GB2045125A - Combination drilling and screwing- up tools - Google Patents

Abstract

A combination tool, for sequentially drilling a hole and driving a fastener into the hole, comprising: an elongate drill (12, 12') having a drilling section extending from a drill tip at one end of the drill and having a drill mount (18, 22') at or near the other end of the drill, the drill mount tapering progressively inwardly with increasing distance from the drill tip for mounting the drill either directly or indirectly through an adaptor (14) having a tapered bore complementary to the drill mount, to a power tool chuck 32, either the drill or the adaptor having a section (24, 20') of polygonal or other non-circular configuration which, after a hole has been drilled and before a fastener has been driven therein, is inserted within an aperture (34') of complementary polygonal shape at one end of an elongate drive collar (14'), the drill tip and the drilling section being received in a bore (38') extending longitudinally in the drive collar, and the other end of the drive collar having a fastener-engaging recess (42') for driving the head of a self-tapping fastener. <IMAGE>

Description

SPECIFICATION Combination tools The present invention relates to combination tools for sequentially drilling a hole and driving a fastener into the hole.

Combination tools of this type have been disclosed in our U.S. Patents Nos. 3,965,510 and 4,107,800 to which the reader is hereby directed to refer. In each of those disclosures, a drill is retained in a mandrel by means of a setscrew. The mandrel has a stem which is slidablytelescopically received in a sleeve. The sleeve has a fastener-engaging socket at its end closer to the drill. When the stem is in its forward position, it is contained within the sleeve and the drill is in its projecting or operative position. When the stem is in its rearward position, the drill is withdrawn into the sleeve and the socket is foremost such that it can engage and drive a fastener.

These combination tools have proved highly successful for most drilling and driving applications.

However, certain limitations of these tools render them not entirely suitable for certain applications.

More specifically, these tools are not well suited for use with a high-powered rotary hammer or hammer drill as it is sometimes known, which is capable of both rotational and percussive driving. When subjected to the high vibration of such a powertool, the setscrew which retains the drill in the combination tool tends to vibrate loose, regardless of the amount of torque used to tighten it.

Afurther problem with these combination tools occurs with large drill sizes which, coincidentally, require high-powered tools to drive them and their corresponding fasteners. For every inch of length added to the drill, roughly two inches must be added to the tool, one inch to the sleeve and one inch to the stem which must reach through that sleeve. For large fastener sizes, this means the connection of the stem to the powertool is a substantial distance from the fastener-engaging socket, and even furtherfrom the leading tip of the fastener which is being driven.

This means the combination tool is subjected to undesirably high rotational and longitudinal bending torques and the fastener is subjected to a greater risk of canting or misalignment. Further, these combination tools must have a longitudinal recess if used with a drill and, therefore, can only then be used with an external-type driver or socket wrench.

Although the above-mentioned U.S. Patents Nos.

3,965,510 and 4,107,800 are primarily concerned with providing an axial clearance between torque transmitting surfaces of the fastener-engaging socket and the adjacent free end of the combination tool, to prevent over-torque of a fastener driven thereby, it should be appreciated that the present invention is not restricted to the provision of such an axial clearance, even though it is in practice a preferred feature.

In accordance with the present invention a combination tool, for sequentially drilling a hole and driving a fastener into the hole, comprises: an elongate drill having a drilling section extending from a drill tip at one end of the drill and having a drill mount at or near the other end of the drill, the drill mount tapering progressively inwardly with increasing distance from the drill tip for mounting the drill either directly, or indirectly through an adaptor, to a power tool chuck, either the drill or the adaptor if there is one presenting a section of polygonal configuration which, after a hole has been drilled and before a fastener has been driven therein, is inserted within an aperture of complementary polygonal shape at one end of an elongate drive collar, the drill tip and the drilling section being received in a bore extending longitudinally in the drive collar, and the other end of the drive collar having a fastener-engaging recess for driving the head of a self-tapping fastener.

If the adaptor is not present, clearly the drill mount is for mounting directly to a power tool chuck.

If the adaptor is present, however, it should include a tapered bore receiving the drill mount as well as including a portion tapering progressively inwardly with increasing distance from the drill tip for mounting the adaptor to a power tool chuck.

Preferably, said polygonal section and said polygonal aperture are hexagonal.

