Power tool with a trigger featuring a non-contact sensor

Abstract

Power tool (10, 510, 710) comprising: a housing; a trigger (520) arranged on the outside of the housing, the trigger comprising a magnet (516); a motor (308) inside the housing, the motor being configured to generate a rotary output for a drive mechanism; the drive mechanism comprising a driver blade (26) for driving a fastener into a workpiece; a Hall effect sensor (524) being configured to detect a position of the trigger (520) based on the proximity of the magnet (516) to the Hall effect sensor (524); the trigger (520) being configured to pivot relative to the Hall effect sensor (524);and an electronic control unit (304) connected to the Hall effect sensor (524), the electronic control unit (304) being configured to: determine the position of the drive blade (26) and to determine the position of the trigger (520) based on a signal from the Hall effect sensor (524) when it is determined that the drive blade (26) is in a ready position, and to control the drive mechanism depending on the position of the trigger (520).

Description

Related applications

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 596,829, filed November 7, 2023, and U.S. Provisional Patent Application No. 63 / 679,966, filed August 6, 2024, the entire contents of which are hereby incorporated by reference. Area

[0002] The embodiments described here refer to power tools. Overview

[0003] The power tools described herein include a housing, a trigger disposed on an exterior of the housing and including a magnet, a motor within the housing, the motor configured to generate a rotary output for a drive mechanism, a Hall-effect sensor configured to detect a position of the trigger based on a proximity of the magnet to the Hall-effect sensor, and an electronic controller connected to the Hall-effect sensor. The electronic controller is configured to determine the position of the trigger based on a signal from the Hall-effect sensor and to control the drive mechanism based on the position of the trigger.

[0004] In some aspects, the position is a depressed position or a released position

[0005] In some aspects, the Hall effect sensor is a digital Hall effect sensor.

[0006] In some aspects, the Hall effect sensor is configured to detect a changing magnitude of the magnetic flux based on the position of the Hall effect sensor relative to the magnet.

[0007] In some aspects, the electronic control unit is configured to control the drive mechanism in response to the depressed position of the trigger to initiate a firing operation of the power tool.

[0008] In some cases, the Hall effect sensor does not detect the magnet when the trigger is in the down position.

[0009] The power tools described herein include a housing, a trigger disposed on the exterior of the housing and including a metal target portion, and a motor within the housing. The motor is configured to generate a rotary output for a drive mechanism, an inductive sensor is configured to detect a position of the trigger based on a voltage generated in the sensor by the metal target portion, and an electronic controller is connected to the inductive sensor. The electronic controller is configured to determine the position of the trigger based on a signal from the inductive sensor and to control the drive mechanism based on the position of the trigger.

[0010] In some aspects, the trigger position is either a depressed or a released position.

[0011] In some aspects, the current is induced in the metal target portion when the trigger is moved to the depressed position.

[0012] In some aspects, in response to the depressed position of the trigger, the electronic control unit controls the power tool to initiate a firing operation of the power tool.

[0013] In some aspects, the inductive sensor is located on the underside of a printed circuit board.

[0014] In some aspects, the trigger is configured to rotate relative to the inductive sensor.

[0015] In some aspects, the inductive sensor is a binary inductive sensor configured to detect an induced current in response to movement of the target portion of the trigger toward the inductive sensor.

[0016] In some cases, the inductive sensor is configured to send a signal to the control unit in response to the detection of the induced current, indicating that the trigger is depressed.

[0017] The power tools described herein include a housing, a trigger, a motor, a tunneling magnetoresistance ("TMR") sensor, and an electronic controller. The trigger is disposed on an exterior of the housing, the trigger including a magnet connected to the trigger. The motor is located within the housing. The motor is configured to generate a rotary output for a drive mechanism. The TMR sensor is configured to detect a position of the trigger based on a signal generated by the TMR sensor relative to a position of the magnet. The electronic controller is connected to the TMR sensor. The electronic controller is configured to determine the position of the trigger based on the signal generated by the TMR sensor and to control the drive mechanism based on the position of the trigger.

[0018] In some aspects, the position is the depressed position or the released position.

[0019] In some cases, the TMR sensor includes an insulating layer between a well-defined ferromagnetic layer and a free ferromagnetic layer.

[0020] In some aspects, the TMR sensor is configured to detect a first magnetization direction of the precisely defined ferromagnetic layer and a second magnetization direction of the free ferromagnetic layer, wherein when the first magnetization direction and the second magnetization direction are opposite, a detected resistance of the TMR sensor has a maximum value.

[0021] In some aspects, the resistance of the TMR sensor is maximum when the trigger is in the down position.

[0022] In some aspects, the TMR sensor includes a line configured to provide the sensed resistance to the electronic control unit.

[0023] Before the embodiments are explained in detail, it should be understood that the embodiments are not limited in their application to the details of the configurations and arrangements of the components recited in the following description or illustrated in the accompanying drawings. The embodiments may be practiced or carried out in various ways. The terms and terminology used herein are for the purpose of description and not as limiting. The use of "including," "comprising," or "having" and variations thereof is intended to include the elements listed below and their equivalents as well as additional elements. Unless otherwise specified or limited, the terms "attached," "connected," "held," and "coupled," and variations thereof, are used broadly to include both direct and indirect attachments, connections, supports, and couplings.

[0024] Unless the context of their use clearly indicates otherwise, the articles "ein", "eine" and "der / die / das" should not be read as meaning "one" or "only one". Rather, these articles should be interpreted to mean "at least one" or "one or more". When the terms "der / die / das" or "jener / jene / jenes" are used to refer to a noun previously introduced by the indefinite article "ein" or "eine", "der / die / das" and "jener / jene / jenes" also mean "at least one" or "one or more", unless usage clearly indicates otherwise.

[0025] Furthermore, it is understood that embodiments may include hardware, software, and electronic components or modules, which for explanatory purposes may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art will recognize upon reading this detailed description that, in at least one embodiment, the electronically based aspects may be implemented in software (e.g., stored on a non-transitory, computer-readable medium) that may be executed by one or more processing units, such as a microprocessor and / or application-specific integrated circuits ("ASICs").It should therefore be appreciated that a variety of hardware- and software-based devices, as well as a variety of different structural elements, may be used to implement the embodiments. For example, the "servers," "computing devices," "controllers," "processors," etc., discussed in the specification may include one or more processing units, one or more computer-readable media modules, one or more input / output interfaces, and various connections (e.g., a system bus) that interconnect the components.

