GB2153645A

GB2153645A - Conveyor means

Info

Publication number: GB2153645A
Application number: GB08403016A
Authority: GB
Inventors: Gilbert Julien Irenee Strubbe
Original assignee: SPERRY NV
Current assignee: SPERRY NV
Priority date: 1984-02-04
Filing date: 1984-02-04
Publication date: 1985-08-29
Also published as: GB2153645B; GB8403016D0

Abstract

Crop material conveyor means (71) of the paddle type in which the paddles (37) move within a housing (33, 35, 42, 44) and are arranged to have a predetermined clearance with respect to at least certain walls (33, 35, 42) of the housing, and in which crop material flow detecting means (31) are mounted; inserts (47, 48, 49, Fig 4) being provided on said at least certain walls (33, 35, 42) in the vicinity of the detecting means in order to reduce the clearance with the paddles (37) at that location and thereby to prevent the flow of crop material from one pocket between two adjacent paddles (37) to another pocket which would otherwise take place through the clearance between the paddles (37) and said walls (33, 35, 42) of the housing, which flow of crop material would impair the operation of the detecting means (31). <IMAGE>

Description

SPECIFICATION Conveyor means This invention relates to conveyor means, and more particularly to crop conveyor means which may be employed, for example, in combine harvesters.

The terms "grain", "straw", and "tailings" are used principally throughout this specification for convenience and it should be understood that these terms are not intended to be limiting. Thus "grain" refers to that part of the crop which is threshed and separated from the discardable part of the crop material which is referred to as "straw". Incompletely threshed ears are referred to as "tailings".

Also, the terms "forward", "rearward", "left", "right", when used in connection with the combine harvester and/or components thereof are determined with reference to the direction of forward operative travel of the combine harvester but should not be construed as limiting.

In combine harvesters it is often desirable to measure the throughput of the machine in terms of the weight of grain harvested. This is especially useful in a fully automated machine as the amount of grain loss can then be expressed as a percentage of grain harvested. Grain is normally taken from the cleaning mechanism of the combine harvester and conveyed to the grain tank by a paddle type grain elevator and the latter presents a convenient point to measure the amount of grain harvested by way of measuring the amount of grain passing through the elevator.

French Patent Specification No. 2.495.434 discloses such a grain measuring arrangement but this suffers from a serious disadvantage in that the grain flow detecting device will inevitably produce a spurious output. This is because, although the drawings of the French specification show the paddles of the grain elevator in contact with the walls of the latter, whereby discrete mounds of grain are shown carried by the pockets defined by the paddles in conjunction with the walls of the elevator, that is not the situation in practice. If these conditions were to remain, then there would be no problem in measuring the flow of grain through the elevator but in practice, it is necessary to provide a clearance between each paddle and at least certain walls of the grain elevator.If no such clearly ance is provided initially, then clearance will soon be created in use by wear of the paddles. In the meantime, the close fitting paddles will rub the grain against the elevator walls with the result that grain cracking, and sometimes even grinding, occurs which is very undesirable, hence the preference to introduce paddle clearance at the outset.

However, once paddle clearance is achieved either intentionally or through wear, it has been found that when the grain elevator is well loaded (which is the sought-after condition), then some grain falls from one pocket of the grain elevator to the pocket below, then to the next pocket, and so on, through the paddle clearances. Typically, the grain elevator is inclined to the vertical so that some grain will fall from the periphery of one paddle to say the middle of the paddle below, whereby the same grain does not necessarily fall to the next paddle. However, the considerable vibration experienced in a grain elevator, coupled with the relatively small angle of flow of dry grain, means that grain readily spreads to the periphery of each paddle and thus passes through the paddle clearance.

The grain flow detecting means sees this downwardly directed "leaking" of some grain, opposite to the intended direction of transport of all the grain, as a substantially continuous "curtain" of grain and hence produces an output signal indicating that the grain elevator is working at either a higher capacity than the actual true capacity or even at full capacity which is not necessarily so.

The present invention seeks to overcome this problem.

According to the present invention there is provided a crop material conveyor means of the paddle type in which the paddles move within a housing and are arranged to have a predetermined clearance with respect to at least certain walls of the housing, and in which crop material flow de detecting means are mounted; inserts being provided on said at least certain walls in the vicinity of the detecting means in order to reduce the clearance with the paddles at the location and thereby to prevent the flow of crop material from one pocket between two adjacent paddles to another pocket which would otherwise take place through the clearance between the paddles and said walls of the housing, which flow of crop material would impair the operation of the detecting means.

Preferably, each insert has a tapered lead-in edge and has a dimension in the direction of movement of the conveyor means which is twice that of each pocket in the same direction. Each insert may be composed of a synthetic plastics material. Conveniently each paddle is generally rectangular in shape and is connected at one side to an endless conveyor member, with the inserts being provided adjacent the three other sides of the paddles as they pass the detecting means. At least one insert may be adjustably mounted.

The crop material conveyor means may be in the form of an elongate grain elevator or tailings conveyor, or even may be in the form of a paddle wheel structure. The crop conveyor means with the crop material flow detecting means thereon in accordance with the present invention are particularly useful when applied on a combine harvester.

