GB2545333B

GB2545333B - A metalworking cutting device with three screw recesses

Info

Publication number: GB2545333B
Application number: GB1619587.7A
Authority: GB
Inventors: Crane Hugh; Crane Piers
Original assignee: Holemaker Tech Ltd
Current assignee: Holemaker Tech Ltd
Priority date: 2015-11-27
Filing date: 2016-11-18
Publication date: 2019-09-25
Anticipated expiration: 2036-11-18
Also published as: GB2545333A; GB201619587D0; GB201521022D0

Description

A Metalworking Cutting Device With Three Screw Recesses

Field of the Invention

The present invention relates to drill bits. As used herein the term 'drill bit" covers, unless the context is such that a drill bit as such is intended, any cutting device for use with a power tool including drill bits, reamers, taps, hole cutters, hole saws, countersinks and milling cutters. The term "tool" is also used herein to mean such a cutting device.

Background to the Invention A problem with steel structures, especially bridges, is that a lot of complex drilling and hole modification is involved in the strengthening and maintenance of critical parts of the infrastructure. As traffic, freight volumes and weights increase, more metal modification is being carried out to prolong the service life of aging steel structures and increase them to meet modem specifications and capacity requirements. Often, these steel structures are located in remote areas away from workshop facilities.

When building, fabricating, and modifying metal or other structures, especially on site, it is often desirable to perform different operations such as the drilling of holes using a drill bit, the reaming of holes using a reamer bit, or tapping a hole using a tap bit (or operations requiring a hole cutter, holesaw, countersink, or milling cutter). To perform these tasks, a technician often needs to have not only the bits to hand, but also a rotating device such as a drill, magnet drill (or drill press type machine) and impact driver (or wrench). A drill bit (or reamer or tap bit) used on a drill has a different connection to a drill bit (or reamer or tap bit) used on an impact driver or magnet drill.

With revolutionary advances in the power and torque of cordless power tools, there is a need for a new tooling system that has high toolholder clamping accuracy to allow safe and accurate use.

Statements of the Invention

According to the present invention there is provided a metalworking cutting device for use with a power tool having a tool body provided with a cutting surface and, extending from one end of the tool body, a shank being hexagonal in cross-section and having at least three recesses, each recess having a flat base and for receiving a screw which, in use extends transversely to the shank, where the recesses are peripherally spaced about said shank and are located on a common plane, transverse to the shank, and where the at least three recesses which are equally spaced apart about said shank.

Accordingly, the invention provides a cutting device which may be used with an adaptor to allow the cutting device, such as a drill bit, a reamer bit, or a tap (or a a hole cutter, a holesaw, a countersink, or a milling cutter) to be interchangeable in their use with any type of rotating device (power tool).

Three recesses, arranged in a "Y" design, evenly spreads the clamping force over the holding screws and provides a perfectly concentric clamping force and consequent high tool accuracy.

The invention provides a cutting device with a shank which can be mounted accurately and securely in conventional pistol drill type equipment as well as in a range of specialist metalworking tools. Site workers can quickly switch cutting devices from one type of power tool to another without the need to carry several different types of cutting devices.

The provision of multiple spaced apart locking recesses gives both a strong anti-slip design with high mounting accuracy. A cutting device provided with a single, or even two, locking recess results in an uneven clamp hold when the fastener is tightened. With a rotary cutting tool, a slight variation at the shank leads to a multiplied inaccuracy at the cutting tip.

Preferably, the side of each of said recess extends into the shank at an angle of 90° to the shank surface.

The combination of a three recess design and a hexagonal cross section shank gives maximum drive engagement and ensures that there is no slip while in use with a conventional clamping chuck.

Preferably, each of said recesses has a diameter in the range 4.0 to 5.5mm, more preferably in the range 4.9 to 5.2mm and most preferably a diameter of 5 ±0.025 mm.

Preferably, the depth of each of said recesses is from 1.3 to 1.6mm, more preferably from 1.45 to 1.51mm.

Preferably, a length from the centre of each of said recesses to the free end of the shank is 14mm.

