POWER DRILL WITH INTEGRAL BIT HOLDER

Abstract: A power drill (10) having a casing and an integral bit holder (16) in which the bit holder incorporates first, second and third cylinders (18, 20 and 22). The first cylinder forms part of the drill casing, such as a housing (14) for a drive motor portion of the power drill, a housing (12) for a handle portion of the power drill, or a housing (46) for a brace portion of the power drill. The second cylinder is circumferentially mounted on the first cylinder in a manner allowing longitudinal, slidable movement of the second cylinder with respect to the first cylinder, between open and closed positions. The third cylinder is circumferentially fixed with respect to the first cylinder to form an annular recess (26) between the first and third cylinders. When in the closed position, the second cylinder is enclosed within the recess. A plurality of clips (28) are fixed to and circumferentially spaced around the second cylinder. Each clip can removably retain one bit (30). A cap (32) is fixed to one end of the second cylinder to cover the recess when the second cylinder is in the closed position.

Description: POWER DRILL WITH INTEGRAL BIT HOLDER Technical Field This application pertains to a power drill having an integral bit holder in which a plurality of different bits may be stored. The bit holder is slidably movable between closed and open positions. When closed, the holder and its contents are recessed within a suitable portion of the drill's outer casing (i.e. the motor housing, the handle, a hand brace, a hollow core armature, etc). When open, the holder is with- drawn (but not separated) from the casing to expose all of the bits for simultaneous viewing. Background A wide variety of drill bits or other implements can be used with a conventional power drill. Commonly, the bits and/or implements are stored in a separate case. In many situations it would be more convenient to provide a bit storage compartment integral with the drill itself. The drill operator would have ready access to a supply of different bits, thus avoiding the need to locate and manipulate a separate bit storage case. Tools having integral bit storage compartments have been developed. For example, a variety of manually-operated screwdrivers having integral bit storage compartments exist. United States patent number 5,265,504 issued 30 November, 1993 discloses a "Cartridge Type Screwdriver" having a bit storage magazine within the screwdriver handle. A plurality of different bits are held in place by clips provided around the circumference of the storage magazine. By pulling a cap longitudinally away from the handle, one may slidably withdraw the magazine from the handle to expose the bits. A particular bit can be selected and removed from its clip. The user then presses against the cap to slide the storage magazine back inside the handle. Unlike a manually-operated screwdriver, which can be provided with a hollow handle suitable for receiving a bit storage magazine, a power drill has no readily apparent space for receiving a bit storage magazine. The present invention however discloses several embodiments, any of which facilitate integration of a bit holder with a power drill in a manner which preserves the desired compact configuration of a typical power drill and without impairing functionality of either the power drill or the bit holder. Summary of Invention In accordance with one embodiment, the invention provides a power drill having a casing and an integral bit holder in which the bit holder incorporates first, second and third cylinders. The first cylinder forms part of the drill casing, such as a housing for a drive motor portion of the power drill, a housing for a handle portion of the power drill, or a housing for a brace portion of the power drill. The second cylinder is circumferentially mounted on the first cylinder in a manner allowing longitudinal, slidable movement of the second cylinder with respect to the first cylinder, between open and closed positions. The third cylinder is circumferentially fixed with respect to the first cylinder to form an annular recess between the first and third cylinders. When in the closed position, the second cylinder is enclosed within the recess. A plurality of clips are fixed to and circumferentially spaced around the second cylinder. Each clip can removably retain one a bit. A cap is fixed to one end of the second cylinder to cover the recess when the second cylinder is in the closed position. A stop mechanism is provided to prevent complete separation of the first and second cylinders. For example, an outwardly protruding ring may be formed around an outward end of the first cylinder and an inwardly protruding ring formed around an inward end of the second cylinder. When the second cylinder is withdrawn into its open position, the rings butt against one another to prevent further slidable movement of the second cylinder. A retaining mechanism is provided to retain the second cylinder within the recess in the closed position. For example, an outwardly