Power tool accessory

Abstract

Systems and methods are described that provide a power-up fastener assembly configured for use with a detachable implement for a power tool. The power-up fastener assembly can implement various gear train configurations to provide mechanical advantages for manual manipulation of the fastener assembly. The power-up fastener assembly can include a lock mechanism that functions to lock and / or unlock the power-up fastener assembly and its fastening elements. The power-up fastener assembly of the present embodiments can be used in place of a conventional lock nut for attaching a detachable implement to a power tool.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to garden machines having detachable implements, and more particularly to a fastener usable with detachable implements for power tools. BACKGROUND

[0002] Power tools of various configurations are commonly used to perform routine tasks in everyday 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., electric or internal combustion) that outputs power via a shaft, which drives an implement configured for the associated 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.

[0003] The implements can be configured to be detachable from the host 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 dulling the edge sharpened prior thereto, or replacing a dull grass cutting blade with a sharp one, etc.).

[0004] Typically, one or more tools are required to replace (e.g., remove and / or install) the detachable implement. For example, a manual tool in the form of a wrench (e.g., an open end wrench, a socket wrench, or an adjustable wrench) 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.) on a shaft assembly (e.g., a main shaft) of the power tool to which the implement is attached is required to replace the detachable implement. Additionally, a manual tool in the form of a brace or a second wrench is typically required to prevent movement of the shaft and implement when the fastener on the shaft assembly of the power tool to which the implement is attached is tightened or loosened to replace the detachable implement. As an alternative to a second manual tool, some implementations use a pin that can be manually pushed into an aligned hole to lock the main shaft of the power tool. As another alternative to a second manual tool, such as can be implemented with power tools that do 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 main shaft lock.

[0005] In many situations, the fasteners on the power tool to which the implement is attached are tightened in place 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, a wrench used to replace the removable implement must have sufficient length and durability to permit sufficient force to be applied to the nuts that secure the implement to the garden machine, such as when the implement is loosened.

[0006] Storing a hand tool suitable for replacing a removable 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, presence of perceptible vibrations, etc. can cause the hand tool to be dislodged from its storage space and lost. Additionally, power tools having removable implements are often operated in areas that are remote from repair facilities or from places where tools suitable for replacing the removable implement 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 appropriate size for replacing the removable 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.

[0007] The fasteners are often not manipulable by hand (e.g., without the aid of a separate tool) to remove and replace the removable implement, typically due to the force required. For example, as noted above, the fasteners can have been tightened in place with an appropriate torque, where a typical user can not be able to apply sufficient counter-torque (e.g., on the order of 12 Nm) to facilitate loosening of the fasteners. Similarly, a user can not typically be able to apply sufficient torque to the fasteners by hand to sufficiently tighten the fasteners in place to prevent unwanted relative displacement of the implement during use due to driving forces.

[0008] Various special configured detachable implements have been proposed to prevent unwanted relative displacement of the implement during use, even when the fastening means 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 special configured detachable implements typically do not provide a backward compatible solution. Furthermore, the lack of sufficient torque when applying the fastening means by hand to attach the special configured blade to the lawn mower can not cause a frictional interface between the fastening means and the blade to prevent the fastening means from rotating in a release direction and disengaging from the lawn mower. Accordingly, EP 2 798 937 B1 proposes a latch for the fastening means. The proposed latch provides a manually operated latch element, wherein two levers are pivotably mounted on the blade holder and are used to release the fastening means. The configuration of the latch element and the levers on the blade holder exposes these components to objects encountered by the lawn mower, 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, thereby creating a large friction between the relative movement of the components, such as can result in a larger required actuation force, or even loss of the 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 a considerable force. As a result, the latch can suffer damage, or even malfunction, such as can result in the latch no longer being able to be manually manipulated and / or the latch being accidentally released, thereby enabling the fastening means to be detached from the lawn mower.

[0009] Quick connect detachable implements of special configuration have also been attempted. However, such detachable implements and / or their quick connect devices have many drawbacks. For example, the quick connect detachable implements typically utilize a special shank or shape design for torque transmission instead of the commonly used friction flange and nut design, and thus cannot provide a backward compatible solution. Furthermore, many power tools, such as lawn mowers and brush trimmers, have high requirements for the detachable implements (e.g., blades) to withstand impact forces due to impacting other objects, which is typically not satisfied by the solutions of quick connect detachable implements.

[0010] From the foregoing, it can be appreciated that existing solutions are typically insufficient to facilitate the convenient replacement of detachable implements utilized for a variety of different power tools. For example, while the implements have been configured for detachment and reattachment, replacing the detachable implements is typically inconvenient, and sometimes even impossible. Even where the detachable implements can be replaced, doing so is typically inconvenient (e.g., separate tools must be carried, sufficient force must be applied to cause the user's hand to feel pain or discomfort, etc.). SUMMARY

[0011] The present invention relates to systems and methods that provide power-up fastener assemblies configured for use with detachable implements for power tools. The power-up fastener assemblies of the present invention embodiments can implement gear trains configured to provide the mechanical advantages of manually manipulating (e.g., grasping by hand to manually apply a tightening or loosening torque) the fastener assemblies. For example, various power-up gear train configurations can be used with the power-up fastener assemblies according to the concepts of the present invention to provide the necessary mechanical advantages.

[0012] According to the present invention embodiments, a power-up fastener assembly can include a planetary gear device arranged within a hand graspable housing to provide mechanical advantages in fastener manual tightening and / or loosening forces. Additionally or alternatively, the power-up fastener assemblies of the embodiments can include a cycloidal gear device arranged within a hand graspable housing to provide mechanical advantages in fastener manual tightening and / or loosening forces.

[0013] The power-up fastener assemblies of the present invention embodiments can be used in place of conventional lock nuts for attaching detachable implements to power tools. For example, the power-up fastener assemblies of the embodiments can be used to secure blade assemblies to host lawn care machines (e.g., lawn mowers, bush trimmers, lawn edgers, etc.). However, it should be appreciated that the power-up fastener assemblies provided according to the concepts herein can be used in a wide variety of applications and with a wide 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 power-up fastener assemblies are used, the power-up fastener assemblies of the embodiments facilitate the 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 the detachable implement). For example, when used in a lawn mower, the power-up fastener assemblies can be directly operated by hand (e.g., tool-free) to effect installation, removal, replacement, etc. of the cutting blade. Accordingly, the power-up fastener assemblies of the present invention embodiments can provide a tool-free implement replacement mechanism in which replacing (e.g., installing, removing, replacing, etc.) the detachable implement for the host power tool is facilitated without the aid of a separate tool.

[0014] 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 according to embodiments, the fastening element (e.g., a nut or other threaded fastening device) can be rotated by the force multiplier fastener assembly in a fastening direction to secure, install, tighten, etc. a blade or other detachable implement onto a motor shaft, where such rotation is reversible. That is, the fastening element can be rotated in a release direction opposite the fastening direction to unsecure, 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 unsecure or release undesirably or accidentally.

