Abstract:
The present invention provides a mushroom packing apparatus comprising a grading conveyor and a plurality of locations distributed under a longitudinal axis of the grading conveyor, each location being provided, in use, with a container for collecting the mushrooms as they are deposited from the grading conveyor. The apparatus is arranged to weigh the respective container at each location and to facilitate removal of the loaded container once the loaded container has reached a predetermined weight, the apparatus being further adapted to replace each loaded container with an empty container once the respective loaded container has reached a predetermined weight.

Description:
This application is National Stage of PCT/EP01/10243 filed on Nov. 04, 2001. 

   TECHNICAL FIELD AND BACKGROUND OF THE INVENTION 
   The present invention concerns a mushroom packing apparatus. 
   Although the apparatus of the present invention is primarily intended for use in the grading and packing of mushrooms, it will of course be understood from the following description that said apparatus would equally be suited for use with similar delicate items which conventionally require grading and packing. 
   It is a well established practice in the trade of mushroom growing to provide custom built growing houses in which the mushrooms may be grown in a carefully maintained environment. Each growing house conventionally contains rows of growing beds containing compost, on which the mushrooms are grown. The rows of growing beds are separated by passages running therebetween. Therefore, when harvesting the mushrooms, pickers travel along the passages between said rows, picking the mushrooms and depositing them in a basket or similar container for subsequent sorting and packing. 
   It is also known in the art to provide a custom built trolley having a conveyor on which the picked mushrooms are deposited, the trolley further including a number of containers into which the mushrooms are deposited from the conveyor. The conveyor is arranged to grade the mushrooms by size, such that each container includes only mushrooms within a given size range. Once one of the containers has been filled with mushrooms, the picker must cease picking, remove the container from the trolley, and deposit the container in a suitable location for further processing, for example, weighing to determine if the correct market weight of mushrooms has been loaded into the container. If said weight has not been achieved, or indeed if it has been surpassed, the contents of the container must be suitably adjusted. 
   Having removed the filled container from the trolley, the picker must then get an empty container and position it on the trolley in place of the filled container which has been removed. Once this has been effected, the picker may resume picking mushrooms from the bed. It will therefore be appreciated that the picker must also continually observe the containers in the trolley, while simultaneously trying to pick mushrooms, in order to ensure that none of the containers overflow. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the present invention to provide a mushroom packing apparatus which is capable of weighing each of the plurality of containers of mushrooms as the respective container is being filled, and to facilitate the automatic removal of the container to permit an empty container to be located in place of the filled container. 
   It is a further object of the present invention to provide a mushroom packing apparatus which automatically replaces a filled container with an empty container. 
   The present invention therefore provides a mushroom packing apparatus comprising a grading conveyor; a plurality of locations distributed under a longitudinal axis of the grading conveyor, each location being provided, in use, with a container for collecting the mushrooms as they are deposited from the grading conveyor; characterised in that the apparatus is arranged to weigh the respective container at each location and to facilitate removal of the loaded container once the loaded container has reached a predetermined weight. 
   Preferably, each location includes a weighing pan on which, in use, the respective container is seated. 
   Preferably, the apparatus replaces each loaded container with an empty container once the respective loaded container has reached a predetermined weight. 
   Preferably, each location comprises a transporter in operative association, in use, with the respective container, the transporter being arranged to transfer the container, when loaded, from beneath the grading conveyor and to locate an empty container beneath the grading conveyor. 
   Preferably, each weighing pan is shaped and dimensioned to support an empty container adjacent the, in use, container being loaded, the transporter operable to reversibly displace the weighing pan such that the loaded container is transferred from beneath the grading conveyor, while the empty container is simultaneously transferred beneath the grading conveyor. 
   Preferably, each location includes a support table located above and out of contact with the respective weighing pan, the support table being in operative association with the transporter such that the support table is maintained above the weighing pan as the weighing pan is reversibly displaced. 
