GB2477076A

GB2477076A - Apparatus and method for producing straw of a predetermined length

Info

Publication number: GB2477076A
Application number: GB0912331A
Authority: GB
Inventors: Richard Larrington
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-07-16
Filing date: 2009-07-16
Publication date: 2011-07-27
Anticipated expiration: 2029-07-16
Also published as: GB0812984D0; GB0912331D0; GB2477076B

Abstract

Apparatus and method for producing from a supply of straw in strand form, lengths of the straw having an average length within a predetermined length range. The apparatus and method includes means for forming from the supply a stream of the straw, means for moving the straw stream along a predetermined path to a cutting zone which has a rotary cutter unit. The cutter unit includes a rotor32having at least one toothed disc29or the like co-operable with a side face of an associated vertical fin or plate33. The arrangement being such the straw to be cut is caused to fall under gravity onto the rotor32and the fin33to be cut by the relative movement between the disc(s) and the side(s) of the associated fins. The cutting action of the cutter involves lifting the straw from the stream.

Description

HANDLING FIBROUS MATERIAL

This invention relates to the handling of random lengths of fibrous material.

In particular the present invention is concerned with the handling of straw derived from the harvesting of cereals It is well known that in the harvesting of cereal crops such as oats, barley, and wheat that the growing cereal attains various stem lengths and that a conventional manner of present day harvesting is the use of the so-called combine harvester which serves the dual purpose that on being advanced through the growing crop, cuts the growing stems and following such cutting advances the cut crop into regions of the machine in which the actual cereal crop is separated from the associated straw forming stems of the plants and transfers the harvested crop to appropriate temporary storage means and feeds the thus thrashed straw to a discharge region-of the machine.

At this stage the straw is very randomly relatively arranged and is either discharged onto the ground for subsequent packaging into standard sized bales or alternatively fed to a 1 5 baling apparatus which packs the straw into large rectangular brick like packages that are maintained in the brick like form by a plurality of circumscribing strings It will be appreciated that as a result of the cutting and the thrashing of the cut crop the straw material is very randomly arranged and distributed within a bale.

In practice this highly random distribution of the individual lengths of the straw has various applications such as for use as a bedding material for animals or as a protective covering for a field crop such as carrots over the winter months.

When the baled straw is required to be used the content of a bale is presently distributed by machines conveniently called straw spreaders which are arranged to be able initially to remove the binding strings from a bale and to then convey the content of the bale through a region of the machine within which the straw is separated out from its very tight compressed baled state into a loose conglomerate which is conveyed to a discharge zone of the spreader machine from which it is spread onto a field.

It will be understood that the straw as spread onto the field is very randomly distributed tangled mass of pieces of straw or like material pieces having a wide range of individual sizes In practice, has been appreciated that for some applications of the straw material it would be advantageous to be able to provide quantities of straw having defined length ranges in terms of the average lengths of the straw or like material being made available for subsequent use.

it is known to cut straw by means of a rotary cutter arrangement in which the cutting effect is produced by rotary blade cooperating with an corner or edge region of a hard metal block. It has been found that with such an arrangement there is an inherent risk of a stones or other hard elements of detritus that may be present in a bale may become trapped between the rotating cutter blade and the associated cutting block/edge with the result that the blade runs the risk of being damaged.

It is an object of the present invention to provide means for cutting straw of like other 1 5 materials in such manner that the risk of blade damage is reduced.

Broadly according to a first aspect of the invention there is provided a method of producing from a supply of straw lengths of the straw having an average length within a predetermined length range, including forming from the supply a stream of the straw, moving the straw along a predetermined path stream to a cutting zone, causing the straw when in the vicinity of the cutting zone to fall on to a rotary cutter whose cutting action involves lifting the straw from the stream to be sufficiently as to form above cut upwards the rotor a loose mass of the material which on falling under gravity onto the rotor to be cut by the relative movement between between the rotary cutter and the side(s) of non rotary fins/plates.

