Patent Description:
Powered ratcheting wrenches typically include a motor, a drive assembly driven by the motor, and a rotating output for applying torque to a fastener. The motor may be powered by electricity (e.g., a DC or AC source) or pressurized air.

According to its title and abstract <CIT> relates to a ratchet-type torque wrench which is configured such that power supplied from an air motor is transmitted to a ratchet unit via a reduction gear unit in order to rotate a spindle connected to the ratchet unit. The torque wrench includes a ratchet housing accommodating the ratchet unit, a body coupled with the ratchet housing and accommodating the air motor, a strain gage bonded to the ratchet housing, a battery box accommodated within the body, and a circuit board fixed to a housing cover covering the ratchet housing and having a torque adjustment circuit provided thereon. The circuit board is connected to the battery box via a conductive wire running though a wiring groove formed on the body. Leads of the strain gage are connected to the circuit board within the housing cover.

According to its title and abstract <CIT> relates to a torque wrench with wireless transmission function, including at least one wrench body having an end to which a tool head is coupled for coupling with a tool piece, such as wrench socket, for application of torque, at least one toque-strain bar, which is coupled to the tool head of the wrench body, at lest one torque sensor, which is mounted to the toque-strain bar to detect the value of the torque transmitted to the toque-strain bar, at least one angular position sensor, which is set inside the wrench body to detect a horizontal angle of the body and the tool head, at least one detection and processing circuit, which is arranged in the wrench body and connected to the torque sensor and the angular position sensor to convert detected torque and angle into digital torque and angle data for displaying or issuing an alarm and to transmit the torque and angle data in a bi-directional wireless manner, and at least one control receiver, which receives the torque and angle data from the detection and processing circuit for subsequent applications.

According to its title and abstract <CIT> relates to a system and method for optimizing a production process using electromagnetic-based local positioning capabilities. The system includes a handheld tool for executing steps of a sequence within a work cell. An electromagnetic marker connected to the tool emits a magnetic field within the cell. A receptor detects the magnetic field and generates a raw position signal in response thereto. A control unit updates an assembly setting of the tool. The host executes a control action when a position determined using the raw data is not equal to an expected position in the sequence. The method calculates the present position of a torque wrench using magnetic fields generated by the marker and measured by a receptor array, and calculates a present position of the tool or a fastener. The present position of the fastener may be compared to an expected position in the calibrated sequence, and the torque wrench may be disabled when the fastener position is not equal to the expected position.

According to its title and abstract <CIT> relates to a method for measuring torque measurement and generating a notifier, including searching for one or more wirelessly pairable load applying devices for applying a load to an object; displaying to a user those paired one or more load applying devices; responsive to selecting one of the displayed one or more load applying devices, receiving one or more of the group consisting of load measurements transmitted from the selected load applying device; and generating a notifier based on the proximity of the one or more of the group consisting of load measurements and torque measurements and a target value.

According to its title and abstract <CIT> relates to a torque wrench which comprises a handle, a wrench head having a ratcheting workpiece engaging portion, and a tensor beam defining a longitudinal axis and having a rectangular cross-section perpendicular to the longitudinal axis. A first strain gauge is coupled to one side of the tensor beam, and a second strain gauge is coupled to another side orthogonal to the one side. A processor coupled to the first and second strain gauges converts an output signal from one of the strain gauges into an equivalent torque value. The tensor beam is intermediate the handle and the wrench head and is rotatably coupled to the wrench head and is rotatable, with respect to the tensor beam, between a first position in which the processor processes an output signal from the first strain gauge and a second position in which the processor processes an output signal from the second strain gauge assembly.

According to its title and abstract <CIT> relates to a control and monitoring arrangement for "intelligent" tools which is preset with a reference value for at least one assembly parameter for each assembly operation by a control unit, and each of which signals the actual value measured by means of incorporated sensors in respect of said assembly parameter to the control unit which compares that measured value to the reference value. In the control unit a plurality of reference values and/or tolerance limits in respect of difference assembly tasks is stored. Each of the tools can be used without particular operating steps, in a freely selectable sequence, for different assembly tasks at different assembly locations. The arrangement has a recognition means which, for each assembly location at which an assembly task is to be carried out, generates a recognition signal for identifying the assembly location and/or the tool, when the tool moves into the area of the assembly location, the recognition signal being transmitted to the control unit and there serving to select the at least one reference value which is desired for the respective assembly task in question and/or the associated tolerance limits.

In one aspect of the invention there is provided a power tool in accordance with the appended claims.

The invention is capable of other embodiments and of being practiced or of being carried out in various ways in accordance with the appended claims.