[0026] Relative terms such as "approximately," "approximately," "substantially," etc., used in connection with a quantity or condition, will be understood by those skilled in the art to include the stated value and to have the meaning given by the context (e.g., the term includes at least the degree of error associated with the accuracy of measurement, the tolerances associated with the particular value [e.g., manufacturing, application, use, etc.], etc.). Such terminology should also be considered to disclose the range defined by the absolute values ​​of the two endpoints. For example, the phrase "from about 2 to about 4" also indicates the range "from 2 to 4." Relative terminology may refer to plus or minus a percentage (e.g., 1%, 5%, 10%) of a stated value.

[0027] It should be understood that although certain drawings depict hardware and software in particular devices, these depictions are for illustrative purposes only. Functions described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functions performed by multiple components may be consolidated and performed by a single component. In some embodiments, the depicted components may be combined or separated into separate software, firmware, and / or hardware. For example, rather than being housed in and executed by a single electronic processor, logic and processing may be distributed among multiple electronic processors.Regardless of how they are combined or distributed, the hardware and software components may be located on the same computing device or distributed among different computing devices interconnected by one or more networks or other suitable communications links. Similarly, a component that performs a particular function may also perform additional functions not described herein. A device or structure that is "configured" in a particular manner is at least configured in that manner, but may also be configured in a manner not explicitly listed.

[0028] Accordingly, where the claims claim that an apparatus, method or system comprises, for example, a controller, control unit, electronic processor, computing device, logic element, module, memory module, communication channel or network or other element configured in a particular way to perform, for example, a plurality of functions, the claim or claim element should be construed as meaning one or more such elements, each of the one or more elements being arranged as claimed to perform, for example, one or more of the specified multiple functions, so that the one or more elements as a group jointly perform the multiple functions.

[0029] Other aspects of the embodiments will become apparent upon consideration of the detailed description and the accompanying drawings. Short description of the drawings Fig. 1 shows a power tool according to some embodiments. Fig. 2 shows a partial cross-section of the power tool of Fig. 1. Fig. 3 shows a control system for the power tool from Fig. 1, according to some embodiments. Fig. 4A is a schematic view of the power tool of Fig. 1, showing a driver blade in a driven or bottom dead center position. Fig. 4B is a schematic view of the power tool of Fig. 1, showing a driver blade in a non-driven or top dead center position prior to actuation. Fig. 5A and Fig. 5B show a user interface for the power tool of Fig. 1, according to some embodiments. Fig. 6 is a flowchart of a method for detecting a trigger position in the power tool of Fig. 1, according to some embodiments. Fig. 7A and Fig. 7B show a user interface for the power tool of Fig. 1, according to some embodiments. Fig. 8 is a flowchart of a method for detecting a trigger position in the power tool of Fig. 1 according to some embodiments. Fig. 9A and Fig. 9B show a user interface for the power tool of Fig. 1, according to some embodiments. Fig. 9C shows a circuit board for the power tool of Fig. 1, according to some embodiments. Fig. 9D shows a detection section of the circuit board of Fig. 9C, according to some embodiments. Fig. 10 is a flowchart of a method for detecting a trigger position in the power tool of Fig. 1, according to some embodiments. Fig. 11A and Fig. 11B show a user interface for the power tool of Fig. 1, according to some embodiments. Fig. 12 is a flowchart of a method for detecting a trigger position in the power tool of Fig. 1, according to some embodiments. Fig. 13A and Fig. 13B show a user interface for the power tool of Fig. 1, according to some embodiments. Fig. 14 is a flowchart of a method for detecting a trigger position in the power tool of Fig. 1, according to some embodiments. Fig. 15A and Fig. 15B show a user interface for the power tool of Fig. 1, according to some embodiments. Fig. 15C shows a circuit board for the power tool of Fig. 1, according to some embodiments. Fig. 16 is a flowchart of a method for detecting a trigger position in the power tool of Fig. 1, according to some embodiments. Detailed description

[0030] The embodiments described herein relate to a power tool, such as a screwdriver or nailer, with a sensor located in a handle of the power tool. In some embodiments, the sensor may be a linear magnetic sensor configured to detect a varying amount of magnetic flux based on the proximity of the magnetic sensor to a magnet located in the housing. In some embodiments, the sensor may be an inductive sensor configured to detect an induced current when a target of a trigger is moved along a length of the sensor.

[0031] Fig. 1 shows a power tool 10, such as a nailer (e.g., a gas spring-driven nailer) capable of driving fasteners (e.g., single-headed nails, double-headed or duplex nails, wire nails, staples, etc.) from a magazine 14 into a workpiece. The power tool 10 is powered by a removable and rechargeable battery 12.

[0032] In relation to Fig. 2, the power tool 10 does not require an external source of compressed air, but includes an external storage chamber cylinder 30 of pressurized gas that is in fluid communication with a cylinder 18. In the illustrated embodiment, the cylinder 18 and the movable piston 22 are disposed within the storage chamber cylinder 30. The power tool 10 includes a damper 112 disposed below the piston 22 to stop the piston 22 in a driven position and absorb the impact energy of the piston 22. The damper 112 is configured to evenly distribute the impact energy of the piston 22 across the entire damper 112 when the piston 22 is rapidly decelerated upon reaching a driven position (i.e., a bottom dead center position).The damper 112 is disposed within the cylinder 18 and is clamped by a drive mechanism or lifter housing portion 106 that is bolted to the lower end of the cylinder 18. As illustrated, the damper 112 is received in a cutout 114 formed in the lifter housing portion 106. The cutout 114 coaxially aligns the damper 112 relative to a tappet or driver blade 26. Although the term driver blade is used herein, the term tappet may be used in place of driver blade. The driver blade 26 is configured to move with the piston 22 along the same path of travel (e.g., from top dead center to bottom dead center).

