AU666271B2 - Improved shredding apparatus - Google Patents

Description

6 27 1

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

P/,aoI Regulalion 3.2 o r e o ,o ego• oe e o• o roo• 0o Name of Applicant: Actual Inventor: Address for service ALLPOWER INDUSTRIES AUSTRALIA LTD KEITH FRANKLIN BILLING in Australia: CARTER SMITH BEADLE 2 Railway Parade Camberwell Victoria 3124 Australia Invention Title: IMPROVED SHREDDING APPARATUS Details of Associated Provisional Application: PL 9551 filed 22 June 1994 The following statement is a full description of this invention, including the best method of performing it known to us -2- This invention relates to shredding apparatus, and particularly relates to improvements in shredding apparatus for cutting or tearing garden waste such as leaves and twigs into small pieces for use as compost.

Conventional domestic shredders are electrically powered, and have an electric motor mounted on a base, with a generally vertical shaft.

The motor drives a circular plate containing blades. A hopper is located above the plate, such that material placed into the hopper is shredded by the blades, and ejected through a chute. A separate, smaller, entry to the blades is provided for thicker branches.

One problem with conventional shredders arises from the need to prevent an operator's hand or arm from reaching the moving blades. Some shredders have tall •oooo hoppers which by virtue of their size prevent the hand from reaching the blades.

S....This results in a costlier, heavier machine.

Another variant is to restrict the opening into the hopper to a size, through 15 which only fingers are capable of passing, but which is located sufficiently far from the blades for the arrangement to be safe. Unfortunately, the restricted entrance presented to leaves and the like by the safety slot can cause clogging of the slot and loading of the shredder becomes extremely difficult.

*Conventional shredders also have a single size outlet to the previously S 20 mentioned chute. This does not permit any adjustments to be made to cater for Sdifferent types of material to be shredded.

It is an object of this invention to provide an improved shredder which overcomes problems associated with conventional shredders.

Accordingly, the invention provides, a shredding apparatus including a hopper having an inlet opening for receiving material to be shredded, shredding means in an end of said hopper distal from said opening, at least one internal baffle positioned within said hopper for restricting direct access to said shredding means from said inlet opening, and an outlet for the removal of material which has been shredded.

By providing at least one internal baffle for restricting direct access to the DG CR flI4SC3Ocdr19 BGC:RR#13-14.SPC 31 •otobr 1995 -3shredding means, an operator's arm or hand cannot easily reach the shredding means during operation of the shredding apparatus.

In a preferred form of the invention the at least one baffle comprises two baffles displaced axially along the hopper and preferably positioned on diametrically opposite sides of said hopper.

The at least one baffle is inclined towards the shredding means to facilitate the conveyance of material to said shredding means.

The outlet for said shredding apparatus may include an outlet opening in the hopper into which a removable restriction means is insertable to decrease the size oooee 10 of the outlet opening.

ta The outlet may further include an outlet chute which abuts the hopper such that material shredded by the shredding means passes through the outlet opening in the hopper to the outlet chute.

Preferably, the end of the outlet chute distal from the hopper is pivotally 15 mounted on a bed plate. The hopper which may be fixed to the outlet chute is secured to the bed plate by a releasable latch. When the releasable latch is disengaged, the hopper and outlet chute are both able to pivot about the pivotal mounting on the bed plate. In this way, maintenance, adjustment and inspection of the shredding means and restriction means can be conducted.

20 The features, objects and advantages of the present invention will become S" more apparent from the description of the preferred embodiment and accompany drawings, in which:- Fig. 1 is a perspective view of an embodiment of a shredder; Fig. 2 is a plan view of the hopper section shown in Fig, 1; Fig. 3 is a sectional view through line 3-3 of Fig. 2; Fig. 4 is a sectional view along line 4-4 of the embodiment %lhown in Fig. 1; Fig. 5 is a sectional view of the connection between the hopper and the exit chute; and Fig. 6 is a plan view along line 5-5 of Fig. Referring to the drawings, a shredding apparatus 100 in accordance with the JIISPE-.3OI3414 21 Jun 1994 -4invention is shown having a hopper 102, a shredding means and an outlet for the removal of material which has been shred.

In the embodiment of the invention the shredding apparatus 100 may have a base 104 formed from legs 106, 108 and a V-shaped support member 110.

Elements 106, 108, 110 are bolted together by nut/bolt combinations.

Wheels 112 are located on an axle arrangement 114, which also assists the erection of base frame 104. A leg element with a wheel arrangement at the bottom (not shown) may be substituted for leg 106.

