GB2310700A - Drill screw with plug - Google Patents

Drill screw with plug Download PDF

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Publication number
GB2310700A
GB2310700A GB9604402A GB9604402A GB2310700A GB 2310700 A GB2310700 A GB 2310700A GB 9604402 A GB9604402 A GB 9604402A GB 9604402 A GB9604402 A GB 9604402A GB 2310700 A GB2310700 A GB 2310700A
Authority
GB
United Kingdom
Prior art keywords
plug
fixing
head
threaded
shank
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Withdrawn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
GB9604402A
Other versions
GB9604402D0 (en
Inventor
Anthony Morrish
Original Assignee
Anthony Morrish
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 Anthony Morrish filed Critical Anthony Morrish
Priority to GB9604402A priority Critical patent/GB2310700A/en
Publication of GB9604402D0 publication Critical patent/GB9604402D0/en
Publication of GB2310700A publication Critical patent/GB2310700A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16BDEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS, WEDGES, JOINTS OR JOINTING
    • F16B13/00Dowels or other devices fastened in walls or the like by inserting them in holes made therein for that purpose
    • F16B13/002Dowels or other devices fastened in walls or the like by inserting them in holes made therein for that purpose self-cutting

Abstract

A fixing 10 for a solid or cavity wall comprises a drill screw 12 including a drill tip 16, an elongate shank 14 and a head 17 for engagement with a rotatable driver, and a fitted plug 30. The shank 14 has a plain portion 22 and a threaded portion 21 extending from the head 17 midway down the shank 14. The plug 30 is tubular and slotted for assembly onto the plain portion 22 of the shank 14 and has a circumferential flange 34 having an outer diameter greater than that of the drill tip 16. Helical slots 36 in the plug allow drill debris to pass back out of a bore 112 during drilling. In use the circumferential flange 34 abuts the outer surface of a wall 110 and on further drilling the threaded portion 21 engages with the plug 30 which expands into engagement with the bore 112. Articles may be clamped under the head 17, or secured by means of a threaded counterbore provided in the head 17.

Description

SELF LOCATING FIXING The present invention relates to a self locating fixing, particularly but not exclusively a fixing which is intended for use in combination with a powered driver. The fixing is particularly suitable for masonry, concrete, rock and other very hard materials.

Fixings such as threaded screws are commonly used for holding objects on hard surfaces such as brick, concrete, breeze block or rock and the like. In order to retain a threaded screw in such material, it is necessary to predrill a hole larger than the external diameter of the screw, insert a plug made of plastics or fibrous material into the hole, and finally to insert the screw into the plug, which forces the plug radially outwardly and binds the plug against the sidewall of the hole. Such steps are time consuming since they require the use of several tools and there is the possibility of loss of the loose parts. These disadvantages are especially acute when working in an awkward environment, such as up a ladder.

It is thus an object of this invention to provide a fixing which can be attached more easily than the conventional kind.

According to the invention there is provided a fixing comprising a drill screw and a plug, the drill screw having a drill tip, an elongate shank and a head for engagement in use with a rotatable driver, the shank having a plain portion adjacent the tip and a threaded portion proximal thereof, the plug being provided about the plain portion and said tip having a greater radial extent than the plug, and the plug being adapted for internal engagement by the threaded portion in use, whereby the outer periphery of the plug is urged outwardly.

In use, the tip drills a hole into a substrate, into which hole the plug will pass. When the plug is internally engaged by the threaded portion, the outer periphery of the plug is urged outwardly to grip the sidewall of the hole.

The plug may be tubular, and preferably is cylindrical. The plain portion of the shank may be longer than the plug and is preferably of circular cross-section.

The threaded portion is preferably substantially the same length as the plug and in the preferred embodiment is immediately adjacent the head.

The plug may include a lateral projection at the end thereof nearest the head; the projection is preferably a circular flange. The plug may include an external helical slot along the length thereof which may extend through the plug to the interior thereof. The helical slot is advantageous as it allows drilling debris to be expelled from the hole, and provides a degree of resilience and deformability to the plug.

The plug may be made of plastics or fibrous material.

Articles may be attached by means of a slot or slotted hole engaged under the head of the fixing.

A fixing may be provided in combination with an article to be fixed to a substrate; the fixing being assembled in an aperture smaller than the radial extent of the head so that the article may be fixed directly to the substrate as the hole is drilled.

A preferred specific embodiment of a fixing according to the invention will now be described by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a somewhat schematic side elevation of a fixing according to the invention prior to installation; Figure 2 shows a partial axial cross-section of the fixing of Figure 1 as installed in a cavity wall; Figure 3 shows a partial axial cross-section of the fixing of Figure 2 as installed in a solid wall and Figure 4 shows a side elevation of a drill screw of the fixing according to Figure 1.

Referring to Figure 1, a fixing 10 comprises a drill screw 12 and a plug 30. The drill screw 12 (which is illustrated without a plug 30 in Figure 4) comprises an elongate shank 14 of circular cross section, having at one end a drill tip 16 and at the other end a head 17. The drill tip 16 may be of any suitable kind; as illustrated the drill tip 16 comprises a conical head having an axial groove 18 for transportation of debris and a cutting edge 19, on the groove, defined by a tungsten carbide insert. The shank 14 has diameter substantially smaller than the diameter of the drill tip 16 and hence the bore which would be cut in a substrate by the tip. The head 17 is coaxial with the shank 14 and of any suitable form, for example with a slot 20.

The head 17 is larger in diameter than the drill tip 16.

A helically threaded portion 21 of the shank 14 extends from the head end of the shank 14 to approximately the midpoint thereof. The remaining portion 22 of the shank 14 is plain. The major diameter of the threaded portion 21 is smaller than that of the drill tip 16, but larger than that of the plain portion 22.

