NZ720208A - Wood Chipper and Chipper assembly for a Wood Chipper - Google Patents

Abstract

chipper assembly (14) for a wood chipper (10), the chipper assembly (14) including: a body (22) adapted to be rotatably driven by a motor (16) of the wood chipper (10). The body (22) having a centre (26) and a rim (28); a cutting part (30) adapted to be coupled to the body (22) toward the centre thereof and being arranged to cut material fed into an inlet (18) the wood chipper (10); and a directing part (32) adapted to be coupled to the body (22) toward the rim (28) relative to the cutting part (30), the directing part (32) being arranged to direct cut material and air toward an discharge (20) of the wood chipper (10). A wood chipper (10) including the chipper assembly (14) is also disclosed. hereof and being arranged to cut material fed into an inlet (18) the wood chipper (10); and a directing part (32) adapted to be coupled to the body (22) toward the rim (28) relative to the cutting part (30), the directing part (32) being arranged to direct cut material and air toward an discharge (20) of the wood chipper (10). A wood chipper (10) including the chipper assembly (14) is also disclosed.

Description

Wood Chipper and Chipper assembly for a Wood Chipper Technical Field The invention relates to a chipper assembly for a wood chipper and a wood chipper having such a chipping assembly.

Background Wood chippers are typically used to form chips from wood or similar plant material fed into the wood chipper. Such wood chippers include a housing having an inlet chute, an outlet chute and a chipping or cutting arrangement between the inlet and outlet chutes to cut or chip the wood or similar plant material. The cutting arrangement may include one or more rotating cutting elements that are arranged to cut or chip the wood or similar plant material. A motor such as a petrol motor carried by the wood chipper may drive the one or more cutting elements.

A problem with these wood chippers is that the cutting elements may become obstructed, or at least substantially slowed in rotation, by material being cut that may cause in efficiencies in the chipping and may result in the motor stalling.

Another problem with these wood chippers relates to the wearing of the cutting elements and the changes that occur to the cutting clearance between the cutting elements that affects the efficiencies in the chipping and/or the period of use of the cutting elements.

The invention disclosed herein seeks to overcome one or more of the above- identified problems or at least provide a useful alternative.

Summary In accordance with a first main aspect there is provided, a chipper assembly for a wood chipper, the chipper assembly including: a body adapted to be rotatably driven by a motor associated with the wood chipper, the body having a centre and a rim; a cutting part adapted to be coupled to the body toward the centre thereof and being arranged to cut material fed into an inlet the wood chipper; and a directing part adapted to be coupled to the body toward the rim relative to the cutting part, the directing part being arranged to direct cut material and air toward a discharge of the wood chipper.

In an aspect, the body includes a front side arranged to face the inlet, and wherein the cutting part is arranged to extend at least partially along the front side in a radial direction from an inner position at least one of at or proximate to the centre to an outer position toward the rim of the body.

In another aspect, the body includes a front side arranged to face the inlet, wherein the cutting part and directing part are coupled to the front side with the cutting part extending at least partially along the front side between the centre and the rim of the body and the directing part is arranged to extend from the front side.

In yet another aspect, the body includes a front side arranged to receive material from the inlet to which cutting part and the directing part are coupled, wherein the cutting part includes a cutting edge arranged substantially parallel to and extending along to the front side and wherein the directing part includes a directing face arranged substantially perpendicular to and extending from the front side.

In yet another aspect, the front side includes a central portion that is raised relative to a skirting lower portion, the cutting part being coupled to the central portion and the directing part being coupled to the skirting lower portion.

In yet another aspect the central portion, include an outlet channel extending to the skirting lower portion.

In yet another aspect, the channel is a recessed segment and is located adjacent to a cutting edge of the cutting part.

In yet another aspect, wherein a plurality of the directing parts are provided at spaced apart locations around the skirting lower portion, the plurality of the directing parts being omitted from an outlet zone proximate to the outlet channel.

In yet another aspect, the cutting part is arranged such that a cutting edge thereof is spaced apart from the central portion thereby defining a depth of cut between the cutting edge and the central portion.

In yet another aspect, a cutting edge of the cutting part extends at least partially over the outlet channel.

In yet another aspect, the outlet channel is segment shaped and the cutting edge of the cutting part extends substantially along a radial side of the segment.

