Multiple bit screwdriver

A multiple bit screwdriver comprising a plurality of tool bits, an elongate member defining an axial passage adapted to receive said bits therein positioned tip to end so that the foremost bit operably extends from the passage and is rotatable with the elongate member, first and second retainers connected to the elongate member near each end of the passage and extending radially inward into the passage to engage frictionally the foremost and last bits to prevent said bits from falling out of either end, and a motion restricting member within the passage having an expandable engagement portion that cooperates with at least one tool bit to permit the movement of bits within the passage in one direction only. The engagement portion is expandable in response a tool bit being pushed therethrough in one direction, but resists expanding when a tool bit is being pushed in the opposite direction.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a multiple bit screwdriver, and more particularly, to a pocket screwdriver having multiple interchangeable tool bits received and retained removably in a tubular handle body.

2. Description of the Related Prior Art

Since a variety of screwdriver bit types are required for different purposes, various modular screwdrivers have been suggested. An example of the conventional modular screwdriver generally includes a handle and tool bits with various head types or tips. In use, a desired tool bit is selected and secured to one end of the handle, and the remaining tool bits are received in a casing. Carrying of the handle and the casing with multiple tool bits received therein for outdoor use in relatively inconvenient to the user.

An example of a multiple bit screwdriver is U.S. Pat. No. 4,827,812 granted on May 9, 1989 to Markovetz, describing a screwdriver using a hollow shaft with first and second ends. The first end has an interior cavity adapted to engage a shank of a screwdriver tip. A magnet is attached to the interior of the hollow shaft for holding the screwdriver tip inserted in the first end. The magnet divides the hollow shaft in a storage compartment and tool-receiving compartment. A torque cap is used. It consists of three segments: a first segment is sized for insertion into the torque cap-receiving hole; a second segment extends from the first segment and is sized for insertion into the storage compartment; and a third segment extends also from the first segment, oppositely to the second segment. The first and second segments are fitted with detent balls. The above pocket screwdriver presents several shortcomings. First, it has a limited capacity for storage, due to the space taken by first and second segments. Secondly, the magnet prevents the use of this screwdriver near computers or other magnet sensitive devices.

U.S. Pat. No. 5,450,775 granted on Sep. 19, 1995 to Kozak for a “Multiple function driving tool” describes a tool having first and second ends with the first end having an opening for receiving a screwdriver tip, while the second end has an opening for receiving a tube which is releasably retained, in relation to the handle, by a collet. The handle has opposed side openings extending from the second end to a point near the collet. The tube is mounted for a limited axial sliding movement relative to the handle, from a position where one of its ends is retained by the collet, to a position where it is no longer retained by the collet. Thus, one can position the tube in alignment with the side opening in the handle. The tube is also mounted for pivoting movement when it is in alignment with the side opening, to a generally transversally extending position. The tube is of a length sufficient to always project outwardly of the handle, when the tube is generally in actually aligned relation to the handle. Kozak's structure has several shortcomings. First, the pivoting of the whole tube in the handle and its limited axial sliding movement relative to the handle complicates the tool configuration. Second, due to this complicated structure the components do not easily cooperate.

U.S. Pat. No. 5,842,394, granted on Dec. 1, 1988 to Hwang for a “Multiple bit screwdriver” discloses a tubular handle body with a first end position, and opposite second end position and an axial bore formed through the first and second end positions. A plurality of tool tips are inserted into the axial bore via the first end position, and are removable from the axial bore via the second end position. Each of the tool tips has a bit portion and a connecting sleeve on one end of the bit portion. The connecting sleeve has an axial blind hole formed therein to allow extension of the bit portion of an adjacent tool bit therein. First and second spring units are respectively provided on the first and second end portions, where they extend radially inward into the axial bore. The first spring unit engages frictionally and resiliently the connecting sleeve of a first one of the tool tips, that is located in the first end portion of the handle body, so as to prevent the tool tips from falling out of the first end portion. The second spring unit engages frictionally and resiliently the connecting sleeve of the second one of the tool tips that has the bit portion extending out of the second end portion. The second spring prevents the tool bits from falling out of the second portion. An important shortcoming of this screwdriver is its reliance on special, non-standardized, bits which are not common in the field of interchangeable screwdriver bits.

