AU655492B2 - A weighing apparatus - Google Patents

Description

a r ,i 655492 -1- Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

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a a e 9 e eo Name of Applicant: N B MacDonald Engineering Limited Actual Inventors: Neil Bruce MacDonald and Norman Lawrence Murton a i L ~L, Address for Service: Invention title: R K MADDERN ASSOCIATES, 345 King William Street, Adelaide, South Australia, Australia "A Weighing Apparatus" The following statement is a full description of this invention, including the best method of performing it known to us.

TITLE: A WEIGHING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to improvements in and relating to weighing apparatus for grading systems.

More particularly but not exclusively, the present invention relates to grading systems for use in the grading of fruits. For the sake of simplicity, this is the use in respect of which the invention will be described in the specification. It is to be a. appreciated, however, that this is by way of example S only.

.g To the present time in the grading of fruits, the fruits have typically been singulated onto separate .O 15 cups. The required characteristics of the fruit are O C' sensed either by optical or weighing means to detect for example shape and/or colour and/or weight, before the cup is tipped at an appropriate station so as to discharge the fruit of that particular characteristic 20 from the cup.

The optical sensing arrangements do not provide for the weight selection of fruit, which is required in many markets.

The weighing arrangements on the other hand, suffer from various problems. Firstly, in utilising the tipping of the cups themselves in order to eject fruit, the weight of the cup needs to be lifted up, thus I. Cr ,i S I o eo oo r o ,o o u m ooo r aoJ o* 0 So -2requiring additional tipping forces. Secondly, due to the drag force existing between the cups and the conveyor, accurate weighing is difficult as the drag forces tend to distort the true weight of the fruit/cup combination.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide a weighing apparatus and/or weighing method for a grading system which in its preferred embodiments will at least obviate the disadvantages in such systems to the present time or at least will provide the public with a useful choice.

Further objects of this invention will become apparent from the following description.

BRIEF SUMMARY OF THE INVENTION According to one aspect of the present invention, there is provided a carriage for use in a weight grading apparatus, having an article carrying portion and a carriage transporting portion, linkage means which pivotally connect said article carrying portion with said carriage transporting portion to enable the pivoting of said article carrying portion away from said carriage transporting portion when, in use, said carriage arrives at a weighing station, said carriage

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i -3transporting portion including a downwardly depending connector assembly which, in use, can be connected with a carriage transporting means extending beneath said carriage transporting portion to move said carriage, the distancing of said carriage transporting portion with its connector assembly from said article carrying portion enabling the weight of said article carrying portion and its contents to be sensed substantially disassociated from any effect of forces imposed by the movement of the carriage transporting means.

o .According to a further aspect of the present invention, there is provided a weighing apparatus for a grading system incorporating a plurality of carriages 0o substantially as hereinabove defined.

considered in all its novel aspects will become apparent

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At 1* i i 0 000000 0 *4 0 o a o 0* 4 -4from the following description given by way of example of possible embodiments thereof.

BRIEF DESCRIPTION OF TM DRAWINGS In the accompanying drawings: Figure 1: Shows a side view of a carriage according to one embodiment of the present invention and including part of a fruit positioned thereon; Figure 2: Shows an end view of Figure 1 in the direction of arrow A with the carriage in its lowered position; Figure 3: Shows a plan view of Figure 1; Figure 4: Shows an underneath view of the carriage of Figure 1; Figure 5: Shows a cross sectional view through the carriage of Figure 1; Figure 6: Shows diagrammatically the carriage of the preceding figures at a weighing station and with the carriage in its raised position.

Figure 7: Shows very diagrammatically a view showing the tipping action of the carriage at a selected station; Figure 8: Shows an end view of the tipping action of Figure Figure 9: Shows vcry diagrammatically a view of the tipping station but with the 1 htipping action not activated; Fiqures 10a, b, c: Shows very diagrammatically, and t lrespectively, a plan view of the chain, and cross sectional end views showing the two types of linkage J connections to the chain.

