FIELD

[0001] The present disclosure relates to the field of actuation mechanisms for hand operated tools, and more particularly, to resettable advancement mechanisms.

BACKGROUND

[0002] Tools having cutting elements require replacement or sharpening of the cutting elements in order to maintain their efficiency and/or ability to perform their intended purpose. For example, a cutting tool, such as a chain saw, has a cutting chain for cutting wood or other material. Over time, the cutting chain can become dull. Maintaining the sharpness of the cutting chain is particularly important for maintaining cutting efficiency which can also improve the safety of using the chain saw.

[0003] Industrial-sized sharpeners are available to sharpen cutting chains for chain saws, but their use is cumbersome and time-consuming. Typically, the cutting chain must be removed from the chain saw and left with an operator of the industrial-sized chain sharpener until the chain has been sharpened and is ready for pickup.

[0004] Other sharpeners are available that allow the cutting chain to remain on the saw during sharpening. Such tools typically include a fixture that clamps on to the chain saw to guide a hand file for individually sharpening each saw tooth of the cutting chain. While such tools are portable, their use is time-consuming because the operator must hand file each tooth separately.

[0005] While some chain saws have been equipped with sharpening mechanisms having stone(s) that sharpen the cutting chain without additional tools, actuation of these sharpening mechanisms relies upon the operator being able to control the engagement of the stone to a desired depth. Thus, damage could result to the cutting chain or to the saw depending upon how the stone engages with the cutting chain. Therefore, there is a need for an improved advancement mechanism. SUMMARY

[0006] One embodiment takes the form of an advancement mechanism comprising a post that is positionable in at least a first position and a second position, such as an actuated and an unactuated position. The advancement mechanism also includes an engagement mechanism housing having an upper housing section and a lower housing section. Additionally, the advancement mechanism can include a first rotational control mechanism having a pawl and a ratchet that controls advancement of the post, and can include a first bias member biasing the pawl of the first rotational control mechanism to the ratchet. The pawl can have a plurality of pawl teeth on the upper surface of the pawl. The ratchet can also have a plurality of ratchet teeth on the upper surface of the ratchet. A second bias member can be included to bias the post in a first position (for example, an unactuated position). The first rotational control mechanism and the lower housing section are configured such that the ratchet teeth and the pawl teeth are off-set from each other when the post is in the unactuated position. When the post is moved to a second position (for example, an actuated position), the ratchet teeth and pawl teeth align thereby advancing the ratchet teeth.

[0007] The arrangement of ratchet teeth and pawl teeth allows for controlled extension or advancement of the post. When the post reciprocates within the engagement housing and is moved from the unactuated position into the actuated position, the bosses of the ratchet disengage from the guide rails and slide out of pawl slots located within the lower housing of the engagement housing, thereby allowing the ratchet teeth to fully engage the pawl teeth. Because of the ratchet teeth and pawl teeth engagement, the bosses of the ratchet advance to the next guide rail and the next pawl slot. As the post is moved back into the unactuated position, the bosses of the ratchet are forced into alignment with the guide rails such that the bosses advance and slide into the next pawl slot, thereby off-setting the pawl teeth and the ratchet teeth again. Therefore, each time the post is actuated, the ratchet advances one pawl slot, and the post extends a predetermined advancement distance.

[0008] In another embodiment, the advancement mechanism can also include a second rotational control mechanism that resets the advancement mechanism. A second bias member can position the second rotational control mechanism in mating engagement with the post. The second bias member can be coupled to the second rotational control mechanism at a first end and to the engagement mechanism housing at a second end. The second rotational control mechanism can be configured to rotate in a single direction, which prevents uncontrolled advancement of the post. The second rotational control mechanism can allow the operator to rotate the post in a direction that reverses the extension or advancement of the post. As the operator rotates the post in the reverse direction, the post is retracted through the engagement mechanism housing. As the post retracts through the engagement mechanism housing, the advancement of the post is reversed and the advancement mechanism can be returned to its original home position.

