Sawtooth-shaped blade and tool with blade

Abstract

The insert (100) comprises an exposed serrated cutting edge (101) and a first line of weakness (102) behind and spaced apart from the exposed serrated cutting edge (101), the line of weakness (102) being shaped to provide a second serrated cutting edge when the insert (100) is broken along the line of weakness. The tool blade (100) may be a saw blade (100), and / or a spacing between a foremost point of the exposed serrated cutting edge (101) and a foremost point of the second serrated cutting edge (102) may be at least 2 mm. A tool comprising such a blade 100 and a tool for breaking such a blade (100) along a line of weakness (102) are also provided.

Description

TECHNICAL FIELD

[0001] The present invention relates to serrated blades for use in cutting tools, and to tools incorporating such blades, for example, jigsaws, hand tools (i.e. tools held in the hand and operated without electrical or other power) and oscillating cutting tools such as the electrically powered tools commonly known as multi-tools. In particular, the invention relates to blades having multiple usable cutting edges, such that a worn or dull cutting edge can be broken off the blade to expose a new cutting edge for use. A tool for breaking off a blade portion to expose a new cutting edge is also disclosed. BACKGROUND

[0002] Blades inevitably wear and become dull with use. A worn or otherwise damaged blade will be thrown away, and although it can be recycled, a significant amount of material and cost is wasted. In particular, for multi-tools, it is common for the tool to comprise a two-part blade assembly: an attachment section comprising an attachment formation for mating with the oscillating tool; and a blade section comprising a cutting blade. The two components are welded together, and when the blade section is worn, the entire assembly is discarded. Similarly, blades in many kinds of tool have an attachment portion integral with or permanently connected to the blade, so that not only the sharp portion is discarded once worn. A significant amount of waste is therefore generated. SUMMARY

[0003] It is an object of the present invention to provide a blade for a cutting tool that can be used for a longer period of time to reduce waste.

[0004] According to a first aspect, there is provided a blade comprising an exposed serrated cutting edge and at least one line of weakness behind and spaced from the exposed serrated cutting edge, the line of weakness being shaped to provide a second serrated cutting edge when the blade is broken along the line of weakness.

[0005] The blade can not be a straight edge blade for an oscillating tool (also known as a multi-tool). For example, the blade can be any shaped blade for a hand tool, or can be a circular oscillating blade for a multi-tool.

[0006] According to a second aspect, a cutting tool insert is provided, the cutting tool insert including an exposed serrated cutting edge and a first weakening line, the first weakening line being behind and spaced apart from the exposed serrated cutting edge, the shape of the weakening line being determined to provide a second serrated cutting edge when the insert breaks along the weakening line, and wherein the distance between the foremost point of the exposed serrated cutting edge and the foremost point of the second serrated cutting edge is at least 2 mm.

[0007] Tool blades can be (non-powered) hand tool blades.

[0008] The tool blade can be a saw blade.

[0009] The blade can be as described with respect to the first aspect.

[0010] According to a third aspect, a saw blade is provided, the saw blade including an exposed serrated cutting edge and at least one weakening line, the at least one weakening line being behind and spaced apart from the exposed serrated cutting edge, the shape of the weakening line being determined to provide a second serrated cutting edge when the blade breaks along the weakening line.

[0011] The blade can be as described with respect to the first or second aspect.

[0012] Regarding any of the foregoing aspects:

[0013] The cutting tool has a serrated leading edge for use in cutting. After a period of use, the serrated leading edge will become worn / dull. At this point, the front portion of the tool may break off along a weakening line. A new serrated edge will then emerge at a slightly smaller tip of the tool. The forward-facing points along the weakening line form the serrations of the new serrated edge. The weakening line defines several points, at least generally forward-facing, along the length of the cutting edge.

[0014] Different saw tooth designs are useful for effectively cutting through different materials, such as metal, dry wood, raw wood, plastic, etc., and the shape, size, spacing and angle of the saw teeth can be selected accordingly.

[0015] The weakening line can be weaker at and around the forward-facing cutting point of each tooth, and stronger in the valley between adjacent teeth. This can help provide a sharp cutting point.

[0016] The weakening line may include a series of alternating weakened portions and stronger connecting portions, the weakened portions being arranged to facilitate breakage of the blade along the weakening line, and the stronger connecting portions being arranged to keep these portions of the blade connected until breakage is desired. The connecting portions may be located in the valleys between the teeth (serrations). Each tooth tip may have a weakened portion (optionally in the form of a gap / cut-off portion of the blade) around it to ensure that these tips remain sharp and retain their shape. The weakened portions may extend around at least 10%, 20%, 30%, 40%, or 50% of the tooth height. Additionally or alternatively, the weakened portions may extend to a forward-facing point at one end of the weakening line, which may be located at the lateral edge of the blade. This ensures complete breakage at the end of the weakening line and optionally forms a sharp angle. This also applies to each end of the weakening line.

[0017] The average thickness of the material forming the blade along the weakening line or each weakening line can be lower than the average thickness of the material forming the blade adjacent to the weakening line or each weakening line.

[0018] The tool insert may further include additional weakening lines following the first weakening line. The shape of each additional weakening line can be determined to provide an additional serrated cutting edge when the insert breaks along the weakening line.

[0019] In embodiments with multiple weakening lines spaced apart along the blade surface, blade life can be further increased. For example, there can be ten weakening lines, each spaced apart one after another and extending along the length of the blade. This provides eleven serrated cutting edges (including the original serrated cutting edge at the front of the blade before any breakage), and thus the blade can last eleven times longer than a standard blade with the same properties, while still using only minimal additional material (in some cases, the blade can be slightly wider than a standard blade to allow space for all the weakening lines parallel to the length of the cutting edge, but even so, the total amount of material used may be lower, for example, less than twice the material for a blade lasting eleven times longer, noting that the attachment portion of the blade typically contributes a large portion of the total blade material).

[0020] In some embodiments, each serrated cutting edge (both the original exposed edge and those edges provided by the weakening lines upon breakage) may be arranged to provide at least substantially the same size, shape, and optionally spacing for providing serrations. In some embodiments, all weakening lines may be identical to each other. The shape of the original cutting edge may also be the same as or different from the provided cutting edges.

[0021] In other embodiments with multiple weakening lines, different serration designs can be used for different weakening lines. For example, the blade may include nine weakening lines, divided into three groups of three. Each group of three may include three different serration designs, such as (i) a serrated edge suitable for cutting dry wood, (ii) a serrated edge suitable for cutting green wood, and (iii) a serrated edge suitable for plastic. Thus, the user can break off one or more blade sections to expose the blade with the desired cutting edge. This improves usability and avoids the need for the user to purchase or carry multiple blades, for example, for DIY projects. In such embodiments, the size, spacing, and / or shape of the serrations may be constant along the weakening lines but different between the weakening lines.

[0022] In some embodiments, each serrated cutting edge (both the initial (original) cutting edge and those exposed by breaking the blade along a weakening line) may take the form of at least a generally straight line, with serrations along that at least generally straight line. The weakening line, or each weakening line, may be at least generally parallel to the exposed serrated cutting edge and any other weakening line.

[0023] In other embodiments, each serrated cutting edge may take the form of a circle or an arc, with serrations along the circle or arc. The weakening line, or the curve of each weakening line, may be concentric with the curve of the exposed serrated cutting edge, and optionally locally parallel to the curve of the exposed serrated cutting edge.

[0024] The weakening line, or each weakening line, can be or is included in the material forming the blade, at the point of each tooth of the serrated cutting edge formed by the weakening line, the shape of which defines the shape of the cutting point of the tooth. The gap can have at least a substantially constant width. Each gap can have at least a substantially identical width. Optionally, the gap width can be between 0.05 mm and 0.40 mm, or between 0.1 mm and 0.3 mm, optionally 0.2 mm.

