Power tool brake dopping

Abstract

A power tool described herein includes an electric motor, a driver blade, a trigger switch, a safety switch, and an electronic controller. An electronic controller is connected to the electric motor, the trigger switch, and the safety switch. The electronic controller is configured to: initiate a retraction cycle by controlling the electric motor to move the driver blade from the first position to the second position; determining a position of the driver blade during the retraction cycle; initiating a braking cycle of the electric motor in response to the position of the driver blade exceeding the first threshold; and, in response to detecting the first actuation of the trigger switch and the second actuation of the safety switch, aborting the braking cycle.

Description

[0001] Related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 582,584, filed September 14, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to power tools, and more particularly, to power tools with electronic control systems. Utility Model Content

[0004] The power tool described herein includes an electric motor, a driver blade, a trigger switch, a safety switch, and an electronic controller. The electronic controller is connected to the electric motor, the trigger switch, and the safety switch. The electronic controller is configured to: initiate a retraction cycle by controlling the electric motor to move the driver blade from a first position to a second position; determine a position of the driver blade during the retraction cycle; initiate a braking cycle of the electric motor in response to the position of the driver blade exceeding a first threshold; and terminate the braking cycle in response to detecting a first actuation of the trigger switch and a second actuation of the safety switch.

[0005] The method described in this application for controlling an electric motor of a power tool includes: initiating a retraction cycle by controlling the electric motor to move a driver blade of the power tool from a first position to a second position; determining the position of the driver blade during the retraction cycle; initiating a braking cycle of the electric motor in response to the position of the driver blade exceeding a first threshold; and terminating the braking cycle in response to detecting a first actuation of a trigger switch and a second actuation of a safety switch.

[0006] Before explaining any specific embodiment in detail, it is to be understood that the specific embodiment is not limited to the application in the configuration details and component arrangements described in the following description or shown in the accompanying drawings. The specific embodiments can be implemented or realized in various ways. In addition, it is to be understood that the words and terms used in this application are for illustrative purposes and should not be considered as limiting. The use of "including", "comprising", "having" and their variations is meant to cover not only the items listed thereafter, but also their equivalents and additional items. Unless otherwise specified or limited, the terms "mounted", "connected", "supported" and "coupled" and their variations are used in a broad sense to cover both direct mounting, connection, support and coupling, and indirect mounting, connection, support and coupling.

[0007] The articles "a," "an," and "the" should not be construed as meaning "one" or "only one," unless the context clearly indicates otherwise. Instead, these articles should be construed as meaning "at least one" or "one or more than one." Similarly, when the term "the" or "said" is used to refer to a noun previously introduced by the indefinite article "a" or "an," "the" or "said" means "at least one" or "one or more than one," unless the context clearly indicates otherwise.

[0008] Furthermore, it should be understood that embodiments may include hardware, software, and electronic components or modules, and that, for purposes of discussion, these hardware, software, and electronic components or modules may be shown and described as if most components were implemented solely in hardware. However, upon review of the embodiments herein, one of ordinary skill in the art will recognize that, in at least one embodiment, electronic aspects may be implemented in software (e.g., stored on a non-transitory computer-readable medium), which may be executed by one or more processing units, such as microprocessors and / or application-specific integrated circuits ("ASICs"). Therefore, it should be noted that embodiments may be implemented using a plurality of hardware- and software-based devices and a plurality of different structural components. For example, terms such as "server," "computing device," "controller," and "processor" described herein may include one or more processing units, one or more computer-readable media modules, one or more input / output interfaces, and various connectors (e.g., a system bus) connecting these components.

[0009] When relative terms are used in relation to quantities or conditions, such as "about," "approximately," and "substantially," those of ordinary skill in the art will understand that the stated value is inclusive, and that the meaning of the term is dictated by the context (e.g., the term includes at least the degree of error associated with measurement precision, the tolerance associated with the particular value (e.g., manufacturing, assembly, use tolerances, etc.)). Such terms should also be considered to disclose ranges defined by the absolute values ​​of the two endpoints. For example, the expression "from about 2 to about 4" also discloses a range of "from 2 to 4." Relative terms can refer to positive or negative percentages of the indicated value (e.g., 1%, 5%, 10%).

[0010] It should be understood that although some of the figures show hardware and software located within specific devices, these depictions are for illustrative purposes only. The functions performed by one component described herein can be performed by multiple components in a distributed manner. Similarly, the functions performed by multiple components can be combined and performed by a single component. In some specific embodiments, the components shown can be combined or divided into separate software, firmware and / or hardware. For example, logic and processing can be distributed between multiple electronic processors rather than being located within and performed by a single electronic processor. Regardless of how they are combined or divided, the hardware components and software components can be located in the same computing device, or can be distributed between different computing devices connected by one or more networks or other suitable communication links. Similarly, the components that perform specific functions can also perform additional functions not described in this application. For example, a device or structure that is "configured" in a certain manner is configured at least in this manner, but can also be configured in ways that are not explicitly listed.

[0011] Accordingly, in a claim, if an apparatus, method or system is described as, for example, comprising a controller, a control unit, an electronic processor, a computing device, a logic element, a module, a memory module, a communication channel or network or other element configured in some manner to, for example, perform multiple functions, such a claim or an element of a claim should be interpreted as meaning one or more of such elements, i.e., any one of the one or more elements is configured as described in the claim to, for example, implement any one or more of the listed multiple functions, so that the one or more elements together as a group perform the multiple functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Power tools according to some specific embodiments are presented.

[0013] Figure 2A According to some specific embodiments Figure 1 Partial cross-sectional view of a power tool.

[0014] Figure 2B According to some specific embodiments Figure 1 Partial cross section of a power tool.

[0015] Figure 2C According to some specific implementations Figure 1 A side view of a portion of a power tool with parts of the power tool removed to show the rotary lifter and lifter sensor.

[0016] Figure 2D According to some specific implementations Figure 1A top view of a portion of a power tool with parts of the power tool removed to reveal the lifter sensor.

[0017] Figure 3 According to some specific embodiments, the Figure 1 Control systems for power tools.

[0018] Figure 4 Demonstrates methods for use according to some specific embodiments Figure 1 Wireless communication controller for power tools.

[0019] Figure 5 According to some specific embodiments, the Figure 1 Communication systems for power tools and external equipment.

[0020] Figure 6A According to some specific implementations Figure 1 Schematic diagram of a power tool showing the driver blade in the drive or bottom dead center position.

[0021] Figure 6B According to some specific implementations Figure 1 Schematic diagram of a power tool showing the driver blade in the undriven or top dead center position.