Secured to base frame 104 is a bed plate 116, to which a drive means shown 10 as electric motor 118 is secured. The shaft of motor 118 extends through an aperture in bed plate 116. An electrical contact block is provided on motor 118 for the attachment of a lead 120.

The shredding means is secured to shaft 104 and is shown as cutters 122 and in use adapted to rotate the cutters 122 relative to plate 124, which is secured to bed 15 plate 116. The type of shredding means is well known in the art and may consist of 4 cutting blades rotating in a cutting plane and a disrupter extending perpendicularly from the centre of the rotating blades.

The shredding apparatus has an outlet which includes an outlet opening in said hopper and an outlet chute 126 abutting the hopper 102 such that material shred 20 by said shredding means passes from the apparatus by the outlet chute 126. The outlet chute 126 is fixed or may be integrally formed with hopper 102.

Apertured lugs 128 are provided on bed plate 116 for the location of an outlet chute. Near the outlet end of chute 126 there are located apertures, which are intended to be in register with the aperture 130 of lugs 128. Nut/bolt combinations, secure bed plate 116 and outlet/chute together for relative rotation. This enables the outlet chute to be swung from the operating position shown in Fig. 1 to a maintenance position where the shredding means (cutters 122) are exposed.

The hopper 102 is secured to bed plate 116 by an over-centre catch 132, and a lock screw is provided to hold the hopper to base plate 116 by engaging an aperture in lug 134. Removal of the lock screw preferably actuates means (not JIISPE.30W13414 21 June 1994 shown) to switch off power to motor 118.

Hopper 102 is generally cylindrical, but is preferably adapted, when the shredder is on level horizontal ground, to be at a slight angle between 15'-250 to the vertical (see Fig. The entrance to the hopper has a frusto-conical lip 136, which in use is generally in a horizontal plane, and has a handle 138 secured to it by nut/bolt combinations (not shown). A restricted diameter entrance 140 for sticks, twigs and the like is provided at the lower end of hopper 102, leading to cutters 122 (see Fig. 4).

Located within hopper 102 is at least one internal baffle 142/144. When a S 10 single baffle is used baffle 142 is located by bolting or by using an apertured lug, eoeo Sto the "low'" side 146 of the entrance 148 to the hopper interior. The baffle 142 preferably forms an anglk. of between 50'-70' with the wall of the hopper and Sextends into the interio" of the hopper 102.

The baffle 142 is of such a size that preferably it intersects and extends 15 beyond a direct line from the "low" side 146 of the entrance 148 to the corresponding diametrically opposite side of the shredding means.

By adjusting the angle of inclination of the hopper 1102 and the length of the .:.hopper, the size of the baffle can be altered but still prevent direct access to the shredding means from the entrance 148 and without unnecessarily restricting the 20 cross-sectional area presented to material introduced into the hopper.

When two or more baffles are used, the first baffle is positioned as in the case of a single baffle and a second baffle 144 may be attached to the hopper at a position axially displaced from the first baffle along the longitudinal axis of the hopper 102 but on the diametrically opposition side of the hopper.

The second baffle 144 may also be inclined towards the shredding means at an angle of 50'-70' to the wall of the hopper.

By using two baffles 142/144 on diametrically opposite sides of the hopper, the size of the baffles can be reduced thereby limiting unnecessary restriction of the cross sectional area presented to the material fed into the hopper. The two baffle arrangement also has the advantage in that any direct line from any point of the JIISPE.341314 21 June 1994 -6entrance 148 to the hopper to any point on the shredding means is intersected by one or both of the baffles. This not only prevents direct access to the sh-dding means from the entrance 148 but makes any access to the shredding means from the entrance 148 with an operator's arm extremely difficult thus further improving the safety of the apparatus.

The ov"Iet opening 150 from the base (in use) of hopper 102 to outlet chute 126 (actually the space between chute 126 and bed plate 116) is constituted by a removed portion of the circumferential wall 152 of hopper 102.

A particular size of outlet opening 150 has generally been selected, in prior art apparatus, as an average size able to cater, more or less, for all materials.

However, it is known that hard materials such as sticks or twigs need more work on them to shred them, compared, say, with wet leaves.

