Drill bit accessory

Abstract

A deburring accessory (100) is coupled to a drill bit (10) to provide a drill bit assembly, thereby enabling deburring of a bore drilled by the drill bit. The deburring accessory (100) includes a base element (200) and at least one cutting insert (300) coupled to the base element. The base element (200) is non-rotatably and externally mounted to the drill bit (10). The cutting insert (300) has at least one respective cutting edge configured for deburring the bore, and is movably mounted with respect to the base element to allow relative movement between the cutting insert and the base element between stowed and deployed positions. In the stowed position the cutting insert is stowed within the base element. In the deployed position the cutting edge is projecting laterally with respect to the base element sufficiently such that, when coupled to the drill bit in the drill bit assembly, the cutting edge is capable of deburring the bore.

Description

[0001] DRILL BIT ACCESSORY

[0002] TECHNOLOGICAL FIELD

[0003] The presently disclosed subject matter relates to drill bits, in particular to drill bits configured for de-burring holes drilled by the drill bits.

[0004] BACKGROUND

[0005] Burrs are commonly generated around the front and back edges of a hole or bore that is drilled or bored through a metal plate by a rotary cutting tool, such as for example a twist drill or the like.

[0006] Such burrs are often undesirable and are commonly removed via a separate machining operation after the drill bit is removed from the hole or bore. Conventionally, such procedures are exclusively used when operating with twist drills made from carbide or the like to drill or bore holes through metal plates.

[0007] Alternatively, it is also known to incorporate a deburring cutter in the drill bit itself for removing the burrs during the drilling operation.

[0008] By way of non-limiting example, IL166077 discloses a deburring tool having an indexable cutting insert having four cutting edges. The cutting insert has a main body portion and a guide groove. The cutting insert is slidably retained in an insert pocket with the main body portion of the insert located in a generally rectangular slot of the insert pocket and with the guide groove located and engaging a guide member portion of the insert pocket. The cutting insert is moveable between a retracted position and an extended position by means of a spring which biases the cutting insert towards the extended position. The sliding movement of the cutting insert is performed by the sliding of the guide member within the guide groove.

[0009] Also way of non-limiting example, US 7,217,070 discloses a deburring tool having an indexable cutting insert having four cutting edges. The cutting insert has a main body portion and a protruding guide member. The cutting insert is slidably retained in an insert pocket with the main body portion of the insert located in a generally rectangular slot portion of the insert pocket and with the guide member located and engaging a guide groove portion of the insert pocket. The cutting insert is moveable between a retracted position and an extended position by means of a spring which biases the cutting insert towards the extended position. The sliding movement of the cutting insert is performed by the sliding of the guide member within the guide groove.

[0010] Also way of non-limiting example, US 3,940,214 discloses a twist drill bit for drilling through metal and having a cutter recessed in the spiral portion of the drill auger and spring tensioned to be biased outwardly beyond the peripheral surface of the drill to remove burrs raised by the drill bit as it passes through the metal in either direction.

[0011] Also way of non-limiting example, JP3348751 discloses a radially extended slit that is opened above the chip space part of a body. A blade is inserted in the slit in such a way as to freely go in and out from the opening of the slit, and a spring is disposed between the inner end face of the slit and the spring receiver of the blade so as to push out the blade partially from the opening by the elastic resiliency of the spring. An oblong hole extended in the going in-out direction of the blade is opened in the blade, and a pin is passed through the oblong hole from the body so as to limit the protruding length of the blade from the opening.

[0012] Also way of non-limiting example, CN104190969 relates to the field of tool equipment, in particular to a double-blade chamber cutter. The double-blade chamber cutter comprises a cutter head and a cutter handle. The cutter head is arranged on the front section of the cutter handle. The cutter head and the cutter handle are integrally formed. The double-blade chamber cutter is characterized in that the cutter head comprises two cutting edge mounting parts arranged on the cutter head; cutting edges are arranged on the outer sides of the cutting edge mounting parts; the cutter head is conical; a chip groove is formed between the mounting parts; the upper side face of the cutter head is provided with vent holes communicated with the upper surface of the cutter handle; the side surface of the cutter handle is provided with a plurality of round holes communicated with the vent holes; the middle portion of the cutter handle is provided with a cavity; one side of the cavity is provided with an opening, a circular-arc-shaped protrusion is arranged at the opening, and the inner side of the circular-arc- shaped protrusion is arranged in the cutter handle; the inner side edge of the circular-arc-shaped protrusion is connected with the inner surface of an inner cavity of the cutter handle through a spring; the circular-arc- shaped protrusion is provided with a cutting edge. The double -blade chamber cutter is good in heat dissipation effect and capable of removing burrs.

[0013] Also way of non-limiting example, US 5,417,525 discloses a deburring attachment for a honing tool. Burrs formed at the ends of a bore during a honing operation performed by a single pass honing tool are removed by a deburring attachment which is carried on the leading end of the tool. The attachment includes one set of spring-loaded blades which remove burrs at one end of the bore as the tool is retracted from the bore and further includes an axially spaced set of spring-loaded blades which remove burrs at the opposite end of the bore during retraction of the tool.

[0014] Also way of non-limiting example, US 2020 / 001377 discloses a drill bit with chamfering function has a body, a chamfering blade, an abutting rod, an elastic element, an adjusting element, and a drill bit. The body is a hollow tube, and has an internal space, a blade opening, a pivot segment, and a connecting end. The chamfering blade is pivotally connected to the body, selectively extends out of the blade opening, and has a blade portion, a blade pivot portion, and an abutting portion. The abutting rod is disposed in the internal space and abuts against the abutting portion. The elastic element is disposed in the internal space and is compressed between the abutting rod and the adjusting element. The adjusting element is disposed in the internal space for adjusting an amount of compression of the elastic element. The drill bit is securely connected to the connecting end of the body.

[0015] Also way of non-limiting example, US 10,105,765 discloses a combined drill and chamfer tool for producing boreholes in a workpiece and for subsequently producing a chamfer on at least one bore edge of the borehole, comprising a drill bit, which is secured in a rotationally fixed manner in a base body, and at least one chamfering blade arranged behind the drill bit in the axial direction, said chamfering blade being mounted in a blade window arranged in the drill shank and spring-loaded so as to be displaceable transversely to the longitudinal axis of the combined tool, wherein the drill body comprising the drill bit and the drill shank is made of a solid hard metal material, and wherein a spring-loaded, displaceable control bolt is located in a central longitudinal bore of the solid hard metal drill, the front tip of said bolt controlling the transverse displacement of the chamfering blade, which is transversely displaceable within the blade window. Also way of non-limiting example, US 2011 / 164937 discloses a cutting tool which comprises a drill bit having an integrated deburring tool or tip which is displaceable between an extended and retracted position in order to enable both drilling and deburring operations to be carried out using a single tool, and which incorporates a number of features to increase the speed at which the deburring tip extends and retracts.

[0016] GENERAL DESCRIPTION

[0017] According to a first aspect of the presently disclosed subject matter, there is provided a deburring accessory configured for being coupled to a drill bit to provide a drill bit assembly, to thereby enable deburring of a bore drilled by the drill bit of the drill bit assembly, the deburring accessory comprising a base element and at least one cutting insert coupled to the base element, wherein: the base element is configured for being non-rotatably and externally mounted with respect to the drill bit; the at least one cutting insert has at least one respective cutting edge configured for deburring the bore; the at least one cutting insert is movably mounted with respect to the base element to allow relative movement between the at least one cutting insert and the base element between a stowed position and a deployed position, wherein in the stowed position the at least one cutting insert is stowed within the base element; wherein in the deployed position said at least one cutting edge is projecting laterally with respect to the base element sufficiently such that, when coupled to the drill bit in the drill bit assembly, the at least one cutting edge is capable of deburring the bore.