A combine harvester incorporating the present invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which Figure l is a diagrammatic side view of the combine harvester, Figure2 is an enlargement of a portion of Figure 1 with certain components broken away, Figure 3 is an enlargement of the portion of Fig- ure 2 indicated at 111, Figure 4 is a section on the line IV-IV of Figure 3, and Figure 5 is a graph of the grain flow signal in percentage of the maximum grain flow signal against the actual percentage of maximum throughput capacity.

Referring to Figure 1, the combine harvester 1 is of the so-called rotary type and comprises a main chassis or frame 2 supported on a front pair of traction wheels 3 and a rear pair of steerable wheels 4. Supported on the main chassis 2 are an operators platform 5 with a driver's seat 6 and a steering wheel 7, a grain tank 8, a threshing and separating mechanism indicated generally at 9, a grain cleaning mechanism 11 and an engine (not shown). The engine provides the motive power for the various driven components of the machine as well as for the traction wheels 3 which are driven via a belt variator (also not shown). A conventional header 12 and straw elevator 13 extend forwardly of the main chassis 2, and the header is pivotally secured to the chassis for generally vertical movement which is controlled by extensible hydraulic cylinders 14.

As the combine harvester 1 is propelled forwardly over a field with standing crop, the latter is severed from the stubble by a sickle bar 10 on the header 12, whereafter a reel 15 and a header auger 16 convey the cut crop to the straw elevator 13 which supplies it to the threshing and separating mechanism 9. The crop received within the threshing and separating mechanism 9 is threshed and separated that is to say the crop (which may be wheat, corn, rice, soybeans, rye, grass seed, barley, oats or other similar crops) is rubbed and beaten, whereby the grain, seed or the like, is loosened and separated from the straw, stalks, coils or other discardable part of the crop.

Grain which has been separated from the straw falls onto the grain cleaning mechanism 11 which comprises means to separate chaff and other impurities from the grain, and means to separate unthreshed crop material (tailings). Cleaned grain is then conveyed to the grain tank 8 by a paddle-type grain elevator 17, and the tailings are reprocessed in separate tailings rethreshers (not shown) and returned to the cleaning mechanism 11 for repeat cleaning action.

The header 12 is of the grain type, but clearly other forms of header may be employed (for example a corn header), depending on the crop to be harvested.

A threshing portion 18 of the threshing and separating mechanism 9 comprises a rotatable threshing cylinder 19 cooperable with a stationary threshing concave 21. Rearwardly of the threshing mechanism 18, a deflector beater, or so-called straw beater, 22 with an associated beater grate is provided. The straw beater 22 has a smaller diameter than the threshing cylinder 19 and is arranged above the level of the discharge end of the threshing concave 21. The straw beater 22 and beater grate have substantially the same width as the threshing mechanism 16.

A separator portion of the threshing and separating mechanism 9 comprises a first separator rotor or cylinder 23 and a second rotor or cylinder 24 cooperable with respective concaves 25 and 26.

The second motor 24 is mounted within a separator housing 27 and both of these components have a width substantially exceeding the width of the first rotor 23 which is the same width as the beater 22 and the threshing mechanism 18. Preferably, the rotor housing 27 has a width approximately twice that of the rotor 23.

The mat of crop material received by the separator rotor 24 from the separator rotor 23 is divided into two (by means not shown) and the resulting two portions moved spirally around the rotor 24 to respective ends thereof to complete the separating action. On reaching the ends of the rotor 24, the mats of crop material (straw) are propelled by the rotor through respective straw hoods 28 for discharge from the machine.

The grain elevator 17 is fitted with a grain flow detecting device indicated generally at 31 in Figure 1 and shown in greater detail in Figures 2, 3 and 4.

The detecting device 31 is of the photo-electric type and comprises a light source 32 mounted in one wall 33 of the elevator and a photo-sensitive device 34 mounted in the opposed wall 35 and in optical alignment with the light source. The output of the photo-sensitive device 34 depends on the quantity of light falling thereon which is a function of the amount of grain being moved between the components 32 and 34 on the paddles 37 of the elelevator.

The grain elevator 17 is otherwise conventional and comprises an endless chain 38 on which the paddles 37 are mounted at regular intervals on pairs of angled brackets 39 carried by the appropriate chain links with each pair attached to a metal support plate 41 to which in turn is connected a paddle 37 composed of a flexible material, although being sufficiently rigid for the intended load carrying function. It will be seen from Figure 4 that each paddle 37 is spaced from the two opposite walls 33 and 35 and from the outer, interconnecting wall 42. However, each paddle 37 is in sliding contact with the intermediate wall 43 of the elevator, which wall divides the operative and return runs 44, 45 of the elevator.

As discussed above, paddle wear will inevitably take place due to contact with an elevator wall or walls but the paddles 37 are shown in contact with the wall 43 because in use this contact exists in as much as the chain 38 itself is not able to support the paddles in spaced relationship with respect to all the elevator walls, whereby contact with the "bottom" intermediate wall occurs. Accordingly, wear of the adjacent side of each paddle 37 takes place. In order to limit transverse movement of the paddle 37 due to flexing of the chain 38, a longitudinally-extending central strip 46 is provided on the intermediate wall 43 in the operative run 44 of the elevator. This strip 46 is normally spaced from the paddles 37 which pass thereover by virtue of cut-outs 40 in the paddles. The strip also serves to reinforce the intermediate wall 43.

