CLAIM OF PRIORITY

[0001] This application claims priority to U.S. Provisional Application Serial No. 61/780,238 entitled "Nail Holding Mechanism for an Impact Power Tool" by Dayal et al., filed March, 13, 2013, U.S. Provisional Application Serial No. 61/781,354 entitled "Clamping Nail Holder" by Dayal et al, filed March 14, 2013, U.S. Provisional Application Serial No. 61/781,366 entitled "Nail Holding Mechanism" by Hlinka et al, filed March 14, 2013, and U.S. Provisional Application Serial No. 61/781,816 entitled "Nail Holding Mechanism" by Bernardi, filed March 14, 2013, the disclosures of which are hereby incorporated herein by reference in their entirety.

TECHNICAL FIELD

[0002] This disclosure relates generally to power tools, and, more particularly, to fastener holding mechanisms for power tools.

BACKGROUND

[0003] Impact hammer devices are portable power tools that are commonly used to drive nails into a receiving medium such as wood or drywall. Impact hammers typically include an actuator, or motor, that rotates an output shaft. A transmission converts the rotational motion of the actuator output shaft into reciprocating linear movement of a striking mechanism. The striking mechanism typically extends into a magnetized sleeve. A nail is placed in the sleeve and held therein by the magnetic force in the magnetized sleeve. The nail is then pressed against the receiving medium and the impact hammer is activated. Each reciprocating strike of the striking mechanism advances the nail further into the receiving medium until the nail is fully inserted in the receiving medium.

[0004] Existing impact hammers produce difficulties in aligning the nail with the receiving medium and retaining the nail in the desired position as the nail is driven into the receiving medium. The aligning sleeve is typically designed to be large enough to accommodate a head of a large nail. Smaller nails, however, will not be held securely in a sleeve designed for a large nail head, resulting in the nail wobbling within the sleeve. Failure to properly align the nail within the sleeve can result in the nail being driven into the receiving medium at an undesirable angle or at an improper location. What is needed, therefore, are improvements to nail holding mechanisms for impact hammers.

SUMMARY

[0005] In one embodiment, a fastener holding system for a power tool is configured to securely clamp a fastener while enabling the fastener holding system to pivot out of the way of the power tool to enable the fastener to be driven completely into a surface. The fastener holding mechanism includes a mounting mechanism configured to attach to a housing of a power tool and a holder pivotably connected to the mounting mechanism. The holder includes a holder body having a clamp configured to retain a fastener and a release lever extending away from the holder body and the clamp. The release lever is configured to engage a surface during operation of the power tool such that engagement of the release lever with the surface opens the clamp and pivots the holder away from the fastener. [0006] In another aspect, the fastener holding system further comprises an actuator connected to the clamp and configured to open the clamp upon activation of the actuator. This feature can suitably be combined with other features disclosed herein.

[0007] In yet another aspect of the above embodiment, the fastener holding system further comprises a pivot pin pivotably coupling the holder body and the mounting mechanism.

Engagement of the release lever with the surface pivots the holder body about the pivot pin away from the fastener, and the pivoting of the holder body away from the fastener opens the clamp. This feature can suitably be combined with other features disclosed herein.

[0008] In another embodiment, a power tool comprises a housing defining a sleeve recess, a driven element, and a sleeve at least partially surrounding the driven element and at least partially retractable into the sleeve recess of the housing. The sleeve defines a first slot extending longitudinally along a length of the sleeve.

[0009] In another aspect, the first slot extends through an entire radial width of the sleeve and the first slot extends along an entire longitudinal length of the sleeve from a first end of the sleeve to a second opposite end of the sleeve. This feature can suitably be combined with other features disclosed herein.

[0010] In yet another aspect of this embodiment, the power tool further comprises a support member fixed to the housing in the sleeve recess and extending into the first slot in the sleeve. The sleeve is configured to move longitudinally relative to the support member and the housing. This feature can suitably be combined with other features disclosed herein.

[0011] In another aspect, the sleeve has a first end positioned in the sleeve recess and a second opposite end outside the sleeve recess, and the first slot extends from the second end of the sleeve to an intermediate position between the first end and the second end of the sleeve. This feature can suitably be combined with other features disclosed herein.

