DEVICE AND METHOD FOR CHANGING TOOL BIT IN A POWER TOOL

PRIORITY

[0001] This application claims priority, under 35 U.S.C. § 119(e), to U.S. Provisional Application No. 60/919,352, filed March 22, 2007, which is incorporated by reference.

TECHNICAL FIELD

[0002] This application relates to a device and method for changing the tool bit in a power tool, such as a router.

BACKGROUND

[0003] A power tool, such as a router, generally includes a motor that rotates a spindle. Coupled to the end of the spindle is a tool holder that holds a tool bit. The tool holder holds the tool bit in place so that the tool bit rotates together with the spindle. The tool holder generally includes a collet that holds the tool bit and a nut that is threaded onto the spindle to compress the collet about the tool bit.

[0004] Frequently, during use, a user desires to remove and change the tool bit from the tool holder of the tool. In order to remove the tool bit, the nut of the tool holder generally must be unthreaded from the spindle. In order to perform this function, the spindle generally must be held in place while the nut is rotated. This is generally achieved using a pair of wrenches, where the user holds the spindle using a first wrench with one hand while using the other hand to turn the nut. In other embodiments, the tool may include a spindle lock button that is held by the user with one hand, while a wrench is used to loosen or tighten the nut with the other hand.

SUMMARY

[0005] In an aspect, a device is disclosed for removing a tool bit from a power tool having a motor, a spindle rotationally coupled to the motor, and a tool holder coupled to the spindle for holding the tool bit. The device includes a first wrench that is removably attachable to the power tool at a first point of contact and that abuts against a surface to prevent rotation of the spindle of the tool without requiring the user to hold the first wrench. A second wrench is configured for

Title: DEVICE AND METHOD FOR CHANGING TOOL BIT IN A POWER TOOL Applicants: Carroll et al. Docket No. P-US-JK- 11807-PCT the user to apply a rotational force to the tool holder while the first wrench is preventing rotation of the spindle, in order to loosen or tighten the tool holder.

[0006] Implementations of this aspect may include one or more of the following features. The first wrench includes a curved member. The first wrench includes a first notch substantially at the first point of contact. The first notch is configured to engage a spindle of the power tool to prevent rotation of the spindle. The curved member includes second and third points of contact against the surface at opposite end portions of the curved member. The first wrench includes second and third notches at the opposite end portions. The second wrench includes a first notch on a first end of the second wrench for applying rotational force to the tool holder. The second wrench includes a second notch substantially at the center of the second wrench. The first and second wrenches are substantially identical.

[0007] In another aspect, a system includes a power tool having a motor, a spindle rotationally coupled to the motor, and a tool holder coupled to the spindle for holding a tool bit. A first wrench is removably attachable to the power tool at a first point of contact and that abuts against a surface to prevent rotation of the spindle of the tool without requiring the user to hold the first wrench. A second wrench is configured for the user to apply a rotational force to the tool holder while the first wrench is preventing rotation of the spindle, in order to loosen or tighten the tool holder.

[0008] Implementations of this aspect may include one or more of the following features. The first wrench includes a curved member. The first wrench includes a first notch substantially at the first point of contact. The first notch is configured to engage a spindle of the power tool to prevent rotation of the spindle. The curved member includes second and third points of contact against the surface at opposite end portions of the curved member. The first wrench includes second and third notches at the opposite end portions. The second wrench includes a first notch on a first end of the second wrench for applying rotational force to the tool holder. The second wrench includes a second notch substantially at the center of the second wrench. The first and second wrenches are substantially identical.

Title: DEVICE AND METHOD FOR CHANGING TOOL BIT IN A POWER TOOL Applicants: Carroll et al. Docket No. P-US-JK-1 1807-PCT

[0009] In another aspect, there is disclosed a device for removing a tool bit from a power tool having a motor, a spindle rotationally coupled to the motor, and a tool holder coupled to the spindle for holding a tool bit. The device includes a first curved wrench that is removably attachable to a power tool at a first contact point on an intermediate portion of the first curved wrench and that has opposite end portions that abut against a work surface at second and third contact points for hands-free prevention of rotation of the spindle. A second wrench is configured for the user to apply a rotational force to a tool holder while the first wrench is preventing rotation of the spindle, in order to loosen or tighten the tool holder. In one implementation of this aspect, the first wrench and second wrench are substantially identical.

[0010] In another aspect, a method includes coupling a first wrench to a spindle of a power tool so that the first wrench rests against a surface with at least two points of contact to prevent rotation of the spindle without use of a hand. A second wrench is coupled to the tool holder to remove or attach a tool bit while the first wrench prevents rotation of the spindle. In one implementation, this method may also include applying a second portion of the first wrench to the spindle and using both hands to apply forces to the first wrench and the second wrench to remove or attach a tool bit.

