This document relates, generally, to a ratcheting tool, and in particular, to a ratcheting tool having a torque limiting clutch.
A ratcheting tool, or ratchet, may include a head portion that can engage a work piece (for example, a fastener), and a handle portion extending from the head portion for manipulation by a user. Rotation of the ratcheting tool in a first direction (i.e., rotation of the handle portion about the head portion), may cause a corresponding rotation of the work piece engaged with the head portion (for example, a tightening or a loosening of a fastener). Rotation of the ratcheting tool in a second direction (opposite the first direction) may allow the handle portion of the ratcheting tool to be repositioned, while the head portion remains stationary, to provide for additional rotation in the first direction (and corresponding additional tightening or loosening of the fastener). This ratcheting action may provide for relatively rapid tightening or loosening of a fastener while the tool remains engaged with the fastener. Some ratcheting tools may be relatively simple hand tools, while some ratcheting tools may be operated in both a power driven mode and a manual mode. Effective control of a maximum amount of torque output by the ratcheting tool and/or applied to the work piece/fastener may simplify use of the tool, may protect the work piece/fastener from damage, and may enhance the utility of the tool.
Users face many problems or hinderances in the use of common powered ratchets. One problem is that a user may receive a reactionary force or kickback from the tool that can cause harm to the user. Another issue that users face in using powered ratchets is the necessity to use and/or purchase different tools or different ratchets to perform a job. Another problem users face is the necessity to purchase an entirely new ratchet or service the existing ratchet when a drive head is damaged. Therefore, a need exists for a ratchet tool with a torque limiting clutch.
In one aspect, A ratchet may include a housing, a motor in the housing, an output drive mechanism coupled to the housing, a torque selector coupled to the housing, the torque selector including a collar rotatably coupled to the housing, wherein the collar is rotatable to a plurality of positions corresponding to a plurality of torque settings, so as to provide for selection of a maximum output torque of the ratchet, and a clutch assembly selectively coupling the motor and the output drive mechanism
In another aspect, a ratchet tool may include a housing, a motor in the housing, an output drive mechanism coupled to the housing, and a clutch assembly selectively coupling the motor and the output drive mechanism. The clutch assembly may include a planetary gear set coupled to an output shaft of the motor, a ring gear having an inner circumferential surface configured to selectively engage the planetary gear set, a pin cage having a plurality of openings formed therein, a clutch washer, a plurality of clutch pins respectively received in the plurality of openings in the pin cage, each of the plurality of clutch pins having a first end thereof in contact with a first side of the clutch washer, and a second end thereof in contact with an axial end portion of the ring gear, a spring cage having a plurality of recesses formed in a first side thereof, a plurality of springs each having a first end thereof received in a respective recess of the plurality of recesses in the spring cage, and a second end thereof in contact with a second side of the clutch washer, and a pressing plate positioned proximate a second side of the spring cage.
In another aspect, a ratchet tool with clutch may include a housing, a motor in the housing; n output drive mechanism coupled to the housing, a torque selector coupled to the housing, the torque selector including a collar rotatably coupled to the housing, wherein the collar is rotatable to a plurality of positions corresponding to a plurality of torque settings, so as to provide for selection of a maximum output torque of the ratchet tool, and a clutch assembly selectively coupling the motor and the output drive mechanism. The clutch assembly may include a planetary gear set coupled to an output shaft of the motor, a ring gear having an inner circumferential surface configured to selectively engage the planetary gear set, a pin cage having a plurality of openings formed therein, a clutch washer, a plurality of clutch pins respectively received in the plurality of openings in the pin cage, each of the plurality of clutch pins having a first end thereof in contact with a first side of the clutch washer, and a second end thereof in contact with an axial end portion of the ring gear, a spring cage having a plurality of recesses formed in a first side thereof, a plurality of springs each having a first end thereof received in a respective recess of the plurality of recesses in the spring cage, and a second end thereof in contact with a second side of the clutch washer, and a pressing plate positioned proximate a second side of the spring cage.
