GB2580372A - Screw with retractable drill bit - Google Patents

Screw with retractable drill bit Download PDF

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Publication number
GB2580372A
GB2580372A GB1900186.6A GB201900186A GB2580372A GB 2580372 A GB2580372 A GB 2580372A GB 201900186 A GB201900186 A GB 201900186A GB 2580372 A GB2580372 A GB 2580372A
Authority
GB
United Kingdom
Prior art keywords
screw
drill bit
hollow recess
elongate hollow
hole
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB1900186.6A
Inventor
Bailey Andrew
Gosling Niki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DePuy Ireland ULC
Original Assignee
DePuy Ireland ULC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by DePuy Ireland ULC filed Critical DePuy Ireland ULC
Priority to GB1900186.6A priority Critical patent/GB2580372A/en
Publication of GB2580372A publication Critical patent/GB2580372A/en
Withdrawn legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/16—Bone cutting, breaking or removal means other than saws, e.g. Osteoclasts; Drills or chisels for bones; Trepans
    • A61B17/1613—Component parts
    • A61B17/1615—Drill bits, i.e. rotating tools extending from a handpiece to contact the worked material
    • A61B17/1617—Drill bits, i.e. rotating tools extending from a handpiece to contact the worked material with mobile or detachable parts
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
    • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/84—Fasteners therefor or fasteners being internal fixation devices
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
    • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/84—Fasteners therefor or fasteners being internal fixation devices
    • A61B17/86—Pins or screws or threaded wires; nuts therefor
    • A61B17/8605—Heads, i.e. proximal ends projecting from bone
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
    • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/84—Fasteners therefor or fasteners being internal fixation devices
    • A61B17/86—Pins or screws or threaded wires; nuts therefor
    • A61B17/8625—Shanks, i.e. parts contacting bone tissue
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
    • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/84—Fasteners therefor or fasteners being internal fixation devices
    • A61B17/86—Pins or screws or threaded wires; nuts therefor
    • A61B17/8625—Shanks, i.e. parts contacting bone tissue
    • A61B17/8635—Tips of screws
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
    • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/84—Fasteners therefor or fasteners being internal fixation devices
    • A61B17/86—Pins or screws or threaded wires; nuts therefor
    • A61B17/8685—Pins or screws or threaded wires; nuts therefor comprising multiple separate parts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B25/00—Screws that cut thread in the body into which they are screwed, e.g. wood screws
    • F16B25/0036—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw
    • F16B25/0094—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw the screw being assembled or manufactured from several components, e.g. a tip out of a first material welded to shaft of a second material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B25/00—Screws that cut thread in the body into which they are screwed, e.g. wood screws
    • F16B25/10—Screws performing an additional function to thread-forming, e.g. drill screws or self-piercing screws
    • F16B25/103—Screws performing an additional function to thread-forming, e.g. drill screws or self-piercing screws by means of a drilling screw-point, i.e. with a cutting and material removing action
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
    • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/84—Fasteners therefor or fasteners being internal fixation devices
    • A61B17/86—Pins or screws or threaded wires; nuts therefor
    • A61B17/8605—Heads, i.e. proximal ends projecting from bone
    • A61B17/861—Heads, i.e. proximal ends projecting from bone specially shaped for gripping driver
    • A61B17/862—Heads, i.e. proximal ends projecting from bone specially shaped for gripping driver at the periphery of the screw head
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
    • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/84—Fasteners therefor or fasteners being internal fixation devices
    • A61B17/86—Pins or screws or threaded wires; nuts therefor
    • A61B17/864—Pins or screws or threaded wires; nuts therefor hollow, e.g. with socket or cannulated
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B37/00—Nuts or like thread-engaging members
    • F16B37/12—Nuts or like thread-engaging members with thread-engaging surfaces formed by inserted coil-springs, discs, or the like; Independent pieces of wound wire used as nuts; Threaded inserts for holes
    • F16B37/122—Threaded inserts, e.g. "rampa bolts"
    • F16B37/125—Threaded inserts, e.g. "rampa bolts" the external surface of the insert being threaded
    • F16B37/127—Threaded inserts, e.g. "rampa bolts" the external surface of the insert being threaded and self-tapping

Landscapes

  • Health & Medical Sciences (AREA)
  • Orthopedic Medicine & Surgery (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Surgery (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Veterinary Medicine (AREA)
  • General Engineering & Computer Science (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Public Health (AREA)
  • General Health & Medical Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Neurology (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Geometry (AREA)
  • Dentistry (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Processing Of Stones Or Stones Resemblance Materials (AREA)