The plug 30 is tubular and slotted for assembly onto plain portion of the shank 14. The internal diameter of the plug 30 is approximately the same as that of the plain portion 22 of the shank 14, the outer diameter being slightly smaller than that of the drill tip 16. The outer circumferential surface of the plug 30 defines a gripping surface 32 which have some surface pattern to aid purchase against the bore sidewall in use. The plug 30 is about half the length of the shank 14 as illustrated. At the outer end of the plug 30 there is a circumferential flange 34, having an outer diameter greater than that of the drill tip 16.

The plug 30 has two helical through-slots 36 extending along the length thereof.

The plug 30 is adapted for engagement in use by the threaded portion 22, in which case the external diameter will increase to become greater than that of the drill tip 16. Whilst allowing for such deformation, the plug 30 can be made of any inexpensive and suitably deformable material such as polythene or a fibrous material.

Figure 2 demonstrates use of the fixing 10 in a cavity wall 100. In order to install the fixing 10, the head 17 is engaged by means of the slot 20 with a rotational driver (not shown). The drill screw 12 is rotated rapidly by means of the driver, and a bore 102 is drilled into the cavity wall 100 by means of the drill tip 16. Debris caused by drilling is passed back via the helical slots 36 in the plug 30. Eventually, the drill tip 16 penetrates through the cavity wall 100 creating a throughbore 102. The fixing 10 is pushed through to enter the throughbore 102 as far as is permitted by the flange 32. Further rotation of the drill screw 12 causes the threaded portion 21 to engage the plug 30; the consequent deformation of the plug 30 causes the gripping surface 32 to engage the sidewall to give a secure fixing.

Figure 3 shows the fixing as described above installed in a solid substrate 110. As in Figure 2, the drill screw 12 is rotated by means of a driver. However, in this case, the drill tip 16 cuts a blind bore 112. Initially, as in Figure 2, drill debris is passed back and out of the bore via the helical slots 36. As the bore 112 is lengthened, eventually the circumferential rib 34 of the plug 30 abuts the outer face of the wall 110. Further drilling causes the threaded portion 21 to engage with the plug 30. The plug 30 is deformed and engages the bore securely as described above.

The fixing 10 described above can be installed, as described, without the need to change hand tools during installation. There is no risk of losing parts.

Articles may be secured under the head 17 and retained in the usual way. The head of the screw may also itself constitute a fixing, for example by means of a threaded counterbore.

The foregoing is a description of a preferred embodiment only. The proportions and materials of the fixing may be changed to suit circumstances and are not limited to those described herein.

Claims (14)

CLAIMS:
1. A fixing comprising a drill screw and a plug, the drill screw having a drill tip, an elongate shank and a head for engagement in use with a rotatable driver, the shank having a plain portion adjacent the tip and a threaded portion proximal thereof, the plug being provided about the plain portion and said tip having a greater radial extent than the plug, and the plug being adapted for internal engagement by the threaded portion in use whereby the outer periphery of the plug is urged outwardly.
2. The fixing of Claim 1 wherein the plug is tubular.
3. A fixing according to Claim 1 or Claim 2 wherein the plug is cylindrical.
4. A fixing according to any preceding claim wherein the plain portion is longer than said plug.
5. A fixing according to any preceding claim wherein the plain portion is of circular cross section.
6. A fixing according to any preceding claim wherein the threaded portion is substantially the same length as said plug.
7. A fixing according to any preceding claim wherein the threaded portion is immediately adjacent said head.
8. A fixing according to any preceding claim wherein said plug includes a lateral projection at the end thereof nearest said head.
9. A fixing according to Claim 8 wherein said projection is a circular flange.
10. A fixing according to Claim 8 or Claim 9 wherein said plug includes an external helical slot along the length thereof.
11. A fixing according to Claim 10 wherein said slot extends through the plug to the interior thereof.
12. The fixing of any preceding claim wherein the plug is made of plastics material.
13. The fixing of any one of Claims 1 to 11 wherein the plug is made of fibrous material.
14. A fixing substantially as described herein with reference to the drawings appended hereto.
GB9604402A 1996-03-01 1996-03-01 Drill screw with plug Withdrawn GB2310700A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9604402A GB2310700A (en) 1996-03-01 1996-03-01 Drill screw with plug

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9604402A GB2310700A (en) 1996-03-01 1996-03-01 Drill screw with plug

Publications (2)

Publication Number Publication Date
GB9604402D0 GB9604402D0 (en) 1996-05-01
GB2310700A true GB2310700A (en) 1997-09-03

Family

ID=10789696

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9604402A Withdrawn GB2310700A (en) 1996-03-01 1996-03-01 Drill screw with plug

Country Status (1)

Country Link
GB (1) GB2310700A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1688628A1 (en) * 2005-02-04 2006-08-09 Günther Hartl Threaded expansion dowel

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3851560A (en) * 1972-10-02 1974-12-03 Deane C Self-drilling expansion roof bolt
US5190425A (en) * 1991-10-21 1993-03-02 Illinois Tool Works Inc. Anchor
US5297909A (en) * 1993-04-13 1994-03-29 Tsay Leu Wen Self-drilling expansion drill

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3851560A (en) * 1972-10-02 1974-12-03 Deane C Self-drilling expansion roof bolt
US5190425A (en) * 1991-10-21 1993-03-02 Illinois Tool Works Inc. Anchor
US5297909A (en) * 1993-04-13 1994-03-29 Tsay Leu Wen Self-drilling expansion drill

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1688628A1 (en) * 2005-02-04 2006-08-09 Günther Hartl Threaded expansion dowel

Also Published As

Publication number Publication date
GB9604402D0 (en) 1996-05-01

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Legal Events

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)