WO2001023128A1

WO2001023128A1 - Non-lubricated chainsaw blade

Info

Publication number: WO2001023128A1
Application number: PCT/NZ2000/000146
Authority: WO
Inventors: Michael John Kelly
Original assignee: Michael John Kelly
Priority date: 1999-09-28
Filing date: 2000-08-03
Publication date: 2001-04-05
Also published as: AU6326800A

Abstract

A lightweight non-lubricated flexible line (typically stainless steel wire) chainsaw blade driven by rotating pulley means. The blade having spaced cutting members (92) which do not require lubrication during operation and which can also function as gear teeth (100) driven by a drive pulley (98).

Description

TITLE: NON-LUBRICATED CHAINSAW BLADE

FIELD

This invention relates to chainsaw blades in particular but, not exclusively to a chainsaw blade of light-weight construction which is non-lubricated.

BACKGROUND ART

Chainsaws and chainsaw blades are well known. It is a problem of the prior art that although chainsaw blades must be robust enough to perform their designated tasks, such blades are often of heavy construction due to the wear and tear encountered in normal operation which also requires the blade to be constantly lubricated by oil or other lubricants. Depending on the material being sawn, the oil or other lubricants can retain paniculate matter which can act as an abrasive contributing to further wear. Furthermore, heavier blades impose greater loads and demands on the power plant of the chainsaw.

OBJECT OF INVENTION

It is an object of the present invention to seek to alleviate at least one of the above mentioned problems of prior art chainsaws and chainsaw blades or to at least provide the public with a useful choice.

SUMMARY OF THE INVENTION

In one aspect the invention resides in a non-lubricated flexible line chainsaw blade including in combination a base comprising a continuous loop of flexible line, the continuous loop adapted to be driven by rotating pulley means, a plurality of cutting members spaced along the line, the cutting members adapted to saw material, typically timber without requiring lubrication of the line or the cutting members, each cutting member comprising a cutting tip attached to a tip carrier fixed to the line, wherein in operation, timber or other materials can be sawn by moving the cutting members in rapid succession against the material being sawn.

In another aspect the invention resides in a chainsaw including in combination powered drive means adapted to drive a pulley means, said pulley means, comprising a drive pulley and an idler nose pulley co-operating with support roller means and/or friction plate means to support a non-lubricated flexible line chainsaw blade with a cutting tip carrier as herein above described.

Preferably the drive means includes planetary gearing means to increase torque to drive the pulley means.

Preferably the flexible line is a stainless steel marine grade wire or rope of approximately between 2mm and 5mm in diameter.

In another version, the wire consists of two separate wires with their respective joints located on separate tip carriers thereby reducing the stress on a single joint.

In the alternative, the wire consists of a single wire that is looped twice over pulleys of the pulley means.

Preferably the wire is brazed or swaged to the tip carrier or a combination of both methods in a 5mm long joint.

In the alternative the flexible line is of a material of equivalent tensile strength and durability to stainless steel marine grade wire or rope.

Preferably the diameter of the drive pulley and idler nose pulley are such that the wire does not go beyond its U point and work harden.

Preferably the idler nose pulley includes an anti-kickback operation incorporating a groove for the line and spaced circumferential recesses to accommodate the tip carrier and cutting tip at or below the circumference of the pulley. - _> -

In the alternative, the idler nose pulley is a plain roller without recesses to accommodate the tip carrier and cutting tip if the anti-kickback design is incorporated in the tip carrier design.

Preferably support rollers are only one option for supporting the flexible line between pulleys. An alternative option may be to replace the support rollers with a replaceable friction plate or wear strip made of a composite plastic or oζher suitable material.

In the alternative, a hardened steel guide could be used in place of rollers or a wear strip. This option however, would require oil lubrication.

Suitably, the guide bar of the chainsaw can include the use of metals that improve cooling and bearing life by having increased heat dissipation qualities for example copper and/or aluminium or other alloys having similar characteristics.

Preferably the support rollers are 3mm wide, however the pitch and length of the tip carriers and the cutting tips will determine the diameter and spacing of the support rollers.

Preferably the support rollers are made of any suitable material that does not require lubrication and is of a suitable strength. Typically this material can be nylon or other plastics.

Preferably the support rollers are replaceable by means of a snap lock or slide mechanism.