[0033] As in Fig. 2, the storage chamber cylinder 30 is concentric with the cylinder 18. The cylinder 18 has an annular inner wall that guides the piston 22 and the driver blade 26 along a drive axis 400 (see Fig. 4A and Fig. 4B) to compress the gas in the storage chamber cylinder 30. The storage chamber cylinder 30 has an annular outer wall that circumferentially surrounds the inner wall. The cylinder 18 has a threaded portion and the storage chamber cylinder 30 has corresponding threads at a lower end of the storage chamber cylinder 30, so that the cylinder 18 can be screwed to the storage chamber cylinder 30 at the lower end. The cylinder 18 is adapted to be axially attached to the storage chamber cylinder 30.

[0034] Fig. 3 shows a control system 300 for the power tool 10. The control system 300 includes a controller 304. The controller 304 is electrically and / or communicatively connected to a variety of modules or components of the power tool 10. For example, the illustrated controller 304 is electrically connected to a motor 308 (e.g., a brushless motor), a battery interface 312, one or more sensors 316 (connected to a trigger 320 disposed on the exterior of the housing), one or more additional sensors 324 (e.g., current sensors, position sensors, voltage sensors, etc.), a temperature sensor 328, a wireless communication controller 338, one or more indicators 332, a power button 334, a power input module 340, and a gate controller 344 (connected to an inverter 348). The motor 308 includes a rotor, a stator, and a shaft that rotates about a longitudinal axis.

[0035] The controller 304 includes combinations of hardware and software that, among other things, control the operation of the power tool 10, monitor the operation of the power tool 10, activate one or more indicators 332 (e.g., an LED), and the like. The gate controller 344 is configured to control the inverter 348 to convert a DC power supply into phase signals for powering the phases of the motor 308. The current sensor 324 is configured to detect, for example, a current between the inverter 348 and the motor 308. The temperature sensor 328 is configured to detect, for example, the temperature of the inverter 348. In some implementations, the temperature sensor 328 is configured to detect, for example, the temperature of the rechargeable battery 12.

[0036] The control unit 304 includes a variety of electrical and electronic components that power, control the operation, and protect the components and modules within the control unit 304 and / or the power tool 10. For example, the control unit 304 includes, among other things, a processing unit 352 (e.g., a microprocessor, a microcontroller, an electronic control unit, an electronic processor, or other suitable programmable device), a memory 356, input units 360, and output units 364. The processing unit 352 includes, among other things, a control unit 368, an arithmetic logic unit ("ALU") 372, and a plurality of registers 376 (in Fig. 3 as a register group) and is implemented using a known computer architecture (e.g., a modified Harvard architecture, a von Neumann architecture, etc.). The processing unit 352, the memory 356, the input units 360 and the output units 364, as well as the various modules or circuits connected to the control unit 304, are connected by one or more control and / or data buses (e.g., common bus 380). The control and / or data buses are in Fig. 3 is shown generally for illustrative purposes. The use of one or more control and / or data buses for interconnection and communication between the various modules, circuits, and components is known to those skilled in the art in view of the invention described herein.

[0037] The memory 356 is a non-transitory computer-readable medium and includes, for example, a program storage area and a data storage area. The program storage area and the data storage area may include combinations of different memory types, such as ROM, RAM (e.g., DRAM, SDRAM, etc.), EEPROM, flash memory, a hard disk, an SD card, or other suitable magnetic, optical, physical, or electronic storage devices. The processing unit 352 is connected to the memory 356 and executes software instructions, which may be stored in a RAM of the memory 356 (e.g., during execution), a ROM of the memory 356 (e.g., on a generally persistent basis), or another non-transitory computer-readable medium such as another memory or a floppy disk.The software included in the embodiment of the power tool 10 may be stored in the memory 356 of the controller 304. The software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. The controller 304 is configured to retrieve and execute, among other things, instructions related to the control operations and methods described herein from the memory 356. In other constructions, the controller 304 includes additional, fewer, or different components.

[0038] The battery interface 312 includes a combination of mechanical components (e.g., rails, grooves, locks, etc.) and electrical components (e.g., one or more terminals) configured and operable to form an interface (e.g., a mechanical, electrical, and communicative connection) between the power tool 10 and a battery. For example, power supplied from the battery to the nailer is passed through the battery interface 312 to the power input module 340. The power input module 340 includes combinations of active and passive components to regulate or control the power received from the battery before the power is passed to the controller 304. The battery interface 312 also supplies power to the inverter 348, which is switched by the switching FETs to selectively power the motor 308.For example, the battery interface 312 also includes a communication line 384 to provide a communication line or connection between the controller 304 and the battery.

[0039] The indicators 332 include, for example, one or more light-emitting diodes ("LEDs"). The indicators 332 may be configured to indicate conditions or information associated with the power tool 10. For example, the indicators 332 are configured to indicate measured electrical characteristics of the power tool 10, the status of the device, and the like. The one or more user input modules 340 may be operatively coupled to the controller 304 to select, for example, a forward or reverse mode of operation, a torque and / or speed setting for the power tool 10 (for example, using torque and / or speed switches), and the like.

[0040] The controller 304 may be configured to determine whether a fault condition exists in the power tool 10 and generate one or more control signals related to the fault condition. For example, the controller 304 may calculate or store in memory 356 predetermined operating thresholds and limits for the operation of the power tool 10. For example, if a potential thermal failure (e.g., of a FET, the motor 308, etc.) is detected or predicted by the controller 304, the power supply to the motor 308 may be limited or interrupted until the potential for thermal failure is reduced.If the controller 304 detects one or more such fault conditions of the nailer or determines that a fault condition of the power tool 10 no longer exists, the controller 304 may be configured to provide information and / or control signals to another component of the power tool 10 (e.g., the battery interface 312, the indicators 332, etc.). The signals may be configured to, for example, trigger or open a high-resistance trace of the nailer, reset a switch, and the like.

[0041] The controller 304 may be configured to determine the state of charge ("SOC") of the rechargeable battery 12. The controller 304 may also be configured to receive signals from a monitoring circuit (e.g., including sensors 324, etc.) configured to detect the SOC or voltage of the battery cells of the rechargeable battery 12 and send the voltage measurements to the controller 304. The voltage level of the battery cells may be determined, for example, by measuring the total open-circuit voltage of the battery cells or by summing the voltage measurements of the individual battery cells.In some embodiments, the monitoring circuit is additionally configured to detect a discharge current of the battery cells (e.g., using a current sensor) and / or a temperature of the rechargeable battery 12 (e.g., using a temperature sensor) and to transmit the detected current and / or temperature measurements to the controller 304. The monitoring circuit is further configured to receive commands from the controller 304 during operation of the power tool 10. In some embodiments, the SOC, a detected current, and / or a detected temperature of the rechargeable battery 12 are determined by the battery 12 and transmitted to the controller 304.

