GB2137912A

GB2137912A - Combined screw-driver attachment and power drill

Info

Publication number: GB2137912A
Application number: GB08309540A
Authority: GB
Inventors: Charles Glen Dunn
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-04-08
Filing date: 1983-04-08
Publication date: 1984-10-17
Also published as: DE3412913A1; GB2137912B; JPS59196175A; GB8309540D0

Abstract

The combination of a power tool and a drive attachment has a chuck 1 within which is secured a drill bit 3. The chuck 1 has a polygonally shaped spigot 2 on which is received a tubular screwdriver attachment 5. A polygonally shaped socket 9 of the attachment 5 receives the spigot 2 in complementary manner so that rotary drive can be transmitted from the chuck 1 to the screwdriver tip 8 with the drill bit 3 accommodated within the tubular portion 6. In a modification the chuck provides a polygonally shaped socket which receives a complementary shaped end part of the screwdriver attachment to provide rotational drive to the attachment. <IMAGE>

Description

SPECIFICATION The Combination of a Power Tool and a Drive Attachment Technical Field and Background Art This invention relates to the combination of a power tool such as a drill and a drive attachment (such as a screw driver, a nut-runner or other tool) requiring a rotary drive which is coupled to the power tool to provide that drive.

It is well known to use a power drill to bore a hole in wood or masonry and then to use the same drill, for example, to drive a screw into the hole. This normally involves first removing the drill bit from the chuck of the power drill and then inserting the screw driver bit and retightening the chuck. This is time consuming and, in the majority of instances, inconvenient. In an attempt to alleviate the requirement for removing the drill bit is has hitherto been proposed, for example in GB-A-2,063,1 14, to use a screw driver in the form of a sleeve or tube which fits over the drill bit and can therefore be operated without removing the bit. This results in a considerable saving in time where a large number of holes have to be bored and screws individually inserted.In the aforementioned prior publication rotary drive to the screwdriver sleeve is achieved by complementary engagement of a ring of teeth on the sleeve with the toothed locking ring of a conventional multi-jawed chuck on a power drill.

It is believed that such a toothed drive arrangement between a power tool and a screwdriver or other tool requiring a rotary drive which is temporarily coupled to the power tool is unnecessarily complicated and expensive. In an attempt to simplify the drive arrangement, my copending Patent Application No. 82 00 492 provides for the sleeve or tubular portion which is intended to fit over the drill bit mounted in the chuck to have at one end drive means adapted to provide a direct driving engagement with the chuck jaws or the chuck head of the power tool; in a preferred arrangement of my prior proposal the drive connection between the tubular portion and the chuck jaws is achieved by providing lugs or projections on the tubular portion which are arranged to be closely received between the jaws of the chuck.Whilst this latter proposal provides a simple and efficient rotary coupling it is not suitable for drills of the type which do not employ chuck jaws or where the jaws are not conveniently available to be engaged by the tubular portion. It is an object of the present invention to provide a simple means of coupling between a power tool and a drive attachment such as a screwdriver and which coupling is a modification of my prior proposal and may usefully serve to provide a rotary drive coupling in the absence of chuck jaws on the power drill.

Statement of Invention and-Advantages According to the present invention there is provided the combination of a power tool having an axially rotatable chucking device for mounting a drill to extend axially therefrom and a drive attachment, said drive attachment comprising an axially extending tubular portion for fitting axially over a drill when mounted in the chucking device and there being provided coupling means for locating the drive attachment on the chucking device and transmitting rotational drive from the chucking device to the drive attachment, and wherein the coupling means comprises a spigot part and a socket part located one on each of the drive attachment and the chucking device, said parts engaging axially one within the other and being of non-circular radial section to abut each other and transmit said rotational drive.

By the present invention the socket and spigot parts are intended to engage each other as the tubular portion is fitted axially on to the chucking device so that the parts are restrained from rotation relative to each other and thereby drive can be imparted from the chucking device to the drive attachment. Usually the socket and spigot parts will engage with each other in substantially complementary manner. The rotary drive is preferabiy transmitted between the socket and spigot parts by abutment of opposing flat faces on those parts and to achieve this the socket and spigot parts will usually be of square, hexagonal or other polygonal shape in radial section.The present invention is particularly advantageous when applied to power drills in which the drill bit is secured in the chucking device without the use of chuck jaws, such securing being achieved, for example, by the use of a bayonet-type fitting or retractable detents within the chucking device which are engageable with seatings in the drill bit (usually the detents are displaced by an axially slidable sleeve on the chucking device) as are well known in the relevant art.These latter forms of fittings for the drill bit are usually used in hammer or percussion drills where the drill bit is mounted to be reciprocated axially; however with hammer or percussion drills it is well known for the chucking device to be capable of rotary drive only and a rotatable part of this device may then be suitably shaped to receive the drive attachment (such as a screwdriver) in accordance with the present invention.

The socket part preferably receives the spigot part as a close sliding fit so that the frictional engagement between those parts is sufficient to retain the drive attachment on the chucking device. If required, provision can be made between the chucking device and the drive attachment to facilitate separation of the socket and spigot parts, for example by insertion of an appropriate tool such as a lever or drifter between the end of the drive attachment and the chucking device.

Preferably the socket part is located on the drive attachment as it is likely to be more convenient to form that part to the required polygonal or other shape in the end of the tubular portion than it is on the chucking device; furthermore, the machining or other forming of a polygonal or other shaped spigot part on the chucking device is unlikely to detract from the technical or aesthetic characteristics of the power tool. The socket part will usually be tubular but may have a wall which is castellated or otherwise discontinuous, for example to provide openings for ciearing detritus.

