Power Tools

Abstract

The present invention discloses a power tool, which comprises a motor unit (2), a battery unit (6) and a handle unit (4), wherein the motor unit (2) comprises a motor (10) and a drive shaft (38) connected to the motor (10), and the battery unit (6) is configured to accommodate a battery; the handle unit (4) connects the motor unit (2) and the battery unit (6) to each other, and the handle unit (4) comprises: a frame (18) extending from the motor unit (2) to the battery unit (6); a control button (26) arranged mounted to the frame (18) for controlling the power tool; a circuit board (20) mounted to the frame (18) and connected to the control button (26); a cable (24, 36) interconnecting the battery unit (6), the circuit board (20) and the motor unit (2); an antenna (86) connected to the circuit board (20) for communication between the power tool and an external device; and a pair of outer handle covers (14) for covering the handle unit (4); wherein the frame (18) is made of a conductive material.

Description

Technical Field

[0001] In a first aspect, the present invention relates to the field of power tools for assembly lines and industrial applications, such as pistol tools or other hand-held tools. In a second aspect, the present invention also relates to the field of power tools in general, even for hobby and construction related applications. Background Art

[0002] The manufacture and application of power tools such as pistol-type tools have certain challenges, especially in industrial environments, such as assembly plants. Such plants usually have electromagnetic compatibility (EMC) and electrostatic discharge (ESD) standards that need to be followed and met. If these requirements are not met, problems may occur for workers (such as workers with pacemakers), or problems may occur with sensitive equipment and sensitive assembly parts in general. In view of these EMC and ESD standards, today's power tools are grounded through cables if the power tool is a cable-connected tool, or when the power tool is connected to a controller near the assembly area, the power tool is grounded, where the controller has a ground level and provides the same ground level to the tool. One problem that arises from this is that due to the extensive use of plastic materials in actual tools, the tool or power tool does not have the same ground level on the entire tool, and the plastic electrically isolates multiple parts (such as motors and battery adapters) from each other, resulting in different ground levels in the same tool. In particular, the handle portion of the tool is widely made of plastic, so the motor unit, battery adapter, and battery do not have the same ground level, which leads to problems with EMC and ESD standards because it is not completely certain what kind of ground level the different parts of the tool have. One solution to this is to introduce two metal plates into the housing of the handle on both inner sides of the handle, wherein the metal plates extend from the battery adapter to the motor unit. However, these metal plates are cumbersome to install, as they need to be bent at the edges and otherwise adapted, and they are also difficult to fit when the tool is produced, thus making the tool expensive for the following reasons:

[0003] Until today, printed circuit boards (PCBs), controllers, buttons (especially control buttons for controlling tools), cables, antennas and other components are pressed into one of the two handle housings, and then the other handle housing is pressed just on the first handle housing and tightened. The handle housings are usually left and right handle housings. As you can imagine, this leads to some challenges and uncertainties in the actual placement of components once the handles are closed. These challenges are further increased when each handle housing needs to accommodate a metal plate to provide the same ground level across the entire tool. In addition, it is cumbersome and expensive to provide a metal plate that fits the handle housing and does not damage any other components (such as cables or antennas). The assembly of components in one housing of the handle also makes it very difficult to repair power tools and replace components. Typically, the entire handle must be disassembled, the components replaced, and then the handle reassembled, which takes time, resulting in long downtime for such power tools or pistol-style tools.

[0004] Another disadvantage of prior art power tools is that the connections or interfaces between the handle and the battery adapter and the battery, respectively, are quite rigid. When the power tool is impacted, for example by being dropped on the ground, it tends to disconnect at the interfaces or junctions between the battery adapter and the handle, respectively. Summary of the invention

[0005] It is therefore an object of the present invention to provide an improved power tool.

[0006] Another object of the present invention is to provide a power tool, such as a pistol-style tool, which is reliable, robust and easy to assemble.

