GB2227540A - Self-countersinking screws - Google Patents

Self-countersinking screws Download PDF

Info

Publication number
GB2227540A
GB2227540A GB8927599A GB8927599A GB2227540A GB 2227540 A GB2227540 A GB 2227540A GB 8927599 A GB8927599 A GB 8927599A GB 8927599 A GB8927599 A GB 8927599A GB 2227540 A GB2227540 A GB 2227540A
Authority
GB
United Kingdom
Prior art keywords
screw
screw fastener
fastener according
head
tapered face
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Withdrawn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
GB8927599A
Other versions
GB8927599D0 (en
Inventor
David Ian Quarmby
Original Assignee
David Ian Quarmby
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
Priority to GB898901659A priority Critical patent/GB8901659D0/en
Application filed by David Ian Quarmby filed Critical David Ian Quarmby
Publication of GB8927599D0 publication Critical patent/GB8927599D0/en
Publication of GB2227540A publication Critical patent/GB2227540A/en
Application status is Withdrawn legal-status Critical

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
    • F16B35/00Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws
    • F16B35/04Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws with specially-shaped head or shaft in order to fix the bolt on or in an object
    • F16B35/06Specially-shaped heads
    • F16B35/065Specially-shaped heads with self-countersink-cutting means

Abstract

A screw is provided with material removing formations 17, 32, 46 or 64 so that it is self-countersinking. Other formations are shown. <IMAGE>

Description

Improvements in or Relating to Screw Fasteners The present invention relates to screw fasteners of the kind having a screw-threaded shank terminating at one end in a head by means of which the fastener is driven into position.

An example of a screw fastener of this kind is a wood screw of which the head is normally of a generally conical shape tapering towards the shank from an end face which is slotted to receive screwdriver hlad. Stch crews may Se countersunk by providing the mouth of the receiving hole in the wood with a conical enlargement in which the screw head seats to lie flush with the wood surface. Alternatively, a deeper recess ray be provided so that the screw head is located below the surface and can be covered by a plug. In either case, countersinking requires a preliminary operation involving a special tool.

It is an object of the present invention to provide an improved screw fastener which is capable of self countersinking.

According to the invention there is provided a screw fastener of the kind set out above wherein the head is provided with material-removing means such that the fastener forms its own countersinking recess as it is driven into position.

Preferrably, the material-removing means comprises one orCf cutting edges formed on the tapered face of the head. Such cutting edges may be provided by grooves, steps, ridges, teeth or flutings for example. Helical grooves will assist in removing cut material from the cutting zone.

Preferred embodiments of self-countersinking screw according to the invention will now be described, with referrence to the accompanying drawings, wherein: Fig. 1 is a side elevation of the head of a first embodiment of screw according to the invention; Fig. 2 is a sectional view of the screw of Fig. 1, taken through the shank looking towards the head, and showing the conical face of the head; Fig. 3 illustrates two uses of the screw; Fig. 4 is a view of the screw head of Fig. 1, from the right in Fig. 1; Fig. 5 is a similar view to Fig. 1, but showing the disposition of both cutting edges; Fig. 6 is a view similar to Fig. 2, but with four cutting edges; Fig. 7 is a view similar to Fig. 1 and Fig. 8 a view similar to Fig. 2 of a third embodiment of screw according to the invention; Fig. 9 is a view similar to Fig. 1 of a fourth embodiment of screw according to the invention;; Fig. 10 is a view similar to Fig. 1 and Fig. 11 a view similar to Fig. 2 of a fifth embodiment of screw according to the invention; Fig. 12 is a view similar to Fig. 1 and Fig. 13 a view similar to Fig. 2 of a sixth embodiment of screw according to the invention; Fig. 14 is a view similat to Fig. 1 of a seventh embodiment of screw according to the invention; and Fig. 15 is a view similar to Fig. 2, and Fig. 16 a perspective view of the head of an eigth embodiment of screw according to the invention.

Refering first to the embodiment shown in Figs. 1 to 5, a wood screw 10 has a conical head 11 on the end of a screw threaded shank 12, and an end face 13 has a screw-driver engagement slot 14. In accordance with the invent5oi' the conical sloping face of the head 11 is provided with cutting means in the form of a pair of steps 15, 16 at diametrically opposite sides of the head, which each provide a lip or cutting edge 17, and may be regarded as teeth. Fig. 2 shows that the steps are tangential to the shank, and they slope relative to the axis of the screw, so that loosened material is directed up out of the bore, as the screw is rotated. Fig. 4 shows the face of step 15, and the reverse slope of step 16.