<FIG> illustrates a battery-powered hand-held ratcheting torque wrench <NUM>. The wrench <NUM> includes a main housing <NUM> and a battery pack <NUM> attached to the main housing <NUM>. The battery pack <NUM> is a removable and rechargeable <NUM>-volt battery pack and includes three (<NUM>) Lithium-ion battery cells. In other constructions, the battery pack may include fewer or more battery cells such that the battery pack is a <NUM>-volt battery pack, an <NUM>-volt battery pack, or the like. Additionally or alternatively, the battery cells may have chemistries other than Lithium-ion such as, for example, Nickel Cadmium, Nickel Metal-Hydride, or the like.

The battery pack <NUM> is inserted into a cavity in the main housing <NUM> in the axial direction of axis A (<FIG>) and snaps into connection with the main housing <NUM>. The battery pack <NUM> includes a latch <NUM> (<FIG>), which can be depressed to release the battery pack <NUM> from the wrench <NUM>. In other constructions, the wrench <NUM> includes a cord and is powered by a remote source of power, such as an AC utility source connected to the cord. In another construction, the wrench <NUM> may be a pneumatic tool powered by pressurized air flow through a rotary air vane motor, not shown. In this construction, instead of the battery pack <NUM> and electric motor <NUM>, the wrench <NUM> includes a rotary air vane motor (not shown) and a connector (not shown) for receiving pressurized air. In other constructions, other power sources may be employed.

With reference to <FIG>, the wrench <NUM> includes a motor <NUM>, a motor drive shaft <NUM> extending from the motor <NUM> and centered about the axis A, and a drive assembly <NUM> coupled to the drive shaft <NUM> for driving an output assembly <NUM>. The output assembly <NUM> defines a central axis B substantially perpendicular to axis A, and will be described in greater detail below. As illustrated in <FIG> and <FIG>, the wrench <NUM> also includes an actuator, such as a paddle <NUM>, for actuating an electrical switch <NUM> to electrically connect the motor <NUM> to the battery pack <NUM>.

With reference to <FIG>, the drive assembly <NUM> includes a planetary geartrain <NUM> positioned between the motor <NUM> and the output assembly <NUM>, and located within a gear housing <NUM>. The planetary geartrain <NUM> includes a sun gear <NUM> coupled for co-rotation with the motor drive shaft <NUM>, a planet carrier <NUM>, three planet gears <NUM> rotatably supported upon the carrier <NUM>, and a ring gear <NUM> fixed within the gear housing <NUM>. Accordingly, torque received from the motor <NUM> is increased by the planetary geartrain <NUM>, which also provides a reduced rotational output speed compared to the rotational speed of the motor drive shaft <NUM>.

The drive assembly <NUM> also includes a multi-piece crankshaft <NUM> having an eccentric member <NUM>, which is described in further detail below, a drive bushing <NUM> on the eccentric member <NUM>, and two needle bearings <NUM> supporting the crankshaft <NUM> for rotation in the gear housing <NUM> and a head <NUM>, respectively, which is coupled to the gear housing <NUM>. With reference to <FIG> and <FIG>, the output assembly <NUM> includes a yoke <NUM> and an anvil <NUM> rotatably supporting the yoke <NUM> within the head <NUM>. The anvil <NUM> includes an output member <NUM> (<FIG>), such as a square head for receiving sockets. The output assembly <NUM> also includes a pawl <NUM> pivotably coupled to the yoke <NUM> by a pin <NUM> and a shift knob <NUM>. The yoke <NUM>, anvil <NUM>, and shift knob <NUM> are centered along the axis B. As shown in <FIG>, the output assembly <NUM> also includes a spring <NUM> and spring cap <NUM> supported for co-rotation with the shift knob <NUM>. To adjust the direction of rotation where torque is transferred though the output assembly <NUM>, the shift knob <NUM> is rotated between two positions, causing the pawl <NUM> to pivot about the pin <NUM> (through sliding contact with the spring cap <NUM>) between a first position where torque is transferred to the anvil <NUM> (by the yoke <NUM>) in a clockwise direction of rotation, and a second position where torque is transferred to the anvil <NUM> in a counterclockwise direction of rotation. A combination of at least the yoke <NUM> and anvil <NUM> may comprise a ratchet mechanism. The output assembly <NUM> further includes a detent (e.g., a ball <NUM>) and spring <NUM> biasing the ball <NUM> outward for retaining sockets on the output member <NUM>, as shown in <FIG>.