[0025] A weakening line, or each weakening line, may include:

[0026] (i) forming gaps in the material of the blade in the region at each point of the serration; and

[0027] (ii) A solid portion of the blade material is formed in the valley region between adjacent pairs of saw teeth.

[0028] In some embodiments, the gap may extend around the entire serration, and the solid portion may extend across the entire valley. In other embodiments, the gap may extend around the peak or tip of the serration, and the solid portion may extend out of the valley and into a portion of the serration. In other embodiments, the gap may extend around the entire serration and along at least a portion of the valley. The higher the proportion of the weakening line formed by the gap, the more easily the blade breaks. A minimum of 25% to 30% of the length of the weakening line may consist of the solid portion.

[0029] The weakening lines, or each weakening line, may be or include a solid material line, the thickness of which is less than the thickness of the blade between the weakening lines. Optionally, the thickness of the material forming the weakening lines varies along the weakening lines, being thinnest in the region of the serrated cutting points and thickest in the valleys between the serrated cutting points.

[0030] In addition to regions having two or more distinct non-zero thicknesses along the weakening lines or for each weakening line, gaps (i.e., regions with zero thickness) may exist. In embodiments with gaps (i.e., regions with zero thickness along the weakening lines), the blade may have a thickness T between the weakening lines, and the solid portions along the weakening lines (between the points of the serrations / in the valleys) may be thinner than the thickness T.

[0031] The weakening line, or each weakening line, can be or include a row of perforations passing through the blade. Optionally, the perforations are larger and / or more closely spaced in the region of the sawtooth cutting point.

[0032] In embodiments with one or more gaps along the weakening line, one of the gaps forming part of the weakening line may extend to the edge of the blade at one end (or at each end) of the cutting edge, such that the gap forms the extreme point of the blade. This helps to ensure that the blade breaks off and cuts precisely to its end.

[0033] In embodiments with one or more gaps along the weakening line:

[0034] (i) At least one of the gaps may be generally V-shaped, with the point of the V facing forward; and / or

[0035] (ii) At least one of the gaps may be generally W-shaped, with two points facing forward and one point facing backward (or vice versa).

[0036] Each valley along the weakening line can take the form of a straight line parallel to the cutting edge between the forward-facing serrations.

[0037] Each gap along the weakening line can be a continuous gap extending between a pair of adjacent valleys and defining the shape of the forward-facing sawtooth. The gap can have at least a substantially constant width.

[0038] Each gap may have a width of at least 0.1 mm and optionally 0.1 mm to 0.5 mm along the blade surface (perpendicular to the overall direction of the weakening line).

[0039] The distance between the foremost point of the exposed serrated cutting edge and the foremost point of the second serrated cutting edge can be at least 2 mm, optionally at least 3 mm or 4 mm, and optionally in the range of 4 mm to 6 mm.

[0040] The weakening line or each weakening line may include at least 20%, 25%, 30%, or 35% of the length of the weakening line of solid material with the same thickness as the rest of the blade.

[0041] The weakening line, or each weakening line, may comprise a solid material having the same thickness as the remainder of the blade for at least 25%, 30%, 35%, 45%, or 50% of the length of the cutting edge parallel to the blade length. It should be understood that the serrations cause the total length of the weakening lines to be greater than the total blade length.

[0042] The cutting point of the serration can be located at one extreme end of the serrated cutting edge. Alternatively, the cutting point can be located at each extreme end of the serrated cutting edge, resulting in a forward-facing point at each transverse end of the blade. This helps ensure that the blade breaks off and cuts precisely to its tip.

[0043] According to the fourth aspect, a tool is provided that includes a blade as described in any of the preceding aspects.

[0044] The tool can be a (non-powered) hand tool. Additionally or alternatively, the tool can be a saw.

[0045] According to a fifth aspect, a blade breaking tool is provided for breaking off the exposed edge of a serrated blade as described in any one of the first to third aspects, wherein the blade breaking tool includes a channel whose size and shape are determined for receiving the exposed serrated cutting edge and a front portion of the blade extending from the exposed serrated cutting edge, and the channel has a depth corresponding to the interval between the exposed serrated cutting edge and a (first) weakening line behind the exposed serrated cutting edge, such that only the first portion of the blade is received within the channel.

[0046] The channel depth can be at least 2 mm.

[0047] Blade breaking tools can be straight or curved to match the blade they are intended to be used with.

[0048] Therefore, a tool can be provided for breaking off a worn edge along the next / nearest or only weakening line. The tool includes a body having a slit or channel therein for receiving the leading edge of the blade, i.e., the cutting edge and a portion of the blade immediately following the exposed cutting edge. In some cases, the tool can be long enough to receive the full length of the cutting edge. In other cases, the cutting edge of the blade can be longer than the tool, such that only a portion of the cutting edge can be inserted into the tool at a given time.

[0049] The exposed cutting edge (or at least its foremost point) is typically placed on the base of the channel during use.

[0050] The depth of the channel is preferably only less than the distance between the exposed cutting edge and the adjacent weakening line, the distance being measured along the surface of the blade and approximately, at least locally, perpendicular to the cutting edge / blade length.

[0051] For blades with multiple weakening lines, the spacing between all adjacent pairs of weakening lines is preferably at least approximately equal to the spacing between the first weakening line and the original exposed cutting edge, so that the same tool can be easily used for each section to be broken. Therefore, the depth of the channel is preferably only less than the spacing between the weakening lines.

[0052] Controlling the channel depth helps ensure that the blade breaks only along the weakening line closest to the front / closest to the exposed cutting edge, so that the serrated edge is not wasted by breaking two or more blade sections at once.

[0053] According to the sixth aspect, a set of parts is provided, the set of parts comprising:

[0054] The blade as described in any one of the first to third aspects; and

[0055] The blade-breaking tool as described in the fifth aspect, wherein the size and shape of the channel of the tool are determined to accommodate the blade.

[0056] According to the seventh aspect, a method is provided for exposing a new cutting edge of a serrated blade for use, the method comprising:

[0057] The foremost portion of the blade according to any one of the first to third aspects is inserted into the channel of the tool according to the fifth aspect, such that at least a portion of the exposed cutting edge of the blade rests on the base of the channel; and

[0058] Move the tool relative to the blade in a direction at least roughly perpendicular to the blade so as to break off the portion of the blade between the exposed cutting edge and the weakening line behind it.

[0059] According to another aspect, a cutting blade is provided, the blade including an exposed serrated cutting edge and at least one weakening line behind and spaced apart from the exposed serrated cutting edge, the shape of the weakening line being determined to provide a second serrated cutting edge when the blade breaks along the weakening line.

[0060] The blade may have any of the features described with respect to the first, second, and / or third aspects. A blade-breaking tool according to the fifth aspect may be provided for the blade in this aspect.

[0061] According to another aspect, a blade assembly for an oscillating tool is provided, the blade assembly comprising:

[0062] An attachment section having an attachment configuration for matching with an oscillating tool; and

[0063] The blade section has a serrated leading edge.

[0064] At least one weakening line is provided behind the serrated leading edge along the width of the blade section, each weakening line defining at least one point generally facing forward.

[0065] The blade section may be made of carbide steel. The blade section may have any of the characteristics described with respect to the first, second and / or third aspects of the blade.

[0066] Each weakening line can be formed by multiple cuts. These cuts can be spaced along the width of the blade segment, with the front portion of the blade segment in front of the cuts attached to the rear portion of the blade segment behind the cuts at least by material in the transverse space between the cuts. The cuts can be through cuts, whereby the blade segment is completely cut through the material. Alternatively, the cuts can be partial cuts, whereby the blade segment is thinned.

[0067] One of these cuts may extend to the forward-facing point at the lateral edge of the blade section. Another cut may extend to the forward-facing point at the other lateral edge of the blade section.

[0068] At least one of these cuts may be generally V-shaped, with the point of the V facing forward.