[0018] For example, said cutting insert comprises a cam element operative for cooperating with the bore to thereby cause the cutting insert to transit from the deployed position to the stowed position, and said cutting insert is biased to the deployed position.

[0019] Additionally or alternatively, for example, the base element is configured for being transversely mounted with respect to the drill bit. Additionally or alternatively, for example, the base element is configured for peripherally engaging an external surface portion of an external surface of the drill bit. For example, the base element is configured for being mounted in overlying relationship with respect to the external surface portion of the external surface of the drill bit.

[0020] Additionally or alternatively, for example, the base element comprises an engagement member having a peripheral inner wall and a lateral opening. For example, said peripheral inner wall is configured for abutting the external surface portion of the drill bit.

[0021] Additionally or alternatively, for example, said peripheral inner wall is configured for angularly circumscribing a longitudinal axis of the drill bit about a circumscribing angle, wherein said circumscribing angle is greater than 180° and less than 360°. For example, said circumscribing angle is between 200° and 300°. For example, said circumscribing angle is between 270° and 290°.

[0022] Additionally or alternatively, for example, the peripheral inner wall includes at least two non-converging abutment surfaces diametrically spaced one from the other, each said abutment surface being configured for abutting a part of the external surface portion of the external surface of the drill bit in the drill bit assembly. For example, comprising two said abutment surfaces parallel one to the other. Additionally or alternatively, for example, wherein the peripheral inner wall includes an additional flat surface interconnecting said two abutment surfaces.

[0023] Additionally or alternatively, for example, said peripheral wall is complementary to the external surface portion of the drill bit.

[0024] Additionally or alternatively, for example, wherein the peripheral inner wall has a non-circular transverse cross- section.

[0025] Additionally or alternatively, for example, wherein the peripheral inner wall has a polygonal transverse cross- section.

[0026] Additionally or alternatively, for example, wherein said engagement member is U-shaped, and comprises two arm elements and a base element joining corresponding ends of the two arm elements, and wherein the corresponding free ends of the arm elements define said transverse opening. For example, said transverse opening is configured to allow the U-shaped engagement member to engage with the drill bit in a transverse direction. Additionally or alternatively, for example, said engagement member defines an insertion channel transversely extending between the transverse opening and the base element. For example, the insertion channel defines a plurality of cross-sectional areas orthogonal to and along a transverse direction between the transverse opening and the base element, each said cross-sectional area being not less than a corresponding said cross-sectional area at the transverse opening.

[0027] Additionally or alternatively, for example, said base element further comprises a locking member configured for locking the base element with respect to the drill bit in the drill bit assembly.

[0028] Additionally or alternatively, for example, the deburring accessory comprises one said cutting insert, movably mounted with respect to a hole provided in the base element, such as to enable the cutting insert to be moved between the stowed position and the deployed position.

[0029] Additionally or alternatively, for example, the deburring accessory comprises one said cutting insert, wherein said cutting insert is movably mounted with respect to the base element such as to enable the cutting insert to be moved between the stowed position and the deployed position, the cutting insert configured for deburring in an opposite rotational direction relative to the drill bit rotational direction of the drill.

[0030] Additionally or alternatively, for example, the deburring accessory comprises one said cutting insert, wherein said cutting insert is movably mounted with respect to the base element such as to enable the cutting insert to be moved between the stowed position and the deployed position, the cutting insert configured for deburring in a clockwise rotational direction.

[0031] For example, said cutting insert is configured for deburring a bore inlet of a bore drilled by the drill bit of the drill bit assembly. Alternatively for example, said cutting insert is configured for deburring a bore exit of a bore drilled by the drill bit of the drill bit assembly.

[0032] Additionally or alternatively, for example, the deburring accessory comprises one said cutting insert, wherein said cutting insert is movably mounted with respect to the base element such as to enable the cutting insert to be moved between the stowed position and the deployed position, the cutting insert configured for deburring in a counterclockwise rotational direction.

[0033] For example, said cutting insert is configured for deburring a bore inlet of a bore drilled by the drill bit of the drill bit assembly. Alternatively, for example, said cutting insert is configured for deburring a bore exit of a bore drilled by the drill bit of the drill bit assembly.

[0034] Additionally or alternatively, for example, said cutting insert is biased to the deployed position, for example in the absence of external radial forces acting on the cutting insert.

[0035] Additionally or alternatively, for example, said cutting insert comprises a cam element configured for cooperating with the bore to thereby cause the cutting insert to transit from the deployed position to the stowed position. For example, said cam element has a convex surface facing a rotational direction opposed a rotation direction of the drill bit assembly when operated for deburring.

[0036] Additionally or alternatively, for example, said cutting insert, in particular the cutting edge thereof, is made from carbide.

[0037] Additionally or alternatively, for example, said cutting insert, in particular the cutting edge thereof, is made from any one of: tungsten carbide-cobalt; tungsten carbidetitanium carbide composite; tungsten carbide-cobalt-chromium; silicon carbide; boron carbide; calcium carbide; titanium carbide; zirconium carbide; hafnium carbide.

[0038] Additionally or alternatively, for example, the deburring accessory is configured for being mounted to a said drill bit that is made from carbide.

[0039] Additionally or alternatively, for example, the deburring accessory is configured for being mounted to a said drill bit that is made from any one of: high-speed steel (HSS), including cobalt steel; tungsten carbide-cobalt; tungsten carbide-titanium carbide composite; tungsten carbide-cobalt-chromium; silicon carbide; boron carbide; calcium carbide; titanium carbide; zirconium carbide; hafnium carbide. Additionally or alternatively, for example, said free ends of the arm elements define a transverse width at the transverse opening, said transverse width being 70% of an average diameter of a shank of the drill bit.

[0040] Additionally or alternatively, for example, the defines a cylindrical envelope in the stowed position, the cylindrical envelope having an envelope diameter, wherein the envelope diameter is within ±5% and ±10% of an average diameter of a shank of the drill bit.

[0041] According to a second aspect of the presently disclosed subject matter, there is provided a drill bit assembly, comprising a drill bit and a deburring accessory, the drill bit comprising a shank and a body, the deburring accessory being as defined herein regarding the first aspect of the presently disclosed subject matter, and wherein the trimming accessory is non-rotatably mounted to the drill bit.

[0042] For example, the drill bit is made from carbide, or from any one of: tungsten carbide-cobalt; tungsten carbide-titanium carbide composite; tungsten carbide-cobalt- chromium; silicon carbide; boron carbide; calcium carbide; titanium carbide; zirconium carbide; hafnium carbide.

[0043] In at least some other examples, for example, the drill bit is made from materials which can be machined by other than just grinding, for example non-carbide metals, for example high-speed steel (HSS), including cobalt steel.

[0044] Additionally or alternatively, for example, the external surface portion of the external surface of the drill bit is located in the shank.

[0045] Additionally or alternatively, for example, the drill bit is configured as a twist drill bit.

[0046] Additionally or alternatively, for example, the drill bit comprises a countersink drill portion configured for countersinking the bore drilled by the drill bit assembly.

[0047] According to a third aspect of the presently disclosed subject matter, there is provided a method for providing a drill bit assembly, comprising: providing a drill bit comprising a shank and a body; providing a deburring accessory as defined herein regarding the first aspect of the presently disclosed subject matter; transversely and non-rotatably mounting the deburring accessory to the drill bit.

