WO1992021469A1

WO1992021469A1 - An attachment for a drive shaft of a drill or like rotary tool

Info

Publication number: WO1992021469A1
Application number: PCT/AU1992/000264
Authority: WO
Inventors: Carlton Eugine Lonel; Jim Cain
Original assignee: JACK HAMMER HARDWARE Pty Ltd
Current assignee: JACK HAMMER HARDWARE Pty Ltd
Priority date: 1991-06-05
Filing date: 1992-06-05
Publication date: 1992-12-10
Anticipated expiration: 1993-12-05

Abstract

An attachment for a drive shaft of a drill or like rotary tool is provided. The attachment comprises two tool bit holding means (1, 3), one (1) being for connecting with the drive shaft (7) and for holding one tool bit (17) and the other (3) being for holding the other tool bit (33), each of the tool bit holding means (1, 3) being releasably interconnectable with the tool bits (17, 33) in place, and, in use, so drive can be imparted from the one (1) connected with the drive shaft (7), to the other, the interconnection being such that the tool bit holding means (3) can be fitted to or removed from the other (1) depending on which tool bit (17, 33) is required.

Description

AN ATTACHMENT FOR A DRIVE SHAFT

OF A DRILL OR LIKE ROTARY TOOL

FIELD OF THE INVENTION This invention relates to an attachment for a drive shaft of a drill or like rotary tool and relates particularly, but not exclusively, to such for use with an electric drill.

DESCRIPTION OF PRIOR ART Hitherto, it has been most troublesome for persons drilling holes for screws to place a drill bit into the chuck of a drill, drill the hole, remove the drill bit, insert a screw driver bit and then proceed to drive the screw home. The problem of interchanging the drill bit with the screw driver bit requires the manual releasing of the chuck and the subsequent tightening of the chuck. The process must be repeated many times if a number of holes and screws are to be provided.

OBJECT AND STATEMENT OF INVENTION The present invention has been devised with the principal object of providing an attachment which will make the task of making the drill ready for drilling holes or for driving screws easier.

Therefore, in accordance with a first broad aspect of the present invention there is provided an attachment for a drive shaft of a drill or like rotary tool; such attachment comprising two tool bit holding means, one being for connecting with the drive shaft and for holding one tool bit and the other being for holding the other tool bit, each of the tool bit holding means being releasably interconnectable with the tool bits in place, and so, in use, drive can be imparted from the one connected with the drive shaft, to the other, the interconnection being such that the appropriate one of the tool bit holding means can be fitted to or removed from the other depending on which tool bit is req-uired.

Most preferably, the connection of the first tool bit holding means to the second tool bit holding means is such that the tool bits held thereby will be axially aligned. It is particularly preferred that the second tool bit holding means comprise a drill chuck. It is also preferred that there be releasable holding means comprising pin means on one of the tool bit holding means for locating in slot means in the other of the tool bit holding means and that the releasing of the interconnection is effected by axial twisting or rotation of one of the tool bit holding means relative to the other about the central axis of the drive shaft.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention can be more clearly ascertained examples of preferred embodiments will now be described with reference to the accompanying drawings wherein:

Figure 1 is an exploded isometric view of one preferred attachment means;

S B T Figure 2 is a side view in assembled relationship and in part section of the attachment means shown in Figure 1;

Figure 3 is a side view similar to that in Figure 2 showing the first tool bit holding means spaced from the second tool bit holding means;

Figure 4 is a side view in part section showing a different embodiment;

Figure 5 is an exploded side view in part section of the embodiment shown in Figure 4; and Figure 6 is an exploded isometric view of the embodiment shown in Figures 4 and 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the embodiments shown in Figures 1 through 3, there is shown an attachment device comprising a fir~t tool bit holding means 1 and a second tool bit hoi ,ing means 3. The first tool bit holding means is fastened to a drill or like rotary tool 5 by removing the conventional chuck therefrom and by screwing the first tool bit holding means 1 onto the drive shaft 7. The first tool bit holding means 1 is manufactured from a suitable material such as steel. It is generally circular in transverse cross section and has a central body part 9 with a rear circumferential flange 11. The forward nose 13 is tapered and has a hexagonal bore 15 extending axially thereinto from the forward nose 13. The hexagonal bore 15 is of a standard size to receive standard sized hexagonal work tools such as screw driver bits 17. The central body part 9 has a radially outwardly extending pin 19 and three spring detent balls 21 circumferentially in line with the pin 19. The spring detent balls 21 are urged by spring means (not shown) to a radially outermost position from the central body part 9. A magnet (not shown) can be provided in the hexagonal bore 15 to magnetically hold the screw driver bit 17 in the hexagonal bore 15.

SUBSTITUTESHEET The second tool bit holding means 3 comprises a cup shaped body part 23 which is screw fitted to a conventional drill chuck 25. Thus, the cup shaped body part 23 can be machined from a suitable material such as steel and arranged with a forward spigot 27 which is externally screw threaded so that the cup shaped body part 23 can be connected with the chuck 25.

