GB2261615A - Bale shredder apparatus - Google Patents

Abstract

The apparatus, typically tractor mounted for agricultural use in distributing animal fodder or bedding, has a receiver 16 for the bale with a power driven shredding rotor 26. The rotor has breaker blade(s) 40 on its face acting directly on the bale and centrifugally swinging shredding blades 42 which extend radially to co-act with fixed blades 46 projecting inwardly from the wall of a shredding chamber for further shredding and chopping of the material. The rotor also includes fan blades 38 blowing the shredded material along one or more chutes 48 typically delivering to either or both sides of the direction of travel as required. The shaft 24 of rotor 26 is driven from a PTO connection (28, Figure 3) from tractor. Chutes 48 are connected to extensions 52 which prevent operator's hand reaching chute 48. Rotor may be journalled about non-vertical axis. Receiver 16 may be swung open. <IMAGE>

Description

BALE SHREDDER This invention relates to apparatus for shredding fibrous material which has been compressed into bales for storage and handling, particularly but not exclusively apparatus for agricultural use in the form of a mobile machine for shredding and distributing baled animal bedding or fodder such as straw, hay, or silage.

One type of bale in very common use in agriculture is rectangular measuring about 35x48cm in lateral section and about 85 to 95cm in length (the length varies somewhat). These can be manhandled quite readily and are hereinafter referred to as "small square bales" as distinct from the much more bulky large square or cylindrical bales which may weight from about 500kg (in the case of dry straw) up to about 1000kg (in the case of green fodder such as silage) and needing powered devices for lifting and transport.

Various bale shredding and straw or fodder chopping devices are known but many are slow in operation, of complex and costly construction, not readily mobile, and/or do not provide effective or consistent fine shredding of the fibres themselves of the material but rather merely free the coarse material from the bale.

GB-B-2122480 describe and claims bale shredders having a bale receiver presenting a face of a bale to a toothed shredding rotor driven about an axis generally normal to said face in use, the action of the rotor also discharging the shredded material removed from the bale face to distribute it from the shredder and this type of shredder is hereinafter referred to as an "axial feed shredder".

The object of the present invention is to provide a bale shredder which is speedy, simple and reliable in operation, mobile, which will readily distribute the shredded material to required locations, and which provides consistent fine shredding of the material.

According to the invention there is provided shredding apparatus for baled fibrous material comprising a receiver in which a bale to be shredded is operatively placed, a shredding rotor acting to remove and shred material from a face of the bale so placed in use, said rotor being operatively rotatably driven about an axis generally normal to said face in use, at least one delivery duct, and means for discharging material shredded from said face of the bale along said duct; characterised in that the rotor includes first formations acting to remove material from the bale face and second formations operatively projecting radially into a gap defined between the periphery of a main part of the rotor and wall structure defining a shredding chamber surrounding the rotor; and in that there are further formations projecting radially inwardly from said wall structure to coact with the second formations of the rotor to provide a shredding action on the material as it passes into or through said gap.

Conveniently said rotor further includes said means for discharging in the form of fan blades for blowing the shredded material along said duct.

The rotor main part may comprise a pair of axially spaced discs with said fan blades mounted between them.

Preferably the further formations of the rotor are blades mounted so that they are urged to a fully extended position by centrifugal force.

Said second formations may be arranged in sets spaced angularly of the rotor, each set comprising a plurality of chopping blades.

The blades of each set may be carried on a common pivot pin of the rotor for said swinging movement and are preferably arranged to act on opposite sides of said further formations.

Said wall structure may include a ridged surface for retarding the material to be fully acted on by the second formations.

Preferably the receiver can be swung open for access to the shredding rotor.

The delivery duct may include a laterally outer chute section having a front opening barred by one or more partitions to divide it into narrower openings without substantial obstruction of outward flow therethrough, but which will prevent insertion of a hand or arm to reach the rotor formations for safety.

An example of the invention is now more particularly described with reference to the accompany drawings wherein Figure 1 is a sectional front elevation of a bale shredder, Figure 2 is a sectional plan view thereof, and Figure 3 is a side elevation of the shredder.

This example is a tractor-mounted and powered axial feed shredder for use with small square bales (as referred to above). It comprises a chassis frame 10 having three point linkage mountings 12 for attaching it to the rear of a tractor in use and ground engaging skids 14 forming a stand for the shredder when detached from the tractor or lowered for loading with bales.

A cylindrical bale receiver 16 is mounted on a vertical axis in its position of use. The receiver has an open top and is of a height and diameter which will accommodate and locate a square bale stood on end.

Receiver 16 has hinges 18 at its lower rear edge so that it can be swung open to the position shown in broken lines in Figure 3 to provide access for maintenance or repair and is secured in the upright position by a front securing screw 20. The extreme bottom of the chamber defined by receiver 16 is closed by a fixed horizontal floor 22 (Figure 1).

