WO2016187665A1

WO2016187665A1 - Chainsaw links, chainsaw chains and methods of manufacture

Info

Publication number: WO2016187665A1
Application number: PCT/AU2016/050405
Authority: WO
Inventors: Thomas Beerens
Original assignee: Thomas Beerens
Priority date: 2015-05-26
Filing date: 2016-05-26
Publication date: 2016-12-01

Abstract

A wood-cutting chainsaw chain of modular construction comprises a plurality of links disposed along a longitudinal centreline of the chain. The links include apertured joiner links, apertured cutter links and apertured driver links. The links are fastened together by pins passed through overlapping and/or adjacent links and one or more of the links are welded to the overlapping and/or adjacent links. The cutter links can comprise a pair of side walls joined to an enclosed top portion and are distributed between the joiner links.

Description

TITLE

CHAINSAW LINKS, CHAINSAW CHAINS AND METHODS OF MANUFACTURE

FIELD OF THE INVENTION

[0001] This invention relates in general to chainsaws and relates in particular to chainsaw cutter links and wood-cutting chainsaw chains with multiple links including joiner links, drive links and cutter links. The invention also relates to methods of joining such links to manufacture chainsaw chains. Embodiments of the present invention are applicable to hand held chainsaws and industrial saw chain based mechanised wood harvesters and processors.

DESCRIPTION OF THE PRIOR ART

[0002] With reference to Figures 1, 2 and 3, a conventional wood-cutting chainsaw chain 5 typically comprises a plurality of chain links joined together by rivets 10. The chain links include left cutter links 12 for cutting one part or a left side of a slot in the wood and right cutter links 14 for cutting one part or a right side of the slot in the wood. Both left and right cutter links 12, 14 rest on and move along guide bar rails 16, 18 of a guide bar 20 of the chainsaw. Driver links or tangs 22 engage a drive sprocket at a machine end of the chainsaw, engage nose sprockets at a tip end of the guide bar, and locate the chain in a groove 23 of the guide bar. The driver links or tangs 22 can rotate freely on the rivets 10 and the apertures 24 in the driver links 22 are effectively the outer of a plain metal bearing. Skip links or joiner links 26 formed from a pair of side plates 28 provide spacing between cutter links 14 to allow the swarf to be carried out from the cut wood log. The side plates also sit on and move along the rails 16, 18 of the guide bar 20. The rivets 10 provide the inner bearing face to contact the apertures 24 in the driver links 22. The rivets 10 comprise three sections - two small diameter riveting sections 29 which form the rivet head 30 on each side of the chain, and a large diameter central bearing section 32 which allows rotation of the driver link 22. The rivet heads are typically formed by being spun. Lubrication is added to the guide bar 20 to lubricate rivet-to-driver link bearing face. Each cutter link 12, 14 comprises sharpened cutting edges 34, 35 on a top portion and a projection in the form of a depth gauge 36 which assists in limiting the depth of the cut. The void 38 between the cutting edge 34 and the depth gauge 36 is known as the throat or gullet. A bottom portion of the cutter links 12, 14 comprise a heel 40 and toe 42.

[0003] One problem with conventional chains and in particular with conventional chains in the wood harvesting industry, is a phenomenon called 'chain shot' . Typically a chain will have a primary break and the chain will whip causing one or more secondary breaks allowing one or more small pieces of the chain to be ejected at very high speed exposing machine operators and ground personnel to the risk of serious injury or death. Chains typically break due to wearing of the chain links, cracking of the rivets and/or overloading the rivets. During cutting there is often significant force between a heel 40 of the cutter links and the guide bar rails 16, 18. This causes the bottom portion of the cutter links 12, 14 to wear and when the wear is high enough the chain will break. The rivets 10 must rotate in the apertures 24 in the driver links. This rotation causes heat, which can cause localized cracking which can cause the chain to fail. The shoulders of the rivets 10 are under a lot of stress, which, along with high chain tensions and/or poor quality rivet heat treatment and/or materials, can overload the rivets causing the chain to break.

[0004] Another problem with conventional wood-cutting chainsaw chains is that of asymmetrical design and orientation of the cutter blades. As shown in Figures 1 and 2, one blade projects left of the chain centreline while another leading or following blade projects right of the chain centreline. Such a structure and arrangement of blades causes imbalance because when the saw chain is in motion one blade cuts to the left and a following blade cuts to the right. The cutters are angled resulting in significant sideways force on the chain when cutting. These forces put excessive load on the guide bar rails thus opening the guide bar groove and applying excessive load to the heel of the cutter links causing premature chain breakage.

[0005] A further problem caused by conventional chainsaw chain blades is that the blades are of open-top construction and not able to hold cut material or swarf to a sufficient extent and carry it through and discharge it from the saw. [0006] Furthermore, chainsaw users are always looking for improved performance, such as faster cutting, less power consumption, longer times between sharpening, and longer life.

OBJECT OF THE INVENTION

[0007] One preferred object of at least some embodiments of the present invention is to provide a chainsaw chain with cutting links which are provided with a swarf chip forming and holding void or throat.

[0008] Another or alternative preferred object of at least some embodiments of the invention is to provide a chain saw cutting link or links which are of a closed top profile for forming swarf chip segments and transporting the segments for discharge from the saw.

[0009] A further or alternative preferred object of at least some embodiments of the invention is to provide a method of manufacturing a chainsaw chain using a system of links joined to form a chain by passing pairs of pins through pairs of pin holes of overlapping adjacent links and welding the pins to the links and chainsaw chains produced by such methods.

[0010] Another or alternative preferred object of at least some embodiments of the present invention is to provide a useful commercial alternative to existing chainsaw chains and/or methods of manufacturing chainsaw chains and/or which address or at least ameliorate one or more of the aforementioned problems.

SUMMARY OF THE INVENTION

[0011] Generally, some embodiments of the present invention relate to cutter links for a chainsaw chain serving as chip-forming cutter links and formed with cutting edges of a closed configuration which form a central swarf -holding cavity.

[0012] Generally, some embodiments of the present invention relate to methods of joining links of a chainsaw chain by passing pins through pin receiving holes in the links and welding the pins to the links and chainsaw chains so formed. Such embodiments can comprise conventional cutter links and/or the cutter links according to embodiments of the present invention.

