Patent Description:
Power tools having integral bit storage compartments are known in the industry. They enable the user to have the bits readily available for use without requiring a separate bit storage case.

<CIT>, discloses a power drill with an integral, retractable bit holder, in which the bits are held by clips in an array about the circumference of a cylindrical member within the casing of the power drill. The device is useful for holding bits of the same diameter. However, modern bit-using power tools such as impact drivers operate with bits having a range of diameters, such as hex bits, socket adaptors, screwdriver bits, nut drivers, nut setters and pilot drills. Some of these bits have diameters that are much larger than others. Such bits cannot be held by known integral bit holders. There is a need in the power tool industry for a device which can provide integral storage within the power tool of bits having a range of diameters.

Some other examples are known from <CIT>, <CIT>, <CIT> or <CIT>.

The invention provides a bit holder, and a power tool with an integral bit holder, which enables convenient storage within the casing of the power tool of bits having different diameters.

One aspect of the invention provides a retractable bit holder for a bit-using power tool, comprising: a tube configured for longitudinal slidable movement along a cylindrical member of a casing of the power tool between open and closed positions; a bit-mounting member extending radially outwardly from the tube and having a plurality of clip members projecting from and circumferentially spaced around the bit-mounting member, each of the clip members being configured for removably retaining a bit; the bit-mounting member having a first portion with an outer surface at a first radial distance from the tube and a second portion with an outer surface at a second radial distance from the tube, the first radial distance being greater than the second radial distance; the bit holder being sized to provide a recess between the bit-mounting member and an internal wall within the casing of the power tool in the closed position. In other embodiments of the bit holder, the bit-mounting member has more than two portions thereof with an outer surface at different radial distances from the tube, for example, three, four, five or more such portions.

Another aspect of the invention provides a bit-using power tool, such as an impact driver, having a casing with an internal cylindrical member, an internal wall spaced from the cylindrical member, and a retractable bit holder, the bit holder comprising: a tube configured for longitudinal slidable movement along the cylindrical member of the casing between open and closed positions; a bit-mounting member extending radially outwardly from the tube and having a plurality of clip members projecting from and circumferentially spaced around the bit-mounting member, each of the clip members being configured for removably retaining a bit; the bit-mounting member having a first portion with an outer surface at a first radial distance from the tube and a second portion with an outer surface at a second radial distance from the tube, the first radial distance being greater than the second radial distance; the bit holder being sized to provide a recess between the bit-mounting member and the internal wall of the casing in the closed position.

According to another aspect of the invention, the bit-holder is within a cartridge that is detachably connected to the power tool.

Further aspects of the invention and features of specific embodiments are described below.

The bit holder <NUM> is for use in combination with an impact driver <NUM> or other bit-using power tool, such as a power drill or screwdriver. As seen in <FIG> and <FIG>, it is configured to be held within and be retractable from the casing <NUM> of the impact driver and to hold bits <NUM> having various diameters, including hex bits, socket adaptors, screwdriver bits, nut drivers and pilot drills. The bit holder <NUM> comprises a tube <NUM>, a bit-mounting member <NUM>, two collars 21A, 21B and an end cap <NUM>. The tube and the bit-mounting members may be integrally formed of molded plastic.

Referring to <FIG> and <FIG>, the casing <NUM> of the impact driver has an interior cylindrical cavity <NUM> defined by a circumferential wall <NUM>. Within this cavity a cylindrical member <NUM> is affixed to the casing concentrically with the wall <NUM> by a mounting screw <NUM> and support plate <NUM> and extends rearwardly towards the open back end <NUM> of the casing. (In this disclosure, references to "forward" and "rearward" are relative to the power tool, i.e., "rearward" is to the right in the view of <FIG>.

The cylindrical member <NUM> fits within the tube <NUM> of the bit holder, the tube being configured for longitudinal sliding movement on the cylindrical member between an open position, in which the bit holder extends from the casing <NUM>, and a closed position, in which the bit holder is positioned within the casing, with only the end cap <NUM> being outside it. The tube <NUM> is also rotatable on the cylindrical member <NUM> so that a user can rotate the bit holder to select a specific bit.

The bit-mounting member <NUM> extends radially outwardly from the tube <NUM>. It has a portion 20A directly at the outer surface of the tube <NUM> and a portion 20B that is spaced radially outwardly from the tube <NUM> and the portion 20A by radially-extending stand-offs <NUM>, as seen in <FIG>, <FIG> and <FIG>. Clip members <NUM> are arranged around the circumference of the bit-mounting member, at its radially-outward surface, spaced apart from each other and configured for removably retaining the bits <NUM>.

