GB2068324A - Improvements in and relating to feed assemblies - Google Patents

Abstract

A feed assembly comprising two relatively slow-moving feed belts 10, 11 (Fig. 1) which laterally convey rows of tubers in receptacles from a supply hopper 13 and over an inspection correction area to receptacles on downwardly-inclined cross-transfer planting belts 16, 17. <IMAGE>

Description

1 GB 2 068 324A 1

SPECIFICATION

Improvements in and relating to feed assemblies The present invention relates to a feed assem bly and in particular, but not exclusively, to a feed assembly for tubers such as potatoes, bulbs and the like, and to a planting machine incorporating such an assembly.

Potato planters are already known in which a belt feed is used to collect potatoes from a hopper and place them in the ground. It is usual practice with such machines to have an operative keep an eye on the feed assembly of the planter to detect doubles and gaps in the stream of potatoes passing through the ma chine. This imposes a top limit on the planting speed of the machine in so far as it must at all times be operated slow enough to allow for this inspection and, when necessary, interven tion, to be carried out effectively.

According to the present invention a feed assembly for feeding objects from an input location towards an output location comprises first and second conveyors of which the first conveyor is arranged to transport the objects in receptacles in lateral ly-travel ling rows from the input location for discharge on to the second conveyor, and the second conveyor is arranged to transport the objects of each said row, one object after the other, in receptacles towards the output location.

Where the assembly is to be used for feeding potatoes or other tubers in a planting 100 machine, it is an advantage of the assembly that the first conveyor has only to move by one lateral row spacing to discharge a whole row of tubers on to the second conveyor, so that it is possible, by having the rows closely packed together on the first conveyor, for the first conveyor to move relatively slowly and yet provide a high discharge rate of tubers on to the second conveyor for planting. This relatively slow movement of the first conveyor facilitates the inspection and intervention re ferred to above without the corresponding loss in planting speed associated with the previ ously available machines. The same advan tages would be present, however, if, for exam ple, an assembly according to the present invention formed part of a fruit-packing plant since it would allow a relatively long inspec tion and intervention period for a relatively fast delivery rate of approved fruit from the second conveyor of the assembly. Equally, an assembly according to the present invention might be used in a production line in a factory where individual components had to be ap proved at some state of the manufacturing and/or packaging process.

According to a preferred feature of the invention, the first conveyor is arranged to expose several rows of objects simultaneously vention purposes so as to give greater time for inspection and intervention than would be the case if say only one row at a time were so exposed.

The assembly preferably includes means for driving the first conveyor intermittently so as to prolong the time for which each row of receptacles is present at the input location.

Conveniently, the first and second convey- ors are so arranged that at the moment of discharge of the objects from the first conveyor to the second conveyor, the receptacles of the first conveyor are lined up with receptacles of the second conveyor.

Conveniently, the second conveyor inclines downwardly towards the output location and includes receptacle-defining object-locating members which are spaced apart from one another along the length of the second conveyor by an amount in excess of the predicted maximum dimension of the objects to be carried. In one such embodiment, the first conveyor comprises a belt having compartments providing said receptacles for the ob- jects and the second conveyor comprises a belt in which the objectlocating members adjacent one another in the direction of belt movement (i.e. movement of the second conveyor belt considered relative to the machine chassis) are separated by substantially twice the lengths of said compartments. As an alternative to compartments, the first conveyor belt might instead have cups providing the receptacles for the objects.

If the second conveyor comprises a belt, the object-locating members may take the form of flights extending across, or partially across, the belt width of the second conveyor. In one such embodiment, successive objectlocating members are arranged on alternating sides of the second conveyor centre line with those on one side staggered in relation to those on the other side. In this case the assembly preferably includes a distributor arranged to divert successive objects, or groups of objects, of each row of objects discharged from the first conveyor to alternate sides of the second conveyor. Thus with a row of six objects, for example, the first, third and fifth objects in a row might be discharged on the side of the second conveyor nearer one end of the machine, say, while the second, fourth and sixth objects might be discharged on to the side of the conveyor nearer the other end of the machine.

In preferred embodiments, the assembly includes a compensating conveyor arranged to compensate for any empty receptacle in the first conveyor by discharging an object into the otherwise empty receptacle of the second conveyor.

Conveniently, in this case, the assembly further includes automatic inspection and control means arranged to sense the absence of at any given moment for inspection and inter- 130 an object in the first conveyor and to actuate 2 GB 2 06B 324A 2 the compensating conveyor.

