Power tool and locking mechanism for manual torque application

Abstract

The invention relates to a motorized tool and a locking mechanism allowing the tool to be used for applying a manual load or torque. The motorized tool is provided with a direct drive mechanism. The tool comprises a driving lug, a motor and a locking mechanism. Wherein the drive lug is adapted to be actuated in a first rotational direction and a second rotational direction by a gear assembly; a motor adapted to drive the gear assembly to thereby drive the drive lug to apply a motorized torque; the locking mechanism is adapted to allow manual torque to be applied by the drive lug.

Description

Technical Field

[0001] The present invention relates generally to power tools and, more particularly, to locking a power tool to perform manual loading. Background Art

[0002] Power hand tools (such as, for example, power direct drive tools, power ratchets, impact wrenches, and other drivers) are commonly used in automotive, industrial, and household applications to install and remove threaded fasteners and to apply torque and / or angular displacement to a workpiece (such as, for example, a threaded fastener). Power hand tools typically include an output member (such as a drive lug or drive chuck), a trigger switch actuable by a user, an electric motor housed in a housing, and other components (such as, for example, a switch, a light emitting diode (LED), and a battery).

[0003] Traditional motorized ratchets utilize a switch located on the tool's head to select the direction of rotation of the tool's output. Because the switch is located on the head, changing direction can be challenging for the user without first removing the tool from the fastener. This is particularly challenging when the tool is engaged with the fastener in a confined space and the tool's head is not easily accessible to the user.

[0004] When using a powered direct-drive tool, you may want to apply a manual load to the workpiece while using the tool. For example, manual torque application offers the advantage of greater control over the amount of torque applied. However, manual torque application is not easy with traditional powered direct-drive tools because the drive lug rotates freely during manual torque application. Therefore, in order to manually apply torque with a powered torque tool, the drive lug must be rotationally locked. Summary of the Invention

[0005] The present invention generally relates to a gear system and locking mechanism for a power tool. The tool generally includes a tool housing, an output assembly (such as a direct drive mechanism with a drive lug) suitable for providing torque to a workpiece, a trigger, and a motor housed in the housing. The output assembly includes a gear assembly that connects the motor to the output assembly (such as a drive lug). The gear assembly includes spur gears, bevel gears and / or worm gear drives to produce the required gear ratios to meet the speed and torque requirements required by the output assembly. In one embodiment, the gear assembly includes a plurality of spur gears that are arranged to provide a low-profile power tool. The tool may include a switching trigger to allow control of the forward and reverse rotation direction of the motor; or the tool may include a single trigger with a separate switch to change the direction of the motor.

[0006] When using the tool, a trigger can be actuated to power the motor to rotate the drive lug, thereby applying torque to the workpiece in a motorized torque application mode. In order for a user to manually rotate the tool in a manual torque application mode to apply manual torque to the workpiece, the drive mechanism must be rotationally locked relative to the tool to prevent rotational motion. Otherwise, when manually applying torque to the workpiece, the gears would be back-driven and the motor would rotate, preventing any torque from being transmitted to the workpiece.

[0007] The present invention includes various embodiments that lock the transmission mechanism or otherwise prevent the drive mechanism from rotating relative to the tool so that the tool can be used to apply manual torque to a workpiece by a user manually rotating the tool in a manual torque application mode.

[0008] In one embodiment, the present invention includes a power tool comprising a drive unit and a motor having a motor shaft adapted to rotationally drive the drive unit. The power tool includes a gear assembly operably coupled to the motor shaft and the drive unit and adapted to transmit rotational motion of the motor shaft to the drive unit. The power tool also includes a locking mechanism adapted to selectively prevent rotation of at least one of the motor shaft, the gear assembly, and the drive unit to permit manual torque application via the power tool.

[0009] The locking mechanism can be any of a variety of types of locking mechanisms. For example, the locking mechanism can include a locking button that, when actuated, causes all high-side or low-side switching elements to be in an on state to prevent the motor shaft from rotating. The locking mechanism can include an electric brake that allows the motor shaft to rotate when power is supplied to the motor, and selectively prevents the motor shaft from rotating when power is not supplied to the motor. The locking mechanism can include a plate that can be moved between a locked position and an unlocked position, wherein when in the locked position, the plate prevents the motor shaft from rotating; and when in the unlocked position, the plate allows the motor shaft to rotate. The locking mechanism can include a locking lever that can be moved between a locked position and an unlocked position, wherein when in the locked position, the locking lever prevents the motor shaft from rotating; and when in the unlocked position, the locking lever allows the motor shaft to rotate. The locking mechanism can include a sprag clutch.

