Method for producing a guide bar for a chain saw and guide bar for a chain saw

Abstract

The present disclosure relates to a method (100) for producing a chain saw guide bar (5). The method comprises the following steps: providing (120) an elongated core plate (5) extending along a plane and having a length (Lc) in a longitudinal direction (D) and a width (Wc) perpendicular to the longitudinal direction (D) in the plane, comprising a pair of opposing long side edges (33) and at least one detachable element (31) extending along at least one of the long side edges of the core plate. Arranging (140) side plates (23a, 23b) on each side of the core plate (25) to form a sandwich structure and joining (160) the plates (23a, 23b, 25) to form the elongated guide bar (5), wherein the at least one detachable element (31) remains attached to the core plate (25). The present disclosure also relates to a guide bar (5) for a chain saw (1). The guide bar (5) comprises a laminated structure of at least three layers, comprising a first side panel (23a), a second side panel (23b) and a core panel (25) arranged between the first side panel (23a) and the second side panel (23b), wherein the core panel (25) is provided with at least one detachable element (31). The present disclosure also relates to an alternative method (200) for producing a chain saw guide bar (5).

Description

Technical Field

[0001] The present invention relates to the field of chain saws, and in particular to a guide rod and a method for producing the guide rod. Background Art

[0002] Chain saws are commonly used in private and commercial settings to cut wood or perform other rigorous cutting operations. They can be powered by a gasoline engine or electric motor (e.g., via a battery or wired connection) to rotate a chain around a guide bar at a relatively high speed. The chain includes cutting teeth that engage the wood or other material to cut the material as the teeth pass over the surface of the material at high speed.

[0003] The guide bar generally has a laminated structure comprising an inner layer or plate member sandwiched between a pair of outer layers or plate members. The length and width of the inner layer are generally smaller than the length and width of the outer layer, and their shapes are substantially the same, so that a guide groove around the entire periphery of the guide bar is defined between the outer layers. When the guide bar is used in a chain saw, the guide teeth of the saw chain slide in the groove.

[0004] An exemplary laminated guide rod for use in a chain saw is described in EP 1 448 344. However, there is always a need for further improvements in laminated guide rods and methods of producing laminated guide rods in order to cope with the harsh operating conditions of chain saws and to improve the performance of chain saws. Summary of the invention

[0005] An object of the present invention is to solve or at least alleviate some or all of the above problems. To this end, a method for producing a chain saw guide bar is provided. The method includes providing an elongated core plate extending along a plane and having a length in the longitudinal direction and a width perpendicular to the longitudinal direction in the plane, the core plate including a pair of opposing long side edges and at least one detachable element extending along a portion of at least one of the long side edges. The method may also include arranging side panels on each side of the core plate to form a sandwich structure, and joining the panels to form an elongated guide bar, wherein at least one detachable element remains attached to the core plate.

[0006] The three plates may be attached to each other by welding (typically spot welding or pressure welding), brazing, adhesives, mechanical fasteners (such as rivets or bolts), or other well-known attachment means.

[0007] By providing the core plate with at least one removable element, the guide bar base plate can be processed without mechanically handling the actual core plate and thereby affecting any components to be included in the final product. Instead, the core plate can be handled via the removable element.

[0008] The detachable element can be used as a detachable spacer, which supports the inwardly facing side walls of the side panels and thereby maintains a clear distance between the side panels during the joining process. In the case where the panels (side panels and core panel) are made of metal (e.g. steel), deformations may occur between the panels if heat is provided to the panels during the joining process. By providing the core panel with at least one detachable element, deformations between the panels can be reduced, thereby producing an elongated guide rod with two side panels that are identical in size to each other, located side by side in parallel planes, with the core panel and at least one detachable element in between. According to an embodiment, the core panel has the same thickness as the detachable element in a direction perpendicular to the plane of the core panel.

