Powered fastener driver

Abstract

A powered fastener driver has a motor, a biasing member configured to store a force for driving a fastener, a lifter configured to release the force, a piston configured to be urged by the force toward a bottom dead center position to drive the fastener into a workpiece, and a magnet coupled to the lifter for rotation with the lifter. The magnet is formed as a single piece comprising a first pair of poles and a second pair of poles, the first pair of poles comprising a first north face and a first south face, and the second pair of poles comprising a second north face and a second south face. The first north pole face is adjacent to the second south pole face, and the pole interface is defined between the first pair of poles and the second pair of poles. The sensor is configured to detect the pole junction. The controller is configured to control the motor based on the detection of the pole interface.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 359,534, filed July 8, 2022, the entire contents of which are incorporated herein by reference. Background Technology

[0003] This disclosure relates to power tools, such as power fastener actuators, and more specifically, to battery-powered power tools.

[0004] There are various power tools known in the art. For example, fastener actuators known in the art are used to drive fasteners (e.g., nails, flathead screws, U-shaped screws, rivets, etc.) into workpieces. These fastener actuators operate using various methods known in the art (e.g., compressed air generated by an air compressor, electrical energy, flywheel mechanisms, etc.), but these designs often face limitations in power, size, and cost. Utility Model Content

[0005] In one aspect, this disclosure provides a powered fastener actuator. The powered fastener actuator includes a motor, a lifter configured to rotate about a rotation axis via the motor, and a biasing member configured to store a force for driving the fastener. The lifter is configured to release the force. The powered fastener actuator also includes a piston and a magnet coupled to the lifter to rotate with the lifter, the piston being configured to be pushed to a lower dead center position by the force of the biasing member to drive the fastener into a workpiece. The magnet is formed as a single piece including a first pair of poles, the first pair of poles including a first north pole face and a first south pole face, and the single piece also includes a second pair of poles, the second pair of poles including a second north pole face and a second south pole face. The first north pole face and the second south pole face are adjacent. A pole junction is defined between the first pair of poles and the second pair of poles. The powered fastener actuator also includes a sensor configured to detect the pole junction and a controller configured to control the motor based on the detection of the pole junction.

[0006] In another aspect, the present disclosure provides a powered fastener driver including a motor, a contact trip configured to be movable from a first position to a second position in response to engagement with a workpiece, a biasing member configured to bias the contact trip toward the first position, and a magnet coupled to the contact trip for movement therewith. The magnet is formed as a single piece including a first pair of poles including a first north pole face and a first south pole face, and a second pair of poles including a second north pole face and a second south pole face. The first north pole face is adjacent to the second south pole face. A pole interface is defined between the first pair of poles and the second pair of poles. The powered fastener driver further includes a sensor configured to detect the pole interface, and a controller configured to deactivate the motor to prevent release of the fastener when the contact trip is in the first position based on detection of the pole interface.

[0007] In another aspect, the present disclosure provides a powered fastener driver including a motor, a lifter configured to be rotatable about an axis of rotation by the motor, and a drive biasing member configured to store a force for driving a fastener, the lifter being configured to release the force. The powered fastener driver further includes a piston configured to be pushed toward a bottom dead center position by the force of the drive biasing member to drive the fastener into a workpiece, a contact trip configured to be movable from a first position to a second position in response to engagement with the workpiece, and a trip biasing member configured to bias the contact trip toward the first position. A first magnet is coupled to the lifter for rotation therewith. The first magnet is formed as a first single piece including a first pair of poles, a second pair of poles, and a first pole interface between the first pair of poles and the second pair of poles. The powered fastener driver further includes a first sensor configured to detect the first pole interface, and a second magnet coupled to the contact trip for movement therewith. The second magnet is formed as a second single piece including a third pair of poles, a fourth pair of poles, and a second pole interface between the third pair of poles and the fourth pair of poles. The powered fastener driver further includes a second sensor configured to detect the second pole interface, and a controller configured to stop the motor based on a position of the first pole interface, and configured to deactivate the motor to prevent release of the fastener based on a position of the second pole interface.

[0008] Other features and aspects of the present disclosure will become apparent upon consideration of the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a perspective view of a powered fastener driver.

[0010] Figure 2 isFigure 1 A side view of the powered fastener driver, with some parts removed for clarity, showing the drive mechanism, launching mechanism, and lifting assembly.

[0011] Figure 3 yes Figure 1 Side view of the drive mechanism, launching mechanism, and lifting assembly of the power fastener driver.

[0012] Figure 4 yes Figure 3 A perspective view of the elevator assembly and the launch mechanism.

[0013] Figure 5 yes Figure 4 A perspective view of a portion of the elevator assembly shown.

[0014] Figure 6 yes Figure 5 A top view of a portion of the elevator assembly shown.

[0015] Figure 7 yes Figure 1 A top view of the power fastener driver in the first position of the contact trip unit.

[0016] Figure 8 yes Figure 1 A top view of the power fastener driver in the second position of the contact trip unit.

[0017] Figure 9 yes Figure 1 A perspective view of the power fastener actuator, showing the lift assembly and contact trip unit.