With reference to <FIG>, the head <NUM> is formed from steel as one piece and includes a cylindrical portion <NUM>, an adjacent shoulder portion <NUM>, and spaced first and second ears <NUM>, <NUM> between which the yoke <NUM> is received. The first ear <NUM> includes a first aperture <NUM> and the second ear <NUM> includes a second aperture <NUM>. The first and second apertures <NUM>, <NUM> are centered about the axis B. The yoke <NUM> is received between the first and second ears <NUM>, <NUM> in a direction perpendicular to axis B. The anvil <NUM> is received in the first and second apertures <NUM>, <NUM> and the shift knob <NUM> is received in the first aperture <NUM>. The first ear <NUM> includes an outer surface <NUM> facing away from the second ear <NUM>. The shift knob <NUM> is fully recessed within the first ear <NUM> such that the shift knob <NUM> does not cross a plane defined by the outer surface <NUM> and is positioned entirely on a side of the outer surface <NUM> on which the output member <NUM> is located, as can be seen by the cross section views of <FIG>. The outer surface <NUM> is opposite and facing away from the output member <NUM>.

As illustrated in <FIG>, the output assembly <NUM> of the wrench <NUM> includes a single-pawl ratchet design. The pawl <NUM> is disposed between the first and second ears <NUM>, <NUM>. The yoke <NUM> is oscillated between a first direction and a second direction about axis B by the eccentric member <NUM>. An inner diameter of the yoke <NUM> defined by an aperture includes teeth <NUM> (<FIG> and <FIG>) that mate with angled teeth <NUM> of the pawl <NUM> when the yoke <NUM> moves in the first direction. The yoke teeth <NUM> slide with respect to the angled teeth <NUM> of the pawl <NUM> when the pawl <NUM> moves in the second direction opposite the first direction such that only one direction of motion is transferred from the yoke <NUM> to the output member <NUM>. The shift knob <NUM> cooperates with the spring <NUM> and the spring cap <NUM> to orient the pawl <NUM> with respect to the pin <NUM> such that the opposite direction of motion is transferred from the yoke <NUM> to the output member <NUM> when the shift knob <NUM> is rotated to a reverse position. In other constructions of the wrench <NUM>, the output assembly <NUM> may alternatively include a dual-pawl design.

With reference to <FIG>, the wrench <NUM> further includes a transducer assembly <NUM> positioned inline and coaxial with the axis A, the motor <NUM>, and the head <NUM>. As explained in further detail below, the transducer assembly <NUM> detects the torque output by the output member <NUM> when the wrench <NUM> is manually rotated about axis B (with the motor <NUM> deactivated), and indicates to a user (via a display device) when the torque output reaches a pre-defined torque value or torque threshold. For example, the wrench <NUM> may include a light emitting diode (LED) <NUM> (<FIG>) for illuminating a workpiece during use of the wrench <NUM>. But, in response to a pre-defined torque value or torque threshold being reached when the wrench <NUM> is manually rotated about axis B, the LED <NUM> may flash to signal the user that the pre-defined torque value is reached.

With reference to <FIG> and <FIG>, the transducer assembly <NUM> is positioned between and interconnects the head <NUM> and the gear housing <NUM>. The transducer assembly <NUM> includes a frame <NUM> defining a first cylindrical mount <NUM> that receives a portion of the gear housing <NUM> and that is affixed thereto (e.g., by fastening), which in turn is attached to (or alternatively integral with) the housing <NUM>. The frame <NUM> also includes a second cylindrical mount <NUM> that receives the cylindrical portion <NUM> of the head <NUM> and that is affixed thereto (e.g., by fastening). The frame <NUM> further includes two beams <NUM> extending between the first and second cylindrical mounts <NUM>, <NUM>. In other embodiments as illustrated in <FIG>, a transducer assembly <NUM>, which is otherwise similar to transducer assembly <NUM>, may include a frame that is integrally formed with the head <NUM> such that the frame of the transducer assembly <NUM> and the head <NUM> are a single monolithic component.

With reference to <FIG> and <FIG>, the beams <NUM> are parallel and offset from the axis A such that an air gap <NUM> exists between the beams <NUM>. Also, the transducer assembly <NUM> includes one or more sensors (e.g., strain gauges <NUM>) coupled to each of the beams <NUM> for detecting the strain on each of the beams <NUM> in response to a bending force or moment applied to the beams <NUM>. The strain gauges <NUM> are electrically connected to a high-level or master controller of the wrench <NUM> for transmitting respective voltage signals generated by the strain gauges <NUM> proportional to the magnitude of strain experienced by the respective beams <NUM>, which is indicative of the torque applied to a workpiece (e.g., a fastener) by the output member <NUM> when the wrench <NUM> is manually rotated about axis B (with the motor <NUM> deactivated). Although the transducer assembly <NUM> includes two beams <NUM>, in other embodiments, the transducer assembly <NUM> may alternatively be formed with fewer or greater than two beams <NUM> and a corresponding number of strain gauges <NUM>. For example and with reference to <FIG>, transducer assembly <NUM> is formed with a single beam <NUM> and a single strain gauge <NUM> extending between the first and second cylindrical mounts <NUM>, <NUM>.