[0015] 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 operation of the lock mechanism to allow the force multiplier to rotate in a release direction, otherwise the force multiplier fastener assembly can only rotate in a fastening direction. Additionally or alternatively, the lock mechanism 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 mechanism 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 servicing). According to some examples, rotation of the detachable implement and corresponding force multiplier fastener assembly at a certain speed provides sufficient centrifugal force to cause a pawl of the lock mechanism in the force multiplier fastener assembly to engage and lock the fastening element (e.g., a nut), thereby inhibiting rotation of the force multiplier fastener assembly and fastening element 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 force multiplier fastener assembly and fastening element therein in a fastening direction and / or a release direction. According to another example, a lock pawl of the lock mechanism of the force multiplier fastener assembly engages by gravity when the force multiplier fastener 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 force multiplier fastener assembly is facing upward (e.g., the host power tool is in a service orientation).

[0016] The foregoing has outlined rather broadly the features and technical advantages of the present application so as to provide an overall understanding of the detailed description that follows. Additional features and advantages of the present application will be described hereinafter that form the subject of the claims of the application. Those skilled in the art will appreciate that the conception, upon which, the disclosure is based, can be readily utilized as the basis for the designing of other structures for carrying out the same purposes of the present application. It will be realized by those skilled in the art that such equivalent structures do not depart from the spirit and scope of the application as set forth in the appended claims. It is therefore BRIEF DESCRIPTION OF DRAWINGS

[0017] 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:

[0018] Figure 1 A portion of a power tool is shown to which a power-up fastener assembly according to embodiments of the present application is provided;

[0019] Figures 2A-2E A plurality of different views of a power-up fastener assembly according to embodiments of the present application implementing an exemplary planetary gear train are shown;

[0020] Figures 3A-3E A plurality of different views of a power-up fastener assembly according to embodiments of the present application implementing an exemplary cycloidal gear train are shown;

[0021] Figure 4A Details of an exemplary lock mechanism for a power-up fastener assembly according to embodiments of the present application are shown in FIG. 7B. DETAILED DESCRIPTION

[0022] Figure 1A 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 (dadoblade), etc.

[0023] exist Figure 1 In 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.

[0024] like Figure 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 Figure 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... Figure 1Not 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 Figure 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.

[0025] An example of a power tool 100 illustrates a force-enhancing fastener assembly 130 of the present invention for securing a removable device 120 to the shaft 111 of a motor assembly 110. The force-enhancing fastener assembly 130 can, for example, be used in place of a conventional lock nut for attaching the removable device 120 to the power tool 100 (e.g., in some cases, a conventional lock nut is modified, or in others, the initial fastener device is activated). According to embodiments of the invention, the force-enhancing fastener assembly 130 facilitates manual (e.g., by hand) application of force to loosen (e.g., in the release direction) and / or tighten (e.g., in the tightening direction) the force-enhancing fastener assembly 130 to replace the removable device 120.

[0026] Through specific examples that aid in understanding the concept of this invention, one can use... Figures 2A-2E A booster fastener assembly 130 replaces the blade for a bush trimmer or lawnmower (e.g., a bush trimmer or lawnmower mechanism of a power tool 100 with a blade configuration detachable device 120). Manually actuating the booster 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 trimmer or lawnmower. When a new blade is attached to the motor shaft, actuating the booster fastener assembly 130 can tighten the fastener assembly onto the shaft 111, thereby attaching the blade to the bush trimmer or lawnmower.

[0027] The force-amplifying fastener assembly 130 of this embodiment implements a force-amplifying gear train configured to provide the mechanical advantage of manually operating the fastener assembly. During operation of the force-amplifying gear train of the force-amplifying fastener assembly 130, the force applied by the user to the force-amplifying fastener assembly 130 (e.g., by manually applying tightening or loosening torque by gripping the housing of the fastener assembly) (e.g., torque applied in the tightening direction and / or torque applied in the releasing direction) is amplified as it is transmitted to the fastening elements of the fastener assembly. Thus, the force that the user can appropriately apply to the rotation of the fastening elements is greater than the force that the user can apply directly to engage the fastening elements.

[0028] Various force-amplifying gear configurations can be used with the force-amplifying fastener assembly 130 of the embodiments to provide necessary mechanical advantages. According to some embodiments of the invention, the force-amplifying fastener assembly 130 may include a planetary gear arrangement disposed within a hand-gripable housing to provide mechanical advantages in terms of manual tightening and / or loosening force of the fastener. Alternatively or additionally, the force-amplifying fastener assembly 130 of the embodiments may include a cycloidal gear arrangement disposed within a hand-gripable housing to provide mechanical advantages in terms of manual tightening and / or loosening force of the fastener. The mechanical advantages provided by such force-amplifying gear configurations, for example, can provide a force amplification of approximately 3 to 15 times between the manual force applied to the housing of the fastener assembly and the counter-stress applied to the fastening elements of the fastener assembly. Therefore, the force applied to the fastening element (as amplified by the force-enhancing fastener assembly 130 of the embodiment) is sufficient to overcome the static force that positions the fastener element with appropriate torque (e.g., intentionally to prevent undesirable relative displacement of the detachable device during use due to driving forces and / or impacts; or unintentionally due to undesirable relative displacement due to inertial tightening associated with the applied driving force). Furthermore, the force-enhancing gear system of the embodiments of the invention facilitates the implementation of a reliable locking mechanism.

[0029] According to embodiments of the invention, the force-enhancing fastener assembly 130 can be manually engaged by a user to fasten and / or loosen the removable appliance 120 to and / or from the power tool 100 without the aid of a separate tool. Accordingly, the force-enhancing fastener assembly 130 of the embodiments can provide a tool-free appliance replacement configuration.

[0030] Embodiments of the power tool 100 can be configured to facilitate the replacement of the removable tool 120 using the force-adjusting fastener assembly 130 without the aid of a separate tool. For example, the power tool 100 may include a motor shaft locking device 140 that works cooperatively with the force-adjusting fastener assembly 130 to facilitate the replacement of the power tool 100 relative to the removable tool 120. According to some examples, the motor shaft locking device 140 may be engaged without the aid of a separate tool to prevent movement of the shaft 111 when the removable tool 120 is attached to and / or removed from the shaft 111. For example, the motor shaft locking device 140 may 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 may include a one-way bearing that acts as a reverse rotation lock for the shaft 111. According to yet another example, the motor shaft locking device 140 may include a locking collar configuration, wherein the locking collar includes a wide slot section and a narrow slot section configured to selectively allow and assemble rotation of the shaft 111. For example, in the operation of some example locking collars, when the shaft 111 is within the wide slot section, the shaft 111 and the locking collar do not engage and the shaft 111 rotates freely. However, when the locking collar slides laterally relative to the shaft 111, the shaft 111 is arranged within the narrow slot section such that the shaft 111 engages with the locking collar, thereby inhibiting rotation of the shaft 111 (e.g., a portion of the shaft 111 arranged adjacent to the locking collar may have a square cross-section configured to cooperate with the narrow slot section of the locking collar to engage and inhibit rotation of the shaft 111 when the motor shaft locking device 140 is engaged).