[0009] The advancement mechanism described herein can automatically increase the advancement distance of the post thereby reducing the possible over extension of the sharpening stone for sharpening a cutting chain. The advancement mechanism is also resettable allowing for replacement of the sharpening stone and/or sharpening mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The foregoing features of the present disclosure will be more readily understood by reference to the following detailed description, taken with reference to the accompanying drawings, in which:

[0011] FIG. 1 is an exemplary cut-away view of one embodiment of advancement mechanism configured according to the teachings of this disclosure;

[0012] FIG. 2 is an exemplary exploded view of the advancement mechanism depicted in

FIG. 1;

[0013] FIG. 3 is an exemplary cut-away view of the engagement mechanism housing according to an embodiment of the advancement mechanism; [0014] FIG. 4A is an exemplary top plan view of the ratchet according to an embodiment of the advancement mechanism;

[0015] FIG. 4B is an exemplary side elevational view of the ratchet according to the embodiment of the advancement mechanism depicted in FIG. 4A;

[0016] FIG. 5 A is an exemplary top plan view of the pawl according to another embodiment of the advancement mechanism;

[0017] FIG. 5B is an exemplary side elevational view of the pawl according to the embodiment of the advancement mechanism depicted in FIG. 5 A;

[0018] FIG. 6A is an exemplary top plan view of the second rotational control mechanism according to yet another embodiment of the advancement mechanism;

[0019] FIG. 6B is an exemplary side elevational view of the second rotational control mechanism according to the embodiment of the advancement mechanism depicted in FIG. 6A;

[0020] FIG. 7 is an exemplary perspective view of the advancement mechanism assembled in a chain saw (shown in a cut-away) having a sharpening mechanism and with the cutting chain removed;

[0021] FIG. 8 is an exemplary side elevational view of the advancement mechanism assembled in a chain saw (shown in a cut-away) having a sharpening mechanism;

[0022] FIG. 9 is an exemplary perspective view of the sharpening mechanism depicted in

FIGS. 7 and 8;

[0023] FIG. 10 is an exemplary cut-away view of the sharpening mechanism depicted in

FIG. 9 in a retracted position; [0024] FIG. 11 is an exemplary cut-away view of the sharpening mechanism depicted in

FIG. 9 in an extended position; and

[0025] FIG. 12 is an exemplary perspective view of the linkage arm depicted in FIGS. 7 and 8.

DETAILED DESCRIPTION

[0026] A resettable advancement mechanism configured according to the present teachings will hereinafter be described more fully with reference to the accompanying drawings in which exemplary embodiments of the system are illustrated. This system can, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those persons skilled in the art. In the figures and description, like reference numbers refer to like elements throughout.

[0027] Power tools equipped with cutting elements can lose some of their efficiency and/or effectiveness over time as the cutting elements dull or otherwise become worn. For example, the cutting chain of a chain saw can be rapidly dulled by unintentional brief contact with dirt or other abrasive materials during use. The operator needs a sharpening mechanism that can allow the cutting chain to be sharpened quickly and/or easily in the work area. Utilizing such a sharpening mechanism, the operator can continue cutting with reduced delay and/or inconvenience. As described herein, a resettable advancement mechanism is disclosed that conveniently enables sharpening of the cutting element on the power tool. While the embodiments described herein focus on the implementation of the resettable advancement mechanism with a sharpening mechanism for a chain saw and its cutting chain, other power tools having cutting element(s) are also considered within the scope of this disclosure. Examples of other power tools having cutting elements include edgers, reciprocating saws, and the like.