<FIG> illustrate yet another transducer assembly <NUM> usable with the torque wrench <NUM> of <FIG>. The transducer assembly <NUM> includes a frame <NUM> having two cylindrical mounts <NUM>, <NUM> and a beam <NUM> extending therebetween. Unlike the beams in the previously described transducer assemblies, the beam <NUM> is hollow and has a substantially square cross-sectional shape (<FIG>). As such, the beam <NUM> includes four walls 434a-d connected together at right angles, with each wall 434a-d having a wall thickness <NUM> of about one millimeter to about three millimeters. More specifically, the wall thickness <NUM> of each wall 434a-d is about two millimeters. The transducer assembly <NUM> also includes a strain gauge <NUM> on each of the walls 434a, 434b on an exterior surface thereof for detecting the strain on the beams <NUM>. In other embodiments, each of the walls 434a-d may include an associated strain gauge <NUM>. Because the beam <NUM> is hollow, an air gap <NUM> exists through which the crankshaft <NUM> extends.

<FIG> illustrate yet another transducer assembly <NUM> usable with the torque wrench <NUM> of <FIG>. The transducer assembly <NUM> includes a frame <NUM> having two cylindrical mounts <NUM>, <NUM> and a beam <NUM> extending therebetween. Similar to the beam <NUM>, the beam <NUM> is hollow but has a substantially tubular cross-section (<FIG>) rather than a square cross-section. The beam <NUM> has a wall thickness <NUM> of about <NUM> millimeters to about <NUM> millimeters. More specifically, the wall thickness <NUM> is about one millimeter. The transducer assembly <NUM> also includes two strain gauges <NUM> disposed on the exterior surface of the beam <NUM> and spaced apart <NUM> degrees from each other. In other embodiments, the beam <NUM> may include more than two strain gauges <NUM> that are spaced apart at various angular intervals. Because the beam <NUM> is hollow, an air gap <NUM> exists through which the crankshaft <NUM> extends.

With reference to <FIG> and <FIG>, the multi-piece crankshaft <NUM> includes a first shaft <NUM> having the eccentric member <NUM> at a front end thereof and a second shaft <NUM> having a rear end coupled for co-rotation with the carrier <NUM>. The first and second shafts <NUM>, <NUM> are coupled for co-rotation via a universal joint (i.e., U-joint <NUM>). Alternatively, a swivel spline or a flexible shaft, or another coupling that permits misalignment between the shafts <NUM>, <NUM> while also transmitting torque from the shaft <NUM> to the shaft <NUM>, may be used instead of the U-joint <NUM>. Furthermore, the shafts <NUM>, <NUM> may be integrally formed as a single flexible shaft. The U-joint <NUM> is disposed within the air gap <NUM> between the two beams <NUM> of the transducer assembly <NUM> to permit misalignment between the shafts <NUM>, <NUM> along the axis A when the beams <NUM> experience bending. Particularly, the U-joint <NUM> includes a socket <NUM> and a pin <NUM> that is received within the socket <NUM> such that the pin <NUM> is allowed to pivot within the socket <NUM>. As a result, the U-joint <NUM> permits the first shaft <NUM> to rotate about a longitudinal axis that is non-collinear with the axis A of the motor drive shaft <NUM>.

With reference to <FIG>, the wrench <NUM> also includes a display device <NUM> with which the transducer assembly <NUM> interfaces (i.e., through the high-level or master controller) to display the numerical torque value output by the output member <NUM> when the wrench <NUM> is manually rotated about axis B with the motor <NUM> deactivated. Such a display device <NUM> (e.g., a display screen) may be situated on the housing <NUM> and/or the gear housing <NUM>, or may be remotely positioned from the wrench <NUM> (e.g., a mobile electronic device). In an embodiment of the wrench <NUM> configured to interface with a remote display device, the wrench <NUM> would include a transmitter (e.g., using Bluetooth or WiFi transmission protocols, for example) for wirelessly communicating the torque value achieved by the output member <NUM> to the remote display device. With reference to <FIG>, the on-board display device <NUM> indicates the numerical torque value measured by the transducer assembly <NUM>. The wrench <NUM> also includes a visual indicator, such as an LED <NUM>, and an audible indicator, such as a buzzer <NUM>, that may work in conjunction with or separately from the LED <NUM> to indicate to a user when a pre-defined torque setting is reached. A user may also adjust the pre-defined torque settings using buttons <NUM> provided adjacent the display device <NUM>.