Preferably the cutting members comprise cutting tips of tungsten carbide steel with a hollow cutting face to increase a hook or cutting angle of the cutting tip. Preferably the cutting tip is 7mm long and 3.2mm high with a thickness of 2.5mm.

Preferably the tensile grade of the cutting tip would be matched to the required application for example, having the grading of H40c. K10 or K20.

Preferably the cutting tip is attached by braze material or welded directly to a tip carrier at an angle that provides the best cutting results.

Preferably the angle is 45° however it may be varied depending on the type of operation and material to be sawn. Preferably the cutting tip carrier includes in combination a channel member adapted to straddle a guide bar or support roller assembly of a chainsaw, the channel member including stepped first and second portions, the first portion adapted for mounting a cutting tip, the second portion adapted to provide a non-cutting skid surface to material being sawn, wherein in operation, rotation of the cutting tip carrier over a circular idler nose pulley of the chainsaw causes the second portion to pivot outwardly with respect to the first portion wherein an arc circumscribed by the non-cutting skid surface is marginally greater than the arc circumscribed by the cutting tip as measured from a centre of rotation of the nose pulley and whereby the cutting tip is prevented from catching and kicking-back on the material.

Preferably the tip carrier is fabricated from 1mm thick, 1006 or 1070 grade steel depending on trial experiments.

Preferably the tip carrier is U-shaped but can be any other suitable shape.

Preferably the tip carrier can be formed using a small press of less than 6 ton of pressure.

Preferably the tip carrier is 10mm long and is 5.5mm wide with an initial length of the sides of the tip carrier being 8.25mm.

Preferably the cutting tip is joined to the cutting tip carrier by brazing using resistance brazing technology. Suitably this can be done if the tip carrier is made of AISI 1035 grade or lower carbon steel.

Suitably opposing surfaces of the cutting tip and the tip carrier are prepared and cleaned prior to brazing by resistance brazing technology.

Alternatively if a higher grade carbon steel such as AISI 1055 or AISI 1070 is used then induction brazing is required.

Preferably filler material used in the braze can be applied as a paste or a flux and wire combination.

Preferably the estimated brazing cycle time is 6 seconds per cutting tip or less. Preferably the brazing bond strength will exceed 100 kilograms force under shear application.

Preferably there are four options available to make the joint between the tip carrier to the wire strong enough to resist separation if a hard object is struck which include:

1. a braze joint similar to the cutting tip to tip carrier joint with possibly the addition of a cap over the wire.

2. a swaged joint which would be an option achievable by changing the tip carrier design, and

3. a combination of both the braze and swage methods preferably using a tip carrier with a hole formed for the wire to pass through and be positioned before fixing in place,

4. the brazing of the two- wire option wherein the ends of the wires are joined onto two separate tip carriers.

Preferably all four methods would result in a joint which exceeds 100 kgf under shear force.

Preferably the tip carrier while having the principal function of retaining the cutting tip also has a number of other functions. These functions include:

^• To stabilise the cutting tip during cutting by transferring the loads, side and downward onto support rollers,

• The cutting tip carriers act as driving teeth which are driven by a drive pulley.

• As the flexible line stretches during use, the sides of the cutting tip carrier help to keep the flexible line located along a centre of a guide bar to prevent it from moving off the bar. the length of the tip carrier size need only be long enough to serve this function which again is determined by trial and error.

^• An anti-kick back feature could be incorporated into the shape if required. Preferably the overall width of the cut or kerf is 6mm which is derived from the sum of 5.5mm of the width of the cutting tip carrier plus twice 0.25mm of the cutting tip to side plate clearance.

BRIEF DESCRIPTION OF DRAWINGS

In order to more fully understand the present invention reference will now be made to the accompanying drawings wherein:

Figure 1 is a diagrammatic side view of the present invention, according to Example 1,

Figure 2 is a cross sectional view of part of the embodiment of Figure 1,

Figure 3 is a plan view of part of the embodiment of Figures 1 and 2, and

Figure 4 is a perspective view of a modified tip carrier,

Figure 5 is a side view of an idler nose pulley according to Example 2,

Figure 6 is a perspective view of a cutting tip carrier of an anti-kickback design according to Example 3,