[0031] According to some embodiments of the invention, regardless of the specific configuration of the motor shaft locking device 140, the motor shaft locking device 140 can operate cooperatively with the force-enhancing fastener 130 to facilitate the attachment of the removable device 120 to or removal of the removable device 120 from the motor shaft assembly of the power tool 100 without the use of additional tools. For example, the operator of the power tool 100 can install and / or remove the removable device 120 by engaging the motor shaft locking device 140 (e.g., by manual or automatic engagement) and loosening or tightening the force-enhancing fastener assembly 130 by manual operation.

[0032] It should be understood that embodiments of the force-enhancing fastener assembly 130 described herein may be used with or without another configuration of the power tool 100 to facilitate the replacement of the removable tool 120. For example, some embodiments of the force-enhancing fastener assembly 130 may be used without a motor shaft locking device (e.g., a power tool 100 without a motor shaft locking device 140). In one example, a user may manually prevent the removable tool 120 from rotating (e.g., by grasping the unsharpened portion of the blade configuration of the removable tool 120, such as the handle portion, with one hand) while manually manipulating the force-enhancing fastener assembly 130 in the fastening direction with the other hand.

[0033] Figures 3A-3E and Figures 2A-2E Details of several different embodiments of the force-enhancing fastener assembly 130 are shown. In particular, Figures 3A-3E Details of an embodiment of a force-boosting fastener assembly 130 are shown, which implements a planetary gear configuration to provide the mechanical advantage of manually operating the fastener assembly. Similarly, Figures 2A-2E Details of an embodiment of a force-amplifying fastener assembly 130 are shown, which implements a cycloidal gear configuration to provide the mechanical advantage of manually operating the fastener assembly. While planetary gear and cycloidal gear configurations are shown in the illustrated examples, it should be understood that other forms of gear trains (e.g., double reduction gear configurations, reverse gear configurations, etc.) can be utilized in addition to or as alternatives to planetary and / or cycloidal gear configurations. Furthermore, various types of gear arrangements (e.g., gear train configurations including combinations of planetary and cycloidal gear arrangements) can be utilized in the gear trains of some embodiments of the force-amplifying fastener assembly 130.

[0034] First see Figure 2A An exemplary embodiment of the planetary gear configuration is implemented therein. Figure 2B and Figure 2A The planetary gear configuration of an embodiment of the force-amplifying fastener assembly 130 in its assembled state is shown. Figure 2B As shown in the isometric top view, the planetary gear configuration presented includes a top housing 210. Accordingly, as... Figure 2C As shown in the isometric bottom view, the planetary gear configuration includes a bottom structure 220. It should be understood that although the views, housings, and structures are referred to as top and bottom, the names are relative, and there is no limitation on the exemplary power-enhancing fastener assembly being arranged or utilized in any particular orientation relative to the top and bottom. For example, when used with the lawnmower implementation of the power tool 100, the top housing 210 can be oriented downwards when mounted on the shaft 111 and with the detachable tool 120 in the form of a mower blade attached to the power tool 100.

[0035] The top housing 210 and bottom structure 220 are configured to cooperatively enclose the planetary gear train and fastening elements of the exemplary force-enhancing fastener assembly. For example, in Figure 2D and Figure 1 As can be seen in the partially exploded view, the bottom structure 220 can form a cup-shaped structure, the size and shape of which are determined to nest within a cup-shaped outer shell formed by the top shell 210. According to some examples, the top edge circumference of the bottom structure 220 may terminate at or very close to the bottom-facing surface of the top shell 210 when fully nested within the top shell 210, for example, to enclose components of a planetary gear train and provide a substantially enclosed area that inhibits the penetration of debris and / or other substances. However, the nesting relationship between the top shell 210 and the bottom structure 220 of the embodiment allows for relative rotational movement between the top shell and the bottom structure (e.g., the top shell 210 may rotate while the nested bottom structure 220 remains stationary).

[0036] According to an exemplary embodiment, the locking tabs 211a to 211d of the top housing 210 facilitate the sliding of the bottom structure 220 into the cavity of the cup-shaped outer shell formed by the top housing 210, wherein once the bottom structure 220 is fully nested within the top housing 210, these locking tabs maintain the nested relationship between the top housing and the bottom structure. For example, in the illustrated embodiment, the bottom structure 220 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 engagement of the locking tabs 211a to 211d of the top housing 210 with the bottom structure 220, thereby facilitating the maintenance of the nested relationship between the top housing and the bottom structure. Alternatively or additionally, this relationship between the bottom edge circumference of the top housing 210 and the bottom edge circumference of the bottom structure 220 can be configured to prevent debris and / or other substances from penetrating into the area enclosed by the top housing and the bottom structure.

[0037] The top housing 210 of the embodiment can be configured to facilitate manual manipulation by a user. For example, the size and shape of the top housing 210 can be determined to facilitate hand gripping, allowing the user to manually apply torque (e.g., torque in the tightening and / or releasing direction) to the force-enhancing fastener assembly 130. Alternatively or additionally, the top housing 210 may include surface features that facilitate gripping and force application (e.g., ribs, surface irregularities, rubber-coated molding, etc.). For example, the illustrated embodiment of the top housing 210 includes ribs 213a to 213d arranged circumferentially around the top housing, which may be used to enable the user to grip the force-enhancing fastener assembly 130 and / or enhance the user's grip on it.

[0038] The bottom structure 220 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 221 of the bottom structure 220 in the illustrated embodiment can be determined to allow one end of the shaft 111 to be inserted therein. According to some examples, the shaft aperture 221 can 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., Figures 2A-2E 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).

[0039] Figure 2C 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 230 in response to manual operation (e.g., by hand gripping to manually apply torque in the tightening or loosening direction) of the fastener assembly. Accordingly, as Figure 2D As shown, the top housing 210 of the exemplary embodiment includes the sun gear 212 of the planetary gear train in the illustrated planetary gear configuration of the force-reinforcing fastener assembly 130. Figure 2E As shown, the bottom structure 220 includes a ring gear 222 of an exemplary planetary gear train. Figures 2A-2E The planetary gear assembly 240, visible in a further exploded view (omitting some components of the exemplary embodiment of the force-amplifying fastener assembly 130), includes planetary gears 242a to 242c that mesh between the sun gear 212 and the ring gear 222 to provide an implementation of a planetary gear arrangement. Specifically, 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, wherein once the bottom structure 220 is fully nested within the top housing 210, the planetary gears 242a to 242c are enclosed within the internal regions of the top housing and the bottom structure, providing gear engagement between the sun gear 212 and the ring gear 222.

[0040] According to an embodiment, 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 rotates (e.g., in response to a user manually applying a torque force to it), the sun gear 212 of the embodiment will rotate accordingly. Similarly, the ring gear 222 may rotate correspondingly to or not correspondingly to the bottom structure 220. The enclosed relationship of the planetary gear assembly 240 within the internal region of the bottom structure 220 nested within the top housing 210 allows for relative rotational movement of the gear plate 241 relative to the top housing and the bottom structure. For example, the top housing 210 may rotate while the nested bottom structure 220 remains stationary, and the gear plate 241 may rotate at a speed different from that of the top housing 210. That is, the rotation of the top housing 210, and thus the sun gear 212 meshing with the planetary gears 242a to 242c, causes the planetary gears to rotate in the opposite direction, wherein the planetary gears 242a to 242c mesh with the ring gear 222 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 larger torque force.

