Handheld power tool

Abstract

Disclosed is a hand-held power tool (1) comprising: a tool (30); a power source (10) configured to provide power to the tool (30); a first handle (h1); and a second handle (h2) arranged at a distance from the first handle (h1). The hand-held power tool (1) is configured to be supported via each of the first and second handles (h1, h2) during operation of the hand-held power tool (1). The hand-held power tool (1) further comprises a first sensor assembly (a1) configured to provide data representative of an external force (Fe1, Fe1 ') applied to the first handle (h1), and a second sensor assembly (a2) configured to provide data representative of an external force (Fe2, Fe2') applied to the second handle (h2).

Description

Technical Field

[0001] The present disclosure relates to a handheld power tool, which includes: a tool; a power source configured to provide power to the tool; a first handle; and a second handle arranged at a distance from the first handle. Background Art

[0002] A handheld power tool is a tool designed to be supported by one or both hands of a user during operation. In addition, a handheld power tool includes a tool that can be driven by a power source rather than only by manual labor. The power source may include, for example, an internal combustion engine, an electric motor, a pneumatic motor, etc.

[0003] Today, there are many types of power tools on the market. Examples are chain saws, circular saws, jigsaws, trimmers, hedge trimmers, lawn mowers, shrub trimmers, multi-functional tools, etc. Power tools are used, for example, for industrial, construction, gardening, household chores, and cutting, shaping, sanding, grinding, wiring, polishing, etc. purposes around the house.

[0004] All types of handheld power tools have some common problems. One problem is safety. That is, a power tool may include a sharp tool and a powerful power source for providing power to the tool, which poses a safety risk.

[0005] Another problem is ergonomics. That is, a handheld power tool may be operated for a long time, especially when used by a professional. Therefore, it is advantageous if a handheld power tool can be designed to be operated in a convenient and ergonomic manner.

[0006] When designing a power tool and related parts and components, another common problem is user-friendliness. That is, it is advantageous if a handheld power tool and related parts and components are designed such that a user can operate the power tool in a simple and intuitive manner.

[0007] Another problem (at least partially related to some of the problems detailed above) is that it may be difficult to identify when a handheld power tool is being used in the wrong way. Incorrect operation of a handheld power tool may burden the user and may increase the energy consumption of the handheld power tool when performing a specific task. In addition, incorrect operation of a handheld power tool may impair the operation efficiency and operation result and may lead to potential dangerous situations.

[0008] Another problem (at least partially related to some of the problems detailed above) is that it may be difficult to identify when the operating efficiency of the tool of a hand-held power tool decreases, which is caused by, for example, wear of the tool and / or blockages on the tool. A decrease in the operating efficiency of the tool may cause stress to the user and may increase the energy consumption of the hand-held power tool when performing a specific task.

[0009] Another problem encountered in designing a hand-held power tool is how to add different features and functions while keeping the weight of the power tool light. The light weight of the hand-held power tool is preferred because the weight of the power tool can cause stress to the user's hands, arms and back. In addition, the light weight allows the user to operate the hand-held power tool in a safer manner.

[0010] In addition, generally speaking, in today's consumer market, it is advantageous if a product includes different features and functions while having conditions and / or characteristics suitable for cost-effective manufacturing and assembly. Summary of the Invention

[0011] The object of the present invention is to overcome or at least mitigate at least some of the above problems and disadvantages.

[0012] According to one aspect of the present invention, this object is achieved by a hand-held power tool, which includes: a tool; a power source configured to provide power to the tool; a first handle; and a second handle arranged at a distance from the first handle. The hand-held power tool is configured to be supported via each of the first handle and the second handle during the operation of the hand-held power tool. The hand-held power tool further includes: a first sensor assembly configured to provide data representing an external force applied to the first handle; and a second sensor assembly configured to provide data representing an external force applied to the second handle.

[0013] Since the hand-held power tool includes a first sensor assembly and a second sensor assembly, each of which is configured to provide data representing an external force applied to the corresponding first handle and second handle, and since the second handle is arranged at a distance from the first handle, a hand-held power tool is provided that can reliably obtain the current usage data of the hand-held power tool during operation.

[0014] That is, since the hand-held power tool is configured to be supported via each of the first handle and the second handle during operation of the hand-held power tool, data representing external forces applied to the first handle and the second handle can clearly indicate the current usage of the hand-held power tool. As an example, data representing external forces applied to the first handle and the second handle can indicate whether the user is gripping the hand-held power tool by holding each of the first handle and the second handle with one hand respectively. In addition, data representing external forces applied to the first handle and the second handle can indicate whether the user is pressing the tool of the hand-held power tool against an object. In addition, data representing external forces applied to the first handle and the second handle can indicate whether the hand-held power tool is being used in a correct manner.

[0015] In addition, since the hand-held power tool includes a first sensor assembly and a second sensor assembly, each of which is configured to provide data representing external forces applied to the corresponding first handle and second handle, the hand-held power tool can improve operational safety. This is because when data representing external forces applied to the first handle and the second handle indicates that the user is using the hand-held power tool in an incorrect and / or potentially dangerous manner, the data can be used to notify the user of the hand-held power tool.

[0016] Therefore, a hand-held power tool is provided that overcomes or at least mitigates at least some of the above problems and disadvantages. Thus, the above object is achieved.

[0017] Optionally, the hand-held power tool includes a control device configured to provide an estimated tool force representing the force applied to the tool based on data from the first sensor assembly and the second sensor assembly. Therefore, a hand-held power tool is provided that can provide a reliable estimated tool force in a simple, effective, and reliable manner. That is, since the hand-held power tool includes a first sensor assembly and a second sensor assembly, each of which is configured to provide data representing external forces applied to the corresponding first handle and second handle, and since the second handle is arranged at a distance from the first handle, the control device can provide a reliable estimated tool force in a simple and effective manner.

[0018] As a further result, a hand-held power tool is provided that can obtain more detailed current usage data, which can more clearly indicate the current usage of the hand-held power tool and can more clearly and reliably indicate whether the hand-held power tool is being used in a correct manner.

[0019] Optionally, the control device is configured to adjust the power output of the power source based on the tool force estimate. Thus, the operating efficiency of the handheld power tool can be improved. This is because the power output of the power source can be adjusted such that the power output increases as the tool force estimate increases and vice versa. Thus, in this way, at least substantially automatic control of the power output of the power source of the handheld power tool can be performed based on the external forces applied to the first and second handles of the handheld power tool.

[0020] Furthermore, due to these features, a handheld power tool is provided that can be operated in a simpler, more ergonomic, and more user-friendly manner.

[0021] Optionally, the tool is set to operate in at least two different operating directions, and wherein the tool force estimate represents the current operating direction of the tool. Thus, a handheld power tool is provided that can obtain data indicating the current operating direction of the tool in a simple, effective, and reliable manner. A further result is that a handheld power tool is provided that can obtain more detailed current usage data, which can more clearly indicate the current usage of the handheld power tool and more clearly and reliably indicate whether the handheld power tool is being used in the correct manner.

[0022] Optionally, the control device is configured to estimate the operating efficiency of the tool based on the tool force estimate and the current operating data of the power source. Thus, a handheld power tool is provided that can reliably estimate the operating efficiency of the tool. Thus, a handheld power tool is provided that can obtain more detailed current usage data, which can more clearly indicate the current usage of the handheld power tool and more clearly and reliably indicate whether the handheld power tool is being used in the correct manner. In addition, for example, if the operating efficiency of the tool drops below a threshold efficiency, the handheld power tool can notify the user.

[0023] The reduction in the operating efficiency of the tool may be caused, for example, by tool clogging and / or tool wear. In other words, due to these features, a handheld power tool is provided that can reliably estimate the wear state and / or the clogging state of the tool.

[0024] Optionally, the handheld power tool includes a user interface unit configured to output data representing the estimated operating efficiency of the tool. Thus, a handheld power tool is provided that can be used in a simpler and more user-friendly manner. In addition, a handheld power tool is provided that can reduce energy consumption. This is because the user can be notified of the operating efficiency of the tool and measures can be taken in response thereto, such as cleaning, replacing, or sharpening the tool of the handheld power tool.

[0025] Optionally, the power source of the hand-held power tool includes an internal combustion engine. According to these embodiments, the current operating data of the power source may include one or more of the following items: the current rotational speed of the internal combustion engine, the current torque of the internal combustion engine, the current power of the internal combustion engine, the current temperature of the internal combustion engine, the current throttle position of the air supply system of the internal combustion engine, the current throttle position of the actuator for controlling the power output of the internal combustion engine, etc. In this way, the operating efficiency of the tool can be estimated in a simple, effective and reliable manner.