protruding member may be formed around an outward end of the first cylinder and a mating notch may be formed around an inner circumferential surface of the cap. The member and the notch are sized and shaped such for snap-fit engagement of the member within the notch when the second cylinder is in the closed position. In accordance with another embodiment, the invention provides a power drill having a casing and an integral bit holder, in which the bit holder takes the form of a storage compartment such as a drawer which can be slidably moved with respect to a recess in the casing, between open and closed positions. A plurality of clips are fixed within the storage compartment, with each clip again removably retaining one bit. In yet another embodiment, a recess is provided within the power drill's electric motor armature. A bit storage container can then be removably, slidably inserted within the recess. The bits can be stored loosely within the storage container. Alternatively, a first cylinder can be fixed within the armature recess and a second cylinder circumferentially mounted on the first cylinder for longitudinal, slidable movement of the second cylinder with respect to the first cylinder, between open and closed positions. A third cylinder is circumferentially fixed with respect to the first cylinder to form an annular recess between the first and third cylinders, such that the second cylinder is enclosed within the recess when in the closed position. A plurality of bit-retaining clip members are fixed to and circumferentially spaced around the second cylinder. A cap is fixed to one end of the second cylinder to cover the recess when the second cylinder is in the closed position. Brief Description of Drawings Figure 1 is a schematic side elevation depiction of a power drill including a sectional illustration of a bit holder mounted outside the drive motor housing portion of the drill's outer casing. Figure 2 is similar to Figure 1 , but shows the bit holder in hidden line detail. Figure 3 is a right side sectional view taken with respect to line 3-3 shown in Figure 1. Figure 4 is similar to Figure 2, but shows the bit holder in the opened position. Figure 5A is a schematic pictorial illustration of the embodiment of Figures 1-4, showing the bit holder in the opened position. Figure 5B is an exploded schematic pictorial illustration of the embodiment of Figures 1-4. Figure 6 is a partially sectioned side elevation view of another embodiment of the invention in which the bit holder is mounted around the drill's drive motor, inside the drive motor housing portion of the drill's outer casing. Figure 7 depicts the opened position of the Figure 6 bit holder. Figure 8 is a pictorial illustration schematically depicting the provision of integral bit holders in the drive motor housing, handle housing and secondary hand brace portions of a power drill's outer casing. Figure 9 A is a schematic, side elevation view depiction of a power drill incorporating a further embodiment of the invention in which the bit holder comprises a drawer-like storage compartment mounted atop the power drill's outer casing. Figure 9B is a sectional, rear elevation view of the Figure 9 A embodiment. Figure 9C is a top oblique pictorial view of the Figure 9A embodi- ment, showing the bit holder in the opened position. Figure 10A is a schematic, partially fragmented, side elevation view depiction of a power drill incorporating yet another embodiment of the invention in which a bit holder is received within an electric motor armature having a hollow core. Figure 10B is an exploded and partially fragmented illustration of the embodiment depicted in Figure 10 A. Figure 10C is similar to Figure 10B, but shows the bit storage holder positioned within the drill casing. Figure 10D is a partially fragmented, oblique rear pictorial illustration of the embodiment of Figures 10A-10C, further showing the motor armature received within a stator core and showing the opened position of a clip-type bit holder mounted for slidable advance or retraction relative to armature's hollow core. Figure 10E is similar to Figure 10D, but shows the bit holder in the closed position. Description Figures 1 through 5B depict a typical power drill 10 having a hard plastic external casing shaped to form a handle housing portion 12, a drive motor housing portion 14, etc. An integral bit holder 16 is formed around drive motor housing portion 14. Bit holder 16 incorporates first, second and third cylinder portions 18, 20 and 22. First cylinder 18 is formed by the drill casing's drive motor housing portion 14 within which the drill's drive motor (not shown) is contained. Second cylinder 20 is circumferentially mounted around first cylinder 18 to allow longitudinal, slidable movement of second cylinder 20 with respect to first cylinder 18 as bit holder 16 is moved between its opened and closed positions as hereinafter explained. Third cylinder 22 is circumferentially fixed with respect to first cylinder 18 by annular flange 24. The external diameter of first cylinder 18 is only