[0022] Figure 7A is an enlarged cross-sectional view of a portion of a power tool illustrating a passage for replenishing pressure in the power tool, according to some embodiments.

[0023] Figure 7B According to some specific embodiments Figure 7A An enlarged cross-sectional view of a portion of a similar power tool illustrating a check valve positioned in a passageway.

[0024] Figure 8 A power tool (e.g., Figure 1 block diagram of a power tool).

[0025] Figures 9A-9B Shows the built-in Figure 1 Sensor board for brushless DC motors in power tools.

[0026] Figure 10A Battery packs according to some specific embodiments are shown.

[0027] Figure 10B Groups of battery cells are shown according to some embodiments.

[0028] Figure 11ABattery packs according to some specific embodiments are shown.

[0029] Figure 11B Groups of battery cells are shown according to some embodiments.

[0030] Figures 12A-12D is a flow chart of an exemplary process for controlling an operational sequence of a power tool, according to some embodiments.

[0031] Figure 13 Waveforms of an electric motor used to drive a power tool are shown according to some specific embodiments.

[0032] Figure 14 Waveforms are shown for an electric motor used to drive a power tool, according to some embodiments, wherein a brake abort sequence is initiated. DETAILED DESCRIPTION

[0033] The specific embodiments described herein relate to an electronic control system for a power tool, such as a nail gun or fastener driver. The electronic control system can control the operating cycle of the power tool, which can be divided into a drive sequence and a retraction sequence. In the drive sequence, the driver blade is driven from a top dead center position to a bottom dead center position. In the retraction sequence, the driver blade is retracted from the bottom dead center position to the bottom dead center position. In some specific embodiments, for example, when the driver blade approaches the top dead center position, the driver blade can be pneumatically driven during the drive sequence and retracted by an electric motor during the retraction sequence.

[0034] In various embodiments, the electronic control system may administer an electronic braking sequence during the retraction sequence. The electronic braking sequence may extend the life of the power tool by reducing wear. For example, an effective braking sequence slows the speed of the electric motor and helps ensure that the electric motor stops quickly during the retraction cycle. However, because the braking sequence reduces the operating speed of the electric motor, the braking sequence may reduce the operating cycle rate of the power tool. Therefore, under operating conditions where the user desires to prioritize increasing the firing rate, the electronic control system may selectively skip the braking sequence (or abort the braking sequence if it has already begun), thereby increasing the operating cycle rate of the power tool. In addition, the electronic braking sequence may consume additional current from the battery pack. Thus, introducing the abort sequence reduces the overall current draw of the battery pack, thereby increasing the battery pack life of the power tool.

[0035] Figure 1A power tool 10, such as a fastener driver or nail gun 10 (e.g., a gas spring-driven nail gun), is shown operable to drive fasteners (e.g., single-head nails, double-head nails, or duplex nails, tacks, staples, etc.) stored in a magazine 14 into a workpiece. The nail gun 10 is powered by a removable and rechargeable battery pack 12. In various embodiments, a drive cycle of the nail gun 10 is initiated in response to the trigger 24 and / or the safety catch 28 being depressed. In some embodiments, the power tool 10 includes a mode selector 32 that allows a user to select between a first operating mode and a second operating mode. Although the methods and control techniques described herein are primarily described with reference to a nail gun or other fastener driver (e.g., a stapler) by way of example, the methods and control techniques described herein may also be implemented in other power tools 10.

[0036] Figure 2A According to some specific embodiments Figure 1 A partial cross-sectional view of the power tool 10. Figure 2A The nail gun 10 does not require an external source of air pressure. Instead, it includes an external storage chamber cylinder 30 for compressed air, which is in fluid communication with the cylinder 18. In the illustrated embodiment, the cylinder 18 and the movable piston 22 are positioned within the storage chamber cylinder 30. The nail gun 10 includes a bumper 112 positioned below the piston 22 to stop the piston 22 in the drive position and absorb the impact energy of the piston 22. The bumper 112 is configured to evenly distribute the impact force of the piston 22 throughout the bumper 112 during the rapid deceleration of the piston 22 once it reaches the drive position (i.e., bottom dead center position). The bumper 112 is disposed within the cylinder 18 and secured in place by a drive mechanism or elevator housing portion 106 threaded onto the bottom end of the cylinder 18. As shown, the bumper 112 is received within a cutout 114 formed in the elevator housing portion 106. The notch 114 is coaxially aligned with the bumper 112 relative to the striker or driver blade 26. Although the term driver blade is used herein, the terms striker and driver blade are used interchangeably. The driver blade 26 is configured to move along the same path of motion as the piston 22 (e.g., from top dead center to bottom dead center).

[0037] like Figure 2A As shown, the storage chamber cylinder 30 is concentric with the cylinder 18. The cylinder 18 has an annular inner wall which is arranged along the drive axis 600 (see FIG. Figure 6A and 6B) guides piston 22 and driver blade 26 to compress gas within storage chamber cylinder 30. Storage chamber cylinder 30 has an annular outer wall circumferentially surrounding an inner wall. Cylinder 18 has a threaded portion, and storage chamber cylinder 30 has corresponding threads at its lower end, allowing cylinder 18 to be threadably coupled to storage chamber cylinder 30 at its lower end. Thus, cylinder 18 is configured to be axially secured to storage chamber cylinder 30.

[0038] like Figure 2A As shown, the driver blade 26 can define the drive axis 62 and include a plurality of driver blade teeth or lift teeth 74 formed along an edge of the driver blade 26, and the plurality of driver blade teeth or lift teeth 74 can extend in the direction of the drive axis 62. In various embodiments, the lift teeth 74 protrude laterally from the edge 78 relative to the drive axis 62. During a drive sequence, the driver blade 26 and the piston 22 can move along the drive axis 62 between a top dead center position and a bottom dead center position (e.g., a drive position). In some embodiments, the driver blade 26 can remain in a ready position, which can be positioned between the top dead center position and the bottom dead center position. In the top dead center position, the piston 22 can be positioned near or adjacent to the top end 19 of the cylinder 18, and in the bottom dead center position, the piston 22 can be positioned near or adjacent to the bottom end 20 of the cylinder 18.

[0039] The nail gun 10 may also include a rotary elevator 66 supported within the elevator housing portion 106. The rotary elevator 66 may include a plurality of rollers 90 supported by a plurality of pins 94. The elevator 66 may be supported on the elevator frame 70 and may receive torque from the electric motor to rotate the elevator 66. When the elevator 66 rotates (e.g., when driven by the electric motor), the rollers 90 engage the elevator teeth 74 formed on the driver blade 26 to return the driver blade 26 from a bottom dead center position to a top dead center position along the drive axis 62.