In yet another aspect, the plurality of directing parts are provided in the form of vanes having a generally rectangular body arranged at an angle relative to the body so as generate an airflow toward the discharge the when the body is rotated.

In yet another aspect, the body includes a circular base plate arranged to support the cutting parts and the directing parts.

In yet another aspect, the cutting part is provided in the form of two cutting blades that each extend from opposing sides of the centre in a radial direction toward the rim.

In yet another aspect, each of the blades is at least one of a unitary construction and formed from multiple sections.

In yet another aspect, the plurality of directing parts are provided in the form of vanes having a generally rectangular body arranged at an angle relative to the body so as generate an airflow toward the discharge the when the body is rotated.

In yet another aspect, the chipper assembly includes a counter cutting part fixedly coupled to a housing of the wood chipper, the cutting part being moveable past the counter cutting part so as to effect a cutting action on the material.

In accordance with a second main aspect there is provided, a wood chipper including a chipper assembly as defined in any one of the previous claims, the wood chipper including a housing in which the body of the chipper assembly is rotatably mounted to a motor, a material inlet arranged to direct material toward the cutting part of the chipper assembly and a material discharge arranged to receive cut material from the directing part of the chipper assembly.

In an aspect, the a counter cutting part fixedly coupled to the housing, the cutting part being moveable past the counter cutting part so as to effect a cutting action on the material.

In accordance with a third main aspect there is provided, a wood chipper including a housing having an inlet, a discharge and a chipper assembly adapted to cut material introduced to the inlet and provide cut material to the discharge, the chipper assembly including a body adapted to be rotatably driven by a motor, the body having a centre and a rim; a cutting part adapted to be coupled to the body toward the centre thereof and being arranged to cut material fed into the inlet; and a directing part adapted to be coupled to the body toward the rim relative to the cutting part, the directing part being arranged to direct cut material and air toward the discharge of the wood chipper.

In an aspect, the body includes a front side arranged to face the inlet, and, wherein the front side includes a central portion that is raised relative to a skirting lower portion, the cutting part being coupled to the central portion and the directing part being coupled to the skirting lower portion.

In another aspect, the inlet is dimensioned to be about the same size or smaller that the central portion so as to direct material to the central portion and cutting parts carried thereby.

In yet another aspect, the wood chipper includes a counter cutting part fixedly coupled to the housing, the cutting part being moveable past the counter cutting part so as to effect a cutting action on the material.

In yet another aspect, the housing includes a removable panel having an aperture therein that provides the inlet.

In yet another aspect, the counter cutting part is fixed to an inside face of the removable panel adjacent the aperture.

In yet another aspect, the housing is spiral shaped so as to create airflow toward the discharge upon rotation of the body and directing part carried thereby.

Brief Description of the Figures The invention is described, by way of non-limiting example only, by reference to the accompanying figures, in which; Figure 1 is a perspective view illustrating a wood chipper; Figure 2 is an exploded parts perspective view illustrating the wood chipper showing a housing and a chipping assembly; Figure 3 is a top side perspective view of the chipping assembly; Figure 4 is a bottom side perspective view of the chipping assembly; Figure 5 is an exploded parts top side perspective view of the chipping assembly; Figure 6 is a top view illustrating the chipping assembly; Figure 7 is a side view illustrating the chipping assembly; Figure 8 is a bottom view illustrating the chipping assembly; Figure 9 is a sectional view illustrating the chipper assembly along section A- A as shown in Figure 6; Figure 10 is a perspective front view of a removable cover plate of a housing of the wood chipper; and Figure 11 is a perspective back view of the removable cover plate showing a counter cutting part.

Detailed Description Referring to Figures 1 and 2, there is shown a wood chipper 10 including a housing 12 having a chipper or chipping assembly14 and a motor 16 arranged to drive the chipper assembly14. An inlet 18 is provided to feed material to the housing 12 for cutting or chipping by the chipper assembly14 and a discharge or outlet 20 is provided from the housing 12 to allow for the discharge of air and any cut material from the housing 12 and chipper assembly14. The wood chipper 10 includes a supporting frame 13 on which the housing 12 and the motor 16 are mounted and wheels 15 are to allow for transportation of the wood chipper 10.