In Fig. 3, two applications are shown. To the right, a screw 10 is normally countersunk, with the end face 13 flush with the top surface 18 of the wood. To the left, another screw lOis received in a deeper recess 19, which may be closed by a plug 20. In the prior art, counter-sinking, and provision of recessed bores had to be done with a special tool prior to driving the screw. Using the screw 10 according to the invention, however, this requirement is eliminated, as the screw is self countersinking, and can be driven to any required depth.

The remaining Figures of the drawings illustrate a plurality of possible alternative embodiments. Thus in Fig. 6, a screw is shown very similar to screw 10, except that it has four radially extending and angularly equispaced steps 21, 22, 23, 24 with respective cutting edges 25, 26, 27, and 28.

Figs. 7 and 8 illustrate a screw 30 with flutings 31 with ridges 32 between the flutings which provide the cutting edges. In Fig. 9, a screw 40 has inclined ridges 41, and in Figs. 10. 11, a screw 45 has a large number of protrusions or nobs 46 formed on the conical surface 47 of the head. These may be provided by sintering particles of a cutting or abrasive material such as carborundum to the surface 47, or metallic bonding of metal shavings to the surface. With an appropriate choice of particle composition, the screw may be made to be capable of self-countersinking in harder materials such as metals or certain plastics or composite materials.

Figs. 12 and 13 show a screw 50 provided with helical flutings 51, with ridges 52 between which provide the cutting edges. In Fig. 14, a screw head 55 has helical grooves 56, separated by lands 57. The lips of the grooves form the cutting edges. The grooves provide an escape channel for removal of material pulverised by the action of the cutting edges.

Finally, Figs. 15 and 16 show a screw 60 with a head 61 with a generally square end face 62, the head being frustopyramidical in shape, and the edges 63, 64, 65., and 66 providing the cutting edges.

Other polygonal shapes, especially hexagonal and octagonal may be provided.

The slope of the conical face may be about 450 as in a conventional screw, but it is preferred that the angle should be in the order of 55 , e.g. from 50 to 600, as in Fig, 12. This makes it possible to accommodate a deep-cut cross slot for a Philips screw driver, and the flutings or cutting edges can be moe easily rrfssfd out.

When the cutting edge is helical, boring is aided by removal of material along the step (Figs. 1-5) or the flutings (Fig. 12), or grooves (Fig. 14). The cutting edge has a shearing action on the material and not simply a reaming or scraping action.

It will be appreciated that the cutting edges and projections, grooves etc. described above are material removing means within the scope of the present invention, and that alternative means of this kind may be provided.

Although the invention has been largely described in relation to wood screws, it will be understood that it is equally applicable to other screw fasteners, for use in other materials, e.g. for metal when made of an appropriately hard material.

Claims (1)

  1. Claims
    1. A screw fastener having a generally tapered head with an end face and a tapered face, wherein the head is provided with material removing means such that the fastener is self countersinking as it is driven into position.
    2. A screw fastener according to Claim 1, wherein the material removing means comprises one or more cutting edges formed on the tapered face of the head.
    3. A screw fastener according to Claim 2, wherein the cutting edge or edges are provided by one or more teeth or projections.
    4. A screw fastener according to Claim 2, wherein the cutting edges are provided by a pair of diametrically opposite steps formed in the head.
    5. A screw fastener according to Claim 4 wherein there are four such steps.
    6. A screw fastener according to Claim 5 wherein the steps extend radially from the axis of the screw.
    7. A screw fastener according to Claim 4 or 5 wherein the steps are tangential to the shank of the screw.
    8. A screw fastener according to Claim 2 wherein the cutting edges are ridges between flutings formed in the tapered face of the screw head.
    9. A screw fastener according to Claim 8 wherein the flutings are helical.
    10. A screw fastener according to Claim 3 wherein projections are in the form of nobs or pimples formed on the tapered face.
    11. A screw fastener according to Claim 10 wherein the nobs or pimples comprise particles of a cutting or abrasive material sintered or otherwise bonded to the tapered face.
    12, A screw fastener according to Claim 2, wherein the tapered face is formed with helical grooves, the lips of which provide cutting edges.
    14. A screw fastener according to Claim 2 or 3, wherein t the head is pyramidical, of square cross-section, and the inclined edges of which provide the cutting edges.
    15. A screw fastener according to any one of Claims 1 to 13 wherein the tapered face is conical.
    16. A self-countersinking screw fastener substantially as hereinbefore described, with reference to and as illustrated in any of the accompanying drawings.
GB8927599A 1989-01-27 1989-12-06 Self-countersinking screws Withdrawn GB2227540A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB898901659A GB8901659D0 (en) 1989-01-27 1989-01-27 Improvements in or relating to screw fasteners

