Power tool accessory

Abstract

Systems and methods are described that provide a power boost fastener assembly (130) configured for use with a detachable implement for a power tool. The power boost fastener assembly (130) can implement various gear train configurations to provide mechanical advantages for manual manipulation of the fastener assembly. The power boost fastener assembly (130) can include a lock mechanism that functions to lock and / or unlock the power boost fastener assembly and its fastening elements. In some examples, the power boost fastener assembly (130) can include a grip member assembly for facilitating manual application of torque. Additionally or alternatively, the power boost fastener assembly (130) can include a removable and replaceable outer surface cover configured to protect at least a portion of the power boost fastener assembly. The power boost fastener assembly (130) of the present embodiments can be used in place of a conventional lock nut for attaching a detachable implement to a power tool.

Description

[0001] Cross Reference to Related Applications

[0002] This application is a continuation-in-part of application number PCT / CN2021 / 089276, filed April 23, 2021, entitled “FORCE AMPLIFIED FASTENER FOR POWER TOOL IMPLEMENTS,” which application’s entire disclosure is incorporated herein by reference. TECHNICAL FIELD

[0003] The present invention relates generally to garden machines having detachable implements, and more particularly to fasteners usable with detachable implements for power tools. BACKGROUND

[0004] Power tools of various configurations are commonly used to perform routine tasks in daily life. For example, personnel engaged in work and leisure-related tasks use power tools in the form of garden machines, such as lawn mowers, brush trimmers, string trimmers, edgers, and the like, on a daily basis. These power tools typically include some form of motor (e.g., an electric motor or an internal combustion engine) that outputs power via a shaft, which drives an implement configured for the relevant task. As examples, a lawn mower can drive an implement in the form of a grass-cutting blade, a brush trimmer can drive an implement in the form of a multi-purpose cutting blade, a string trimmer can drive an implement in the form of a line in the form of a string spool head, and an edger can drive an implement in the form of an edging blade.

[0005] The implements can be configured to be detachable from the main power tool. For example, detachable implements can be utilized to permit selection of a configuration of the implement for a particular task (e.g., selectively installing a grass-cutting blade configured for mulching or trimming collection, etc.), and / or to facilitate replacement or repair of a damaged implement (e.g., removing a grass-cutting blade and re-installing it after sharpening a dulled edge, or replacing a dull grass-cutting blade with a sharp one, etc.).

[0006] Typically, one or more tools are required to replace (e.g., remove and / or install) a detachable implement. For example, a hand tool in the form of a wrench (e.g., an open-end wrench, a socket wrench, or an adjustable wrench) is required to replace the detachable implement, the hand tool being sized to engage a fastener (e.g., a locking nut assembly, such as a reusable nut with a lock washer, a disposable nyloc nut, etc.) that attaches the implement to a shaft assembly (e.g., a spindle) of the power tool. Additionally, a hand tool in the form of a brace or a second wrench is often required to prevent the shaft and implement from moving when the fastener that attaches the implement to the shaft assembly of the power tool is tightened or loosened to replace the detachable implement. As an alternative to a second hand tool, some implementations use a pin that can be manually pushed into an aligned hole to lock the spindle of the power tool. As another alternative to a second hand tool, such as can be implemented with a power tool that does not provide a reverse rotation operation, the shaft bearing of the power tool can be replaced by a one-way bearing that functions as a spindle lock.

[0007] In many situations, the fastener that attaches the implement to the power tool is placed in position with an appropriate torque (e.g., intentionally, such as to prevent unwanted relative displacement of the implement during use due to driving forces and / or impacts; or unintentionally, such as due to inertial tightening associated with application of driving forces). Accordingly, the wrench used to replace the detachable implement must have sufficient length and durability to permit sufficient force to be applied to the nut that fastens the implement to the garden machine, such as when loosening the implement.

[0008] Storing a hand tool suitable for replacing a detachable implement on or with the power tool is often difficult or impractical. For example, even where such a hand tool of a certain size and bulk can be provided in some form of storage space on the power tool, the often rough use, the presence of perceptible vibrations, etc. can cause the hand tool to be dislodged from its storage space and lost. Additionally, power tools with detachable implements are often operated in areas that are remote from repair facilities or from places where tools suitable for replacing detachable implements are conveniently or routinely stored. For example, a lawn mower, string trimmer, or edger can be operated in a home environment where the owner has very limited tool selection, and thus the operator can not have access to a hand tool of the appropriate size for replacing a detachable implement. In another example, a lawn mower or brush trimmer can be operated on a field or other large tract of land that is relatively remote from a tool supply, and while the operator can carry replacement cutting blades, the operator can still not have access to sufficient tools for replacing the cutting blades.

[0009] Typically, the removable implement cannot be removed and replaced by hand (e.g. without the aid of a separate tool) due to the force required. For example, as mentioned above, the fastener can already be in place with the appropriate torque, where a typical user can not be able to apply sufficient counter torque (e.g. approximately 12 Nm) to facilitate loosening of the fastener. Similarly, a user can typically not be able to apply sufficient torque to the fastener by hand to sufficiently seat the fastener, preventing unwanted relative displacement of the implement during use due to driving forces.

[0010] Various specially configured removable implements have been proposed to prevent unwanted relative displacement of the implement during use, even where the fastener is applied by hand without significant torque. For example, the blade holder of EP 2 798 937 B1, the disclosure of which is incorporated herein by reference, comprises two pins that protrude into corresponding openings in the blade to provide a rotational fixed connection with the blade. Such specially configured removable implements typically do not provide a backwards compatible solution. Furthermore, a lack of sufficient torque when applying the fastening means by hand to attach the specially configured blade to a lawnmower can not cause a frictional interface between the fastening means and the blade to prevent rotation of the fastening means in a release direction and disengagement from the lawnmower. Accordingly, EP 2 798 937 B1 proposes a latch for the fastening means. The proposed latch provides a manually operated latch element, where two levers are pivotably mounted on the blade holder and used to release the fastening means. The configuration of the latch element and levers on the blade holder exposes these components to objects encountered by the lawnmower, and / or objects propelled by impacting the rotating blade. For example, the design of the fastening means exposes the components to dirt that accumulates on the surfaces and clearances of the moving components, creating large friction between the relative movement of the components, such as can result in a greater required actuation force, or even loss of intended functionality. The design of the fastening means likewise exposes the components to various objects (e.g. rocks, gravel, branches of trees, etc.) that can impact the components of the fastening means with considerable force. As a result, the latch can suffer damage, or even functional failure, such as can result in the latch no longer being able to be manipulated by hand and / or the latch being accidentally released, enabling the fastening means to be detached from the lawnmower.

[0011] Specialized quick connect detachable implements have also been attempted. However, such detachable implements and / or their quick connect apparatuses have a number of drawbacks. For example, quick connect detachable implements typically utilize a specialized shank or shape design for torque transmission in place of the commonly used friction flange and nut design, thus not providing a backward compatible solution. In addition, many power tools, such as lawn mowers and brush trimmers, have high requirements for the impact forces that detachable implements (e.g., blades) can withstand as a result of striking other objects, which is often not satisfied by the solutions of quick connect detachable implements.

[0012] From the foregoing, it can be appreciated that existing solutions are often inadequate to facilitate the convenient replacement of detachable implements utilized for a variety of different power tools. For example, while implements have been configured for detachment and reattachment, replacing detachable implements is often inconvenient, and sometimes even impossible. Even where detachable implements can be replaced, doing so is often inconvenient (e.g., separate tools must be carried, forces must be applied that are sufficient to cause a user's hand to ache or become uncomfortable, etc.). SUMMARY

[0013] The present invention relates to systems and methods that provide power enhancing fastener assemblies configured for use with detachable implements for power tools. The power enhancing fastener assemblies of the present invention embodiments can implement gear trains configured for providing the mechanical advantages of manually manipulating (e.g., grasping by hand to manually apply tightening or loosening torque) the fastener assemblies. For example, various power enhancing gear train configurations can be used with the power enhancing fastener assemblies according to the concepts of the present invention to provide the necessary mechanical advantages.

[0014] According to present invention embodiments, a power enhancing fastener assembly can include a planetary gear arrangement disposed within a hand graspable housing to provide mechanical advantages in fastener tightening and / or loosening forces. Additionally or alternatively, the power enhancing fastener assemblies of embodiments can include a cycloidal gear arrangement disposed within a hand graspable housing to provide mechanical advantages in fastener tightening and / or loosening forces.

[0015] The force multiplier fastener assembly of embodiments of the present application can be used in place of a conventional lock nut for attaching a detachable implement to a power tool. For example, the force multiplier fastener assembly of embodiments can be used to secure a blade assembly to a host lawn care machine (e.g., a lawn mower, a bush trimmer, a lawn edger, etc.). However, it should be appreciated that the force multiplier fastener assembly provided in accordance with the concepts herein can be used in a wide variety of applications and with a variety of host power tool configurations, such as lawn care machines without blade implements (e.g., string trimmers) and / or other forms of power tools (e.g., woodworking saws). Regardless of the particular power tool configuration with which the force multiplier fastener assembly is used, the force multiplier fastener assembly of embodiments facilitates a user manually applying force by hand to loosen (e.g., release direction) and / or tighten (e.g., tightening direction) the fastener (e.g., to replace a detachable implement). For example, when used in a lawn mower, the force multiplier fastener assembly can be directly operated by hand (e.g., tool-less) to effect installation, removal, replacement, etc. of a cutting blade. Accordingly, the force multiplier fastener assembly of embodiments of the present application can provide a tool-less implement replacement mechanism in which replacing (e.g., installing, removing, replacing, etc.) a detachable implement with respect to a host power tool is facilitated without the aid of a separate tool.

[0016] The force multiplier fastener assembly of embodiments of the present application can include a lock mechanism that functions to lock and / or unlock the force multiplier fastener assembly and its fastening element. In operation in accordance with embodiments, the fastening element (e.g., a nut or other threaded fastening device) can be rotated by the force multiplier fastener assembly in a tightening direction to secure, install, tighten, etc. a blade or other detachable implement onto a motor shaft, where this rotation is reversible. That is, the fastening element can be rotated in a release direction opposite the tightening direction to loosen, release, etc. the blade or other detachable implement from the motor shaft. The lock mechanism of embodiments can lock the force multiplier fastener assembly such that the fastening assembly does not undesirably or accidentally release.

[0017] The lock mechanism of embodiments of the force multiplier fastener assembly can rely on user action to unlock and / or lock the lock mechanism. For example, a user can squeeze one or more members of the lock mechanism to unlock the operation of the lock mechanism to enable the force multiplier to rotate in a release direction, otherwise the force multiplier fastener assembly can only rotate in a tightening direction. The lock mechanism lever that is squeezed by the user to unlock the operation of the lock mechanism can directly or indirectly interact with the lock interface. For example, a button portion to receive user action (e.g., squeeze or press) can include a lever arm of the lock pawl of the lock mechanism that directly causes an unlock movement. In another example, a button portion to receive user action can include a member separate from the lock pawl of the lock mechanism and that indirectly causes an unlock movement (e.g., by engaging a lever arm of the lock pawl, by engaging a ring actuator that in turn engages the lock pawl, etc.).

[0018] Additionally or alternatively, the lock mechanisms of embodiments can be locked and / or unlocked in response to one or more forces other than from a user unlock / lock action. For example, the lock mechanisms of some embodiments can be locked and / or unlocked by centrifugal force (e.g., locked to prevent rotation in a release direction while the detachable implement is spinning), or by gravity when the power tool is arranged in a particular orientation (e.g., unlocked when the head of the power tool on which the detachable implement is secured is flipped upside down for user service). According to some examples, rotation of the detachable implement and corresponding power-up tightener assembly at a certain speed provides sufficient centrifugal force to cause a pawl of the lock mechanism in the power-up tightener assembly to engage and lock a tight component (e.g., a nut), thereby inhibiting rotation of the power-up tightener assembly and the tight component therein in a release direction. According to this example, when the power tool is stopped, a biasing spring can pull the locking pawl to a disengaged position, so the user can rotate the power-up tightener assembly and the tight component therein in a tight direction and / or a release direction. According to another example, a lock pawl of the lock mechanism of the power-up tightener assembly engages by gravity when the power-up tightener assembly is facing the ground (e.g., the host power tool is in a use orientation), and the locking pawl of the lock mechanism is released when the power-up tightener assembly is facing upward (e.g., the host power tool is in a service orientation).

[0019] The power-up tightener assemblies of embodiments of the present invention can include one or more features for facilitating user gripping and manually applying a tightening or loosening torque. For example, embodiments of the power-up tightener assemblies can include one or more retractable gripping members (e.g., flip-up handles that can be arranged in a stowed position and a use position) arranged on the power-up tightener assembly (e.g., on a surface within the tight / release rotation plane of the power-up tightener assembly) to facilitate user gripping and manually applying a tightening or loosening torque. The retractable gripping members of embodiments can be configured to cause the gripping members to remain in the stowed position during operation of the host power tool. Additionally or alternatively, according to further examples, embodiments of the power-up tightener assemblies can include surface features (e.g., rib structures, surface texturing, rubber overmolding, etc.) to facilitate gripping and applying force. Some embodiments can, for example, include a cap structure that includes rib structures and / or other surface texturing around the periphery of the structure to facilitate user gripping and manually applying a tightening or loosening torque.

[0020] Embodiments of the power-up fastener assembly can be used in relatively harsh environments and / or under other conditions that can subject the power-up fastener assembly or components thereof to abrasive wear, foreign matter intrusion, etc. For example, the power-up fastener assembly can be used relative to a bush hog, string trimmer, lawn mower, etc., and thus be in contact with a number of different abrasive surfaces (e.g., rock, concrete, sand, etc.) and / or potentially invasive materials (e.g., soil, dirt, sand, etc.). Accordingly, the power-up fastener assembly of some embodiments can include one or more removable / replaceable outer surface coverings for providing protection with respect to components of the power-up fastener assembly. According to some examples, a replaceable boot can be provided having a removable / replaceable outer surface covering some portions of the remainder of the power-up fastener assembly. Such a replaceable boot can have a protective surface to withstand wear due to operation of the host power tool in abrasive conditions. Additionally or alternatively, the replaceable boot can cover or enclose one or more areas of the power-up fastener assembly, thereby inhibiting foreign matter intrusion. The power-up fastener assembly of some embodiments can include a replaceable cap having a removable / replaceable outer surface to cover some portions of the remainder of the power-up fastener assembly and having a protective surface to withstand wear due to operation of the host power tool in abrasive conditions. The removable / replaceable outer surface structure (e.g., replaceable boot, replaceable cap, etc.) can include surface features (e.g., rib structure, surface texturing, rubber overmolding, etc.) that facilitate gripping and application of force.

