WO2008133530A1

WO2008133530A1 - Automated weigh-hopper internal elevator

Info

Publication number: WO2008133530A1
Application number: PCT/NZ2007/000149
Authority: WO
Inventors: Geoffrey Andrew Furniss
Original assignee: Geoffrey Andrew Furniss
Priority date: 2007-05-01
Filing date: 2007-06-11
Publication date: 2008-11-06

Abstract

An automated weigh-hopper elevator/dispenser system is disclosed, featuring reduced weighed item drop height. Although developed for use in handling and packing machinery whereby soft fruit is dispensed into shallow produce display packaging after weighing, it may also be applied to the handling of fragile manufactured items.

Description

Title: Automated weigh-hopper internal elevator Field of the invention

Gentle handling of some natural or manufactured items is necessary to avoid damage to them during inspection, packing or transport. Such damage is often the result of sudden deceleration following a fall, so if any fall is an intrinsic part of normal handling procedures, such fall height is a factor to be minimised to control product damage rates. Fruit, particularly soft varieties, exemplify such fragility and handling issues.

Background to the invention

Post-harvest handling of soft fruit progressively damages it, as in the case of cherries. Pitting of the cherry surface represents a cumulative record of its abuse, whether by wind on the tree, by fingers when picking it, or at any of the handling steps required to grade and pack it for display and sale. Surface pitting development is mostly caused by these impact events, which progressively degrade the fruit economic value and life, so every technique to limit impact damage is useful.

Impact occurs during each occasion that any fruit is changed in its relative velocity by contact with an adjacent surface, be that surface the stem of an adjacent fruit, a container wall or another fruit. Acceleration by gravity during transfer of fruit from one container to another or machine handling at any step during grading or packing are the most common causes of relative velocity generation, with consequent structural damage of the fruit flesh when it is suddenly decelerated on impact. To limit the impact energy by minimising every fall height is therefore to minimise value loss prior to consumption.

Some prior art [e.g., PCT/NL2005/000323] addresses these concerns, whereby a bridging device is used to both transport relatively delicate products from a higher level to a lower level, and uniformly fill a relatively large container with them. Another bridging method [PCT/DK2006/000295] utilises a rocking duplex dispenser as level- shifting device for bulk produce onto dual conveyors.

In contrast, the present invention seeks merely to achieve the transport function of small volumes from one level to another, and gentle deposition of delicate products in random order into small containers. It is novel in that it combines the weighing function, the bridging function and the gentle dispensing function into one simple mechanism through association with calculation and control means.

Brief description of drawings

Figure 1 : Whole assembly viewed from rear, showing load-bar transducer and elevator drive means.

Figure 2: Electronic processor system comprising hardware and software typically required for determining flap positional control.

Figure 3: Elevator and flap positions at initial fill and final release positions.

Figure 4: Flap angular motion of flap relative to elevator endless conveyor, as determined by flap cam position.

Figure 5: Side plate showing cam track and path switch diversionary mechanism.

Figure 6: Side plate showing path switch diversionary mechanism in upwards return path position showing spring motion return direction.

Figure 7: Flap side view showing elevators and cam follower attachment.

Figure 8: Cutaway view showing drive roller pulleys.

Detailed description of the invention

Two normally horizontal flaps 1 disposed adjacent with a minimal gap between comprise the moveable floor of a weigh hopper/elevator, two sides of which are formed by vertical fixed plates 2 disposed laterally so as to contain between them a pair of vertically oriented endless conveyors 3 forming the other two sides of the weigh hopper, to which the flaps are attached. The flaps are maintained in juxtaposed relationship during vertical travel inside the box-section formed by the fixed and movable sides. The whole weigh hopper assembly functions as such due to its attachment to a conventional load-weigh bar transducer 4 connected to a conventional electronic processor system 5 which outputs a weight signal. A conventional computer algorithm 6 defines the relationship between the conditions of weigh-hopper empty and weigh- hopper full, such as to determine the rate at which the endless conveyors to which the flaps are attached are driven downwards by motor means 7 to preserve a constant and minimal soft produce fall distance 8 from feed conveyor 9 to the progressively filled weigh-hopper produce surface 10.