A rotor shaft 24 projects upwardly through floor 22 coaxially of receiver 16 and mounts a shredding rotor 26 within the lowermost part of said chamber and which will be described in further detail below.

Shaft 24 is operatively driven from a PTO connection 28 powered from the tractor in use through a step-up gearbox 30 mounted below floor 22. In this example rotor 26 is driven at approximately three times the speed of the PTO input.

Rotor 26 comprises axially spaced upper and lower discs 32, 34 (Figure 1) of lesser diameter than the internal diameter of receiver 16 so as to leave a narrow annular gap 36 between the disc peripheries and the receiver wall.

Four centrifugal fan blades 38 are located between the discs and also serve to interconnect the discs to add to the rigidity of the rotor.

The top face of upper disc 32 (which the end of the bale will rest on in operation) is provided with angled or other upstanding breaker blades 40 to assist in the initial removal of material from the bale bottom. having in mind the high speed of rotation a single breaker blade may suffice for some applications; in the present example there are two, one mounted on an angle bracket secured to the centre of disc 32 to project upwardly and radially outwardly, and a further blade radially spaced therefrom and also angled radially upwardly and outwardly but at a less acute angle than the first blade.

Rotor 26 also has shredding formations in the form of sets of flat rectangular chopping blades 42 which project radially beyond the margin of discs 32 and 34.

In this example four such sets are provided at equiangular spacing about the disc axis and each set comprises an uppermost blade 42a (Figure 1) immediately above the outer margin of upper disc 32 and four lower blades 42b mounted between the two discs. The blades of each set are attached to the two discs by a common pivot pin 44 on which they can swing so that they are urged to the fully extended position by centrifugal force as the disc rotates but will swing back within the envelope of revolution of the discs if they meet with any substantial obstruction or loading of material. When fully extended their radially outer end edges are in close proximity to the inner wall of receiver 16.Said blades are spaced from each other along pivot pin 44 by washers, said spacing leaving a somewhat larger vertical gap between upper blade 42a and the uppermost of the lower blades 42b at the periphery of upper disc 32.

Fixed shredding formations cooperate with blades 42 and, in this example, take the form of a series of sixteen fixed chopping blades 46 mounted on and spaced equiangularly round the lower margin of receiver 16 to project radially inwardly so that they lie just below the plane of the upper chopping blades 42a of the rotor.

Blades 46 are constituted by the horizontal limb of an L shaped angle component whose downwardly directed vertical limb is welded to the inner face of the receiver wall.

The series of vertical bars formed by these vertical limbs both reinforces the wall in the region of heaviest wear and forms a ridged surface which helps to retard the material in the region of moving chopping blades 42b to be fully acted on thereby.

The chopping zone constituted by the lowermost region of receiver 16 which is occupied by rotor 26 is provided with tangential delivery chutes 48 immediately below the plane of fixed blades 46 and opening to the left and right of the path of travel of the shredder in use. One or other (or both) said chutes can be selectively opened or closed by means of respective spring loaded swinging gates 50 operated by pull cords (not shown) accessible to the driver of the tractor.

Chutes 48 are fabricated as fixed extensions of the receiver 16 and are only of short length terminating within the area of chassis 10. As these chutes and the fixed chopping blades 46 are mounted on the hinged receiver the whole assembly including the part of the receiver defining the chopping zone can be swung clear to give full access to all the chopping blades for maintenance or replacement, or to repair any damage which might be caused by foreign bodies, or to clear any blockage which might occur. For safety the drive to the rotor should be disconnected or disabled if and when the receiver is swung open and it is contemplated that a safety interlock might be provided to ensure that this is done.

The shredder is of compact construction and its direct mounting on the tractor makes it easily and fully manoeuvreable in confined spaces. It is therefore most desirable that its overall lateral width in operation should be kept to a minimum. Recent machinery safety regulations require that moving parts such as the blades of rotor 26 cannot be reached by a user's arm or hand e.g. inserted through ducts 48. The latter are, in themselves, too short to prevent this and it is also desirable that further direction is given to material blown from the chopping zone by the action of the fan blades for effective lateral distribution thereof. Each chute 48 is therefore provided with a lateral extension 52 mounted on the outer side of chassis 10 in alignment with the respective chute 48.

Each extension 52 is a rectangular box-like sheet metal structure whose top is substantially on a level with the top of duct 48 but which extends substantially below the level of the bottom of the duct. The bottom of extension 52 is open which permits heavier and larger portions of material which may be discharged from chute 48 on starting up to drop clear onto the ground without choking the extension. The outer face of the extension remote from chute 48 is open except for a face plate 54 at the lower part and the front opening so defined is barred by a pair of spaced parallel partitions 56 dividing the opening into three narrower portions without substantially obstructing direct flow outwardly from chute 48.These partitions and the vertical depth of extension 52 make it impossible for an operator's hand or arm to be inserted to reach chute 48 or touch the moving parts of the rotor, yet the outward projection of extensions 52 laterally of the chassis is within the overall width of the propelling tractor so that passage through gates and doors is not prevented.

