Edge trimmer blade with coated surfaces

Abstract

Embodiments of a blade for a lawn edging tool are disclosed. The blade comprises a blade body with a first main surface, a second main surface, and a secondary surface. The second main surface faces the first main surface, and the secondary surface connects the first main surface and the second main surface around the circumference of the blade body. A coating layer is arranged at least partially around the circumference of the blade body on the secondary surface. The coating layer comprises particles of a carbide or an abrasive material.

Description

Reference to related patent applications

[0001] The present application claims priority over U.S. Preliminary Application No. 63 / 746.383, filed on January 17, 2025, U.S. Preliminary Application No. 63 / 727.937, filed on December 4, 2024, and U.S. Provisional Application No. 63 / 725.198, filed on November 26, 2024, which are hereby incorporated in their entirety by reference. BACKGROUND OF THE INVENTION

[0002] The present disclosure relates generally to tool knives. The present disclosure relates specifically to a knife for an edge trimmer with a coated edge. SUMMARY OF THE INVENTION

[0003] Various embodiments of the present disclosure relate to a knife for an edge cutter with a coating along one or more knife edges. In various embodiments, areas of the edge-cutting knife subject to high wear include a coating, in particular a cutting edge with carbide or abrasive particles.

[0004] In a first aspect, embodiments of the disclosure relate to a blade for a lawn edging tool. The blade comprises a blade with a first main surface, a second main surface, and a secondary surface. The second main surface is opposite the first main surface, and the secondary surface connects the first main surface and the second main surface around a circumference of the blade. A coating layer is arranged on the secondary surface at least partially around the circumference of the blade body. The coating layer comprises at least one abrasive material or a carbide.

[0005] In a second aspect, embodiments of the disclosure relate to the knife according to the first aspect, wherein the secondary surface comprises a first longitudinal edge, a second longitudinal edge, a first side edge, and a second side edge. The second longitudinal edge is opposite the first longitudinal edge, and the second side edge is opposite the first side edge. The first longitudinal edge and the second longitudinal edge each comprise a first length, and the first side edge and the second side edge each comprise a second length. The second length is shorter than the first length.

[0006] In a third aspect, embodiments of the disclosure relate to the knife according to the second aspect, in which the coating layer is arranged on each of the first side edge and the second side edge.

[0007] In a fourth aspect, embodiments of the disclosure relate to the knife according to the second aspect, in which the coating layer is arranged on each of the first longitudinal edge and the second longitudinal edge.

[0008] In a fifth aspect, embodiments of the disclosure relate to the knife according to the fourth aspect, wherein the coating layer on each of the first longitudinal edge and the second longitudinal edge comprises a first coating section and a second coating section, which is separated from the first coating section by a blank section.

[0009] In a sixth aspect, embodiments of the disclosure relate to the knife according to the fourth aspect or the fifth aspect, in which the coating layer is further arranged on the first side edge and the second side edge.

[0010] In a seventh aspect, embodiments of the disclosure relate to the knife according to any one of aspects three to six, wherein the coating layer is further arranged in one or more strips on at least one of the first principal surface or the second principal surface.

[0011] In an eighth aspect, embodiments of the disclosure relate to the knife according to the sixth aspect, wherein the first longitudinal edge comprises a first curved region arranged proximal to the first lateral edge, and the second longitudinal edge comprises a second curved region arranged proximal to the second lateral edge. The coating layer is arranged in the first curved region and in the second curved region.

[0012] In a ninth aspect, embodiments of the disclosure relate to the knife according to any one of the first to eighth aspects, wherein the coating layer comprises particles of at least one of carbide, nitride, boride, oxide or diamond in a binder.

[0013] In a tenth aspect, embodiments of the disclosure relate to the knife according to any aspect from the first to the ninth aspect, wherein the coating layer further comprises a barrier layer arranged between the secondary surface and the carbide material.

[0014] In an eleventh aspect, embodiments of the disclosure relate to an edge-cutting knife. The edge-cutting knife comprises a knife body with a first main surface, a second main surface, and a secondary surface. The second main surface is opposite the first main surface, and the secondary surface connects the first main surface and the second main surface around a circumference of the knife body. The secondary surface comprises a first longitudinal edge, a second longitudinal edge, a first side edge, and a second side edge. A coating layer is arranged on at least one of the first main surface, the second main surface, the first longitudinal edge, the second longitudinal edge, the first side edge, or the second side edge. The coating layer has a hardness in the range of 800 HV to 1500 HV.

[0015] In a twelfth aspect, embodiments of the disclosure relate to the edge-cutting knife of the eleventh aspect, wherein an average distance between the first principal surface and the second principal surface defines a thickness of the knife body and wherein the thickness is in a range of 1 mm to 5 mm.

