Patent ID: 12186877

DETAILED DESCRIPTION

Before any embodiments are explained in detail, it is to be understood that the embodiments are not limited in its application to the details of the configuration and arrangement of components set forth in the following description or illustrated in the accompanying drawings. The embodiments are capable of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.

In addition, it should be understood that embodiments may include hardware, software, and electronic components or modules that, for purposes of discussion, 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, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic-based aspects may be implemented in software (e.g., stored on non-transitory computer-readable medium) executable by one or more processing units, such as a microprocessor and/or application specific integrated circuits (“ASICs”). As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components, may be utilized to implement the embodiments. For example, “servers” and “computing devices” described in the specification can include one or more processing units, one or more computer-readable medium modules, one or more input/output interfaces, and various connections (e.g., a system bus) connecting the components.

FIGS.1-5illustrate a power tool100that includes a housing105. The housing105includes a handle portion110, a motor housing portion112, and an input control device115. The motor housing portion112houses a motor therein. The handle portion110extends away from the motor housing portion112. The input control device115is, for example, a button or a switch that is configured to control an operational mode of the power tool100. The input control device115is located on a top portion120of the housing105. More particularly, as illustrated, the input control device115is positioned on a top portion of the motor housing portion112, away from the handle portion110. For example, the illustrated input control device115is on a (top) side of the motor housing portion112opposite from a (bottom) side of the motor housing portion from which the handle portion110extends. The input control device115is located above the handle portion110, a motor of the power tool100, a trigger125of the power tool100, an output spindle130of the power tool100, a battery pack for powering the power tool100, etc. By locating the input control device115on the top portion120of the housing105and remote from or away from the handle portion110, the handle portion110can be made more compact. For example, by locating the input control device115on the top portion120of the housing105, a physical lever typically located near a trigger for a power tool can be removed to make the handle portion110of the power tool100more compact.

The input control device115, which may also be referred to as a mode selector, generates a mode signal when actuated by a user of the power tool100. The input control device115, in some embodiments, includes an electro-mechanical push button that generates a pulse in response to each actuation (e.g., depression). The button may be spring biased such that actuation momentarily depresses the button in a direction of the housing105(overcoming the biasing force of the spring) and then the biasing spring returns the button to an extended position when actuation is completed. In some embodiments, the input control device115includes a touch switch, such as a capacitance switch. The generated mode signal is configured to control an operational mode of the power tool100. For example, the input control device115is configured to modify the operational mode of the power tool100among a motor forward mode of operation, a motor reverse mode of operation, and a locked tool mode of operation.

FIG.6illustrates a simplified block diagram of the power tool100, which includes a controller200and a power source202. The power source202provides DC power to the various components of the power tool100and may be a power tool battery pack that is rechargeable and uses, for instance, lithium ion cell technology. In some instances, the power source202may receive AC power (e.g., 120V/60 Hz) from a tool plug that is coupled to a standard wall outlet, and then filter, condition, and rectify the received power to output DC power.

The controller200is electrically and/or communicatively connected to a variety of modules or components of the power tool100. For example, the illustrated controller200is connected to one or more indicators205, a power input module210, a battery pack interface215, one or more sensors220, a user input module225, a trigger switch230(connected to a trigger235), and a FET switching bridge240(e.g., including one or more switching FETs). The controller200includes combinations of hardware and software that are operable to, among other things, control the operation of the power tool100, activate the one or more indicators205(e.g., a light emitting diode (LED)), monitor the operation of the power tool100, etc.

The controller200includes a plurality of electrical and electronic components that provide power, operational control, and protection to the components and modules within the controller200and/or the power tool100. For example, the controller200includes, among other things, a processing unit250(e.g., a microprocessor, a microcontroller, or another suitable programmable device), a memory255, input units260, and output units265. The processing unit250includes, among other things, a control unit270, an arithmetic logic unit (“ALU”)275, and a plurality of registers280(shown as a group of registers inFIG.6), and is implemented using a known computer architecture (e.g., a modified Harvard architecture, a von Neumann architecture, etc.). The processing unit250, the memory255, the input units260, and the output units265as well as the various modules connected to the controller200are connected by one or more control and/or data buses (e.g., common bus285).

The memory255is a non-transitory computer readable medium that includes, for example, a program storage area and a data storage area. The program storage area and the data storage area can include combinations of different types of memory, such as read-only memory (“ROM”), random access memory (“RAM”) (e.g., dynamic RAM [“DRAM”], synchronous DRAM [“SDRAM”], etc.), electrically erasable programmable read-only memory (“EEPROM”), flash memory, a hard disk, an SD card, or other suitable magnetic, optical, physical, or electronic memory devices. The processing unit250is connected to the memory255and executes software instructions that are capable of being stored in a RAM of the memory255(e.g., during execution), a ROM of the memory255(e.g., on a generally permanent basis), or another non-transitory computer readable medium such as another memory or a disc. Software included in the implementation of the power tool100can be stored in the memory255of the controller200. The controller200is configured to retrieve from memory and execute, among other things, instructions related to the control of the power tool described herein.