[0040] Figure 2B According to some specific embodiments Figure 1 Partial cross section of the power tool 10. Figure 2BAs shown in the embodiment of FIG. , in various embodiments, the nail gun 10 includes one or more sensors that can be used to directly detect or estimate the position of the driver blade 26. In some embodiments, the one or more sensors include one or more blade sensors 102 configured to monitor the position of the driver blade 26. In various embodiments, the one or more sensors include one or more elevator sensors 120 configured to monitor the position of the rotary elevator 66. In various embodiments, the blade sensors 102 monitor the movement of the elevator teeth 74, thereby allowing the controller to use sensor signals to determine the position of the driver blade 26 as the driver blade 26 moves between the top dead center position (or the ready position) and the bottom dead center position. For example, the blade sensor 102 can include a phototransistor 102a located on a first side of the driver blade 26 and coupled to the elevator frame 70, and a light emitter 102b located on an opposite side of the driver blade 26. As the driver blade 26 moves, the elevator teeth 74 pass through a light beam (e.g., a laser beam, an infrared beam, etc.) emitted by the optical sensor 102 (e.g., from the light emitter 102b to the phototransistor 102a). By measuring the time intervals during which the light beam is blocked, the controller can calculate the position of the driver blade 26 .

[0041] In various embodiments, the blade sensor 102 includes any combination of one or more inductive sensors, capacitive sensors, magnetic sensors (e.g., Hall effect sensors, anisotropic magnetoresistive sensors, tunnel magnetoresistive sensors, giant magnetoresistive sensors, etc.), and / or absolute or relative position sensors (e.g., encoders). For example, an inductive sensor can detect the presence of a lifter tine 74 by monitoring a change in inductance as the lifter tine 74 moves past the sensor. Similar to the optical sensors 102a and 102b, a controller can monitor the number and duration of lifter tine 74 passes, and this information can be used to determine the position of the driver blade 26. A capacitive sensor can monitor a change in capacitance as the lifter tine 74 moves past the sensor. Similar to the aforementioned sensors, a controller can monitor the number and duration of lifter tine 74 passes, and this information can be used to determine the position of the driver blade 26. A magnetic sensor can monitor a change in magnetic field as the lifter tine 74 moves past the sensor. Similar to the aforementioned sensors, a controller can monitor the number and duration of lifter tine 74 passes, and this information can be used to determine the position of the driver blade 26.

[0042] In some embodiments, the nail gun 10 includes an elevator sensor 120 that is coupled to the elevator frame 70 and is positioned to detect the angular position of the elevator 66. The position of the elevator 66 can be directly correlated to the position of the driver blade 26. Therefore, the controller can determine the position of the driver blade 26 based on the angular position data of the elevator sensor 120.

[0043] Figure 2CAccording to some specific implementations Figure 1 A side view of a portion of the power tool 10 with portions of the power tool removed to illustrate the rotary lifter 66 and the lifter sensor 120 . Figure 2D According to some specific implementations Figure 1 A top view of a portion of the power tool 10 with portions of the power tool removed to reveal the lifter sensor 120. Figure 2C and Figure 2D In various embodiments, the elevator sensor 120 includes an inductive sensor 275 coupled to the elevator frame 70 and a sensor target 275 coupled for rotation with the elevator 66. Thus, the sensor target 275 rotates with the elevator 66. As the elevator 66 rotates, the sensor target 275 passes by the inductive sensor 275, and the inductive sensor detects the position of the sensor target 275 based on, for example, changes in a magnetic field. Because the sensor target 275 is coupled for rotation with the elevator 66, readings from the sensor target 275 provide data corresponding to the angular position of the elevator 66. This angular position data can be directly correlated to the position of the drive blade 26. Therefore, the controller can determine the position of the drive blade 26 based on the angular position data from the inductive sensor 275.

[0044] In various embodiments, the lifter sensor 120 includes any combination of one or more inductive sensors, capacitive sensors, magnetic sensors (e.g., Hall effect sensors, anisotropic magnetoresistive sensors, tunnel magnetoresistive sensors, giant magnetoresistive sensors, etc.), and / or absolute or relative position sensors (e.g., encoders). In some embodiments, the controller processes sensor data from a combination of the optical sensor 102, the inductive sensor, the capacitive sensor, the magnetic sensor, the lifter sensor 120, and / or the inductive sensor 275, and determines the position of the drive blade 26 based on the combination of the sensor data.

[0045] Figure 3 An exemplary control system 300 for a nail gun 10 is shown. The control system 300 includes a controller 304. The controller 304 may be electrically and / or communicatively connected to various modules or components of the nail gun. For example, the controller 304 is shown electrically connected to a motor 308 (e.g., see Figure 9A and 9BThe motor 308 includes a motor 815 in FIG. 1 ), a battery pack interface 312, a trigger switch 316 (connected to the trigger 24), one or more sensors 324 (e.g., any combination of the blade sensor 102, inductive sensor, capacitive sensor, magnetic sensor, lifter sensor 120, and / or inductive sensor 275 described above), and a temperature sensor 328, a wireless communication controller 338, one or more indicators 332, one or more user input modules 336 connected to the mode selector 32, a safety switch 386 connected to the safety catch 28, a power input module 340, and a door controller 344 (connected to the inverter 348). The motor 308 includes a rotor, a stator, and a shaft that rotates about a longitudinal axis.

[0046] The controller 304 includes a combination of hardware and software operable to, among other things, control the operation of the nail gun 10, monitor the operation of the nail gun 10, activate one or more indicators 332 (e.g., LEDs), etc. The door controller 344 is configured to control the inverter 348 to convert DC power into phase signals for driving the plurality of phases of the motor 308. The current sensor 324 is configured to, for example, sense the current between the inverter 348 and the motor 308. The temperature sensor 328 is configured to, for example, sense the temperature of the inverter 348. In some embodiments, the temperature sensor 328 is configured to, for example, sense the temperature of the rechargeable battery pack 12.

[0047] The controller 304 includes a plurality of electrical and electronic components that provide power, operational control, and protection to the controller 304 and / or components and modules within the nail gun 10. For example, the controller 304 includes, among other things, a processing unit 352 (e.g., a microprocessor, a microcontroller, an electronic processor, an electronic controller, or another suitable programmable device), a memory 356, an input unit 360, and an output unit 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 the Figure 3 ), and are implemented using known computer architectures (e.g., modified Harvard architecture and von Neumann architecture). The processing unit 352, memory 356, input unit 360, output unit 364, and various modules or circuits connected to the controller 304 are connected via one or more control buses and / or data buses (e.g., common bus 380). Figure 3 The control bus and / or data bus are generally shown for illustration. In view of the invention described in this application, it is known to those skilled in the art to use one or more control buses and / or data buses to achieve interconnection and communication between different modules, circuits and components.