[0010] In another embodiment, the present invention includes a power tool comprising a drive portion and a motor having a motor shaft adapted to drive the drive portion. The power tool includes a gear assembly operably coupled to the motor shaft and the drive portion and adapted to transmit rotational motion of the motor shaft to the drive portion, wherein the gear assembly includes a worm gear coupled to the motor shaft and a spur gear meshingly engaged with the worm gear, and wherein the spur gear is unable to rotate the worm gear when a manual load is applied to the drive portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] To facilitate understanding of the claimed subject matter, embodiments thereof are shown in the accompanying drawings. By examining these embodiments, when considered in conjunction with the following description, the claimed subject matter, its construction and operation, and its many advantages should be readily understood and appreciated.

[0012] Figure 1 is a perspective view of an exemplary tool incorporating an embodiment of the present invention.

[0013] Figure 2 yes Figure 1 A side plan view of an exemplary tool.

[0014] Figure 3 According to one embodiment of the present invention Figure 1 and Figure 2 A perspective view of an exemplary tool showing the internal components of the tool head.

[0015] Figure 4 is an enlarged perspective view showing Figure 3 The internal components of the tool's head.

[0016] Figure 5 yes Figure 1 and Figure 2 A cross-sectional side view of the head of an exemplary tool.

[0017] Figure 6 According to one embodiment of the present invention Figure 1 and Figure 2 A perspective view of an exemplary tool showing internal components of the tool.

[0018] Figure 7 is a schematic diagram illustrating high-side switches and low-side switches for controlling a brushless DC motor according to one embodiment of the present invention.

[0019] Figure 8 is a perspective view of an exemplary tool according to another embodiment of the present invention showing interior portions of the tool.

[0020] Figure 9 is a perspective view of a head and motor of an exemplary tool according to another embodiment of the present invention.

[0021] Figure 10 is a cross-sectional view of an exemplary tool according to another embodiment of the present invention.

[0022] Figure 11 yes Figure 10 A cross-sectional view of the head of an exemplary tool.

[0023] Figure 12 is a perspective view of internal components of a head of an exemplary tool according to another embodiment of the present invention.

[0024] Figure 13 is a perspective view of internal components of a head of an exemplary tool according to another embodiment of the present invention.

[0025] Figure 14 According to one embodiment of the present invention Figure 13 An enlarged view of the sprag clutch of an exemplary tool.

[0026] Figure 15 According to one embodiment of the present invention Figure 14 Cross-section of a sprag clutch. DETAILED DESCRIPTION

[0027] Although the present invention is susceptible of embodiment in many different forms, a preferred embodiment of the invention is shown in the drawings and will be described in detail herein. It should be understood that this disclosure should be considered as an example of the principles of the invention and is not intended to limit the broad aspects of the invention to the embodiments shown. As used herein, the term "present invention" is not intended to limit the scope of the claimed invention, but is merely a term used to discuss exemplary embodiments of the invention for illustrative purposes.

[0028] The present invention generally relates to a gear system and locking mechanism for a power tool. The tool generally includes a tool housing, an output assembly (such as a direct drive mechanism having a drive lug) suitable for providing torque to a workpiece, a trigger, and a motor housed in the housing. The output assembly includes a gear assembly that connects the motor to the output assembly (such as the drive lug). The drive lug can engage with a tool extension (such as a sleeve that can engage with the workpiece). The gear assembly includes spur gears, bevel gears, and / or worm gear drives to produce the desired gear ratios to meet the speed and torque requirements required by the output assembly. In one embodiment, the gear assembly includes a plurality of spur gears that are configured to provide a low or slender profile for the power tool. The tool can include a toggle trigger to selectively reverse the direction of rotation of the motor; or the tool can include a single trigger with a separate switch to change the direction of the motor.

[0029] When using the tool, the trigger can be actuated to provide power to the motor to rotate the drive lug, thereby applying torque to the workpiece in a motorized torque application mode. In order to apply manual torque to the workpiece by manually rotating the tool by the user in a manual torque application mode, the transmission mechanism must be locked in place relative to the tool, otherwise the gears will be reversed and the motor will be rotated when manual torque is applied, thereby hindering the manual torque application to the workpiece. The present invention includes various alternative embodiments that can selectively or automatically rotate the locking transmission mechanism so that manual torque can be applied. Therefore, the present invention provides the ability to selectively use a power tool (such as the tool disclosed herein) in motorized or powered torque application (wherein torque is applied to the workpiece by a motor) or manual torque application (wherein torque is applied to the workpiece by manually rotating the tool by the user). This is beneficial, for example, when more manual control of torque application is required. The benefit of manual torque application is that torque application can be better controlled.