[0016] In a thirteenth aspect, embodiments of the disclosure relate to an edge-cutting knife of the eleventh aspect or the twelfth aspect, wherein the first longitudinal edge and the second longitudinal edge each have a length in the range of 150 mm to 250 mm.

[0017] In a fourteenth aspect, embodiments of the disclosure relate to the edge-cutting knife of the thirteenth aspect, wherein the first side edge and the second side edge each have a length in the range of 35 mm to 65 mm.

[0018] In a fifteenth aspect, embodiments of the disclosure relate to the edge-cutting knife of any one of the eleventh to fourteenth aspects, wherein the coating layer is arranged on the first side edge and on the second side edge, and wherein the coating layer extends over at least 50% of the length of each of the first side edge and the second side edge.

[0019] In a sixteenth aspect, embodiments of the disclosure relate to the edge-cutting knife of the fifteenth aspect, wherein the coating layer is also arranged on each of the first longitudinal edge and the second longitudinal edge. On each of the first longitudinal edge and the second longitudinal edge, the coating layer comprises a first coating section and a second coating section. The first coating section is separated from the second coating section by a bare section without a coating layer, and each of the first coating sections and the second coating sections extends over at least 25% and less than 50% of a length of the respective first longitudinal edge and second longitudinal edge.

[0020] In a seventeenth aspect, embodiments of the disclosure relate to the edge-cutting knife of the sixteenth aspect, wherein the coating layer further comprises at least one strip arranged on at least one of the first principal surfaces or the second principal surface.

[0021] In an eighteenth aspect, embodiments of the disclosure relate to the edge-cutting knife of the seventeenth aspect, wherein the knife body defines an opening extending from the first principal surface to the second principal surface, and wherein the at least one strip comprises a first strip and a second strip arranged on opposite sides of the opening.

[0022] In a nineteenth aspect, embodiments of the disclosure relate to the edge-cutting knife of the sixteenth aspect, wherein the first longitudinal edge comprises a first curved region arranged proximal to the first lateral edge, and the second longitudinal edge comprises a second curved region arranged proximal to the second lateral edge. The coating layer is arranged in the first curved region and in the second curved region.

[0023] In a twentieth aspect, embodiments of the disclosure relate to the edge-cutting knife of any of the eleventh to nineteenth aspects, wherein the coating layer comprises particles of at least one of the following materials in a binder: carbide, nitride, boride, oxide or diamond.

[0024] Further features and advantages are set forth in the following detailed description and are, in part, readily apparent to those skilled in the art from the description or by carrying out the embodiments as described in the written description, which includes the accompanying drawings. It should be understood that both the foregoing general description and the following detailed description are exemplary.

[0025] The accompanying drawings, which are included for further understanding, form part of this description. The drawings illustrate one or more embodiments and, together with the description, serve to explain the principles and operation of the various embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] This application will be better understood with reference to the following detailed description in conjunction with the attached figures, where the same reference numerals denote the same elements: The Fig. Figures 1A-1C show an edge-cutting power tool comprising its use, with a coated blade, according to an exemplary embodiment of the present disclosure; Fig. Figures 2A-2E show a knife with a carbide coating in various configurations according to exemplary embodiments of the present disclosure; Fig. Figure 3 shows a cross-section of a knife with a coated edge comprising a barrier layer and a carbide layer, according to an exemplary embodiment of the present disclosure; Fig. Figure 4 schematically shows a deposition process for applying the coating layer to the edge of a material strip for the knife body according to an exemplary embodiment of the present disclosure. Fig. Figure 5 shows a cross-sectional view of a knife with a coated edge comprising only the carbide layer, according to an exemplary embodiment of the present disclosure. Fig. Figure 6 shows a flowchart of a method for applying the coating layer to the edge of the knife body according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0027] With general reference to the figures, various embodiments of a blade for an edge-cutting power tool with a carbide edge are shown. In various embodiments, areas of the edge-cutting blade subject to high wear comprise a carbide layer and, in particular, a carbide cutting edge. A carbide deposition method for forming a carbide layer on an edge-cutting blade is also shown. Exemplary edge cutting power tool

[0028] Fig. Figure 1A shows an exemplary embodiment of an edge-cutting power tool 10. The edge-cutting power tool 10 comprises a drive mechanism 12, which is arranged at a first end 14 of the edge-cutting power tool 10, and an edge-cutting device 16, which is arranged at a second end 18 of the edge-cutting power tool 10. A rod 20 is arranged between the drive mechanism 12 and the edge-cutting device 16. The drive mechanism 12 comprises a first handle 22, which includes an actuating mechanism, for example, one or more triggers or pushbuttons, for activating the drive mechanism 12 to drive the edge-cutting device 16. A user holds the first handle 22 in a first hand to control the operation of the drive mechanism 12.Furthermore, in one or more embodiments, a second handle 24 is arranged on the rod 20 near the drive mechanism 12, with which the user steers and holds the power tool 10 with a second hand.

