DUST COLLECTION SYSTEM FOR A POWER TOOL

Abstract

A dust collection accessory prevents the transmission of noise from a DC motor in a dust collection accessory to a power path in a power tool. A dust collection system (S) for a power tool comprises a power tool (1) having an AC motor (7) which can be driven by means of a switch (21), and a tool body power path extending from a mains power (20) to the AC motor (7), and a dust collection accessory (60) which can be attached to the power tool (1) for collecting dust generated by the power tool (1) during use, and a suction area (80), a dust collector (65), a fan wheel (94), a DC motor (92), a battery pack (101), and a dust collector power path extending from the battery pack (101) to the DC motor (92) and being electrically separated from the tool body power path when the dust collection accessory (60) is attached to the power tool (1).The power tool (1) has a reaction unit (22, 27, 97) which drives the DC motor (92) in response to an actuation of the switch (21), wherein the reaction unit (22, 27, 97) is electrically isolated from a signal path of the switch (21).

Description

BACKGROUND 1. Technical field

[0001] The disclosure relates to a dust collection system for a power tool comprising an electric power tool and a dust collection accessory that attaches to the power tool to collect dust generated by the power tool during use. 2. State of the art

[0002] When a power tool, such as a hammer drill, is used to work on a target material, such as concrete or stone, a dust collection attachment is attached to the power tool to prevent dust generated by the target material from being dispersed. The dust collection attachment includes a suction portion that sucks in dust, a dust collector that collects the sucked-in dust, and a dust collection motor that includes a fan impeller that generates suction force, as disclosed, for example, in JP 6 211 433 B2.

[0003] The housing of the dust collection accessory is slid onto the body of the power tool, e.g., from below, to attach the dust collection accessory to the power tool. When attached, a male plug on the dust collection accessory is located in a female connector on the power tool and is electrically connected to the latter. The power tool receives mains power via a power cable. When the trigger is pressed to turn on a switch, the mains power is used to drive a drive motor and is also supplied to a controller on the dust collection accessory. The controller converts the supplied power into direct current (DC) and uses the DC current to drive a dust collection motor, which is a DC motor. When the switch is turned off, the supply of power from the power tool to the controller is stopped, thereby stopping the dust collection motor. SHORT SUMMARY

[0004] In the known dust collection system for the power tool, the power tool and the dust collection accessory are electrically connected, and the DC motor in the dust collection accessory is operated in response to the switch on the power tool being turned on and off. Thus, the DC motor generates noise that can reach the mains power via the power path to the power tool. Such a power tool cannot pass an electromagnetic interference (EMI) test, and thus, noise mitigation measures must be taken.

[0005] One or more aspects of the present disclosure are directed to a dust collection system for a power tool that prevents transmission of noise from a DC motor in a dust collection accessory to a power path in a power tool.

[0006] A first aspect of the present disclosure provides a dust collection system for a power tool, the system a power tool that an AC motor which can be driven by means of a switch, and a tool body power path extending from a mains power to the AC motor, and a dust collection accessory attachable to the power tool for collecting dust generated by the power tool during use, wherein the dust collection accessory a suction area, a dust collector configured to collect dust sucked through the suction area, a fan configured to generate a suction force at the suction area, a DC motor configured to rotate the fan wheel, a battery pack configured to supply power to the DC motor, and a dust collector power path extending from the battery pack to the DC motor, wherein the dust collector power path is electrically separated from the tool body power path when the dust collection accessory is attached to the power tool, wherein the power tool comprises a reaction unit configured to drive the DC motor in response to an actuation on the switch, the reaction unit being electrically isolated from a signal path of the switch.

[0007] The dust collection system according to the above-described aspect of the present disclosure prevents transmission of noise from the DC motor in the dust collection accessory to the power path in the power tool. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal cross-sectional view of a dust collection system for a power tool. Fig. Figure 2 is an enlarged view of an area on the left side of a line AA in Fig. 1. DETAILED DESCRIPTION

[0008] Embodiments of the disclosure will now be described with reference to the drawings.

[0009] Fig. 1 is a longitudinal center cross-sectional view of an exemplary dust collection system S for a power tool (hereinafter referred to simply as a dust collection system). The dust collection system S includes a hammer drill (power tool) 1 to which a dust collection accessory 60 is attached.

