WO1996039019A1

WO1996039019A1 - Loading conveyor

Info

Publication number: WO1996039019A1
Application number: PCT/GB1996/001356
Authority: WO
Inventors: Lee Sheridan Russell
Original assignee: KENSAL Ltd
Current assignee: KENSAL Ltd
Priority date: 1995-06-06
Filing date: 1996-06-06
Publication date: 1996-12-12
Anticipated expiration: 1997-12-06
Also published as: GB9511392D0; AU6009596A

Abstract

A loading conveyor suitable for the loading of mushrooms at the time of harvesting is mounted on a trolley (10) adapted to be wheeled between mushroom growing beds. The loading conveyor (20) has a pair of arms (20, 21) articulated about respective vertical axes (22, 23) to a support frame (24), the frame (24) being pivoted about a vertical axis (25) to the trolley (10). A link (27) ensures the arms (20, 21) remain parallel throughout the pivoting movement thereof. A pair of endless belts (34, 35) extend round respective pairs of first and second pulleys (30, 32; 31, 33). The arms may extend either forwardly of the trolley or to one side thereof over a growing bed, the belts serving stably to maintain the arms in either of these two positions by acting with the arms as an over-centre mechanism.

Description

LOADING CONVEYOR

This invention relates to a loading conveyor, and in particular (but not exclusively) to such a conveyor suitable for use when harvesting mushrooms. The invention also relates to the combination of such a conveyor together with a grading trolley arranged to grade mushrooms supplied thereto by the loading conveyor.

Though the loading conveyor of this invention may be used with items other than mushrooms, including both delicate grown produce and manufactured products, since the loading conveyor is intended primarily for use with the harvesting of mushrooms it will hereinafter be described expressly with reference to such produce. It must however be understood that the invention is not to be regarded as limited solely to the handling of mushrooms.

It is known to grow mushrooms on a commercial basis in growing sheds having fixed beds arranged in rows along the length of the shed, with an aisle between each adjacent pair of rows. When the mushrooms are to be harvested, an operator walks along the aisle and selectively cuts those mushrooms considered to be sufficiently mature to be harvested. Though the operator may deposit the harvested mushrooms into a basket for subsequent sorting and packaging externally of the mushroom shed, there have been developed graders in the form of a wheeled trolley which may be pulled by the operator along the aisle, and into which the operator feeds the mushrooms as they are harvested. The grader includes a mushroom conveyor configured to allow the grading of the harvested mushrooms, whereby the mushrooms are distributed into appropriate containers dependent upon the size of the mushroom caps.

As each mushroom is harvested, it has to be fed on to the conveyor of the grader. Though various in-feed arrangements have been proposed, it is difficult for an operator quickly and easily to feed mushrooms one at a time on to the conveyor with the mushrooms in the correct orientation for proper grading. It must of course be borne in mind that in view of the delicate nature of the harvested caps, mushrooms must be handled with considerable care in order to avoid damage to the harvested caps.

The present invention aims at providing a loading conveyor assembly suitable for use for example with a grading trolley intended to be pulled along the aisle between rows of growing beds for mushrooms, which loading conveyor facilitates the loading of mushrooms on to the grading conveyor and so minimises the risk of damage to harvested caps, and at the same time allows an operator to harvest mushrooms more easily and quickly.

According to one aspect of the present invention, there is provided a loading conveyor suitable for use when harvesting mushrooms, comprising a support frame, a pair of arms each articulated to the support frame about a respective generally vertical axis, means linking the arms so that the arms remain substantially parallel during articulating movement thereof, each arm having associated therewith a respective endless belt which extends around a first pulley provided at or adjacent the end of the arm articulated to the support frame and a second pulley at or adjacent the end of the arm remote from the support frame, and means to drive the belts such that the facing runs of the two belts move from the free ends of the arms towards the support frame. It will be appreciated that the loading conveyor of the present invention is particularly suitable for use with a grading trolley of the kind described hereinbefore. In this case, the loading conveyor may be attached to the grading trolley, to feed mushrooms placed on the loading conveyor to the grading conveyor of the grader. Thus, the loading conveyor should be mounted at the inlet to the grading conveyor so as to project forwardly therefrom; in this way, an operator may easily deposit harvested mushrooms on to the loading conveyor defined by the respective pairs of endless belts, and the articulated arms allow the loading conVeyor to be directed towards a bed being harvested. Consequently, an operator may more easily load mushrooms into the grading trolley, with a reduced risk of damage to those mushrooms. Operator efficiency is thus enhanced allowing greater productivity with fewer damaged mushrooms.