Figure 2 clearly shows that the cup shaped body part 23 and the forward spigot 27 are hollow. In use, the body part 9 and the forward nose 13 and the screw driver bit 17 on the first tool bit holding means 1 are fitted within the hollow cup shaped body part 23 and into the hollow forward spigot 27 as shown by Figure 2. An internal circumferential groove 29 is provided in the cup shaped body part 23 and positioned to align with the spring detent balls 21. Thus, when the second tool bit holding means 3 is fitted over the first tool bit holding means 1, the spring detent means in the form of balls 21 engage in the circumferential groove 29 and assist in holding the second tool bit holding means 3 to the first tool bit holding means 1. The pin 19 can pass along a slot 31 which has a longitudinally axially extending component and then a circumferentially axially extending component. Thus, the second tool bit holding means 3 can be fitted to the first tool bit holding means by passing the pin 19 along the slot 31 and then rotating the first tool bit holding means 1 relative to the second tool bit holding means 3 so that the pin locates in the circumferentially extending portion of the slot 31. Accordingly, when a drill bit 33 is fastened to the chuck 25, the second tool bit holding means 3 can then be fastened or attached or connected with the first tool bit holding means 1. Thus, in this condition, the drill 5 can be made ready to drill a hole with a drill bit 33. When it is required to drive a screw with the drill 5, the second tool bit holding means 3 can be released from the first tool bit holding means 1 by axial rotation of the first tool bit holding means 1 relative to the second tool bit holding means 3 so the pin 19 retraces along the circumferentially extending component of the slot 31 and then by relatively moving the two tool bit holding means apart, thereby disengaging the spring detent balls 21 from the internal groove 29 and so the pin 19 then moves along the axially extending component of the slot 31.

When it is required to drill a further hole with the drill 33 then the second tool bit holding means 3 can be reconnected with the first tool bit holding means 1 by reversing the above procedure. The circumferential flange 11 on the first tool bit holding means 1 is provided to locate against the rear of the cup shaped body part 23 of the second tool holding means 3 and to be of the same external diameter as the cup shaped body part 23. This arrangement provides for a neat and secure fastening of the first tool bit holding means 1 relative to the second tool bit holding means 3 and this coupled with the spring detent balls 21 assist in maintaining good axial alignment of the components. It is to be observed that the central longitudinal axis of the screw driver bit 17 is aligned with the central longitudinal axis of the drill bit 33. Positive drive from the drive shaft 7 of the drill 5 is effected through the pin 19 in the slot 31 even when the drill is reversed in direction. Referring now to Figures 4 through 6 where like components to the previous embodiment have like numerical designations, there is shown an even further embodiment. In this embodiment, the conventional chuck on the drill is removed and the first tool bit holding means 1 is screwed

SUBSTITUTESHEET onto the drive shaft 7. The first tool bit holding means 1 comprises a central body part 41 which is provided with a circumferentially extending groove 43. The groove 43 extends radially in from the circumferentially outermost surface to an inner region. It is noted that there is a rear bore 45 in which the drive shaft 7 of the drill 5 is screw threadably received. Thus, the groove 43 extends radially inwardly towards the bore 45. The forward end of the first tool bit holding means 1 is provided with a hexagonal bore 15 in the same manner as in the previous embodiment. Thus, the hexagonal bore 15 is of a size to receive conventional sized hexagonal tool bits such as screw driver bit 17. A permanent magnet (not shown) may also be provided in the bore 15 to magnetically hold the screw driver bit 17 or other tool in that bore. The body part 41 has three openings 47 therein as will be explained hereinafter. The openings 47 extend in a direction parallel with the longitudinal central axis of the central body part 41. The second tool bit holding means 3 is also cup shaped with a cup shaped body part 49 with a forward spigot 51 (see Figure 4) which is externally screw threaded so it can screw threadably engage with the chuck 25. Thus, the chuck 25 can be held secured and drive thereto effected with the cup shaped body part 49. It is noted that the cup shaped body part 49 has a central longitudinally extending bore 53 therein in which can be received the screw driver bit 17 when the second tool bit holding means 3 is fastened to the first tool bit holding means 1. Three hexagonal drive bolts 55 are screw threaded into respective screw threaded bores 57 in the cup shaped body part 49 so that the heads 59 thereof extend rearwardly of the chuck 25. The bolts 55 are equally spaced angularly around the central longitudinal axis of the body part 49. The openings 47 in the first tool bit holding means 1 comprise three bores 61 (not clearly shown) of a diameter which will allow the heads 59 of the bolts 55 to pass therethrough. Figure 5 shows only one of the bores 61. Accordingly, the three bores 61 are equally spaced apart around the body part 49. The bores 61 extend to further bores 63 of a diameter corresponding to the shaft diameters of the bolts 55. Thus, the openings 47 are provided by two bores - bore 61 and bore 63 - which interconnect. Thus, the second tool bit holding means 3 can be fastened to the first tool bit holding means 1 by passing the heads 59 of the bolts 55 through the larger diameter bores 61 and so that the heads 59 pass into the groove 43. Thus, the width of the groove 43 is marginally greater than the depth of the heads 59 of the bolts 55. When the heads 59 pass into the groove 43, the first tool bit holding means 1 can be angularly rotated relative to the second tool bit holding means 3 so that the shafts of the bolts 55 rotate in the openings 47 to locate in the smaller diameter bores 63. The rear face of the second tool bit holding means 3 is provided with an internal chamfer 65 and the forward edge of the body part 49 of the first tool bit holding means 1 is provided with an external chamfer 67. The two chamfers 65 and 67 are complementary. Accordingly, by appropriate adjustment of the bolts 55, by screwing them into or out of the body part 49, it is possible to tightly mate the chamfers 65 and 67 to provide good secure interconnection of the first tool bit holding means 1 with the second tool bit holding means 3. A hexagonal key can be passed into the openings 47 through the rear of the first tool bit holding means 1 prior to connection of the first tool bit holding means 1 to the drive shaft 7 of the drill 5. Thus, the heads 59 of the bolts 55 can be used to tightly urge the two chamfers 65 and 67 into close mating relationship.