[0069] At least one of the incisions can be approximately W-shaped, with two points facing forward and one point facing backward.

[0070] The cut can be beveled. Therefore, the serrations can be beveled.

[0071] Multiple cut lines can be provided, which are spaced apart along the length of the blade section.

[0072] The aforementioned blade assembly can be provided in combination with a tool for breaking off the front portion of the blade segment, the tool including a body having a slit for receiving the front portion of the blade segment.

[0073] Those skilled in the art will understand that the features described with respect to one aspect of the invention can be applied to another aspect of the invention with necessary modifications.

[0074] The unique serrated design shared by all aspects allows for the removal of sections of the blade to provide new, sharp cutting edges, such as once the initially exposed cutting edge becomes worn.

[0075] The serration techniques described in this article can be applied to any tool with serrated cutting edges, such as multi-tools and saws, including: wire saws; reciprocating saws; multi-tools / oscillating cutting tools (all shapes and sizes); chopping saws (hard and flexible blades); hand / crosscut saws (including flat teeth, M-tooth, American teeth, champion teeth, spear teeth, and perforated spear tooth designs); jigsaws; bow saws; wire saws; keyhole saws; Japanese saws; panel saws / back saws; pruning saws; veneer saws; wall panel / dryboard / gypsum board saws; camping saws; bone saws; band saws (including standard shapes, hook-cut, rounded, skip-tooth, rake-type or regular, wavy, per tooth (ETS), and variable or modified); reel saws; and tension saws.

[0076] It should be recognized that each of the tool categories listed above has a variety of different blade shapes falling within that category, and the broken serration design described herein can be applied to all known blade designs. Furthermore, the broken serration design described herein is not limited to its application to the tools listed above. Attached Figure Description

[0077] The embodiments of the present invention will now be described in detail below by way of example only, with reference to the accompanying drawings, in which:

[0078] Figure 1 A wire saw blade with a "broken" tooth design is shown;

[0079] Figure 2 A reciprocating saw blade with a "broken" tooth design is shown;

[0080] Figure 3 It shows Figure 2 A portion of the reciprocating saw blade is shown, displaying a close-up view of the cutting edge;

[0081] Figure 4 Two different saw blades with a similar "broken" tooth design are shown;

[0082] Figure 5A tool is shown that can be used to break Figures 1 to 4 A portion of the blade shown in any of the images is used to expose a new cutting edge;

[0083] Figure 6 A circular insert for an oscillating cutting tool is shown;

[0084] Figure 7 It shows Figure 7 A close-up view of a portion of the blade;

[0085] Figure 8 Two views of the tool are shown; this tool can be used to break... Figure 6 and Figure 7 The blade shown is part of the cutting edge to expose a new cutting edge;

[0086] Figure 9 A close-up view of the blade serrations / cutting points and their interconnections is shown;

[0087] Figure 10 It is a diagram illustrating the variation of weakening lines with the same roughly jagged shape;

[0088] Figure 11 A straight-edged insert for an oscillating cutting tool is shown; and

[0089] Figure 12 Is with Figure 11 A view of the remaining blade adjacent to the broken blade portion.

[0090] In the accompanying drawings, the same reference numerals are used for the same or corresponding features. Detailed Implementation

[0091] Figure 1 A wire saw blade 100 is shown, i.e., a blade arranged to form part of a wire saw. The blade 100 includes attachment sections 111 arranged for attaching the blade to the remainder of the wire saw. The attachment sections 111 include attachment features, such as one or more notches, protrusions, openings (e.g., threaded holes or holes for bolts to pass through), the shape and size of which are determined to mate with the remainder of the tool to facilitate attachment. In the illustrated example, the attachment sections 111 are integral with the blade 100, but in other examples, they may be permanently attached to the remainder of the blade (e.g., by welding) or combined in other ways known in the art.

[0092] A wire saw can be a manual wire saw (i.e., a hand tool) or a power wire saw.

[0093] The back of the blade 100 shown (i.e., on) Figure 1The uppermost edge 110 in the orientation depicted is smooth / flat and is not arranged for cutting.

[0094] The front part of the blade 100 (i.e., at) Figure 1 The lowest edge in the orientation depicted is the cutting edge 101, and it is serrated, having a plurality of teeth or serrations along the cutting edge 101. The cutting edge 101 extends in a straight line along a portion of the length of the blade 100, and teeth 101a of the same shape and size are evenly spaced along the cutting edge. Each tooth 101a is cut such that it bends toward the attachment section 111 in the example shown. It should be understood that in other examples, the teeth 101a may have different shapes, sizes and spacings (with respect to the teeth shown and / or the spacing between them), and Figure 1 Provided only by way of non-restrictive examples.

[0095] Each tooth or serration 101a can be described as having a cutting point—that is, the tip of the serration pointing outward from the blade 100; the forward-facing point of each serration 101a can be described as the cutting point—which engages with the material to be cut during use. The blade 100 further includes valleys between the teeth 101a; in the example shown, the valleys have a flat base parallel to the length of the blade, but alternatively they can be curved or actually V-shaped.

[0096] exist Figure 1 In the example shown, the pitch P is approximately 2 mm from tooth to tooth, and the insert has approximately twelve teeth per inch (i.e., TPI = 12). Inserts as described herein typically have between approximately 12 and 24 TPI. The number of teeth per inch can vary, among other variables, depending on what material the insert is intended to cut, and therefore this number is provided only by way of non-limiting example.

[0097] The wire saw blade 100 shown, for example, may have a blade thickness T of approximately 1.2 mm. This blade design can be selected to provide rough cutting for wood. The total length of the blade 100, including the attachment portion 111, may be approximately 100 mm. Again, it should be understood that these details are provided by way of non-limiting example only. The break-off blade design described herein can be applied to any number of TPI (teeth per inch) and different pitches. Similarly, the serrated edges can be optimized in different examples for wood, metal, plastic, composite materials, or any desired material to be cut, and the shape, size, and spacing of the teeth can be varied accordingly.

[0098] The blade 100 is made of a sheet of material such as steel (e.g., carbide steel). This material is chosen to be hard and strong enough to cut any substrate the saw intends to cut. The edges of the teeth 101a (and particularly the edges in the area of ​​the cutting point) may be beveled or otherwise sharpened to facilitate cutting.

[0099] The blade 100 further includes a weakening line 102. The weakening line 102 extends along the entire length of the blade, the exposed cutting edge 101 (and slightly beyond in the illustrated example). The weakening line 102 is located behind and spaced apart from the first exposed cutting edge 101, such that it lies between the cutting edge 101 and the back of the blade 110. The shape of the weakening line 102 is defined to provide a second serrated cutting edge when the blade 100 breaks along the weakening line 102.

[0100] The distance between the foremost point of the exposed serrated cutting edge 101 and the foremost point of the weakening line 102 can be at least 2 mm, 3 mm, or 4 mm, and optionally at least 5 mm or 6 mm. The distance between the foremost point of the exposed serrated cutting edge 101 and the foremost point of the weakening line 102 can be no greater than 20 mm or 15 mm, and optionally no greater than 10 mm. The distance between the foremost point of the exposed serrated cutting edge 101 and the foremost point of the second serrated cutting edge 102 can be at least 2 mm, 3 mm, or 4 mm, and optionally at least 5 mm, 6 mm, 7 mm, or 8 mm. It should be understood that, as described in more detail below, the weakening line 102 can have a non-negligible width (e.g., including a gap 102a with a non-negligible width in the insert material), such that the foremost point of the second serrated cutting edge is slightly behind the foremost point of the weakening line 102.

[0101] The shape of the weakening line 102 can be determined to match the exposed cutting edge 101. In the example shown, the weakening line 102 defines a set of teeth that are identical to and aligned with the teeth 101a of the exposed cutting edge 101, such that the teeth of the weakening line 102 are aligned with each tooth of the exposed cutting edge 101.

