CA1142000A - Self-drilling, self-tapping fastener - Google Patents

Self-drilling, self-tapping fastener

Info

Publication number
CA1142000A
CA1142000A CA000372182A CA372182A CA1142000A CA 1142000 A CA1142000 A CA 1142000A CA 000372182 A CA000372182 A CA 000372182A CA 372182 A CA372182 A CA 372182A CA 1142000 A CA1142000 A CA 1142000A
Authority
CA
Canada
Prior art keywords
self
conical segment
drilling
segment
flat side
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.)
Expired
Application number
CA000372182A
Other languages
French (fr)
Inventor
John E. Bettini
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.)
Illinois Tool Works Inc
Original Assignee
Illinois Tool Works Inc
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 Illinois Tool Works Inc filed Critical Illinois Tool Works Inc
Application granted granted Critical
Publication of CA1142000A publication Critical patent/CA1142000A/en
Expired 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 OR WEDGES; JOINTS OR JOINTING
    • F16B25/00Screws that cut thread in the body into which they are screwed, e.g. wood screws
    • F16B25/0036Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw
    • F16B25/0084Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw characterised by geometric details of the tip
    • 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 OR WEDGES; JOINTS OR JOINTING
    • F16B25/00Screws that cut thread in the body into which they are screwed, e.g. wood screws
    • F16B25/001Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by the material of the body into which the screw is screwed
    • F16B25/0031Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by the material of the body into which the screw is screwed the screw being designed to be screwed into different materials, e.g. a layered structure or through metallic and wooden parts
    • 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 OR WEDGES; JOINTS OR JOINTING
    • F16B25/00Screws that cut thread in the body into which they are screwed, e.g. wood screws
    • F16B25/0036Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw
    • F16B25/0042Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw characterised by the geometry of the thread, the thread being a ridge wrapped around the shaft of the screw
    • F16B25/0068Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw characterised by the geometry of the thread, the thread being a ridge wrapped around the shaft of the screw with multiple-threads, e.g. a double thread screws
    • 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 OR WEDGES; JOINTS OR JOINTING
    • F16B25/00Screws that cut thread in the body into which they are screwed, e.g. wood screws
    • F16B25/10Screws performing an additional function to thread-forming, e.g. drill screws or self-piercing screws
    • F16B25/103Screws 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

Abstract

SELF-DRILLING, SELF-TAPPING FASTENER

ABSTRACT

A self-drilling, self-tapping screw has a drill tip formed by a pair of conical segments. Each segment has a flat side and a rounded tip with one segment being longitudinally offset with respect to the other. The shorter, offset segment may have a greater included angle. At least a portion of the flat side of the second segment is coplanar with the flatside of the first segment. The screw preferably includes a quad-lead thread having two crests with a first diameter and two crests with a second larger diameter.

Description

~2~
SELF-DRII,LING, SEl,F-TAPPING FASTENER

BRIEF DESCRIPTION OF THE INVENTION

The present invention cornprises an improved self-drilling, self-tapping screw. The drill point includes two half-conical segments with flat sides and rounded tips. The segrnents are longitudinally offset along the axis of the screw with respect --to one another and portions of the flat sides are coplanar. The two angles included by the conical segments may be different with the angle of the segment nearer the head end preferably being the larger of the two. The self-tapping thread may take any of several forms: it may be a machine thread, a type B
thread, or a quad-lead thread having two threads with a first crest diameter and two threads with a second larger crest diameter .

The screw of the present invention is particularly adapted for fastening wallboard or other panel material to steel studs.
The self-drilling, self-tapping screw of the present invention has shown itself to be a faster driller than other drill screws, requires less complicated manufacturing steps and tooling to make and, therefore, can be rnanufactured more economically.
Further, the conical segment positioned nearer the head extrudes the relatively thin metal in the stud during drilling providing greater thread engagement with the screw. This greater thread engagement results in higher pullout values (i. e., greater holding power) for the fastener. The embodiment i ., . --1--utilizing the quad-lead thread can be utilized to further increase thread en~agement due to its increased thread density.
Although particularly adapted for steel studs, the fastener of the present invention can be utilized in wood applications without the need for modifying its configuration. The flatness of the drill tip prevents the flutes from packing with wall-board particles which can prove troublesome for other screw configurations.