[0010] The hammer drill 1 has a housing including an inner housing 2, a motor housing 3, an upper outer housing 4, and a lower outer housing 5. The inner housing 2 houses a percussion assembly 6 extending in the front-to-back direction. The motor housing 3 is connected to a lower portion of the inner housing 2. The motor housing 3 houses a motor (an alternating current motor or an AC motor) 7. The motor 7 is held in the motor housing 3 with a rotating shaft 8 extending upward. The rotating shaft 8 has its upper portion supported by a bearing 9 held in the inner housing 2. The rotating shaft 8 has a drive pinion 10 at its upper end. The drive pinion 10 projects into the inner housing 2.

[0011] The upper outer housing 4 is located above the motor housing 3 and covers the outer surface of the inner housing 2.

[0012] The lower outer casing 5 has a front cylinder 11 and a handle 12. The front cylinder 11 covers the upper surface of the motor casing 3 from below. The front cylinder 11 accommodates a tool body controller 13 behind the motor casing 3. The tool body controller 13 has a control circuit board (not shown) and extends vertically. The front cylinder 11 has a front guide groove 14 in the lateral center of its front surface. The front guide groove 14 extends vertically. An upper engagement recess 15 is located above and to the front of the front guide groove 14 for receiving the dust collection accessory 60. As shown in Fig. As shown in Figure 2, the front cylinder 11 has side engagement recesses 16 on its right and left surfaces for receiving the dust collection accessory 60. A pair of side guide grooves 17 are located at the front and rear of each side engagement recess 16. The side guide grooves 17 extend upward from the lower end of the front cylinder 11.

[0013] The handle 12 extends rearwardly from a lower portion of the front cylinder 11 and then upwardly to connect to the rear end of the upper outer casing 4.

[0014] The handle 12 is connected to a power cable 20 at its lower portion. The power cable 20 is electrically connected to the tool body controller 13. The handle 12 includes a main switch (switch) 21 and an auxiliary switch (second switch) 22 above the power cable 20. The main switch 21 pushes a piston 23 forward. The main switch 21 is connected to a main line wire (signal path) 24. The main line wire 24 is electrically connected to the tool body controller 13. The main line wire 24 is used to input an on signal to the tool body controller 13 when the piston 23 is pushed. The power path extending from the power cable 20 to the motor 7 via the tool body controller 13 is an example of a tool body power path extending from mains power to an AC motor in one or more aspects of the disclosure.The power path is also an example of a tool body power path extending from the line power to the AC motor via a tool body controller in one or more aspects of the disclosure.

[0015] The auxiliary switch 22 pushes a piston 25 forward. The auxiliary switch 22 has a lever 26 at its front. The auxiliary switch 22 is connected to an auxiliary power wire 27. The auxiliary power wire 27 extends downward into the handle 12 between the main switch 21 and the inner surface of the handle 12.

[0016] The lower surface of the front cylinder 11 of the lower outer housing 5 has a connection opening 28 below the tool body control 13. The connection opening 28 is open downward. The connection opening 28 has a female connector 29 extending downward. The auxiliary power wire 27 is connected to the female connector 29.

[0017] The handle 12 has a switching lever 30 located in front of the main switch 21 and the auxiliary switch 22. The switching lever 30 is pivotable in the front-to-back direction about its lower end. In a normal state, the switching lever 30 is in contact with the piston 23 of the main switch 21 and protrudes forward from the handle 12. The switching lever 30 has a pressing portion 31 above the position at which the switching lever 30 is in contact with the piston 23. The pressing portion 31 is located in front of the lever 26 of the auxiliary switch 22.

[0018] When the protruding switching lever 30 is pushed rearward, the switching lever 30 pushes the piston 23 to turn on the main switch 21 and also pushes the piston 25 with the pushing portion 31 and the lever 26 to turn on the auxiliary switch 22. The pushing portion 31 has a predetermined length so that the auxiliary switch 22 is turned on earlier than the main switch 21.