[0026] According to some other embodiments, the power source of the hand-held power tool includes an electric motor. According to these embodiments, the current operating data of the power source may include one or more of the following items: the current rotational speed of the electric motor, the current torque of the electric motor, the current power of the electric motor, the current temperature of the electric motor, the current throttle position of the actuator for controlling the electric motor, the current voltage supplied to the electric motor, the current current supplied to the electric motor, etc. In this way, the operating efficiency of the tool can be estimated in a simple, effective and reliable manner.

[0027] Optionally, the hand-held power tool includes a user interface unit configured to output data indicating the tool force estimate. Thus, a hand-held power tool is provided that can be used in a simpler, more ergonomic and more user-friendly manner. This is because the output of the data indicating the tool force estimate value can indicate whether the actual force applied to the tool is within the preferred force range. A further consequence is that a hand-held power tool is provided that can improve operating efficiency and reduce tool wear. In addition, a hand-held power tool is provided that can be operated in a safer manner.

[0028] Optionally, the user interface unit is configured to output a first type of signal when the tool force estimate value is below a threshold force, and is configured to output a second type of signal distinguishable from the first type of signal when the tool force estimate value exceeds the threshold force. Thus, a hand-held power tool is provided that can be used in a simpler, more ergonomic and more user-friendly manner. This is because the user can be notified when the tool force estimate value exceeds the threshold force, and the user can respond thereto by reducing the force applied to the tool. As a further result, a hand-held power tool is provided that can improve operating efficiency and reduce tool wear. In addition, a hand-held power tool is provided that can be operated in a safer manner.

[0029] Optionally, the hand-held power tool includes a control device configured to render the power source inoperable when data from the first sensor assembly and the second sensor assembly indicates that no external force is applied to one of the first handle and the second handle. Thus, a hand-held power tool is provided that can significantly improve operational safety. This is because it can be ensured that during operation of the hand-held power tool, the hand-held power tool is held, which is achieved by holding one hand on the first handle and one hand on the second handle.

[0030] Optionally, the hand-held power tool includes a control device configured to render the power source inoperable when a sudden increase in the external force applied to one of the first handle and the second handle is detected. Thus, a hand-held power tool is provided that can significantly improve operational safety. This is because in a situation where danger may occur, such as when the external force applied to one of the first handle and the second handle suddenly increases due to a sudden movement of the hand-held power tool (such as a sudden rotation of the hand-held power tool), the power source cannot operate. For example, such a sudden movement of the hand-held power tool may occur when the moving tool of the hand-held power tool hits an object with an unfavorable part of the tool, causing a so-called recoil of the hand-held power tool.

[0031] Optionally, the tool is a cutting tool configured to operate in a cutting plane, and each of the first sensor assembly and the second sensor assembly is configured to provide data representing the external force applied to the respective first handle and second handle in a direction parallel to the cutting plane. Thus, a hand-held power tool is provided that can acquire the current usage data of the hand-held power tool in a more effective and reliable manner during operation. In addition, the data representing the external force applied to the first handle and the second handle can more reliably indicate the current usage of the tool of the hand-held power tool. In addition, a hand-held power tool is provided that can provide a more reliable tool force estimate representing the force applied to the tool based on the data from the first sensor assembly and the second sensor assembly.

[0032] Optionally, the cutting plane extends through each of the first sensor assembly and the second sensor assembly. Thus, a hand-held power tool is provided that can acquire the current usage data of the hand-held power tool in a more effective and reliable manner during operation. In addition, the data representing the external force applied to the first handle and the second handle can more reliably indicate the current usage of the tool of the hand-held power tool. In addition, a hand-held power tool is provided that can provide a more reliable tool force estimate representing the force applied to the tool based on the data from the first sensor assembly and the second sensor assembly.

[0033] Optionally, the first handle includes a gripping portion configured to be gripped by a user's hand during operation of the hand-held power tool, and wherein the first sensor assembly includes two sensor units disposed on at least substantially opposite two sides of the gripping portion of the first handle. Accordingly, a hand-held power tool is provided that can acquire current usage data of the hand-held power tool in a more efficient and reliable manner during operation. This is because when estimating the usage of the hand-held power tool based on data representing the external force applied to the first handle, the gripping force on the gripping portion of the first handle can be compensated. In addition, a hand-held power tool is provided that can provide a more reliable tool force estimate representing the force applied to the tool based on data from the first sensor assembly and the second sensor assembly.

[0034] Optionally, the hand-held power tool includes a control device configured to provide a first resultant force estimate representing the resultant force applied to the first handle by comparing force data acquired from the two sensor units of the first sensor assembly, and wherein the control device is configured to provide a tool force estimate representing the force applied to the tool at least partially based on the first resultant force estimate. Accordingly, a more reliable and accurate tool force estimate representing the force applied to the tool can be provided. This is because when providing the tool force estimate, the gripping force on the gripping portion of the first handle can be compensated.

[0035] Optionally, the second handle includes a gripping portion configured to be gripped by a user's hand during operation of the hand-held power tool, and wherein the second sensor assembly includes two sensor units disposed on at least substantially opposite two sides of the gripping portion of the second handle. Accordingly, a hand-held power tool is provided that can acquire current usage data of the hand-held power tool in a more efficient and reliable manner during operation. This is because when estimating the usage of the hand-held power tool during use based on data representing the external force applied to the first handle, the gripping force on the gripping portion of the second handle can be compensated. In addition, a hand-held power tool is provided that can provide a more reliable tool force estimate representing the force applied to the tool based on data from the first sensor assembly and the second sensor assembly.

[0036] Optionally, the hand-held power tool includes a control device configured to provide a second resultant force estimate representative of the resultant force applied to the second handle by comparing force data obtained from two sensor units of the second sensor assembly, and wherein the control device is configured to provide a tool force estimate representative of the force applied to the tool at least in part based on the second resultant force estimate. Thus, a more reliable and accurate tool force estimate representative of the force applied to the tool can be provided. This is because when providing the tool force estimate, the gripping force on the gripping portion of the second handle can be compensated for.

[0037] Optionally, the first sensor assembly and the second sensor assembly include a plurality of sensor units, and wherein each sensor unit includes a force-sensitive resistor. Thus, a hand-held power tool is provided that is capable of providing data representative of the external forces applied to the first and second handles in a robust, efficient, and reliable manner. In addition, a hand-held power tool is provided that has conditions and characteristics suitable for being manufactured and assembled in a cost-effective manner while being capable of providing reliable data representative of the external forces applied to the first and second handles.

[0038] Furthermore, since each sensor unit includes a force-sensitive resistor, a hand-held power tool is provided that is capable of providing data representative of the external forces applied to the first and second handles without significantly increasing the size or weight of the first and second handles. This is because the force-sensitive resistor has a relatively thin thickness and low weight while being capable of providing reliable data representative of the external forces applied to the first and second handles.

[0039] Furthermore, since each sensor unit includes a force-sensitive resistor, a hand-held power tool is provided that is capable of providing data representative of the external forces applied to the bent portions of the first and second handles. This is because the force-sensitive resistor has a high bending ability while being capable of providing reliable data representative of the external forces applied to the first and second handles.

[0040] Furthermore, due to the high bending ability, the force-sensitive resistor can be integrated in the softer outer layer of the respective first and second handles or can be arranged adjacent to the softer outer layer of the respective first and second handles.

[0041] In addition, since each sensor unit includes a force-sensitive resistor, a handheld power tool is provided that has a lower need for cable routing and laying, while being able to provide reliable data representing the external forces applied to the first and second handles. Also for this reason, a handheld power tool is provided that can provide reliable data representing the external forces applied to the first and second handles without significantly increasing the size or weight of the first and second handles, nor significantly increasing the size or weight of the handheld power tool.

[0042] Optionally, the handheld power tool includes a control device configured to adjust the power output of the power source based on data from the first sensor assembly. Thus, a handheld power tool is provided that can be operated in a more ergonomic and user-friendly manner. This is because adjusting the power output of the power source based on data from the first sensor assembly eliminates the need for a conventional throttle actuator for adjusting the power output of the power source.

[0043] Thus, in this way, a handheld power tool is provided in which the user does not need to adjust the power output of the power source by actuating a separate actuator (such as using a finger). Instead, the user can control the power output of the power source by adjusting the gripping force of the hand gripping the first handle.

[0044] As a further result of these features, it can be ensured that the user grips the first handle in a safe manner when operating the handheld power tool. In addition, the user can grip the first handle of the handheld power tool with all fingers of the hand in a safe manner during operation of the handheld power tool.

