GB2056247A - Egg incubation - Google Patents

Abstract

The invention provides an artificial incubation method and apparatus in which the weight of the incubating eggs is monitored, and the relative humidity of the atmosphere to which the eggs are exposed is adjusted to maintain the rate of weight loss of the eggs at a predetermined value or within a predetermined range or to vary the said rate of weight loss according to a predetermined programme.

Description

SPECIFICATION Egg incubation The present invention relates to the artificial incubation of eggs and provides an artificial incubation method in which the weight of the incubating eggs is monitored, and the relative humidity of the atmosphere to which the eggs are exposed is adjusted to maintain the rate of weight loss of the eggs at a predetermined value or within a predetermined range or to vary the said rate of weight loss according to a predetermined programme.

The invention also provides egg incubation apparatus comprising support means for carrying the incubating eggs, a hygrostat for controlling the relative humidity of the atmosphere surrounding the supported incubating eggs, a sensor for monitoring the weight of the supported incubating eggs, and means for adjusting the hygrostat according to the rate of weight loss to control the said relative humidity so that the said rate of weight loss is maintained at a predetermined value or within a predetermined range or varied according to a predetermined programme.

The rate of weight loss, which would be expressed as a percentage of the original nett egg mass, could if desired be displayed continuously or at intervals.

The sensor for monitoring the weight is suitably a device (mechanical or preferably electrical) for continuously or periodically sensing the weight of the eggs plus the support means or relevant part thereof and activating a calculator to derive (and in some cases display) the rate of weight loss of the eggs expressed as a percentage per predetermined unit time of the original nett egg mass. Preferably, the apparatus will generate a signal which is indicative of this rate of weight loss and which automatically operates the hygrostat control if necessary to adjust the relative humidity as described above.In a simple case, when the rate of weight loss is above a predetermined optimum value the relative humidity will be increased and when it is below the predetermined optimum value the relative humidity will be decreased, so that the rate of weight loss is maintained close to the optimum value.

A simple microprocessor could be used to receive signals from an electrical weight sensing device (e.g. a stress sensor), calculate therefrom the said rate of weight loss of the eggs, and automatically instruct the appropriate adjustment of the hygrostat.

The incubating eggs could for example be supported in conventional manner on a number of trays suspended one above the other from a single suspension point or axis, in which case the stress sensor or the like could be located at the suspension point or axis. The trays might instead be supported on a trolley, in which case the stress sensor might be disposed under a foot or wheel of the trolley.

The method and apparatus according to the invention are illustrated, purely by way of example, by the following description of preferred embodiments, to be read with reference to the accompanying drawings, in which: FIG. 1 is a block diagram showing the weight sensing monitor and associated electronic components of an apparatus according to the invention, and FIG. 2 is a schematic diagram of a suitable weight sensing monitor for use in the invention, this comprising a strain gauge and mechanical multiplier.

In Fig. 1 the arrows indicate the direction of data flow.

The apparatus shown in Fig. 1 has a strain gauge assembly 1 to which the weight of the support (not shown) carrying the eggs to be incubated is applied. Strain gauge assembly 1 is connected in series via high voltage amplifier 2, potential divider 3 and analogue to digital (A/D) converter 4 (and optionally 'parallel in serial out' or 'serial in parallel out' converter 5 which may be required to provide A/D converter data in suitable form for microprocessing) to a microprocessor central processing unit (MPU) 7. MPU 7 is provided with a random acess memory (RAM) 6 and programme 8, push button(s) 9 being operable to request specific information from the MPU/RAM -- e.g. total weight loss from zero time, average percentage loss, percentage loss from zero time, total weight loss (or percentage) projected forward to day eighteen of incubation period, etc.The programme 8 may be in any one of several forms, e.g. (a) suitably programmed read only memory (ROM); (b) suitably programmed erasable programmable read only memory (EPROM); (c) cassette or tape recorder in conjunction with suitable electronic interface unit; (d) hard wired electronic integrated circuit logic units combined to produce suitable programme; (e) punch cards in conjunction with suitable electronic interface unit; -(f) floppy disc store with suitable electronic interface unit; (g) keyboard entry in conjunction with suitable electronic interface unit; or (h) magnetic core store with suitable electronic interface unit.

