GB2129353A

GB2129353A - Combination hole-drilling and fastener driving tools

Info

Publication number: GB2129353A
Application number: GB08326863A
Authority: GB
Inventors: Paul Carl Roger Fernberg
Original assignee: ITW Ltd
Current assignee: ITW Ltd
Priority date: 1982-10-11
Filing date: 1983-10-07
Publication date: 1984-05-16
Also published as: GB2129353B; GB8326863D0

Abstract

A combination tool, for sequentially drilling a hole and driving a fastener into the hole, comprises a drill unit (10, 14) which is removably attachable by coupling means (38, 40) to a drive unit (28), the drive unit being capable of attachment to rotary drive means (36), and the drive unit presenting fastener-engaging drive surfaces on a part (22), with the coupling means (38, 40) being located radially outwardly of the fastener- engaging drive surfaces to avoid interference therewith, thereby allowing the drill unit (10, 14) to be coupled, preferably by a bayonet attachment, without first removing male fastener-engaging drive surfaces on a detachable part (22) from the drive unit (28). <IMAGE>

Description

SPECIFICATION Combination hole-drilling and fastener-driving tools The aim of the present invention is to improve one of our parent company's previous proposals for a combination hole-drilling and fastenerdriving tool, namely US patent 4 349 929 to which the reader is invited to refer. A problem with that combination tool has been that, if its drive unit is presenting male fastener-engaging drive surfaces, its drill unit cannot be attached to the drive unit without first removing those male fastener-engaging drive surfaces. Naturally, this is a time consuming and frustrating operation particularly if needing to be repeated at frequent intervals. The obvious alternative of attaching the drill unit to the power drill or other rotary drive means, and attaching the drive unit at the free end of the drill unit, gives a much longer combination tool which can be difficult to handle.

A combination tool in accordance with the present invention, for sequentially drilling a hole and driving a fastener into the hole, comprises a drill unit which is removably attachable by coupling means to a drive unit, the drive unit being capable of attachment to rotary drive means, and the drive unit presenting fastener-engaging drive surfaces, with the coupling means being located radially outwardly of the fastener-engaging drive surfaces to avoid interference therewith.

The fastener-engaging drive surfaces can thus be male such as a Phillip's head or a flat blade, or be female such as a hexagonal or square socket wrench, or be interchangeably male or female as required.

The coupling means could be for example a threaded interengagement, a friction fit or a clasped attachment, but is preferably a bayonet attachment and includes a projection on the drive unit for releasable interengagement with a slot in the drill unit.

The drive unit may include a detachable part presenting male fastener-engaging drive surfaces at one end and a polygonai outline at its other end which is releasably securable in a socket of complementary outline forming female fastenerengaging drive surfaces in a body part of the drive unit. Indeed, different sizes or types of the detachable part may be securable by for example a grommet within the socket in said body part of the drive unit. Moreover, the socket in said body part of the drive unit may be replaceable. Said body part of the drive unit may be formed with a shank for releasable attachment to the rotary drive means, the shank having a bore extending therethrough and opening into the socket to permit a rod to push said detachable part of the drive unit out of the socket.

The drill unit may include a drill part which is formed separately from a body part. Indeed, different sizes of drill part may be securable by for example a grommet within a bore at one end of the body part of the drill unit. Alternatively, a given size of drill part may be formed integrally with the body part, especially if the drill unit is to be subjected to a rotary hammer action.

In either event, that is to say regardless of whether or not the drill part can be separated from the body part, a countersinking unit may be provided for releasable attachment to the body part of the drill unit to surround a trailing end of the drill part of the drill unit.

In the event that the drill part is formed separately from the body part, a countersinking unit may be provided for releasable attachment to the body part of the drill unit after the drill part of the drill unit has been removed, and/or a hole boring unit may be provided for releasable attachment to the body part of the drill unit after the drill part of the drill unit has been removed.

As explained in our parent company's US patent 4 21 8 795 the drive unit may also present an axial clearance such as a cylindrical recess by the fastener-engaging drive surfaces to prevent over-torque of a fastener driven thereby.

Several combination tools, in accordance with the present invention, will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an exploded side view of an entire combination tool also indicating a power tool chuck; Figures 2 to 4 are respectively left-hand end, axial cross-section and right-hand end views of the body part of the drive unit shown in Figure 1; Figure 5 is an axial cross-section of the body part of the drill unit shown in Figure 1; Figure 6 is an axial cross-section taken on the line VI--VI of Figure 5; Figure 7 is a section on line VIl-VIl of Figure 6; Figure 8 is similar to Figure 6 but shows a modified body part for the drill unit;; Figures 9 and 10 are side views of different countersinking units for use with the modification shown in Figure 8; Figure 11 is a side view of a hole boring unit for use with the modification shown in Figure 8; Figures 12 and 13 are together similar to Figure 3 but show a modified body part for the drive unit and a replaceable socket for use therewith; and Figure 14 is a side view of an integrally formed drill unit.

It will be clear from Figures 1 to 7 of the accompanying drawings that drill 10 is securable within bore 12 at one end of drill unit body 14 by screwing grommet 1 6 into threaded hole 1 8. Also, hexagonal shank 20 of Phillip's head driver 22 is securable within socket 24 extending from cylindrical recess 26 at one end of drive unit body 28 by screwing grommet 30 into threaded hole 32.

During both drilling and driving operations, shank 34 of the drive unit body 28 is telescopically received in known manner in power tool chuck 36, shown in dotted line because it is not part of the combination tool.