[0021] The foregoing has outlined rather broadly the features and technical advantages of the present application so as to provide an overall understanding of the BRIEF DESCRIPTION OF DRAWINGS

[0022] For a more complete understanding of the present application, reference is now made to the following descriptions taken in conjunction with the accompanying drawings in which:

[0023] FIG. 1 A portion of a power tool is shown, a power-up fastener assembly being provided for the power tool in accordance with embodiments of the present application;

[0024] FIGS. 2A-2E Several different views of a force-amplifying fastener assembly implementing an exemplary planetary gear train according to an embodiment of the present invention are shown;

[0025] FIGS. 3A-3E Several different views of a force-amplifying fastener assembly implementing an exemplary cycloidal gear train according to an embodiment of the present invention are shown;

[0026] FIG. 4A Figure 4B FIG. 5A Figure 5B FIG. 6A Figure 6B FIGS. 7A-7F , FIGS. 8A-8E , FIG. 9A Figure 9B illustrates details of an exemplary locking mechanism for a force-enhancing fastener assembly according to an embodiment of the present invention;

[0027] FIGS. 10A-10C Several different views of the gripping component assembly according to embodiments of the present invention are shown; and

[0028] FIGS. 11A-11C and FIGS. 12A-12D Details of an exemplary removable / replaceable outer surface cover according to an embodiment of the present invention are shown. Detailed Implementation

[0029] FIG. 1 A portion of a power tool configured to utilize a detachable device is shown, wherein a force-enhancing fastener assembly according to embodiments of the invention is provided to facilitate the replacement (e.g., installation, removal, replacement, etc.) of the detachable device. The power tool 100 may include various configurations of motorized tools configured to perform one or more tasks using a corresponding configuration of the detachable device 120. For example, in some embodiments, the power tool 100 may include a garden machine in the form of a lawnmower or shrub trimmer, and the detachable device 120 may include cutting blades (e.g., low-lift / side-exhaust blades, cover blades, removal blades, brush blades, etc.). According to other embodiments, the power tool 100 and the detachable device 120 may include configurations such as: string trimmers and string reel heads, leaf blowers, cultivators, hedge trimmer blades and / or shrub trimmer attachments, lawn trimmers and trimming blades, woodworking saws and cross-cutting blades, coarse-tooth saw blades and / or grooving saw blades, etc.

[0030] exist FIG. 1In one example, the power tool 100 includes a motor assembly 110 that drives the detachable appliance 120. The motor assembly 110 in the embodiments may include various motor configurations. For example, some embodiments of the motor assembly 110 may include an electric motor powered by a battery, power line, solar collector, generator, etc., such as a direct current (DC) motor (e.g., a brushed motor, a brushless motor, etc.) or an alternating current (AC) motor (e.g., an induction motor, a synchronous motor, etc.). According to some embodiments, the motor assembly 110 may include an internal combustion engine powered by a combustible fuel source, such as a gasoline engine or a diesel engine.

[0031] like FIG. 1 As shown in the example, the shaft assembly of the motor assembly 110 is used to drive the detachable tool 120 during the operation of the power tool 100. Accordingly, in FIG. 1 In the example, the detachable device 120 is coupled to the first end of the shaft 111, which is shown passing through the body of the motor assembly 110. It should be understood that, although... FIG. 1 Not shown, but the shaft assembly may include structures other than shaft 111. For example, the shaft assembly of motor assembly 110 may include a mounting plate or liner attached to shaft 111 for mating with removable device 120. For example, the mounting plate or liner may be provided as a device that can prevent or suppress relative axial movement between the removable device and the shaft assembly (e.g., the mounting plate or liner may be configured to provide a clamping mating, thereby using clamping force to provide a frictional mating; and / or a form-fitting mating, thereby providing an interference fit using a structure that receives or extends into the device to prevent relative axial movement). As another example, the shaft assembly of motor assembly 110 may include a drive gear mechanism and / or a transmission (e.g., providing speed and / or direction control, increasing / decreasing rotational speed and / or torque, etc.). Accordingly, although FIG. 1 The example illustrates motor assembly 110 directly driving detachable device 120; however, according to embodiments, a gear train may be used between the output shaft of motor assembly 110 and detachable device 120. Regardless of the specific structure of the shaft assembly of motor assembly 110, detachable device 120 is removably coupled (e.g., directly or indirectly) to shaft 111 to receive power from motor assembly 110 during operation of power tool 100.

[0032] The power tool 100 can be used to perform a variety of tasks, such as cutting, drilling, driving, and the like. The power tool 100 can be used to perform these tasks by attaching a tool bit 120 to the power tool 100. The tool bit 120 can be attached to the power tool 100 by a fastener assembly 130. The fastener assembly 130 can be a power-assisted fastener assembly 130 that is configured to facilitate the manual (e.g., hand) application of force to loosen (e.g., release) and / or tighten (e.g., secure) the fastener assembly 130 to replace the tool bit 120.

[0033] By way of specific examples that assist in understanding the concepts of the present application, the power-assisted fastener assembly 130 of FIG. 1 the power-assisted fastener assembly 130 can be used in place of a blade for a bush-hog or lawn mower (e.g., a bush-hog or lawn mower configuration of the power tool 100 that implements a blade configuration tool bit 120). The manually actuated power-assisted fastener assembly 130 can loosen the fastener assembly and allow it to be removed from the shaft 111, thereby loosening the blade and facilitating its removal from the bush-hog or lawn mower. When attaching a new blade to the motor shaft, actuating the power-assisted fastener assembly 130 can tighten the fastener assembly on the shaft 111 to thereby attach the blade to the bush-hog or lawn mower.

[0034] The power-assisted fastener assembly 130 of the present embodiments implements a power-assisted gear train that is configured to provide the mechanical advantage of manually manipulating the fastener assembly. In operation of the power-assisted gear train of the power-assisted fastener assembly 130, the force (e.g., tightening torque applied in the tightening direction and / or loosening torque applied in the release direction) applied by the user to the power-assisted fastener assembly 130 (e.g., grasping the housing of the fastener assembly with the hand to manually apply the tightening or loosening torque) is increased as it is transmitted to the fastening element of the fastener assembly. In this way, the user can be able to apply a force to the rotation of the fastening element that is greater than the force that the user can directly apply to the fastening element.

[0035] Various force multiplication gear train configurations can be used with the force multiplication fastener assembly 130 of embodiments to provide the necessary mechanical advantage. According to some embodiments of the present application, the force multiplication fastener assembly 130 can include a planetary gear arrangement disposed within a hand graspable housing to provide mechanical advantage in fastener manual tightening and / or loosening forces. Additionally or alternatively, the force multiplication fastener assembly 130 of embodiments can include a cycloidal gear arrangement disposed within a hand graspable housing to provide mechanical advantage in fastener manual tightening and / or loosening forces. The mechanical advantage provided by such force multiplication gear train configurations of embodiments can provide, for example, a force amplification of approximately 3 to 15 times between the manual force applied to the housing of the fastener assembly and the corresponding force applied to the fastener element of the fastener assembly. Thus, the force applied to the fastener element (as amplified by the force multiplication fastener assembly 130 of embodiments) is sufficient to overcome the static force to seat the fastener element at the appropriate torque (e.g., intentionally to prevent unwanted relative displacement of the detachable implement during use due to driving forces and / or impacts; or unintentionally due to inertial tightening associated with the application of driving forces). Moreover, the force multiplication gear train configurations of embodiments of the present application facilitate the implementation of a reliable lock mechanism.

[0036] According to embodiments of the present application, the force multiplication fastener assembly 130 can be manually engaged by a user to fasten and / or unfasten the detachable implement 120 to / from the power tool 100 without the aid of a separate tool. Accordingly, the force multiplication fastener assembly 130 of embodiments can provide a tool-free implement change configuration.

[0037] Embodiments of the power tool 100 can be configured to facilitate the replacement of the detachable implement 120 using the power-up fastener assembly 130 without the aid of a separate tool. For example, the power tool 100 can include a motor shaft locking device 140 that functions in cooperation with the power-up fastener assembly 130 to facilitate the replacement of the power tool 100 relative to the detachable implement 120. According to some examples, the motor shaft locking device 140 can be engaged without the aid of a separate tool to prevent the shaft 111 from moving when the detachable implement 120 is attached to and / or removed from the shaft 111. For example, the motor shaft locking device 140 can include a pin that can be pushed into an alignment hole to lock the shaft 111 of the power tool 100. According to another example, the motor shaft locking device 140 can include a one-way bearing that functions as a reverse rotation lock for the shaft 111. According to yet another example, the motor shaft locking device 140 can include a lock collar configuration in which the locking collar includes a wide slot section and a narrow slot section that are configured to selectively allow and assemble rotation of the shaft 111. For example, in operation of the lock collar of some examples, when the shaft 111 is within the wide slot section, the shaft 111 and the locking collar do not interface and the shaft 111 is free to rotate. However, when the lock collar is slid laterally relative to the shaft 111, the shaft 111 is disposed within the narrow slot section such that the shaft 111 and the locking collar interface to inhibit rotation of the shaft 111 (e.g., a portion of the shaft 111 disposed adjacent to the locking collar can be provided with a square cross-section that is configured to cooperate with the narrow slot section of the locking collar to interface and inhibit rotation of the shaft 111 when the motor shaft locking device 140 is engaged).

[0038] According to some embodiments of the present disclosure, regardless of the specific configuration of the motor shaft locking device 140, the motor shaft locking device 140 can operate in cooperation with the power-up fastener assembly 130 to facilitate the attachment and removal of the detachable implement 120 to and from the motor shaft assembly of the power tool 100 without the use of additional tools. For example, an operator of the power tool 100 can install and / or remove the detachable implement 120 by engaging the motor shaft locking device 140 (e.g., by manual manipulation or automatic engagement) and manually manipulating to loosen or tighten the power-up fastener assembly 130.

[0039] It should be appreciated that embodiments of the power boost fastener assembly 130 herein can be used with or without additional configurations of the power tool 100 to facilitate replacement of the detachable implement 120. For example, some embodiments of the power boost fastener assembly 130 can be used without cooperation of a motor shaft locking device (e.g., a power tool 100 is implemented without the motor shaft locking device 140). In one example, a user can manually prevent rotation of the detachable implement 120 (e.g., by grasping a non-sharpened portion of a blade configuration of the detachable implement 120, such as a handle portion, with one hand) while manually manipulating the power boost fastener assembly 130 in a fastening direction with the other hand.

[0040] FIGS. 2A-2E and FIGS. 3A-3E Details of various embodiments of the power boost fastener assembly 130 are shown. In particular, FIGS. 2A-2E Details of embodiments of the power boost fastener assembly 130 are shown that implement a planetary gear configuration to provide mechanical advantages of manually manipulating the fastener assembly. Similarly, FIGS. 3A-3E Details of embodiments of the power boost fastener assembly 130 are shown that implement a cycloidal gear configuration to provide mechanical advantages of manually manipulating the fastener assembly. While a planetary gear configuration and a cycloidal gear configuration are shown in the illustrated examples, it should be appreciated that other forms of gear trains (e.g., a double reduction gear configuration, a reverse gear configuration, etc.) can be utilized in addition to or as an alternative to the planetary gear configuration and / or the cycloidal gear configuration. Moreover, multiple types of gear devices can be utilized in the gear train of some embodiments of the power boost fastener assembly 130 (e.g., a gear train configuration that includes a combination of planetary gear devices and cycloidal gear devices).

[0041] Referring first to FIGS. 2A-2E an example embodiment in which a planetary gear configuration is implemented. FIG. 2A and FIG. 2B A planetary gear configuration of an embodiment of the power boost fastener assembly 130 is shown when in an assembled state. As shown in the isometric top view of FIG. 2A the illustrated planetary gear configuration includes a top housing 210. Accordingly, as shown in the isometric bottom view of FIG. 2B the illustrated planetary gear configuration includes a bottom structure 220. It should be appreciated that while the views, housing, and structure are referred to as top and bottom, the designations are relative and there is no limitation on the example power boost fastener assembly being arranged or utilized in any particular orientation relative to the top and bottom. For example, when used with a lawnmower implementation of the power tool 100, the top housing 210 can be oriented to face downward when mounted on the shaft 111 and attaching the detachable implement 120 in the form of a grass shearing blade to the power tool 100.

[0042] The top housing 210 and the bottom structure 220 are configured to cooperatively enclose the planetary gear train and fastening element of the example force multiplier fastener assembly. For example, as can be seen in the exploded view of FIG. 2A, the top housing 210 can be formed as a cup-shaped outer shell that is sized and shaped to nest within the cup-shaped bottom structure 220. According to some examples, the top edge circumference of the bottom structure 220 can terminate at or very near the bottom-facing surface of the top housing 210 when fully nested within the top housing 210, such as to enclose components of the planetary gear train and provide a substantially closed area that inhibits penetration of debris and / or other matter. However, the nested relationship of the top housing 210 and the bottom structure 220 of the embodiments allows for relative rotational movement between the top housing and the bottom structure (e.g., the top housing 210 can be rotated while the bottom structure 220 nested within is held stationary). FIG. 2C and FIG. 2D As can be seen in the partially exploded view of FIG. 2B, the bottom structure 220 can form a cup-shaped structure that is sized and shaped to nest within the cup-shaped outer shell formed by the top housing 210. According to some examples, the top edge circumference of the bottom structure 220 can terminate at or very near the bottom-facing surface of the top housing 210 when fully nested within the top housing 210, such as to enclose components of the planetary gear train and provide a substantially closed area that inhibits penetration of debris and / or other matter. However, the nested relationship of the top housing 210 and the bottom structure 220 of the embodiments allows for relative rotational movement between the top housing and the bottom structure (e.g., the top housing 210 can be rotated while the bottom structure 220 nested within is held stationary).

[0043] According to example embodiments, the locking tabs 211a-d of the top housing 210 can facilitate the sliding of the bottom structure 220 into the cavity of the cup-shaped outer shell formed by the top housing 210, where the locking tabs hold the top housing and the bottom structure in a nested relationship once the bottom structure 220 is fully nested within the top housing 210. For example, the bottom structure 220 of the illustrated embodiment substantially closes the gap between the bottom edge circumference of the top housing 210 and the bottom edge circumference of the bottom structure 220 to facilitate the engagement of the locking tabs 211a-d of the top housing 210 with the bottom structure 220, thereby facilitating the holding of the top housing and the bottom structure in a nested relationship. Additionally or alternatively, this relationship of the bottom edge circumference of the top housing 210 and the bottom edge circumference of the bottom structure 220 can be configured to prevent the penetration of debris and / or other matter into the area enclosed by the top housing and the bottom structure.