[0045] In addition, since the need for a conventional throttle actuator for adjusting the power output of the power source is eliminated, a handheld power tool is provided that has conditions and characteristics suitable for being manufactured and assembled in a cost-effective manner. In addition, a handheld power tool with a lighter weight is provided.

[0046] Optionally, the handheld power tool includes a third sensor assembly and a control device operably connected to the third sensor assembly, the third sensor assembly including at least one force-sensitive resistor, and wherein the control device is configured to adjust a setting or switch between at least two different states based on an input from the third sensor assembly. Thus, the third sensor assembly can be used as a robust, effective, and reliable input unit for controlling the control device. In addition, since the third sensor assembly includes at least one force-sensitive resistor, the third sensor assembly can be made compact and lightweight.

[0047] In addition, due to the high bending ability of the force-sensitive resistor, the force-sensitive resistor can be integrated in or disposed adjacent to a softer outer layer of the handheld power tool. In addition, a handheld power tool is provided that has a lower need for cabling and routing of cables to the third sensor assembly. In addition, the third sensor assembly can be provided with a variable switching limiter to allow input based on the pressing force applied to the third sensor assembly.

[0048] Optionally, the handheld power tool is a chainsaw or a power cutter. Accordingly, a chainsaw or a power cutter having at least some of the above advantages is provided.

[0049] Other features and advantages of the present invention will become apparent when the appended claims and the following detailed description are studied. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Aspects of the present invention, including its particular features and advantages, will be readily understood from the following detailed description and the exemplary embodiments discussed in the drawings, in which:

[0051] Figure 1 A first side view of a handheld power tool according to some embodiments of the present invention is shown,

[0052] Figure 2 is shown Figure 1 a second side view of the handheld power tool shown in, and

[0053] Figure 3 is shown Figure 1 and Figure 2 a third side view of the handheld power tool shown in. DETAILED DESCRIPTION

[0054] Aspects of the present invention will now be described more fully. Throughout, like reference numerals represent like elements. For the sake of brevity and / or clarity, well-known functions or constructions will not be described in detail.

[0055] Figure 1 A first side view of a handheld power tool 1 according to some embodiments of the present disclosure is shown. The handheld power tool 1 includes a tool 30 and a power source 10 configured to provide power to the tool 30. According to the illustrated embodiment, the handheld power tool 1 is a chainsaw that includes a tool 30 in the form of a cutting chain movably disposed around a guide bar 32. In Figure 1 the cutting chain and the guide bar 32 are schematically shown. The power source 10 is configured to rotate the cutting chain around the guide bar 32.

[0056] According to some other embodiments, the handheld power tool 1 mentioned herein may be other types of handheld power tools 1, such as power cutters, circular saws, trimmers, hedge trimmers, multi-functional tools, etc. Obviously, according to these embodiments, the handheld power tool 1 may include other types of tools 30 in addition to the cutting chain, such as circular saw blades, trimming heads, hedge trimmer cutting assemblies, etc.

[0057] According to the illustrated embodiment, the power source 10 of the handheld power tool 1 is an internal combustion engine. More specifically, according to the illustrated embodiment, the power source 10 is a small two-stroke internal combustion engine. The handheld power tool 1 includes a fuel tank 13 configured to store fuel, which is supplied to the internal combustion engine during operation of the internal combustion engine.

[0058] According to some other embodiments, the handheld power tool 1 may include other types of power sources 10, such as electric motors. According to these embodiments, the handheld power tool 1 may include a battery for supplying power to the electric motor during its operation. As an alternative or additionally, the handheld power tool 1 may include other types of devices for supplying power to the electric motor during its operation, such as a connector for connecting the electric motor to a power cord.

[0059] The handheld power tool 1 includes a first handle h1 and a second handle h2. The second handle h2 is separated from the first handle h1 and is arranged at a distance from the first handle h1. The handheld power tool 1 is configured to be supported via each of the first handle h1 and the second handle h2 during operation of the handheld power tool 1. In other words, the handheld power tool 1 is configured to be supported by both hands of the user during operation of the handheld power tool 1, that is, the handheld power tool is configured to be supported by grasping the first handle h1 with one hand and the second handle h2 with the other hand.

[0060] According to the illustrated embodiment, the first handle h1 is a rear handle arranged at the rear portion of the handheld power tool 1, and the second handle h2 is a so-called front handle. According to the illustrated embodiment, the second handle h2 is attached to the tool body of the handheld power tool 1 in the region of the tool portion 30' of the handheld power tool 1. The tool portion 30' is the portion of the handheld power tool 1 that is connected to the tool 30 of the handheld power tool 1. In other words, according to the illustrated embodiment, the second handle h2 of the handheld power tool 1 is arranged closer to the tool 30 of the handheld power tool 1 than the first handle h1. In addition, the second handle h2 is arranged at a position between the tool 30 of the handheld power tool 1 and the first handle h1 of the handheld power tool 1.

[0061] The first handle h1 includes a gripping portion h1' configured to be gripped by a user's hand during operation of the hand-held power tool 1. Similarly, the second handle h2 includes a gripping portion h2' configured to be gripped by a user's hand during operation of the hand-held power tool 1. The second handle h2 is formed by an elongated and curved body to allow the user to grip the gripping portion h2' of the second handle h2 in a convenient manner from various directions, which allows the user to operate the hand-held power tool 1 in different orientations relative to the gravitational field in a convenient and safe manner.

[0062] According to an embodiment herein, the hand-held power tool 1 includes: a first sensor assembly a1 configured to provide data representing an external force applied to the first handle h1; and a second sensor assembly a2 configured to provide data representing an external force applied to the second handle h2. According to the illustrated embodiment, the first sensor assembly a1 is disposed on the first handle h1, and the second sensor assembly a2 is disposed on the second handle h2. The data representing the external forces applied to the first handle h1 and the second handle h2 can clearly indicate the current usage of the hand-held power tool 1, as further explained herein.

[0063] According to the illustrated embodiment, the first sensor assembly a1 includes two sensor units u1, u2 disposed on at least substantially opposite two sides S1, S2 of the gripping portion h1' of the first handle h1. More specifically, according to the illustrated embodiment, the first sensor assembly a1 includes: a first sensor unit u1 disposed on a first side S1 of the gripping portion h1' of the first handle h1; and a second sensor unit u2 disposed on a second side S2 of the gripping portion h1' of the first handle h1, wherein the second side S2 is opposite to the first side S1.

[0064] Similarly, according to the illustrated embodiment, the second sensor assembly a2 includes two sensor units u1', u2' disposed on at least substantially opposite two sides S1', S2' of the gripping portion h2' of the second handle h2. More specifically, the second sensor assembly a2 includes: a first sensor unit u1' disposed on a first side S1' of the gripping portion h2' of the second handle h2; and a second sensor unit u2' disposed on a second side S2' of the gripping portion h2' of the second handle h2, wherein the second side S2' is opposite to the first side S1'.

[0065] In Figure 1 is shown the hand-held power tool 1 when viewed directly towards one side of the hand-held power tool 1. Further, in Figure 1In FIG. , the hand-held power tool 1 is shown positioned in its normal upright storage position on a flat horizontal support surface Hs. When the hand-held power tool 1 is positioned in its normal upright storage position on the flat horizontal support surface Hs, the bottom side portion 42 of the hand-held power tool 1 rests on (i.e., abuts against) the flat horizontal support surface Hs. According to the illustrated embodiment, the second handle h2 is arranged at a distance from the first handle h1, the distance being measured in a direction parallel to the bottom side portion 42 of the hand-held power tool 1.

[0066] As mentioned, according to the illustrated embodiment, the hand-held power tool 1 is a chain saw, which includes a tool 30 in the form of a cutting chain movably arranged around a guide bar 32. The cutting chain is a cutting tool configured to operate in a cutting plane P. In Figure 1 FIG. , the cutting plane P is perpendicular to the flat horizontal support surface Hs and perpendicular to Figure 1 the viewing direction.

[0067] Furthermore, according to the illustrated embodiment, the tool 30 is arranged to operate in at least two different operating directions od1, od2. Each of the at least two different operating directions od1, od2 coincides with the cutting plane P. According to the illustrated embodiment, the cutting plane P and each of the at least two different operating directions od1, od2 are substantially perpendicular to the bottom side portion 42 of the hand-held power tool 1, i.e., when the hand-held power tool 1 is positioned in its normal upright storage position on the flat horizontal support surface Hs, substantially perpendicular to the flat horizontal support surface Hs.