[0013] According to one aspect of the invention, but not necessarily the broadest aspect, there is provided a chain for a wood-cutting chainsaw comprising a plurality of links disposed along a longitudinal centreline of the chain, wherein each of the links comprises a pair of apertures to join each link to an overlapping and/or adjacent link by pins passed through the overlapping and/or adjacent links, wherein at least one of the pins is welded to the overlapping and/or adjacent links.

[0014] Preferably, all of the pins are welded to the overlapping and/or adjacent links.

[0015] Suitably, exposed ends of the pins are welded to the overlapping and/or adjacent links on one or both sides of the chain.

[0016] Preferably, the plurality of links comprise joiner links and cutter links connected by vertically-disposed driver links between a cavity formed between side walls of the joiner links and a cavity formed between side walls of the cutter links.

[0017] Preferably, the side walls of one or more of the joiner links and/or the side walls of one or more of the cutter links are joined to at least one respective top wall and the respective top wall of each cutter link extends above a level of a respective top wall of the joiner links.

[0018] Suitably, at least one of the cutter links comprises side walls having laterally overhung top portions which extend above a height of the joiner links.

[0019] Suitably, the side walls of the cutter links have a greater internal separation than an external width of each joiner link, each cutter link being adapted to be placed over a joiner link. [0020] One or more of the driver links may comprise a protrusion abutting an adjacent driver link.

[0021] In some embodiments, a depth gauge is formed on a separate link from a cutter link.

[0022] According to another aspect of the invention, there is provided a cutter link for a wood-cutting chainsaw chain, the cutter link comprising a pair of side walls joined to an enclosed top portion formed from at least one top wall.

[0023] Preferably, the enclosed top portion is formed into an enclosed chamber having a cutting edge surrounding a void or throat leading into the chamber for formation, holding and discharging a wood waste chip.

[0024] Suitably, the enclosed top portion comprises a plurality of folded panels formed by pairs of outwardly angled lower panels on one side and pairs of inwardly-angled upper panels joined on the other side, the top edge of both upper panels being connected to the at least one top wall. The at least one top wall may be flat, raised or angled.

[0025] The at least one raised or angled top wall may be symmetrical or asymmetrical about a centreline of the cutter link.

[0026] Preferably, the cutter link further comprises a depth gauge extending upwards from each side wall of the cutter link. One or more of the depth gauges may comprise an outwardly flared upper portion. Alternatively, the depth gauges may be offset.

[0027] Suitably, a bottom edge of each side wall of the cutter link is inwardly curved.

[0028] Preferably, the cutter links are adapted to be placed over chain segments comprising a plurality of joiner links joined by driver links.

[0029] Suitably, one or more of the links are formed in one piece. [0030] Suitably, the chain is in the form of one of the following: a length of chain comprising two free ends; an endless loop.

[0031] According to a further aspect of the invention, there is provided a method of making a chainsaw chain comprising a plurality of links, each link comprising apertures formed in and extending through the links, the method comprising joining overlapping and/or adjacent links by passing pins through the correspondingly-aligned apertures and welding one or more of the pins to the respective links.

[0032] According to another aspect of the invention, there is provided a method of making a chainsaw chain comprising a plurality of links, including one or more of the aforementioned cutter links, each link comprising apertures formed in and extending through the links, the method comprising joining overlapping and/or adjacent links by passing rivets through the correspondingly-aligned apertures.

[0033] Preferably, the plurality of links include at least one joiner link, cutter link and driver link and the method comprises passing a pair of pins through a single wall of the driver link fitted between joiner links and/or cutter links so that a pair of pins extends between two opposite side walls of each joiner link and cutter link while at the same time extending through longitudinally-adjoining driver links.

[0034] The method may comprise positioning at least one of the cutter links above and in vertical alignment with one of the joiner links after the joiner link has been joined to adjacent driver links such that the cutter link lies over the joiner link to straddle the joiner link which has been pre-assembled with other adjacent joiner links and with driver links interposed therebetween to form a partial segment of a chain.

[0035] The method may further comprise sleeving a pair of hollow roll pins into a pair of respective apertures of corresponding diameter in a joiner link, passing a pair of relatively narrower diameter pins through side walls of the flat-topped cutter link and into an axial hole of a respective one the pair of hollow roll pins, and welding at least one of the pins to the joiner links and the cutter links. [0036] According to another aspect of the invention, there is provided a method of making a chainsaw chain comprising at least one joiner link, cutter link and driver link, each link comprising apertures formed in and extending through the links, the method comprising sleeving a pair of hollow pins into a pair of respective apertures of corresponding diameter in a joiner link, passing a pair of relatively narrower diameter pins through side walls of the cutter link and into an axial hole of a respective one the pair of hollow pins.

[0037] The method may further comprise welding or riveting at least one of the pins to the joiner links and the cutter links.

[0038] According to a yet further aspect of the invention, there is provided a woodcutting chainsaw chain comprising a plurality of links in the form of joiner links and cutter links connected by vertically-disposed driver links between a cavity formed between side walls of the joiner links and a cavity formed between side walls of the cutter links.

[0039] Suitably, the side walls of one or more of the joiner links and/or the side walls of one or more of the cutter links are joined to at least one respective top wall.

[0040] Suitably, the links are connected by one or more pins and one or more of the pins are welded to adjacent links. Alternatively, or additionally, at least some of the links are connected by one or more rivets.

[0041] Suitably, one or more of the pins joining the links of the chain is selected from the following: a cylindrical pin of constant diameter; a stepped pin having two or more different axial diameters; a pin having an axial hole partially or fully therethrough; a pin being asymmetrical about a longitudinal axis.

[0042] According to a yet further aspect of the invention, there is provided a machine comprising the aforementioned chainsaw chain and/or one or more of the aforementioned cutter links.

[0043] Suitably, the machine can be one of the following: a mechanised wood harvester; a mechanised wood processor; a mechanised chainsaw; a handheld chainsaw. [0044] Further forms and/or features of the present invention will become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is an isometric view of an assembled segment of a prior art chainsaw chain.

[0046] Figure 2 is an exploded isometric view of the chainsaw chain segment of Figure 1.