[0009] In one embodiment, the method may further include hardening and tempering the guide rods while at least one removable element remains attached to the core plates. After the plates have been joined together, they may be further exposed for hardening and tempering. Hardening is used to impart specific mechanical properties to the guide rods to increase durability, especially where chains run. Tempering is a low temperature heat treatment (150-650°C) designed to eliminate stresses and brittleness caused by cooling and produce desired mechanical properties. Deformation between the plates may be further reduced by providing the core plates with at least one removable element that remains attached to the core plates during these heating processes.

[0010] In one embodiment, the method may further include removing at least one detachable element to form at least a portion of the guide groove along the edge of the guide rod. During the joining process and / or the hardening and tempering process, at least one detachable element may act as a spacer between the core plate and the side plate, thereby preventing deformation between the plates. After the guide rod has been formed, the detachable element no longer serves any function and can be removed from the guide rod.

[0011] When at least one detachable element has been removed, a portion of the guide groove may be formed along the edge of the guide bar. Depending on the size of the at least one detachable element or the number of detachable elements, the guide groove may be formed along the entire periphery of the guide bar. Different types of chain saws require different grooves, so the depth and width of the groove are selected to meet the requirements.

[0012] In one embodiment, providing the core plate may include cutting a metal sheet to form an elongated core plate having a length and width less than the corresponding length and width of the side plate. The elongated guide bar may have a rear end rigidly mounted to the saw housing or the engine of the chain saw and a front end away from the saw housing. The front end may include a sprocket that receives the saw chain and guides the chain around the front end of the guide bar. Each of the plates (i.e., the core plate and the side plate) has a length from the rear end to the front end of the guide bar. The side plates have the same size, while the width and length of the core plate are slightly less than the side plates, thereby creating a groove around the periphery of the guide bar. With the help of a drive link in the saw chain, the saw chain can be driven in the groove around the guide bar. In order to reduce the stress of the saw chain, it is preferred that the drive link is precisely fitted in the guide groove and travels straight in the guide groove. If the width is too large, the saw chain may move sideways, and if the width is too small, the saw chain may get stuck in the guide groove, which has a negative impact on the function and durability of the saw chain and the guide bar.

[0013] In one embodiment, providing the core plate may further comprise integrally forming the core plate with the at least one detachable element.By doing this from a single piece of material, a large amount of time and material may be gained, which may reduce the production cost of the guide rod.

[0014] In one embodiment, providing the core panel may also include cutting or stamping the core panel to create a gap between the core panel and at least one removable element, the gap extending along a portion of at least one of the long side edges of the core panel in addition to at least one connection configured as a frangible bridge. By creating a gap along at least one of the long side edges of the core panel having at least one connection, the core panel and the removable element can be easily formed as one piece and will allow for simple removability from one another. After the guide rods have been formed, the removable element can be easily removed from the core panel due to the thin, frangible bridge.

[0015] In one embodiment, providing the core plate may further comprise providing the at least one frangible bridge with a thickness perpendicular to the plane of the guide rod of at least 0.5 mm, preferably between 0.5-0.8 mm.

[0016] In one embodiment, providing the core plate may further comprise providing at least one frangible bridge with a length of at least 1 mm along the outer edge of the guide rod, the length preferably being between 1-3 mm. The frangible bridge may be designed so that the detachable element can be handled during the production step without being accidentally detached, but it must still be possible to detach the element from the core plate in an effective manner after the guide rod has been formed. It has been shown that a thickness of at least 0.5 mm and a length of at least 1 mm demonstrate that the cross-sectional area of ​​the frangible bridge can withstand a load of 1000 N, and this is sufficient to handle the loads during production and may also easily destroy the bridge after the guide rod has been formed.

[0017] In one embodiment, providing the core plate may include providing the core plate with a plurality of frangible bridges. The number of frangible bridges may depend on the length of the elongated guide rod. The chain saw may be used to cut media of various sizes, wherein the length of the guide rod may vary for different applications. In most cases, the guide rod is relatively long and may be much longer than the main body of the chain saw. The frangible bridges may be evenly distributed along the entire length of the guide rod.