[0044] The top housing 210 of the embodiments can be configured to facilitate manual manipulation by a user. For example, the top housing 210 can be sized and shaped to facilitate grasping by hand, such that a user can manually apply a torque force (e.g., torque in a fastening direction and / or a release direction) to the force multiplier fastener assembly 130. Additionally or alternatively, the top housing 210 can include surface features (e.g., rib structures, surface texturing, rubber overmolding, etc.) that facilitate grasping and application of force. For example, the illustrated embodiment of the top housing 210 includes rib structures 213a-d arranged around the circumference of the top housing, such as can be used to enable a user to grasp the force multiplier fastener assembly 130 and / or enhance the user's grasp thereof.

[0045] The bottom structure 220 of the illustrated embodiment is configured for accepting insertion of a drive member of a power tool, such as the shaft 111 of the power tool 100, to facilitate interfacing of the drive member with the fastening element of the power-up fastener assembly 130. For example, the shaft aperture 221 of the illustrated embodiment of the bottom structure 220 can be sized and shaped to permit insertion of one end of the shaft 111 therein. According to some examples, the shaft aperture 221 can be shaped or otherwise configured (e.g., including the undulating circumference of the illustrated embodiment, a square circumference, a hexagonal circumference, etc.) to interface with one or more components (e.g., the standoff 121 of the power-up fastener assembly 130, as can be disposed on the shaft 111) external to the power-up fastener assembly 130, such as to inhibit or prevent rotational movement (e.g., to avoid unwanted loosening of the fastening element due to inertial forces when the power tool is stopped or braked). FIG. 1

[0046] FIGS. 2A-2E The power-up fastener assembly 130 of the illustrated embodiment implements a planetary gear train configured for providing a mechanical advantage of applying a tightening or loosening torque to the fastening element 230 in response to manual manipulation (e.g., grasping by hand to manually apply a torque in a fastening direction or a loosening direction) of the fastener assembly. Accordingly, as shown in FIG. 2C the top housing 210 of the example embodiment includes a sun gear 212 of the planetary gear train in the illustrated planetary gear configuration of the power-up fastener assembly 130. As shown in FIG. 2D the bottom structure 220 includes a ring gear 222 of the example planetary gear train. In FIG. 2E the planetary gear assembly 240 (omitting some components of the example embodiment of the power-up fastener assembly 130) visible in the further exploded view includes planetary gears 242a-c that interface between the sun gear 212 and the ring gear 222 to provide an implementation of a planetary gear device. In particular, the planetary gear assembly 240 of the illustrated embodiment is received within a cavity of a cup-shaped structure formed by the bottom structure 220, with the planetary gears 242a-c being enclosed within an interior region of the top housing and the bottom structure and providing a geared interface between the sun gear 212 and the ring gear 222 once the bottom structure 220 is fully nested within the top housing 210.

[0047] ​According to embodiments, the sun gear 212 is attached to or formed as part of the top housing 210, while the ring gear 222 is attached to or formed as part of the bottom structure 220. Accordingly, when the top housing 210 is rotated (e.g., in response to a user manually applying a torque force thereto), the sun gear 212 of embodiments will correspondingly rotate. Similarly, the ring gear 222 rotates or does not rotate in correspondence with the bottom structure 220. The enclosed relationship of the planetary gear assembly 240 within the interior region of the bottom structure 220 nested within the top housing 210 allows for relative rotational movement of the gear plate 241 with respect to the top housing and the bottom structure. For example, the top housing 210 can rotate with the bottom structure 220 nested therein remaining stationary, and the gear plate 241 can rotate at a different speed than the top housing 210. That is, rotation of the top housing 210, and thus the sun gear 212 which is engaged with the planetary gears 242a-c, causes the planetary gears to rotate in opposition, with the planetary gears 242a-c engaged with the ring gear 222 which is held stationary by the bottom structure 220 causing the gear plate 241 to rotate in the direction of the top housing 210 / sun gear 212, albeit at a reduced rotational rate and with a greater torque force.

[0048] The planetary gear assembly 240 includes a fastener element housing 243 configured for accepting the fastener element 230 in coaxial correspondence with the shaft aperture 221. Accordingly, the fastener element housing 243 of the illustrated embodiment includes a shaft aperture 244 sized and shaped to permit insertion of one end of the shaft 111 therein, with the fastener element disposed within a receiving cavity 245 of the fastener element housing 243 can interface with the shaft 111. The illustrated embodiment of the fastener element housing 243 is sized and shaped to extend into and nest within the inner circumference of the sun gear 212 when the planetary gear assembly 240 is enclosed within the nested top housing and bottom structure. Accordingly, the fastener element 230 disposed within the receiving cavity 245 can be captured in the space between the fastener element housing 243 of the present embodiments and the top housing 210.

[0049] The fastener element housing 243 can be attached to or formed as part of the gear plate 241 of the illustrated embodiment. Accordingly, when the gear plate 241 is rotated, the fastener element housing 243 of the embodiment will correspondingly rotate. The receiving cavity 245 of the embodiment is configured to facilitate rotation of the fastener element 230 in correspondence with the gear plate 241. The fastener element 230 of the embodiment can comprise a nut or other threaded fastening device configured to be rotated on the drive member in a tightening direction and a loosening direction. For example, the illustrated embodiment of the fastener element 230 comprises a nut that is appropriately threaded onto an end of the shaft 111 of the power tool 100, such as can be used to secure, mount, tighten, etc. the detachable implement 120 onto the shaft 111. Accordingly, the receiving cavity 245 of the fastener element housing 243 of the illustrated embodiment is shaped to receive the fastener element 230 and provide control of its movement relative to the shaft 111. For example, the illustrated embodiment of the receiving cavity 245 comprises a hexagonal circumference to correspond to the shape of the exemplary nut implementation of the fastener element 230.

[0050] While FIGS. 2A-2E The fastener element 230 of the illustrated example is described as being disposed in the receiving cavity 245 of the fastener element housing 243 on the gear plate 241, it will be appreciated that other configurations of fastener elements can be utilized in accordance with embodiments of the present application. For example, instead of providing the fastener element 230 as a separate component (nut), some embodiments of the fastener element 230 can be integrally formed with another component of the power-up fastener assembly 130. As a particular example, the fastener element 230 can be formed as a suitably threaded portion of the shaft aperture 244 sized and shaped to correspond to the size and shape of an end of the shaft 111.

[0051] In FIGS. 2A-2E Operation of the power-up fastener assembly 130 of the embodiment, when the shaft 111 is inserted through the apertures 221 and 244 and interfaces with the fastener element 230, a user can manually grasp the top housing 210 and rotate it in a tightening direction or a loosening direction to correspondingly rotate the fastener element 230 relative to the shaft 111. The sun gear 212, the planet gears 242a-c, and the ring gear 222 of the planetary gear train provide a mechanical advantage of applying a tightening or loosening torque to the fastener element 230. A mechanical advantage corresponding to the size relationship between the sun gear 212 and the planet gears 242a-c (e.g., on the order of 3 to 5 times) can be realized between the torque manually applied to the top housing 210 and the resulting torque applied to the fastener element 230.

[0052] Having described embodiments of the power-up fastener assembly 130 implementing a planetary gear train, reference is now made to FIGS. 3A-3E an exemplary embodiment in which a cycloidal gear configuration is implemented. FIG. 3A andFIG. 3B An embodiment of the cycloidal gear configuration of the force multiplier assembly 130 is shown in its assembled state. As shown in the isometric top view of FIG. 3A the illustrated cycloidal gear configuration includes a top housing 310. Accordingly, as shown in the isometric bottom view of FIG. 3B the illustrated cycloidal gear configuration includes a bottom structure 320. It should be appreciated that while the views, housings, and structures are referred to as top and bottom, the designations are relative and there is no limitation on the exemplary force multiplier assembly being arranged or utilized in any particular orientation relative to top and bottom. For example, when used with a lawnmower implementation of the power tool 100, the top housing 310 can be oriented to face downward when mounted on the shaft 111 and attaching the detachable implement 120, which will be in the form of a grass-cutting blade, to the power tool 100.

[0053] The top housing 310 and the bottom structure 320 are configured to cooperatively enclose the cycloidal gear train and fastening element of the exemplary force multiplier assembly. For example, as can be seen in the partially exploded view of FIGS. 3C-3E the bottom structure 320 can form a cup-shaped structure sized and shaped to nest within a cup-shaped enclosure formed by the top housing 310. According to some examples, the top edge circumference of the bottom structure 320 can terminate at or very near the bottom-facing surface of the top housing 310 when fully nested within the top housing 310, such as to enclose components of the cycloidal gear train and provide a substantially closed area that inhibits penetration of debris and / or other matter. The nested relationship of the top housing 310 and the bottom structure 320 of the embodiment allows for relative rotational movement between the top structure and the bottom structure (e.g., the top housing 310 can rotate while the bottom structure 320 nested within it remains stationary).

[0054] As can be seen in the isometric top view of FIGS. 3A-3E the exemplary cycloidal gear configuration of the force multiplier assembly 130 includes a bottom housing 301 configured to enclose components of the gear train and / or a locking mechanism used therewith within the cup-shaped structure of the top housing 310. The bottom housing 301 of the illustrated example includes a substantially planar bottom housing that can be attached to the top housing 310 by various fastening means (e.g., screws, adhesives, welding, locking tabs, etc.) to enclose some or all of the area within the concave surface of the top housing cup-shaped structure. For example, the bottom structure 320 can be enclosed by the bottom housing 301 with at least a portion of the bottom structure 320 disposed within the concave surface of the top housing cup-shaped structure. According to embodiments of the present invention, the bottom structure 320 is free to rotate axially relative to the top housing 310 and the bottom housing 301 attached to the top housing 310.

[0055] In the illustrated example, the size of the bottom structure 320 is designed to provide clearance relative to components of an embodiment of the lock mechanism (described in detail below). The configuration of the bottom housing 301 can provide a skirt flange and / or other structure to substantially enclose the gap between the bottom edge circumference of the top housing 310 and the bottom edge circumference of the bottom structure 320, thereby preventing debris and / or other matter from penetrating into the area of the lock mechanism and / or helping to maintain the top housing in a nested relationship with the bottom structure.

[0056] The top housing 310 of an embodiment can be configured to facilitate manual manipulation by a user. For example, the size and shape of the top housing 310 can be designed to facilitate grasping by hand, such that a user can manually apply a torque force (e.g., torque in the tightening direction and / or the release direction) to the power-up fastener assembly 130. Additionally or alternatively, the top housing 310 can include surface features (e.g., rib structures, surface texturing, rubber overmolding, etc.) that facilitate grasping and application of force. For example, the illustrated embodiment of the top housing 310 includes rib structures 313a-313h arranged around the circumference of the top housing, such as can be used to enable a user to grasp the power-up fastener assembly 130 and / or enhance the user's grasp thereof.

[0057] The bottom structure 320 of the illustrated embodiment is configured to accept insertion of a drive member of a power tool, such as the shaft 111 of the power tool 100, to facilitate interfacing of the drive member with the fastening element of the power-up fastener assembly 130. For example, the size and shape of the shaft aperture 321 of the illustrated embodiment of the bottom structure 320 can be designed to permit insertion of one end of the shaft 111 therein. According to some examples, the shaft aperture 321 can be shaped or otherwise configured (e.g., including the undulating circumference of the illustrated embodiment, a square circumference, a hexagonal circumference, etc.) to interface with one or more components of the power-up fastener assembly 130 external to the fastening element (e.g., the FIG. 1 residing member 121 of the power tool 100, as can be arranged on the shaft 111), such as to inhibit or prevent rotational movement (e.g., thereby avoiding unwanted loosening of the fastening element due to inertial forces when the power tool is stopped or braked).

[0058] FIGS. 3A-3E The power-up fastener assembly 130 of an embodiment implements an epicyclic gear train configured to provide a mechanical advantage in applying a tightening or loosening torque to the fastening element 330 in response to manual manipulation (e.g., grasping by hand to manually apply torque in the tightening direction or the release direction) of the fastener assembly. Accordingly, as FIG. 3CAs shown, the top housing 310 of the example embodiment includes an eccentric receiver 312 configured to provide eccentric rotation of the shaft 346 of the cycloidal gear train in the illustrated cycloidal gear configuration of the booster assembly 130. The eccentric receiver 312 of the embodiment is arranged to be slightly eccentric within the bottom-facing surface of the top housing 310, with the eccentric receiver 312 rotating about or around the center point of the bottom-facing surface as the top housing 310 rotates. As shown, the eccentric receiver 312 of the example embodiment includes a shaft 346 that is received within a bearing 345 of the example embodiment. The bearing 345 of the example embodiment is arranged to be slightly eccentric within the top housing 310, with the bearing 345 rotating about or around the center point of the top housing 310 as the top housing 310 rotates. As shown, the shaft 346 of the example embodiment is received within a hole 347 of the bearing 345, with the shaft 346 being arranged to rotate within the hole 347 as the top housing 310 rotates. As shown, the shaft 346 of the example embodiment is received within a hole 348 of the eccentric receiver 312, with the shaft 346 being arranged to rotate within the hole 348 as the top housing 310 rotates. FIG. 3D As shown, the bottom structure 320 includes a ring gear 322 of the example cycloidal gear train. In the further exploded view, the cycloidal gear assembly 340 (with some components of the example embodiment of the booster assembly 130 omitted) is seen to interface between the eccentric receiver 312 and the ring gear 322 to provide an implementation of the cycloidal gear device. The cycloidal gear assembly 340 of the illustrated embodiment includes a cycloidal disc 341 and roller pins 342a-f arranged on a pin plate 343, with the roller pins 342a-f being inserted into corresponding ones of the apertures 344a-f of the cycloidal disc 341 when the cycloidal gear assembly 340 is assembled. The shaft 346 of the cycloidal disc 341 interfaces with the eccentric receiver 312 via the bearing 345 of the illustrated embodiment. The cycloidal gear assembly 340 of the illustrated embodiment is received within the cavity of the cup-shaped structure formed by the bottom structure 320, with the cycloidal gear assembly 340 being enclosed within the interior region of the top and bottom structures and providing an interface between the eccentric receiver 312 and the ring gear 322 once the bottom structure 320 is fully nested within the top housing 310. FIG. 3E

[0059] ​According to embodiments, the eccentric receiver 312 is formed as part of or otherwise affixed to the top housing 310, while the ring gear 322 is affixed to or formed as part of the bottom structure 320. Accordingly, when the top housing 310 is rotated (e.g., in response to a user manually applying a torque force thereto), the eccentric receiver 312 of embodiments correspondingly rotates eccentrically (e.g., about a center point of a bottom surface of the top housing 310), thereby causing the cycloidal gear assembly 340 to correspondingly rotate eccentrically via the shaft 346. Similarly, the ring gear 322 rotates or does not rotate correspondingly with the bottom structure 320. The enclosed relationship of the cycloidal gear assembly 340 within the interior region of the bottom structure 320 nested within the top housing 310 allows for relative rotational movement of the pin plate 343 with respect to the top housing and the bottom structure. For example, the top housing 310 can rotate with the bottom structure 320 nested therein remaining stationary, and the pin plate 343 can rotate at a different speed than the top housing 310. That is, rotation of the top housing 310, and thus the eccentric receiver 312 interfacing with the cycloidal disc 341, causes the cycloidal disc to correspondingly rotate in an eccentric motion, with the cycloidal disc 341 meshing with the lobes of the ring gear 322 held stationary by the bottom structure 320 engaging the roller pins 342a-f via the apertures 344a-f to transfer rotational force to the pin plate 343, albeit at a reduced rotational rate and with greater torque force.