[0068] According to the illustrated embodiment, the cutting plane P extends through each of the first sensor assembly a1 and the second sensor assembly a2. In other words, according to the illustrated embodiment, the cutting plane P extends through each of the first sensor unit u1 and the second sensor unit u2 of the first sensor assembly a1 and through each of the first sensor unit u1' and the second sensor unit u2' of the second sensor assembly a2.

[0069] As mentioned herein, the first side S1 of the gripping portion h1' of the first handle h1 may be the side of the gripping portion h1' of the first handle h1 that faces away from the bottom side 42 of the hand-held power tool 1. The first side S1 of the gripping portion h1' of the first handle h1 may also be referred to as the top side of the gripping portion h1' of the first handle h1. Similarly, as mentioned herein, the first side S1' of the gripping portion h2' of the second handle h2 may be the side of the gripping portion h2' of the second handle h2 that faces away from the bottom side 42 of the hand-held power tool 1. The first side S1' of the gripping portion h2' of the second handle h2 may also be referred to as the top side of the gripping portion h2' of the second handle h2. Each of the first sides S1, S1' of the gripping portions h1', h2' of the first and second handles h1, h2 may be configured to form an adjacent surface for the palm of the user's hand.

[0070] In addition, as mentioned herein, the second side S2 of the gripping portion h1' of the first handle h1 may be the side of the gripping portion h1' of the first handle h1 that faces the bottom side 42 of the hand-held power tool 1. The second side S2 of the gripping portion h1' of the first handle h1 may also be referred to as the bottom side of the gripping portion h1' of the first handle h1. Similarly, as mentioned herein, the second side S2' of the gripping portion h2' of the second handle h2 may be the side of the gripping portion h2' of the second handle h2 that faces the bottom side 42 of the hand-held power tool 1. The second side S2' of the gripping portion h2' of the second handle h2 may also be referred to as the bottom side of the gripping portion h2' of the second handle h2. Each of the second sides S2, S2' of the gripping portions h1', h2' of the first and second handles h1, h2 may be configured to form an adjacent surface for the fingers of the user's hand.

[0071] When the hand-held power tool 1 is positioned on a flat horizontal support surface Hs in its normal upright storage position, the first and second handles h1, h2 of the hand-held power tool 1 can be accessed in an easy manner because when the hand-held power tool 1 is positioned on a flat horizontal support surface Hs in its normal upright storage position, the intended gripping directions of the gripping portions h1', h2' of the first and second handles h1, h2 are substantially perpendicular to the flat horizontal support surface Hs.

[0072] The reason for using the word "normally" in the expression "normal upright storage position" in this text is that the handheld power tool 1 may be positioned on the flat horizontal support surface Hs in another orientation relative to the flat horizontal support surface Hs. For example, its side is located on the flat horizontal support surface Hs. However, if this is the case, the cutting plane P of the tool 30, and each of the at least two different operating directions od1, od2 of the tool 30, and the expected gripping directions of the gripping portions h1', h2' of the first and second handles h1, h2 will not be substantially perpendicular to the flat horizontal support surface Hs. In addition, if this is the case, the bottom side portion 42 of the handheld power tool 1 will clearly not rest on the flat horizontal support surface Hs.

[0073] According to the illustrated embodiment, each of the sensor units u1, u2, u1', u2' of the first sensor assembly and the second sensor assembly a1, a2 includes a force-sensitive resistor. In other words, each of the first sensor unit and the second sensor unit u1, u2 in the first sensor assembly a1 and the first sensor unit and the second sensor unit u1', u2' in the second sensor assembly a2 includes a force-sensitive resistor.

[0074] The force-sensitive resistor contains a material whose resistance changes when a force is applied to the material. The resistance of the force-sensitive resistor changes substantially linearly with the magnitude of the force applied to the force-sensitive resistor. The force-sensitive resistor is sometimes referred to as a force-sensing resistor, or simply an FSR resistor. The force-sensitive resistor typically contains a conductive polymer whose resistance changes with the force applied to its surface.

[0075] The force-sensitive resistor can be provided as a polymer sheet or ink that can be applied by screen printing. In addition, the force-sensitive resistor typically contains both conductive and non-conductive particles suspended in a matrix. These particles are small in size, typically in the sub-micron range, and are arranged to reduce the temperature dependence of the force-sensitive resistor and improve its mechanical properties. Applying a force to the surface of the force-sensitive resistor causes the particles to contact the conductive electrodes, thereby changing the resistance of the force-sensitive resistor. The force-sensitive resistor is durable, requires a relatively simple interface, and is associated with lower wiring requirements for wires such as those for power supply. In addition, the force-sensitive resistor typically has a small thickness. According to the illustrated embodiment, the thickness of the force-sensitive resistor of each sensor unit u1, u2, u1', u2' is less than 1 mm. In addition, the force-sensitive resistor can be provided in a cost-effective manner and has good shock resistance.

[0076] By using force - sensitive resistors in a first sensor assembly and second sensor assemblies a1, a2, a mechanically robust solution is provided that does not require moving parts to provide data representative of an external force applied to first and second handles h1, h2.

[0077] According to the illustrated embodiment, the force - sensitive resistors of each sensor unit in a first sensor unit u1 and a second sensor unit u2 in the first sensor assembly a1 are arranged between a stiffer core structure of the first handle h1 and a softer outer layer of the first handle h1. The softer outer layer of the first handle h1 can be made of an elastic material such as an elastic polymer. The stiffer core structure of the first handle h1 can be made of metal or a stiffer type of polymer. The term "stiffer" used in this context means that the stiffer core structure has a higher stiffness compared to the softer outer layer of the first handle h1.

[0078] Similarly, according to the illustrated embodiment, the force - sensitive resistors of each sensor unit in a first sensor unit and a second sensor unit u1’, u2’ in the second sensor assembly a2 are arranged between a stiffer core structure of the second handle h2 and a softer outer layer of the second handle h2. The softer outer layer of the second handle h2 can be made of an elastic material such as an elastic polymer. The stiffer core structure of the first handle h1 can be made of metal or a stiffer type of polymer. The term "stiffer" used in this context means that the stiffer core structure of the second handle h2 has a higher stiffness compared to the softer outer layer of the second handle h2.

[0079] According to other embodiments, the force - sensitive resistors of one or more sensor units u1, u2, u1’, u2’ can be integrated into the softer outer layers of the handles h1, h2 of the handheld power tool 1. In both types of embodiments, the force - sensitive resistors can be arranged inside the outer surface of each of the first handle h1 and the second handle h2. By arranging the force - sensitive resistors inside the outer surface of each of the first handle h1 and the second handle h2, a robust and reliable solution is provided to obtain data representative of the external force applied to the first handle h1 and the second handle h2.

[0080] The handheld power tool 1 includes a control device 21. The control device 21 is operatively connected to each of the first sensor assembly and the second sensor assemblies al, a2. That is, more specifically, the control device 21 is configured to obtain data from each sensor unit u1, u2, u1’, u2’ of the first sensor assembly and the second sensor assemblies a1, a2, where the data represents the resistance value of the force - sensitive resistor of each sensor unit u1, u2, u1’, u2’. In this way, the control device 21 can obtain data representative of the external force applied to the first handle h1 and the second handle h2.

[0081] Figure 2 shows Figure 1 a second side view of the handheld power tool 1 shown. In Figure 2 it, the handheld power tool 1 held by the user in a first usage scenario is shown, where the user holds the first handle h1 with one hand and the second handle h2 with the other hand. In Figure 2 it, for reasons of simplicity and clarity, the hands of the user are omitted.

[0082] In Figure 2 the first usage scenario shown, the user operates the tool 30 of the handheld power tool 1 along a first operation direction od1 of the at least two different operation directions od1, od2 mentioned above. Further, in Figure 2 the first usage scenario shown, the user uses the lower side portion of the tool 30 to cut an object 50. According to the illustrated embodiment, the normal vector of the lower side portion of the tool 30 is substantially parallel to Figure 1 the normal vector of the lower side portion 42 of the handheld power tool 1 shown.

[0083] In Figure 2 it, a local gravity vector gv is shown. In Figure 2 the first usage scenario shown, from the perspective of the angle relative to the local gravity vector gv, the object 50 is located below the tool 30 of the handheld power tool 1. The object 50 can be, for example, a log, a branch, etc. When operating the tool 30 along the first operation direction od1, a force Ft is applied to the tool 30. The direction of the force Ft applied to the tool 30 is substantially opposite to the first operation direction od1. Further, in Figure 2 the first usage scenario shown, the direction of the force Ft applied to the tool 30 is substantially opposite to the direction of the local gravity vector gv.

