GB1591881A

GB1591881A - Liquid metering apparatus

Info

Publication number: GB1591881A
Application number: GB5061277A
Authority: GB
Original assignee: Grundy Teddington Ltd
Current assignee: Alumasc Grundy Ltd
Priority date: 1978-04-27
Filing date: 1978-04-27
Publication date: 1981-07-01

Description

(54) LIQUID METERING APPARATUS (71) We, GRUNDY (TEDDINGTON) LIMITED, a British Company of Somerset Road, Teddington, Middlesex TW11 8TD, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention concerns a liquid metering system for liquids under pressure and has for its main object to provide an apparatus of compact form and which is capable of dispensing metered quantities of liquid accurately and speedily.

The invention is primarily for the dispensing of beverages such as beers in bulk from pressurised casks, and according to a preferred arrangement the invention seeks to provide an apparatus utilising a conventional beer or the like cooler and which also serves to meter the desired quantities e.g. l pint.

According to this invention there is provided a liquid metering apparatus for liquid under pressure said system comprising a coiled tube having its ends secured adjacently in a manifold, a piston element within the tube, seatings for the piston at each end of the tube, a liquid inlet pipe and an outlet pipe to the manifold, sensing means for sensing the piston when on the one or the other seating, valve means carried by the manifold said valve means controlling passage ways between the tube ends and the inlet and outlet and being actuated by a manual control, which control also opens or closes a dispense point from the outlet pipe with the valve means arranged so that when said control is actuated with the piston or plunger on the one seating at one end of the tube the valve means connect the liquid inlet to the said one end and the other end to the outlet whereby the volume of liquid in the tube is expelled, the liquid flow being cut-off by the valve means actuated by the sensing means when the piston reaches the seating at the other tube end, next actuation of the manual control opening the dispense point outlet and actuating the valve means in a reverse direction of liquid flow so that thc liquid inlet is connected to the other tube end and the outlet to the one said end whereby the piston is forced along the tube to expel the volume of liquid in the tube, the liquid flow being cut-off by the valve means actuated by the sensing means when the piston reaches the seating at the one end of the tube.

In the preferred arrangement above mentioned, a cooling system of generally conventional form is used this comprising a water bath having a refrigerating unit therein the water being agitated to maintain a substantially constant temperature which is thermostatically controlled. A coiled tube of good heat conductivity is located within the bath so that liquid therein is maintained at desired temperature. This coiled tube, generally referred to as the "product tube" is, according to this invention, utilised as the liquid measure, being of such bore and length that the internal volume between the seatings is of the required volume e.g. 2 pint.

Preferably a fob trap is included between the manifold and dispense point, the fob trap comprising a chamber of capacity greater than the dispensed volume and a float operated switch means arranged to render the dispense control inoperative when the liquid level falls below a predetermined level. In an embodiment the dispense point has a manually operable switch and a solenoid dispense valve, the switch initiating dispensing of the liquid.

Preferably the sensing means comprise photo-electric means.

The photo-electric means conveniently provide a signal to an electronic control to effect the change over of the valve means after a dispense and when the piston or plunger engages a seating.

The apparatus conveniently includes a bistable circuit operative to connect the valve means in one or other directions of flow, a latch circuit operative through a dispense point switch to initiate the flow by opening the valve means, in the selected flow direction, the latch maintaining the valve means open until operation of the sensing means which effects closure of the valve means through the latch and changes the state of the bistable.Preferably the bistable circuit comprises a flip-flop controlling a relay which effects energizing of the valve means, the latch comprising an operational amplifier arranged to be momentarily unbalanced by the dispense point switch and thereafter held unbalanced by the sensing means after the ball has left one or other seating, the balanced condition being restored when the ball again reaches a seating, to close the valve means.

A valve at the dispense point may be arranged to operate simultaneously with the valve means.

An embodiment according to the invention will now be described with reference to the accompanying drawings wherein: Figure l shows schematically and in perspective an arrangement for a beer metering dispenser in conjnction with a cooling unit, Figure 2 shows a modified arrangement of Figure 1, and Figure 3 shows a schematic diagram of the electrical circuit severing to control and dispensing and metering process.