[0030] See also Figures 1 to 7 , shows a tool 100, such as a motorized direct-drive tool. The tool 100 includes a tool housing 102, an output assembly 104 (such as a direct-drive head assembly) operably coupled to the tool housing 102, a motor 106 disposed within the tool housing 102 and operably coupled to the output assembly 104, and a trigger 108 operably coupled to the motor 106 and actuatable to operate the motor 106 to operate the output assembly 104. In one example, the tool housing 102 can include a first housing portion 110 and a second housing portion 112 (forming a first side and a second side of the housing 102, respectively) that are coupled together in a clamshell manner and coupled to the output assembly 104. In another example, the tool housing 102 (including the first housing portion 110 and the second housing portion 112) can be a single, integrated or unitary piece.

[0031] The tool housing 102 may enclose or house the internal components of the tool 100, such as the motor 106, the switch assembly 114 (e.g., Figure 6 ), motor control electronics and / or a controller (which may be incorporated into the switch assembly 114 or separate), and power source components, such as terminals 116 adapted to be operably coupled to a battery (such as a rechargeable battery that may be housed within a battery receiving portion 118 of the tool housing 102). The tool may also include, for example, a display for configuring and setting the tool, one or more indicators (such as light emitting diodes), and other components for operating the tool. The tool housing 102 may also include a textured or knurled grip to improve the user's grip on the tool 100 during use.

[0032] The motor 106 is disposed and supported in the tool housing 102 and is operably coupled to the trigger 108 via the switch assembly 114. The motor 106 includes a motor shaft 120 (eg, Figure 5 ), the motor shaft is operably coupled to the output assembly 104, which will be described in further detail below. Thus, when the user actuates the trigger 108, the motor 106 is operated and rotates the output assembly 104 in the desired rotational direction.

[0033] The motor 106 can be a brushless or brushed type motor or any other suitable motor. A power source can be associated with the tool 100 to provide electricity or other forms of power (such as, for example, electric power, hydraulic power, or pneumatic power) to the tool 100 to operate the motor 106. In one embodiment, the power source (not shown) can be housed within a battery receiving portion 118 of the tool housing 102, opposite the output assembly 104, in the middle of the tool 100, or any other portion of the tool 100 / tool ​​housing 102. The power source can also be an external component that is not housed by the tool 100 but is operably coupled to the tool 100 by, for example, a hose, wired, or wireless means. In one embodiment, the power source is a removable and rechargeable battery that is adapted to be disposed within the battery receiving portion 118 of the tool housing 102 and electrically coupled to corresponding terminals 116 of the tool 100.

[0034] The output assembly 104 includes an output assembly housing adapted to house the components of the direct-drive mechanism, including a drive portion 122 and a gear assembly 124 operatively coupled to and adapted to drive the drive portion 122. In one embodiment, the output assembly housing includes a first output assembly housing portion 126 and a second output assembly housing portion 128. The components of the drive portion 122 and the gear assembly 124 can be assembled into the first output assembly housing portion 126, and the second output assembly housing portion 128 can serve as a cover and be coupled to the first output assembly housing portion 126 to house these components.

[0035] For example, the drive portion 122 may include a drive lug 130. The drive lug 130 is adapted to apply torque to a workpiece (such as a fastener) by means of an adapter, a drill bit, or a socket (such as a two-way ratchet square or hexagonal drive) coupled to the drive lug 130. As shown, the drive lug 130 is oriented at an angle of approximately 90 degrees relative to the longitudinal axis of the tool 100 and / or the tool housing 102 and is a square "male" connector designed to mate or match a female connector (such as a socket, for example). However, the drive lug 130 may be oriented at other angles relative to the longitudinal axis. Alternatively, the drive portion 122 may include a "female" connector designed to mate with a male connector. The drive portion 122 may also be configured to directly engage a workpiece without being coupled to an adapter, a drill bit, or a socket.

[0036] The gear assembly 124 operably couples the drive portion 122 to the motor shaft 120 and is adapted to transmit the rotational motion of the motor shaft 120 to the drive portion 122. Figures 3 to 6 The gear assembly 124 includes a first bevel gear 132 coupled to the motor shaft 120, a second bevel gear 134 meshing with the first bevel gear 132, and a plurality of spur gears adapted to transmit the rotational motion of the motor shaft 120 and the first and second bevel gears 132, 134 to the drive portion 122. In one example, the gear assembly 124 includes first to sixth spur gears 136, 146. However, it should be appreciated that more or fewer spur gears may be used depending on the application.