Abstract

A screw 2 with an integral, retractable drill bit 4 comprises a drive head 6 and a threaded shaft 8 extending from the drive head 6 to a screw tip 10. The threaded shaft 8 comprises an elongate hollow recess 12 extending through the interior of the threaded shaft 8 to the screw tip. The retractable drill bit 4 comprises a coupling portion 14 disposed within the elongate hollow recess 12 at the tip 10 of the screw 2 and an elongate drill shaft 16 extending from the tip 10 of the screw 2 to a drill tip 18. The drill bit 4 is coupled to the screw 2 to prevent relative rotation of the drill bit 4 and the screw 2 during drilling of a hole, such that the drill bit 4 and screw 2 are locked to rotate together when driven via the drive head 6 of the screw 2 to drill the hole. The drill bit 4 is coupled to the screw 2 to prevent retraction of the drill bit 4 into the elongate hollow recess 12 of the screw 2 during drilling of the hole but allow retraction of the drill bit 4 into the elongate hollow recess 12 of the screw 2 during screwing of the threaded shaft 8 into the hole after drilling.

Description

SCREW WITH RETRACTABLE DRILL BIT
Field of Invention
The present invention relates to a screw and more particularly to a screw with an integral, retractable drill bit.
Background of Invention
A screw is a type of fastener, typically, although not exclusively, made of metal. A screw comprises a shaft and a head disposed at one end of the shaft for driving the shaft in a rotational manner using a suitable tool. Various types of head can be provided to be driven by a range of different types of tool. The shaft is tapered to a point or tip at an opposite end to the screw head. The shaft comprises a helical ridge, known as a male or external thread, disposed along an outer surface of the shaft. A screw can be driven into a material via rotation while applying a force in a direction along the shaft from head to tip. The tip penetrates the material and the thread cuts grooves in the material pulling the screw into the material and preventing pull-out. There are many types of screw for a variety of materials and applications and for use with a variety of tools. Materials commonly fastened by screws include wood, sheet metal, and plastic. Screws are also widely used in surgical applications for fastening implant components and/or bone.
For relatively soft materials, a screw can be driven directly into the material via rotation while applying a force in a direction along the shaft from head to tip using an appropriate screw driver tool. However, it can be difficult to drive a screw directly into a very hard material. Furthermore, it can be difficult to drive a screw directly into a very brittle material without fracturing the material. In such cases, one approach is to first drill a hole into the material and then drive the screw into the drilled hole. The hole must be drilled such that its diameter is sufficiently large to allow the screw to be driven into the hole while being sufficiently small that the thread of the screw cuts into an interior side wall of the hole to ensure that the screw is firmly coupled to the material preventing pull-out.
One problem with the aforementioned approach is to ensure that the drill bit used to drill the hole is of the correct diameter, relatively to the diameter of the shaft of the screw, such that the screw can be driven into the drilled hole with the thread of the screw cutting into an interior side wall of the hole to ensure that the screw is firmly coupled to the material preventing pull-out. Often a range of drill bits of varying size will be available and a user will need to select the correct size of drill bit for the screw which is to be utilized. This selection will often be made based on visual inspection and is thus prone to error, even when a suitably sized drill bit is available to the user. In some circumstances, a user may not possess a suitably sized drill bit and thus a correct selection is impossible.
Another issue is ensuring that the hole is formed to the desired depth for a given screw. If the hole is drilled to a depth which is shorter than the length of the shaft of the screw, and the material is very hard, it may be difficult to fully drive the screw into the material after the tip of the shaft reaches the end of the hole which has been drilled. Furthermore, if the material is very brittle, driving the tip of the screw into the base of a hole can lead to fracture of the material.
Alternatively, if the hole is drilled to a depth which is significantly longer than the length of the shaft of the screw, a cavity will remain between the tip of the screw and the end of the hole after the screw has been fully inserted into the hole. This can lead to undue weakening of the material structure. Furthermore, the cavity may serve as a space for moisture, mould, or infection to develop.
Yet another problem is ensuring that the screw is correctly aligned with a drilled hole when driving the screw into the hole. Incorrect alignment of the screw while driving the screw into the hole can lead to difficulties in fully inserting the screw. Alternatively, misalignment of the screw and can lead to fracture of the material or damage to the screw.
Yet another problem is that the drilling and screwing methodology requires multiple steps involving changes of equipment. A suitable drill bit must first be selected. Then the drill bit must be mounted onto a drill and corrected locating for the drilling operation. After drilling, a suitable screw must be selected and carefully aligned with the drilled hole. A suitable screw driver must then be selected and coupled to the screw head. Care must be taken when driving the screw into the hole to ensure that the screw remains aligned with the hole during the screwing process. As such, the entire process can take some considerable time and care.
Finally, since the drill bit must be removed from the drilled hole prior to insertion of a screw, debris, for example in the form of solid or liquid contamination, may enter the drilled hole prior to insertion of the screw. This may impede the screw during insertion and screw driving and/or may be a source of moisture, mould, or infection.
It is an aim of the present invention to address the aforementioned problems. Summary of Invention According to one aspect of the invention as described herein there is provided a screw with an integral, retractable drill bit, wherein the screw comprises a drive head and a threaded shaft extending from the drive head to a screw tip, wherein the threaded shaft comprises an elongate hollow recess extending through the interior of the threaded shaft to the screw tip, wherein the retractable drill bit comprises a coupling portion disposed within the elongate hollow recess at the tip of the screw and an elongate drill shaft extending from the tip of the screw to a drill tip, wherein the drill bit is coupled to the screw to prevent relative rotation of the drill bit and the screw during drilling of a hole, such that the drill bit and screw are locked to rotate together when driven via the drive head of the screw to drill the hole, and wherein the drill bit is coupled to the screw to prevent retraction of the drill bit into the elongate hollow recess of the screw during drilling of the hole but allow retraction of the drill bit into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole after drilling.