[0084] Figure 3 shows Figure 1 and Figure 2 a third side view of the handheld power tool 1 shown. In Figure 3 it, the handheld power tool 1 held by the user in a second usage scenario is shown, where the user holds the first handle h1 with one hand and the second handle h2 with the other hand. In Figure 3 it, for reasons of simplicity and clarity, the hands of the user are omitted.

[0085] In Figure 3 the second usage scenario shown, the user operates the tool 30 of the handheld power tool 1 along a second operation direction od2 of the at least two different operation directions od1, od2 mentioned above. In Figure 3 the second operation direction od2 shown is different from that in Figure 2opposite to the first operating direction od1 shown therein. In Figure 3 In the second usage case shown, the user uses the upper side of the tool 30 to cut the object 50. According to the illustrated embodiment, the normal vector of the upper side of the tool 30 is substantially opposite to Figure 1 the normal vector of the lower side 42 of the hand-held power tool 1 shown. Also in Figure 3 it, a local gravity vector gv is shown. In Figure 3 In the second usage case shown, the object 50 is located above the tool 30 of the hand-held power tool 1 from the perspective of the local gravity vector gv. The object 50 can be, for example, a log, a branch, etc.

[0086] When the tool 30 is operated along the second operating direction od2, a force Ft is applied to the tool 30. The direction of the force Ft applied to the tool 30 is substantially opposite to the second operating direction od2. Further, in Figure 3 the second usage case shown, the direction of the force Ft applied to the tool 30 substantially coincides with the direction of the local gravity vector gv.

[0087] In Figure 2 and Figure 3 it, external forces Fe1, Fe1' applied to the first handle h1 and external forces Fe2, Fe2' applied to the second handle h2 are shown. Hereinafter, if not otherwise indicated, reference is made to Figures 1 to 3 simultaneously.

[0088] The external force Fe1 represents an external force applied to the first side S1 of the gripping portion h1' of the first handle h1. The external force Fe1' represents an external force applied to the second side S2 of the gripping portion h1' of the first handle h1. The external force Fe2 represents an external force applied to the first side S1' of the gripping portion h2' of the second handle h2. The external force Fe2' represents an external force applied to the second side S2' of the gripping portion h2' of the second handle h2.

[0089] As mentioned, the first sensor assembly a1 is configured to provide data representing the external forces Fe1, Fe1' applied to the first handle h1, while the second sensor assembly a2 is configured to provide data representing the external forces Fe2, Fe2' applied to the second handle h2. More specifically, according to the illustrated embodiment, each of the first sensor assembly a1 and the second sensor assembly a2 is configured to provide data representing the external forces Fe1, Fe1', Fe2, Fe2' applied to the respective first handle h1 and second handle h2 in a direction parallel to the cutting plane P.

[0090] According to the illustrated embodiment, the control device 21 is configured to provide a tool force estimate representing the force Ft applied to the tool 30 based on data from the first sensor assembly and the second sensor assemblies a1, a2. In other words, according to the illustrated embodiment, the control device 21 is configured to provide a tool force estimate representing the force Ft applied to the tool 30 based on data from the sensor units u1, u2, u1', u2' of the first sensor assembly and the second sensor assemblies a1, a2, where the data represents the current external forces Fe1, Fe1', Fe2, Fe2' applied to the first handle and the second handle h1, h2. The tool force estimate may indicate the current operating directions od1, od2 of the tool 30, as further explained herein. As an alternative or in addition, the tool force estimate may indicate the estimated magnitude of the force Ft applied to the tool 30.

[0091] Figure 2 and Figure 3 The lengths of the arrows representing the external forces Fe1, Fe1', Fe2, Fe2' in Figure 2 indicate the magnitudes of the respective external forces Fe1, Fe1', Fe2, Fe2'. As can be seen from Figure 2 there are two opposing external forces Fe1, Fe1' applied to the first handle h1. The two opposing external forces Fe1, Fe1' applied to the first handle h1 are due to the fact that the user grasps the gripping portion h1' of the first handle h1 in the first usage scenario depicted in

[0092] However, when comparing Figure 2 with Figure 1 it can be seen that the magnitude of the external force Fe1' acting on the second side S2 of the gripping portion h1' of the first handle h1 is greater than the magnitude of the external force Fe1 acting on the first side S1 of the gripping portion h1' of the first handle h1. In other words, in the first usage scenario depicted in Figure 2 the user gently lifts the first handle h1 upward (i.e., in a direction substantially opposite to the local gravity vector gv) while grasping the gripping portion h1' of the first handle h1.

[0093] In addition, in Figure 2 the resultant force Fr1 applied to the first handle h1 is shown. The resultant force Fr1 is the sum of the external force Fe1' acting on the second side S2 of the gripping portion h1' of the first handle h1 and the external force Fe1 acting on the first side S1 of the gripping portion h1' of the first handle h1.

[0094] Similarly, as can be seen from Figure 2 there are two opposing external forces Fe2, Fe2' applied to the second handle h2. The two opposing external forces Fe2, Fe2' applied to the second handle h2 are due to the fact that the user inFigure 2 This is caused by the fact that in the first usage situation depicted in

[0095] However, when comparing Figure 2 and Figure 1 it can be seen that the magnitude of the external force Fe2’ acting on the second side portion S2’ of the gripping portion h2’ of the second handle h2 is smaller than the external force Fe2 acting on the first side portion S1’ of the gripping portion h2’ of the second handle h2. In other words, in the first usage situation depicted in Figure 2 while gripping the gripping portion h2’ of the second handle h2, the user gently presses the second handle h2 downward (i.e., in a direction substantially coinciding with the local gravity vector gv).

[0096] In Figure 2 the resultant force Fr2 applied to the second handle h2 is shown. The resultant force Fr2 is the sum of the external force Fe2 acting on the first side portion S1’ of the gripping portion h2’ of the second handle h2 and the external force Fe2’ acting on the second side portion S2’ of the gripping portion h2’ of the second handle h2.

[0097] The following description is made with reference to Figure 3 and Figure 1 When comparing Figure 3 and Figure 1 it can be seen that in the second usage situation depicted in Figure 3 the magnitude of the external force Fe1’ acting on the second side portion S2 of the gripping portion h1’ of the first handle h1 is smaller than the external force Fe1 acting on the first side portion S1 of the gripping portion h1’ of the first handle h1. In other words, in the second usage situation described in Figure 3 while gripping the gripping portion h1’ of the first handle h1, the user gently presses the first handle h1 downward (i.e., in a direction substantially coinciding with the local gravity vector gv).

[0098] In Figure 3 the resultant force Fr1 applied to the first handle h1 is shown. The resultant force Fr1 is the sum of the external force Fe1 acting on the first side portion S1 of the gripping portion h1’ of the first handle h1 and the external force Fe1’ acting on the second side portion S2 of the gripping portion h1’ of the first handle h1.

[0099] Similarly, as shown in Figure 3 there are two opposite external forces Fe2, Fe2’ applied to the second handle h2. The two opposite external forces Fe2, Fe2’ applied to the second handle h2 are caused by the fact that in the second usage situation depicted in Figure 3 the user grips the gripping portion h2’ of the second handle h2.

[0100] However, when comparing Figure 3 and Figure 1 it can be seen that the magnitude of the external force Fe2' acting on the second side portion S2' of the grip portion h2' of the second handle h2 is greater than the external force Fe2 acting on the first side portion S1' of the grip portion h2' of the second handle h2. In other words, in the second usage case described in Figure 3 while gripping the grip portion h2' of the second handle h2, the user gently lifts the second handle h2 upward (i.e., in a direction substantially opposite to the local gravity vector gv).

[0101] In Figure 3 the resultant force Fr2 applied to the second handle h2 is shown. The resultant force Fr2 is the sum of the external force Fe2' acting on the second side portion S2' of the grip portion h2' of the second handle h2 and the external force Fe2 acting on the first side portion S1' of the grip portion h2' of the second handle h2.

[0102] The magnitudes and directions of the resultant forces Fr1, Fr2 applied to the first handle h1 and the second handle h2 indicate the magnitude and direction of the force Ft applied to the tool 30.

[0103] As mentioned, according to the illustrated embodiment, the control device 21 is configured to provide a tool force estimate representing the force Ft applied to the tool 30 based on data from the sensor units u1, u2, u1', u2' of the first sensor assembly and the second sensor assemblies a1, a2, where the data represents the current external forces Fe1, Fe1', Fe2, Fe2' applied to the first handle and the second handle h1, h2. The control device 21 may be configured to use calculations and / or tabular data to provide the tool force estimate. The calculations and / or tabular data may be adjusted considering the mass and / or the center of mass of the hand-held power tool 1.

