Improvements in Milking Apparatus.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Milking Apparatus.
We, WILLIAM HENRY LAWRENCE, of 102, Kenmure Street, Pollokshields, in the
County of Glasgow, North Britain, Engineer, and ROBERT KENNEDY, of 109, South
Portland Street, in the same County, Dairyman, do hereby declare the nature of
this invention to be as follows, that is to say: -
This invention relates to milking apparatus partly of the kind described in our
Patent Specification Nos. 6129 and 14619 of 1896, and has for its object to improve
the construction and action of various parts of the general apparatus, and to render
it more satisfactorily applicable to large as well as to small milking establishments.
In carrying out our present invention we may employ suction-producing
apparatus of any suitable known kind; and we employ pulsating action to make
the suction acting on the cow's teats to vary intermittently but regularly between
proper maximum and minimum degrees of suction, which degrees of suction being
determined and the apparatus adjusted for them will by our improved apparatus
be maintained with practical uniformity. The pulsation apparatus is of the kind
described in our earlier specifications hereinbefore referred to, being worked by
suction and capable of being placed as near as possible to the cows or portion of
the cows to be operated on by one pulsator. In this way not only is prevented
inequality in the pulsating action which takes place when pulsation is produced
at the further end of tubing extending some distance and having branches to
various parts of a byre or milking place, but also the backward and forward move-
ments of air along long lengths of tubing such air being accompanied by vapor
from the milk pails which fouls the tubing and renders it liable to taint the air
thus passing backwards and forwards and through the air and accompanying vapor
to taint the milk.
In pulsation apparatus of the kind hereinbefore referred to we cause the valve
recess, in the piston of the pulsator cylinder or in a separate piece moved by the
piston to control three ports of which the middle one communicates with a down-
wardly extending tube dipping into a vessel the lower part of which is preferably
of glass. The top of the vessel is provided with nozzles to be connected to the teat
cups. One of the other ports controlled by the piston or valve is connected by a
pipe or passage to a closed milk receptacle which is also connected to suction-
producing apparatus, so that when the piston or valve puts this port and the
middle port in communication the suction (or maximum suction) operates through
the dipping tube and vessel and connections to the teat cups. The third port com-
municates with an air inlet valve or passage, or with minimum suction apparatus
arranged as hereinafter described. The dipping tube is perforated at its upper
part the perforations being covered by an external band of thin rubber acting as
a valve. The bottom end of the dipping tube becomes sealed with milk, and when
the minimum suction, that is the greater pressure, is by the piston or valve made
to act in the tube it expands the rubber band on the tube and thereby gets access
above the milk in the vessel to the pipes connected to the teat cups. This arrange-

page_text: ment of the parts of the apparatus prevents or greatly diminishes variations of
suction in the milk receptacle.
In combination with suction-actuated pulsators we employ devices to prevent
the degree of suction increasing beyond what is considered safe for the cows; and
we also employ devices and arrangements to prevent the degree of suction becom-
ing less than sufficient to retain the teat cups on the cows teats, the varying or
pulsating action being between those two degrees. For altering the degree of
suction from the maximum to the minimum it has heretofore been proposed to
admit some air into each pulsator at each pulsation; but such air has to be drawn
from the byre or milking place, or from the outside by a special valve and pipe
for each pulsator. It has been the practice to employ what has been termed a
vacuum reservoir for the maximum suction; but by our present invention we also
employ a second vacuum reservoir or an equivalent for the minimum degree of
suction. We arrange two lines of piping from the two reservoirs which with the
suction-producing apparatus may be outside the byre or milking place; and from
those we connect a pair of branches to each pulsator. The pulsator puts the tubes
connected to the teat cups in communication alternately at each pulsation with
the maximum and minimum branch pipes, and not alternately with a single
vacuum reservoir and with the air. With the improved arrangement the mini-
mum degree of vacuum can be much more satisfactorily controlled and regulated,
and a multiplicity of air inlet valves is avoided, the minimum degree of vacuum
being regulated for the entire installation by devices applied to its reservoir or
equivalent.