The aforementioned configuration integrates a screw and drill bit such that the drill bit is automatically of the correct size (diameter and length) for the associated screw. The integrated structure also ensures that the drill bit and screw are in the correct aligned during both the drilling and screwing operations. As the screw is driven over the drill bit which remains in the hole during screwing, the drill bit aids to hold the screw in the correct alignment during screwing. Furthermore, since no change of tooling is required to transition between drilling and screwing, the time and complexity of the operation is significantly reduced. Further still, since the drill bit is not removed prior to insertion of the screw, there is no possibility of contaminants entering the hole between the drilling and screwing operations.
There are several possibilities for the coupling configuration between the drill bit and screw. For example, the coupling portion of the retractable drill bit may comprise one or more projections and the elongate hollow recess of the screw may comprise one or more complimentary recesses to prevent relative rotation of the drill bit and the screw during drilling of a hole, such that the drill bit and screw are locked to rotate together when driven via the drive head of the screw to drill the hole. Alternatively, the coupling portion of the retractable drill bit may comprise one or more recesses and the elongate hollow recess of the screw may comprise one or more complimentary projections to prevent relative rotation of the drill bit and the screw during drilling of a hole, such that the drill bit and screw are locked to rotate together when driven via the drive head of the screw to drill the hole. Since the integrated structure uses the same drive head on the screw for both the drilling and screwing operations, it is important to ensure that the coupling structure between the drill bit and screw is sufficiently robust to prevent relative rotation during at least the drilling step. During the screwing step the drill bit may remain coupled to the screw in order to rotate with the screw or may be freed such that the screw rotates over the drill bit as it retracts into the elongate hollow recess of the screw. That is, while the coupling must be such as to allow translational motion of the drill bit into the elongate hollow recess of the screw during screwing, the coupling may be such as to allow or prevent relative rotation motion between the two components during screwing.
The drill bit must be coupled to the screw in such a way as to prevent translational motion (retraction) of the drill bit into elongate hollow recess during the drilling step but allow translational motion (retraction) of the drill bit into elongate hollow recess during the screwing step. A number of different ways of achieving this functionality are envisaged. For example, the drill bit is coupled to the screw by one or more of: a breakable coupling which is sufficiently strong to prevent retraction of the drill bit into the elongate hollow recess of the screw during drilling but is breakable to allow retraction of the drill bit into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole after drilling; a deformable coupling which is sufficiently rigid to prevent retraction of the drill bit into the elongate hollow recess of the screw during drilling but is deformable to allow retraction of the drill bit into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole after drilling; a defined fit between an external surface of the drill bit and an internal surface of the elongate hollow recess of the screw such that at least a portion of the external surface of the drill bit and an internal surface of the elongate hollow recess of the screw are in physical contact with the fit providing sufficient force to resist retraction of the drill bit during drilling but which force can be overcome to enable the drill bit to retract into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole after drilling; a blocking part which is disposed in the elongate hollow recess of the screw to prevent retraction of the drill bit into the elongate hollow recess of the screw during drilling and which is removable from the elongate hollow recess of the screw to allow retraction of the drill bit into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole after drilling; and a screw thread coupling which runs in an opposite direction to a cutting profile of the drill bit.
Examples of breakable couplings include adhesives and 3-dimensional printed lattice structures or support structures from the manufacturing process itself (e.g. self-supporting honeycomb-type structures). The breakable coupling may be selected according to a particular application and specifically related to the hardness of the material into which the integrated drill bit and screw is to be inserted. The strength of the coupling must be sufficient to withstand the forces of the drilling operation without the drill bit retracting into the screw. After the drilling operation the coupling may be broken in a number of ways. For example, the screw head may be struck with an impactor instrument (e.g. a hammer) to break the coupling prior to the screwing operation. Alternatively, the screw may be subjected to a pulling force to break the coupling. Alternatively still, the coupling may be constructed to break when rotated in an opposite direction to that of the drilling rotation. That is, the coupling may be constructed in an asymmetric manner so that it is string when subjected to translation and rotation in a drilling direction but weak when subjected to translation and/or rotation in an opposite direction.
If a deformable, rather than breakable, coupling is provided, the deformable coupling may comprise an elastomeric structure or a mechanical latch mechanism. An elastomeric projection or ring may be provided in the elongate hollow recess of the screw which inhibits retraction of the drill bit but which can be deformed under an additional translation and/or rotation force to deform and allow the drill bit to retract. Alternative a mechanical latching mechanism can be provided. For example, a latch can be provided which locks the drill bit and screw together against the translational and rotational forces of the drilling operation but which is released when a translational and/or rotational force is applied in a different direction, e.g. by rotating the screw in an opposite direction or via a pull and/or twist release.