[0047] Figure 3 is a sectional view of the chainsaw chain segment of Figure 1 along Section line A-A of Figure 1.

[0048] Figures 3 to 12A inclusive are views of a first embodiment of the invention.

[0049] Figure 4 is an isometric assembly view of a segment of a chain in one embodiment of the invention when mounted into a corresponding part of a chainsaw guide bar channel.

[0050] Figure 5 is an exploded view of the assembled chainsaw chain segment shown in Figure 4.

[0051] Figure 6 is an isometric view of a joiner link of the chain segment shown in

Figure 4.

[0052] Figure 6A is a profile or end view of the joiner link of Figure 6.

[0053] Figure 7 is an isometric view of a flat-topped cutter link of the invention as shown in Figure 4.

[0054] Figure 7 A is a profile or end view of the flat-topped cutter link of Figure 7. [0055] Figure 8 is an isometric view of an angled/raised-top cutter link of the assembled segment of Figure 3.

[0056] Figure 8A is profile or end view of the angled/raised-top cutter link of Figure

8.

[0057] Figure 9 is an isometric view of a driver link of Figures 4 and 5.

[0058] Figure 9 A shows the link of Figure 9 in profile.

[0059] Figure 10 is an end view of one embodiment of a pin.

[0060] Figure 10A is a side view of the pin of Figure 7.

[0061] Figure 11 is an elevation of a complete chainsaw guide bar, part of which is shown in Figure 4.

[0062] Figure 11 A is a partial section view of the guide bar of Figure 11 along line B-

B.

[0063] Figure 12 is a side view on a reduced scale of the assembly of Figure 4 with

Section line C-C for Figure 12A.

[0064] Figure 12A is an enlarged scale section view along line C-C of Figure 12.

[0065] Figures 13 to 22 are views of another or second embodiment of the saw chain of the invention.

[0066] Figure 13 shows an exploded view of driver links, joiner links and pins of an assembled chain segment shown in Figure 14.

[0067] Figure 14 is an isometric view of a partially assembled chain segment comprising the driver links, joiner links and pins of Figure 13 prior to installation of cutter links. [0068] Figure 15 is an exploded view of the chain segment of Figure 14 showing cutter links and pins in position prior to installation.

[0069] Figure 16 is an isometric view of all the components of Figure 15 assembled into the chain segment.

[0070] Figure 17 is an isometric view of all the components of Figures 13 to 16 assembled into a chain segment and in-situ with respect to a chainsaw guide bar.

[0071] Figure 18 is a side view on a reduced scale of the components of Figures 13 to

17 with Section lines D-D and E-E for Figures 19 and 20.

[0072] Figure 19 is a Section along the line D-D of Figure 18.

[0073] Figure 20 is a Section along the line E-E of Figure 18.

[0074] Figure 21 is an isometric view of a further modified flat-top cutter link with an inwardly-curved bottom edge and depth gauges formed with outwardly flared upper portions.

[0075] Figure 22 is a profile view of the cutter link of Figure 21.

[0076] Figure 23 is an isometric view of a further modified angled/raised-top cutter link omitting depth gauges and comprising an inwardly-curved bottom edge.

[0077] Figure 24 is a profile view of the cutter link of Figure 23.

[0078] Figure 25 is an isometric view of a further modification of the second embodiment of the invention and shows a rounded-top cutter link comprising off-set height gauges and a sidewall with a curved bottom edge.

[0079] Figure 26 is an end view of the rounded-top cutter link of Figure 25. [0080] Figure 27 is an isometric view of another embodiment of a flat-top cutter link of the invention comprising curved bottom edges and split into two sections along an axial centreline.

[0081] Figure 28 is an end or profile view of the cutter link of Figure 27.

[0082] Figure 29 is an isometric view of another embodiment of a split- section flat- top cutter link split into a tongue and groove configuration and comprising curved bottom edges and depth gauges.

[0083] Figures 30 is an end or profile view of the cutter link of Figure 29.

[0084] Figure 31 is an isometric exploded view of the two-piece flat-top cutter link shown in Figures 29 and 30.

[0085] Figure 32 is an isometric view of a pre-formed or post-formed pin or rivet with a stepped diameter and without an axial hole.

[0086] Figure 33 is an isometric view of a different embodiment of a stepped- diameter, pre-formed or post-formed pin or rivet without an axial hole.

[0087] Figure 34 is an isometric view of a pre-formed or post-formed pin or rivet of stepped diameter of similar configuration to that of Figure 32, but with a central axial hole.

[0088] Figure 35 is an isometric view of a similar embodiment of pin/rivet to that of

Figure 33, but which is provided with an axial hole.

[0089] Figure 36 is an isometric view of a different embodiment of pin/rivet which is of the roll pin type.

[0090] Figures 37 to 40 are views of another or third embodiment of the saw chain of the invention. [0091] Figure 37 shows an exploded view of driver links, joiner links and pins of a chain segment.

[0092] Figure 38 is an isometric view of a partially assembled chain segment comprising the driver links, joiner links and pins of Figure 37 prior to installation of cutter links.

[0093] Figure 39 is an exploded view of assembled components of Figure 40 and shows cutter links, depth gauge links and pins prior to installation onto the pre-assembly of Figure 38.

[0094] Figure 40 is an isometric view of all the components of Figure 39 assembled into a chain segment.

[0095] Figures 41 to 44 are views of another or fourth embodiment of the saw chain of the invention.

[0096] Figure 41 is an exploded view of assembled components of Figure 42 also showing cutter links, depth gauge links, additional side plates and pins prior to installation onto the pre-assembly of Figure 42.

[0097] Figure 42 is an isometric view of all the components of Figure 41 assembled into a chain segment.

[0098] Figure 43 is a side view on a reduced scale of the components of Figures 41 and 39 with Section line F-F for Figure 44.

[0099] Figure 44 is a section along the line F-F of Figure 43.

[0100] Figures 45 to 47 are profile views of alternative cutter links.

[0101] Figures 48 to 50 are views of another or fifth embodiment of the saw chain of the invention. [0102] Figure 48 is an isometric view of all the components of Figure 50 assembled into a chain segment.

[0103] Figure 49 is a side view on a reduced scale of the components of Figures 50 with Section line G-G for Figure 49A.