[0060] The cycloidal gear assembly 340 includes a fastening element 330 arranged to correspond coaxially with the shaft aperture 321. For example, the illustrated embodiment of the fastening element 330 includes a portion of an aperture in the pin plate 343 sized and shaped to correspond to the size and shape of one end of the shaft 111 of the power tool 100 and is appropriately threaded to engage this end of the shaft 111, such as can be used to secure, mount, tighten, etc. the detachable implement 120 onto the shaft 111. Accordingly, the fastening element 330 of the illustrated embodiment includes a threaded fastening device integrally formed with another component of the power-up fastener assembly 130 and configured to rotate on the drive member in a fastening direction and a release direction.

[0061] While FIGS. 3A-3EThe fastener element 330 of the illustrated example is described as being integrally formed with the pin plate 343, but it should be appreciated that other configurations of fastener elements can be utilized in accordance with embodiments of the present application. For example, instead of a portion of another component being configured to provide the fastener element 330, some embodiments of the fastener element 330 can include a separate component (e.g., a nut). For example, a fastener element housing can be attached to or formed as part of the pin plate 343 and can have a shaft aperture sized and shaped to allow an end of the shaft 111 to be inserted therein, with the fastener element being disposed within a receiving cavity of the fastener element housing.

[0062] In FIGS. 3A-3E In operation of the power-up fastener assembly 130 of embodiments, when the shaft 111 is inserted through the aperture 321 and interfaces with the fastener element 330, a user can grasp the top housing 310 by hand and rotate it in a tightening direction or a loosening direction to rotate the fastener element 330 correspondingly relative to the shaft 111. The eccentric receiver 312, the cam plate 341, the ring gear 322, and the roller pins 342a-f of the cam and roller gear train provide a mechanical advantage in applying a tightening or loosening torque to the fastener element 330. That is, a mechanical advantage corresponding to a relationship between the number of lobes on the cam plate and the ring gear (e.g., about 3 to 15 times) can be achieved between the torque applied manually to the top housing 310 and the resulting torque applied to the fastener element 330.

[0063] As can be appreciated from the foregoing, the power-up fastener assembly 130 is configured to provide a mechanical advantage in rotating the fastener element by implementing a power-up gear train configuration in accordance with embodiments of the present application. In accordance with aspects of the present application, a user can be able to apply a tightening or loosening torque by hand that is sufficient to cause frictional interfacing between the power-up fastener assembly 130 and a corresponding detachable implement to prevent undesirable relative displacement of the detachable implement during use of the power tool, to overcome increased frictional interfacing due to inertial tightening of the fastener assembly during use of the power tool, and / or to prevent undesirable loosening or separation of the power-up fastener assembly during use of the power tool. For example, the power-up fastener assembly 130 of embodiments can facilitate tightening of its fastener element by hand sufficiently to retain a detachable implement on a reversible power tool such that relative movement of the detachable implement in either direction is kept below 15° when torque is applied to the detachable implement by operation of the power tool.

[0064] The force multiplier assembly 130 of some embodiments of the present application can include a lock mechanism that functions to lock and / or unlock the force multiplier assembly and its fastening element. For example, in addition to or as an alternative to the frictional interface between the force multiplier assembly 130 and the detachable appliance 120 described above, a lock mechanism of an embodiment can be used to prevent unwanted relative displacement of the detachable appliance. Accordingly, in operation according to some examples, the lock mechanism can be utilized to lock the force multiplier assembly 130 such that the fastening assembly is not undesirably or accidentally released. For example, a lock mechanism of an embodiment of the present application can lock movement of the top housing of the force multiplier assembly relative to the bottom structure, wherein unwanted rotation of the fastening element in the fastening direction and / or the release direction can be prevented. Thus, such an embodiment of a lock mechanism can indirectly act on the fastening element to prevent unwanted rotation in one or more directions. Additionally or alternatively, a lock mechanism of an embodiment of the present application can directly act on the fastening element, such as by directly interfacing with one or more surfaces thereof to prevent unwanted rotation in one or more directions.

[0065] FIG. 4A and FIG. 4B illustrate details of an exemplary lock mechanism implemented for an embodiment of the planetary gear train configuration of FIGS. 2A-2E . FIG. 4A The lock mechanism 400 of the example illustrated in FIGS. 4A and 4B includes lock elements 410a and 410b disposed in the bottom side of the top housing 210. The lock elements 410a and 410b are configured to engage the bottom structure 220 FIG. 2D and provide locking of movement of the top housing 210 relative to the bottom structure 220 of the force multiplier assembly 130. For example, the lock elements 410a and 410b of the illustrated embodiment include teeth 411a and 411b, respectively, that are configured to interface with the teeth of the ring gear 222 FIG. 2D of the bottom structure 220. For example, the lock elements 410a and 410b can be slidably coupled to the bottom side surface of the top housing 210, wherein when the lock elements are slid radially outward, the teeth 411a and 411b engage the teeth of the ring gear 222 and prevent movement of the top housing 210 relative to the bottom structure 220. Additionally, the lock elements 410a and 410b can be slid radially inward to a point where the teeth 411a and 411b disengage the teeth of the ring gear 222 and permit movement of the top housing 210 relative to the bottom structure 220.

[0066] The lock elements 410a and 410b of embodiments of the lock mechanism 400 can be unlocked and / or locked with user action. For example, the springs 401a and 401b can provide a biasing force to hold the lock elements 410a and 410b in a radially outward position (e.g., the lock mechanism 400 is in a locked state) respectively. A user can apply a force (e.g., a squeezing force) to a portion of the lock elements 410a and 410b that is accessible via a corresponding opening in the top housing 210 to cause the lock elements to slide radially inward (e.g., the lock mechanism 400 is in an unlocked state) to thereby disengage the lock mechanism. Alternatively, the lock elements of the lock mechanism 400 can be configured to move between a locked position and an unlocked position in response to one or more forces other than from a user unlock / lock action. For example, the lock elements 410a and 410b can be provided with a weighted pivot member, where when the power tool 100 is operating, centrifugal forces can act on weights disposed at either end of the weighted pivot member to cause the lock elements 410a and 410b to move radially outward (e.g., to place the lock mechanism 400 in a locked state). When the power tool 100 is not operating or is disposed in a service orientation, a biasing spring and / or gravity can be utilized to cause the weighted pivot member to facilitate the lock elements 410a and 410b to move radially inward (e.g., to place the lock mechanism 400 in an unlocked state).

[0067] In operation according to the illustrated embodiment of the lock mechanism 400, when the lock mechanism 400 is in a locked state, movement of the top housing 210 relative to the bottom structure 220 in the tightening direction and the release direction is prevented. For example, the size and shape of the teeth 411a and 411b are designed to correspond to the size and shape of the teeth of the ring gear 222 to thereby provide a locking engagement (e.g., when the lock elements 410a and 410b are in a radially outward position), which inhibits rotation in either direction. However, alternative embodiments can provide teeth 411a and 411b of different configurations to facilitate preventing movement of the top housing 210 relative to the bottom structure 220 in a first direction (e.g., the release direction) when the lock elements 410a and 410b are in a radially outward position, while allowing movement of the top housing 210 relative to the bottom structure 220 in a second direction (e.g., the tightening direction) when the lock elements 410a and 410b are in a radially outward position. For example, the teeth 411a and 411b can be provided in a sawtooth configuration, where the angled sides of the sawteeth permit relative movement of the top housing 210 relative to the bottom structure 220 in the first direction, while the straight sides of the sawteeth prevent relative movement of the top housing relative to the bottom structure 220 in the second direction. In the illustrated example, movement of the top housing 210 relative to the bottom structure 220 in the release direction is prevented, but movement in the tightening direction is not prevented.

[0068] FIG. 5A and FIG. 5B show as can be implemented forFIGS. 2A-2E Details of an exemplary locking mechanism implemented in another embodiment of the planetary gear system configuration. FIG. 5A The locking mechanism 500 shown in the example of Figure 5B includes locking elements 510a and 510b disposed in the bottom side of the top housing 210. Locking elements 510a and 510b are configured to engage the bottom structure 220. FIG. 2D ), and provides locking of the top housing 210 relative to the bottom structure 220 of the force-enhancing fastener assembly 130. For example, locking elements 510a and 510b of the illustrated embodiment include teeth 511a and 511b, respectively, which are configured to engage with the ring gear 222 of the bottom structure 220. FIG. 2D The teeth of the locking elements 511a and 511b engage with the teeth of the ring gear 222 and prevent the top housing 210 from moving relative to the bottom structure 220 when the locking elements slide radially outward. Alternatively, the locking elements 510a and 510b can slide radially inward to a point where the teeth 511a and 511b disengage from the teeth of the ring gear 222 and allow the top housing 210 to move relative to the bottom structure 220.

[0069] The lock elements 510a and 510b of embodiments of the lock mechanism 500 can move between the locked and unlocked positions in response to various forces, such as centrifugal force and / or gravitational force. For example, the lock mechanism 500 can be placed in the locked state to prevent rotation in the release direction when the detachable implement is spinning fast enough for the lock elements 510a and 510b to slide outward and for the teeth 511a and 511b to engage the teeth of the ring gear 222. According to the illustrated example, the counterweights of the lock elements 510a and 510b are sufficient to cause the lock elements to slide against the tensile bias of the springs 501a and 501b such that the teeth 511a and 511b move outward in response to centrifugal force resulting from the detachable implement and the corresponding power-boost fastener assembly rotating at a sufficient speed and engage the teeth of the ring gear 222. According to this example, when the power tool 100 is stopped, the springs 501a and 501b can provide a biasing force to pull the lock elements 510a and 510b such that they slide inward sufficiently to disengage the teeth 511a and 511b from the teeth of the ring gear 222. Additionally or alternatively, the lock mechanism 500 can be placed in the unlocked state to allow rotation in the release direction by gravity when the power tool 100 is arranged in a particular orientation (e.g., unlocked when the head of the power tool on which the detachable implement is fastened is flipped upside down for user servicing). Additionally or alternatively, according to some embodiments, the lock mechanism 500 can be unlocked and / or locked with user action. For example, the springs 501a and 501b can be arranged to provide a biasing force to hold the lock elements 510a and 510b, respectively, such that the teeth 511a and 511b are arranged in a radially outward position (e.g., the lock mechanism 500 is in the locked state). A user can exert a force (e.g., a squeezing force) (e.g., press the lock elements) on a portion of the lock elements 510a and 510b that is accessible via a corresponding opening in the top housing 310 to cause the lock elements to slide such that the teeth 511a and 511b slide radially inward (e.g., the lock mechanism 500 is in the unlocked state) to disengage the lock mechanism.

[0070] In operation of the illustrated embodiment according to lock mechanism 500, movement of top housing 210 relative to bottom structure 220 in the tightening direction and the release direction is prevented when lock mechanism 500 is in the locked state. For example, the size and shape of teeth 511a and 511b are designed to correspond to the size and shape of the teeth of ring gear 222 to thereby provide a locking engagement (e.g., when lock elements 510a and 510b are in the radially outward position), which inhibits rotation in either direction. However, alternative embodiments can provide teeth 511a and 511b in different configurations to facilitate preventing movement of top housing 210 relative to bottom structure 220 in a first direction (e.g., the release direction) when lock elements 510a and 510b are in the radially outward position, while allowing movement of top housing 210 relative to bottom structure 220 in a second direction (e.g., the tightening direction) when lock elements 510a and 510b are in the radially outward position. For example, teeth 511a and 511b can be provided in a sawtooth configuration, with the angled sides of the sawteeth permitting relative movement of top housing 210 relative to bottom structure 220 in the first direction, while the straight sides of the sawteeth prevent relative movement of top housing 210 relative to bottom structure 220 in the second direction. In the illustrated example, movement of top housing 210 relative to bottom structure 220 in the release direction is prevented, but not in the tightening direction.

[0071] FIG. 6A and FIG. 6B illustrate details of an example exemplary lock mechanism implemented for a cycloidal gear train configuration embodiment of FIGS. 3A-3E . FIG. 6A The lock mechanism 600 of the illustrated example of FIGS. 6A and 6B includes lock elements 610a and 610b arranged in the bottom side of top housing 310. Lock elements 610a and 610b are configured to engage bottom structure 320 FIG. 3D ) and provide locking of movement of top housing 310 relative to bottom structure 320 of force multiplier tightener assembly 130. For example, lock elements 610a and 610b of the illustrated embodiment include teeth 611a and 611b, respectively, that are configured to interface with teeth 323 FIG. 3D ) arranged on the outer circumference of ring gear 322 of bottom structure 220. For example, lock elements 610a and 610b can include pawls pivotally coupled to the bottom side surface of top housing 310, where when the lock elements are pivoted, teeth 611a and 611b move radially inward such that the teeth engage teeth 323 of ring gear 322 and prevent movement of top housing 310 relative to bottom structure 320. Additionally, lock elements 610a and 610b can be pivoted radially outward to a point where teeth 611a and 611b disengage teeth 323 of ring gear 322 and permit movement of top housing 310 relative to bottom structure 320.

[0072] Lock elements 610a and 610b of embodiments of the lock mechanism 600 can be unlocked and / or locked with user action. For example, springs 601a and 601b can provide a biasing force to hold the lock elements 610a and 610b in a radially inward position (e.g., the lock mechanism 600 is in a locked state) respectively. A user can exert a force (e.g., a squeezing force) on button portions of arms 612a and 612b of the lock elements 610a and 610b respectively that are accessible via corresponding openings in the top housing 310 to cause the lock elements to pivot between a locked position and an unlocked position (e.g., the lock mechanism is in an unlocked state) to disengage the lock mechanism. Additionally or alternatively, the lock elements of the lock mechanism 600 can be configured to move between the locked position and / or the unlocked position in response to one or more forces other than from a user unlock / lock action. For example, the arms 612a and 612b can have counterweights, where centrifugal forces can act on the pivoting members of the counterweights when the power tool 100 is operating to urge the lock elements 610a and 610b to pivot (e.g., to place the lock mechanism 600 in the locked state). The lock mechanism 600 of some embodiments can be placed in the unlocked state by gravity to allow rotation in the release direction when the power tool 100 is in a particular orientation (e.g., unlocked when the head of the power tool on which the detachable implement is secured is flipped upside down for user servicing).

