AU2009100494A4 - Saw unit drive mechanism - Google Patents

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR AN INNOVATION PATENT Name of Applicant: ROSIN DEVELOPMENTS PTY LTD Actual Inventor: PAUL ROSIN Address for Service: Chrysiliou Law Patent and Trade Mark Attorneys 114-115/Biztek, 20 Dale Street Brookvale NSW 2100 Invention Title: Saw Unit Drive Mechanism The following statement is a full description of this invention, including the I est method of performing it known to me/us: c:docs\patcnts\applications\I8272.doctp SAW UNIT DRIVE MECHANISM FIELD OF THE INVENTION The present invention relates to harvesting attachments for logging machine: and, in particular to a saw unit drive mechanism of the harvesting attachment whih 5 allows for continuous rotation of the saw unit. BACKGROUND OF THE INVENTION In the logging industry, logging machines or harvestors are used in the auto ation of the logging process. These harvestors include harvesting heads or attach ents which include saw units which are used to cut the trees. The saw units need :o 10 move from a retracted non-cutting position and through a cutting path in order that the trees are cut. When the cut is completed, the saw unit or blade retracts into the original position. Known harvestors use reciprocal movement of hydraulic cylinders to pivot t e saw units. Therefore the amount of rotation of the saw unit which is able to be ot tained 15 is limited by the length of the cylinder stroke. It is considered that the if the amount of rotation of the saw unit could be inc eased to 3600 the efficiency and cutting power of the harvestor would be enhanced. OBJECT OF THE INVENTION It is an object of the present invention to provide a saw unit drive mechanism 20 which provides the above mentioned advantages. At the very least, the inven ion provides an alternative to previously known drive mechanisms for saw units. DISCLOSURE OF THE INVENTION According to one aspect of the present invention, there is disclosed a saw unil drive apparatus adapted to pivotally move a cutter head of a saw unit, the apparatus cacmm databasedocs\patentscomplete\1 8272.doc 2 including a pivotable member having a pivot point, the cutter head being mountable on the pivotable member with the cutter head offset from the pi ot point, wherein the pivotable member is rotatable about the pivot point such that the cutter head and pivotable member are rotatable about 360*. 5 In the preferred form of the invention, the cutter head is mounted on a member which has an externally geared slew ring associated therewith, the slew ring forming the pivot point and being rotated by a drive motor with pinion gear. In one preferred form, the saw unit includes a chain saw cutter bar and chair tensioning unit which are offset from the pivot point. In other forms, the sav unit 10 includes circular saws witb an axis offset from the pivot point. BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the invention will now be described with reference to th accompanying drawing which is: Fig. 1 is a partial cutaway side view of a saw pivot assembly of a preferred 15 embodiment; and Fig. 2 is a partial cutaway plan view of the saw pivot assembly of Fig. 1. BEST MODE OF CARRYING OUT THE INVENTION A saw pivot drive assembly 10 is illustrated in the drawings. The assembly 1) includes a cutter head 11 being made up of a saw chain cutter bar 12, a saw cl ain 20 13, a saw chain sprocket 14 and a saw chain tensioning unit 15. The cutter had 11 is adapted to cut through trees after they are grabbed by a harvestor attachmer t (not illustrated) by means of pivotal movement through 360*. The saw chain type :utter head 11 is one form of cutter head and other forms such as disc like cutter hea Is are also within the scope of the present invention. c:acmm databaseldocskpatentscomplete\18272.doc 3 The saw chain sprocket 14 is driven by a saw motor 16 and the rotatable culer head 11 is mounted on a saw pivot plate 17 with the sprocket 14 aligned win the saw chain cutter bar 12 to drive the saw chain 13. The saw pivot plate 17 is pivotally mounted on a saw pivot mount plate 18 ty 5 means of a slew ring 19 which is fixedly connected to the saw pivot plate 1 and rotatably mounted to the saw pivot mount plate 18. A saw pivot motor 20 is adapted to rotate the slew ring 19 by means of a pinion gear 21 mounted on haft 22 of the motor 20. The motor 20 is preferably a hydraulic motor. The motOr 20 is also used to operate a chain lube pump 23 via a chain lube pump adaptor 24 10 In operation, the cutter head II is activated by the saw motor 16 and when tl ke trees are to be cut, the saw pivot motor 20 is started and the cutter head 11 is rotated as required by the pinion gear 21 which interacts with the slew ring 19 which rotates, the cutter head 11 which is fixedly connected to the slew ring 19 also rotating. As seen from the above description, the cutter head 11, ie the saw chain cutter b ar 12 15 and saw chain 13, is able to rotate a full 3600. Throughout the specification, the word "comprise" and its derivatives are ini ended to have an inclusive rather than an exclusive meaning unless the context req ires otherwise. The foregoing describes only some embodiments of the present invention, 20 modifications obvious to those skilled in the art can be made thereto without departing from the scope of the present invention. c-cmm database\docs\patentskcomplete\18272.doc

Claims (5)

1. A saw unit drive apparatus adapted to pivotally move a cutter head of a c aw unit, the apparatus including a pivotable member having a pivot point, t e cutter head being mountable on the pivotable member with the cutter he d 5 offset from the pivot point, wherein the pivotable member is rotatable a out the pivot point such that the cutter head and pivotable member are rotata >le about 3600.

2. The apparatus according to claim 1, wherein the pivotable member has a1 externally geared slew ring associated therewith. 10

3. The apparatus according to claim 2, wherein the slew ring forms the pivc t point and is rotatable by a drive motor with pinion gear.

4. The apparatus according to any one of the preceding claims, wherein the cutter head of the saw unit includes a chain saw cutter bar and chain tensioning unit which are offset from the pivot point. 15

5. The apparatus according to any one of claims I to 3, wherein the saw uni: includes a circular saw with an axis offset from the pivot point. c:\cmm databasedocs\patents\oomplete\18272.doc