[0042] Fig. 4A and Fig. 4B show a partial sectional view of the power tool 10. As previously described with reference to Fig. 2, the power tool 10 includes the cylinder 18 and the piston 22 disposed within the outer storage chamber cylinder 30. The piston 22 is configured to drive the driver blade 26. The power tool 10 does not require an external supply of compressed air and instead includes the outer storage chamber cylinder 30 communicating with the cylinder 18 via a pressurized fluid (e.g., gas). The driver blade 26 defines a drive axis 400. During a drive cycle, the driver blade 26 and the piston 22 are movable between a top dead center (“TDC”) position (as shown in Fig. 4B) and a driven or bottom dead center (“BDC”) position (as shown in Fig. 4A) movable.

[0043] In operation, the lifter housing portion 106 drives the piston 22 and driver blade 26 toward the TDC position by activating the motor 308. As the piston 22 and driver blade 26 are driven toward the TDC position, the gas above the piston 22 and the gas within the storage chamber cylinder 30 are compressed. Before reaching the TDC position, the motor 308 is deactivated, and the piston 22 and driver blade 26 are held in a standby position intermediate between the TDC and BDC positions until released, for example, by the user pulling the trigger 320. Once released, the compressed gas above the piston 22 and within the storage chamber cylinder 30 drives the piston 22 and driver blade 26 to the driven position, initiating a firing action and driving a fastener into the workpiece.The illustrated power tool 10 therefore operates on the principle of a gas spring, which uses the lifter housing section 106 and the piston 22 to further compress the gas in the cylinder 18 and in the storage chamber cylinder 30.

[0044] Fig. 5A and Fig. 5B illustrates a first embodiment of a user interface 500 for a power tool 510 (e.g., power tool 10). The user interface 500 includes a circuit board 504 and a trigger 520 (e.g., trigger 320) of the power tool 510. The trigger 520 is disposed adjacent a side 508 of the circuit board 504 and is configured to be depressed by a user. When depressed, the trigger 520 moves a magnet 516 attached to the trigger 520 proximate a trigger sensing portion 512 of the circuit board 504. A trigger return spring 515 is configured to return the trigger 520 to a non-depressed position when the trigger 520 is not depressed. Although a pivoting trigger is shown, embodiments with non-pivoting triggers (for example, linearly movable triggers) are also conceivable.

[0045] The sensing section 512 includes a magnetic sensor (e.g., a Hall-effect sensor) 524. The trigger 520 includes the magnet 516 attached to an outer end of the trigger 520. The Hall-effect sensor 524 is located within the power tool 510, such that when the trigger 520 is pulled, the magnet 516 is sensed by the Hall-effect sensor 524. The magnetic sensor 524 may be a linear magnetic sensor 524 that senses a varying amount of magnetic flux depending on the proximity of the magnetic sensor 524 to the magnet 516. When the magnetic sensor 524 detects that the magnet 516 is in close proximity to the magnetic sensor 524, the magnetic sensor 524 sends a signal to the controller 304 to determine that the trigger 520 is depressed, initiating a firing operation of the power tool 510. In some embodiments, the magnetic sensor 524 is a digital Hall-effect sensor 524.The digital Hall-effect sensor can output a digital signal (e.g., a pulse-width modulated [“PWM”] signal) based on the magnitude of the detected magnetic flux from magnet 516. In other embodiments, magnetic sensor 524 is an analog Hall-effect sensor that outputs an analog signal. In some embodiments, magnetic sensor 524 is connected to trigger 520, and magnet 516 is connected to circuit board 504 or the housing of power tool 510.

[0046] Fig. 6 is a flowchart of a method 600 for sensing the position of the trigger 520 to control the power tool 510 (e.g., to initiate the firing operation of the power tool 10). The method 600 begins when the power tool 10 is turned on (block 605). The controller 304 is configured to execute the method 600 and begins controlling the motor 308 based on the current received from the battery 12 (block 610). In some embodiments, the motor 308 is stationary until a firing operation is initiated. The controller 304 is configured to determine the position of the driver blade 26 (block 615), for example, based on a sensed position of the driver blade 26 (e.g., based on the motor rotation position, a sensor that directly senses the position of the driver blade 26, etc.).If the position of the driver blade 26 is determined to be in the ready position (e.g., BDC) (block 620), the controller is configured to determine a position of the trigger 520 based on a sensed position of the magnet 516 (block 615). If the magnet 516 is not sensed, the method 600 returns to block 625 to determine the position of the trigger 520. If the trigger 520 is determined to be depressed in block 630, the controller 304 generates a command to release the driver blade 26 (block 635).

[0047] Fig. 7A and Fig. 7B illustrates one embodiment of a user interface 700 for a power tool 710 (e.g., power tool 10). The user interface 700 includes a circuit board 704 and a trigger 720 (e.g., trigger 320) of the power tool 710. The trigger 720 is disposed adjacent a side 708 of the circuit board 704. When depressed, the trigger 720 moves a magnet 716 attached to the trigger 720 away from a trigger sensing portion 712 of the circuit board 704. A trigger return spring 715 is configured to return the trigger 720 to a non-depressed position when the trigger 720 is not depressed. Although a pivoting trigger is illustrated, embodiments with non-pivoting triggers (e.g., linearly translatable triggers) are also contemplated.