The chipper assembly14 includes a rotatable supporting body 22, one or more cutting parts 30 and one or more directing parts 32. The supporting body 22 includes a front side 23 having a centre 26, a backside 25 and a skirting rim 28.

Referring additionally to Figures 3 to 9, the cutting parts 30 are adapted to be coupled to the front side 23 of body 22 toward the centre 26 thereof and are arranged to cut material fed into the wood chipper 10 via the inlet 18. More specially, the cutting parts 30 arranged to extend at least partially along the front side 23 in a radial direction from an inner position at least one of at or proximate to the centre 26, to an outer position toward the rim 28 of the body. The directing parts 32 are adapted to be coupled to the front side 23 of the body 22 toward the rim 28 relative to the cutting part 30, the directing parts 32 being arranged to direct cut material and air into the housing 12 and toward the discharge 20.

In more detail, the front side 23 of the supporting body 22 includes a central portion 34 that is raised relative to a skirting lower circumferential portion 35, the cutting parts 30 are coupled to the central portion 34 and the directing part or parts 32 is coupled to the skirting lower circumferential portion 35. More specifically, the circumferential portion 35 includes a face 36 to which the directing parts 32 are coupled and the central portion 34 includes a further face 38 to which cutting edges 40 of the cutting parts 30 are offset to define a depth of cut for material being cut by the cutting parts 30.

In this example, the cutting parts 30 are arranged to extend radially outwardly from the centre 26 toward the rim 28. The cutting parts 30 terminate at the periphery of the central portion 34 and hence short of the rim 28. The cutting edge 40 is provided along one side of each of the cutting parts 30. The cutting edge 40 includes a chamfered surface 41 having a tip 43 elevated from the further face 38 thereby defining the depth of cut.

The central portion 34 includes exhaust or recess 50 arranged to allow passage of cut material and air from a region proximate to the cutting parts 30. In this example, the exhaust or recess 50 are provided in the form of two segment shaped channels 52 fanning outwardly to a channel opening 54 at or proximate to the skirting lower circumferential portion 35. The depth of the channels 52 being defined by the face 36 of the lower circumferential portion 35.

The cutting edge 40 is arranged to extend along and overhang radial edges of each of the two segment shaped channels 52 to deposit cut material into the channels 52 which are then urged via circumferential forces toward the skirting circumferential portion 35 and into the housing 12. The directing parts 32 are provided in the form of a plurality vanes 55 upstanding and extending generally perpendicularly to the face 36 of the circumferential portion 35. The vanes 55 include generally rectangular body 56 arranged at an angle relative to a radial axis of the support body 22 to as generate an airflow when rotated thereby providing an exhaust airstream to carry cut material from the housing 12 through the discharge 20. The skirting lower circumferential portion 35 may include slots 59 in which the rectangular body 56 of the vanes 55 are received and welded in place.

The vanes 55 are located substantially around the circumferential portion 35 with the cutting parts 30 being located inwardly of the vanes 55. However, the directing parts 32 in the form of the vanes 55 are omitted from the region or zone at or toward the channel opening 54 of the channels 52 so as provide a clear passage of material through the channels 52 into the housing 12. The vanes 55 extend past and stand proud of the central portion 34 and include curved corners 57.

Turning to the configuration of the supporting body 22 in more detail, in this example, the supporting body 22 includes a plate 24 that is preferably arranged as a base plate or backing plate is generally disk shaped. A shaft 17 extends from the motor 16 and coupled to or at the centre 26 of the plate 24. Accordingly, the motor 16 may directly rotatably drive the plate 24 and the mass of and carried by the plate 24 may act as a flywheel thereby maintaining rotational inertia during operation. The plate 24 provides the face 36 of the skirting lower circumferential portion 35 to which the directing parts 32 are mounted.

The supporting body 22 further includes a further plate 44 and mounting blocks 46 that together define, at least in part, the central portion 34 and the further face 38 thereof. The further plate 44 is supported in an elevated or suspended position relative to the plate 24 by the directing parts 32 and the blocks 46. The cutting parts are provided in the form of generally flat elongate knives or blades 48 having the cutting edge extending along one side thereof. The blades 48 are arranged to be releasably coupled to the mounting blocks 46 so as to allow for the blades 48 to be removed for sharpening or replacement.