Each bit has a portion <NUM> of its length with a common diameter, and the clip members are uniform in size and hold the bits by this common diameter portion. For example, the common diameter portion <NUM> of the bits may have a diameter of about <NUM> to <NUM> inches measured across the flat portions of a hexagonal shank, or about <NUM> to <NUM> inches measured across the corners of the hexagonal shank. Some of the bits have a portion <NUM> of their length with a larger diameter than that of the common diameter portion <NUM>. For example, while conventional hex bits 16A are substantially uniform in diameter throughout their length, a nut driver 16B may have a portion <NUM> with a larger maximum diameter, e.g., <NUM> to <NUM> inches, and a socket adaptor 16C may have a portion <NUM> with a maximum diameter of <NUM> to <NUM> inches.

The bit-mounting member <NUM> is configured to hold bits <NUM> having different maximum diameters. To accommodate such bits, the bit-mounting member <NUM> has portions thereof with an outer surface at different radial distances from the tube <NUM>, as shown in <FIG>. There are at least two such portions having an outer surface with different radial distances, to accommodate bits having at least two different maximum diameters. In the illustrated embodiments of the bit holder <NUM>, the bit-mounting member <NUM> has five such portions, namely, a first portion <NUM> with an outer surface at a first radial distance <NUM> from the tube <NUM>, a second portion <NUM> with an outer surface at a second radial distance <NUM> from the tube, a third portion <NUM> with an outer surface at a third radial distance <NUM> from the tube, a fourth portion <NUM> with an outer surface at a fourth radial distance <NUM> from the tube, and a fifth portion <NUM> with an outer surface at a fifth radial distance <NUM> from the tube.

The first radial distance <NUM> is greater than the second radial distance <NUM>, such that bits held by clip members <NUM> on the second portion <NUM> of the bit-mounting member are positioned closer to the tube <NUM> than bits held by clip members on the first portion <NUM> of the bit-mounting member. Similarly, the third radial distance <NUM>, the fourth radial distance <NUM> and the fifth radial distance <NUM> are less than the first radial distance <NUM> and are different from the second radial distance <NUM> and from each other, being intermediate to radial distances <NUM> and <NUM>, to accommodate bits of various different maximum diameters.

In other embodiments of the bit holder, the bit-mounting member <NUM> has fewer or more portions thereof with an outer surface at different radial distances from the tube <NUM>, for example, two, three, four, or more than five such portions.

As seen in <FIG>, <FIG> and <FIG>, the first portion <NUM> of the bit-mounting member <NUM> has a part <NUM> that extends longitudinally along one circumferential portion of the tube <NUM> (this is approximately half of the circumference in the illustrated embodiment). The remaining circumferential portion of the tube is not covered by the longitudinal extension <NUM> of the bit-mounting member <NUM>. When the bit holder <NUM> is in the closed position within the casing <NUM>, there is an annular recess <NUM> between the bit-mounting member (and the bits held by it) and the internal circumferential wall <NUM> of the casing. The radial distance within the annular recess <NUM> between the circumferential wall <NUM> and the uncovered portion of the tube <NUM> is greater than the radial distance between the circumferential wall <NUM> and the longitudinally-extending part <NUM> of the bit-mounting member. This results in a radially larger space within the annular recess <NUM> for the storage of bits <NUM> having relatively larger maximum diameters, such as nut drivers 16B and socket adaptors 16C, held by the clip members <NUM> on the second portion <NUM>, the third portion <NUM>, the fourth portion <NUM> and the fifth portion <NUM> of the bit-mounting member.

The bits <NUM> held by clip members <NUM> on the first portion <NUM> of the bit-mounting member <NUM> are adjacent to the longitudinally-extending part <NUM> of the first portion <NUM>. Since these bits, such as hex bits 16A, have a relatively smaller maximum diameter, they fit snugly into this relatively smaller space between the bit-mounting member <NUM> and the circumferential wall <NUM> of the casing.

As seen in <FIG>, the bit holder <NUM> includes two collars 21A, 21B fitted snugly around the opposed inner and outer ends respectively of the tube <NUM> to prevent the bits <NUM> from escaping longitudinally from the bit holder, should they not be firmly seated in the clip members. The bit holder also includes a cap <NUM> affixed on its outward end. This cap covers the open back end <NUM> of the casing and provides a grip for a user to retract the bit holder <NUM> from the casing <NUM>.

In some embodiments, means are provided to prevent complete separation of the bit holder from the casing when the bit holder is slidably moved from the closed position to the open position. For example, as shown in <FIG> and <FIG>, this may take the form of an outwardly-protruding ring <NUM> around the outward end of the cylindrical member <NUM> and an inwardly protruding ring or shoulder <NUM> around the inward end of the tube <NUM>. When the bit holder is moved into the open position, the opposing faces of the rings <NUM>, <NUM> are brought into abutment against one another, preventing separation of the bit holder from the casing.