[0048] The sensing section 712 includes a magnetic sensor (e.g., a Hall-effect sensor) 724. The trigger 720 includes the magnet 716 attached to an outer end of the trigger 720. The Hall-effect sensor 724 is located within the power tool 710, such that the magnet 716 is sensed by the Hall-effect sensor 724 when the trigger 720 is not pulled. The magnetic sensor 724 may be a linear magnetic sensor 724 that senses a varying amount of magnetic flux depending on the proximity of the magnetic sensor 724 to the magnet 716. If the magnetic sensor 724 does not detect that the magnet 716 is in close proximity to the magnetic sensor 724, the magnetic sensor 724 sends a signal to the controller 304 to determine that the trigger 720 is depressed, and a firing operation of the power tool 710 is initiated. In some embodiments, the magnetic sensor 724 is a digital Hall-effect sensor 724.The digital Hall-effect sensor may output a digital signal (e.g., a pulse-width modulated [“PWM”] signal) based on the magnitude of the detected magnetic flux from the magnet 716. In some embodiments, the magnetic sensor 724 is connected to the trigger 720, and the magnet 716 is connected to the circuit board 704 or the housing of the power tool 710.

[0049] Fig. 8 is a flowchart of a method 800 for sensing the position of the trigger 720 to control the power tool 710 (e.g., to initiate the firing operation of the power tool 10). The method 800 begins when the power tool 10 is turned on (block 805). The controller 304 is configured to execute the method 800 and begins controlling the motor 308 based on the current received from the battery 12 (block 810). In some embodiments, the motor 308 is stationary until a firing operation is initiated. The controller 304 is configured to determine the position of the nailer driver blade 26 based, for example, on a sensed position of the driver blade 26 (e.g., based on the motor rotational position, a sensor that directly senses the position of the driver blade 26, etc.) (block 815).If the position of the driver blade 26 is determined to be in the ready position (e.g., BDC) (block 820), the controller is configured to determine a position of the trigger 720 based on a sensed position of the magnet 716 (block 815). If the magnet 716 is sensed, the method 800 returns to block 825 to determine the position of the trigger 720. If the magnet 716 is not sensed, the trigger 720 is determined to be depressed in block 830, and the controller 304 generates a command to release the driver blade 26 (block 835).

[0050] Fig. 9A and Fig. 9B illustrates a user interface 900 for a power tool 910 (e.g., power tool 10). The user interface 900 includes a circuit board 904 and a trigger 920 (e.g., trigger 320) of the power tool 910. The trigger 920 is disposed adjacent a first side or bottom 908 of the circuit board 904 and is configured to be depressed by a user such that the trigger 920 moves (e.g., linearly) with respect to the circuit board 904. A trigger return spring 916 is configured to return the trigger 920 to a non-depressed position when the trigger 920 is not depressed. The trigger 920 includes a target portion 928 (e.g., a metallic target) that can be engaged by a trigger sensing portion 912 of the circuit board 904.Although a non-pivoting trigger is shown (e.g., configured for linear movement), embodiments with pivoting triggers are contemplated.

[0051] Fig. 9C shows a bottom view of a circuit board 904. The circuit board 904 includes the trigger sensing portion 912 disposed on the first side or bottom surface 908 of the circuit board 904. The trigger sensing portion 912 has a generally rectangular shape, and its length provides a generally linear path for the target portion 928 of the trigger 920 of the power tool 10 to travel when the trigger 920 is depressed (e.g., by a user).

[0052] Fig. 9D shows the trigger sensing section 912 with an inductive sensor 924 (e.g., with interlaced sinusoidal inductive paths 932). In the illustrated embodiment, the inductive sensor 924 is configured to sense an induced current when the target section 928 of the trigger 920 is moved along the length of the sensor 924 (e.g., along the range of motion 934). A target length 936 of the sensor 924 may be predetermined so that induced currents sensed in response to movement of the target section 928, for example, along the interlaced sinusoidal inductive paths 932, are predictable. A voltage curve of the received sinusoidal inductive traces can be created and used to determine the position of the target portion 928 of the trigger 920 as the target portion 928 of the trigger 920 is moved along the inductive sensor 924.The position of target length 936 can be used to determine the position of trigger 920. In some embodiments, for example, the inductive sensor includes target portion 928 (e.g., a metallic sensing target) and an oscillation circuit on circuit board 904. The oscillation circuit includes a coil for generating a magnetic field and a sensor coil (e.g., conductive traces 932). The magnetic field generating coil generates a high-frequency magnetic field. As target portion 928 moves toward the magnetic field generating coil, a current is induced in target portion 928 by the high-frequency magnetic field. As target portion 928 approaches the resonant circuit, the oscillations in the resonant circuit are reduced or attenuated. The sensor coil detects this change in oscillation and outputs a detection signal related to the proximity of target portion 928 to the resonant circuit.The location of the target section corresponds to the extent of depression of the trigger 920. As in . Fig. As shown in Figure 9D, the inductive sensor 924 may include a line 940 configured to provide a voltage signal to another component of the power tool 10 (e.g., the controller 304) for further processing and control of the power tool 910. In some embodiments, the inductive sensor 924 is connected to the trigger 920, and the target portion 928 is connected to the circuit board 904 or the housing of the power tool 910.

[0053] Fig. 10 is a flowchart of a method 1000 for sensing the position of the trigger 920 to control the power tool 910 (e.g., to initiate the firing operation of the power tool 10). The method 1000 begins when the power tool 10 is turned on (block 1005). The controller 304 is configured to execute the method 1000 and begins controlling the motor 308 based on the current received from the battery 12 (block 1010). In some embodiments, the motor 308 is stationary until a firing operation is initiated. The controller 304 is configured to determine the position of the driver blade 26 (block 1015), for example, based on a sensed position of the driver blade 26 (e.g., based on the motor rotation position, a sensor that directly senses the position of the driver blade 26, etc.).If the position of the driver blade 26 is determined to be in the ready position (e.g., BDC) (block 1020), the controller is configured to determine a position of the trigger 920 based on a sensed position of the target portion 928 using the inductive sensor 924 (block 1015). If no induced current (i.e., eddy current) is sensed by the inductive sensor 924 corresponding to the target portion 928 located within the target length 936 of the sensor 924, the method 1000 returns to block 1025 to determine the position of the trigger 920. When an induced current is detected by the inductive sensor 924 corresponding to the target portion 928 located within the target length 936 of the sensor 924, the trigger 920 is determined to be depressed in BLOCK 1030, and the controller 304 generates a command to release the driver blade 26 (BLOCK 1035).