In one modification of our improved apparatus a closed vessel or so-called
vacuum reservoir has a pipe extending from its bottom down to an open tank con-
taining water and placed so that the column of water (which rises up the pipe)
corresponds to the maximum degree of vacuum, the quantity of water in the tank
being such that the bottom of the pipe is never unsealed. The vacuum reservoir
is connected to exhausting or vacuum-producing apparatus such as a steam ejector
or pump. If the vacuum increases beyond the proper degree the water rises in the
reservoir, and if the increase continues ultimately acts on a float by which it moves
a valve controlling the supply of steam thus preventing excessive suction and at
the same time saving the suction-producing power. There is a second vacuum
reservoir having a pipe descending to the same or a second tank but of a shorter
length than that of the other descending pipe and corresponding to the proper
minimum vacuum. This second reservoir may be of comparatively small capacity,
the entire pipe may be of a suitable size or it may have at its upper end an enlarge-
ment sufficient for a float which acts on an air inlet valve, the valve port com-
municating with a pipe which is the second of the pipes hereinbefore referred to as
extending to the byre or milking place.
In one modification of the device for controlling the steam supply to the ejector
or pump, an equilibrium valve is fitted in the steam pipe and its spindle is fixed
to two diaphragms in a casing, a smaller diaphragm enclosing a space at the top
of the casing and a larger one enclosing a space between the two diaphragms.
The latter space is connected by a pipe to a three-way valve which is acted on by
the float hereinbefore mentioned as in the maximum vacuum reservoir and which
when the float is in its lowest position admits air to the space between the two
diaphragms. The space above the smaller diaphragm is connected by a pipe to the
top of the maximum reservoir or to the pipe proceeding thence to the byre or milk-
ing place. The steam valve is loaded so as with the valve open to suitably balance
the atmospheric pressure acting on the smaller diaphragm against the vacuum
above it; and when the float shifts the valve it acts on and thereby connects the
space between the two diaphragms with the vacuum atmospheric pressure then
acting on the larger diaphragm and closing the steam valve.
When a pulsator puts the tubes connected to the teat cups in communication
with the minimum vacuum pipe some of the partially rarefied air in that pipe
passes through the pulsator: and the degree of vacuum becoming or tending to

page_text: become greater in the minimum vacuum pipe, the air inlet valve hereinbefore
referred to admits some air. As the milking apparatus continues working this air
inlet valve will remain just sufficiently open to continuously admit what air is
needed to maintain the minimum vacuum practically uniform.
Instead of employing the pipes with columns of water to control the vacuum
in the maximum and minimum reservoirs, suitably loaded diaphragms or pistons
may be employed being arranged so as when the degrees of vacuum vary from the
proper amounts to move valves one in connection with the maximum reservoir
controlling the supply of steam or other fluid working the suction-producing
apparatus, and the other moving the air inlet valve of the minimum vacuum
reservoir. The air-inlet valve piece is preferably of a conical or tapered form so
as to open the port very gradually.
When the mode of obtaining suction for milking purposes is by the descent
of water from a closed reservoir by a pipe of suitable length, the reservoir being
periodically filled with water by gravitation or by pumping it up to a sufficiently
elevated tank, we apply automatic devices for effecting the refilling of the reser-
voir. For this purpose a float lever within the reservoir is connected to a valve
which in one position admits water and in another puts the bottom of the reservoir
in communication with the descending pipe. The float lever or a bellcrank arm
of it is connected by a tension spring to a separately centered lever which is con-
nected to the valve. The strokes of the levers are across the line passing through
their centres, and the float-lever arm when moving from one side to the other of
the line stretches the spring without moving the valve lever until the line of the
strain of the spring just passes the line through the centre of the valve lever and
the point of attachment of the spring to that lever, and then the full force of the
spring acts to move the valve lever over. Two reservoirs may be combined and
arranged so that each is in action when the other is being refilled.