In an embodiment of the invention, it is proposed to cater for these different types of materials by restricting the size of outlet opening 150 with a removable 15 restricting means shown as orifice restrictor (Fig. Such a restrictor is in the form of an apertured plate 155 which is adapted to be secured by bolting or the like to chute 126, and an upstanding curved flange 157 conforming to the shape of the hopper interior which is adapted to temporarily replace part of the "removed" wall 152. Thus introduction of the restrictor 154 reduces outlet opening 150 by re- 20 introducing part of wall 152 removed to create the outlet opening 150.

We have already seen how easy it is to move hopper/chute 102/126 from its operating position by removing lock screw opening catch 132 and rotating hopper/chute 102/126 to a position where exit 150 may be exposed. Prior art apparatus has the hopper/chute secured by three manually-operable screws.

Once opened, restrictor 154 may be secured to chute 126 to restrict exit 150.

This would be done if hard material is to be shredded. It has been found that by restricting the outlet opening from hopper 102, the residence time of material in the hopper and in the vicinity of the shredding means is longer and the material will be struck more often by cutting blades 122 and will accordingly be more finely shredded. P .dmoval of restriction 154 will allow for shredding of softer material JIISPE.30W'114 21 June 1994 -7such as leaves.

For ease of fabrication, it is preferable that the hopper 102 and outlet chute 126 be formed as an integral unit and to have the hopper 102 and bed plate 116 aligned at right angles. Since the apparatus 100 preferably adopts on level ground, a hopper orientation inclined to the vertical, the outlet chute 126 has a down angle to the horizontal equivalent to the vertical inclination of the hopper. The inclination on the outlet chute 126 thus assists shredded material to more easily pass through the outlet chute under the effects of gravity and through chute exit 156 to a bin or the like for disposal.

10 It can be seen that the shredder of this invention is an improvement over prior apparatus.

:i The claims form part of the disclosure of the invention.

s o s r o jnISPE3V13414 21 June 1994

Claims (9)

1. A shredding apparatus including a hopper having an inlet opening for receiving material to be shredded, shredding means in an end of said hopper distal from said opening, at least one internal baffle positioned within said hopper for restricting direct access to said shredding means from said inlet opening, and an outlet for the removal of material which has been shredded.

2. The shredding apparatus in accordance with claim 1, wherein said at least one internal baffle comprises two baffles positioned in said hopper substantially O 10 diametrically opposite each other and axially displaced apart. V The shredding apparatus in accordance with claim 1 or claim 2 wherein said at least one baffle is inclined towards the shredding means to facilitate the conveyance of material to said shredding means.

4. The shredding apparatus according to claim 3 wherein the at least one baffle 15 is included at an angle of 50'-70° to the hopper wall. 0 The shredding apparatus according to any one of the preceding claims wherein the shredding means consists of rotatable cutling blades rotated by drive means.

6. The shredding apparatus according to any one of the preceding claims wherein said outlet includes an outlet opening in said hopper and a removable restriction means insertable into said outlet opening to decrease the size of the outlet opening.

7. The shredding apparatus in accordance with claim 6 wherein said outlet BGCRR#13414.SPC 31 Ocober 1995 -9- further includes an outlet chute abutting said hopper such that material shredded by said shredding means passes through said outlet opening to said outlet chute.

8. The shredding apparatus according to claim 7 wherein the end of said outlet chute distal from said hopper is pivotally mounted on a bed plate.

9. The shredding apparatus according to claim 8 wherein said outlet chute is fixed to said hopper, said hopper being secured to said bed plate by a releasable latch, such that when the releasable latch is disengaged, the hopper and outlet chute pivot about the pivotal mounting on said bed plate.

10. A shredding apparatus substantially as hereinbefore described with reference 10 to the accompanying drawings.

11. The steps, features or integers disclosed in the accompanying specification or drawings, individually or in any combination. DATED this 21 June, 1994 CARTER SMITH BEADLE 15 Fellows Institute of Patent Attorneys of Australia Patent Attorneys for the Applica.t ALL POWER INDUSTRIES AUSTRALIA LTD IISPB.30\13414 21 June 199 ABSTRACT A shredding apparatus 100 for cutting or tearing garden waste including a hopper 102 having an opening 148 for receiving material to he shredded. The hopper has an inlet opening 148 and a shredding means 122 positioned at an end of the hopper distal to the opening. The hopper is provided with at least one baffle 142 and preferably two baffles 142/144 to prevent direct access to the shredding means 122 from the opening. In a preferred form, a removable restriction means 154 is provided in the outlet opening 150 of the hopper to restrict the flow of material from the shredding 10 apparatus thus increasing the time period which material spends in proximity to the shredding means. e* Jl1SPE.30W13414 21 June 1994