Conveniently, the automatic inspection and control means comprises a first such means, a second automatic inspection and control means also being provided to sense the absence of objects in receptacles of the compensating conveyor and to provide a limited continued actuation of the compensating conveyor when desirable.

Conveniently, the compensating conveyor, when actuated, moves at a significantly greater speed than the first and second conveyors to increase the probability of its being able to fill an otherwise empty receptacle of the second conveyor when one or more e.g. two, successive receptacles of the compensating conveyor are themselves empty.

Conveniently, the, or each, conveyor inspected by an automatic inspection and con- trol means, has the floor region of its receptacles apertured and the automatic inspection and control means comprises a lamp on one side of the conveyor and on the opposite side of the conveyor a photocell adapted to receive light from the lamp whenever the unobstructed aperture in a receptacle so allows.

Conveniently, the compensating conveyor lies alongside the first conveyor.

Conveniently, the compensating conveyor is basically of generally similar construction to the first conveyor.

The invention further includes a tuber-planting machine in which one or more of the feedassemblies, according to the invention, are incorporated to feed tubers from a supply hopper at the input location to an output location at the trailing side of a furrow-forming share.

Conveniently, the machine includes two such assemblies with the first conveyors of the assemblies arranged to move in line with the direction of motion of the machine over the ground and the second conveyors of the assemblies crossing one behind the other and arranged to move transversely to said direction of motion so that, in operation, tubers from the first conveyor of each said assembly are discharged by the associated second conveyor at an output location positioned to the rear of the first conveyor of the other said assembly.

Alternatively, the machine may include two said assemblies with the second conveyors of the assemblies arranged to move in line with the direction of motion of the machine over the ground and the first conveyors of the assemblies arranged to move transversely to said direction of motion.

Conveniently, the machine may be provided with one or more additional conveyors adapted to discharge tubers from the second conveyor or conveyors to ground with little or no relative horizontal motion between the tu ber and the ground.

An embodiment of the invention will now 130 be described, by way of example only, with reference to the accompanying drawings in which:Figure 1 shows a perspective view of a potato-planting machine according to the invention with parts of the machine omitted or broken away for clarity; Figure 2 shows a side view of the machine; Figure 3 shows a plan view of the machine; Figure 4 shows a front view of the machine; Figure 5 shows a rear view of the machine; Figure 6 shows, on an enlarged scale, a detail of the distributor appearing in earlier Figures of the drawings; Figure 7 shows a detail of the machine in the region of the planting location with parts of the machine omitted or broken away for clarity; Figure 8 shows a plan view of a modified form of machine; Figure 9, 10, 11 show plan, side and end views of a second embodiment of the invention; Figures 12 and 12a show end and side views of the drive for the compensator belts in this second embodiment; Figure 13 is a circuit diagram of an actuating and control system for the compensator belts; Figures 14a, b and care plan, end and side views respectively of a moulded plastic link for use in the feed conveyors or compensating conveyors of either embodiment; Figure 15a shows on an enlarged scale that portion of the machine indicated by arrow A in Fig. 11 and Fig. 15 b shows to the same enlarged scale a plan view of that portion.

Thus referring especially to Figs. 1 to 5 of the drawings, a two-row la ndwheel-d riven ma- chine for planting chitted seed potatoes includes two feed belts 10, 11 arranged side by side at the top of the machine to convey the tubers from a supply hopper 13 to two crosstransfer belts 16, 17 at the rear of the ma- chine. These latter belts incline downwardly in opposite directions from the discharge ends of feed belts 10, 11 to planting locations 19, 20 and it will be observed that because belts 16, 17 are arranged one behind the other, the associated fed belts 10, 11 have to extend rearwardly by different amounts as will most clearly be seen from Fig. 3. Moreover, because the cross-transfer belts are inclined in opposite directions to one another, the output or planting location 19 associated with the first pair of belts (10, 16) will be to the rear of the feed belt 11 of the second pair while the output or plating location 20 associated with the second pair of belts (11, 17) will be to the rear of the feed belt 10 of the first pair.