[0012] In another aspect, the housing includes a tool housing and a transmission housing pivotably connected to the tool housing, and the sleeve recess is defined in the transmission housing. This feature can suitably be combined with other features disclosed herein.

[0013] In yet another aspect, the sleeve includes an inner aperture having a circumferential surface and the first slot extends radially outwardly from the inner aperture of the sleeve and defines a slot outer surface. This feature can suitably be combined with other features disclosed herein.

[0014] In another aspect, the first slot is defined in the circumferential surface of the inner aperture of the sleeve and includes a first outer surface. The power tool further comprises a second slot defined in the circumferential surface of the inner aperture of the sleeve including a second outer surface, and the first and second slots are disposed on opposite sides of the circumferential surface of the inner aperture. A first clamping member is positioned in the first slot and a second clamping member is positioned in the second slot. A first spring is disposed in the first slot braced on the first outer surface of the first slot and the first clamping member and configured to bias the first clamping member toward the inner aperture. A second spring is disposed in the second slot braced on the second outer surface of the second slot and the second clamping member and configured to bias the second clamping member toward the first clamping member. This feature can suitably be combined with other features disclosed herein.

[0015] In yet another aspect, the first clamping member includes a first end disposed proximate to an opening of the first slot, a second end recessed within the first slot, and a first beveled surface extending from the second end at an outer side of the first clamping member toward an inner side of the first clamping member at an intermediate position of the first clamping member between the first and second ends. The second clamping member includes a third end disposed proximate to an opening of the second slot, a fourth end recessed within the second slot, and a second beveled surface extending from the fourth end at an outer side of the second clamping member toward an inner side of the second clamping member at an intermediate position of the second clamping member between the third and fourth ends. The first beveled surface is configured to engage the driven element to urge the first clamping member toward the first outer surface and the second beveled surface is configured to engage the driven element to urge the second clamping member toward the second outer surface as the sleeve retracts into the sleeve recess. This feature can suitably be combined with other features disclosed herein.

[0016] In another aspect, the driven element includes a reciprocating striking rod and a protective sleeve positioned between the reciprocating striking rod and the first and second beveled surfaces. The protective sleeve is configured to absorb impact forces when the striking rod contacts the first and second beveled surfaces. This feature can suitably be combined with other features disclosed herein.

[0017] In another aspect, the first slot is defined in an outer circumferential surface of the sleeve. The power tool further comprises a second slot defined in an inner circumferential surface of the sleeve spaced circumferentially around the sleeve from the first slot and a clamping system having a first protruding member and a second protruding member. The first protruding member fits complementarily in the first slot and the second protruding member fits complementarily in the second slot so that the first and second protruding members retain the clamping system in engagement with the sleeve. This feature can suitably be combined with other features disclosed herein. [0018] In yet another aspect, the clamping system includes a first clamping member, a second clamping member, and a biasing member. The first clamping member includes the first and second protruding members, and the biasing member is configured to bias the second clamping member with respect to the first clamping member such that a clamping opening defined between the first and second clamping members is biased toward a closed position. This feature can suitably be combined with other features disclosed herein.

[0019] In another embodiment, the power tool further comprises a pivot pin extending through a first orifice in the first clamping member and a second orifice in the second clamping member. The biasing member includes a torsional spring disposed around the pivot pin and braced on the first and second clamping members such that the biasing member urges the second clamping member to pivot with respect to the first clamping member to bias the clamping opening toward the closed position.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a cross-sectional schematic view of an impact hammer having a retractable sleeve.

[0021] FIG. 2 is a perspective view of the impact hammer of FIG. 1 in a 180 degree orientation.

[0022] FIG. 3 is a perspective view of the retractable sleeve of FIG. 1.

[0023] FIG. 4 is a cross-sectional view of the retractable sleeve of FIG. 1 in an initial position.

[0024] FIG. 5 is a cross-sectional view of the retractable sleeve of FIG. 1 in a driving position.

[0025] FIG. 6 is a cross-sectional view of the retractable sleeve of FIG. 1 in a partially retracted position. [0026] FIG. 7 is a cross-sectional view of the retractable sleeve of FIG. 1 in a fully retracted position.

[0027] FIG. 8 is a perspective view of another retractable sleeve in an initial position.