[0041] The planetary gear assembly 240 includes a fastening element housing 243 configured to receive a fastening element 230 coaxially corresponding to a shaft bore 221. Accordingly, the fastening element housing 243 of the illustrated embodiment includes a shaft bore 244, the size and shape of which are determined to allow one end of a shaft 111 to be inserted therein, wherein a fastening element disposed within a receiving cavity 245 of the fastening element housing 243 can mate with the shaft 111. The size and shape of the fastening element housing 243 of the illustrated embodiment are determined to extend into and be nested within the inner circumference of the sun gear 212 when the planetary gear assembly 240 is enclosed within a nested top and bottom housing structure. Accordingly, the fastening element 230 disposed within the receiving cavity 245 can be captured in the space between the fastening element housing 243 and the top housing 210 of the embodiment of the invention.

[0042] The fastening element housing 243 may be attached to or formed as part of the gear plate 241 of the illustrated embodiment. Accordingly, when the gear plate 241 rotates, the fastening element housing 243 of the embodiment will rotate accordingly. The receiving cavity 245 of the embodiment is configured to cause the fastening element 230 to rotate correspondingly with respect to the gear plate 241. The fastening element 230 of the embodiment may include a nut or other threaded fastening device configured to rotate on the power member in both a fastening and release direction. For example, the illustrated embodiment of the fastening element 230 includes a nut that is suitably screwed into to engage one end of the shaft 111 of the power tool 100, for example, for securing, mounting, tightening, etc., of a removable tool 120 onto the shaft 111. Accordingly, the receiving cavity 245 of the fastening element housing 243 of the illustrated embodiment is shaped to receive the fastening element 230 and provide control over its movement relative to the shaft 111. For example, the illustrated embodiment of receiving cavity 245 includes a hexagonal circumference, corresponding to the shape of the exemplary nut implementation of fastening element 230.

[0043] Although Figures 2A-2E The fastening element 230 shown in the example is described as being disposed in the receiving cavity 245 of the fastening element housing 243 on the gear plate 241; however, it should be understood that fastening elements of other configurations can be utilized according to embodiments of the invention. For example, instead of providing a separate component (nut) for the fastening element 230, some embodiments of the fastening element 230 may be integrally formed with another component of the force-enhancing fastener assembly 130. As a particular example, the fastening element 230 may be formed as a suitable threaded portion of the shaft bore 244, the size and shape of which are determined to correspond to the size and shape of one end of the shaft 111.

[0044] exist Figures 3A-3E In the operation of the force-amplifying fastener assembly 130 of the embodiment, when the shaft 111 is inserted through the orifices 221 and 244 and abuts against the fastener element 230, the user can grasp the top housing 210 by hand and rotate it in the tightening or loosening direction to rotate the fastener element 230 accordingly relative to the shaft 111. The sun gear 212, planet gears 242a to 242c, and ring gear 222 of the planetary gear train provide the mechanical advantage of applying tightening or loosening torque to the fastener element 230. A mechanical advantage corresponding to the magnitude relationship (e.g., approximately 3 to 5 times) between the torque manually applied to the top housing 210 and the resulting torque applied to the fastener element 230 can be achieved between the torque applied to the top housing 210 and the torque applied to the fastener element 230.

[0045] An embodiment of the force-increasing fastener assembly 130 has already been described; now, reference is made to... Figure 3A An exemplary embodiment of the cycloidal gear configuration is implemented therein. Figure 3B and Figure 3AThe cycloidal gear configuration of an embodiment of the force-amplifying fastener assembly 130 in its assembled state is shown. Figure 3B As shown in the isometric top view, the cycloidal gear configuration presented includes a top housing 310. Accordingly, as Figures 3C-3E As shown in the isometric bottom view, the cycloidal gear configuration includes a bottom structure 320. It should be understood that although the views, housing, and structure are referred to as top and bottom, the names are relative, and there is no limitation on the exemplary power-enhancing fastener assembly being arranged or utilized in any particular orientation relative to the top and bottom. For example, when used with the lawnmower implementation of the power tool 100, the top housing 310 can be oriented downwards when mounted on the shaft 111 and the detachable device 120 in the form of a mower blade is attached to the power tool 100.

[0046] The top housing 310 and bottom structure 320 are configured to cooperatively enclose the cycloidal gear train and fastening elements of the exemplary force-enhancing fastener assembly. For example, in Figures 3A-3E As can be seen in the partially exploded view, the bottom structure 320 can form a cup-shaped structure, the size and shape of which are determined to nest within a cup-shaped outer shell formed by the top shell 310. According to some examples, the top edge circumference of the bottom structure 320 may terminate at or very close to the bottom-facing surface of the top shell 310 when fully nested within it, for example, to enclose components of a cycloidal gear train and provide a substantially enclosed area that inhibits the penetration of debris and / or other substances. The nesting relationship between the top shell 310 and the bottom structure 320 of the embodiment allows for relative rotational movement between the top and bottom structures (e.g., the top shell 310 can rotate while the nested bottom structure 320 remains stationary).

[0047] As in Figure 1 As can be seen, an exemplary cycloidal gear configuration of the force-enhancing fastener assembly 130 includes a bottom housing 301 configured to enclose components of the gear train and / or a locking mechanism used therewith within a cup-shaped structure of a top housing 310. The illustrated bottom housing 301 comprises 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 a region within the concave surface of the cup-shaped structure of the top housing. For example, a bottom structure 320 can be enclosed by the bottom housing 301, wherein at least a portion of the bottom structure 320 is disposed within the concave surface of the cup-shaped structure of the top housing. According to an embodiment of the invention, the bottom structure 320 is freely axially rotatable relative to the top housing 310 and the bottom housing 301 attached to the top housing 310.

[0048] In the example shown, the size of the bottom structure 320 is determined to provide a clearance relative to the components of an embodiment of the locking mechanism (described in detail below). The configuration of the bottom housing 301 may provide a skirt flange and / or other structures to significantly close 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 substances from penetrating into the area of ​​the locking mechanism and / or helping to maintain the nested relationship between the top housing and the bottom structure.

[0049] The top housing 310 of the embodiment can be configured to facilitate manual operation by the user. For example, the size and shape of the top housing 310 can be determined to facilitate hand gripping, allowing the user to manually apply torque (e.g., torque in the tightening and / or releasing direction) to the force-enhancing fastener assembly 130. Alternatively or additionally, the top housing 310 may include surface features that facilitate gripping and force application (e.g., ribs, surface irregularities, rubber-coated molding, etc.). For example, the illustrated embodiment of the top housing 310 includes ribs 313a to 313h arranged circumferentially around the top housing, which may be used to enable the user to grip the force-enhancing fastener assembly 130 and / or enhance the user's grip on it.

[0050] The bottom structure 320 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 321 of the bottom structure 320 in the illustrated embodiment can be determined to allow one end of the shaft 111 to be inserted therein. According to some examples, the shaft aperture 321 can 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., Figures 3A-3E 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).