The blades 48 include a blade face 47 that is elevated relative to the face 38 of the central portion 34. In some examples, the blades 48 may be formed to be symmetrical so as allow each one of the blades 48 to be flipped, rotated or interchanged with the other of the blades 48. This may assist with the even wearing of the blade 48 and longevity of the blades 48. The blades 48 include apertures 60 through which fasteners 62 are passed to coupled with likewise arranged treaded apertures 64 of the mounting blocks 46.

Referring additionally to Figures 10 and 11 with reference to Figure 1 and 2, the wood chipper 10 further including a counter cutting part 70 fixedly coupled to the housing 12, the cutting part 30 being moveable past the counter cutting part 70 so as to effect a cutting action on the material. The counter cutting part 70 includes a cutting edge 72 arranged pass in a cutting position close to and generally parallel to the moving cutting part 30. The counter cutting part 70 is coupled to a removable panel cover 74 of the housing 12 and the counter cutting part 70 may itself be adapted to be removable from the removable panel 74 for maintenance or replacement.

The inlet 18 is provided in the removable panel cover 74 and is arranged to cover the circumferential portion 35 and the directing parts 32 and leave the central portion 34 exposed to material to be cut entering the inlet 18. Accordingly, the inlet 18 is about or smaller in size than the central portion 34 that assist to direct cut material to the cutting parts 30 and also allows the face of the central portion 34 to define the cutting depth and inhibit cut material passing to far into the housing 12 and potentially blocking the housing 12. In this example, an elongate chute 80 is coupled to the inlet 18 to direct material to the inlet 18.

The housing 12 has a generally circular shape that spirals toward the discharge . An elongate discharge chute 82 is coupled to the discharge to direct cut material away from the housing 12. The housing 12 thereby being arranged to provide a passage for material into the cutting assembly 14, receiving cut material into the housing 12, directing the cut material through the housing and discharging the cut material through to discharge 20 to the discharge chute 82.

The wood chipper 10 and parts thereof may be generally fabricated from commonly available materials such as metal and metal alloys. The motor may be a two or four stoke petrol motor arranged to directly drive the shaft 17. Electric motors may also be utilised and the wood chipper 10 or the wood chipper 10 may be driven by an external motor via three point tractor linkage and splined coupling.

Advantageously, there has been described a wood chipper having a chipper assembly including a rotatable supporting body having cutting parts located toward the centre and directing parts located toward the rim. The cutting parts located toward the centre allow the cutting action to be carried out on the high torque and low speed region of the supporting body thereby assisting to cut material without stalling of the motor. The directing parts located toward the rim then assist to remove cut material form the cutting parts and the housing, and direct the cut material through a discharge of the housing. The generally metal material of the support assembly also assists by creating a flywheel effect to maintain inertia when material to be cut is acted on by the cutting parts.

A further advantage of the wood chipper is that the cutting edge of the cutting parts is elevated from the central portion and extends in a radial direction outwardly thereof toward the rim. The cutting edge of the fixed counter blade is fixed to the housing so as to meet in the cutting condition generally parallel with the cutting edge of the cutting parts. Accordingly, when the cutting edge wears and become shorter, the cutting edges wear in the same cutting plane and, the clearance distance between respective cutting edges of the cutting part and fixed cutting part in the cutting condition remains constant.

Whilst the above invention has been described primarily in relation to chipping or cutting wood material. The terms wood used herein is to be construed broadly to include any wood, wood like material or material containing wood or wood like material such as green waste that may be chipped or cut by the above described invention.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any known matter or any prior publication is not, and should not be taken to be, an acknowledgment or admission or suggestion that the known matter or prior art publication forms part of the common general knowledge in the field to which this specification relates.

While specific examples of the invention have been described, it will be understood that the invention extends to alternative combinations of the features disclosed or evident from the disclosure provided herein.

Many and various modifications will be apparent to those skilled in the art without departing from the scope of the invention disclosed or evident from the disclosure provided herein.