In more detail, the feed belts 10, 11 each comprise 3-ply rubber belting 22 divided up into 60 mm square-section compartments 23 for the tubers by L-section cross-bars 24 (mounted at 70 mm pitch) and seven longitudi- 1 c 3 a GB2068324A 3 nal rows of attachments 26 each formed of two blocks 27 which can separate when the belt changes direction as may be seen from Fig. 2 for example. The edge regions of the two feed belts are punched with rows of 12 mm diameter holes 28 (Fig. 3) at 70 mm pitch longitudinally so that each pair of opposed holes lies between successive rows of compartments in the feed belt concerned.

These holes allow the belts to be positively driven by rollers 30, 31 each fitted with twelve equispaced drive pegs (not shown) at the same pitch as the holes 28.

The --tonne capacity supply hopper 13 at 2 the rear of the machine is partially divided into two equal sections by a ridged plate 34. Each section has a narrow-throated roundededged outlet located directly over one of the feed belts 10, 11 which provide a moving floor surface to that section. A sloping floor plate 35 is also fitted in the hopper to expose only a few rows of compartments 23 at a time to the associated hopper outlet (36) for loading purposes. The sloping floor plate of the hopper is slotted so that it can be moved to suit the ' width of the hopper outlet to different tuber sizes.

To allow the stream of tubers carried by the feed belts 10, 11 to be inspected and any corrections made when an excess or deficiency of tubers is observed, an almost horizontal inspection section of each feed belt runs exposed before reaching the discharge roller 3 1. This section is six rows long for belt 10 and eight for belt 11 allowing adequate time for inspection and correction of any one row before it passes out of the inspection area for discharge on to the cross-transfer belts 10, 11. Correction can be manual, semi-automatic or automatic as appropriate. In the manuallycorrected version shown in Figs. 1 to 5 of the drawings, a small auxiliary hopper 37 is provided for convenience between conveyors 10, 11 for excess or replacement potatoes. This hopper is pivoted at its top edge so that its contents can be easily tipped into supply hppper 13 as and when necessary.

Reference numeral 38 indicates a support platform for operatives involved in the inspec- tion/correction operation.

An alternative form of belt made up of a large number of identical injection-moulded plastics units, each providing one tuber compartment, is also envisaged for feed belts 10, 11. Details of this are given hereafter in respect of the embodiment of Fig. 9 onwards, Returning now to the embodiment illustrated in Figs. 1 to 5 of the drawings, the rollers 31 (at the upper ends of feed belts 10, 11) are mounted on a common axle 40 carrying at both ends Geneva wheels 41 provided with twelve equispaced radial slots and twelve concave peripheral surfaces, as best seen from Fig. 2. This arrangement gives a positive anti- backlash intermittent drive to feed belts 10, 11 in response to a continuous rotation of drivers 42 each of which comprises a doublyflanged cylindrical unit with a singleprojecting drive peg 42'. This peg is adapted to enter in turn each of the twelve slots in the associated Geneva wheel so as to move that wheel from a first position in which the peg first enters the slot concerned to a second position in which it leaves it. The engagement of the cylindrical hub part of the driver with the concave inter-slot regions of the Geneva wheel will lock the latter agbinst rotation until the drive peg enters the next slot in the Geneva wheel to repeat the intermittent drive described above.

As has been already discussed above, the rollers 30, 31 each carry twelve equispaced drive pegs pitched at the same pitch as belt holes 28 which in turn are positioned so that successive holes 28 are spaced apart by the length of one tuber-carrying compartment in the feed belt concerned. By suitably relating the positions of the drive pegs on rollers 30, 31 to the positions of the slots in Geneva wheels 41 when this wheel is locked by its driver 42, the drive arrangement will be such that each feed belt 10, 11 will move forward by just one row of compartments for every revolution of driver 42 and each such move will bring a new row of compartments to the associated hopper outlet 36 and will discharge the endmost row on to the crosstransfer belts 16, 17.

A chain and sprocket connection 43 trans- mits the intermittent drive of rollers 31 to the lower belt-supporting rollers 30.

The driver 42 also drives a gear box 44 through a chain and sprocket connection 45. A second chain and sprocket connection 46 connects the gear box with one drum (48) of each set of three drums (48, 49, 50) on which the cross-transfer belt 16, 17 are mounted (Fig. 5). As indicated by way of ' example at 51, these belts are centrally aper- tured to allow a positive drive by rollers 49 which carry drive pegs (not shown) at the same pitch. Typically, 12 mm diameter holes will be used at a 125 mm longitudinal pitch. Alternative methods of achieving this positive drive would be to use timing belts, chain drive or identical moulded plastics sections.