Figure 6a is a plan view of the cutting tip carrier of Figure 6,

Figure 7 shows the operation of the cutting tip carrier of Figure 6,

Figure 8 shows a side view of a chainsaw blade assembly according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

Figure 1 of Example 1 shows a side view of a drive pulley 10, guide bar 12 with support rollers 14. 16, cutting tips 18, 20 and tip carriers 22. 24. The drive pulley has recesses to function as a gear wheel to engage the tip carriers which function as gear teeth. In the preferred embodiment, the cutting tips are joined to the tip carriers by combining current metal join technologies principally associated with brazing. The brazed joint between the cutting tip and a tip carrier both as unprepared surfaces can be achieved by resistance brazing technology. This is normally only possible if the tip carrier is preferably of a AISI 1035 grade or a lower grade of carbon steel. If high grades of carbon steel such as AISI 1055 or AISI 1070 are used then induction brazing technology is normally required. In the brazing operation, the filler material used may be applied as a paste or a flux and wire combination. The estimated brazing cycle time is preferably about 6 seconds or less per cutting tip to tip carrier joining operation.

Preferably the bond strength between the cutting tip and the tip carrier will exceed 100 kgf under shear loading.

Preferably the cutting tips are manufactured from tungsten carbide steel, however traditional high carbon steel may be used for lower priced versions.

Preferably the drive pulley is of a resilient durable plastics material such as nylon, polypropylene or other material suitable for the purposes. Guides can be used to guide the tip carrier on to the drive pulley and bar.

Preferably the guide bar is a rigid flat material to prevent undesirable flexing of the entire blade assembly (not shown), however it can be of the same material as the drive pulley. The guide bar has roller supports 14. 16 for the chainsaw blade wire 26. Importantly, the drive pulley or any other pulleys must be of a suitable radius to prevent any deformation beyond the yield point of the wire 26 of the blade. The pulley preferably has a diameter of between 100mm and 200mm for a wire diameter of between 2mm and 5mm. The support rollers can alternatively be replaced or used in combination with a friction plate or wear strip (both not shown) made of a low friction composite plastics or other suitable material. Preferably the support rollers are 3mm in width with the pitch and length of the tip carrier and the cutting tip determining the roller diameter and spacing of the rollers. Preferably the rollers are made of any suitable material which provides the requisite strength. Materials which are considered preferable include nylon, polypropylene, polyvinylchloride, teflon coated plastics, and plasticised fibre. Preferably the rollers are replaceable items which can be replaced in the field of use by means of a snap lock or slide system if required.

Figure 2 shows a cross sectional view through line A-A of Figure 1. As shown in Figure 2. the tungsten carbide cutting tip 30 is preferably 7mm in length, is 3.2mm in height and 2.5mm thick. For this cutting tip configuration, the guide bar 32 is preferably about 410mm in length. The cutting tip has a hollowed round cutting face to increase the hook or cutting angle of the cutting tip. The grade of the tungsten carbide of the cutting tip will preferably be matched to the type of application, for example, the cutting tip may be H40c or K10 or K20, ETC. or whatever grade is required. The cutting tip 30 is preferably attached by brazing or welding to the tip carrier 34 at a 45° angle, however, other angles which provide better results for different applications may be used. The tip carrier for a nominal 410 long guide bar depending on trial and error is preferably made from 1mm thick, 1006 or 1007 grade steel and is preferably U shaped but can be any other suitable shape and incorporate an anti- kickback feature if required. The preferable dimensions of the tip carrier are 10mm long and more preferably 8.25mm in length with a width of 5.5mm. The tip carrier has the principal function of retaining the cutting tip. The tip carrier preferably has other functions which include:

• Stabilising the cutting tip by transferring any sideways and downwards loads to the support rollers 36:

• Acting as teeth to augment the cutting action of the cutting tips;

• Helping to keep the blade in alignment with the guide bar 32 to reduce any tendency of the blade wire from "jumping off the support rollers and drive pulley assembly. Preferably the length of the sides of the tip carrier need only be long enough to serve this purpose.

^• Preventing kickback if this is required.

