GB2383549A

GB2383549A - A tool for use with a plurality of interchangeable bits

Info

Publication number: GB2383549A
Application number: GB0129499A
Authority: GB
Inventors: Jan Ibrahim
Original assignee: JANCO DESIGN Ltd
Current assignee: JANCO DESIGN Ltd
Priority date: 2001-12-10
Filing date: 2001-12-10
Publication date: 2003-07-02
Also published as: GB0129499D0

Abstract

A tool for use with a plurality of interchangeable bits comprises a head 16 for holding a bit when using the tool, a bit holder 18 for holding a plurality of bits, which bit holder is movable relative to the head, and moving means for moving a bit from the bit holder to the head. Preferably, the tool comprises a barrel 14 which has the head at its distal end and the bit holder at its proximal end, a rotatable cylinder comprising a plurality of chambers 22 within each of which a bit can be held, which chambers are selectably positionable over the proximal end of the barrel, and a shaft 26 which is axially movable from a retracted position to an extended position, such that on being moved from the retracted position to the extended position the shaft can engage a bit held in the chamber positioned over the proximal end of the barrel, and push the bit along the barrel to the head at the distal end thereof. The tool may be a drill or a screwdriver.

Description

TOOL The present invention relates to a tool, in particular a tool for use with a plurality of interchangeable bits.

Tools which are usable with a plurality of interchangeable bits are well known in the art. For example, conventional electric drills and screwdrivers have a chuck which is openable and closable, for example with a key, for use with a variety of interchangeable drill bits or screwdriving bits, and conventional so-called socket sets comprise a tool body for use with a plurality of socket bits, which bits may for example be held by the tool by a snap-fit. In this way, a user is provided with a single tool which is usable for a plurality of operations, for example holes of greatly varying diameters can be drilled using a single drill.

However, such conventional tools have certain disadvantages.

Typically, the tool will only hold a single bit at any one time, i. e. the bit which is currently being used. Thus, if a user wishes to perform a number of operations which require a number of different bits without returning to the tool box, or other container where the bits are held, between each operation then the user must carry the required'bits in a free hand, available pocket, or other suitable carrier from the location of one operation to another. Many bits may be largely indistinguishable from one another by touch alone, i. e. when carried in a pocket, which adds to the inconvenience of use for the user. Furthermore, when the user wishes to change the bit being used for another, the user must remove the previous bit from the tool, and insert the new bit. Bit removal and insertion is a two-handed operation, and removed bits are often merely placed to one side on a convenient surface before

and/or after use, where they may be forgotten or lost.

The present invention seeks to overcome the problems associated with such conventional tools.

According to the present invention there is provided a tool for use with a plurality of interchangeable bits, which comprises a head for holding a bit when using the tool, a bit holder for holding a plurality of bits, which bit holder is movable relative to the head, and moving means for moving a bit from the bit holder to the head.

Herein"bit"is used as a generic term for any implement which is usable with a tool to enable the tool to perform its function, for example a drill bit, a socket (of a socket set), a screwdriver shank, and the like. Thus, a"plurality of interchangeable bits" refers to a set of bits, each of which is designed to mate with a single tool, for example in the case of drill bits by each drill bit having a universal shank.

The present invention thus provides a tool by which different bits for different operations can be held and carried by a user from the location of one operation to another. Thus, the user can perform the different operations without returning to, for example, the tool box between each operation, and the need to carry the required bits in a free hand, available pocket, or other suitable carrier is obviated. Also, the tool of the present invention allows for one bit to be changed for another without removal of either bit from the tool. Thus, the user may remove and insert a bit using a single hand, without removal of the bit from the tool, which increases convenience of use for the user, and helps prevent misplacement or loss of bits.

The tool of the present invention comprises a head for holding a bit when using the tool. The head of the tool should hold each bit sufficiently securely to allow it to perform its function. For example, the tool of the present invention is particularly useful for operations which require axial rotation of the tool, for example loosening and tightening screws or nuts, in which preferred embodiments the head must hold the bit so as to restrict relative rotation therebetween.

This may conveniently be achieved by the head having a recess of polygonal, for example square or hexagonal, cross section, with each bit having a projection of corresponding cross section which mates with the head recess. Alternatively, if the tool is to be used for an operation which requires the application of force in an axial direction, for example a punching or scoring operation, then the bit must be held within the head such that axial movement of the bit relative to the head is restricted. For example, the moving means may be lockable in position once a bit has been moved from the holding means to the head, thus restricting such axial movement. Other means for preventing relative movement between the head and each bit include magnetism, and other conventional locking mechanisms. In particularly preferred embodiments, substantially all relative movement between the bit and head is restricted, including both axial and rotational movement.