[0102] The blade 100 is designed to break along the weakening line 102 to remove the front portion 1 of the blade 100 and expose a new cutting edge 102 for use. The weakening line 102 defines the shape of the new second cutting edge. Thus, the weakening line 102 extends to the edge of the blade 100 at each end of the weakening line 102 to facilitate breaking off the entire portion of the blade 100.

[0103] The weakening line 102 is weaker than the surrounding material of the blade 100 so as to allow the blade 100 to break in the desired manner, leaving a newly exposed cutting edge of the desired shape. This can be achieved by weakening the blade material along a line along the blade 100—for example, by cutting it (e.g., laser cutting it), thinning it, acid etching it, or otherwise treating it, by removing some blade material along a line along the blade 100 while still leaving enough material to attach the front part of the blade to the rear part, and / or by manufacturing multiple separate blade sections of the desired shape and joining them together (e.g., using adhesives or spot welding) in a manner that makes the attachment weaker than the body material, thereby allowing breakage along the weakening line (which can also be considered as the attachment line between blade sections).

[0104] exist Figure 1 In the example shown, the weakening line 102 includes a set of gap or slit portions 102a and a set of connecting portions 102b, where the blade material has been removed and where the material is retained (“solid portions”), thus connecting the front portion of the blade 100 to the rest of the blade. In the example shown, the gap 102a surrounds the (forward-facing) tooth 101a, and the solid portion 102b is located in the valley between the teeth. Therefore, even if separating the front portion from the rest of the blade deforms the shape of the new second cutting edge in the region of the solid portion 102b, the tooth profile is maintained.

[0105] In the example shown, the gaps 102a are at least generally V-shaped, with their forward-facing points providing a cutting edge for the teeth 101a. The solid portions 102b are straight and, in the example shown, parallel to the length of the insert, extending between the rearward tips of adjacent V-shaped gaps 102a. In the example shown, each solid portion 102b is approximately equal in length to the tooth along the insert 100, such that approximately 50% of the length of the weakening line 102 parallel to the insert at the cutting edge is solid—these solid portions provide sufficient rigidity for cutting and sufficient strength to prevent accidental separation of the front portion 1 during use. The shape of the teeth means that the weakening line 102 itself can be much less than 50% solid, because the profile of each tooth is longer than the tooth width or the gap between the teeth—for example, the weakening line 102 can be solid for at least 25%, 30%, 35%, or 40% of its length.

[0106] In some examples, the material of the solid portion 102b can be thinned to facilitate a clean break along the intended line 102, while in other examples, the solid portion can have the same thickness as the body blade material. The solid material of the weakening line 102 has the same thickness as... Figure 1The remaining part of the blade in the example shown has the same thickness, but this can be changed, for example, by etching shallow lines along the weakening lines in the material of the solid part to facilitate complete fracture when being broken off.

[0107] The average thickness of the material forming the blade along the weakening line 102 is thus lower than the average thickness T of the material forming the blade 100 adjacent to the weakening line 102l between the exposed cutting edge 101 and the weakening line. In the above example, the gap 102a is actually a region where the thickness of the weakening line is zero. In other examples, the gap 102a can be replaced by a thinner part of the material (e.g., thinned by etching), and the gap has a thickness greater than zero while still being lower than the average blade thickness T away from the weakening line. In some examples, the weakening line 102 can be thinned along its entire length, but is thinned much more at and around the forward-facing cutting points than between the cutting points, for example having thicknesses T1, T2, and the thicknesses T1, T2 can both be less than the average blade thickness T away from the weakening line 102, where T1 is less than T2 (0 ≤ T1 < T2 ≤ T). The thickness at and around the cutting points is T1; the material can be thinned to thickness T1 around the entire serration / tooth, and the material is thinned to a second thickness T2 between the teeth (e.g., in the straight valleys between adjacent serrations). In other examples, the material can be thinned only around the forward part of the tooth to thickness T1 - for example, in the range of the frontmost 10%, 25%, 50%, or 75% of the tooth. Using the thinnest around the tip can help ensure a neat and sharp cutting tip of the desired shape, thus minimizing the risk of tooth deformation when broken off. In some examples, the valleys can be V-shaped or U-shaped instead of straight - the reduced thinning T2 can be used in and for these regions of the rear-facing tips - for example, above the range of the rearmost 10%, 25%, 50%, or 75% of the weakening line. In some examples, the thickness can vary smoothly between T1 and T2 instead of stepping sharply from one thickness to another. In some examples, more than two different thicknesses can be used along the weakening line 102, for example having an intermediate thickness T3 that extends along a part of the weakening line 102 between the forward-facing tip (having thickness T1) and the valley (having thickness T2).

[0108] In an alternative example, the material of the weakening line 102 can have the same thickness as the material of the rest of the blade 100, but can have a different structure or composition such that the weakening line is more brittle and breaks more easily. In such an example, when the blade 100 is formed, the weakening line 102 can be integrally formed.

[0109] In some embodiments with multiple weakening lines 102, each weakening line 102 is identical and thus requires the same force to break. In other such embodiments, the first weakening line 102 may be the weakest, and thus the first segment 1 is the most easily broken, and subsequent weakening lines 103, etc., may be sequentially stronger, making subsequent segments 2, etc., more difficult to break—this can reduce the risk of accidentally removing multiple segments at once. For example, the gap 102a may be longer along the weakening line closer to the exposed cutting edge (e.g., extending through some valleys and around the teeth, or around more teeth), and / or the material may be more weakened. The variation may be localized, for example, increasing by 2%-5% between consecutive weakening lines 102.

[0110] A kerf is defined as the width of the cut or the width of material removed by a cutting process—for example, Figure 1 and Figure 2 The flat blade shown can have a kerf size that is at least approximately equal to the width of the sheet of material forming the blade, i.e., the blade thickness T. However, it is known in the art that a selected tooth offset or kerf size can be applied to a selected serration design—for example, by angulating alternating teeth in different directions—to increase the kerf size in the material being cut. This can be referred to as the kerf size of the blade. The kerf size determines the width of material removed, for example, by a cutting or sawing process (which may be laser cutting, or any other suitable technique known in the art). When forming the blade, this kerf design can be stamped into the blade for each weakening line 102. It should be understood that having a gap 102a around the teeth (opposite to the weakened solid material) can help achieve the desired kerf design / tooth offset, but in some embodiments, the solid material may still be present around the teeth and can be (further) weakened by the stamping process, thus facilitating later breakage along the weakening line.

[0111] return Figure 1 In the example shown, at each end of the cutting edge (on the left and right sides in the illustrated orientation—these can be referred to as the lateral edges of the cutting edge), the weakening line 102 extends forward to the edge of the blade material. In particular, in the example shown, this provides a longer cut or gap region 102a of the weakening line 102 beyond the cutting edge at the end adjacent to the attachment portion 111.

[0112] exist Figure 1 In the example shown, gap 102a is formed by laser cutting. Other techniques known to those skilled in the art can be used to produce such gap 102a, such as metal stamping, which can be used either as an alternative to laser cutting or in conjunction with it. Figure 1In the example shown, the gap 102a has a non-negligible width and is therefore shown as having two laser-cut edges 120a, 120b instead of a single line. For example, the gap 102a can have a width of 0.1 mm to 0.5 mm, and optionally about 0.3 mm. This gap width can provide some flexibility to the blade 100 without unduly weakening it, and / or can facilitate the breaking of the first blade portion 1 without distorting the tooth profile.

[0113] More than one weakening line 102 can be provided, and multiple blade portions 1 can be broken sequentially, one blade portion per weakening line 102. For example, the blade 100 can have 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 weakening lines 102. The weakening line closest to the exposed cutting edge 102 can be referred to as the first weakening line 102. The maximum total depth of the blade portions 1 to be removed can be set such that a sufficient thickness of blade material remains between the final weakening line and the back 110 of the blade 100 to provide sufficient strength and rigidity for cutting.