[0028] FIG. 9 is a perspective view of the retractable sleeve of FIG. 7 in a driving position.

[0029] FIG. 10 is a perspective view of the retractable sleeve of FIG. 7 in a partially retracted position.

[0030] FIG. 11 is a perspective view of the retractable sleeve of FIG. 7 in a fully retracted position.

[0031] FIG. 12 is a cross-sectional view of a nail holding mechanism in a closed extended position.

[0032] FIG. 13 is a cross-sectional view of the nail holding mechanism of FIG. 12 in a closed extended position with the springs removed to show the spring pins.

[0033] FIG. 14 is a cross-sectional view of the nail holding mechanism of FIG. 12 in an open retracted position.

[0034] FIG. 15 is a perspective view of the nail holding mechanism of FIG. 12 in the closed extended position, with the cap removed for clarity.

[0035] FIG. 16 is a perspective view of the nail holding mechanism of FIG. 12 in an open extended position, with the cap removed for clarity.

[0036] FIG. 17 is a perspective view of a protective shell of the nail holding mechanism of FIG. 12.

[0037] FIG. 18 is an exploded view of the nail holding mechanism of FIG. 12, showing the components of the nail holding mechanism. [0038] FIG. 19 is a cross-sectional view of a clamping nail holder attached to an impact hammer.

[0039] FIG. 20 is a side view of the clamping nail holder of FIG. 19 attached to an impact hammer.

[0040] FIG. 21 is a side perspective view of the clamping nail holder of FIG. 19.

[0041] FIG. 22 is an end view of the clamping nail holder of FIG. 19.

[0042] FIG. 23 is an end perspective view of the clamping nail holder of FIG. 19.

[0043] FIG. 24 is a side perspective view of a retractable sleeve for use with the clamping nail holder of FIG. 19.

[0044] FIG. 25 is a side view of a nail holding mechanism in a working position.

[0045] FIG. 26 is a side view of the nail holding mechanism of FIG. 25 in a retracted position.

[0046] FIG. 27 is a perspective view of a nail clamp of the nail holding mechanism of FIG. 25 with a nail being loaded into the nail clamp.

[0047] FIG. 28 is a front view of the nail holding mechanism of FIG. 25 with a nail gripped in the nail clamp.

[0048] FIG. 29 is a side view of another nail holding mechanism in a working position.

[0049] FIG. 30 is a side view of the nail holding mechanism of FIG. 29 in a retracted position.

DETAILED DESCRIPTION

[0050] For the purposes of promoting an understanding of the principles of the embodiments described herein, reference is now made to the drawings and descriptions in the following written specification. No limitation to the scope of the subject matter is intended by the references. This disclosure also includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the described embodiments as would normally occur to one skilled in the art to which this document pertains.

[0051] FIG. 1 is a cross-sectional view of an impact hammer 100. The impact hammer 100 includes a tool housing 104, a motor 108, a transmission housing 112, a striking rod 116, also referred to as a driven element, and a retractable sleeve 120. The motor 108 includes an output shaft 110 that rotates in response to activation of the motor 108 in the impact hammer 100. The transmission housing 112 includes a sleeve recess 1 14, and is pivotable with respect to the tool housing 104 to enable the impact hammer to be used in a 90 degree orientation, as shown in FIG. 1, a 180 degree orientation, as shown in FIG. 2, or another desired orientation.

[0052] FIG. 3 depicts a close-up view of the retractable sleeve 120 of the impact hammer 100. The retractable sleeve 120 extends from the transmission housing 112 and partially surrounds the striking rod 116. The retractable sleeve 120 is generally cylindrical, and includes a slot 124 extending longitudinally along the entire length of the sleeve 120 and extending entirely through a radial width of the sleeve 120. A fixed support member 128 is positioned within the slot 124. The retractable sleeve 120 is configured to retract into the sleeve recess 114 of the transmission housing 112, while the fixed support member 128 remains in a fixed position relative to the transmission housing 112, such that the slot 124 of the retractable sleeve 120 slides around the fixed support member 128. In some embodiments, the circumferential width of the slot and the width and length of the fixed support member are larger or smaller than shown in FIG. 3.