Publications (2)

Publication Number Publication Date
GB8927599D0 GB8927599D0 (en) 1990-02-07
GB2227540A true GB2227540A (en) 1990-08-01

Family

ID=10650600

Family Applications (2)

Application Number Title Priority Date Filing Date
GB898901659A Pending GB8901659D0 (en) 1989-01-27 1989-01-27 Improvements in or relating to screw fasteners
GB8927599A Withdrawn GB2227540A (en) 1989-01-27 1989-12-06 Self-countersinking screws

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB898901659A Pending GB8901659D0 (en) 1989-01-27 1989-01-27 Improvements in or relating to screw fasteners

Country Status (1)

Country Link
GB (2) GB8901659D0 (en)

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4019157C1 (en) * 1990-06-15 1992-01-30 Sfs Stadler Holding Ag, Heerbrugg, Ch
DE9202650U1 (en) * 1992-02-28 1993-07-01 Schraubenwerk Tambach Gmbh, O-5809 Tambach-Dietharz, De
WO1996038676A1 (en) * 1995-05-29 1996-12-05 Ejot Verbindungstechnik Gmbh & Co. Kg Countersunk head screw
GB2314133A (en) * 1996-06-13 1997-12-17 Chao Hsin Yu Self-countersinking screw
GB2358688A (en) * 2000-01-26 2001-08-01 Martin James Killeavy Self countersinking woodscrew
US6302631B1 (en) * 1999-09-21 2001-10-16 Seiichiro Takasaki Wood screw having a head with side ridges
GB2382854A (en) * 2001-12-05 2003-06-11 Terry Gell Countersink screw
DE102006023708B3 (en) * 2006-05-19 2007-10-18 Ludwig Hettich & Co. Countersunk head screw for fastening e.g. wood, has cylindrical shank, and conical countersunk head with two edges provided at lower side, where edges mark end of partial surfaces lying on lower side
WO2010088647A1 (en) * 2009-02-02 2010-08-05 The Boeing Company Fastener relief path
EP2317159A1 (en) * 2009-10-28 2011-05-04 SPAX International GmbH & Co. KG Screw, in particular for fibre boards connected by cement
EP2522865A1 (en) * 2011-05-12 2012-11-14 Berner Trading Holding GmbH Countersunk head screw
EP2546533A1 (en) * 2011-07-12 2013-01-16 Yih Shwei Bolt Industrial Co., Ltd. Screw
WO2013170180A1 (en) * 2012-05-10 2013-11-14 Simpson Strong-Tie Company, Inc. Fastener with multiple threaded regions
US8945232B2 (en) 2012-12-31 2015-02-03 Wright Medical Technology, Inc. Ball and socket implants for correction of hammer toes and claw toes
US9044287B2 (en) 2010-06-02 2015-06-02 Wright Medical Technology, Inc. Hammer toe implant method
US9474561B2 (en) 2013-11-19 2016-10-25 Wright Medical Technology, Inc. Two-wire technique for installing hammertoe implant
US9498266B2 (en) 2014-02-12 2016-11-22 Wright Medical Technology, Inc. Intramedullary implant, system, and method for inserting an implant into a bone
US9498273B2 (en) 2010-06-02 2016-11-22 Wright Medical Technology, Inc. Orthopedic implant kit
US9523383B2 (en) 2013-03-26 2016-12-20 Simpson Strong-Tie Company, Inc. Variable thread fastener
US9545274B2 (en) 2014-02-12 2017-01-17 Wright Medical Technology, Inc. Intramedullary implant, system, and method for inserting an implant into a bone
US9603643B2 (en) 2010-06-02 2017-03-28 Wright Medical Technology, Inc. Hammer toe implant with expansion portion for retrograde approach
US9724139B2 (en) 2013-10-01 2017-08-08 Wright Medical Technology, Inc. Hammer toe implant and method
US9724140B2 (en) 2010-06-02 2017-08-08 Wright Medical Technology, Inc. Tapered, cylindrical cruciform hammer toe implant and method
US9808296B2 (en) 2014-09-18 2017-11-07 Wright Medical Technology, Inc. Hammertoe implant and instrument
US10080597B2 (en) 2014-12-19 2018-09-25 Wright Medical Technology, Inc. Intramedullary anchor for interphalangeal arthrodesis