[0114] Each blade portion 1 to be broken may have a depth D extending beyond the foremost point of its trailing edge, wherein the depth D is at least 2 mm, 3 mm, or 4 mm, and optionally at least 5 mm, 6 mm, 7 mm, or 8 mm. In the example shown, the depth D is approximately 6 mm. The minimum depth of each blade portion 1 may be set such that the blade portion is wide enough to provide sufficient strength and rigidity for cutting and to avoid the risk of the blade portion 1 breaking during use.

[0115] Figure 2 The illustration shows the application of a similar "broken" tooth design to different saw blades 100a with different tooth shapes. The following description focuses on the differences, as can be seen from [reference]. Figure 1 The description can help us understand common characteristics. Figure 2 The example shown is a reciprocating saw blade 100a, which includes an exposed first serrated cutting edge 101 and two weakening lines 102, 103 following it, each weakening line defining a new serrated cutting edge that can be used after a portion 1, 2 of the saw blade 100 has been broken off. Figure 1 As shown in the example, the original cutting edge 101 and the weakening lines 102, 103 are in the form of serrated straight lines, parallel to each other and spaced apart across the width of the blade 100.

[0116] In the example shown, the depth D of each blade portion 1, 2 is approximately 6 mm to 10 mm, and specifically approximately 8 mm. The total range of each blade portion 1, 2 perpendicular to the blade length is greater than the depth D, because it additionally includes the range of the blade portion 1, 2 entering the valley of the weakening lines 102, 103 after the foremost point of the next cutting edge.

[0117] Figure 2 The blade 100a shown has a thickness T of approximately 0.9 mm, a length L of approximately 150 mm (including the attachment portion 111 and the length of the cutting edge), and a width W of approximately 20 mm (from the back 110 to the front edge 101), and a TPI of approximately ten teeth per inch (determined by the pitch P). In this example, the teeth 101a are symmetrical, and the edges are straight rather than curved. The teeth 101a are again equally spaced. It should be understood that the tooth design can be adapted as needed for a given saw (or other bladed tool), and the break-off design as described herein can be adapted accordingly.

[0118] Unlike Figure 1 The blade 100 shown in the image, Figure 2 The blade 100a shown does not have the same tooth separation on the original cutting edge 101 and the weakening lines 102, 103—instead, the teeth 101 on the weakening lines 102, 103 are wider spaced than the teeth on the original cutting edge 101 (although each tooth has the same shape and nearly the same size, the spacing between the teeth is larger on the weakening lines than on the initial cutting edge). This is depicted to illustrate the fact that the serrated cutting edges 101, 102, 103 do not necessarily have to be the same, even though they are usually the same. In fact, a deliberate choice can be made for the serrated pattern of the leading edge 101 having, for example, no flat valleys, because the blade 100a never breaks along the leading edge 101 / no part of the blade is located in front of the leading edge, so there is never a need for a solid portion 102b on the leading edge 101—this choice facilitates manufacturing.

[0119] like Figure 1 The weakening lines 102 of the blade 100 are formed by laser cutting.

[0120] Figure 3 Provided Figure 2 A close-up view of a portion of the first blade section 1 of the blade 100a, showing seven forward-facing cutting points.

[0121] Figure 4 Two different saw blades 100b and 100c with similar tooth designs are shown. Again, the following description focuses on the differences between these blades and the aforementioned blades 100 and 100a. Figure 4The blade 100b shown on the left is a Scorpion® type saw blade for hand sawing or similar applications, with a length L of approximately 240 mm (including attachment portion 111), or a length L of approximately 210 mm. E (Without attachment portion 111). Length L E This can correspond to the length of the cutting edge (the straight length along the saw blade—i.e., excluding the additional line length due to the saw teeth). The attachment portion 111 includes an aperture 111a arranged to facilitate securing the blade 100b to a handle (not shown). It should be understood that the design of the attachment portion 111 can be appropriately adjusted according to the intended tool.

[0122] Figure 4 The blade 100c shown on the right is part of a panel saw (hand tool), with the attachment portion mainly hidden within the handle 113 to which the blade 100c is fixed.

[0123] Each blade 100b, 100c has an alternating pattern of longer and shorter teeth 101a along the cutting edge 101. Therefore, the serrations 101 can be considered W-shaped rather than V-shaped.

[0124] Each blade 100b, 100c is shown with a single weakening line 102 behind the exposed cutting edge 101, but it should be understood that more weakening lines may be provided in other examples. Furthermore, the weakening lines 102 are spaced apart and parallel to the exposed cutting edge 101 behind it. The weakening lines 102 take approximately the same shape as the exposed cutting edge 101, such that the second cutting edge exposed once the front portion 1 of the blade 100b, 100c is broken has the same shape as the first cutting edge 101, except that the valleys between the serrations are flat relative to the weakening lines. Thus, the cutting points have the same shape and pattern, but the valleys between the cutting points are flat rather than V-shaped.

[0125] As can be seen in the close-up view of insert 100b, in this example, the longer teeth of the first cutting edge 101 are aligned with the shorter teeth of the second cutting edge, and thus offset from the longer teeth of the second cutting edge. In other examples, such as insert 100c where the longer teeth are aligned with each other, the alignment may be different.

[0126] Figure 4 The second blade 100c shown has teeth 101 with Figure 4The teeth of the first blade 100b shown are very similar (and only a close-up is shown for convenience), but it should be noted that the tooth orientation is reversed—the Scorpion® blade 100b has alternating longer and shorter teeth 101 pointing forward (downward in the shown orientation), such that the cutting point / peak of a tooth 101 is not at the same level as the cutting point / peak of a tooth on either side, while the “W” of the panel saw blade 100c is the opposite, such that all the cutting points / peaks of the teeth are at the same level, but the valleys between them alternate in depth. Different tooth designs are better suited to different materials to be cut and the expected sawing angle, thus allowing the blades to be designed accordingly.

[0127] For the aforementioned blades 100 and 100a, Figure 4 The first cutting edge 101 of the blades 100b and 100c has angled peaks and valleys, while the weakening line 102 has blunted / flattened valleys 102b between the angled peaks 102a to provide a connection to the blade material behind it. The kerfs (in this case, laser kerfs 120a and 120b) are again used to create a gap around the forward-facing tooth 101, the gap being separated by multiple portions of solid material in the valleys 102b.

[0128] The aforementioned cutting blades 100, 100a, 100b, and 100c are all at least approximately straight (i.e., the cutting edge is generally straight). For example... Figure 5 As shown, the design is at least substantially the same as that of the blade breaking tool 150, and can therefore be used to break the desired portions 1 and 2 of the separating blade 100.

[0129] Tool 150 includes block 150, which has a length L along its length. C Extended channel 152. In the example shown, channel 152 extends along the entire length of block 150, opening at one end so that blade 100 or a portion of blade 100 can slide into it from either end. Channel 152 may also be referred to as a slit or groove. In some examples, channel 152 may be closed at one end and open at the other.

[0130] Channel 152 has a depth D selected to correspond to the blade depth D. C The depth D C The channel depth D is defined as the depth between the foremost point of the rear edge and the foremost point of the front edge of blade sections 1 and 2. C It can be selected to be equal to or slightly less than the blade depth D, such that only the foremost blade portion 1 (or blade portion 2 once blade portion 1 is removed) can be located within channel 152 to be broken.

[0131] In the example shown, the channel depth D CBetween 2 mm and 10 mm, more specifically, between 4 mm and 10 mm, and even more specifically, 6 mm. The channel 152 is chosen to have a width slightly wider than the blade thickness T (e.g., 0.5 mm or 1 mm wider than the blade thickness) so that the blade 100 can easily slide into the channel 152, but without much lateral movement within the channel.