[0104] Figure 49A is a section along the line G-G of Figure 49.

[0105] Figure 50 is an exploded view of assembled components of Figure 48 showing cutter links, side plates, driver links and pins prior to installation onto the assembly of Figure 48.

[0106] Figures 51 to 54 are views of another or sixth embodiment of the saw chain of the invention.

[0107] Figure 51 is an isometric view of all the components of the sixth embodiment assembled into a chain segment.

[0108] Figure 52 is a side view on a reduced scale of the components of Figures 51 with Section lines H-H and J-J for Figures 53 and 54.

[0109] Figure 53 is a section along the line H-H of Figure 52.

[0110] Figure 54 is a section along the line J-J of Figure 52.

[0111] Figures 55 to 58 are views of another or seventh embodiment of the saw chain of the invention.

[0112] Figure 55 is an isometric view of all the components of the seventh embodiment assembled into a chain segment.

[0113] Figure 56 is a side view on a reduced scale of the components of Figures 55 with Section lines K-K and L-L for Figures 57 and 58. [0114] Figure 57 is a section along the line K-K of Figure 56.

[0115] Figure 58 is a section along the line L-L of Figure 56.

[0116] Figures 59 to 61 are views of another or eighth embodiment of the saw chain of the invention.

[0117] Figure 59 is an isometric view of all the components of the eighth embodiment assembled into a chain segment.

[0118] Figure 60 is a side view on a reduced scale of the components of Figures 59 with Section line M-M for Figure 60A.

[0119] Figure 60A is a section along the line M-M of Figure 60.

[0120] Figure 61 is an exploded view of the assembled components of Figure 59 showing cutter links, side plates, driver link and stepped pins prior to installation onto the assembly of Figure 59.

[0121] Figures 62 to 66 are isometric views of different embodiments of pins.

[0122] Skilled addressees will appreciate that elements in the drawings are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the relative dimensions of some of the elements in the drawings may be distorted to help improve understanding of embodiments of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0123] Referring to the accompanying drawings and to the first embodiment of the invention shown in Figures 4 to 12A, in Figure 4 there is shown in a modular construction a segment of a chain of a wood-cutting chainsaw of the type used for tree harvesting. The segment comprises a basic building unit of four links joined end-to-end comprising, when viewing from left to right; two identical joiner links 100, a flat-top cutter link 200 (also featured enlarged and described in more detail in relation Figure 7 and 7A), and an angled/raised-top cutter link 300 (also featured enlarged and described in more detail in relation to Figures 8 and 8A). When assembled and placed end-to-end in abutment, respective ends of any two of these links 100, 200, 300 are joined by inserting pins 500 through respective pin holes formed in each of four links 100, 200, 300, as shown in Figure 5, and in each of three, walled-type driver links 400. Driver links 400 are adapted to be interposed between and within the walls of adjacent joiner links 100 and/or cutter links 200 and to be fastened thereto by pins passed through link joining pin holes formed in all links. The pins are then welded to the joiner links 100 and/or the cutter links 200, 300 whilst permitting relative movement of the driver links 400 thus allowing the chain to move around the guide bar 600.

[0124] At the bottom of Figure 5 there is shown a plurality of identical joining pins

500. Pins 500 are adapted to be passed through corresponding pin holes of the links, such as pin holes 424, 425 of driver link 400 shown in Figure 9. Pins 500 are fastened to links by welding the pins thereto after being interposed between and to extend partway alongside walls of any two of the above-mentioned joiner links 100 or cutter links 200 when disposed end-to- end with edges of side walls in abutment and with pairs of side wall pin holes thereof in alignment with corresponding pin hole pairs of driver links 400. Each of the four respective chain links 100, 200, 300 shown in Figures 4 to 8 have a top wall joined to side walls and have open ends. Side walls have straight bottom edges adapted to lie upon, and be supported by and to slide along a respective one of two-spaced apart guide bar rails 611 and 612 formed on either side of a slot or groove 613 of the chainsaw guide bar 600 shown in Figures 11 and 11 A. The driver link 400 also rests on the guide bar rails 611, 612 of guide bar 600. A dependent bottom section 412 of each walled driver link 400 (see Figure 9 A) also rests upon the guide bar rails 611 and 612.

[0125] In Figure 5 there is also shown an arrangement of links and parts which are separated and spatially-aligned and which include the same sets of four chain links shown in Figure 1. In a similar manner there is shown in Figure 5 a plurality of identical walled driver links 400 for fitment within and to bridge the joiner links 100 and cutter links 200. In Figure 5 there is also shown a plurality of eight separated, identical, cylindrically- shaped link-joining pins 500. In association with a respective walled driver link 400, one pair of adjacent pins is used to join any two adjacent links. Two adjacent pins of a pair of pins are used to respectively fasten two adjacent links via a driver link 400 placed therebetween and inserting each pin through correspondingly-aligned pin holes formed in all of the links including an associated driver link 400 placed therebetween. Pins 500 are respectively adapted to be aligned with respective pin holes 424 and 425 extending through the side walls of drive link 400 and holes 124, 125 in joiner link 100 (shown in Figure 6) and passed through the holes. When each link has been fitted during fabrication of the chain, a pair of pins extends between the two opposite side walls of each individual link while at the same time extending through adjoining links, for example through flat-topped cutter link 200 and raised-top (angle-top) cutter link 300.

[0126] Figure 11 shows a complete chainsaw guide bar 600 as in Figure 4 and also referred to later on in Figures 11 A, 12, 12A, 17 to 20 and 43 to 44.

[0127] In Figure 6 and 6A, each joiner link 100 is provided with a top section 113. A pair of pin/rivet holes 124, 125 is formed in each side wall 111, 112 of the joiner link 100.