As shown in Figure l a bath l containing water 2 has a refrigerating unit therein, an agitator (not shown) also being provided. A coiled tube 3 of stainless steel is provided within the bath. This arrangement of "beer cooler" is conventional.

A manifold block 5 of transparent plastic is mounted on the outside of the bath, and the ends of the coil 3 are brought out of the bath in parallel adjacent rclation and each secured in a bore in the manifold block. A ball 11 of rubber or like material forms a piston element and is located in the coil and ores. The ball when at the one or the other end of the ciol and in a bore, engages on a seating (not shown) valve fashion. A lightdependent resistor 12 is mounted on the manifold at one side and a light source 13 is mounted at the other side. The ball when on either seating interrupts the light beam.

Solenoid actuated valves A,A, B,B, are provided, mounted on the manifold. Beer from a pressurised cask is led to the block via an inlet pipe 4, and an outlet pipe 6 connects to a manually actuated control located on a counter or the like. The solenoid valves are connected in pairs, each one inlet and one outlet valve so that those of each pair operate together. Appropriate bores or porting are provided in the manifold. so that alternate valve pair operation changes over the inlet and outlet with respect to the coil ends. The solenoids are operated by appropriate electronic control means 1 9 later described, the manual control consisting of a press button 9 which operates a solenoid 10 connected to the electronic means.

In operation, assuming the ball is at the coil end A on its seating, then on pressing the button 9 beer flows from the cask to the coil end A, the ball being moved along the coil piston fashion the beer in the coil thus being forced out of the coil end B and through the outlet pipe and a metered quantity of beer is dispensed between locations A and B. When so dispensed the ball reaches the seating at end B to close the outlet and the interruption of the beam results in change over for the next actuation, when a further operation of the press button 9 results in beer flowing from the inlet to the coil end B to force out the quantity in the tube between locations B and A.

A pump may be included between the keg and manifold 5, and in addition a fob trap may be provided between the keg and pump.

The fob trap consists of a chamber having a volume considerably in excess of a half pint. The chamber has an outlet and inlet, both of which are positioned low down so as to be below beer level at all times. Beverage passes through the chamber and any fob which is in the system floats to the top of the chamber and results in a lowering of the beverage level. The chamber also houses a float switch which is connected in series with the dispense signal button in the bar. When the beverage level falls below its switching point, the button 9 becomes inoperative, thus preventing the meter from being operated when the beverage supply fails.

Since the capacity of the chamber is larger than the half pint, the meter is able to finish dispensing a complete half pint without becoming unprimed.

Figure 2 shows an arrangement which is generally similar to that shown in Figure 1 but the manifold block, valves, and associated components are mounted on lid of the water bath. In this arrangement, two light dependent resistors 12, 12a are employed, the light source 13 being located between them. the light being seen by both resistors.

Referring to Figure 3, the manifold includes four solenoid operated valves which are connected in two pairs. Each pair comprises a valve controlling the inlet 4 and outlet 6. The first pair of valves RA cause the inlet 4 to be connected to the end A of the coil 3 and the outlet 8 of the coil 3 to be connected to the outlet 6. The other pair of solenoids RB when energised cause the inlet 4 to be connected to the end B of the coil 3, and for the end A of the coil 3 to be connected to the outlet 6. Appropriate energisation of either pair of coils establishes the direction of flow of beverage through the coil 3 and hence to the outlet 8. One or other pairs of the solenoids RA or RB are placed into circuit through changeover contacts associated zith a relay C which is driven through transistor Q1 from the output of a bi-stable flip-flop FF. Relay C contacts are energised together with operation of the tap solenoid D and the pump relay E.