[0029] In one or more embodiments, the drive mechanism 12 is electrically driven. For example, the drive mechanism 12 can be, as in Fig. Figure 1A shows a removable battery pack 26. In one or more other embodiments, the drive mechanism 12 can be electrically powered via a mains cable connected to a wall socket. In one or more further embodiments, the drive mechanism can, for example, be powered by an internal combustion engine that runs on gasoline.

[0030] Fig. Figure 1B shows a detailed view of the edge-cutting device 16. The edge-cutting device 16 operates with a rotating blade 28. The blade 28 is mounted on a shaft 30, which is driven by the drive mechanism 12. The drive mechanism 12 can drive the shaft 30 in various ways. For example, the drive mechanism 12 can drive a drive shaft located inside the rod 20, which is mechanically connected to the shaft 30 via a gear, such as a bevel gear assembly. In this way, actuation of the drive mechanism 12 at the first end 14 of the power tool 10 causes the blade 28 of the edge-cutting device 16 at the second end 18 of the power tool 10 to rotate.

[0031] In one or more embodiments, the blade 28 is at least partially enclosed by a cover 31 to provide protection against accidental contact with the blade 28. Furthermore, in one or more embodiments, the cover 31 may include a wheel 32 that rolls across the ground and adjusts the depth of the blade 28 during edging. In yet another embodiment, the cover 31 includes a flap 34 configured to prevent grass, dirt, and other debris from being thrown back at the user during edging.

[0032] Fig. Figure 1C shows the power tool 10 in operation. In particular, a user 200 holds the power tool 10 and moves it, for example, along a boundary 202 between a grass section 204 and a paved surface 206. As shown in Fig. As shown in Figure 1C, the wheel 32 rolls over the paved surface 206, with the blade 28 pointing towards the grass 204 and the cover 31 towards the paved surface 206. Example of the coating on the knife

[0033] The Fig. Figures 2A-2E show exemplary embodiments of the blades 28 configured for use with the power tool 10. As explained in more detail below, each embodiment of the blades 28 comprises one or more edges that are at least partially coated with a carbide layer. Each blade 28 comprises a body 29 with a first principal surface 35 and a second principal surface 36 opposite the first principal surface 35. A secondary surface 37 of the blade body 29 connects the first principal surface 35 to the second principal surface 36 around the circumference of the blade body 29. The first principal surface 35, the second principal surface 36, and the secondary surface 37 together define the boundaries of the body 29 of the blade 28.

[0034] In one or more embodiments, an average distance between the first main surface 35 and the second main surface 36 defines a thickness of the knife 28, wherein the thickness is in a range of 1 mm to 5 mm, in particular in a range of 2 mm to 4 mm and most especially in a range of 2 mm to 3 mm.

[0035] As in the Fig. As shown in Figures 2A-2E, the knife 28 comprises a central opening 38 extending from the first main surface 35 through the body 29 to the second main surface 36. In one or more embodiments, the central opening 38 has a diameter in the range of 20 mm to 30 mm, in particular about 25 mm. The shaft 30 (as shown in Figures 2A-2E) Fig. (shown in 1B) is inserted through the central opening 38 to connect the knife 28 to the edge cutting device 16.

[0036] The secondary surface 37 comprises a first longitudinal edge 37a, a second longitudinal edge 37b, a first lateral edge 37c, and a second lateral edge 37d. The first longitudinal edge 37a is opposite the second longitudinal edge 37b, and the first lateral edge 37c is opposite the second lateral edge 37d. The edges 37a-d define a generally rectangular perimeter of the knife 38, wherein the first longitudinal edge 37a and the second longitudinal edge 37b are longer than the first lateral edge 37c and the second lateral edge 37d. In one or more embodiments, the first longitudinal edge 37a and the second longitudinal edge 37b each have a length in the range of 150 mm to 250 mm, particularly in the range of 175 mm to 225 mm, and most especially in the range of 195 mm to 205 mm.In one or more embodiments, the first side edge 37c and the second side edge 37d each have a length in the range of 35 mm to 65 mm, in particular in the range of 45 mm to 55 mm and most especially in the range of 47 mm to 52 mm.

[0037] As in relation to the in the Fig. As explained in the embodiments shown in Figures 2A-2E, the knife 28 comprises a coating layer 39 on one or more of the first main surface 35, the second main surface 36 or the edges 37a-d.

[0038] With reference to Fig. In embodiment 2A, the knife 28 comprises the coating layer 39 on the first side edge 37c and the second side edge 37d. In one or more embodiments, the coating layer 39 covers at least 50% of each side edge 37c, 37d, in particular at least 75% of each side edge 37c, 37d, and most particularly at least 90% of each side edge 37c, 37d. In one or more embodiments, the coating layer 39 covers up to 100% of each side edge 37c, 37d. In one or more embodiments, the coating layer 39 is continuous or interrupted along the length of each side edge 37c, 37d.