The indicators205include, for example, one or more light-emitting diodes (“LED”). The sensors220include, for example, one or more current sensors, one or more speed sensors, one or more Hall Effect sensors, one or more temperature sensors, etc. The battery pack interface215includes a combination of mechanical and electrical components configured to, and operable for, interfacing (e.g., mechanically, electrically, and communicatively connecting) the power tool100with the power source202. For example, power provided by a battery pack (an example of the power source202) to the power tool100is provided through the battery pack interface215to the power input module210. The power input module210includes combinations of active and passive components to regulate or control the power received from the battery pack prior to power being provided to the controller200. The battery pack interface215also supplies power to the FET switching bridge240to be switched by the switching FETs to selectively provide power to a motor245. With reference back toFIG.1, the motor245is housed within the motor housing portion112and is configured to drive the output spindle130, either via a direct drive coupling or a transmission (e.g., including planetary gears). Referring back toFIG.6, the battery pack interface215also includes, for example, a communication line290for providing a communication line or link between the controller200and a battery pack.

In some embodiments, the tool includes Hall sensors246(for example, three Hall sensors) mounted on a printed circuit board (not shown) positioned axially adjacent to the motor245at different radial positions (e.g., 120 degrees apart from one another). The Hall sensors246output motor feedback information, such as an indication (e.g., a pulse) each time a magnet of the rotor rotates across a face of one of the Hall sensors246. Based on the motor feedback information from the Hall sensors246, the controller200can determine the position, velocity, and acceleration of the rotor. The controller200also receives user controls from user input225and the trigger switch230. In response to the motor feedback information and user controls, the controller200transmits control signals to the FET switching bridge240to drive the motor245. In some embodiments, the power tool100may be a sensorless power tool that does not include a Hall sensor246or other position sensor to detect the position of the rotor. Rather, the rotor position may be detected based on the inductance of the motor245or the back emf generated in the motor245. Although not shown, the controller200and other components of the power tool100are electrically coupled to the power source202such that the power source202provides power thereto.

In some embodiments, the FET switching bridge240includes a switch bridge having a plurality of high side power switching elements (for example, field effect transistors (FETs)) and a plurality of low side power switching elements (for example, FETs). The controller200provides the control signals to control the high side FETs and the low side FETs to drive the motor based on the motor feedback information and user controls, as noted above. For example, in response to detecting a pull of the trigger235and the input from the user input module225, the controller200provides the control signals to selectively enable and disable the FETs (e.g., sequentially, in pairs) resulting in power from the power source202to be selectively applied to stator coils of the motor126to cause rotation of a rotor. More particularly, to drive the motor245, the controller200enables a first high side FET and first low side FET pair (e.g., by providing a voltage at a gate terminal of the FETs) for a first period of time. In response to determining that the rotor of the motor245has rotated based on a pulse from the Hall sensors246, the controller200disables the first FET pair, and enables a second high side FET and a second low side FET. In response to determining that the rotor of the motor126has rotated based on pulse(s) from the Hall sensors246, the controller200disables the second FET pair, and enables a third high side FET and a third low side FET. In response to determining that the rotor of the motor245has rotated based on further pulse(s) from the Hall sensors246, the controller200disables the third FET pair and returns to enable the first high side FET and the first low side FET. This sequence of cyclically enabling pairs of high side FET and a low side FET repeats to drive the motor245. Further, in some embodiments, the control signals include pulse width modulated (PWM) signals having a duty cycle that is set in proportion to the amount of trigger pull of the trigger235, to thereby control the speed or torque of the motor245. In some embodiments, to drive the motor in a first direction (e.g., forward), the sequence of cyclically enabling pairs of the high side FETs and the low side FETs proceeds in a first order (e.g., pair 1, pair 2, pair 3, pair 1, pair 2, etc.), and to drive the motor in a second direction (e.g., reverse), the sequence of cyclically enabling pairs of the high side FETs and the low side FETs proceeds in a second order (e.g., pair 3, pair 2, pair 1, pair 3, pair 2, etc.).