   Preferably, the apparatus includes a stop associated with each location, the stop arranged to engage, in use, the respective empty container when located beneath the grading conveyor, such as to hold the empty container beneath the grading conveyor as the transporter retracts the weighing pan. 
   Preferably, the stop is further arranged to engage the respective loaded container once the loaded container has been transferred from beneath the grading conveyor, such as to prevent the loaded container from being drawn back beneath the grading conveyor as the transporter retracts the weighing pan. 
   Preferably, the apparatus is provided with a magazine in operative association with each location, each magazine containing, in use, a number of empty containers, the magazine being adapted to deposit an empty container at the respective location as required. 
   Preferably, the apparatus includes a lateral conveyor which runs adjacent each location, onto which lateral conveyor the transporter deposits the loaded containers, in order that the loaded containers may be conveyed from the apparatus. 
   Preferably, the apparatus includes a storage compartment into which the lateral conveyor feeds the loaded containers. 
   Preferably, the storage compartment is removably secured to the apparatus. 
   Preferably, the apparatus is shaped and dimensioned to pass between adjacent rows of mushroom beds in a mushroom house. 
   Preferably, once a predetermined number of empty containers within any of the magazines has been reached, a warning signal is generated to alert an operator that the respective magazine requires refilling. 
   Preferably, the apparatus includes a controller adapted to halt the grading conveyor while any loaded container is being replaced with an empty container, and to restart the grading conveyor once said replacement has been effected. 
   Preferably, a warning signal is generated once a predetermined number of loaded containers have been deposited in the storage compartment. 
   Preferably, the apparatus is mobile in order to permit the apparatus to be driven between the rows of mushroom beds. 
   Preferably, the apparatus includes sensors adapted to guide the apparatus, as the apparatus is driven, between the rows of mushroom beds. 
   As used herein, the term “grading conveyor” is intended to mean a conveyor for transporting items of a range of sizes, the conveyor being adapted to deposit items at appropriate locations along the length of the conveyor, dependent on the size of those items, such a loading conveyor generally taking the form of a pair of oppositely disposed endless belts, the spacing between the belts gradually increasing along the length thereof. 
   As used herein, the term “transporter” is intended to embrace any mechanical means capable of transferring a container from a first position to a second position and back again, the transporter preferably being in the form of a table on which the container is supported, the table being capable of reciprocating linear translations which are effected by conventional mechanical/hydraulic/pneumatic means. 
   As used herein, the term “magazine” is intended to mean a compartment attached to a machine, in which one or more items are stored, the compartment adapted to feed the items to the machine in a suitable fashion. 
   As used herein, the term “mushroom bed” is intended to mean compost bags, compost blocks, trays or shelves containing compost or the like, or any other similar growing systems in which mushrooms are grown, the beds generally being arranged in elongate rows having corresponding passages therebetween, which passages allow access to the beds for the purpose of harvesting the mushroom. 

   
     DETAILED DESCRIPTION OF THE DRAWINGS 
     The present invention will now be described with reference to the accompanying drawings, in which; 
       FIG. 1  illustrates a perspective view of the device according to the present invention; 
       FIG. 2  illustrates the apparatus of  FIG. 1  having several components omitted for the purposes of clarity; and 
       FIG. 3  illustrates a perspective view of one of six weighing pans and associated components forming part of the apparatus of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the accompanying drawings, there is illustrated a mushroom packing apparatus, generally indicated as  10 , for expediting the processing and packing of mushrooms  62 . The apparatus  10  consists mainly of a base  12  mounted on a plurality of wheels  60 , thereby allowing the apparatus  10  to be manoeuvred through a mushroom house (not shown). The base  12 , in  FIG. 1  of the drawings, is shown in dotted outline, and has been completely omitted from  FIG. 2  for the purposes of clarity. Located at a leading edge of the apparatus  10  is a loading conveyor  18  consisting of a first arm  19  and a second arm  21  in parallel spaced relation. The mushrooms  62 , once picked, are placed on the loading conveyor  18  such that the cap is supported by the first arm  19  and the second arm  21 , with the mushroom stalk suspended between the first arm  19  and the second arm  21 . The loading conveyor  18  is capable of swivelling from side to side about a pair of pivot pulleys  23  in order to be in close proximity to either mushroom bed (not shown) defining the row (not shown) along which the apparatus  10  is drawn. The first and second arms  19 ,  21  are adapted to remain parallel to one another as the loading conveyer  18  is drawn through an arc about the pivot pulleys  23 . 