[0039] With reference to Fig. In 2B, the knife 28 comprises the coating layer 39 on the first longitudinal edge 37a and the second longitudinal edge 37b. In one or more embodiments, the coating layer 39 comprises a first coating section 60a and a second coating section 60b with a bare (i.e., uncoated) section 62 located between the first coating section 60a and the second coating section 60b. In one or more embodiments, the first coating section 60a extends along the first longitudinal edge 60a from the first side edge 37c to less than 50% of the length of the first longitudinal edge 60a, for example, to 40% of the length of the first longitudinal edge 60a. In one or more embodiments, the first coating section 60a extends along the first longitudinal edge 60a from the first side edge 37c to at least 25% of the length of the first longitudinal edge 60a.In one or more embodiments, the second coating section 60b extends along the first longitudinal edge 60a from the second side edge 37d to less than 50% of the length of the first longitudinal edge 60a, for example, to 40% of the length of the first longitudinal edge 60a. In one or more embodiments, the second coating section 60b extends along the first longitudinal edge 60a from the second side edge 37d to at least 25% of the length of the first longitudinal edge 60a. The second longitudinal edge 37b can comprise a first coating section 60a, a second coating section 60b, and a blank section 62, as described with respect to the first longitudinal edge 37a.

[0040] With reference to Fig. 2C The knife 28 comprises the coating layer 39 at the first longitudinal edge 37a, the second longitudinal edge 37b, the first side edge 37c and the second side edge 37d. In one or more embodiments, the coating layer 39 at the first side edge 37c and the second side edge 37d is as described in relation to Fig. 2A described, and the coating 39 on the first longitudinal edge 37a and the second longitudinal edge 37b is as described in relation to Fig. 2B described. Thus, the in Fig. 2C embodiment as a combination of the features relating to Fig. 2A and Fig. The embodiments shown and described in 2B are considered.

[0041] Fig. Figure 2D shows a further embodiment of the knife 28, in which the coating layer 39 is provided on the first longitudinal edge 37a, the second longitudinal edge 37b, the first side edge 37c and the second side edge 37d, as shown in Fig. 3C shown, and in the embodiment of Fig. In embodiment 2D, the knife 28 further comprises one or more strips 64 of the coating layer 39 on the first main surface 35 and / or the second main surface 36. In one or more embodiments, the strips 64 have a length that is 10% to 40% of the length of the first longitudinal edge 37a. As in Fig. As shown in Figure 2D, the knife 28 comprises a strip 64 on each side of the central opening 38, positioned proximal to the respective side edge 37c, 37d; however, in one or more other embodiments, the knife 28 may comprise a plurality of strips 64 arranged on each side of the central opening 38 and spatially separated from each other between the first longitudinal edge 37a and the second longitudinal edge 37b.

[0042] In one or more other embodiments, including those in Fig. In the embodiment shown in Figure 2E, the first longitudinal edge 37a and the second longitudinal edge 37b each comprise a curved region 66. In one or more embodiments, the curved region 66 of the first longitudinal edge 37a is arranged proximal to the first lateral edge 37c, and the curved region 66 of the second longitudinal edge 37b is arranged proximal to the second lateral edge 37d.

[0043] In one or more embodiments, the curved area 66 has a maximum depth from the longitudinal edge 37a, 37b in a range of 5 mm to 30 mm, in particular in a range of 10 mm to 20 mm.

[0044] In one or more embodiments, the knife 28 comprises the coating layer 39 over the curved area 66 of both the first longitudinal edge 37a and the second longitudinal edge 37b. Furthermore, in one or more embodiments, the coating layer 39 is also arranged on the first side edge 37c and the second side edge 37d. Exemplary method for applying a coating

[0045] In various embodiments, the knife 28 shown here is used as in the Fig. 3-6 shown trained. As in Fig. As shown in Figure 3, the coating layer 39 comprises a hard phase layer 40 and optionally a barrier layer 42, which is applied to the knife body 29. The knife body 29 forms the most substantial part of the knife 28. In one or more embodiments, the hard phase layer 40 is applied directly to the knife body 29, for example, to one or more of the edges 37a-d, the first main surface 35, and / or the second main surface 36. In one or more other embodiments, however, the barrier layer 42 can optionally be arranged between the knife 29 and the hard phase layer 40, continuously separating the knife 29 from the hard phase layer 40. In one or more such embodiments, the barrier layer 42 can be used to prevent the diffusion of elements from the knife body 29 into the hard phase layer 40, which could cause the hard phase layer 40 to become too brittle.

[0046] In one or more embodiments, the knife body 29 is formed from a steel alloy, such as 65Mn steel.