A defined fit can provide a press-fit force which can resist retraction during drilling but which can be overcome to allow retraction of the drill bit during screwing. The defined fit can be tailored via ribs or equivalent projections, e.g. on the interior surface of the screw. The ribs can give an indication of the depth of retraction of the drill bit by providing bumps which can be felt by an operator during retraction of the drill bit. For example, every 5 mm (or some other pitch length) an operator may feel feedback as the drill bit retracts over a rib/bump. The external surface of the drill bit and the internal surface of the elongate hollow recess of the screw may have complimentary features to provide this tactile feedback.
Alternatively still, a blocking part can be used which is disposed in the elongate hollow recess of the screw to prevent retraction of the drill bit during drilling and which is removed from the elongate hollow recess of the screw to allow retraction of the drill bit into the elongate hollow recess of the screw during screwing. In this case, the drive head of the screw can be provided with an opening to the elongate hollow recess, and the blocking part can be inserted and removed via the opening. For example, the drive head can be in the form of a socket and a rod or bolt can be inserted through the drive head down the elongate hollow recess to abut the coupling portion of the drill bit within the screw and prevent retraction of the drill bit. The blocking part may have a length which is substantially the same as the distance between the top of the drill bit and the drive head. The blocking part may be provided with an upper drive head part which is configured to couple to the drive head of the screw in such a way that it is held in position during driving of the drive head with a suitable complimentary drive tool.
The elongate hollow recess may comprise one or more elongate rails or grooves along which the coupling portion of the drill bit can slide during retraction of the drill bit into the elongate hollow recess. The elongate rails or grooves may also provide the structure by which the drill bit is prevent from rotating relative to the screw during the drilling step whilst also provide a controlled and smooth retraction of the drill bit into the elongate hollow recess during the screwing step. Furthermore, the coupling which prevents retraction of the drill bit during drilling may be provided within or between the one or more elongate rails or grooves. For example the deformable or breakable coupling.
The elongate hollow recess may further comprise one or more stoppers disposed in the elongate hollow recess to stop the drill bit when fully retracted into the elongate hollow recess. For example, if the drive head of the screw is provided with an opening to the elongate hollow recess then one or more stoppers may be provided to prevent the drill bit from fall out through such an opening in the drive head. In the arrangement where one or more elongate rails or grooves are provided within the elongate hollow recess, the one or more stoppers may be provided at the end of the one or more elongate rails or grooves at the drive head end of the screw.
The elongate drill shaft has a diameter which is smaller than a diameter of the elongate hollow recess of the screw to enable retraction of the elongate drill shaft into the elongate hollow recess. The difference in diameter may be extremely small to allow a good fit between the drill bit and the elongate hollow recess with little or no gap between an outer surface of the drill bit and an inner surface of the elongate hollow recess. However, in certain applications this may mean that the diameter of the drill bit is significantly smaller than an outer diameter of the screw. As such, the hole formed by the drill bit may be too small for the screw to be readily driven into the hole. In such a situation, the drill bit may further comprise one or more tabs or wings extending from the elongate drill shaft defining a drilling diameter which is larger than the diameter of the elongate hollow recess of the screw but smaller than an outer diameter of the threaded shaft of the screw. In this way, the elongate drill shaft can still be retracted into the screw while also enabling a hole to be formed which has a diameter larger than the diameter of the elongate hollow recess so as to be optimized for receiving the screw. In such circumstances the one or more tabs or wings can be provided at or near the drill tip. Furthermore, the screw tip can be provided with one or more cut-out portions which are complimentary to the one or more tabs/wings. The one or more cut-out portions are configured to receive the one or more tabs when the drill bit is fully retracted into the elongate hollow recess of the screw. As such, the drill bit can be fully retracted with the tabs/wings received in the cut-out portions.
The screw and drill bit can be provided/sold as a pre-constructed integrated device. Alternatively, a system comprising the screw and the drill bit car be provided, wherein the screw and drill bit are configured to be coupled together to form the screw with integral, retractable drill bit as previously described. In use, a user couples the screw and drill bit to form the integrated device prior to drilling and screwing the integrated device into a material.
While the presently described device can be used in a range of applications, surgical applications are of particular interest. Surgical applications in particular require minimal tissue damage, minimal contamination, maximum precision, and speed and ease of use in challenging surgical environments. Accordingly, a surgical apparatus is also provided comprising the screw with integral, retractable drill bit or the drill bit and screw system as previously described. The surgical apparatus may further include a surgical implant component. Such a surgical apparatus can thus be used for attaching a surgical implant component.
Brief Description of the Drawings