[0051] Figure 3C The force-amplifying fastener assembly 130 of the embodiment implements a cycloidal gear train, which is configured to provide the mechanical advantage of applying tightening or loosening torque to the fastening element 330 in response to manual operation (e.g., by hand gripping to manually apply torque in the tightening or loosening direction) of the fastener assembly. Accordingly, as Figure 3DAs shown, the top housing 310 of the exemplary 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 force-amplifying fastener assembly 130. The eccentric receiver 312 of the embodiment is arranged slightly eccentrically within the bottom-facing surface of the top housing 310, wherein as the top housing 310 rotates, the eccentric receiver 312 rotates about or around a center point on the bottom-facing surface. Figure 3E As shown, the bottom structure 320 includes a ring gear 322 of an exemplary cycloidal gear train. Figures 3A-3E In a further exploded view, the cycloidal gear assembly 340 (omitting some components of the exemplary embodiment of the force-enhancing fastener assembly 130) engages 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 disk 341 and roller pins 342a to 342f arranged on a pin plate 343, wherein when the cycloidal gear assembly 340 is assembled, the roller pins 342a to 342f are inserted into corresponding orifices 344a to 344f of the cycloidal disk 341. The shaft 346 of the cycloidal disk 341 engages with the eccentric receiver 312 via a bearing 345 of the illustrated embodiment. The cycloidal gear assembly 340 of the illustrated embodiment is received within the cavity of a cup-shaped structure formed by the bottom structure 320, wherein once the bottom structure 320 is fully nested within the top housing 310, the cycloidal gear assembly 340 is enclosed within the internal regions of the top and bottom structures and provides engagement between the eccentric receiver 312 and the ring gear 322.

[0052] According to an embodiment, the eccentric receiver 312 is formed as part of or otherwise attached to the top housing 310, while the ring gear 322 is attached to or formed as part of the bottom structure 320. Accordingly, when the top housing 310 rotates (e.g., in response to a user manually applying a torque force to it), the eccentric receiver 312 of the embodiment rotates eccentrically (e.g., about the center point of the bottom surface of the top housing 310), thereby causing the cycloidal gear assembly 340 to rotate eccentrically via the shaft 346. Similarly, the ring gear 322 may rotate correspondingly or not correspondingly with the bottom structure 320. The enclosed relationship of the cycloidal gear assembly 340 within the internal region of the bottom structure 320 nested within the top housing 310 allows for relative rotational movement of the pin plate 343 relative to the top housing and the bottom structure. For example, the top housing 310 may rotate while the bottom structure 320 nested therein remains stationary, and the pin plate 343 may rotate at a speed different from that of the top housing 310. That is, the rotation of the top housing 310, and thus the eccentric receiver 312 which is mated with the cycloidal disk 341, causes the cycloidal disk to rotate in an eccentric motion, wherein the cycloidal disk 341, which engages with the convex angle of the ring gear 322 held stationary by the bottom structure 320, engages the roller pins 342a to 342f via orifices 344a to 344f to transmit rotational force to the pin plate 343, albeit at a reduced rotational rate and with a greater torque force.

[0053] The cycloidal gear assembly 340 includes a fastening element 330 arranged coaxially with a shaft bore 321. For example, the illustrated embodiment of the fastening element 330 includes a portion of a bore in a pin plate 343, the size and shape of which are determined to correspond to the size and shape of one end of the shaft 111 of the power tool 100 and are suitably threaded to engage that end of the shaft 111, for example, for securing, mounting, gelling, etc., of a removable device 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 force-enhancing fastener assembly 130 and configured to rotate on the power member in both a fastening and release direction.

[0054] Although Figures 3A-3EThe fastening element 330 shown in the example is described as being integrally formed with the pin plate 343; however, it should be understood that other configurations of fastening elements may be utilized according to embodiments of the invention. For example, instead of being part of another component configured to provide the fastening element 330, some embodiments of the fastening element 330 may include separate components (e.g., a nut). For example, the fastening element housing may be attached to or formed as part of the pin plate 343 and may have a shaft bore whose size and shape are determined to allow one end of the shaft 111 to be inserted therein, wherein the fastening element may be arranged within a receiving cavity of the fastening element housing.

[0055] exist Figure 4A In the operation of the force-amplifying fastener assembly 130 of the embodiment, when the shaft 111 is inserted through the orifice 321 and abuts against the fastener element 330, the user can grasp the top housing 310 by hand and rotate it in the tightening or loosening direction to rotate the fastener element 330 accordingly relative to the shaft 111. The eccentric receiver 312, cycloidal disk 341, ring gear 322, and roller pins 342a to 342f of the cycloidal gear train provide the mechanical advantage of applying tightening or loosening torque to the fastener element 330. That is, a mechanical advantage corresponding to the relationship (e.g., approximately 3 to 15 times) between the torque manually applied to the top housing 310 and the resulting torque applied to the fastener element 330 can be achieved.

[0056] As can be understood from the foregoing, the force-amplifying fastener assembly 130 according to embodiments of the invention is configured to provide the mechanical advantages of rotating the fastening element by implementing a force-amplifying gear train configuration. According to aspects of the invention, a user may be able to apply a tightening or loosening torque by hand sufficient to create frictional engagement between the force-amplifying fastener assembly 130 and the corresponding removable device to prevent undesirable relative displacement of the removable device during use of the power tool, overcome increased frictional engagement due to inertial tightening of the fastener assembly during use of the power tool, and / or prevent undesirable loosening or separation of the force-amplifying fastener assembly during use of the power tool. For example, the force-amplifying fastener assembly 130 of the embodiments can facilitate sufficient manual tightening of its fastening element to hold the removable device on a reversible power tool, such that relative movement of the removable device in either direction is maintained below 15° when torque is applied to the removable device by operation of the power tool.

[0057] Some embodiments of the force-enhancing fastener assembly 130 of the present invention may include a locking mechanism that functions to lock and / or unlock the force-enhancing fastener assembly and its fastening elements. For example, in addition to or as an alternative to the frictional engagement between the force-enhancing fastener assembly 130 and the removable device 120 described above, the locking mechanism of the embodiments may be used to prevent undesirable relative displacement of the removable device. Accordingly, in operation according to some examples, the locking mechanism may be used to lock the force-enhancing fastener assembly 130 so that the fastening assembly is not undesirably or accidentally released. For example, the locking mechanism of the embodiments of the present invention may lock the movement of the top housing of the force-enhancing fastener assembly relative to the bottom structure, wherein undesirable rotation of the fastening element in the fastening direction and / or release direction may be prevented. Thus, this embodiment of the locking mechanism may act indirectly on the fastening element to prevent undesirable rotation in one or more directions. Alternatively or additionally, the locking mechanism of the embodiments of the present invention may act directly on the fastening element, for example by directly engaging one or more of its surfaces to prevent undesirable rotation in one or more directions.

[0058] Figures 2A-2E Figure 4B shows the target Figure 4A Details of an exemplary locking mechanism implemented in the planetary gear system configuration of the embodiment. Figure 2D The locking mechanism 400 shown in the example of Figure 4B includes locking elements 410a and 410b disposed in the bottom side of the top housing 210. Locking elements 410a and 410b are configured to engage the bottom structure 220. Figure 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 410a and 410b of the illustrated embodiment include teeth 411a and 411b respectively, which are configured to engage with the ring gear 222 of the bottom structure 220. Figure 5A The teeth of the locking elements 411a and 411b 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 410a and 410b can slide radially inward to a point where the teeth 411a and 411b disengage from the teeth of the ring gear 222 and allow the top housing 210 to move relative to the bottom structure 220.