[0047] In one or more embodiments, the hard-phase layer 40 comprises one or more carbide materials or abrasive particles in a binder. In one or more embodiments, the carbide materials comprise at least one of tungsten carbide (WC), chromium carbide (e.g., Cr3C2), titanium carbide (TiC), tantalum carbide (TaC), or niobium carbide (NbC), among other possibilities. In one or more embodiments, the abrasive particles comprise at least one of nitrides (e.g., cubic boron nitride and silicon nitride), borides (e.g., silicon boride), oxides (e.g., aluminum oxide), or diamond. In one or more embodiments, the binder comprises at least one of nickel, cobalt, chromium, iron, or molybdenum, among other possibilities. In one or more embodiments, the hard-phase layer 40 comprises the carbide or abrasive material in an amount ranging from 25 wt.% to 95 wt.%, particularly from 30 wt.% to 90 wt.%.In one or more embodiments, the hard phase layer 40 comprises binder material in an amount ranging from 5 wt.% to 75 wt.%, in particular from 10 wt.% to 70 wt.%. In one or more particular embodiments, the hard phase layer 40 is formed from a powder mixture comprising tungsten carbide (WC) in cobalt (Co) and chromium (Cr).

[0048] In one or more embodiments in which the barrier layer 42 is provided, the barrier layer 42 comprises a metal or alloy that is different from the material of the knife body 29 in order to prevent diffusion of the material of the knife body 29 into the hard phase layer 40. In particular, the barrier layer 42 does not contain the primary elemental constituent of the metal or alloy of the knife body 29. For example, if the knife body 29 is made of a steel alloy, the barrier layer 42 does not contain iron. In one or more embodiments, the barrier layer 42 comprises a cobalt-chromium alloy, which in particular comprises about 28 wt.% to about 29 wt.% chromium, about 5 wt.% to about 6 wt.% molybdenum, and the remainder cobalt.

[0049] Fig. Figure 4 shows an embodiment of an arrangement for applying the hard phase layer 40 (and the barrier layer 42, if present) to a strip of material 44 for the knife body 29. As in Fig. As shown in Figure 4, a laser 46 emits a beam 48 onto an edge surface 50 of the strip 44, melting the strip 44 in the region of the edge surface 50. A nozzle 52 directs powder 54 of the material of the hard-phase layer 40 (or the barrier layer 42, if present) onto the molten edge surface 50 of the strip 44, causing the powder 54 to melt and fuse with the knife strip 44. During application, the strip 44, the laser 46, and the nozzle 52 move relative to each other. In one or more embodiments, the laser 46 and the nozzle 52 are stationary, and the strip 44 moves past the laser 46 and the nozzle 52. In one or more other embodiments, the laser 46 and the nozzle 52 move over a stationary strip 44.

[0050] In one or more embodiments, the powder 54 comprises particles of the abrasive or the metals that constitute the hard phase layer 40. In one or more embodiments, the powder 54 of the hard phase layer 40 comprises metal alloy powder and carbon powder. In such embodiments, carbides (such as tungsten carbide and / or chromium carbide) precipitate in the melt pool and solidify in the metal matrix during cooling. The metal alloy particles can generally be spherical and have a size of up to 120 micrometers, particularly in the range of 11 to 53 micrometers. The carbon powder can have a flocculent morphology with an average particle size of up to 120 micrometers, particularly in the range of 7 to 11 micrometers.

[0051] In one or more other embodiments, the powder comprises 54 carbide particles and binder particles. In one or more embodiments, the carbide particles comprise, for example, tungsten carbide and the binder particles cobalt and / or chromium. In one or more embodiments, the powder comprises 54 abrasive particles and binder particles.

[0052] In one or more embodiments, a wire comprising the material of the hard phase layer 40 and / or the barrier layer 42 is fed into the melt bath formed by the laser 46 instead of a powder.

[0053] In one or more embodiments, the hard phase layer 40 is applied in several layers. Each layer has a thickness in the range of 0.1 mm to 0.2 mm, in particular about 0.15 mm. In one or more such embodiments, the hard phase layer 40 can, for example, comprise two to five layers. In one or more embodiments, the hard phase layer 40 has a total thickness in the range of about 0.4 mm to 1 mm, in particular about 0.6 mm to about 0.8 mm.

[0054] Fig. Figure 5 shows a cross-section of a strip 44 onto which the hard phase layer 40 is directly applied. As can be seen, the applied hard phase layer 40 forms a parabolic surface on the edge surface 50 of the strip 44. In one or more embodiments, the parabolic surface can be essentially smooth, but in one or more other embodiments, the parabolic surface can have a rough texture, such as a weld seam.