The light dependent resistors are connected to one input of an operational amplifier F forming a latch and this is adjusted by a potentiometer G to establish the correct operating point. The output of the operational amplifier F drives transistor Q2 which is connected with relay H. When the ball 11 lies in the path of the light, that is when it is on its seating at one or other ends of the coil, the relay H is not energised. The button 9 serves to momentarily unbalance the operational amplifier and causes relay H to be energised, thus allowing the tap solenoid D and one or other pairs of the solenoids RA or RB to be energised via relay C. The beverage is dispensed, and after the ball 11 lifts from its seating the light dependent resistors 12 are illuminated by the light source 13 and maintain the operational amplifier out of balance, thus holding relay H energised.When the ball 11 reaches the seating at the other end of the coil the light is interrupted and the operational amplifier de-energises realy H, thus shutting down the supply. At the same time capacitor C1 provides an impulse-like charge to be fed to the flip-flop which then changes state causing relay C to either energise or de-energise according to the previous position, and thus for the appropriate energising line to be connected to the other of the relay pairs RA or RB. The next actuation of the bar switch 9 will cause the appropriate pair of relays RA or RB to be energised and thus the beverage will flow in the opposite direction, terminating once again with the ball 11 interrupting the light to the light dependent resistor 12.When the button 9 is again depressed capacitor C1 will have already provided a further pulse to the flip-flop upon earlier de-energisation of relay H and relay C is then effective to produce appropriate energisation of the correct relay pair RAorRB.

Should the flip-flop not be correctly synchronised with the direction of flow, then on operation of the button 9 the beverage will be caused to flow in a direction which forces the ball 11 onto the seating at the end of the coil, and no beverage will be dispensed. The next operation of the button 9 will synchronise the system and cause the appropriate relay pair RA or RB to be energised according to the position of the ball 11.

WHAT WE CLAIM IS: 1. A liquid metering apparatus for liquid under pressure said system comprising a coiled tube having its ends secured adjacently in a manifold, a piston element within the tube, seatings for the piston at each end of the tube, a liquid inlet pipe and an outlet pipe to the manifold, sensing means for sensing the piston when on the one or the other seating, valve means carried by the manifold said valve means controlling passageways between the tube ends and the inlet and outlet and being actuated by a manual control, which control also opens or closes a dispense point from the outlet pipe with the valve means arranged so that when said control is actuated with the piston or plunger on the one seating at one end of the tube the valve means connect the liquid inlet to the said one end and the other end to the outlet whereby the volume of liquid in the tube is expelled, the liquid flow being cut-off by the valve means actuated by the sensing means when the piston reaches the seating at the other tube end, next actuation of the manual control opening the dispense point outlet and actuating the valve means in a reverse direction of liquid flow so that the liquid inlet is connected to the other tube end and the outlet to the one said end whereby the piston is forced along the tube to expel the volume of liquid in the tube, the liquid flow being cut-off by the valve means actuated by the sensing means when the piston reaches the seating at the one end of the tube.

2. A liquid metering apparatus as claimed in Claim 1, wherein a fob trap is included between the manifold and dispense point, the fob trap comprising a chamber of capcity greater than the dispensed volume and a float operated switch means arranged to render the dispense control inoperative when the liquid level falls below a predetermined level.

3. A liquid metering apparatus as claimed in Claim 1 or 2, wherein the dispense point has a manually operable switch and a solenoid dispense valve, the switch initiating dispensing of the liquid.

4. Liquid metering apparatus as claimed in any preceding claim, wherein the sensing means comprise photo-electric means.

5. Liquid metering apparatus as claimed in Claim 4, wherein the photo-electric means provide a signal to an electronic control to effect the change-over of the valve means after a dispense operation and when the piston engages a seating.

6. Liquid metering apparatus as claimed in Claim 5, wherein the valve means comprise two pairs of solenoid-operated valves actuated by the electronic control to effect the change over of the direction of liquid flow through the tube.

7. Liquid metering apparatus as claimed in any one of the preceding claims for the dispensing of beverages from a pressurised bulk supply including a refrigerated water bath in which the greater part of the coiled tube is located.