[0073] In operation according to the illustrated embodiment of the lock mechanism 600, when the lock mechanism 600 is in the locked state, movement of the top housing 310 relative to the bottom structure 320 in the release direction is prevented while movement in the tightening direction is permitted. For example, the teeth 611a and 611b and the teeth 323 of the illustrated embodiment are arranged in a sawtooth configuration, where the angled sides of the sawteeth permit relative movement of the top housing 310 relative to the bottom structure 320 in a first direction, while the straight sides block relative movement of the top housing 310 relative to the bottom structure 320 in a second direction. In the illustrated example, movement of the top housing 310 relative to the bottom structure 320 in the release direction is blocked, but not in the tightening direction. Alternative embodiments of the lock mechanism 600 can be configured to prevent movement of the top housing 310 relative to the bottom structure 320 in both the tightening and release directions when the lock mechanism 600 is in the locked state. For example, the teeth 611a and 611b and the teeth 323 can be sized and shaped to provide a locking engagement (e.g., the teeth 611a and 611b engage the teeth 323 as the lock elements 610a and 610b pivot) that inhibits rotation in either direction.

[0074] According to the example of the lock mechanism 600 described above, the lock elements 610a and 610b manipulated by the user (e.g., squeezing their button portions) themselves provide the locking interface with the base structure for locking movement of the top housing 310 of the power-up fastener assembly 130 relative to the base structure 320. That is, the user can interact with the lock elements 610a and 610b, which in turn cause the lock elements to directly interact with the locking interface of the lock mechanism 600. Additionally or alternatively, embodiments of the lock mechanism can provide for user operation that indirectly interacts with the locking interface.

[0075] FIGS. 7A-7F Details are shown regarding embodiments of the power-up fastener assembly 130 that implement a planetary gear configuration (e.g., similar to the planetary gear configuration described above FIGS. 2A-2E to provide the mechanical advantages of manually manipulating the fastener assembly, where indirect interaction with the locking interface is provided. In particular, FIGS. 7A-7F the power-up fastener assembly 130 of embodiments of the

[0076] FIG. 7A and FIG. 7B embodiments of the power-up fastener assembly 130 are shown in their assembled state. As shown in the isometric top view of FIG. 7A the planetary gear configuration includes a top housing 710 and a base structure 720. It should be appreciated that while the view, housing, and structure are referred to as top and bottom, the designations are relative and there is no limitation on the example power-up fastener assembly being arranged or utilized in any particular orientation relative to top and bottom. For example, when used with a lawnmower implementation of the power tool 100, the top housing 710 can be oriented to face downward when mounted on the shaft 111 and attaching the detachable implement 120, which will be in the form of a grass-cutting blade, to the power tool 100.

[0077] The top housing 710 and the base structure 720 are configured to cooperatively enclose the planetary gear train and fastening element of the example power-up fastener assembly. For example, in FIG. 7C and FIG. 7DAs can be seen in the partial exploded view, the bottom structure 720 can form a cup-shaped structure sized and shaped to accept the circumference of the top housing 710. According to some examples, the circumferential edge of the top housing 710 can terminate at or very near the top inner circumference of the bottom structure 720 or very near the top inner circumference of the bottom structure when fully nested within the bottom structure 720, such as to enclose the components of the planetary gear train and provide a substantially closed area that inhibits penetration of debris and / or other matter. However, the nested relationship of the top housing 710 and the bottom structure 720 of embodiments allows for relative rotational movement between the top housing and the bottom structure (e.g., the top housing 710 can rotate while the bottom structure 720 remains stationary).

[0078] The bottom structure 720 of the illustrated embodiment is configured for accepting insertion of a drive member of a power tool, such as the shaft 111 of the power tool 100, to facilitate interfacing of the drive member with the fastening element of the power-boost fastener assembly 130. For example, the shaft aperture 721 of the illustrated embodiment of the bottom structure 720 can be sized and shaped to permit insertion of one end of the shaft 111 therein. According to some examples, the shaft aperture 721 can be shaped or otherwise configured (e.g., including the undulating circumference of the illustrated embodiment, a square circumference, a hexagonal circumference, etc.) to interface with one or more components (e.g., the FIG. 1 residing member 121 of the power-boost fastener assembly 130, such as to inhibit or prevent rotational movement (e.g., to avoid unwanted loosening of the fastening element due to inertial forces when the power tool is stopped or braked).

[0079] FIGS. 7A-7F The power-boost fastener assembly 130 of embodiments of the power tool 100 implements a planetary gear train configured to provide a mechanical advantage in applying a tightening or loosening torque to the fastening element 730 in response to manual manipulation of the fastener assembly (e.g., grasping by hand to manually apply a torque in a fastening direction or a loosening direction). Accordingly, as FIG. 7C and FIG. 7DAs shown, the top housing 710 of the example embodiment includes a gear plate 741 that houses the planetary gears 742a-742c that interface with a ring gear 722 housed within the bottom structure 720 to provide a planetary gear arrangement implementation of the power-up fastener assembly 130. The ring gear 722 is attached to or formed as part of a gear plate 743 that is nested within the bottom structure 720, which has a fastener element 730 attached thereto or formed as part thereof. Thus, when the ring gear 722 is rotated, the gear plate 743 and the fastener element 730 of the embodiment will correspondingly rotate. When the top housing 710 is rotated relative to the bottom structure 720 (e.g., in response to a user manually applying a torque force thereto), the gear plate 741 of the embodiment will correspondingly rotate to cause rotation of the ring gear 722 by operation of the planetary gear train, and thus the gear plate 743 and the fastener element 730 will rotate in a corresponding direction, albeit at a slower rotational rate with increased torque.

[0080] The fastener element 730 of the embodiment can include a threaded fastening device configured to rotate in a fastening direction and a release direction on the drive member. For example, the illustrated embodiment of the fastener element 730 is suitably threaded onto one end of the shaft 111 of the power tool 100, such as can be used to secure, mount, tighten, etc. the detachable implement 120 onto the shaft 111.

[0081] While FIGS. 7A-7F The fastener element 730 of the illustrated example is described as being attached to or formed as part of the gear plate 743, but it should be appreciated that other configurations of fastener elements can be utilized in accordance with embodiments of the present application. For example, the fastener element 730 can include a separate component (e.g., a nut) disposed within a fastener element housing of the gear plate 743 in accordance with some embodiments.

[0082] In FIGS. 7A-7F operation of the power-up fastener assembly 130 of the embodiment, when the shaft 111 is inserted through the aperture 721 and interfaces with the fastener element 730, the top housing 710 can be rotated in a fastening direction to correspondingly rotate the fastener element 730 relative to the shaft 111. The planetary gear train of the power-up fastener assembly provides a mechanical advantage in applying torque to the fastener element 730. However, FIGS. 7A-7FThe illustrated embodiment of the force multiplier fastener assembly 130 includes a lock mechanism 700 configured to provide locking of movement of the top housing 710 relative to the gear plate 743 nested within the bottom structure 720 of the force multiplier fastener assembly. In particular, the lock mechanism 700 of the illustrated embodiment is configured to prevent relative movement in a first direction (e.g., a release direction) when the lock element 750 is in a radially outward position, while allowing relative movement in a second direction (e.g., a tightening direction) when the lock element 750 is in the radially outward position.

[0083] For example, FIGS. 7A-7F The lock mechanism 700 of the illustrated example includes a lock element 750 arranged in a pivotal relationship with the bottom structure 720 for engaging an arm 762 of a lock element 760 also arranged in a pivotal relationship with the bottom structure 720. The lock element 760 is configured to engage a locking ring 723 FIG. 7E ) and provide locking of movement of the top housing 710 relative to the gear plate 743 of the force multiplier fastener assembly 130. For example, the lock element 760 of the illustrated embodiment includes teeth of the arm 761 configured to interface with teeth 724 arranged on an outer circumference of the locking ring 723, where the locking ring 723 also includes teeth 725 on an inner circumference thereof that engage teeth of the planetary gears 742a-742c. According to some embodiments, the ring gear 722 can include teeth 724 arranged on an outer circumference thereof for engaging the teeth of the arm 761 (e.g., to provide a locked configuration of the ring gear 722, such as in the event the locking ring 723 is omitted). From FIG. 7E It can be seen from the illustrated embodiment that the teeth of the arm 761 are provided in a sawtooth configuration, where the angled sides of the sawteeth permit relative movement of the top housing 710 relative to the gear plate 743 in a first direction, while the straight sides block relative movement of the top housing 710 relative to the gear plate 743 in a second direction. In the illustrated example, movement of the top housing 710 relative to the gear plate 743 in the release direction is blocked, but movement in the tightening direction is not blocked.

[0084] In operation according to embodiments, the lock element 760 can include a pawl pivotally coupled to the bottom structure 720, whereby when the lock element pivots the arm 761 moves radially inward and its teeth engage the teeth 724 of the locking ring 723 and prevent movement of the top housing 710 relative to the gear plate 743. However, the arm 761 of the lock element 760 can pivot radially outward to a point where its teeth disengage the teeth 724 of the locking ring 723 and permit movement of the top housing 710 relative to the gear plate 743 in the release direction. According to embodiments of the lock mechanism 700, the lock element 760 can pivot such that the teeth of the arm 762 engage the teeth 724 of the locking ring 723. From FIG. 7FAs can be seen, the teeth of the arm 762 of the illustrated embodiment are arranged in a sawtooth configuration, with the angled side of the sawtooth permitting relative movement of the top housing 710 relative to the gear plate 743 in the second direction, while the straight side of the sawtooth prevents relative movement of the top housing 710 relative to the gear plate 743 in the first direction. In the illustrated example, movement of the top housing 710 relative to the gear plate 743 in the tightening direction is prevented, but movement in the loosening direction is not prevented.

[0085] The lock elements 750 and 760 of embodiments of the lock mechanism 700 can be unlocked and / or locked with user action. The spring 770 (e.g., a torsion spring and / or other biasing force source) of some embodiments can provide a biasing force to maintain the arm 761 of the lock element 760 in a radially inward position (e.g., the lock mechanism 700 is in a locked state), and correspondingly the arm 762 of the lock element 760 in a radially outward position. The arm 762 of the illustrated embodiment can engage the arm 751 of the lock element 750, and thereby cause the arm 751 to assume a radially outward position (e.g., under the force exerted by the spring 770). In addition to or in place of the spring 770 indirectly providing a force to cause the arm 751 to assume a radially outward position, a torsion spring and / or other biasing force source can be provided in relation to the arm 751 to directly cause the arm 751 to assume a radially outward position.

[0086] A user can exert a force (e.g., a squeezing force) on the button portion of the arm 751 of the lock element 750 (e.g., a surface area of the distal end of the arm 751) to cause the lock element 760 to pivot between a locked position and an unlocked position (e.g., the lock mechanism is in an unlocked state) to thereby disengage the lock mechanism FIG. 7F ). The arm 751 can be configured, for example, to provide a relatively large surface area of its button portion for a user to squeeze (e.g., to facilitate user interaction, such as with a gloved hand). According to some examples, the button portion of the arm 751 can be adapted to facilitate user interfacing with the lock mechanism to facilitate grasping and exerting a force (e.g., be marked to indicate an area to exert a squeezing pressure, surface texturing, rubber overmolding, etc., to permit exertion of a squeezing force without slipping, etc.). In the unlocking operation, the arm 751 of the lock element 750 can engage the arm 762 of the lock element 760 against the biasing force of the spring 770 to cause the arm 762 to assume a radially inward position, and correspondingly the arm 761 of the lock element 760 to assume a radially outward position. As shown, for example, where the surface of the top housing is shown as transparent, the teeth of the arm 761 can be disengaged from the teeth 724 of the locking ring 723. Correspondingly, the lock mechanism 700 can be placed in an unlocked state, and a user can be able to move the top housing 710 relative to the gear plate 743 (e.g., rotate in a loosening direction) (e.g., to provide a force-boosted rotation of the fastener element 730 relative to the shaft 111). FIG. 7F ​

[0087] FIGS. 8A-8E Details are shown regarding another embodiment of a force multiplier fastener assembly 130 that implements a planetary gear configuration (e.g., similar to the planetary gear configuration described above FIGS. 2A-2E with respect to the force multiplier fastener assembly 130 of the embodiment of FIGS. 8A-8E provides a button portion that includes a separate member from the lock pawl of the lock mechanism for receiving user action (e.g., depression) to indirectly cause an unlock movement by engaging the lever arm of the lock pawl, as described in further detail below.

[0088] FIG. 8A and FIG. 8B A planetary gear configuration of an embodiment of the force multiplier fastener assembly 130 is shown in its assembled state. As shown in the isometric top view of FIG. 8A , the illustrated planetary gear configuration includes a top housing 810. Correspondingly, as shown in the isometric bottom view of FIG. 8B , the illustrated planetary gear configuration includes a bottom structure 820. It should be appreciated that while the views, housings, and structures are referred to as top and bottom, the designations are relative and there is no limitation on the exemplary force multiplier fastener assembly being arranged or utilized in any particular orientation with respect to top and bottom. For example, when used with a lawnmower implementation of the power tool 100, the top housing 810 can be oriented to face downward when mounted on the shaft 111 and attaching the detachable implement 120, which will be in the form of a grass-cutting blade, to the power tool 100.

[0089] The top housing 810 and the bottom structure 820 are configured to cooperatively enclose the planetary gear train and fastening elements of the exemplary force multiplier fastener assembly. For example, as can be seen in the partially exploded view of FIG. 8C , the bottom structure 820 can form a cup-shaped structure sized and shaped to nest within a cup-shaped enclosure formed by the top housing 810. According to some examples, the top edge circumference of the bottom structure 820 can terminate at or very near the bottom-facing surface of the top housing 810 when fully nested within the top housing 810, such as to enclose components of the planetary gear train and provide a substantially closed area that inhibits penetration of debris and / or other matter. However, the nested relationship of the top housing 810 and the bottom structure 820 of the embodiment allows for relative rotational movement between the top housing and the bottom structure (e.g., the top housing 810 can rotate while the bottom structure 820 nested within it remains stationary).

[0090] The bottom structure 820 of the illustrated embodiment is configured to receive the insertion of a drive member of a power tool, such as the shaft 111 of the power tool 100, to facilitate engagement of the drive member with the fastening element of the force-enhancing fastener assembly 130. For example, the size and shape of the shaft aperture 821 of the bottom structure 820 in the illustrated embodiment may be designed to allow one end of the shaft 111 to be inserted therein. According to some examples, the shaft aperture 821 may be shaped or otherwise configured (e.g., including the wavy circumference, square circumference, hexagonal circumference, etc. of the illustrated embodiment) to be external to one or more components of the force-enhancing fastener assembly 130 (e.g., FIG. 1 The dwelling part 121, which may be arranged on the shaft 111, is engaged, for example, to suppress or prevent rotational movement (e.g., thereby avoiding undesirable loosening of the fastening element due to inertial forces when the power tool stops or is braked).

