Fluent material handling – with receiver or receiver coacting mea – With testing or weighing receiver content
Reexamination Certificate
1999-07-22
2001-09-04
Thorpe, Timothy S. (Department: 3746)
Fluent material handling, with receiver or receiver coacting mea
With testing or weighing receiver content
C141S094000, C417S018000, C417S053000
Reexamination Certificate
active
06283173
ABSTRACT:
This invention relates to a forecourt fuel pump, and in particular to such a fuel pump provided with a processing unit arranged to monitor and control the delivery of fuel as well as the display of information concerning such delivery.
Current designs of forecourt fuel pumps, adapted for the metered delivery of petroleum spirit (petrol) or diesel fuels, are usually provided internally with a processing unit including a microprocessor, in order to facilitate the operation of the pump and the display of information concerning the delivery of fuel. Such a processing unit readily lends itself to this use, especially as the price per unit of fuel delivered is likely to change frequently, and at short notice; a processing unit may be arranged to allow the easy input of information such as the price per unit of fuel delivered, by a site operator.
It is further known, for example from U.S. Pat. No. 5,450,883, to utilise a processor better to control the delivery of fuel by sensing vapour pressures in the pipelines through which the fuel flows in the course of fuel delivery. If then there is a fault in the vapour recovery system of the pump, the processor can automatically take remedial action. Modern microprocessors are extremely powerful and generally are under utilised in process operations such as the control of a forecourt fuel pump. A microprocessor may be configured to handle a large number of input and output lines (i/o lines) through a number of separate ports, and a typical application such as a fuel pump does not require the use of all of the i/o lines and ports which a typical microprocessor is able to accommodate. The present invention aims at utilising in an efficient and beneficial manner for a site operator at least some of the spare processing capacity of a typical processing unit employing a microprocessor as incorporated within a forecourt fuel pump, in order to achieve safer operation of a fuel pump.
According to the present invention, there is provided a forecourt fuel pump including a casing within which is located means for metering and delivering to a flexible hose liquid fuel to be dispensed, and a processing unit arranged to monitor and control the delivery of fuel as well as to display information concerning such delivery, wherein the pump is provided with at least one sensor within the casing for an environmental parameter external to the metering and delivery means, but which parameter is directly concerned with the safety of operation of the pump, the sensor providing an electrical output which is supplied to the processing unit, and the processing unit is arranged to monitor the electrical output and to provide an indication if the sensed value of said parameter falls outside a pre-set range.
The environmental parameter sensed by the sensor may be one of a number of different possible parameters, any one of which might have an effect on the operation of the fuel pump. However, it would be possible for there to be more than one sensor, each of which senses a different environmental parameter, and each such sensor being connected to a respective i/o line of the processing unit. In this way, the fuel pump may be configured to sense its own environment within which it is operating, and either to provide information about that environment or possibly even to shut down operation of the pump in the event that the sensed environment falls outside permissible pre-set ranges.
For example, one of the sensed parameters may be hydrocarbon vapour within the casing of the fuel pump. Hydrocarbon vapour may form an explosive mixture with air, and in the event that there is even a very small leakage of pumped fuel, there can be a potentially dangerous build-up of vapour within the casing of the pump. By having the sensor detect the presence of any such hydrocarbon vapour within the pump casing, a warning to the site operator may be given as soon as the level of vapour rises above a relatively low value. Either simultaneously with that, or if no action is taken to investigate and correct the position, the pump may arrange for all pumping activities to be terminated, in order to minimise the likelihood of a dangerous situation arising.
Another possibility is for the sensor to be arranged to sense the presence of liquid in the lower region of the casing of the fuel pump. The detection may be of any liquid, though particularly hydrocarbons. This is most important in the case of the pumping relatively less volatile fuels, such as diesel fuel. However, an accumulation of water or other liquids in the lower region of a fuel pump could give rise to problems, such as contamination, corrosion, and so on, and thus it is preferred for a sensor to be provided for any liquid accumulating within the casing of the pump.
Yet another possibility is for there to be a sensor for the temperature within the casing of the fuel pump. If the temperature should rise above some pre-determined level, dangerous situations could arise especially where the pump is pumping liquid petroleum spirit. In this case, the processing unit may be arranged to close shut-off valves supplying fuel to the fuel pump as well as closing down the electrical supply to the pump, in order to minimise the risk of a fire. By having the processing unit closing shut-off valves for the fuel, in the event that there is already a fire when the increased temperature is sensed, the likelihood of the fire developing and being fed with fuel is reduced.
Alternatively, or in addition, a sensor may be arranged to sense the temperature of the liquid fuel being pumped. Similar action may be taken if the fuel temperature rises above some pre-set maximum, dependent upon the nature of the fuel, as in the case where the temperature within the pump casing is sensed.
The fuel pump may further be provided with one or more sensors arranged to sense at least one environmental parameter outside the casing of the fuel pump. Such an additional sensor may also provide an electrical output which is supplied to the processing unit, and the processing unit is arranged to monitor the additional electrical output and to provide an indication if the sensed value falls outside a pre-set range. The sensed parameter may also be at least one of hydrocarbon vapour, liquids and temperature, for example in a duct or other housing associated with the supply of fuel to the fuel pump.
The processing unit of the fuel pump may further be provided with a quantity sensor, arranged to sense the quantity of fuel remaining in a storage tank from which the fuel pump draws fuel. Such a quantity sensor may provide a further electrical output which is also supplied to the processing unit of the fuel pump, the processing unit being arranged to monitor that further electrical output and to shut down the pumping of the fuel if the sensed quantity remaining in the storage tank falls below a pre-set value.
Though it is advantageous for the processing unit within a fuel pump to have separate i/o lines for each sensor sensing an environmental parameter associated with the pump, it is possible that more parameters are to be sensed at more locations than there are spare i/o lines and ports on the processing unit. In this case, it is a relatively simple matter to multiplex together various sensor outputs, and to supply the multiplexed signal to a single port of the processing unit, the processing unit running an appropriate programme in order separately to sense the output of each sensor by suitable de-multiplexing of the signal. Conveniently, each multiplexed sensor output is of the same kind—for example hydrocarbon vapour or temperature.
REFERENCES:
patent: 3632988 (1972-01-01), Yamawaki et al.
patent: 4576312 (1986-03-01), Swick, Jr.
patent: 4850233 (1989-07-01), Carlin et al.
patent: 5507325 (1996-04-01), Finlayson
patent: 5533890 (1996-07-01), Holst et al.
patent: 5782275 (1998-07-01), Hartsell, Jr. et al.
Andrus Sceales Starke & Sawall LLP
Gartenberg Ehud
Thorpe Timothy S.
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