[0128] Referring now to Figures 7 and 7A, the flat-topped cutter link 200 has side walls 211, 212 and a closed flat top 217. The side walls extend upwardly and extend outwardly beyond the vertical plane of side walls 211, 212 to form an overhung structure in relation to the side walls which are bridged by the flat top 217 to form a hollow open- bottomed pentagonal structure forming a wood chip segment-forming void. The top structure of the raised or angled top cutter link 200 is formed by multiple folds into a plurality of panel faces to achieve a multi-faceted structure. As shown by Figures 4 and 4 A, the five faces 213, 214, 215, 216 and 217 are all mutually disposed at an angle and form a convex roof of the raised-top cutter link 200. Each panelled face of the cutter link top may have a sharp cutting leading edge and preferably at least three of the leading edges 218, 219, 220 are cutting edges. The above-described five panels or faces form a pentagonal- shaped void 221 which is a structure designed to form and hold cut wood chip segments and carry the wood chip segments along and discharge them with minimum waste.

[0129] As also shown in Figure 7, a pair of depth gauges 222, 223 are formed as leading edge pronged portions or vertical projections extending upwards co-planar to side walls 211, 212 of each flat-top cutter link 200. A pair of pin/rivet holes 224, 225 is formed in each side wall of the flat-topped cutter link. [0130] Referring now to Figures 8 and 8 A of the drawings, the angled/raised-top cutter link 300 shown therein has the angled top formed by two folded half panels 311, 312 mutually-disposed at 45 degrees to form an apex. The lower edge of each of the half panels of the angled top is folded to form a respective vertically-disposed intermediated panel 313, 314. One or more cutting edges 315 are formed on leading edges of the overhung structure. A cut wood chip segment forming and holding void 316 is formed within the enclosed panelled top structure. A pair of pin/rivet holes 324, 325 is formed in each side wall 326, 327 of the angled top cutter link 300.

[0131] In Figures 9 and 9 A, each drive link 400 is provided with a raised bearing contact member 412 and a lubrication channel 413.

[0132] In the end view shown in Figure 11A, the guide bar 600 is provided with a drive link-receiving groove 613, which terminates in a pair of shoulders forming shelves 611,

612 upon which there is adapted to rest, the bottom edges of side walls of each of the four links 100, 200, 300 and driver link 400.

[0133] The vertical section of the assembled chain of the invention shown in Figure

12A shows a flat-topped cutter link 200 of the invention and which is fastened to one of the plurality of driver links 400 (also shown separately in Figures 5 and 9 of the drawings). The two bottom edges of each of the side walls 211, 212 of flat-topped cutter link 200, rest slidably upon a respective guide bar rail 611, 612 formed by the flat top edge of each side wall 610 of the guide bar 600. Walls 610 define the longitudinally-extending central groove

613 of rectangular section adapted to receive and hold a complementary-shaped, flat lower and downwardly-dependent bottom portion 411 of each driver link 400, the bottom portion 411 of one such driver link being shown in section in Figure 12A.

[0134] Referring to the second embodiment of the chainsaw chain of the invention illustrated in Figures 13 to 22, and more specifically from Figures 13 to 15 and 18 to 20, there is shown an alternative method of manufacturing a chainsaw chain according to the invention. The alternative method comprises assembling chain segments, each segment formed by assembling together four identical joiner links onto the flat-faced driver links 450 placed vertically and extending partly between four pairs of the identical side plates 150 shown in Figure 13 and joining all these links together by passing pins 550 thereinto and welding the links together to obtain the chain segment structure shown in Figure 14.

[0135] Referring to Figure 15, after the initial assembly step up to Figure 14, a pair of cutter links comprising flat- topped cutter link 250 and raised/angled to cutter link 350 both shown placed in a ready-for- final-assembly position above the chain joiner link and driver link structure, each cutter link is then lapped over and fixed to a respective joiner link by passing a longer length and narrower-diameter pin 560 first through a respective one of two pin holes of corresponding diameter formed in and extending through the side walls of each cutter link 250, 350 and then repeating the step by passing a second long pin through corresponding aligned holes of the respective cutter link, driver link and joiner link side plates.

[0136] With reference to Figures 21 and 22, each cutter link 250, 350 of the second embodiment has also been modified by having its planar depth gauges formed with outwardly flared upper portions 222a and 223a.

[0137] Another modification of the invention is that in the construction of the second embodiment, all of the walled driver links 400 of the first embodiment are now replaced by planar driver links 450, i.e. flat faced driver links, as shown more clearly and separately in Figures 10, 16 and 17.

[0138] Referring to the second and further embodiments of the invention shown in

Figures 13 to 22, there is shown a sub-assembly of part of a chainsaw chain the structure of which is modified with respect to the embodiment shown in Figures 4 to 12A, but still in association with the same guide bar 600, but with cutter links having modified depth gauges and two-piece joiner links.

[0139] Figure 13 shows separate components used for fabricating and assembling the intermediate saw chain segment structure of Figure 14, prior to fixture thereon of two cutter links 250, 350, as shown in Figures 15 and 18. The components of Figure 13 comprise four pairs of identical side plates 150 forming joiner links, each of which being provided with a pair of pin/rivet joining holes 154, 155. Four driver links 450 are provided with a pair of pin/rivet holes. Each driver link 450 is adapted to be vertically sandwiched between the side plates 150 forming the joiner links and thereafter all joined laterally by passing therethrough eight hollow, wide diameter pins/rivets 550 and thereafter welding pins/rivets 550 to the links to obtain the structure shown in Figure 14. Both the flat-top cutter link 250 and the raised top cutter link 350 have been modified by having off-set depth gauges 222, 223, 322, 323 respectively. Two-piece joiner links are formed by joining a pair of identical side plates 150 by welding pins or rivets 550 after assembling a chain and then placing it into a guide channel 613 of the same type of chainsaw guide bar 600 as in the first embodiment of the invention.

[0140] In the second embodiment of the invention further illustrated in Figure 15, four identical joiner links 150 are joined end to end by vertically disposed drive links 450 interposed between ends of the joiner links 150. Each respective cutter link, comprising flattop cutter link 250 and raised or convexly-angled cutter link 350, is positioned over and in vertical alignment with a respective joiner link 150 after the joiner link has been joined to a respective adjacent flat-faced driver link 450 during a saw chain assembly step. The flat-top cutter link 250 is over the joiner link 150 to straddle the link which has been pre-assembled with other and adjacent joiner links and with driver links 450 interposed therebetween to form a partial segment of a chain. The flat-topped cutter link 250 has a pair of fastening pins holes formed therein which is adapted to align with a corresponding pair of pin holes in a joiner link 150 thereby enabling a pair of longer-length and relatively thin or relatively-narrower- diameter pins 560 to first pass through the side walls of the flat-top cutter link 250 and then into the axial hole of one of each of one of a pair respective and relatively wider-diameter pins 550 previously sleeved into a hole of corresponding diameter in a joiner link 150. Thereafter, the pins are welded to the links, and the procedure is repeated with the raised-top cutter link 350 to form the assembly of the chain segment shown in Figure 16.