[0048] 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 a combination of different types of memory, such as ROM, RAM (e.g., DRAM, SDRAM, etc.), EEPROM, flash memory, a hard drive, 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 the RAM of the memory 356 (e.g., during execution), in the ROM of the memory 356 (e.g., typically in permanent storage), or in another non-transitory computer-readable medium (e.g., another memory or an optical disk). The software included in embodiments of the nail gun 10 may be stored in the memory 356 of the controller 304. The software includes, for example, firmware, one or more application programs, 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 processes and methods described herein from the memory 356. In other constructions, the controller 304 includes additional, fewer, or different components.

[0049] The battery pack interface 312 includes a combination of mechanical components (e.g., rails, slots, latches, etc.) and electrical components (e.g., one or more terminals) that are configured and operable to couple (e.g., mechanically, electrically, and communicatively connect) with the nail gun 10 via the battery pack. For example, power provided to the nail gun by the battery pack is provided to the power input module 340 via the battery pack interface 312. The power input module 340 includes a combination of active and passive components to condition or control the power received from the battery pack before supplying power to the controller 304. The battery pack interface 312 also supplies power to the inverter 348, which selectively supplies power to the motor 308 through switching by the switching FET. The battery pack interface 312 also includes, for example, communication lines 384 to provide a communication line or link between the controller 304 and the battery pack 110.

[0050] Indicator 332 may include, for example, one or more light emitting diodes ("LEDs"), etc. Indicator 332 may be configured to display the status of or information associated with nail gun 10. For example, indicator 332 may be configured to indicate a measured electrical characteristic of nail gun 10, a device condition, etc. One or more user input modules 336 may be operatively coupled to controller 304, for example, to select a forward or reverse operating mode, a torque and / or speed setting for nail gun 10 (e.g., using a torque and / or speed switch), etc. In some embodiments, one or more user input modules 336 may include a combination of digital and analog input or output devices, such as one or more knobs, one or more dials, one or more switches, one or more buttons, etc., as needed to achieve the desired level of operation of the nail gun. In some embodiments, one or more user input modules 336 may receive signals wirelessly from a device external to nail gun 10 (e.g., a user's mobile phone).

[0051] The controller 304 can be configured to determine whether a fault condition exists in the nail gun 10 and generate one or more control signals related to the fault condition. For example, the controller 304 can calculate or store in memory 356 predetermined operating thresholds and limits for the operation of the nail gun 10. For example, when the controller 304 detects or predicts a potential thermal failure (e.g., a thermal failure of an FET, motor 308, etc.), power to the motor 308 can be limited or interrupted until the likelihood of a thermal failure decreases. If the controller 304 detects one or more such fault conditions in the nail gun, or determines that the fault condition in the nail gun 10 no longer exists, the controller 304 can be configured to provide information and / or control signals to another component of the nail gun 10 (e.g., the battery pack interface 312, the indicator 332, etc.). The signal can be configured to, for example, trigger or open a high-impedance trace in the nail gun, reset a switch, etc.

[0052] The controller 304 can be configured to determine the state of charge ("SOC") of the rechargeable battery pack 12. The controller 304 can also be configured to receive signals from monitoring circuitry (e.g., including sensor 324 ) configured to sense the SOC levels or voltage values ​​of the cells of the rechargeable battery pack 12 and transmit the voltage readings to the controller 304. The cell voltage levels can be determined by, for example, measuring the total open-circuit voltage of the cells or by aggregating the voltage measurements of each cell. In some embodiments, the monitoring circuitry is additionally configured to sense the discharge current of the cells (e.g., using a current sensor) and / or the temperature of the rechargeable battery pack 12 (e.g., using a temperature sensor) and transmit the current and / or temperature readings to the controller 304. The monitoring circuitry is further configured to receive commands from the controller 304 during operation of the nail gun 10. In some embodiments, the sensed current and / or sensed temperature of the rechargeable battery pack 12 is determined by the battery pack 12 and transmitted to the power tool 10.

[0053] Figure 4 is a diagram of a wireless communication controller 338, wherein the wireless communication controller 338 includes a processor 400, a memory 405, a real-time clock ("RTC") 410, an antenna, and a transceiver 415. The wireless communication controller 338 enables the nail gun 10 to communicate with an external device 505 (e.g., see Figure 5 ) communications. The radio antenna and transceiver 415 work together to transmit and receive wireless messages to and from the external device 505 and processor 400. The memory 405 may store instructions to be executed by the processor 400 and / or data related to communications between the nail gun 10 and the external device 505. The real-time clock (RTC) 410 can increment and accurately display time independently of other device components. When the battery pack 12 is connected to the nail gun 10, the RTC 410 can receive power from the battery pack 12. The processor 400 for the wireless communication controller 338 controls wireless communications between the nail gun 10 and the external device 505. For example, the processor 400 associated with the wireless communication controller 338 buffers incoming and / or outgoing data, communicates with the controller 304, and determines the communication protocol and / or settings used in wireless communications. Communications via the wireless communication controller 338 can be encrypted to protect data exchanged between the nail gun 10 and the external device 505 from third-party interference.

[0054] In the illustrated embodiment, the wireless communication controller 338 is a Bluetooth® controller. The Bluetooth® controller communicates with the external device 505 using the Bluetooth® protocol. Therefore, in the illustrated embodiment, the external device 505 and the nail gun 10 are within communication range (i.e., nearby) of each other when exchanging data. In other embodiments, the wireless communication controller 338 communicates via different types of wireless networks using other protocols (e.g., Wi-Fi, ZigBee, proprietary protocols, etc.). For example, the wireless communication controller 338 can be configured to communicate via Wi-Fi over a wide area network (such as the Internet) or a local area network, or via a piconet (e.g., using infrared or NFC communication).

[0055] In some specific embodiments, the network is a cellular network, such as a Global System for Mobile Communications ("GSM") network, a General Packet Radio Service ("GPRS") network, a Code Division Multiple Access ("CDMA") network, an Evolution-Data Optimized ("EV-DO") network, an Enhanced Data Rates for GSM Evolution ("EDGE") network, a 3GSM network, a 4GSM network, a 4G LTE network, a 5G New Radio Technology, a Digital Enhanced Cordless Telecommunications ("DECT") network, a Digital AMPS ("IS-136 / TDMA") network, or an Integrated Digital Enhanced Network ("iDEN"), etc.