[0019] The impact assembly 6 has a tool holder 35. The tool holder 35 is rotatably held in a front region of the inner housing 2. The tool holder 35 is cylindrical and extends in the front-to-back direction. A countershaft 36 is supported on the front side of the rotating shaft 8 in the inner housing 2. The countershaft 36 extends vertically. A crankshaft 37 is supported behind the rotating shaft 8 in the inner housing 2. The crankshaft 37 extends vertically. The countershaft 36 receives a gear 38. The crankshaft 37 receives a gear 39. The gear 38 and the gear 39 mesh with the drive pinion 10 on the rotating shaft 8. The countershaft 36 receives a first bevel gear 40 at its upper end.

[0020] The tool holder 35 is connected to a shift sleeve 41 by means of splines. Behind the shift sleeve 41, a second bevel gear 42 is externally mounted to the rear end of the tool holder 35 in a rotatable manner. The second bevel gear 42 meshes with the first bevel gear 40 on the countershaft 36. With the shift sleeve 41 engaged in a rearward position, the second bevel gear 42 transmits rotation of the first bevel gear 40 to the tool holder 35. The shift sleeve 41 is switched between a forward position and the rearward position by means of a shift knob 51. The shift knob 51 is located on the rear surface of the upper outer housing 4.

[0021] The inner housing 2 holds a cylinder 43 in its rear portion. The cylinder 43 is coaxially placed in a rear portion of the tool holder 35. The cylinder 43 accommodates a piston 44 that is movable back and forth. The crankshaft 37 has an eccentric pin 45 projecting from its upper portion. The piston 44 and the eccentric pin 45 are connected by a connecting rod 46. The cylinder 43 accommodates a striking piston 48 that is movable back and forth at the front of the piston 44, with an air chamber 47 located between the piston 44 and the striking piston 48. The tool holder 35 has a striking pin 49 at the front of the striking piston 48. The striking pin 49 comes into contact with a bit B placed in the front end of the tool holder 35. The tool holder 35 has an actuating sleeve 50 which is attached externally to its front area.The actuating sleeve 50 can be actuated to attach and remove the bit B.

[0022] In the hammer drill 1, the switch lever 30 is pressed to turn on the main switch 21. The main switch 21 provides an on signal via the main line wire 24 to the tool body controller 13, which then supplies power to the motor 7 to rotate the rotary shaft 8. The crankshaft 37 then rotates to move the piston 44 back and forth via the connecting rod 46. This causes the impact piston 48 to strike the bit B via the impact pin 49. When the switch sleeve 41 is switched to the rear position via the switch knob 51, the mode is switched to a hammer drilling mode. In the hammer drilling mode, the rotation of the countershaft 36 is transmitted to the tool holder 35 via the second bevel gear 42. When the switch sleeve 41 is switched to the front position, the mode is switched to a hammer mode. In the hammer mode, the impact is simply carried out without the tool holder 35 rotating.

[0023] The dust collection accessory 60 is now described.

[0024] The dust collection accessory 60 includes a box-like housing 61. The housing 61 includes a main portion 62, a front protruding portion 63, and a rear protruding portion 64. The main portion 62 extends vertically. The front protruding portion 63 extends forward from an upper portion of the main portion 62. A dust box 65 is removably attachable to the front of the main portion 62 and the bottom of the front protruding portion 63. The rear protruding portion 64 extends rearward from a lower portion of the main portion 62. The main portion 62 and the rear protruding portion 64 can be attached to the hammer drill 1.

[0025] The main portion 62 has an upper engagement projection 66 projecting upwardly on its upper surface. The upper engagement projection 66 is insertable into the upper engagement recess 15 on the front cylinder 11 of the hammer drill 1.

[0026] The main portion 62 has an engagement plate 67 at an upper portion of its rear surface. The engagement plate 67 extends vertically. The engagement plate 67 is engageable with the front guide groove 14 on the front surface of the front cylinder 11.

[0027] A pair of right and left side plates 68 extend from the rear surface of the main portion 62 to the upper surface of the rear protruding portion 64. The space between the pair of side plates 68 accommodates the front cylinder 11 of the hammer drill 1 from above. Each side plate 68 has a pair of front and rear ribs 69 on its inner surface. The pair of ribs 69 are fitted into the pair of side guide grooves 17 on the side surfaces of the front cylinder 11.