[0018] In one embodiment, providing the core plate may further comprise providing at least one removable element with at least one gripping element integrally formed with the removable element. In order to more easily remove the removable element from the core plate, the removable element may be provided with at least one gripping element. The gripping element may be integrally formed with the removable element at one of the long side edges, and thus production costs may be reduced. After the guide rod is formed, only the gripping element extends out of the guide slot, and the long side edge of the removable piece is arranged edge to edge with the long side edge of the side plate.

[0019] For example, the gripping element may be a hole or a hook. The shape may be elongated and formed as a rectangle or an oval. The shape should be easy to grip with fingers.

[0020] In one embodiment, providing the core plate may include providing at least one detachable element with a gripping element for each frangible bridge. The gripping element may be arranged at the frangible bridge such that a straight line passing through the gripping element and the frangible bridge is perpendicular to the longitudinal axis of symmetry of the guide rod. Thus, it will be easier to provide the force required to break the frangible bridge and thereby remove the detachable element from the core plate after forming the guide rod.

[0021] In one embodiment, removing at least one removable element from the core plate may comprise gripping the gripping element to remove the at least one removable element from the core plate and pulling along the plane of the guide rod in a direction transverse to the longitudinal direction. Since this may allow the removable element to be automatically removed from the core plate, production costs may be further reduced. The gripping element may also be provided with a centrally located passage in the form of a through hole. A rod may be automatically introduced into the hole to provide a force to break the frangible bridge.

[0022] In one embodiment, providing the core plate may include providing the core plate with at least one cutout hole, which may be covered by a side plate so that an enclosed space is formed within the guide bar. The weight of the guide bar is an important parameter in order to facilitate and improve the working efficiency of the chain saw operator. By providing the core plate with at least one cutout hole, the weight of the guide bar may be reduced. The cutout hole may be closed / covered by a side plate to maintain the stiffness of the guide bar. Depending on the desired degree of weight reduction and the acceptable or reasonable degree of stiffness reduction, a number of cutout holes may be provided, which may be optionally evenly distributed on the core plate. For example, approximately 50%-90% of the area of ​​the core plate may be provided with cutout holes. The shape and size of each cutout hole may vary.

[0023] According to a second aspect, some or all of the above problems are solved or at least alleviated by a guide bar for a chain saw. The guide bar comprises: a laminated structure of at least three layers, including a first side plate, a second side plate, and a core plate arranged between the first side plate and the second side plate, wherein the core plate is provided with at least one detachable element. The at least one detachable element can be formed integrally with the core plate. When the at least one detachable element is removed from the core plate, a part of the guide groove can be formed.

[0024] By providing the core plate with support elements during the joining process of the plates and / or the subsequent heat treatment, the width of the guide groove around the periphery of the guide bar will be maintained in the formed guide bar. It is important that the width of the guide groove is uniform around the guide bar to reduce stress on the saw chain. The support elements will only be present during the manufacturing process, thereby ensuring the correct width of the guide groove. The support elements are connected to the core plate by means of thin bridges at several locations along the long side edges of the core plate. The bridges are designed so that the support elements can be handled during the manufacturing process without being accidentally disassembled, but can be disassembled from the core plate after the last production step.

[0025] According to a third aspect, some or all of the above-mentioned problems are solved or at least alleviated by a method for producing a chain saw guide bar. The method comprises: arranging a side plate on each side of a core plate, thereby forming a sandwich structure with a guide groove between the side plates; arranging a spacer in the guide groove; joining the core plate and the side plate to form an elongated guide rod. Subsequent method steps may include hardening and tempering the guide rod, and removing the spacer from the guide groove. The spacer can be manually assembled in the guide groove before the joining and hardening and tempering processes, and manually removed after the guide rod has been formed. The spacer supports the inwardly facing side walls of the side plate and thereby maintains a clear guide groove between the side plates during the joining process. Compared with an automatic process, this method may involve relatively more manual labor and may increase production costs, but may nevertheless lead to an improvement in the manufacturing accuracy of the guide rod.

