DESCRIPTION OF THE PRIOR ART It has long been known that the shelf life of eggs can be prolonged by coating them with a mineral oil such as paraffin oil. Various mechanical devices have been devised for carrying this out on a commercial scale.

In a current typical set up, eggs are passed on a conveyor beneath an oil dispenser which continuously atomises a fine mist of oil over the eggs as they pass by. Such an arrangement has a number of disadvantages.

Firstly, if there is an egg missing from the row of eggs being conveyed, oil is still atomised into the empty egg space. This gives rise to wastage and contamination of the conveyor and surrounding air. Secondly, the amount of oil consumed for each egg can be as much as 0.5 gm due to overspray. This is far in excess of what is needed to achieve the necessary preservation. Thirdly, because the entire egg is coated in such processes, this can lead to the egg slipping out of its correct orientation when it is packaged (eggs are packed with their blunt ends uppermost). Fourthly, the excess oil present on such eggs can stain the cartons in which they are packed and from a marketer's point of view this is highly undesirable as it off-putting to the consumer. Fifthly, the oil atomising equipment includes a bulk supply of oil which is open to the atmosphere. This can result in contamination of the oil and failure to meet standard health and safety regulatory requirements. Sixthly because of the overspray using such equipment, there is a large quantity of oil which has to be collected. This oil is too expensive to discard and as a consequence is recycled for further recoating. This can lead to further contamination of the oil and result in a low quality end

product.

OBJECT OF THE INVENTION It is therefore an object of the invention to provide an alternative form of apparatus for oiling eggs which ameliorates or at least reduces the aforementioned disadvantages, or provides the public with a useful alternative.

SUMMARY OF THE INVENTION Accordingly, in its broadest aspect, the invention comprises an egg oiling apparatus comprising an oil microspray and an egg sensor, said apparatus being constructed and arranged such that when an egg is detected at a predetermined distance from the microspray by the sensor, the sensor emits a signal so that a predetermined aliquot of oil is sprayed from the microspray onto the blunt end of the egg.

In a narrower aspect, the invention includes an egg transporting means for collecting, moving and depositing eggs, said transporting means comprising a plurality of individual egg retaining means which are designed to orientate each egg so that as the egg is transported along a predetermined path, the blunt end of the egg is brought into close proximity with the sensor and microspray.

DETAILED DESCRIPTION OF THE INVENTION The apparatus is designed so that oil is only sprayed on the blunt end of the egg since this is the end which contains the air cell and is the only part of the egg that needs to be coated to provide the desired degree of preservation. Preservation can be achieved to such an extent using this apparatus that the shelf-life of the eggs is increased by up to five or six weeks over the uncoated counterpart.

The microspray is suitably designed to have one or more minute orifices, preferably about four, through which the oil is ejected under controlled pressure onto a small surface area of the egg. Suitably, the spray time will be in the order of milliseconds to achieve the necessary amount of coating. Such a small time interval also means that there is no interruption in the transportation of the eggs in the equipment past the microspray, that is, there is a continuous movement of eggs at a relatively high rate.

The quantity of oil which is typically ejected is of the order of 20 milligrams per egg and will generally lie somewhere within the range of 10-30 mgm.

This quantity is at least one order of magnitude less than the amount of oil which is used in current oiling systems and represents a significant saving.

The microspray is preferably supplied with oil from a closed receptacle using associated hydraulic pumping gear in a known manner. By utilizing a closed receptacle, contamination of the oil by outside influences is prevented and the quality of the coated egg is maximized. Furthermore, because there is no wastage due to overspray, there is no recycling of oil to the receptacle.

The type of oil which is normally used with this equipment is conventional food grade paraffin oil known as 15 grade white oil. However other oils and additives may also be effectively used.

The sensor can be a photodetector with standard circuitry which is connected to the circuitry controlling the pumping gear; once again using known principles. Suitably the sensor is located in close proximity to the microspray in the upstream path of the egg retaining means so that the eggs pass by the sensor before reaching

the microspray.

Preferably, the individual egg retaining means each comprises a fingered grip arrangement which grips each egg and orientates the egg into a substantially horizontal position with the blunt end of the egg pointing outwardly with respect to the egg transporting means. Such an arrangement enables the microspray and sensor to be designed as separate attachments which can be fitted on to the exterior of the transporting means and therefore be in an accessible position for maintenance purposes. More importantly however, it enables the egg oiling apparatus to be retrofitted to the egg transporting means.

Suitably, the microspray outlet is arranged to be spaced from a passing egg by no more than two centimetres, and is preferably spaced at about 0.5 cm.

This arrangement minimises the possibility of the oil not being sprayed onto the exact required location of the egg- After passing by the microspray outlet, the eggs are oriented into a vertical position by the retaining means and then placed in trays, with their blunt, or coated, ends uppermost. The oil which has been sprayed at one or more points on the eggs, i. e. dependent upon the number of orifices in the microspray, flows down over the eggs to form a uniform coating over the top air cell containing portion of the eggs only. The eggs are then preferably chilled overnight to enable the oil to be completely absorbed into the shell before they are sent to market.

DESCRIPTION OF THE DRAWING Figure 1 is a schematic representation of an egg oiling apparatus according to the present invention.

DESCRIPTION OF PREFERRED EMBODIMENT A preferred embodiment of the invention will now be described with reference to the drawing.

The egg oiling apparatus as depicted comprises an egg transporting means 10 which collects eggs 11 which have been cleaned and dried, from a source A and transports them in the direction indicated by the heavy arrow B to a packaging depository C. The transporting means is designed to move the eggs at a fast uniform rate. Because of the unique coating apparatus, this rate can be in excess of 100,000 eggs per hour which is approximately double the rate achievably by conventional equipment.

The transporting means 10 includes a plurality of egg retaining means 12 comprising articulated finger elements which individually grasp the eggs and orientate the eggs substantially horizontally with their blunt ends 12a facing outwardly, that is in a direction away from the apparatus. When the eggs are in the horizontal orientation, they pass by a photodetector 13 which senses them individually and relays a signal to an associated control 18.

After passing by the photodetector, the eggs then proceed past a microspray 14 having four minute openings (not shown) in the end adjacent to the passing eggs. The end of the microspray is separated from the passing eggs by about 10 mm.

The microspray is connected to a source 15 of grade white oil in a sealed container 15 by way of a pump 16. The pump is designed to pump a predetermined aliquot of oil, for a predetermined time interval, through the openings in the microspray 14 so as to impact upon the blunt end of the passing egg as shown by the dotted lines.

The operation of pump 16 is controlled by circuitry 17 which, in turn, is controlled by photodetector control 18.

Spraying of an egg with oil only occurs when the egg 11 is directly adjacent to the end of the microspray 14 and has been previously detected by the photodetector 13.

It will be appreciated from the foregoing description that the present invention addresses and overcomes all the previously mentioned disadvantages of conventional egg oiling apparatus, and thus represents a significant improvement in the art.

Whilst the above has been given by way of illustrative example of the invention, many modifications and variation may be made thereto by persons skilled in the art without departing from the broad scope and ambit of the invention as herein set forth.