Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~ '~77303
This invention relates to a head for controlling
operation of a push/pull type valve or tap in a liquid delivery
line. A typical example is a beer tap for serving draft beer.
sACXG~OUND O~ ~HB I~V~NTION
There are numerous situations in which foaming in
liquids creates serious problems in liquid delivery lines. The
foaming may result in the delivery of incorrect quantities or in
wastage due to material foaming out of a container.
While the invention is not limited to any one
particular application, it is very useful in the control of draft
beer delivery and so will be discussed in that context. There
are a number of problems associated with the serving of draft
beer which result in a substantial loss of profits otherwise
arising out of the sale oE beer. These include losses arising
out of a bartender dispensing free drinks and losses arising out
of the difficulty of dispensing draft beer using a conventional
tap.
The problem of free drinks can be readily remedied by
the replacing of the conventional handle with a closed automatic
controller which will open the tap only in response to recorded
input commands. The precise quantity o~ beer emanating from the
tap can thus be monitored.
The problem of ~osses arising out of the inherent
defficiencies of the tap present a more dlfficult problem. One
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major cause of losses at the tap is the fact that the speed of
opening and closing the tap i5 very important in controlling
foaming. If the tap is opened too quickly, the leading edge of
the beer is immediately disturbed and foaming in the tap
results. This type of foaming pro'pagates itself~ so that a very
high proportion of the beer is in a foamed state when it arrives
in the glass so that a very large "head" arises on the beer. It
is then necessary to continue to add beer until the foam flows
out of the glass and the beer reaches the required level or else
to simply pour off the foam and begin the process of pouring the
beer once again.
If the tap is closed too quickly, the leading edge of
the beer which is colliding with the closed valve in the tap will
immediately begin foaming, so that, no matter how the tap is
turned on for the next beer, there will already be foam in the
system which will then move into the glass.
While one not involved in the business might consider
that the losses to which reference is made above are trivial,
that in fact is not the case. The losses are of substantial
significance.
It goes without saying that it is very difficult for
even a conscientious barman to open and close the beer tap at the
proper speed. The fact that a busy barman will want to get as
many containers of beer from the tap as quickly as possible is a
substantial disadvantage in this respect. This is quite apart
from the fact that it is difficult in any event to ~ind the
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proper speed for opening the tap.
It is against this background that the present
invention arises. A flow controller head has now been devised
which prevents tampering and significantly reduces foaming by
controlling the speed of opening and closing of the tap or other
push/pull t~pe valve in a liquid delivery line.
PRIOR ~T
Applicant is not aware of any specific prior art
documents relevant to the invention. There have been proposed
from time to time controllers which have a relatively complicated
system of electric motors and linkages to control pouring, but
these have not proven satisfactory.
BRIE~ SUM~ ~ Y OF T~E INVE~ION
It has now been discovered that a pneumatically
15 actuated piston can be utilized to open and close a push/pull
valve at a controlled rate of speed. The rate is controlled by
predetermining one of the pressure of the air driving the piston
or the size of the fluid passages to the piston chamber and then
adjusting the other of the two to achieve the desired speed. It
is preferred that the size of the passages be chosen based on the
available air pressure.
Thus, the invention provides a liquid flow controller
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head comprising a housing, a Eirst chamber within the housing, a
piston having first and second sides and mounted in the chamber
in sea]ed sliding engagement therewith, the piston adapted to
engage and operate a push/pull activation lever of a liquld
dispensing tap, and fluid passages through the housing into the
chamber on opposite sides of the piston, and wherein the size of
the fluid passages is chosen such that, when either passage is
charged with compressed air at a predetermined pressure, the
piston will slide responsive to the pressure at a predetermined
speed.
In a preferred embodiment the controller head includes
in addition a second chamber in the housing joined to the first
chamber, a piston rod connected to the piston and in sealed
sliding engagement with the second chamber, and a third partially
threaded chamber in the housing joined to the second chamber and
adapted to threadedly engage the valve control lever housing of a
conventional beverage tap, whereby, when so engaged, the piston
rod is in operative engagement with the lever.