In accordance\with a further aspect of the invention there is provided apparatus for producing from a supply of straw in strand form lengths of the straw having an average length within a predetermined length range, including means for forming from the supply a stream of he straw, means for moving the straw stream along a predetermined path to a cutting zone including a rotary cutter unit including a rotor having at least toothed disc or S -3-the like co-opperable with a\side face of an associated vertical fin/ptate, the arrangement being such the straw to be cut is caused to fall under gravity onto the rotor and the\fin/plate to be cut by the relative movement between the disc(s) and the side(s) of the associated fins/plates.

Preferably, the stream of material is compressed at a predetermined location of said path sufficiently to ensure that a compact stream/layer of straw or other material is produced and the cutting the predetermined lengths of the straw from the compact stream is effected whilst the straw or other material i«= in the compressed condition.

In a preferred arrangement the straw I that is to be formed into the stream is torn by rotary means from the leading face of a bale of the straw or like material being fed towards into physical engagement with teeth or the like members provided on the rotary means.

Preferably the straw forming the stream is compressed by being passed between a nip produced between a rotating roll or the like and a support surface for the layer of straw..

Preferably the cutting means includes a rotary cutter whose rate of rotation is arranged to 1 5 define the amount of straw that can pass said cutting line between cutting strokes.

Preferably the rotary' cutter incorporates a plurality of equiangularly disposed cutter blades that are successively advanced past the cutting line whereby the length the stream to be cut at each cutting stroke is defined by the length of the stream that is advanced beyond the cutting line between successive cutting.

For a better understanding of the invention and to show how to carry the same into effect reference will now be made to the accompanying drawing in which:-Figure 1 schematically illustrates an embodiment of the apparatus for cutting straw or like material derived from bales thereof into cut lengths within selectable ranges of cut lengths; Figure 2 schematically illustrates the construction of a material cutting rotary cutting arrangement. and; Figure 3 illustrates to a larger scale detail of the cutting arrangement Referring now to Figure 1 of the drawings which schematically illustrates apparatus 1 for producing from bales 2 of straw or like fibrous material cut lengths of the straw or like material having lengths within predetermined ranges. Hereinafter the material will be referred to as straw.

The apparatus includes a bale support platform 3 mounted upon a vehicle chassis 4. The bales are arranged to be advanced to be progressively into a main section 5 of the apparatus 1.

Within this main section 5 the straw is pulled i.e., torn away from the leading ends 6 of the bales 2 as they are moved into the engagement with a pair rotating bale engaging members 7 and 8 each having a central shaft 9 rotatable about an axis transverse to the direction of the advance of the bales 2. The members 7 and 8 are rotated in the direction of the arrows 10 by a schematically illustrated rotational drive arrangement 12.

The members 7 and 8 each incorporate two groups of side by side radially directed plates (not separately shown) that are angularly inclined relative to the associated shaft axis with 1 5 each such plate having a plurality of outwardly directed peripheral teeth. The groups of plates on each shaft are so set with respect to the shaft such that the plates to one side of the centre of the shaft length are inclined to the shaft axis in one direction whilst the plates to the other side of the central region of the shaft length are inclined in the opposite sense.

By reason of the inclination and the spacing of the plates and the set of the teeth thereupon the co-operation between the plates and the leading face 6 of a bale 2 creates a generally vertical tearing movements in conjunction with generally laterally directed tearing movements. This combination of vertical and generally horizontal movements enables the teeth on the plates to tear the strawl from the leading face of the bale.

The straw torn from the bales can be considered to move/drop into a loose straw handling section 13 of the apparatus This section 13 includes a support platform 14 and a closed housing 15.

By reason of the shaping of the housing 15 the loose straw torn from the leading faces 6 of the bales 2. feeds onto a continuous feed conveyor belt 16 operationally moving in the direction of the feed of the bales into the apparatus..

The -conveyor belt 16 is conventionally mounted upon rolls 17 including a drive roll located at the upstream end of the conveyor belt 16 Additional rolls (not shown) can if thought necessary be provided along the length of the conveyer at spacings that ensure that the conveyor belt presents a generally horizontal moving surface upon which the loose straw is deposited.