[0141] It will be further noted that the structure of the flat- top cutter link 250 of the second embodiment, as shown in Figures 15 to 22, is modified by having inwardly-curved side wall bottom edges 251.

[0142] Figure 18 shows a side view on a reduced scale of an assembled chain segment of the second embodiment of the invention positioned on guide bar 600 and in relation to the Sections D-D of Figures 19 and E-E of Figure 20. Figure 19 shows a drive link 450 pinned between a pair of identical side plates 150a, 150b which are joined together by a wide- diameter, hollow roll pin 550 to form the joiner link 150. The bottom edge of each side plate is in slidable contact with a respective edge or rail of the guide bar 600. The lower portion of the driver link 450 is slidably housed within the central groove 613 of the guide bar 600. The Section E-E of Figure 20 is taken through a flat-top cutter link 250 of Figure 18 and further includes a narrower-diameter, longer, solid pin 560 passed into the wider-diameter, hollow pin 550 to join the flat-top cutter link 250 to the joiner link 150, and also to the drive link 450.

[0143] Figures 23 and 24 illustrate a further modified angled/raised-top cutter link 650 omitting depth gauges 222, 223, 222a, 223a of previously described embodiments and having sidewalls comprising an inwardly-curved bottom edge 226.

[0144] Figures 25 and 26 illustrate a yet further modification of the second embodiment of the cutter link and shows a cutter link 750 comprising a rounded top 752, offset height gauges 754, 756 and sidewalls comprising a curved bottom edge 226.

[0145] Figures 27 and 28 illustrate another embodiment of a flat-top cutter link 850 having sidewalls comprising curved bottom edges 226, a flat top 852 and depth gauges wherein the cutter link 850 is split into two sections along an axial centreline 854.

[0146] Figures 29 and 30 illustrate another embodiment of a split-section flat-top cutter link 950 having sidewalls comprising curved bottom edges 226, a flat top 952 and depth gauges wherein the flat top 952 is split into a tongue and groove configuration. Figure 31 is an isometric exploded view of the two-piece, flat-top cutter link 950 shown in Figures 29 and 30.

[0147] Figure 32 illustrates a pre-formed or post-formed pin or rivet 500A with a stepped or increased diameter 502 about a central region of the pin and without an axial hole.

[0148] Figure 33 illustrates a different embodiment of a stepped diameter, pre-formed or post-formed pin or rivet 500B without an axial hole. In this embodiment, pin 500B comprises a central stepped or increased diameter 502 and a stepped or increased diameter 504 at each end of the pin. The increased diameter regions 504 are thinner than the central stepped or increased diameter region 502 and comprise a tapered diameter portion 506.

[0149] Figure 34 shows a pre-formed or post-formed pin or rivet 500C having a stepped or increased diameter 502 of similar configuration to that of Figure 32, but with a central axial hole 508.

[0150] Figure 35 shows a similar embodiment of pin/rivet to that of Figure 33, but pin/rivet 500D is provided with a central axial hole 508.

[0151] Figure 36 illustrates a different embodiment of pin/rivet 500E which is of the roll pin type having a central axial hole 508.

[0152] Reference is now made to Figures 37 to 47 and yet further embodiments of the present invention.

[0153] In Figures 37 to 443 the driver link 460 has been modified by the addition of a protrusion 465. The protrusion of each driver link abuts an adjacent driver link.

[0154] In Figures 39 to 44 the depth gauge link 760 is a separate link from the angled/raised-top cutter link 360 and the flat- topped cutter link 260 is separate from the depth gauge link 760. Both the flat-topped cutter link 260 and the angled/raised-top cutter link 360 omit the depth gauges.

[0155] In Figures 37 to 44 the joiner link 160 has been modified by the addition of a notch 161 to the bottom edge of each side plate.

[0156] In Figures 43 and 44 an additional joiner link 170 has been added.

[0157] Figure 43 shows a side view on a reduced scale of an assembled chain segment of the fourth embodiment of the invention positioned on guide bar 600 and in relation to the Section F-F of Figure 44. Figure 44 shows a driver link 460 pinned between a pair of identical side plates 160a, 160b which are joined together by a wider-diameter, hollow roll pin 550 to form the joiner link. The bottom edge of each side plate is in slidable contact with a respective edge or rail of the guide bar 600. The Section F-F of Figure 43 is taken through a joiner link 170 of Figure 43 and illustrates a narrower diameter, longer, solid pin 570 passed into the wider-diameter hollow pin 550 to join the side plates 170a, 170b.

[0158] The alternative cutter link 360A shown in Figure 45 comprises a profile that is symmetrical about a centreline. The enclosed top portion of cutter link 360A is formed from two folded top walls or panels 311, 312 folded about the centreline and sloping from the side walls to the centreline to form a v-shaped trough. The alternative cutter links 360B, 360C shown in Figures 46 and 47 comprise a profile that is asymmetrical about a centreline. Cutter link 360B has an enclosed top portion that slopes from one side wall to the other sidewalk The enclosed top portion of cutter link 360C is formed from two folded top walls or panels 311, 312 folded about the centreline such that top wall or panel 311 is flat from one of the sidewalls to the centreline and top wall or panel 311 slopes from centreline to the other side wall. The alternative cutter links of Figures 45 to 47 are nonetheless chip-forming cutter links formed with cutting edges of a closed configuration which form a central swarf-holding cavity.

[0159] Reference is now made to Figures 48 to 50 and further embodiments of the present invention. Figures 48 to 50 illustrate a chain segment comprising conventional left cutter links 12, right cutter links 14, driver links 22, joiner links 26 comprising pairs of side plates 28 that move along guide bar 20. However, in accordance with the further embodiments of the present invention, one or more of the pins 500 passing through apertures 24 in driver links, cutter links 12, 14 and side plates 28 are welded to one or more of the adjacent links through which the pins pass. Apertures 24 in the links are of a larger diameter than the conventional apertures to suit the welded pins.

