GB2219539A

GB2219539A - Multiple-bit screwdriver

Info

Publication number: GB2219539A
Application number: GB8813817A
Authority: GB
Inventors: Archibald Mervin Mckenzie
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-06-10
Filing date: 1988-06-10
Publication date: 1989-12-13
Anticipated expiration: 2008-06-10
Also published as: GB8813817D0; GB2219539B

Abstract

A multiple-bit screwdriver has a handle 2 with a plurality of bits in a circular array of longitudinal bores 3 within a handle magazine. The bits are held in place by retaining springs 52. The bit ends when stored are visible through a cut-out 50 in the handle. A selected bit is removed from the magazine by inserting a second bit into one end 54 of the bore, thereby forcing the selected bit out of the bore through the opposite end 53. An O-ring 55 frictionally retains the displaced bit until it is pulled from the bore. Double-ended bits may be utilised. <IMAGE>

Description

MULTIPLE BIT SCREWDPIVER SPECIFICATION This invention relates to screwdrivers and more particularly to screwdrivers having handles for storing multiple interchangeable bits.

The variety of screwdriver bit sizes and types which are required for most purposes makes it practical and economical to utilize a screwdriver handle having interchangeable bits. Various designs are in use wherein a single screwdriver handle can be fitted with multiple interchangeable bits where such bits can be stored in the handle, thereby reducing the number and expense of screwdriver tools required to drive the various sizes and head configurations of screws. In the most common of these designs, the multiple bits are stored loosely in a hollow handle. To select a particular bit, an end cap on the handle is unscrewed, all the bits are removed from the handle, the desired bit is selected and secured in a chuck, the remaining bits are returned to the handle and the end cap is replaced.The problem with this design is that the bits are frequently dropped and misplaced, and on some models the handle itself is not well suited for the manual act of driving the screw as the end cap may become loosened while the handle is being turned.

Various handle configurations have been suggested which involve storing the multiple bits securely in the handle and utilising some mechanism to transfer the selected bit to the chuck. Most of these are too cumbersome to use and expensive to manufacture to have achieved acceptance. An example is the multi-chambered tool holder described in United States patent No.

3,405,749 which utilises an arrangement which requires manipulating bits to fall out of or back into the handle through a rotatable disc and a cone-shaped end pIece before or after being secured in the chuck end.

Another proposed solution is that disclosed in United States patent No. 4,434,828. In this design, the bits are stored in the handle in transverse bores in transverse orientation with respect to the long axis of the screwdriver. The bores have sleeves of resilient material which hold the bits in place by friction. To remove one of the bits for use the user removes the bit previously used and presses it into the opening in the sleeve holding the desired bit, thereby freeing the desired bit and storing the bit previously used. The selected bit is secured to the end of the screwdriver shaft by a magnet.

This arrangement has a number of problems. The length and number of bits which can be used is limited by the width and length of the screwdriver handle respectively. The embodiment shown in the patent has only four bits, which is too few for the full variety of screw heads encountered. Double-ended bits are less practical in the design of US-A-4,434,828 due to the limitation on the length of the bits. A further problem lies in the visibility of the stored, recessed bits when a selection is made. Finally, in the design according to US-A-4,434,828, one hand is holding the screwdriver while the other is pushing out the selected bit from above, and with nothing to hold the selected bit once it has been displaced it is liable to be dropped.

The present invention overcomes the aforementioned problems by providing a multiple bit screwdriver wherein the bits are held in a circular arrav of bores in the transparent handle of the screwdriver parallel to the longitudinal axis of the screwdriver. The bit which is in use is held in the screwdriver shaft by a magnet. A rotatable end cap is provided with a slot whereby, when a bit is selected, the slot in the end cap is aligned with the bore holding the bit, and the previously-used bit is inserted into the bore, thus displacing the selected bit so that it can be readily grasped. The magnet holds the displaced bit on the screwdriver until it is removed. Double-ended bits may be used in this arrangement to double the number of bits available. Means may be provided to lock the end cap in position and also to hold the selected bit in the handle until it is removed.

According to a further aspect of the invention, the rotatable end cap may be dispensed with, leaving the ends of the longitudinal bores open. Also, the means for retaining the bit in the screwdriver shaft may comprise a hexagonal socket with an exterior co-axial tube capping the socket and having a hexagonal opening.

The tube is spring-biassed to rotate the hexagonal opening into and out of alignment with the hexagonal socket. The bias is such that the opening is out of alignment with the socket when the external tube is released, and consequently when a hexagonal-ended bit is inserted through the opening into the socket and the external tube is released, a frictional pressure is applied to the bit which retains it in the socket.