SUMMARY OF THE INVENTION

There is, accordingly, a need for a multiple bit screwdriver, which overcomes the disadvantages of the prior art. It is further desirable to have a multiple bit screwdriver, which is simple to assemble, practical to use and which can accommodate standardized interchangeable screwdriver bits that are widely available in the industry.

Accordingly, in some embodiments of the present invention there is provided a multiple bit screwdriver comprising a plurality of tool bits, each bit having a tip and a shank; an elongate member having a first end and an opposite second end and defining an axial passage therethrough between the first and second ends, the passage being adapted to receive said tool bits therein positioned tip to end in a manner such that the tip of the foremost bit is able to operably extend from the first end, and wherein at least a portion of the passage near the first end is contoured for engagement with the shank of the foremost so that said bit is rotatable with the elongate member; a first retainer connected to the elongate member at the first end and extending radially inward into the passage to engage frictionally the foremost bit to prevent said bit from falling out of the first end; a second retainer connected to the elongate member at the second end and extending radially inward into the passage to engage frictionally the last bit to prevent said bit from falling out of the second end; a motion restricting member within the passage having an engagement portion that cooperates with at least one tool bit to permit the movement of bits within the passage in a first direction from the second end to the first end but not in the opposite direction. The motion restricting member may be tubular and mounted coaxially within the passage. In some embodiments, the engagement portion of the motion restricting member comprises a stricture portion expandable between a resting state in which the stricture portion has an outlet that is narrower than the cross-sectional dimension of a tool bit shank, and an expanded state in which the outlet is large enough to permit a tool bit to pass therethough. In some embodiments, the stricture portion is expandable in response a tool bit being pushed therethrough in the first direction by a user, but which resists expanding when a tool bit is being pushed in the opposite direction. In some embodiments, the stricture portion comprises a plurality of longitudinal projections extending from the tubular portion of motion restricting member and gradually tapering toward the axis of the passage in the first direction, and each of the projections is deformable radially in response to the movement of a tool bit through the stricture portion in the first direction, but is resilient axially to restrict movement of the tool bit in the opposite direction. The contoured portion of the passage may be hexagonal in cross section so as to accommodate tool bits having hexagonal shanks. In some embodiments, the first retainer comprises a tip member connected to the first end of the elongate member and having an elastomeric flange portion that extends inwardly into the passage to define a tip opening that is slightly less than the cross sectional dimensions of a tool bit shank. The second retainer comprises an elastomeric ring member connected to the elongate member adjacent the second end and being coaxially aligned with the passage, the ring member defining an inlet opening at the second end of the passage that is slightly less than the cross sectional dimensions of a tool bit shank.

In some embodiments of the present invention, there is provided a multiple bit screwdriver comprising a plurality of tool bits, each bit having a tip and a shank; a tubular member having a tip end and an opposite cap end and defining a first axial cavity extending from the tip end to the cap end; a cap member having a connecting portion and a back end portion, and defining a second axial cavity extending from the connecting portion to the back end portion, the cap member further being connected at the connecting portion to the cap end of the tubular member such that the first and second cavities align axially to define an axial passage extending between the tip end of the tubular member and the back end portion of the cap member, said passage being adapted to receive said bits therein positioned tip to end in a manner such that the tip of the foremost bit is able to operably extend from the tip end, and wherein at least a portion of the passage near the tip end is contoured for engagement with the shank of the foremost so that said bit is rotatable with the tubular member; a first retainer connected to the tip end of the tubular member and extending radially inward into the passage to engage frictionally the foremost bit to prevent said bit from falling out of the tip end; a second retainer connected to the cap member near the back end portion and extending radially inward into the passage to engage frictionally the last bit to prevent said bit from falling out of the back end portion; a motion restricting member mounted within the second cavity of the cap member and having an engagement portion that cooperates with at least one tool bit to permit the movement of bits within the passage in a first direction from the back end to the tip end, but not in the opposite direction. The motion-restricting member may be tubular and mounted coaxially with the passage. In some embodiments, the engagement portion of the motion restricting member comprises a stricture portion expandable between a resting state in which the stricture portion has an outlet that is narrower than the cross-sectional dimension of a tool bit shank, and an expanded state in which the outlet is large enough to permit a tool bit to pass therethough. The stricture portion may be expandable in response a tool bit being pushed therethrough in the first direction by a user, but resists expanding when a tool bit is being pushed in the opposite direction. In some embodiments, the stricture portion comprises a plurality of longitudinal projections extending from the tubular portion of motion restricting member and gradually tapering toward the axis of the passage in the first, and each of the projections is deformable radially in response to the movement of a tool bit through the stricture portion in the first direction, but is resilient axially to restrict movement of the tool bit in the opposite direction. The contoured portion of the passage may be hexagonal in cross section so as to accommodate tool bits having hexagonal shanks. In some embodiments, the first retainer comprises a tip member connected to the tip end of the tubular member and having a elastomeric flange portion that extends inwardly into the passage to define a tip opening that is slightly less than the cross sectional dimensions of a tool bit shank. The second retainer comprises an elastomeric ring member connected adjacent the back end portion of the cap and being coaxially aligned with the passage, the ring member defining an inlet opening at the second end of the passage that is slightly less than the cross sectional dimensions of a tool bit shank.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring toFIGS. 1 to 16, a multiple bit screwdriver100generally comprises an elongate member120, which according to the illustrated embodiment, includes an tubular member200with a tip end260and an opposite cap end264, and a cap member or cap400. A tip member or tip300is connected to the tip end260and the cap400is connected to the cap end264. A motion restricting member500, and a second retainer member such as O-ring600, are received within cap400. Screwdriver100further includes interchangeable screwdriver bits216, each having a tool tip222and a shank220that is hexagonal in cross section.