[0160] Reference is now made to Figures 51 to 54 and yet further embodiments of the present invention. Figures 51 to 54 illustrate a chain segment comprising conventional left cutter links 12, right cutter links 14, driver links 450, joiner links 26 comprising pairs of side plates 150 that move along guide bar 600. However, in accordance with the further embodiments of the present invention, hollow pins 550 are sleeved through apertures in identical side plates 150a, 150b and driver link 450 sandwiched between the side plates 150a, 150b. Left cutter link 12 is fixed to a respective side plate 150b of the joiner link 26 by passing a longer length and narrower-diameter rivet/pin 560 through the hollow pin 550 and through an aperture in the cutter link 12. Right cutter link 14 is attached in the same manner on the other side of another joiner link. Apertures in the cutter links for allowing rivet pins therethrough are smaller than the apertures in the cutter links required for pins that are welded.

[0161] Reference is now made to Figures 55 to 58 and further embodiments of the present invention. Figures 55 to 58 illustrate a chain segment comprising conventional left cutter links 12, right cutter links 14, driver links 450, joiner links 26 comprising pairs of side plates 150 that move along guide bar 600 and hollow pins 550 and longer length and narrower-diameter pin 560, as described in relation to the embodiments of Figures 51 to 54. However, in this embodiment, pin 560 is welded to one or more of the adjacent links through which the pin 560 passes.

[0162] Reference is now made to Figures 59 to 61 and yet further embodiments of the present invention. Figures 59 to 61 illustrate a chain segment comprising conventional left cutter links 12, right cutter links 14, driver links 22, joiner links 26 comprising pairs of side plates 28 that move along guide bar 20. In this embodiment, a stepped pin 500A (as shown in Figure 32) comprising a stepped or increased diameter 502 about a central region of the pin is passed through an aperture 24 in driver link 22. One end of the stepped pin 500A is passed through a side plate 26 with a smaller diameter hole than the aperture 24 in the driver link 22 on one side and the other end of the stepped pin 500A is passed through an aperture in left cutter link 12, also of smaller diameter than the aperture 24 in the driver link 22. Stepped pin 500A is then welded to one or more of the adjacent links through which the stepped pin 500A passes.

[0163] Figures 62 to 66 illustrate further embodiments of some of the pins that can be used in some embodiments of the present invention. Such pins can comprise a plurality of steps or regions of differing diameters, which can occupy different lengths of the pin, depending on the thickness and size of the links and the diameter of the apertures to be accommodated. As shown in Figure 62, pin 500F comprises three regions 510, 512, 514 of different diameter. A first region 510 at one end is of the narrowest diameter, a central or second region 512 is of an intermediate diameter and a third region 514 at an opposite end is of the largest diameter. Figure 63 illustrates another embodiment of a pin 500G comprising a first region 516 of a smaller diameter and a second region 518 of a larger diameter, wherein the smaller diameter occupies approximately 75% of the length of the pin 500G. With reference to Figure 64, pin 500H comprises a first region 510 at one end of the narrowest diameter, a central or second region 502 of the largest diameter and a third region 520 at an opposite end of an intermediate diameter. Figure 65 shows a pin 500J comprising a first region 510 at one end of the narrowest diameter and a second region 522 of a larger diameter, wherein the larger diameter region 522 occupies approximately 66% of the length of the pin 500J. With reference to Figure 66, some pins are not symmetrical about their longitudinal axis. For example, pin 500K comprises a central region 502 of increased diameter (compared with smaller diameter regions 510 on either side) which comprises a helical groove or channel 524 for communicating lubrication, such as oil, to the links of the chainsaw.

[0164] Although not shown in Figures 62 to 66, it will be appreciated that any of the embodiments of the pins 500F - 500K can comprise an axial hole extending partially or fully therethrough. Skilled addressees will also envisage further variations to the pins described herein as may be required or desirable for particular link configurations and combinations, such as chamfers, fillets, dimples or axial holes having a different geometry. The pins can be integrally formed or formed from multiple parts.

[0165] Hence, according to embodiments of the present invention, one, a plurality, or all of the pins in the chain can be welded to the overlapping and/or adjacent links. The pins can be welded on one side or on both sides of the chain. As a further variation of the methods of making a chainsaw chain according to the invention, the links may be assembled and joined using any combination of welding and/or riveting.

[0166] Hence, embodiments of the present invention address or at least ameliorate one or more of the aforementioned problems of the prior art. In the embodiments in which one, a plurality, or all of the pins in the chain are welded to the overlapping and/or adjacent links, the pin is no longer required to be so small in the riveting section. As the pin is welded into the chain, the diameter of the pin no longer causes a corresponding weakness in the side plates of the chain. As the chain wears, the reduction of material in that section is no longer critical to the strength of the chain. There is consequently increased wear resistance of the links, longer life of the chain and reduced risk of chain breakage and chain shot. The cutter links according to some embodiments of the present invention and chains comprising such links provide a symmetrical loading on a chainsaw chain. For at least some of the embodiments, cutting requires less power because of the more symmetrical loading. There is also increased strength of the cutting link assembly, more efficient discharge the swarf and a smoother-cut log surface is achieved resulting in less wastage of wood from logs.

[0167] In this specification, the terms "comprises", "comprising" or similar terms are intended to mean a non-exclusive inclusion, such that an apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.

[0168] Reference in this specification to any prior publication (or information derived from it) or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that the prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

[0169] Whilst the foregoing description is of particular embodiments and methods of manufacturing the invention, it will be understood by persons skilled in this particular technology that variations, modifications, substitutions and additions may be made without departing from the scope of this invention as defined by the attached claims.

Claims

1. A wood-cutting chainsaw chain comprising a plurality of links disposed along a longitudinal centreline of the chain, wherein each of the links comprises a pair of apertures to join each link to an overlapping and/or adjacent link by pins passed through the overlapping and/or adjacent links, wherein at least one of the pins is welded to the overlapping and/or adjacent links.