[0059] Locking elements 410a and 410b of embodiments of locking mechanism 400 can be unlocked and / or locked by user actions. For example, springs 401a and 401b can provide biasing forces to hold locking elements 410a and 410b in radially outward positions (e.g., locking mechanism 400 in a locked state). A user can apply a force (e.g., a compressive force) to a portion of locking elements 410a and 410b accessible via corresponding openings in the top housing 210 to cause the locking elements to slide radially inward (e.g., locking mechanism 400 in an unlocked state), thereby disengaging the locking mechanism. Alternatively, the locking elements of locking mechanism 400 can be configured to move between a locked position and an unlocked position in response to one or more forces other than those from a user's unlocking / locking action. For example, locking elements 410a and 410b can be provided with counterweight pivot members, wherein when the power tool 100 is operated, centrifugal force can act on the weights arranged at both ends of the counterweight pivot members to cause locking elements 410a and 410b to move radially outward (e.g., placing the locking mechanism 400 in a locked state). When the power tool 100 is not operated or is arranged in a maintenance orientation, bias springs and / or gravity can be used to cause the counterweight pivot members to promote the locking elements 410a and 410b to move radially inward (e.g., placing the locking mechanism 400 in an unlocked state).

[0060] In operation according to the illustrated embodiment of the locking mechanism 400, when the locking mechanism 400 is in the locked state, movement of the top housing 210 relative to the bottom structure 220 in both the fastening and release directions is prevented. For example, the size and shape of teeth 411a and 411b are determined 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 locking elements 410a and 410b are in the radially outward position), which suppresses rotation in either direction. However, alternative embodiments may provide teeth 411a and 411b with different configurations to help prevent movement of the top housing 210 relative to the bottom structure 220 in a first direction (e.g., the release direction) when the locking elements 410a and 410b are in the radially outward position, while allowing movement of the top housing 210 relative to the bottom structure 220 in a second direction (e.g., the fastening direction) when the locking elements 410a and 410b are in the radially outward position. For example, teeth 411a and 411b can be configured in a sawtooth shape, wherein the beveled side of the sawtooth allows relative movement while the bulkhead side prevents relative movement, thereby preventing the top housing 210 from moving relative to the bottom structure 220 in one direction (e.g., the release direction) but not preventing movement in another direction (e.g., the fastening direction).

[0061] Figures 2A-2E Figure 5B shows how it can be targeted Figure 5ADetails of an exemplary locking mechanism implemented in another embodiment of the planetary gear system configuration. Figure 2D 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. Figure 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. Figure 6A 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.

[0062] Locking elements 510a and 510b of embodiments of the locking mechanism 500 can move between a locked position and an unlocked position in response to various forces, such as centrifugal force and / or gravity. For example, the locking mechanism 500 can be placed in a locked state to prevent rotation in the release direction when the removable device spins fast enough to cause locking elements 510a and 510b to slide outward and engage the teeth 511a and 511b with the teeth of the ring gear 222. According to the example shown, the counterweights of locking elements 510a and 510b are sufficient to cause the locking elements to overcome the tensile bias of the sliding of springs 501a and 501b, such that the teeth 511a and 511b move outward in response to the centrifugal force generated by the rotation of the removable device and the corresponding force-enhancing fastener assembly at a sufficient speed and engage the teeth of the ring gear 222. According to this example, when the power tool 100 stops, springs 501a and 501b can provide a biasing force to pull locking elements 510a and 510b, causing them to slide sufficiently inward, thereby disengaging teeth 511a and 511b from the teeth of ring gear 222. Alternatively or alternatively, when the power tool 100 is arranged in a particular orientation (e.g., when the head of the power tool to which the removable tool is fastened is flipped up and down for user maintenance), the locking mechanism 500 can be placed in an unlocked state by gravity to allow rotation in the release direction. Alternatively or alternatively, according to some embodiments, the locking mechanism 500 can be unlocked and / or locked using user actions. For example, springs 501a and 501b can be arranged to provide a biasing force to hold locking elements 510a and 510b respectively, such that teeth 511a and 511b are arranged in a radially outward position (e.g., the locking mechanism 500 is in a locked state). The user can apply force (e.g., squeezing force) (e.g., pressing the locking element) to a portion of the locking elements 510a and 510b accessible through the corresponding opening in the top housing 310 to cause the locking elements to slide, thereby causing the teeth 511a and 511b to slide radially inward (e.g., the locking mechanism 500 is in the unlocked state) and disengage the locking mechanism.

[0063] In operation according to the illustrated embodiment of the locking mechanism 500, when the locking mechanism 500 is in the locked state, movement of the top housing 210 relative to the bottom structure 220 in both the fastening and release directions is prevented. For example, the size and shape of teeth 511a and 511b are determined 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 locking elements 510a and 510b are in the radially outward position), which suppresses rotation in either direction. However, alternative embodiments may provide teeth 511a and 511b with different configurations to help prevent movement of the top housing 210 relative to the bottom structure 220 in a first direction (e.g., the release direction) when the locking elements 510a and 510b are in the radially outward position, while allowing movement of the top housing 210 relative to the bottom structure 220 in a second direction (e.g., the fastening direction) when the locking elements 510a and 510b are in the radially outward position. For example, teeth 511a and 511b can be configured in a sawtooth shape, wherein the beveled side of the sawtooth allows relative movement while the bulkhead side prevents relative movement, thereby preventing the top housing 210 from moving relative to the bottom structure 220 in one direction (e.g., the release direction) but not preventing movement in another direction (e.g., the fastening direction).

[0064] Figures 3A-3E Figure 6B shows the target Figure 6A Details of an exemplary locking mechanism implemented using a cycloidal gear system configuration in an embodiment. Figure 3D The locking mechanism 600 shown in the example of Figure 6B includes locking elements 610a and 610b disposed in the bottom side of the top housing 310. Locking elements 610a and 610b are configured to engage the bottom structure 320. Figure 3D ), and provides locking of the top housing 310 relative to the bottom structure 320 of the force-enhancing fastener assembly 130. For example, locking elements 610a and 610b of the illustrated embodiment include teeth 611a and 611b, respectively, which are configured to engage with teeth 323 arranged on the outer circumference of the ring gear 322 of the bottom structure 220. Figure 7A For example, locking elements 610a and 610b may include pawls pivotally coupled to the bottom surface of the top housing 310, wherein when the locking elements pivot, teeth 611a and 611b move radially inward such that they engage the teeth 323 of the ring gear 322 and prevent the top housing 310 from moving relative to the bottom structure 320. Additionally, locking elements 610a and 610b may pivot radially outward to a point where teeth 611a and 611b disengage from the teeth 323 of the ring gear 322 and allow the top housing 310 to move relative to the bottom structure 320.