Preferably, the total length of the shank is from 25 to 35mm, more preferably is 28mm.

Preferably, a largest diameter of the shank is up to 12.5mm, more preferably from 11 to 12.5mm and most preferably from 12.49 to 12.5mm.

Preferably, each fastener is in the form of a screw, for instance, a grub screw.

The present invention also provides a tool assembly comprising a cutting device of the invention and an adaptor comprising a sleeve to receive the shank of a cutting device and a plurality of fasteners to secure the adaptor to the shank at each recess thereof, said adaptor further comprising a part shaped to engage with a power tool.

The present invention further provides a kit comprising a plurality of different cutting devices of the invention and a plurality of different adaptors, each adaptor being as defined above.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of examples only, with reference to the accompanying drawings in which:

Figures 1A, IB and 1C show views of a drill bit, reamer and tap, all in accordance with the present invention;

Figure ID is a cross section through the shank of a drill bit of the invention;

Figures 2 A and 2B show views of two different adaptors for use with the present invention; and

Figure 3 illustrates the loading of a countersink of the invention into an adaptor.

Referring to Figure 1A of the accompanying drawings, there is shown a tool in the form of a drill bit 1. Drill bit I has a tool body 2 with a hexagonal shank 3 at one end. Shank 3 includes three recesses 4 to receive fasteners such as grub screws 5. The recesses 4 are located on a common plane transverse to shank 3 and are peripherally equally spaced about shank 3. The remainder of the tool body 2 has a spiral cutting surface 6 to drill holes.

The largest diameter of shank 3 is 12.5mm. The length of shank 3 is 28mm and the recesses 4 are located 14mm from the free end of shank

Referring to Figure IB of the accompanying drawings, there is shown a tool in the form of a reamer bit 10. Reamer bit 10 has a tool body 12 with a hexagonal shank 13 at one end. Shank 13 includes three recesses 14 to receive fasteners such as grub screws 15. The recesses 14 are located on a common plane transverse to shank 13 and are peripherally equally spaced about shank 13. The remainder of the tool body 12 has a cutting surface 16 to ream holes.

The largest diameter of shank 13 is 12.5mm. The length of shank 13 is 28mm and the recesses 14 are located 14mm from the free end of shank 13.

Referring to Figure 1C of the accompanying drawings, there is shown a tool in the form of a tap bit 20. Tap bit 20 has a tool body 22 with a hexagonal shank 23 at one end. Shank 23 includes three recesses 24 to receive fasteners such as grub screws 25. The recesses 24 are located on a common plane transverse to shank 23 and are peripherally equally spaced about shank 23. The remainder of the tool body 22 has a cutting surface 26 to ream holes.

The largest diameter of shank 23 is 12.5mm. The length of shank 23 is 28mm and the recesses 24 are located 14mm from the free end of shank 23.

Referring to Figure ID of the accompanying drawings, a cross section of the shank 3 of the drill bit 1 shows the recesses 4 arranged on alternate hexagonal faces of the shank 3. Each recess 4 has a flat base 4A and a circular threaded side which extends vertically from the surface of the side of the hexagonal shank where the recess lies.

The recesses 4 have a diameter of 5mm and a depth of 1,5mm.

The tools 1, 10, 20 shown in Figures 1A, IB, and 1C can be driven by a rotating device in the form of a drill. The hexagonal shank 3, 13, 23 of each tool can simply be connected to the chuck of drill as is well known in the art.

If however a drill is not to hand and it is desired to connect the shank 3, 13, 23 of each tool to an impact driver, an adaptor 30 as shown in Figure 2A can be used. Adaptor 30 has a sleeve 37 at one end with a hexagonal recess 37A to receive the hexagonal shank 3, 13 or 23.

Sleeve 37 has three threaded apertures 37B to receive fastener grub screws 5, 15, 25 which pass through the apertures 37B into a shank recess 4, 14, 24 to secure the adaptor 30 to the tool shank 3,13, 23. Adaptor 30 has at its other end a shaped head 38 to engage with a rotating device in the form of an impact driver.