[0055] If the optional barrier layer 42 is provided, the barrier layer 42 is deposited on the strip 44, and subsequently the hard phase layer 40 is deposited on the barrier layer 42. The barrier layer 42 is deposited using substantially the same arrangement and method as described in relation to Fig. Figure 4 shows and describes the process. In particular, the laser 46 is directed across the edge surface 50 of the strip 44 to melt the edge surface 50, while the powder 54 of the barrier layer 42 is directed into the molten edge surface 50. After the barrier layer 42 has been applied, the laser 46 is directed across the barrier layer 42 to melt at least a section of the barrier layer 42, and powder 54 of the hard phase layer 40 is directed through the nozzle 52 onto the molten barrier layer 42. With reference to Fig. 4 are the laser and nozzle used to apply the barrier layer 42, not necessarily the same laser and nozzle used to apply the hard phase layer 40.

[0056] In one or more embodiments, the powder 54 of the barrier layer 42 comprises particles with an average size in the range of 15 micrometers to 45 micrometers. In one or more embodiments, the particles of the powder 54 generally have a spherical shape. In one or more embodiments, the barrier layer 42 is applied with a thickness of approximately 0.1 mm. The final barrier layer 42 can consist of one or more layers of the barrier layer material 42, which are applied over the strip 44 by one or more passes of the laser 46 and the nozzle 52.

[0057] Since the barrier layer 42 (if present) and the hard-phase layer 40 can each be built up in one or more layers, several laser / nozzle stations can be used to apply each individual layer sequentially. For example, a moving strip 44 of the knife body 29 can pass by several laser / nozzle stations where the layers of barrier material and carbide material are applied.

[0058] If present, the barrier layer 42 ensures continuous separation between the hard phase layer 40 and the knife body 29. Specifically, the barrier layer 42 separates the hard phase layer 40 from the knife body 29 across the thickness of the strip 44 and along the length of the strip 44. As explained above, the separation provided by the barrier layer 42 prevents the diffusion of elements from the knife body 29 into the hard phase layer 40, which can lead to the formation of brittle phases in the hard phase layer 40, particularly in the case of carbide materials, and thus to premature failure of the knife 28.

[0059] After the application of the hard phase layer 40 (and optionally the barrier layer 42), the strip 44 can optionally be heat-treated in an oven to refine the hard phase and eliminate porosity and cracks in the hard phase layer 40. In one or more embodiments, the heat treatment comprises heating the strip at a rate in the range of 80 °C / min to 140 °C / min (particularly at about 120 °C / min) to a temperature in the range of 1050 °C to 1200 °C (particularly to about 1115 °C) for a period of 1 minute to about 10 minutes (particularly about 3 minutes), holding at this temperature for a period of 1 minute to about 10 minutes (particularly about 3 minutes), and then quenching in air to room temperature. In one embodiment, the hard phase layer 40 has a blunt, rounded edge after deposition, as shown in the Fig. 3 and Fig. Figure 5 shows that in one or more embodiments, the strip 44 can optionally be ground after heat treatment (if performed) to achieve a desired edge profile of the knife 28. Furthermore, the strip 44 can be divided into individual knives 16, for example by cutting or punching the strip 44.

[0060] Additionally, as in the Fig. As shown in Figures 2A-2E, the coating layer 29 is present on both the longitudinal edges 37a, 37b and the side edges 37c, 37d. After the coating layer 29 has been applied to one of the longitudinal edges 37a, 37b or the side edges 37c, 37d of the strip 44, it may be necessary to apply the coating layer 39 to the other of the longitudinal edges 37a, 37b or the side edges 37c, 37d after the strip 44 has been cut or punched into individual knives 28. In one or more embodiments, the coating layer 39 can be applied to the first main surface 35 and / or the second main surface 36 while the strip 44 is still in place or after it has been cut / punched into individual knives 28.

[0061] Fig. Figure 6 shows a flowchart of a process 100 for manufacturing a knife 28 according to the present disclosure. In particular, the process 100 describes the embodiment in which the optional barrier layer 42 is provided. In a first step 101 of the process, the edge surface 50 of a knife body 29 or a strip of the knife body 29 is heated, in particular melted (i.e., heated to a molten state). As in Fig. As shown in Figure 4, heating can be carried out using a laser, but other means for heating the edge surface 50 are also possible, such as electron beam, induction heating, and plasma arc. After the edge surface 50 has melted, in a second step 102 a powder or wire made of the barrier layer 42 material is applied to the edge surface 50 to form the barrier layer 42. As shown in Fig.As shown in Figure 4, the heating (step 101) and the application (step 102) can be carried out essentially simultaneously. In a third step 103, the barrier layer 42 is heated, in particular melted, and in a fourth step 104, the hard phase layer 40 is applied over the barrier layer 42. As explained above, the hard phase layer 40 can be applied as a powder or wire. For example, a powder of metal particles and carbon flakes can be applied so that carbides precipitate in the melt pool, or powders of carbide or abrasive particles and binder material can be applied. In another example, a wire made of the hard phase material can be inserted into the melt pool, or several wires (e.g., one containing the hard phase particles and one containing the binder) can be inserted into the melt pool.Furthermore, as explained above, the barrier layer material 42 and the hard phase layer material 40 can be applied in multiple layers by passing the heating device and nozzle several times. Additionally, the barrier layer 42 and the hard phase layer 40 can be applied to the knife 28 or the strip 44 by passing the knife 28 or the strip 44 under several stations of the heating device and the nozzle, each station configured to provide the desired mixture of powders / wires for forming the barrier layer 42 and the hard phase layer 40. In an optional fifth step 105, the knife 28 or the strip 44 is heat-treated, and in an optional sixth step 106, the knife 28 or the strip 44 is ground to form a desired edge profile.