Also preferably, the fastener-engaging recess forms part of a socketwhich is releasably secured to the remainder of the drive collar. The socket may have a polygonal stem portion which is releasably secured in a correspondingly shaped recess in the remainderofthe drive collar by the friction exerted by a spring-biased ball extending partially through a hole formed in the remainder of the drive collar. A similar spring-biased ball arrangement preferably releasably secures said polygonal section to said polygonal aperture in the drive collar.

Because the bore in the drive collar for receiving the drill trip and the drilling section, when said polygonal section and said polygonal aperture are in mating engagement, does not need to extend completely through the entire length of the drive collar, the fastener-engaging recess can include torque transmitting surfaces which are not only spaced by an axial clearance from said other end of the drive collar, but are in the form of a screwdriver rather than just a socket wrench.

Various 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 perspective view of the drilling portion of a combination tool; Figure 2 is a perspective view partially in section of the combination tool in its fastener driving mode; Figure 3 is a cross section of the assembled tool taken through a retainer; Figure 4a, 4b and 4c depict three alternative configurations of the tapered section of the drill and tapered bore therefor; Figure 5 is a perspective view in partial cross section of an alternate embodiment of the invention; Figure 6 is an exploded perspective view of a further combination tool; Figure 7 is a perspective view of the socket shown in Figure 6 with the end of the drive collar shown in section to indicate the manner of attachment; and Figure 8 is an end view of the drill shown in Figure 6.

The components of the combination tool used in the drilling mode are shown in Figure 1. The drill is shown generally at 12 and the adaptor at 14. The drill has three basic sections: a first fluted drilling section 16; a second tapering section 18; and a third knockout section 20. In this, the preferred embodiment, the knockout section is formed at the end of a reduced cylindrical portion 22.

Adaptor 14 has a first outer section 24 which has a polygonal configuration for reasons set forth hereinafter. The adaptor has a second outer section 26 separated from the first by an annular flange 28.

This second section is tapered downwardly away from the flange and may be generally circular in cross section such that this end of the adaptor is generally frustoconical. Tapered section 26 is adapted to be received in a similarly shaped aperture 30 in chuck 32 of a hammer drill or similar driving tool. The chuck has a radially extending opening 34 into which knockout wedge 36 can be inserted to aid removal of the drill and adaptor from the chuck.

As best seen in Figure 2, adaptor 14 has a longitudinally extending axial bore 38 therein, at least a portion of which has a taper which is complementary to and adapted to receive and mate with tapered section 18 of the drill. These mating tapers form a sufficiently tight frictional drive such that no slippage occurs under load, in a manner that is well known in the art. The remaining portion of the bore in this embodiment is cylindrical and receives the similarly shaped portion 22 of the drill. Knockout section 20 extends beyond the longitudinal bore 38.

When wedge 36 is inserted into opening 34, it will initially engage knockout section 20 permitting removal of the drill from adaptor 14. This will permit easy changing of a drill for a different size fastener without the need to remove or replace the adaptor.

Further insertion into the opening will cause the wedge to break the frictional grip of the chuck on the tapered outer section 26 permitting removal of the adaptor from the chuck.

Also shown in Figure 2, is the drive collar shown generally at 40. The drive collar has a first portion 42 which has an internal aperture 44 which is complementary to the polygonal section 24 of adaptor 14. A second portion 46 has a longitudinally extending bore 48 which has sufficient length and diameter to accomodate the largestfluted drill section 16 with which it will be used. A third portion 50 can include a removable socket 52 which has a fastener-engaging recess 54 which is adapted to engage and drive the head of a self-tapping fastener 56.

The socket has a hexagonal stem portion 58 integral therewith which is received in a similarly shaped recess of the body portion of the drive collar 40. The stem 58 of the socket is maintained in the recess by means of a spring-biased ball retainer 60.

An identical retainer 62 is employed to hold the drive collar 40 on adaptor 14 and this retainer is shown in some detail in Figure 3. A tapering hole 64 is formed through the wall of the drive collar in portion 42 (and 50). The inner or minor diammeter of the hole is less than the diameter of spherical ball 66. A strip of spring steel 68 extends about the periphery of the drive collar in a groove provided therefor. The spring strip 68 has a partial spherical indentation 70 which engages over the ball 66 and maintains the strip against rotational displacement. When the collar is slipped over the polygonal outer section of the adaptor (depicted here as hexagonal), the lateral face of the hexagon engages the ball which is projecting into the hexagonal aperture 44 and forces it outwardly against the bias of spring 68.This retainer increases the frictional forces and retains the respective members in engagement until manually separated. This retainer cannot be vibrated loose as can a setscrew. Although the drive transmitting section 24 and its corresponding aperture have been depicted as hexagonal, it will be understood that this shape is merely exemplary and other polygonal configurations are equally effective.