[0054] Fig. 11A and Fig. 11B illustrates a user interface 1100 for a power tool 1110 (e.g., power tool 10). User interface 1100 includes a circuit board 1104 and a trigger 1120 (e.g., trigger 320) of power tool 1110. Trigger 1120 is disposed adjacent a first side or bottom 1108 of circuit board 1104 and is configured to be depressed by a user such that trigger 1120 moves (e.g., linearly) with respect to circuit board 1104. A trigger return spring 1116 is configured to return trigger 1120 to a non-depressed position when trigger 1120 is not depressed. The trigger 1120 includes a magnet 1128 that can be sensed by a tunneling magnetoresistance ("TMR") sensor 1112, for example, on the circuit board 1104. In some embodiments, the TMR sensor 1112 is mounted on a different circuit board.For example, the TMR sensor 1112 may be mounted on a circuit board positioned behind the trigger 320 such that the circuit board and the TMR sensor 1112 are perpendicular to a movement axis of the trigger 1120. In some embodiments, the TMR sensor 1112 detecting the magnet 1128 indicates that the trigger 1120 is being depressed. In other embodiments, the TMR sensor 1112 not detecting the magnet 1128 indicates that the trigger 1120 is being depressed. Although a non-pivoting trigger is shown (e.g., configured for linear movement), embodiments with pivoting triggers are also conceivable.

[0055] For example, the TMR sensor 1112 includes an insulator layer between a precisely defined ferromagnetic layer and a free ferromagnetic layer. The magnetization direction of the precisely defined ferromagnetic layer is fixed, while the magnetization direction of the free ferromagnetic layer can be changed. A magnetic field generated by the magnet 1128 can interact with the TMR sensor 1112 to control the magnetization direction of the free ferromagnetic layer. When the magnetization directions of the free ferromagnetic layer and the precisely defined ferromagnetic layer are the same, the resistance of the TMR sensor 1112 is at a minimum value. When the magnetization directions of the free ferromagnetic layer and the precisely defined ferromagnetic layer are opposite, the resistance of the TMR sensor 1112 reaches a maximum value.By monitoring the resistance of the TMR sensor 1112, the actuation of the trigger 1120 can be detected contactlessly using the TMR sensor 1112. In other words, the TMR sensor 1112 is configured to detect a position of the trigger 1120 based on a resistance generated in the TMR sensor 1112 by the magnet 1128. The TMR sensor 1112 may include a line configured to forward the detected resistance to another component of the power tool 10 (e.g., the controller 304) for further processing. In some embodiments, the TMR sensor 1112 is connected to the trigger 1120, and the magnet 1128 is connected to the circuit board 1104 or the housing of the power tool 1110.

[0056] Fig. 12 is a flowchart of a method 1200 for sensing the position of the trigger 1120 to control the power tool 1110 (e.g., to initiate the firing operation of the power tool 10). The method 1200 begins when the power tool 10 is turned on (block 1205). The controller 304 is configured to execute the method 1200 and begins controlling the motor 308 based on the current received from the battery pack 12 (block 1210). In some embodiments, the motor 308 is stationary until a firing operation is initiated. The controller 304 is configured to determine the position of the nailer driver blade 26 based, for example, on a sensed position of the driver blade 26 (e.g., based on the motor rotational position, a sensor that directly senses the position of the driver blade 26, etc.) (block 1215).If the position of the driver blade 26 is determined to be in the ready position (e.g., BDC) (block 1220), the controller is configured to determine a position of the trigger 1120 based on a sensed resistance of the TMR sensor 1112 (block 1215). If the sensed resistance reaches the minimum value, the method 1200 returns to block 1225 to determine the position of the trigger 1120. If the sensed resistance reaches the maximum value, the trigger 1120 is determined to be depressed in block 1230, and the controller 304 generates a command to release the driver blade 26 (block 1235). In some embodiments, the sensed resistance being at a minimum value causes the controller 304 to generate a command to release the driver blade 26 in block 1235.

[0057] Fig. 13A and Fig. 13B illustrates one embodiment of a user interface 1300 for a power tool 1310 (e.g., power tool 10). The user interface 1300 includes a circuit board 1304 and a trigger 1320 (e.g., trigger 320) of the power tool 1310. The trigger 1320 is disposed adjacent a side 1308 of the circuit board 1304. When depressed, the trigger 1320 moves a magnet 1316 attached to the trigger 1320 away from the circuit board 1304. A trigger return spring 1315 is configured to return the trigger 1320 to a non-depressed position when the trigger 1320 is not depressed. Although a pivoting trigger is illustrated, embodiments with non-pivoting triggers (e.g., linearly translatable triggers) are also contemplated.

[0058] A sensing section 1312 is disposed on the circuit board 1304 and includes a magnetic sensor (e.g., a Hall-effect sensor) 1324. The trigger 1320 includes the magnet 1316 attached to an outer end of the trigger 1320. The magnetic sensor 1324 is located within the power tool 1310, so that when the trigger 1320 is not pulled, the magnet 1316 is sensed by the magnetic sensor 1324. The magnetic sensor 1324 may be a linear magnetic sensor 1324 that senses a varying amount of magnetic flux depending on the proximity of the magnetic sensor 1324 to the magnet 1316. If the magnetic sensor 1324 does not detect that the magnet 1316 is in close proximity to the magnetic sensor 1324, the magnetic sensor 1324 sends a signal to the controller 304 to determine that the trigger 1320 is depressed, and a firing operation of the power tool 1310 is initiated.In some embodiments, the magnetic sensor 1324 is a digital Hall-effect sensor 1324. The digital Hall-effect sensor may output a digital signal (e.g., a pulse-width modulated [“PWM”] signal) based on the magnitude of the detected magnetic flux from the magnet 1316. In some embodiments, the magnetic sensor 1324 is connected to the trigger 1320, and the magnet 1316 is connected to the circuit board 1304 or the housing of the power tool 1310.