The connection between the drive 42 and the machine's landwheels (52), is effected by a multi-sprocket chain drive arrangement 54 (also shown in Figs. 4 and 5) incorporating sprung chain tensioners. This enables the speed of the feed belts (10, 11) and the cross-transfer belts (16, 17) to be changed relative to the landwheel speed if it is desired to vary the planting distance between adjacent tubers in the direction of machine travel.

As can best be seen from Fig. 2, the crosstransfer belts 16, 17 are divided longitudinally into compartments 56, 57 and 59, 60 respectively by transverse flights 6 1. Distribu- 4 GB2068324A 4 tors 62, 63 (see also Fig. 6) are arranged as shown in Fig. 2 so that alternate potatoes from each row on belt 10 are discharged into compartments 56, say, and the remainder into compartments 57 while alternate potatoes from each row on belt 11 are discharged into compartments 59, say, the remainder into compartments 60. In accordance with a preferred feature of the invention, each corn- partment 56-60 is arranged to be twice the length of the feed belt compartments 23 so that as the cross-transfer belts drop to the planting locations 19, 20 the tubers will roll or slide forward until they reach the dividing flights 61, thus ensuring accurate spacing of the tubers at release from belts 16, 17.

The timing of the machine is so arranged that each feed belt 10, 11 will discharge its row of potatoes only when the compartments of the corresponding transfer belts 16, 17 are directly in-line with the feed belt compartments. This ensures the delivery of one tuber into each compartment 56-60. The relative compartment positions of the feed and crosstransfer belts can be accurately adjusted, if necessary, to obtain this result by removing and replacing the chain of connection 46 one link either way in relation to the gear box drive 44 until the necessary compartment- compartment alignment is achieved.

Row width can be changed by relocating the position of the cross-transfer belt lower rollers 50, the land wheels 52 and furrow openers 68.

These latter elements take the form of a share 69 (Fig. 7) having a cutaway 70 at its inner wall to allow the relevant cross-transfer - belt to discharge tubers into the furrow formed by the V-form front- section 71 of the share.

Concave disc-ridgers 74, 75 (mouldboard ridgers may be used instead if desired), are fitted at the rear of the machine to cover the potatoes and allow the complete planting operation to be completed in one run.

The illustrated machine is intended to be semi-mounted for planting but for transporting and turning at the end of the rows, it can be fully mounted. In operation, the belts 10, 11 will transport potatoes out of the hopper outlet, and upwardly with the regular intermittent movement produced by drive arrangement 41, 42. The upward inclination of these initial positions of the feed belts will encourage any excess tubers on the belts to roll back into supply hopper 13.

At their upper regions, the feed belts 10, 11 assume a roughly horizontal positions so that the tubers can travel almost horizontally over an inspection and correction area (77) as above described. After this, they are discharged six at a time from each feed belt on to one of the cross-transfer belts 16, 17 for downward transfer and eventual discharge into the furrow formed by the shares 69 at opposite sides of the machine.

In an automised version of the first embodiment somewhat diagrammatically illustrated in Fig. 8, each belt 101 11 is provided with an investigation and control means including an optical sensing unit which will scan successive rows of compartments in the two feed belts.

For convenience only, the position of one pair of lamps (80) and photocells (81) for one of the two sensing units 80, 81 for the machine of Fig. 8 are indicated instead in Fig. 2, it being appreciated that the complete optical sensing unit in Fig. 8 will comprise a row of such lamps and photocells spanning the entire width of each of the two belts 10, 11 as shown in Fig. 8.

A signal from one of the photocells 81 on detection of an empty compartment in its associated feed belt is used to actuate one of a pair of corresponding compensator belts 83, 84 which will operate to fill the otherwise empty compartment in the planting belts 16, 17.

The automatic nature of this operation makes the hopper 37 and platform 38 of the Fig. 2 machine superfluous and these items are therefore omitted in the Fig. 8 version.

In more detail, the optical sensing units each take the form of a row of lamps 80 on one side of the feed belts and a row of photocells 81 on the other side of the belts with each photocell positioned to detect the light from its corresponding lamp through an appropriate aperture provided in the floor re- gion of each of the feed belt compartments. Of course, if any one compartment contains a tuber (as it normally will do) when eaching the sensing unit, then this tuber will block the aperture in that compartment and no light will be received by the photocell from its associated lamp. It is only when the tuber is absent and light from a lamp can reach its photocell through the unobstructed aperture in the belt compartment that the sensing unit will oper- ate as above described.