[0053] Operation of the retractable sleeve 120 of the impact hammer 100 is illustrated in FIGS. 4-7. The nail 200 is inserted into the retractable sleeve 120 until the head of the nail 200 abuts the striking rod 116. In some embodiments, the retractable sleeve or the fixed support member is magnetized to facilitate retention of the nail in the sleeve. In other embodiments, the striking rod is magnetized to facilitate retention of the nail head against the striking rod. The slot 124 in the retractable sleeve 120 serves as a viewing window to enable the user to see the nail 200 and align the nail 200 at a desired location on the workpiece 204. The impact hammer 100 is arranged such that the nail 200 is pressed against the workpiece 204 to depress the striking rod 116 into the transmission housing 112, as shown in FIG. 5, and the impact hammer 100 is activated. Once the impact hammer 100 is activated, the motor 108 rotates the output shaft 110, and a transmission device (not shown) located within the transmission housing 112 converts the rotational motion of the output shaft 110 into a reciprocating striking motion of the striking rod 116, driving the nail 200 into the workpiece 204.

[0054] As the nail 200 is driven into the workpiece 204, the end surface of the retractable sleeve 120 abuts the surface of the workpiece 204 and the retractable sleeve 120 is pushed into the sleeve recess 114 of the transmission housing 112. The slot 124 enables the retractable sleeve 120 to slide past the fixed support member 128 as the sleeve 120 retracts into the sleeve recess 114 of the transmission housing 112, as shown in FIG. 6. The slot 124 further enables the user to continuously view the nail 200 through the slot 124 until the impact hammer 100 reaches the position of FIG. 6 to ensure the desired alignment of the nail 200 in the workpiece 204. The striking rod 116 continues to drive the nail 200 into the workpiece 204 until the head of the nail 200 is flush with the workpiece 204, as shown in FIG. 7. Once the nail 200 is flush with the workpiece 204, the impact hammer 100 is disengaged from the nail 200 and workpiece 204 and the retractable sleeve 120 returns to the initial position of FIG. 4.

[0055] Another embodiment of a retractable sleeve 320 for an impact hammer 100 is shown in FIGS. 8-11. The retractable sleeve 320 is substantially cylindrical and surrounds the striking rod 116. The sleeve 320 includes a slot 324 extending entirely through a radial width of the sleeve 320 along a portion of the length and circumference of the sleeve 320. In some embodiments, the size of the slot 324 is larger or smaller than shown in FIGS. 8 and 11, and in other embodiments the slot is positioned in a different location around the circumference of the retractable sleeve. The retractable sleeve 320 of the embodiment of FIGS. 8-11 is configured to retract into a sleeve recess (not shown in FIGS. 8-11) of the transmission housing 112 in a similar manner as the retractable sleeve 120 of the embodiment of FIGS. 1-7.

[0056] In operation, the nail 200 is inserted into the retractable sleeve 320 until the head of the nail 200 abuts the striking rod 116, as shown in FIG. 8. The slot 324 in the retractable sleeve 320 enables the user to see the nail 200 and align the nail 200 at a desired location on the workpiece 204. The impact hammer 100 is arranged such that the nail 200 is pressed against the workpiece 204 to depress the striking rod 116 into the transmission housing 112, as shown in FIG. 9, and the impact hammer 100 is activated. Activation of the impact hammer 100 moves the striking rod 116 in a reciprocating motion to drive the nail 200 into the workpiece 204.

[0057] As the nail 200 is driven into the workpiece 204, the end surface of the retractable sleeve 320 abuts the surface of the workpiece 204 and the opposite end of the retractable sleeve 120 is forced into the sleeve recess of the transmission housing 112. As shown in FIG. 10, the slot 324 enables the user to see the nail 200 as the nail 200 is driven into the workpiece 204. The striking rod 116 continues to drive the nail 200 into the workpiece 204 until the head of the nail 200 is flush with the workpiece 204, as shown in FIG. 11. The slot 324 enables the user to view the nail 200 until the nail is driven flush with the workpiece 204 to ensure the desired alignment of the nail 200 in the workpiece 204. Disengaging the impact hammer 100 from the nail 200 returns the retractable sleeve 320 to the initial position shown in FIG. 8. [0058] FIG. 12 is a cross-sectional view of a nail holding system 400 that replaces the retractable sleeve 120 of the impact hammer 100 of FIG. 1. The nail holding mechanism 400 includes a first clamp 404, a second clamp 408, a retractable sleeve 412, and a connecting sleeve 416. The connecting sleeve 416 is mounted to a tool housing 420 of the impact hammer to retain the nail holding mechanism 400 on the impact hammer. The impact hammer further includes a striking rod 424, also referred to as a driven element, extending through the center of the tool housing 420, connecting sleeve 416, and retractable sleeve 412. A sleeve recess 425 is defined within the connecting sleeve 416 and the tool housing 420, in the region between the striking rod 424 and the connecting sleeve 416 and tool housing 420.

