Fruit handling equipment

A conveying assembly for fruit handling, comprising a carriage (20) adapted to be attached to a conveying chain arranged to displace the carriage in a conveying direction, a cup (30) adapted to support a single piece of fruit, the cup being secured to the carriage via a parallelogram linkage (41, 42, 22, 35) extending transversely to the conveying direction, the cup being pivotally secured to the linkage to be moveable from a conveying position to a discharge position, the linkage having release means (60) to cause the cup to pivot relative to the linkage transversely of the conveying direction to the discharge position to effect discharge of the fruit, the linkage allowing the cup to be vertically displaceable to effect weighting of the fruit.

INTRODUCTION

This invention relates to fruit handling equipment and more particularly to conveyor systems for use in such equipment.

BACKGROUND OF THE INVENTION

Fruit handling equipment conventionally comprises a conveyor that includes a plurality of fruit carrying cups that support fruit that can be transported from one end of the conveyor to another. It is usual that the fruit is caused to rotate through a photographic zone and is then passed through a weighing zone. A computer sorts the fruit by weight, size and blemish and determines when the fruit should be discharged from the carrying cups to suitably positioned discharge bins along the length of the conveyor. The cups include a tipping mechanism to effect discharge.

There are a number of patents that disclose this kind of equipment of which the following contain typical disclosures: Australian patents 649963, 656424, 658686, 696009, 701354.

There is however an ongoing need to improve the accuracy and efficiency of this type of equipment. The accuracy of weighing fruit is of particular concern. The high speeds at which this equipment operates also lead to potential damage to the fruit or premature discharge that results in the same effect.

It is these considerations that have brought about the present invention.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided a conveying assembly for fruit handling equipment comprising a carriage adapted to be attached to a conveying chain arranged to displace the carriage, a cup adapted to support a single piece of fruit, the cup being secured to the carriage via a parallelogram linkage extending transversely to the conveying direction, the cup being pivotally secured to the linkage, means to cause the cup to pivot relative to the linkage transversely of the conveying direction to effect discharge, the linkage allowing the cup to be vertically displaceable to effect weighing of the fruit.

Preferably, rollers are positioned adjacent either side of the cup in the conveying direction, the rollers being vertically displaceable to assume an upper position in which the rollers lift the fruit clear of the cup. The assembly preferably also includes means to cause rotation of the rollers to rotate the fruit at the upper position.

Preferably, the cup has a concave support surface supported by a centrally positioned post, the post being pivotally secured to the carriage via the parallelogram linkage.

In a preferred embodiment the parallelogram linkage comprises each arm having ends pivotally connected to the post and the carriage.

Preferably, the lower arm has an elbow joint which can be displaced to a bent configuration thus causing the post and cup to tilt to effect discharge.

The rollers are preferably interconnected by a double ‘Z’ shaped bar that is supported by the carriage to axially pivot to raise/lower the rollers, the support of the bar allowing vertical displacement of the bar.

The accompanying drawings illustrate fruit handling equipment especially for use in the sorting and weighing of fruit such as apples. The fruit handling equipment comprises an endless conveyor on which is clipped a series of carriages20. The conveyor is driven about spaced sprockets. Each carriage20supports a fruit carrying cup30on each side. Each carriage20also supports rollers70on each side that can lift the fruit clear of the carrying cups30and rotate the fruit past a camera in a photographic zone (FIG. 10) allowing the fruit to be viewed for size and blemish. The conveyor also includes a weighing zone (FIG. 3) in which the fruit carrying cups pass over a load cell W. A solenoid (not shown) can be activated to cause the fruit carrying cups30to tip (FIG. 9) to eject selected fruit off the conveyor. The conveyor is run by a computer that ensures that the fruit is sorted by size, weight and blemish at high speed as it moves along the conveyor.

Equipment of the kind described above is disclosed in a number of the applicant's earlier patents including AUB 658686 and 696009.

In the system shown inFIG. 1that is the subject of this application each carriage20includes a rectangular platform80with a pair of downwardly extending legs21,22. The underside of the platform supports a chain clip23that allows the carriage to clip onto the chain (not shown) of a conveyor. Each leg21,22, supports a T-shaped support cup30via a transversely extending parallel linkage40. By transverse it is understood that the linkage comprises an upper linkage41and lower linkage42that extend transversely of the conveyor or perpendicular to the line of travel.

Each T-shaped cup30comprising a dished recess31bordered by five arcuate fingers32spaced to define gaps33therebetween. The dish shaped cup31is supported by a downwardly extended central post35. The post terminates in a lower abutment surface36and is pivotably secured to the lower linkage42about a pivot point37and to the upper linkage41throughout pivot point38.

As shown inFIG. 1, the upper linkage41comprises an elongate bar43with a forked end44that is pivotably secured about the pivot point38. The bar43supports a transverse beam45that is pivotably mounted across projecting flanges formed on the leg21or22.

