AU2013204543B1 - Electromagnetic moisture meter for a cotton picker baler - Google Patents

Abstract

A microwave moisture system is installed on the tray or handler of a cotton picker-baler. A transmitting antenna is positioned on one side of the handler and a receiving antenna is positioned on the opposite side of the handler in 5 such a way as the bale passes between the two antennae the amount of electromagnetic energy absorbed by the bale and the reduction in velocity of the electromagnetic signal through the bale are both measured by an electronic system. Either or both of these signals may be used to determine the moisture content of the bale. The point at which the bale is to be 10 measured for moisture is determined by inputs from a combination of position sensors which may include the microwave signal itself. By positioning the moisture meter across the handler of the picker-baler the present invention measure the moisture content of the bale that has been produced by the picker bailer rather than being located insider the cotton 15 picker.

Description

1 Electromagnetic moisture meter for a cotton picker baler FIELD OF THE INVENTION This invention relates to a method and means to measure moisture 5 content in cotton bales particularly at harvest by picker-balers. BACKGROUND OF THE INVENTION In the process of making bales of cotton the measurement of moisture is critical because of its relevance on fibre quality. Dry cotton can be harvested cleanly and efficiently, but may suffer undue damage in the 10 gin. On the other hand harvesting and ginning wet cotton leads to significant issues in processing and quality. Moisture in picked cotton is an important measurement because it often determines the efficiency of how the cotton will be ginned. The moisture content may also determine the future quality of the cotton if left in 15 plastic wrapped bales for a period of time during which the colour and other properties of the cotton may deteriorate. Typically, the picking of the cotton is commenced in the morning once the cotton is dry enough to pick, the picking continues often well into the night until the dew on the cotton raises the moisture level to a point 20 where picking should no longer be continued. In 2007 a cotton picking machine that also made the picked cotton into a round bale wrapped in plastic was commercially released by John Deere. The machine is known as a "picker-baler". At the rear of the picker baler is a mechanism which pivots on the machine and is hydraulically 25 controlled to collect the bale as it emerges from the bale making section and then lowers the bale to the ground. This mechanism is most commonly termed the handler but can also be referred to as the tray, carrier or tailgate. There are a number of approaches in measuring moisture in cotton lint one of which includes measurement of the electrical or dielectric 2 properties. Measuring moisture using electromagnetic signals and in particular microwave signals has been used for many years in many applications, including the measurement of moisture in cotton modules prior to cotton ginning and in cotton bales after the ginning process. Typically 5 moisture meters are designed to go inside the chamber where the bales are being made. There is currently no non-contact moisture meter available to measure the moisture of the bale as it is ejected from the rear of a picker baler. 10 It is an object of the present invention to provide an apparatus and method that may be used with cotton gin that can measure moisture content in a bale of cotton. SUMMARY OF THE INVENTION Therefore in one form of the invention there is proposed a cotton 15 picker of the type adapted to harvest cotton and produce a cotton bale including: a handler adapted to receive the bale from the picker and movable between a first closed position, and intermediate position to hold the cotton bale and an open position to release the bale to the ground; 20 an electrical or electromagnetic moisture measuring apparatus having a transmitter on one side of the handler and a receiver on the other side and a computational means adapted to produce a result indicative of the amount of moisture in the cotton bale. Advantageously both the transmitter and receiver are housed on 25 separate franes. Advantageously the handler moves between a first closed position, an intermediate measurement position and a bale release position and wherein when in said first closed position the handler is raised upwardly and a means is provided to make the moisture measurement system inoperable.

2a Advantageously the means is at least one position switch.