In another aspect, a ratchet tool with limiting clutch may include a housing, a motor in the housing, an output drive mechanism coupled to the housing, and a clutch assembly selectively coupling the motor and the output drive mechanism. The clutch assembly may include a planetary gear set coupled to an output shaft of the motor, a ring gear having an inner circumferential surface configured to selectively engage the planetary gear set, a pin cage, a clutch washer, a clutch interface coupled to the pin cage, wherein the pin cage having a end thereof in contact with a first side of the clutch washer, and the clutch interface having an end in contact with an axial end portion of the ring gear, a spring cage having a plurality of recesses formed in a first side thereof, a plurality of springs each having a first end thereof received in a respective recess of the plurality of recesses in the spring cage, and a second end thereof in contact with a second side of the clutch washer, and a pressing plate positioned proximate a second side of the spring cage.
This implementation of the invention, in particular, may be desired because it reduces the amount of reactionary force to a user and thus reduces the risk of harm to a user because the detection of maximum force can release the engagement of the motor and the output mechanism. This implementation of the invention may also be desired, in particular, because the coupling portion as configured to be removably coupled provides the user the ability to switch out one tool interface for another tool interface, thereby providing a user with options for different head assemblies and creating a plurality of different tools for many different jobs. Thus, to a relatively large extent, the interchangeable functionality of the drive assembly permits a user to forgo hauling multiple heavy tools and instead grants a user the ability to carry smaller tool heads for use with one main tool to perform different jobs.
The terminology used herein is for the purpose of describing implementations or embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms, “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the root terms “can”, “include”, “can include”, “may”, and/or “have”, when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of at least one other feature, step, operation, element, component, and/or groups thereof.
As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such process, method, article, or apparatus.
For definitional purposes and as used herein “connected” or “attached” includes operation or physical, whether direct or indirect, affixed or coupled, as for example, a connection of the clutch assembly 220 to an input shaft 260, or crank shaft 260. Thus, unless specified, “connected” or “attached” is intended to embrace any operationally functional connection.
As used herein “substantially,” “generally,” “slightly” and other words of degree are relative modifiers intended to indicate permissible variation from the characteristic so modified. It is not intended to be limited to the absolute value or characteristic which it modifies but rather possessing more of the physical or functional characteristic than its opposite, and preferably, approaching or approximating such a physical or functional characteristic.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following descriptions of embodiments of the invention taken in conjunction with the accompanying drawings:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the present invention, and such exemplifications are not to be construed as limiting the scope of the present invention in any manner
A schematic view of an exemplary power driven tool 100, such as, for example, a power driven ratcheting tool 100, is shown in
As shown in
A plurality of clutch pins 226 may be positioned between the clutch washer 224 and a corresponding axial end portion of a ring gear 227. Each of the plurality of clutch pins 226 may extend through a corresponding opening in a pin cage 225, such that the clutch pins 226 are axially movable in the openings in the pin cage 225. A first end of each of the clutch pins 226 may be positioned adjacent to, or against, or contacting, a second side of the clutch washer 224. A second end of each of the clutch pins 226 may be positioned adjacent to, or against, or contacting, the corresponding axial end portion of the ring gear 227. As the plurality of clutch pins 226 are axially movable in the openings in the pin cage 225, compression and/or release of the compression of the plurality of clutch springs 223, and axial movement of the clutch washer 224 in response to the compression/release of the clutch springs 223, may cause corresponding axial movement of the clutch pins 226 positioned against the axial end portion of the ring gear 227.
A planetary gear set 228 may be selectively engaged with an inner circumferential surface of the ring gear 227. The planetary gear set 228 may be coupled to a shaft of the motor 210. The planetary gear set 228 may be driven in response to a force transmitted thereto from the motor 210 via the motor shaft, to selectively transfer power from the motor 210 to the output mechanism 230, based on an engagement state provided by the clutch assembly 220. Some embodiments of the clutch assembly 220 may include the pressing plate 221, the spring cage 222, the plurality of clutch springs 223, the clutch washer 224, the pin cage 225, the plurality of clutch pins 226 and the ring gear 227 but may include fewer or more components to provide output torque control of the tool 200. Operation of the clutch assembly 220, and corresponding engagement and/or disengagement of the motor 210 and the output mechanism 230, will be discussed in more detail below.