In operation, adaptor 14 is inserted into aperture 30 in the chuck. An appropriate sized drill 12 for the particularfastener 56 to be used, is selected and inserted in the adaptor. A hole 72 is then drilled in workpiece 74. The drive collar is then slipped over the drill 12 onto adaptor 14, an appropriate sized socket 52 having been preassembled on the body of the collar. Recess 54 engages and rotationally drives the head of the self-tapping fastener 56, advancing the fastener into hole 72. An enlarged non-driving recess 55, or axial clearance, which has a depth equal to the thickness of the head, allows the head to be seated against the workpiece without danger of over-torquing. If the fastener were over-torqued, the threads in the workpiece could be stripped or the head of the fastener twisted off.It will be seen that the fastener-engaging recess can be kept comparitively close to the power tool which is of particular importance with the more powerful drivers.

Figures 4a, 4b, and 4c indicate three possible configurations of the tapered section 18 on the drill.

Figure 4a indicates the preferred configuration already described in which the taper begins outside the adaptor and the section 18 continuously tapers to a point beyond the flange 28. Figure 4b shows an alternative embodiment in which the taper begins outside the adaptor and is continuous through the knockout section 20b. Athird alternative is depicted in Figure 4c in which a cylindrical portion extends into the adaptor and tapered section 18c is totally contained by the adaptor 14c.

An alternative embodiment, particularly adapted for use with larger drill sizes, is shown in Figure 5. In this embodiment, longitudinal bore 138 does not extend the entire length of the adaptor 114, but only to a second knockout opening 135 which is provided to remove the drill bit from the adaptor. In this embodiment, the elongated thin diameter portion can be omitted making the larger diameter drill bits less subject to breakage.

It will be understood that the configuration of the different sized drills which are used with a particular adaptor will be standardized and that a number of sockets 52 will be provided for the different sized fastener heads. It should also be noted that this tool can be utilized to insert other types of fasteners such as certain types of expansion fasteners, for example.

Further, it is contemplated that the spring steel biasing member 68 can be replaced by expedient biasing means such as an elastomeric ring.

Figures 6 to 8 show another combination tool of the present invention comprising a drill shown generally at 12' and a drive collar shown generally at 14'. The drill 12' consists of a one-piece, threesectioned member with all of the sections lying along a common axis. The first section 16' is the drilling section which has two flutes extending thereabout in a conventional manner. The first section extends from the drill tip 18' at its one end to the larger diametered second section 20' at its other.

As can be seen most clearly in Figure 8, the second section has a generally hexagonal configuration for reasons which will become clear herebelow.

The third section 22' gradually tapers downwardly from the portion adjacent the second section to a flat end 28' opposite the drill tip. The third section has a generally circular cross section and, accordingly, the section is frustoconical. The third section is adapted to be inserted into a similarly-shaped, axiallyextending aperture 26' of a rotary hammer 24'.

When the drill bit is inserted into the chuck, the flat end 28' thereof will project beyond the end of the aperture 26' and will project into recess 30'. This will permit removal of the bit by the insertion of a knockout pin (not shown) into recess 30'. The major diameter of the third section exceeds the minimum dimension of the second section which is measured from the center of one face diametrically to the opposite extremity.

The drive collar 14' has at least three distinct portions. The first portion 32' has a longitudinal opening 34' which has a hexagonal configuration that is complementary to, and adapted to receive, the hexagonal second section of the drill. This drive-receiving portion 32' thereby permits the torque of the driver to be transmitted to the drive collar by means of the drill. The second portion 36' has a longitudinally extending passageway 38' of sufficient diameter and length to accomodate the largest sized drill bit with which it is to be used. The third portion includes a socket 40' with a fastenerengaging recess 42' which has a hexagonal configuration adapted to engage the head 46' of a threadcutting screw 44'.As shown in Figures 6 & 7, the socket 40' may be made removable by the use of a hexagonal stem 48' made integral with the socket 40' and adapted to be received in a similarly shaped aperture. This will permit the use of a variety of sized sockets for different sized fastener heads. It has been found beneficial to include a cylindrical recess 50' which has a diameter greater than the maximum diameter of head 46' and a depth substantially equal to the thickness of the head. This non-driving recess will prevent over-torquing of the fastener which may cause stripping of the threads which have been cut in the material or twist off the fastener head.