On reaching target weight, the feed hopper is stopped, and the flaps are driven further downwards to release the weigh-hopper contents into a waiting receptacle 11 pre-placed beneath it. The produce handling fall is thereby reduced by the factor of elevator movement 12.

The release process occurs by changing flap angle 13 from horizontal to vertical such as to increase the flap to flap gap 14 from minimal to maximal, during which time the flaps are smoothly rotated away from each other to vertically downwards, allowing the produce resting on them to slip a short distance to fill the waiting receptacle. The motor means 7 are then reversed to restore the flaps to their original position in readiness for the next produce delivery by the feed conveyor.

Flap position during these operations is defined by a cam-track 15 enclosing a cam follower 16 connected to one of each flap lateral edges 17 adjacent to the vertical fixed plates, into which the cam-track is inscribed. The cam track comprises a vertically oriented combined linear 18 and looped 19 planar path which, under the influence of gravity on each flap and spring-operated path switch diversionary mechanism 20, controls the cam into different paths on flap travel down and up such that whereas the flaps are horizontal during descent until produce release point is reached, on ascent the alternate looped path is taken, leaving the flaps relaxed downwards until they are again near their highest elevation when they are forced back into their horizontal position ready to receive produce. After cam movement through the path switch diversionary mechanism, its spring motion 21 restores the cam path into its normal form ready to guide the cam directly downwards thereby maintaining the flap in its horizontal position during downwards motion.

The vertically oriented endless conveyors forming opposing sides of the weigh-hopper each comprise, in mirror-image relationship, conventional belting, jointed section or any similar flexible strip disposed around an upper pulley roller 22 which is driven by motor means. A conveyor support structure edge 23, functions as a passive lower pulley. The flap is attached to or formed from the flexible strip material in a manner sufficiently rigid to support its share of the produce load 24 yet enable sufficiently free rotation to 90 dispense it in the manner described. In the preferred embodiment the flap is hinged 25 from a jointed belt section 26 and its angular relationship 13 relative to the belt is defined by its attached cam follower and associated cam track.

The described embodiments of the invention are intended to be merely exemplary and numerous variations and modifications will be apparent to those skilled in the art. All 95 such variations and modifications are intended to be within the scope of the present invention as defined in this description,

Claims

ClaimsWhat I claim is:

1. An automated weigh-hopper elevator system, wherein a movable floor is

100 lowered to maintain weigh-hopper contents surface level closely similar to the initial floor level, and when the weigh-hopper is full, the moveable floor acts to dispense the hopper contents.

2. An automated weigh-hopper elevator system as claimed in claim 1, wherein the moveable floor comprises a plurality of parts each controlled in position and

105 time to act first as support for hopper contents, then as dispensing agents for hopper contents release.

3. An automated weigh-hopper elevator system as claimed in claim 1, wherein the moveable floor parts position and time control is firstly a calculated product of hopper contents mass and its relationship to a target mass, and secondly

110 comprises sequential elements of a dispensing duty cycle, and thirdly a return sequence to achieve initial conditions.

4. An automated weigh-hopper elevator system as claimed in claim 2, wherein the moveable floor comprises parts adjustable in angular relationship to the weigh- hopper sides.

115 5. An automated weigh-hopper elevator system as claimed in claim 2, wherein the moveable floor parts are each attached to vertically oriented conveyors wherein the weigh-hopper sides are formed from said vertically oriented conveyors.

6. An automated weigh-hopper elevator system as claimed in claim 2, wherein the moveable floor parts angular relationship to the weigh-hopper vertically oriented

120 conveyors is defined by cam and cam-follower means, wherein the downward release path and upward return path are separately defined.

7. An automated weigh-hopper elevator system as claimed in claim 5, wherein the weigh-hopper floor comprises two hinged flaps attached to two vertically oriented conveyors forming opposing sides of the weigh-hopper mechanism. An automated weigh-hopper elevator system substantially as described and as illustrated in the accompanying drawings.