[0104] According to some embodiments, the control device 21 is configured to provide a first resultant force estimate representing the resultant force Fr1 applied to the first handle h1 by comparing force data obtained from the two sensor units u1, u2 of the first sensor assembly a1. According to these embodiments, the control device 21 may be configured to provide a tool force estimate representing the force Ft applied to the tool 30 at least in part based on the first resultant force estimate.

[0105] Similarly, according to some embodiments, the control device 21 is configured to provide a second resultant force estimate representing the resultant force Fr2 applied to the second handle h2 by comparing force data obtained from the two sensor units u1, u2 of the second sensor assembly a2. According to these embodiments, the control device 21 may be configured to provide a tool force estimate representing the force Ft applied to the tool 30 at least in part based on the second resultant force estimate.

[0106] In addition, according to some other embodiments, the handheld power tool 1 may include one or more other types of devices configured to provide data indicating the current force Ft applied to the tool 30 to the control device 21, wherein the control device 21 is configured to provide a tool force estimate at least in part based on this data. As an example, according to some embodiments, the handheld power tool 1 includes a sensor configured to sense the current orientation of the handheld power tool 1 relative to the local gravity vector gv. Such a sensor may include, for example, an accelerometer and / or a gyroscope. According to these embodiments, the control device 21 of the handheld power tool 1 may be configured to provide a tool force estimate at least in part based on the data from the sensor. In this way, a more reliable tool force estimate can be provided.

[0107] As can be understood from the above, according to the illustrated embodiments, each of the first handle h1 and the second handle h2 includes a pair of sensor units u1, u2, u1', u2' arranged opposite to each other on the grip portions h1', h2' of the respective first handle h1 and second handle h2. According to some other embodiments, one or both of the first handle h1 and the second handle h2 may include one or more additional sensor units along the length of the grip portions h1', h2' of the handles h1, h2. For example, the second handle h2 may include one or more additional sensor units, such as a pair of sensor units arranged opposite to each other and different from the above-mentioned pair of sensor units u1', u2' at another part of the elongated curved body of the second handle h2.

[0108] According to Figures 1 to 3 The handheld power tool 1 according to the illustrated embodiments may be operated in a certain orientation relative to the local gravity field, in which the cutting plane P and the operating directions od1, od2 of the tool 30 are substantially perpendicular to the local gravity vector gv. This orientation of the handheld power tool 1 may also be referred to as a horizontal orientation because when the handheld power tool 1 is oriented relative to the gravity field in this way, the cutting plane P and the operating directions od1, od2 of the tool 30 are substantially parallel to the horizontal plane. In Figure 1 it, a side portion 12 of the second handle h2 is shown. When the handheld power tool 1 is operated in this horizontal orientation relative to the local gravity field, the side portion 12 of the second handle h2 is used to be gripped. According to some embodiments, one or more additional sensor units according to the above are arranged at the side portion 12 of the second handle h2.

[0109] The control device 21 may be operatively connected to the one or more additional sensor units and may be configured to estimate a current orientation of the hand-held power tool 1 relative to a local gravitational field based on data from the one or more additional sensor units. Further, according to these embodiments, the control device 21 may be configured to provide a tool force estimate based on data from the sensor units u1, u2 disposed on the first handle h1 (i.e., based on data from the first sensor assembly a1) when one or more additional sensor units on the side portion 12 of the second handle h2 indicate that the side portion 12 is being gripped.

[0110] As Figure 1 shown, according to the illustrated embodiments, the hand-held power tool 1 includes a user interface unit 6. The user interface unit 6 may include one or more of the following: a display, a light-emitting unit, a light-emitting diode, a speaker, and a communication device configured to wirelessly transmit data to an external device 60. The communication device may wirelessly transmit data via a wireless connection such as the Internet, or a wireless local area network (WLAN)), or a wireless connection for exchanging data over a short distance using short-wavelength (i.e., ultra-high frequency (UHF) radio waves in the industrial, scientific, and medical (ISM) band of 2.4 GHz to 2.485 GHz). The external device 60 may include, for example, a computer, a tablet, a smart phone, headphones, a headset, etc.

[0111] According to some embodiments, the user interface unit 6 is configured to output data indicative of the external forces Fe1, Fe1’, Fe2, Fe2’ applied to the first handle h1 and the second handle h2. In this way, a user of the hand-held power tool 1 can receive information indicative of the current external forces Fe1, Fe1’, Fe2, Fe2’ applied to the first handle h1 and the second handle h2.

[0112] Further, according to some embodiments, the user interface unit 6 is configured to output data indicative of the tool force estimate. Thus, a hand-held power tool 1 is provided that can be used in a simpler, more ergonomic, and more user-friendly manner. This is because the output of data indicative of the tool force estimate can indicate whether the actual force Ft applied to the tool 30 is within a preferred force range. A further result is that a hand-held power tool 1 is provided that can improve operation efficiency and can reduce wear of the tool 30. In addition, a hand-held power tool 1 is provided that can be operated in a safer manner.

[0113] In embodiments where the user interface unit 6 includes a display, one or more light-emitting units, etc., the data indicative of the tool force estimate may be output in the form of a visual representation of the tool force estimate. The visual representation of the tool force estimate may be in the form of, for example, a number, a symbol, text, light intensity, and / or color.

[0114] In an embodiment where the user interface unit 6 includes a speaker or the like, data indicating the tool force estimate value can be output in the form of an auditory representation of the tool force estimate value. The auditory representation of the tool force estimate value can be in the form of, for example, a tone, a frequency, a speaker voice, a sound intensity, etc.

[0115] In an embodiment where the user interface unit 6 includes a communication device configured to wirelessly transmit data to an external device 60, the data indicating the tool force estimate value can be adjusted such that when the data is received in the external device 60, the external device 60 outputs, for example, a visual and / or auditory representation according to the tool force estimate value described above.

[0116] According to some embodiments, the user interface unit 6 is configured to output a first type of signal when the tool force estimate value is below a threshold force, and is configured to output a second type of signal distinguishable from the first type of signal when the tool force estimate value exceeds the threshold force. In an embodiment where the user interface unit 6 includes a display, one or more light emitting units, etc., each of the first type of signal and the second type of signal can include a visual representation such as a number, a symbol, text, a light intensity, and / or a color.

[0117] In an embodiment where the user interface unit 6 includes a speaker or the like, each of the first type of signal and the second type of signal can include an auditory representation in the form of, for example, a tone, a frequency, a speaker voice, a sound intensity, etc.

[0118] In an embodiment where the user interface unit 6 includes a communication device configured to wirelessly transmit data to an external device 60, the first signal and the second signal can contain data that is adjusted such that when the external device 60 receives the first type of signal, the external device 60 outputs a first type of visual and / or auditory representation, and wherein when the external device 60 receives the second type of signal, the external device 60 outputs a second type of visual and / or auditory representation.

[0119] The user interface unit 6 of the handheld power tool 1 can include a combination of the above-described contents, that is, the handheld power tool can include a combination of two or more of the following: a visual output unit located on the handheld power tool 1; an auditory output unit located on the handheld power tool 1; and a communication device configured to wirelessly transmit data to an external device 60.

[0120] The user interface unit 6 can be configured to continuously output data, such as data indicating the tool force estimate value. In this way, continuous interaction with the user of the handheld power tool 1 can be achieved, which is beneficial to the use of the handheld power tool 1. In addition, a handheld power tool 1 is provided that can improve the operation efficiency and reduce the wear of the tool 30. In addition, a handheld power tool 1 is provided that can be operated in a safer manner.

[0121] According to some embodiments, the control device 21 is configured to adjust the power output of the power source 10 based on the tool force estimate value. According to these embodiments, the control device 21 can be configured to increase the power output of the power source 10 when the tool force estimate value increases, and can be configured to decrease the power output of the power source 10 when the tool force estimate value decreases. Thus, in this way, at least substantially automatic control of the power output of the power source 10 of the handheld power tool can be performed based on the tool force estimate value representing the force Ft applied to the tool 30. Therefore, due to these features, a handheld power tool 1 is provided that can be operated in a simpler, more ergonomic and more user-friendly manner.

[0122] As mentioned, according to the illustrated embodiments, the power source 10 is an internal combustion engine. According to these embodiments, the control device 21 can be configured to adjust the power output of the internal combustion engine by adjusting the amount of air and / or fuel supplied to the cylinders of the internal combustion engine. In an embodiment where the power source 10 of the handheld power tool 1 is an electric motor, the control device 21 can be configured to adjust the power output of the electric motor by controlling the amount of current and / or voltage supplied to the electric motor.