[0028] Referring to FIGS. 1 and 2, the resettable advancement mechanism 530 can function as a resettable indexing mechanism. The resettable advancement mechanism 530 can include: a post 600 that is positionable in a first position and a second position, an engagement mechanism housing 610 through which the post 600 reciprocates, a first rotational control mechanism 620 having a pawl 624 biased by a first bias member 630 to a ratchet 622, and a second bias member 640 biasing the post 600 in the first position. The first rotational control mechanism 620 provides automatic advancement of the post 600 by a predetermined amount. The first bias member 630 and the second bias member 640 can be a helical spring, a coil spring, a compression spring, a tension spring, and/or other similar bias member that can bias the ratchet 622 to the pawl 624 or that can bias the post 600 in a first position.

[0029] The first position and the second position of the post 600 can be an unactuated and an actuated position, respectively. In the unactuated position, the second bias member 640 is uncompressed. In the actuated position, the second bias member 640 is compressed. In some embodiments, the resettable advancement mechanism 530 can have a knob 700 coupled to the post 600. The knob 700 can be configured to actuate the resettable advancement mechanism 530 and move the post 600 into the actuated position and the unactuated position. In some embodiments, the knob 700 can be rotatably coupled to the post 600, allowing the operator to turn, twist, or rotate the knob 700. The individual components of the resettable advancement mechanism 530 are described below in more detail.

[0030] As shown in FIGS. 1 and 2, the post 600 can be an elongate member. The post 600 can have a threaded portion 602 for mating engagement with the first rotational control mechanism 620. The post 600 can be disposed within the engagement mechanism housing 610 such that it can reciprocate therein. The engagement mechanism housing 610 can be cylindrical in shape to accommodate the post 600. The engagement mechanism housing 610 can have a partial wall 612 separating the engagement mechanism housing 610 into an upper housing section 614 and a lower housing section 616, as illustrated in FIGS. 2 and 3. The lower housing section 616 has a plurality of guide rails 650 configured for engagement with the first rotational control mechanism 620.

[0031] The first rotational control mechanism 620 has a ratchet 622 and a pawl 624, as illustrated in FIG. 2. The ratchet 622 has a plurality of ratchet teeth 623 on its upper surface, as shown in FIG. 4B. The pawl 624 has a plurality of pawl teeth 625 on its upper surface, as illustrated in FIG. 5B. The pawl teeth 625 are shaped and configured for engagement with the ratchet teeth 623. The pawl 624 can be coupled to the post 600. For example, if the post 600 has a threaded portion 602, the pawl 624 can have a threaded through-hole for engagement with the threaded portion 602 of the post 600.

[0032] As illustrated in FIGS. 2, 4A, and 4B, the ratchet 622 has a plurality of bosses 652 on its outer perimeter that are configured for engagement with the guide rails 650 of the lower housing section 616 when the post 600 reciprocates within the engagement mechanism housing 610. The lower housing section 616 can also have a plurality of pawl slots 670 along the inner perimeter of the lower housing section 616 in between corresponding guide rails 650, as illustrated in FIGS. 2 and 3. The bosses 652 also reciprocate within the pawl slots 670 as the ratchet 622 advances about the pawl 670. Referring now to FIGS. 1 and 2, when the bosses 652 on the ratchet 622 engage the guide rails 650, the ratchet teeth 623 and the pawl teeth 625 are off-set from each other. Then, when the post 600 is actuated to reciprocate within the engagement mechanism housing 610, the bosses 652 of the ratchet 622 disengage the guide rails 650, allowing the ratchet teeth 623 to align with the pawl teeth 625. The ratchet teeth 623 and the pawl teeth 625 are angled and shaped such that when the ratchet teeth 623 and the pawl teeth 625 are aligned, the ratchet 622 rotates and advances to the next guide rail 650 and thus the bosses 652 slide into the next pawl slot 670. When the post 600 reciprocates within the engagement mechanism housing 610 to return to the unactuated position, the first bias member 630 and second bias member 640 cooperate to position the ratchet 622 so that it engages the guide rails 650, thereby returning the ratchet teeth 623 into an off-set alignment with the pawl teeth 625. Thus, the first rotational control mechanism 620 and the lower housing section 616 are configured such that when the post 600 is in the unactuated position, the ratchet teeth 623 and the pawl teeth 625 are off-set from each other and such that when the post 600 is in an actuated position, the ratchet teeth 623 and the pawl teeth 625 are aligned thereby advancing the ratchet teeth 623.

