AU2006201725A1 - Log block cutter - Google Patents

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT (Original) APPLICATION NO:

LODGED:

COMPLETE SPECIFICATION LODGED:

ACCEPTED:

PUBLISHED:

RELATED ART: NAME OF APPLICANT: ACTUAL INVENTOR(S): ADDRESS FOR SERVICE: INVENTION TITLE: Dante Vincenzo Chiera Dante Vincenzo Chiera LORD AND COMPANY, Patent and Trade Mark Attorneys, of 4 Douro Place, West Perth, Western Australia, 6005, AUSTRALIA.

LOG BLOCK CUTTER The following Statement is a full description of this invention including the best method of performing it known to me/us:

TITLE

LOG BLOCK CUTTER 3 FIELD OF THE INVENTION The present invention relates to an apparatus for cutting logs into blocks.

q BACKGROUND TO THE INVENTION It is known to require logs and felled tree trunks to be cut into blocks. Typically such an operation is conducted when the wood from the logs is to be used as a fuel, or for wood-chipping purposes. Typically, it is required to cut logs into lengths of about cm for these purposes.

Currently, the cutting of logs into blocks is achieved by use of a saw, usually a circular saw, having a reciprocating action. The log to be cut is placed onto a conveyor, and then moved forward in stages. At each stage the saw cuts through the log to create a block.

There are several problems encountered with the use of such an apparatus. Principle among these is a need for the log to be stationary when being cut by the saw. This requires conveying apparatus which is capable of both moving the log in an axial direction and holding the log in a stationary position when each cut is made. In addition to being mechanically complex, this arrangement is also relatively timeconsuming.

A further problem encountered is that the machinery required to perform this Ki operation is not readily transportable. As a result, logs are required to be transported Sto the machinery, rather than the machinery being transported to a convenient location q close to the logs (for instance, within a plantation).

Ki Finally, the operations of many saws are must be adjusted, where possible, to q accommodate woods of differing hardness and moisture content. In many cases, particular saws are limited in the range of types of wood they can successfully cut.

The present invention attempts to overcome at least in part some of the aforementioned disadvantages of previous log cutting apparatus.

SUMMARY OF THE INVENTION In accordance with one aspect of the present invention there is provided a log cutting apparatus comprising a first drum and a second drum, each drum having a plurality of blades extending outwardly therefrom substantially in a radial direction, each drum being arranged to rotate such the outer edges of the blades of each drum substantially describe a cylinder, the cylinder of the first drum being substantially tangential to the cylinder of the second drum along a line of action, wherein the drums are arranged to contra-rotate such that the outer edges of corresponding blades of the first and second drums approach each other as the approach the line of action, and wherein, in use, logs passing between the first and second drums can be cut by the blades.

BRIEF DESCRIPTION OF THE DRAWINGS Ki The present invention will now be described, by way of example, with reference to Sthe accompanying drawings, in which: Figure 1 is an upper perspective of a log cutting apparatus in accordance with the present invention; and Ki Figure 2 is a schematic cross-section of the log cutting apparatus of Figure 1.

D

DESCRIPTION OF PREFERRED EMBODIMENTS Ki Referring to the Figures, there is shown a log cutting apparatus 10, shown within a housing 12. The log cutting apparatus 10 comprises a first drum 14, mounted on a first axle 16, and a second drum 18, mounted on a second axle 20. The first axle 16 and the second axle 20 are both mounted substantially vertically.

Each of the first and second drums 14, 18 has a plurality of blades 22 extending outwardly therefrom, substantially in a radial direction. Each blade 22 has a main portion 24 extending from its respective drum 14, 18, and a relatively small end portion 26 remote from the respective drum 14, 18. The end portion 26 is angled with respect to the main portion 24 at an angle of about 150 to the direction of the main portion 24.

The blades 22 are arranged such that each blade has an outer edge 28 which is substantially vertical. As a drum 14, 18 rotates the outer edges 28 of the drum's blades 22 substantially describe a cylinder. The cylinder thus described in relation to the first drum 14 is substantially tangential to the cylinder described in relation to the second drum 16. The two cylinders meet along a line of action Adjacent blades 22 on a drum 14, 18 are spaced apart, with a part cylindrical recess Ki 32 between adjacent blades 22. Each part cylindrical recess 32 includes a wood Sreleasing lever 34.

Each wood releasing lever 34 is hinged about a lower point 36 of its cylindrical portion 32. An upper portion 38 of the wood releasing lever 34 extends substantially Ki vertically of the hinge 36. The highest part 40 of the upper portion 38 is angled so as to be directed away from the drum 14, 18.