[0018] Figure 10 yes Figure 1 A plan view of the magnet in a power fastener driver.

[0019] Figure 11 yes Figure 10 Elevation view of the magnet. Detailed Implementation

[0020] Before providing a detailed description of any embodiment of this disclosure, it should be understood that this disclosure is not limited to its application in the construction details and component arrangements described below or shown in the accompanying drawings. This disclosure can be implemented or carried out in other ways and in various manners. Furthermore, it should be understood that the wording and terminology used in this application are for illustrative purposes only and should not be considered limiting.

[0021] Figure 1Powered tools are shown, such as a powered fastener driver 10 (e.g., a cable nailer) for driving fasteners 12 (e.g., U-shaped nails in a group of U-shaped nails) placed within a cartridge 14 into a workpiece. The powered fastener driver 10 can also be used to drive nails, flathead nails, rivets, or other types of fasteners into a workpiece. The driver 10 includes a nosepiece 18 that sequentially receives fasteners 12 from the cartridge 14 prior to each fastener driving operation. The nosepiece 18 includes a contact trip unit 20 that allows the driver 10 to operate in a single-shot mode. In some embodiments of the driver 10, the contact trip unit 20 may allow operation in a single-shot mode and / or an impact or burst mode. The driver 10 includes a housing 22 defining a head portion 26, a handle portion 30, and a battery socket portion 34 for receiving a battery pack 38. In the illustrated embodiment, the housing 22 is longitudinally divided into a first housing portion and a second housing portion at a dividing line 24. The driver 10 further includes a buckle 40 that is fixed to the housing 22 and adjacent to the battery socket portion 34.

[0022] Reference Figure 2 The driver 10 includes a trigger 42 that selectively powers a drive mechanism 46, which is enclosed within a handle portion 30 of the driver 10. The drive mechanism 46 includes an electric motor 50, a gearbox 54 that receives torque from the motor 50, and an output shaft 56 driven by the gearbox 54. In some embodiments, the motor 50 is a brushed DC motor that receives power from a battery pack 38. In some embodiments of the driver 10, the motor 50 may be configured as a brushless DC motor.

[0023] The powered fastener actuator 10 includes a launching mechanism 62 within a head portion 26 of a housing 22. The launching mechanism 62 is coupled to a drive mechanism 46 and is operable to perform fastener driving operations. The launching mechanism 62 includes a movable member (e.g., a piston 66) for reciprocating motion within the head portion 26, a biasing member (e.g., one or more compression springs 70, 72) disposed on the piston 66, and a component attached to the piston 66. Figure 4 The piston 66 and driver plate 74 within the head portion 26 are biased by a biasing member 70, which pushes the piston 66 and driver plate 74 to a driven position or bottom dead center (BDC) position to drive the fastener 12 into the workpiece. In the illustrated embodiment, the biasing member includes a pair of nested compression springs 70, 72 that act simultaneously to push the piston 66 and driver plate 74 to the BDC position.

[0024] The lifting assembly 58 is positioned between the drive mechanism 46 and the launching mechanism 62, and is operated by the drive mechanism 46 to overcome the bias of the bias member 70, causing the piston 66 and the driver plate 74 to return to the top dead center (TDC) position. During the drive cycle, the bias member 70 of the launching mechanism 62 pushes the driver plate 74 and the piston 66 from the TDC position to the bottom dead center (BDC) position to launch the fastener into the workpiece. The lifting assembly 58, driven by the drive mechanism 46, is operable to move the piston 66 and the driver plate 74 from the BDC position towards the TDC position, stopping before reaching the TDC position.

[0025] The intermediate preparatory position of the TDC position is used to prepare the launching mechanism 62 for subsequent fastener driving operations.

[0026] Now refer to Figure 2 and Figure 3 The actuator 10 further includes a primary guide member (e.g., primary guide post 80) and a secondary guide member (e.g., secondary guide post 82) that slidably support the piston 66. The secondary guide member slidably supports a bracket 86 coupled to move with the piston 66 and is spaced apart from the primary guide post 80. The secondary guide post 82 is positioned between the primary guide post 80 and the lifter assembly 58 and is configured to slidably support the bracket 86. Since the piston 66 and the bracket 86 are integrally formed as a single piece in the illustrated embodiment, both the primary guide post and the secondary guide posts 80, 82 slidably support the piston 66. In the illustrated embodiment, a primary guide axis 90 extends centrally through the primary guide post 80, and a second guide axis 94 extends centrally through the second guide post 82. The primary guide axis 90, the secondary guide axis 94, and the drive axis 78 are oriented parallel to each other and each transverse to the motor axis 76. The main guide post and the secondary guide posts 80 and 82 are each cylindrical posts, and each defines a guide surface without any threads so that the piston 66 can move freely along the main guide post and the secondary guide posts 80 and 82 in response to the rotation of the lifter assembly 58.

[0027] Now refer to Figure 4 The image shows in detail the lift assembly 58 and the piston 66. The piston 66 defines a first bore 116, a second bore 120 formed in the bracket 86, and a cavity 124. The first bore 116 is sized to receive and support the main guide post 80 along the main guide axis 90. Figure 3 The second hole 120 is sized to receive and support the secondary guide post 82 along the secondary guide axis 94. Figure 3 Cavity 124 surrounds the first hole 116 and is sized to receive bias member 70. Figure 3 In the illustrated embodiment, the bracket 86 is integrally formed with the piston 66. In other embodiments, the bracket 86 may be formed separately from the piston 66, and may be coupled to the piston 66.