In the vicinity of the detecting device 31 the elevators walls 33, 35, and 42 are provided with re spective inserts 47, 48 and 49 of a synthetic plastics material, each insert having a dimension in the direction of movement of the chain 38 which is twice that of a pocket defined by adjacent paddles 37, as seen in the same direction. The leading edges 47', 48' and 49' (47' not being seen) of the inserts 47, 48 and 49 are tapered so as to provide a lead-in for the paddles as they enter the reduced cross-sectional area of the operative run 44 of the elevator defined by the inserts. The insert 49 may be adjustably mounted in the wall 42 in order to accommodate wear of the paddles 37 on the edge adjacent the intermediate wall 43 which occurs as explained above. The inserts 47 and 48 are apertured to accommodate the devices 32 and 34, respectively.

It has been found that the provision of the inserts 47, 48 and 49 in accordance with the present invention gives rise to a significant improvement in the accuracy of the grain flow detecting device 31 as is illustrated in the graph of Figure 5 giving the grainflow signal S in percentage of the maximum signal against the capacity C in percentage of the maximum capacity of the elevator. Thus, ideally, both percentages should fully correspond to each other. The chain line plot 51 of Figure 5 resulted from the grain elevator being operated without the inserts 47, 48 and 49 in position and it will be seen therefrom that the grainflow detection means indi cate a throughput which is in excess of the actual throughput.When the inserts 47, 48 and 49 were employed, the full line plot 52 of Figure 5 resulted and it will be seen that this plot is linear and that the grainflow detection means give an accurate indication of the actual throughput (at least in the major portion of the graph as indicated at A). This clearly demonstrates that the "curtain" of grain falling down the operative run 44 of the elevator as a result of the clearance between the paddles 37 and the walls 33, 35 and 42 produces inaccurate measurement if not interrupted at the point of measurement by the inserts. As already explained, this curtain of grain results from the considerable vibration to which the elevator 17 is subjected in use which shakes the grain to the periphery of each paddle 37 and thence through the paddle clearance to the paddle below. It will be seen that the present invention provides a simple but highly effective solution to the problem of measuring ac curately the amount of grain being harvested.

The invention may be applied to any other crop conveyor in a combine harvester in respect of which the crop material being conveyed thereby is to be measured. One such conveyor is a tailings conveyor.

More generally, and as already mentioned, the invention may be applied to any crop conveyor of the paddle type, and thus, equally may be applied to e.g. an independent stationary crop conveyor.

Claims

1. Crop material conveyor means (17) of the paddle type in which the paddles (37) move within a housing (33, 35, 42, 44) and are arranged to have a predetermined clearance with respect to at least certain walls (33, 35, 42) of the housing, and in which crop material flow detecting means (31) are mounted; characterized in that inserts (47, 48, 49) are provided on said at least certain walls (33, 35, 42) in the vicinity of the detecting means in order to reduce the clearance with the paddles (37) at that location and thereby to prevent the flow of crop material from one pocket between two adjacent paddles (37) to another pocket which would otherwise take place through the clearance between the paddles (37) and said walls (33, 35, 42) of the housing, which flow of crop material would impair the operation of the detecting means (31).

2. Crop material conveyor means according to claim 1, characterized in that each insert (47, 48, 49) has a tapered lead-in edge (47', 48', 49').

3. Crop material conveyor means according to claim 1 or 2, characterized in that each insert (47, 48, 49) has a dimension in the direction of movement of the conveyor means (17) which is twice that of each pocket in the same direction.

4. Crop material conveyor means according to any of the preceding claims, characterized in that each insert (47, 48, 49) is composed of a synthetic plastics material.

5. Crop material conveyor means according to any of the preceding claims, characterized in that each paddle (37) is generally rectangular in shape and is connected at one side to an endless conveyor member (38), and wherein the inserts (47, 48, 49) are provided adjacent the three other sides of the paddles (37) as they pass the detecting means (31).

6. Crop material conveyor means according to claim 5, characterized in that the paddles (37) are mounted on an endless chain (38).

7. Crop material conveyor means according to any of the preceding claims, characterized in that each paddle (37) is composed of flexible material.

8. Crop material conveyor means according to any of the preceding claims, characterized in that said means are in the form of a grain elevator (17).

9. Crop material conveyor means according to any of claims 1 to 7, characterized in that said means are in the form of a tailings conveyor.

10. Crop material conveyor means according to any of claims 1 to 4, characterized in that said means of the paddle wheel type.

11. Crop material conveyor means according to any of the preceding claims, characterized in that the detecting means (31) is of the photo-electric type.

12. Crop material conveyor means according to any of the preceding claims, characterized in that at least one insert (47, 48, 49) is adjustably mounted in the housing to accommodate paddle wear.

13. A combine harvester, characterized in that a crop material conveyor means of the paddle type according to any of the preceding claims is provided thereon.