slightly smaller than the internal diameter of second cylinder 20, allowing second cylinder 20 to slide longitudinally with respect to first cylinder 18 without "wobbling". The internal diameter of third cylinder 22 is sufficiently larger than the external diameter of second cylinder 20 to define an annular bit storage recess 26 between second and third cylinders 20, 22. A plurality of clips 28 are fixed to and circumferentially spaced around the external surface of second cylinder 20. Each of clips 28, which are preferably made of a flexible, resilient plastic material, removably retain a single bit in snap-in, snap-out fashion as seen in Figure 5 A. Thus, when bit holder 16 is in the closed position depicted in Figure 2, clips 28 retain bits 30 (Figure 5 A) within recess 26. Cap 32 is fixed on the outward end of second cylinder 20. Cap 32 covers the outward end 34 of recess 26 when bit holder 16 is in the closed position depicted in Figure 2. An optional "stop means" is provided to prevent complete separation of first and second cylinders 18, 20 when bit holder 16 is slidably moved from the closed to the opened position. Specifically, an outwardly protruding ring 36 is formed around the outward end of first cylinder 18 and an inwardly protruding ring 38 is formed around the inward end of second cylinder 20. When second cylinder 20 is moved into the opened position depicted in Figure 4, the opposing faces of rings 36, 38 are brought into abutment against one another. Since ring 36 is fixed to first cylinder 18 which in turn forms part of the drill casing, the aforesaid abutment prevents further slidable movement of second cylinder 20 in the outward direction, thereby preventing separation of second cylinder 20 from first cylinder 18. A "retaining means" is provided to retain second cylinder 20 within annular recess 26 when bit holder 16 is in the closed position depicted in Figures 1 and 2. Specifically, a member 31 (Figure 5B) having a series of outwardly protruding flexible, finger-like members 40 (Figure 1), separated by slit apertures 41 , is circumferentially formed or fitted over the outward end of first cylinder 18. A bevelled rim 42 is provided around the outward inside end of second cylinder 20. Bevelled rim 42 fits flush against the flat inward face of cap 32, thus forming a notch ring 42 around the inner circumferential surface of cap 32. When cap 32 is pressed inwardly to slidably advance bit holder 16 into its closed position within recess 26, members 40 are compressed radially inwardly as their radially protruding portions encounter the inner circumferential surface 44 of second cylinder 20. When the radially protruding portions of members 40 encounter notch ring 42, those portions "snap" radially outwardly to seat themselves within notch ring 42. Collars 43, 45 are fitted snugly around the opposed ends of second cylinder 20 to prevent bits 30 from escaping longitudinally away from recess 26, should any such bits not be firmly pressed within a correspon- ding one of clips 28 and/or become dislodged therefrom. Note that it may in some cases be desirable to eliminate the aforementioned "stop means", for example in order to facilitate rapid interchange of separate "cartridges" pre-loaded with different bits (i.e. each such "cartridge" comprising second cylinder 20, clips 28, bits 30, member 31 , collars 43, 45 and cap 32). Figures 6 and 7 depict an alternative embodiment of the invention in which the first cylinder (here designated 18 A) comprises the external surface of the drill's drive motor 19; and, the third cylinder (here designated 22 A) is formed by the external portion of the drill's hard plastic casing which surrounds drive motor 19. Screws 21 extend through overlapped flange portions of first and third cylinders 18 A, 22A respectively to fix those two cylinders with respect to one another and define annular recess 26 therebetween. Apertures 33, 35, 37 are provided in cap 32, in third cylinder 22 A and between third cylinder 22 A and the forward portion of the drill's casing to facilitate passage of cooling air around drive motor 19 as indicated by arrows 39. Construction and operation of the Figure 6-7 embodiment is otherwise identical to that of the Figure 1-5B embodiment, as indicated by the use of the same reference numerals in both sets of Figures. As illustrated by Figure 8, the bit holder may alternatively be configured to fit within handle portion 12 of drill 10 or within secondary hand brace portion 46 thereof. Indeed, drill 10 may be equipped with any or all of the three bit holders 16A, 16B and 16C schematically depicted in Figure 8. Bit holder 16A, which surrounds the drill's drive motor, may take the form of either of the embodiments previously described with respect to Figures 1-5B or with respect to Figures 6-7. Bit holders 16B and 16C may be similar in construction and operation to either of the aforementioned Figure 1-5B or Figure 6-7 bit holder embodiments, except that instead of utilizing the drive motor or its housing to constitute the first cylindrical shaft, it is necessary