The separable socket 40' is secured to the remainder of the drive collar by a ball-spring shown generally at 52'. A similar means 54' is used to retain the collar on the drill when it is to be employed.

Since ball-springs 52' and 54' are substantially identical only one need be described in detail.

Ball-spring 52' comprises a spherical ball 56' and a spring clip 58'. The clip 58' extends about a substantial portion of the drive collar and may be accomodated in a groove 60' extending about the periphery thereof. The clip has an identation 62' to accomodate a portion of the ball 56'. A recess 64' is drilled in the side wall of the drive collar in the center of the respective inner hexagon-forming wall. The inner diameter of recess 64' is insufficient to permit the ball to pass through. The diameter of the ball is greater than the wall thickness of the drive collar 14' such that when the hexagonal aperture is empty, spring clip 58' biases ball 56' so that it projects beyond the surface of the inner wall. Indentation 62' prevents the clip 58' from rotating relative to the drive collar and also permits the clip to remain in groove 60' when the ball is displaced.

When stem 48' is inserted into the hexagonal aperture thereof, or drive collar 14' slipped over drill 12', one face of the corresponding hexagonal shank will engage the respective ball 56' and displace it outwardly. Spring 58' will maintain the ball in gripping frictional engagement with that face and hold the two members together until manual removal is effected.

In operation, an appropriately sized drill 12' for the particular size of fastener 44' is inserted into chuck 24' of a rotary hammer. It will be understood that each drill bit has the same size second and third sections. Tapered section 22' is engaged and frictionally driven by tapered aperture 26'. The hole 64' is drilled into the workpiece 66' by the drilling portion 16'. Drive collar 14' is then slipped over the drill with hexagonal aperture 34' engaging section 20'. Ball-spring 54' retains collar 14' against axial displacement. An appropriately sized socket 40' has been preassembled on the drive collar and ballspring 52' retains it thereon. The head of the self-tapping fastener 44' is inserted in socket 42' and the fastener is driven into the just-drilled hole.

The features which render the present invention better suited for use with rotary hammers should be obvious in light of the foregoing discussion. The various retaining means cannot vibrate loose. Collar 14' need be increased only one inch for every inch of drill length, as opposed to the two inch increase previously necessary. Rotary hammers are made to accomodate tapered driver bits so no adapter is necessary. If the hexagonal surface 20' should become damaged i.e., by rounding of the corners, it can be replaced much more simply and cheaply than if the drive surface were on the driver itself. The sockets and drills may be easily changed for different sized fasteners.

Although a particular embodiment has been disclosed, it will be understood by those skilled in the art that various changes can be made. More particularly it will be understood that the mating hexagonal members can take any polygonal configuration: triangular, rectangular, pentagonal, octagonal, etc.

In fact, any non-circular configuration (elliptical, lobular, etc.) might be used. Hexagonal is the most conventional driving shape and, for this reason, it has been depicted. It will further be understood that if desired the tapering section 22' may have a cross section other than round, i.e. rectangular, elliptical, etc. In fact, this section could be cylindrical and be retained by a ball or pin engaging in a groove. Also the spring clip could take the form of an equivalent means such as an elastic polyurethane band.

Claims (16)

1. A combination tool, for sequentially drilling a hole and driving a fastener into the hole, comprising: an elongate drill having a drilling section extending from a drill tip at one end of the drill and having a drill mount at or near the other end of the drill, the drill mount tapering progressively inwardly with increasing distance from the drill tip for mounting the drill either directly, or indirectly through an adaptor, to a power tool chuck, either the drill or the adaptor if there is one presenting a section of polygonal configuration which, after a hole has been drilled and before a fastener has been driven therein, is inserted within an aperture of complementary polygonal shape at one end of an elongate drive collar, the drill tip and the drilling section being received in a bore extending longitudinally in the drive collar, and the other end of the drive collar having a fastener-engaging recess for driving the head of a self-tapping fastener.

2. A combination tool according to claim 1, in which the adaptor is not present and the drill mount is for mounting directly to a power tool chuck.

3. A combination tool according to claim 1, in which the adaptor is present and includes a tapered bore receiving the drill mount as well as including a portion tapering progressively inwardly with increasing distance from the drill tip for mounting the adaptor to a power tool chuck.