[0028] Each side plate 68 has a recess 70 extending vertically on its outer surface. The recess 70 receives a hook plate 71. The hook plate 71 is a strip plate that fits into the recess 70 and extends vertically. As shown in Fig. 2, the hook plate 71 has the inner surface connected to a shaft 72 in its intermediate region. The shaft 72 extends in the front-to-back direction in the recess 70. The hook plate 71 is pivotable about the shaft 72. A lower portion of the hook plate 71 is urged laterally outward by a coil spring 73 between the hook plate 71 and the inner surface of the recess 70. Thus, the hook plate 71 is in a locking position in which its upper portion is biased laterally inward, as indicated by the solid lines in Fig. 2. The hook plate 71 has an engagement rod 74 at its upper end. In the locking position, the engagement rod 74 projects inward from the side plate 68 through a through hole 75 in the recess 70. With the dust collection accessory 60 attached to the hammer drill 1, the engagement rod 74 engages the side engagement recess 16 on the front cylinder 11. When the lower portion of the hook plate 71 is pushed toward the recess 70, the hook plate 71 inclines to an unlocking position in which the engagement rod 74 is unlocked from the side engagement recess 16, as shown by the two-dot chain lines in Fig. 2 shown.

[0029] The rear protruding portion 64 has a receptacle 76 on its upper surface. When the dust collection accessory 60 is attached, the receptacle 76 is in contact with the lower surface of the front cylinder 11. The rear protruding portion 64 has a connecting cylinder 77 that projects upward on its upper surface behind the receptacle 76. The connecting cylinder 77 is located on the rear protruding portion 64 at its lateral center. The connecting cylinder 77 holds a male connector 78 that extends upward. When the dust collection accessory 60 is attached, the connecting cylinder 77 is connected to the connecting opening 28 on the lower surface of the front cylinder 11. The male connector 78 is thus connected to the female connector 29 in the connecting opening 28.

[0030] The front protruding portion 63 receives a channel 80. The channel 80 has the front end (suction area) open forward on the front surface of the front protruding portion 63. The channel 80 extends rearward in the front protruding portion 63 and then turns in the main portion 62. The channel 80 has the lower end open on the front surface of the main portion 62 below the front protruding portion 63.

[0031] The dust box (dust collector) 65 is attached to the housing 61 from the front below the front protrusion 63. The dust box 65 has a lid 81 and a box body 82 hinged together at their lower ends. The lid 81 holds a filter 83 on its front inner surface. The box body 82 covers the filter 83 from the front.

[0032] The main portion 62 has an engaging shaft 84 extending laterally from the lower end of its front surface. The box body 82 has a receiving recess 85 extending laterally from the lower surface. The engaging shaft 84 engages with the receiving recess 85, and an elastic strip 86 at the upper end of the lid 81 engages with the lower surface of the front projecting portion 63. The dust box 65 is thus removably attached to the housing 61. The lid 81 has an inlet opening 87 in its upper region and an outlet opening 88 in its lower region. The inlet opening 87 is connected to the lower end of the duct 80. The outlet opening 88 is located behind the filter 83.

[0033] The main section 62 has a motor chamber 90 defined behind the outlet opening 88. When the dust box 65 is attached, the outlet opening 88 is aligned with an opening 91 in the front surface of the motor chamber 90 and is connected to the motor chamber 90.

[0034] The motor chamber 90 accommodates a dust collection motor (DC motor) 92. The dust collection motor 92 is supported by a rotating shaft 93 extending downward. A dust collection fan (fan) 94 is fixed to the rotating shaft 93. The main section 62 has outlets (not shown) in its right and left surfaces radially outward from the dust collection fan 94.

[0035] The dust collection motor 92 is connected to a positive and a negative lead wire 95. The lead wires 95 extend through a partition between the main section 62 and the rear protruding section 64 to the interior of the rear protruding section 64. The rear protruding section 64 houses a dust collector controller 96, which includes a control board (not shown). The lead wires 95 are electrically connected to the dust collector controller 96. The dust collector controller 96 is electrically connected to the male connector 78 via a signal lead wire 97.