[0026] It is worth noting that the embodiments of the present invention can be embodied by all possible combinations of the features recited in the claims. In addition, it should be understood that various embodiments described for the device can be combined with the method defined according to the second aspect of the present invention, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and further objects, features and advantages of the present invention will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, with reference to the accompanying drawings, in which like reference numerals will be used for similar elements, and in which:

[0028] Figure 1 A side view of a chain saw is shown;

[0029] Figure 2 A side view of the guide rod is shown;

[0030] Figure 3 Shows from Figure 2 Schematic diagram of the cross-section of the guide rod, the cross section is along Figure 2 The plane indicated by the line II in FIG.

[0031] Figure 4 Shows Figure 2 A side view of a perforated core plate of a guide rod;

[0032] Figure 5A Shown according to Figure 4 A side view of a core panel with removable elements;

[0033] Figure 5B Shown include Figure 5A A side view of a guide rod of a core plate in FIG.

[0034] Figure 5C Shows Figure 5B Schematic diagram of a cross section of a guide rod, the cross section is along Figure 5B The plane indicated by the line II-II in FIG.

[0035] Figure 6 yes Figure 5A An enlarged view of the cross section indicated by the dashed line in FIG.

[0036] Figure 7 A method for producing a guide rod is shown; and

[0037] Figure 8 An alternative method of producing the guide rod is shown.

[0038] All the figures are schematic, not necessarily to scale, and generally only show parts which are necessary to elucidate the embodiments, wherein other parts may be omitted. DETAILED DESCRIPTION

[0039] Figure 1 1 shows a side view of the chain saw 1. Figure 1 As shown, the chain saw 1 includes a housing 3 in which a power unit or motor is housed. The power unit may be an electric motor or an internal combustion engine. The chain saw 1 also includes a guide bar 5 attached to the housing along one side of the housing 3. The guide bar 5 extends outward from the housing 3. An endless saw chain link 6 can be driven around the guide bar 5 in response to operation of the power unit to enable the chain saw 1 to cut wood or other materials. The chain saw 1 may also include a set of handles 7, one of which is provided with a trigger 11 to facilitate operation of the power unit when the trigger 11 is actuated. When the trigger 11 is actuated (e.g., pressed), the rotational force of the power unit can be coupled to the saw chain. A clutch cover 13 may be provided to secure the rear end 5a of the guide bar 5 to the housing 3 and cover the clutch between the components and assemblies that couple the power unit to the saw chain. As shown in FIG. Figure 1 As shown, the clutch cover 13 may be attached to the housing 3 via a nut 15 which also passes through the rear portion 5 a of the guide rod 5 .

[0040] Figure 2 Shown according to Figure 1 The guide bar 5 is elongated and has a housing 3 (such as a housing 3) mounted to the chain saw 1. Figure 1 The guide bar 5 may be provided with a rear end 5a of the guide bar 5 or an engine and a front end 5b opposite the rear end 5a in the longitudinal direction D of the guide bar 5. The length of the guide bar 5 may vary depending on the application. It may have a length of, for example, 13, 15 or 18 inches and may be significantly longer than the chain saw 1. The front end 5b of the guide bar 5 may accommodate a nose sprocket arrangement (not shown), which may include a sprocket (not shown) that may be rotatable to engage the saw chain when the saw chain rotates around the front end 5b of the guide bar 5. The rear end 5a of the guide bar 5 may be provided with a slot 17 and an aperture 19 that is provided on either side of the slot 17 (above and below the slot) to secure the guide bar 5 to the housing 3 via a nut 15, such as Figure 1 The guide bar 5 can be fixed by tightening the nut 15, and when the desired chain tension is reached, the tension of the saw chain can be adjusted according to the movement of the guide bar 5 and the subsequent tightening of the nut 15. The nose sprocket is attached to the front end 5b of the guide bar 5 via a pin 21 extending perpendicular to the plane of the guide bar 5.