   The mushrooms  62  proceed along the loading conveyor  18 , extending from and contiguous with the end of which is a first feed belt  14  and a second feed belt  16 , again in opposed spaced relation to one another. Both the first feed belt  14  and the second feed belt  16  are endless belts which, at adjacent respective faces thereof, are uni-directional in motion. The mushrooms  62  are therefore supported by the first feed belt  14  and the second feed belt  16  in a manner identical to that of the loading conveyor  18 , and are drawn therealong in the direction of movement of the adjacent respective faces of the first feed belt  14  and the second feed belt  16 . After passing from the loading conveyor  18  to the first and second feed belts  14 ,  16 , the mushrooms  62  traverse a pair of rotary blades  20  located beneath the first and second feed belts  14 ,  16 . The rotary blades  20  remove the roots (not shown) from the mushrooms  62 , which are deposited in a root bin  22  located beneath the rotary blades  20 . It will nonetheless be appreciated that any other suitable means, mechanical or otherwise, for removing the roots and/or stalk (not shown) may be adopted in place of the rotary blades  20 . The root bin  22  is shown in dotted outline in  FIG. 1 , and has been completed omitted from  FIG. 2  for the purposes of clarity. 
   The opposing respective lengths of the first feed belt  14  and the second feed belt  16  are positioned relative to one another such that the gap located therebetween increases in width along the direction of travel of the first and second feed belts  14 ,  16 . It will therefore be appreciated the once the gap between the first and second feed bets  14 ,  16  increases beyond the diameter of the cap of a mushroom  62 , the mushroom  62  will drop between the first and second feed belts  14 ,  16 . It will also be understood that the mushrooms  62  will vary in size from one to the next, the orientation of the first and second feed belts  14 ,  16  thereby causing mushrooms  62  of different size to pass between the first and second feed belts  14 ,  16  at various positions corresponding to the size of the mushrooms  62 . The first and second feed belts  14 ,  16  are therefore arranged to grade the mushrooms  62  and release them at predetermined locations along the length thereof. 
   Located beneath the first and second feed belts  14 ,  16  are a plurality of weighing pans  24  each of which, in use, have a container, preferably such as a punnet  26  located thereon for receiving the mushrooms  62  as they drop between the first and second feed belts  14 ,  16 . In both  FIGS. 1 and 2  of the drawings, only one of the weighing pans  24  is shown with a punnet  26  located thereon. The first and second feed belts  14 ,  16  are arranged such that at the first weighing pan  24 , the space therebetween has been set to match the cap diameter of the smallest mushrooms  62  being picked, and at the last weighing pan  24  the largest mushrooms  62  being picked. In the present embodiment of the invention the apparatus  10  includes six weighing pans  24  and respective punnets  26 , thereby separating the mushrooms  62  into six individual size brackets. It will however be appreciated that the apparatus  10  may be configured to include any number of weighing pans  24  and punnets  26 , to suit the size of the mushrooms  62  being picked and packaged. The orientation of the first and second feed belts  14 ,  16  must be adapted to suit the number of weighing pans  24  included in the apparatus  10 , in addition to the range of sizes of mushrooms  62  being picked. The apparatus  10  is therefore provided with a control unit  58  incorporating a visual display (not shown) and user interface (not shown) which allows the operator to monitor the various functions of the apparatus  10 . The control unit  58  allows an operator to vary the space between the first and second feed belts  14 ,  16  via the user interface (not shown). Alternatively, the necessary adjustment may be made manually to the first and second feed belts  14 ,  16 . 
