Liquid dispensing system

Abstract: Liquid dispensing systems include a plurality of sources (102, 202) of liquid pumped by pumps (104, 204) each with a single metering pump and each to a plurality of remote dispensing stations (109, 209) via conduits (110, 210) under the control of a control station (301). The control station (301) can select and enable any one of the remote stations (109, 209) whilst disabling all other remote stations (109, 209) from dispensing that particular liquid (102) but allowing dispensing of another liquid (202), monitor each of the flow meters and produce a display at the dispensing station (109, 209) of the volume of liquid (102, 202) which has been dispensed at that station, effect zero readings at all other dispensing stations for that liquid, and produce a display of dispensed liquid at the control station (301).

Description: This invention concerns liquid dispensing systems for dispensing measured quantities of a liquid at a number of discrete locations. British Patent Specification 2122574 describes such a system in which a single pump is used to supply a flow of the liquid to any one of a number of outlets from a single supply of the liquid. The flow of liquid through the various outlets is monitored by a single metering device, and each outlet is provided with an indication of the metered amount of liquid which has been dispensed through that outlet. The system allows only one outlet to be energised at a time so that all outlets other than that through which liquid is to be dispensed are blocked from dispensing liquid whilst that outlet is allowed to dispense liquid. According to the present invention there is provided a liquid dispensing system comprising; (a) a plurality of sources of liquid; (b) a plurality of pump means, one for pumping liquid from each of the sources of liquid; (c) a plurality of meters, one for metering the quantity of liquid pumped by each of the plurality of pumps; (d) a plurality of remote dispensing stations, each with a display for indicating the volume of liquid dispensed at that station; (e) means for directing liquid to each of the dispensing stations; (f) means for directing the liquid from one of the pump means to at least one of the dispensing stations; and (g) a control station including electronic control means (i) to select and enable any one dispensing station whereby a particular liquid is dispensable at that station; (ii) to disable all other dispensing stations whereby the selected liquid is not dispensable at any of those stations; (iii) to monitor each of the meters; (iv) to produce a reading on a display associated with said one station, said reading corresponding to the volume of the selected liquid passing through the meter and being dispensed at that station; (v) to effect a zero or null reading on all of the displays associated with the other dispensing stations for dispensing the particular liquid from the particular source; and (vi) to produce an indication on a display at the control station as to the quantity of liquid dispensed at the enabled dispensing station and the liquid dispensed. The present invention enables a number of different liquids to be displayed from a number of dispensing stations using a single control station. This has the advantage that all of the dispensing stations can be under central control whilst enabling the dispensing of various liquids and stock to be monitored from a central position. Although it is possible to allow for simultaneous dispensing of different liquids from different dispensing stations, this will necessitate disabling the dispensing of any one liquid from others of the dispensing stations. However, it is possible to dispense the same liquid simultaneously from more than one dispensing station by using the same liquid in different liquid sources, other dispensing stations served from those sources of liquid then being disabled. This can provide the system with an increased degree of flexibility since it can be used to dispense simultaneously either two different liquids or the same liquid, depending on the liquids placed in the respective sources. It is also preferred that the control station can be set so that control of the dispensing of liquid from the respective dispensing stations can be controlled either from the control station or from the individual dispensing stations. This enables the various operators of the system at the dispensing stations to effect the dispensing of different liquids according to their particular choice of liquid, an indication of the type and the amount of liquid dispensed being given at both the dispensing station and at the control station. The latter information can then be used to update stock records of the various liquids. The invention is further described hereinafter with reference to the accompanying diagrammatic drawing which is a schematic illustration of a liquid dispensing system in accordance with the invention. A system in accordance with the invention for dispensing either of two liquids will now be described with reference to the accompanying drawing. The method of dispensing each liquid is essentially similar to that used for the single liquid which is dispensed by the specific embodiment described in British Patent Specification 2122574, but with a number of components duplicated and some others omitted, as will be apparent from the following description. Tanks 101 and 201 respectively contain liquids 102 and 202 which are to be dispensed from the system, and pumps 103 and 203 serve to provide respective flows of liquids 102 and 202 from the tanks 101 and 201. The volume of liquid flowing from the tanks 101 and 201 is monitored by meters 104 and 204 respectively, the liquid being dispensed by any one of a number of dispensing stations 105 for the liquid from tank 101 and by any one of a further number of dispensing stations 205 for the liquid from tank 201. In order for each dispensing station 105, 205 to be supplied with an indication as to how much liquid is being delivered from it, it is imperative that only that dispensing station can be supplied with that liquid at any one time. A single control box 301 monitors the outputs from the meters 104 and 204 to provide an indication of the volume of the liquid which has passed though those meters, and the control box 301 serves to inactivate all other dispensing stations. The volume indication is passed from the meters 104 and 204 along lines 107 and 207, respectively. Inactivation of dispensing stations which would otherwise dispense a particular liquid is effected in the manner similar to that described in British Patent Specification 2122574. All but one of the dispensing stations for the other liquid can be disabled in an analogous manner, but one can still be activated even though dispensing of the first liquid is activated. The display box 301 includes a single numeric display 302 which indicates the volume of liquid which has been dispensed through one or other of the activated dispensing stations 105, 205, the particular liquid being dispensed being indicated by an alpha-numeric display 303. Each dispensing station 105, 205 has an associated electrically operated dispensing valve 109, 209 through which the respective liquids can be dispensed when a particular dispensing station 105, 205 is activated and a manually operable valve (not shown) is opened. The control box 301 effects control of the various dispensing stations 105 and 205 in a similar manner to that described in British Patent Specification 2122574. However, instead of the valves 109, 209 at the various dispensing stations 105, 205 being controlled by electrical signals passed along dedicated lines for those signals, control signals for the various valves 109 and 209 are passed along lines 110 and 210 which are used to feed electronic signals from the control box 301 to the dispensing stations to allow displays 111 and 211 at the respective dispensing stations to give an indication of dispensed volume corresponding to that indicated on the display 302 for that station and for resetting other slave meters to zero when they are deactivated. Dispensing can then be effected manually by an operator at the particular dispensing station where the operator is located once the station has been activated. The volume of liquid dispensed through the respective valves 109 and 209 is monitored by the respective meters 104 and 204, and an electronic signal corresponding to the monitored dispensed volume is then passed along the lines 110 and 210, the signals passing along the lines 110 and 210 being electronically coded so that only one of the dispensing stations responds, all other dispensing stations registering zero. Activation of the various dispensing stations is effected from the control box 301 via a numeric key pad 304, an indication of the selected dispensing station, the liquid dispensed at that station, and the dispensing station to which the reading on the display 302 applies are shown on the alpha-numeric display 303. Stock levels can also be displayed on the alpha-numeric display 303, for example by a selector switch (not shown) which enables the system to be switched between dispensing and stock control modes. Control of the valves 109 and 209 by electronic signals passed along the lines 110 and 210 has the advantage that if a fault occurs at one station 105 or 205, it need not necessarily lead to the whole system being closed, but merely that the faulty station becomes inoperable. Systems in accordance with the present invention particularly lend themselves to control by microprocessors, and this can enable other functions to be performed, for example the monitoring of stock levels with a number of different liquids being dispensed from a plurality of dispensing stations. Although the system illustrated in the accompanying drawing has been described as being controlled from the control box 301, it is preferred that the control box can be configured so that the dispensing stations can dispense liquid on demand without an enabling signal from an operator at the control box. In that instance, the other dispensing stations would be blocked from dispensing the liquid which is to be dispensed from the enabled station. However, it is preferable that dispensing stations for the other liquid would then be capable of being activated. It should be appreciated that although the present invention has been particularly described with reference to the dispensing of liquids from two different sources, the control box 301 can be arranged to control the dispensing of liquids from three or more sources. Systems in accordance with the present invention preferably include means for providing a printout of the amount of liquid dispensed in a particular dispense and/or the amount of the various liquids which are dispensed from the system over a period of time, for example to facilitate stock control. Systems in accordance with the invention preferably enable a log of the dispenses which have taken place over a period of time to be downloaded to a personal computer for further processing of the data concerned. It is particularly preferred to provide systems in accordance with the invention with means for allowing the systems to respond only following the input of a personal identification number (PIN number). This can, for example, be via a key pad at the control box where, for example, a supervisor's PIN number could be inserted, or via a key pad situated at each of the various dispensing stations where individual operatives dispensing the various liquids would insert their respective PIN numbers. Access to different levels of data held by the system could then be controlled by PIN number. The use of PIN numbers has the advantage of providing the systems with improved security. Key pads at the various dispensing stations have the advantage that not only can they be used to input PIN numbers, they can be used for other purposes, for example to insert a job number associated with a particular dispense. Systems in accordance with the present invention can be used to monitor the dispensing of a variety of liquids, but it is of particular value for the dispensing of different grades of lubricating oil.