According to a further aspect of the invention, the longitudinal bores may not extend completely through the handle, but may only extend part-way from the nose piece, which itself is provided with a longitudinal bore and rotates separately from the handle. According to this aspect of the invention the nose pierce is spring-biassed to hold it in the position selected while allowing it to be rotated to a new position.

The invention will now be described in more detail with reference to a number of embodiments ans with reference to the accompanying drawings, in which: Figure 1 is a plan view of a first embodiment of screwdriver in accordance with the invention; Figure 2 is a cross-sectional view taken along lines II-II of Figure 1 and showing the process of selecting a bit; Figure 3 is a cross-sectional view taken along lines III-III of Figure 1; Figure 4 is a left-end view of the end of the screwdriver of Figure 1; Figure 5 is a right-end view of the screwdrIver of Figure 1; Figure 6 is a perspective view of the screwdriver partially cut away to show the interior retaining spring; Figure 7 is a perspective view of the retaining spring shown in Figure 6; Figure 8 is a cross-sectional view of a second embodiment of screwdriver taken along lines A-A of Figures 9 and 10;; Figure 8A is a side view of the chuck of the embodiment of the invention shown in Figure 8 with a bit in place; Figure 9 is a left-end view of the screwdriver shown in Figure 8; Figure 10 is a right-end view of the screwdriver shown in Figure 8; Figure 11 is a perspective view of the retaining spring shown in Figure 10; Figure 12 is a front view, partially cut away, of a further variation of the chuck shown in Figure 8, partially cut away in cross-section; Figure 13 is a cross-sectional view of a magnetic chuck as shown in Figure 2; Figure 13A is a cross-sectional view taken along line E-E of Figure 13; Figure 13B is a cross-sectional view taken along line F-F of Figure 13; Figure 13C is a cross-sectional view taken along line G-G of Figure 13;; Figure 14 is a front view of a third embodiment of screwdriver in accordance with the invention; Figure 15 is a longitudinal cross-sectional view through the screwdriver of Figure 14; Figure 16 is a right-end view of the embodiment of the screwdriver shown in Figure 15; Figure 17 is a cross-sectional view of the nose piece of the screwdriver of Figure 15; Figure 13 is an end view of the nose piece shown in Figure 17; and Figure 19 is a cross-sectional view taken along line VI-VI of Figure 15.

Preferring first to Figures 1 and 2, the screwdriver 1 has a handle section 2 made of transparent plastics material and having longitudinal bores 3, a nose piece 5 also composed of a transparent material and also having longitudinal bores 7, and an end cap 9. Handle sections 2 and 5 are attached to a hexagonal metal shaft 11. Also secured to shaft 11 is an end tube 13 which is provided with a magnet 15 and a hexagonal bore 17. End cap 9 has a central bore 19 in which is situated a coil spring 21. A washer 23 is secured to the end of shaft 11 by a clip 25 and bears against one end of coil spring 21. End cap 9 has a surface 27 at one end of bore 19 which bears against the opposite end of coil spring 21. End cap 9 also has a circular knob 29 which fits into the end of one of the longitudinal bores 3.

As shown in Figure 4, the end cap 9 is provided with a slot 31 which may be aligned with bore 3 when knob 29 is disposed in the end of another bore. Slot 31 can be aligned with any particular bore by pulling the end cap away from handle section 2, thus compressing coil spring 21 and removing knob 29 from bore 3. The end cap may then be rotated to align the slot 31 with the desired bore and released to return knob 29 to be secured in the end of a bore by the coil spring.

In operation, each bore 3 twill have stored in it a single-ended or double-ended screwdriver bit 33. The operating bit 33 is held in the end of shaft 13 by magnet 15 and is prevented from rotating by the hexagonal shape of bore 17 which conforms with the hexagonal shape of bit 33 and which is sized to fit the bit snugly. Six bits are stored in the handle section 2 of the screwdriver. These bits are initially loaded into the handle by inserting each bit individually through slot 31 in the end cap and then successively rotating the end cap to the next bore 3 for loading the next bit. The bits are prevented from falling out of the handle by virtue of frictional contact with a rubber O-ring 35 around shaft 11 which projects a small distance into bores 3 through a small slot in the walls of the bores.

Alternatively, a leaf spring 41 adapted to lie in a slot in each bore could be used to retain the bits in each bore. The leaf spring is shown in Figure 7. It has a central aperture 43 to receive central shaft 11 and six spring arms which extend into each bore and bear against a stored bit to permit it to slide easily in the bore but preventing the bit from falling out of the bore.