BRIEF DESCRIPTION OF PREFERRED EMBODIMENTS 10 Referring to the accompanying drawings, a carriage 1 has a body 2 on which are rotatably mounted a pair of I spaced apart wheels 3 at each end. Suitably, an axle or !the like 4 extends between opposed wheels 3 and carries within the body 2, a tapered roller assembl' 15 Positioned between the tapered rollers 5, as seen particularly in Figure 3 for example, is a tipping mechanism 6. The tipping mechanism 6 is shown provided .with a recessed body portion having side walls 8 forming a trough. The walls 8, in conjunction with the tapered ,20 rollers 5, provide a base to accommodate a fruit or H other item 9. A downwardly and outwardly depending ,j lever 7 can control the tipping of the mechanism 6 suitably about its pivotal connection 10 with the carriage body 2. End rollers 11, such as rubber tubes or the like, are provided for the carriage body 2 so as to act to prevent a fruit or item 9 rolling off the

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-6carriage 1 but also to assist the rotation of the fruit 9 for singulation and colour sorting purposes.

The rollers 11 are shown provided on bifurcated legs 40 on the carriage body 2 so that they can move vertically as required.

The base 2A of the carriage body 2 is shown connected with a carriage transporting assembly including a base plate 13 having a connector 12, seen particularly in Figure 2, which can engage about a link 23 of conveyor chain 24. In this way, the carriage 1 can be dragged along by the chain 24 from the singulation station, where in a suitable manner single o fruit are accommodated on each carriage 1, to the 94 0 Pt weighing station and then to the various discharge stations and then around the end chain sprockets for the return trip to collect the next fruit.

The direction of travel is indicated by arrow X in Figure 1, a guide assembly 44 assisting in controlling the direction of movement.

S" S 20As seen particularly in Figure 4 the base plate 13 has a pair of link arms 14 pivotally connecting the base plate 13 at its respective flanges 15, with respective Slegs or flanges 16 provided for the underside of the base 2A of the body 2 itself. As seen particularly in Figure 5 for example, the base plate 13 also has a pair of pins 17 extending upwardly therefrom to be located in respective oversized apertures in the underside of the -7body base 2A. These pins 17, apart from providing a vertical location of the base plate 13 relative to the body 2, principally, and suitably by means of oversized heads 18, ensure that on the return trip, when the carriage 2 is upside down, the base plate 13 and linkage associated therewith are not disconnected from the body 2.

In Figures 1 and 2, the wheels 3 are shown engaged with a track 38. This is the situation at the oa 10 singulation station and shortly thereafter. In this position the chain 24 is dragging the carriage 1 along 4*4400 0 in the direction X and the base 2A of the carriage body °o a, *o 2 is now in substantial contact with the base plate 13, as shown in Figure 2. This is also indicated in Figure 1 where the link arms 14 are not horizontal showing that 0::o the base 2A and the base plate 13 will be contacting.

Prior to the weighing station, however, the disposition of the rail 38, relative to the chain 24, insofar as vertical height is concerned, changes. This is shown o a 20 diagrammatically in outline in Figure 1 where the rail w 38 is shown distancing itself vertically from the chain 24 by a vertical incline provided tor the rail 38. This vertical distance, possibly of the order of 3mm, is sufficient to cause the wheels 3 to lift up and rotate, resulting in their rotating the rollers 5 and thus rotating the article 9 for singulation and colour sorting. The vertical spacing then diminishes with rail

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-8- 38 (which then terminates) returning back to its original position and with the base 2A of the carriage body in substantial contact with base plate 13, as shown in Figure 2.

Then, again prior to the weighing station, and referring to Figures 5 and 6, the disposition of a load cell carrier beam 41, relative to the chain 24, insofar as vertical height is concerned, changes. This is shown diagrammatically in outline in Figure 5 where the beam 41 is shown distancing itself vertically from the chain ,o~o 24 by a vertical incline provided for the beam 41. The 4 upper surfaces of the beam 41 support the front and rear 9 °,9legs, 2B, 16 of the carriage body base 2A, and this S• vertical distance, possibly of the order of 1.5mm, is sufficient to cause the links 14 to pivot, resulting in the carriage body base 2A being lifted into a spaced 04 apart relationship relative to the base plate 13. The 9S t4 pins 17 are now positioned higher in their respective apertures in the carriage body base 2A, as shown in 20 S 2 Figure 6.