The detailed working of the optical sensing units and the operation of the two compensator belts 83, 84 will not be described in any detail here for the arrangement of Fig. 8, as it is virtually identical with that described for these items in respect of the second embodiment of the invention to be discussed below with reference to Fig. 9 onwards. In this respect it ought to be noted that as with this later embodiment, the compensator belts of the Fig. 8 arrangement will also be provided with their own individual optical sensors similar and similarly placed to those shown in Fig. 8 for the feed belts 10, 11. This means that if by ill-fortune the relevant compartment of the compensator belt is also empty when it is called into use', then this relatively fast-moving compensator belt can be stepped forward e.g. by a further one or two compartments, say, until a tuber-bearing compartment of the corn- ?.r i.- 1W il k GB 2 068 324A 5 pensator belt arrives which compartment can deposit a tuber in the otherwise empty compartment of the planting belt.

Turning now to Figs. 9 to 11, these show respectively somewhat diagrammatic plan, side and end views of the second embodiment 'referred to above, Fig. 10 being a partially cut away side view with part of a feed belt and the hopper omitted.

Because of the constructional and operational similarities between many of the items in the two embodiments, the same reference numerals have been used for like items, where convenient, and the construction and operation of the second embodiment will mainly be described in detail below only where it differs significantly from the embodiment of Figs. 1 to 8.

Bearing this in mind, it will be seen from a comparison of Figs. 3 and 8 on the one hand with Fig. 9 on the other hand, that the principal difference between the first embodiment and the second embodiment is that in the first embodiment the tubers are trans- ferred along the length of the machine from the hoppers 13, 14 to transverse planting belts 16, 17 whereas in the second embodiments, the tubers are transferred transversely inwards from the two sides of a partially divided hopper 13 towards a pair of planting belts 16, 17 lying in-line with the direction of movement of the machine. It will be appreciated that these latter belts are arranged to move in a sense such as to reduce the relative motion between the ground and the tuber at the instant of tuber discharge from the machine.

Referring now to Figs. 9 to 11 in more detail, it will be appreciated that, as before, one comparator belt of each pair 83 and 84 will be arranged on operation to load a tuber on to the near side row of planting-belt compartments 56, 59 while the other compensator belt of each pair will operate to load a tuber into the other row of planting-belt compartments 57, 60. This result is achieved by providing a first chute 85 for loading the far side row of compartments (Figs. 8 and 9) and, if necessary, a second chute 86 for loading the nearside row (Fig. 8).

The control circuitry for the compensator belts is shown in block diagram form in Fig. 13. Thus, referring now to Fig. 13, it will be seen that the photocells 81 referred to earlier are connected to delay memory 88 which in turn feeds into a main memory 89.

A synchroniser 90 driven by a shaft 91 of the planting belt assembly feeds a loading signal 92, 93 to each of the two memories in order that they should only accept information from the photocells 81 when the apertures in the compartment floors are in line both with the lamps 80 and with the associated photo cells 81 of their optical sensing systems.

Because of the construction of the machine, however, the lamps and their photocells have to be mounted two compartments in advance of the discharge end of feed belts 10, 11 and this information has therefore to be retarded by two steps so that it is only passed on from the memories when the compartments concerned have actually reached their point of discharge on to the planting belts 16, 17. This retardation is achieved by stepping sig- nals 94, 95.

The fact that one rowof tuber-receiving compartments on the planting belt is spaced from the feed belt discharge by a greater amount than the other row of tuber-receiving compartments, will also affect the synchronisation of the compensator belt discharge with the feed belt compartments and in the illustrated embodiment this discrepancy is corrected by a synchronising selector 98 again controlled by an appropriate signal (99) from the synchroniser 90.

From the selector 98, the output of main memory 89 is fed to shapers 100, 10 1 and amplifiers 102, 103, these latter being ar- ranged to supply drive pulses to a pair of solenoid-operated wrapped- spring clutch and brake units 105, 106 or similar units shown also in Figs. 12 and 12 a. It is these units which, when energised, drive the associated one of the compensator belts 83, 84 forward, normally by one compartment, to discharge a single tuber into the otherwise empty space in the appropriate half of the planting belt 16, 17.