[0028] The bracket 86 includes a first protrusion 98 and a second protrusion 102 vertically spaced from the first protrusion 98 along an axis 94. The first and second protrusions 98 and 102 each extend toward the lifter assembly 58. In the illustrated embodiment, the first protrusion 98 extends further from the bracket 86 (e.g., toward the lifter assembly 58) than the second protrusion 102. In other words, the first protrusion 98 is longer than the second protrusion 102. The lifter assembly 58 includes a first eccentric pin 104 and a second eccentric pin 108, which selectively engage one of the corresponding first and second protrusions 98 and 102 formed on the bracket 86 of the piston 66. In the illustrated embodiment, the second eccentric pin 108 extends further from the lifter assembly 58 (e.g., toward the bracket 86) than the first eccentric pin 104; therefore, the second eccentric pin 108 is sized to engage with the second protrusion 102. In other words, the second eccentric pin 108 is longer than the first eccentric pin 104. The construction of the lifter assembly 58 and the bracket 86 allows the piston 66 and the actuator plate 74 to be displaced from the BDC position to the TDC position in a single fastener drive cycle. Because the secondary guide post 82 is positioned adjacent to and close to the lifter assembly 58 (e.g., in the bore 120), the physical deflection of the bracket 86—and therefore the amount of bending stress borne by the bracket 86—is reduced as the piston moves toward the TDC position in the lifter assembly 58.

[0029] Continue to refer to Figure 2 and Figure 3 The fastener driver 10 includes a frame 112 coupled to a housing 22 for supporting a lifter assembly 58 and a first end of each of the main and secondary guide posts 80, 82. The frame 112 also defines a housing that serves as a component of a gearbox 54, in which a gear train (not shown) is located. In other words, the gearbox 54 is integrally formed on the frame 112. An output shaft 56 extends through an aperture in the frame 112, while the lifter assembly 58 is adjacent to and close to a vertical surface of the frame 112, which is oriented perpendicular to axis 76. An end cap 114 within the housing 22 supports opposing second ends of each of the main and secondary guide posts 80, 82. The end cap 114 includes a base 115. Figure 3The top of the spring 70 is mounted on the base 115. The frame 112 is constructed as a single component that supports the lift assembly 58 while allowing rotatable movement of the lift assembly 58, and rigidly supports the main guide post and secondary guide posts 80, 82 within the housing 22. In the illustrated embodiment, the frame 112 has a first portion positioned within the head portion 26 of the housing 22 and a second portion positioned within the handle portion 30. The construction of the frame 112 allows the launching mechanism 62 and the drive mechanism 46 to be assembled separately (e.g., as shown in the diagram). Figure 3 (As shown) and inserted into the housing 22. This allows for a more compact arrangement of the launching mechanism 62 and the driving mechanism 46, thereby reducing the overall size of the driver 10.

[0030] Now refer to Figure 2 The powered fastener actuator 10 includes a length L defined between the front end of the actuator 10 (e.g., the front end of the contact trip unit 20) and the rear end of the housing 22 (e.g., the head portion 26). The length L of the actuator 10 is less than or equal to 18 cm. In the illustrated embodiment, the length L is 16.5 cm. In some embodiments, the length L can be in the range of 12.5 cm to 18 cm. In some embodiments, the length L can be in the range of 12.5 cm to 16.5 cm.

[0031] Now refer to Figure 5 and Figure 6 The lifting assembly 58 includes an outer peripheral surface 130. Each of the eccentric pins 104, 108 is arranged close to the outer peripheral surface 130. Additionally, a first eccentric pin 104 is positioned at a first radial distance R1 relative to the axis of rotation of the lifting assembly 58 (i.e., the motor axis 76). A second eccentric pin 108 is positioned at a second radial distance R2, which is less than the first radial distance R1 of the first eccentric pin 104. Thus, the eccentric pins 104, 108 of the lifting assembly 58 are positioned at different radial distances R1, R2 relative to the axis 76. In other words, the eccentric pins 104, 108 are radially offset from each other.

[0032] Now refer to Figure 2As piston 66 moves from bottom dead center (BDC) to top dead center (TDC), the lifter assembly 58 rotates, causing the second eccentric pin 108 to engage with the second protrusion 102 of the support 86 of piston 66. Because the second eccentric pin 108 is positioned at a smaller second radial distance R2 than the first eccentric pin 104, the reaction torque exerted by spring 70 on motor 50 is smaller when piston 66 is stationary in a preparatory position between BDC and TDC. Additionally, because the first eccentric pin 104 is shorter than the second eccentric pin 108, only the second eccentric pin 108 can engage with the second protrusion 102 during rotation of lifter assembly 58. In other words, the first eccentric pin 104 has a first height, and the second eccentric pin has a second height greater than the first height.