The upper surface of the beam 41 at the weighing station also accommodates a weighing rail 19, so, as also shown very diagrammatically in Figure 6, what this i means is that the lower ends of the carriage body base legs 2B and 16, in engaging the weighing rails 19, disassociate the carriage body 2 both from the base plate 13 and the connector 12, and therefore from the Q- Tj -9drag forces associated with the chain 24. Looking from above, the weighing rails 19 can be of a zig-zag shape, as indicated by the rear portion 19A in outline in Figure 6, and so positioned that the base legs 2B and 16, which as seen in Figure 4 are offset laterally, will engage simultaneously with the start of the respective portions of the weighing rails 19 as the carriage 1 reaches the weighing station.

As shown in Figure 5 particularly, at the weighing 10 station the link arms 14, in the position shown as 14' o are now substantially horizontal so that the horizontal o, drag forces on the chain 24 and plate 13 are not able to a o o" Sbe translated into vertical forces influencing the weight reading.

In Figures 10, by way of explanation, the 9 connector 12 is shown as being of two types, 12A and 12B. The former, in Figure 10b provides an internal connection to the captive links 24a of the chain 24, while in Figure 10c the latter connector 12B, provides *l 20 an external connection to the fetter links of 24b the 4 0 chain 24. Both types of connector 12 are therefore provided to enable the carriages to be positioned The load cell or the like 20, see Figure 6, will generally average several readings of weight as the carriage is moved over the weighing rails 19. The average weight w'll then be provided as an input signal

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I I '4 44 444 44 4 4i 4 *I 44 4( 4 44( to one of the discharge stations so that a fruit of a particular weight range will be discharged at that particular station.

Referring briefly to Figures 7 and 8, it is seen that a solenoid 21 has in this instance been activated.

This has in turn activated an arm 22 which has caused tipper lever 7 to rise up onto the tipper ramp 43 so that the fruit will be tipped off at that particular weighing station. The activation of the solenoid 21 10 corresponds with the arrival at that station of the carriage 1 with a fruit of the required weight.

In the alternative, as shown in Figure 9, where the fruit was not of the required weight, the arm 22 has remained deactivated and in this case, the tipper lever 7 passes underneath the tipper ramp 43 so that the fruit is not discharged. It is seen therefore that rather than having to raise a cup carrying the fruit for the tipping action, only the tipper mechanism 6 needs to be raised.

20 Also in utilising a single chain 24, this avoids the need to use the customary cross rods connecting cups between a pair of carrying chaini, The pivotal drag linkage of the present invention enables the drag effect of the chain 24 to be substantially eliminated from affecting the detected weight of the carriage/fruit. It is mentioned that as the relative vertical positioning of the beam 41 and the chain 24 requires to be set to t I r' 3 Note: No legalization or other witness required To: The Commissioner of Patents -11ensure that there is an effective disassociation of the carriage body 2 from the connector assembly 12 at the weighing station, by the pivoting of the arms 14, a vertical adjustment of the beam 41 may be suitably provided.

Moreover it will be appreciated that the pivotal connection of the base 13 with the carriage body base 2A provides for an essentially frictionless lift of the corirn ec.Qr ss e.sN carriage 2 from the. uli 12, which frictionless disengagement is then present also during the weighing operation.

Due to the above described arrangement and in particular, the disassociation of the chain 24 from the carriage 1 at the weighing station, the following 15 advantages are believed to be achievable in the present 1 invention namely: i) Weighing accuracy; ii) Improved fruit handling at an increased through put; iii) Improved machine reliability and simplicity of maintenance.