The automatic valve-moving mechanism just described is applicable for acting
on the distribution valve of the pulsator.
When the suction-producing apparatus consists of a pump worked by a hand
or by animal power, the devices hereinbefore described as for acting on the steam
supply, may be arranged to open a by-pass valve putting the opposite ends of the
pump cylinder in communication and thereby relieving the piston.
The pulsators may be worked by means of the maximum vacuum operating in
conjunction with the minimum vacuum instead of with air of atmospheric pressure
the parts being suitably proportioned to suit the available difference of pressure.
With such arrangement no atmospheric air from the byre or milking place will
have direct access to the pulsators.
Dated this Sixth day of April 1897.
EDMUND HUNT,
Applicants' Agent.
Improvements in Milking Apparatus.
We, WILLIAM HENRY LAWRENCE, of 102, Kenmure Street, Pollokshields, in the
County of Glasgow, North Britain, Engineer, and ROBERT KENNEDY, of 109, South
Portland Street, in the same County, Dairyman, do hereby declare the nature of
this invention and in what manner the same is to he performed, to be particularly
say:-
described and ascertained in and by the following statement, that is
This invention relates to milking apparatus partly of the kind described in our
-

page_text: Patent Specification Nos. 6129 and 14619 of 1896, and has for its object to improve
the construction and action of various parts of the general apparatus, and to
render it more satisfactorily applicable to large as well as to small milking estab-
lishments.
In carrying out our present invention we may employ suction-producing
apparatus of any suitable known kind, and we employ pulsating action to make
the suction acting on the cows' teats to vary intermittently but regularly between
proper maximum and minimum degrees of suction, which degrees of suction being
determined and the apparatus adjusted for them will by our improved apparatus
be maintained with practical uniformity. The pulsation apparatus is of the kind
described in our earlier specifications hereinbefore referred to, being worked by
suction and capable of being placed as near as possible to the cows or portion of
the cows to be operated on by one pulsator. In this way not only is prevented
inequality in the pulsating action which takes place when pulsation is produced
at the further end of tubing extending some distance and having branches to
various parts of a byre or milking place, but also the backward and forward move-
ments of air along long lengths of tubing such air being accompanied by vapor
from the milk pails which fouls the tubing and renders it liable to taint the air
thus passing backwards and forwards and through the air and accompanying
vapor to taint the milk.
In combination with the suction-actuated pulsators we employ devices to pre-
vent the degree of suction increasing beyond what is considered safe for the cows;
and we also employ devices and arrangements to prevent the degree of suction
becoming less than sufficient to retain the teat cups on the cows' teats, the varying
or pulsating action being between those two degrees. For altering the degree of
suction from the maximum to the minimum it has heretofore been proposed to
admit some air into each pulsator at each pulsation; but such air has to be drawn
from the byre or milking place, or from the outside by a special valve and pipe
for each pulsator. It has been the practice to employ what has been termed a
vacuum reservoir for the maximum suction; but by the present invention we also
employ a second vacuum reservoir, (or an equivalent) for the minimum degree of
suction. We arrange two lines of piping from the two reservoirs which with the
suction-producing apparatus may be outside the byre or milking place; and from
these we connect a pair of branches to each pulsator. The pulsator puts the tubes
connected to the teat cups in communication alternately at each pulsation with
the maximum and minimum branch pipes, and not alternately with a single
vacuum reservoir and with the air. With the improved arrangement the minimum
degree of vacuum can be much more satisfactorily controlled and regulated, and
a multiplicity of air inlet valves is avoided, the minimum degree of vacuum being
regulated for the entire installation by devices applied to its reservoir or equivalent.
When a pulsator puts the tubes connected to the teat cups in communication
with the minimum vacuum pipe some of the partially rarefied air in that pipe
passes through the pulsator; and the degree of vacuum becoming or tending to
become greater in the minimum vacuum pipe, the air inlet valve herein before
referred to admits some air. As the milking apparatus continues working this
air inlet valve will remain just sufficiently open to continuously admit what air
is needed to maintain the minimum vacuum practically uniform.