[0059] The retractable sleeve 412 includes an annular cap 448 attached to the retractable sleeve 412 by threaded members 460 (FIG. 18) and configured to retain the clamps 404 and 408 within the indentation 428 of the retractable sleeve 412. The retractable sleeve 412 is configured to telescope into the connecting sleeve 416 as the cap 448 is pressed against a receiving medium. The retractable sleeve 412 further includes two first spring pins 434 and two second spring pins 438 extending from an upper and lower inner surface, respectively, of the retractable sleeve 412.

[0060] The first and second clamps 404 and 408 are positioned within slots or indentations 426 and 428 (FIG. 15), respectively, in the outer forward surface of the retractable sleeve 412. Two first springs 432 are mounted on the spring pins 434 (FIG. 13) in a radially outer surface of the indentation 426 to urge the first clamp 404 downwardly in the view of FIG. 12. Two second springs 436 (FIG. 12) are mounted on the second spring pins 438 (FIG. 13) in a radially outer surface of the second indentation 428 to urge the second clamp 408 upwardly such that, in the absence of an external object between the clamps 404 and 408, the first clamp 404 and the second clamp 408 engage one another. In some embodiments, the nail holding mechanism includes one or three or more first and second springs to provide a desired force acting on the first and second clamps, respectively. In another embodiment, the first springs are configured to generate a force that is less than a force generated by the second springs.

[0061] The first clamp 404 further includes a clamping projection 440 (FIGS. 15 and 16) that extends from a front face of the first clamp 404 to a rearward first beveled surface 442. The first beveled surface 442 extends from an outer circumferential side of the first clamp 404 at a rearward end of the first clamp 404 to an intermediate position on the inner side of the first clamp 404. The second clamp 408 includes a clamping indentation 444 (FIGS. 15 and 16) extending from a front face of the second clamp 408 to a rearward second beveled surface 446. The second beveled surface 446 extends from an outer circumferential side of the second clamp 408 at a rearward end of the second clamp 408 to an intermediate position on the inner side of the second clamp 408. As shown in FIG. 15, when the clamp is closed, the clamping projection 440 is engaged with the clamping indentation 444. When a nail is positioned between the first 404 and second 408 clamps, the clamping projection 440 presses the nail into a fixed position within the clamping indentation 444.

[0062] The striking rod 424 includes an end surface 456 and is mounted within the tool housing 420, extending through the connecting sleeve 416 and a portion of the retractable sleeve 412. The striking rod 424 is configured to be driven in a reciprocating striking motion by an electric or pneumatic actuator in the impact hammer. A protective shell 452, shown in more detail in FIG. 17, partially surrounds the striking rod 424, extending to an end of the striking rod 424 such that the striking rod 424 does not impact the beveled surfaces 442 and 446 or the clamps 404 and 408 and cause wear to the beveled surfaces 442 and 446 and the clamps 404 and 408. [0063] In operation, the nail holding mechanism 400 begins in the closed position of FIG. 12, and is opened by pressing the cap 448 in the direction of the tool housing 420. The cap 448 pushes the retractable sleeve 412 into the connecting sleeve 416 and beveled surfaces 442 and 446 of the clamps 404 and 408, respectively, against the protective shell 452 of the striking rod 424. As the beveled surfaces 442 and 446 are pressed against the protective shell 452, the shell 452 urges the first clamp 404 upwardly and the second clamp 408 downwardly, resulting in FIG. 14. Once the clamp is opened, the user inserts a nail between the first 404 and second 408 clamps, pressing the head of the nail against the end surface 456 of the striking rod 424. When the pressure on the cap 448 is released, the retractable sleeve 412 slides out of the connecting sleeve 416, while the first spring 432 urges the first clamp 404 downwardly and the second spring 436 urges the second clamp 408 upwardly to clamp the nail in a groove formed between the clamping projection 440 of the first clamp 404 and the clamping indentation 444 of the second clamp 408.