[0091] FIGS. 8A-8E The force-amplifying fastener assembly 130 of the embodiment implements a planetary gear train configured to provide the mechanical advantage of applying tightening or loosening torque to the fastening element 830 in response to manual operation (e.g., by hand gripping to manually apply torque in the tightening or loosening direction) of the fastener assembly. Therefore, as FIG. 8C and FIG. 8D As shown, the bottom structure 820 of the exemplary embodiment includes a gear plate 843 housing planetary gears 842a-842c, which mesh with a ring gear 822 attached to or formed as part of the bottom structure 820. The gear plate 843, having the ring gear 822 and planetary gears 842a-842c, is housed within the bottom structure 820 to provide a planetary gear arrangement embodiment of the force-amplifying fastener assembly 130. According to an embodiment, the gear plate 843 nested within the bottom structure 820 has fastening elements 830 attached to or formed as part of it. Thus, when the ring gear 822 rotates, the gear plate 843 and fastening elements 830 of the embodiment will rotate accordingly. When the top housing 810 (e.g., in response to a user manually applying a torque force to it) rotates relative to the bottom structure 820, the gear plate 843 and fastening elements 830 of the embodiment will rotate accordingly through the operation of the planetary gear train, albeit at a slower rate of rotation with increased torque.

[0092] The fastening element 830 of the embodiment may include a threaded fastening device configured to rotate on a drive member in a fastening direction and a release direction. For example, the illustrated embodiment of the fastening element 830 may be suitably screwed into engagement one end of the shaft 111 of the power tool 100, for example, it may be used to secure, mount, tighten, etc., a removable tool 120 onto the shaft 111.

[0093] Although FIGS. 8A-8EThe fastening elements 830 of the illustrated example are described as being attached to or formed as part of the gear plate 843, but it should be appreciated that other configurations of fastening elements can be utilized in accordance with embodiments of the present application. For example, the fastening elements 830 can comprise separate components (e.g., nuts) disposed within fastening element housings of the gear plate 843 in accordance with some embodiments.

[0094] In FIGS. 8A-8E operation of the power-up fastener assembly 130 of embodiments, when the shaft 111 is inserted through the aperture 821 and interfaces with the fastener elements 830, the top housing 810 can be rotated in a fastening direction to correspondingly rotate the fastener elements 830 relative to the shaft 111. The planetary gear train of the power-up fastener assembly provides a mechanical advantage in applying torque to the fastener elements 830. However, FIGS. 8A-8E The illustrated embodiments of the power-up fastener assembly 130 include a lock mechanism 800 configured to provide locking of movement of the top housing 810 relative to the gear plate 843 nested within the bottom structure 820 of the power-up fastener assembly. In particular, the lock mechanism 800 of the illustrated embodiments is configured to prevent relative movement in a first direction (e.g., a release direction) when the lock element 850 is in an upward position, while allowing relative movement in a second direction (e.g., a fastening direction) when the lock element 850 is in a downward position.

[0095] For example, FIGS. 8A-8E The lock mechanism 800 of the illustrated example includes a lock element 850 disposed in linear traverse relationship with the bottom structure 820 for engaging a lock element 860 also disposed in linear traverse relationship with the bottom structure 820. In accordance with FIGS. 8A-8E The linear traverse relationship of the lock elements 860 and 860 provides for movement thereof orthogonally (e.g., upwardly and downwardly) relative to the gear plane of the bottom structure 820 in accordance with examples. In accordance with the illustrated embodiments, the lock element 860, which includes a ring or ring portion at least partially encircling the ring gear 822 of the bottom structure 820, is configured to engage a lock element 870 disposed in pivotal relationship with the bottom structure 820. The lock element 870 includes an arm 872 having a ramped portion 873 configured to interface with the lock element 860 FIG. 8D). The lock element 870 is further configured to engage the locking ring 823 and provide locking of movement of the top housing 810 relative to the gear plate 843 of the force multiplier fastener assembly 130. For example, the lock element 870 of the illustrated embodiment includes teeth of the arm 871 that are configured to interface with the teeth 824 disposed on the outer circumference of the locking ring 823, where the locking ring 823 further includes teeth 825 on its inner circumference that engage the teeth of the planetary gears 842a-842c. According to some embodiments, the ring gear 822 can include teeth 824 disposed on its outer circumference for engaging the teeth of the arm 871 (e.g., to provide a locked configuration of the ring gear 822, such as in the case where the locking ring 823 is omitted). From FIG. 8D As can be seen in, the teeth of the arm 871 of the illustrated embodiment are set in a sawtooth configuration, where the angled side of the sawtooth permits relative movement of the top housing 810 relative to the gear plate 843 in a first direction, while the straight side blocks relative movement of the top housing 810 relative to the gear plate 843 in a second direction. In the illustrated example, movement of the top housing 810 relative to the gear plate 843 in the release direction is blocked, but movement in the fastening direction is not blocked.

[0096] In operation according to embodiments, the lock element 870 can include a pawl pivotally coupled to the bottom structure 820, such that when the lock element is pivoted the arm 871 moves radially inward and its teeth engage the teeth 824 of the locking ring 823 and prevent movement of the top housing 810 relative to the gear plate 843. However, the arm 871 of the lock element 870 can be pivoted radially outward to a point where its teeth disengage the teeth 824 of the locking ring 823 and permit movement of the top housing 810 relative to the gear plate 843 in the release direction. According to embodiments of the lock mechanism 800, the lock element 870 can be pivoted such that the teeth of the arm 872 engage the teeth 824 of the locking ring 823. From FIG. 8E As can be seen in, the teeth of the arm 872 of the illustrated embodiment are set in a sawtooth configuration, where the angled side of the sawtooth permits relative movement of the top housing 810 relative to the gear plate 843 in a second direction, while the straight side blocks relative movement of the top housing 810 relative to the gear plate 843 in a first direction. In the illustrated example, movement of the top housing 810 relative to the gear plate 843 in the fastening direction is blocked, but movement in the release direction is not blocked.

[0097] Lock elements 850, 860, and 870 of embodiments of lock mechanism 800 can utilize user action to unlock and / or lock the lock mechanism. Springs 880a-880d (e.g., compression springs and / or other biasing force sources) of some embodiments can provide a biasing force to hold lock element 860 in an upward position such that ramped portion 873 allows arm 872 of lock element 870 to be disposed in a radially outward position, and correspondingly allows arm 871 of lock element 870 to be disposed in a radially inward position (e.g., lock mechanism 800 is in a locked state). According to embodiments, a torsion spring (e.g., similar to spring 770 of FIG. 7E and FIG. 7F ) and / or other biasing force source can be utilized to provide a biasing force to hold arm 871 of lock element 870 in a radially inward position when lock element 860 is disposed in an upward position. Furthermore, the biasing force of embodiments to hold lock element 860 in an upward position can correspondingly hold lock element 850 in an upward (e.g., un-depressed) position. For example, a portion of lock element 860 of the illustrated embodiment can engage a bottom portion of lock element 850 and thereby cause lock element 850 to reach an upward position (e.g., under the force exerted by springs 880a-880d). In addition to or in lieu of springs 880a-880d indirectly providing a force to cause lock element 850 to reach an upward position, a compression spring and / or other biasing force source can be provided in relation to lock element 850 to directly cause lock element 850 to reach an upward position.

[0098] A user can exert a force (e.g., a depression force) on a button portion of lock element 850 (e.g., a surface area of a top portion of lock element 850) to cause lock elements 850 and 860 to move downward and cause lock element 870 to pivot between a locked position and an unlocked position (e.g., the lock mechanism is in an unlocked state) to disengage the lock mechanism FIG. 8E ). Lock element 850 can be configured, for example, to provide a relatively large surface area of its button portion for a user to depress (e.g., to facilitate user interaction, such as with a gloved hand). According to some examples, the button portion of the top surface of lock element 850 can be adapted to facilitate user interfacing with the lock mechanism to facilitate grasping and exerting a force (e.g., be marked to indicate areas to exert a squeezing pressure, surface texturing, rubber overmolding, etc., to allow a squeezing pressure to be exerted without slipping, etc.). In an unlocking operation, a bottom surface of lock element 850 overcomes the biasing force of springs 880a-880d to engage lock element 860, causing lock element 860 to reach a downward position. Lock element 860 in turn can engage ramped portion 873 of arm 872 and cause arm 872 to reach a radially inward position, and correspondingly arm 871 of lock element 870 to be in a radially outward position. As FIG. 8EAs shown, the surface of the top housing is shown as transparent, thus the teeth of the arm 871 can disengage the teeth 824 of the locking ring 823. Accordingly, the lock mechanism 800 can be placed in an unlocked state, and the user can be able to move the top housing 810 relative to the gear plate 843 (e.g., rotate in a loosening direction) (e.g., to provide a boosted rotation of the fastener element 830 relative to the shaft 111).

[0099] FIG. 9A and FIG. 9B illustrate details of an exemplary lock mechanism as can be implemented for another embodiment of a cycloidal gear train configuration embodiment of the FIGS. 3A-3E . FIG. 9A The lock mechanism 900 of the example illustrated by FIGS. 9A and 9B includes lock elements 910a and 910b disposed in the bottom side of the top housing 310. The lock elements 910a and 910b are configured to engage the bottom structure 320 FIG. 3D ), and provide locking of movement of the top housing 310 relative to the bottom structure 320 of the boosted fastener assembly 130. For example, the lock elements 910a and 910b of the illustrated embodiment include teeth 911a and 911b, respectively, that are configured to interface with teeth 323 FIG. 3D ) disposed on the outer circumference of the ring gear 322 of the bottom structure 220. For example, the lock elements 910a and 910b can include pawls pivotally coupled to the bottom side surface of the top housing 310, where when the lock elements are pivoted, the teeth 911a and 911b move radially inward such that the teeth engage the teeth 323 of the ring gear 322 and prevent movement of the top housing 310 relative to the bottom structure 320. Additionally, the lock elements 910a and 910b can pivot radially outward to a point where the teeth 911a and 911b disengage the teeth 323 of the ring gear 322 and permit movement of the top housing 310 relative to the bottom structure 320.

[0100] The lock elements 910a and 910b of embodiments of the lock mechanism 900 can pivot between a locked position and an unlocked position in response to various forces, such as centrifugal force and / or gravitational force. For example, the lock mechanism 900 can be placed in a locked state to prevent rotation in the release direction when the detachable implement is spinning fast enough to cause the lock elements 910a and 910b to pivot and cause the teeth 911a and 911b to engage the teeth 323. According to the illustrated example, the weighted arms 912a and 912b of the lock elements 910a and 910b, respectively, can cause the lock elements to pivot such that the teeth 911a and 911b move inward and engage the teeth 323 in response to centrifugal force generated due to the detachable implement and the corresponding power-boosted fastener assembly rotating at sufficient speed. According to this example, when the power tool 100 is stopped, the springs 901a and 901b can provide a biasing force to pull the lock elements 910a and 910b such that they pivot sufficiently to cause the teeth 911a and 911b to disengage from the teeth 323. Additionally or alternatively, the lock mechanism 900 can be placed in an unlocked state to allow rotation in the release direction by gravity when the power tool 100 is arranged in a particular orientation (e.g., unlocked when the head of the power tool on which the detachable implement is fastened is flipped upside down for user servicing). Additionally or alternatively, according to some embodiments, the lock mechanism 900 can be unlocked and / or locked with user action. For example, the springs 901a and 901b can be arranged to provide a biasing force to hold the lock elements 910a and 910b, respectively, such that the teeth 911a and 911b are arranged in a radially inward position (e.g., the lock mechanism 900 is in a locked state). A user can exert a force (e.g., a squeezing force) on a portion of the lock elements 910a and 910b that is accessible via a corresponding opening in the top housing 310 (e.g., press the weighted arms 912a and 912b) to cause the lock elements to pivot such that the teeth 911a and 911b move radially outward (e.g., the lock mechanism 900 is in an unlocked state) to disengage the lock mechanism.

[0101] In operation of the illustrated embodiment of lock mechanism 900, when lock mechanism 900 is in the locked state, movement of top housing 310 relative to bottom structure 320 in the release direction is prevented while movement in the secure direction is permitted. For example, teeth 911a and 911b and teeth 323 of the illustrated embodiment are arranged in a ratcheting configuration in which the angled sides of the ratchet permit relative movement while the straight sides block relative movement, thereby preventing movement of top housing 310 relative to bottom structure 320 in one direction (e.g., the release direction) but not the other (e.g., the secure direction). Alternative embodiments of lock mechanism 900 can be configured to prevent movement of top housing 310 relative to bottom structure 320 in both the secure and release directions when lock mechanism 900 is in the locked state. For example, the size and shape of teeth 911a and 911b and teeth 323 can be designed to provide a locking engagement (e.g., teeth 911a and 911b engage teeth 323 as lock elements 910a and 910b pivot) that inhibits rotation in either direction.

[0102] It will be appreciated that the foregoing lock mechanisms are substantially protected by the structure of the force multiplier fastener assembly 130. For example, the lock mechanisms 400, 500, 600, 700, 800, and 900 of the illustrated embodiments are disposed within the area of the cup-shaped enclosure formed by the top housing and / or bottom structure. Furthermore, embodiments of the lock mechanisms can be completely encapsulated by the top housing and bottom structure (e.g., as provided by top housing 210 and bottom structure 220 with respect to the example of lock mechanism 500, and by top housing 310, bottom structure 320, and bottom housing 301 with respect to the example of lock mechanism 900), thereby providing additional protection to the lock mechanisms. Accordingly, the lock mechanisms of embodiments of the present application can be protected from damage and accidental release, such as might otherwise be damaged, causing accidental release of the latching mechanism and removal of the fastening device from the lawn mower.

[0103] As discussed above with respect to the example embodiments of the force multiplier fastener assembly, manual manipulation of the fastener assembly (e.g., grasped by hand to manually apply a torque in the secure or release direction) can be utilized to supply a secure or unsecure torque through a gear train configured to provide a mechanical advantage to the application of torque to the secure element of the force multiplier fastener assembly. Accordingly, the force multiplier fastener assembly of embodiments of the present application can include one or more features to facilitate user grasping and manual application of a tightening or unsecuring torque. For example, the top housing and / or other structure of the force multiplier fastener assembly of embodiments can be configured to include one or more features to facilitate manual manipulation by a user.

[0104] According to the above examples, the size and shape of the top housing of the force multiplier fastener assembly can be designed to facilitate grasping by hand, such that the user can manually apply a torque force. Additionally or alternatively, surface features can be provided that facilitate grasping and applying force (e.g., ribbing, surface texturing, rubber overmolding, etc.). According to some examples of the force multiplier fastener, additional and / or alternative structures can be provided to facilitate the user applying torque.