[0037] like Figure 5 As shown, first bevel gear 132 is disposed on motor shaft 120 and is rotatable therewith. First bevel gear 132 is further supported within first output assembly housing portion 126 by bearing 150. The inner diameter of bearing 150 engages the outer surface of the shaft portion of first bevel gear 132 (e.g., via an interference fit or press fit), and the outer diameter of bearing 150 engages the inner bearing surface of first output assembly housing portion 126 (e.g., via a clearance fit, interference fit, or press fit). First bevel gear 132 also includes gear teeth that meshingly engage with the gear teeth of second bevel gear 134.

[0038] Second bevel gear 134 and first spur gear 136 are coupled to and rotatable with first gear shaft 152. Second bevel gear 134 is coupled to and disposed adjacent a first end of first gear shaft 152, which is supported within first output assembly housing portion 126 by bearing 154. First spur gear 136 is coupled to and disposed adjacent a second end of first gear shaft 152, which is supported within second output assembly housing portion 128 by bearing 156.

[0039] Second spur gear 138 and third spur gear 140 are coupled to and rotatable with second gear shaft 158. Second spur gear 138 is coupled to and disposed near a first end of second gear shaft 158, which is supported within second output assembly housing portion 128; and third spur gear 140 is coupled to and disposed near a middle or second end of second gear shaft 158, which is supported within first output assembly housing portion 126. Second spur gear 138 is also aligned with and includes gear teeth that meshingly engage with the gear teeth of first spur gear 136.

[0040] Fourth spur gear 142 and fifth spur gear 144 are coupled to and rotatable with third gear shaft 160. Fourth spur gear 142 is coupled to and disposed near a first end of third gear shaft 160, which is supported within second output assembly housing portion 128; and fifth spur gear 144 is coupled to and disposed near a middle portion or second end of third gear shaft 160, which is supported within first output assembly housing portion 126. Fourth spur gear 142 is also aligned with the gear teeth of third spur gear 140 and includes gear teeth that meshingly engage with the gear teeth of third spur gear 140.

[0041] The sixth spur gear 146 is coupled to and rotatable with the fourth gear shaft 162, which is supported within the first output assembly housing portion 126. The sixth spur gear 146 is also aligned with the gear teeth of the fifth spur gear 144 and the gear teeth of the output gear portion 148 of the drive portion 122, and includes gear teeth that meshingly engage with the gear teeth of the fifth spur gear 144 and the gear teeth of the output gear portion 148 of the drive portion 122. Figure 5 As shown, the drive portion 122 is supported within the first and second output assembly housing portions 126 and 128 by bearings 164 and 166 , respectively, which are disposed on opposite sides of the output gear portion 148 , with the drive lug 130 extending from the first output assembly housing portion 126 .

[0042] The trigger 108 can be actuated by a user to selectively cause the power source to provide power; the trigger 108 is operable to cause the motor 106 to provide torque to the output assembly 104, thereby rotating the drive portion 122 / drive lug 130 in a desired rotational direction. The trigger 108 can also be operably coupled to the switch assembly 114, which is adapted to cause the power source to provide power to the motor 106 when the trigger 108 is actuated.

[0043] In one embodiment, the trigger 108 is a switching trigger that can rotate or pivot in a first switching direction and a second switching direction to cause the motor 106 to rotate the motor shaft 120, wherein the first switching direction drives the motor shaft 120 in a first motor direction (or first rotational direction) and the second switching direction drives the motor shaft 120 in a second motor direction (or second rotational direction). The rotational direction of the drive portion 122 / drive lug 130 can correspond to the motor direction, so the rotational direction can be selected by actuating the trigger 108 in the desired first switching direction or second switching direction. In addition, the trigger 108 and / or the switch assembly 114 can also include a variable speed mechanism. In this regard, when the trigger 108 is actuated, the further the trigger 108 is actuated, the faster the motor will operate.

[0044] In another example, the trigger 108 can be a linearly depressible trigger, wherein a user can depress the trigger 108 inward to selectively cause the power source to provide power and the motor 106 to provide torque to the output assembly 104 and rotate the drive portion 122 / drive lug 130 in a desired rotational direction. The trigger 108 can also be operably coupled to a switch assembly 114, which, when the trigger 108 is actuated, is adapted to cause the power source to provide power to the motor 106. The trigger 108 can also be biased outward relative to the tool housing 102, such that a user can depress the trigger 108 inward to operate the tool 100 and, by releasing the trigger 108, bias the trigger 108 outward relative to the tool housing 102 to deactivate the tool 100 due to the biasing properties of the trigger 108. The trigger 108 and the switch assembly 114 can also be a variable-speed mechanism. In this regard, when the trigger 108 is actuated or pressed, the motor will operate at a faster speed the further the trigger 108 is pressed. However, any suitable trigger 108 or switch may be implemented without departing from the spirit and scope of the present invention.