4. A combination tool according to claim 3, in which the bore for receiving the drill mount extends longitudinally entirely through the adaptor.

5. A combination tool according to claim 3, in which the bore for receiving the drill mount extends longitudinally only partially through the adaptor and is intercepted by a transversely extending drill knock-out opening.

6. A combination tool according to any preceding claim, in which said polygonal section and said polygonal aperture are hexagonal.

7. A combination tool according to any preceding claim, in which the fastener-engaging recess forms part of a socket which is releasably secured to the remainder of the drive collar.

8. A combination tool according to claim 7, in which the socket has a polygonal stem portion which is releasably secured in a correspondingly shaped recess in the remainder of the drive collar by the friction exerted by a spring-biased ball extending partially through a hole formed in the remainder of the drive collar.

9. A combination tool according to any preceding claim, in which said polygonal section is releasably secured to said polygonal aperture by the friction exerted by a spring-biased ball extending partially through a hole formed in the drive collar.

10. A combination tool according to any preceding claim, in which the drill mount is of frusto-conical configuration.

11. A combination tool according to any preceding claim, in which the fastener-engaging recess provides torque transmitting surfaces spaced from said other end of the drive collar by an axial clearance to prevent over-torque of a self-tapping fastener driven thereby.

12. A combination tool according to claim 11, in which the torque transmitting surfaces are in the form of a socket wrench.

13. A combination tool according to claim 11, in which the torque transmitting surfaces are in the form of a screwdriver.

14. A combination tool according to claim 1 and substantially as herein before described with reference to Figures 1 to 4a, or Figure 4b, or Figure 4c, or Figure 5, or Figures 6 to 8, of the accompanying drawings.

15. A combination tool, for sequentially drilling a hole and driving a fastener into the hole, comprising a drill and a drive collar; the drill being formed in one-piece with a drill tip, a first section, a second section and a third section all extending along a common axis; the first section including a fluted drilling section extending from the drill tip to the start of the second section, the second section having a polygonal configuration which defines a radial dimension extending from one apex of the polygon to a diametrically opposed portion of the second section, and the third section joining the second section and having a major radial dimension exceeding said radial dimension of the second section and gradually tapering inwardly towards the end opposite to the drill tip, the third section being adapted to be received in a correspondingly shaped aperture of a power tool chuck;the drive collar including first, second and third portions, the first portion constituting a drive receiving portion and having a polygonal aperture corresponding to and being adapted to receive the polygonal second section of the drill, the second portion having a longitudinally extending bore of sufficient diameter and length to house the drill tip and the drilling section of the drill, and the third portion including a fastener-engaging recess adapted to engage and drive the head of a self-tapping fastener; whereby in use the drill may be inserted in and frictionally driven by a chuck to create a hole in a workpiece, and the drive collar may then be slipped over the drill to permit torque to be transmitted to the drive collar from the drill by the mating polygonal section and polygonal aperture, the fdstener-eng aging recess of the drive collar thus causing a fastener to advance into the just-drilled hole.

16. A combination tool, for sequentially drilling a hole and driving a fastener into the hole, comprising a drill, an adaptor and a drive collar; the drill being formed in one-piece with a drill tip, a first drilling section, a second tapering section, and a third knock-out section; the adaptor being formed in one-piece with a first outer section of polygonal configuration, a second outer section which is tapered and is adapted to be received in a corres pondinglyshaped aperture of a powertool chuck, and an internal longitudinal extending bore, at least a portion of which has a taper that is complementary to that of the second section of the drill and is adapted to mate therewith, the drill tip and drilling section projecting from one end of said bore, when the drill is assembled with the adaptor, and the knock-out section projecting beyond the other end of said bore for permitting engagement by a knockout wedge; the drive collar having a first portion with an internal aperture which is complementary to the polygonal section of the adaptor, a second portion which has a longitudinally extending bore of sufficient diameter and length to house the drill tip and drilling section of the drill, and a third portion which has a fastener-engaging recess adapted to engage and drive the head of a self-tapping fastener; whereby in use the tapered section of the adaptor is inserted in a complementary aperture in a chuck and frictionally driven thereby, the drill being inserted into the adaptorwhere it is frictionally retained and driven by said mating tapers such that a hole is drilled in a workpiece, the drive collar then being slipped over the drill and onto the adaptor and used to advance a self-tapping fastener into the hole.