[0007] The inventors of the present invention have found that the above challenges and problems faced by prior art power tools (e.g., pistol-type tools) can be overcome by providing a power tool having a battery unit, a handle unit, and a motor unit, wherein the handle unit includes a frame that interconnects the battery unit and the motor unit. The frame is thus made of a strong and stable conductive material, such as aluminum or conductive fiber (e.g., metal fiber) reinforced plastic. The advantage of this solution is that the PCB, controller, cable, antenna, communication unit, and other components can be assembled to the frame instead of being assembled into the handle housing. This allows the power tool to be assembled cleanly with the same ground level throughout the tool. By providing an adapter between the frame and the battery unit (the adapter can absorb vibration and impact, wherein the adapter is also made of conductive material, such as aluminum, steel, or metal fiber reinforced plastic), the power tool can be further made resistant to damage at the handle-battery unit interface. The inventors further recognize that this damage resistance can be further increased when an inner handle cover and an outer handle cover with different amounts of glass fiber embedded in the plastic are provided, wherein the inner handle cover is made to be less hard than the outer handle cover.

[0008] A power tool, such as a pistol tool or any other handheld power tool, is disclosed herein, comprising a motor unit, a battery unit, and a handle unit, wherein the motor unit comprises a motor and a drive shaft connected to the motor, the battery unit is configured to receive a battery, the handle unit interconnects the motor unit and the battery unit, and the handle unit comprises:

[0009] - a frame extending from the motor unit to the battery unit;

[0010] - a control button mounted to the frame for controlling the pistol-style tool;

[0011] - a printed circuit board mounted to the frame and connected to the control buttons;

[0012] - cables that interconnect the battery unit, the printed circuit board, and the motor unit;

[0013] -An antenna connected to the printed circuit board for communication between the pistol-style tool and an external device;

[0014] - a pair of outer handle covers, which are used to cover the handle unit;

[0015] Characterized in that the frame is made of a strong and impact-resistant conductive material.

[0016] In such an embodiment, the frame provides a base for mounting all other components in the handle, while at the same time, when the battery is connected, the frame provides a common ground level across the entire tool from the motor unit to the battery unit and the battery. Thus, the frame serves as a mounting platform for the other components in the handle unit.

[0017] Since the frame provides a base for mounting components, one of the outer handle covers can be removed and all components remain clean and tidy in place, which facilitates maintenance and repair of the pistol-grip tool.

[0018] In an embodiment, the frame may be made of a metal such as aluminum, steel or titanium, or of a conductive fiber reinforced plastic.

[0019] All of these materials are conductive, so they are able to ground the entire power tool.

[0020] In an embodiment, the handle unit may further include an adapter connected to the frame and the battery unit, wherein the adapter is electrically conductive and is designed to have shock absorbing capabilities.

[0021] The adapter may be integrally formed with the frame or the battery unit or both. The adapter helps reduce the risk of the pistol-style tool breaking at the interface handle unit-battery unit, for example in the event of a fall.

[0022] In embodiments, the adapter may also be made from a metal such as aluminum, steel or titanium, or from a conductive fiber reinforced plastic.

[0023] This helps to establish conductivity from the motor unit to the battery unit.

[0024] In another embodiment, the adapter may include a longitudinal web and at least one arcuate element connected to the longitudinal web, and the adapter may include a conductive adapter-battery cell fastening mechanism and a conductive adapter-frame fastening mechanism.

[0025] The above-mentioned design of the adapter helps to improve the vibration absorption performance of the adapter and ensures good and reliable connection with the handle unit and the battery unit respectively.

[0026] The adapter may include two arched elements and one web or two webs and two arched elements for increased stability and reliability.

[0027] In an embodiment, the frame may include a frame-motor unit fastening mechanism and a frame-adapter fastening mechanism, wherein the frame-motor unit fastening mechanism and the frame-adapter fastening mechanism are conductive, and the mechanisms are used to connect the frame to the motor unit and the adaptor, and thereby to the battery unit.