A pulse generator 10 to operate the programming section produces one clock pulse for each stage of the programme after receipt of a pulse from the time clock 12 to start the sequence and to switch off at the end of the programme, 12 being an electronic digital clock circuit wired to produce an output pulse at preselected times.

Connected to clock circuit 12 are a digital time display 11, a crystal oscillator 13 for maintaining correct time during mains failure, and a 50/60 Hz mains AC wave form 14 to provide a reference for clock 12 when the mains supply is stable; when the mains supply is not stable, crystal oscillator 1 3 alone will be used to provide the clock reference.

The output from MPU 7 is optionally fed to a decoder 1 5 for conversion to a form suitable for printer or digital display 1 6 and/or comparator 1 7.

Decoder 15 may not be necessary if the output from MPU 7 is in suitable form, but when present may for example be a parallel in serial out or serial in parallel out decoder.

Where 1 6 is a digital display it may be shared with clock 12, 11 with use of appropriate select buttons.

Connected to electronic comparator circuit 1 7 is a keyboard 1 8 (or digital decade switches or the like) for setting upper and lower reference limits for comparison with data coming from MPU 7.

Outputs 19 to 23 from comparator 17 operate a humidifier (not shown), alarm (not shown) or conventional humidistat (not shown) as follows: output 19 - weight loss very low, incubator humidity above upper set limit -- alarm sounded; output 20 -- weight loss low, incubator humidity above required figure -- humidifier switches off or left off; output 21 - weight loss high, incubator humidity below required figure -- humidifier switches on or left on; output 22 - weight loss very high, humidity below lower set limit -- alarm sounded; output 23 - to conventional humidistat for first 24 hours of incubation.

In operation, the weight of the eggs and their support (not shown) is sensed and converted to an analogue low level electrical signal by the strain gauge assembly 1. This may or may not be fitted with a mechanical multiplier as shown in Fig. 2.

The object of the mechanical multiplier is to maintain the weight applied to the strain gauge near to the maximum the gauge can handle so that any change of weight to be measured is as large as possible when applied to the gauge. The analogue electrical signal is then applied to DC amplifier 2 in order to cause the greatest change of voltage possible for a change from zero load to maximum load applied to the gauge, within the limits of the electronic devices used. Correction may be applied via controlled feedback to this stage to compensate for any non-linearity arising from the gauge itself.

This voltage swing is reduced by potential divider 3 to provide a change of voltage at the input to A/D converter 4 such that maximum load applied to the strain gauge causes the converter to produce the highest count possible with a digital change of 1 having some practical significance e.g. 1 = 1 Ib or 1 kg or 1 oz or 1 gram, etc. A backoff voltage from a source of opposite polarity to the amplifier output could be applied to the potential divider to compensate for tare of gauge and trolley or other assembly which produces a non-changing weight applied to the strain gauge.

The object of using high voltage amplification followed by a potential divider is to reduce to the smallest possible value the weight applied to the gauge which will produce a digital change of 1, i.e.

to maximise the sensitivity.

More than one potential divider may be used, inserted selectively in the circuit by either manual mechanical switching or electronically when the input reaches a pre-set level. This will enable one digit to be equated to, for instance, one gram on the lowest range, 1 kg on the next range, etc, thus gaining the greatest practical benefit from the increased sensitivity provided by use of the mechanical multiplier and high voltage DC amplification.

The digital clock 1 2 may be a separate unit, or a clock division programme may be used as part of the overall programme applied to the MPU.

However, in order to simplify the explanation of circuit function it will be assumed that a separate clock is used. The clock provides the following outputs: the time in hours and minutes; a count of days 1 to 18; and an output pulse at preselected times during the day, e.g. every 12 hours. This output pulse triggers the programme pulse generator 10 which then counts the steps of the programme to a preselected number or until the last step of the programme itself inhibits the programme pulse generator until a further pulse from the clock restarts the cycle.