[0132] Inserting the blade 100 into the channel 152 and then twisting / bending the blade while capturing the foremost blade portion 1 within the channel allows the foremost blade portion 1 to be neatly and broken off by hand without the user having to grip the serrated edge 101.

[0133] In the example shown, the length L of block 150 and therefore channel 152 C Approximately 50 mm. The blade length L, and more specifically, the edge length L of the blade used for cutting. E Typically greater than 50 mm—tool 150 can be applied to a portion of the blade length and then continue moving, where successive breaking actions (depending on the blade stiffness) are performed on different portions of the blade 100. In some examples, tool 150 can be positioned centered relative to the cutting edge, and even if tool 150 is shorter than the cutting edge, a single breaking action may be sufficient to separate the front blade portion 1. In other examples, such as for a shorter blade 100 or a longer tool 150, the entire length of the cutting edge can be fitted within the tool 150 at once. In this case, slit 152 may have a closed end instead of an open end.

[0134] In the example shown, the height H of block 150 C The dimensions are between 6 mm and 20 mm, and more specifically, approximately 8 mm. It should be understood that the size of the block 150 can be selected as needed for ease of handling and portability—the channel dimensions are set solely based on the blade 100, and the blade breaking tool 150 as a whole can take any desired shape (e.g., it does not need to be a cuboid). In some examples, the blade breaking tool 150 can be provided as part of a packaging housing for the blade 100 or as part of a packaging housing for a cutting tool including the blade 100—for example, a hard plastic toolbox may have marked channels for breaking the blade 100 on its lid or side.

[0135] Tool 150 is designed to assist in the complete separation of sections 1 and 2 of blade 100. Channel depth D CThe cuttings are carefully selected to ensure that only the foremost broken segment 1 is removed. Therefore, each tool 150 (and particularly the channel 152 of each tool) is designed with the parameters of the blade 100 it uses in mind—the size and shape of the channel 152 are determined to accommodate the blade 100 at the correct depth. This depth is at least approximately equal to the distance between the separation portions (i.e., the distance between the weakening lines 102, 103 or between the exposed cutting edge 101 and the first weakening line 102 behind that exposed cutting edge). This depth is approximately 6 mm or equal to 6 mm in the various examples described herein, but can be appropriately varied for different blades.

[0136] Figure 6 A circular oscillating blade 100d for a multi-tool or similar is shown, combined with a breaking tool 150a suitable for the circular blade 100d. An attachment portion 111 is centered relative to the blade 100d and takes the form of a universal connection point 111, as is known for multi-tool blades.

[0137] The exposed cutting edge 101 extends circumferentially around the insert 100d, forming an arc of approximately 270° with clearance for attachment to the tool. Two weakening lines 102 and 103 are located behind and spaced apart from the exposed cutting edge 101. The first weakening line 102 is spaced approximately 6 mm from the exposed cutting edge 101. The second weakening line 103 is spaced approximately 6 mm from the first weakening line 102. Therefore, each insert portion 1, 2 has a depth D of approximately 6 mm. Thus, the first weakening line 102 and the second weakening line 103 form an arc with radii 6 mm and 12 mm smaller than the radius R of the exposed cutting edge 101, respectively. These arcs are concentric circles.

[0138] In the example shown, the teeth 101a, 102a, 103a of the exposed cutting edge 101 and the weakening lines 102, 103 are aligned at an angle (their peaks lie on the same radial line). For the example discussed above, to facilitate the connection of the material in front of the weakening line to the material behind it, the valley 102b of the weakening lines 102, 103 is flattened, but the original cutting edge 101 can have sharp peaks and valleys.

[0139] Apart from the shape of the blade 100d, and especially the curvature of the cutting edge, the features and options correspond to the features and options of the blades 100-100c described above, and will not be repeated here.

[0140] Figure 7 A close-up view of a portion of the blade 100d is shown. Between each pair of teeth 102a, a "breakpoint" or connection point of solid material 102b is provided in each valley of the weakening line 102.

[0141] It should be understood that this design can be applied to any pitch P of the teeth—that is, for any number of teeth per inch. However, for relatively large gaps between teeth, it may be desirable to weaken or thin the solid material in the connecting portion 102b to facilitate breakage. Similarly, for relatively large teeth, thinning of the material or the use of multiple smaller perforations can replace the large gaps completely surrounding each tooth 102a, 103a to improve the overall blade strength or stiffness. In some examples, the weakening line may include multiple different blade weakening techniques—for example, shaped gaps around serrated points and perforations arranged in rows along the valleys between the serrated points (i.e., smaller and optionally circular gaps or holes through the blade material).

[0142] exist Figure 7 Two weakening lines 102 and 103 are shown; it will be understood that more or fewer weakening lines 102 and 103 may be provided in other examples, which are limited only by the blade size and the required strength.

[0143] Tool 150a has a curved shape to suit use with curved blade 100d. Tool 150a can slide onto and around the edge of blade 100d / blade 100d can slide into and along the channel 152a of tool 150a. Channel 152a is open at the end to allow this insertion and relative movement. Again, the depth D of channel 152a... C The depth of the portion 1 designed to be broken, corresponding to the blade 100d, and the thickness T of the channel 152a are selected. C It is selected to be equal to or slightly greater than the blade thickness.

[0144] Other sizes of tool 150a, such as H C It can be selected as needed for aesthetics and ease of use, provided that access to channel 152a is not blocked.

[0145] Figure 8 A top view and a perspective view of the bending tool 150a are shown. The tool 150a takes the general form of an arc, which in the example shown is oriented at an angle of approximately 90°—in other examples, a shorter or longer arc may be provided. The straight-line distance A between the ends of the tool 150a (and more specifically, the channel 152a) may be approximately 60 mm.

[0146] The curved tool 150a has a generally constant thickness, except in the upper / outer portion of the channel 152a, where angled corners or chamfers are provided at each outer corner of the tool. This allows for a more comfortable grip on the tool 150a near the weakening line of the blade during use.

[0147] As described above with respect to another tool 150, a single breaking motion with tool 150a may be sufficient to separate blade portion 1, or tool 150a may be repeatedly applied to blade 100d at different locations, where multiple breaking motions are used to completely separate blade portion 1. The radius R of tool 150a is selected to suit the radius of blade 100d. In particular, the radius of channel 152a at its base may precisely match the radius of the blade before any portions 1, 2 have been removed / for the largest blade size. It should be understood that the radius of the blade will decrease as portions are removed, and therefore the fit of subsequent portions 2 may be worse. For a generally circular blade 100d with a large number of removable portions 1, 2, 3, ..., an adjustable tool 150a or multiple tools 150a of different sizes may be provided.

[0148] exist Figure 8 In the example shown, the channel depth is approximately 6 mm to match the spacing between the cutting edge 101 and the weakening lines 102, 103. This can be appropriately adjusted according to the depth D of the blade portions 1, 2.

[0149] A channel thickness T of approximately 1.4 mm can be selected. C This can be appropriately adjusted according to the thickness of the blade 100 to receive the blade slidably without much lateral movement freedom (e.g., only 0.1 mm to 1.0 mm wider than the blade thickness T).

[0150] The tool height H can be selected as desired for ease of use / practical comfort. C It should be understood that the overall shape and size of tool 150a can vary significantly, provided that access to channel 152a is permitted.

[0151] Figure 9 A close-up view of the exposed (first) cutting edge 101 of the straight blade 100 and the first weakening line 102 thereafter is provided, which provides a second cutting edge once the first blade portion 1 is removed.

[0152] In the example shown, the serration height S of the second cutting edge 102 H Slightly lower than the serration height of the first cutting edge 101, this is due to the space occupied by the gap between the cuts around the serrations. In the example shown, the serration height S of the first cutting edge 101 is... H The serration height S of the second cutting edge 102 is approximately 2.5 mm. HThe pitch can be approximately 2.3 mm; for example, the gap has a width of approximately 0.2 mm. In the example shown, the pitch P from the serration peak to the serration peak of the first cutting edge 101 is approximately 2.5 mm, and for the first weakening line 102 it is approximately 3.5 mm. The wider pitch of the weakening line allows for more space for the valley 102b, in which the first blade portion 1 connects to the second blade portion 2, while providing serrations of similar size and shape to the first, exposed cutting edge.

