GB2173081A - Straw spreading machine - Google Patents

Abstract

A machine for applying straw to crops comprises a wheeled chassis 1 for carrying a large bale of straw (not shown). At least two spinners 9, 10 are positioned at the rear of the chassis to remove straw from the bales as they are moved rearwards by a conveyor 5. The spinners rotate at high speed and fling the straw rearwards for collection by a hood 27 which channels the straw through a downwardly directed opening 8. Each spinner comprises a shaft with a row of triangular teeth arranged about the shaft in a screw formation, which changes direction mid-way along the shaft. Frames 30, 31 are provided to carry additional bales and tip them onto the chassis to replace those used up. <IMAGE>

Description

SPECIFICATION Straw spreading machine Root crops such as carrots require some form of added protection from frost over the winter months if they are to be left in the ground. The usual way of achieving this protection isto cover therm manually with a layer of straw. Obviously, if the crops areto be adequately protected the whole crop must be covered to at least a minimum depth, but on the other hand, it is costly and wasteful to use a greater depth than is necessary, orto waste straw covering areas other than those containing the crops.The main requirement therefore isforan even layerofstrawto be laid down in a ci early defined area and thefirstaim ofthis invention isto provide a machine capable of meeting this requirement.

A further aim is to provide a machine which utilises large bales of straw such as the large rectangular hesston bales measuring approximately8ft. by4ft. by 4ft. and weighing around half a ton. A majorobstacle to using such bales is thatthey can be very densely compacted, particularly in wet seasons. The machine musttherefore be capable of breaking upthesebales otherwise it is of no practical use.

GB 1 594744 discloses a machine which breaks up and distributes straw from a large baleforanimal feed. The bale is fed to a large rotatabletined drum which removes the straw from the bale, and an air cu rrentthen blows the straw from the tines. The straw is collected by a hood and fed through a defined opening. However, it is clearfrom both the size ofthe drum and the fact thatthe straw must be blown off the tines, that the drum rotates at a relatively low speed.

Such a machine would therefore be incapable of breaking up heavily compacted bales since the drum would tend to stall. Furthermore, even with bales of average density straw could not be supplied at an adequate rate to make the machine suitable for crop protection.

According to the present invention, the answer lies in the provision of a machineforapplying strawto crops, comprising a wheeled chassis for carrying a large bale of straw, at leasttwo spinners for removing strawfromthe bale, each spinnercomprising a rotatable shaft carrying a plurality oftooth-like elements, feed means for feeding the bales to the spinners, powered drive means for driving the spinners ata speed such that the straw removed from the bale is thrown clear ofthe spinners, and a hood arranged to collect the strawthrown out by the spinners and channel it th rough a defined downwardly directed opening.

The use of art least two spinners rotating at a relatively high speed allows even the most densely compacted bales to be broken up. Furthermorn, the straw can be deposited at a useable rate in a clearly defined area.

The tooth-like elements are preferably arranged about the shaft in a screw formation so that successive teeth attack different areas ofthe bale. The screw formation preferably changes direction partway along the shaft so that the straw is dispersed as it is flung from the spinners.

The invention will now be exemplified with refer encetothe accompanying drawings, in which: Figure 7isa detailed safe view of a straw spreading machine in accordance with the invention, Figure 2 is a section ll-ll of Fig. 1, Figure 3 is a sectional detail ofthe spinners incorporated in the machine, Figure 4 is a section Ill-Ill of Fig. 1, and Figures 5 to 8show general side views of modified machines.

The machine of Fig. 1 comprises a chassis 1 having guide rails 1 a upstanding from opposite sides and mounted on a pair of wheels 2. At the front end ofthe chassis there is a tow bar 3 for attachmentto a tractor orsimilarfarm vehicle, and a jack4which can be loweredforsupport.

The chassis is of sufficient length to carry two Hesston bales (not shown) end-to-end, and has an endless belt 5 mounted on rollers 6. The belt is driven hydraulically from the tractor so as to feed the bales rearward at a predetermined rate relative to the chassis.