[0048] According to a fourth aspect of the presently disclosed subject matter, there is provided a method for providing a bore in a material, the material having a material outer surface and a material thickness, the method comprising:

[0049] (a) providing a drill bit assembly as defined herein regarding the second aspect of the presently disclosed subject matter;

[0050] (b) operating the drill bit assembly to drill a bore into the outer surface and through the material thickness, the bore having a bore inlet and a bore exit;

[0051] (c) while maintaining the drill bit assembly in the bore, allowing the at least one cutting insert to deploy from the stowed position to the deployed position;

[0052] (d) operating the drill bit assembly to debur at least one of the bore inlet and the bore exit.

[0053] For example, the material is in the form of a plate made from at least one of aluminum and titanium.

[0054] Additionally or alternatively, for example, the material is in the form of a plate made from a sandwich including overlaid layers of any one of: aluminum and titanium; carbon fibre reinforced polymer (CFRP), aluminum and titanium; CFRP and titanium; CFRP and aluminum.

[0055] Alternatively, for example, the material is in the form of a composite material in the form of a solid laminate or a sandwich,

[0056] Additionally or alternatively, for example, the method further comprises countersinking the bore inlet with the drill bit assembly.

[0057] Additionally or alternatively, for example, in step (b) the drill bit assembly is rotated in a clockwise to drill the bore, and in step (d) the drill bit assembly is rotated in a counter-clockwise direction to debur the at least one of the bore inlet and the bore exit. Alternatively, for example, in step (b) the drill bit assembly is rotated in a counter- clockwise to drill the bore, and in step (d) the drill bit assembly is rotated in a clockwise direction to deb r the at least one of the bore inlet and the bore exit.

[0058] According to another aspect of the presently disclosed subject matter there is provided a drill bit comprising a shank, a body, a deburring cutting edge, and a countersink drill portion, the body being configured as a twist drill, the deburring cutting edge being configured for deburring a bore drilled by the drill bit, the countersink drill portion being configured for countersinking the bore drilled by the drill bit. For example, the drill bit is made from carbide, or from any one of: tungsten carbide-cobalt; tungsten carbide-titanium carbide composite; tungsten carbide-cobalt-chromium; silicon carbide; boron carbide; calcium carbide; titanium carbide; zirconium carbide; hafnium carbide.

[0059] For example, according to this aspect of the presently disclosed subject matter, the deburring cutting edge can be provided via a deburring accessory mounted to the drill bit, for example as disclosed herein regarding the first aspect of the presently disclosed subject matter.

[0060] A feature of at least one example of the presently disclosed subject matter is that a drill bit assembly can be provided for enabling deburring of holes / bores drilled by the drill bit assembly while still accommodated in the drilled bore.

[0061] Another feature of at least one example of the presently disclosed subject matter is that a deburring accessory can be provided for a drill bit that is made from hardened steel, for example carbide or the like, which is conventionally incapable of being machined other than by grinding.

[0062] Another feature of at least one example of the presently disclosed subject matter is that a single drilling tool can be provided for carrying out the functions of drilling a hole, deburring the hole, and countersinking the hole, in sequential operations.

[0063] BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, examples will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: Fig. 1 schematically illustrates in isometric view a drill bit assembly according to an example of the presently disclosed subject matter.

[0065] Fig. 2A schematically illustrates in isometric view a deburring accessory according to an example of the presently disclosed subject matter, the deburring accessory being included in the drill bit assembly of Fig. 1, the deburring accessory being in a deployed position; Fig. 2B schematically illustrates in isometric view the deburring accessory example of Fig. 2A in a stowed position.

[0066] Fig. 3 schematically illustrates in side view a drill bit according to an example of the presently disclosed subject matter, the drill bit being included in the drill bit assembly of Fig. 1.

[0067] Fig. 4 schematically illustrates in exploded isometric view the drill bit assembly example of Fig. 1.

[0068] Fig. 5 schematically illustrates in front view an example of the base element of the deburring accessory example of Fig. 2A.

[0069] Fig. 6A schematically illustrates in front isometric view an example of the cutting insert of the deburring accessory example of Fig. 2A; Fig. 6B schematically illustrates in back isometric view the example of Fig. 6A.

[0070] Fig. 7 schematically illustrates in back isometric view an example of the biasing member of the deburring accessory example of Fig. 2A.

[0071] Fig. 8A schematically illustrates in side view the drill bit assembly example of Fig. 1 aligned with respect to a material; Fig. 8B schematically illustrates in side view the drill bit assembly example of Fig. 1 drilled into the material; Fig. 8C schematically illustrates in side view the drill bit assembly example of Fig. 1 ready for deburring the exit that was previously drilled into the material; Fig. 8D schematically illustrates in side view the drill bit assembly example of Fig. 1 ready for deburring the inlet that was previously drilled into the material; Fig. 8E schematically illustrates in side view the drill bit assembly example of Fig. 1 ready for countersinking the inlet that was previously drilled into the material. Fig. 9A schematically illustrates in side cross-sectional view an example of a material to be drilled by the drill bit assembly example of Fig. 1; Fig. 9B schematically illustrates in side cross-sectional view another example of a material to be drilled by the drill bit assembly example of Fig. 1; Fig. 9C schematically illustrates in side cross- sectional view another example of a material to be drilled by the drill bit assembly example of Fig. 1; Fig. 9D schematically illustrates in side cross-sectional view another example of a material to be drilled by the drill bit assembly example of Fig. 1; Fig. 9E schematically illustrates in side cross-sectional view another example of a material to be drilled by the drill bit assembly example of Fig. 1; Fig. 9F schematically illustrates in side cross-sectional view another example of a material to be drilled by the drill bit assembly example of Fig. 1; Fig. 9G schematically illustrates in side cross-sectional view another example of a material to be drilled by the drill bit assembly example of Fig. 1.

[0072] DETAILED DESCRIPTION

[0073] Referring to Figs. 1, 2A, 2B, 3 and 4, a deburring accessory 100 for a drill bit 10 or the like according to a first example of the presently disclosed subject matter, comprises base element 200 and at least one cutting insert 300 coupled to the base element 200.

[0074] It is to be noted that the deburring accessory 100, in particular the base element 200, is not part of the drill bit 10 per se, and is distinct from the drill bit 10.

[0075] The deburring accessory 100 is configured for being externally mounted to the drill bit 10, in particular to an externally-facing external surface portion 15 of the drill bit 10, more in in particular to a fully externally-facing external surface portion 15 of the drill bit 10, to provide a drill bit assembly 900, thereby enable deburring of a hole or bore drilled by the drill bit assembly 900 while the drill bit 10 is still inserted in the bore.

[0076] In at least this example, the drill bit 10 is a twist drill bit.

[0077] Referring in particular to Fig. 3, the drill bit 10 has a body 16 integrally formed with a shank 12, and defines a longitudinal axis LA. Herein, and unless otherwise stated, "axially" refers a direction parallel to or coaxial with the longitudinal axis LA, while "transverse", "transversely" and so on refer to a direction nominally orthogonal (or at least partially orthogonal) to the longitudinal axis LA.

[0078] The shank 12 is provided at one longitudinal end of the drill bit 10. The shank 12 is configured to be coupled to a powered rotary source, for example a chuck of an electric drill.