[0036] The rear protrusion portion 64 receives a battery mounting portion 100. A battery pack 101 is slidably mounted on the battery mounting portion 100 from the rear side and attached thereto to supply power to the dust collection accessory 60. The battery mounting portion 100 includes a terminal block 102. The terminal block 102 is electrically connected to the battery pack 101 mounted on the battery mounting portion 100. The terminal block 102 is electrically connected to the dust collector controller 96 via a power lead wire 103. A power path extending from the battery pack 101 to the dust collection motor 92 via the dust collector controller 96 is an example of a dust collector power path extending from a battery pack to a DC motor in one or more aspects of the disclosure.

[0037] The dust collector controller 96 includes an indicator lamp (indicator) 98. The indicator lamp 98 is exposed on the side surface of the rear protruding portion 64. The indicator lamp 98 is, for example, a light-emitting diode (LED). The dust collector controller 96 monitors the power level of the battery pack 101 attached to the battery mounting part 100. When the power level of the battery pack 101 decreases to less than or equal to a predetermined threshold, the dust collector controller 96 turns on or flashes the indicator lamp 98 to indicate the decrease in power level.

[0038] The rear protrusion portion 64 is placed below the front cylinder 11 of the hammer drill 1, with the ribs 69 on the side plates 68 vertically aligned with the side guide grooves 17 on the front cylinder 11. The dust collection attachment 60 is then moved vertically relative to the hammer drill 1. This causes the ribs 69 to fit into the side guide grooves 17 from below and also causes the upper engagement projection 66 on the main portion 62 to fit into the upper engagement recess 15 on the front cylinder 11 from below. The engagement plate 67 on the main portion 62 engages the front guide groove 14 on the front cylinder 11 from below.

[0039] The front cylinder 11, moving relatively downward, comes into contact with the hook plates 71 on the side plates 68 and causes the hook plates 71 to pivot from the locking position to the unlocking position. This allows relative movement of the dust collection accessory 60. When the dust collection accessory 60 is attached, the engagement rods 74 on the hook plates 71 are in the locking position and are engaged with the side engagement recesses 16 on the front cylinder 11. This restricts downward movement of the dust collection accessory 60 relative to the hammer drill 1. The attachment of the dust collection accessory 60 is thus completed.

[0040] After the installation is completed, the connecting cylinder 77 on the rear protruding portion 64 is connected to the connecting hole 28 on the front cylinder 11, and the male connector 78 is connected to the female connector 29. The auxiliary switch 22 is thus electrically connected to the dust collector controller 96 via the auxiliary power wire 27 and the signal line wire 97.

[0041] Bit B is attached to the hammer drill 1. Bit B is a dust suction bit that has a dust suction path along its axis with a suction opening at the front end. The bit can externally accommodate a hose fitting (not shown) on its outer circumference. A flexible hose 105 connects between the hose fitting and the front end of the duct 80 on the dust collection accessory 60, where suction is generated.

[0042] This defines a dust collection path R so that air can flow between the bit B and the dust collection accessory 60. As indicated by the dashed arrows in Fig. 1, the dust collection path R extends from the bit B to the outlets via the flexible hose 105, the duct 80, the dust box 65 and the motor chamber 90.

[0043] To perform work using the dust collection system S, the switch lever 30 is depressed, with the tip of the bit B pressed against the target surface of a target material. This first turns on the auxiliary switch 22. The auxiliary switch 22 provides an on signal via the auxiliary power wire 27 and the signal line wire 97 to the dust collector controller 96. The dust collector controller 96 receives power from the battery pack 101 via the terminal block 102 and the power line wire 103 and supplies power to the dust collection motor 92 via the line wires 95. This drives the dust collection motor 92 to rotate the rotary shaft 93 and the dust collection fan 94. This causes the dust collection path R to have a negative pressure to generate a suction force at the tip opening of the bit B. The auxiliary switch 22, the auxiliary power wire 27, and the signal line wire 97 are examples of a reaction unit in one or more aspects of the disclosure.The auxiliary power wire 27 and the signal line wire 97 are examples of a second signal path in one or more aspects of the disclosure.