[0028] These fastening mechanisms provide reliable and strong connections between the handle unit and the motor unit, the handle unit and the battery unit and the adapter, respectively. At the same time, the fastening mechanisms are conductive and are used to provide the same ground level on the entire pistol-type tool.

[0029] In an embodiment, the handle unit may further include a pair of inner handle covers configured to be arranged around the frame and the printed circuit board and configured to be arranged on inner sides of the pair of outer handle covers.

[0030] The pair of inner handle covers are made of glass fiber reinforced plastic containing 20 to 30 weight percent of glass fiber, and wherein the pair of outer handle covers are made of glass fiber reinforced plastic containing 25 to 35 weight percent of glass fiber.

[0031] The pair of inner handle covers can further improve the shock resistance of the pistol-type tool. In particular, if the amount of glass fiber is selected to be smaller in weight percentage than the glass fiber in the pair of outer handle covers, the distribution of shock or load in the event of an impact can be improved, because the pair of inner handle covers is allowed to deform under less force or shock than the pair of outer handle covers, which leads to an optimized load distribution and thus a higher shock resistance.

[0032] In an embodiment, the frame may further include a bolt opening configured to receive a bolt for fastening the printed circuit board and the pair of inner handle covers, the bolt being made of a conductive material and configured to physically contact the printed circuit board.

[0033] The bolt may be advantageous for a clean and secure assembly, while it may provide grounding for the printed circuit board. Alternatively, the grounding may be provided by a conductive sleeve arranged around the bolt.

[0034] In an embodiment, at least one of the pair of inner handle covers includes a channel for receiving and embedding a cable.

[0035] This will result in a better and safer arrangement of the cables and thereby a more durable pistol tool.

[0036] In an embodiment, the frame may include a receiving cavity for mounting a control button.

[0037] Such a receiving cavity facilitates the replacement of the control button in case of a breakage of the control button. The control button and its trigger can be fastened in the trigger adapter respectively by means of a splint or the like, which is embedded in the receiving cavity by means of a spring. Removing the splint will facilitate the replacement of the control button. Of course, other solutions can be used, but the receiving cavity also facilitates the assembly of the control button.

[0038] In an embodiment, the handle unit may further include an insulating protective element connected to the frame between the frame and the printed circuit board.

[0039] The insulating protection element may be made of an electrically insulating and relatively soft material, so that it can protect printed circuit boards and other sensitive electrical components from electrical discharges or shocks, for example.

[0040] In an embodiment, the outer handle cover may extend from the motor unit to the battery unit.

[0041] This provides a stable covering of the handle unit.

[0042] Conductive and strong material

[0043] Here, the term "conductive and strong material" generally refers to a certain type of metal (such as aluminum, steel, titanium or alloys thereof), or fiber reinforced plastic, where the fibers may be conductive carbon fibers or metal fibers.

[0044] Fastening mechanism

[0045] Here, the term "fastening means" generally refers to threads, bolts, holes and screw combinations used to fasten components to each other. Other fastening mechanisms, such as form-fit or press-fit connections, even connections caused by adhesives or connections caused by conductive adhesives, etc. are also covered by this term. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] For purposes of illustration, the present invention will now be described in more detail by way of embodiments and with reference to the accompanying drawings, in which:

[0047] Figure 1 Schematically shows a perspective view of a pistol-type tool according to the present invention;

[0048] Figure 2 The perspective view schematically shows Figure 1 a pistol-style tool with certain parts removed to better illustrate the features;

[0049] Figure 3 The perspective view schematically shows Figure 2 A pistol-style tool with more parts removed to better illustrate the features;

[0050] Figure 4 A pair of inner handle covers of a pistol-style tool are schematically shown in perspective view;

[0051] Figure 5 The perspective view schematically shows Figure 3 a pistol-style tool in which the inner handle cover is removed;