BRI~F SUMMARY O~ T~E DRaWI~GS
In drawings which illustrate embodiments of the
nvention,
FIGURE 1 is a cross section through a controller
according to the invention mounted on a beverage tap; and
FIGURE 2 is a perspective view of a controller
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according to the invention mounted on a beverage tap.
While the lnvention will be described in conjunction
with illustrated embodiments, it will be understood that lt is
not intended to limit the invention to such embodiments. On the
contrary, it is intended to cover all alternatives, modifications
and equivalents as may be included within the spirit and scope of
the invention as defined by the appended claims.
DETAII,ED DES~RIPTI02~_OF T~IP. PREFERRED l~MBODIM~3NTS
In the following description, similar features in the
drawings have been given similar reference numerals.
The controller head 10 is constructed within a housing
12~ ~ousing 12 includes the first preferably cylindrical chamber
14 in which the piston 16 is located. The piston 16 is in
sliding engagement with the sidewall of chamber 14. The piston
16 is sealed around its edge 18 by the sealing ring 20.
Fluid passages 22 and 24 pass through housing 12 into
chambex 14 and enter that chamber on opposite sides 26 and 28
respectively of piston 16. Fittings 30 and 32 are provided in
housing 12 at the entrances to passages 2~ and 24 respectively
for connection of fluid delivery lines. The fluid is preferably
compressed air, although other gases may be chosen.
The piston rod 34 extends from the side 26 of piston 16
into a second pxeferably cylindrical chamber 36 in housing 12.
The rod 34 is in sliding engagement with the sidewall of chamber
;
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36 and is sealed by a sealing ring 38.
Rod 3~ is provided with a slot 40 adapted to engage the
activation lever 42 of a conventional beverage tap 44.
In the usual arrangement for serving beverages such as
beer, a handle assembly is engaged with the threaded section 46
of housing 48 of tap 44.
In the present case a third chamber 50 is provided in
housing 12 of the controller head lO. The chamber 50 is threaded
to engage the threaded section 46 of housing 48 of tap 44. The
controller head lO can then simply be screwed onto the threaded
section 46 of tap 4~ in place of the conventional handle with the
top 52 of lever 42 received in the slot 40.
The lever 42 is capable of rotation about the seating
of the ball 54 which through the linkage 56 opens and closes the
tap seal 58. Beer flow is inward at 59 and out at 60.
As indicated above, a key factor in the onset of
foaming in certain foamable liquids such as beer is the speed at
which the delivery tap is opened and closed. Since the human
element in utilizing a conventional tap handle makes it virtuallv
impossible to open and close the tap at the proper speed, this is
done by controlling the rate of movement of the piston 16. This
is achieved by co-ordinating the pressure of the operating fluid
and the size of passages 22 and 24.
~ompressed air is normally available at a bar or other
beverage sales location to drive various types of liquids as may
be required. In a typical case the line pressure is 75 to 100
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psi. In the present invention with a piston 16 having a diameter
of about 1.375 inches and driven by air at a pressure of 75 to
100 psi, passages 22 and 24 having a diameter of about 0.031
inches will cause piston 16 to move at an appropriate speed to
open and close the tap 52 at a speed which will substantial
reduce foaming in beer. The entry of the compressed air to the
passages 22 and 24 can be controlled in a number of ways. For
example, a timed opening may be electronically controlled to
deliver a preset quantity of beer, or a manual control on the air
line may be utilized.
The preferred piston speed is in the range of about 12
to about 18 inches per minute or about 0.20 to about 0.33 inches
per second.
Thus it is apparent that there has been provided in
accordance with the invention a head for controlling operation of
a push/pull type valve or tap in a li~uid delivery line that
fully satisfies the objects, aims and advantages set forth
above. While the invention has been described in conjunction
~ith specific embodiments thereof, it is evident that many
alternatives, modifications and variations will be apparent to
those skilled in the art in light of the foregoing description.
Accordingly, it is intended to embrace all such alternatives,
modifications and variations as fall within the spirit and broad
scope of the in~ention.