[0044] The main switch 21 is turned on after the auxiliary switch 22 is turned on. The main switch 21 provides an on signal via the main line wire 24 to the tool body controller 13. The tool body controller 13 receives mains power via the power cable 20 and supplies operating power to the motor 7. This drives the motor 7 to rotate the rotary shaft 8, which then rotates the countershaft 36 and the crankshaft 37. The piston 44 reciprocates regardless of whether the hammer drilling mode or the hammer mode is selected. This causes the percussion piston 48 to strike the bit B by means of the striker pin 49.

[0045] The dust generated from the target material is sucked into the dust suction path in the bit B and enters the duct 80 via the flexible hose 105. The dust then enters the dust box 65 through the dust collection path R, is captured by the filter 83, and collected in the box body 82.

[0046] Any noise generated at the dust collection motor 92 during operation is not transmitted to the power path or signal path at the hammer drill 1, which is electrically separated from the dust collection motor 92.

[0047] When the work is completed, the switch lever 30 is released and the main switch 21 is turned off. This causes the tool body control 13 to stop supplying power to the motor 7 and deactivate the hammer drill 1.

[0048] When the switch lever 30 is released, the dust collector controller 96 waits for a predetermined delay time (a few seconds) to elapse after determining that the auxiliary switch 22 has been turned off. After the delay time, the dust collector controller 96 stops supplying power to the dust collection motor 92. This causes the dust remaining in the dust collection path R to move into the dust box 65 when the hammer drill 1 is deactivated.

[0049] To remove the dust collection accessory 60 from the hammer drill 1, the lower portions of the right and left hook plates 71 are pressed to move the hook plates 71 to the unlocking position. This unlocks the engagement rods 74 from the side engagement recesses 16 on the front cylinder 11 to allow relative movement of the dust collection accessory 60. The dust collection accessory 60 is moved relatively away from the hammer drill 1 in a reverse manner to that used when attaching the dust collection accessory 60. This unlocks the ribs 69 on the side plates 68 from the side guide grooves 17 on the front cylinder 11 and also unlocks the engagement plate 67 on the main portion 62 downward from the front guide groove 14. At the same time, the upper engagement projection 66 on the main portion 62 is removed from the upper engagement recess 15 on the front cylinder 11. The removal of the dust collection accessory 60 is now complete.

[0050] To empty the dust in the dust box 65, the elastic strip 86 is pressed downward to release it from the front protruding portion 63. The dust box 65 is pulled forward around the engaging shaft 84 to remove it from the housing 61. The lid 81 is opened to empty the dust in the box body 82.

[0051] As described above, the dust collection system S includes the hammer drill 1, which has the motor 7 driven by mains power via the main switch 21 operable using the switch lever 30. The dust collection system S also includes the dust collection accessory 60 attachable to the hammer drill 1 for collecting dust generated by the hammer drill 1 during use. The dust collection accessory 60 includes the duct 80, the dust box 65 that collects the dust sucked through the duct 80, the dust collection fan 94 that generates suction force at the duct 80, the dust collection motor 92 that rotates the dust collection fan 94, and the battery pack 101 for supplying power to the dust collection motor 92.

[0052] When the dust collection accessory 60 is attached to the hammer drill 1, the tool body power path extending from the power cable 20 to the motor 7 is electrically separated from the dust collector power path extending from the battery pack 101 to the dust collection motor 92. The dust collection system S includes the reaction unit (the auxiliary switch 22, the auxiliary power wire 27, and the signal line wire 97) that drives the dust collection motor 92 in response to an operation on the main switch 21, with the reaction unit electrically separated from the signal path of the main switch 21.

[0053] This prevents transmission of noise from the dust collection motor 92 to the power path of the hammer drill 1. The tool can thus pass the EMI test without any noise protection measures.

[0054] The hammer drill 1 includes the tool body controller 13, which controls the motor 7 in response to an operation of the main switch 21. The power path extending from the mains power to the motor 7 via the tool body controller 13 is electrically separated from the power path extending from the battery pack 101 to the dust collection motor 92.

[0055] With the tool body controller 13, noise is prevented from being transmitted from the dust collection motor 92 to the power path in the hammer drill 1.

[0056] The reaction unit includes the auxiliary switch 22 on the hammer drill 1. The auxiliary switch 22 is separate from the main switch 21 and operable in response to an operation on the main switch 21. The reaction unit also includes the auxiliary power wire 27 and the signal line wire 97, which electrically connect the auxiliary switch 22 and the dust collection motor 92 when the dust collection accessory 60 is attached to the hammer drill 1.