[0041] Figure 3 Shows Figure 2 The cross section of the guide rod is taken along the plane indicated by line II. The guide rod 5 can be formed as a three-piece laminate having a pair of side panels 23a, 23b and a core panel 25. The core panel 25 is Figure 4, and is elongated and extends along a plane. It has a length Lc in the longitudinal direction D and a width Wc perpendicular to the longitudinal direction D. The core plate 25 is sandwiched between the side plates 23a, 23b. The side plates 23a, 23b are generally made of the same material, which may be steel or other sufficiently rigid and durable material. The core plate 25 may be made of another material different from the side plates 23a, 23b. The length Lc and width Wc of the core plate 25 may be smaller than the corresponding length Ls and width Ws of the side plates 23a, 23b, which are of the same shape so that a guide groove 27 surrounding the entire outer edge of the guide bar 5 is defined between the side plates 23a, 23b. Different types of saw chains require different guide grooves 27, so the depth and width of the guide groove 27 are selected to meet the requirements of the saw chain. The width of the guide groove 27 is determined by the thickness of the core plate 25, and the depth of the guide groove 27 is determined by the difference in length Lc, Ls and width Wc, Ws between the core plate 25 and the side plates 23a, 23b.

[0042] The weight of the guide bar 5 is an important parameter to facilitate and improve the working efficiency of the operator of the chain saw 1. In order to reduce the weight of the guide bar 5, the core plate 25 can be provided with cutout holes 29 having different shapes and sizes, such as Figure 4 As shown. Up to 80% of the surface of the core plate 25 may be provided with the cutout holes 29, which maintains sufficient rigidity for the guide rod 5. In the guide rod 5, the cutout holes 29 are covered by the side plates 23a, 23b to form a closed space.

[0043] Another alternative to reduce the weight of the guide rod is to use a core plate 25 of a low density material (such as aluminum or plastic material). If the core plate 25 is made of aluminum or plastic material to reduce the weight of the guide rod 5, the manufacturing method of the guide rod 5 may become more complicated and make the guide rod 5 more expensive.

[0044] The three plates 23a, 23b, 25 can be attached to each other by welding (usually spot welding or pressure welding), brazing, adhesives and / or mechanical fasteners (such as rivets or bolts) and / or other well-known attachment methods. After the plates 23a, 23b, 25 have been joined together, they can be further exposed for hardening and tempering. The hardening process is used to give the guide rod 5 specific mechanical properties to increase durability, especially where the chain runs. Tempering is a low temperature heat treatment (150-650°C) designed to eliminate stress and brittleness caused by cooling and produce desired mechanical properties.

[0045] A key characteristic of the guide bar 5 is the width of the guide groove 27, and it is desirable for the saw chain to fit accurately and travel straight within the guide groove 27. Lateral movement of the saw chain in the guide groove 27 is detrimental to the performance of the chain saw 1 and will increase wear on the guide bar 5 and saw chain. During the joining process and subsequent heat treatment steps, the width of the guide groove 27 may change due to deformation from the heat input into the steel.

[0046] One solution to this problem is to fit a plate having the same thickness as the core plate 25 in the guide groove 27, which serves as a spacer to prevent the side plates 23a, 23b from collapsing inward during the joining process and the subsequent heat treatment step. It is suspected that fitting the spacer in the guide groove 27 before the joining process and removing the spacer after the heat treatment step may require a lot of manual work, which may increase the manufacturing cost of the guide rod 5.