[0105] According to embodiments of the present application, structures provided to facilitate the user applying torque can include one or more gripping members. FIGS. 10A-10C Details are shown regarding a gripping member in the form of a flip-up handle assembly 1000 that is provided to facilitate the user applying torque. FIGS. 7A-7F Embodiments of the force multiplier fastener assembly 130 show exemplary implementations of a flip-up handle assembly 1000 according to the concepts herein.

[0106] The flip-up handle assembly 1000 of the illustrated embodiments provides a retractable handle (e.g., an over / under handle that can be arranged in a stowed position and a use position) to facilitate the user grasping and manually applying a tightening or loosening torque relative to the force multiplier fastener assembly. For example, as shown in FIGS. 10A-10C The flip-up handle assembly 1000 of the embodiments includes a handle 1010 that is hingedly arranged relative to a plate 1020 such that the handle 1010 can be arranged in a use position (as shown in FIG. 10A and FIG. 10C and a stowed position (as shown in FIG. 10B For example, the handle 1010 can be mounted using pins 1011a and 1011b that are arranged through ends of the handle proximate the plate 1020. The pins 1011a and 1011b can, for example, interface with hinge pin knuckles arranged on the plate 1020 (e.g., the plate 1020 of some embodiments can provide a mounting plate for securing the flip-up handle assembly 1000 to a force multiplier fastener assembly). According to FIG. 7A , FIG. 7C and FIG. 7F of the force multiplier fastener assembly 130, the pins 1011a and 1011b interface with hinge pin vias of the top housing 710 (e.g., the plate 1020 of this embodiment can provide a spring plate for urging the handle 1010 to remain in the use position and / or the stowed position). Regardless of the particular mounting configuration of the pins 1011a and 1011b, embodiments of the flip-up handle assembly 1000 provide for pivoting of the handle 1010 about an axis of the pins 1011a and 1011b.

[0107] The flip-up handle assembly 1000 can be arranged on a surface of a component of the force multiplier fastener assembly that will have a torque applied. As FIG. 7A ,FIG. 7C and FIG. 7F As shown in exemplary embodiments of the power-up fastener assembly 130, the flip-up handle assembly 1000 can be disposed on the upper surface of the top housing 710 within the gear plane or other fastening / release rotational plane of the power-up fastener assembly. For example, the plate 1020 can be fastened to the upper surface of the top housing 710 using one or more fastening means (e.g., adhesive, screws, nails, rivets, bolts, locking tabs, etc.). The handle 1010 of the flip-up handle assembly 1000 can be disposed in a use position (e.g., as shown in FIG. 7F , FIG. 10A and FIG. 10C to facilitate user grasping of the component and application of force thereto. Thus, a user can easily grasp the handle 1010 with a hand to manually apply a fastening or loosening torque relative to the top housing 710 to operate the power-up fastener assembly to fasten or loosen the fastening element 730. The handle 1010 of the flip-up handle assembly 1000 can be disposed in a stowed position (e.g., as shown in FIG. 7A , FIG. 7C and FIG. 10B to enable use of a primary power tool to which the power-up fastener assembly is attached without interference from and / or damage to the handle.

[0108] The handle 1010 of embodiments can be configured to facilitate user grasping. The illustrated embodiment of the handle 1010 includes a "U" shaped configuration that provides a suitable surface area for a user to apply force and a void to allow a thumb and / or one or more fingers to pass therethrough to facilitate a slip-resistant grip of the handle. However, it should be appreciated that other shaped handles (e.g., "T" shaped, hook shaped, etc. configurations) can be utilized in accordance with the concepts herein. Features in addition to or in lieu of handle shape can be utilized to facilitate user grasping. For example, embodiments of the handle 1010 can include surface features (e.g., surface texturing, rubber overmolding, finger grips, etc.) to facilitate grasping and application of force.

[0109] Embodiments of the flip-up handle assembly 1000 and / or the power-up fastener assembly 130 are configured such that the handle 1010 can be stowed such that it is not damaged during use or interferes with use of a primary power tool. For example, the component of the power-up fastener assembly on which the flip-up handle assembly 1000 is disposed can be configured to provide protection to certain aspects of the handle 1010 when the handle 1010 is disposed in a stowed position. As FIG. 7A , FIG. 7C and FIG. 7FAs shown in the example, the top housing 710 provides a recess in which the handle 1010 can be nested when positioned in the storage position, thereby providing a structure that protects the handle during use of the power tool to which the power-enhancing fastener assembly is attached. Alternatively or additionally, the handle 1010 and plate 1020 of the embodiments are configured to retain the handle 1010 in the storage position to prevent the handle from interfering with the operation of the power tool and / or to prevent damage to the handle. For example, as... FIGS. 10A-10C As shown, the plate 1020 of the illustrated embodiment includes leaf spring portions 1021a and 1021b, which are configured to abut against the end portion of the handle 1010 near the plate 1020. The lower surfaces 1012a and 1021b of the embodiment may be configured, for example, to allow the handle 1010 to rest in a storage position, while the adjacent surfaces 1013a and 1013b may be configured to allow the handle 1010 to rest in a use position. In operation according to the embodiment, when the handle 1010 is rotated away from the use position or the storage position, transition features between the lower surface and the adjacent surface (e.g., the apex between the lower surface 1012a and the adjacent surface 1013a, and the apex between the lower surface 1012b and the adjacent surface 1013b) engage the corresponding leaf springs (e.g., leaf spring portions 1021a and 1021b, respectively). The engagement of these transition features causes the handle 1010 to be biased or increased in bias, and causes the handle to remain in its current position (e.g., the use position or the storage position) or to transition completely to another position (e.g., the storage position or the use position). Accordingly, once placed in the storage position, the handle 1010 of the embodiment is caused to remain in that position until the user intentionally moves it from that position. Similarly, once placed in the use position, the handle 1010 of the embodiment is caused to remain in that position until the user intentionally moves it from that position.

[0110] The force-boosting fastener assembly of the embodiments can be used in harsh environments and / or other conditions that may cause wear and / or damage to the force-boosting fastener assembly and / or its components. For example, some examples of the force-boosting fastener assembly 130 may be used relative to power tools (such as bush trimmers, line trimmers, lawnmowers, etc.) and subjected to abrasive wear (e.g., due to contact with rocks, concrete, sand, etc.) and / or penetration by various materials (e.g., soil, mud, sand, etc.). Accordingly, embodiments of the force-boosting fastener assembly may include one or more removable / replaceable outer surface covers, such as having a protective surface for a portion of the force-boosting fastener assembly. For example, such removable / replaceable outer surface covers may be used to maximize the lifespan of the force-boosting fastener assembly, at least in part, by providing a protective cover that can be easily replaced by the user.

[0111] For example, FIGS. 11A-11CAn example of a removable / replaceable outer surface cover in the form of a replaceable sheath is shown, which is configured to cover a portion of a force-enhancing fastener assembly 130 according to an embodiment of the invention. FIGS. 11A-11C The replaceable sleeve 1100 shown provides coverage of at least a portion of the top housing of the force-boosting fastener assembly 130 (e.g., the outer circumference of the top surface of the top housing). Additionally, the replaceable sleeve 1100 of the illustrated embodiment provides coverage of at least a portion of the side or circumferential surfaces of the force-boosting fastener assembly 130 (e.g., the cup-shaped sides of the top housing and / or bottom structure). While providing coverage of multiple different portions of the force-boosting fastener assembly 130, the replaceable sleeve 1100 of the embodiment can be configured to facilitate user access to one or more features of the force-boosting fastener assembly. For example, a gripping member aperture 1101a can be provided to allow access to one or more gripping members (e.g., FIGS. 10A-10C Access to the handle 1010 of the flip-top handle assembly 1000. Alternatively or alternatively, a locking element aperture 1101b may be provided to allow access to one or more locking elements (e.g., FIG. 4A Locking elements 410a and 410b of locking element 400 in Figure 4B FIG. 6A The button portions of arms 612a and 612b of the locking elements 610a and 610b in Figure 6B, FIGS. 7A-7F The locking mechanism 700 and the locking element 750, etc. are touched.

[0112] The replaceable sheath 1100 can have one or more protective surfaces (e.g., wear resistant surfaces, abradable surfaces, sacrificial surfaces, etc.) configured to provide protection to one or more surfaces and / or components of the power-boost fastener assembly. For example, the replaceable sheath 1100 of embodiments can be constructed of a relatively hard material (e.g., steel, titanium, and / or composites thereof) to provide wear resistant surfaces that are very slow to wear through and / or very slow to otherwise fail in the operation of the power tool under abrasive conditions, thereby protecting the surface and / or underlying components. As another example, the replaceable sheath 1100 of embodiments can be constructed of a less hard material (e.g., aluminum, zinc alloy, and / or composites thereof) to provide abradable surfaces that are somewhat slow to wear through and / or somewhat slow to otherwise fail in the operation of the power tool under abrasive conditions, thereby protecting the surface and / or underlying components. In yet another example, the replaceable sheath 1100 of embodiments can be constructed of a somewhat softer material (e.g., plastic, hard rubber, and / or composites thereof) to provide sacrificial surfaces that bear the brunt of the wear caused by the operation of the power tool under abrasive conditions. It should be appreciated that embodiments of the replaceable sheath 1100 can be constructed of more than one material and / or materials having different properties. For example, some embodiments of the replaceable sheath 1100 can include an inner layer comprising a somewhat softer material (e.g., plastic or hard rubber) and an outer layer comprising a relatively hard material (e.g., steel or titanium). The inner layer of such a configuration can help to reduce material costs, reduce distortion caused by installing and removing the replaceable sheath on and from the power-boost fastener assembly, etc., while the outer layer provides protection to both the inner layer, as well as one or more components of the power-boost fastener assembly. Regardless of the particular material or materials from which the replaceable sheath 1100 is made, the replaceable sheath of embodiments provides a replaceable cover to provide protection with respect to one or more aspects of the power-boost fastener assembly.

[0113] The protrusions of the replaceable sheath 1100 surface covering at least a portion of the force-adjusting fastener assembly 130 can cover, or otherwise provide coverage to, one or more surfaces and / or components of the force-adjusting fastener assembly, and withstand impacts and abrasions during operation of the power tool to protect the surfaces, components, and / or other parts of the force-adjusting fastener assembly and inhibit damage thereto. For example, the replaceable sheath 1100 surface covering the outer circumference of the top housing of the force-adjusting fastener assembly can protect the top housing or a portion thereof and / or components thereon (e.g., the handle of the gripping member). Similarly, the replaceable sheath 1100 surface covering the circumferential surface of the force-adjusting fastener assembly can protect the side surfaces or circumferential surfaces or a portion thereof, and / or components thereon (e.g., the button of the locking member). Alternatively or concurrently, the replaceable sheath 1100 surface covering at least some portions of the force-enhancing fastener assembly 130 may cover and protect and / or seal one or more areas of the force-enhancing fastener assembly (e.g., the interface between components of the force-enhancing fastener assembly), thereby inhibiting foreign matter ingress. For example, the replaceable sheath 1100 surface covering the outer circumference of the top housing of the force-enhancing fastener assembly 130 may protect the interface between the top housing and the bottom structure (e.g., FIGS. 7A-7F The interface between the top housing 710 and the bottom structure 720 in the embodiment provides protection and prevents material from entering the internal cavity of the force-enhancing fastener assembly.

[0114] The replaceable sleeve of embodiments of the present invention may include one or more features configured to facilitate removably maintaining association between the replaceable sleeve and components of the force-enhancing fastener assembly. For example, the replaceable sleeve may include multiple different attachment points (e.g., through holes, channels, slots, gaskets, etc.) for receiving one or more fasteners (e.g., screws, bolts, rivets, adhesives, etc.) and / or attachment members (e.g., tabs, clips, latches, snaps, rings, etc.). Alternatively or additionally, the replaceable sleeve of embodiments of the present invention may include a variety of different forms of attachment members (e.g., tabs, clips, latches, rings, etc.) configured to engage a portion of one or more components of the force-enhancing fastener assembly for releasable attachment. For example, FIGS. 11A-11CThe illustrated embodiment of the replaceable boot 1100 includes locking tabs 1102a-1102c that are configured to facilitate the sliding of components of the power fastener assembly into a cavity of a cup-shaped housing formed by the replaceable boot, whereby the locking tabs engage one or more components of the power fastener assembly and maintain the replaceable boot in a nested relationship with other components of the power fastener assembly once the components of the power fastener assembly are fully nested within the replaceable boot 1100. For example, the locking tabs 1102a-1102c can provide spring tabs that deform radially outward to allow a structure of one or more components (e.g., a cup-shaped structure formed by the base structure 720) to enter a cavity of a cup-shaped housing formed by the replaceable boot. Once the structure of the power fastener assembly is fully nested within the cavity, the locking tabs 1102a-1102c can spring radially inward such that the clamps, barbs, and / or other features of the locking tabs engage corresponding features (e.g., a bottom edge, detents, slots, etc.) of the components of the power fastener assembly (e.g., the base structure 720) and removably retain the replaceable boot thereto. According to some examples, a gap between a bottom edge circumference of the replaceable boot 1100 and a bottom edge circumference of a corresponding base structure (e.g., the base structure 720) is small enough to facilitate the locking tabs 1102a-1102d engaging the base structure to maintain the replaceable boot and the base structure in a nested relationship. Additionally or alternatively, such a relationship with respect to a portion of the replaceable boot 1100 and a corresponding portion of a component of the power fastener assembly can be configured to prevent debris and / or other matter from seeping into an area enclosed and / or protected by the replaceable boot.

[0115] FIGS. 12A-12D Another example of a removable / replaceable outer surface cover having a protective surface for at least some portions of a power fastener assembly is illustrated. In particular, FIGS. 12A-12D The removable / replaceable outer surface cover of the example can be provided in the form of a replaceable cap configured to cover a portion of the power fastener assembly 130 according to embodiments of the present disclosure. In the illustrated example, an embodiment of the replaceable cap 1200 is provided in a configuration to cover at least a portion of a top surface of the power fastener assembly 130. Further, the replaceable cap 1200 of the illustrated embodiment can include one or more features (e.g., rib structures, surface texturing, rubber overmolding, gripping members, etc.) to facilitate gripping and application of force. For example, the illustrated embodiment of the replaceable cap 1200 includes rib structures arranged around a circumference of the replaceable cap, such as can be used to enable a user to grasp the power fastener assembly 130 and / or enhance a user’s grasp thereof.