A lower portion 42 of the wood releasing lever 34 is substantially L-shaped, projecting horizontally away from the hinge 36 and vertically downwards beneath the drum 14, 18.

The lower portion 42 of the wood releasing lever 34 is arranged to engage with a guiding member 44. The guiding member 44 comprises a curved bar located beneath the drum 14, 18, forward of the line of action 30. In use, as the drum 14, 18 rotates, the lower portion 42 is engaged by the guiding member 44 and pushed towards the axle 16, 20. This causes the wood releasing lever 34 to rotate about its hinge 34, moving the upper portion 38 away from the drum 14, 18.

Each of the axles 16, 20 has a spur gear 46 mounted at an upper end thereof. The spur gears 46 engage through a region about the line of action 30, causing the drums 14, 18 to contra-rotate at the same speed. It will be appreciated that a suitable driving motor can be applied to one of the spur gears 46 in order to drive the log cutting apparatus In use, the axles 16, 20 rotate such that successive pairs of corresponding blades 22 on the first and second drums 14, 18 are brought adjacent to each other, meeting along the line of action 30. A log (not shown) is introduced between the drums 14, 18 from the rear.

As a pair of blades 22 meets the log, the rotation of the drums 14, 18 causes the blades 22 to sink into the log, and to move the log forward. As the blades 22 meet along the line of action 30, the cut into the log is complete and a block separates from the log. This block is ejected from the front of the log cutting apparatus In some circumstances wood can remain engaged within a recess 32 following completion of the cut. As the drum 14, 18 continues rotating, the wood releasing lever 34 is caused to rotate, with the upper portion 38 pushing against any engaged wood and expelling it from the recess 32.

In a preferred embodiment of the invention, the housing 12 includes a shaving portion adjacent each drum 14, 18. The shaving portions are located on opposed sides of the housing 12, and act to prevent any wood stuck on a blade 22 from passing around the drum 14, 18 from the front of the apparatus 10 to the rear.

Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.

Claims (11)

1. A log cutting apparatus comprising a first drum and a second drum, each drum Shaving a plurality of blades extending outwardly therefrom substantially in a radial direction, each drum being arranged to rotate such the outer edges of the blades of i each drum substantially describe a cylinder, the cylinder of the first drum being Ki substantially tangential to the cylinder of the second drum along a line of action, wherein the drums are arranged to contra-rotate such that the outer edges of corresponding blades of the first and second drums approach each other as the Ki approach the line of action, and wherein, in use, logs passing between the first and second drums can be cut by the blades.

2. A log cutting apparatus as claimed in claim 1, wherein each blade has a main portion extending from the drum and an end portion which is angled with respect to the main portion.

3. A log cutting apparatus as claimed in claim 2, wherein the end portion is angled at about 150 with respect to the main portion.

4. A log cutting apparatus as claimed in any preceding claim, wherein the first drum and the second drum are each associated with spur gears, the spur gear of the first drum being meshed with that of the second drum so as to require the first and second drums to contra-rotate.

5. A log cutting apparatus as claimed in claim 4, wherein the spur gear are driven by a driving gear.

6. A log cutting apparatus as claimed in any preceding claim, wherein the drums and the line of action are substantially vertical. INO

7. A log cutting apparatus as claimed in any preceding claim, wherein the log (Ni Scutting apparatus includes a plurality of wood releasing levers, the wood releasing levers being located on each drum between adjacent blades.

8. A log cutting apparatus as claimed in claim 7, wherein each wood releasing Slever is hinged about a lower end of the drum, and has an upper portion extending (-i _above the hinge and a lower portion extending below the hinge. A log cutting apparatus as claimed in claim 8, wherein the lower portion is Ssubstantially L-shaped, and extends beneath the drum. A log cutting apparatus as claimed in claim 9, wherein the lower portion is arranged to engage with a curved guiding member, the action of the lower portion against the guiding member causing the wood releasing lever to rotate about its hinge.

11. A log cutting apparatus as claimed in any one of claims 8 to 10, wherein the upper portion of the wood releasing lever has an upper end which projects away from the drum.

12. A log cutting apparatus as claimed in any preceding claim, wherein each drum includes a wood shaving portion adjacent its cylinder, the wood shaving portion acting to prevent wood stuck on a blade from passing around the drum.

13. A log cutting apparatus as herein above described with reference to, and as shown in, the accompanying drawings. DATED THIS 10TH APRIL 2006. Dante Vincenzo Chiera By his Patent Attorneys LORD AND COMPANY PERTH, WESTERN AUSTRALIA