4 The latter two advantages are particularly achievable due to the pivotal forces required to move the fruit of the particular weight at the appropriate time being minimised by requiring only the pivoting of the central portion of the carriage as opposed, to the A .fS> Cwfi -12entire carriage. The first advantage of course, namely weighing accuracy, is achievable because of the disassociation between the carriage and chain as mentioned previously.

Where in the foregoing description reference has been made to specific components or integers of the invention having known equivalents then such equivalents are herein incorporated as if individually set forth.

Although this invention has been described by way 0 10 of example and with reference to possible embodiments ,.,t4S a thereof it is to be understood that modifications or improvements may be made thereto without departing from the scope of the invention as defined in the appended claims.

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Claims (4)

1. 2. A carriage as claimed in Claim 1 wherein said linkage means connects said carriage transporting portion with a base of said article carrying portion.
2. 3. A carriage as claimed in Claim 2 wherein said linkage means comprises at least one link arm pivotally connected between said carriage transporting portion and said base. Ir I iii r US. *A -14-
3. 4. A carriage as claimed in Claim 3 wherein at least one upwardly projecting member extends from said carriage transporting portion into and through oversized apertures provided in said base so as to provide a vertical alignment and holding action between said base and said carriage transporting portion. A carriage as claimed in any one of the preceding claims including a controllable ejecting means to eject said article from said carriage, and wherein So said ejecting means comprises a pivotal lever qan which on operation causes the tilting of a substantially central portion of said article 4 4o
4. 44.* 0 carrying portion. 6. A carriage for a weight grading apparatus o949 sr00 4.4 substantially as herein described with reference o to the accompanying drawings. 7. A weight grading apparatus including a plurality of the carriages as claimed in any one of the 20 44, 20preceding claims in combination with a control means to control the pivoting of said article carrying portion, and said carriage transporting means, said control means comprising a support means to support said article carrying portion wherein in use, an increased spacing between said support means and said carriage transporting means prior to said weighing station causes the lifting of said article carrying portion away from the carriage transporting portion. L. i I.P r! t.;cl i. R 1 tt t- iti t C t c ii 4 tI C ii 4 ii C 4 8. A weight grading apparatus as claimed in Claim 7 wherein said carriage transporting means comprises a single chain extending beneath said carriages and connected thereto. 9. A weight grading apparatus as claimed in Claim 8 wherein said carriages include at least one pair of rotatable means engageable with a track and wherein in use an increased spacing between said track and said chain causes the lifting up of said rotatable means and their rotation and the consequential rotation of said article. 10. A weight grading apparatus as claimed in Claim 9 when having carriages as claimed in Claim 5 and including a controllable arm which is operable on the arrival of one of said carriages carrying one of said articles of a required weight to cause the operation of said article ejecting means. 11. A weight grading apparatus as claimed in Claim wherein said controllable arm when operated feeds said pivotal lever of said carriage onto a raised platform to tilt said article carrying portion and eject said article. 12. A weight grading apparatus substantially as herein described with reference to the accompanying drawings. Dated this 24th day of October 1994 Is N B MACDONALD ENGINEERING LIMITED By its Patent Attorneys G R K MADDERN ASSOCIATES L_ 1 -e A- I ii Fi .4-~tii b;r ABSTRACT a 1 *0 I St I C (1 C L A WEIGHING APPARATUS In Figure 1 a carriage 1 for a weight grading apparatus is pulled along by a chain 24, in a direction indicated by arrow X, carrying its contents 9 to a weighing station and then to a tipping station where, if the contents are of a required weight, the contents will be tipped out. Legs 2B and 16 of the carriage body base 2A engage a support beam (19) which, at the weighing station, has an increased vertical spacing apart from the chain 24, sufficient to cause the links 14 to pivot into a substantially horizontal position. This lifts the carriage body base 2A away from a carriage base 13 which is connected through connector 12 with the chain 24. The legs 2B and 16 of the bodiy 2 as they engage the weighing rails 19 can now provide a weight reading for the carriage body 2 and the contents 9 which is not influenced by the forces imposed on the base 13 by the moving chain 24. -h i