To permit drilling, the drill unit body 14 with attached drill 10 is attached by coupling means to the drive unit body 28 with attached Phillip's head driver 22. The coupling means is a bayonet attachment, with a projection 38 being formed on the drive unit body 28 for releasable interengagement with a slot 40 in the drill unit body 14. For ease of manufacture the slot 40 is formed by cutting to the shape of a T, but as the projection 38 engages only arm 42 of the slot 40, the slot 40 need only be formed to the shape of an L. The slot 40 is formed at one end of a sleeve 44 presented by the drill unit body 14, with the other end of the sleeve 44 including an annular wall 46 and a conical chamber 48. The wall 46 contacts the leading end of the drive unit body 28 and the chamber 48 receives the driving end of the Phillip's head driver 22.Rotary power from the chuck 36 can thus be transmitted to the drill 10.

To permit driving, the drill unit body 14 with attached drill 10 is removed by rotating against the direction of drilling and withdrawing axially to expose the Phillip's head driver 22 and the cylindrical recess 26. A threaded fastener with an appropriate head partly located with the cylindrical recess 26 can thus be driven into a workpiece until the drive unit body 28 contacts the workpiece. Rotation of the drive unit body 28 by the chuck 36 continues to drive the fastener until its head moves out of engagement with the Phillip's head driver 22.

A threaded fastener with a hexagonal head can alternatively be driven by the socket 24 with the cylindrical recess 26 again preventing over-torque.

The Phillip's head driver 22 must of course first be removed from the socket 24. As pulling out may be awkward, a bore 50 is provided within the shank 34 through which a rod (not shown) may be inserted to push out the Phillip's head driver 22.

Naturally, instead of the use of both of the grub screws 1 6 and 30, either or both of the drill 10 and the Phillip's head driver 22 may be formed, just at their non-drilling or non-driving ends, with a Morse or other taper which extends partly across a knock-out opening extending transversely of the drill unit body 14 or the drive unit body 28, this method of releasable attachment being well known per se.

Various modifications of the above-described combination tool are shown in Figures 8 to 1 4 of the accompanying drawings, but to facilitate ease of understanding similar reference numbers will be used to indicate similar parts with appropriate suffixes.

With regard to Figure 8, therefore, it is just necessary to explain that leading end 52 of drill unit body 1 4a is of reduced cross-section, compared with the corresponding end of the drill unit body 14, to reduce marking and scuffing on a workpiece.

The reduced area of the leading end 52 also facilitates use of the combination tool with the optional attachments shown in Figures 9 to 11. A countersinking unit 54 is shown in Figure 9 with any arrangement of teeth at end 56 and a bore 58 for receiving a replaceable drill 1 Oa carried by the drill unit body 14a. The unit 54 thus surrounds a trailing end of the drill 1 Oa and can be left in place on the drill unit body 1 4a during drilling. An alternative countersinking unit 60 is shown in Figure 10 having teeth coming to a point at apex 62. Finally, a hole boring unit 64 is shown in Figure 11 including a centralising pointed shank 66 and a wider cutting body 68.All of the units 54, 60 and 64 are held onto the leading end 52 of the drill unit body 1 4a by screwing a grommet (not shown) into a threaded hole 70 opening into a bore 72 which actually receives the leading end 52 of the drill unit body 14a.

It may be convenient for the socket 24 in the drive unit body 28 to be replaceable, and such an arrangement is shown in Figures 1 2 and 1 3. The socket 24a may be formed of a high grade hardened carbon tool steel with the remainder of the drive unit body 28a being formed of low grade mild steel. The advantage of this arrangement is that, in the event that repeated use wears the hexagonal female fastener-engaging drive surfaces presented by the socket 24a, it is cheaper to replace just the socket 24a than the entire drive unit body 28.

Figure 14 schematically illustrates a drill 1 Ob which is formed integrally with a drill unit body 14b.

Claims

1. A combination tool, for sequentially drilling a hole and driving a fastener into the hole, comprises a drill unit which is removably attachable by coupling means to a drive unit, the drive unit being capable of attachment to rotary drive means, and the drive unit presenting fastener-engaging drive surfaces, with the coupling means being located radially outwardly of the fastener-engaging drive surfaces to avoid interference therewith.

2. A combination tool according to claim 1 , in which the coupling means is a bayonet attachment.

3. A combination tool according to claim 2, in which the bayonet attachment includes a projection on the drive unit for releasable interengagement with a slot in the drill unit.

4. A combination tool according to any preceding claim, in which the drive unit includes a detachable part presenting male fastenerengaging drive surfaces at one end and a polygonal outline at its other end which is releasably securable in a socket of complementary outline forming female fastener-engaging drive surfaces in a body part of the drive unit.

5. A combination tool according to claim 4, in which the socket in said body part of the drive unit is replaceable.

6. A combination tool according to claim 4 or claim 5, in which said body part of the drive unit is formed with a shank for releasable attachment to the rotary drive means, the shank having a bore extending therethrough and opening into the socket to permit a rod to push said detachable part of the drive unit out of the socket.

7. A combination tool according to any one of claims 1 to 6, in which a drill part of the drill unit is formed separately from a body part of the drill unit.

8. A combination tool according to claim 7, in which a countersinking unit is provided for releasable attachment to the body part of the drill unit after the drill part of the drill unit has been removed.

9. A combination tool according to claim 7 or claim 8, in which a hole boring unit is provided for releasable attachment to the body part of the drill unit after the drill part of the drill unit has been removed.

10. A combination tool according to any one of claims 1 to 6, in which a drill part of the drill unit is formed integrally with a body part of the drill unit.

11. A combination tool according to any preceding claim, in which a countersinking unit is provided for releasable attachment to the body part of the drill unit to surround a trailing end of the drill part of the drill unit.

12. A combination tool substantially as hereinbefore described with reference to Figures 1 to 7, or Figures 1 to 7 as modified by any of Figures 8 toll, or Figures 12 and 13, or Figure 14, of the accompanying drawings.