Embodiments of the present invention are described by way of example only with reference to the accompanying drawings in which: Figures 1(a) and 1(b) show cross-sectional views of a screw with an integral, retractable drill bit in: (a) a drilling configuration with the drill bit extending from the screw tip and coupled against retraction; and (b) in a retracted configuration after the screw has been driven over the drill bit; Figure 2 shows a perspective view of a screw with an integral, retractable drill bit including two tabs/wings extending from the drill bit at the drill tip to provide a larger diameter cutting surface optimized relative to the outer diameter of the screw; Figure 3 shows; another perspective view of the device of Figure 2 showing a drive head with an opening to the elongate hollow recess within the screw; Figure 4 shows a transparent view of the device of Figures 2 and 3 showing the coupling portion of the drill bit within the screw tip, the coupling portion having a plurality of projections which are disposed in complimentary grooves in the elongate hollow recess within the screw to hold the drill bit from rotating relative to the screw during a drilling operation; Figure 5 shows a cross-sectional view of a screw with an integral, retractable drill bit showing elongate grooves along the elongate hollow recess within the screw with the coupling portion of the drill bit having a plurality of projections which are disposed in the grooves; Figures 6(a) to 6(c) show perspective, plan, and cross-sectional views of a screw with an integral, retractable drill bit; Figures 7(a) to 7(b) show perspective and plan views of a drill bit for use in a screw with integral, retractable drill bit device; Figures 8(a) to 8(c) show perspective, plan, and cross-sectional views of a screw for use in a screw with integral, retractable drill bit device; Figures 9(a) and 9(b) show various views of a screw and drill bit system comprising a blocking part; Figures 10(a) and 10(b) show views of a screw and drill bit system in which the drill bit comprises two tabs or wings and the screw tip is provided with two cut-out portions configured to receive the tabs/wings when the drill bit is fully retracted into the screw; and Figure 11 shows a screw and drill bit system in which the drill bit is coupled to the screw by a screw thread coupling which runs in an opposite direction to a cutting profile of the drill bit.
It will be noted that corresponding reference numbers are used for corresponding parts throughout the drawings.
Detailed Description
Figures 1(a) and 1(b) show cross-sectional views of a screw 2 with an integral, retractable drill bit 4 in extended and retracted configurations respectively.
The screw 2 comprises a drive head 6 and a threaded shaft 8 extending from the drive head 6 to a screw tip 10. The threaded shaft 8 comprises an elongate hollow recess 12 extending through the interior of the threaded shaft 8 to the screw tip 10.
The retractable drill bit 4 comprises a coupling portion 14 disposed within the elongate hollow recess 12 at the tip 10 of the screw and an elongate drill shaft 16 extending from the tip 10 of the screw to a drill tip 18.
The drill bit 4 is coupled to the screw 2 to prevent relative rotation of the drill bit 4 and the screw 2 during drilling of a hole, such that the drill bit 4 and screw 2 are locked to rotate together when driven via the drive head 6 of the screw to drill the hole.
The drill bit also has a coupling 20 to the screw to prevent retraction of the drill bit 4 into the elongate hollow recess 12 of the screw 2 during drilling of the hole but allow retraction of the drill bit 4 into the elongate hollow recess 12 of the screw during screwing of the threaded shaft 8 into the hole after drilling.
As described in the summary section, the aforementioned configuration integrates a screw 2 and drill bit 4 such that the drill bit 4 is automatically of the correct size (diameter and length) for the associated screw. The integrated structure also ensures that the drill bit 4 and screw 2 are in the correct aligned during both the drilling and screwing operations. As the screw 2 is driven over the drill bit 4 which remains in the hole during screwing, the drill bit 4 aids to hold the screw in the correct alignment during screwing. Furthermore, since no change of tooling is required to transition between drilling and screwing, the time and complexity of the operation is significantly reduced. Further still, since the drill bit 4 is not removed prior to insertion of the screw 2, there is no possibility of contaminants entering the hole between the drilling and screwing operations.
As described in the summary section, the coupling 20 may be a breakable or deformable coupling to prevent translational motion (retraction) of the drill bit into elongate hollow recess during the drilling step but allow translational motion (retraction) of the drill bit into elongate hollow recess during the screwing step. Alternatively, a blocking part can be is disposed in the elongate hollow recess of the screw in the extended configuration shown in Figure 1(a) to prevent retraction of the drill bit into the elongate hollow recess of the screw during drilling. The blocking part can then be removed from the elongate hollow recess of the screw to allow retraction of the drill bit into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole as shown in Figure 1(b).
Figure 2 shows a perspective view of a screw 2 with an integral, retractable drill bit 4. The elongate drill shaft 16 has a diameter which is smaller than a diameter of the elongate hollow recess of the screw 2 to enable retraction of the elongate drill shaft 16 into the elongate hollow recess of the screw 2. The drill bit 4 further comprises two tabs or wings 22 extending from the elongate drill shaft 16 defining a drilling diameter d which is larger than the diameter of the elongate hollow recess of the screw 2 but smaller than an outer diameter of the threaded shaft 8 of the screw 2. In this way, the elongate drill shaft 16 can still be retracted into the screw 2 while also enabling a hole to be formed which has a diameter larger than the diameter of the elongate hollow recess so as to be optimized for receiving the screw 2. The two tabs or wings 22 are provided at or near the drill tip 18. Furthermore, the screw tip 10 can be provided with one or more cut-out portions which are complimentary to the tabs/wings 22. The one or more cut-out portions can be configured to receive the tabs/wings 22 when the drill bit 4 is fully retracted into the elongate hollow recess of the screw 2. As such, the drill bit 4 can be fully retracted with the tabs/wings 22 received in the cut-out portions.
Figure 3 shows; another perspective view of the device of Figure 2 showing a drive head 6 with an opening 24 to the elongate hollow recess within the screw 2. As previously described, the opening 24 can be used to insert a blocking part as a means of preventing retraction of the drill bit during drilling. Furthermore, the opening 24 can be used to remove material/debris as a result of the drilling process.
Figure 4 shows a transparent view of the device of Figures 2 and 3 showing the coupling portion 14 of the drill bit 4 within the screw tip 10. The coupling portion has a plurality of projections 26 which are disposed in complimentary grooves in the elongate hollow recess within the screw 2 to hold the drill bit 4 from rotating relative to the screw 2 during a drilling operation.