When the suction-producing apparatus consists of a pump worked by hand or
by animal power, devices for acting on the steam supply, may be arranged to open
a by-pass valve putting the opposite ends of the pump cylinder in communication
and thereby relieving the piston.
The pulsators may be worked by means of the maximum vacuum operating in
conjunction with the minimum vacuum instead of with air of atmospheric pressure
the parts being suitably proportioned to suit the available difference of pressure.
With such arrangement no atmospheric air from the byre or milking place will
have direct access to the pulsators.

page_text: And in order that the said invention and the manner of performing the same.
may be properly understood we hereunto append three sheets of explanatory draw-
ings to be hereinafter referred to and representing various portions of milking
apparatus as made with our improvements.
Figures, 1, to 6, on Sheet, 1, of the drawings show the improved pulsation-
producing apparatus, Figure, 1, being a plan, Figures, 2, and 3, elevations as at
right angles to each other, Figure, 4, a vertical section; and Figures, 5, and 6,
enlarged vertical and horizontal sections of the pulsation cylinder and valve
details.
Figure, 7, is an elevation of one modification of the suction-producing apparatus,
Figure, 8, being an enlarged section of a detail; and Figures, 9 to 12, on Sheet, 2,
are enlarged sectional views of parts of the apparatus. Figure, 13, is a vertical
section of apparatus for controlling the minimum suction; and Figure, 14, is a
vertical section of another modification of the suction-producing apparatus.
Figure, 15, on Sheet, 3, is a vertical section of apparatus to be used when the
suction is produced by hand or animal power.
In these drawings the same reference letters and numerals are used to mark
the same or like parts wherever they are repeated.
In the pulsation-producing apparatus (Figures, 1 to 6, Sheet, 1) the maximum
suction pipe, F1, is connected to a milk receptacle, J, and the minimum suction
pipe is connected, by a flexible branch tube or otherwise, to a pipe, H 1. The pul-
sating action is produced by means of a double-ended or elongated piston, K,
working in a cylinder, K1, middle parts being as it were cut away from the upper
halves of both piston and cylinder. The cylinder passages, K2, are partly in an
upper piece, K3, which in a central cylindrical chamber formed in it has a four-
way oscillating valve, L, which puts the cylinder passages alternately in com-
munication with inlet and exhaust passages, K4, one being connected by a
pipe, K5, with the minimum suction branch pipe, H1, and the other by a
pipe, K 6, with a pipe, M, in which the maximum suction acts. The piston ends
are packed by cup leathers, K 7, which are kept out by helically coiled annular
springs placed in grooves. The pipe, M, forms a connection between the pulsation
apparatus and the milk receptacle, J, in which the maximum suction is maintained
by means of the pipe, F1, and which is otherwise closed during a milking opera-
tion. The pipe, M, also serves as a convenient handle for lifting the pulsation
apparatus by when transferring it from one receptacle to another, a bracket, M 1,
on the apparatus bearing against the receptacle when the apparatus is in position.
The valve, L, is moved by a part, L1, which moves partly with it, and is itself
moved by means of a crank pin, L2, formed on it. On a stud fixed in the cylinder
there is centered a lever, N, which extends between the valve and the cylinder at
the part where the cylinder and piston are cut away, and this lever is moved by a
stud, N 1, on the piston. A helical spring, N 2, connects the end of the lever, N,
to the crank pin, L2, of the valve, L, L1. As in the arrangement shown in
Figure, 1, and hereinbefore described the centres of the lever, N, and valve crank
pin, L2, bisect the angles between the extreme positions of the lever and crank
pin; and when the lever is, by the action of the piston moving from one extreme
position to the other, it does not move the valve crank pin, L2, until the line of
the spring (which is between the two) just crosses the axis of the valve, but then
the spring which is in a stretched condition forcibly and quickly shifts the valve
The piece, L1, directly acted on by the spring, is fitted to the valve, L,
with a small extent of play between clutch-like engaging parts, so that motion of
the piece, L1, is well started before the resistance of the valve is encountered.