[0059] Fig. 14 is a flowchart of a method 1400 for sensing the position of the trigger 1320 to control the power tool 1310 (e.g., to initiate the firing operation of the power tool 10). The method 1400 begins when the power tool 10 is turned on (block 1405). The controller 304 is configured to execute the method 1400 and begins controlling the motor 308 based on the power received from the battery 12 (block 1410). In some embodiments, the motor 308 is stationary until a firing operation is initiated. The controller 304 is configured to determine the position of the nailer driver blade 26 based, for example, on a sensed position of the driver blade 26 (e.g., based on the motor rotation position, a sensor that directly senses the position of the driver blade 26, etc.) (block 1415).If the position of the driver blade 26 is determined to be in the ready position (e.g., BDC) (block 1420), the controller is configured to determine a position of the trigger 1320 based on a detected position of the magnet 1316 (block 1415). If the magnet 1316 is detected, the method 1400 returns to block 1425 to determine the position of the trigger 1320. If the magnet 1316 is not detected, the trigger 1320 is determined to be depressed in block 1430, and the controller 304 generates a command to release the driver blade 26 (block 1435).

[0060] Fig. 15A and Fig. 15B show an embodiment of a user interface 1500 for a power tool 1510 (e.g., power tool 10). The user interface 1500 includes a circuit board 1504 and a trigger 1520 (e.g., trigger 320) of the power tool 1510. The trigger 1520 is disposed adjacent a first side 1508 of the circuit board 1504 and is configured to be depressed by a user such that the trigger 1520 moves (e.g., pivots) with respect to the circuit board 1504. A trigger return spring 1515 is configured to return the trigger 1520 to a non-depressed position when the trigger 1520 is not depressed. The trigger 1520 includes a target portion 1528 (e.g., a metallic target) that is engaged by a trigger sensing portion 1512 (see Fig. 15C) of the circuit board 1504. Although a pivoting trigger is illustrated, non-pivoting triggers (e.g., linear translation triggers) are also included in some embodiments.

[0061] Fig. 15C shows the trigger sensing section 1512 with an inductive sensor 1524. In the illustrated embodiment, the inductive sensor 1524 is a binary inductive sensor configured to sense a voltage when the target portion 1528 of the trigger 1520 is moved toward the sensor 1524. In some embodiments, the inductive sensor 1524 functions in the same manner as the inductive sensor 1524. A voltage curve can be created and used to determine the position of the target portion 1528 of the trigger 1520 when the target portion 1528 of the trigger 1520 is moved relative to the inductive sensor 1524. The trigger sensing section 1512 is located within a housing cover 1513 (see Fig. 15B) of the power tool 1510 such that when the trigger 1520 is pulled, the target portion 1528 is detected by the inductive sensor 1524. When the inductive sensor 1524 detects that the trigger sensing portion 1512 is proximate to the inductive sensor, the inductive sensor 1524 is configured to send a signal to the controller 304 to indicate that the trigger 1520 is depressed. A firing operation of the power tool 1510 may be initiated. In some embodiments, the inductive sensor 1524 is connected to the trigger 1520 and the target portion 1528 is connected to the circuit board 1504 or the housing of the power tool 1510.

[0062] Fig.16 is a flowchart of a method 1600 for sensing the position of the trigger 1520 to control the power tool 1510 (e.g., to initiate the firing operation of the power tool 10). The method 1600 begins when the power tool 1510 is turned on (block 1605). The controller 304 is configured to execute the method 1600 and begins controlling the motor 308 based on the current received from the battery pack 12 (block 1610). In some embodiments, the motor 308 is stationary until a firing operation is initiated. The controller 304 is configured to determine the position of the nailer driver blade 26 based, for example, on a sensed position of the driver blade 26 (e.g., based on the motor rotation position, a sensor that directly senses the position of the driver blade 26, etc.) (block 1615).If the position of the driver blade 26 is determined to be in the ready position (e.g., BDC) (block 1620), the controller is configured to determine a position of the trigger 1520 based on a sensed position of the target portion 1528 using the inductive sensor 1524 (block 1615). If an induced current (i.e., eddy current) is not sensed by the inductive sensor 1524, the method 1600 returns to block 1625 to determine the position of the trigger 1520. If an induced current is sensed by the inductive sensor 1524, the trigger 1520 is determined to be depressed in block 1630, and the controller 304 generates a command to release the driver blade 26 (block 1635). Representative characteristics

[0063] Representative features are listed in the following provisions, which may stand alone or be combined in any combination with one or more features indicated in the text and / or drawings of the description.

[0064] Determination 1. A power tool comprising: a housing; a trigger disposed on an exterior of the housing, the trigger including a magnet; a motor within the housing, the motor configured to generate a rotary output for a drive mechanism; a Hall effect sensor configured to detect a position of the trigger based on a proximity of the magnet to the Hall effect sensor; and an electronic controller connected to the Hall effect sensor, the electronic controller configured to: determine the position of the trigger based on a signal from the Hall effect sensor, and control the drive mechanism based on the position of the trigger.

[0065] Clause 2. The power tool according to clause 1, where the position is either a depressed position or a released position.

[0066] Provision 3. The power tool according to any of the preceding provisions, in which the Hall-effect sensor is a digital Hall-effect sensor.

[0067] Clause 4. The power tool according to any preceding clause, wherein the Hall effect sensor is configured to detect a changing amount of magnetic flux based on the position of the Hall effect sensor relative to the magnet.

[0068] Provision 5. The power tool according to provision 4, wherein, in response to the trigger being in the depressed position, the electronic control device is arranged to control the drive mechanism to initiate a firing operation of the power tool.

[0069] Provision 6. The power tool according to any of the preceding provisions, in which the Hall effect sensor does not detect the magnet when the trigger is in the depressed position.

[0070] Provision 7. A power tool comprising: a housing; a trigger disposed on an exterior of the housing, the trigger including a metal target portion; a motor within the housing, the motor configured to generate a rotary output for a drive mechanism; an inductive sensor configured to detect a position of the trigger based on a current induced by the inductive sensor in the metal target portion and generate an output signal; and an electronic controller connected to the inductive sensor, the electronic controller configured to: determine the position of the trigger based on the output signal from the inductive sensor and control the drive mechanism based on the position of the trigger.

[0071] Regulation 8. The power tool as defined in Regulation 7 in which the trigger position is either a depressed or a released position.

[0072] Regulation 9. The power tool according to Regulation 8, in which the current is induced in the metal target portion when the trigger is moved to the depressed position.

[0073] Regulation 10. The power tool according to Regulation 9, wherein the electronic control device, in response to the trigger being in the depressed position, controls the power tool to initiate a firing operation of the power tool.