[0047] Another solution is Figures 5A-5C , wherein an embodiment of the guide rod 5 comprises a core plate 25 provided with a spacer in the form of at least one detachable element 31 integrally formed with the core plate 25, such as Figure 5A The core plate 25 may be formed by cutting a metal sheet to form an elongated plate having a pair of opposing long side edges 33 extending along the longitudinal direction D. The detachable element 31 may be formed by, for example, cutting (such as water jet cutting or laser cutting) or stamping a sheet metal to provide a gap 35 ( Figure 6 ). Preferably, the two removable elements 31 are formed by providing a gap 35 along each long side edge 33 of the core plate 25. The width of the gap is between 0.1-0.6 mm. Preferably, the width of the gap is between 0.2-0.4 mm, and most preferably, the gap is 0.3 mm. The width of the removable element 31 corresponds to the depth of the guide groove 27 in the guide rod 5 to be formed, wherein the long side edges of the removable element 31 are flush with the long side edges of the side plates 23a, 23b and form the straight outer edge of the guide rod 5, as shown in FIG. Figure 5C The width of the detachable element 31 may be wider than the depth of the guide groove 27, but if the width of the detachable element 31 is the same as the depth of the guide groove 27 formed, it is easier to handle and distinguish the core plate 25.

[0048] The detachable element 31 may serve as a detachable spacer which rests and supports the inwardly facing side surfaces of the side panels 23a, 23ba and thereby maintains a well-defined distance between the side panels 23a, 23b during the joining process.

[0049] In order to keep the removable element 31 attached to the core plate 25 during the manufacturing steps to form the guide rod 5, there should preferably be at least one connection between these parts 25, 31. This connection can be formed as an interruption of the gap 35 formed between the parts 25, 31, thereby creating a frangible bridge 37, such as Figure 6 Best shown.

[0050] The width of the frangible bridge 37 is designed so that the removable element 31 can be handled during the production steps without being accidentally removed from the core plate 25, but it should still be possible to remove the element 31 from the core plate 25 in an effective manner after the guide rod 5 has been formed. It has been shown that a width of at least 0.5 mm and a length of at least 1 mm provide a cross-sectional area of ​​the frangible bridge 37 that can withstand a load of 1000 N, and this is sufficient to handle the loads during production. The bridge 37 can also be easily broken after the guide rod 5 has been formed. Preferably, the width perpendicular to the plane of the guide rod 5 is between 0.5-0.8 mm. The length along the outer edge of the guide rod 5 is preferably between 1-2 mm.

[0051] The number of frangible bridges 37 depends on the length of the elongated guide rod 5 formed. Figure 5A The core plate 25 is provided with 4 frangible bridges 37 for each detachable element 31, but this is only an example. Depending on the application of the guide rod 5 formed, fewer and more frangible bridges 37 can be used.

[0052] like Figures 5A-5C and Figure 6 As can be seen, the removable element 31 may also be provided with at least one gripping element 39 to more easily remove the removable element 31 from the core plate 25 after the guide rod 5 has been formed. The gripping element 39 may be formed integrally with the core plate 25 and may be formed as a protrusion at the long side edge of the removable element 31. For example, the gripping element 39 may be a hole or a hook. The shape may be elongated and formed as a rectangle or an oval, which makes it easy to grip with the fingers. In order to facilitate the removal of the removable element 31 from the core plate 25 after the guide rod 5 has been formed, the gripping element 39 protrudes from the formed guide rod 5, as shown in FIG. Figure 5B Or 5C. Each removable element 31 may be provided with a gripping element 39 for each frangible bridge 37. The gripping element 39 may be arranged opposite to the frangible bridge 37 so that a straight line passing through the gripping element 39 and the frangible bridge 37 is perpendicular to the longitudinal symmetry axis of the guide rod 5. Thus, the force applied to the gripping element 39 affects the frangible bridge 37 so that the connection between the removable element 31 and the core plate 25 is broken.

[0053] The gripping element 39 may also be provided with a channel 41. The channel 41 ( Figure 6 ) may be centrally arranged in the gripping element 39. The element may be introduced into the channel 41 to apply a force to break the frangible bridge 37 and thereby remove the removable element 31 from the core plate 25. This step may be performed automatically.