In operation of the wrench <NUM>, the user first sets a pre-defined torque value or setting using the buttons <NUM> and the feedback provided by the display device <NUM>. Subsequently, the user actuates the paddle <NUM>, which activates the motor <NUM> to provide rapid bursts of torque to the output member <NUM>, causing it to rotate, as the yoke <NUM> pivotably reciprocates about the axis A. In this manner, a fastener (e.g., a bolt or nut) can be quickly driven by the output member <NUM> to a seated position on a workpiece. After the fastener is seated on the workpiece, the user may release the paddle <NUM>, thereby deactivating the motor <NUM>. Alternatively, the control system of the wrench <NUM> may be configured to deactivate the motor <NUM> upon the fastener becoming seated on the workpiece without requiring the user to release the paddle <NUM>. In either case, when the motor <NUM> is deactivated, the transducer assembly <NUM> may remain active to measure the torque imparted on the output member <NUM> and the fastener in response to the wrench <NUM> being manually rotated about the axis B by the user. At this time, the output member <NUM> becomes effectively rotationally locked to the head <NUM> (and therefore the housing <NUM>) when the anvil <NUM> and connected pawl <NUM> back-drive the yoke <NUM> which, in turn, is unable to further back-drive the eccentric member <NUM> on the crankshaft <NUM>.

As the user applies a rotational force or moment on the wrench about axis B (with the motor deactivated), the beams <NUM> of the transducer assembly <NUM> undergo bending and therefore experience strain. The controller of the wrench <NUM>, which may be implemented as an electronic processor <NUM> (<FIG>), monitors the signals output by the strain gauges <NUM>, interpolates the signals to a torque value, compares the measured torque to one or more pre-defined values or settings input by the user, and activates the LED <NUM> (and/or the LED <NUM> to vary a lighting pattern of the workpiece) to signal the user of the wrench <NUM> that a final desired torque value has been applied to a fastener. The wrench <NUM> may also activate the buzzer <NUM> when the final desired torque value has been applied to a fastener to provide an audible signal to the user.

<FIG> is a block diagram of one embodiment of a power tool <NUM> communicating with a remote device <NUM>. In some embodiments, the power tool <NUM> is the ratcheting torque-wrench <NUM> described above. In other embodiments, the power tool <NUM> may be a different power tool such as a drill/driver, a hammer drill, or the like. The remote device <NUM> is, for example, a smart telephone, a laptop computer, a tablet computer, a desktop computer, or the like.

The power tool <NUM> includes a power supply <NUM>, a motor <NUM>, an inverter bridge <NUM>, an electronic processor <NUM>, a torque sensor <NUM>, a position sensor <NUM>, and a transceiver <NUM>. In some embodiments, the power tool <NUM> further includes the above-mentioned LED <NUM>, strain gauges <NUM>, display device <NUM>, buzzer <NUM>, and buttons <NUM>, which are electrically connected to the electronic processor <NUM> and operate as discussed above. The remote device <NUM> includes a device electronic processor <NUM>, a device memory <NUM>, a device transceiver <NUM>, and a device input/output interface <NUM>. The device electronic processor <NUM>, the device memory <NUM>, the device transceiver <NUM>, and the device input/output interface <NUM> communicate over one or more control and/or data buses (for example, a communication bus <NUM>). <FIG> illustrates only one example embodiment of a power tool <NUM> and a remote device <NUM>. The power tool <NUM> and/or the remote device <NUM> may include more of fewer components and may perform functions other than those explicitly described herein.

As described above, the power supply <NUM> may be a battery pack (e.g., battery pack <NUM>), an AC utility source, or the like. The motor <NUM> is, for example, an electric brushless DC motor (such as, the electric motor <NUM>) controlled by the electronic processor <NUM> through the inverter bridge <NUM>.

In some embodiments, the electronic processor <NUM> is implemented as a microprocessor with separate memory. In other embodiments, the electronic processor <NUM> may be implemented as a microcontroller (with memory on the same chip). In other embodiments, the electronic processor <NUM> may be implemented using multiple processors. In addition, the electronic processor <NUM> may be implemented partially or entirely as, for example, a field-programmable gate array (FPGA), an applications specific integrated circuit (ASIC), and the like and a memory may not be needed or may be modified accordingly. The device electronic processor <NUM> may be implemented in various ways including ways that are similar to those described above with respect to electronic processor <NUM>. In the example illustrated, the device memory <NUM> includes non-transitory, computer-readable memory that stores instructions that are received and executed by the device electronic processor <NUM> to carry out the functionality of the remote device <NUM> described herein. The device memory <NUM> may include, 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 types of memory, such as read-only memory and random-access memory.

The transceiver <NUM> enables wired or wireless communication between the power tool <NUM> and the remote device <NUM>. In some embodiments, the transceiver <NUM> is a transceiver unit including separate transmitting and receiving components, for example, a transmitter and a receiver. The device transceiver <NUM> enables wired or wireless communication between the remote device <NUM> and the power tool <NUM>. In some embodiments, the device transceiver <NUM> is a transceiver unit including separate transmitting and receiving components, for example, a transmitter and a receiver.