For this configuration of the cutting tip and tip carrier, the overall width of the cut or kerf is approximately 6mm. The 6mm is derived from a tip carrier width of 5.5mm with a 0.25mm tip to side plate (not shown) clearance on either side of the tip carrier. Figure 3 shows a top view of a cutting tip 50. tip carrier 52, blade wire 54 and guide bar 56 of the preferred embodiment as described in Figures 1 and 2. The blade wire is preferably 2mm in diameter and can be made from any material which enables a permanent attachment of the tip carrier 52 to the wire 54. In this version, the wire is preferably standard high tensile steel wire of a marine or higher grade.

Preferably the tip carrier is brazed or swaged to the blade wire.

Preferably each tip carrier is formed with a groove (now shown) or with a through bore (not shown) of similar diameter to the blade wire. On assembly the blade wire is threaded through the bores, or laid in the grooves of the tip carriers. With the tip carriers at appropriate spacings along the blade wire each tip carrier is fixed in position by either or both of a swaging and brazing operation. The tips may be secured to the respective tip carriers either in the same or in a subsequent brazing operation.

As illustrated in Figure 4, a central area 58 of the web portion 57 of a tip carrier 56' may be punched out to a U-shape roughly corresponding with the cross section of the wire. The wire 54 may be threaded between the web 57 and the formation 58 and thereafter the formation 58 may be pinched or swaged to the wire to prevent relative movement of the carrier 56' along the wire.

Preferably the wire is joined to form a continuous loop at a tip carrier to provide a joint of 5mm in length. As previously mentioned, the radius of the drive pulley (not shown) or any other end rollers or pulleys (not shown) must be such that the wire is not worked beyond its yield point to result in any work hardening of the wire.

Example 2

Figure 5 shows a side view of an idler pulley 60 with an anti-kickback design according to Example 2.

The idler pulley has spaced circumferential recesses 62 to accommodate the cutting tip 64 and tip carrier 66 and a groove (not shown) to locate the wire 68. As the outer diameter of the pulley is slightly greater, say, in the order of 1.0mm greater than the diameter of the arc circumscribed by the cutting tip, the idler pulley will not catch on the material being cut, thereby affording an anti-kickback feature.

Example 3

Figure 6 is a perspective view of a preferred tip carrier design according to Example 3. The tip carrier 70 has a mounting surface 73 for brazing a cutting tip (not shown) and is stepped to an anti-kickback heel portion 72. the operation of which is described in Figure 7. The deep channel 74 formed by the sides of the tip carrier 76. 78 locates the tip carrier over the support rollers or guide bars (both not shown) preventing the tip carrier from rotating along the direction of the cut.

Figure 6a shows a plan view of the preferred tip carrier 70 wherein there is shown a cutting tip 80 mounted on the mounting surface 73 anti-kickback heel, 72. The tip carrier in this design has been changed to give a larger foot length by making the tip carrier the female part of a drive tooth arrangement. This allows the use of a fewer number of support rollers and possibly eliminates the need for guides at the idler nose pulley.

Figure 7 shows tip carriers 70 of the design according to Figure 6 in operation as they revolve over an idler nose pulley 82. The anti-kickback heel portion 72 rocks outwardly in an arc 86 in the order of a millimetre 88 beyond the arc 84 circumscribed by the cutting tips 80. Any material in the cutting path is brushed by the non-cutting heel portions 72 thereby eliminating the material being caught by the teeth resulting in a dangerous kickback.

Figure 8 shows a side view of a flexible line chainsaw blade assembly 90 according to the invention. The cutting tips 92. are mounted on cutting tip carriers 94 which are connected by means of a flexible wire 96. The cutting tips also function as "gear teeth" which are driven by the drive sprocket 98 shown with spaced recesses 100 adapted to engage the ''gear teeth" of the cutting tip carriers. Also shown are support rollers 102 mounted on the guide bar 104 and an idler nose pulley 60 as described in Figure 5 of Example 2.

ADVANTAGES The advantages of the present invention include a lower manufacturing and sale cost when compared to prior art chainsaw blades;

The lower friction operation and the fact that no lubrication of the blade by oil or other lubricants is necessary, the narrower kerf due to the dispensing with of chainsaw chain links and a chain bar or guide bar which does not have to be fabricated from hardened steel, are further advantages.