Figure 5 shows a cross-sectional view of a screw 2 with an integral, retractable drill bit 4 showing elongate grooves 28 along the elongate hollow recess 12 within the screw 2 with the coupling portion 14 of the drill bit 4 having a plurality of projections 26 which are disposed in the grooves 28. The coupling portion 14 of the drill bit 4 can slide during retraction of the drill bit 4 into the elongate hollow recess 12. The elongate grooves or flutes 28 also provide the structure by which the drill bit 4 is prevent from rotating relative to the screw 2 during the drilling step whilst also provide a controlled and smooth retraction of the drill bit 4 into the elongate hollow recess 12 during the screwing step.
The elongate hollow recess 12 further comprises stoppers 30 disposed in the elongate hollow recess to stop the drill bit 4 when fully retracted into the elongate hollow recess 12. The drive head 6 of the screw 2 is provided with an opening 24 to the elongate hollow recess and the stoppers 30 are provided to prevent the drill bit from fall out through such the opening 24 in the drive head 6. In the illustrated arrangement, the stoppers are provided by end portions of the grooves 28.
Figures 6(a) to 6(c) show perspective, plan, and cross-sectional views of a screw with an integral, retractable drill bit. The device is similar in construction and function to those previously described. Figures 7(a) to 7(b) show perspective and plan views of the drill bit component while Figures 8(a) to 8(c) show perspective, plan, and cross-sectional views of the screw component. The screw and drill bit components can be provided/sold as a pre-constructed integrated device. Alternatively, a system comprising the screw and the drill bit components can be provided. A user can then couple the screw and drill bit components to form the integrated device prior to drilling and screwing the integrated device into a material.
Figures 9(a) and 9(b) show various views of a screw and drill bit system comprising a blocking part. The blocking part system includes a pin component 30 and a socket component 32 as shown in Figure 9(a). As shown in Figure 9 (b), the pin component 30 is disposed in the elongate hollow recess of the screw 2 to prevent retraction of the drill bit 4 into the elongate hollow recess of the screw during drilling. In this regard, the drive head 6 of the screw 2 has an opening to the elongate hollow recess 12 and the pin 30 is insertable and removable via the opening. The socket component 32 fits over the pin 30 and the drive head 6 of the screw 2 to hold the pin within the screw during drilling. The socket and pin can then be removed to allow retraction of the drill bit into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole after drilling.
Figures 10(a) and 10(b) show a perspective view and a cross-sectional view of a screw and drill bit system in extended and retracted form. The drill bit 4 comprises two tabs or wings 22 extending from the elongate drill shaft 16 defining a drilling diameter d which is larger than the diameter of the elongate hollow recess of the screw 2 but smaller than an outer diameter of the threaded shaft 8 of the screw 2. In this way, the elongate drill shaft 16 can still be retracted into the screw 2 while also enabling a hole to be formed which has a diameter larger than the diameter of the elongate hollow recess so as to be optimized for receiving the screw 2. The two tabs or wings 22 are provided at or near the drill tip 18. Furthermore, the screw tip 10 is provided with two cut-out portions 34 which are complimentary to the tabs/wings 22. The two cut-out portions 34 are configured to receive the tabs/wings 22 when the drill bit 4 is fully retracted into the elongate hollow recess of the screw 2 as shown in Figure 10(b). As such, the drill bit 4 can be fully retracted with the tabs/wings 22 received in the cut-out portions.
In accordance with yet another alternative configuration, the screw is provided with a thread which is opposite to the drill bit thread. Such a configuration is shown in Figure 11. The drill bit 4 may comprise a standard right hand thread/cutting profile 36 and the screw 2 may comprise a left hand thread 38 or vice versa. In such an arrangement, the system can be drilled to depth in the normal fashion and then the drive means switched into an opposite rotational mode for the screwing step. The drill tip section digs into the material being screwed causing the drill bit 4 to retract and the screw thread 38 to engage and drive into the material. Advantageously, the threads of the drill bit 4 and screw 2 have the same or a similar pitch.
In one configuration as shown in Figure 11, a left handed thread 40 can be provided on an internal surface of the screw 2, on a top section of the drill bit 42, and on an outer surface 38 of the screw. In this way, when drilling in a normal direction (clockwise) the drill bit 4 does not retract and the left hand threads do not engage. However, once drilling is completed the drive means is reversed to an opposite direction (counter-clockwise) and then the drill bit 4 retreats back into the screw 2 at the same time as the screw engages and progress into the medium in which the screw 2 is disposed. As the drill bit retreats into the screw the left hand thread 42 on the drill bit engages with the left hand thread 40 on the interior of the screw such that the drill bit screws back into the elongate hollow recess of the screw as the left hand thread 38 on the outer surface of the screw engages and progress into the medium in which the screw 2 is disposed. The configuration could alternatively be reversed such that a right hand thread is provided on the internal surface of the screw, the top section of the drill bit, and the outer surface of the screw. In this case, a left handed drill bit cutting profile is provided and drilling is performed in an anti-clockwise (reverse) direction. This would then allow the device to be screwed in the normal direction with the drill bit retracting during screwing.
As previously described in the summary section, while the presently described device can be used in a range of applications, surgical applications are of particular interest. Surgical applications in particular require minimal tissue damage, minimal contamination, maximum precision, and speed and ease of use in challenging surgical environments. Accordingly, a surgical apparatus is also provided comprising the screw with integral, retractable drill bit or the drill bit and screw system as previously described. The surgical apparatus can include a surgical implant component. Such a surgical apparatus can thus be used for attaching a surgical implant component.
While this invention has been described above in relation to certain embodiments it will be appreciated that various alternative embodiments can be provided without departing from the scope of the invention which is defined by the appending claims.