The device input/output interface <NUM> may include one or more input mechanisms (for example, a touch pad, a keypad, a button, a knob, and the like), one or more output mechanisms (for example, a display, a speaker, and the like), or a combination thereof, or a combined input and output mechanism such as a touch screen.

The torque sensor <NUM> is used to measure an output torque of the power tool <NUM>. In the example illustrated, the torque sensor <NUM> is a current sense resistor (e.g., a current sensor) connected in a current path of the power tool <NUM>. The torque sensor <NUM> therefore measures a motor current (which is directly proportional to the output torque) flowing to the motor <NUM> and provides an indication of the motor current to the electronic processor <NUM>. As illustrated, according to the present invention the power tool <NUM> includes both the torque sensor <NUM> providing a current-based torque measurement, and the strain gauges <NUM> providing a strain-based torque measurement. However, in some embodiments not covered by the present invention, one, but not both, of the torque sensor <NUM> and the strain gauges <NUM> are provided in the power tool <NUM> to provide torque measurement data to the electronic processor <NUM>.

The position sensor <NUM> is used to measure an absolute or relative position of the power tool <NUM>. In one example, the position sensor <NUM> is an inertial measurement unit including one or more of an accelerometer, a gyroscope, a magnetometer, and the like. The position sensor <NUM> may determine a position of the power tool <NUM> based on a dead reckoning technique. That is, the position sensor <NUM> may calculate a position of the power tool <NUM> by using a previously determined position, and advancing that position based upon readings from the accelerometer, the gyroscope, the magnetometer, etc..

<FIG> is a flowchart illustrating one example method <NUM> of determining peak torque for fastening operations of the power tool <NUM>. <NUM>, not covered by the present invention. As illustrated in <FIG>, the method <NUM> includes detecting that the power tool <NUM> is performing a fastening operation for a first fastener (at block <NUM>). The electronic processor <NUM> may determine that the power tool <NUM> is performing a fastening operation for a first fastener based on signals from the motor activation switch <NUM>, the position sensor <NUM>, and/or the torque sensor <NUM>. For example, the electronic processor <NUM> may determine that a fastening operation has begun when the electronic processor <NUM> receives an activation signal from the motor activation switch <NUM> in response to depression of the paddle <NUM> or when the electronic processor <NUM> receives a positive torque signal (for example, over an activation threshold) from the torque sensor <NUM>.

The electronic processor <NUM> may determine that the fastening operation is for the first fastener based on the position of the power tool <NUM> as indicated by the position sensor <NUM>. In some embodiments, the electronic processor <NUM> may assign a first position signal received from the position sensor <NUM> to the first fastener and store the first position corresponding to the first fastener. That is, the electronic processor <NUM> determines, based on an output from the position sensor <NUM>, that the power tool <NUM> is at a first location. The electronic processor <NUM> provides an indication that the power tool <NUM> is at a first location in response to determining that the power tool <NUM> is at the first location. For example, the electronic processor <NUM> may provide the indication to the remote device <NUM>, which displays that the power tool <NUM> is fastening a first fastener. Similarly, when the power tool <NUM> is moved to a second position, for example, to fasten a second fastener, the electronic processor <NUM> determines that the power tool <NUM> is at a second location and, in response, provides an indication that the power tool <NUM> is at the second location.

The method <NUM> also includes determining, using the torque sensor <NUM> of the power tool <NUM>, torque values for the fastening operation (at block <NUM>). The torque sensor <NUM> detects the output torque of the power tool <NUM> during the fastening operation. As described above, in some embodiments, the torque sensor <NUM> is a current sensor and provides an indication of a motor current to the electronic processor <NUM>. The electronic processor <NUM> determines the torque output of the power tool <NUM> based on the motor current reading.

The method <NUM> further includes recording, using the electronic processor <NUM> of the power tool <NUM>, the torque values for the fastening operation to generate recorded torque values for the fastening operation (at block <NUM>). The electronic processor <NUM> may receive torque values from the torque sensor <NUM>, for example, every <NUM> millisecond. The electronic processor <NUM> may record or store the torque values for the fastening operation corresponding to the first fastener. In some embodiments, as further described below, the torque values may only be recorded when the fastener starts moving (i.e., upon overcoming the static friction). The electronic processor <NUM> determines that the first fastener has started moving due to the fasting operation based on, for example, signals from the hall-sensor of the motor <NUM>. The recording of the torque values is started after the determination that the first fastener has started moving. In some embodiments, the torque values are recorded along with an indication of the identity of the fastener determined in block <NUM> (e.g., first fastener, second fastener, etc.), of the location of the fastener determined in block <NUM> (e.g., first location, second location, etc.), or both. In some embodiments, the data recorded in block <NUM> is stored in a memory of the power tool <NUM>, in the device memory <NUM> of the remote device <NUM> (after transmission from the transceiver <NUM> to the device transceiver <NUM>), or both.