   The weighing pans  24  monitor the weight of each individual punnet  26  as it is filled with mushrooms  62 . Each weighing pan  24  has a load cell (not shown) located therebeneath, on which the respective weighing pan  24  is seated, each load cell (not shown) being connected to the control unit  58  in order to allow the control unit  58  to monitor the weight of each individual punnet  26 . Once a predetermined weight has been reached, the apparatus  10  is adapted to remove the respective punnet  26  and replace the filled punnet  26  with an empty punnet  26 . The punnets  26  are preferably chosen such that, when full with mushrooms  62 , they are market ready. The predetermined weight for each filled punned  26  can be set via the user interface (not shown) of the control unit  58 . 
   The apparatus  10  is provided with a plurality of magazines  44 , the number of which corresponds to the number of weighing pans  24  present, each magazine  44  capable of holding a plurality of empty punnets  26 . Each magazine  44  is also adapted to be capable of housing and dispensing punnets  26  of different sizes. In  FIGS. 1 and 2  only a single magazine  44  is shown, located adjacent the end weighing pan  24 . Each magazine  44  is located adjacent a respective weighing pan  24 . In use, each magazine  44  incorporates a pair of oppositely disposed feeders  46 , one of which has been removed in both  FIGS. 1 and 2  for clarity. The feeders  46  are adapted to deposit a single punnet  26  from the respective magazine  44  as required, as is described hereinafter in detail. In use, once a first preset number of punnets  26  within each magazine  44  has been reached, a warning light (not shown) is illuminated in order to alert an operator that the respective magazine  44  will shortly require refilling with empty punnets  26 . A warning buzzer (not shown) will then sound if a lower preset limit of empty punnets  26  within the magazine  44  is reached. The control unit  58  will halt the feed belts  14 ,  16  if the punnets  26  within any magazine  44  run out. At this point a signal may be transmitted to a remote terminal (not shown), requesting a fresh supply of empty punnets  26 . The control unit  58  may further be adapted to transmit to the remote terminal (not shown) such information as the total number of punnets  26  filled by the apparatus  10 ; the weight of each punnet  26 ; the average weight of the punnets  26 ; the combined weight of mushrooms  62  packed by the apparatus  10 ; an operator identification number or the like, etc. 
   In order to effect replacement of a full punnet  26 , the apparatus  10  includes a plurality of selectors  30 , each weighing pan  24  having a selector  30  in operative association therewith. The selectors  30  comprise a crossbar  31 , a pair of lateral arms  33  extending substantially vertically downward from the crossbar  31 , each arm  33  incorporating a stop  35  extending substantially perpendicularly from the free end thereof. Each selector  30  is arranged and dimensioned such that the feed belts  14 ,  16  pass beneath the crossbar  31  and between the pair of lateral arms  33 , thereby preventing the mushrooms  62  from fouling the selectors  30  as the mushrooms  62  traverse the feed belts  14 ,  16  and drop into the punnets  26 . In  FIG. 3 , it can be seen that the feed belts  14 ,  16  have been omitted for the purposes of clarity. Each selector  30  is mounted to the apparatus  10  via a link  36 , to a selector cam  32  driven by a selector motor  34 . The selector motor  34  is arranged to rotate the selector cam  32  in order to effect elevation of the selector  30  to the extent that the stops  35  are located distal the respective weighing pan  24  a distance greater than the depth of the punnet  26 , as shown in  FIG. 3 , the application of which is hereinafter described. 