[0079] The body 16 comprises a generally cylindrical portion 19 joined to a pointed end 14 at the other longitudinal end of the drill bit 10. The pointed end 14 comprises a plurality of cutting edges (not shown) for forming a hole (interchangeably referred to herein as a bore) in the material into which the drill bit 10 or drill bit assembly 900 is being drilled.

[0080] A plurality, typically two, spiral auger portions or flutes (not shown) axially extend from the pointed end 14 to a washout portion at a longitudinal position 13. The flutes are generally formed as helical grooves having cutting lips to facilitate removal of chips and passage of cutting fluid, during drilling operations.

[0081] In at least this example the drill bit 10 further comprises a countersink element 18 for countersinking the drill hole made by the pointed end 14. However, in at least some alternative variations of this example, the respective drill bit can omit the countersink element.

[0082] In at least this example, the body 16 has a cylindrical outer surface 17 extending between the longitudinal position 13 and the countersink element. In at least some alternative variations of this example, the respective longitudinal position 13 can be next to the respective countersink element, and thus omits any significant fully cylindrical outer surface next to the countersink element.

[0083] In at least this example, the drill bit 10 is made from a hardened steel, in particular from carbide (conventionally made from tungsten carbide), for example as provided by Widia (Germany), and the drill bit 10 is thus too hard for any drilling, reaming or other machining operations to be carried out on the drill bit itself other than grinding. Thus, such drill bits conventionally can only be machined using grinding tools. Alternatively, the drill bit 10 can be made from any other similar hard materials, for example from any one of: tungsten carbide-cobalt; tungsten carbide-titanium carbide composite; tungsten carbide- cobalt-chromium; silicon carbide; boron carbide; calcium carbide; titanium carbide; zirconium carbide; hafnium carbide.

[0084] While the deburring accessory 100 finds particular use in combination with a drill bit 10 made from hard materials that can only be machined via grinding, the deburring accessory 100 can nevertheless also be used with drill bits that are made from less hard materials, and materials that can be machined in other ways other than, or in addition to, grinding. Thus, in at least some alternative variations of these examples, the drill bit 10 can be made from non-carbide materials, and for example can be machined not just by grinding, and for example can be made from materials such as for example high-speed steel (HSS), including for example cobalt steel.

[0085] Alternatively, or optionally, the drill bit 10 can have a hard coating, for example a titanium nitride coating.

[0086] The choice of material for the drill bit 10 can in general depend on the specific requirements of the intended application, and each type of carbide material listed above has unique properties and applications, depending on factors including for example hardness, wear resistance, heat resistance, and chemical stability.

[0087] Referring again to Fig. 2A, the deburring accessory 100 has a deburring accessory longitudinal axis LAD, that is at least parallel with, and in at least this example co-axial with, the longitudinal axis LA of the drill bit 10 in the drill bit assembly 900.

[0088] Referring again also to Fig. 1 and Fig. 4, deburring accessory 100, and in particular the base element 200, is configured for being non-rotatably and externally mounted to the drill bit 10.

[0089] In at least this example, the deburring accessory 100, and in particular the base element 200, is in particular configured for being transversely mounted to the drill bit 10, i.e., along a transverse direction TD, in particular along a transverse insertion path TIP.

[0090] Referring again to Fig. 2 A, the base element 200 comprises an engagement member 240 and a locking member 280.

[0091] The engagement member 240 has a peripheral inner wall 243 and a transverse opening 260. In at least this example, the engagement member 240 has a first face 101 and second face 102. The first face 101 is axially spaced from a second face 102 along the accessory longitudinal axis LAD by the engagement member thickness dimension TA.

[0092] In at least this example, the engagement member 240 is U-shaped, and comprises a first arm element 241, a second arm element 242, and a base 244.

[0093] The base 244 is joined (in at least this example, integrally joined) to corresponding ends 241A, 242A of the two arm elements 241, 242, respectively.

[0094] The corresponding free ends 241B, 242B of the two arm elements 241, 242, respectively, define transverse opening 260.

[0095] The transverse opening 260 is configured to allow the engagement member 240 to engage with the drill bit 10 in a transverse direction TD.

[0096] The engagement member 240 has a convex outer surface 240A peripherally extending between the free ends 241B, 242B, around the two arm elements 241, 242 and the base 244, and axially extending between the first face 101 and the second face 102. While in at least this example the outer surface 240A is cylindrical, in at least some alternative variations of this example, the respective outer surface can instead be non- cylindrical, for example faceted (i.e., having a generally (open) polygonal axial crosssection).

[0097] The engagement member 240 defines an insertion channel IC transversely extending between the transverse opening 260 and the base 244. As will become clearer herein, the insertion channel IC essentially receives and is engaged with respect to, an external surface portion 15 of the drill bit 10, in the drill bit assembly 900.

[0098] In at least this example, the peripheral inner wall 243 includes two arm abutment surfaces 241C, 242C diametrically spaced one from the other with respect to the deburring accessory longitudinal axis LAD. The two arm abutment surfaces 241C, 242C are provided by the two arm elements 241, 242, respectively.

[0099] In at least this example, the peripheral inner wall 243 also includes an additional base abutment surface 244C, provided by the base 244, and interconnecting the two arm abutment surfaces 241C, 242C. Each one of the two arm abutment surfaces 241C, 242C and the base abutment surface 244C is configured for abutting a corresponding part of the external surface portion 15 of the external surface of the drill bit 10 in the drill bit assembly 900.

[0100] In at least this example, the two arm abutment surfaces 241C, 242C are parallel one to the other. However, in at least some alternative variations of this example, the respective arm abutment surfaces can non-parallel and / or non-flat; for example, the respective arm abutment surfaces can be diverging with respect to one another in a direction from the base 244 to the transverse opening 260, and / or can be curved. Thus, in at least such examples including the illustrated example, the respective arm abutment surfaces non-converging with respect to one another in a direction from the base 244 to the transverse opening 260.

[0101] Referring in particular to Fig. 5, the insertion channel IC defines a plurality of cross-sectional areas CA orthogonal to and along the transverse direction TD (parallel to the transverse insertion path TIP), between the engagement opening 260 and the base 244. In at least this example, each such cross-sectional area CA has the same shape and at least the same width dimension (in a direction extending between the two arm abutment surfaces 241C, 242C). Each such cross-sectional area CA within the insertion channel IC is not less than a corresponding cross-sectional area CAo at the engagement opening 260.

[0102] Furthermore, and referring also to Fig. 3 and to Fig. 4, the free ends of the arm elements 241, 242, define a transverse width TW at the engagement opening 260, wherein the transverse width TW is about 70% of an average diameter SD of the shank 12 of the drill bit 10, i.e., 70+5%, or 70+10%, of average diameter SD.

[0103] In at least this example, and referring again to Fig. 5, the peripheral inner wall 243 is configured for angularly circumscribing the deburring accessory longitudinal axis LAD (and thus for angularly circumscribing the longitudinal axis LA of the drill bit 10 in the drill bit assembly 900) about a circumscribing angle 0, wherein the circumscribing angle 0 is greater than 180° and less than 360°. In at least this example, the circumscribing angle 0 is about 280°. However, in at least some alternative variations of this example, the respective the circumscribing angle 0 can be any suitable in the range between 200° and 300°, for example in the range between 270° and 290°. Without being bound to theory, the inventors consider that providing a circumscribing angle 0 that is greater than 180° and less than 360° allows on the one hand to provide a practical insertion channel IC of reasonable width, and on the other hand facilitates coupling of the respective engagement member 240 to the drill bit 10.