[0057] The dust collection motor 92 can thus be operated in response to an operation on the main switch 21 while being reliably separated from the signal path of the main switch 21.

[0058] The motor 7 is activated after the dust collection motor 92 is activated in response to an on operation on the main switch 21.

[0059] The dust collection accessory 60 is activated to generate suction power before the hammer drill 1 is activated. This enables reliable dust suction simultaneously with the operation of the hammer drill 1.

[0060] The dust collection motor 92 is deactivated after the motor 7 is deactivated in response to an off operation on the main switch 21.

[0061] This allows dust to be moved in the dust box 65 without remaining in the dust collection path R after the hammer drill 1 has been deactivated.

[0062] The dust collection accessory 60 is vertically movable relative to the hammer drill 1 for attachment to and removal from the hammer drill 1. The dust collection accessory 60 is electrically connected to the hammer drill 1 for activating the reaction unit after attachment to the hammer drill 1.

[0063] The dust collection accessory 60 is thus easily attachable to and detachable from the hammer drill 1. When attached, the dust collection accessory 60 can be automatically operated in response to an operation of the main switch 21. This improves usability.

[0064] The system includes indicator light 98 that indicates that battery pack 101 has a power level less than or equal to a predetermined level.

[0065] The user can therefore promptly replace or charge the battery pack 101.

[0066] The indicator lamp 98 provides a visual indication.

[0067] The user can therefore easily notice a decrease in performance.

[0068] Modifications of the disclosure are described below.

[0069] The auxiliary switch included in the reaction unit can be located below or to the side of the main switch, rather than above it. The structure of the auxiliary switch can also be modified if appropriate.

[0070] The reaction unit may have a different structure than the auxiliary switch. For example, a single switch may have two signal paths that are electrically separated from each other. In this case, a first signal path may be connected to the tool body controller via the main power wire, and a second signal path may be connected to the dust collection accessory via the auxiliary power wire.

[0071] With this structure, the DC motor can also be operated in response to an operation on the switch while being reliably isolated from the signal path of the switch for the AC motor.

[0072] In the hammer drill, the position and orientation of the motor, the position and orientation of the tool body controller, and the position where the power cable is connected are not limited to the above-described embodiments. For example, the motor may have a rotating shaft extending forward or diagonally forward. The tool body controller may extend laterally. The power cable may be connected to the rear surface of the handle. The tool body controller may be omitted.

[0073] The structure of the impact assembly is not limited to the embodiments described above. The selectable operating modes may include a drilling mode.

[0074] The power tool is not limited to a hammer drill and can be another power tool, such as an electric hammer.

[0075] Although the dust suction bit is attached to the power tool as the front-end tool in the embodiments described above, any front-end tool other than the dust suction bit may be attached. In this case, a cylindrical accessory with a hose fitting may be attached to the front end of the power tool to cover the outer surface of the front-end tool. The hose fitting may be connected to the suction area on the dust collection accessory using a flexible hose.

[0076] The dust collection accessory can be attached to the power tool in the front-to-back direction instead of the vertical direction, for example.

[0077] In the dust collection accessory, the position and orientation of the DC motor and the position and structure of the dust box are not limited to the embodiments described above. For example, the DC motor can be mounted with its rotating shaft extending upward or laterally. The DC motor and the fan impeller can have separate shafts, and rotation can be transmitted from the rotating shaft of the DC motor to the fan impeller shaft.

[0078] The dust collector is not limited to a dust box and can have a cyclone structure without a filter. The dust collection path can thus be modified if appropriate.

[0079] The battery pack can be slid sideways instead of from the back to attach to the battery mounting bracket. Multiple battery packs can be attached.

[0080] For example, in the dust collection accessory, the flexible hose may be connected to the top surface or side surface of the housing instead of the front surface. The dust collection accessory may be attached without a flexible hose. For example, the dust collection accessory may include a sliding cylinder that defines a dust collection path inside and protrudes from the housing. The sliding cylinder may have a suction opening at the front end for receiving a front-end tool.

[0081] The indication is not limited to a lamp and can, for example, be a display using letters or numbers. The indication can use a sound, such as an electric tone, or it can use both a lamp and a sound.