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB602614A (en) * 1945-08-10 1948-05-31 Mark Bryan Improvements in or relating to screws
GB972653A (en) * 1960-05-31 1964-10-14 Maxwell Seely Woosnam Improvements in or relating to fixing screws
GB1120844A (en) * 1965-07-22 1968-07-24 James Henry Thomas Harrington Improvements in screws
US3903784A (en) * 1972-01-03 1975-09-09 Anchor Bolt And Screw Company Self-countersinking fastener head
US3916757A (en) * 1973-10-30 1975-11-04 Illinois Tool Works Fasteners
DE3201034A1 (en) * 1982-01-15 1983-07-28 Usto Aufzuege U Schallschutzan Self-counter sinking screw
DE3217684A1 (en) * 1982-04-14 1983-10-27 Klaus Schlagkamp Countersunk wood screw
DE3344048A1 (en) * 1982-12-09 1984-06-14 Shinjo Seisakusho Yk Screw with countersink cutters
EP0268961A1 (en) * 1986-11-22 1988-06-01 Peri-Werk Artur Schwörer GmbH &amp; Co.KG Countersunk head screw
GB2210428A (en) * 1987-11-05 1989-06-07 George Nicholas Pillans The self-countersingking screw

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB602614A (en) * 1945-08-10 1948-05-31 Mark Bryan Improvements in or relating to screws
GB972653A (en) * 1960-05-31 1964-10-14 Maxwell Seely Woosnam Improvements in or relating to fixing screws
GB1120844A (en) * 1965-07-22 1968-07-24 James Henry Thomas Harrington Improvements in screws
US3903784A (en) * 1972-01-03 1975-09-09 Anchor Bolt And Screw Company Self-countersinking fastener head
US3916757A (en) * 1973-10-30 1975-11-04 Illinois Tool Works Fasteners
DE3201034A1 (en) * 1982-01-15 1983-07-28 Usto Aufzuege U Schallschutzan Self-counter sinking screw
DE3217684A1 (en) * 1982-04-14 1983-10-27 Klaus Schlagkamp Countersunk wood screw
DE3344048A1 (en) * 1982-12-09 1984-06-14 Shinjo Seisakusho Yk Screw with countersink cutters
EP0268961A1 (en) * 1986-11-22 1988-06-01 Peri-Werk Artur Schwörer GmbH &amp; Co.KG Countersunk head screw
GB2210428A (en) * 1987-11-05 1989-06-07 George Nicholas Pillans The self-countersingking screw