[0065] Locking elements 610a and 610b of embodiments of locking mechanism 600 can be unlocked and / or locked by user actions. For example, springs 601a and 601b can provide biasing forces to hold locking elements 610a and 610b in radially inward positions (e.g., when locking mechanism 600 is locked). A user can apply forces (e.g., compressive forces) to arms 612a and 612b of locking elements 610a and 610b, respectively accessible via corresponding openings in the top housing 310, to pivot the locking elements between a locked position and an unlocked position (e.g., when locking mechanism is unlocked), thereby disengaging the locking mechanism. Alternatively or additionally, the locking elements of locking mechanism 600 can be configured to move between locked and / or unlocked positions in response to one or more forces other than user unlocking / locking actions. For example, arms 612a and 612b may have counterweights, wherein when the power tool 100 is operated, centrifugal force can act on the pivoting members of the counterweights to cause locking elements 610a and 610b to pivot (e.g., placing the locking mechanism 600 in a locked state). When the power tool 100 is in a particular orientation (e.g., when the head of the power tool to which the detachable tool is secured is flipped up and down for unlocking during user maintenance), the locking mechanism 600 in some embodiments may be placed in an unlocked state by gravity to allow rotation in the release direction.

[0066] In operation according to the illustrated embodiment of the locking mechanism 600, when the locking 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 allowing movement in the fastening direction is permitted. For example, teeth 611a and 611b and tooth 323 of the illustrated embodiment are configured in a serrated shape, wherein the beveled side of the serrations allows relative movement while the straight side prevents relative movement, thereby preventing movement of the top housing 310 relative to the bottom structure 320 in one direction (e.g., the release direction) but not preventing movement in another direction (e.g., the fastening direction). Alternative embodiments of the locking mechanism 600 may be configured to prevent movement of the top housing 310 relative to the bottom structure 320 in both the fastening and release directions when the locking mechanism 600 is in the locked state. For example, the size and shape of teeth 611a and 611b and tooth 323 can be correspondingly determined to provide locking engagement (e.g., teeth 611a and 611b engage tooth 323 when locking elements 610a and 610b pivot), which suppresses rotation in either direction.

[0067] Figures 3A-3E Figure 7B shows how it can be targeted Figure 7A Details of an exemplary locking mechanism implemented using a cycloidal gear system configuration in another embodiment. Figure 3DThe locking mechanism 700 shown in the example of Figure 7B includes locking elements 710a and 710b disposed in the bottom side of the top housing 310. Locking elements 710a and 710b are configured to engage the bottom structure 320. Figure 3D ), and provides locking of the top housing 310 relative to the bottom structure 320 of the force-enhancing fastener assembly 130. For example, the locking elements 710a and 710b of the illustrated embodiment include teeth 711a and 711b, respectively, which are configured to engage with teeth 323 arranged on the outer circumference of the ring gear 322 of the bottom structure 220. ​ For example, locking elements 710a and 710b may include pawls coupled to the bottom surface of the top housing 310, wherein when the locking elements pivot, teeth 711a and 711b move radially inward such that they engage the teeth 323 of the ring gear 322 and prevent the top housing 310 from moving relative to the bottom structure 320. Additionally, locking elements 710a and 710b may pivot radially outward to a point where teeth 711a and 711b disengage from the teeth 323 of the ring gear 322 and allow the top housing 310 to move relative to the bottom structure 320.

[0068] Locking elements 710a and 710b of embodiments of the locking mechanism 700 can pivot between a locked position and an unlocked position in response to various forces, such as centrifugal force and / or gravity. For example, the locking mechanism 700 can be placed in a locked state to prevent rotation in the release direction when the removable device spins fast enough to pivot the locking elements 710a and 710b and engage the teeth 711a and 711b with the teeth 323. According to the example shown, the counterweight arms 712a and 712b of the locking elements 710a and 710b can respectively pivot the locking elements such that the teeth 711a and 711b move inward and engage the teeth 323 in response to centrifugal force generated by the rotation of the removable device and the corresponding force-enhancing fastener assembly at a sufficient speed. According to this example, when the power tool 100 stops, springs 701a and 701b can provide a biasing force to pull locking elements 710a and 710b, causing them to pivot sufficiently, thereby disengaging teeth 711a and 711b from tooth 323. Alternatively or alternatively, when the power tool 100 is arranged in a particular orientation (e.g., when the head of the power tool to which a removable tool is fastened is flipped up and down for user maintenance), the locking mechanism 700 can be placed in an unlocked state by gravity to allow rotation in the release direction. Alternatively or alternatively, according to some embodiments, the locking mechanism 700 can be unlocked and / or locked using user actions. For example, springs 701a and 701b can be arranged to provide a biasing force to hold locking elements 710a and 710b respectively, such that teeth 711a and 711b are arranged in a radially inward position (e.g., the locking mechanism 700 is in a locked state). The user can apply force (e.g., compressive force) to a portion of the locking elements 710a and 710b accessible through corresponding openings in the top housing 310 (e.g., pressing the counterweight arms 712a and 712b) to pivot the locking elements, thereby causing the teeth 711a and 711b to slide radially outward (e.g., the locking mechanism 700 is in the unlocked state) and disengage the locking mechanism.

[0069] In operation according to the illustrated embodiment of the locking mechanism 700, when the locking mechanism 700 is in the locked state, movement of the top housing 310 relative to the bottom structure 320 in the release direction is prevented while allowing movement in the fastening direction is permitted. For example, teeth 711a and 711b and tooth 323 of the illustrated embodiment are configured in a serrated shape, wherein the beveled side of the serrations allows relative movement while the straight side prevents relative movement, thereby preventing movement of the top housing 310 relative to the bottom structure 320 in one direction (e.g., the release direction) but not preventing movement in another direction (e.g., the fastening direction). Alternative embodiments of the locking mechanism 700 may be configured to prevent movement of the top housing 310 relative to the bottom structure 320 in both the fastening and release directions when the locking mechanism 700 is in the locked state. For example, the size and shape of teeth 711a and 711b and tooth 323 can be correspondingly determined to provide locking engagement (e.g., teeth 711a and 711b engage tooth 323 when locking elements 710a and 710b pivot), which suppresses rotation in either direction.

[0070] It should be understood that the aforementioned locking mechanism is essentially protected by the structure of the force-enhancing fastener assembly 130. For example, the locking mechanisms 400, 500, 600, and 700 of the illustrated embodiments are arranged within the area formed by the top housing into a cup-shaped outer shell. Furthermore, embodiments of the locking mechanism can be completely enclosed by the top housing and bottom structure (e.g., the example of locking mechanism 500 is provided by top housing 210 and bottom structure 220, while the example of locking mechanism 700 is provided by top housing 310, bottom structure 320, and bottom housing 301), thereby providing additional protection for the locking mechanism. Accordingly, the latching mechanism of the embodiments of the invention can be protected from damage and accidental release, such as damage that could otherwise occur, resulting in accidental release of the latching mechanism and removal of the fastening device from the lawnmower.

[0071] 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.

[0072] Although the invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the spirit and scope of the invention as defined by 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.