In addition, due to the simple and light weight construction of the present invention, more usable power is available for the actual cutting operation from the chainsaw power plant than is available with the use of prior art chainsaw blades which by their nature and use have to be of a robust and heavy construction. The blade of the present invention retains the ability of prior art chainsaw blades to be resharpened with existing automatic sharpening equipment with minor modifications. Where tungsten carbide steel is used, a normal carborundum grinding wheel can be replaced with a diamond grit wheel. It is anticipated that the life span of chainsaw blades of the present invention is largely determined by the degree of stretch of the blade wire and with better materials, could easily outlast any present conventional chainsaw blade.

Tip Carrier

The tip carrier is a key element in the design: it allows the use of wire as a means of interconnecting the cutting tips while enabling cut angles of the cutting tip to be greater than 0 degrees to the direction of the cut for example, square or 90 degrees to the direction of rotation of the cutting blade.

Cutting angles greater than 0 degrees use less power in the cutting action and reduce the load to cut any given amount of material, in particular, wood fibre. The increased angles of, say, 45 degrees create a free cutting action thereby reducing the build up of material on the cutting tip.

The tip carriers prevent the wire rotating in a perpendicular direction to the cut, allowing cutting tips to be asymmetrical in shape and ensure the tip's cutting face is always presented to the material being cut at the correct orientation. The tip carriers distribute the loads created during the process of cutting to the guide bar and keeps the wire running down the guide bar. The tip carriers are designed to prevent the wire coming off the guide bar on its non-tension side (opposite to the cutting side) when the user has tensioned the cutting blade correctly.

In addition, the tip carriers form teeth to transmit the drive from the drive wheel to the cutting blade. The tip carrier shape can be optimised to better perform this task and reduce the wear on the drive wheel than with existing wire systems that use cutting tips as the drive teeth themselves.

Wire

The wire replaces the common chain link system used on existing chainsaws. Wire has a lower cost and allows for a lower cost manufacturing process. In addition, wire has fewer moving parts and will stretch less than a link chain. Importantly, there are no joints on a wire that require lubrication.

Further design options

Features of this new design and its low cost create various opportunities.

Building Industry

The wire and tip carriers could be driven around a round bar of say 250mm in diameter or another shape which maximises its advantages for use like a foot shape for timber having a reduced kerf design for example. 3.5mm in width.

Uses of the invention could include cut-off saws for large timber beams etc or hand held power saws. Advantages would include more compact machines giving far greater cutting depths due to the wire rotating around the bar as opposed to a blade turning around a bearing.

The 5-inch depth of cut for a hand held gas powered saw would be a significant advantage in cutting large floor support timbers and beams on a building site. The new tip carrier design will give better control over the cut compared to conventional cutting chains and should be equivalent to existing circular saws. The tip design and configuration could be changed to suit the application such as zero degree hook and smaller tip carriers at closer pitch. The low friction operation would suit applications such as the cutting of steel studs, portals in steel frame house building and aluminium extrusions. Existing circular saws generate a lot of heat due to the large contact area of a rotating saw.

Outdoor garden and lawn products

The light total moving mass of the new design gives opportunities to design line trimmers that are more easily controlled than a line trimmer using a rotating blade. The shape of the bar can be optimised to take full advantage of the new design and help the end user to achieve better control.

VARIATIONS

Finally various other alterations or modifications may be made to the foregoing without departing from the scope of this invention as herein set forth.

Throughout the description and claims of this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps.

Claims

CLAIMS:

1. A non-lubricated flexible line chainsaw blade including in combination a base comprising a continuous loop of flexible line, the continuous loop adapted to be driven by rotating pulley means, a plurality of cutting members spaced along the line, the cutting

5 members adapted to saw material, typically timber, without requiring lubrication of the line or the cutting members, each cutting member comprising a cutting tip attached to a tip carrier fixed to the line, wherein in operation, timber can be sawn by moving the cutting members in rapid succession against the material being sawn.

2. A flexible line chainsaw blade as claimed in claim 1 wherein the flexible line is a 10 stainless steel marine grade wire or rope.

3. A flexible line chainsaw blade as claimed in claim 2 wherein the wire consists of two separate wires with their respective joints located on separate tip carriers thereby reducing the stress on a single joint.

4. A flexible line chainsaw blade as claimed in claim 2 wherein the flexible line consists 15 of a single wire that is looped twice over pulleys of the pulley means.

5. A flexible line chainsaw blade as claimed in any one of the preceding claims wherein the flexible line is brazed or swaged to the tip carrier.