It is most preferred for the arms of the loading conveyor to be arranged to project at one of two pre¬ defined angular positions with respect to the support frame. To that end, there may be provided means limiting the angular articulation of each arm in the direction away from the other arm. By having the axis of articulation of each arm spaced from the axis of rotation of the first pulley associated with that arm and positioned such that the belt passing around the first and second pulleys forms an over-centre mechanism, the arm will be urged to stay at its angularly-limited position. To allow this to be achieved, the spacing between the axes of rotation of the two first pulleys may be smaller than the spacing between the axes of articulation of the two arms. There will thus be minimum tension in the two belts when the arms are at either one of their two angularly- limited positions, with the belts being stretched to a greater extent at all other intermediate positions. In this way, two stable positions are defined when the arms are at their two angularly-limited position^ and all other intermediate positions are unstable. For this, the belts must be resiliently extensible at least to a limited extent, and to be under tension when fitted to the apparatus.

In order to maintain the two arms parallel to one another for all angular positions thereof, a link may be arranged symmetrically with respect to the articulation axes of the arms to the support frame, whereby the link in conjunction with the arms and the support frame forms a parallelogram linkage. Such a link may have an adjustable length to permit accurate setting-up.

The support frame itself may be pivoted about a generally vertical axis to a main frame and be settable to a selected one of a number of different angularly- spaced positions. In this case, a manually-releasable mechanism may be provided to lock the support frame in the selected one position. Preferably, the support frame has two pre-set angularly-spaced positions, essentially equi-spaced to each side of the centre line of the loading conveyor - and in this case, the articulation of the two arms may be limited to two positions equi-spaced each side of the centre line of the support frame. Conveniently, the two pre-set angularly-spaced positions of the support frame are at ± φ° to the centre line of the main frame and the movement of the arms is limited to ±φ° with respect to the support frame. In this way, the arms may project from the main frame at any one of four stable positions, namely: a) with the support frame turned clockwise through + φ° and the arms at their clockwise limiting position of +φ°; b) with the support frame turned clockwise through + φ° and the arms at their counter-clockwise limiting position of -φ° . c) with the support frame turned counter-clockwise through -φ° and the arms at their clockwise limiting position of +φ°; and d) with the support frame turned counter-clockwise through -φ ° and the arms at their counter¬ clockwise limiting position of —φ° . By making the total angular movement of the support frame 2φ° and also the included angle between the arms at their two limiting positions equal to 2φ° , the arms project from the main frame in the same direction, at positions b) and c) above. There are thus three lines of projection of the arms.

This invention extends to a loading conveyor of the invention as described above, in combination with a trolley intended to be wheeled between rows of mushroom growing beds with the arms of the loading conveyor articulated so as to project either along the line of advancement of the trolley or laterally thereof so as to project towards or even partially overlie a mushroom growing bed. In such a case, the main frame of the loading conveyor may comprise a suitable part of the trolley itself.

The trolley may be an essentially conventional grading trolley and so include a grading conveyor arranged to deposit mushrooms in appropriate containers dependent upon the size of those mushrooms. The loading conveyor serves to feed harvested mushrooms on to the grading conveyor, which conveniently comprises a pair of endless belts running around suitable pulleys with the spacing between the belts gradually increasing whereby mushrooms carried by their caps resting on those belts will fall therebetween when the belt spacing becomes greater than the cap diameter. The trolley may also include a stalk-cutter, to sever the stalks of successive fed mushrooms to a uniform length.

Preferably, the grading conveyor of the trolley extends around respective pairs of pulleys on the same axes as the first pulleys of the loading conveyor. By coupling together those pulleys, the drive means for the grading conveyor will cause rotation of the first pulleys of the loading conveyor and so in turn serve as the drive means for the loading conveyor. By way of example only, one specific embodiment of harvesting trolley incorporating a loading conveyor of this invention will now be described in detail, reference being made to the accompanying drawings, in which:— Figure 1 is a diagrammatic side view of the harvesting trolley together with the loading conveyor; Figure 2 is a diagrammatic plan view of the loading conveyor, showing the principle of operation thereof; Figure 3 is a plan view of the loading conveyor, but in an unstable position; and

Figure 4 is a side view of the loading conveyor of Figure 3.

In Figure 1 , there is shown a grading trolley 10 of a generally known design, for use in a mushroom growing shed. The trolley is provided with wheels 11 and 12 so that it may be pulled along an aisle between adjacent rows of growing beds, and includes a belt grading conveyor 13 which serves to grade mushrooms supplied to that conveyor and to deposit those mushrooms into appropriate containers 14 dependent upon the size of the mushrooms. The conveyor 13 has two endless belts running around associated pulleys with the spacing between the facing (conveying) runs of the two belts gradually increasing away from the inlet end 15 of the conveyor. The caps of conveyed mushrooms rest on those runs and when the spacing between those runs becomes equal to the size of a conveyed mushroom, the mushroom falls between the belts and into the container 14 therebelow. A motor 16 is provided to drive both the grading conveyor 13 and also a feed conveyor 17 which is configured to feed mushrooms on to the grading conveyor 13. The feed conveyor also has a pair of endless belts and mushrooms are carried by their caps on the facing runs of those belts. The operator, in the known grading trolley, places mushrooms one at a time on the inlet end 18 of the feed conveyor so that the mushrooms are carried 'to and deposited on the grading conveyor 13. Whilst being carried on the feed conveyor 17, the mushrooms move past an adjustable stalk cutter 19, to sever the stalks of all the carried mushrooms to the same length, below the conveyor.