[0033] For example, the lift assembly 58 is driven by the drive mechanism 46 to rotate in a first direction, causing the first and second eccentric pins 104 and 108 to engage sequentially with the first and second protrusions 98 and 102, thereby causing the piston 66 and the drive plate 74 to return from the BDC position to the TDC position. Since the radius R2 of the second eccentric pin 108 is smaller than the radius R1 of the first eccentric pin 104, the linear velocity of the second eccentric pin 108 is less than the linear velocity of the first eccentric pin 104 when the lift assembly 58 is rotated by the motor 50. Therefore, by returning the piston 66 to the TDC position more quickly...

[0034] At the TDC position, the higher linear velocity of the first eccentric pin 104 increases the firing speed, while the lower linear velocity of the second eccentric pin 108 reduces the reaction torque on the motor 50.

[0035] Reference Figures 7-8 The contact trip unit 20 is configured to respond to engagement with the workpiece from a first position ( Figure 7 Move to the second position. Figure 8 A biasing member 88, such as a spring, biases the contact trip unit 20 to a first position. In the illustrated embodiment, the biasing member 88 comprises a helical spring; however, other types of biasing members may be used, such as a resilient material, or other types of springs may be used. The contact trip unit 20 is configured to support the magnet 202 such that the magnet 202 is in the first position ( Figure 7 ) and the second position ( Figure 8The magnet 202 is fixedly movable relative to the housing 22 and together with the contact trip unit 20. The contact trip unit 20 may include a body 204 extending generally parallel to the drive axis 78 and a support portion 206 extending laterally and transversely to the body 204. The support portion 206 may extend generally perpendicular to the body 204, or in other embodiments at any angle. As shown, the support portion 206 may be arranged in a plane generally in the same plane as the body 204, or may be offset (or deviated) from the body 204 in a parallel plane spaced apart from the body 204, or in other embodiments, may be offset from the body 204 in a plane transverse to the body 204 (e.g., inclined relative to the body 204). The support portion 206 may be formed as a single unit with the body 204. The support portion 206 supports the magnet 202 such that the magnet 202 is fixedly movable together with the contact trip unit 20. The magnet 202 may have any suitable shape and is not limited to the generally rectangular shape shown in this application. The powered fastener driver 10 includes a sensor 222 configured to sense a magnet 202. For example, the sensor 222 senses the approach of the pole junction of the magnet 202 (described in detail below). The sensor 222 is fixedly supported relative to the housing 22. In other embodiments, the magnet 202 may be fixedly supported relative to the housing 22, and the contact trip unit 20 may be configured to support the sensor 222 so that the magnet 202 moves fixedly together with the contact trip unit 20.

[0036] It should be understood that magnet 202 and sensor 222 can be similarly arranged on any part of any power tool. The power fastener actuator 10 is one embodiment of a power tool and can be used to drive U-shaped fasteners, nails, flathead screws, rivets, or other types of fasteners into a workpiece. In any other type of power tool, such as, but not limited to, impact drills, impact wrenches, drills, vibratory tools, band saws, reciprocating saws, circular saws, miter saws, other saws, thread cutters, vacuum cleaners, rotary hammers, grinders, drum machines, ratchet machines, etc., magnet 202 can also be coupled to any movable component (movable between a first position and a second position relative to housing 22). The movable component includes any material piece movable relative to the housing of the power tool between the first and second positions. The material components may include rigid bodies that translate (e.g., slide) between a first position and a second position, rigid bodies that rotate, pivot, or sway between a first position and a second position, flexible bodies that bend between a first position and a second position, cantilever bodies that bend between a first position and a second position, tough bodies that elastically deform between a first position and a second position, and compressible bodies that elastically deform between a first position and a second position. The contact trip unit 20 is only one embodiment of a movable component. The sensor 222 provides the controller 234 with signals that can be used to control any aspect of the power tool. This application provides a control motor 50 as one embodiment. The control motor 50 may include enabling the motor, disabling the motor, stopping the motor, controlling the motor speed, controlling the motor direction, etc. In other embodiments, other functions of the power tool may be controlled, such as modes, signals, light, direction, speed, depth, distance, etc.

[0037] Sensor 222 is configured to sense the position of magnet 202, and therefore also sense the position of contact trip unit 20. For example... Figures 7-8The schematically shown controller 234 is configured to receive a signal from sensor 222 and control motor 50 in response to the signal. The signal indicates the position of magnet 202, and therefore also the position of contact trip 20. More specifically, controller 234 can be configured to deactivate motor 50 in response to a signal indicating that contact trip 20 is in a first position. Deactivating motor 50 can include disallowing motor 50 from being enabled (e.g., providing power) in response to trigger 42 being actuated. For example, power activation of motor 50 is prohibited even when trigger 42 is actuated. Deactivation of motor 50 is a safety function that prevents release of fasteners when nose member 18 is not engaged with workpiece. Controller 234 can be configured to allow motor 50 to be enabled when contact trip 20 is not in the first position, for example, when contact trip 20 is in a second position, which can include any desired position other than the first position. When contact trip 20 is sensed by sensor 222 as no longer in the first position, controller 234 can allow motor 50 to be enabled. In other embodiments, when the contact trip 20 is sensed to be in the second position by, for example, a second sensor (not shown, but structurally essentially the same as sensor 222 and arranged in a position suitable for sensing the magnet 202 in the second position), the controller 234 may allow the motor 50 to be activated. Simultaneously with allowing the motor 50 to be activated, actuation of the trigger 42 will provide power to the motor 50 to operate it. Therefore, when the nose 18 engages with the workpiece and the contact trip 20 is pressed to the second position (or simply to a position other than the first position), the motor 50 will be activated when the trigger 42 is actuated.