The head is conveniently positioned at a distal end of an elongate arm, which can provide mechanical advantage for the user, for example in operations requiring the application of rotational forces or leverage, and can allow the head to be passed through relatively narrow gaps. In preferred embodiments, the elongate arm comprises a barrel which extends from the head at the distal end to a proximal end adjacent the

bit holder, through which barrel a bit can be moved by the moving means from the bit holder to the head.

The tool of the present invention also comprises a bit holder for holding a plurality of bits, which bit holder is movable relative to the head. The bit holder conveniently has a plurality of chambers in each of which a bit can be held. The bit holder may be for example a rotatable cylinder, or a laterally moveable magazine, which is moveable relative to the head such that each chamber in turn may be positioned such that a bit held within the chamber can be moved by the moving means from the chamber to the head. The number of bits which can be held by the bit holder, for example the number of chambers of the bit holder, is only limited by practical considerations, such as size of the tool and ease of use.

However, for handheld tools the bit holder may typically be designed to hold from 4 to 12 bits, for example from 6 to 8 bits. A particularly preferred bit holder comprises a cylinder having a plurality of chambers, for example from 6 to 8 chambers, more particularly 6 chambers, which cylinder is rotationally mounted such that each chamber is moveable into a position such that a bit held therein can be selected for use and moved by the moving means from the chamber to the head. When the bit is no longer required, it may be returned to the empty chamber in which it was originally held. The bit holder may be removable from the tool in order to allow a user to replace one, some or all of the bits held within the bit holder. Alternatively, the bit holder may not be removable from the tool, and a user may replace a bit by moving the bit to be replaced to the head of the tool, manually removing the bit therefrom, replacing the replaced bit with a replacement bit, and moving the replacement bit back to the bit holder. The tool of the present invention thus allows the user to

select and replace those bits to be held within the tool.

The tool of the present invention further comprises moving means for moving a bit from the bit holder to the head. In a preferred embodiment, the moving means comprises a shaft which is axially moveable relative to the head and which can be used to push a bit from the bit holder to the head, for example by passing through an opening in a chamber of the bit holder. The moving means may conveniently further comprise a button, by which it is moveable axially forwards and backwards by the user. Preferably, the moving means is lockable in a position so as to restrict axial movement of a bit at the head, and may further be lockable in a position so as to prevent engagement of the moving means with a bit held in the bit holder. In a particularly preferred embodiment the moving means comprises a shaft having a locking mechanism which is locked and unlocked by a user by pressing and releasing a button. The shaft is moveable within a guide formed in a handle of the tool, from a retracted position in which it does not engage a bit held within the bit holder, to an extended position in which it axially restricts axial movement of a bit at the head. In this preferred embodiment, the moving means is lockable in the retracted and extended positions. Thus, to operate this preferred moving means, a user of the tool selects the desired bit for a particular operation, presses the button to release the moving means from the retracted position, slides the button forwards within the guide to thereby move the shaft axially forwards to engage the selected bit within the bit holder, continues to slide the button forwards until the shaft has pushed the bit to the head of the tool, i. e. the moving means is in the extended position, and then releases the button to lock the moving means in the extended position and thereby restrict axial movement of the

bit at the head.

A particularly preferred tool of the present invention comprises a barrel which has the head at its distal end and the bit holder at its proximal end, a rotatable cylinder comprising a plurality of chambers within each of which a bit may be held, which chambers are selectably positionable over the proximal end of the barrel, and a shaft which is axially movable from a retracted position to an extended position, such that on being moved from the retracted position to the extended position the shaft can engage a bit held in the chamber positioned over the proximal end of the barrel, and push the bit along the tube to the head at the distal end thereof.

An embodiment of the present invention will now be described in detail with reference to the accompanying drawings in which: Figure 1 is an isometric view of a tool according to the present invention; Figure 2 is a side view of the tool of Figure 1; Figure 3 is a plan view of the tool of Figure 1 ; Figure 4 is a front view of the tool of Figure 1; Figure 5 is an exploded view of the moving means of the tool of Figure 1 ; Figure 6 is a partial cross-sectional view of the tool of Figure 1 in which the moving means is in a retracted position; and Figure 7 is a partial cross-sectional view of the tool of Figure 1 in which the moving means is in an extended position.

As shown in the Figures, a preferred tool according to the present invention comprises a body 10 including a handle 12,

an elongate barrel 14 attached to the body 10, the barrel 14 having a head 16 at its distal end, a cylindrical bit holder 18 adjacent the proximal end of the tube 14, and moving means 20 for moving a bit from the bit holder 18 to the head 16.