[0033] In an alternative embodiment, the pawl 624 can have a plurality of pawl ribs 672 along its outer perimeter that are configured for mating engagement with the pawl slots 670 of the lower housing section 616. FIG. 5A illustrates the pawl ribs 672. The pawl ribs 672 remain engaged with the pawl slots 650 when the post 600 is actuated to reciprocate within the engagement mechanism housing 610, thereby preventing rotation of the pawl 624 during actuation.

[0034] In another embodiment, the upper housing section 614 can have a plurality of post slots 680 disposed along the inner perimeter of the upper housing section 614, as illustrated in FIG. 2. The post 600 can have a plurality of post ribs 682 disposed along the outer perimeter of the post. The post ribs 682 can be configured to engage the post slots 680 when the post 600 reciprocates within the engagement mechanism housing 610. The post ribs 682 remain engaged with the post slots 680 as the post 600 is in the actuated position and as the first rotational control mechanism 620 engages and disengages with the guide rails 650. The post 600 does not rotate during actuation of the advancement mechanism 530 because the post ribs 682 remain engaged with the post slots 680 as the post 600 is actuated. As a result, the resettable advancement mechanism 530 advances in a controlled manner such that the post 600 is not advanced farther than the operator intended and such that the post 600 is not advanced by an inadvertent actuation of the knob 700. The post slots 680 can be tapered to facilitate engagement with the post ribs 682, which further ensures controlled movement of the resettable advancement mechanism 530 and prevents rotation of the post 600 during actuation. The entrance of the post slots 680 can also be tapered, thereby facilitating alignment of the post ribs 682 with the post slots 680.

[0035] In another alternative embodiment, the resettable advancement mechanism 530 can include a reset mechanism. The reset mechanism 660 can be a second rotational control mechanism that is configured to rotate in a single direction. Referring to FIGS. 1 and 2, the second rotational control mechanism 660 is configured for mating engagement with the post 600 and is coupled to the post 600 by the second bias member 640. In other embodiments, the second rotational control mechanism 660 can be integral to the post 600 or joined to it by fasteners or welding or adhesives. The second bias member 640 in at least one example does not couple the post with the second rotational control mechanism but only applies a force to retract the post. The second bias member 640 is coupled to the second rotational control mechanism 660 at a first end and coupled to the engagement mechanism housing 610 at a second end. The second rotational control mechanism 660 is configured for mating engagement with a plurality of rotational control slots 670 in the upper housing 614. In the exemplary embodiment illustrated in FIGS. 6A and 6B, the second rotational control mechanism 660 has a plurality of fins 662 shaped so that the second rotational control mechanism 660 and post 600 can only rotate in a single direction. The second rotational control mechanism 660 allows the operator to rotate the post 600 in one direction, such as a reverse direction. For example, the operator rotates the post 600 in a direction opposite the direction that advances the post 600. As the operator rotates the post 600 in this opposite or reverse direction, the ratchet 622 is also rotated in a reverse direction to retract the post 600 through the engagement mechanism housing 610. The operator can reset the resettable advancement mechanism 530 to its original home position, or the operator can reverse the resettable advancement mechanism 530 using the second rotational control mechanism 660, if the advancement mechanism 530 has been advanced too far. The original home position of the resettable advancement mechanism 530 is the position of the resettable advancement mechanism 530 before any actuations have been made to advance the post 600. Although FIGS. 1, 2, 6A, and 6B depict a reset mechanism 660 that is a single integrated unit, one of ordinary skill in the art will appreciate that the rest mechanism 660 can be multiple pieces that are fastened together, for example it can be held together with machine screws or the like. In other examples, the multiple pieces can be welded together thereby forming a single unified structure.