[0011] Advantages may include one or more of the following. The tool holder can be loosened and tightened while only using one hand to apply forces to the tool holder. The first wrench provides greater leverage than an ordinary spindle lock to prevent rotation of the spindle. The first wrench enables a package with smaller height than a package with a spindle lock. The design provides for greater ease of use and reduced or equal cost as compared to a spindle lock or an ordinary two wrench design. The pair of wrenches may alternatively be used with both hands in an ordinary manner. Other advantages and features will be apparent from the description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a perspective view of a router and a first wrench.

[0013] FIG. 2 is a perspective view of the router with the first wrench applied to the spindle and resting on a surface to prevent rotation of the spindle.

Title: DEVICE AND METHOD FOR CHANGING TOOL BIT IN A POWER TOOL Applicants: Carroll et al. Docket No. P-US-JK-11807-PCT

[0014] FIG. 3 is an end view of the router and the first wrench of FIG. 2.

[0015] FIG. 4 is a perspective view of the router with the first wrench of FIG. 2 with a second wrench being used to loosen or tighten a tool holder of the router.

DETAILED DESCRIPTION

[0016] Referring to FIG. 1, a power tool, e.g., a router 10, includes a motor housing 12 that houses a motor, a spindle 14 coupled to the motor, and a tool holder 16, coupled to the spindle 14. The spindle 14 includes flats 18 configured to receive a wrench to prevent rotation of the spindle 14. The tool holder 16 includes a collet 20 configured to hold a tool bit (not shown) and a nut 22 configured to thread over the spindle 14 and compress the collet 20 to hold the tool bit in the collet 20. The nut 22 is configured to receive a second wrench to tighten or loosen nut 22 around the collet 20 to release or attach the tool bit.

[0017] In an implementation, the first wrench comprises a first wrench 30 that includes a curved element 32 having a concave bottom edge 34, a convex top edge 36, and side edges 38, 40, which meet at corners 48, 50, 52, and 54. Defined in the top edge is a first notch 42 disposed substantially at the center of the top edge 36. Defined in the side edges 38, 40 are second and third notches 44 and 46.

[0018] Referring also to FIGS. 2 and 3, the first notch 42 has a geometrical configuration, e.g., square or hexagonal, to non-rotationally engage a similar or different geometrical configuration defined by the flats 18 on the spindle 14 at a first point of contact 60. When first notch 42 is engaged with the flats 18 at the first point of contact 60, the corners 52 and 54 can rest against a surface 62, e.g., a tabletop, at second and third points of contact 64 and 66. In this way, the first wrench 30 prevents rotation of the spindle 14 without requiring the user to hold the first wrench 30 or the router 10 with a hand.

[0019] Referring also to FIG. 4, in an implementation, the second wrench comprises a second wrench 70 that includes a curved element 72 having a concave bottom edge 74, a convex top edge 76, and side edges 78, 80. Defined in the top edge 76 is a first notch 82 disposed substantially at the center of the top edge 76. Defined in the side edges 78, 80 are second and third notches 84 and 86, each having a geometrical configuration (e.g., square or hexaganol) to

Title: DEVICE AND METHOD FOR CHANGING TOOL BIT IN A POWER TOOL Applicants: Carroll et al. Docket No. P-US-JK-11807-PCT non-rotationally engage a similar or different geometrical configuration defined by the nut 22. In this way, the second wrench 70 can be used to loosen the nut 22 to release a tool bit or to tighten the nut 22 to attach a tool bit in the collet 20. The second wrench 70 is shown as being identical to the first wrench 30, which may reduce manufacturing costs. It should be understood, however, that the first and second wrenches may have different configurations.

[0020] In use, the user applies the first notch 42 of the first wrench 30 to the flats 18 on the spindle and places the router 10 and first wrench 30 on a surface, such as table 62, with the corners 52 and 54 abutting the table 62 at the first and second contact points 64 and 66. This enables the first wrench 30 to prevent rotation of the spindle hands-free, i.e., without requiring the user to hold the first wrench 30 or the router 10. Next, the user engages the nut 22 with the second 84 or third 86 notch of the second wrench 70 and turns the second wrench 70 to loosen or tighten the nut 22 to remove or attach a tool bit. Thus, the tool bit can be removed or attached using a one-handed operation. Alternatively, the first and second wrenches may be used in a two-handed operation by holding the first wrench 30 with one hand to engage the flats 18 on the spindle 14 with the second or third notch 44 or 46 of the first wrench 60 and holding the second wrench 70 with the other hand to engage the nut 22 with the second or third notch 84 or 86 of the second wrench 70 and turn the nut 22.

[0021] Numerous modifications may be made to the exemplary implementations described above. For example, the configuration or shape of the first wrench could be different. The first wrench may omit the second and/or third notches, may have a different shape, and/or may have the first notch located off-center from the first notch. The second wrench may be different from the first wrench, including having a different shape and configuration and a greater or fewer number of notches. For example, the second wrench may omit the center notch and one of the second and third notches. The user can enhance the holding power of the first wrench by pressing down on the motor housing with one hand while turning the second wrench. The wrenches may be used with other types of power tools, e.g.., drills, and may be used with other types of tool holders, e.g., chucks. These and other implementations are within the scope of the following claims.