The lower linkage42is illustrated in greater detail inFIGS. 5 and 6and comprises an inner arm51(FIG. 6) that is pivotably supported by the flanges of the leg21of the carriage20. The arm51has a pair of projecting parallel webs52,53each having downwardly projecting legs54and55. The webs are pivotably secured to either side of an outer linkage56(FIG. 5) that has a central body portion57with projecting webs58,59that are pivotably secured to either side of the lower pivot point37of the post35. The body portion57includes a downwardly extended abutment60and a pair of stops62on either side of the front face of the forward end. As shown with particular reference toFIGS. 1 & 2the inner arm57and outer linkage56operate as an elbow. When in the position shown inFIGS. 1 & 2, the legs54,55abut the stops62and the linkage assumes a straight extended position. As shown inFIG. 8when the abutment60is contacted by a solenoid (not shown) it causes the outer linkage56to move inwardly and upwardly towards the carriage20to reduce the effective length of the linkage42causing the lower end of the post35to move inwardly towards the carriage causing the fruit carrying cup to tip outwardly to ultimately assume the position inFIG. 9in which the forward end46of the frame43abuts a stop47on the underside of the platform. In this position the cup30is at an angle of 45° to the vertical end the contents have been ejected. To return the cup to the vertical position the underside of the cup recess31rides up a ramp (not shown) that has the effect of pushing the cup up to the vertical. At the same time the legs54,55of the inner arm51of the lower linkage42latch against the stops62.

FIG. 1also illustrates the location of a pair of rollers70on a double Z-shaped bar71that it clipped across the carriage platform80. The free ends or stub axles72,73of the bar71extend transversely from the carriage and the rollers70are in the form of spaced concentric discs75with tapering peripheries. The tapering peripheries of the discs75are aligned with the gaps33between the fingers32of the carrying cups30as shown inFIG. 2. As shown inFIG. 10the rollers70are arranged to ride up a ramp76which causes the bar71to pivot about the platform80to lift the rollers through the gaps33between the fingers32to lift the fruit carried on the cup clear of the cup30. As shown inFIG. 10, the rollers70on the adjacent carriage20would extend through the right hand side of the carrying cup30so that each side of the cup is engaged by the roller peripheries.

The double Z-shaped bar71results in the stub axles72,73being parallel but offset to the central position77that is supported by the upper surface of the carriage platform80as shown inFIG. 4. The support for the rollers is a single support on the extreme edge at both sides of the carriage. The central portion77of the bar locates within elongate slots78with arcuate ends79formed in the upper surface81of the carriage base80. The location of the central portion77of the bar70allows it to pivot along its axis but also provides a degree of vertical movement (preferably 3 mm or 4 mm) to accommodate distortions in the assembly that might cause the roller70to lift clear of the ramp76on one side when lifted by the ramp on the other side. The slight tilting of the bar due to the vertical movement ensures that the rollers remain on the ramps on each side of the conveyor.

FIG. 10is a side view of the conveyor with the rollers70in the upper position projecting through the gaps between the fingers32of the conveying cups30to lift the fruit clear of the cups.

Although not shown, the rollers70are first supported by the stub axles72,73in the upper position as they complete the return pass and become upright as they round the drive sprocket, a first elongated surface (not shown) supports the roller stub axles72,73until the periphery of the rollers engages a friction surface76shown inFIG. 10.

The frictional contact of the roller peripheries with the surface76causes the rollers to axially rotate which has the effect of causing the fruit to rotate. Although not shown, the fruit move through a photographic zone where they are filmed as they rotate by a CCD camera. When the conveyor moves the fruit past the photographic zone the fruit remain rotating on the rollers70that engage the ramps76. However as shown inFIG. 10a stabilising ramp90then supports the stub axles72,73of the rollers70. Once the rollers70have been supported by their stub axles72,73by the ramp90they effectively become disassociated with the friction surface76and slowly free-wheel to a stationary position whilst supported on the stabilising ramps90that engage the stub axles. The stabilising ramp90as shown inFIG. 10diverges downwardly to lower the rollers70to an inoperative position as shown on the right hand side ofFIG. 10in which the fruit are again supported by the cups30. The subsidiary ramp90has the effect of causing the rollers to cease rotating which reduces the likelihood of the fruit bouncing off the cups. Thus when the fruit are lowered onto the cups to be weighed as shown inFIG. 3they are not rotating and are less likely to bounce off the cups30.

To weigh fruit carried in the cups30the rollers70assume the lower position shown inFIG. 3in which there the peripheries are well clear of the underside of each cup35. The abutment36at the end of the post35of each cup30rides up a ramp R onto a weighing cell W. This causes the cup30and linkage40to pivot through a small vertical movement causing the post and linkage40to disengage from the stop47on the underside of the carriage platform80. In this way, the parallel linkage ensures that there is no component of the horizontal movement in the vertical component that is interpreted by the load cell. The fact that the linkage is a parallelogram allows the load to be borne by the load cell W on a single abutment36of a reduced cross-section. This improves the accuracy of the weighing. However, the use of a transverse parallel linkage avoids the need to ensure that the linkage is horizontal or parallel to the load surface. In a longitudinal linkage any deviation from the horizontal or parallel introduces vertical components that distort the load reading and reduce the accuracy. A transverse linkage does not have this constraint and is thus easier to tolerance and set up.