The movement direction of the conveyor belt 16 is indicated by the arrows 20. A further rotary member 9not shown)can if thought necessary positioned above the conveyer belt 16 near the input end thereof this member 21rotating in the same direction as the shafts 9 as indicated by the arrows 22. This rotary member can have has four equiangularly spaced radial arms that bear upon the straw deposited upon the conveyor belt 16 in such manner as to define the maximum size of straw lengths that will be able to pass to the discharge region of the apparatus and to initiate the spreading of the straw, across the surface of the conveyor belt into a stream of layered straw.

A vertical straw deflector plate can bes located above rotary member. The positioning of the plate in this location serves to deflect straw torn away be the upper roll 7 downwards towards the rotary member so that it mixes with that torn away by the lower roll 8.

In practice, the tearing away action on the straw bale will produce a wide range in the lengths of the straw including small fragments and dust. The provision of and the shaping of the housing 15 assists in diverting all lengths of the straw down towards the conveyor 16.

Thus at this stage of its travel through the apparatus 1 the straw is being initially formed into a layer of relatively even thickness and compression.

Further along its travel this initial layered stream of straw 24 passes beneath a smaller diameter roll 25 rotating in a direction indicated by arrows 26. The roll 25 is carried by a support arrangement 27 which enables selectively positioning of the roll above the conveyor belt 16 according to the depth of the straw stream considered appropriate for the intended use of the straw.

The discharge end of the conveyor terminates at a material cutting/chopping zone 28 in which the straw stream cut i.e., chopped in such manner that after passing through the chopping zone the individual lengths of chopped straw are within a predetermined range.

In practice, assuming that the feed of the stream of straw or like material by the conveyor belt 16 to be constant the length of the stream cut way by the rotary cutter wilt be determined by the rate of rotation of the rotary cutter. It will be appreciated that the original straw torn from the bales 2 is chopped into short lengths within a desired size range.

The cutting zone 28 incorporates a rotary straw cutter arrangement 29 which is illustrated in further detail in Figures 2 and 3 As has been mentioned the apparatus includes a vehicle chassis. As shown in the Figure 1 the chassis mounted at its rear end rear road running wheels 40 and includes a vehicle tow bar arrangement 41 at the end thereof at which the bales 2 are provided.

Referring now to Figures 2 and 3 these Figures illustrate in greater detail the cutter arrangement of Figure 1. The cutter arrangement 29 includes a rotor 30 having central tubular shaft 32 upon which are mounted a plurality of discs 33 having at their outer peripheries a series of triangular teeth 34. The discs 33 are so positioned and inclined in the longitudinal direction of and set relative to the shaft 32 that they effectively form a spiral formation relative to the shaft 32 whereby when the rotor is rotating the teeth of adjacent discs appears to move towards and away from each other. In other words the discs are relatively inclined to each other in such manner that they diverge outwardly relative to each other from a narrower separation to a diametrically opposite wider region. Figure 3 in particular illustrates the position when the disc teeth are closest to the fin/plate In this embodiment the rotor 30 is rotated in such direction that the straw falling from the conveyor l6so falls onto the rotor 30 that is rotating in such direction that the straw falling onto the discs 33 is forcibly lifted upwards and is dispersed into the closed housing 15 (not shown in Figure 2).

That is the resulting interaction between the straw and the rotating rotor 30 deflects the straw upwards within the housing and in such manner that the leading end region of the stream of the straw arriving at the end of the conveyor 16 is randomly separated and forcibly directed upwardly into the upper regions of the housing at the straw discharge end of the apparatus.

The housing 13 at this location is provided with a number of shaped vertical fins 35 (only one being shown in Figure 2) that extend towards the rotor 30 and are so positioned as to enter into the closer locations of the mutually inclined discs 32.

This arrangement enables straw to enter between adjacent discs 32 of the rotor. This arrangement ensures that the straw that has been lifted upwards by the rotor rotation is caused, during its fall under gravity, to fall back between the fins 35 onto the rotating rotor 1 0 30 to be entrained thereby to be carried partially around the rotor. This action effectively splits the straw across the fins thereby splitting the straw into a size range set by the spacing of the fins.

The relative positioning of the discs and fins is such that the cutter teeth 33 of the rotor discs 32 move past the side of the adjacent fin 35 whereby the tip of a disc tooth does not 1 5 form a nip with the fins within which detritus could be trapped since such detritus is freeto fall sideways of the discs and fins.