[0104] As best seen in Figs. 2A and 5, the two arm abutment surfaces 241C, 242C are non-parallel with respect to the base abutment surface 244C. While in at least this example, the two arm abutment surfaces 241C, 242C are nominally orthogonal with respect to the base abutment surface 244C, in at least some alternative variations of this example the respective arm abutment surfaces can be non-parallel with respect to the respective base abutment surface. In any case, such an arrangement, coupled with the feature that the external surface portion 15 of the drill bit 10 is generally complementary shaped in at least this example, ensures that the deburring accessory 100 is non-rotatably mounted with respect to the drill bit 10 in the drill bit assembly 900, and thus the deburring accessory 100 and the drill bit 10 turn together as a single body in the drill bit assembly 900, when this is turned about the longitudinal axis LA, for example by a drill or other powered tool.

[0105] In at least some alternative variations of this example, the respective peripheral inner wall can have any suitable non-circular transverse cross-section to thereby prevent relative rotation between the respective deburring accessory and the respective drill bit in the respective drill bit assembly. For example, the respective peripheral inner wall can have a polygonal transverse cross-section.

[0106] Referring in particular to Fig. 4 the external surface portion 15 is in the form of a peripheral recess formed on the external surface of the drill bit. It is to be noted that such an external recess has outer surfaces that are all externally-facing, i.e., all the outer surfaces are radially facing outwardly away from the longitudinal axis LA, and none of the outer faces are facing one another. The external surface portion 15 defines the axial location on the drill bit 10 on which the deburring accessory 100 is to be mounted, wherein the aft face 102 of the deburring accessory 100 is at an axial spacing XI from the tip 14 of the drill bit 10.

[0107] Referring also to Fig. 8 A, the axial spacing XI is such that using the drill bit assembly 900 to drill through a material 800 having a material thickness MT the deburring accessory 100 (at least the portion thereof including the cutting insert 300) will axially pass through the full material thickness MT, while the chuck, the countersink 18 and the cylindrical outer surface 17 (aft of the external surface portion 15) will still be on the other side of the material 800 and not in contact therewith.

[0108] The engagement member 240 is configured for peripherally engaging the external surface portion 15 of the external surface 11 of the drill bit 10.

[0109] The external surface 11 of the drill bit 10 can be defined as the cylindrical surface of the cylindrical portion 19 of the body 16.

[0110] In at least this example, the engagement member 240 is configured for being mounted in circumferential overlying relationship with respect to the external surface portion 15 of the external surface 11 of the drill bit 10.

[0111] For this purpose, and referring again to Figs. 3 and 4, the external surface portion 15 is radially recessed with respect to the external surface 11 of the drill bit 10, sufficiently such that when the engagement member 240 is coupled with respect to the drill bit 10 to provide the drill bit assembly 900, the outer surface 240A of the engagement member 240 is generally flush with the external surface 11 of the drill bit 10.

[0112] By "generally flush with" is meant that the outer surface 240A of the engagement member 240 has an accessory diameter DA that is between about ± 5% to about ±10% of the drill diameter SD of the external surface 11 of the drill bit 10.

[0113] In particular, the deburring accessory 100 defines a cylindrical envelope in the stowed position SP thereof, the cylindrical envelope having an envelope diameter, wherein, in at least this example, the envelope diameter is within ±5% and ±10% of an average diameter of a shank of the drill bit.

[0114] In at least this example, the external surface portion 15 is generally complementary to the shape of the peripheral inner wall 243 of the engagement member 240.

[0115] In at least this example, the external surface portion 15 comprises a peripheral outerfacing surface 143 including first and second drill bit abutment surfaces 141C, 142C, complementary to and configured for abutting with the two arm abutment surfaces 241C, 242C respectively, and a third drill bit abutment surface 144C, complementary to and configured for abutting with base abutment surface 244C.

[0116] In at least this example, and as best seen in Fig. 4, the first, second, and third drill bit abutment surfaces 141C, 142C, 144C are nominally flat, and are radially recessed with respect to the external surface 11 of the drill bit 10.

[0117] Similarly to the peripheral inner wall 243 of the engagement member 240, mutatis mutandis, the first and second drill bit abutment surfaces 141C, 142C are joined to the third drill bit abutment surface 144C in a nominally orthogonal manner, in at least this example.

[0118] The recessed but outwardly facing nature of the three drill bit abutment surfaces 141C, 142C, 144C enables these three drill bit abutment surfaces 141C, 142C, 144C to be provided in the drill bit 10 via a material removing process, for example via grinding.

[0119] Accordingly, conventional grinding techniques can be used on the drill bit 10 to thereby provide the peripheral outer-facing surface 143. Accordingly, such a peripheral outer-facing surface 143 can be provided for the drill bit 10, even in implementations of this example in which the drill bit 10 is made from hardened steel, in particular from carbide or the like, which conventionally cannot be machined via milling, drilling or other similar machining operations other than grinding.

[0120] Referring again to Fig. 2A and to Fig. 4, the locking member 280 is configured for locking the base element 200, and in particular the engagement member 240 with respect to the drill bit 10 in the drill bit assembly 900.

[0121] In at least this example, the locking member 280 is in the form of a locking nut, having an external thread 282 complementary to an internal thread 284 provided in a first through hole 285 formed in the engagement member 240 (in at least this example, in one of the arm elements, for example the first arm element 241). When the accessory 100 is coupled to the drill bit 10, the locking member 280 is screwed into the hole 285 into locking abutment with the peripheral outer-facing surface 143.

[0122] Referring to Figs. 1, 2A, 2B, 6A and 6B, in at least this example, the accessory 100 has a single cutting insert 300, having a single cutting edge 310. However, in at least some alternative variations of this example, the respective accessory can instead have more than one cutting insert, for example two or three cutting inserts, each cutting insert having one or more cutting edges.

[0123] For example, the cutting edge 310 is made of or comprises a diamond tip or a poly crystalline diamond (PCD) tip. Alternatively, the whole of the cutting insert or at least the cutting edge 310 thereof can be made from carbide or from any one of: tungsten carbide-cobalt; tungsten carbide-titanium carbide composite; tungsten carbide-cobalt- chromium; silicon carbide; boron carbide; calcium carbide; titanium carbide; zirconium carbide; hafnium carbide.

[0124] In at least this example, and referring to Fig. 2A and Fig. 2B, the cutting insert 300 is movably mounted with respect to the base element 200 to allow relative movement between the cutting insert 300 and the base element 200 between the stowed position SP (Fig. 2B) and a deployed position DP (Fig. 2A).

[0125] In the stowed position SP the cutting insert 300 is stowed within the base element 200.

[0126] In the deployed position DP the cutting edge 310 is projecting laterally with respect to the base element 200 sufficiently such that, when coupled to the drill bit 10, the cutting edge 310 is capable of deburring the bore that was drilled via the drill bit 10 in the drill bit assembly 900.

[0127] The cutting inert 300 comprises a radially projecting body 330, having a cutting surface 315 defining at least one respective cutting edge 310. The cutting edge 310 is configured for deburring the bore that was previously drilled by the drill bit 10 in the drill bit assembly 900, as will become clearer herein.

[0128] The body 330 comprises a flange 340 at a base end thereof.

[0129] The body 330 is moveably mounted with respect to a second hole 390 provided in the engagement member 240, such as to enable the cutting insert 300 to be transitioned between the stowed position SP (Fig. 2B, for example) and the deployed position DP (Fig. 2 A, for example). The flange 340 prevents the body 330 from being radially ejected away from the body 330, and in the deployed position DP, the flange 340 abuts the peripheral inner wall 243. In particular, the body 330 is reciprocably mounted with respect to a second hole 390 provided in the engagement member 240 (in at least this example, in one of the arm elements, for example the second arm element 242), to thereby enable the body 330 to be reversibly linearly displaced along a reciprocation axis RA between the stowed position SP and the deployed position DP.