[0116] The replaceable cap 1200 can have one or more protective surfaces (e.g., wear surfaces, abraded surfaces, sacrificial surfaces, etc.) configured to provide protection to one or more surfaces and / or components of the power fastener assembly. For example, the replaceable cap 1200 of embodiments can be constructed of a relatively hard material (e.g., steel, titanium, and / or composites thereof) to provide wear surfaces that are very slow to wear through and / or very slow to otherwise fail in the operation of the power tool in abrasive conditions, thereby protecting the surface and / or components underneath. As another example, the replaceable cap 1200 of embodiments can be constructed of a less hard material (e.g., aluminum, zinc alloy, and / or composites thereof) to provide abraded surfaces that are somewhat slow to wear through and / or somewhat slow to otherwise fail in the operation of the power tool in abrasive conditions, thereby protecting the surface and / or components underneath. In yet another example, the replaceable cap 1200 of embodiments can be constructed of a somewhat softer material (e.g., plastic, hard rubber, and / or composites thereof) to provide sacrificial surfaces that bear the brunt of the wear caused by the operation of the power tool in abrasive conditions. It should be appreciated that embodiments of the replaceable cap 1200 can be constructed of more than one material and / or materials having different properties. For example, some embodiments of the replaceable cap 1200 can include an inner layer comprising a somewhat softer material (e.g., plastic or hard rubber) and an outer layer comprising a relatively hard material (e.g., steel or titanium). The inner layer of such a configuration can help to reduce material costs, reduce distortion due to installation and removal of the replaceable cap, etc., while the outer layer provides protection to both the inner layer, as well as one or more components of the power fastener assembly. Regardless of the particular material or materials from which the replaceable cap 1200 is made, embodiments of the replaceable cap provide a replaceable cover to provide protection with respect to one or more aspects of the power fastener assembly.

[0117] The surface of the replaceable cap 1200 that covers at least a portion of the cover-up booster fastener assembly 130 can be a protrusion that covers one or more surfaces and / or components of the booster fastener assembly, or otherwise provides coverage thereof, and accepts impact and wear during operation of the power tool to protect surfaces, components, and / or other portions of the booster fastener assembly and inhibit damage thereto. For example, the surface of the replaceable cap 1200 that covers the top housing of the booster fastener assembly can provide protection to the top housing or a portion thereof and / or components thereon. Further, the surface of the replaceable cap 1200 that covers the top housing of the booster fastener assembly extends radially beyond (e.g., over) the side surface or circumferential surface of the booster fastener, and thus can provide protection to one or more components thereon (e.g., the button of the locking member, etc.). Additionally or alternatively, the surface of the replaceable cap 1200 that covers at least some portions of the booster fastener assembly 130 can cover and protect and / or enclose one or more areas of the booster fastener assembly (e.g., interfaces between components of the booster fastener assembly), thereby inhibiting the ingress of foreign matter. For example, the surface of the replaceable cap 1200 that covers the top housing of the booster fastener assembly 130 can provide protection to the interface between the top housing and the bottom structure (e.g., the interface between the top housing 710 and the bottom structure 720 of the embodiment of FIG. 10), and inhibit the ingress of material into the interior cavity of the booster fastener assembly. FIGS. 7A-7F

[0118] The replaceable cap 1200 of the embodiment has a removable / replaceable outer surface that covers some portions of the remainder of the booster fastener assembly for providing protection thereto. Accordingly, the replaceable cap of the embodiments of the present application can include one or more features configured to facilitate removably maintaining the replaceable sheath in association with components of the booster fastener assembly. For example, the replaceable cap of the embodiments of the present application can include a variety of different forms of attachment members (e.g., tabs, clips, snaps, clasps, etc.) configured to engage a portion of one or more components of the booster fastener assembly for releasable attachment therewith. Additionally or alternatively, the replaceable cap can include a variety of different attachment points (e.g., vias, channels, slots, pads, etc.) for accepting one or more fasteners (e.g., screws, bolts, nails, rivets, adhesives, etc.) and / or attachment members (e.g., tabs, clips, snaps, clasps, etc.). For example, FIGS. 12A-12D The illustrated embodiment of the replaceable cap 1200 includes a fastener 1201 (e.g., a mechanical screw) arranged through a via in the top housing thereof for threaded engagement with the top housing of the booster fastener assembly. FIGS. 12A-12D The illustrated embodiment of the replaceable cap 1200 further includes torque members 1202a and 1202b FIG. 12D configured to engage corresponding features of components of the booster fastener assembly (e.g.,​FIG. 12C The receiving element shown in the top housing of the top housing in the middle) helps to transfer tightening or loosening torque from the replaceable cap to other parts of the force-enhancing fastener assembly.

[0119] The removable / replaceable outer surface cover of embodiments of the present invention can be used alone or in combination. For example, some embodiments of the present invention may provide a replaceable sleeve (e.g., replaceable sleeve 1100) in combination with a replaceable cap (e.g., replaceable cap 1200) for protecting components of the force-enhancing fastener assembly in a form that can be easily replaced by the user.

[0120] The force-enhancing fastener assembly of this invention is configured to provide the mechanical advantage of rotating the fastening element, allowing the user to manually apply tightening or loosening torque by hand for tool-free replacement of removable tools. The configuration of the force-enhancing fastener assembly described herein can be used to replace conventional lock nuts for attaching removable tools to power tools, and even, in some cases, to modify conventional lock nuts. Accordingly, the force-enhancing fastener assembly of this invention allows for backward-compatible removable tool configurations.

[0121] Although the invention and its advantages have been described in detail, it should be understood that various changes, modifications, and alterations may be made herein without departing from the spirit and scope of the invention as defined in the appended claims. Furthermore, the scope of this application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, apparatuses, methods, and steps described in the specification. As will be readily understood by those skilled in the art from the disclosure of this invention, processes, machines, manufactures, compositions of matter, apparatuses, methods, or steps that are currently existing or will be developed in the future and perform substantially the same function or achieve substantially the same results as the corresponding embodiments described herein can be utilized according to the invention. Therefore, the appended claims are intended to include such processes, machines, manufactures, compositions of matter, apparatuses, methods, or steps within their scope.

[0122] Furthermore, the scope of this application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, material compositions, apparatuses, methods, and steps described in the specification.

Claims

1. A power-up fastener assembly for removably coupling a detachable implement to a power tool, the power-up fastener assembly comprising: a top housing; a bottom structure, wherein the top housing and bottom structure are configured to nest with one another and provide an enclosed area for housing one or more components of the power-up fastener assembly; a fastening element disposed between the top housing and the bottom structure and at least partially within the enclosed area, wherein the fastening element is configured to engage with a shaft of the power tool; a power-up gear train comprising a plurality of gears and at least one gear plate disposed in the enclosed area and in mechanical communication with the top housing, the bottom structure, and the fastening element, wherein the power-up gear train provides a mechanical advantage of applying torque to the fastening element in response to applying torque to the top housing; and a lock mechanism at least partially disposed within the enclosed area and functioning to inhibit rotation of the fastening element relative to the shaft in at least one rotational direction.

2. The booster assembly of claim 1, wherein, the lock mechanism comprising: a first lock element configured to prevent relative movement of the top housing relative to the gear plate in a first direction while allowing relative movement in a second direction when the lock mechanism is in a locked configuration.

3. The booster assembly of claim 2 wherein, the first lock element is configured to prevent relative movement of the top housing relative to the gear plate in the second direction while allowing relative movement in the first direction when the lock mechanism is in an unlocked configuration.

4. The booster assembly of claim 2 wherein, the first lock element comprises a lock pawl, and wherein the lock mechanism further comprises: a second lock element disposed in a pivotal relationship with the bottom structure, wherein the second lock element is configured to allow the lock pawl to enter a locked position of the lock mechanism locked configuration when a portion of the second lock element is in a radially outward position and to urge the lock pawl to enter an unlocked position of the lock mechanism unlocked configuration when the portion of the second lock element is in a radially inward position.

5. The booster assembly of claim 2 wherein, the first lock element comprises a lock pawl, and wherein the lock mechanism further comprises: a second lock element disposed in a linear traversing relationship with the bottom structure, wherein the second lock element is configured to allow the lock pawl to enter a locked position of the lock mechanism locked configuration when a portion of the second lock element is in an un-depressed position and to urge the lock pawl to enter an unlocked position of the lock mechanism unlocked configuration when the portion of the second lock element is in a depressed position.

6. The booster assembly of claim 5, wherein, the first lock element urges the lock pawl to enter the unlocked position via a third lock element.

7. The power-up fastener assembly of claim 1, further comprising: a grip member assembly disposed on a top surface of the top housing, wherein the grip member assembly is configured to facilitate a user manually applying torque to the top housing.

8. The booster assembly of claim 7, wherein, the grip member assembly comprising: a plate affixed to the top housing; and a handle hingedly disposed relative to the plate, wherein the handle is configured to be disposed in a use position and a storage position.

9. The booster assembly of claim 8, wherein, the plate comprising: a spring plate configured to urge the handle to remain in the use position when the handle is positioned in the use position and to remain in the storage position when the handle is positioned in the storage position.

10. The booster assembly of claim 1, further comprising: a removable and replaceable outer surface cover configured to provide a protective surface to at least a portion of the booster assembly.

11. The force multiplier fastener assembly set forth in Claim 10 wherein, the removable and replaceable outer surface cover comprises: a replaceable sheath covering at least a portion of the top housing and at least a portion of the bottom structure, wherein the replaceable sheath provides a protective surface to the at least a portion of the top housing and the at least a portion of the bottom structure, and wherein the replaceable sheath is configured to provide protection to at least a portion of the lock mechanism.

12. The booster assembly of claim 10, wherein, the removable and replaceable outer surface cover comprises: a replaceable cap covering at least a portion of the top housing, wherein the replaceable cap provides a protective surface to the at least a portion of the top housing, and wherein the replaceable cap is configured to provide protection to at least a portion of the lock mechanism.

13. A method for removably coupling a detachable implement to a power tool, the method comprising: docking a booster assembly with a shaft of the power tool, wherein the booster assembly comprises a top housing, a bottom structure, a fastening element, a booster gear train, and a lock mechanism, wherein the top housing and bottom structure are configured to nest with one another and provide an enclosed area for housing one or more components of the booster assembly; wherein the fastening element is disposed between the top housing and the bottom structure and at least partially within the enclosed area, wherein the fastening element is configured to engage with the shaft of the power tool, wherein the booster gear train comprises a plurality of gears and at least one gear plate disposed in the enclosed area and in mechanical communication with the top housing, the bottom structure, and the fastening element, wherein the booster gear train provides a mechanical advantage of exerting a torque at the fastening element in response to a torque applied to the top housing, and wherein the lock mechanism is at least partially disposed within the enclosed area and functions to inhibit rotation of the top housing relative to the gear plate in at least a loosening direction; engaging a first lock element of the lock mechanism and bringing a second lock element of the lock mechanism into an unlocked position configured to allow rotation of the top housing relative to the gear plate in a loosening direction; and applying a torque to the top housing in the loosening direction and causing a torque at the fastening element in the loosening direction, wherein rotation of the top housing relative to the gear plate causes the booster gear train to provide a mechanical advantage of causing a torque at the fastening element.

14. The method of claim 13, wherein, the second lock element is configured to prevent relative movement of the top housing relative to the gear plate in the loosening direction when the lock mechanism is in a loosening configuration, while allowing relative movement in a tightening direction when the lock mechanism is in a locking configuration.

15. The method of claim 14, wherein, the second lock element is configured to prevent relative movement of the top housing relative to the gear plate in the tightening direction when the lock mechanism is in an unlocked configuration, while allowing relative movement in the loosening direction when the lock mechanism is in a locked configuration.

16. The method of claim 14, wherein, the second lock element comprises a lock pawl, and wherein the first lock element is disposed in a pivoting relationship with the bottom structure, the method further comprising: releasing the first lock element to move to a radially outward position and causing the second lock element to enter a locked position, the locked position configured to inhibit rotation of the top housing relative to the gear plate in the loosening direction.

17. The method of claim 14, wherein, The second lock element includes a lock pawl, and wherein the first lock element is arranged in linear traverse relation with the bottom structure, the method further comprising: releasing the first lock element to move to an un-depressed position and causing the second lock element to enter a locked position.

18. The method of claim 13, further comprising: moving a handle of a grip member assembly arranged on a top surface of the top housing between a storage position and a use position, wherein the grip member assembly is configured to facilitate a user manually applying torque to the top housing, and wherein applying torque to the top housing in the loosening direction comprises: applying torque to a handle of the grip member assembly arranged on a top surface of the top housing in the loosening direction.

19. The method of claim 18, wherein, The grip member assembly includes a spring plate affixed to the top housing, and wherein the spring plate is configured to cause the handle to remain in the use position when the handle is positioned in the use position and to cause the handle to remain in the storage position when the handle is positioned in the storage position.

20. The method of claim 13, further comprising: covering at least a portion of the force multiplier fastener assembly with a removable and replaceable outer surface cover, the outer surface cover configured to provide a protective surface to at least a portion of the force multiplier fastener assembly.

21. The method of claim 20, wherein, The removable and replaceable outer surface cover includes a replaceable sheath covering at least a portion of the top housing and at least a portion of the bottom structure, wherein the replaceable sheath provides a protective surface to the at least a portion of the top housing and the at least a portion of the bottom structure, and wherein the replaceable sheath is configured to provide protection to at least a portion of the lock mechanism.

22. The method of claim 20, wherein, The removable and replaceable outer surface cover includes a replaceable cap covering at least a portion of the top housing, wherein the replaceable cap provides a protective surface to the at least a portion of the top housing, and wherein the replaceable cap is configured to provide protection to at least a portion of the lock mechanism.

23. A system for removably coupling a detachable implement to a power tool, the system comprising: A power-up fastener assembly comprising a top housing, a bottom structure, a fastening element, a power-up gear train, and a lock mechanism, wherein the top housing and bottom structure are configured to nest with one another and provide an enclosed area for housing one or more components of the power-up fastener assembly; wherein the fastening element is disposed between the top housing and the bottom structure and at least partially within the enclosed area, wherein the fastening element is configured to engage with a shaft of the power tool, wherein the power-up gear train comprises a plurality of gears and at least one gear plate disposed in the enclosed area and in mechanical communication with the top housing, the bottom structure, and the fastening element, wherein the power-up gear train provides a mechanical advantage of applying torque to the fastening element in response to applying torque to the top housing, and wherein the lock mechanism is at least partially disposed within the enclosed area and functions to inhibit rotation of the top housing relative to the gear plate in at least a loosening direction; and An outer surface cover configured to provide a removable and replaceable protective surface for at least a portion of the power-up fastener assembly.

24. The system of claim 23, wherein, The outer surface cover comprises: A replaceable sheath covering at least a portion of the top housing and at least a portion of the bottom structure, wherein the replaceable sheath provides a protective surface for the at least a portion of the top housing and the at least a portion of the bottom structure, and wherein the replaceable sheath is configured to provide protection for at least a portion of the lock mechanism.

25. The system of claim 23, wherein, The outer surface cover comprises: A replaceable cap covering at least a portion of the top housing, wherein the replaceable cap provides a protective surface for the at least a portion of the top housing, and wherein the replaceable cap is configured to provide protection for at least a portion of the lock mechanism.

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