[0036] Operation of the resettable advancement mechanism 530 will now be described with reference to FIGS. 1 and 2. In an unactuated position, the ribs 682 are not engaged with the post slots 680 of the upper housing section 614, and the bosses 652 of the ratchet 622 are engaged with guide rails 650 of the lower housing section 616. Because the bosses 652 are engaged with the guide rails 650, the ratchet teeth 623 are off-set from the pawl teeth 625.

[0037] To actuate the post 600 and move the post 600 out of an unactuated position into an actuated position, a force is applied on the post 600 by applying a force to the knob 700. The force applied to the knob 700 is transferred to the post 600, thereby moving the post 600 into the actuated position. When the post 600 is moved into the actuated position, the post 600 reciprocates within the engagement mechanism housing 610 and compresses the second bias member 640. As the post 600 is moved into the actuated position, the post ribs 682 engage the post slots 680 of the upper housing section 614. When the post ribs 682 are positioned in the post slots 680, the post 600 cannot rotate. Because the post 600 is coupled to the ratchet 622, the ratchet 622 moves as the post 600 is moved into the actuated position. When the post 600 is moved into the actuated position and reciprocates within the engagement mechanism housing 610, the bosses 652 of the ratchet 622 disengage the guide rails 650 of the lower housing section 616. As the bosses 652 disengage the guide rails 650, the ratchet teeth 623 become aligned with the pawl teeth 625, which have been shaped and angled to advance the ratchet 622 to the next guide rail 650. The alignment of the pawl teeth 625 and the ratchet teeth 623 thereby advances the resettable advancement mechanism 530 a predetermined advancement distance. The first bias member 630 biases the pawl 624 to the ratchet 622, which facilitates the alignment of the ratchet teeth 623 and the pawl teeth 625 to advance the resettable advancement mechanism 530. Thus, when the ratchet 622 is advanced to the next guide rail 650, the post 600 is advanced an incremental or predetermined advancement distance through the through-hole of the ratchet 622. For example, if the resettable advancement mechanism 530 includes a post having a threaded portion 602 and a threaded ratchet 622, when the ratchet 622 is advanced to the next guide rail 650, the threaded portion 602 of the post 600 advances and becomes further engaged with the threads of the ratchet 622. Thus, with each advancement of the ratchet 622 along the guide rails 650, the ratchet 622 is wound around the threaded portion 602 of the post 600, which pulls the post 622 further through the ratchet 622 and causes the post 600 to advance forward.

[0038] To return the post 600 back to the unactuated position, the applied force is removed from the knob 700, allowing the second bias member 640 to bias the post 600 back into the unactuated position. When the second bias member 640 biases the post 600 to the unactuated position, the bosses 652 of the ratchet 622 are pulled back into the guide rails 650 thereby providing an off-set alignment of the ratchet teeth 623 and the pawl teeth 625 again. Thus, when the post 600 has been moved from an unactuated position to an actuated position and back to an unactuated position, the ratchet 622 advances one guide rail 650, which corresponds to a predetermined advancement distance of the resettable advancement mechanism 530. The predetermined advancement distance is based on the thread pitch of the post 600 and the ratchet 622 and the number of the ratchet teeth 623. Therefore, the predetermined advancement distance can be adjusted by increasing or decreasing the thread pitch of the post 600 and corresponding thread pitch of the ratchet 622. For example, the illustrated embodiment has twelve threads per inch. The predetermined advancement distance can also be adjusted by increasing or decreasing the number of ratchet teeth 623, pawl teeth 625, and guide rails 650. For example, the illustrated embodiment has twelve ratchet teeth 625 and pawl teeth 625. When the first rotational mechanism 620 has been advanced one guide rail 650, the distal end 532 of the post 600 has also been advanced by a predetermined advancement distance. The distal end 532 of the post 600 can be configured to advance the movement of another device, such as the stone of a chain saw sharpening mechanism, or it can be configured to actuate other types of hand operated tools.