In operating the exemplary power driven ratcheting tool 200 in the power driven mode, power may be transmitted from the motor 210 (via the motor shaft 212) to the planetary gear set 228, and on to the input shaft 260, or crank shaft 260. The crank shaft 260 may in turn transmit power to the output mechanism 230, for operation of ratcheting components of the output mechanism 230. In particular, in the power driven mode, power is transmitted from the motor 210 to the output mechanism 230 in this manner in a condition in which the ring gear 227 is rotationally locked, or essentially restricted from rotation. In a condition in which the ring gear 227 slips, or is allowed to rotate, power output by the motor 210 is not transmitted to the output mechanism 230. That is, in the condition in which the ring gear 227 slips, the planetary gear set 228 may continue to rotate in response to power transmitted thereto from the motor 210; however, due to the slippage, or rotation of the ring gear 227, that power will no longer be transmitted through the crank shaft 260 to the ratcheting components of the output mechanism 230. The torque level at which the ring gear 227 transitions from a fixed, or rotationally locked, or non-rotating state, to the slipped, or rotationally unlocked, or rotating state, may be controlled by the clutch assembly 220, based on the maximum output torque level set, or selected through manipulation of the collar 270.
As noted above, the second end portions of the clutch pins 226 may be positioned adjacent to, or in contact with, the axial end portion 227A of the ring gear 227. The axial end portion 227A of the ring gear 227 may be contoured, defining a ramped surface 229 including one or more ramps on the axial end portion 227A of the ring gear 227. In the example implementation illustrated in
The second end portions of the clutch pins 226 may engage, or contact, the axial end portion 227A of the ring gear 227, moving, or sliding along the ramp surface 229 of the ring gear 227. The clutch pins 226 and the ramped surface 229 are pressed against each other by a force applied by the clutch springs 223. The magnitude of the force applied by the clutch springs 223, causing the clutch pins 226 to move axially, may vary based on an amount of compression of the clutch springs 223. As the output torque level increases, an output torque level greater than a set threshold (corresponding, for example, to the maximum output torque level set or selected through manipulation of the collar 270) will cause the springs to compress, and cause the clutch pins 226 riding in the ramped surface 229 to jump, or ride over, the ramps 229A, 229B, 229C, causing the ring gear 227, and the clutch assembly 220, to slip or rotate. That is, as an amount of detected amount of output torque, and in particular, detected resistance torque, increases, the clutch pins 226 move along the ramped surface 229, and up the ramps 229A, 229B, 229C. Due to the geometry of the ramps 229A, 229B, 229C, movement of the clutch pins 226 up the ramps in this manner causes the clutch pins 226 to move axially, toward the clutch washer 224, thus moving the clutch washer 224 axially and compressing the clutch springs 223. In response to detection of a torque level exceeding the maximum output torque level (set, for example through manipulation of the collar 270), the clutch pins 226 will move, or travel, or jump over the ramps, disengaging the ring gear 227 and causing the ring gear 227, and the clutch assembly 220, to slip. In this slipped condition, the ring gear 227 will continue to rotate, or slip, while the trigger 296 is depressed and the motor 210 is generating power, but torque will not be transmitted to the crank shaft 232.