Tubular member200defines a first axial cavity218extending from the tip end260to the cap end264. Cap400includes a connecting end portion440for connecting to the cap end264of the tubular member200, and a back end portion444. Within cap400is defined a second axial cavity450extending from the connecting end portion440to the back end portion444. When tubular member200and cap400are connected to define the elongate member, the first and second cavities align axially to define an axial passage within the elongate member, the passage having a first end that is commensurate with tip end260of tubular member200and an opposite second end that is commensurate with back end portion444of cap400for receiving and storing screwdriver bits216arranged in a tip to end orientation in axially spaced relation to elongate member. The overall length of the elongate member, hence the axial passage, is preferably such that in the operable configuration of the screwdriver as shown inFIG. 7, the foremost bit extends from the tip end260with its tool tip222exposed, and the shank of the last bit is entirely within cap400.

Tubular member200has, in cross section, a generally trapezoidal periphery with rounded corners. Towards tip300, tubular member200extends axially and changes in a truncated cone202, followed by a first cylindrical end204at tip end260. One of the external faces of tubular member200has, on a part of its length, a flattened surface206. First cylindrical end204has a reduced cross section in comparison with the smallest cross section of truncated cone202to define a first shoulder208. Tubular member200, at the end where cap400is disposed, extends into a second cylindrical end212, having a reduced cross section in comparison with the main cross section of tubular member200to define a second shoulder214. Cylindrical end212is provided on its periphery with a longitudinally extending rib215.

Axial cavity218of tubular member200includes a hexagonal portion232that is hexagonal in cross section and commensurate with the shank220of bits216to allow easy passage longitudinally of the bits therethrough. Accordingly, hexagonal portion232is contoured for rotating engagement with the shank220of bits216so that the bits are rotatable with the tubular member. In the illustrated embodiment, the hexagonal portion232extends from tip end260to a junction235located proximate to the cylindrical end212, and a cylindrical portion234that extends from the junction235to the cap end264. However, the hexagonal portion may be of varied length provided that at least a portion of the axial passage near the first end is hexagonal and thereby contoured for rotating engagement with at least the foremost bit. The cross sectional dimension of the first axial cavity in the cylindrical portion234is larger than the cross sectional dimension of the first axial cavity in the hexagonal portion232.

Tip300is preferably of an elastomeric material and has truncated hollow cone form which extends as a continuation of truncated cone202of tubular member200for aesthetics. A cylindrical opening302passes through tip300except at the outer end where an inwardly extending centering flange or rim304is formed. The latter has a circular aperture, which dimensionally coincides with hexagonal cross section of hexagonal section232such that the diameter of the circular aperture is generally equal to the distance between opposing sides of the hexagonal cross section. The purpose of tip300is to frictionally engage the shank220of a screwdriver bit216when such screwdriver bit is within tip300and tip end260, while the screwdriver bit's tip222projects outwardly from tip300. Thus, an interchangeable screwdriver bit216that is located in tip300is prevented from falling out and successive interchangeable screwdriver bits disposed behind it are confined in the axial passage of screwdriver.