Claims (14)

  1. Claims 1. A screw with an integral, retractable drill bit, wherein the screw comprises a drive head and a threaded shaft extending from the drive head to a screw tip, wherein the threaded shaft comprises an elongate hollow recess extending through the interior of the threaded shaft to the screw tip, wherein the retractable drill bit comprises a coupling portion disposed within the elongate hollow recess at the tip of the screw and an elongate drill shaft extending from the tip of the screw to a drill tip, wherein the drill bit is coupled to the screw to prevent relative rotation of the drill bit and the screw during drilling of a hole, such that the drill bit and screw are locked to rotate together when driven via the drive head of the screw to drill the hole, and wherein the drill bit is coupled to the screw to prevent retraction of the drill bit into the elongate hollow recess of the screw during drilling of the hole but allow retraction of the drill bit into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole after drilling.
  2. 2. A screw with an integral, retractable drill bit according to claim 1, wherein the coupling portion of the retractable drill bit comprises one or more projections and the elongate hollow recess of the screw comprises one or more complimentary recesses to prevent relative rotation of the drill bit and the screw during drilling of a hole, such that the drill bit and screw are locked to rotate together when driven via the drive head of the screw to drill the hole; or wherein the coupling portion of the retractable drill bit comprises one or more recesses and the elongate hollow recess of the screw comprises one or more complimentary projections to prevent relative rotation of the drill bit and the screw during drilling of a hole, such that the drill bit and screw are locked to rotate together when driven via the drive head of the screw to drill the hole.
  3. 3. A screw with an integral, retractable drill bit according to claim 1 or 2, wherein the drill bit is coupled to the screw by one or more of: a breakable coupling which is sufficiently strong to prevent retraction of the drill bit into the elongate hollow recess of the screw during drilling but is breakable to allow retraction of the drill bit into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole after drilling; a deformable coupling which is sufficiently rigid to prevent retraction of the drill bit into the elongate hollow recess of the screw during drilling but is deformable to allow retraction of the drill bit into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole after drilling; a defined fit between an external surface of the drill bit and an internal surface of the elongate hollow recess of the screw such that at least a portion of the external surface of the drill bit and an internal surface of the elongate hollow recess of the screw are in physical contact with the fit providing sufficient force to resist retraction of the drill bit during drilling but which force can be overcome to enable the drill bit to retract into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole after drilling; a blocking part which is disposed in the elongate hollow recess of the screw to prevent retraction of the drill bit into the elongate hollow recess of the screw during drilling and which is removable from the elongate hollow recess of the screw to allow retraction of the drill bit into the elongate hollow recess of the screw during screwing of the threaded shaft into the hole after drilling; and a screw thread coupling which runs in an opposite direction to a cutting profile of the drill bit.
  4. 4. A screw with an integral, retractable drill bit according to any preceding claim, wherein the breakable coupling comprises an adhesive or a 3D printed lattice structure.
  5. 5. A screw with an integral, retractable drill bit according to claim 3, wherein the deformable coupling comprises an elastomeric structure or a mechanical latch mechanism.
  6. 6. A screw with an integral, retractable drill bit according to claim 3, wherein the drive head of the screw has an opening to the elongate hollow recess, and the blocking part is insertable and removable via said opening.
  7. 7. A screw with an integral, retractable drill bit according to any preceding claim, wherein the elongate hollow recess comprises one or more elongate rails or grooves along which the coupling portion of the drill bit can slide during retraction of the drill bit into the elongate hollow recess.
  8. 8. A screw with an integral, retractable drill bit according to any preceding claim, wherein the elongate hollow recess comprises one or more stoppers disposed in the elongate hollow recess to stop the drill bit when fully retracted into the elongate hollow recess.
  9. 9. A screw with an integral, retractable drill bit according to any preceding claim, wherein the elongate drill shaft has a diameter which is set relative to a diameter of the elongate hollow recess of the screw to enable retraction of the elongate drill shaft into the elongate hollow recess, and wherein the drill bit further comprises one or more tabs extending from the elongate drill shaft defining a drilling diameter which is larger than the diameter of the elongate hollow recess of the screw but smaller than an outer diameter of the threaded shaft of the screw.
  10. 10. A screw with an integral, retractable drill bit according to claim 9, wherein the screw tip has one or more cut-out portions which are complimentary to the one or more tabs extending from the elongate drill shaft and configured to receive the one or more tabs when the drill bit is fully retracted into the elongate hollow recess of the screw.
  11. 11. A system comprising a screw and a drill bit, wherein the screw and drill bit are configured to be coupled together to form the screw with integral, retractable drill bit according to any preceding claim.
  12. 12. A surgical apparatus comprising the screw with integral, retractable drill bit according to any one or claims 1 to 10 or the system of claim 11.
  13. 13. A surgical apparatus according to claim 12, wherein the surgical apparatus includes a surgical implant component.
  14. 14. Use of the screw with integral, retractable drill bit according to any one of claims 1 to 10 for attaching a surgical implant component.
GB1900186.6A 2019-01-07 2019-01-07 Screw with retractable drill bit Withdrawn GB2580372A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1900186.6A GB2580372A (en) 2019-01-07 2019-01-07 Screw with retractable drill bit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1900186.6A GB2580372A (en) 2019-01-07 2019-01-07 Screw with retractable drill bit