[0038] Reference Figures 10-11 Magnet 202 is a multipole magnet comprising two or more pairs of poles (e.g., see the first and second pairs of poles 224, 226 described below) and is formed as a single piece having two or more pairs of poles. Magnet 202 includes a north pole face 210 and an adjacent south pole face 214, respectively, from different pairs of poles. In the illustrated embodiment, the north pole face and the south pole face 210, 214 are coplanar, and the north pole face and the south pole face 210, 214 together define a plane P parallel to the drive axis 78. F ( Figure 11 The North Pole face 210 and the South Pole face 214 pass through the polar boundary perpendicular to the drive axis 78 (by plane P). D (Indicates) separation. Polar boundary P D Separate one pair of poles (e.g., the first pair 224) from another pair of poles (e.g., the second pair 226). The north and south pole faces 210 and 214 both face the printed circuit board (PCB) 216 parallel to the drive axis 78. Figure 9 ).like Figure 11As shown, magnet 202 includes a second south pole face 218 on the side of magnet 202 opposite to the north pole face 210, and a second north pole face 220 on the side of magnet 202 opposite to the south pole face 214. The orientation of the magnetic field lines in magnet 202 is generally parallel to the polar junction P. D More specifically, magnetic field lines extend from the north pole face 210 to the south pole face 218, defining the first pair of poles 224, and magnetic field lines extend from the north pole face 220 to the south pole face 214, defining the second pair of poles 226. The polarity of the magnetic field lines in the first pair of poles 224 is opposite to the polarity of the magnetic field lines in the second pair of poles 226.

[0039] More specifically, magnet 202 is formed as a piece comprising two or more pairs of poles (e.g., a first pair of poles 224 comprising a north pole face 210 and a south pole face 218, and a second pair of poles 226 comprising a north pole face 220 and a south pole face 214, and in some configurations may include any number of more pairs of poles magnetized into a single piece of magnet 202). Two or more pairs of poles 224, 226 are magnetized into the single piece of magnet 202. That is, unlike magnetizing each pair of poles 224, 226 into a separate magnet and fixing the magnets together, the single piece of magnet 202 is magnetized (e.g., double magnetization, triple magnetization, or quadruple magnetization, etc.) at the pole junction P during or after the formation of the entire single piece of material of magnet 202. D A shorter transition length L is formed at this point. T In other words, the transition length between the north pole face 210 and the adjacent south pole face 210 is smaller, resulting in a denser magnetic field line extending orthogonally to both the north pole face 210 and the south pole face 214 than the magnetic field line achieved by fixing two separately magnetized magnets together. Transition length L T It can be used as a plane P F The middle passes through the polar boundary P D The linear distance is measured. The transition length can be measured along a linear direction parallel to the direction of movement of magnet 202. This creates a unique pole junction P. D P, the polar boundary D This facilitates more precise signaling of the magnet 202 (and any movable member coupled to the magnet 202) according to this disclosure. Specifically, due to the linear transition length L between the north pole flux from the north pole surface 210 and the south pole flux from the south pole surface 214... T Surprisingly small, sensor 222 can sense the polar junction P within a narrower range of positions. D The precise location. (In other words, the signaling location is more precisely defined.) Therefore, any control function triggered by the position of magnet 202, or a control function dependent on the position of magnet 202, can be activated more precisely.

[0040] The single magnet 202 is also easier to arrange into the power tool 10 during assembly. In contrast, it can be difficult to place individual magnetized material pieces (i.e., individual magnets) close together during assembly due to the mutual repulsion and attraction between the electromagnetic forces between magnets. For example, the north pole face 210 and the south pole face 214 may tend to come together due to magnetic attraction, making it difficult to assemble (insert, or orient, or fix) the north pole face 210 adjacent to the south pole face 214 as described and illustrated in this application. Additional steps, processes, time, labor, and / or materials may be required to assemble multiple magnets close to each other. Therefore, cost savings can also be achieved by forming and magnetizing the magnet 202 into a single material piece with two or more pairs of poles.