[0064] The user then presses the nail into a receiving medium and activates the impact hammer to impart a reciprocating motion on the striking rod 424. As the striking rod 424 reciprocates, the nail is driven into the receiving medium. Once the nail is driven into the receiving medium to a point where the cap 448 abuts the surface of the receiving medium, the user continues to press the cap 448 against the surface of the receiving medium to force the retractable sleeve 412 into the connecting sleeve 416. The cap 448 additionally presses the first and second clamps 404, 408 such that the beveled surfaces 442 and 446 engage the protective shell 452 of the striking rod 424. As the cap 448 is pressed further, the clamps 404 and 408 are pushed upwardly and downwardly, respectively, until the clamps 404 and 408 are no longer in the path of the striking rod 424 and protective shell 452. The reciprocating motion of the striking rod 424 continues to drive the nail further into the receiving medium until the striking rod 424 reaches the end of the cap, as shown in FIG. 14, where the striking rod 424 drives the nail flush with the surface of the receiving medium.

[0065] FIG. 19 depicts a perspective view of a clamping nail holder 500 attached to an impact hammer, for example configured to be mounted to or replace the retractable sleeve 120 of the impact hammer 100 of FIG. 1. The clamping nail holder 500 includes a fixed clamp 504 and a free clamp 508, connected to one another by a clamping pin 512 (FIGS. 20-22). The fixed clamp 504 and the free clamp 508 define a clamping region 514 (FIGS. 22 and 23) configured to clamp a nail to guide the nail during a driving operation. The fixed clamp 504 and the free clamp 508 are biased by two torsional springs 516 and 520 (FIG. 20) surrounding the clamping pin to minimize the clamping region 514, as shown in FIGS. 22 and 23. In one embodiment, the two torsional springs 516 and 520 each have a spring force of approximately 4.3 newtons to urge the clamp to close around a nail. In another embodiment, the torsional springs 516 and 520 are stock number TO-5041L springs manufactured by Century Spring Corp., though different springs are used in other embodiments.

[0066] The fixed clamp 504 includes two mounting pins 524 and 528, a stopping member 532, and an opening flange 536. The mounting pins 524 are press fit into holes in the fixed clamp 504 and extend from a rear face of the fixed clamp 504. The free clamp 508 includes another stopping member 540 and another opening flange 544. The opening flange 544 of the free clamp 508 and the opening flange 536 of the fixed clamp 504 are configured such that the opening flange 544 of the free clamp 508 is moved toward the opening flange 536 of the fixed clamp 504 to overcome the force generated by the torsional springs 516 and 520 and pivot the free 508 clamp about the clamping pin 512, opening the clamping nail holder 500. As shown in FIG. 22, the first and second clamps 504 and 508 each include an indentation that defines a recess 548 in a rear surface of the clamping nail holder 500.

[0067] FIG. 24 illustrates the retractable sleeve 560 for use with the clamping nail holder 500. The retractable sleeve 560 has an inner aperture or central opening 564 and two pin slots 568 and 572. One of the pin slots 568 opens into the central opening 564, while the other pin slot 572 opens to an exterior surface of the retractable sleeve 560. The pin slots 568 and 572 are configured to accommodate the mounting pins 524 and 528 of the fixed clamp 504 to attach the fixed clamp 504 to the retractable sleeve 560.

[0068] FIGS. 19 and 20 illustrate the clamping nail holder 500 attached to the retractable sleeve 560 of the impact hammer. The mounting pins 524 and 528 fit into the pin slots 572 and 568, respectively, to attach the nail holder 500 to the retractable sleeve 560. The retractable sleeve 560 is slidably mounted within a connecting sleeve 576 that connects the retractable sleeve 560 to the tool shaft 580. As the nail holder 500 is pressed against a receiving medium, the retractable sleeve 560 is configured to telescope into the connecting sleeve 576 and tool shaft 580. The tool shaft 580 houses the striking pin 584, which moves in a reciprocating manner against a nail that abuts an end surface 588 of the striking pin 584 to drive the nail into a receiving medium. The stopping members 532 and 540 extend against an outer surface of the retractable sleeve 560 from the nail holder 500 toward the connecting sleeve 576 and tool shaft 580.