[0073] 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 force-boosting fastener assembly for removably attaching a detachable tool to a power tool, the force-boosting fastener assembly comprising: The top shell that forms the cup-shaped outer shell; The bottom structure nested within the area of ​​the cup-shaped outer shell; A fastening element is disposed between the top housing and the bottom structure and within the area of ​​the cup-shaped housing, wherein the fastening element is configured to engage with the shaft of the power tool; A force-amplifying gear train, arranged in the region of the cup-shaped housing and mechanically connected to the top housing, the bottom structure, and the fastening element, provides mechanical advantages in applying torque to the fastening element in response to torque applied to the top housing; and A locking mechanism is arranged within the cup-shaped housing of the top housing and functions to inhibit the fastening element from rotating relative to the shaft in at least one rotational direction.

2. The force-enhancing fastener assembly as claimed in claim 1, wherein, The top housing, bottom structure, power-boosting gear train, and fastening element work together to facilitate the mounting and removal of the detachable device from the shaft of the power tool without the need for manual manipulation of the top housing using additional tools.

3. The force-enhancing fastener assembly as claimed in claim 1, wherein, The amplifying torque applied to the fastening element by the amplifying gear system is in the same direction as the torque applied to the top housing.

4. The force-enhancing fastener assembly as claimed in claim 1, wherein, The bottom structure forms a cup-shaped structure, and the fastening element and the power-enhancing gear system are arranged in the area enclosed by the cup-shaped outer shell of the top housing and the cup-shaped structure of the bottom structure.

5. The force-enhancing fastener assembly as claimed in claim 4, wherein, The power-boosting gear system includes: A planetary gear configuration in which a cup-shaped structure of the bottom structure provides a ring gear of the planetary gear configuration, and a sun gear of the planetary gear configuration is attached to the top housing within the cup-shaped housing.

6. The force-enhancing fastener assembly as claimed in claim 5, wherein, The planetary gear configuration includes: A gear plate attached to a plurality of planetary gears meshing with the sun gear and the ring gear, wherein the fastening element rotates directly in response to the rotation of the gear plate.

7. The force-enhancing fastener assembly as claimed in claim 4, wherein, The power-boosting gear system includes: A cycloidal gear configuration, wherein the cup-shaped structure of the bottom structure provides the ring gear of the cycloidal gear configuration, and the eccentric shaft of the cycloidal gear configuration is attached to the top housing within the cup-shaped housing.

8. The force-enhancing fastener assembly as claimed in claim 7, wherein, The cycloidal gear configuration includes: A cycloidal gear mechanically connected to the eccentric shaft and the ring gear; and A pin plate, which is mechanically connected to the cycloidal gear via multiple roller pins, wherein the fastening element rotates directly in response to the rotation of the pin plate.

9. The force-enhancing fastener assembly as claimed in claim 1, wherein, The locking mechanism functions to prevent the fastening element from rotating relative to the shaft in both rotational directions.

10. The force-enhancing fastener assembly as claimed in claim 1, wherein, The locking mechanism is engaged to prevent the fastening element from rotating relative to the shaft by centrifugal force.

11. The force-enhancing fastener assembly as claimed in claim 1, wherein, The locking mechanism disengages, thus no longer inhibiting the rotation of the fastening element relative to the axis, without requiring direct user interaction with the locking mechanism.

12. A method for removably attaching a detachable tool to a power tool, the method comprising: The force-amplifying fastener assembly is coupled to the shaft of the power tool, wherein the force-amplifying fastener assembly includes: a top housing forming a cup-shaped housing; a bottom structure nested within a region of the cup-shaped housing; a fastening element disposed between the top housing and the bottom structure and within the region of the cup-shaped housing; and a force-amplifying gear train disposed within the region of the cup-shaped housing and in mechanical communication with the top housing, the bottom structure, and the fastening element, wherein the force-amplifying fastener assembly is coupled to the shaft of the power tool such that the fastening element engages with the shaft; A torque is applied to the top housing and a torque is generated at the fastening element in the same direction as the torque applied to the top housing, wherein the amplifying gear system provides the mechanical advantage of generating torque at the fastening element; and The fastening element is prevented from rotating relative to the shaft in at least one direction of rotation by operating a locking mechanism arranged in the area of ​​the cup-shaped outer shell of the top housing.

13. The method of claim 12, wherein, Applying torque to the top housing is a result of manually manipulating the top housing, and this mechanical advantage makes the torque generated at the fastening element sufficient to attach the detachable tool to the power tool without the aid of additional tools in order to use the power tool.

14. The method of claim 12, wherein, The bottom structure forms a cup-shaped structure, and the fastening element and the power-enhancing gear system are arranged in the area enclosed by the cup-shaped outer shell of the top housing and the cup-shaped structure of the bottom structure.

15. The method of claim 14, wherein, The power-boosting gear system is configured as a planetary gear configuration, wherein the cup-shaped structure of the bottom structure provides the ring gear of the planetary gear configuration, and wherein the sun gear of the planetary gear configuration is attached to the top housing within the cup-shaped housing.

16. The method of claim 15, wherein, The planetary gear configuration includes a gear plate attached to a plurality of planetary gears that mesh with the sun gear and the ring gear, wherein the fastening element rotates directly in response to the rotation of the gear plate.

17. The method of claim 14, wherein, The power-boosting gear system is configured as a cycloidal gear, wherein the cup-shaped structure of the bottom structure provides the ring gear of the cycloidal gear configuration, and wherein the eccentric shaft of the cycloidal gear configuration is attached to the top housing within the cup-shaped housing.

18. The method of claim 17, wherein, The cycloidal gear configuration includes a cycloidal gear mechanically connected to the eccentric shaft and the ring gear. The cycloidal gear configuration also includes a pin plate mechanically connected to the cycloidal gear via a plurality of roller pins on the pin plate. The fastening element rotates directly in response to the rotation of the pin plate.

19. The method of claim 12, wherein, The locking mechanism functions to prevent the fastening element from rotating relative to the shaft in both rotational directions.

20. The method of claim 12, wherein, The locking mechanism is engaged to prevent the fastening element from rotating relative to the shaft by centrifugal force.

21. The method of claim 12, wherein, The locking mechanism disengages, thus no longer inhibiting the rotation of the fastening element relative to the axis, without requiring direct user interaction with the locking mechanism.

22. A system for removably attaching a detachable tool to a power tool, the system comprising: A force-increasing fastener assembly includes a top housing, a bottom structure, and a force-increasing gear train in mechanical communication with the top housing and the bottom structure, wherein the force-increasing gear train is configured to provide the mechanical advantage of inducing torque at the fastening element in response to applying torque to the top housing; A retaining element, disposed on the shaft of the power tool or the detachable fixture and configured to engage with the bottom structure, thereby preventing the bottom structure from rotating relative to the top housing when torque is applied to the top housing; and A locking mechanism, disposed within the cup-shaped housing of the top housing, functions to inhibit rotation of the fastening element relative to the shaft in at least one rotational direction. The top housing forms a cup-shaped outer shell, and the bottom structure is nested within the area of ​​the cup-shaped outer shell. The fastening element is arranged between the top housing and the bottom structure and within the area of ​​the cup-shaped outer shell. The power amplifying gear system is arranged within the area of ​​the cup-shaped outer shell.

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