[0056] Wireless communication controller 338 is configured to receive data from controller 304 and transmit the information to external device 505 via antenna and transceiver 415. In a similar manner, wireless communication controller 338 is configured to receive information (e.g., configuration and programming information) from external device 505 via antenna and transceiver 415 and transmit the information to controller 304.

[0057] Figure 5 A communication system 500 is shown. The communication system 500 includes at least one power tool (e.g., the illustrated nail gun 10) and an external device 505. The nail gun 10 and the external device 505 can communicate wirelessly when within communication range of each other. The nail gun 10 can transmit status, operational statistics, sensor data, stored usage information, and the like associated with the nail gun 10. While the nail gun 10 is illustrated, any other type of power tool can be provided with the same or similar communication functionality.

[0058] More specifically, the nail gun 10 can monitor, record, and / or transmit various operating parameters. The external device 505 can also transmit data to the nail gun 10 for operational configuration, firmware updates, or sending commands. The external device 505 also allows the user to set the operating parameters, safety parameters, tool mode selection, etc. of the nail gun 10.

[0059] For example, the external device is a smartphone (as shown), a laptop computer, a tablet computer, a personal digital assistant ("PDA"), or other electronic device capable of wirelessly communicating with the nail gun 10 and providing a user interface. The external device 505 provides a user interface and allows a user to access and interact with the nail gun 10. The external device 505 can receive user input to determine operating parameters, enable or disable features, and so on. The user interface of the external device 505 provides an easy-to-use interface for the user to control and customize the operation of the nail gun 10 or other type of power tool.

[0060] In addition, if Figure 5 As shown, the external device 505 can also share operational data obtained from the nail gun 10 with a remote server 525 connected via the network 515. The remote server 525 can be used to store the operational data obtained from the external device 505, provide additional functionality and services to the user, or a combination of both. In some embodiments, storing information on the remote server 525 enables the user to access the information from multiple different locations. In some embodiments, the remote server 525 collects information from various users about their power tool devices and provides statistics or metrics to the users based on the information obtained from different power tools. The network 515 can include various networking elements (routers 510, hubs, switches, cell towers 520, wired connections, wireless connections, etc.) for connecting to, for example, the Internet, a cellular data network, a local area network, or a combination thereof, as described above. In some embodiments, the nail gun 10 is configured to communicate directly with the remote server 525 via an additional wireless interface or via the same wireless interface that the nail gun 10 uses to communicate with the external device 505.

[0061] Figure 6A and Figure 6B A partial cross-sectional view of the nail gun 10 is shown. As described above with reference to FIG. 2 , the nail gun 10 includes a cylinder 18 and a piston 22 positioned within an outer reservoir cylinder 30. The piston 22 is configured to drive a driver blade 26. The nail gun 10 does not require an external source of air pressure, but rather includes an outer reservoir cylinder 30 of compressed fluid (e.g., gas) that is in communication with the cylinder 18. The driver blade 26 defines a drive axis 600. During a drive cycle, the driver blade 26 and the piston 22 may be at a top dead center ("TDC") position (e.g., Figure 6B shown) and the drive position or bottom dead center ("BDC") position (as shown) Figure 6A shown).

[0062] In operation, by energizing the motor 308 during the retraction cycle, the elevator housing portion 106 drives the piston 22 and the driver blade 26 toward the TDC position. As the piston 22 and the driver blade 26 are driven toward the TDC position, the gas above the piston 22 and the gas within the reservoir cylinder 30 are compressed. Before reaching the TDC position, the motor 308 is turned off, and the piston 22 and the driver blade 26 are held in a ready position between the TDC and BDC positions until they are released by a user actuating the trigger 24. Upon release, the compressed gas above the piston 22 and within the reservoir cylinder 30 drives the piston 22 and the driver blade 26 to the driven position, thereby driving the fastener into the workpiece. Thus, the illustrated nail gun 10 operates based on the principle of a gas spring, utilizing the elevator housing portion 106 and the piston 22 to further compress the gas within the cylinder 18 and the reservoir cylinder 30.

[0063] For example, refer to Figure 7A and 7B The nail gun 10 includes a check valve 700 (or similar valve) positioned between the bumper 112 and the outer reservoir cylinder 30 and within the passage 705. As the piston 22 compresses the bumper 112, the check valve 700 responds to pressure. More specifically, as the piston 22 is driven from the ready position to the driven position, it impacts the bumper 112, which seals off the inner cylinder 18, thereby forming an air reservoir or intermediate chamber 710. When the driver blade 26 approaches the BDC position, the intermediate chamber 710 forms between the bottom of the cylinder 18 and the bumper 112 (in some cases, between the bumper 112 and the piston 22). That is, when the piston 22 impacts the bumper 112, the intermediate chamber 710 is completely sealed (i.e., not in fluid communication with the external atmosphere). As the piston 22 compresses the bumper 112, the pressure in the intermediate chamber 710 increases, opening the check valve 700. The increased air pressure, through the open check valve 700, introduces a small amount of pressurized air into the outer reservoir cylinder 30, thereby increasing the pressure applied to the cylinder 18, which can compensate for potential or actual air pressure losses in the nail gun 10. Thus, air pressure can be increased by utilizing the compression of the buffer that occurs at the end of each firing event of the nail gun 10. This can avoid the need to attach a separate compressor to the cylinder 18 to increase the pressure on the piston 22, for example. In effect, the supplemental compression of the buffer 112 and the opening of the check valve 700 can create an onboard air compressor for the nail gun 10.

[0064] By repeatedly compressing the buffer 112 using the piston 22 to replenish the pressure in the reservoir cylinder 30, a small amount of air pressure (e.g., approximately 0.01–0.015 psi) is added each time the piston 22 compresses the buffer 112. Extending this to 1,000 nails fired by the nail gun 10, this can be extrapolated to an increase in pressure of approximately 10–15 psi, or 10–15% of the total tank pressure. While this increase in pressure is relatively small compared to the total tank pressure, the pressure increase due to the compression of the buffer 112 and the opening of the check valve 700 is sufficient to maintain adequate tank pressure after accounting for pressure losses (e.g., due to infiltration, minor debris intrusion, or minor mechanical wear).

[0065] Figure 8 A simplified block diagram of an embodiment 800 of a nail gun 10 is shown, wherein the nail gun 10 performs a braking sequence for the electric motor of the nail gun 10. The nail gun 800 includes a power supply 805, switches or field-effect transistors ("FETs") 810, a motor 815, a Hall-effect sensor 820, a motor controller 825 (e.g., controller 304), a user input 830, and other components 835 (e.g., a battery pack fuel gauge, work lights (LEDs), current / voltage sensors, etc.). The power supply 805 provides DC power to the various components of the nail gun 800 and can be a rechargeable power tool battery pack (e.g., battery pack 12) that utilizes, for example, lithium-ion battery technology. In some embodiments, the power supply 805 can receive AC power (e.g., 120V / 60Hz) from a tool receptacle coupled to a standard wall outlet and then filter, condition, and rectify the received power to output DC power.