The above described grading trolley is known in the art and will not be described in further detail here.

In this embodiment of the present invention, a loading conveyor 20 is provided at the inlet end 18 of the feed conveyor 17, to facilitate the loading of mushrooms on to that feed conveyor. The loading conveyor has a pair of arms 20 and 21 , articulated about respective generally vertical axes 22 and 23 to a support frame 24, itself pivoted about a generally vertical axis 25 to the main frame 26 of the trolley 10 (see Figures 2 and 3). A link 27 is pivoted at its two ends 28 and 29 to the two arms 20 and 21 respectively, and forms in conjunction with those arms and the support frame 24 a parallelogram linkage so that the arms 20 and 21 remain parallel irrespective of the articulating movement thereof. To permit accurate alignment of the arms, the link 27 may be in two parts with a left and right-hand threaded adjuster joining the two parts, whereby rotation of the adjuster varies the effective length of the link.

Mounted on the support frame 24 is a pair of first pulleys 30 and 31 , one associated with each arm 20 and 21 respectively. These first pulleys have their axes of rotation arranged vertically but spaced from the axes of articulation 22 and 23 of the respective arms 20 and 21. At its free end, each arm 20 and 21 carries a respective second pulley 32 and 33, and a pair of endless belts 34 and 35 extend around the first and second pulleys whereby the two facing runs 36 and 37 of the two endless belts define a conveyor for mushrooms. The belts are resiliently extensible and, as fitted, are under tension to ensure proper running and operation of the conveyor.

An abutment face 38 (Figure 3) is provided on each arm and engages a corresponding surface (not shown) on the support frame 24 in order to define a limiting position for the angular movement of the arm in the direction away from the other arm. Thus, the maximum clockwise angular movement of arm 20 is defined by its abutment face 38; and the maximum counter¬ clockwise movement of arm 21 is defined by its abutment face 38. The configuration of the axes of rotation of the first pulleys 30 and 31 , the diameter of those pulleys and the axes 22 and 23 of articulation of the arms 20 and 21 to the support frame 24 all are such that in conjunction with the belts 34 and 35 there is formed for each arm an over-centre arrangement which tends to keep the arm at its limiting position. The combined tension of the two belts thus keeps the two arms at either one of the two limiting positions, and all other intermediate positions of the arms are essentially unstable, including the central position illustrated in Figure 3. The support frame 24 pivots about axis 25 and may be locked by mechanism 40 at either one of two angularly-spaced extreme positions. Mechanism 40 includes a spring-loaded plunger 41 which may drop into either one of two extreme position holes 42 formed in upper plate 43 of the support frame 24, or in a central position hole as shown. The plunger 41 has an enlarged head to facilitate lifting thereof by an operator.

The first pulleys 30 and 31 are each in the form of a double pulley having two grooves. Belts 34 and 35 run in the upper groove of the associated pulley and belts 44 of the feed conveyor 17 run in the lower grooves. In' this way, a cap carried by the belts 34 and 35 will be deposited on the belts of the feed conveyor, to be carried into the grading trolley, for grading therein. Moreover, the belts 34 and 35 of the loading conveyor will be power-driven by the motor 16 which drives the belts 44 of the feed conveyor and so rotates the double pulleys 30 and 31 , in turn driving the belts 34 and 35.

The limiting positions of the arms 20 and 21 are defined to be at ±20° with respect to the support frame 24 - that is to say, the total angular movement of the arms between their two limiting positions is 40°. Moreover, the two defined pre-set positions for the support frame 24 are at ±20° with respect to the main frame of the grading trolley 10 - that is to say, the total angular movement of the support frame with respect to the grading trolley is 40°. In the above way, the arms and support frame may both be at their extreme clockwise positions as shown in Figure 2, with the arms projecting at 40° with respect to the centre line 45 of the grading trolley. When the arms and support frame are both at their extreme counter-clockwise positions (not shown), the arms will again project at 40° with respect to the centre line 45 of the grading trolley, but in the opposite sense. When the arms are at their extreme clockwise position but the support frame is at its counter-clockwise position, or the arms are at their extreme counter-clockwise position but the support frame is at its clockwise position, the arms will project forwardly along the centre line 45 of the grading trolley.