[0041] When the trip unit 20 is in the first position ( Figure 7 When magnet 202 approaches sensor 222 on PCB 216, as described in further detail below, sensor 222 is configured to detect the presence of magnet 202 when contact trip 20 is in a first position. More specifically, sensor 222 detects the pole junction (by plane P) D (This is indicated) as further detailed below. When the contact trip unit 20 is in the second position ( Figure 8 When the magnet

[0042] 202 is separated from sensor 222. In the illustrated embodiment, sensor 222 is a Hall effect sensor. Sensor 222 may be a North Pole or South Pole Hall effect sensor. As briefly discussed above, in other embodiments, two or more sensors 222 may be used, such as one North Pole Hall effect sensor and one South Pole Hall effect sensor. The North Pole Hall effect sensor includes logic for filtering the desired polarity (in this case, North Pole). The South Pole Hall effect sensor includes logic for filtering the desired polarity (in this case, South Pole). Thus, one or more sensors 222 may be configured to send a signal to controller 234 based on the detected polarity (e.g., whether the voltage on the Hall effect sensor is positive or negative) and the detected magnitude. In contrast, a typical Hall effect sensor may only output magnitude and therefore cannot distinguish polarity. Therefore, a typical Hall effect sensor may not be able to detect the difference between North Pole and South Pole flux and thus cannot send a signal to controller 234 based on whether North Pole or South Pole flux is detected.

[0043] When the trip unit 20 reaches the first position ( Figure 7 When ), sensor 222 detects P at the pole junction. D The signal transmission position relative to sensor 222 has been reached. Specifically, sensor 222 has detected the polarity junction P. DThe signaling position has been reached because the detected polar flux has dropped to zero, which is due to the south pole magnetic flux from south pole 214 canceling out the north pole magnetic flux from north pole 210. In some embodiments, the signaling position is determined by the polar junction P. D The position of the magnet 202 is defined by its intersection with the center of the sensor 222. In other embodiments, the signal transmission position is defined by the position of the pole junction P. D The position of the magnet 202 is defined by the deviation from the center of the sensor 222, and takes into account the following factors: (1) the timing of the sensor 222 sending a signal to the controller 234; (2) the electronic logic delay of the controller 234 for interpreting the signal received from the sensor 222 to determine that the contact trip unit 20 has reached the first position; and (3) the speed at which the contact trip unit 20 moves toward the first position.

[0044] In response to a signal output by sensor 222 to controller 234 indicating that the detected polar flux has dropped to zero (e.g., a predetermined flux), controller 234 deactivates motor 50, thereby preventing further application of fasteners. Compared to a magnet with a single pole face (e.g., north pole) facing PCB 216 and sensor 222, sensor 222, having a north pole face 210 and a south pole face 214 facing PCB 216, can more accurately detect when the contact trip unit 20 reaches the first position by detecting when the polar flux drops to zero. Hall effect sensors that detect the single pole face of a magnet are more susceptible to changes in the detected magnetic flux based on the distance between the separated single pole face magnet and the Hall effect sensor. By more accurately determining when the contact trip unit 20 reaches the first position, potential damage due to overtravel is reduced throughout the mechanical stack.

[0045] Controller 234 can be configured to enable motor 50 in response to a signal from sensor 222, the signal corresponding to a non-zero flux value. The triggered non-zero value can be any value greater than zero, or it can be a predetermined non-zero value programmed into controller 234 to trigger the enabling of motor 50. In other embodiments, the triggered flux value can be provided by a second sensor (not shown, but discussed above). The triggered flux value can be zero flux, which corresponds to the polarity P detected by the second sensor. D It has reached the corresponding signaling position for the second sensor.

[0046] It should be understood that in other arrangements, alternative configurations may be employed, such as a North Pole and an South Pole face, along with sensors for detecting the North Pole Hall effect and / or sensors for detecting the South Pole Hall effect, to detect the polar boundary P at the signaling location based on flux intensity increasing from zero or decreasing towards zero. DIn some implementations, the magnet may include two or more pole junctions P. D For example, magnet 202 may include three, four, or any number of coplanar pole faces 210, 214 (e.g., north and south poles continuously alternating along the length of magnet 202), with pole faces 210, 214 defining a pole junction P between each pair of adjacent coplanar poles 210, 214. D At such a point P with multiple polar boundaries D In one implementation, a Hall effect sensor 222 capable of detecting the same pole (e.g., both detecting the North Pole or both detecting the South Pole, rather than one detecting the North Pole and the other the South Pole) can be arranged at a first position and a second position. In any implementation, the signal for disabling the motor 50 can be generated based on the flux intensity reaching (e.g., decreasing to or increasing to) a threshold that can be zero or non-zero, and can depend on whether the flux intensity has reached zero and subsequently increases.

[0047] Through including 210 and 214 (polar junction P) with the North Pole and South Pole faces. D A single magnet 202 (between the north and south poles 210, 214) and sensor 222 have a more precise sensing window for determining when the contact trip unit 20 reaches the first and / or second position. This allows controller 234 to control motor 50 more precisely, achieving advantages typically only available with conventional limit switches, while simultaneously increasing component lifespan, as the combination of magnet 202 and sensor 222 has a longer lifespan than conventional limit switches. In other embodiments, magnet 202 with north and south poles 210, 214 can be used in other applications and tools requiring a precise sensing window.