As previously indicated with reference to the machine of Fig. 8 however, account has also to be taken of the fact that the relevant compartment of the compensator belts may itself be empty and it is for this reason that in addition to the control system so far described, each compensator belt is itself provided with similar positioned lamps 80' and photocells 81' as also shown in Fig. 13 but not in any of the other Figures. When these detect empty compartments in the compensator belts 83, 84, signals indicative of the presence of thse empty compartments are fed to a delay memory (107) similar to the delay memory 88 associated with feed belts 10, 11. like memory 88 memory 107 is also provided with loading signal 108 and stepping signal 109 from a synchroniser (110), so that, as before, the delay memory will take due account of the positioning and operating times of the optical sensing system. This time, however, the synchroniser is driven by a shaft 111 of the compensator belt arrangement.

As shown in Fig. 13, the outputs 112, 113 of memory 107 are arranged to drive the units 105, 106 in parallel with the outputs of the main memory 89 so that on detection of an empty compartment in feed belts 10, 11, the drive unit 105 or 106 for the appropriate compensator belt will continue to operate, hopefully until a full compartment in the rela- 6 GB 2 068 324A 6 tively fast-moving compensator belt has been able to discharge its contents into the otherwise empty compartment of the planting belt concerned.

As already mentioned, the clutch and brake units 105, 106 are also seen in Figs. 12 and 12a which show, in somewhat diagrammatic form, the drive system for the compensator belts 83, 84 associated with feed belt 10 and planting belt 16, say. Thus, referring again to these Figures, the input shafts 118, 119 to the two units are driven from a continuously driven shaft 120 which may, for example, be a lay-shaft powered from the land wheel 52 or some indirect source. When, say, unit 105 is operated, as above described, on detection of an odd-numbered empty compartment in thefeed belt 10, then it will connect input shaft 118 to chain sprocket 121 of the unit. This in turn drives the head pulley assembly 123 to move the compensator belt 84 by the amount necessary to discharge a tuber into the other wise unfilled compartment in planting belt 16.

A similar head pulley asssembly 124 is pro vided for belt 83, which is similarly driven from a chain sprocket 125 of unit 106 to discharge a tuber into the other side of plant ing belt 16 whenever an even-numbered empty compartment is detected in belt 10.

Reference numerals 126, 127 indicate two free-wheeling rear sprocket assemblies for belts 84, 83 mounted on a common axle 128 which can be repositioned by tensioner 129 to adjust the tension in the two belts.

Turning now to the actual construction of the feed belts and the compensating belts in the various embodiments described above, it is envisaged that the compartmented belt of Figs. 1 to 5 or Fig. 8 might be replaced by one made up of a large number of indentical injection-moulded plastics units, each providing one tuber compartment, e.g. with six units making up one width of the belt. With such an arrangement the feed belt would typically be made up of 264 (conveyor 10) or 288 (conveyor 11) indentical units. These units would be joined by 6 mm steel rods on which would be mounted small plastic rollers thus making a belt which should be relatively strong, accurate, easily indexed and, because of mass production of the components, cheap. A plastic inset cover would be used to reduce compartment size to discourage "doubles" occurring when small tubers were being planted.

One such arrangement is in fact used for the feed belts 10, 11 and compensator belts 83, 84 of the embodiment of Fig. 9 onwards. The different structure of these belts will have been noticed from Fig. 9 etc. but is perhaps best understood from Figs. 14a, b, cwhich show a plan, end and front view respectively, of one compartment-defining link of the belts. Basically, each link 135 comprises two side walls 136, 137 which co-operate with a floor portion 138 and the rear walls 140 of the link 135 and the preceding link (not shown) of the belt to define a downwardly tapering compartment 141 shaped and dimensioned satisfacto- rily to contain the tuber to be planted. For a potato planting machine, for example, the maximum plan are of the compartment might be 4500 square mm tapering down to 1700 square mm. The floor portion 138 of the link is apertured at 142 to allow passage of the optical detector light beam if the tuber is absent from the compartment when it reaches the detector.