Claims (21)

The claims defining the Invention are as follows:

1. A chipper assembly for a wood chipper, the chipper assembly including: a body adapted to be rotatably driven by a motor associated with the wood chipper, the body having a centre and a rim; a cutting part adapted to be coupled to the body toward the centre thereof and being arranged to cut material fed into an inlet the wood chipper; and a directing part adapted to be coupled to the body toward the rim relative to the cutting part, the directing part being arranged to direct cut material and air toward an discharge of the wood chipper.

2. The chipper assembly according to claim 1, wherein the body includes a front side arranged to face the inlet, and wherein the cutting part is arranged to extend at least partially along the front side in a radial direction from an inner position at least one of at or proximate to the centre to an outer position toward the rim of the body.

3. The chipper assembly according to claim 1, wherein the body includes a front side arranged to face the inlet, the front side including a central portion that is raised relative to a skirting lower portion, and wherein the cutting part is coupled to the central portion and the directing part is coupled to the skirting lower portion.

4. The chipper assembly according to claim 3, wherein the central portion includes an outlet channel extending to the skirting lower portion.

5. The chipper assembly according to claim 4, wherein a plurality of directing parts are provided at spaced apart locations around the skirting lower portion, the plurality of the directing parts being omitted from an outlet zone proximate to the outlet channel.

6. The chipper assembly according to claim 4, wherein the cutting part is arranged such that a cutting edge thereof is spaced apart from the central portion thereby defining a depth of cut between the cutting edge and the central portion.

7. The chipper assembly according to claim 4, wherein a cutting edge of the cutting part extends at least partially over the outlet channel.

8. The chipper assembly according to claim 7, wherein the outlet channel is segment shaped and the cutting edge of the cutting part extends substantially along a radial side of the segment.

9. The chipper assembly according to claim 5, wherein the plurality of directing parts are provided in the form of vanes having a generally rectangular body arranged at an angle relative to the body so as generate an airflow toward the discharge the when the body is rotated.

10. The chipper assembly according to any one of the previous claims, wherein the body includes a circular base plate arranged to support the cutting part and the directing part.

11. The chipper assembly according to any one of the previous claims, wherein the cutting part is provided in the form of two cutting blades that each extend from opposing sides of the centre in a radial direction toward the rim.

12. The chipper assembly according to 11, wherein each of the blades is at least one of a unitary construction and formed from multiple sections.

13. The chipper assembly according to any one of the previous claims, wherein chipper assembly includes a counter cutting part fixedly coupled to a housing of the wood chipper, the cutting part being moveable past the counter cutting part so as to effect a cutting action on the material.

14. A wood chipper including a chipper assembly as defined in any one of claim 1 to 12, the wood chipper including a housing in which the body of the chipper assembly is rotatably mounted to a motor, a material inlet arranged to direct material toward the cutting part of the chipper assembly and a material discharge arranged to receive cut material from the directing part of the chipper assembly.

15. The wood chipper according to claim 14, further including a counter cutting part fixedly coupled to the housing, the cutting part being moveable past the counter cutting part so as to effect a cutting action on the material.

16. A wood chipper including a housing having an inlet, a discharge and a chipper assembly adapted to cut material introduced to the inlet and provide cut material to the discharge, the chipper assembly including a body adapted to be rotatably driven by a motor, the body having a centre and a rim; a cutting part adapted to be coupled to the body toward the centre thereof and being arranged to cut material fed into the inlet; and a directing part adapted to be coupled to the body toward the rim relative to the cutting part, the directing part being arranged to direct cut material and air toward the discharge of the wood chipper.

17. The wood chipper according to claim 16, wherein the body includes a front side arranged to face the inlet, and, wherein the front side includes a central portion that is raised relative to a skirting lower portion, the cutting part being coupled to the central portion and the directing part being coupled to the skirting lower portion.

18. The wood chipper according to claim 17, wherein the inlet is dimensioned to be about the same size or smaller that the central portion so as to direct material to the central portion and cutting parts carried thereby.

19. The wood chipper according to claim 18, further including a counter cutting part fixedly coupled to the housing, the cutting part being moveable past the counter cutting part so as to effect a cutting action on the material.

20. The wood chipper according to claim 19, wherein the housing includes a removable panel having an aperture therein that provides the inlet.

21. The wood chipper according to claim 20, wherein the counter cutting part is fixed to an inside face of the removable panel adjacent the aperture.