[0048] For example, in some embodiments, magnet 202' (schematically shown in) Figure 9 The sensor 222' and the sensor 222' can be coupled to the lift assembly 58, such as Figure 9As shown. Magnet 202' and sensor 222' are the same as those described in this application and therefore do not need to be described again. Refer to the description of magnet 202 and sensor 222 in this application. Magnet 202' and sensor 222' can be provided as additional or alternative components to magnet 202 and sensor 222. Sensor 222' is arranged on PCB 216' and is operatively coupled to controller 234 to send signals to controller 234. In the illustrated embodiment, magnet 202' can be coupled to lift assembly 58 to rotate with lift assembly 58, and sensor 222' can be arranged adjacent to lift assembly 58 and fixed relative to housing 22 to detect magnet 202' in the same manner as sensor 222 and magnet 202 described in this application. Magnet 202' can be coupled to the outer peripheral surface 130 of lift assembly 58 or to any other suitable surface of lift assembly 58. In other embodiments, magnet 202' may be arranged adjacent to lift assembly 58, and sensor 222' may be coupled to lift assembly 58.

[0049] More specifically, magnet 202' can be positioned such that sensor 222' detects an intermediate preparatory position of lift assembly 58 (as described above). In the intermediate preparatory position, spring 70 is at least partially loaded, and rotation of motor 50 is stopped. In the intermediate preparatory position, launching mechanism 62 is ready for subsequent fastener driving operation. Controller 234 is configured to stop rotation of motor 50 when lift assembly 58 reaches the intermediate preparatory position. Controller 234 can be configured to stop rotation of motor 50 in response to a signal from sensor 222'. At this moment in the drive cycle, lift assembly 58 is ready to drive fasteners in response to subsequent actuation of trigger 42 and to allow motor 50 to be activated (as described in this application, depending on the position of contact trip 20).

[0050] In other embodiments, a single magnet 202 with multiple pole pairs can be arranged on any part of any power tool. The position of the single magnet 202 can be sensed by a sensor 222 arranged on any part of any power tool. The controller 234 can be programmed to initiate any control scheme based on the position of the magnet 202 and / or the sensor 222.

[0051] During operation, the operator presses the nose 18 of the power fastener actuator 10 down onto the engaged workpiece, thereby pressing the contact trip 20 to move it from a first position to a second position. When the contact trip 20 is no longer in the first position (or, in some embodiments, the second position), the motor 50 is enabled when the operator actuates the trigger 42. When the operator releases the power fastener actuator 10 from the workpiece, the contact trip 20 returns to the first position under the bias of the bias member 88, and the motor 50 is deactivated, preventing the actuation of the trigger 42 from powering the motor.

[0052] In response to the actuation of trigger 42, motor 50 rotates in a drive cycle. Each drive cycle begins and ends with piston 66 and drive plate 74 in an intermediate preparatory position between the BDC and TDC positions, and can be closer to the TDC position as bias member 70 is at least partially loaded. To end a drive cycle, controller 234 stops the rotation of motor 50 in response to a signal from sensor 222'. When trigger 42 is actuated to begin a subsequent second drive cycle, lifter assembly 58 again rotates motor 50 past the TDC position, which releases bias member 70 and drives piston 66 and drive plate 74 toward the BDC position, causing drive plate 74 to move along drive axis 78 by spring force, thereby driving fastener 12 into the workpiece. After releasing bias member 70, lifter assembly 58 returns piston 66 to the intermediate preparatory position, ready for another subsequent drive cycle. Whenever sensor 222' detects that the lift assembly 58 is in the intermediate ready position, controller 234 stops the rotation of motor 50 and is configured to start the rotation of motor 50 in a new drive cycle when contact trip 20 is pressed and trigger 42 is subsequently actuated.

[0053] While this disclosure has been described in detail in conjunction with specific preferred embodiments, variations and modifications are possible within the scope and spirit of one or more independent aspects of this disclosure. For example, magnet 202 and sensor 222 can be used in other types of power tools to more accurately sense the position of any movable part therein.

[0054] Therefore, this disclosure provides a more accurate position sensing mechanism, wherein the position sensing mechanism employs a multipole magnet 202 and a sensor 222 configured to detect the pole junctions of the multipole magnet 202.

Claims

1. A power-driven fastener driver, characterized in that, include: motor; A lifter configured to rotate about a rotation axis via the motor; A biasing member configured to store a force for driving a fastener, wherein the lifter is configured to release the force; A piston configured to be pushed to a lower dead center position by the force of the biasing member to drive the fastener into the workpiece; A magnet coupled to the elevator to rotate together with the elevator, the magnet being formed as a single piece, the single piece including a first pair of poles, the first pair of poles including a first north pole face and a first south pole face, the single piece further including a second pair of poles, the second pair of poles including a second north pole face and a second south pole face, wherein the first north pole face is adjacent to the second south pole face, and wherein a pole boundary is defined between the first pair of poles and the second pair of poles; Sensor, the sensor being configured to detect the polar junction; and A controller configured to control the motor based on detection at the pole junction.

2. The power fastener driver according to claim 1, characterized in that, The polar junction is configured to be detected by the sensor when the elevator reaches the intermediate preparatory position, and the controller is configured to stop the motor in response to the elevator reaching the intermediate preparatory position.

3. The power fastener driver according to claim 1, characterized in that, The magnet is arranged on the outer periphery of the elevator.

4. The power fastener driver according to claim 1, characterized in that, The first north pole face and the first south pole face are each configured to face the sensor.