The user input module225is operably coupled to the controller200, for example, to select a forward mode of operation, a reverse mode of operation, or a power tool lock mode of operation for the power tool100. The user input module225includes, for example, the input control device115located on the top portion of the housing105. Each time the input control device115is actuated by a user of the power tool100, the controller200receives a mode signal from the use input module225. Each time the controller200receives that mode signal from the user input module225, the power tool100mode of operation is changed. In some implementations, the controller200sequentially switches among each of the forward mode of operation, the reverse mode of operation, and the power tool lock mode of operation. For example, the power tool100can include a first mode of operation, a second mode of operation, and a third mode of operation. If the power tool100is currently operating in the first mode of operation, a mode signal from the user input module225will cause the controller200to switch to the second mode of operation. If the power tool100is currently operating in the second mode of operation, a mode signal from the user input module225will cause the controller200to switch to the third mode of operation. If the power tool100is currently operating in the third mode of operation, a mode signal from the user input module225will cause the controller200to switch to the first mode of operation.

In some embodiments, the first mode of operation is the forward mode of operation in which the controller200controls the FET switching bridge240to drive the motor245in a first (forward) direction in response to depression of the trigger235and the generation of a trigger signal. In some embodiments, the second mode of operation is the reverse mode of operation in which the controller200controls the FET switching bridge240to drive the motor245in a second (reverse) direction, which is opposite the first (forward) direction, in response to depression of the trigger235. In some embodiments, the third mode of operation is the lock mode of operation in which the controller200prevents or suppresses driving of the motor245(e.g., by sending control signals to the FET switching bridge240or by not sending control signals to the FET switching bridge240), even when the trigger signal is generated responsive to the trigger235being depressed. In other words, in the lock mode of operation, the controller200ignores user depression of the trigger235and does not drive the motor245in response to user depression of the trigger235.

In some embodiments, the indicators205include LEDs to provide an indication of the mode of the power tool100as selected by the input control device115. With reference back toFIG.2, an LED of the indicators205may be associated with each symbol (i.e., forward arrow symbol205A, reverse arrow symbol205B, and lock symbol205C) shown on the input control device115. The controller200illuminates the LED associated with the current mode of operation of the power tool100(e.g., the forward arrow205A is illuminated when in the forward mode of operation, the reverse arrow205B is illuminating when in the reverse mode of operation, and the lock symbol205C is illuminated when in the lock mode of operation).

FIG.7is a flow diagram of a method300of controlling an operating mode of a power tool, according to some embodiments. The method300is described with reference to the power tool100described above. However, in some embodiments, the method is implemented using other power tools.

In block310, a mode signal is received in a controller200of the power tool100from an input control device115positioned on a top portion120of a housing105of the power tool100positioned above a handle portion110of the housing105. For example, each time a user actuates the input control device115a mode signal is received by the controller200. In some embodiments, the mode signal is a pulse signal.

In block320, the controller200selects a different one of a plurality of operational modes of the power tool100responsive to the mode signal. In some embodiments, the operational modes include at least a forward mode and a reverse mode. In some embodiments, the operational modes also include a lock mode of operation. Stated another way, in block320, the controller200may change a current operational mode of the tool (selected from the plurality of operational modes) to another operational mode (selected from the plurality of operational modes).

In block330, the controller200operates the motor245according to the selected operational mode. For example, in the forward mode of operation, the controller200controls the FET switching bridge240to drive the motor245in a forward direction in response to a depression of the trigger235and the generation of a trigger signal by the trigger switch230. In the reverse mode of operation, the controller200controls the FET switching bridge240to drive the motor245in a reverse direction, which is opposite the forward direction, in response to a depression of the trigger235and the generation of a trigger signal by the trigger switch230. In the lock mode of operation, the controller200prevents or suppresses driving of the motor245by not sending control signals to the FET switching bridge240even when the trigger signal is generated responsive to the trigger235being depressed. In other words, in the lock mode of operation, the controller200ignores user depression of the trigger235and does not drive the motor245in response to user depression of the trigger235.

Operation of the power tool100according to the method300ofFIG.7may continue after the tool is operated in block330by remaining in block330for subsequent actuations of the trigger235in the current operational mode, or by looping back to block310responsive to another actuation of the input control device115and generation of the mode signal. In some embodiments, block330is bypassed when the input control device115is actuated a subsequent time before the trigger235is actuated. Accordingly, at least in some embodiments, the controller200may sequentially switch (i.e., cycle) through the operational modes each time an instance of the mode signal is received, and need not first operate the motor according to a selected mode before cycling to a next operational mode. For example, with successive actuations of the input control device115, the controller200may cycle the operational mode from forward, to reverse, to lock, back to forward, to reverse, to lock, and so forth. In other examples, a different order of operational modes is used when cycling (e.g., forward, lock, reverse, forward, lock, reverse, and so forth).

Thus, embodiments described herein provide, among other things, a power tool including an input control device located on a top portion of a housing for changing an operational mode of the power tool.