[0052] Figure 6 An adapter for connecting the handle unit to the battery unit is schematically shown in a perspective view;

[0053] Figure 7 The handle unit-battery unit connection is schematically shown in the perspective view;

[0054] Figure 8 A frame with control buttons is schematically shown in a perspective view; and

[0055] Fig. 9 This is a schematic diagram of the exploded view of the handle unit and the battery unit. DETAILED DESCRIPTION

[0056] Figure 1 A pistol tool 1 is shown having a motor unit 2, a handle unit 4 and a battery unit 6. The pistol tool 1 is shown without a battery, but it is clear that a battery can be connected to the battery unit 6. The motor unit 2 includes a motor housing 12 and a motor 10 (see Figure 2 ). The motor 10 drives a drive shaft 38 having a bit connector 40 (see Figure 2 ). The handle unit 4 includes a reverse button 28 to change the rotation direction of the motor and the shaft 38 and the bit connector 40, respectively. The handle unit 4 then further includes a control button 26 having a trigger 62 and a pair of outer handle covers 14 arranged to cover the handle unit 4. The pair of outer handle covers 14 extend from the motor unit 2 to the battery unit 6 and are fastened to the motor unit 2 and the battery unit 6 by an outer handle cover fastening mechanism 72, such as Figure 2 The outer handle cover fastening mechanism 72 includes a threaded hole, a bolt and a hole combination, such as Figure 1 and Figure 2 as shown in .

[0057] Now go to Figure 2 , Figure 2 Shown with Figure 1 The same pistol-style tool 1, but with the front cover and bit adapter removed, and the left outer handle cover removed. Each of the pair of outer handle covers 14 includes a reverse button recess 46 extending through the outer handle cover 14. The reverse button recess 46 is also formed in the frame 18 of the handle unit 4, which holds the printed circuit board ( Figure 6 ) and other components as further explained herein.

[0058] Figure 2 The frame 18 shown in FIG. 1 extends downwardly from the motor unit 2 to the battery unit 6 and is made of a conductive material to provide a uniform ground level throughout the pistol tool 1. A control button 26 having a trigger 62 located in a trigger adapter 64 is also shown. Figure 2 Further shown is a pair of inner handle covers 16 of the handle unit 4, at least one of which includes a cable channel 74 that connects the motor unit 2 to the handle unit 4 and its printed circuit board (see Figure 6 ) and the battery unit 6 are connected to each other by a cable 24. The cable 24 further connects the antenna 54 arranged on both sides of the handle unit 4 with the printed circuit board and the controller ( Figure 2 The battery unit 6 comprises a battery receiver 34 for receiving the battery in a form-fitting manner, such as a sliding and locking mechanism. As described in the introduction, the pair of outer handle covers 14 is made of 25% to 35%, preferably 30%, glass fibers embedded in plastic, wherein the percentages relate to weight percentages, and the pair of inner handle covers 16 is made of 20% to 30%, preferably 25%, glass fibers embedded in plastic. Such different amounts of glass fibers lead to an optimal distribution of the loads in the event of vibrations and impacts and / or deformations in the pistol-type tool 1.

[0059] Now go to Figure 3 , Figure 3Some additional features of the pistol-type tool 1 according to the present invention are shown in more detail. The frame 18 includes a frame-motor unit fastening mechanism 42 and a receiving cavity 44 for receiving the control button 26 having a trigger 62 and a trigger adapter 64. The frame-motor unit fastening mechanism 42 includes a conductive bolt, a threaded hole, and a hole combination. The trigger 62 is locked in the trigger adapter 64 by a clamp 66, which also makes it easier to replace the trigger 62 in the event of damage to the trigger 62. A spring is embedded in the receiving cavity 44 (at Figure 3 Not visible in , see Fig. 9 ), the spring pushes the control button 26 away from the accommodating cavity 44. The frame 18 has an upper portion that is wider than the width at the actual handle of the handle unit 4. The frame 18 is further made of aluminum and is basically a spline or metal spline.