[0066] As the rotor's magnet rotates across the surface of the Hall effect sensors 820, each Hall effect sensor 820 outputs motor feedback information, such as an indication (e.g., a pulse). Based on the motor feedback information from the Hall effect sensors 820, the motor controller 825 can determine the position, speed, and / or acceleration of the rotor of the motor 815. The motor controller 825 also receives user control from a user input 830, such as by depressing the trigger 24. In response to the motor feedback information and the user control, the motor controller 825 transmits control signals to control the FETs 810 to drive the motor 815. By selectively enabling and disabling the FETs 810, power from the power supply 805 is selectively applied to the stator coils of the motor 815 to rotate the rotor. Although not shown, the motor controller 825 and other components of the nail gun 800 are electrically coupled to the power supply 805 so that the power supply 805 provides power thereto.

[0067] Figure 9A and 9BThe motor 815 in the nail gun 800 is shown. The motor 815 includes a rotor 905, a front bearing 910, a rear bearing 915 (collectively referred to as bearings 910, 915), a position sensor board assembly 920 located within the stator envelope of the motor 815, and a motor shaft 935. The stator coils 925 are parallel to the length of the rotor axis 930. To detect rotor position, a rotor magnet 940 is positioned adjacent to the Hall effect sensor 820 on the position sensor board assembly 920. Embedding the rotor 905, bearings 910, 915, and position sensor board assembly 920 within the stator envelope allows the motor 815 to be more compact in the axial direction.

[0068] Figure 10A A rechargeable battery pack 12 according to some embodiments is shown. The rechargeable battery pack 12 includes a housing 1005, a user interface portion 1010 for providing an indication of the state of charge of the rechargeable battery pack 12, and a device interface portion 1015 for connecting the rechargeable battery pack 12 to a device (e.g., a power tool, a nail gun 10, etc.). The rechargeable battery pack 12 includes a plurality of battery cells 1020 within the housing 1005.

[0069] Figure 10B A group 1025 of battery cells 1020 is shown that includes, for example, ten individual battery cells 1020. Battery cells 1020 can be located within housing 1005 of rechargeable battery pack 12. In some embodiments, rechargeable battery pack 12 includes more than 10 or fewer than 10 battery cells within housing 1005.

[0070] Figure 11A A battery pack 1100, such as the rechargeable battery pack 12, is shown for powering a power tool. The battery pack 1100 includes a battery housing 1130 and a reference Figure 11B A plurality of battery cells 1190.

[0071] Figure 11B An interior view 1145 of a battery housing 1130 is shown, including a wall portion 1165 having an interior surface 1180 and an exterior surface 1175. The interior surface 1180 defines an interior cavity 1170. The exterior surface 1175 includes a top surface portion 1115 and a bottom portion 1185. Figure 11B , the battery cells 1190 arranged in the cavity 1170 are connected in series to the battery contacts 1105. Figure 11A , a plurality of contacts 1105 (see Figure 11B ) are disposed on the top surface portion 1115 within the battery contact housing extension 1110. The housing extension 1110 is configured to be matingly engaged with one or more power tools or power accessories. A battery level indicator 1120 is also disposed on the housing ( Figure 11A ), while additional battery charging, monitoring and indication components 1155 are arranged in cavity 1170 ( Figure 11B ).like Figure 11A As shown, two clips 1135 are coupled to the housing 1130 for releasably securing the housing 1130 to the power tool apparatus.

[0072] Figures 12A-12D 1 is a flow chart of an exemplary process 1200 for controlling an operating sequence of a power tool 10. In step 1202, the power tool 10 is powered on. For example, the power input module 340 provides direct current to the controller 304 and components of the control system 300. In step 1204, the controller 304 monitors the selection of an operating mode. In various embodiments, the user input module 336 monitors user input and determines whether the power tool 10 is in a first operating mode or a second operating mode. In some embodiments, the power tool 10 includes one or more switches, such as a mode selector 32, that can be toggled to select an operating mode or switch between operating modes. In some embodiments, the power tool 10 includes a graphical user interface that is output to a display. A user can select an operating mode by interacting with the graphical user interface. The user input module 336 can detect whether one or more switches have been toggled, one or more positions of one or more switches, and / or user selections on the graphical user interface to determine whether the first operating mode or the second operating mode is selected.

[0073] In step 1206, the controller 304 determines whether the first operating mode is selected. In response to determining that the first operating mode is not selected (the answer is "no" in decision block 1206), the controller 304 determines whether the second operating mode is selected in step 1208. In response to determining that the second operating mode is not selected (the answer is "no" in decision block 1208), the controller 304 continues to monitor for selection of an operating mode in step 1210, such as by monitoring the user input module 336. Process 1200 returns from block 1210 to decision block 1206. In response to determining that the first operating mode is selected (the answer is "yes" in decision block 1206), the controller 304 is configured to monitor the safety switch 386 (see FIG. 1212 ) at step 1212. Figure 12B). In step 1214, the controller 304 is configured to monitor the trigger switch 316. In step 1216, the controller 304 is configured to determine whether the safety switch 386 is actuated. In various embodiments, the safety switch 386 can be actuated by the user depressing the safety catch 28. In response to determining that the safety switch 386 is not actuated (the answer is "no" in decision block 1216), the controller 304 can continue to monitor the safety switch 386 at block 1212 and monitor the trigger switch 316 at block 1214. In response to determining that the safety switch 386 is actuated (the answer is "yes" in decision block 1216), the controller 304 determines whether the trigger switch 316 is actuated. In various embodiments, the trigger switch 316 can be actuated by the user depressing the trigger 24.

[0074] In response to determining that the trigger switch 316 is not actuated (the answer is "no" in decision block 1218), the controller 304 may continue to monitor the safety switch 386 at block 1212 and the trigger switch 216 at block 1214. In response to determining that the trigger switch 316 is actuated (the answer is "yes" in decision block 1218), the controller 304 initiates the drive sequence and drives the driver blade 26 from the top dead center position (or in some embodiments, from the ready position) to the bottom dead center position (e.g., according to any of the techniques described above) at block 1220. In step 1222, the controller 304 initiates the retraction sequence. For example, the controller 304 activates the motor 308 to begin retracting the driver blade 26 from the bottom dead center position to the top dead center position (or in some embodiments, to the ready position). In step 1224, the controller 304 monitors the position of the driver blade 26. In various embodiments, the controller 304 monitors the sensor 324 to determine the position of the driver blade 26 (e.g., according to any of the techniques described above). In some embodiments, controller 304 monitors sensor 324 to determine the position of elevator 66 and determines the position of drive blade 26 based on the position of elevator 66 (eg, according to any of the techniques described above).