If however a drill or impact driver is not to hand and it is desired to connect the shank 3, 13, 23 of each tool to a magnet drill, an adaptor 40 as shown in

Figure 2B can be used. Adaptor 40 has a sleeve 47 at one end with a hexagonal recess 47A to receive a tool hexagonal shank 3, 13 or 23. Sleeve 47 has three threaded apertures 47B to receive fastener grub screws 5, 15, 25 which pass through the apertures 47B into a shank recess 4, 14, 24 to secure the adaptor 40 to the tool shank 3, 13, 23. Adaptor 40 has at its other end a shaped head 48 to engage with a rotating device in the form of a magnet drill.

Referring to Figure 3 of the accompanying drawings, there is illustrated a countersink 51 of the invention, this tool having a hexagonal cross section shank 53 and three recesses 55 located on alternate hexagonal faces and being centred on a common transverse plane extending through shank. Figure 3 shows the countersink 51 about to be loaded into an adaptor 57which includes a cylindrical body portion 59 within which is centrally located a hexagonal cross section blind bore 61 which is sized to accommodate shank 53. Three equally spaced apart threaded holes 63 extend from the outer surface of body portion 59 radially inwards to bore 61 and, when shank 53 is located within bore 61, align with recesses 55. Grub screws 65 are then screwed into holes 63 and then into recesses 55 to provide a secure and balanced connection between the countersink 51 and the adaptor 57.

A wide range of different size tools of the type shown in Figures 1A, IB, 1C can be produced, along with different shapes of adaptors such as shown in

Figures 2A and 2B to suit different types of rotating devices. A kit of tools and adaptors can be provided, the kit comprising a plurality of different tools and a plurality of different adaptors as described above.

In addition to adaptors to connect tools to different types of rotating devices, other adaptors can be provided, e.g. to create extensions for tools.

Claims

1. A metalworking cutting device for use with a power tool having a tool body provided with a cutting surface and, extending from one end of the tool body, a shank being hexagonal in cross-section and having at least three recesses, each recess having a flat base and for receiving a screw which, in use extends transversely to the shank; wherein the recesses are peripherally spaced about said shank and are located on a common plane, transverse to the shank; and wherein the at least three recesses which are equally spaced apart about said shank.

2. A cutting device according to Claim 1, wherein the cutting device is one of a drill bit, a reamer, a tap, a hole cutter, a hole saw, a countersink, or a milling cutter.

3. A cutting device according to Claim 2, wherein the side of each of said recess extends into the shank at an angle of 90° to the shank surface.

4. A cutting device according to any of the preceding claims, wherein each of said recesses has a diameter in the range 4.0 to 5.5mm.

5. A cutting device according to Claim 4, wherein each of said recesses has a diameter in the range 4.9 to 5.2mm.

6. A cutting device according to Claim 5, wherein each of said recesses has a diameter of 5 ±0.025 mm.

7. A cutting device according to any of the preceding claims, wherein the depth of each of said recesses is from 1.3 to 1.6mm.

8. A cutting device according to Claim 7, wherein the depth of each of said recesses is from 1.45 to 1.51mm.

9. A cutting device according to any of the preceding claims, wherein a length from the centre of each of said recesses to the free end of the shank is 14mm.

10. A cutting device according to any of the preceding claims, wherein the total length of the shank is from 25 to 35mm.

11. A cutting device according to Claim 10, wherein the total length of the shank is 28mm.

12. A cutting device according to any of the preceding claims, wherein a largest diameter of the shank is up to 12.5mm.

13. A cutting device according to Claim 12, wherein the largest diameter of the shank is from 11 to 12.5mm.

14. A cutting device according to Claim 13, wherein the largest diameter of the shank is from 12.49 to 12.5mm.

15. A tool assembly comprising a cutting device as claimed in any of the preceding claims and an adaptor comprising a sleeve to receive the shank of the cutting device and a plurality of fasteners to secure the adaptor to the shank at each recess thereof, said adaptor further comprising a part shaped to engage with a power tool.

16. A kit comprising a plurality of different cutting devices according to any of Claims 1 to 14 and a plurality of different adaptors, each adaptor being as defined in Claim 15.