   The plurality of weighing pans  24  are mounted on a transporter  25  which is substantially planar in form and is located adjacent to and co-planar with the lower face of each of the plurality of weighing pans  24 , the transporter  25  being capable of a reversible translation, by conventional mechanical/pneumatic/hydraulic means (not shown), across the base  12  such that the weighing pans  24  extend outwardly over a lateral conveyor  38 . Therefore, in use, at the start-up of the apparatus  10 , prior to an operator feeding mushrooms  62  onto the loading conveyor  18 , the respective feeder  46  lowers an empty punnet  26  from each magazine  44  onto a support table  27  located directly beneath the respective magazine  44 . Each support table  27  is secured to the transporter  25  but is maintained above and out of contact with the respective weighing pan  24  located beneath said support table  27 . In both  FIGS. 1 and 2  only a single support table  27  is shown beneath the single magazine  44  shown, although it will be understood that each weighing pan  24  has a support table  27  associated therewith. At this point each of the selectors  30  are in the raised position as shown in  FIG. 3 , and the transporter  25  is driven across the base  12 , thereby moving each of the empty punnets  26  into position beneath the respective raised selector  30 , and the feed belts  14 ,  16 . Each of the selectors  30  is then lowered, and the transporter  25  is then driven back across the base  12 . The plurality of support tables  27  therefore return with the transporter  25 , and as the empty punnets  26  are held between the respective pair of stops  35 , the support tables  27  are drawn from beneath the empty punnets  26 , at which point the empty punnets  26  drop onto the weighing pans  24 . The control unit  58  then zeroes the reading shown for the weight of each of the weighing pans  24 , such that, on mushrooms being deposited in the plurality of punnets  26 , only the weight of the mushrooms  62  themselves will register, as opposed to the combined weight of the mushrooms  62  and the respective punnet  26 . Each of the selectors  30  are then moved to the raised position, prior to operation of the apparatus  10 . 
   Each magazine  44  then deposits a further empty punnet  26  onto the support table  27  located therebeneath, at which point the apparatus is ready for operation. As each support table  27  is located above and out of contact with the respective weighing pan  24 , the empty punnet  26  deposited thereon will not affect the reading for the weight shown on the respective weighing pan  24 . The loading conveyor  18  and the first and second feed belts  14 ,  16  may therefore be activated by means of the user interface (not shown), and mushrooms  62  are deposited onto the loading conveyor  18  to be deposited into the plurality of punnets  26  located beneath the feed belts  14 ,  16 , as hereinbefore described. 
   Therefore, during use, mushrooms  62  are continually fed to the apparatus  10 , which are graded into the plurality of punnets  26  located on the weighing pans  24 , the weight of mushrooms on each of the weighing pans  24  being carefully monitored by means of the respective load cell (not shown) and the control unit  58 . Once the predetermined weight had been reached in any of the punnets  26 , the apparatus  10  effects removal and replacement of said full punnet  26 . The loading conveyor  18  and the feed belts  14 ,  16  are therefore halted momentarily, and the transporter  25  is driven across the base  12 , as hereinbefore described. This thus results in each of the empty punnets  26  located on the plurality of support tables  27  being transferred beneath the feed belts  14 ,  16 , such that the feed belts  14 ,  16  can be reactivated to continue grading the mushrooms  62  into said empty punnets  26  now in position beneath the feed belts  14 ,  16 . In addition, the plurality of punnets  26  located on the weighing pans  24  are now located above the lateral conveyor  38 . At this stage the selector  30  associated with the full punnet  26  to be removed is lowered about the empty punnet  26  on the respective support table  27 , such that the pair of stops  35  are disposed on either side of said empty punnet  26 . Once the selector  30  has been lowered, the transporter  25  is driven back across the base  12 , during which translation the loading conveyor  18  and the feed belts  14 ,  16  are again momentarily halted. 