[0060] Figure 3 The inner handle covers 16 are further shown, wherein at least the left inner handle cover includes a cable channel 74 (at Figure 3 The inner side has no cables shown) for accommodating the cables and keeping them neatly in place during and after assembly. A pair of inner handle covers 16 are fastened to the battery unit 6 by inner handle cover fastening mechanisms 76, which also include threaded holes, bolts, and hole combinations. Figure 3 Also visible in the figure are the threaded holes of the outer handle cover fastening mechanism 72 and the bolts 60 for fastening the pair of inner handle covers 16 to the frame 18. The bolts 60 also help to hold the printed circuit board in place and connected to the frame 18.

[0061] Figure 4 A pair of inner handle covers 16 are shown including a base 78 where the inner handle cover fastening mechanism 76 is located.

[0062] Figure 5 Since the pair of inner handle covers 16 are not shown, the frame 18 of the handle unit 4 is more clearly shown. Mounted on the frame 18 is a printed circuit board 20 or circuit board 20, which includes various circuits 52 and a communication unit 56. The circuit board 20 also includes a computer processing unit (CPU) 55, and the circuit board 20 is mounted to the frame 18 by bolts 60 and is connected to the battery unit 6 by cables 36. The bolts 60 also provide a grounding function because they electrically connect the frame 18 to the circuit board 20 through the sleeve 84, as shown in FIG. Fig. 9 An insulating protective element 21 is arranged between the circuit board 20 and the frame 18 (see Fig. 9The insulating protective element 21 is made of rubber or another suitable material that electrically insulates the circuit board 20 from the frame 18, and the insulating protective element 21 also serves as a cushion to protect the circuit board 20 from vibration and other physical impacts. The frame 18 is connected to the battery cell 6 through the adapter 30, which is also Figure 6 . The adapter 30 is made of a conductive material, such as a metal such as aluminum, titanium or steel, or a plastic reinforced with conductive fibers. The adapter 30 is designed as a shock absorbing element, which can absorb shock in the event that the pistol-type tool 1 falls or receives additional impact via the battery cell 6 when the battery is connected. The frame 18 is connected to the adapter 30 via an adapter-frame fastening mechanism 50, and the adapter 30 is connected to the battery cell 6 via an adapter-battery cell fastening mechanism 82. The adapter 30 is connected to the battery cell 6 via the battery cell housing 70.

[0063] Figure 6 The adapter 30 is shown in more detail. The adapter 30 includes a longitudinal web 88 and two arched elements 90. The arched elements 90 are integrally connected to the longitudinal web 88. On the sides of the arched elements 90 that are not connected to the longitudinal web 88, they include feet 91 that facilitate the installation of the adapter 30 and increase stability when the adapter 30 is installed. The holes of the adapter-frame fastening mechanism 50 are shown at the highest point of the arched element 90, and the holes are designed to accommodate screws or bolts of the adapter-frame fastening mechanism 50. The holes of the adapter-battery cell fastening mechanism 82 are shown on one end of the longitudinal web 88, and the holes are used to accommodate screws or bolts of the adapter-battery cell fastening mechanism 82. Another hole of the adapter-battery cell fastening mechanism 82 is shown on a foot 91 of the arched element 90. Figure 6 An exemplary embodiment of the adapter 30 is shown, but other solutions and designs are obviously possible. The holes and the arched elements 90 may be arranged differently, or the adapter 30 may only include one or more arched elements 90. In addition, the adapter may include two longitudinal webs 88 instead of one. However, the arched elements 90 are advantageous because they provide the ability to absorb shocks, etc.