As can be seen from Figure 2, when the arms are at either of their two extreme limiting positions with respect to the support frame, one of the second pulleys (32 or 33) is displaced forwardly with respect to the other second'pulley. This gives an easy feed-in for a mushroom held by its cap so that the operator may properly locate the mushroom with respect to the loading conveyor and deposit the cap on the facing runs 36 and 37, to be conveyed into the grading trolley. Damage to the mushrooms will thus be minimised and productivity may be increased, by the easy access to the loading conveyor coupled with the ease of depositing harvested mushrooms on to the loading conveyor.

Claims

1. A loading conveyor suitable for use when harvesting mushrooms, comprising a support frame, a pair of arms each articulated to the support frame about a respective generally vertical axis, means linking the arms so that the arms remain substantially parallel during articulating movement thereof, each arm having associated therewith a respective endless belt which extends around a first pulley provided at or adjacent the end of the arm articulated to the support frame and a second pulley at or adjacent the end of the arm remote from the support frame, and means to drive the belts such that the facing runs of the two belts move from the free ends of the arms towards the support frame.

2. A loading conveyor as claimed in claim 1, wherein, for each arm, the axis of articulation of the arm is spaced from the axis of rotation of its associated first pulley.

3. A loading conveyor as claimed in claim 2, wherein there is provided means limiting the angular articulation of each arm in the direction away from the other arm, the axis of articulation of each arm is positioned with respect to the axis of rotation of the associated first pulley and the belts are resiliently extensible such that the belts passing around the first and second pulleys of each arm tend to maintain the arm at its angularly-limited position.

4. A loading conveyor as claimed in claim 3, wherein each belt acting in conjunction with its associated arm and the support frame forms an over- centre mechanism which serves to maintain the arm at its angularly-limited position.

5. A loading conveyor as claimed in claim 3 or claim 4, wherein the spacing between the axes of rotation of the two first pulleys is smaller than the spacing between the axes of articulation of the two arms.

6. A loading conveyor as claimed in any of the preceding claims, wherein a link extends between the two arms and is symmetrically arranged with respect to articulation axes of the arms to the support frame, which link in conjunction with the arms and the support frame forms a parallelogram linkage.

7. A loading conveyor as claimed in any of the preceding claims, wherein the support frame is pivoted about a generally vertical axis to a main frame and is settable to a selected one of a number of different angularly-spaced positions.

8. A loading conveyor as claimed in claim 7, wherein manually-releasable means are provided to lock the support frame in a selected one position.

9. A loading conveyor as claimed in claim 7 or claim 8, wherein the support frame has two pre-set angularly-spaced positions, essentially equi-spaced to each side of the centre line of the loading conveyor.

10. A loading conveyor as claimed in claim 9, wherein the articulation of the two arms is limited to define two extreme positions equi-spaced to each side of the centre-line of the support frame.

11. A loading conveyor as claimed in claim 9 and claim 10, wherein the two pre-set angularly-spaced positions of the support frame are at ± φ° to the centre-line of the main frame, and the movement of the arms is limited to ± φ° with respect to the support frame.

12. A loading conveyor as claimed in any of claims 7 to 11, wherein the main frame comprises a trolley intended to be wheeled between rows of mushroom growing beds, the arms being articulated so as to project along the line of advancement of the trolley or laterally thereof towards or partially overlying a mushroom growing bed .

1 3 . A loading conveyor as claimed in claim 1 2 , wherein the trolley includes a further conveyor having a pair of endless belts extending around respective pairs of pulleys so as to define a mushroom conveying run, arranged so that mushrooms carried by the loading conveyor are discharged from the belts thereof on to the further conveyor .

1 4 . A loading conveyor as claimed in claim 1 3 , wherein the further conveyor has a pair of pulleys arranged co-axially with and coupled to the first pulleys respectively of the loading conveyor, whereby drive is imparted to said f irst pulleys from the further conveyor.

1 5 . A loading conveyor as claimed in any of claims 1 2 to 1 4 , wherein there is provided a stalk-cutter below the further conveyor whereby mushrooms carried by the further conveyor have their respective stalks cut to a uniform length .

1 6. A loading conveyor as claimed in any of claims 1 2 to 1 5 , wherein the trolley incorporates a grading conveyor to which mushrooms are supplied, the grading conveyor being arranged to di s tribute conveyed mushrooms into various receptacles dependent upon a physical parameter of those mushrooms .

17. A loading conveyor as claimed in any of claims 1 to 10 in combination with a grading trolley arranged to receive mushrooms from the loading conveyor and sort those mushrooms into various receptacles dependent upon the determined grade of those mushrooms .