[0045] In one example, the motor 106 is a brushless DC (BLDC) motor, and the tool 100 includes motor control electronics and / or one or more controllers (which may be incorporated into the switch assembly 114 or separate) operably coupled to the motor 106 and adapted to control the motor 106. For example, see Figure 7The motor control electronics may include a printed circuit board (PCB) having one or more switching elements disposed thereon. The switching elements may be field-effect transistors (FETs), such as metal-oxide-semiconductor field-effect transistors (MOSFETs). In one embodiment, the switching elements may include three high-side switching elements H1, H2, and H3 and three low-side switching elements L1, L2, and L3, each of which may be operable in either a first state, or conducting state, or a second state, or non-conducting state. The switching elements are controlled by the PCB to selectively apply power from a power source (e.g., a battery pack) to the motor 106 to achieve the desired commutation. By selectively activating specific high-side and low-side switching elements, the motor control electronics or controller operates the motor 106 by sending current signals through coils located on the stationary portion of the motor 106, known as the stator. When current flows through the coils, the coils apply magnetic forces to the rotating portion of the motor 106, known as the rotor. The rotor contains permanent magnets that interact with the magnetic forces generated by the stator windings. By selectively activating successive combinations of high-side and low-side switching elements in a specific sequence to send a specific sequence of current signals through the windings of the stator, the stator generates a rotating magnetic field that interacts with the rotor, thereby causing the rotor to rotate, thereby causing the motor shaft 120 to rotate in a desired direction and at a desired speed in a well-known manner.

[0046] Thus, when the tool 100 is used in the motorized torque application mode, the trigger 108 is actuated, and the motor control electronics and / or one or more controllers rotate the motor shaft 120 in response to the actuation of the trigger 108, thereby rotating the first bevel gear 132. The first bevel gear 132 rotates the second bevel gear 134 and the first spur gear 136. The first spur gear 136 rotates the second spur gear 138 and the third spur gear 140. The third spur gear 140 rotates the fourth spur gear 142 and the fifth spur gear 144. The fifth spur gear 144 rotates the sixth spur gear 146, and the sixth spur gear 146 rotates the drive portion 122 / drive lug 130 and applies motorized torque to the workpiece.

[0047] However, the user may wish to apply a manual load or torque to the workpiece in a manual torque application mode by manually rotating the tool 100. In this case, the tool 100 includes a locking mechanism that locks the rotation of the drive mechanism (i.e., the drive portion 122 and / or the gear assembly 124) relative to the tool 100 to prevent the drive portion 122 and / or the gear assembly 124 from back-driving and rotating the motor shaft 120.

[0048] See also Figure 6In one embodiment, the tool 100 includes a locking mechanism in the form of a locking button 170 that is operably coupled to the motor control electronics and / or one or more controllers. When the user selectively depresses or otherwise actuates the locking button 170, the motor control electronics and / or one or more controllers activate all high-side switching elements (H1, H2, and H3), i.e., place all high-side switching elements in an on state. This causes the motor 106 to rotate, maintain, or lock the position of the rotor and / or motor shaft 120, and allows the tool 100 to be used in a manual torque application mode, in which the user can apply manual torque to the workpiece by manually rotating the tool 100. During manual loading or torqueing, the high-side switching elements (H1, H2, and H3) prevent the drive portion 122 and / or the gear assembly 124 from being backdriven.

[0049] Alternatively, when the user presses or otherwise actuates the lock button 170, the motor control electronics and / or one or more controllers activate all low-side switch elements (L1, L2, and L3), i.e., place all low-side switch elements in an on state. This causes the motor 106 to rotate to maintain or lock the position of the rotor and / or motor shaft 120 and allows the tool 100 to be used in a manual torque application mode, in which the user can apply manual torque to the workpiece by rotating the tool 100 by hand. During manual loading or torqueing, the low-side switch elements (L1, L2, and L3) prevent the drive portion 122 and / or the gear assembly 124 from being driven in reverse.

[0050] See also Figure 8In another embodiment, the tool 100 includes a locking mechanism in the form of an electric shutoff brake 270. The electric shutoff brake 270 can be operably coupled to the rear end of the motor shaft 120 and / or the rotor of the motor 106 located behind the motor 106, between the motor 106 and the switch assembly 114. Alternatively, the electric shutoff brake 270 can be operably coupled to the front end of the motor shaft 120 between the motor 106 and the gear assembly 124. The electric shutoff brake 270 can also be operably coupled to the trigger 108, the switch assembly 114, the motor control electronics, and / or the controller. When the trigger 108 is not actuated (i.e., the motor is not powered), the electric shutoff brake 270 is normally in a locked position and automatically locks the rotational position of the motor shaft 120, thereby locking the rotation of the drive section 122 and / or the gear assembly 124 relative to the tool 100. The electric shutoff brake 270 can mechanically clamp the friction material to the motor shaft 120 and / or the rotor of the motor 106 by means of spring clamping to rotationally retain and prevent the motor shaft 120 and / or the rotor from rotating, thereby allowing the tool 100 to be used in a manual torque application mode in which the user can apply manual torque to the workpiece by manually rotating the tool 100. During manual loading or torqueing, the electric shutoff brake 270 prevents the drive section 122 and / or the gear assembly 124 from being backdriven.