[0130] The body 330 further comprises a cam element 360 transversely opposed to the cutting surface 310. The cam element 360 comprises a rounded convex surface 370 configured for cooperating with the bore that is drilled by the drill bit 10 in the drill bit assembly 900 to thereby cause the respective cutting insert to transit from the deployed position DP to the stowed position SP. Furthermore, the convex surface 370 is configured for abutting an inner cylindrical surface of the bore in the stowed position SP, as will become clearer herein.

[0131] When mounted with respect to the hole 390, the convex surface 370 is facing a rotational direction opposed to a rotation direction of the drill bit assembly 900 when operated for deburring, while concurrently the cutting edge 310 is facing the rotation direction of the drill bit assembly 900 when operated for deburring.

[0132] The cutting insert 300 is biased to the deployed position DP in the absence of external radial forces acting on the cutting insert 300 (in a radial direction towards the accessory longitudinal axis LAD). In at least this example, the cutting insert 300 comprises a biasing member 380 configured for radially biasing the body 330 towards the deployed position DP.

[0133] In at least this example, and referring also to Fig. 7, the biasing member 380 comprises a first housing 382 and a second housing 384, the second housing 384 being telescopically movable with respect to the first housing 382 about a housing reciprocation axis HRA that is parallel with or coaxial with reciprocation axis RA when the citing insert 300 is mounted with respect to the hole 390.

[0134] The first housing 382 is configured for being accommodated in a recess 389 provided in the underside of the body 330 (Figs. 6 A, 6B).

[0135] The second housing 384 has a rounded free end 385, configured for being in abutment with the peripheral outer-facing surface 143 in the drill bit assembly 900. In at least this example, a spring element (not shown) is accommodated inside the first housing 382 and the second housing 384, and the spring element is pre-tensioned to bias the first housing 382 and the second housing 384 away from one another along the housing reciprocation axis HRA.

[0136] Thus, when the cutting insert 300 is mounted with respect to the hole 390 in the drill bit assembly 900, and in the absence of external radial forces acting on the cutting insert 300 (in a direction towards the accessory longitudinal axis LAD), the spring element pushes the first housing 382 and the second housing 384 away from one another along the housing reciprocation axis HRA. Since the second housing 384 is in abutment with the peripheral outer-facing surface 143 of the drill bit 11, the spring element causes the first housing 382 to move away from the second housing 384 along the housing reciprocation axis HRA until the flange 340 comes into abutting contact with the peripheral inner wall 243, at the deployed position DP.

[0137] In at least this example, the body 330 is insertable in the hole 390 in any one of two orientations. In a first orientation, as shown in Fig. 2 A, the cutting edge is facing in a tangential direction TD away from the base 244, while in a second orientation, the cutting edge 310 is facing in a tangential direction towards the base 244. This feature allows the user the flexibility to use the deburring accessory 100 in applications in which it is required to rotate during deburring in a clockwise direction, or in which it is required to rotate the deburring accessory 100 during deburring in the counter clockwise direction.

[0138] In any case, it is to be noted that the deburring accessory 100 rotates during deburring in a rotational direction that is opposite to the rotational direction of the drill bit 10 during drilling. Thus, if the drill bit 10 is configured for drilling while rotating in a clockwise direction, the respective deburring accessory 100 is configured for deburring while rotating during deburring in the counter-clockwise direction; conversely, if the drill bit 10 is configured for drilling while rotating in a counter-clockwise direction, the respective deburring accessory 100 is configured for deburring while rotating during deburring in the clockwise direction. Thus, such a choice of rotational direction for deburring, and the corresponding orientation of the body 330, is exercised prior to the deburring accessory 100 being mounted to the drill bit 10 according to the drilling rotational direction of the drill bit 10 to provide the drill bit assembly 900, and prior to the bore being drilled by the drill bit 10 in the drill bit assembly 900. In general, the precise configuration of the cutting insert 300, in particular the position and shape of the respective cutting edge 310, depends on the rotational direction of the drill bit 10 and on whether the bore inlet or bore exit of the bore that is being drilled by the drill bit, is to be deburred.

[0139] There are thus at least four different configurations of the cutting insert 300: a first configuration, in which the cutting insert 300 is configured for deburring the bore inlet of the drilled bore while rotating in a clockwise direction; the drilling direction being counter-clockwise; a second configuration, in which the cutting insert 300 is configured for deburring the bore inlet of the drilled bore while rotating in a counterclockwise direction; the drilling direction being clockwise; a third configuration, in which the cutting insert 300 is configured for deburring the bore exit of the drilled bore while rotating in a clockwise direction; the drilling direction being counter-clockwise; a fourth configuration, in which the cutting insert 300 is configured for deburring the bore exit of the drilled bore while rotating in a counterclockwise direction; the drilling direction being clockwise.

[0140] Referring to Figs. 8A to 8E, the drill bit assembly 900 can be used for drilling into any suitable or desired material.

[0141] For the purpose of example, such a material is illustrated in Figs. 8A to 8E as a plate 800 having a plate material thickness MT, the plate 800 having a first face 802 and a second plate 804 spaced apart by the material thickness MT.

[0142] By way of non-limiting example, the plate 800 can be made from at least one of aluminum and titanium, or made from a sandwich including overlaid layers including various combinations of aluminum, and / or titanium and / or carbon fibre reinforced polymer (CFRP), for example any one of: overlaid layers of aluminum and titanium; overlaid layers of CFRP, aluminum and titanium; overlaid layers of CFRP and titanium; overlaid layers of CFRP and aluminum. For example, and referring to Fig. 9A, the plate 800 can be made from two overlaid layers - a first layer 800A made from aluminum overlaid over a second layer 800B of CFRP. For example, the first layer 800A can be 11mm thick, and the second layer 800B can be 16mm thick.

[0143] Alternatively, for example, and referring for example to Fig. 9B, the plate 800 can be made from two overlaid layers - a first layer 800B made from CFRP overlaid over a second layer 800C of titanium.

[0144] Alternatively, for example, and referring for example to Fig. 9C, the plate 800 can be made from three overlaid layers - a first layer 800B made from CFRP overlaid over a second layer 800C of titanium, which is overlaid over a third layer 800A of aluminum. For example, intermediate thin layers 800D of thermoreactive paper can be provided between the first layer 800B and the second layer 800C, and between the second layer 800C and the third layer 800A. For example, the first layer 800B can be 3.3mm thick, the second layer 800C can be 2.0mm, and the third layer 800A can be 3.5mm thick.

[0145] For example, and referring to Fig. 9D, the plate 800 can be made from two overlaid layers - a first layer 800A made from aluminum overlaid over a second layer 800C of titanium.

[0146] Alternatively, and also by way of non-limiting example, the plate 800 can be made from any suitable composite materials, for example in the form of solid laminates or in the form of a composite sandwich structure, for example made from non-metallic materials.

[0147] For example, and referring to Fig. 9E, the plate 800 can be a solid laminate made from two overlaid layers - a first layer 800G of a first material overlaid over a second layer 800H of a second material.