2. The chain of claim 1, wherein all of the pins are welded to the overlapping and/or adjacent links.

3. The chain of claim 1 or 2, wherein exposed ends of the pins are welded to the overlapping and/or adjacent links on one or both sides of the chain.

4. The chain of any preceding claim, wherein the plurality of links comprise joiner links and cutter links connected by vertically-disposed driver links between a cavity formed between side walls of the joiner links and a cavity formed between side walls of the cutter links.

5. The chain of claim 4, wherein the side walls of one or more of the joiner links and/or the side walls of one or more of the cutter links are joined to at least one respective top wall.

6. The chain of claim 5, wherein the respective top wall of each cutter link extends above a level of a respective top wall of the joiner links.

7. The chain of claim 5 or 6, wherein at least one of the cutter links comprises side walls having laterally overhung top portions which extend above a height of the joiner links.

8. The chain of any one of claims 4 to 8 wherein the side walls of the cutter links have a greater internal separation than an external width of each joiner link, each cutter link being adapted to be placed over a joiner link.

9. The chain of any one of claims 4 to 8, wherein one or more of the driver links comprises a protrusion abutting an adjacent driver link.

10. The chain of any preceding claims comprising a depth gauge formed on a separate link from a cutter link.

11. The chain of any preceding claim comprising one or more of the cutter links as claimed in any one of claims 12 to 19.

12. A cutter link for a wood-cutting chainsaw chain, the cutter link comprising a pair of side walls joined to an enclosed top portion formed from at least one top wall.

13. The cutter link of claim 9, wherein the enclosed top portion is formed into an enclosed chamber having a cutting edge surrounding a void or throat leading into the chamber for formation, holding and discharging a wood waste chip.

14. The cutter link of claim 9 or 10, wherein the enclosed top portion comprises a plurality of folded panels formed by pairs of outwardly angled lower panels on one side and pairs of inwardly-angled upper panels joined on the other side, the top edge of both upper panels being connected to the at least one top wall.

15. The cutter link of claim 9, 10 or 11, wherein the at least one top wall is flat, raised or angled.

16. The cutter link of claim 12, wherein the at least one raised or angled top wall is symmetrical or asymmetrical about a centreline of the cutter link.

17. The cutter link of any one of claims 9 to 13, further comprising a depth gauge extending upwards from each side wall of the cutter link, wherein one or more of the depth gauges: comprises an outwardly flared upper portion; are offset.

18. The cutter link of any one of claims 9 to 14, wherein a bottom edge of each side wall of the cutter link is inwardly curved.

19. The cutter link of any one of claims 9 to 13, wherein the cutter links are adapted to be placed over chain segments comprising a plurality of joiner links joined by driver links.

20. The chain of any one of claims 1 to 11, or the cutter link of any one of claims 12 to 19, wherein one or more of the links are formed in one piece.

21. The chain of any one of claims 1 to 11 or 20, wherein the chain is in the form of one of the following: a length of chain comprising two free ends; an endless loop.

22. A wood-cutting chainsaw chain comprising one or more of the cutter links as claimed in any one of claims 12 to 19.

23. A method of making a chainsaw chain comprising a plurality of links, each link comprising apertures formed in and extending through the links, the method comprising joining overlapping and/or adjacent links by passing pins through the correspondingly-aligned apertures and welding one or more of the pins to the respective links.

24. A method of making a chainsaw chain comprising a plurality of links, including one or more cutter links as claimed in any one of claims 12 to 19, each link comprising apertures formed in and extending through the links, the method comprising joining overlapping and/or adjacent links by passing rivets through the correspondingly- aligned apertures.

25. The method of claim 23 or 24, wherein the plurality of links include at least one joiner link, cutter link and driver link, the method comprising passing a pair of pins through a single wall of the driver link fitted between joiner links and/or cutter links so that a pair of pins extends between two opposite side walls of each joiner link and cutter link while at the same time extending through longitudinally- adjoining driver links.

26. The method of claim 24 or 25, comprising positioning at least one of the cutter links above and in vertical alignment with one of the joiner links after the joiner link has been joined to adjacent driver links such that the cutter link lies over the joiner link to straddle the joiner link.

27. The method claim 26, further comprising sleeving a pair of hollow pins into a pair of respective apertures of corresponding diameter in a joiner link, passing a pair of relatively narrower diameter pins through side walls of the cutter link and into an axial hole of a respective one the pair of hollow pins, and welding at least one of the pins to the joiner links and the cutter links.

28. A method of making a chainsaw chain comprising at least one joiner link, cutter link and driver link, each link comprising apertures formed in and extending through the links, the method comprising sleeving a pair of hollow pins into a pair of respective apertures of corresponding diameter in a joiner link, passing a pair of relatively narrower diameter pins through side walls of the cutter link and into an axial hole of a respective one the pair of hollow pins.

29. The method of claim 28, further comprising welding or riveting at least one of the pins to the joiner links and the cutter links.

30. A wood-cutting chainsaw chain comprising a plurality of links in the form of joiner links and cutter links connected by vertically-disposed driver links between a cavity formed between side walls of the joiner links and a cavity formed between side walls of the cutter links.

31. The chain of claim 30, wherein the side walls of one or more of the joiner links and/or the side walls of one or more of the cutter links are joined to at least one respective top wall.

32. The chain of claim 30 or 31, wherein the links are connected by one or more pins and one or more of the pins are welded to adjacent links.

33. The chain of claim 30, 31 or 32 wherein the links are connected by one or more rivets.

34. The chain as claimed in any one of claims 1 to 11, 20 to 22 or 30 to 33, the cutter link as claimed in any one of claims 12 to 19 and/or the method as claimed in any one of claims 23 to 29, wherein one or more of the pins joining the links of the chain is selected from the following: a cylindrical pin of constant diameter; a stepped pin having two or more different axial diameters; a pin having an axial hole partially or fully therethrough; a pin being asymmetrical about a longitudinal axis.

35. A machine comprising the chainsaw chain as claimed in any one of claims 1 to 11, 20 to 22 or 30 to 33 and/or the cutter link as claimed in any one of claims 12 to 19.

36. The machine of claim 34 being one of the following: a mechanised wood harvester; a mechanised wood processor; a mechanised chainsaw; a handheld chainsaw.