[0051] Once the trigger 108 is actuated, the tool 100 operates in the motorized torque application mode to apply motorized torque to the workpiece, and power is applied to the electric shutoff brake 270, thereby releasing the electric shutoff brake 270 (i.e., placing it in the unlocked position), for example, by means of a solenoid. When the electric shutoff brake 270 is released, the motor shaft 120 and / or the rotor of the motor 106 are allowed to rotate to apply motorized torque to the workpiece. When the trigger 108 is released, the electric shutoff brake 270 returns to its normal locked position, automatically locking the motor shaft 120 and / or the rotor to prevent rotation, and the tool 100 can be used again in the manual torque application mode, in which the user can apply manual torque to the workpiece by manually rotating the tool 100.

[0052] See also Figure 9In another embodiment, the tool 100 includes a locking mechanism in the form of a mechanical locking mechanism 370. The mechanical locking mechanism 370 includes a plate 372, a plate guide 374, a biasing member 376, and a hexagonal portion 378 that is coupled to or formed on the rear end of the motor shaft 120. The plate guide 374 can be a separate component that is disposed in the tool housing 102 behind the motor 106 and coupled to the tool housing 102 or formed directly within the tool housing 102. The plate guide 374 includes a first plate slot 380 and a second plate slot 382 that are adapted to receive first and second side portions of the plate 372, respectively, and to allow the plate 372 to slide within the first slot 380 and the second plate slot 382.

[0053] The plate 372 is slidably disposed in the first plate slot 380 and the second plate slot 382 and includes a locking hole 384 and a locking button 386 extending from one end of the plate 372. The locking button 386 is adapted to extend from the tool housing 102 when the mechanical locking mechanism 370 is assembled into the tool housing 102. The locking hole 384 includes a first hole portion 388 that receives the hexagonal portion 378 and is larger than the hexagonal portion 378, and a second hole portion 390 that is adapted to engage opposite sides of the hexagonal portion 378 when the hexagonal portion 378 is disposed in the second hole portion 390.

[0054] Biasing member 376 can be in the form of a spring or other type of biasing member. Biasing member 376 applies a biasing force to the end of plate 372 opposite locking button 386 to bias plate 372 in a first direction, thereby positioning hexagonal portion 378 within first aperture portion 388. When hexagonal portion 378 is positioned within first aperture portion 388, mechanical locking mechanism 370 is in an unlocked position. In the unlocked position, tool 100 can be used in a motorized torque application mode to apply a motorized torque to a workpiece.

[0055] However, when the user selectively depresses the locking button 386 to overcome the force of the biasing member 376, the plate 372 slides or moves along the first and second slots in the second direction so that the hexagonal portion 378 is disposed in the second hole portion 390. When the hexagonal portion 378 is disposed in the second hole portion 390, the edge of the plate 372 surrounding the second hole portion 390 engages the opposite side of the hexagonal portion 378 and prevents the motor shaft 120 and / or the rotor of the motor 106 from rotating, and the mechanical locking mechanism 370 is in the locked position. In the locked position, the motor shaft 120 is prevented from rotating, allowing the tool 100 to be used in the manual torque application mode, in which the user can apply manual torque to the workpiece by manually rotating the tool 100.

[0056] When the locking button 386 is released, the biasing member 376 biases the plate 372 in a first direction such that the hexagonal portion 378 is disposed within the first hole portion 388 , thereby placing the mechanical locking mechanism 370 in the unlocked position.

[0057] See also Figure 10 and Figure 11 In another embodiment, the tool 100 includes a locking mechanism in the form of a locking lever 470 and a biasing member 472. In this embodiment, the first bevel gear 132 is modified to include gear teeth 474 on the end of the shaft portion proximate the motor 106. The mechanical locking lever 470 includes locking teeth 476. When the locking lever 470 is set in the locked position, the locking teeth 476 engage the gear teeth 474 to prevent the gear assembly 124 and / or the motor shaft 120 from rotating, thereby allowing the tool 100 to be used in a manual torque application mode, in which the user can apply manual torque to the workpiece by manually rotating the tool 100.