Atthe rear ofthechassis there is an upstanding rectangularframe 8 olFgreaterwidth thanthe bales, and which supports a pair of spinners 10 10 mounted one above the other. Each spinner comprises a shaft 11 1 (Figs. 2 and 3) carrying a radial screw 12, which changes direction at the centretoform left and right hand screw portions, 1 2a and 1 2b.As can be seen in the sectional detail of Fig. 3, the outer periphery ofthe screw 12 is formed with a row of triangular pointed teeth 13. (in Fig. 2theteeth have been omitted for ease of illustration.) The spinners are mounted horizontally in bearings 14,those ofthe upperspinner9 being mounted directly on the rear ofthe frame 8, and those of the lower spinner 10 being mounted on stand-offs 15. At one side of the machine, the shafts 11 carry toothed wheels 16 which are coupled together by a chain 17. The lower shaft also carries an additional toothed wheel 18 which is coupled by a chain 19 to a toothed wheel 20 which is driven from the power take-off of the tractor via a transmission shaft 7, gearbox 21 and an auxiliary shaft 22.Chains 17 and 19 havetensioners 23, 24 respectively, and the chains and wheels are protected by a cover 25 which in Fig. 1 is cut away for clarity.

At the top of frame 8 five guide fingers 26 project forwardly, theirforemost ends being upturned to guide the bales into contact with the spinners.

The spinners 9, 10 are covered by a deflector hood 27 secured to the frame 8. The hood is closed at the top, rear and sides, but is downwardly open to form a defined, downwardly directed rectangular opening 28. The lower rear edge ofthe hood is provided by a depending flap 27' which is hinged to the hood to swing rearwardly. The closed sides of the hood are each provided with a shield 29 which depends an adjustable distance below the lower edge of the hood.

Two frames, 30, are hinged to each guide rail 1 a The drawing(s) originally filed was (were) informal and the print here reproduced is taken from a later filed formal copy.

(Figs. 1 and 4). A ram 32,33 is connected between each frame and the chassis to movetheframe between a horizontal, outwardly extending bale carrying position and a substantially vertical position, as shown.

In use,the machine is coupled to a tractor and two Hesston bales are loaded end-to-end onto the chassis 1. With the frames 30,31 in the horizontal position a further bale can be loaded onto each frame so thatthe machine can carry up to six bales. As the machine is towed over a crop of carrots or other crop requiring protection from frost, the conveyorfeeds the bales on the chassis 1 slowly rearwards guided by rails 1 a so thatthe rearmostbale is brought into contact with the spinners 9, 10. The spinners rotate at between 300 and 600 rpm so thattheteeth 13 tearstrawfrom the bale.

The screwformation ensures that each tooth attacks a portion ofthe bale which is Iaterallyoffsetfromthatof the previous tooth. The spinners thus progressively attack the entire width ofthe bale. Hesston bales are formed in layers and it is found that the layers tend to be stripped offbythe spinners and consequentlyvery little unseparated straw reaches the opening 28. In addition, the vertical non-alignment ofthe spinners ensures thatthey simultaneously attack different layers ofthe bale, further assisting in its separation.

Only a small percentage ofthe straw actually has-its strands broken by the spinners and the majority is simply pulled from the bale intact. The guide fingers 26 preventthe bale from being lifted by the spinners.

The bales are thus evenly and effectively broken up.

The speed at which the spinners rotate, assisted by the tapering triangular shape of the teeth, ensures that the straw removed from the bale is thrown clear ofthe spinners in a generally rearwardly direction. Furth ermore,theoppositehandedscrewportions, 12a, 12b, tend to cause the strawto be thrown outwardly in a divergent path. The straw is then collected by the hood 27 and directed through the opening 28. Flap 27' assists in spreading the strawto an even depth.

Shields 29 are adjusted in height so thatthey are just above ground level. They shieldthefalling straw from cross-winds so thatthe machine can be used in all the most severe weatherconditions.

The straw isthus spread onto the crop in a strip of even width and depth so thatthe crop is given a good even protection without waste of straw. The depth of covering can of course be controlled by varying the speed at which the machine is fowed. It will be noted thatthe straw is deposited in a layer which is wider than the bales themselves.

When the two centre bales have been used up, one afterthe other, the rams 32,33 are actuated to raise one frontframe 30 and one rearframe 31 and tip replacement bales onto the conveyor 5. When these have been used the other two frames are raised to enable the last two bales two be utilised.

The machine of Fig. 5 is the same as that of Fig. 1 exceptthatitis modified bythe addition of third spinner 34 mounted in the hood opening 28, its shaft again being horizontal. This breaks up any pieces of bale which might get past the spinners 9 and 10when verytightlycompacted bales are used.

The machine of Fig. 6 also has three spinners 9, 10 and 35, butthese are all mounted on the frame 8to attackthe bale. Each spinner is set slighflyforward relative to the one below. Since the gap between the spinners is reduced, this too ensures that pieces of highly compacted bales are unlikelyto get past the spinners.