[0148] Alternatively, for example, and referring for example to Fig. 9F, the plate 800 can be in the form of a sandwich made from three overlaid layers - a middle layer 800J or core sandwiched between a first outer layer 800K made from a first material and a second outer layer 800L made from a second material. The first material and the second material can be the same material or different materials one from the other. The core middle layer 800J can be, for example, in the form of a honeycomb or other suitable structure. Alternatively, for example, and referring for example to Fig. 9G, the plate 800 can be in the form of a sandwich made from a plurality of overlaid layers, for example five overlaid layers 800M, 800N, 800P, 800Q, 800R.

[0149] In use, the drill bit assembly 900 is first coupled via the shank 12 to a powered rotary source, for example a chuck of an electric drill.

[0150] The drill bit assembly 900 can then be used for drilling and deburring a bore in a material 800.

[0151] In at least this example, the deburring accessory 100 is operated to deburr the bore exit of the bore drilled by the drill bit, and uses a respective cutting insert according to the above third or fourth configurations thereof, depending on the rotational drilling direction of the drill bit 10.

[0152] Referring again to Fig. 8 A, the drill bit assembly 900 is first aligned with the material 800 such that the longitudinal axis LA is intersecting the target position TA on the material 800 where it is desired to drill a bore. For example a suitable jig (not shown) can be provided to control the position and orientation of the drill bit assembly 900 with respect to the material 800, to thereby align the longitudinal axis LA with the desired drilling axis DA through the target position TA.

[0153] Referring again to Fig. 8B, the drill bit assembly 900 is turned by the powered rotary source and advanced along the drilling axis DA and into the material 800 while rotating in a drilling rotational direction DRD to thereby drill the bore 850 in the material 800 along the drilling axis DA, the bore 850 having a bore inlet 852 at the front face 802 of the material, and a bore exit 854 at the back face 804 of the material 800.

[0154] As the drill bit 10 advances past the bore inlet 852 and into the bore 850, the cam element 360, in which the rounded convex surface 370 is facing the rotational direction DRD of the drill bit assembly 900 while drilling, cooperates with the inside of the bore 850. As a result, the deburring accessory 100 transitions from the deployed position DP to the stowed position SP, and the body 330 of the cutting insert 300 is pushed into the second hole 390, enabling the drill bit 10 to continue drilling and advancing through the thickness of the material 800. Referring again to Fig. 8C, as the drill bit 10 of the drill bit assembly 900 drills the bore exit 854 on the back face 804 of the material 800, the drill bit assembly 900 is advanced further along the drilling axis DA until the deburring accessory 100 has passed the bore exit 854, or at least the cutting insert 300 of the deburring accessory 100 has fully passed axially the bore exit 854. At that point there is no external force acting on the body 330, since the body 330 is no longer in radial contact with the inner surface of the bore 850, and the body 330 thus transitions to the deployed position DP.

[0155] The drill bit assembly 900 can now be partially retracted towards the bore exit 854 until the cutting insert 300 is in contact with the exit 854. The drill bit assembly 900 can be rotated in deburring rotational direction BRD that is opposite to that previously used for the drilling operation, and the cutting edge 310 deburs the bore exit 854.

[0156] For example, the drilling rotational direction DRD is in the clockwise direction, while the deburring rotational direction BRD is in the counter-clockwise direction. Alternatively, for example, the drilling rotational direction DRD is in the counter-clockwise direction, while the deburring rotational direction BRD is in the clockwise direction.

[0157] Once deburring of the bore exit 854 is completed, the drill bit assembly 900 can optionally reverse the rotational direction again to the original drilling rotational direction DRD, and in any case the drill bit assembly 900 is slowly pulled back out of the bore 850. As the rounded convex surface 370 is also rounded in the axial direction (and optionally the rounded convex surface 370 is again facing the rotational direction DRD of the drill bit assembly 900 while drilling), the cam element 360 again cooperates with the inside of the bore 850, and is pushed into the second hole 390, enabling the deburring accessory 100 to again transition from the deployed position DP to the stowed position SP.

[0158] Optionally, and referring to Fig. 8E, in examples in which the drill bit 10 also comprises a countersink element 18, the drill bit assembly 900 can provide a countersink 856 to the drilled bore at the bore inlet 852.

[0159] Thus, according to an aspect of the present disclosed subject matter, the drill bit assembly 900 enables all three functions of drilling, deburring and countersinking of the bore 850 to be performed during one combined operation via a single tool (i.e., the drill bit assembly 900), without separating the drill bit assembly 900 from the bore 850. In at least some alternative variations of this example, the deburring accessory 100 can instead deburr the bore inlet 852 in a similar manner to the bore exit 854, mutatis mutandis, and as illustrated in Fig. 8D, and uses a respective cutting insert according to the above first or second configurations thereof, depending on the rotational drilling direction of the drill bit.

[0160] In the method claims that follow, alphanumeric characters and Roman numerals used to designate claim steps are provided for convenience only and do not imply any particular order of performing the steps. Finally, it should be noted that the word “comprising” as used throughout the appended claims is to be interpreted to mean “including but not limited to”.

[0161] While there has been shown and disclosed examples in accordance with the presently disclosed subject matter, it will be appreciated that many changes may be made therein without departing from the scope of the presently disclosed subject matter as set out in the claims.

Claims

CLAIMS:

1. A deburring accessory configured for being coupled to a drill bit to provide a drill bit assembly, to thereby enable deburring of a bore drilled by the drill bit of the drill bit assembly, the deburring accessory comprising a base element and at least one cutting insert coupled to the base element, wherein: the base element is configured for being non-rotatably and externally mounted to the drill bit; the at least one cutting insert has at least one respective cutting edge configured for deburring the bore; the at least one cutting insert is movably mounted with respect to the base element to allow relative movement between the at least one cutting insert and the base element between a stowed position and a deployed position, wherein in the stowed position the at least one cutting insert is stowed within the base element; wherein in the deployed position said at least one cutting edge is projecting laterally with respect to the base element sufficiently such that, when coupled to the drill bit in the drill bit assembly, the at least one cutting edge is capable of deburring the bore.

2. The deburring accessory according to claim 1, wherein the base element is configured for being transversely mounted with respect to the drill bit.

3. The deburring accessory according to any one of claims 1 to 2, wherein the base element is configured for peripherally engaging an external surface portion of an external surface of the drill bit.

4. The deburring accessory according to claim 3, wherein the base element is configured for being mounted in overlying relationship with respect to the external surface portion of the external surface of the drill bit.

5. The deburring accessory according to any one of claims 1 to 4, wherein the base element comprises an engagement member having a peripheral inner wall and a lateral opening.

6. The deburring accessory according to claim 5, wherein said peripheral inner wall is configured for abutting the external surface portion of the drill bit.

7. The deburring accessory according to any one of claims 3 to 6, wherein said peripheral inner wall is configured for angularly circumscribing a longitudinal axis of thedrill bit about a circumscribing angle, wherein said circumscribing angle is greater than 180° and less than 360°.

8. The deburring accessory according to claim 7, wherein said circumscribing angle is any one of: between 200° and 300°; between 270° and 290°.

9. The deburring accessory according to any one of claims 5 to 8, wherein the peripheral inner wall includes at least two non-converging abutment surfaces diametrically spaced one from the other, each said abutment surface being configured for abutting a part of the external surface portion of the external surface of the drill bit in the drill bit assembly.

10. The deburring accessory according to claim 9, comprising two said abutment surfaces parallel one to the other.

11. The deburring accessory according to any one of claims 9 to 10, wherein the peripheral inner wall includes an additional flat surface interconnecting said two abutment surfaces.

12. The deburring accessory according to any one of claims 5 to 11, wherein said peripheral wall is complementary to the external surface portion of the drill bit.