One type of clutch setting can limit the torque transmitted from the motor 210 to the output mechanism 230. The amount of compression of the clutch springs 223, affecting the positioning and movement of the clutch pins 226 along the ramped surface 229, may vary based on an amount of output torque, and in particular, resistance torque, detected, affecting the axial position of the pressing plate 221. The axial position of the pressing plate 221 may vary based on contact, or interface, or engagement of the pressing plate 221, and in particular, the first and second arms 221A and 221B of the pressing plate 221, with an interior geometry of the collar 270. As the collar 270 is manipulated into a physical position corresponding to the selected maximum output torque level, this interaction, or engagement, between the pressing plate 221 (i.e. the first and second arms 221A, 221B of the pressing plate 221) and the interior geometry of the collar 270 may affect the torque level which causes the ring gear 227, and the clutch assembly 220, to slip or rotate. This interface, or interaction, will be described in more detail with respect to
A second clutch type of setting may not limit the amount of the torque transmitted from the motor 210 to the output mechanism 230. The clutch collar 270 has a setting where it positions the clamping plate 221 and spring cage 222 axially toward the clutch washer 224, pins 226, and ring gear 227, in such a way as to prevent the pins 226 from axially moving out of the way of the ring gear ramp 229B. The pins 226 are limited axially by the position of the spring cage 222, and therefore prevent the ring gear 227 from slipping or rotating even though high torsional loading may be experienced at the output of the ratchet mechanism. In this implementation, based on the clutch setting, the power from the motor is not disengaged from the output mechanism and there may be a hard stop that prevents the ring gear from every spinning. It is a mechanical locking that prevents the ring gear from ever slipping.
In some implementations, the torque level at which the ring gear 227 slips may be further affected by the coefficient of friction between the clutch pins 226 and the ramped surface 229 of the ring gear 227, the contour, or angle of the ramps formed on the ramped surface 229, the magnitude of the force applied to the clutch pins 226 by the compression of the clutch springs 223, and other such factors.
As shown in
That is, as the collar 270 is rotated, the first and second arms 221A, 221B of the pressing plate 221 move along the ramped surface 275 on the inner circumferential portion of the collar 270. The geometry, or contouring, or ramping of the ramped surface 275 causes the pressing plate 221 to move axially (for example, to the left or to the right in the example orientation shown in
As noted above, in some implementations, the exemplary power driven ratcheting tool 200 may be operated in a power driven mode, and in a manual mode (in which power is not transmitted from the motor 210 to the output mechanism 230 to implement a power ratcheting function). In some situations, a user may wish to operate the ratcheting tool in the manual mode, to allow for manual, or hand tightening of a work piece/fastener. This may also provide an advantage in protecting bits and fasteners from over stripping by the power driven ratcheting tool. In the exemplary power driven ratcheting tool 200, in accordance with implementations described herein, the clutch assembly 220 is substantially entirely contained within the confines of the ratchet head housing 294. The structural integrity of the ratchet head housing 294, and containment of the clutch assembly 220 within the confines of the ratchet head housing 294, may allow manual torque to be transferred, through the ratchet head housing 294, to, for example, a square drive or square drive assembly of the output mechanism 230, while still allowing the slip clutch assembly 220 to operate, and slip at a selected maximum output torque level as described above. This may allow the power driven ratcheting tool, in accordance with implementations described herein, to be effectively operated in the manual mode.
As previously noted, the exemplary implementation described above includes a pressing plate 221 having two arms 221A, 221B extending radially therefrom, at diametrically opposed positions, for ease of discussion and illustration. In some implementations, the pressing plate 221 may include more, or fewer arms extending radially outward from therefrom, and/or arranged at different positions on the pressing plate 221. Similarly, the exemplary implementation described above includes a plurality of clutch springs 223 received in the spring cage 222. In some implementations, the clutch assembly 220 may include more, or fewer, clutch springs 223 and/or a different arrangement of clutch springs 223 than illustrated. Further, the exemplary implementation described above includes three clutch pins 226A, 226B, 226C interacting with three ramps 229A, 229B, 229C on the ramped surface 229 of the ring gear 227, for ease of discussion and illustration. In some implementations, the clutch assembly 220 may include more, or fewer clutch pins 226 and/or more or fewer ramps formed on the ramped surface 229 of the ring gear 227.
The exemplary implementation described above includes the pressing plate 221 and the spring cage 222 as separate components, simply for ease of discussion and illustration. In some implementations, the pressing plate 221 and the spring cage 222 may be formed as a single unit, or integrally formed. Similarly, the exemplary implementation described above includes the clutch washer 224 and the pin cage 225 as separate components, simply for ease of discussion and illustration. In some implementations, the clutch washer 224 and the pin cage 225 may be formed as a single unit, or integrally formed.