[0062] If the barrier layer 42 is not provided, the process 100 can comprise the steps of melting the edge surface of the knife body (step 101) followed by, or simultaneously with, the application of the hard-phase layer material to the molten edge surface (step 104). Thus, the process 100 can consist of these two steps, i.e., without applying the barrier layer (steps 102 and 103) and without further edge processing (heat treatment step 105 and grinding step 106).

[0063] In the knife 28 according to the present disclosure, which was manufactured according to the disclosed method, the barrier layer 42 (if present) generally exhibits the lowest hardness, while the hard phase layer 40 exhibits the highest hardness. The material of the knife 29 generally has a hardness that lies between that of the barrier layer 42 and the hard phase layer 40. Furthermore, the material of the knife body 29, particularly if it is a steel alloy, may exhibit a hardness gradient due to the hardening caused by the heat-affected zone in the knife body 29 during the heating of the edge surface 50 and the barrier layer 42 during the application of the barrier layer 42 and the carbide layer 40.

[0064] In embodiments where this is provided, the barrier layer 42 remelts during the application of the hard phase layer 40, but the material of the barrier layer 42 can be selected such that it does not harden during this remelting and cooling. Instead, the barrier layer 42 may soften, as the remelting can homogenize it. Nevertheless, slight diffusion may occur between the knife 29 and the barrier layer 42, as well as between the barrier layer 42 and the hard phase layer 40, which can increase the hardness of the barrier layer 42 at the interfaces with the knife 29 and the hard phase layer 40, respectively.

[0065] After heat treatment, the knife body 29 in one or more embodiments has a hardness in the range of 600 HV to 700 HV in an area adjacent to the barrier layer 42, the barrier layer 42 has a hardness in the range of 400 HV to 550 HV, and the hard phase layer 40 has a hardness in the range of 800 HV to 1500 HV.

[0066] Further details are shown and described in the attached figures.

[0067] It should be understood that the figures illustrate exemplary embodiments in detail and that the present application is not limited to the details or methods set forth in the description or illustrated in the figures. It should also be understood that the terminology is used for descriptive purposes only and should not be considered restrictive.

[0068] Furthermore, modifications and alternative embodiments of various aspects of the disclosure will be obvious to the person skilled in the art in view of this description. Accordingly, this description is to be understood as illustrative only. The constructions and arrangements shown in the various exemplary embodiments serve only for illustration. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values ​​of parameters, fastening arrangements, use of materials, colors, orientations, etc.) without substantially departing from the novel teachings and advantages of the subject matter described herein.Some elements depicted as being formed in one piece may consist of multiple parts or elements; the position of the elements may be reversed or otherwise varied; and the type or number of discrete elements or positions may be changed or varied. The sequence or order of processes, logical algorithms, or procedural steps may be varied or rearranged according to alternative embodiments. Other substitutions, modifications, changes, and omissions may also be made in the design, operating conditions, and arrangement of the various exemplary embodiments without departing from the scope of this disclosure.

[0069] Unless expressly stated otherwise, no method set forth herein is intended to be interpreted as requiring its steps to be performed in a particular order. Accordingly, if a method claim does not actually specify an order in which its steps are to be performed, or if the claims or descriptions do not expressly state that the steps are restricted to a particular order, no particular order is intended to be inferred. Furthermore, the article used herein is intended to comprise one or more components or elements and should not be interpreted as meaning only one component or element.

[0070] Different embodiments of the disclosure relate to any combination of features, and any such combination of features may be claimed in this or future applications. Each of the features, elements, or components of each of the exemplary embodiments discussed above may be used alone or in combination with each of the features, elements, or components of each of the other embodiments discussed above.

[0071] While the present application lists specific combinations of features in the appended claims, various embodiments of the invention relate to any combination of any features described herein, whether or not such a combination is currently claimed, and any such combination of features may be claimed in this or future applications. Each of the features, elements, or components of any of the exemplary embodiments described above may be used alone or in combination with any of the features, elements, or components of any of the other embodiments described above.