[0153] The weakening line 102 includes a gap 102a surrounding the serration peaks and a solid material portion 102b in the valley between the serrations. The weakening line 102 includes straight portions parallel to the length of the blade 100 between the forward-facing serrations. In the example shown, each straight portion / valley has a valley width T of approximately 2 mm. W For the angled bevel of the serration, 0.75 mm is left on each side of the valley 102b.

[0154] These comparisons between the first cutting edge 101 and the weakening line 102 are provided only by way of non-limiting example, and it will be understood that the sawtooth height, angle, and spacing P can all be selected individually for each (exposed and exposed) cutting edge 101, 102, 103 as needed.

[0155] Figure 10 The diagram illustrates three different ways in which the blade 100 can cut serrations. For example, the exposed cutting edge 101 has a height S. H In the case of a zigzag pattern of serrated edges, there are no flat valleys between them, and it is desirable to provide weakening lines 102, 103 with the same serration peak spacing and angle, but flat valleys 102b are provided between them to connect the blade portions 1, 2, and the placement of the valleys 102b is optional. Sections of the blade within these "valleys" 102b remain uncut to maintain blade integrity, while in various examples, other sections 102a of the blade material along the weakening lines 102, 103 are completely removed (or thinned in other examples). The longer the valley 102b, the stronger the blade, and consequently, the more difficult it is to break the blade portion. The shorter the valley 102b, the weaker the blade, and consequently, the easier it is to break the blade portion. In various embodiments, the valleys may have a maximum length of 6 mm, and optionally a maximum length of 4 mm or 3 mm. Therefore, heights H1, H2, and H3 (with valley 102b located at these heights) must be selected to provide sufficient strength for the insert to perform its function, while also allowing for effective and complete breakage along the weakening line 102. It should be understood that this balance will depend on the intended material to be cut, the insert thickness, and the insert material (typically carbide steel).

[0156] For a given blade 100 with a gap around the serrated peaks, the strength of the blade 100 and the ease with which the blade can be broken are determined by the amount of material remaining between each serration of the blade. Figure 10 In the diagram, A, B, and C represent the distances between the tips of the saw teeth and the valleys 102b, which form the break points of the weakening line 102. The deeper the "valley" between the saw teeth in the uncut portion (i.e., the greater the distances A, B, and C), the easier it is for the blade portion 1 to break, because the solid connecting portion of the weakening line 102 is shorter—meaning less connecting material.

[0157] In summary, between each pair of forward-facing tips of the serrations, there is a trough, and at the bottom of each trough, there is a connection point between the foremost blade segment 1 and the segment 2 behind it. The lower the connection point into the trough, the easier it is to break blade segment 1, because less material is needed to hold segments 1 and 2 together.

[0158] In some examples, the depths A, B, and C can vary between the weakening lines, for example, so that the first segment 1 of blade 100 is easier to break than the subsequent segments. This reduces the risk of breaking more than one segment 1 or 2 at a time.

[0159] Figure 11 A blade 100e for a multi-tool is shown, which has a different... Figure 6 The cutting edge of the 100d blade shown is straight, with a circular cutting edge. It can be provided with... Figure 6 Similar to the attachment portion 111 shown, as will be appreciated, both straight and round cutting inserts can be used with the same oscillating cutter. The following discussion focuses on the differences from the inserts 101-101d described above to avoid repetition.

[0160] In this example, the cutting edge extends across the entire length L of the insert 100e (here, to be consistent with the inserts 100-100c described above, the insert length L is defined as parallel to the cutting edge; however, it should be understood that, considering...) Figure 11 The overall dimensions of the blade 100e shown are more commonly referred to as the blade width, and the longer range of the blade from its front to its back is described as its length.

[0161] The blade 100e, similar to most known multi-tool blades, has an attachment section 111 that is formed separately from the rest of the blade. The attachment section 111 is formed by... Figure 11 The spot weld 111a, schematically indicated in the diagram, is permanently bonded to the remainder of the blade. Other ways of bonding these sections are possible, and in some examples, the attachment section 111 and the remainder of the blade may instead be made of a single continuous sheet of material (e.g., carbide steel).

[0162] Figure 11 The cutting blade 100e has eight weakening lines 102-109 behind the exposed cutting edge 101, thus providing a total of nine cutting edges 101-109 that can be used consecutively, breaking off one blade portion 1-8 at a time when the currently exposed cutting edge is worn, damaged, or otherwise no longer needed. In the example shown, the weakening lines 102-109 are identical to each other, such that each cutting edge 102-109 they provide is substantially the same. For the first exposed cutting edge 101 shown, the pitch is slightly smaller because for the first edge, the valley 102b, which serves as a connecting portion, is not required. In other examples, all cutting edges 101-109 may be identical, or there may be variations between the cutting edges 101-109.

[0163] By providing a tool 150 with a slit 150a (which is slightly smaller than the spacing D between lines 101-109), the initial portion of blade segment 1 can be reliably broken off along the first weakening line 102, and each subsequent blade segment 2-8 can correspondingly be broken off along the next weakening line 103-109 at each stage. In this example, this can be done eight times before the blade 100e is finally completely worn and must be discarded, each time exposing a new, sharp, serrated edge.

[0164] In the example shown, the cutting edges 101-109 end at the cutting peak of the serration on either side of the insert 100e (rather than in the valley or midway through the serration) – this helps to provide a clean cut to the right side of the insert 100e. At each extreme lateral edge of the insert 100e, on each weakening line, the gap 102a extends all the way to the edge of the insert material to form points 101a, 102a, 103a at each edge of the insert 100e. This means that when the front portion 1 is removed to expose the new serrated edges 102-109, the new serrated edges are also able to cut along their length. This can be important for fine, detailed cutting work that often uses oscillating tools.

[0165] Figure 12 Provided Figure 11 A close-up view of a portion of the blade, showing the second blade segment 2 separated from the rest of the blade 100e. An arrow diagram between the second blade segment 2 and the third blade segment 3 illustrates how the blade segments are assembled together. The first blade segment 1 is not shown—in fact, this first blade segment has been removed.

[0166] Note the space / trough 102b between the sawtooths in front of and behind the weakening line 103 (i.e., in Figure 11The portion (joined together by the continuous material connecting the front portion 2 and the rear portion 3) has been broken off, causing the front blade section 2 to separate from the rest of the blade 100e. In some examples, the valley 102b may include perforated lines or shallow etched lines into the material to facilitate a neat break along the weakening lines 102-109. In other examples, the material in the valley 102b may be the same as the blade material within the blade sections 1-8, and the weakening lines across the valley 102b may be defined only by the weakening points at the ends and beginnings of the serrations 102a sandwiched between the valleys 102b. In the example shown, these serrations 102a are defined by gaps (continuous areas of cut material outlining the serration peaks), but in other examples, the material may be weakened differently to define the serrations, for example, by thinning the material (e.g., by etching) or by providing a row of discontinuous perforations instead of continuous gaps. For example, closely spaced perforations may be provided around the teeth, and wider-spaced perforations may be provided in the valleys between the teeth.

[0167] Any of the aforementioned blades 100-100e can be supplied as a set of parts together with blade-breaking tools 150, 150a of appropriate shape.

[0168] The method of exposing the new cutting edge of the 100-100e serrated insert for use can be performed using this kit of parts in the following manner:

[0169] Insert the foremost portion of the blade 100-100e into the channels 152, 152a of the blade breaking tools 150, 150a, such that at least a portion of the exposed cutting edge 101 of the blade rests on the base of the channel; and

[0170] Move the blade breaking tool 150, 150a relative to the blade 100-100e in a direction at least generally perpendicular to the blade plane so as to break the blade portion 1 between the exposed cutting edge 101 and the weakening line 102 behind it.

