Improvements in Apparatus for Delivering Measured Quantities of Liquid.
Year: 1888

page_text: Date of Application, 1st Sept., 1888
Complete Specification Left, 20th June, 1889-Accepted, 27th July, 1889
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Delivering Measured Quantities
of Liquid.
I, FRANOIS EDWARD MAC MAHON, of No. 2 Princes Mansions, Victoria Street,
Westminster, in the County of Middlesex, Engineer, do hereby declare the nature
of this invention to be as follows:-
According to this invention the liquid to be measured is delivered into a vessel
preferably a cylinder displacing a float or piston in it, the amount of the fluid
which can enter the vessel being regulated by arresting the travel of the piston.
This arrangement is peculiarly suitable for measuring taps for the sale of liquors.
For this purpose I so arrange that turning the tap not only admits liquid into the
measuring chamber, but also arrests the movement of the piston at a point dependent
upon the angle through which the tap has been turned.
The measuring vessel consists of a cylinder having its lower end coned the
connection with the supply and delivery pipe being at the apex of the cone. A
solid cylinder with a similar coned end fits closely in the measuring vessel and
forms the piston. The cylinder and piston are connected together by an extensible
india rubber tube which forms an air and fluid tight joint between them and avoids
the necessity of employing any packing or stuffing box. The cylinder is prolonged
upwards beyond the piston, and has cut in it two longitudinal slots which form guides
for the ends of a sliding cross-bar above the piston, by which the travel of the
piston is limited. The ends of this bar project outwards and enter a cam groove in
a tube fitting outside the cylinder and capable of turning upon it, so that the distance
the piston and with it the cross bar can be raised is dependent upon the angle
through which the cam has been turned. The cam tube carries a toothed wheel
which engages with a pinion worked by the cock which is a three-way cock as is
usual. The apparatus is so arranged that the first motion of the cock turns on the
liquid into the measuring vessel, without rotating the cam tube. As the tap continues
to be turned the cam tube is rotated and the cross bar above the piston is raised, so
that the piston is free to be displaced by the entering liquid. To draw off a
measured quantity of liquid the tap is first turned through the angle corresponding
to the desired quantity of liquid (which is indicated on a dial actuated by the cock)
and is thus turned back again. The first effect of this backward movement is merely
to shut off the supply. When this has been done and the tap continues to turn,
the cam tube is rotated back again and the piston thereby forced down, so that the
liquid in the measuring chamber is delivered.
A counting and registering apparatus may be advantageously added to the
apparatus.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Delivering Measured Quantities
of Liquid.
1, FRANCIS EDWARD MAC MAHON, of No. 2 Princes Mansions, Victoria Street,
Westminster, in the County of Middlesex, Engineer, do hereby declare the nature of
this invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
According to this invention the liquid to be measured is delivered into a vessel

page_text: connected to the delivery nozzle and liquid is escaping from the cylinder. The
height to which the piston can be raised by the incoming fluid is limited and
therefore the quantity of fluid which can be admitted is determined in the following
manner :-
Fixed to the cylinder and through it to the frame-work and cock is an inner
casing upon which an outer casing is free to turn. The inner casing has in it two
vertical slots e el in which two pins b' ' fixed to the piston bare free to work up
and down. The outer casing has in it two can slots each with an incline and
steps which receive the ends of the pins & and limit their rise so that the height
to which the piston can be raised is determined by the angle through which the
casing is turned. The casing carries a toothed are which is driven by a
pinion gearing with a wheel which is free to turn on the axis of the handle k
of the cock. The wheel h has in it a semi-circular slot which receives a pin
carried by the disc which is fixed to the axis k¹ of the cock.
When it is desired to obtain a measured quantity of fluid the handle k is turned
The effect of the
from the position shown in Figure 4 in the direction of the arrow.
first motion is to turn the wheel h pinion g and casing and thereby owing to the
inclines to slightly raise the piston whilst the cock is still open to the air so that
a small quantity is sucked in. This air assists in expelling the last of the liquid at
the conclusion of the operation and thereby prevents the tap from dripping. As the
handle is continued to be turned the parts are brought into the position shown in
Figure 3 with the cylinder connected to the supply- d. The casing carries a
pointer and the handle k is continued to be turned until this hand points to the
figure on the dial (Figure 2) which corresponds to the quantity of fluid which it is
desired to draw. The piston is now free to rise until the pins &¹ are arrested by one
or other of the steps in the cam slots corresponding to the angle through which
the casing has been turned. As the fluid enters the cylinder the piston bis forced
up until it is arrested as above described. In order to show when the piston is fully
up and the desired quantity of liquid has therefore entered the cylinder a second
index or hand m is provided. The stem m¹ of this hand carries a pin m³ which
projects through a helical slot in a tube fixed to the pistol b, the result is that as the
piston rises the hand m is caused to turn following the hand and when the piston b
ceases to rise by reason of the pins 1 having come against one or other of the
steps the hand m will stop immediately abovo the hand in whatever position the
latter may be. The handle & is now turned off again. The first part of the motion
only brings the plug into the position shown in Figure 5 putting the cylinder into
communication with the delivery nozzle without turning the casing f for the pin "
moves free in the slot A'. The fluid now passes out of the cylinder and the piston
descends being pressed down by the spring and as it clears the steps fit is caused
to rotate back again by the spring f. The last portion of the fluid is expelled by the
expansion of the small quantity of air which was drawn into the cylinder during the
first rise of the piston. The passages in the cock are made somewhat bell mouthed so
that they can operate at the different angles necessary to enable the varying quantities
to be drawn off.
It will be obvious that the action of the apparatus may be reversed the measuring
vessel being kept normally full of liquid of which more or less is delivered according
to the angle through which the tap is turned. It will also be obvious that by using
a heavy piston the spring & may be dispensed with.
Although I have shewn the cylinder with double walls having the india rubber
between them and also the india rubber supported by alternate rings inside and
outside these being the best means known to me of carrying out my invention I
would observe that these details of construction form the subject of a separate
application for a Patent made by me.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I would state that I make
no general claim to delivering measured quantities of liquid by admitting it to or

page_text: drawing it off from a cylinder whose capacity is regulated by interposing a stop or
stops in the way of the piston so as to limit its travel nor do I make any general
claim to apparatus for delivering measured quantities of fluid in which the quantity
delivered depends upon the angle through which the tap is turned, but what I
claim is
1. Apparatus for delivering measured quantities of liquid in which the measuring
vessel consists of a cylinder having a piston working within it, the length of travel
of the piston being regulated by a stop or stops which come against steps in a cam
tube rotated by the turning of the cock substantially as described.
2. In apparatus for delivering measured quantities of liquid making the measuring
vessel air tight by means of a flexible tube one end of which is connected to the
cylinder and the other end to the piston substantially as described.
3. In apparatus such as is claimed in the preceding claims providing two indicators
one to show for what quantity the apparatus is set the other to show when that
quantity has entered the measuring vessel substantially as described.
4. The combination of the cylinder the piston, the flexible tube the cam tube and
the cock all substantially as described.
Dosted 1
10
1000