to provide a separate first cylindrical shaft fixed within drill handle 12 (in the case of bit holder 16B) or within secondary hand brace 46 (in the case of bit holder 16C) upon which the remaining portions of the respective bit holders may be slidably mounted for movement between open and closed positions. The diameter of the second cylinder portion of the particular bit holder utilized will determine the number of bits which may be stored within the bit holder. For example, the diameter of second cylinder 20 depicted in the embodiment of Figures 1-5 is comparatively large (about 2.9 inches or 7.4 cm) facilitating provision of up to twenty clips 28 around second cylinder 20, within which up to twenty separate bits may be removably stored. The external diameter of second shaft 20 depicted in the Figure 6-7 embodiment will however be somewhat reduced in comparison to that of the Figure 1-5 embodiment, since the Figure 6-7 embodiment is more closely conformed around drive motor 19 itself. This provides a more compact overall drill profile, but reduces the bit holder's bit storage capacity somewhat. Figures 9A-9C depict a further embodiment of the invention in which the bit holder comprises a drawer-like storage compartment mounted atop the drill's outer casing. Specifically, Figures 9A-9C depict an arcuate storage compartment or enclosure 50 formed as an integral part of the hard plastic external casing of power drill 10. A bit holding drawer or tray 52 having an arcuate shape (best seen in Figures 9B and 9C) conforming to that of enclosure 50 is mounted for slidable advance or retraction of tray 52 with respect to recess 54 defined within enclosure 50. A plurality of clips 56 are fixed to tray 52. Each of clips 56, which are preferably made of a flexible, resilient plastic material, removably retain a single bit 30 in snap-in, snap-out fashion as seen in Figure 9C. Thus, when tray 52 is in the closed position depicted in Figure 9A, clips 56 retain bits 30 within recess 54. A detent mechanism (not shown) or other similar means can be provided within enclosure 50 to retain tray 52 in the closed position. A stop means such as a downwardly protruding flange (not shown) can be provided on an inward portion of enclosure 54 to bear against a corresponding inwardmost portion of tray 52 in order to prevent complete separation of tray 52 from enclosure 50, although this is not necessary. Figures 10A-10E depict yet another embodiment of the invention in which the bit holder is received within an electric motor armature having a hollow core. Specifically, instead of having a conventional solid longitudinal shaft, armature 60 has a hollow core shaft which defines a cylindrical recess 62 extending longitudinally within armature 60. A bearing ring 64 is mounted circumferentially around one end of armature 60 and a conventional fan assembly 66 is mounted around the opposed end thereof. A pair of ribs 68 are formed within drill casing 70 to supportably surround bearing ring 64 as shown in Figure 10A. A cylindrical bit holder 72 having a closed end 74 and an outwardly flanged, open end 76 is provided. Bit holder 72 is sized for removable, slidable insertion within recess 62, as is also best seen in Figure 10A. Bits 30 can be stored loosely within bit holder 72 and open end 76 thereof can subsequently be closed by affixing cap 78 thereover. Alternatively, as shown in Figure 10D (which also depicts a stator core 80 surrounding armature 60) a clip-type bit holder 82 similar to either of the embodiments previously described with respect to Figures 1-5B or with respect to Figures 6-7 can be provided. Bit holder 82 is thus similar in construction and operation to either of the aforementioned Figures 1- 5B or Figures 6-7 bit holder embodiments, except that instead of utilizing the drive motor or its housing to constitute the first cylindrical shaft, it is necessary to fix a separate first cylindrical shaft to closed end 74 upon which shaft the remaining portions of the bit holder (i.e. the second and third shafts, etc.) may be slidably mounted for movement between open and closed positions, as previously described. Note that the outer cylindrical wall of bit holder 72 depicted in Figures 10A-10C serves as the "third cylinder" . As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. For example, the invention is readily adaptable for use with power tools similar to power drills, such as electric screw guns, electric screw drivers or hand-held power operated grinding tools. As another example, it is not essential that the bit holder's first second and third cylinder portions be cylindrical in cross-section. A cylindrical cross- sectional shape is preferred since this allows the second cylinder portion to be rotated relative to the drill for easy simultaneous viewing of the stored bits. Other cross-sectional shapes such as hexagonal, octagonal, rectangular, etc. will work although such shapes may not facilitate rotation as aforesaid and may reduce the bit holder's bit storage capacity. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.