The barrel 14 is preferably constructed from steel, or other sufficiently strong material, and is machined so as to be of hexagonal cross section along its length. The barrel 14 is fitted to the body 10 by fasteners 15 (Figure 4), for example bolts. The barrel 14 further engages the body 10 by virtue of engaging members 17 (one of which is shown in Figure 2). The engaging members 17 provide resistance to rotation between the barrel 14 and body 10 when torque is applied when the tool is being used to apply rotational force, for example when screwdriving. The bits (not shown in Figures 1 to 5, one of which is shown under reference 32 in Figures 6 and 7) for use with the tool have a corresponding shank of hexagonal cross section, which thus restricts relative rotational movement of the bit within the head 16. The barrel 14 extends from the body 10 substantially along the longitudinal axis thereof. The remainder of the tool may be made from any suitable material, conveniently suitable plastics material.

The cylindrical bit holder 18 is rotationally mounted to the body 10, and comprises six chambers 22 for each holding a bit. The bit holder 18 is mounted eccentrically on the body 10 from the longitudinal axis of the tool, such that rotation of the bit holder 18 causes each chamber 22 in turn to pass through the longitudinal axis of the tool adjacent the proximal opening of the barrel 14. The bit holder 18 has a diameter and mounting such that each of the chambers 22 is moveable in turn over the proximal opening of the barrel 14. The diameter of each chamber 22 substantially corresponds to the width of the

barrel 14. To ensure correct positioning of a chamber 22 over the proximal opening of the barrel 14, the bit holder 18 is clickable between six discrete positions, each position corresponding to one of the chambers 22 of the bit holder 18.

The handle 12 comprises a guide slot 24 and houses a shaft 26 which is axially moveable within the handle 12. The handle 12 further includes longitudinal grooves 25 (Figures 1 and 2) to act as grips for the user. The shaft 26 is attached to a button 28, which is axially moveable along the guide slot 24.

The shaft 26 is axially moveable from a retracted position (as shown in Figures 1 to 4 and 6) to an extended position (as shown in Figure 7), and is lockable in the retracted and extended positions by virtue of a locking piece 34 (Figure 5) which engages with indentations 30 in the guide slot 24 at the retracted and extended positions. In the retracted position (Figures 1 to 4 and 6), the shaft 26 extends through the handle 12 of the tool to a position adjacent the chamber 22 which is over the proximal opening of the barrel 14, and in the extended position (Figure 7) the shaft 26 extends through the chamber 22 which is over the proximal opening of the barrel 14, along the barrel 14 to a position adjacent the head 16, so as in use to hold a bit in the head 16.

The handle 12 includes an end cap 13 which is fitted over the proximal end of the handle 12 following assembly of the locking mechanism, to protect the latter during use.

The locking mechanism of the tool of the preferred embodiment shown in the Figures is shown in more detail in Figure 5. The locking mechanism comprises a locking piece 34, a spring 36, and a housing 38. The locking piece 34 has a hollow substantially cylindrical body 35 having a radially extending

flange 40 around the lower periphery thereof. The spring 36 is housed within the locking piece 34, which in turn sits within the housing 38. The button 28 has an underside fitting 42 which fits over the cylindrical body 35, such that the button 28 sits over the cylindrical body 35 within the housing 38. The spring 36 biasses the locking piece 34 and button 28 outwards, such that the button 28 and hence locking piece 34 may be pressed downwards against the force of the spring 36 by a user of the tool. The button 28 remains engaged with the housing 38 despite the outwardly biassing force of the spring 36 by virtue of lower projections 44 which engage with an inner lip (not shown) of the housing 38. The shaft 26 is attached to the housing 38.

As previously described, the handle 12 comprises a guide slot 24 along which the button 28, and hence the locking mechanism, can be slid by the user between the retracted position and the extended position, the guide slot 24 having an increased width by virtue of indentations 30 at the retracted and extended positions. The guide slot 24 is sufficiently wide along its length to allow the cylindrical body 35 to pass therethrough, but sufficiently narrow not to allow the flange 40 to pass therethrough, except at the retracted and extended positions by virtue of indentations 30. Thus, in the retracted and extended positions the biassing force of the spring 36 holds the flange 40 between the indentations 30, locking the shaft 26 in position. The flange 40 is released from between the indentations 30 by pressing the button 28 against the force of the spring 36, and moving the button 28 along the guide slot 24. The shaft 26 is locked in (the retracted or extended) position once again by releasing the button 28.

In the preferred embodiment shown in the Figures, the distal

end of the shaft 26 contains a magnet 27, for use with bits having a magnetic shank. In this way, the shaft 26 can more securely hold a bit in the head 16 due to the attractive forces between the magnetic end of the shaft 26 and bit shank.