[0074] Regulation 11. The power tool as defined in any of Regulations 7-10 in which the inductive sensor is located on the underside of a printed circuit board.

[0075] Regulation 12. The power tool as defined in any of Regulations 7-11 in which the trigger is arranged to pivot in relation to the inductive sensor.

[0076] Regulation 13. The power tool of any of Regulations 7-12, wherein the inductive sensor is a binary inductive sensor arranged to detect an induced current in response to the metal target portion of the trigger being moved toward the inductive sensor.

[0077] Regulation 14. The power tool according to Regulation 13, wherein the inductive sensor is arranged, in response to the detection of the induced current, to send a signal to the electronic control unit indicating that the trigger is depressed.

[0078] Provision 15. A power tool comprising: a housing; a trigger disposed on an exterior of the housing, the trigger including a magnet connected to the trigger; a motor within the housing, the motor configured to generate a rotary output for a drive mechanism; a tunneling magnetoresistance (“TMR”) sensor configured to detect a position of the trigger based on a signal generated by the TMR sensor that is related to a position of the magnet; and an electronic controller connected to the TMR sensor, the electronic controller configured to determine the position of the trigger based on the signal generated by the TMR sensor and to control the drive mechanism based on the position of the trigger.

[0079] Regulation 16. The power tool as defined in Regulation 15, where the position is either a depressed position or a released position.

[0080] Regulation 17. The power tool according to Regulation 16, in which the TMR sensor comprises an insulator layer between a well-defined ferromagnetic layer and a free ferromagnetic layer.

[0081] Clause 18. The power tool according to clause 17, wherein the TMR sensor is arranged to detect a first magnetization direction of the precisely defined ferromagnetic layer and a second magnetization direction of the free ferromagnetic layer, and, when the first magnetization direction and the second magnetization direction are opposite, a detected resistance of the TMR sensor is at a maximum value.

[0082] Regulation 19. The power tool as defined in Regulation 18 in which, when the trigger is in the depressed position, the detected resistance of the TMR sensor is at its maximum value.

[0083] Regulation 20. The power tool as defined in either Regulation 18 or 19, wherein the TMR sensor comprises a lead arranged to supply the measured resistance to the electronic control unit.

[0084] Thus, the embodiments described herein provide systems and methods for detecting the trigger position to initiate the firing operation of the nailer. Various features and advantages are set forth in the following claims. 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] US 63 / 596,829

[0001] US 63 / 679,966

[0001]

Claims

[1] Power tool comprising: a housing; a trigger disposed on the outside of the housing, the trigger comprising a magnet; a motor within the housing, the motor configured to generate a rotary output for a drive mechanism; a Hall-effect sensor configured to detect a position of the trigger based on the proximity of the magnet to the Hall-effect sensor; and an electronic control unit connected to the Hall effect sensor, the electronic control unit being configured to: to determine the position of the trigger based on a signal from the Hall effect sensor, and to control the drive mechanism depending on the position of the trigger. [2] A power tool according to claim 1, wherein the position is either a depressed position or a released position. [3] Power tool according to claim 2, wherein the Hall effect sensor is a digital Hall effect sensor. [4] The power tool of claim 2, wherein the Hall effect sensor is configured to detect a changing magnitude of the magnetic flux based on the position of the Hall effect sensor relative to the magnet. [5] The power tool of claim 4, wherein the electronic controller is configured to control the drive mechanism to initiate a firing operation of the power tool in response to the trigger being in the depressed position. [6] A power tool according to claim 2, wherein the Hall effect sensor does not detect the magnet when the trigger is in the depressed position. [7] Power tool comprising: a housing; a trigger disposed on the exterior of the housing, the trigger including a metal target portion; a motor within the housing, the motor configured to generate a rotary output for a drive mechanism; an inductive sensor configured to detect a position of the trigger based on a current induced by the inductive sensor into the metal target portion and to generate an output signal; and an electronic control unit connected to the inductive sensor, the electronic control unit being configured to: to determine the position of the trigger based on the output signal of the inductive sensor and to control the drive mechanism based on the position of the trigger. [8] A power tool according to claim 7, wherein the position of the trigger is either a depressed or a released position. [9] A power tool according to claim 8, wherein the current is induced in the metal target portion when the trigger is moved to the depressed position. [10] The power tool of claim 9, wherein the electronic controller, in response to the trigger being in the depressed position, controls the power tool to initiate a firing operation of the power tool. [11] Power tool according to claim 7, wherein the inductive sensor is arranged on the underside of a printed circuit board. [12] A power tool according to claim 7, wherein the trigger is arranged to pivot with respect to the inductive sensor. [13] The power tool of claim 7, wherein the inductive sensor is a binary inductive sensor configured to detect an induced current in response to the metal target portion of the trigger being moved toward the inductive sensor. [14] A power tool according to claim 13, wherein the inductive sensor is arranged, in response to the detection of the induced current, to send a signal to the electronic control unit indicating that the trigger is depressed. [15] Power tool comprising: a housing; a trigger disposed on the outside of the housing, the trigger including a magnet connected to the trigger; a motor within the housing, the motor configured to generate a rotary output for a drive mechanism; a tunnel magnetoresistance (“TMR”) sensor configured to detect a position of the trigger based on a signal generated by the TMR sensor relative to a position of the magnet; and an electronic control unit connected to the TMR sensor, the electronic control unit being configured to: to determine the position of the trigger based on the signal generated by the TMR sensor and to control the drive mechanism based on the position of the trigger. [16] A power tool according to claim 15, wherein the position is either a depressed position or a released position. [17] A power tool according to claim 16, wherein the TMR sensor comprises an insulator layer between a well-defined ferromagnetic layer and a free ferromagnetic layer. [18] Power tool according to claim 17, wherein the TMR sensor is configured to detect a first magnetization direction of the precisely defined ferromagnetic layer and a second magnetization direction of the free ferromagnetic layer, and, when the first magnetization direction and the second magnetization direction are opposite, a detected resistance of the TMR sensor has a maximum value. [19] A power tool according to claim 18, wherein when the trigger is in the depressed position, the detected resistance of the TMR sensor has the maximum value. [20] A power tool according to claim 18, wherein the TMR sensor comprises a line arranged to supply the measured resistance to the electronic control unit.