[0072] In various exemplary embodiments, the relative dimensions, angles, lengths, and radii, as shown in the figures, are to scale. The actual dimensions of the figures represent the relative dimensions, angles, and proportions of the various exemplary embodiments. Various exemplary embodiments extend to different ranges around the absolute and relative dimensions, angles, and proportions that can be determined from the figures. Various exemplary embodiments include any combination of one or more relative dimensions or angles that can be determined from the figures. Furthermore, actual dimensions not expressly stated in this description can be determined using the dimensional ratios measured in the figures in combination with the dimensions expressly stated in this description. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 746.383

[0001] US 63 / 727.937

[0001] US 63 / 725.198

[0001]

Claims

[1] A blade for a motorized power tool, the blade comprising: a knife body with a first principal surface, a second principal surface and a secondary surface, wherein the second principal surface is opposite the first principal surface and the secondary surface connects the first principal surface and the second principal surface around the circumference of the knife body; and a coating layer that is arranged at least partially around the circumference of the knife body on the adjacent surface; wherein the coating layer comprises at least one of an abrasive material or carbides. [2] The knife according to claim 1, wherein the secondary surface comprises a first longitudinal edge, a second longitudinal edge, a first lateral edge and a second lateral edge; where the second longitudinal edge is opposite the first longitudinal edge; where the second side edge is opposite the first side edge; wherein the first longitudinal edge and the second longitudinal edge each comprise a first length; and wherein the first lateral edge and the second lateral edge each comprise a second length, the second length being smaller than the first length. [3] The knife according to claim 2, wherein the coating layer is arranged on each of the first side edge and the second side edge. [4] The knife according to claim 2, wherein the coating layer is arranged on each of the first longitudinal edge and the second longitudinal edge. [5] The knife according to claim 4, wherein the coating layer on each of the first longitudinal edge and the second longitudinal edge comprises a first coating section and a second coating section, wherein the first coating section is separated from the second coating section by a blank section without a coating layer. [6] The knife according to claim 4, wherein the coating layer is further arranged on the first side edge and the second side edge. [7] The knife according to claim 6, wherein the coating layer is further arranged in one or more strips on at least one of the first main surface or the second main surface. [8] The knife according to claim 6, wherein the first longitudinal edge comprises a first curved region arranged proximal to the first lateral edge, and the second longitudinal edge comprises a second curved region arranged proximal to the second lateral edge; and wherein the coating layer is arranged in the first curved region and in the second curved region. [9] The knife according to claim 1, wherein the coating layer comprises particles of at least one of the following materials: carbide, nitride, boride, oxide or diamond in a binder. [10] The knife according to claim 1, wherein the coating layer further comprises a barrier layer arranged between the secondary surface and the carbide material. [11] An edge cutting knife, the edge cutting knife comprising: a knife body with a first principal surface, a second principal surface and a secondary surface, wherein the second principal surface is opposite the first principal surface, the secondary surface connects the first principal surface and the second principal surface around a circumference of the knife body and the secondary surface comprises a first longitudinal edge, a second longitudinal edge, a first lateral edge and a second lateral edge; and a coating layer that is arranged on at least one of the first main surface, the second main surface, the first longitudinal edge, the second longitudinal edge, the first side edge and the second side edge; the coating layer has a hardness in the range of 800 HV to 1500 HV. [12] The edge cutting knife according to claim 11, wherein an average distance between the first main surface and the second main surface defines a thickness of the edge cutting knife, wherein the thickness is in a range of 1 mm to 5 mm. [13] The edge cutting knife according to claim 12, wherein the first longitudinal edge and the second longitudinal edge each have a length in a range of 150 mm to 250 mm. [14] The edge cutting knife according to claim 13, wherein the first side edge and the second side edge each have a length in the range of 35 mm to 65 mm. [15] The edge cutting knife according to claim 11, wherein the coating layer is arranged on the first side edge and on the second side edge and wherein the coating layer extends along at least 50% of a length of each of the first side edge and the second side edge. [16] The edge cutting knife according to claim 15, wherein the coating layer is also arranged on each of the first longitudinal edge and the second longitudinal edge; wherein at each of the first longitudinal edge and the second longitudinal edge the coating layer comprises a first coating section and a second coating section; wherein the first coating section is separated from the second coating section by a bare section without a coating layer; and wherein both the first coating section and the second coating section extend over at least 25% and less than 50% of the length of the respective first and second longitudinal edges. [17] The edge cutting knife according to claim 16, wherein the coating layer further comprises at least one strip arranged on at least one of the first main surface or the second main surface. [18] The edge cutting knife according to claim 17, wherein the knife body defines an opening extending from the first main surface to the second main surface, and wherein the at least one strip comprises a first strip and a second strip arranged on opposite sides of the opening. [19] The edge cutting knife according to claim 16, wherein the first longitudinal edge comprises a first curved region arranged proximal to the first side edge, and the second longitudinal edge comprises a second curved region arranged proximal to the second side edge; and wherein the coating layer is arranged in the first curved region and in the second curved region. [20] The edge cutting knife according to claim 11, wherein the carbide material comprises particles of at least one of carbide, nitride, boride, oxide or diamond in a binder.

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