In other embodiments, this separation-prevention means <NUM>, <NUM> is not provided, in order to permit the removal of the bit holder <NUM> from the casing <NUM> and the interchange of separate bit holders pre-loaded with different bits. A bit holder <NUM> removed from the casing may be kept in a separate retrieval canister for convenient access and use.

Retaining means are provided to retain the bit holder <NUM> in place within the cavity <NUM> when it is in the closed position. Suitable retaining means for this purpose are known in the art, as disclosed for example in <CIT> and <CIT> to Fruhm. As seen in <FIG> and <FIG>, the retaining means comprises a retaining pin <NUM> affixed to the outward end of the cylindrical member <NUM>. The retaining pin has radially outwardly-protruding flexible finger-like members <NUM>, separated by slit apertures, and holds a spring <NUM> arranged to bias the finger-like members <NUM> outwardly. The retaining means includes a bevelled rim <NUM> of the tube <NUM> at the inward face of the end cap <NUM>. As the bit holder <NUM> is slid into the closed position, the finger-like members <NUM> are compressed radially inwardly, and when they encounter the bevelled rim <NUM> they snap radially outwardly to seat themselves within the bevelled rim. This releasably retains the bit holder <NUM> in the closed position.

The retaining pin <NUM> also creates the sliding frictional fit of the bit holder along the cylindrical member <NUM> of the casing, by virtue of the finger-like members <NUM> pressing on the inner surface of the tube <NUM> as the bit holder <NUM> is moved between the open and closed positions.

<FIG> illustrate an embodiment of the invention in which the bit holder <NUM> is in a bit cartridge <NUM> that is detachable from the power tool <NUM>. The structure and operation of the bit holder <NUM> in this embodiment is essentially the same as in the embodiment of <FIG>. This detachable cartridge embodiment facilitates the interchange of bit cartridges that are pre-loaded with different bits. It is distinct from the embodiments referred to above in which the bit holder <NUM> is removable from the casing <NUM> of the power tool.

In the embodiment pf <FIG>, the power tool <NUM> has a casing <NUM> which comprises two parts, namely a casing first part <NUM> and a casing second part <NUM>. The casing first part has the power tool handle <NUM> and contains the motor and all parts of the power tool apart from the detachable bit cartridge.

The casing second part <NUM> comprises the casing wall <NUM> (corresponding to the wall <NUM> of the embodiment of <FIG>) and contains the cylindrical member <NUM>. The casing second part <NUM> holds the bit-holder <NUM>. These parts together comprise the bit cartridge <NUM>.

Referring to <FIG>, the wall <NUM> of the bit cartridge <NUM> extends forwardly of an end wall <NUM> of the casing second part <NUM>, forming a short cylindrical extension <NUM>. Four bayonet members <NUM> extend into this extending section <NUM> from the end wall <NUM>. The bayonet members have a straight part and an angled part.

An end cap <NUM> is attached to the rearward end <NUM> of the casing first part <NUM> by means of screws <NUM> that extend through holes <NUM> in the end cap and into the body of the casing first part. The end cap <NUM> is configured to fit partly within the extending section <NUM> of the bit cartridge. The end cap has four slots <NUM> configured to receive the bayonet members <NUM>. The slots <NUM> and bayonet members <NUM> are configured such that when the bayonet members <NUM> are inserted into the slots <NUM> and the bit cartridge <NUM> is rotated, angled end portions of the bayonet members engage the end cap <NUM> and releasably lock the bit cartridge <NUM> to the casing first part <NUM>. Rotation of the bit cartridge in the opposite direction disengages the bayonet members from the end cap to release the bit cartridge. The user can then replace the bit cartridge by another bit cartridge holding different bits.

Throughout the foregoing description and the drawings, in which corresponding and like parts are identified by the same reference characters, specific details have been set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

Claim 1:
A retractable bit holder (<NUM>) for a bit-using power tool (<NUM>), comprising:
a tube (<NUM>) configured for longitudinal slidable movement along a cylindrical member (<NUM>) of a casing (<NUM>) of the power tool between open and closed positions;
a bit-mounting member (<NUM>) extending radially outwardly from the tube and having a plurality of clip members (<NUM>) projecting from and circumferentially spaced around the bit-mounting member, each of the clip members being configured for removably retaining a bit (<NUM>); characterized by
the bit-mounting member (<NUM>) having a first portion (<NUM>) with an outer surface at a first radial distance (<NUM>) from the tube and a second portion (<NUM>) with an outer surface at a second radial distance (<NUM>) from the tube, the first radial distance being greater than the second radial distance;
the bit holder being sized to provide a recess (<NUM>) between the bit-mounting member and an internal wall (<NUM>) within the casing of the power tool in the closed position.