IMPROVEMENTS IN METERS FOR MEASURING FLUIDS, AND IN PACKINGS AND COUNTING APPARATUS TO BE USED THEREWITH, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO OTHER PURPOSES
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by Henry Law at the Office of
the Commissioners of Patents, with his Petition, on the 2nd April
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 OTHER PURPOSES," to bo as follows:-
The first part of my Invertion consists in so arranging the piston
rods of double piston meters that they cross each other at right angles
at the central points of their respective strokes, and in place of employing
connecting rods and cranks for limiting and controlling the motions of
the piston rods, I employ a toothed wheel whose pitch diameter is
exactly equal to half the stroke of the pistons, working within and
geared with a toothed hoop whose pitch diameter is exactly double that
of the wheel. I connect the piston rods by means of pins with this
wheel upon opposite sides of the same, the axes of the pins being at
right angles to the plane of the wheel, and exactly on its pitch circle,
and at opposite extremities of the same diameter; then in conformity with
a well known property of the circle, the pins to which the piston rods

page_text: are connected will describe perfectly straight lines at right angles with
each other, the motions of each being so regulated and controlled that
the strokes will always be equal, that the one piston will always be at
the end of its stroke when the other is at the middle of its stroke, and
that when one piston is on what mechanics call its dead center its
motion is continued by that of the other piston. Furthermore, in place
of converting the reciprocating motion of the piston rods into a rotary
motion and moving the slide valves for admitting the fluid to be
measured to alternate sides of the pistons by the usual means of excentrics,
cranks, or cams, I impart motion to each valve directly from the rod
belonging to the piston moved by the fluid admitted by the other valve,
so that each piston rod actuates the valve of its fellow. By the general
arrangement here described I obtain a much more rapid closing and
opening of the valves at the end of the strokes than is obtained by the
usual systems. I am thus enabled to reduce the number of moving
pieces to five, namely, the two pistons, the two slide valves, and the
toothed wheel, and as a consequence greatly to reduce the friction of the
machine and to simplify its construction. This part of my Invention
is equally applicable whether to meters with pistons or with diaphragms
or to any form of meter in which there are two pistons or other rods
having a reciprocating motion.
The second part of my Invention is an improvement in the cupped
leathers used as a packing for pistons and stuffing boxes, whether for
meters or other purposes, and consists in interposing a thin metallic
ring between the leather and the surface against which it slides, for the
double purpose of preventing the wear of the cup and of lessening the
friction, the ring should be split and tongued in the usual manner; the
cups may be constructed of leather, mineralized india-rubber, or any
other suitable clastic material.
The third 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 cach wheel a separate dial, and
I then place the several wheels one in advance of the other upon the

page_text: 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 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 detent 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 always in the same direction, 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 front wheel, so that
it moves the space of a notch for each stroke that the detent makes.
The second detent is, however, upheld from contact with the second
notched wheel by bearing upon a smooth rim attached to the back of
the first dial; at one point of this rim corresponding with the zero point
of the first dial is a break which allows the second part of the detent to
fall into contact with and so to actuate for one stroke the second wheel,
but is then again lifted out of contact, so that in fact the second wheel
is only moved through the space of one notch for cach revolution which
the first or front 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 show the move-
ments of the several dials. By this arrangement of the counting
apparatus I obtain great simplicity of construction and compactness of
form.