Cap400has a lateral wall402, which generally has in cross section the same trapezoidal periphery with rounded corners as tubular member200. An interior surface404of the second axial cavity of cap400is basically cylindrical. Cap400has a disk shaped opening406, which is defined by an inwardly extending rounded rim and has a cross section larger than the hexagonal cross section of shank220of screwdriver bits216. Seated within cap400adjacent the opening406is provided a retainer such as elastomeric O-ring600having an internal diameter that is slightly less than the hexagonal cross section of shank220of the interchangeable screwdriver bits216. Accordingly, a portion of the O-ring extends radially inward into the passage to engage frictionally the shank of a bit that is within the cap. It is contemplated that a variety of analagous retainer configurations may be used, such as for example, elastomeric dimples located within cap on the interior404that are dimensioned to frictionally engage the shank of a bit within the cap. Alternatively, an elastomeric retainer may be integrally molded to the cap400in a variety of ways such that a portion thereof engages the shank of a bit within the cap.

At the top of the cap, lateral wall402extends first outwardly and then downwardly forming a clip416. The latter is intended to be disposed, when multiple bit screwdriver100is assembled, above flattened surface206of tubular member200. In the wall of the cap400, adjacent clip416, is provided a rectangular aperture420and a longitudinal channel418that communicates with the rectangular aperture418. The longitudinal channel418is dimensioned to receive rib215of the tubular member200to align the tubular member with the cap400and prevent rotation between the tubular member200and the cap400in the assembled screwdriver100.

Motion restricting member500is generally tubular and includes a cylindrical posterior portion504, a cylindrical mid portion506, an anterior portion508. The motion restricting member500further includes an inlet end510at the posterior portion and an outlet512at the anterior portion. The periphery of posterior portion504of the motion restricting member is dimensioned for a close fit within the interior404of the cap400. On the external periphery of the posterior portion504is tongue518adjacent the inlet end510, which is dimensioned to be complimentary to the rectangular aperture420of the cap400such that the tongue518fits within the aperture518when the motion restricting member500is seated within the cap400. The external cross section of the mid portion506and the anterior portion508are reduced in relation to the external cross section of the posterior portion504so as to form a shoulder514. The internal cross sectional dimensions of the posterior and mid portions are equal to each other, and are preferably slightly larger than shank220of an interchangeable screwdriver bit216to enable passage of the screwdriver bit therethrough.

The anterior portion508of the motion restricting member acts as an engagement portion that cooperates with bits216to permit the movement of bits within the passage in a first direction from the back end to the tip end, but not in the opposite direction. The anterior portion is comprised of six finger-like projections520extending longitudinally from the mid portion506and tapering in the first direction towards the axis of the passage such that the projections define a shape generally that of a truncated cone. The cross sectional dimension of the outlet end512must be smaller than the cross sectional dimensions of the shank222of the screwdriver bits216. Grooves524are defined between the projections and are spaced so that each groove lines up with a corner defined by the hexagonal portion232of the passage218upon assembly of the screwdriver100.

The projections520are resiliently deformable radially in an outward direction relative to the motion restricting member to enable the enlargement of the outlet end512, but are resilient to axial compression. The projections thereby provide a stricture in the motion restricting member. The motion restricting member is preferably constructed of a thermo-plastic or like material which provides the resiliently deformable characteristics and ease of manufacture. However, it would be apparent to a person skilled in the art that other suitable material may be used, including various metals. As a result of the projections520being resiliently deformable, a screwdriver bit216may be inserted into the motion restricting member500from the inlet end510, and by applying an axial force to the bit in the first direction, the tip222of the bit displaces the projections by a cam-like action to enlarge the outlet end512into an expanded state of the projections thus enabling the egress of the bit216from the motion restricting member. Once the screwdriver bit216has passed through the anterior portion, the projections resume their static shape in a resting state. Accordingly, the motion restricting member500allows a one-way passage of the screwdriver bit216therethrough.