Thus, with particular reference to Figures 6 and 7, in use a plurality of interchangeable bits are placed in the bit holder 18, and the desired bit 32 is selected by rotating the bit holder 18 until the chamber 22 containing the desired bit 32 is over the proximal opening of the barrel 14. At this time the shaft 26 is in the retracted position, as shown in Figure 6. The user then depresses the button 28 to unlock the locking piece 34 from the indentations 30 in the guide slot 24 at the retracted position. The user then slides the button 28 along the guide slot 24, which axially moves the shaft 26 into the chamber 22, thus pushing the desired bit 32 in the chamber 22 into and along the barrel 14. If bits 32 having a magnetic shank are used, then the magnetic distal portion 27 of the shaft 26 aids engagement of the shaft 26 with the bit 32. The user continues to push the button 28 until the shaft 26 reaches the extended position, where it can be locked in position by releasing the button 28 thus locking the locking piece within the indentations 30. The bit 32 is now held within the head 16 and may be used by the user, as shown in Figure 7. To change the bit 32 for another held in the bit holder 18, the user performs the reverse operation to that described above, i. e. returns the shaft 26 from the extended position to the retracted position by depressing and sliding the button 28. The previous bit 32 has then been returned to its chamber 22, and the bit holder 18 can be rotated so that the chamber 22 containing the next desired bit is over the proximal opening of the barrel 14, and the above described operation can be repeated.

It will be understood that the embodiments illustrated show applications of the invention only for the purposes of illustration. In practice the invention may be applied to many different configurations, the detailed embodiments being straightforward for those skilled in the art to implement.

Claims

CLAIMS 1. A tool for use with a plurality of interchangeable bits, which comprises a head for holding a bit when using the tool, a bit holder for holding a plurality of bits, which bit holder is movable relative to the head, and moving means for moving a bit from the bit holder to the head.
2. A tool according to claim 1 wherein the head has a recess of polygonal cross section for restricting relative rotational movement between a bit having a projection of corresponding cross section and the head.
3. A tool according to claim 2 wherein the head has a recess of square or hexagonal cross section.
4. A tool according to claim 1,2 or 3 wherein axial movement of a bit is restricted by the moving means being lockable in position once a bit has been moved from the holding means to the head.
5. A tool according to any preceding claim wherein the moving means comprises a shaft having a magnetic distal end.
6. A tool according to any preceding claim wherein the head is positioned at a distal end of an elongate arm.
7. A tool according to claim 6 wherein the elongate arm comprises a barrel which extends from the head at the distal end to a proximal end adjacent the bit holder, through which barrel a bit can be moved by the moving means from the bit holder to the head.

<Desc/Clms Page number 13>
8. A tool according to any preceding claim wherein the bit holder comprises a plurality of chambers in each of which a bit can be held.
9. A tool according to claim 8 wherein the bit holder comprises a cylinder which is rotatable relative to the head such that each chamber in turn may be positioned such that a bit held within the chamber can be moved by the moving means from the chamber to the head.
10. A tool according to claim 8 or 9 wherein the bit holder comprises 4 to 12 chambers.
11. A tool according to claim 10 wherein the bit holder comprises 6 to 8 chambers.
12. A tool according to any preceding. claim wherein the moving means comprises a shaft which is axially moveable relative to the head and which can be used to push a bit from the bit holder to the head.
13. A tool according to claim 12 wherein the moving means further comprises a button, by which the shaft is moveable axially forwards and backwards by the user.
14. A tool according to any preceding claim wherein the moving means is lockable in a position so as to restrict axial movement of a bit at the head.
15. A tool according to any preceding claim wherein the moving means is lockable in a position so as to prevent engagement of the moving means with a bit held in the bit holder.

<Desc/Clms Page number 14>
16. A tool according to any one of claims 12 to 15 wherein the moving means comprises a shaft having a locking mechanism which is locked and unlocked by a user by pressing and releasing a button, the shaft being moveable within a guide formed in a handle of the tool from a retracted position in which it does not engage a bit held within the bit holder, to an extended position in which it axially restricts axial movement of a bit at the head, the moving means being lockable in the retracted and extended positions.
17. A tool according to any preceding claim which comprises a barrel which has the head at its distal end and the bit holder at its proximal end, a rotatable cylinder comprising a plurality of chambers within each of which a bit can be held, which chambers are selectably positionable over the proximal end of the barrel, and a shaft which is axially movable from a retracted position to an extended position, such that on being moved from the retracted position to the extended position the shaft can engage a bit held in the chamber positioned over the proximal end of the barrel, and push the bit along the barrel to the head at the distal end thereof.
18. A tool according to any preceding claim which further comprises a plurality of interchangeable bits.
19. A tool substantially as hereinbefore described with reference to the accompanying drawings.