[0054] In producing a guide rod according to the method (100), if Figure 7As shown, a perforated core plate 25 having at least one removable element 31 including a gripping element 39 is first cut (120) from a single piece of sheet metal, wherein the core plate 25 and the removable element 31 are attached to each other by at least one frangible bridge 37. The core plate 25 is then sandwiched (140) between a pair of side plates 23a, 23b and joined (160) together, such as by welding, to form a guide bar 5. The guide bar 5 may then undergo a hardening and tempering (180) process to provide a guide bar 5 having suitable mechanical properties. The removable element 31 may then be removed (190) from the guide bar 5 to provide a portion of a guide groove 27 along an edge of the guide bar 5. The saw chain may fit precisely within the formed guide groove 27 and travel straight within the formed guide groove.

[0055] According to a second aspect of the present invention, a guide rod 5 is provided, wherein the guide rod 5 comprises a laminated structure of at least three layers: a first side plate 23a, a second side plate 23b, and a core plate 25 arranged between the first side plate 23a and the second side plate 23b, wherein the core plate 25 is provided with at least one detachable element 31. The detachable element 31 may be formed integrally with the core plate 25. If the detachable element 31 is detached from the core plate 25, a part of the guide groove 27 is formed.

[0056] According to the alternative production method (200), Figure 8 , a core plate 25 is arranged (220) between a pair of side plates 23a, 23b to form a sandwich structure having a guide groove 27 between the side plates 23a, 23b. A spacer is arranged (240) within the guide groove 27 and the plates 25, 23a, 23b are joined together, for example by welding (260) to form a guide rod 5. The guide rod 5 can then undergo a hardening and tempering (280) process to provide a guide rod with suitable mechanical properties. The spacer is then removed (290) from the guide groove 27. The spacer can be a plate having the same thickness as the core plate 25, thereby preventing the side plates 23a, 23b from collapsing inwardly in the guide groove 27 during joining, hardening and heat treatment. The spacer, which can be a completely independent component, can be assembled in the guide groove and removed therefrom manually or automatically.

[0057] The invention has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than those disclosed above are equally possible within the scope of the invention as defined by the appended patent claims.

[0058] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

Claims

1. A method (100) for producing a chain saw guide bar (5), the method comprising: - providing (120) an elongated core plate (25), the core plate extending along a plane and having a length (Lc) in a longitudinal direction (D) and a width (Wc) perpendicular to the longitudinal direction (D) in the plane, the core plate (25) comprising a pair of opposite long side edges (33) extending from the rear end of the guide rod to the front end of the guide rod over the entire length of the core plate and at least one detachable element (31) extending from the rear end to the front end along the entire length of at least one of the long side edges (33), wherein providing (120) the core plate (25) further comprises forming the core plate (25) and the at least one detachable element (31) integrally; - arranging (140) side panels (23a, 23b) on each side of the core panel (25) so as to form a sandwich structure; - joining (160) the core plate (25) and the side plates (23a, 23b) to form an elongated guide rod (5), wherein the at least one detachable element (31) remains attached to the core plate (25); The method further comprises removing (190) the at least one detachable element (31) to form at least a portion of the guide groove (27) along an edge of the guide rod (5); Wherein, providing (120) the core panel also includes cutting or punching the core panel (25) to create a gap (35) between the core panel (25) and the at least one removable element (31), wherein the gap (35) extends from the rear end to the front end along at least one of the long side edges (33) of the core panel (25), in addition to at least one connection portion configured as at least one frangible bridge (37).

2. The method (100) of claim 1, further comprising hardening and tempering (180) the guide rod (5) while the at least one detachable element (31) remains attached to the core plate (25).

3. The method (100) according to claim 1 or 2, wherein: The length (Lc) and width (Wc) of the core plate (25) are smaller than the corresponding length (Ls) and width (Ws) of the side plates (23a, 23b).

4. The method (100) according to claim 1 or 2, wherein: Providing (120) the core plate (25) further comprises providing the at least one frangible bridge (37) with a thickness of at least 0.5 mm perpendicular to the plane of the guide rod (5).

5. The method (100) according to claim 4, wherein: The thickness is between 0.5-0.8 mm.

6. The method (100) according to claim 1 or 2, wherein: Providing (120) the core plate (25) further comprises providing the at least one frangible bridge (37) with a length of at least 1 mm along an outer edge of the guide rod (5).