[0123] According to some embodiments, the control device 21 of the handheld power tool 1 is configured to estimate the operation efficiency of the tool 30 based on the tool force estimate value and the current operation data of the power source 10. In an embodiment where the power source 10 is an internal combustion engine, the current operation data of the power source can include one or more of the following items: the current rotational speed of the internal combustion engine, the current torque of the internal combustion engine, the current power of the internal combustion engine, the current temperature of the internal combustion engine, the current throttle position of the air supply system of the internal combustion engine, the current throttle position of the actuator for controlling the power output of the internal combustion engine, etc.

[0124] In an embodiment where the power source 10 of the handheld power tool 1 is an electric motor, the current operation data of the power source can include one or more of the following items: the current rotational speed of the electric motor, the current torque of the electric motor, the current power of the electric motor, the current temperature of the electric motor, the current throttle position of the actuator for controlling the electric motor, the current voltage supplied to the electric motor, the current current supplied to the electric motor, etc.

[0125] The operational efficiency of the tool 30 may be reduced due to, for example, clogging of the tool 30 and / or wear of the tool 30. Wear of the tool 30 may, for example, reduce the sharpness of the tool 30. According to some embodiments, the user interface unit 6 of the hand-held power tool 1 is configured to output data indicating the estimated operational efficiency of the tool 30. Thus, a hand-held power tool 1 that can be used in a simpler and more user-friendly manner is provided. In addition, a hand-held power tool 1 that can reduce energy consumption is provided. This is because the user can be notified of the operational efficiency of the tool 30 and the following measures, such as cleaning, replacing, or sharpening the tool 30 of the hand-held power tool 1, can be taken in response thereto.

[0126] According to some embodiments, the user interface unit 6 is configured to continuously output data indicating the estimated operational efficiency of the tool 30. In this way, continuous interaction with the user of the hand-held power tool 1 can be achieved. As an alternative or in addition, the user interface unit 6 may be configured to output a notification when the estimated operational efficiency of the tool 30 drops below a threshold efficiency. In this way, when the estimated operational efficiency of the tool 30 indicates that the tool 30 of the hand-held power tool 1 needs to be cleaned, replaced, or sharpened, the user of the hand-held power tool 1 can be notified.

[0127] According to some embodiments, the control device 21 of the hand-held power tool 1 is configured to render the power source 10 inoperable when no external force is applied to one of the first handle h1 and the second handle h2. In other words, according to these embodiments, the control device 21 of the hand-held power tool 1 is configured to render the power source 10 inoperable when data from the first sensor assembly a1 and the second sensor assembly a2 indicates that no external force is applied to one of the first handle h1 and the second handle h2. Thus, a hand-held power tool 1 that can significantly improve operational safety is provided. This is because it can ensure that during operation of the hand-held power tool 1, the hand-held power tool 1 is held, which is achieved by holding the first handle h1 with one hand and the second handle h2 with the other hand.

[0128] In addition, according to some embodiments, the control device 21 of the hand-held power tool 1 can be configured to render the power source 10 inoperable when a sudden increase in the external forces Fe1, Fe1', Fe2, Fe2' applied to one of the first handle h1 and the second handle h2 is detected. Thus, a hand-held power tool 1 is provided that can significantly improve operational safety. This is because in a situation where danger may occur, the power source 10 cannot operate, such as when the external forces Fe1, Fe1', Fe2, Fe2' applied to one of the first handle h1 and the second handle h2 suddenly increase due to a sudden movement of the hand-held power tool 1 (such as a sudden rotation of the hand-held power tool 1). For example, such a sudden movement of the hand-held power tool 1 may occur when the moving tool 30 of the hand-held power tool 1 hits an object 50 with an adverse part of the tool 30 (such as the tip of the tool 30). The sudden movement of the hand-held power tool 1 according to the above is sometimes referred to as recoil.

[0129] According to some embodiments, the control device 21 of the hand-held power tool 1 is configured to adjust the power output of the power source 10 based on data from the first sensor assembly a1. According to these embodiments, the control device 21 can be configured to adjust the power output of the power source 10 based on the estimated gripping force on the gripping part h1' of the first handle h1. The control device 21 can be configured to use data from the first sensor unit and the second sensor unit u1, u2 of the first sensor assembly a1 to estimate the gripping force on the gripping part h1' of the first handle h1.

[0130] Due to these features, a hand-held power tool 1 is provided that can be operated in a more ergonomic and user-friendly manner. This is because adjusting the power output of the power source 10 based on data from the first sensor assembly al obviates the need for a conventional throttle actuator for adjusting the power output of the power source 10. Thus, in this way, the user does not need to actuate a separate actuator (such as using a finger) to adjust the power output of the power source 10. Instead, the user can control the power output of the power source 10 by adjusting the gripping force of the hand gripping the gripping part h1' of the first handle h1.

[0131] In addition, due to the elimination of the need for a conventional throttle actuator for adjusting the power output of the power source 10, a hand-held power tool 1 is provided that has conditions and characteristics suitable for being manufactured and assembled in a cost-effective manner. As can be seen from Figures 1 to 3 As seen, according to the illustrated embodiment, the hand-held power tool 1 does not have a conventional throttle actuator at the first handle h1.

[0132] According to the illustrated embodiment, as Figure 1As shown, the hand-held power tool 1 includes a third sensor assembly a3. The third sensor assembly a3 is operatively connected to the control device 21 and includes a force-sensitive resistor. The control device 21 can be configured to adjust settings or switch between at least two different states based on an input from the third sensor assembly a3. The at least two different states can include, for example, an enabled state and a disabled state. In the enabled state, the hand-held power tool 1 is enabled for operation. In the disabled state, the hand-held power tool 1 is disabled and thus cannot be operated.

[0133] According to the illustrated embodiment, the third sensor assembly a3 is arranged at a side portion of the hand-held power tool 1. According to other embodiments, the third sensor assembly a3 mentioned herein can include one or more force-sensitive resistors arranged at different parts of the hand-held power tool 1. For example, the third sensor assembly a3 mentioned herein can include one or more force-sensitive resistors located at the user interface unit 6 of the hand-held power tool 1.

[0134] By using a force-sensitive resistor in the third sensor assembly a3, a mechanically robust input unit for the control device 21 is provided without the need for moving parts. In addition, the third sensor assembly a3 can be provided with a variable switching limiter to allow input based on the pressing force on the third sensor assembly a3.

[0135] The force-sensitive resistor of the third sensor assembly a3 can be integrated into the softer outer layer of the hand-held power tool 1 or can be arranged between the softer outer layer of the hand-held power tool 1 and the harder structural part of the hand-held power tool 1. The term "softer" used in this context means that the stiffness of the softer outer layer of the hand-held power tool 1 is lower than the stiffness of the harder structural part of the hand-held power tool 1.

[0136] The phrase "substantially coincident" used herein can cover an angle between the objects mentioned that is less than 10 degrees or less than 7 degrees.

[0137] The phrase "substantially parallel" used herein can cover an angle between the objects mentioned that is less than 10 degrees or less than 7 degrees.

[0138] The phrase "substantially perpendicular" used herein can cover an angle between the objects mentioned that is in the range of 80 degrees to 100 degrees or in the range of 83 degrees to 97 degrees.

[0139] The phrase "substantially opposite" used herein can cover a minimum angle between the objects mentioned that is greater than 165 degrees or greater than 173 degrees.

[0140] The phrase "substantially opposite two side portions" as used herein may cover that one of these side portions is arranged at an angle within a range of 130 degrees to 180 degrees or within a range of 150 degrees to 180 degrees with respect to the other side portion.

[0141] As mentioned, the first usage situation of the hand-held power tool 1 is shown in Figure 2 and the second usage situation of the hand-held power tool 1 is shown in Figure 3 . Obviously, the hand-held power tool 1 according to the embodiments herein can be used in more usage situations than the first usage situation and the second usage situation depicted in Figure 2 and Figure 3 . As an example, the hand-held power tool 1 according to the embodiments herein can operate in other orientations with respect to the local gravity vector gv than the orientations depicted in Figure 2 and Figure 3 .

[0142] Those skilled in the art should understand that the control device 21 can be configured to use programming instructions when performing a specific task described herein, such as when providing a tool force estimate representing the force Ft applied to the tool 30 based on data from the first sensor assembly and the second sensor assemblies a1, a2. These programming instructions generally consist of a computer program, which ensures that the control device 21 performs the specific task when executed in the control device 21. The computer program can be part of a computer program product, which includes a suitable digital storage medium on which the computer program is stored.