3 BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various implementations of 5 the invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings: Figure 1 illustrates a picker bailer as in known in the prior art and supporting a cotton bale in its rear tray; Figure 2 illustrates the movement of the cotton bale through the picker 10 bailer Figure 3 illustrates a picker bailer embodying the present invention and before releasing a cotton bale; Figure 4 illustrates a picker bailer embodying the present invention when measuring moisture content of a cotton bale; 15 Figure 5 illustrates the present invention when releasing a cotton bale; and Figure 6 is a perspective view of a picker bailer releasing a cotton bale and illustrating in more detail the measurement means. DETAILED DESCRIPTION OF AN EMBODIMENT 20 The following detailed description of the invention refers to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts. Dimensions of certain parts shown in the drawings may have been modified and/or exaggerated for the purposes of clarity or 25 illustration. The apparatus of the present invention uses microwave techniques to measure the moisture content of the cotton in the bale as it emerges from 4 the picker-baler. The instrument measures the velocity of the microwaves and the amount of microwave energy absorbed through the bale of cotton. The velocity of microwaves through air is very close to the velocity of light through space, and the velocity of microwaves through dry cotton is slightly 5 less. However, the velocity of microwaves in water is considerably slower than that in dry cotton. The difference in this velocity or speed is attributed to the dielectric constant (relative permittivity). The dielectric constant for air is close to 1, for dry fibrous material with no air inclusions it is closer to 4 while for pure water it is approximately 10 80. Similarly, the amount of microwave energy absorbed in air is less than dry cotton and in dry cotton is much less than in water. Thus these measurements are a very sensitive method of measuring moisture in a bale of cotton. Turning now to the drawings in detail, there is shown a typical picker 15 bailer 10 including a body 12 and handler 14 adapted to hold a cotton bale 16. The frame 12 includes a rear hinged portion 18 that as shown in Figure 2 swings upwards to allow the cotton bale to be released by the picker bailer. Given that it is desirable to be able to measure the moisture when the 20 bale has been produced and is being ejected from the picker-baler, the present invention provides for a moisture measurement device that uses microwave techniques to measure the moisture content of the cotton in the bale as it has emerged from the picker bailer. The apparatus includes a frame 20 located on one side of the tray and adapted to support a 25 transmitting antenna 22. A frame 24 on the other side of the tray supports a receiving antenna 26 thereby defining a gap through which a cotton bale passes. The transmitting antenna is an active antenna and contains microwave electronics to generate and transmit a beam of microwave 30 energy into the bale 16 and to receive and analyse the signal retuned from the passive receiving antenna 24 on the opposite side of the bale which collects the microwave energy which has not been absorbed by the bale.

5 The person skilled in the art would well understand the necessary electronic systems, power supplies, data collection means and computation means that provide a result to an operator, usually in the form of a display in the cabin of the picker bailer and it is not the intention to discuss these 5 common engineering solutions in detail. Given that when not handling a bale the handler is in the closed position as can be seen in Figure3 there is a risk that if the microwave moisture system is operated it may suffer damage since the microwaves would be highly reflected from the rear hinged portion 18 that is made from 10 metal. Accordingly the system includes further means to ensure that it cannot be operated if in a certain position. This may be achieved by several solutions including a position sensor on the handler, a tilt-switch on the microwave system, or other means. The reader should now appreciate the present invention that whilst it 15 is a microwave system, radio frequency, capacitive systems or conductivity signals could also be used. The microwave moisture system is installed on the tray or handler of the picker-baler. A transmitting antenna is positioned on one side of the handler and a receiving antenna is positioned on the opposite side of the handler in such a way as the bale passes between the 20 two antennae the amount of electromagnetic energy absorbed by the bale and the reduction in velocity of the electromagnetic signal through the bale are both measured by an electronic system. Either or both of these signals may be used to determine the moisture content of the bale. The point at which the bale is to be measured for moisture is determined by inputs from 25 a combination of position sensors which may include the microwave signal itself. By positioning the moisture meter across the handler of the picker baler the present invention measures the moisture content of the bale that has been produced by the picker bailer. By introducing level sensors one ensures that the system does not operate when in a non-desirable position. 30 Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical 6 and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus. 5 Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in this field. In the summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word 10 "comprising" is used in the sense of "including", i.e. the features specified may be associated with further features in various embodiments of the invention.

Claims (4)

1. A cotton picker of the type adapted to harvest cotton and produce a cotton bale including: a handler adapted to receive the bale from the picker and movable between a first closed position, and intermediate position to hold the 5 cotton bale and an open position to release the bale to the ground; an electrical or electromagnetic moisture measuring apparatus having a transmitter on one side of the handler and a receiver on the other side and a computational means adapted to produce a result indicative of the amount of moisture in the cotton bale. 10

2. A cotton picker as in claim 1 wherein both the transmitter and receiver are housed on separate frames

3, A cotton picker as in claim I or claim 2 where the handler moves between a first closed position, an intermediate measurement position and a bale release position and wherein when in said first closed 15 position the handler is raised upwardly and a means is provided to make the moisture measurement system inoperable.

4. A cotton picker as in claim 3 wherein the means is at least one position switch.