Referring to Figure 2, to select a new bit, the operating bit 33 is first removed from the end of shaft 13. The ends of the stored bits may be easily viewed by the user due to the transparency of the handle. The desired bit is selected as indicated above by rotating the end cap 9 to align slot 31 with the bore in which the desired bit is stored. The previous operating bit is then inserted through slot 31 into bore 3, thereby displacing the newly selected bit which is pushed through bore 7 in nose piece 5. Bore 7 is of the same diameter as bore 3, and the magnet 15 in tube 13 holds the newly selected bit in place against the nose piece until the user pulls it out of the handle and places it into bore 17 in the end of the screwdriver shaft 13.

It can be seen that in this manner the user has potentially fourteen different screwdriver ends which can be selected. Because the handle section 2 is transparent, the bit ends are easily viewable for purposes of selection. The refractive effects of the plastic are minimised by the cross-sectional shape of handle section 2 as shown in Figure 3 wherein surfaces 37 and 39 are flat.

A second embodiment of the invention is shown in Figures 8 to 13. In this embodiment, the rotatable end cap is dispensed with. The longitudinal bores 3 extend completely through the handle 2 and are open at both ends. This design has a cut-out in the handle at 50 which allows the bit ends to be visible when stored.

The stored bits are retained by a retaining spring 52 or by a rubber O-ring at the same location resulting in retention due to friction. A bit is selected by removing the working bit from the chuck and inserting it into the end of the opening 54 in which the selected bit is retained. The selected bit is thereby ejected from the bore, where the previous working bit has now replaced it, and is displaced to a position in bore 53 where it is retained by friction with an O-ring 55.

O-ring 55 may also function appropriately if located at 57. The user then pulls the selected bit from the end of bore 53 and mounts it in the chuck.

While the previous magnetic chuck (shown in crosssectional detail in Figures 13, and 13a, 13b and 13c) may also be used in this embodiment, Figure 8 shows an alternative form of chuck. Referring to Figure 12, this chuck consists of a hexagonal socket 61 which is mounted on hexagonal shaft 11. A hexagonal bore 63 in the socket is sized to receive the hexagonal end of a bit. A cap 65 having a hexagonal opening 67, also sized to receive the bit, is mounted on the end of the socket. The cap has an opening 68 to receive a pin 64 which extends from and is fixed on the end of the socket. This allows the cap a certain limited freedom of rotation on the end of the shaft. A spring 69 biasses the cap in ore rotational direction.To mount a bit in the chuck, the user rotates the end cap until the hexagonal opening in the cap is aligned with the hexagonal socket, inserts the hexagonal end of the bit and releases the cap. The spring then causes the cap to rotate out of alignment with the socket, causing a frictional retention of the bit.

Figure 12 shows a further variation of the chuck shown in Figure 8. In this variation, a rubber sleeve 10 is located in the socket which is appropriately sized to provide sufficient friction to retain the bit in the socket, yet allowing it to be inserted and removed.

The foregoing variations on the chuck design are advantageous for the embodiment shown in Figure 8 due to the fact that fairly long bits are required in that embodiment; accordingly, the advantage of a magnetic chuck, namely that the magnetisation reaches the screw being worked on to retain it on the end of the bit, is not as significant.

Figures 14 to 19 show a further embodiment. In this variation the bores 73 do not extend completely through handle 2, but only extend a short depth from the left-hand end of the handle. A nose piece 75 rotates separately on the shaft and is biassed against the handle by a spring 79. The nose piece is provided with one bore 75 which may be aligned with one of the six bores in the handle in order to select a bit. The bits remain stored loosely in bores 73. To select a bit, the working bit 33 is replaced into bore 73 in the handle through bore 77, nose piece 75 is moved against the'spring 79 to remove knobs 74 from the ends of bores 73, nose piece 75 is rotated to align bore 77 with the selected bit, and the nose piece is released wallowing knobs 74 to return into the ends of bores 73. The selected bit then simply drops out of bore 73 by tilting the screwdrIver and the bit is placed in the end of the chuck, which may take the form of one of the chucks described above.

Claims

CLAIMS:

1. A multiple-bit screwdriver comprising: a) a handle provided with a plurality of bores arrayed circumferentially about and parallel to the longitudinal axis of said handle, each said bore being open at both ends thereof and adapted to store a screwdriver bit; b) a shaft secured to and extending from one end of said handle; c) means provided at one end of said shaft for securing said screwdriver bit; and d) means for releasably retaining said bit in said bores; wherein a selected bit is removed from its bore by inserting an elongate object into an open end of the bore containing said selected bit and forcing sald elongate object into said bore, thereby displacing said selected bit.