[0039] In another exemplary embodiment, the resettable advancement mechanism 530 can have a reset mechanism 660 to reverse the advancement of the post 600 of the advancement mechanism 530. As shown in FIGS. 1 and 2, the resettable advancement mechanism 530 has a reset mechanism 660 in the form of a second rotational control mechanism 660. To reverse or reset the resettable advancement mechanism 530, the post 600 is placed in an unactuated position where the post ribs 682 are disengaged from the post slots 680 of the upper housing section 614. The post 600 is then rotated, allowing the post 600 to unscrew and/or unthread from the ratchet 622. Thus, the previous advancement of the post 600 can be reversed. Because the second rotational control mechanism 660 is configured to rotate in only a single direction, the post 600 cannot be rotated in a direction that manually advances the resettable advancement mechanism 530, thereby reducing possible error in operating the advancement mechanism 530. As illustrated in FIG. 6A, a plurality of fins 662 of the second rotational control mechanism 660 only allow clockwise rotation. The shape of the fins 662 can prevent counter-clockwise rotation when configured with the post 600 and the engagement mechanism housing 610, as illustrated in FIG. 1. In other embodiments, the fins 662 can be arranged to allow only counter-clockwise rotation and prevent clockwise rotation. In an alternative embodiment, the upper housing section 614 of the engagement housing can have a plurality of fin slots 664 that engage the fins 662 to allow rotation in a single direction. FIG. 3 illustrates an exemplary embodiment of the engagement mechanism housing 610 having fin slots 664. When the post 600 is rotated in a direction that might permit manual advancement of the post 600, the fins 662 can engage the fin slots 664 in the upper housing section 614 of the engagement mechanism housing 610. When the fins 662 engage the fin slots 664, the second rotational control mechanism 660 can only rotate in one direction and thus the post 600 can only rotate in one direction.

[0040] In another exemplary embodiment, the resettable advancement mechanism 530 can have a stop 626, as illustrated in FIG. 1. The ratchet 622 can engage the stop 626 when the post 600 is in the actuated position. The stop 626 can limit the distance the post 600 and first rotational control mechanism 620 can travel within the engagement housing 610. The ratchet 622 can engage the stop 626 when the resettable advancement mechanism 530 advances to a maximum position.

[0041] FIGS. 7 and 8 illustrate a resettable advancement mechanism 530 configured to advance a sharpening mechanism 100 for a self-sharpening chain saw 500. The resettable advancement mechanism 530 is fixed to the engine housing of the chain saw 500 such that the knob 700 can be partially external to the engine housing, while in other embodiments a knob or button can be located in a recess or the like. In this embodiment, the distal end 532 of the resettable advancement mechanism 530 either directly or indirectly actuates a rod of the sharpening mechanism 100, which in turn actuates the sharpening stone. As the resettable advancement mechanism 530 is actuated, the post 600 is advanced a predetermined increment or advancement distance. Consequently, the distal end 532 of the post 600 of the advancement mechanism 530 is also advanced the predetermined increment or advancement distance. As the distal end 532 is advanced forward from the advancement mechanism 530, the distal end 532 contacts and applies a force either directly or indirectly on the rod of the sharpening mechanism 100. The applied force on the rod then actuates the sharpening stone and moves the sharpening stone to an exposed position where it can contact and sharpen a cutting chain. Thus, the advancement mechanism 530 ensures that the sharpening stone is not advanced out from the sharpening mechanism farther than the operator intended, which could damage a cutting chain 550 of the chain saw 500. If the sharpening stone is worn down, the resettable advancement mechanism 530 can be reversed and reset to an original home position as described above to allow replacement of the sharpening stone. Also, if the sharpening stone has been advanced farther out from the sharpening mechanism than the operator intended, the resettable advancement mechanism 530 can be reversed, which reverses the advancement distance of the sharpening stone.