8. Liquid metering apparatus as claimed in Claim 5, wherein the manifold is secured to a wall or lid of the bath and the outlet is connected to a remotely located dispense

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. tap solenoid D and the pump relay E. The light dependent resistors are connected to one input of an operational amplifier F forming a latch and this is adjusted by a potentiometer G to establish the correct operating point. The output of the operational amplifier F drives transistor Q2 which is connected with relay H. When the ball 11 lies in the path of the light, that is when it is on its seating at one or other ends of the coil, the relay H is not energised. The button 9 serves to momentarily unbalance the operational amplifier and causes relay H to be energised, thus allowing the tap solenoid D and one or other pairs of the solenoids RA or RB to be energised via relay C. The beverage is dispensed, and after the ball 11 lifts from its seating the light dependent resistors 12 are illuminated by the light source 13 and maintain the operational amplifier out of balance, thus holding relay H energised.When the ball 11 reaches the seating at the other end of the coil the light is interrupted and the operational amplifier de-energises realy H, thus shutting down the supply. At the same time capacitor C1 provides an impulse-like charge to be fed to the flip-flop which then changes state causing relay C to either energise or de-energise according to the previous position, and thus for the appropriate energising line to be connected to the other of the relay pairs RA or RB. The next actuation of the bar switch 9 will cause the appropriate pair of relays RA or RB to be energised and thus the beverage will flow in the opposite direction, terminating once again with the ball 11 interrupting the light to the light dependent resistor 12.When the button 9 is again depressed capacitor C1 will have already provided a further pulse to the flip-flop upon earlier de-energisation of relay H and relay C is then effective to produce appropriate energisation of the correct relay pair RAorRB. Should the flip-flop not be correctly synchronised with the direction of flow, then on operation of the button 9 the beverage will be caused to flow in a direction which forces the ball 11 onto the seating at the end of the coil, and no beverage will be dispensed. The next operation of the button 9 will synchronise the system and cause the appropriate relay pair RA or RB to be energised according to the position of the ball 11. WHAT WE CLAIM IS:

1. A liquid metering apparatus for liquid under pressure said system comprising a coiled tube having its ends secured adjacently in a manifold, a piston element within the tube, seatings for the piston at each end of the tube, a liquid inlet pipe and an outlet pipe to the manifold, sensing means for sensing the piston when on the one or the other seating, valve means carried by the manifold said valve means controlling passageways between the tube ends and the inlet and outlet and being actuated by a manual control, which control also opens or closes a dispense point from the outlet pipe with the valve means arranged so that when said control is actuated with the piston or plunger on the one seating at one end of the tube the valve means connect the liquid inlet to the said one end and the other end to the outlet whereby the volume of liquid in the tube is expelled, the liquid flow being cut-off by the valve means actuated by the sensing means when the piston reaches the seating at the other tube end, next actuation of the manual control opening the dispense point outlet and actuating the valve means in a reverse direction of liquid flow so that the liquid inlet is connected to the other tube end and the outlet to the one said end whereby the piston is forced along the tube to expel the volume of liquid in the tube, the liquid flow being cut-off by the valve means actuated by the sensing means when the piston reaches the seating at the one end of the tube.

outlet which caries the manual control.

9. A liquid metering apparatus in accor dancc with any preceding claim comprising a bistable circuit operative to connect the valve means in one or other direction of flow a latch circuit operative through a dis pcnsc point switch to initiate the flow by opening the valve means in the selected flow direction, the latch maintaining the valve means opcn until operation of the sensing means which cffects closure of the valve means through the latch and changes the state of the bistable.

1 0. A liquid metering apparatus in accordance with Claim 9, wherein the bist ablc circuit compriscs a flip-flop controlling a relay which cffccts cncrgising of the valve means, the latch comprising an operational amplifier arranged to be momentarily unbalanced by the dispense point switch and thereafter held unbalanced by the sensing means after the ball has left one or other seating. the balanced condition being restored when the ball again reaches a seating. to close the valve means.

1. A liquid metering apparatus as claimed in Claim 9 or 1 0 wherein a dispense point valve is operated simultaneously with operation of the valve means.

12. A liquid metering apparatus constructed and operating substantially as herein described with reference to the accompanying drawings.