Claims: A liquid dispensing system comprising; (a) a plurality of sources of liquid (102, 202); (b) a plurality of pump means (103, 203), one for pumping liquid from each of the sources of liquid (102, 202); (c) a plurality of meters (104, 204), one for metering the quantity of liquid pumped by each of the plurality of pumps (103, 203); (d) a plurality of remote dispensing stations (105, 205), each with a display (111, 211) for indicating the volume of liquid dispensed at that station; (e) means for directing liquid to each of the dispensing stations (105, 205); (f) means for directing the liquid from one of the pump means (103, 203) to at least one of the dispensing stations (105, 205); and (g) a control station (301) including electronic control means (i) to select and enable any one dispensing station (105, 205) whereby a particular liquid is dispensable at that station; (ii) to disable all other dispensing stations (105, 205) whereby the selected liquid is not dispensable at any of those stations; (iii) to monitor each of the meters (104, 204); (iv) to produce a reading on a display associated with said one station, said reading corresponding to the volume of the selected liquid passing through the meter and being dispensed at that station; (v) to effect a zero or null reading on all of the displays associated with the other dispensing stations (105, 205) for dispensing the particular liquid from the particular source (102, 202); and (vi) to produce an indication on a display (302) at the control station (301) as to the quantity of liquid dispensed at the enabled dispensing station and the liquid dispensed. A system according to claim 1, wherein the dispensing stations (105, 205) can cause the control station (301) to enable a display (111, 211) of dispensed liquid at the enabled dispensing station (105, 205) whilst disabling all of the other dispensing stations (105, 205) for that particular liquid. A system according to either of the preceding claims, wherein two different liquids can be dispensed therefrom. A system according to any of the preceding claims, wherein stock levels of the various liquids can be displayed at the control station (301). A system according to any of the preceding claims, including a control line (110, 210) for feeding electronic signals from the electronic control means (301) to all of the dispensing stations (105, 205) for dispensing one of the said liquids.

Inventors: KNUBLEY JOHN SANSBURY, KNUBLEY, JOHN SANSBURY
Applicants: CASTROL LTD, CASTROL LIMITED
Application year: 1993
Main classification: B67D5
IPC codes: B67D7