With the view of still further insuring the proper action of the valve, the lever, N,
is made with horns, N3, which strike the valve crank pin, L2, as the lever reaches
either of its extreme positions. The rate at which the piston works is adjusted
or regulated by means of conical pointed screw plugs, P, by means of which the
free passage through the cylinder passages, K2, is regulated, these plugs pro-
over.

page_text: jecting more or less into holes formed in the small plates fixed in the joints between
the cylinder, K 1, and the valve piece, K 3.
The piston, K, has formed in its under side a recess, Q, like, that of an ordinary
slide valve, which as the piston moves works over three ports, Q1, Q2, Q3, these
ports_communicating with passages in a piece, R, fixed to the underside of the
cylinder, K 1. One port, Q1, and passage communicates with the minimum
suction pipe, H 1, and another, Q3, with the maximum suction pipe, M. The
middle port, Q2, which which the piston recess, Q, puts alternately in communication
with the other two, communicates with a pipe, R 1, dipping down to near the
bottom of a glass vessel, R2 (which may be an ordinary glass tumbler). The
vessel, R2, is held in position by a bottom plate, R3, connected by springs to the
piece, R, the upper edge of the vessel bearing up against a rubber ring. This
arrangement allows of the glass vessel, R2, being easily detached when required.
Outside of the pipe, R 1, the vessel, R 2, is in communication with a space formed
in the piece, R, and with nozzles, R4, having stopcocks and which are to be con-
nected to the teat cups by means of flexible tubing. Within the piece, R, the
upper part of the pipe, R 1, has perforations made in it which are encircled by a
tube or band, R 5, of thin rubber, the upper edge of which is slit between the holes
to facilitate its opening like a valve. The maximum suction causes milk to be
drawn from the cow's teats into the vessel, R2, whence it passes up the pipe, R 1,
through the piston valve recess, Q, and through the pipe, M, into the receptacle, J.
When from the movement of the piston the middle port, Q2, and pipe, R1, are put
in communication with the minimum suction pipe, H1, the greater actual pressure
of the minimum suction acting in the pipe, R 1, causes the rubber band, R 5, to ex-
pand and acting like a valve to allow air to pass above the milk in the vessel, R 2,
without having to force its way through the milk. When this is taking place the
vessel, R2, is quite shut off from the milk receptacle, J, so that the larger pressure
of the minimum suction has not to be distributed over the large internal space of
the milk receptacle. The lower part of the pipe, R 1, in the glass vessel, R2, is
encircled by a perforated cone, R6, which acts as a strainer to prevent foreign
matters passing with the milk to the milk receptacle, J.
a
In the modification of suction-producing apparatus shown in Figures, 7 to 12,
Sheets, 1, and 2, a closed vessel or so-called vacuum reservoir, A, has a pipe, A 3,
extending from its bottom down to an open tank, A 4, containing water, placed so
that the column of water (which rises up the pipe) corresponds to the maximum
degree of vacuum, the quantity of water in the tank being such that the bottom of
the pipe is never unsealed. The vacuum reservoir, A, is connected by a pipe, F, to
exhausting or vacuum-producing apparatus, such as a steam ejector, S, or it might
be a steam pump. If the vacuum increases beyond the proper degree, the water
rises in the reservoir, A, and if the increase continues, ultimately acts on
float, A5, by which it moves a valve, A 6, controlling the supply of steam, thus
preventing excessive suction, and at the same time saving the suction-producing
power. There is a second vacuum reservoir, G, having a pipe, G 8, descending to
the same tank, A4, or it might be a second one, but of a shorter length than that
of the other descending. pipe, A3, and corresponding to the proper minimum
vacuum. This second reservoir, G, may be of comparatively small capacity; the
entire pipe, G8, may be of a suitable size or it may have at its upper end an
an air inlet
enlargement sufficient for a float, G9 (Figure, 11) which acts on
valve, 9 G, the valve box communicating with a pipe, H, which is the second of
the pipes hereinbefore referred to as extending through the byre or milking place.