The programme 8 controls the central processing unit (MPU) 7 and thereby the whole system. This may be present in one of several forms, e.g. pre-programmed EPROM. The program me would be responsible for performing the mathematical calculations necessary to express the weight loss (or gain) applied to the strain gauge as a percentage of the total weight.

Compensation for tare could be included as well as subroutines selected by push button(s) 9 to generate, for instance, total weight loss (or gain) from time zero. Transfer of data to and from RAM 6 and to the comparator 17 and digital display 1 6 would also be controlled thereby.

The decoder 15 would only be fitted if the data stream from the MPU 7 is in a format incompatable with comparator 17 and/or digital display 16. Data from the MPU 7 may go directly to comparator 1 7 and/or digital display 1 6 or to either via an appropriate decoder as necessary.

The comparator 1 7 compares data from the MPU with levels pre-set by switches, keyboard entry or other type of input. The outputs 1 9-23 signify differences from preset levels as detailed above, and operate indicator lights, audible warnings and other systems via buffer circuits, relays, etc. as necessary.

Output 23 is to maintain a pre-selected level of humidity during the initial 12 or 24 hours as during this period the MPU 7 would have insufficient data to exert a controlling influence relative to input data.

Fig. 2 illustrates one form of strain gauge assembly 1 provided with a mechanical multiplier.

The assembly 1 is a compression-type strain gauge assembly mounted on a bed plate 24 from which a vertical strut 25 extends upwardly, braced by a diagonal brace 26. A load bearing arm 27 is pivoted at 28 to vertical strut 25, an intermediate region of the arm resting on the top edge of assembly 1 which is at the same level as pivot 28.

The load to be measured, i.e. the weight of eggs, tray(s) and trolley or other support, is applied to the distal end 29 of arm 27. The ratio of distance D1 to distance D2 is set to ensure that the load applied to the strain guage assembly 1 is near to the maximum for the gauge concerned. If a tension-type strain gauge is employed instead of a compression-type, it is fitted instead of vertical struct 25 between pivot 28 and bed plate 24, and the gauge assembly 1 shown in Fig. 2 is replaced by a rigid strut having a second pivot or knife edge between the top of the strut and the load bearing arm 27.

Claims (7)

1. An artificial incubation method in which the weight of the incubating eggs is monitored, and the relative humidity of the atmosphere to which the eggs are exposed is adjusted to maintain the rate of weight loss of the eggs at a predetermined value or within a predetermined range of to vary the said rate of weight loss according to a predetermined programme.

2. Egg incubation apparatus comprising support means for carrying the incubating eggs, a hygrostat for controlling the relative humidity of the atmosphere surrounding the supported incubating eggs, a sensor for monitoring the weight of the supported incubating eggs, and means for adjusting the hydrostat according to the rate of weight loss to control the said relative humidity so that the said rate of weight loss is maintained at a predetermined value or within a predetermined range or varied according to a predetermined programme.

3. Egg incubation apparatus comprising support means for carrying the incubating eggs, a device in engagement with the support means for continuously or periodically sensing the weight of the incubating eggs plus support means or constant part thereof and actuating a calculator to calculate the rate of weight loss of the eggs expressed as a percentage of the original nett egg mass, and a hygrostat operable in response to the said rate of weight loss to control the relative humidity of the atmosphere to which the incubating eggs are exposed so that the said rate of weight loss is maintained at a predetermined value or within a predetermined range or varied according to a predetermined programme.

4. Apparatus according to claim 3 including means for displaying the calculated rate of weight loss.

5. Apparatus according to claim 2, 3 or 4 including means for automatically adjusting the hygrostat according to the detected rate of weight loss to so control the relative humidity.

6. A method for the incubation of eggs in which the relative humidity to which the incubating eggs are exposed is controlled according to their weight loss during incubation, the method being substantially as hereinbefore described with reference to the accompanying drawings.

7. Egg incubation apparatus substantially as hereinbefore described with reference to the accompanying drawings.