form what
I term the driving gearing H for, as stated, actuating the dial train. The con-
nection of the drum with the driving gearing by forming on the end of a drum
journal a worm or screw thread d which is no larger diametrically than the bore
of the boxing a¹ for said journal, enables me at any time to readily disconnect the
drum for examination, removal, or repairs, and to expose the gearing, by simply
unscrewing the face plate A¹ of the casing and withdrawing the drum and journal D
from its boxing a¹.
The register box may be filled with oil or equivalent liquid, in order to maintain
the journals of the trains in a constantly lubricated condition, or provision may be.

page_text: made for permitting the water to enter it for such purpose. The work to be done
on various parts of the meter is that of simple turning, planing, boring, milling,
and fitting, by tools of ordinary construction. The vanes which have extended
bearing surfaces, are of uniform thickness throughout and are therefore easily
planed, and this and other advantages as regards construction, will be readily
recognized by expert mechanics.
The action of the meter under pressure of water or other fluid entering the inlet
port will now be readily understood without further explanation; it will also be
understood how the quantity of water discharged at the outlet port, can be
determined by first ascertaining the capacity of the area bounded by the drum
and measuring surface A³, and the vanes, when the latter are in the position
shown in Figure 1, and by noting the speed at which the drum revolves.!
The avoidance of tortuous passages in water meters, being, as stated, an
important desideratum, it is obvious that my meter is in such regard as nearly
perfect as possible, and that the water will take but a slightly curved, and a
comparatively direct course through it. The fact that the water pervades the
recesses has no bearing upon its travel through the meter, as in the recesses it is
in a comparatively quiescent state. By prolonging the journals of the drum and
omitting the indicator gearing, my device can be employed either as a pump or motor.
Such being a description of the construction of a device conveniently embodying
my invention, it is proper for me to add, that while the best operation of a meter
of this class is secured by applying the ports in a horizontal position on opposite
sides of the casing, and in alignment, as shown in the drawings, yet that I do not
restrict myself to placing them exactly opposite to each other, or to introducing
them to the casing in a strictly horizontal disposition, or upon a common level,
because so long as they communicate with the recesses in the cam surfaces, and are
introduced upon opposite sides of the vertical axis of the casing, all the advantages
flowing from the provision of recessed cam ways in communication with said ports
are secured.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
.
1. The herein described drum for a water meter, said drum being slotted and
made in two parts detachably secured to each other and having vanes adapted to
slide in the slots, substantially as set forth.
.
2. The herein described drum for a water meter, said drum being made in two
parts detachably secured to each other, and each part having four sections united
by a central hub, and vanes adapted to the slots between the sections, sub-
stantially as described.
3. The combination of the meter casing, indicator gearing, bearings for the
journals of the drum, and a rotary drum provided with journals one of which
has a threaded end no larger than its bearing to engage with said gearing,
substantially as set forth.
4. The combination of the casing and rotary drum of a water meter, with
transverse rigid vanes carried by the drum and shorter in length than the diameter
of the chamber in which they move, substantially as set forth.
5. The combination of the casing and rotary drum of a water-meter, with
transverse rigid vanes carried by said drum, the said vanes crossing each other and
having notches considerably greater in width than the extent of motion of the
vanes, substantially as set forth.
6. A water-meter, consisting of a casing the working chamber of which is
provided with two concentric surfaces of different radii and with intermediate
eccentric surfaces, and the measuring surface of which is at the bottom, and a
rotary drum carrying rigid vanes shorter than the diameter of said working
chamber, substantially as and for the purpose set forth.

page_text: 7. The combination in a water meter, of a rotary drum having transverse sliding
vanes, with a casing having an upper bearing surface, a lower measuring surface
concentric there with but of greater radius, and intermediate eccentric surfaces or
camways both of which are provided with recesses at least coextensive with their
length, substantially as described.
8. The combination, in a water meter, of a rotary drum having sliding vanes,
with a casing having an upper segmental bearing surface, a lower segmental
measuring surface concentric therewith but of greater radius, and intermediate
eccentric surfaces or cam ways both of which are provided with recesses at least
co-extensive with their length, and provided with ports opening into or com-
municating with said recesses, substantially as set forth.
9. A casing for a vane-provided drum of a water-meter, the working chamber
of which is provided with an upper segmental surface being a bearing for the
peripheral face of the drum, with a lower segmental measuring surface concentric
with said upper surface but of greater radius, and with two intermediate eccentric
surfaces or cam ways each provided with a recess at least co-extensive with its
length, and likewise provided with horizontally disposed opposite ports opening
into said recesses, substantially as and for the purposes set forth.
10. In a water meter, the combination of a drum having sliding vanes and
capable of rotation in either direction, with a casing the working chamber of which
is provided with an upper segmental surface being a bearing for the peripheral
face of said drum, with a lower segmental measuring surface concentric with said
upper surface but of greater radius, and with two intermediate eccentric surfaces
or cam ways each provided with a recess at least co-extensive with its length, and
likewise provided with opposite ports (preferably horizontally disposed) opening
into said recesses, the arrangement being such that, while the water enters and
leaves the meter upon opposite sides and passes through it in a short segmental
course, so as not to be retarded, the vanes during their passage over the cam ways
are under an equilibriated pressure of water in the recesses, substantially as and
for the purposes set forth.
Dated this twenty third day of June 1885.