If from any cause the suction in the minimum reservoir, G, and pipe, H, becomes
too small that is if the pressure becomes too great, some air is withdrawn thence
into the maximum suction pipe, F, through a cup-shaped cylindrical valve, 8 G,
which is suitably loaded, but which rises and cuts off the connection by the action
of atmospheric pressure on its bottom on the proper vacuum being attained.
In one modification of the device for controlling the steam supply to the ejector
or pump, an equilibrium or double-beat valve, T, (Figure 12) is fitted in a

page_text: casing, T 1, attached to the steam pipe, T2, (Figure 7) and its spindle, T3, is fixed
to two flexible diaphragms, T4, T5, in the casing a smaller diaphragm, T4, enclos-
ing a space at the top of the casing and a larger one, T5, enclosing a space between
the two diaphragms. The latter space is connected by a pipe, T 6, to the valve, A 6,
which is a three-way one and is acted on by the float, A5, hereinbefore mentioned,
in the maximum vacuum reservoir, A, and which when the float is in its lowest
position admits air to the space between the two diaphragms, T4, T5. The space
above the smaller diaphragm, T4, is connected by a pipe, T7, to the top of the
maximum reservoir, A, or to the pipe, F, proceeding thence to the byre or milking
place. The steam valve, T, is loaded by means of a weighted lever, T8, so as, with
the valve open, to suitably balance the atmospheric pressure acting on the smaller
diaphragm, T4, against the vacuum above it, and when the float, A 5, shifts the
valve, A6, it thereby connects the space between the two diaphragms, T4, T5,
with the vacuum, atmospheric pressure then acting on the larger diaphragm and
closing the steam valve, T.
Instead of employing the pipes (A3, G8) with columns of water to control the
vacuum in the maximum and minimum reservoirs, suitably loaded diaphragms or
pistons may be employed, being arranged so as when the degrees of vacuum vary
from the proper amounts, to move valves, one in connection with the maximum
reservoir controlling the supply of steam or other fluid working the suction-produc-
ing apparatus, and the other moving the air inlet valve of the minimum vacuum
reservoir. The air-inlet valve piece is preferably of a conical or tapered form so
as to open the port gradually. Figure, 13, Sheet, 2, shows the application of con-
trolling valves to a minimum suction reservoir, G.
This minimum suction apparatus is connected by a branch pipe, F8, to the
maximum suction pipe, F. What may be termed a minimum suction reservoir, G,
which may be of any suitable size, is connected to the maximum suction branch
pipe, F 8, through a port controlled by a conical valve, G 1, the spindle of which
is fixed to and extends through a flexible diaphragm, G2, and has a loaded
lever, G3, applied to it externally. The diaphragm, G2, being acted on by the
external atmospheric pressure causes the valve, G1, to close on the suction in the
reservoir, G, becoming stronger than that decided to be the minimum suction,
the valve opening when the suction in the reservoir, G, is not so strong as it should
be. In order to prevent the suction in the reservoir, G, from remaining too strong
a second valve, G4, is provided its spindle being fixed to a flexible diaphragm, G5,
and acted on by a loaded lever, G6. When this valve is opened by the action of
atmospheric pressure on the diaphragm, G5, it admits some air from a pipe, G7,
which may extend to any desired distance so as to receive air which is uncon-
taminated. A pipe, H, connects the minimum suction apparatus with the pulsa-
tion apparatus next to be described.
When the mode of obtaining suction for milking purposes is by the descent of
water from a closed reservoir by a pipe of suitable length, the reservoir being
periodically filled with water by gravitation or by pumping it up to a sufficiently
elevated tank, we apply automatic devices for effecting the refilling of the reservoir.