Cited By (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4019157C1 (en) * 1990-06-15 1992-01-30 Sfs Stadler Holding Ag, Heerbrugg, Ch
DE9202650U1 (en) * 1992-02-28 1993-07-01 Schraubenwerk Tambach Gmbh, O-5809 Tambach-Dietharz, De
WO1996038676A1 (en) * 1995-05-29 1996-12-05 Ejot Verbindungstechnik Gmbh & Co. Kg Countersunk head screw
GB2314133A (en) * 1996-06-13 1997-12-17 Chao Hsin Yu Self-countersinking screw
GB2314133B (en) * 1996-06-13 1998-03-11 Chao Hsin Yu Countersunk screws
US6302631B1 (en) * 1999-09-21 2001-10-16 Seiichiro Takasaki Wood screw having a head with side ridges
GB2358688A (en) * 2000-01-26 2001-08-01 Martin James Killeavy Self countersinking woodscrew
GB2382854A (en) * 2001-12-05 2003-06-11 Terry Gell Countersink screw
DE102006023708B3 (en) * 2006-05-19 2007-10-18 Ludwig Hettich & Co. Countersunk head screw for fastening e.g. wood, has cylindrical shank, and conical countersunk head with two edges provided at lower side, where edges mark end of partial surfaces lying on lower side
WO2007134679A1 (en) 2006-05-19 2007-11-29 Ludwig Hettich & Co. Countersunk head screw
US8231320B2 (en) 2006-05-19 2012-07-31 Ludwig Hettich & Company Countersunk head screw
US8146230B2 (en) 2009-02-02 2012-04-03 The Boeing Company Method of reducing pressuing during installation of a fastener
WO2010088647A1 (en) * 2009-02-02 2010-08-05 The Boeing Company Fastener relief path
CN102052374A (en) * 2009-10-28 2011-05-11 Spax国际两合公司 Screw in particular for fibre board connected with cement
EP2317159A1 (en) * 2009-10-28 2011-05-04 SPAX International GmbH & Co. KG Screw, in particular for fibre boards connected by cement
US9949775B2 (en) 2010-06-02 2018-04-24 Wright Medical Technology, Inc. Hammer toe implant with expansion portion for retrograde approach
US9877753B2 (en) 2010-06-02 2018-01-30 Wright Medical Technology, Inc. Orthopedic implant kit
US9724140B2 (en) 2010-06-02 2017-08-08 Wright Medical Technology, Inc. Tapered, cylindrical cruciform hammer toe implant and method
US9603643B2 (en) 2010-06-02 2017-03-28 Wright Medical Technology, Inc. Hammer toe implant with expansion portion for retrograde approach
US9498273B2 (en) 2010-06-02 2016-11-22 Wright Medical Technology, Inc. Orthopedic implant kit
US9072564B2 (en) 2010-06-02 2015-07-07 Wright Medical Technology, Inc. Hammer toe implant and method
US9044287B2 (en) 2010-06-02 2015-06-02 Wright Medical Technology, Inc. Hammer toe implant method
EP2522865A1 (en) * 2011-05-12 2012-11-14 Berner Trading Holding GmbH Countersunk head screw
JP2013019536A (en) * 2011-07-12 2013-01-31 Yih Shwei Bolt Industrial Co Ltd screw
EP2546533A1 (en) * 2011-07-12 2013-01-16 Yih Shwei Bolt Industrial Co., Ltd. Screw
US9482258B2 (en) 2012-05-10 2016-11-01 Simpson Strong-Tie Company, Inc. Fastener with multiple threaded regions
WO2013170180A1 (en) * 2012-05-10 2013-11-14 Simpson Strong-Tie Company, Inc. Fastener with multiple threaded regions
AU2013259288B2 (en) * 2012-05-10 2017-03-09 Simpson Strong-Tie Company, Inc. Fastener with multiple threaded regions
US8945232B2 (en) 2012-12-31 2015-02-03 Wright Medical Technology, Inc. Ball and socket implants for correction of hammer toes and claw toes
US9504582B2 (en) 2012-12-31 2016-11-29 Wright Medical Technology, Inc. Ball and socket implants for correction of hammer toes and claw toes
US10278828B2 (en) 2012-12-31 2019-05-07 Wright Medical Technology, Inc. Ball and socket implants for correction of hammer toes and claw toes
US9523383B2 (en) 2013-03-26 2016-12-20 Simpson Strong-Tie Company, Inc. Variable thread fastener
US9724139B2 (en) 2013-10-01 2017-08-08 Wright Medical Technology, Inc. Hammer toe implant and method
US9675392B2 (en) 2013-11-19 2017-06-13 Wright Medical Technology, Inc. Two-wire technique for installing hammertoe implant
US9474561B2 (en) 2013-11-19 2016-10-25 Wright Medical Technology, Inc. Two-wire technique for installing hammertoe implant
US9545274B2 (en) 2014-02-12 2017-01-17 Wright Medical Technology, Inc. Intramedullary implant, system, and method for inserting an implant into a bone
US9498266B2 (en) 2014-02-12 2016-11-22 Wright Medical Technology, Inc. Intramedullary implant, system, and method for inserting an implant into a bone
US9808296B2 (en) 2014-09-18 2017-11-07 Wright Medical Technology, Inc. Hammertoe implant and instrument
US10299840B2 (en) 2014-09-18 2019-05-28 Wright Medical Technology, Inc. Hammertoe implant and instrument
US10080597B2 (en) 2014-12-19 2018-09-25 Wright Medical Technology, Inc. Intramedullary anchor for interphalangeal arthrodesis

Also Published As

Publication number Publication date
GB8927599D0 (en) 1990-02-07
GB8901659D0 (en) 1989-03-15

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