[0075] In some embodiments, the controller 304 monitors the Hall effect sensor 820 at the motor 815 to determine the position of the driver blade 26. The controller 304 can determine the progress of the retraction cycle (e.g., the percentage of movement between the bottom dead center position and the top dead center position, or in some embodiments, the percentage of movement between the bottom dead center position and the ready position). For example, as the rotor magnet 940 passes by the Hall effect sensor 820, the Hall effect sensor 820 detects changes in the magnetic field generated by the rotor magnet 940. By monitoring the number of Hall effect transitions, the Hall effect sensor 820 can be used to determine the number of revolutions of the motor 308, and the controller 304 determines the position of the driver blade 26 based on the extent to which the driver blade 26 has been retracted, where the extent to which the driver blade 26 has been retracted is a function of the number of motor revolutions. For example, the controller 304 can monitor the Hall effect sensor 820 and generate a count of the number of motor revolutions completed during the current retraction cycle. If the number of motor 308 revolutions c required to retract the driver blade 26 from the bottom dead center position to the top dead center position, the controller 304 may calculate the position of the driver blade 26 as a retraction cycle percentage y according to the following equation (1):

[0076]

[0077] In step 1226, the controller 304 determines whether the position of the drive blade 26 has reached or exceeded a threshold value. In some embodiments, the threshold value is expressed as a percentage of the retraction cycle completed by the drive blade 26. In various embodiments, the threshold value ranges from about 50% to about 100%. In some embodiments, the threshold value can be about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100%. In response to determining that the position of the drive blade 26 has not reached or exceeded the threshold value (the answer is "no" in decision block 1226), the controller 304 continues to monitor the position of the drive blade 26 at block 1224.

[0078] In response to determining that the position of the drive blade 26 has reached or exceeded the threshold (the answer is "yes" in decision block 1226), the controller 304 initiates a braking sequence at block 1228. In some embodiments, the motor 308 may be a pulse width modulation controlled motor, and the controller 304 initiates the braking sequence by reducing the duty cycle of the pulse width modulation signal, thereby effectively reducing the average voltage supplied to the motor 308. In various embodiments, the controller 304 reverses the polarity of the power supply to the motor 308, thereby generating a torque on the rotor 905 in a direction opposite to the direction of rotation of the rotor 905.

[0079] In some embodiments, the braking sequence includes a resistive soft braking technique. In this technique, an additional field-effect transistor (FET) can be used to direct current to a dedicated braking resistor. For example, the additional FET can be connected in parallel with the windings of motor 308 (e.g., the windings of stator coil 925) and in series with the braking resistor. This configuration allows the additional FET to control when the braking resistor is connected to the circuit. During normal operation, the additional FET remains off, disconnecting the braking resistor from the windings of motor 308. However, during the braking sequence, the controller 304 can turn on the additional FET, connecting the braking resistor to the windings. The current generated by the back electromotive force (EMF) of the rotating motor 308 can flow through the braking resistor, which dissipates energy as heat, thereby slowing the motor 308. The braking resistor can be sized based on the braking current, which can be set by dividing the back EMF voltage of the rotating motor 308 by the sum of the resistance of the motor 308 and the resistance of the braking resistor.

[0080] In various embodiments, the controller 304 applies a dynamic braking technique, in which the back electromotive force generated by the motor 308 is redirected into the motor windings, thereby generating resistance to slow the rotational speed of the rotor 905. In dynamic braking, the energy generated during braking can be dissipated as heat in the motor windings or through an additional braking resistor. In some embodiments, the controller 304 applies a regenerative braking technique, in which the motor 308 recovers the kinetic energy of the rotor 905 by converting the kinetic energy of the rotor 905 into electrical energy and using the electrical energy to charge the battery pack 12. In some embodiments, the controller 304 can control a mechanical brake, such as a friction pad and / or a brake disc, which can be positioned to physically stop the rotation of the rotor 905. After the braking sequence is completed, the process 1200 returns to block 1204. In various embodiments, the braking sequence includes the controller 304 actuating a mechanical brake, for example, to secure the drive blade 26 in a top dead center position.

[0081] Reference Figure 12A In response to the controller 304 determining that the second mode of operation is selected (the answer is "yes" in decision block 1208), the controller 304 is configured to monitor the safety switch at block 1230 and the trigger switch 316 at block 1232. At step 1234 (see Figure 12C), the controller 304 is configured to determine whether the trigger switch 316 is actuated. In response to determining that the trigger switch 316 is not actuated (the answer is "no" in decision block 1234), the controller 304 may continue to monitor the safety switch 386 at block 1230 and monitor the trigger switch 316 at block 1232. In response to the controller 304 determining that the trigger switch 316 is actuated (the answer is "yes" in decision block 1234), the controller 304 determines whether the safety switch 386 is actuated at block 1236. In response to the controller 304 determining that the safety switch 386 is not actuated (the answer is "no" in decision block 1236), the controller 304 may continue to monitor the safety switch 386 at block 1230 and monitor the trigger switch 316 at block 1232. In response to the controller 304 determining that the safety switch 386 is actuated (the answer is "yes" in decision block 1236), the controller 304 initiates a drive sequence and drives the driver blade 26 from the top dead center position (or in some embodiments, from the ready position) to the bottom dead center position at block 1238 (e.g., according to any of the techniques described above).

[0082] In step 1240, controller 304 activates motor 308 to begin retracting drive blade 26 from the bottom dead center position to the top dead center position (or, in some embodiments, to the ready position). In step 1242, controller 304 is configured to monitor the position of drive blade 26, for example, according to the techniques described above with reference to block 1224, and determine whether the position of drive blade 26 has reached or exceeded a first threshold. In some embodiments, the first threshold ranges from approximately 50% to approximately 100%. For example, the first threshold can be approximately 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100%. In response to controller 304 determining that the position of drive blade 26 has not reached or exceeded the first threshold (the answer is "no" in decision block 1244), controller 304 may continue to monitor the position of drive blade 26 at block 1242. In response to controller 304 determining that the position of drive blade 26 has reached or exceeded the first threshold (“yes” answer in decision block 1244 ), controller 304 initiates a braking sequence for motor 308 , such as according to the techniques described above with reference to block 1228 .