13. The deburring accessory according to any one of claims 5 to 12, wherein the peripheral inner wall has a non-circular transverse cross-section.

14. The deburring accessory according to any one of claims 5 to 13, wherein the peripheral inner wall has a polygonal transverse cross-section.

15. The deburring accessory according to any one of claims 5 to 14, wherein said engagement member is U-shaped, and comprises two arm elements and a base element joining corresponding ends of the two arm elements, and wherein the corresponding free ends of the arm elements define said transverse opening.

16. The deburring accessory according to claim 15, wherein said transverse opening is configured to allow the U-shaped engagement member to engage with the drill bit in a transverse direction.

17. The deburring accessory according to any one of claims 15 to 16, wherein said engagement member defines an insertion channel transversely extending between the transverse opening and the base element.

18. The deburring accessory according to claim 17, wherein the insertion channel defines a plurality of cross-sectional areas orthogonal to and along a transverse directionbetween the transverse opening and the base element, each said cross-sectional area being not less than a corresponding said cross-sectional area at the transverse opening.

19. The deburring accessory according to any one of claims 1 to 18, wherein said base element further comprises a locking member configured for locking the base element with respect to the drill bit in the drill bit assembly.

20. The deburring accessory according to any one of claims 1 to 19, comprising one said cutting insert, movably mounted with respect to a hole provided in the base element, such as to enable the cutting insert to be moved between the stowed position and the deployed position.

21. The deburring accessory according to any one of claims 1 to 19, wherein at least one said cutting insert is movably mounted with respect to the base element such as to enable the cutting insert to be moved between the stowed position and the deployed position, the cutting insert configured for deburring in an opposite rotational direction relative to the drill bit rotational direction of the drill.

22. The deburring accessory according to any one of claims 1 to 19, wherein at least one said cutting insert is movably mounted with respect to the base element such as to enable the cutting insert to be moved between the stowed position and the deployed position, the cutting insert configured for deburring in a clockwise rotational direction.

23. The deburring accessory according to any one of claims 21 to 22, wherein said cutting insert is configured for deburring a bore inlet of a bore drilled by the drill bit of the drill bit assembly.

24. The deburring accessory according to any one of claims 21 to 22, wherein said cutting insert is configured for deburring a bore exit of a bore drilled by the drill bit of the drill bit assembly.

25. The deburring accessory according to any one of claims 1 to 19, wherein at least one said cutting insert is movably mounted with respect to the base element such as to enable the cutting insert to be moved between the stowed position and the deployed position, the cutting insert configured for deburring in a counter-clockwise rotational direction.

26. The deburring accessory according to any one of claims 21 and 25, wherein said cutting insert is configured for deburring a bore inlet of a bore drilled by the drill bit of the drill bit assembly.

27. The deburring accessory according to any one of claims 21 and 25, wherein said cutting insert is configured for deburring a bore exit of a bore drilled by the drill bit of the drill bit assembly.

28. The deburring accessory according to any one of claims 1 to 27, wherein said cutting insert is biased to the deployed position.

29. The deburring accessory according to any one of claims 1 to 28, wherein said cutting insert comprises a cam element configured for cooperating with the bore to thereby cause the cutting insert to transit from the deployed position to the stowed position.

30. The deburring accessory according to claim 29, wherein said cam element has a convex surface facing a rotational direction opposed a rotation direction of the drill bit assembly when operated for deburring.

31. The deburring accessory according to any one of claims 1 to 30, wherein at least the cutting edge of the cutting insert is made from carbide.

32. The deburring accessory according to any one of claims 1 to 30, wherein at least the cutting edge of the cutting insert is made from any one of: tungsten carbide-cobalt; tungsten carbide-titanium carbide composite; tungsten carbide-cobalt-chromium; silicon carbide; boron carbide; calcium carbide; titanium carbide; zirconium carbide; hafnium carbide.

33. The deburring accessory according to any one of claims 15 to 32, wherein said free ends of the arm elements define a transverse width at the transverse opening, said transverse width being 70% of an average diameter of a shank of the drill bit.

34. The deburring accessory according to any one of claims 1 to 33, defining a cylindrical envelope in the stowed position, the cylindrical envelope having an envelope diameter, wherein the envelope diameter is within ±5% and ±10% of an average diameter of a shank of the drill bit.

35. A drill bit assembly, comprising a drill bit and a deburring accessory, the drill bit comprising a shank and a body, the deburring accessory being as defined in any one of claims 1 to 34, and wherein the trimming accessory is non-rotatably mounted to the drill bit.

36. The drill bit assembly according to claim 35, wherein drill bit is made from carbide.

37. The drill bit assembly according to claim 35, wherein drill bit is made from any one of: tungsten carbide-cobalt; tungsten carbide-titanium carbide composite; tungsten carbide-cobalt-chromium; silicon carbide; boron carbide; calcium carbide; titanium carbide; zirconium carbide; hafnium carbide.

38. The drill bit assembly according to claim 35, wherein drill bit is made from any high-speed steel (HSS), including cobalt steel.

39. The drill bit assembly according to any one of claims 35 to 38, wherein the external surface portion of the external surface of the drill bit is located in the shank.

40. The drill bit assembly according to any one of claims 35 to 39, wherein the drill bit is configured as a twist drill bit.

41. The drill bit assembly according to any one of claims 35 to 40, wherein the drill bit comprises a countersink drill portion configured for countersinking the bore drilled by the drill bit assembly.

42. A method for providing a drill bit assembly, comprising: providing a drill bit comprising a shank and a body; providing a deburring accessory as defined in any one of claims 1 to 34; transversely and non-rotatably mounting the deburring accessory to the drill bit.

43. A method for providing a bore in a material, the material having a material outer surface and a material thickness, the method comprising:(a) providing a drill bit assembly as defined in any one of claims 35 to 41;(b) operating the drill bit assembly to drill a bore into the outer surface and through the material thickness, the bore having a bore inlet and a bore exit;(c) while maintaining the drill bit assembly in the bore, allowing the at least one cutting insert to deploy from the stowed position to the deployed position;(d) operating the drill bit assembly to debur at least one of the bore inlet and the bore exit.

44. The method according to claim 43, wherein the material is in the form of a plate made from at least one of aluminum and titanium.

45. The method according to claim 43, wherein the material is in the form of a plate made from a sandwich including overlaid layers of any one of: aluminum and titanium;carbon fibre reinforced polymer (CFRP), aluminum and titanium;CFRP and titanium;CFRP and aluminum.

46. The method according to claim 43, wherein the material is in the form of a composite material in the form of a solid laminate or a sandwich.

47. The method according to any one of claims 43 to 46, further comprising countersinking the bore inlet with the drill bit assembly.

48. The method according to any one of claims 43 to 47, wherein in step (b) the drill bit assembly is rotated in a clockwise to drill the bore, and wherein in step (d) the drill bit assembly is rotated in a counter-clockwise direction to debur the at least one of the bore inlet and the bore exit.

49. The method according to any one of claims 43 to 47, wherein in step (b) the drill bit assembly is rotated in a counter-clockwise to drill the bore, and wherein in step (d) the drill bit assembly is rotated in a clockwise direction to debur the at least one of the bore inlet and the bore exit.

50. A drill bit comprising a shank, a body, a deburring cutting edge, and a countersink drill portion, the body being configured as a twist drill, the deburring cutting edge being configured for deburring a bore drilled by the drill bit, the countersink drill portion being configured for countersinking the bore drilled by the drill bit, and wherein optionally the drill bit is made from carbide.

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