The method <NUM> also includes determining a peak torque value from the recorded torque values, wherein the peak torque value corresponds to the fastening operation (at block <NUM>). The electronic processor <NUM> determines the peak torque value corresponding to the fastening operation from the recorded torque values for the fastening operation. That is, the electronic processor <NUM> may determine that the highest recorded torque value as the peak torque value for the fastening operation. The electronic processor <NUM> provides the peak torque value to the remote device <NUM>.

In some embodiments, in addition to or instead of the electronic processor <NUM>, the device electronic processor <NUM> may determine the peak torque value for the fastening operation from the recorded torque values. For example, the electronic processor <NUM> may provide the torque values for the fastening operation to the remote device <NUM> (e.g., as part of block <NUM>). The remote device <NUM> may store, in the device memory <NUM> or another coupled memory, the torque values received for the fastening operation of the first fastener corresponding to the first fastener. The torque values may be stored with the identity of the fastener, the fastener location, or both to correlate the torque values to the fastening operation of the first fastener. The device electronic processor <NUM> may then determine the peak torque value for the fastening operation from the recorded torque values.

At block <NUM>, the method <NUM> further includes providing an indication of the peak torque value that was determined in block <NUM>. For example, the electronic processor that performed the determination at block <NUM>, whether the electronic processor <NUM> or the device electronic processor <NUM>, outputs the peak torque value at block <NUM>. Providing the indication of the peak torque value may include, for example, displaying the peak value (e.g., on the display device <NUM> or a display of the device I/O interface <NUM>) to inform the user of the peak torque applied to the fastener during the fastener operation, stored in a memory of the power tool <NUM>, the device memory <NUM>, or another coupled memory (e.g., coupled to the remote device <NUM> via a network), or transmission of the peak torque value to another device. Transmission of the peak value may include transmission of the peak torque value from the power tool <NUM> via the transceiver <NUM> to the device transceiver <NUM> of the remote device <NUM>, or may include the remote device <NUM> transmitting the peak torque value to another device (e.g., coupled to the remote device <NUM> via a network).

In some embodiments, after providing the indication of the peak torque value at block <NUM>, the method <NUM> returns to block <NUM> to detect another fastening operation.

In some embodiments, the method <NUM> may further include determining that the fastening operation is completed when the peak torque value exceeds a predetermined torque threshold. The peak torque value is compared to the predetermined torque threshold to determine whether the peak torque value exceeds the predetermined threshold. When the peak torque value exceeds the predetermined torque threshold, the electronic processor <NUM> determines that the fastening operation is complete.

The method <NUM> may also include providing an indication that the fastening operation is completed in response to determining completion of the fastening operation. The electronic processor <NUM> may provide audio (e.g., buzz or beep), visual (e.g., lighting an LED), or a haptic (e.g., vibration feedback) signal to the user through the power tool <NUM> to indicate that the fastening operation was properly completed. In some embodiments, the electronic processor <NUM> stops an operation of the motor <NUM> in response to the indication that the fastening operation is completed.

In some embodiments, the electronic processor <NUM> may stop recording the torque values for the fastening operation when the power tool <NUM> is moved to a new (e.g., second) location. The electronic processor <NUM> determines, using the position sensor <NUM>, that the power tool <NUM> is moved to a second location. The electronic processor <NUM> stops recording torque values (for example, at block <NUM>) in response to determining that the power tool <NUM> is moved to the second location. In addition, the electronic processor <NUM> may provide the position information, the recorded torque values, and/or the peak torque information of the fastening operation to the remote device <NUM> in response to determining that the power tool <NUM> is moved to the second location.

In addition to recording torque values for the fastening operation, the electronic processor <NUM> also detects and records angular displacement of the fastener. The electronic processor <NUM> may measure the angular displacement based on signals received from a Hall-effect sensor unit of the motor <NUM>. The electronic processor <NUM> generates a torque-angle curve based on the recorded torque values and the recorded angular displacement of the fastener. The torque-angle curve illustrates a mapping between the angular displacement of the fastener and the torque output of the power tool <NUM>. <FIG> illustrates an example torque-angle curve <NUM> for the power tool <NUM>. The torque-angle curve <NUM> is useful in determining characteristics of the fastening operation or the fastener as described in detail below.