The machine of Fig. 7 is also similarto that of Fig. 1, butthe side frames 30,31 are ommitted, although they could still be present.Asupportwall 36 is mounted at the front of the chassis and a platform 37 is pivoted on top of thins wall about one quarter oftheway backfrom its front edge. The rear edge ofthe platform 37 carries a pair of depending wheels 38 and a ram 39 connects the overhanging front portion ofthe platform to the supporting wall 36. In use,two bales are loaded onto the chassis 1 as before, and the wheels 38 run on top of the foremost bale.Athird bale can be loaded onto the platform 37 and as the conveyorcarriesthe bales forward, the platform tilts by gravityto depositthe bale on the conveyorto followthe second bale into the spinners. This embodiment is particularly useful where the width ofthe machine is restricted.

The machine of Fig. 8 is suitable for breaking up large round bales which arefed end-on to the spinners. These bales are notoriously difficultto break up and this has previously only been possible by unwinding them using a complex and very expensive machine. The guide fingers 26 are omitted and a third spinner 40 is mounted in front of and at the top of the frame 8. This is enclosed bya cover41 extending forwardlyfrom the frame 8. The cover includes atop wall 42 and two side walls 43 joined to the chassis 1.

The side frames 30,31 are omitted in the drawing but they may still be used.

In each embodiment morethan three spinners could be employed. Also, the bales could be fed to the spinners using chains in place ofthe conveyor, or mechanical or hydraulic pushers could be used.

Instead of being deposited directly onto the crop after leaving the opening 28 the straw could be deposited onto a conveyor which in turn deposits the straw onto the ground.

Although the main advantages ofthe machine are apparent in relation to crop protection the machine could of course be used forother purposes such as breaking up bales of strawfor use as compost for mushroom growers and market gardeners.

Claims (18)

1. A machine for applying straw to crops, comprising a wheeled chassis for carrying a large bale of straw, at least two spinners for removing straw from the bale, each spinner comprising a rotatable shaft carrying a plurality of tooth-like elements, feed means forfeeding the bales to the spinners, powered drive means for driving the spinners at a speed such that the straw removed from the bale isthrown clear of the spinners, and a hood arranged to collectthe straw thrown out by the spinners and channel itthrough a defined downwardly directed opening.

2. A machine according to Claim 1, in which the spinners are mounted substantially horizontal at different levels.

3. A machine according to Claim 1 or 2, in which the tooth-like elements are arranged about the shaft in a screwformation.

4. A machine according to Claim 3, in which the screwformation changes direction partway along the shaft.

5. A machine according to any preceding claim, in which the tooth-like elements are of generaily triangular shape.

6. A machine according to any preceding claim, in which the spinners are mounted such that when the bales are fed to the spinners they attack the bales at different times.

7. A machine according to any preceding claim, in which there is a furtherspinnermounted inthe opening ofthe hood.

8. A machine according to any preceding claim, in which shields of adjustable height are provided on both sides ofthe hood opening.

9. A machine according to any preceding claim, in which the hood is provided with a hinged flap along the rearofthe opening.

10. A machine according to any preceding claim, in which there is at least one frame hinged to a side of the chassis and movable from a bale carrying position to tip the bale therefrom onto the chassis.

11. A machine according to any preceding claim, in which there is a platform mounted to carry a further bale above the bale or bales carried on the chassis and arranged to tip the further bale onto the chassis.

12. A machine according to Claim 11, in which the platform is arranged to rest on the bale carried on the chassis and tip automatically as the bale is fed to the spinners.

13. A machine according to any preceding claim, in which the feed means comprises a power driven conveyor.

14. A machine according to any preceding claim for use with large round bales, the machine including a furtherspinner arranged to attackthe uppermost part ofthe bale and mounted forwardly of the main group of spinners, the further spinner being enclosed by a coverwhich extends forwardly from the hood.

15. A machine according to any preceding claim, including guide means for guiding the bale to the spinners.

16. A machine according to Claim 15 in which the guide means comprises guide fingers for contacting the top ofthe bales and being curved upwardlyattheir front ends.

17. A machineaccordingto Claim 15 or 16, in which the guide means comprises guide rails running along both sides ofthe chassis.

18. Amachineforapplying strawtocropswhich is substantially as described above with reference to Figures 1 to 4, 5,6or7ofthe drawings.