The invention, in its broadest aspect, contemplates a self-drilling, self-tapping screw which comprises a head with drive-engageable surfaces at one end, a drill point at the opposite end, and a threaded region intermediate the two ends. The drill point includes a first conical segment with a flat side and a rounded tip, wherein the edges of the flat side of the first conical segment create a pair of cutting edges diverging from a continuously curved rounded tip at a relatively sharp acute angle~ The cutting edges e~tend for a predetermined axial dis-tance along the screw length, with the first conical segment being at a first longitudinal position along the screw length. A second conical segment with a flat side and a rounded tip is located at a second longitudinal position along the screw length, with the second longitudinal position being nearer the head than said first position and at least a portion of the two flat sides being coplanar The surfaces of each conical segment are smoo~h at least in the longitudinal positions of the cutting edges, and the ~lat side of the second conical segment is coplanar with the flat side of the first conical segment and defines a pair of side edges diverging from the rounded tip of the second conical segment at a relatively sharp acute angle. The side edges of the second conical segment are spaced radially inwardly from associated cutting edges on the first conical segment creating a pair of flat side segments radially inwardly of the cutting edges for a
-2-substantial portion of the predetermined axial distance. The transverse dimension of the drill point in the plane of the cutting edges at any given location is greater than the trans-verse dimension in any longitudinal plane intersecting the cutting edge plane.
These and other features, objects and advantages of the present invention will become more apparent through reading the following specification in conjunction with the appended drawings.

BRIEF DESCRIPTION OF THE DRA~INGS
Fig. 1 is a top elevational view of the fastener of the present invention;
Fig. 2 is an enlarged side elevational view in partial section of the tip region of the fastener of Fig. l;
Fig. 3 is a partial end cross section taken along line 3-3 in Fig. 2;
Fig. 4 is an enlarged top view of the drill tip of the fastener of the present invention;
Fig. 5 is an enlarged side elevational view in partial section of another embodiment of the fastener of the present invention;
Fig. 6 is a cross-sectional end view taken along line 6-6 in Fig. 5;
Fig. 7 is a top elevational view of the drill tip of the Fig. 5 embodiment.

DETAILED DESCRIPTION OF THE INVENTION

The self-drilling, self-tapping screw of the present invention is shown generally at 10. The head 12 of the screw has the same general configuration shown in U.S. patent 3,056,234. This head style has proven to be particularly well adapted for retention in wallboard or the like. Recess 14 provides a plurality of drive-engageable surfaces for rotationally driving the screw.

i --.
I~J~ -3-Threaded region 16 may, preferably, cornprise a quad-lead thread configuration utilizing two threads 18 having a first crest diameter and two threads 20 having a second larger crest diameter. The drill tip shown generally at 22 comprises a first conical segment 24 and a second conical segment 26. Each seyment has a flat side and a rounded tip 28, 30 respectively. Second segment 26 is longitudinally offset with respect to the first conical segment 24 toward head 12. In an alternate embodiment conical segment 26 also may have a larger included angle to make up for its shorter length. The flat sides of the two segments are partially coplanar. The flat sides include portions 32 on the first conical segment 24 which create a pair of cutting edges diverging from the rounded tip 28 at a relatively sharp acute angle. These cutting edges, as shown in the drawings, extend substantially the full axial extent of the drill tip 22.
It will also be noted from -the drawings that the conical segments on the tip are free of thread configurations which could retard the entry rate of the point through the workpiece.
As also will be clearly understood by reference to Figs.
2, 3, S and 6, the axial offsetting of the conical segments, which have their flat surfaces lying along a hypothetical axial center line of a complete cone, will provide a tip that has a transverse dimension in the plane of the cutting edges which will be greater, at any axial position, than at any other longi-tudinal plane extending through the center line of the screw.This will clearly provide relief behind the cutting edges.
The offset between segments 24 and 26 creates two flute areas 32. Due to the drill tips symmetry, it is capable of drilling by rotation of the screw in either direction. This drill tip can, therefore, be incorporated on a screw employing a left hand thread without any modiEication of its configuration. As the drill tip 22 enters the steel stud, the second conical segment 26 , -4-2~