Figures in the Drawings Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying illustrative drawings, in which: Figure 1 is a perspective view of a chucking device on a power drill and a drive attachment engageable therewith to provide a first embodiment of the combination of the present invention where the spigot part is located on the chucking device, and Figure 2 shows a side elevation, in part section, of a second embodiment of the combination in accordance with the present invention in which the spigot part is provided on the drive attachment.

Detailed Description of the Drawings The combination shown in Figure 1 includes a power drill having an axially rotatable chucking device 1 with an axially extending tubular spigot 2. Received co-axially within the bore of the spigot 2 is a drill bit 3, the latter being retained within the chucking device 1 by a bayonet fitting in conventional manner.

The spigot 2 is power driven to impart rotation to the drill bit 3 (which bit may be axially reciprocable in the chucking device for hammer or percussion drilling). For the purpose of the present invention the outer surface of the spigot 2 is machined or otherwise shaped to present a peripherally disposed array of flats 4 and is conveniently of octagonal shape in radial section.

The power drill can readily and temporarily be converted into a power screwdriver by use of a drive attachment 5 which has an axially extending tubular portion 6 having a belled end 7 and a screwdriver end 8. The end 8 is conveniently a screwdriver tip which is mounted and secured in an appropriate seating in the end of the portion 6.

The belled end 7 forms a socket 9 for fitting axially over the drill bit 3 to receive the spigot 2.

The socket 9 comprises a peripherally disposed array of flats 10 and is of polygonal shape in radial section to be substantially complementary to the flats on the spigot 2. Consequentiy, the socket 9 receives the spigot 2 in complementary manner with the faces 4 and 10 being a close sliding fit over each other and respectively opposing each other. The engaging socket and spigot permits rotary drive to be imparted to the screwdriver attachment 5 while the drill bit 3 is conveniently accommodated within the tubular portion 6. The drive attachment 5 may be removable manually from the chucking device but, if required, a drifter or other appropriate tool can be inserted between the end face of the screwdriver attachment and an opposing shoulder of the chucking device to facilitate the axial separation of the two components.

In the embodiment of Figure 2 the chucking device 1 comprises a tubular portion 11 within which the drill bit 3 is axially received. The drill bit 3 is retained within the chucking device in known manner, for example, by radially displaceable detents which engage with seatings in the shank of the drill bit and are displaceable to secure or release the drill bit by axial adjustment of a sleeve 12 which is axially slidable as part of the chuck device.

The tubular portion 11 is power driven to impart rotation to the drill bit 3 and has integrally and co-axially formed therewith a castellated wall 1 3 forming a socket 14 which is co-axial with the bit 3 and opens towards that bit. The socket 14 is hexagonal in radial section with the internal faces of the castellations providing flat face parts for the hexagonal shape.

Mounted on the chucking device 12 is the screwdriver attachment 5 the screwdriver tip of which is conveniently integrally formed at 8a at an end of the tubular part 6 of the attachment.

Similarly to the embodiment in Figure 1 the attachrherit 5- in Figure 2 has a belIed end 7; however this end 7 now serves as a spigot and is received within a socket 14. More particularly, the end 7 is machined or otherwise shapeci so that its external surface is hexago.nal in radial section and complementary to the socket 14. Consequently, the spigot7 is received in the socket 14 so that flat faces 1 5 of the spigot oppose and are in sliding engagement with the respective inner faces of the castellations and the abutment between the respectively opposing faces imparts rotary drive from the chucking device 1 to the screwdriver attachment 5.

It will be appreciated that a nut-runner or other tool can be substituted for the screwdriver tips 8 and 8a.

The axially extending discontinuous castellated wall 1 3 which forms the socket 14 provides a convenient means for clearing detritus from the socket 14. Furthermore, the bell shaped end 7 of the screwdriver attachment may have castellations the openings between which are in radial alignment to the openings in the wall 13 so that a drifter or similar tool can be inserted through those openings to facilitate axial disengagement of the screwdriver attachment from the chucking device.

Claims

1. The combination of a power tool having an axially rotatable chucking device for mounting a drill to extend axially therefrom and a drive attachment, said drive attachment comprising an axially extending tubular portion for fitting axially over a drill when mounted in the chucking device and there being provided coupling means for locating the drive attachment on the chucking device and transmitting rotational drive from the chucking device to the drive attachment, and wherein the coupling means comprises a spigot part and a socket part located one on each of the drive attachment and the chucking device, said parts engaging axially one within the other and being of non-circular radial section to abut each other and transmit said rotational drive.

2. The combination as claimed in claim 1 in which the socket and spigot parts engage each other in substantially complementary manner.

3. The combination as claimed in either claim 1 or claim 2 in which the socket and spigot parts are of polygonal shape in radial section.

4. The combination as claimed in any one of the preceding claims in which the socket part receives the spigot part as a close sliding fit and the drive attachment is retained on the chucking device by frictional engagement between those parts.

5. The combination as claimed in any one of the preceding claims in which the socket part is provided by an end region of the tubular portion which receives the spigot part of the chucking device.

6. The combination as claimed in any one of claims 1 to 4 in which the spigot part is provided by an end region of the tubular portion which is received within an axial extension comprised in the chucking device and which extension forms the socket part.

7. The combination as claimed in any one of the preceding claims in which the socket part is tubular.

8. The combination as claimed in any one of claims 1 to 6 in which the socket part is castellated or otherwise discontinuous to provide openings in the wall of that part.

9. The combination of a power tool and a drive attachment substantially as herein described with reference to Figure 1 or Figure 2 of the accompanying illustrative drawings.