   As all of the selectors  30 , except the selector  30  associated with the full punnet  26  to be replaced, are still in the raised position, as the transport  25  returns across the base  12 , the respective punnets  26  on the support tables  27  and on the weighing pans  24  will be drawn back into their original positions beneath the magazines  44  and the selectors  30  respectively. However, the punnet  26  located between the stops  35  of the lowered selector  30  is maintained in position as the support table  27 , drawn by the transporter  25 , slides along therebeneath. Furthermore, as the transporter  25  and weighing pans  24  return, the full punnet  26  to be replaced will engage the outer stop  35  of the lowered selector  30 , preventing the full punnet  26  from returning beneath the feed belts  14 ,  16 . The weighing pan  24  will therefore be drawn from beneath the full punnet  26 , causing the full punnet  26  to drop onto the lateral conveyor  38 . In a similar fashion, the support table  27  will be drawn from beneath the empty punnet  26  held by the lowered selector  30 , and as hereinbefore described, will therefore drop onto the corresponding weighing pan  24 . It will therefore be appreciated that one or more mushrooms  62  may have been deposited into the empty punnet  26  prior to the empty punnet  26  being drawn from the support table  27  onto the weighing pan  24 . However, as the control unit  58  initially zeroed each weighing pan  24  such as to disregard the weight of an empty punnet  26 , once the aforementioned punnet  26  drops onto the weighing pan  24 , said empty weight will be automatically subtracted so that only the weight of the mushrooms  62 , if any, located therein will be registered by the weighing pan  24 . 
   It will thus be appreciated that the full punnet  26  has been replaced with an empty punnet  26 , the full punnet  26  now being located on the lateral conveyor  38 . The support table  27  from which the empty punnet  26  has been transferred therefore requires an empty punnet  26  to be deposited thereon, in anticipation of the next replacement sequence. An empty punnet  26  is therefore deposited onto said support table  27  from the respective magazine  44 . The apparatus  10  thus continues to grade the mushrooms  62  until another punnet  26  reaches the predetermined filled weight, at which point said punnet  26  will be replaced as hereinbefore described. 
   As described, the full punnet  26  is therefore located on the lateral conveyor  38  and, depending on the location of the full punnet  26 , the control unit  58  advances the lateral conveyor  38  a predetermined distance in order to bring the punnet  26  to the end of the lateral conveyor  38  and onto an end conveyor  52 . Extending rearwardly from the end conveyor  52  is a storage compartment in the form of a storage rack  54  divided into a plurality of rows  64 . Once a punnet  26  is fed from the lateral conveyor  38  to the end conveyor  52 , the control unit  58  deactivates the lateral conveyor  38  and activates the end conveyor  52 , such that the punnet  26  is transferred onto the storage rack  54 . 
   Filled punnets  26  are continually transferred to the storage rack  54  as hereinbefore described, and once a single row  64  has filled with punnets  26 , a slider  40 , driven by a slider motor  42  which is operated by the control unit  58 , moves the incoming punnets  26  across the end conveyor  52  into register with an empty row  64 . The slider motor  42  may be mounted to the storage rack  54 , or alternatively may be mounted to the base  12  beneath the end conveyor  52 . The end conveyor  52  is then activated by the control unit  58 , the punnet  26  within the slider  40  therefore being transferred into the empty row  64  of the storage rack  54 . This operation is continued until the entire storage rack  54  contains filled punnets  26 , or alternatively, until all of the mushrooms  62  have been picked. Each of the punnets  26  is a predetermined weight and is ready to be transferred directly to market, thereby greatly reducing the cost and time associated with post processing of picked mushrooms. 
   In an alternative arrangement, the sequence of events may be varied such that when a full punnet  26  reaches the end conveyor  52 , the slider  40  transfers the punnet  26  to the opposed end thereof, but the end conveyor  52  is not activated. The next punnet  26  to reach the end conveyor  52  is then positioned, by means of the slider  40 , adjacent the previous punnet  26 . This operation is continued until the entire length of the end conveyor  52  is filled with punnets  26 . At this point the end conveyor  52  is activated in order to transfer the punnets  26  into the respective rows  64  of the storage rack  54 . 
   In a further embodiment, the storage rack  54  may be arranged and dimensioned as a vertical rack (not shown) having one or more rows (not shown) extending substantially perpendicularly to the end conveyor  52 . 