A hinged deflector flap 58 (Figure 1) mounted to coact with the upper part of the outer opening of extension 52 can be angled as required to direct the outflow somewhat downwardly if needed.

A carrying platform 60 forms a rearward extension of chassis frame 10 for carrying extra bales ready to be loaded into the receiver 16 and this platform can be folded upwardly and forwardly when the shredder is not in use. Platform 60 also serves to support the receiver 16 when it has been swung open.

In use a bale is dropped into receiver 16 and, as rotor 26 spins at high speed the material is progressively removed from the lower face of the bale, initially by the action of breaker blades 40 and is thrown centrifugally outwards to pass into gap 36 where it is shredded finely by the interaction of the fixed and moving chopping blades. The finely chopped material is swept round centrifugally and is blown by the action of the fan blades 38 to be projected tangentially through one or both of the chutes 48 laterally of the path of travel to either or both sides while the tractor is driven forwards, for example spreading the chopped material as bedding for livestock in cubicles or pens along an access passage of a farm building.In any area where delivery is not required, e.g. when passing an animal watering trough or an area where there are no pens or cubicles the outflow can be temporary stopped by using the appropriate gate 50.

The shredding action is rapid and effective and the output from the shredder, e.g. when baled straw is being used for bedding, is sufficiently finely chopped to be subsequently handled with the dung by automatic or semiautomatic slurry handling and pumping plant without causing clogging of gratings, pipelines or pumps. The fine chopping also facilitates slurry processing in which the solid content and liquid are separated.

Due to the centrifugal action loose material within the receiver 16, particularly when the bale is nearly consumed, tends to ride up the inner wall. To counteract this and direct the material downwards one or more helical or part-helical inwardly projecting ribs 62 may be provided within the chamber. To prevent uncontrolled spinning of the bale on rotor 16 particularly at start-up one or more inwardly projecting short vertical flanges 64 may also be provided on the inner wall e.g. at an upper region of the chamber.

A vertical louvre shaped viewing slot 66 may be provided in the receiver wall, opening tangentially along the direction of rotation of the material to prevent leakage, at a position within sight of the driver of the tractor so that a check can be made as to when a further bale is needed to continue the operation.

It is to be understood that the rotor may be journalled for rotation about a non-vertical axis in some forms of the invention, and/or the bale may be fed along a non-vertical receiver or feed guide to be acted on by the rotor.

Claims (11)

1 Shredding apparatus for baled fibrous material comprising a receiver in which a bale to be shredded is operatively placed. a shredding rotor acting to remove and shred material from a face of the bale so placed in use, said rotor being operatively rotatably driven about an axis generally normal to said face in use, at least one delivery duct and means for discharging material shredded from said face of the bale along said duct.

characterised in that the rotor includes first formations acting to remove material from the bale face and second formations operatively projecting radially into a gap defined between the periphery of a main part of the rotor and wall structure defining a shredding chamber surrounding the rotor; and in that there are further formations projecting radially inwardly from said wall structure to coact with the second formations of the rotor to provide a shredding action on the material as it passes into or through said gap.

2. Apparatus as in Claim 1 wherein the means for discharging includes fan blades carried by the rotor for blowing the shredded material along said duct

3 Apparatus as in Claim 2 wherein the rotor main parts comprises a pair of axially spaced discs having said fan blades mounted between them.

4 Apparatus as in Claim 1 2 or 3 wherein the second formations of the rotor are blades mounted in swinging relationship to the rotor main part and operatively urged to a fully extended position by centrifugal force.

5 Apparatus as in any preceding claim wherein the second formations are arranged in sets angularly spaced around the rotor, each set comprising a plurality of chopping blades

6 Apparatus as in Claim 5 wherein the blades of each set are carried on a respective common pivot pin of the rotor for swinging movement relative to the rotor main part.

7. Apparatus as in Claim 5 or 6 wherein the further formations project radially into a space or spaces between blades of each set.

8. Apparatus as in any preceding claim wherein the wall structure includes a ridged surface in said chamber for retarding the material as it is acted on by the rotor second formations.

9. Apparatus as in any preceding claim wherein said wall structure defining the shredding chamber forms an end part of the receiver and the receiver can be swung open to give access to the shredding rotor for maintenance or repair.

10. Apparatus as in any preceding claim including two delivery ducts directed for discharge of the material to either side of the path of travel of a tractor or other vehicle operatively carrying or drawing the apparatus.

11. Shredding apparatus for baled fibrous material substantially as hereinbefore described with reference to and as shown in the accompanying drawings.