[0069] In operation, the nail holder 500 is attached to the retractable sleeve 560 of the impact hammer by pressing the mounting pins 524 and 528 into the pin slots 572 and 568, respectively. The user then pinches the opening flange 544 toward opening flange 536 to open the clamping region 514 and inserts a nail in the clamping region 514 such that the head of the nail abuts the end surface 588 of the striking pin 584. The user then releases the opening flange 536, releasing energy stored in the torsional springs 516 and 520, which closes the clamping region 514 around the nail. The user then positions the nail against a receiving medium and activates the impact hammer to generate a reciprocating motion in the striking pin 584 to drive the nail into the receiving medium.

[0070] As the nail is driven into the receiving medium, the clamping nail holder 500 presses against the receiving medium, pushing the retractable sleeve 560 into the connecting sleeve 576 and the tool shaft 580. The stopping members 532 and 540 abut the connecting sleeve 576 when the head of the nail reaches the recess 548 defined by the clamps 504 and 508, preventing the striking pin 584 from striking the clamping nail holder 500 and causing damage to the nail holder 500. In some embodiments, the recess in the clamps has a larger depth or a larger diameter to enable use of nails having larger heads. In other embodiments, the stopping members are configured to abut the connecting sleeve prior to the nail head reaching the clamps, eliminating the need for a recess in the clamps.

[0071] Once the stopping members 532 and 540 abut the connecting sleeve 576, the user removes the nail holder 500 from the nail by pinching opening flange 544 toward opening flange 536 to open the clamping region 514. The user then removes the nail holder 500 from the retractable sleeve 560 by sliding the mounting pins 524 and 528 out of the pin slots 572 and 568 and guides the clamping nail holder 500 upwardly, away from the partially-embedded nail through the area opened by pinching the opening flange 544. After the clamping nail holder 500 is removed, the opening flanges 536 and 544 are released, and the torsional springs 516 and 520 close the clamping region 514 and return the clamping nail holder 500 to the rest position. The retractable sleeve 560 then extends beyond the nail to enable the user to use the impact hammer to drive the nail into the receiving medium until the nail head is flush with the receiving medium.

[0072] Although the clamping nail holder illustrated in FIGS. 19-24 is attached to the sleeve by a sliding pin connection, in other embodiments the clamping nail holder is connected to the sleeve by a press fit, a clamping device, or another desired attachment mechanism.

[0073] FIGS. 25 and 26 illustrate another nail holding mechanism 600 for an impact hammer. The nail holding mechanism 600 includes a mount 604, a holder body 608, a nail clamp 612 (FIGS. 27 and 28), a pivot pin 616, and two connecting arms 618. The mount 604 is configured to mount to a housing 650 of the impact hammer to securely attach the nail holding mechanism 600 to the impact hammer. The mount includes grooves 606, in which the connecting arms 618 rest when the nail holding mechanism 600 is in a working position shown in FIG. 25. A connecting arm spring 619 biases the connecting arms 618 toward one another to enable the connecting arms 618 to snap into the grooves 606 when the nail holding mechanism 600 is in the working position. The connecting arm spring 619 flexes to allow the connecting arms 618 to snap out of the groove 606. The pivot pin 616 is used to pivot the body 608 of the nail holding mechanism 600, and the two connecting arms 618 connect the pivot pin 616 to the body 608.