[0058] Biasing member 472 can be in the form of a spring or other type of biasing member. Biasing member 472 applies a biasing force to locking lever 470 in a direction away from the trigger, disengaging locking teeth 476 from gear teeth 474. This places locking lever 470 in an unlocked position. In the unlocked position, tool 100 can be used in a motorized torque application mode to apply a motorized torque to a workpiece.

[0059] The locking lever 470 may include a tab 478 that can be selectively moved by a user in a direction toward the trigger 108 to move the locking lever 470 in the direction toward the trigger 108 and engage the locking teeth 476 with the gear teeth 474. When the locking teeth 476 are engaged with the gear teeth 474, the locking lever 470 is disposed in a locked position and prevents the gear assembly 124 and / or the motor shaft 120 from rotating, thereby allowing the tool 100 to be used in a manual torque application mode in which the user can apply manual torque to a workpiece by manually rotating the tool 100.

[0060] When tab 478 is released, biasing member 472 biases locking lever 470 in a direction away from the trigger to disengage locking teeth 476 from gear teeth 474 and place locking lever 470 in an unlocked position.

[0061] See also Figure 12In another embodiment, the tool 100 includes a locking mechanism in the form of a modified gear assembly, which includes a worm gear 570. The worm gear 570 includes a worm gear 572 coupled to the motor shaft 120 (instead of the first bevel gear 132 described above) and a spur gear 574 engagingly meshing with the worm gear 572 (instead of the second bevel gear 134 described above). In this embodiment, in the motorized torque application mode, the worm gear 572 transmits power through the gear assembly, which includes a plurality of spur gears (such as the first to sixth spur gears 136 to 146 described above) that are adapted to transmit the rotational motion of the motor shaft 120, the worm gear 572, and the spur gear 574 to the drive portion 122.

[0062] In this embodiment, the worm gear 572 provides a higher gear ratio in a smaller area compared to the bevel gears described above. The worm gear 572 also automatically prevents the motor shaft 120 from rotating during manual loading. The spur gear 574 is positioned at an angle of approximately 90 degrees relative to the worm gear 572, and the spur gear 574 cannot rotate the worm gear 572 during manual loading because the spur gear 574 does not provide sufficient rotational force to overcome the friction between the spur gear 574 and the worm gear 572. Thus, the worm gear drive 570 allows motorized torque to be applied to the workpiece by the tool 100, but also prevents the gear assembly and / or the motor shaft 120 from being backdriven, allowing manual torque to be applied to the workpiece by the user manually rotating the tool 100.

[0063] See also Figures 13 to 15In another embodiment, the tool 100 includes a locking mechanism in the form of a bidirectional sprag clutch 670. The bidirectional sprag clutch 670 can be disposed between the motor shaft 120 and the first bevel gear 132. The bidirectional sprag clutch 670 includes an input disc 672 and a driven disc 674. The input disc 672 includes two lugs 676 that push a pair of rollers 678 in either direction. These rollers prevent the sprag clutch 670 from locking and allow power to be transmitted to the transmission section 122 when the tool is used in a motorized torque application mode to apply motorized torque to a workpiece. However, when power is not supplied to the motor 106, the sprag clutch 670 automatically locks the gear assembly 124 to prevent rotation. For example, when the tool is used in a manual torque application mode to apply manual torque to a workpiece by the user manually rotating the tool 100, a manual load is applied to the sprag clutch 670 in either direction, and the plunger or spring 680 pushes the roller 678, respectively, thereby wedging the roller 678 against the inner bearing surface of the tool housing 102 or the first output assembly housing portion 126. The roller 678 locks the gear assembly 124 from rotating during manual torque application, and the sprag clutch 670 remains locked until the tool 100 is driven by a motor or a manual load is applied in the opposite direction.

[0064] Thus, the tool 100 can be used to apply torque to a workpiece in a motorized torque application mode by actuating the trigger 108 (which causes power to be supplied to the motor 106 to rotate the drive lug 130). The tool 100 can also be used to apply torque to a workpiece in a manual torque application mode by manually rotating the tool 100 by a user. As described herein, various locking mechanisms can be used to selectively rotate the locking drive mechanism so that manual torque can be applied to the workpiece. Thus, the present invention provides the ability to selectively use a power tool (such as the tool 100) in either motorized or powered torque application.

[0065] As used herein, the term "coupled" and its functional equivalents are not intended to be necessarily limited to a direct mechanical connection of two or more components. Rather, the term "coupled" and its functional equivalents are intended to refer to any direct or indirect mechanical, electrical, or chemical connection between two or more objects, features, workpieces, and / or environmental substances. In some instances, "coupled" is also intended to mean that one object is integral with another object. As used herein, unless otherwise specifically stated, the terms "a" or "an" may include one or more items.