Claims: WHAT IS CLAIMED IS: 1. A power drill (10) having a casing and an integral bit holder (16), said bit holder comprising: (a) a first cylinder (18) forming a portion of said casing; (b) a second cylinder (20) circumferentially mounted on said first cylinder for longitudinal, slidable movement of said second cylinder with respect to said first cylinder between open and closed positions; (c) a third cylinder (22) circumferentially fixed with respect to said first cylinder to form an annular recess (26) between said first and third cylinders, said second cylinder enclosed within said recess when in said closed position; (d) a plurality of clip members (28) fixed to and circumferentially spaced around said second cylinder, each one of said clip members for removably retaining a bit (30); and, (e) a cap (32) fixed to one end of said second cylinder, said cap for covering said recess when said second cylinder is in said closed position. 2. A power drill as defined in claim 1 , said bit holder further comprising stop means for preventing separation of said first and second cylinders. 3. A power drill as defined in claim 2, said stop means further comprising an outwardly protruding ring (36) formed around an outward end of said first cylinder and an inwardly protruding ring (38) formed around an inward end of said second cylinder for abutment of said rings against one another to prevent said slidable movement in an outward direction when said second cylinder is in said open position. 4. A power drill as defined in claim 1 , further comprising retaining means for retaining said second cylinder within said recess when said second cylinder is in said closed position. 5. A power drill as defined in claim 4, said retaining means further comprising a radially outwardly protruding member (31 , 40) provided around an outward end of said first cylinder and a mating notch (42) formed around an inner circumferential surface (44) of said second cylinder for snap-fit engagement of said member within said notch when said second cylinder is in said closed position. 6. A power drill as defined in claim 2, wherein said casing further comprises a housing (14) for a drive motor portion of said power drill. 7. A power drill as defined in claim 2, wherein said casing further comprises a housing for a handle portion (12) of said power drill. 8. A power drill as defined in claim 2, wherein said casing further comprises a housing for a brace portion (46) of said power drill. . A power drill (10) having a casing and an integral bit holder, said bit holder comprising: (a) a storage compartment (50) mounted on said casing for longitudinal, slidable movement of said storage compartment with respect to a recess (54) in said casing, between open and closed positions; and, (b) a plurality of clip members (56) fixed within said storage compartment, each one of said clip members for removably retaining a bit (30). 10. A power drill as defined in claim 9, wherein said storage compartment further comprises a drawer (52). 11. A power drill having a casing (70), an electric motor armature (60) and an integral bit holder, said bit holder comprising: (a) a recess (62) provided within said electric motor armature; (b) a bit storage container (72) sized and shaped for removable slidable insertion of said container within said recess, said container having a closed end (74) and an opposed open end (76); and, (c) a cap (78) for covering said open end. 12. A power drill having a casing (70), an electric motor armature (60) and an integral bit holder (82), said bit holder comprising: (a) a recess (62) provided within said electric motor armature; (b) a first cylinder fixed within said recess; (c) a second cylinder circumferentially mounted on said first cylinder for longitudinal, slidable movement of said second cylinder with respect to said first cylinder between open and closed positions; (d) a third cylinder (72) circumferentially fixed with respect to said first cylinder to form an annular recess between said first and third cylinders, said second cylinder enclosed within said recess when in said closed position; (e) a plurality of clip members fixed to and circumferentially spaced around said second cylinder, each one of said clip members for removably retaining a bit; and, (f) a cap (78) fixed to one end of said second cylinder, said cap for covering said recess when said second cylinder is in said closed position.

Inventors: FRUHM HERMANN, FRUHM, HERMANN
Applicants: FRUHM HERMANN, FRUHM, HERMANN
Application year: 1999
Main classification: B25F5
IPC codes: B25F5