In practice, the provision of the fins 35 introduces a further desirabfe feature in that they effectively separate, depending upon the positioning of the fins 35, the stream of straw into at least two streams of cut straw (depending upon the number of fins provided) which can be discharged from the apparatus in spaced relationship to provide parallel lines of the cut straw Furthermore, by reason of the nature of the displacement of the straw at the end of the conveyor any stone or other hard debris falls between the fins and does not become trapped by the rotor so that the presence of such hard material does not damage the teeth oftherotor30.

The rotor 30 is rotated in the clockwise direction as indicated by the arrows 36 so that, as has been mentioned herein before, straw or like material is able effectively to fall from the conveyor 16 onto the rotor 30.to be lifted upwards within the housing 13. * -8-

The aforesaid plates/fins 35 are mounted to the rear of the housing 13 in such manner that they project sufficiently towards the rotor 30 as to be able to enter between selected adjacent discs 32, With this arrangement the straw that has been lifted upwards by the rotor in falling downwards is guided back onto the rotor 30. The direction of the rotation of the latter tends to both break up the straw or other material into a loose mass separated into separate streams defined by the space between two adjacent plates or fins 35.

In practice, the removal of straw from bales thereof and the subsequent cutting of the material could under some circumstances result in the production of considerable amounts of dust. As is well known the presence of considerable amounts of dust within a closed environment such as within a machine housing can produce a possible can give rise to the creation of a fire hazard In the circumstances a water tank (not shown) can be positioned in close relationship to the housing 15 and particularly in the vicinity of the rolls 8 and 9.

The tank can be connected with the interior of the housing by means of plastics pipes (not 1 5 shown) having a relatively low melting point such that in the event of fire conditions being produced within the housing the plastics pipes will melt as soon as the ambient temperature attains the melting temperature thereby to allow the interior of the housing to be doused with water.

Claims

CLAIMS1 A method of producing from a supply of straw lengths of the straw having an average length within a predetermined length range, including forming from the supply a stream of the straw, moving the straw along a predetermined path stream to a cutting zone, causing the straw when in the vicinity of the cutting zone to fall on to a rotary cutter whose cutting action involves lifting the straw from the stream to be sufficiently as to form above cut upwards the rotor a loose mass of the material which on falling under gravity onto the rotor to be cut by the relative movement between between the rotary cutter and the side(s) of non rotary fins/plates.
2. Apparatus for producing from a supply of straw in strand form lengths of the straw having an average length within a predetermined length range, including means for forming from the supply a stream of the straw, means for moving the straw stream along a predetermined path to a cutting zone including a rotary cutter unit including a rotor having at least one toothed disc or the like co-operable with a\side face of an associated vertical 1 5 fin/plate, the arrangement being such the straw to be cut is caused to fall under gravity onto the rotor and the fin/plate to be cut by the relative movement between the disc(s) and the side(s) of the associated fins/plates.
3. Apparatus as claimed in claim 2, and wherein each cutter disc is inclined to the axis of rotation of the rotor.
4. Apparatus as claimed in claim 2 or 3, and wherein each fin/plate serves to separate the stream of straw into two streams of cut straw.
5.Apparatusasclaimed in 2,3 or 4, and wherein the discs located to one side of a fin/plate in opposite senses to each other, the arrangement being such that as the rotor rotates the discs effectively reciprocate towards and away from the associated fin/plate.
6 Apparatus as claimed in any one of claims 2 to 5, and wherein means are provided for compressing at a predetermined location of said path the stream sufficiently to ensure that a compact stream layer of straw or other material is produced, and means for cutting the predetermined lengths of the straw from the compressed stream.
7. Apparatus as claimed in claim 6, and wherein the compressed stream of the straw or other material has a predetermined depth.t Apparatus for produdng from a supply of straw in strand form lengths of the straw having an average length within a predetermined length range, substantially as hereinbefore with reference to the accompanying drawlngs 9. A method for producing from a supply of straw In strand form lengths of the straw having an average length within a predetermined length range, substantially as hereinbelbie described with reference to the accompanying drawings.