2. A screwdriver as claimed in claim 1, wherein said elongate object is a second bit and wherein said act of displacing said selected bit results in storage of said selected bit.

3. A screwdriver as claimed in claim 1 or 2, further comprising a cap rotatably mounted on one end of said handle for selecting said selected bit.

4. A screwdriver as claimed in claim 1, 2 or 3, wherein the working end or ends of said stored bits are visible to the user of said screwdriver.

5. A screwdriver as claimed in any preceding claim, wherein said means for releasably retaining said bit comprises flexible means associated with each said bore fixed to the inner surface of and extending into each of said bores, and adapted to bear against and frictionally engage said bit when said bit is stored in said bore, and to permit sliding movement of said bits when said bits are inserted into or displaced from said bore.

6. A screwdriver as claimed in claim 5, wherein said flexible means comprises a band having one end secured to said inner surface of said bore and a second free end located within said bore at a location spaced towards said one end of said handle from said fixed end of said band.

7. A screwdriver as claimed in claim 6, wherein said means for releasably retaining said bit comprises an array of metal bands spaced radially about and fixed to a common circular element, one end of each of said bands being fixed to said common element and the other end being free and located within said bores at a location spaced towards said one end of said handle from said fixed end of said band.

8. A screwdriver as claimed in any preceding claim, wherein an outer ring of said handle is cut away at a point adjacent to but spaced from said one end of said handle, thereby dividing each of said bores into a first longer bore remote from said one end and a second shorter bore adjacent to said one end, the length of said longer bore being greater than the length of said bit, and the length of said shorter bore being shorter than the length of said bit.

9. A screwdriver as claimed in claim 8, further comprising second means for releasably retaining said bit in said second shorter ores.

10. A screwdriver as claimed in claim 9, wherein said second means for releasably retaining said bits comprises flexible means associated with each of' 'said second bores fixed to the inner surface of and extending into each of said second bores, and adapted to bear against and frictionally engage said bit when said bit is stored in said second bore, and to permit sliding movement of said bits when said bits are inserted into or displaced from said second bore.

11. A multiple-bit screwdriver comprising: a) a handle provided with R plurality of bores arrayed circumferentially about and parallel to the longitudinal axis of said handle, each said bore being open at both ends thereof and adapted to store a screwdriver bit; b) a shaft secured to and extending from one end of said handle; c) means provided at one end of said shaft for securing said screwdriver bit; d) a cap rotatably mounted on the second end of said handle and provided with an opening for receiving a screwdriver bit; and e) means for releasably retaining said bit in said bores; wherein a selected bit is remove from its bore by inserting a second bit through said opening in said cap into said bore thereby displacing said selected bit and storing said second bit, and wherein said handle is transparent in the vicinity of the working ends of said stored bits.

12. A screwdriver as claimed in claim 11, wherein said cap is further provided with means for releasably retaining said cap in a given position with respect to said bores.

13. A screwdriver as claimed in claim 12, wherein said locking means comprises engagement means located on said cap for extending into the end of one of said bores and biassing means for releasably retaining'said engagement means in said end of said bore.

14. A screwdriver as claimed in any of claims 11 to 13, wherein said screwdriver bits are provided at both ends with screwdriver blades.

15. A screwdriver as claimed in any of claims 11 to 14, wherein said means for securing said screwdriver bit in said shaft comprises a magnet.

16. A screwdriver as claimed in any of claims 11 to 15, wherein said means for retaining said screwdriver bit in said bore comprises a rubber O-ring.

17. A screwdriver as claimed in any of claims 11 to 15, wherein said means for retaining said screwdriver bit in said bore comprises spring biassing means.

18. A screwdriver as claimed in claim 15, wherein said magnet is adapted to secure said displaced bit against said handle until said bit is removed for use.

19. A multiple-bit screwdriver comprising: a) a handle provided with a plurality of bores arranged circumferentially about and parallel to the longitudinal axis of said handle, each said bore being open at one end thereof adjacent a first end of said handle and adapted to store a screwdriver bit; b) a shaft secured to and extending from said first end of said handle; c) means provided at the end of said shaft remote from said handle for securing said screwdriver bit; d) a nose piece rotatably mounted on said one end of said handle and provided with a bit receiving bore open at both ends and adapted to be aligned with one of said bores in said handle; and e) means for releasably securing said nose piece in a position whereby said bore in said, nose piece is aligned with one of said bores in said handle; wherein a selected bit is removed from a bore in said handle by aligning said bore in said nose piec with said bore in said handle containing said selected bit and allowing said bit to be removed from said handle.

20. A multiple-bit screwdriver substantially as hereinbefore described with reference to the accompanying drawings.