   As an optional component, the apparatus  10  may be provided with a label printer (not shown) or the like which is in communication with the control unit  58 . The label printer (not shown) would preferably be located at or adjacent the storage rack  54  and be arranged to locate a label (not shown) on each filled punnet  26 , which label (not shown) may carry various information such as the weight of mushrooms  62  within the punnet  26 , the date and location of picking, etc. It will also be appreciated that, in an alternative arrangement, an individual transporter (not shown) may be provided for each weighing pan  24 , each transporter (not shown) capable of movement independent of the remaining transporters (not shown). The transporter (not shown) may be in the form of a hydraulic/pneumatic ram (not shown) which is arranged, for example, to push the empty punnet  26  located on the support table  27  towards the full punnet  26  on the corresponding weighing pan  24 . The empty punnet  26  will therefore push the full punnet  26  from beneath the feed belts  14 ,  16  onto the lateral conveyor  38 , to be replaced by the empty punnet  26 . This particular arrangement would therefore permit omission of the plurality of selectors  30  and associated selector cams  32  and selector motors  34 . It will of course be immediately understood that any other suitable means of replacing a full punnet  26  with an empty punnet  26  could be substituted for the transporter  25  and selectors  30  of the present embodiment. 
   In a still further embodiment, the plurality of support tables  27  may be omitted from the apparatus  10  such that punnets  26  are deposited directly from the magazines  44  onto the weighing pans  24 . In such an embodiment, the reading from each weighing pan  24  for the weight thereon is zeroed after the start-up sequence as hereinbefore described, once a pair of empty punnets  26  are located on each weighing pan  24 . However, the loading conveyor  18  and the feed belts  14 ,  16  must be halted for the entire duration of the punnet  26  replacement sequence. This is because the weight recorded for each weighing pan  24  would otherwise continue to rise as mushrooms  62  were deposited into the empty punnets  26  during the period when the empty punnets  26  were temporarily located beneath the feed belts  14 ,  16 . It will therefore be understood that the weighing pans  24  would register the combined weight of the mushrooms in each punnet  26  located thereon, prompting a punnet  26  to be replaced before reaching the required predetermined weight. This particular configuration would therefore be less preferred than the embodiment hereinbefore described. 
   In a similar further mode of operation, an empty punnet  26  is only deposited from the respective magazine  44  onto the weighing pan  24  beside a full punnet  26  when said full punnet  26  is to be replaced. Each of the selectors  30  are in the lowered position during operation of the apparatus  10 , and when a full punnett  26  is to be replaced, the selector  30  associated therewith is raised, and the transporter  25  driven across the base  12 . Each of the lowered selectors  30  therefore maintain the respective punnets  26  in place beneath the feed belts  14 ,  16 , while the full punnet  26  travels with the weighing pan  24  over the lateral conveyor  38 . The raised selector  30  is then lowered ablout the empty punnet  26  located on the weighing pan  24 , and the transporter  25  driven back across the base  12 . As hereinbefore described, the full punnet  26  wil therefore be deposited onto the lateral conveyor  38 , the corresponding empty punnet  26  being maintained beneath the feed belts  14 ,  16  in place of the full punnet  26 . 
   The apparatus  10  is also provided with a power source (not shown), preferably a battery mounted therein, to allow the apparatus  10  to be driven by an operator between the rows of mushroom beds (not shown). As the mushroom beds (not shown) are conventionally quite narrow, the apparatus  10  may be provided with an array of sensors (not shown), such as proximity detectors (not shown) or the like, which are in operative association with the control unit  58  and arranged to automatically guide the apparatus  10  through the rows of mushroom beds (not shown) by steering the wheels  60  in response to information fed from the sensors (not shown). 
   Furthermore, as the passages (not shown) between the rows of mushrooms beds (not shown) are quite narrow, the facility to remove the storage compartment  54  permits the apparatus  10  to be turned around in a relatively confined space, thereby permitting the space within the mushroom house (not shown) to be maximised for the growing of mushrooms  62 . Therefore, in use, when it is required to turn the apparatus  10 , the storage compartment  54  is removed, the apparatus  10  turned, and the storage compartment  54  reconnected to permit the apparatus  10  to be restarted.