In the assembled screwdriver100, the posterior portion504of the motion restricting member is seated within the interior of the cap400such that the tongue518is received within rectangular aperture420, and the inlet end510abuts the O-ring600. The cooperative fit between the tongue and the aperture locks the motion restricting member to the cap by inhibiting rotation and sliding of the motion restricting member in relation to the cap. Preferably, the tongue is located along the periphery of the posterior portion at a position where, when the tongue is received into the aperture, the grooves524of the anterior portion508of the motion restricting member line up with corners233of the hexagonal section232, and the projections line up with the flat surfaces within the hexagonal section. While, in the described embodiment, the tongue and aperture structures are utilized as a method of preventing movement of the motion restricting member within the cap, other methods of immovably connecting the motion restricting member to the cap may be used and would be apparent to persons skilled in the art.

In the preferred embodiment, the length of the motion restricting member500from inlet end510to outlet end512is approximately equal to the length of a screwdriver bit216. However, it is possible to utilize a motion restricting member of varying length. As well, in the assembled multiple bit screwdriver100, the distance from the O-ring600within the cap400to the junction235in the passage218is approximately equal to the length of the motion restricting member500such that, in the assembled screwdriver, the mid and anterior portions506and508of the motion restricting member extend into the cylindrical portion234of the tubular member200, and the outlet end512of the motion restricting member is positioned adjacent the junction235. However, other configurations are possible.

For retaining tip300and cap400on tubular member200, the external surfaces of first and second cylindrical ends204and212, respectively, and the surfaces of cylindrical opening302in tip300, and of interior404in cap400, are knurled or provided with ridges or ribs for snapping. Alternatively, tip300, cap400and tubular member200can be permanently attached by gluing, welding or other means. Since various methods of attachment are well known to persons skilled in the art, further detailed discussion of this aspect of attachment is not deemed necessary.

In operation, screwdriver bits216are inserted into the assembled screwdriver100via the opening406in the cap400, and through the O-ring600, which frictionally engages the shank220of the screwdriver bit216to prevent the screwdriver bit from falling out of the cap. Once a screwdriver bit has been fully inserted into the cap, such that the end of shank220is flush with the opening406of the cap, the screwdriver bit216is situated within the motion restricting member500(FIG. 16). As the a subsequent screwdriver bit is inserted by the application of an axial force in the first direction, it pushes on the screwdriver bit within the motion restricting member to force that screwdriver bit through the anterior portion508of the motion restricting member (FIG. 14). As the shank220of this bit passes through the anterior portion508, the projections520cause the shank220of the bit to rotate into alignment with the hexagonal portion232of passage218in the tubular member200so that the screwdriver bit may pass into the passage218(FIG. 15). Once this screwdriver bit passes completely through the anterior portion508, the projections520return to their resting state to prevent the screwdriver bit from re-entering the motion restricting member (FIG. 16).

The illustrated embodiment of the screwdriver100accommodates five screwdriver bits, and each screwdriver bit is inserted as described. As the last screwdriver bit is inserted, the first or foremost screwdriver bit within the tubular member200emerges from the tip300to expose its tip222and the screwdriver100is in an operable configuration. This foremost screwdriver bit is frictionally held within tip300as described. When the screwdriver100is in the operable configuration, each screwdriver bit abuts the screwdriver bit behind it, and the end of the shank220of the fourth screwdriver bit abuts the projections520(which are in their resting state) of the motion restricting member, thereby preventing the screwdriver bits from being forced backward within the screwdriver100. The last screwdriver bit is situated within the motion restricting member500, and is frictionally held in place by O-ring600as described. When a different operable tip222is required, the screwdriver bit which is within tip300is withdrawn and inserted into the opening406thereby pushing the other screwdriver bits within the screwdriver forward to expose the operable tip222of the subsequent screwdriver bit. This is repeated until the desired operable tip222is exposed.

Advantageously, tubular member200, cap400and motion restricting member500may be injection molded plastic, and the tip member300may be an injection molded elastomer, for ease of manufacture and reduced costs. The bits216may be standardized interchangeable screwdriver bits that are widely available in the industry. The O-ring is also widely available commercially. However, other suitable material may be used as would be apparent to persons skilled in the art.

As required, a detailed embodiment of the present invention is disclosed herein; however, it is to be understood that the disclosed embodiment is merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structures and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.