[0171] For a straight blade breaking tool, the blade breaking tool 150 can rotate about an axis parallel to the length of the channels 152, 152a (which is also parallel to the cutting edge) to break the blade portion 1, or the blade breaking tool 150 can move laterally relative to the blade.

[0172] Similarly, for a curved blade breaking tool, the blade breaking tool 150a can rotate about an axis tangent to the curve of the channel 152a (thus partially parallel to the channel where the tangent contacts the curve of the channel), or the blade breaking tool 150 can move laterally relative to the blade to break off the portion 1 away from the blade.

[0173] Any of these combinations can be defined as providing relative movement of the blade breaking tools 150, 150a and the blades 100-100e perpendicular to the blade plane.

[0174] This relative movement can be generated by moving the blade while the blade breaking tools 150, 150a remain stationary. Similarly, the blade breaking tools 150, 150a can be moved while the blade 100 remains stationary, or both can move.

[0175] Cutting tools comprising any of the blades 100-100e described above may be provided—blades 100-100e may be detachably attached to the cutting tool or may be permanently attached to the cutting tool (e.g., by welding). The cutting tool may be a hand tool or a power tool such as a multi-tool. The cutting tool may be a saw.

[0176] The specific blades and tools described above are provided by way of example only, and various changes and modifications will be apparent to those skilled in the art without departing from the scope of the invention as defined by the appended claims.

Claims

1. A tool insert comprising an exposed serrated cutting edge and a first weakening line behind and spaced apart from the exposed serrated cutting edge, the weakening line being shaped to provide a second serrated cutting edge when the insert breaks along the weakening line, and wherein, The distance between the foremost point of the exposed serrated cutting edge and the foremost point of the second serrated cutting edge is at least 2 mm.

2. The tool blade according to claim 1, wherein, The tool blade is at least one of the following: (i) Saw blades; and (ii) Hand tool blades.

3. A saw blade comprising an exposed serrated cutting edge and at least one weakening line, the at least one weakening line being located behind and spaced apart from the exposed serrated cutting edge, the weakening line being shaped to provide a second serrated cutting edge when the blade breaks along the weakening line.

4. The tool blade according to any one of the preceding claims, wherein, The weakening lines are weaker at and around the forward-facing cutting point of each tooth and stronger in the valleys between adjacent teeth, and optionally, the average thickness of the material forming the blade along the weakening lines or each weakening line is lower than the average thickness of the material forming the blade adjacent to the weakening lines or each weakening line.

5. The tool insert according to any one of the preceding claims further includes an additional weakening line following the first weakening line, each additional weakening line being shaped to provide an additional serrated cutting edge when the insert breaks along the weakening line.

6. The tool blade according to any one of the preceding claims, wherein: (i) Each serrated cutting edge takes the form of at least a generally straight line, has serrations along said at least a generally straight line, and the weakening line or each weakening line is at least generally parallel to the exposed serrated cutting edge; or (ii) Each serrated cutting edge takes the form of a circle or arc, has serrations along the circle or arc, and the weakening line or the curve of each weakening line is concentric with the curve of the exposed serrated cutting edge.

7. The tool blade according to any one of the preceding claims, wherein, The weakening line, or each weakening line, includes: (i) forming gaps in the material of the blade in the region at each point of the serration; and (ii) A solid portion of the blade material is formed in the valley region between adjacent pairs of saw teeth.

8. The tool blade according to any one of the preceding claims, wherein, The weakening line or each weakening line is or includes a solid material line with a thickness less than the thickness of the blade between the weakening lines, and wherein, optionally, the thickness of the material forming the weakening line varies along the weakening line, being thinnest in the region of the serrated cutting point and thickest in the valley between the serrated cutting points.

9. The tool blade according to any one of the preceding claims, wherein, The weakening line or each weakening line is or includes a row of perforations passing through the blade, wherein optionally, the perforations are larger and / or more closely spaced in the region of the sawtooth cutting point.

10. The tool blade according to any one of the preceding claims, wherein, The weakening line, or each weakening line, is or includes a gap at each serration of the serrated cutting edge formed by the weakening line in the material forming the blade, the shape of the gap defining the shape of the serrated cutting point.

11. The tool blade according to claim 7, wherein, The blade has a thickness T between the weakening lines, and wherein the solid portion of the weakening line along the points of the serrations is thinner than the thickness T.

12. The tool blade according to claim 7 or any claim dependent to claim 7, wherein, Apply at least one of the following: (i) One of the gaps forming part of the weakening line extends to the edge of the blade at one end of the cutting edge, such that the gap forms the extreme point of the blade; as well as (ii) Each gap has at least a substantially constant width, all gaps are optionally the same in width, and wherein, optionally, the gap width is in the range of 0.1 mm to 0.3 mm.

13. The tool blade according to claim 7 or any claim dependent on claim 7, wherein: (i) At least one of the gaps is generally V-shaped, with the point of V facing forward; and / or (ii) At least one of the gaps is generally W-shaped, with two points facing forward and one point facing backward.

14. The tool blade according to claim 7 or any claim dependent to claim 7, wherein, Each valley takes the form of a straight line parallel to the cutting edge between the forward-facing serrations.

15. The tool blade according to claim 7 or any claim dependent to claim 7, wherein, Each gap is a continuous gap extending between a pair of adjacent valleys and defining the shape of the forward-facing serrations, the gaps optionally having at least a substantially constant width.

16. The tool blade according to any one of the preceding claims, wherein, The distance between the foremost point of the exposed serrated cutting edge and the foremost point of the second serrated cutting edge is 4 mm to 6 mm.

17. The tool blade according to claim 7 or any claim dependent to claim 7, wherein, Each gap has a width of at least 0.1 mm along the surface of the blade, and optionally from 0.1 mm to 0.5 mm.

18. The tool blade according to any one of the preceding claims, wherein, The weakening line or each weakening line includes at least 25%, 30%, or 35% of a solid material of the same thickness as the rest of the blade along its length.

19. The tool blade according to any one of the preceding claims, wherein, The weakening line or each weakening line comprises at least 30%, 45%, or 50% of the length of the cutting edge parallel to the blade length, of solid material with the same thickness as the rest of the blade.

20. The tool blade according to any one of the preceding claims, wherein, The cutting point of the serration is located at one extreme end of the serrated cutting edge, and optionally, the cutting point of the serration is located at each extreme end of the serrated cutting edge, such that there is a forward-facing point at each lateral end of the blade.

21. A tool comprising a blade according to any one of the preceding claims.

22. The tool according to claim 21, wherein, The tool is at least one of a hand tool and a saw.

23. A blade-breaking tool for breaking off the exposed edge of a serrated blade according to any one of claims 1 to 20, wherein, The blade breaking tool includes a channel sized and shaped to receive the exposed serrated cutting edge and a front portion of the blade extending from the exposed serrated cutting edge, and the depth of the blade breaking tool corresponds to the interval between the exposed serrated cutting edge and a first weakening line behind the exposed serrated cutting edge, such that only a first portion of the blade is received within the channel, the channel having a depth of at least 2 mm.

24. A set of parts, comprising: The blade according to any one of claims 1 to 20; as well as The tool according to claim 23, wherein the size and shape of the channel of the tool are determined to accommodate the blade.

25. A method for exposing a new cutting edge of a serrated blade for use, the method comprising: The foremost portion of the blade according to any one of claims 1 to 20 is inserted into the channel of the tool according to claim 23, such that at least a portion of the exposed cutting edge of the blade rests on the base of the channel; as well as The tool is moved relative to the blade in a direction perpendicular to the blade to break off the portion of the blade located between the exposed cutting edge and the weakening line behind the exposed cutting edge.

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