[0074] The body 608 includes a plunger 620, a plunger spring 624, a channel 626 (FIGS. 27 and 28), and a release lever 628. The plunger 620 is operatively connected to the nail clamp 612 through the channel 626, such that movement of the plunger 620 moves the nail clamp 612. The plunger spring 624 urges the plunger 620 away from the body 608 to bias the nail clamp 612 into the body 608. The release lever 628 is configured to extend below the body 608 of the mechanism 600 to contact a surface of a receiving medium as the impact hammer is operated. [0075] FIGS. 27 and 28 illustrate the nail clamp 612 of the nail holding mechanism 600. The nail clamp 612 has clamping arms 630 that are positioned within the channel 626. The nail clamp 612 is configured such that pressing the plunger 620 toward the body 608 of the tool holder moves the clamping arms 630 away from the body 608. The clamping arms 630 flex resiliently such that the clamping arms 630 open as the clamping arms 630 move out of the channel 626. Once the nail clamp 612 is open and moved away from the body, a nail 654 is inserted into the nail clamp 612. After the plunger 620 is released, the plunger spring 624 urges the nail clamp 612 to retract into the channel 626, compressing the clamping arms 630 and tightening the clamping arms 630 around the nail 654 to hold the nail 654 securely in place, as shown in FIG. 28.

[0076] After the nail 654 is inserted into the nail holding mechanism 600, the nail 654 is pressed against a receiving medium and the impact hammer is activated, driving the nail 654 into the receiving medium as a striking rod (not shown) within a sleeve 658 of the impact hammer repeatedly hammers the nail 654 into the receiving medium. Once the nail 654 has been driven into the receiving medium to the point where the release lever 628 contacts the surface of the receiving medium, the reaction force from the surface of the receiving medium pushes the release lever 628 and holder body 608 upwardly. The release lever 628 and holder body 608 pivot about the pivot point 616, while the nail 654 remains in embedded in the receiving medium. The pivoting of the release lever 628 and the holder body 608 force the clamping arms 630 to spring open to allow the holder body 608 to swing out of the path of the impact hammer without user intervention, enabling the nail 654 to be driven completely into the receiving medium. [0077] FIGS. 29 and 30 illustrate another embodiment of a nail holding mechanism 700. The nail holding mechanism 700 includes a mount 704, a holder body 708, and a nail clamp 712. The mount 704 is configured to mount to a housing 650 of the impact hammer to securely attach the nail holding mechanism 700 to the impact hammer. The nail holding mechanism further includes a pivot pin 716, which is used to pivot the body 708 of the nail holding mechanism 700.

[0078] The body 708 includes a plunger 720 and a release lever 728. The plunger 720 is operatively connected to the nail clamp 712, such that movement of the plunger 720 moves the nail clamp 712. A plunger spring (not shown) located within the body 708 urges the plunger 720 away from the body to pull the nail clamp 712 into the body 708. The release lever 728 is configured to contact a surface of a receiving medium as the impact hammer is used.

[0079] The nail clamp 712 of the embodiment of FIGS. 29 and 30 is similar to the nail clamp 612 of the embodiment of FIGS. 25-28. The nail clamp 712 extends from the body 708 in response to pressure applied to the plunger 720, and the nail clamp 712 opens as the clamp 712 extends from the body 708 to enable the nail to be 654 inserted into the nail clamp 712.

[0080] After the nail 654 is inserted into the nail holding mechanism 700, the nail 654 is pressed against a receiving medium and the impact hammer is activated, driving the nail 654 into the receiving medium as a striking rod (not shown) within a sleeve 658 of the impact hammer repeatedly hammers the nail 454 into the receiving medium. Once the nail 654 has been driven into the receiving medium to the point where the release lever 728 contacts the surface of the receiving medium, the reaction force from the surface of the receiving medium pushes the release lever 728 and body 708 upwardly. The release lever 728 and body 708 pivot about the pivot point 716, while the nail remains in embedded in the receiving medium. The pivoting of the release lever 728 and the body 708 force the nail clamp 712 to spring open and allow the body 708 to swing out of the path of the impact hammer without user intervention, enabling the nail 654 to be driven completely into the receiving medium.

[0081] While the above described embodiments have been illustrated as being attached to an impact hammer, the reader should appreciate that the holding mechanisms are suitable for use in other power tools. For example, the holding mechanisms described herein can be attached to a power drill or a bit driver to retain a threaded fastener, such as a screw, in a desired alignment as the power tool rotationally drives a driven element, for example an output shaft, to force the fastener into a receiving member.

[0082] It will be appreciated that variants of the above-described and other features and functions, or alternatives thereof, may be desirably combined into many other different systems, applications or methods. Various presently unforeseen or unanticipated alternatives,

modifications, variations or improvements may be subsequently made by those skilled in the art that are also intended to be encompassed by the disclosure.