5. The power fastener driver according to claim 1, characterized in that, The sensor is either a North Pole Hall effect sensor configured to filter North Pole flux or a South Pole Hall effect sensor configured to filter South Pole flux.

6. The power fastener driver according to claim 1, characterized in that, The lifter includes a first eccentric pin and a second eccentric pin configured to selectively engage the piston, wherein the first eccentric pin is arranged at a first radial distance relative to the axis of rotation, wherein the second eccentric pin is arranged at a second radial distance relative to the axis of rotation, and wherein the first radial distance and the second radial distance are different from each other.

7. The power fastener driver according to claim 6, characterized in that, The first eccentric pin is shorter than the second eccentric pin.

8. A power-driven fastener driver, characterized in that, include: motor; A contact trip unit configured to move from a first position to a second position in response to engagement with a workpiece; A biasing member configured to bias the contact trip unit toward the first position; A magnet coupled to the contact trip unit for movement together with the contact trip unit, the magnet being formed as a single piece, the single piece including a first pair of poles, the first pair of poles including a first north pole face and a first south pole face, the single piece further including a second pair of poles, the second pair of poles including a second north pole face and a second south pole face, wherein the first north pole face is adjacent to the second south pole face, and wherein a pole boundary is defined between the first pair of poles and the second pair of poles; Sensor, the sensor being configured to detect the polar junction; and A controller configured to deactivate the motor to prevent release of the fastener when the contact trip is in the first position, based on detection at the pole junction.

9. The power fastener driver according to claim 8, characterized in that, The polarity junction is configured to be detected by the sensor when the contact trip unit is in the first position, wherein the controller is configured to deactivate the motor in response to the contact trip unit being in the first position.

10. The power fastener driver according to claim 8, characterized in that, The polarity junction is configured to be detected by the sensor when the contact trip unit is in the second position, wherein the controller is configured to allow the motor to be enabled in response to the contact trip unit being in the second position.

11. The power fastener driver according to claim 8, characterized in that, The first north pole face and the first south pole face are each configured to face the sensor.

12. The power fastener driver according to claim 8, characterized in that, The sensor is either a North Pole Hall effect sensor configured to filter North Pole flux or a South Pole Hall effect sensor configured to filter South Pole flux.

13. The power fastener driver according to claim 8, characterized in that, The contact trip unit includes a body extending generally parallel to the fastener drive axis and a support portion extending from the body, the support portion being configured to support the magnet such that the magnet moves fixedly together with the contact trip unit.

14. The power fastener driver according to claim 13, characterized in that, The supporting portion extends from the side of the main body.

15. The power fastener driver according to claim 8, characterized in that, The magnet includes a third pair of poles and the junction of the second poles.

16. A power-driven fastener driver, characterized in that, include: motor; A lifter configured to rotate about a rotation axis via the motor; A drive biasing member configured to store a force for driving a fastener, wherein the lifter is configured to release the force; A piston configured to be pushed to a lower dead center position by the force of the drive biasing member to drive the fastener into the workpiece; A contact trip unit configured to move from a first position to a second position in response to engagement with the workpiece; A trip unit biasing member, the trip unit biasing member being configured to bias the contact trip unit toward the first position; A first magnet is coupled to the elevator to rotate together with the elevator. The first magnet is formed as a first single piece, which includes a first pair of poles, a second pair of poles, and a first pole junction between the first pair of poles and the second pair of poles. A first sensor, configured to detect the first pole junction; A second magnet is coupled to the contact trip unit to move together with the contact trip unit. The second magnet is formed as a second unit, which includes a third pair of poles, a fourth pair of poles, and a second pole junction between the third pair of poles and the fourth pair of poles. A second sensor, configured to detect the second electrode junction; and A controller configured to stop the motor based on the position of the first pole junction and to deactivate the motor based on the position of the second pole junction to prevent the fastener from being released.

17. The power fastener driver according to claim 16, characterized in that, The controller further includes a trigger configured to actuate the motor, wherein the controller is further configured to stop the motor based on the position at the first pole junction when the first sensor detects that the elevator is in the intermediate preparatory position, and the controller is further configured to start rotation of the motor in a new drive cycle when the second sensor detects that the contact trip unit has left the first position and the trigger is subsequently actuated.

18. The power fastener driver according to claim 16, characterized in that, The first sensor is a North Pole Hall effect sensor configured to filter North Pole flux or a South Pole Hall effect sensor configured to filter South Pole flux, and the second sensor is a North Pole Hall effect sensor configured to filter North Pole flux or a South Pole Hall effect sensor configured to filter South Pole flux.

19. The power fastener driver according to claim 16, characterized in that, The lifter includes a first eccentric pin and a second eccentric pin configured to selectively engage the piston, wherein the first eccentric pin is arranged at a first radial distance relative to the axis of rotation, wherein the second eccentric pin is arranged at a second radial distance relative to the axis of rotation, wherein the first radial distance and the second radial distance are different from each other, and wherein the first eccentric pin is shorter than the second eccentric pin.

20. The power fastener driver according to claim 16, characterized in that, The contact trip unit includes a body extending generally parallel to the fastener drive axis and a support portion extending from the body, the support portion being configured to support the second magnet such that the second magnet moves fixedly together with the contact trip unit.

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