[0082] It is explicitly emphasized that all features disclosed in the description and / or the claims are to be considered separate and independent of each other for the purpose of the original disclosure as well as for the purpose of limiting the claimed invention, regardless of the feature combinations in the embodiments and / or the claims. It is explicitly stated that all range specifications or specifications of groups of units disclose every possible intermediate value or subgroup of units for the purpose of the original disclosure as well as for the purpose of limiting the claimed invention, in particular also as a limit of a range specification. List of reference symbols 1 hammer drill 2 inner housings 3 engine housing 4 upper outer casing 5 lower outer casing 6 Impact assembly 7 Engine 8 Rotating shaft 11 front cylinder 12 Handle 13 Tool body control 20 power cables 21 Main switch 22 additional switches 24 Main line wire 27 Additional power wire 29 female connector 30 gear levers 35 tool holders 44 pistons 48 percussion pistons 49 firing pins 60 Dust collection accessory 61 housings 62 main switch 65 dust box 71 Hook plate 78 male connector 83 filters 92 Dust collection motor 94 Dust collection fan wheel 96 Dust collector control 97 Signal wire 101 Battery Pack 103 Power line wire B Bit R Dust collection path S dust collection system for power tools QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] JP 6 211 433 B2

[0002]

Claims

[1] Dust collection system (S) for a power tool, wherein the system (S) a power tool (1) that an AC motor (7) which can be driven by means of a switch (21), and a tool body power path extending from a mains power (20) to the AC motor (7), and a dust collection accessory (60) attachable to the power tool (1) for collecting dust generated by the power tool (1) during use, wherein the dust collection accessory (60) a suction area (80), a dust collector (65) configured to collect dust sucked in by the suction area (80), a fan wheel (94) configured to generate a suction force at the suction area (80), a DC motor (92) configured to rotate the fan (94), a battery pack (101) configured to supply power to the DC motor (92), and a dust collector power path extending from the battery pack (101) to the DC motor (92), wherein the dust collector power path is electrically separated from the tool body power path when the dust collection accessory (60) is attached to the power tool (1), the power tool (1) has a reaction unit (22, 27, 97) configured to drive the DC motor (92) in response to an actuation of the switch (21), with the reaction unit (22, 27, 97) electrically separated from a signal path of the switch. [2] The dust collection system (S) according to claim 1, wherein the power tool (1) has a tool body controller (13) configured to control the AC motor (7) in response to an operation on the switch (21), and the tool body power path extends from the mains power (20) to the AC motor (7) via the tool body controller (13) and is electrically separated from the dust collector power path. [3] Dust collection system (S) according to claim 1 or 2, in which the reaction unit (22, 27, 97) a second switch (22) on the power tool (1), wherein the second switch (22) is separate from the switch (21) and is operable in response to an actuation on the switch (21), and a second signal path (27, 97) electrically connecting the second switch (22) and the DC motor (92) when the dust collection accessory (60) is attached to the power tool (1). [4] A dust collection system (S) according to claim 1 or 2, wherein the reaction unit has a second signal path separate from the signal path of the switch (21), and the second signal path electrically connects the switch (21) and the DC motor (92) when the dust collection accessory (60) is attached to the power tool (1). [5] A dust collection system (S) according to any one of claims 1 to 4, wherein the AC motor (7) is activated after the DC motor (92) has been activated in response to an operation on the switch (21). [6] Dust collection system (S) according to one of claims 1 to 5, wherein the DC motor (92) is deactivated after the AC motor (7) has been deactivated in response to an off operation on the switch (21). [7] A dust collection system (S) according to any one of claims 1 to 6, wherein the dust collection accessory (60) is vertically movable relative to the power tool (1) to be attached to and removed from the power tool (1), and the dust collection accessory (60) is electrically connected to the power tool (1) for activating the reaction unit (22, 27, 97) when attached to the power tool (1). [8] The dust collection system (S) of any one of claims 1 to 7, wherein the dust collection accessory (60) includes an indicator (98) configured to indicate that the battery pack (101) has a power level less than or equal to a predetermined level. [9] Dust collection system (S) according to claim 8, wherein the display (98) provides a visual display.

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