SUBSTITUTESHEET It is noted that the hexagonal key for this purpose can be passed into the openings 47 through the smaller diameter bores 63 from the rear end of the first tool bit holding means 1. Operation of the attachment can be effected in the same way as the attachment described in the previous embodiment. Whilst the attachment has been described as being made of steel, any other suitable material may be used as, for example, engineering quality plastics. Modifications may be made to the present invention as would be apparent to persons skilled in the art of producing attachment devices of this type and/or the engineering arts.

These and other modifications may be made without departing from the ambit of the invention, the nature of which is to be determined from the foregoing description.

Claims

1. An attachment for a drive shaft of a drill or like rotary tool; such attachment comprising two tool bit holding means, one being for connecting with the drive shaft and for holding one tool bit and the other being for holding the other tool bit, each of the tool bit holding means being releasably interconnectable with the tool bits in place, and so, in use, drive can be imparted from the one connected with the drive shaft, to the other, the interconnection being such that the appropriate one of the tool bit holding means can be fitted to or removed from the other depending on which tool bit is required.

2. An attachment as claimed in claim 1 wherein the connection of the first tool bit holding means to the second tool bit holding means is such that the tool bits held thereby will be axially aligned.

3. An attachment as claimed in claim 1 or claim 2 wherein there is releasable holding means comprising pin means on one of the tool bit holding means for locating in slot means in the other of the tool bit holding means and that the releasing of the interconnection is effected by axial twisting or rotation of one of the tool bit holding means relative to the other about the central axis of the drive shaft.

4. An attachment as claimed in claim 3 wherein one of the tool bit holding means has a body part which is circular in transverse cross section and has a radially outwardly extending pin on its surface, the other tool bit holding means has a body part which is cup shaped to receive said one tool bit holding means therein, said other tool bit holding means having a slot with a longitudinally extending component and a circumferentially extending component, said slot being for receiving said pin to releasably hold said

SUBSTITUTESHEET tool bit holding means together.

5. An attachment as claimed in claim 4 wherein said tool bit holding means also has spring detent means carried by one of said tool bit holding means, and a groove in the other in which said spring detent means can locate when said tool bit holding means are interconnected.

6. An attachment as claimed in claim 3 wherein one of the tool bit holding means has headed drive belt means extending therefrom and the other of the tool bit holding means has a first bore extending thereinto and a second bore extending thereinto parallel with the first bore, the second bore being directly adjacent the first bore and opening into the first bore, said first bore being a diameter which will allow the heads of the drive bolt means to pass therethrough and the diameter of the second bore having sufficient to allow the shaft of the drive bolt means to pass thereinto when one of the tool bit holding means is rotated relative to the other, whereby the tool bit holding means can be releasably interconnected.

7. An attachment as claimed in claim 6 wherein said headed bolt means can be screwed into and out of said one tool bit holding means and provided for adjustment of its length of extension therefrom whereby the head will engage behind said first bore when the tool bit holding means are interconnected, thereby permitting close mating relationship of the interconnected tool bit holding means.

8. An attachment as claimed in claim 7 wherein one of the tool bit holding means is provided with a surface which has a chamfer and the other tool bit holding means is provided with a surface with a complementary chamfer, the two surfaces being in alignment when the tool bit holding means are interconnected, and wherein adjustment of the length of said headed bolt means can bring the two surfaces into close mating relationship.

9. An attachment as claimed in claim 1 wherein one of the tool bit holding means includes a drive chuck and the other includes a bore for drive holding of a tool.

10. An attachment as claimed in claim 9 wherein said bore includes a magnet for magnetically retaining said tool in said bore.

SUBSTITUTESHEET