engages the material and works it, extruding it out the back of the hole being formed. This extrusion increases the surface area of the aperture which is available for thread engagement by threaded region 16. The grea-ter the thread engagement, the larger the pullout values, or holding strength, of the fastener.
The quad-lead helps to further increase the holding strength due to the increased thread density.
A second embodiment is depicted in Figs. 5-7. In this embodiment, the included angle of conical segment 26 is com-paratively larger with respect to segment 24 than in the previousembodiment. Further, whereas the flat side of each segment lay generally along -the hypothetical axial center line in the Fig.
1-4 embodiments, the flat sides of this embodiment are off the center line giving the point a much flatter configuration. The lS threaded region 16 of this embodiment is shown with a type B
thread but can have a machine thread or any other thread form which may be convenient.
The self-drilling, self-tapping screw of the present invention can penetrate ~wallboard or the like and drill into and ~asten into a steel stud. Due to the configuration of the drill tip, the flutes will not become packed with particles of wallboard which can have a detrimental effect on o-ther drill screws. Further, this drill tip extrudes the material of the stud as it drills thereby increasing the available material thickness for thread engagement. Lastly, this fastener is equally well adapted for use with wooden studs and need not be limited to steel stud applications.
Various changes, modifications and alternatives wil:l become apparen-t to a person of ordinary skillin the art as a result of reading the foregoing specification. Accardingly, it is intended that all such changes, modifications ancl alternatives as come within the scope of the appencled claims fall within the boundaries of the present invention.

.

Claims (7)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A self-drilling, self-tapping screw comprising a head with drive-engageable surfaces at one end; a drill point at the opposite end; and a threaded region intermediate said two ends; said drill point including a first conical segment with a flat side and a rounded tip, the edges of the flat side of said first conical segment creating a pair of cutting edges diverging from a continuously curved rounded tip at a relatively sharp acute angle, the cutting edges extending for a predetermined axial distance along the screw length, said first conical segment being at a first longitudinal position along the screw length, a second conical segment with a flat side and a rounded tip, said second conical segment being at a second longitudinal position along the screw length, said second longitudinal position being nearer the head than said first position and at least a portion of the two flat sides being coplanar, the surfaces of each conical segment being smooth at least in the longitudinal positions of the cutting edges, the flat side of the second conical segment being coplanar with the flat side of the first conical segment and defining a pair of side edges diverging from the rounded tip of said second conical segment at a relatively sharp acute angle, the side edges of said second conical segment being spaced radially inwardly from associated cutting edges on said first conical segment creating a pair of flat side segments radially inwardly of said cutting edges for a substantial portion of said predetermined axial distance, the transverse dimension of the drill point in the plane of the cutting edges at any given location being greater than the transverse dimension in any longitudinal plane intersecting said cutting edge plane.
2. The self-drilling, self-tapping screw of Claim 1 wherein the acute angle of the side edges of the second conical segment is different from the acute angle of the cutting edges of said first segment.
3. The self-drilling, self-tapping screw of Claim 2 wherein the acute angle of said second conical segment is greater than the acute angle of said first conical segment.
4. The self-drilling, self-tapping screw of Claim 1 wherein the threaded region of said screw includes at least one helical thread having a first predetermined crest diameter and at least one helical thread having a second predetermined crest diameter larger than said first diameter.
5. The self-drilling, self-tapping screw of Claim 4 wherein said threaded region includes two threads with the first crest diameter and two threads having the second crest diameter.
6. The self-drilling, self-tapping screw of Claim 1 wherein the flat side of each conical segment lies along the respective hypothetical cone's axial center line so that each conical segment comprises generally one radial half of a cone.
7. The self-drilling, self-tapping screw of Claim 1 wherein the flat side of each conical segment lies off the respective hypothetical cone's axial center line so that each conical segment comprises less than one radial half of a cone.
CA000372182A 1980-03-07 1981-03-03 Self-drilling, self-tapping fastener Expired CA1142000A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US12821180A 1980-03-07 1980-03-07
US128,211 1980-03-07