[0064] Figure 7 An enlarged perspective view of the battery cell 6 is shown, and the lower portion of the handle unit 4 is shown. The circuit board 20 mounted on the frame 18 and the adapter-frame fastening mechanism 50 connecting the frame 18 to the adapter 30 are visible. The cable 36 from the battery cell 6 is directly connected to the circuit board 20. The adapter 30 is fastened to the battery cell 6 via the adapter-battery cell fastening mechanism 82. The battery cell housing 70 includes the battery cell electronics 71 (e.g., circuitry and a processor), which are connected to the battery power port (and thereby to the battery) and the cable 3, which leads to the circuit board 20 of the handle unit 4. From Figure 7 It can be clearly seen how the interface handle unit 4-battery unit 6 is designed and how the adapter 30 provides shock protection. The adapter 30 and frame 18 in the figure are made of aluminum to provide good stability and light weight. As described herein, other materials are also possible. Different materials can also be selected for the frame 18 and adapter 30. The screws and bolts used for the fastening mechanism can also be made of aluminum or steel.

[0065] Figure 8 1 and 2 show an exploded view of the various components of the frame 18 and the control button 26. The control button 26 includes a trigger 62, a trigger engager 64, and a spring 68, wherein the trigger engager 64 is embedded in and retains the trigger 62 through a clamp 66 (see Fig. 9 ), the spring 68 is embedded in the accommodating cavity 44 and is used for the control button in the frame 18. Figure 8 Further shown are a reverse button recess 46 and a frame-motor unit fastening mechanism 42. The frame-motor unit fastening mechanism 42 includes a portion at the upper end of the frame 18 that is constructed to be stronger and more solid than the rest of the frame 18. Typically, this portion at the upper portion of the frame 18 is about 20% to 70% thicker than the rest of the frame 18. In a similar manner, the lower end of the frame 18 (the lower end including the adapter-frame fastening mechanism 50) is designed to be thicker and therefore stronger than the rest of the frame 18, also having an increased thickness of about 20% to 70% thicker than the rest of the frame 18. Threaded holes for accommodating bolts and / or screws are embedded in these portions of the upper and lower ends of the frame 18. Figure 8 Further shown is a bolt opening 48 for receiving the bolt 60 and its sleeve 84. Bolt openings 48 are also designed and reserved in the circuit board 20 and the insulating protection element 21 so that these components can be attached to the frame 18 by the bolt 60 and the sleeve 84.

[0066] Fig. 9 The exploded schematic diagram of the handle unit 4 and the battery unit 6 of the pistol-type tool is shown without a pair of outer handle covers 14. However, Fig. 9 The inner handle cover 16, the insulating protective element 21, the frame 18, the circuit board 20, the battery cell housing 70, the trigger 62 of the control button 26, and a pair of antennas 86 for communicating with, for example, a factory network are shown. The circuit board 20 can extend on both sides of the frame 18, such as Fig. 9 As shown, it can also have a portion embedded in the battery cell housing 70 when assembled. When the pistol-type tool is assembled, this portion of the circuit board 20 embedded in the battery cell housing 70 can be positioned just below the adapter 30, for example. Fig. 9It is further shown how the circuit board 20 and the insulating protective element 21 extend around the receiving cavity 44 for the control button. The trigger 62 and the trigger engagement 64 (including the spring 68 and the clamp 66 that holds the trigger 62 in the trigger engagement 64) are also shown. Fig. 9 Pushing the trigger 62 will send a signal to the circuit board 20, for example via a Hall sensor, so that the circuit board 20 controls the motor unit 2 and the motor, respectively.

[0067] The antenna 86 is configured to be attached to the battery cell housing 70 on both sides of the adapter 30. The pair of antennas 86 can thus be connected directly to the circuit board 20 of the pistol tool 1 or via the cable 36 to the circuit board 20 of the pistol tool 1. Fig. 9 Further shown are the bolts 60 and sleeves 84 used to mount the insulating shield element 21 , the circuit board 20 , and the inner handle cover 16 to the frame 18 .

[0068] The frame is shown as a plate-like element, but it is clear that it may have another design and structure, such as a truss or frame design, or it may contain a plurality of holes for optimizing weight.