6. A flexible line chainsaw blade as claimed in claim 1 wherein the flexible line is of a material of equivalent tensile strength and durability to stainless steel marine grade wire or

20 rope.

7. A flexible line chainsaw blade as claimed in any one of the preceding claims wherein the cutting tip includes in combination a channel member adapted to straddle a guide bar or support roller assembly of a chainsaw. the channel member including stepped first and second portions, the first portion adapted for mounting of a cutting tip, the second portion

"> adapted to provide a non-cutting skid surface to material being sawn, wherein in operation, rotation of the cutting tip carrier over a circular idler nose pulley of the chainsaw causes the second portion to pivot outwardly with respect to the first portion wherein an arc circumscribed by the non-cutting skid surface is marginally greater than the arc circumscribed by the cutting tip as measured from a centre of rotation of the nose pulley and whereby the cutting tip is prevented from catching and kicking-back on the material.

8. A flexible line chainsaw blade as claimed in any one of claims 1 to 7 wherein ends of a loop formed by the flexible line is joined at a tip carrier by a braze joint.

9. A flexible line chainsaw blade as claimed in any one of claims 1 to 7 wherein ends of a loop formed by the flexible line are joined at a tip carrier by a swaged joint.

10. A flexible line chainsaw blade as claimed in any one of claims 1 to 7 wherein ends of a loop formed by the flexible line are passed through a hole in a tip carrier and joined by a combination swage and braze joint.

1 1. A flexible line chainsaw blade as claimed in any one of the preceding claims wherein the cutting members comprise cutting tips of tungsten carbide steel with a hollow cutting face to increase a hook or cutting angle of the cutting tip.

12. A flexible line chainsaw blade as claimed in claim 11 wherein the cutting tip is attached to a tip carrier at a cutting angle of 45°.

13. A flexible line chainsaw blade as claimed in claim 1 1 wherein the cutting angle is not 45° but is varied depending on the type of material to be cut.

14. A flexible line chainsaw blade as claimed in any one of the preceding claims wherein the tip carrier is U-shaped.

15. A flexible line chainsaw blade as claimed in any one of the preceding claims wherein the tip carriers act as drive teeth which are driven by a drive pulley of a chainsaw.

16. A flexible line chainsaw blade as claimed in any one of the preceding claims wherein the cutting tip is joined to the tip carrier by using resistance brazing technology.

17. A flexible line chainsaw blade as claimed in any one of the preceding claims wherein the cutting tip is joined to the tip carrier by induction brazing.

18. A chainsaw for a flexible line chainsaw blade as claimed in any one of the preceding claims including in combination powered drive means adapted to drive a pulley means, said pulley means comprising a drive pulley and an idler nose pulley co-operating with support roller means and/or friction plate means to support a non-lubricated flexible line chainsaw blade.

19. A chainsaw as claimed in claim 18 wherein the diameter of the drive pulley and idler nose pulley are such that where wire is used as the flexible, line, the wire does not go beyond its U point and work harden.

20. A chainsaw as claimed in claim 18 or claim 19 wherein the idler nose pulley includes an anti-kickback operation incorporating a groove for the flexible line and circumferential recesses to accommodate tip carriers and cutting tips at or below the circumference of the pulley.

21. A chainsaw as claimed in claim 19 wherein the idler nose pulley is a plain pulley without circumferential recesses.

22. A chainsaw as claimed in any one of claims 18 to 21 wherein there are support rollers for supporting the flexible line between pulleys.

23. A chainsaw as claimed in claim 22 wherein the support rollers are made of any suitable material that does not require lubrication.

24. A chainsaw as claimed in claim 22 wherein the support rollers are replaceable by means of a snap lock or slide mechanism.

25. A chainsaw as claimed in any one of claims 18 to 21 wherein there is a replaceable friction plate or wear strip to support the flexible line between pulleys.

26. A chainsaw as claimed in any one of claims 18 to 21 wherein there is a hardened steel guide in place of rollers or friction plate means.

27. A chainsaw as claimed in any one of claims 18 to 21 wherein the guide bar includes the use of metals having increased heat dissipation properties to improve cooling and bearing life.

28. A flexible line chainsaw blade substantially as herein described with reference to the drawings.

29. A chainsaw for a flexible line chainsaw blade substantially as herein described with reference to the drawings.