Figure, 14, Sheet, 2, shows two cisterns, A1, A2, combined, in one, A 1, of which
a ball float, B, fixed to a bellcrank lever, one arm, B 1, of which is connected by
a spring, B2, to a lever, B3, connected by a link, B4, to a valve rod, C. At the
completion of each stroke or movement the levers, B1, B3, are nearly parallel,
their centres being on a line which bisects the angles between the extreme positions
of the levers. As the lever, B1, moved by the float, proceeds from one extreme
towards the other, it does not move the lever, B3, until it has carried the connect-
ing spring, B2, just past a line passing through the centre or fulcrum of the
lever, B3, and the point of that lever to which the spring is attached. The
spring, B2, is then in a stretched condition and acts suddenly and forcibly in
pulling the lever, B3, over or to its opposite extreme position. The valve rod, C',
moves a distribution piston valve, C1, fitted to work in a cylindrical valve box, C2,

page_text: fixed so as to be partly in one cistern, A 1, and partly in the other, A2, two ports
opening one into each cistern. The valve box is made with three other ports, a
middle one communicating with a discharge pipe, D, and the other two communi-
cating with a pipe, E, through which is supplied from any convenient source water
of a pressure sufficient for filling either cistern. The valve piece, C1, is made with
two recessed parts which form communications according to the position of the
valve, between the cistern ports and the discharge and supply ports. In the
drawing one cistern, A 1, is shown as just filled with water, and with its port just
put into communication with the discharge pipe, D, whilst the other cistern, A2,
is just beginning to receive a fresh supply of water. The valve rod, C, is not fixed
to the valve piece, C1, but passes through a central bore formed therein, and it
acts on the valve piece by collars fixed on it so as to have a small extent of play.
The purpose of this is that the spring, B2, when shifting the lever, 13, may start
the lever and the rod, C, well into motion before the resistance of the valve
piece, C1, is encountered.
Suction is produced in the cistern, A 1, or A 2, from which the water is at any
time being discharged by the weight of the column of water in the discharge
pipe, D, which is extended downwards to a length of about twelve feet (or what-
ever length corresponds to what is considered to be a suitable maximum strength
of suction) the lower end being sealed by dipping into water or having a non-
return valve fitted to it.
At the top of each cistern, A1, A2, there is a valve, F2, opening inwards, con-
trolled by a diaphragm and spring, F3, F4, adjusted so that the valve opens only
when the strength of suction in the cistern reaches the predetermined maximum;
and when either valve is opened it makes communication with a pipe, F, which is,
or is connected to, the main maximum suction pipe of the apparatus.
The
eistern, Al, in which is the float, B, has at the top of it an outlet check valve, F 5,
for the escape of air when the cistern is being filled with water; and the other
cistern, A 2, has a double-acting valve, F 6, to which is attached a small float, F 7,
the valve opening to allow air to escape when the cistern is filling with water and
closing by the action of the float if the water rises too high.
Figure, 15, Sheet, 3, shows in combination with' some parts hereinbefore described
a by-pass valve to be used as herein before mentioned when the suction is produced
by means of a pump worked by hand or animal power. The pump cylinder, V,
has in its end a port, V 1, communicating with a valve box, V2, provided with
inlet and discharge valves, V3, V4, the former communicating by a pipe, V5,
with the interior of the vacuum reservoir cistern, A. The valve box, V2, is pro-
vided with two flexible diaphragms, T4, T5, and connecting pipes, T6, T7, as
described with reference to Figure, 12; and there is a third diaphragm, V6, the
under side of which is acted on by atmospheric pressure, an adjustable spring, V 7,
acting on the spindle opposing the atmospheric pressure to a suitable extent. The
middle diaphragm, T5, acts as the by-pass valve, bearing when closed on a raised
annular edge or seat, VS. On the suction becoming too great it acts in the space
between the diaphragms, T4, T5, as hereinbefore described raising the lower one
and allowing air to enter.