At their leading and trailing edges, each link 135 is provided with hinge portions 143 144 Which fit between hinge portions 144, 143 of the preceding and following links in the belt. The hinge portions of each rows of links in the belts are interconnected by hinge pins (such as pin 150 to Fig. 12 a) constituting the 6 mm steel rods referred to earlier. In the case of feed belts 10, 11, these rods extend beyond the lateral dimensions of the feed belts to provide the link- connecting pins of two chain drives 152, 153 shown in Fig. 9 and, on an enlarged scale, in Figs. 15 a and 15 b. These pin portions of the rods carry rollers 154 engaged by the slots of the sprocket wheel 3 1. For the first embodiment, this wheel is driven from the Geneva wheel 41 shown in Fig. 2 whilst for the second embodiment it is driven by the Geneva wheel 41 shown on the right hand side of Fig. 11 where, for clarity, the sprocket 31 (shown in Figs. 15 a and 15 b) has been omitted. In contrast, on the left-hand side of Fig. 11 it is the Geneva wheel that has been omitted so as more clearly to show the position of sprocket 31 in relation to the machine as a whole.

In the case of the compensating belts, the extending ends of the hinge pin rods engage directly with appropriate recesses in the sprocket assemblies 123, 124 and 126, 127 already described with reference to Figs. 12 and 1 2a. This latter arrangement is completed by plastics guide bars such as bar 157 (Fig. 12 a) which support the hinge portions of the upper runs of the compensator belts.

Although the construction and operation of the second embodiment of Fig. 9 onwards has much in common with the first embodiment of Figs. 1 to 8, it will be seen from the drawings that differences do exist apart from those arising from the different constructions and directions of motion of the various belts. Apart from those already discussed above, it may be helpful to consider for example that whereas in the first embodiment the land wheel 52 drives the Geneva wheel through a multi-sprocket chain-drive connection 54 and then the gear box 44 through a second multisprocket chain-drive connection 45, in the second embodiment the drive from the landwheel 52 is connected directly to the right-angles gear box 44 by connection 54 4 tC 11 1 7 GB 2 068 324A 7 and the gear box 44 then provides a direct drive for planter belts 16, 17 and drives the Geneva wheel 41 through connection 45. In this latter case, a telescopic tube 160 of lemon-shaped cross-section transfers the drive to another right angled gearbox 441 serving the second row of the planter.

To change row widths, the planter units in the above described embodiments have to be repositioned on the planter frame.

On all the machines described above in accordance with the present invention, an additional downward sloping belt running at near land speed e.g. with 12 in (300 mm) longitudinal spaced flights could be installed for each planting belt to give the tubers a discharge speed of almost land speed. This would reduce any tendency the tubers might have to roll forward as they are planted.

As far as performance is concerned, it is envisaged, that typically, the machines illustrated in the drawings could reasonably be expected to reach a planting rate of up to nine potatoes per second for each row of the machine. (18 tubers per second on the 2 row machine). The speed, relative to the remainder of the machine of belts 10, 11 over the inspection/ intervention area 77 would typically be 70-100 mm per second giving a total exposure time of each row for inspection and correction purposes in the machine of Fig. 1 to 5 of above 6 seconds for belt 10 and 8 seconds for belt 11 and in the machines of Fig. 8 onwards of about I second for each belt.

Envisaged advantages of the illustrated embodiments of the invention over prior art designs include their higher planting rate; their planting accuracy at high speed; the fact that examination and correction is possible well in advance of planting; the fact that the slowmoving feed belts are likely to achieve good compartment filling; the fact that the slowmoving feed belts can travel at less than 1 /6th speed of the transfer belts and hence they are unlikely to damage the chitted seed potatoes; the fact that relatively few potatoes are exposed to the feed belts at the hopper outlet should result in less damage to chitted seed; and the fact that exmination should allow the machine to be stopped when major trouble occurs e.g. tuber blockage, without leaving blanks in the rows being planted.

Although optical sensing arrangements have been described throughout for detecting empty compartments in the feed belts and, where present, the compensating belts, it will be appreciated that other arrangements could be used instead for this purpose if desired e.g.

sonic devices, infra-red devices, and mechani- 125 cal feeler devices.

Claims (24)

1. A feed assembly for feeding objects from an input location towards an output location comprises first and second conveyors of which the first conveyor is arranged to transport the objects in receptacles in laterallytravelling rows from the input location, for discharge on to the second conveyor, and the second conveyor is arranged to transport the objects of each said row,.one object after the other, in receptacles towards the associated output location.

2. An assembly as claimed in Claim 1 in which several rows of objects are simultaneously exposed at any given moment for inspection and intervention purposes.

3. An assembly as claimed in Claim 1 or Claim 2 including means for driving the first conveyor intermittently so as to prolong the time for which each row of receptacles is presented at the input location.

4. An assembly as claimed in any preced- ing claim in which the first and second conveyors are so arranged that at the moment of discharge. of the objects from the first conveyor to the second conveyor, the receptacles of the first conveyor are lined up with recep- tacles of the second conveyor.