[0069] The invention has now been described and disclosed, and its advantages have been explained with reference to the embodiments shown in the drawings. The invention encompasses solutions falling within the basic idea of ​​providing a conductive structure within a power tool or in particular a pistol-type power tool, which provides the same ground level throughout the tool.

Claims

1. A power tool, comprising a motor unit (2), a battery unit (6) and a handle unit (4), wherein the motor unit (2) comprises a motor (10) and a drive shaft (38) connected to the motor (10), the battery unit (6) is configured to accommodate a battery, the handle unit (4) connects the motor unit (2) and the battery unit (6) to each other, and the handle unit (4) comprises: - a frame (18) extending from the motor unit (2) to the battery unit (6) and connecting the motor unit (2) and the battery unit (6) to each other; - a control button (26) mounted to the frame (18) for controlling the power tool; - a circuit board (20) mounted to the frame (18) and connected to the control buttons (26); - a cable (24, 36) which connects the battery unit (6), the circuit board (20) and the motor unit (2) to one another; - an antenna (86) connected to the circuit board (20) for communication between the power tool and an external device; - a pair of outer handle covers (14), the pair of outer handle covers (14) being used to cover the handle unit (4) and form a receiving space; wherein the frame (18), the circuit board (20), the cables (24, 36) and the antenna (86) are installed in the accommodation space; Wherein, the frame (18) is made of a conductive material, and wherein the handle unit (4) further comprises a connector (30) connected to the frame (18) and the battery unit (6), wherein the connector (30) is conductive and is designed to have shock absorption capability.

2. The power tool according to claim 1, wherein: The frame (18) is made of metal such as aluminium, steel or titanium or of conductive fibre reinforced plastic.

3. The power tool according to claim 2, wherein: The adapter (30) is made of metal such as aluminum, steel or titanium or of conductive fiber reinforced plastic.

4. The power tool according to claim 2 or 3, wherein: The adapter (30) includes a longitudinal web (88) and at least one arched element (90) connected to the longitudinal web (88), and wherein the adapter (30) includes a conductive adapter-battery cell fastening mechanism (82) and a conductive adapter-frame fastening mechanism (50).

5. A power tool according to claim 2 or 3, wherein: The frame (18) includes a frame-motor unit fastening mechanism (42) and a connector-frame fastening mechanism (50), wherein the frame-motor unit fastening mechanism (42) and the connector-frame fastening mechanism (50) are electrically conductive and are used to connect the frame (18) to the motor unit (2) and the connector (30), and thereby to the battery unit (6).

6. The power tool according to claim 1, wherein: The handle unit (4) further includes a pair of inner handle covers (16) configured to be arranged around the frame (18) and the circuit board (20) and configured to be arranged on the inner side of the pair of outer handle covers (14).

7. The power tool according to claim 6, wherein: The pair of inner handle covers (16) are made of glass fiber reinforced plastic containing 20 to 30 weight percent of glass fiber, and the pair of outer handle covers (14) are made of glass fiber reinforced plastic containing 25 to 35 weight percent of glass fiber.

8. The power tool according to claim 6 or 7, wherein: The frame (18) further includes a bolt (60) and a bolt opening (48), wherein the bolt opening (48) is configured to receive the bolt (60) for fastening the circuit board (20) and the pair of inner handle covers (16), the bolt (60) being made of a conductive material and configured to physically contact the circuit board (20).

9. The power tool according to claim 6 or 7, wherein: At least one of the pair of inner handle covers (16) includes a channel (74) for receiving and embedding a cable (24).

10. The power tool according to claim 1, wherein: The frame (18) includes a receiving cavity (44) for mounting a control button (26).

11. The power tool according to claim 1, wherein: The handle unit (4) further comprises an insulating protective element (21) connected to the frame (18) between the frame and the circuit board (20).

12. The power tool according to claim 1, wherein: The outer handle cover (14) extends from the motor unit (2) to the battery unit (6).

Images