[0143] The control device 21 can include a computing unit, which can take the form of almost any suitable type of processor circuit or microcomputer, such as a circuit for digital signal processing (digital signal processor, DSP), a central processing unit (CPU), a processing unit, a processing circuit, a processor, an application specific integrated circuit (ASIC), a microprocessor, or other processing logic that can interpret and execute instructions. The expression "computing unit" as used herein can represent a processing circuitry system that includes multiple processing circuits, for example, any, some, or all of the circuits mentioned above.

[0144] The control device 21 may further include a storage unit. Wherein, the calculation unit may be connected to the storage unit, and the storage unit may provide, for example, stored program code and / or stored data to the calculation unit, which the calculation unit may require for calculations. The calculation unit may also be adapted to store partial or final calculation results in the storage unit. The storage unit may include a physical device for temporarily or permanently storing data or programs (i.e., sequences of instructions). According to some embodiments, the storage unit may include an integrated circuit containing silicon-based transistors. In different embodiments, the storage unit may include, for example, a memory card, a flash memory, a USB memory, a hard disk, or other similar volatile or non-volatile storage units for storing data, such as ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), etc.

[0145] The control device 21 is connected to the various components of the hand-held power tool 1 for receiving and / or sending input signals and output signals. As an example, the control device 21 is connected to the user interface unit 6 and the sensor units u1, u2, u1', u2' of the first sensor assembly and the second sensor assemblies a1, a2. These input signals and output signals may include waveforms, pulses, or other attributes, and the input signal receiving device may detect these waveforms, pulses, or other attributes as information and convert them into signals that can be processed by the control device 21. These signals may then be provided to the calculation unit. One or more output signal sending devices may be arranged to convert the calculation results from the calculation unit into output signals for transmission to other parts of the control system of the hand-held power tool 1 and / or one or more components targeted by the signals. Each connection to the various components of the hand-held power tool 1 for receiving and sending input signals and output signals may take one or more of the following forms: a cable, a data bus (e.g., a CAN (Controller Area Network) bus), or some other bus configuration, or a wireless connection.

[0146] In the illustrated embodiment, the hand-held power tool 1 includes a control device 21. Alternatively, however, the hand-held power tool may be implemented in whole or in part by two or more control devices or two or more control units.

[0147] The feature that the user interface unit 6 is configured to output data may also be expressed as the control device 21 being configured to output data via the user interface unit 6.

[0148] It should be understood that the foregoing is illustrative of various exemplary embodiments, and the present invention is defined only by the appended independent claims. Those skilled in the art will recognize that modifications can be made to the exemplary embodiments without departing from the scope of the present invention as defined by the appended independent claims, and that different features of the exemplary embodiments can be combined to form embodiments other than those described herein.

[0149] As used herein, the term "comprising" or "including" is open-ended and includes one or more of the stated features, elements, steps, components or functions, but does not exclude the presence or addition of one or more other features, elements, steps, components, functions or groups thereof.

Claims

1. A hand-held power tool (1), comprising: - A tool (30), - A power source (10) configured to supply power to the tool (30), - A first handle (h1), and - A second handle (h2) arranged at a distance from the first handle (h1), wherein the hand-held power tool (1) is configured to be supported via each of the first handle and the second handle (h1, h2) during operation of the hand-held power tool (1), and wherein the hand-held power tool (1) further comprises: - A first sensor assembly (a1) configured to provide data representing an external force (Fe1, Fe1’) applied to the first handle (h1), and - A second sensor assembly (a2) configured to provide data representing an external force (Fe2, Fe2’) applied to the second handle (h2).

2. The hand-held power tool (1) according to claim 1, wherein, The hand-held power tool (1) comprises a control device (21) configured to provide a tool force estimate representing a force (Ft) applied to the tool (30) based on data from the first sensor assembly and the second sensor assembly (a1, a2).

3. The hand-held power tool (1) according to claim 2, wherein, The control device (21) is configured to adjust the power output of the power source (10) based on the tool force estimate.

4. The hand-held power tool (1) according to claim 2 or 3, wherein, The tool (30) is arranged to operate in at least two different operating directions (od1, od2), and wherein the tool force estimate indicates the current operating direction (od1, od2) of the tool (30).

5. The hand-held power tool (1) according to any one of claims 2 to 4, wherein, The control device (21) is configured to estimate the operating efficiency of the tool (30) based on the tool force estimate and the current operating data of the power source (10).

6. The hand-held power tool (1) according to any one of claims 2 to 5, wherein, The hand-held power tool (1) comprises a user interface unit (6) configured to output data indicating the tool force estimate.

7. The hand-held power tool (1) according to claim 6, wherein, The user interface unit (6) is configured to output a first type of signal when the tool force estimate is below a threshold force, and is configured to output a second type of signal distinguishable from the first type of signal when the tool force estimate exceeds the threshold force.

8. A hand-held power tool (1) according to any one of the preceding claims, wherein, The hand-held power tool (1) comprises a control device (21) configured to disable the power source (10) when data from the first sensor assembly and the second sensor assembly (a1, a2) indicates that no external force is applied to one of the first handle and the second handle (h1, h2).

9. The hand-held power tool (1) according to any one of the preceding claims, wherein, The hand-held power tool (1) comprises a control device (21) configured to disable the power source (10) when a sudden increase in an external force (Fe1, Fe1’, Fe2, Fe2’) applied to one of the first handle and the second handle (h1, h2) is detected.

10. A hand-held power tool (1) according to any one of the preceding claims, wherein, The tool (30) is a cutting tool configured to operate in a cutting plane (P), and wherein each of the first and second sensor assemblies (a1, a2) is configured to provide data representative of an external force (Fe1, Fe1’, Fe2, Fe2’) applied to the respective first and second handles (h1, h2) in a direction parallel to the cutting plane (P).

11. The hand-held power tool (1) according to claim 10, wherein, The cutting plane (P) extends through each of the first and second sensor assemblies (a1, a2).

12. A hand-held power tool (1) according to any one of the preceding claims, wherein, The first handle (h1) includes a grip portion (h1’), the grip portion of the first handle being configured to be gripped by a user's hand during operation of the hand-held power tool (1), and wherein the first sensor assembly (a1) includes two sensor units (u1, u2) arranged on at least substantially opposite two sides (S1, S2) of the grip portion (h1’) of the first handle (h1).

13. The hand-held power tool (1) according to claim 12, wherein, The hand-held power tool (1) includes a control device (21) configured to provide a first resultant force estimate representative of the resultant force (Fr1) applied to the first handle (h1) by comparing force data obtained from the two sensor units (u1, u2), and wherein the control device (21) is configured to provide a tool force estimate representative of the force (Ft) applied to the tool (30) at least in part based on the first resultant force estimate.

14. The hand-held power tool (1) according to any one of the preceding claims, wherein, The second handle (h2) includes a grip portion (h2’), the grip portion of the second handle being configured to be gripped by a user's hand during operation of the hand-held power tool (1), and wherein the second sensor assembly (a2) includes two sensor units (u1’, u2’) arranged on at least substantially opposite two sides (S1’, S2’) of the grip portion (h2’) of the second handle (h2).

15. The hand-held power tool (1) according to claim 14, wherein, The hand-held power tool (1) includes a control device (21) configured to provide a second resultant force estimate representative of the resultant force (Fr2) applied to the second handle (h2) by comparing force data obtained from the two sensor units (u1, u2), and wherein the control device (21) is configured to provide a tool force estimate representative of the force (Ft) applied to the tool (30) at least in part based on the second resultant force estimate.

16. The hand-held power tool (1) according to any one of the preceding claims, wherein, The first and second sensor assemblies (a1, a2) include a plurality of sensor units (u1, u2, u1’, u2’), and wherein each sensor unit (u1, u2, u1’, u2’) includes a force-sensitive resistor.

17. A hand-held power tool (1) according to any one of the preceding claims, wherein, The hand-held power tool (1) includes a control device (21) configured to adjust the power output of the power source (10) based on data from the first sensor assembly (a1).

18. The hand-held power tool (1) according to any one of the preceding claims, wherein, The handheld power tool (1) includes a third sensor assembly (a3) and a control device (21) operatively connected to the third sensor assembly (a3), the third sensor assembly (a3) includes at least one force-sensitive resistor, and wherein the control device (21) is configured to adjust settings or switch between at least two different states based on an input from the third sensor assembly (a3).

19. The hand-held power tool (1) according to any one of the preceding claims, wherein, The handheld power tool (1) is a chainsaw or a power cutter.

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