7. The method (100) according to claim 1 or 2, wherein: Providing (120) the core plate (25) further comprises providing the at least one frangible bridge (37) with a length along an outer edge of the guide rod (5) of between 1-3 mm.

8. The method (100) according to claim 1 or 2, wherein: Providing (120) the core panel (25) includes providing the core panel (25) with a plurality of frangible bridges (37).

9. The method (100) according to claim 1 or 2, wherein: Providing (120) the core plate (25) further comprises providing the at least one detachable element (31) with at least one gripping element (39) formed integrally with the detachable element (31).

10. The method (100) according to claim 9, wherein: Providing (120) the core plate (25) includes providing the at least one removable element (31) with a gripping element (39) for each frangible bridge (37).

11. The method (100) according to claim 10, wherein: Providing (120) the core plate (25) includes arranging the gripping element (39) at the frangible bridge (37) such that a straight line passing through the gripping element (39) and the frangible bridge (37) is perpendicular to a longitudinal symmetry axis of the guide rod (5).

12. The method (100) according to claim 9, wherein: Removing (190) the at least one detachable element (31) from the core plate (25) comprises grasping the grasping element (39) to remove the at least one detachable element (31) from the core plate (25) and pulling along the plane of the guide rod (5) in a direction transverse to the longitudinal direction (D).

13. The method (100) according to claim 1 or 2, wherein: Providing (120) the core plate (25) includes providing the core plate (25) with at least one cutout hole (29), the at least one cutout hole (29) being covered by the side plates (23a, 23b) so that a closed space is formed within the guide rod (5).

14. A guide rod (5) for a chain saw (1), the guide rod (5) comprising: A laminated structure of at least three layers, comprising a first side panel (23a), a second side panel (23b) and a core panel (25) arranged between the first side panel (23a) and the second side panel (23b), wherein the core panel extends along a plane and has a length (Lc) in a longitudinal direction (D) and a width (Wc) perpendicular to the longitudinal direction (D) in the plane, wherein the core panel (25) comprises a pair of opposite long side edges (33) extending from the rear end of the guide rod to the front end of the guide rod over the entire length of the core panel and at least one detachable element (31) extending from the rear end to the front end along the entire length of at least one of the long side edges (33); wherein the at least one detachable element (31) is formed integrally with the core panel (25); wherein a portion of the guide groove (27) is configured to be formed by removing the at least one detachable element (31) from the core plate (25); And wherein there is a gap (35) between the core plate (25) and the at least one removable element (31), and in addition to at least one connecting portion configured as at least one frangible bridge (37), the gap (35) extends from the rear end to the front end along at least one of the long side edges (33) of the core plate (25).

15. A method (200) for producing a chain saw guide bar (5), the method comprising: - arranging (220) side panels (23a, 23b) on each side of the core panel (25) so as to form a sandwich structure with guide grooves (27) between the side panels (23a, 23b); - arranging (240) a spacer in said guide groove (27); - joining (260) the core plate (25) and the side plates (23a, 23b) to form an elongated guide rod (5); - hardening and tempering (280) the guide rod (5); and - removing (290) the spacer from the guide groove (27); wherein the spacer is in the form of at least one detachable element formed integrally with the core plate (25); wherein the core plate extends along a plane and has a length (Lc) in a longitudinal direction (D) and a width (Wc) perpendicular to the longitudinal direction (D) in the plane, the core plate (25) comprises a pair of opposite long side edges (33) extending from the rear end of the guide rod to the front end of the guide rod over the entire length of the core plate; and the spacer extends from the rear end to the front end along the entire length of at least one of the long side edges (33); And wherein there is a gap (35) between the core plate (25) and the spacer, and in addition to at least one connecting portion configured as at least one frangible bridge (37), the gap (35) extends from the rear end to the front end along at least one of the long side edges (33) of the core plate (25).

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