Publications (1)

Publication Number Publication Date
GB2580372A true GB2580372A (en) 2020-07-22

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GB1900186.6A Withdrawn GB2580372A (en) 2019-01-07 2019-01-07 Screw with retractable drill bit

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114098892A (en) * 2021-12-09 2022-03-01 北京大学第三医院（北京大学第三临床医学院） Integrated screw rod for drilling and nail placing, electric drill and method

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080166205A1 (en) * 2006-08-31 2008-07-10 Shu-Yun Chuang Fastener with removable element
DE202018103106U1 (en) * 2018-06-04 2018-07-02 Asc & Cawi Kalt- Und Umformtechnik Gmbh Bohrschraube

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080166205A1 (en) * 2006-08-31 2008-07-10 Shu-Yun Chuang Fastener with removable element
DE202018103106U1 (en) * 2018-06-04 2018-07-02 Asc & Cawi Kalt- Und Umformtechnik Gmbh Bohrschraube

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114098892A (en) * 2021-12-09 2022-03-01 北京大学第三医院（北京大学第三临床医学院） Integrated screw rod for drilling and nail placing, electric drill and method
CN114098892B (en) * 2021-12-09 2024-05-03 北京大学第三医院（北京大学第三临床医学院） Integrated screw rod for drilling and nailing, electric drill and method

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