[0042] FIGS. 9-11 illustrate one embodiment of a sharpening mechanism 100 that can be advanced by the resettable advancement mechanism 530 described above. The sharpening mechanism 100 can have a body 110 having a cavity 140 formed therein. A sharpening stone 160 is at least partially located within the cavity 140 of the body 110. A rod 170 is coupled to the stone 160 and passes through the cavity 140 of the body. The distal end of the rod 170 extends beyond an edge of the body 100. A sharpening mechanism bias member 180 biases the stone 160 in a retracted position, where the majority of the sharpening stone 160 is located within the cavity 140. The retracted position is illustrated in FIG. 10. When the resettable advancement mechanism 530 actuates the rod 170 of the sharpening mechanism 100, the distal end of the post 532 contacts and engages the distal end of the rod 170 of the sharpening mechanism either directly or indirectly. This moves the stone 160 from the retracted position (shown in FIG. 10) to an exposed position (shown in FIG. 11). Because the resettable advancement mechanism 530 is advanced by a predetermined advancement distance, the sharpening stone 160 is exposed by that same predetermined advancement distance. Each time the resettable advancement mechanism 530 is actuated the sharpening stone 160 is incrementally advanced and exposed by that predetermined advancement distance. As illustrated in FIG. 8, when the sharpening stone 160 is advanced, it can come into contact with a cutting chain 550 of a chain saw 500 to sharpen the cutting chain 550.

[0043] When the sharpening stone 160 has been advanced and exposed out from the sharpening mechanism 100 more than the operator intended or more than is necessary to sharpen a cutting chain, the resettable advancement mechanism 530 can be reset by rotating the post 600 in a reverse direction to unscrew the post 600 from the ratchet 622 as described above. By reversing the resettable advancement mechanism 530, the advancement distance of the post 600 is reversed.

[0044] Additionally, when the rod 170 of the sharpening mechanism 100 can no longer be advanced or when the sharpening stone 160 needs to be replaced, the resettable advancement mechanism 530 can be reset by unscrewing the post 600 to reverse the advancement distance of the post 600. In another embodiment, the cartridge of the sharpening mechanism 100 can be replaced without resetting the advancement mechanism 530.

[0045] In another exemplary embodiment, such as the one illustrated in FIG. 12, a linkage arm 410 can be used to couple the sharpening mechanism 100 with the resettable advancement mechanism 530. FIGS. 7 and 8 illustrate how a linkage arm 410 can be configured to couple the sharpening mechanism 100 with the resettable advancement mechanism 530. The linkage arm 410 can be pivotably coupled to the engine housing of the chain saw to transfer actuations of the resettable advancement mechanism 530 to the sharpening mechanism 100. For example, when a force is applied to the knob 700 to actuate the resettable advancement mechanism 530, the resettable advancement mechanism 530 advances the linkage contact portion 532 a predetermined advancement distance. The linkage contact portion 532 contacts the linkage arm 410, thereby actuating the sharpening mechanism 100. When the linkage contact portion 532 contacts the linkage arm 410, the linkage arm 410 pivots and engages the rod of the sharpening mechanism 100 to move the sharpening stone from a retracted position to an exposed position, thereby advancing the sharpening stone in a controlled predetermined distance because the resettable advancement mechanism 530 is moved a controlled predetermined advancement distance.

[0046] While the advancement mechanism 530 has been described herein in relation to advancing the movement of a sharpening stone of a sharpening mechanism, one of ordinary skill in the art will appreciate that the advancement mechanism 530 can be implemented to advance movement of components of other types of hand operated tools, such as in caulking guns.

[0047] Exemplary embodiments have been described hereinabove regarding chain sharpening mechanisms and their operation within a chain saw. It should be appreciated, however, that a focus of the present disclosure is resettable advancement mechanisms.

[0048] INDUSTRIAL APPLICABILITY: The present disclosure finds applicability in the power tool and industrial tool industries.