As can be seen in <FIG>, the torque-angle curve includes an initial torque spike <NUM>. In order to begin movement of the fastener, the power tool <NUM> first needs to overcome static friction, which, at least in part, causes the initial torque spike <NUM>. Once the fastener begins moving, the torque output of the power tool <NUM> drops and slowly rises as the fastener is tightened. The torque-spike <NUM> may mislead analysis of the torque-angle curve to determine characteristics of the fastening operation (e.g., the peak torque) or the fastener. Therefore, it may be helpful to remove the initial torque spike <NUM> from the torque-angle curve <NUM>.

<FIG> illustrates a torque-angle curve <NUM> with the torque spike <NUM> removed. In one example, the electronic processor <NUM> may remove the torque angle spike based on the angular displacement of the fastener. That is, the electronic processor <NUM> may only start recording the torque values when the angular displacement is detected. In another example, the electronic processor <NUM> may remove the torque spike <NUM> based on a slope analysis of the torque-angle curve <NUM>. That is, the electronic processor <NUM> may continuously determine a slope of the torque-angle curve <NUM> and remove the portion prior to detecting an abrupt change in slope. Several other techniques are available and can be contemplated by a person of ordinary skill in the art to remove the initial torque spike <NUM>.

The torque-angle curve <NUM> may be used to determine an attribute of the fastener (e.g., the first fastener). For example, the electronic processor <NUM> may determine a type of fastener based on the torque-angle curve. Each type (or kind) of fastener (e.g., a nut, a bolt, a screw, and different diameters, lengths, shapes and materials of each) has a particular torque-angle signature. During manufacturing and testing, torque-angle curves of different types of fastener can be determined by the power tool <NUM> manufacturer. These torque-angle signatures may be stored in a look-up table correlating the type of fastener to its torque-angle signature. During operation, determining the type of fastener is determined by comparing the torque-angle curve to the look-up table stored in a memory of the power tool <NUM> or in the device memory <NUM>.

As an example, the above-described features are useful when the power tool <NUM> is used to tighten a plurality of fasteners, for example, in an assembly line or other ordered assembly process. The power tool <NUM> provides torque values, a torque-angle curve, a peak torque value, and/or position information for each fastening operation to the remote device <NUM>. The remote device <NUM> may use the position information to determine which fastener is being tightened. For example, when the remote device <NUM> receives a position signal indicating that the power tool <NUM> is at a first position and further receives torque values along with or immediately after the position signal, the remote device <NUM> determines that power tool <NUM> is fastening a first fastener based on the position signal indicating that the power tool is at a first position and stores the torque values as corresponding to the fastening operation of the first fastener. Similarly, when the remote device <NUM> receives a position signal indicating that the power tool <NUM> is at a second position, and further receives torque values along with or immediately after the position signal, the remote device <NUM> determines that the fastening operation of the first fastener is completed, that the power tool <NUM> is fastening a second fastener, and stores the torque values as corresponding to the fastening operation of a second fastener. The remote device <NUM> uses the peak torque value and the torque-angle curve for each fastener and determines the type of fastener and whether the fastener was properly tightened. The remote device <NUM> may display an indication on the device input/output interface <NUM> indicating the type of fastener and whether the fastener was properly tightened. Based on this displayed information, the user may return to a particular fastener to re-tighten the fastener when the remote device <NUM> indicates that the particular fastener was not properly tightened.

Claim 1:
A power tool (<NUM>) comprising:
a motor (<NUM>) having a motor drive shaft (<NUM>);
a drive assembly (<NUM>) coupled to the motor drive shaft (<NUM>) and driven by the motor (<NUM>);
an output assembly (<NUM>) coupled to the drive assembly (<NUM>) and having an output member (<NUM>) that receives torque from the drive assembly (<NUM>), causing the output member (<NUM>) to rotate about an axis (B); and
a transducer assembly (<NUM>) disposed between the motor (<NUM>) and the output assembly (<NUM>) to measure the amount of torque applied through the output member (<NUM>), when the motor (<NUM>) is deactivated, in response to the power tool (<NUM>) being manually rotated about the axis (B), I
characterised in that the tool further comprises:
a torque sensor (<NUM>) configured to measure the amount of torque applied through the output member (<NUM>) when the motor (<NUM>) is activated; and
an electronic processor (<NUM>) that is electrically connected to the transducer assembly (<NUM>) and the torque sensor (<NUM>),
wherein in response to the amount of torque measured by the torque sensor (<NUM>) reaching a pre-defined torque setting when the motor (<NUM>) is activated, the electronic processor (<NUM>) deactivates the motor (<NUM>), the transducer assembly (<NUM>) remaining active to measure the amount of torque applied through the output member (<NUM>) while the motor (<NUM>) is deactivated and the power tool (<NUM>) is manually rotated about the axis (B).