5. An assembly as claimed in Claim 4 in which the second conveyor inclines downwardly towards the output location and includes receptacle- defining object-locating members which are spaced apart from one another along the length of the second conveyor by an amount in excess of the predicted maximum dimension of the objects to be carried.

6. An assembly as claimed in Claim 5 in which the first conveyor comprises a belt having compartments providing said recep tacles for the objects and the second conveyor comprises a belt in which the object-locating members adjacent one another in the direction of belt movement are separated by substantially twice the lengths of said compartments.

7. An assembly as claimed in Claim 6 in which said members take the form of flights extending across, or partially across, the belt width of the second conveyor.

8. An assembly as claimed in Claim 7 in which successive object-locating members are arranged on alternating sides of the second conveyor centre line with those on one side staggered in relation to those on the other side.

9. An assembly as Claim 8 including a distributor arranged to divert successive objects, or groups of objects, of each row of objects discharged from the first conveyor to alternate sides of the second conveyor.

10. An assembly as claimed in any preceding Claim including a compensating conveyor arranged to compensate for any empty receptacle in the first conveyor by discharging an object into the otherwise empty receptacle of the second conveyor.

11. An assembly as claimed in Claim 10 8 GB 2 068 324A 8 including automatic inspection and control means arranged to sense the absence of an object in the first conveyor and to actuate the compensating conveyor.

12. An assembly as claimed in Claim 11 70 in which the automatic inspection and control means comprises a first such means, a second automatic inspection and control means also being provided to sense the absence of ob jects in receptacles of the compensating con veyor and to provide a limited continued actu ation of the compensating conveyor when desirable.

13. An assembly as claimed in Claim 12 in which the compensating conveyor, when actuated, moves at a significantly greater speed than the first and second conveyors to increase the probability of its being able to fill an otherwise empty receptacle of the second conveyor when one or more successive recep tacles of the compensating conveyor are themselves empty.

14. An assembly as claimed in any of Claims 10 to 13 in which the or each con veyor inspected by an automatic inspection and control means has the floor region of its receptacles apertured and the automatic in spection and control means comprises a lamp on one side of the conveyor and on the opposite side of the conveyor a photocell adapted to receive light from the lamp when ever the unobstructed aperture in a receptacle so allows.

15. An assembly as claimed in any of Claims 10 to 16 in which the compensating conveyor lies alongside the first conveyor.

16. An assembly as claimed in any of Claims 10 to 15 in which the compensating conveyor is basically of generally similar con struction to the first conveyor.

17. A tuber-planting machine including one or more feed assemblies according to any of Claims 1 to 16 to feed tubers from a supply hopper at the input location to an output location at the trailing side of a furrow forming share.

18. A machine as claimed in Claim 17, including two said assemblies with the first conveyors of the assemblies arranged to move in line with the direction of motion of the machine over the ground and the second conveyors of the assemblies crossing one be hind the other and arranged to move trans versely to said direction of motion so that, in operation, tubers from the first conveyor of each said assembly are discharged by the associated second conveyor at an output loca tion positioned to the rear of the first conveyor of the other said assembly.

19. A machine as claimed in Claim 17 including two said assemblies with the second conveyors of the assemblies arranged to move in line with the direction of motion of the machine over the ground and the first conveyors of the assemblies arranged to move trans- versely to said direction of motion.

20. A machine as claimed in any of Claims 17 to 19 including one or more additional conveyors arranged to discharge tubers from the second conveyor or conveyors to ground with little or no relative horizontal motion between the tuber and the ground.

21. An assembly or machine substantially as hereinbefore described with reference to, and as illustrated in, Figs. 1 to 7 of the accompanying drawings.

22. An asssembly or machine substantially as hereinbefore described with reference to, and as illustrated in, Fig. 8 of the accom- panying drawings.

23. An assembly or machine substantially as hereinbefore described with reference to, and as illustrated in, Figs. 9 to 14 a, b c of the accompanying drawings:

24. An assembly or machine as claimed in Claims 21 or 22 modified as hereinbefore described so as to include one or more first conveyors substantially as hereinbefore described with reference to Figs. 14 a, b, c of the accompanying drawings.

Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd.-1 98 1. Published at The Patent Office, 25 Southampton Buildings, London, WC2A 1AY, from which copies may be obtained.

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