Publications (1)

Publication Number Publication Date
CA1142000A true CA1142000A (en) 1983-03-01

Family

ID=22434207

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000372182A Expired CA1142000A (en) 1980-03-07 1981-03-03 Self-drilling, self-tapping fastener

Country Status (11)

Country Link
JP (1) JPS56134613A (en)
AU (1) AU543900B2 (en)
BR (1) BR8101270A (en)
CA (1) CA1142000A (en)
DE (1) DE3108010A1 (en)
FR (1) FR2477649B1 (en)
GB (1) GB2070996B (en)
IE (1) IE51170B1 (en)
IT (1) IT1137407B (en)
MX (1) MX151872A (en)
ZA (1) ZA811222B (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4439077A (en) * 1982-02-11 1984-03-27 Godsted Kent B Concrete screw anchor
JPS59164410A (en) * 1983-03-07 1984-09-17 インテリア・フアスナ−ズ・インコ−ポレイテツド Screw tool
DE3346704A1 (en) * 1983-12-23 1985-07-04 Richter-System GmbH & Co KG, 6103 Griesheim SELF-TAPING QUICK-SCREW SCREW
SE442047B (en) * 1984-05-23 1985-11-25 Anders Sahlin TRESKRUV
CH682174A5 (en) * 1990-06-23 1993-07-30 Mungo Befestigungstech Ag
JP3245464B2 (en) * 1992-11-26 2002-01-15 株式会社スズキ螺子製作所 Loosening prevention screw
US5779417A (en) * 1997-05-12 1998-07-14 Illinois Tool Works Inc. Fastener having primary and secondary threads
US7040850B2 (en) * 2003-08-04 2006-05-09 Power Products Iii, L.L.C. Fastener for use with frangible material
US20090185880A1 (en) * 2008-01-18 2009-07-23 Yongping Gong Universal fastener
US20150289916A1 (en) * 2014-04-15 2015-10-15 Chester H. Sharps Bone screws having more than three leads
CN111194188B (en) * 2017-10-09 2023-05-30 康曼德公司 Easily-started hollow bone screw

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3093028A (en) * 1959-02-05 1963-06-11 Eaton Mfg Co Self-drilling and self-tapping threaded fastener
DE1400842A1 (en) * 1961-12-01 1969-02-13 Jllinois Tool Works Inc screw
US3207024A (en) * 1962-08-20 1965-09-21 Illinois Tool Works Drill point screw
US3438299A (en) * 1968-01-26 1969-04-15 Illinois Tool Works Extruding screw
FI48297C (en) * 1968-10-23 1974-08-12 Bultfabriks Ab Self-tapping screw and procedure for its manufacture.
DE2913482A1 (en) * 1979-04-04 1980-10-16 Frank Knoche Self-drilling screw design - has non-round tip offset from centre line of shank

Also Published As

Publication number Publication date
JPH0223725B2 (en) 1990-05-25
ZA811222B (en) 1982-09-29
GB2070996A (en) 1981-09-16
IE810488L (en) 1981-09-07
AU543900B2 (en) 1985-05-09
BR8101270A (en) 1981-09-08
IT1137407B (en) 1986-09-10
IE51170B1 (en) 1986-10-29
MX151872A (en) 1985-04-15
AU6763781A (en) 1981-09-10
GB2070996B (en) 1984-01-04
JPS56134613A (en) 1981-10-21
FR2477649A1 (en) 1981-09-11
DE3108010A1 (en) 1982-01-07
IT8120125A0 (en) 1981-03-04
FR2477649B1 (en) 1985-12-06

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