[0083] In step 1248, controller 304 monitors the position of drive blade 26 and determines whether the position has reached or exceeded a second threshold. In various embodiments, the second threshold is less than the first threshold. In some embodiments, the second threshold is equal to the first threshold. In various embodiments, the second threshold is greater than the first threshold. In some specific embodiments, the second threshold ranges from approximately 50% to approximately 100%. For example, the second threshold can be approximately 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100%. In some embodiments, the second threshold can be the same as the first threshold, and decision block 1248 can be omitted. In response to controller 304 determining that the position of drive blade 26 has not reached or exceeded the second threshold (the answer in decision block 1248 is "no"), controller 304 continues to monitor the position of drive blade 26 at decision block 1248. In response to controller 304 determining that the position of drive blade 26 has reached or exceeded the second threshold (“yes” answer at decision block 1248 ), controller 304 is configured to determine whether trigger switch 316 is actuated at decision block 1250 .

[0084] In response to the controller 304 determining that the trigger switch 316 is not actuated (the answer is "no" in decision block 1250), the controller 304 is configured to monitor actuation of the trigger switch 316 and the safety switch 386 at block 1252, and the process 1200 returns to decision block 1250. In response to the controller 304 determining that the trigger switch 316 is actuated (the answer is "yes" in decision block 1250), the controller 304 is configured to determine whether the safety switch 386 is actuated at decision block 1254. In response to the controller 304 determining that the safety switch 386 is not actuated (the answer is "no" in decision block 1254), the controller 304 is configured to monitor actuation of the trigger switch 316 and the safety switch 386 at block 1252, and the process 1200 returns to decision block 1250. In response to the controller 304 determining that the safety switch 386 is actuated (the answer is "yes" at decision block 1254), the controller 304 is configured to abort the braking sequence at block 1256. At step 1258, the controller 304 initiates the drive sequence and drives the drive blade 26 from the top dead center position to the bottom dead center position (e.g., according to any of the techniques described above).

[0085] In some embodiments, when the power tool 10 is in the second operating mode, the controller 304 continuously monitors the sequence of actuation of the trigger switch 316 following actuation of the safety switch 386. In various embodiments, if both the trigger switch 316 and the safety switch 386 are actuated and remain actuated before the controller 304 initiates the braking sequence, the controller 304 bypasses the braking sequence and continues to initiate a new driving sequence when the driver blade 26 reaches, for example, the top dead center position.

[0086] Figure 13 1 is a timing diagram 1300 illustrating waveforms used to drive the motor 308 during a retraction sequence in an embodiment where the motor 308 is a pulse width modulated motor. In various implementations, the controller 304 controls the gate controller 344, which in turn controls switches such as insulated gate bipolar transistors (IGBTs) or metal oxide semiconductor field effect transistors (MOSFETs) in the inverter 348. Figure 13 The waveform output from the door controller 344 to the motor 308 is shown. Figure 13 The vertical axis 1302 represents voltage, and Figure 13 The horizontal axis 1304 represents time. Figure 13 The top row of FIG shows an exemplary waveform provided to motor 308 during a retraction sequence including a braking sequence. During the retraction sequence, the frequency of the PWM signal is high. During a braking cycle, the frequency of the PWM signal is reduced (and / or, in some embodiments, out of phase with the signal in the previous retraction sequence), resulting in a reduced operating speed of motor 308. Figure 13 As shown, in some embodiments of the power tool 10 without the brake abort function enabled, approximately 4.7 operating cycles per second may be achieved.

[0087] Figure 14 is a timing diagram 1400 illustrating waveforms used to drive the motor 308 in an embodiment of the power tool 10 with the brake abort sequence enabled. Figure 14 The vertical axis 1402 represents voltage, and Figure 14 The horizontal axis 1404 represents time. Figure 14 As shown, the braking cycle begins at approximately 1.175 seconds. At approximately 1.24 seconds, the controller 304 issues a command for a brake abort sequence, during which the controller 304 stops the brake motor 308. In some embodiments, including the brake abort sequence can increase the number of operating cycles per second achievable from approximately 4.7 operating cycles per second to approximately 6.1 operating cycles per second.

[0088] Thus, among other things, the embodiments described herein provide a power tool that includes a brake-stop function for increasing the cycle rate (eg, firing rate) of the power tool. The following claims claim various features and advantages.

Claims

1. An electric tool, characterized in that: include: electric motors; drive blades; trigger switch; Safety switch; as well as an electronic controller connected to the electric motor, the trigger switch, and the safety switch, the electronic controller being configured to: initiating a retraction cycle by controlling the electric motor to move the driver blade from a first position to a second position, determining a position of the driver blade during the retraction cycle, initiating a braking cycle of the electric motor in response to the position of the driver blade exceeding a first threshold, and In response to detecting a first actuation of the trigger switch and a second actuation of the safety switch, the braking cycle is terminated.

2. The electric tool according to claim 1, wherein: Further including: one or more sensors connected to the electronic controller, the one or more sensors configured to detect the number of revolutions of the electric motor; Wherein the controller is further configured to determine the position of the drive blade based on signals from the one or more sensors.

3. The electric tool according to claim 1, wherein: Further including: one or more sensors positioned to detect at least a portion of the drive blade; Wherein the controller is further configured to determine the position of the drive blade based on signals from the one or more sensors.

4. The electric tool according to claim 1, wherein: Further including: one or more sensors configured to detect a position of a lifter configured to engage the drive blade; Wherein the controller is further configured to determine the position of the drive blade based on signals from the one or more sensors.

5. The electric tool according to claim 1, wherein The electronic controller is further configured to abort the braking cycle in response to the position of the driver blade exceeding a second threshold.

6. The electric power tool according to claim 5, wherein: The second threshold is smaller than the first threshold.

7. The electric power tool according to claim 1, wherein The first threshold is approximately 75% of the retraction cycle.

8. The electric power tool according to claim 1, wherein The electronic controller is further configured to abort the braking cycle in response to detecting that the trigger switch is actuated before the safety switch.

9. The electric power tool according to claim 1, wherein: The electronic controller is configured to: monitoring an operating mode selector to determine whether the power tool is in a first operating mode or a second operating mode; in response to determining that the power tool is in the first operating mode, initiating a drive cycle in response to detecting that the safety switch is actuated before the trigger switch; as well as In response to determining that the power tool is in the second operating mode, the drive cycle is initiated in response to detecting that the trigger switch is actuated before the safety switch.

10. The electric power tool according to claim 9, wherein The electronic controller is further configured to discontinue the braking cycle in response to the power tool being in the second operating mode.

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