At each place where connections between the maximum and minimum suction
pipes, F, H, have to be made to a pulsator, (W, Figure, 7) a valve box, W 1, shown
enlarged in Figure, S, is fixed on the two pipes, this box being made with nozzles,
W2, W3, for the attachment of rubber connecting tubes. Communication with
either pipe, F, or H, is automatically closed whenever the rubber tube is detached
or atmospheric air has access to either nozzle, W2, or W 3. A simple check
valve, W4, is sufficient for the minimum suction pipe, H; whilst for the maximum
suction pipe, F, there is a loaded valve W 5, fixed to a diaphragm, W 6, externally
subject to atmospheric pressure. When suction is acting in the nozzle, W 2, the
atmospheric pressure holds the valve open, but on atmospheric pressure acting
inside the nozzle the valve closes.

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. In milking apparatus operating by suction the combination with pulsation-
producing apparatus worked by suction, of two main pipes connected to closed
vessels or so-called vacuum reservoirs or their equivalents, such pipes having main-
tained in them respectively maximum and minimum strengths of suction sub-
stantially as and for the purposes herein before described.
2. The combination with the pulsation cylinder of a vessel (R 2) through which
the milk has to pass on its way to the cylinder and thence to the receptacle (J)
the communication with the cylinder being through a dipping tube (R1) the
lower end of which is sealed by the milk, whilst at its upper perforated part a
rubber band acts as a valve to allow minimum-suction air to pass to the teat cups
without passing through the milk substantially as hereinbefore described.
3. In milking apparatus operating by suction and having at a distance from the
main suction producing apparatus pulsation producing apparatus worked by
suction, improved pulsation producing apparatus consisting of a cylinder having
in it a double-ended or elongated piston in which piston is a valve recess controlling
three ports communicating, one with the teat cups, the second with a milk
receptacle in which the maximum suction is maintained, and the third with a pipe
in which the minimum suction is maintained, the said cylinder having a distribu-
tion valve moved by a crank pin on it connected by a spring to a lever moved by
the piston, the axis of the valve and its crank pin being in a line which also passes
through the axis of the lever and bisects the angles between the extreme positions
of the crank pin and lever, the lever consequently not moving the crank pin until
it has moved the spring across the axis of the valve, substantially as hereinbefore
described.
4. In milking apparatus operating by suction produced by means of two cisterns
alternately filled with water, which water descends from each, alternately, through
a pipe extending downwards to a length corresponding to the strength of maxi-
mum suction desired, an automatic distribution valve moved by means of a float
in one of the cisterns, a lever moved by the float being connected by a spring to a
valve lever which shifts the valve, and the centres of the said float lever and valve
lever being on a line bisecting the angles between the extreme positions of the
levers, the float lever consequently at each stroke moving the connecting spring
across the centre of the valve lever before moving the latter, substantially as here-
inbefore described.
5. In milking apparatus operating with maximum and minimum strengths of
suction, a minimum suction reservoir having a suitably loaded valve controlling
communication with a branch pipe from the maximum suction pipe, the said valve
being fixed to a flexible diaphragm acted on externally by atmospheric pressure
and also having a suitably loaded valve controlling communication with an air
inlet pipe and fixed to a flexible diaphragm acted on externally by atmospheric
pressure, substantially as herein before described.
6. The combination of apparatus shown in Figures, 7 to 12, of the accompanying
drawings for producing and controlling or regulating maximum and minimum
strengths of suction substantially as hereinbefore described.
7. The combination of apparatus shown in Figure, 13, of the accompanying
drawings, for controlling or regulating the vacuum in a minimum suction vessel
or reservoir, substantially as and for the purposes hereinbefore described.
8. The valve actuating device as applied to the distributing valve of a suction-
producing water cistern having two compartments, or to the distributing valve of
a pulsation-producing cylinder, and consisting of a valve moving lever, connected
by a spring to a float-moved or piston-moved lever arranged so that the latter lever
has at each stroke to move the spring across the axis of the former before moving
it substantially as hereinbefore described.

page_text: 2004
9. In suction-producing pumping apparatus worked by hand or animal power
the combination of a by-pass valve arranged to open on the maximum strength of
suction being reached substantially as hereinbefore described.
EDMUND HUNT,
Applicants' Agent.