A ratcheting tool, in accordance with implementations described herein, may include a square drive assembly that interfaces with a work piece/fastener to transmit force (for example, rotational, or ratcheting force). In some implementations, a first square drive assembly may be removed from the ratcheting tool and replaced with a second square drive assembly having a different size (for example, interface size) than the first square drive assembly. The ability to interchange square drive assemblies having different interface sizes, without the use of an adapter, may reduce overall size, and may render the ratcheting tool usable in smaller spaces, and for more applications, thus enhancing utility and functionality of the tool. In other implementations, a first square drive assembly may be removed from the ratcheting tool and replaced with a different drive assembly having a different size (for example, a drive assembly with a screwdriver head) than the first square drive assembly. The ability to interchange drive assemblies having different interfaces, without use of an adapter, may render the ratcheting tool usable in smaller spaces, and for more applications, thus enhancing utility and functionality of the tool. Utility and functionality may be further enhanced by a simplified mechanism to release a square drive assembly from the tool, and to securely couple the drive assembly to the tool.
A removable square drive assembly, in accordance with implementations described herein, may be used with a power driven ratcheting tool such as the power driven ratcheting tool 200 described above, which is operable in both a power driven mode and a manual mode, or with a fully manually operated ratcheting tool. A ratcheting tool 300 including a removable square drive assembly 400, in accordance with implementations described herein, is shown in
In some implementations, the square drive assembly 400 may include a retention portion 410, or coupling portion 410, and a working portion 460, or tool interface portion 460. The coupling portion 410 may be removably coupled in an output spindle 335 of the ratcheting tool 300. A release mechanism, in the form of a button 420 in this example implementation, may be movably received in a recess 435 defined in a portion of a housing 430 of the square drive assembly 400 corresponding to the coupling portion 410. A ramped pocket 425 may be defined in the button 420, for example, in an outer circumferential portion of the button 420. A button spring 440 may have a first end 440A positioned at a first end of the recess 435, and a second end 440B fixed to the button 420. A pair of balls 450 (450A, 450B) may be positioned at corresponding openings 430A, 430B in the housing 430. As the coupling portion 410 of the square drive assembly 400 is inserted into the output spindle 335 of the tool 300, the button spring 440 may exert a force on the button 420. The surface of the ramped pocket 425 of the button 420 may transfer the force exerted by the button spring 440 radially, to the pair of balls 450A, 450B. This force transferred to the pair of balls 450A, 450B urge the balls 450A, 450B outward through the openings 430A, 430B, so that the balls 450A, 450B may engage with, or lock into, a groove 337 defined in the output spindle 335, thus locking the square drive assembly 400 in the output spindle 335 of the tool 300. The square drive assembly 400 may be released from the output spindle 335 by depressing the button 420 while pushing or pulling the square drive assembly 400 from the tool 300. Depression of the button 420 compresses the button spring 440, allowing the balls 450A, 450B to disengage the groove 337 in the output spindle 335 and drop into the button ramp pocket 425.
A removable square drive assembly, in accordance with implementations described herein, may allow a user to select a square drive tool that matches a desired interface such as, for example, a socket and the like, without the user of an adapter, thus enhancing utility and functionality to the user. A removable square drive assembly, in accordance with implementations described herein, may allow for easy replacement of a damaged square drive tool, which may be designed to preferentially fail under high loading before other, more expensive and difficult to replace internal parts of the tool, allowing for faster and less costly servicing of the tool. A removable square drive assembly, in accordance with implementations described herein, may be coupled to the ratcheting tool at approximately 180 degrees with respect to a triggering/operation mechanism of the tool, allowing for use of the tool in a relatively small, confined space having limited access, further enhancing utility and functionality.
While certain features of the described implementations have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the scope of the implementations. It should be understood that they have been presented by way of example only, not limitation, and various changes in form and details may be made. Any portion of the apparatus and/or methods described herein may be combined in any combination, except mutually exclusive combinations. The implementations described can include various combinations and/or sub-combinations of the functions, components and/or features of the different implementations described.
Filing Document | Filing Date | Country | Kind |
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PCT/US18/42117 | 7/13/2018 | WO | 00 |