[0066] The content set forth in the foregoing description and accompanying drawings is provided by way of example only and not limitation. Although specific embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of the inventor's contribution. The actual scope of protection claimed is intended to be defined by the following claims when viewed in their proper perspective based on the prior art.

Claims

1. A power tool comprising a drive portion and a motor, the motor having a motor shaft adapted to drive the drive portion, the drive portion adapted to engage a workpiece, the power tool comprising: a gear assembly operatively coupled to the motor shaft and the drive portion and adapted to transmit rotational motion of the motor shaft to the drive portion; as well as A locking mechanism is adapted to prevent rotation of at least one of the motor shaft, the gear assembly, and the drive portion to permit manual application of torque to the workpiece using the power tool.

2. The power tool according to claim 1, wherein: The motor is a brushless motor, and the locking mechanism includes a locking button, wherein when the locking button is actuated, all high-side switching elements or all low-side switching elements are in an on state to prevent the motor shaft from rotating, thereby allowing manual torque application.

3. The power tool according to claim 1, wherein: The locking mechanism includes an electric shutoff brake.

4. The power tool according to claim 3, wherein: The electric shutoff brake is operably coupled to the motor shaft, wherein the electric shutoff brake permits the motor shaft to rotate when power is supplied to the motor and prevents the motor shaft from rotating when power is not supplied to the motor to allow manual torque application.

5. The power tool according to claim 4, wherein: When power is not being supplied to the motor, the electric shutoff brake mechanically clamps the motor shaft to prevent rotation of the motor shaft, thereby allowing manual torque application.

6. The power tool according to claim 1, wherein: The locking mechanism includes a plate that is movable between a locked position and an unlocked position, wherein when the plate is in the locked position, the plate prevents the motor shaft from rotating to allow manual torque to be applied, and when the plate is in the unlocked position, the plate allows the motor shaft to rotate.

7. The power tool according to claim 6, wherein: The locking mechanism includes a biasing member adapted to bias the plate into the unlocked position.

8. The power tool according to claim 6, wherein: The plate includes a first hole portion and a second hole portion, and when the plate is in the unlocked position, the hexagonal portion of the motor shaft is disposed in the first hole portion and the plate allows the motor shaft to rotate; and when the plate is in the locked position, the hexagonal portion of the motor shaft is disposed in the second hole portion and the plate prevents the motor shaft from rotating to allow manual torque to be applied.

9. The power tool according to claim 1, wherein: the locking mechanism including a locking lever movable between a locked position and an unlocked position, wherein when the locking lever is in the locked position, the locking lever prevents rotation of the motor shaft to allow manual torque application; And when the locking lever is in the unlocked position, the locking lever allows the motor shaft to rotate.

10. The power tool according to claim 1, wherein The locking mechanism includes a sprag clutch.

11. The power tool of claim 1, further comprising a trigger that, when actuated, causes power to be supplied to the motor to rotate the motor shaft.

12. The power tool according to claim 11, wherein: The trigger is a switching trigger that is actuatable in a first switching direction and a second switching direction.

13. The power tool according to claim 12, wherein: When the switching trigger is actuated in the first switching direction, the motor rotates the motor shaft in a first rotational direction; and when the switching trigger is actuated in the second switching direction, the motor rotates the motor shaft in a second rotational direction.

14. The power tool according to claim 10, wherein: The sprag clutch is disposed between the motor shaft and the gear assembly.

15. A power tool comprising a drive portion and a motor, the motor having a motor shaft adapted to drive the drive portion, the power tool comprising: a gear assembly operably coupled to the motor shaft and the drive portion and adapted to transmit rotational motion of the motor shaft to the drive portion, wherein the gear assembly includes a worm gear coupled to the motor shaft and a spur gear meshingly engaged with the worm gear, and wherein the spur gear is unable to rotate the worm gear when manual torque is applied through the drive portion. 16 . The power tool according to claim 15 , further comprising a trigger that, when actuated, provides power to the motor to rotate the motor shaft, thereby rotating the drive portion.

17. The power tool according to claim 16, wherein: The trigger is a switching trigger that is selectively actuatable in a first switching direction and a second switching direction.

18. The power tool according to claim 17, wherein: When the switching trigger is actuated in the first switching direction, the motor rotates the motor shaft in a first rotational direction; and when the switching trigger is actuated in the second switching direction, the motor rotates the motor shaft in a second rotational direction.

19. The power tool according to claim 16, wherein: The motor is a brushless motor.

20. The power tool of claim 19, further comprising motor control electronics operably coupled to the motor and the trigger and adapted to control operation of the motor.

Images