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Publication numberUS20030031528 A1
Publication typeApplication
Application numberUS 09/918,656
Publication dateFeb 13, 2003
Filing dateJul 31, 2001
Priority dateJul 31, 2001
Also published asCA2389788A1, CA2389788C, CN1321273C, CN1400402A, DE60221077D1, DE60221077T2, EP1281874A2, EP1281874A3, EP1281874B1, US6926484, US20040101381
Publication number09918656, 918656, US 2003/0031528 A1, US 2003/031528 A1, US 20030031528 A1, US 20030031528A1, US 2003031528 A1, US 2003031528A1, US-A1-20030031528, US-A1-2003031528, US2003/0031528A1, US2003/031528A1, US20030031528 A1, US20030031528A1, US2003031528 A1, US2003031528A1
InventorsGuenther Kram, Chin-Tsai Chen
Original AssigneeKram Guenther Reinhard, Chin-Tsai Chen
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Multi-mate fastener
US 20030031528 A1
Abstract
A threaded fastener has a substantially single helical thread formed upon a shank portion thereof, and a plurality of substantially saw-blade type or serrated teeth are formed upon crest portions of leading ones of individual thread portions of the helical thread. The saw-blade type or serrated teeth cut into side wall portions of any one of a multiplicity of substrates so as to substantially reduce required insertion torque levels, render fastener insertion operations quicker, and enhance fastener pull-out resistance values.
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Claims(33)
What is claimed as new and desired to be protected by Letters Patent of the United States of America, is:
1. A threaded fastener, comprising:
a shank portion;
a head portion formed upon a first end of said shank portion;
a tip portion formed upon a second opposite end of said shank portion;
a substantially continuous single helical thread formed upon said shank portion, wherein individual thread portions of said substantially continuous single helical thread comprise crest portions; and
a plurality of substantially contiguous saw-blade type teeth formed upon peripheral edge portions of said crest portions of said individual thread portions of said substantially continuous single helical thread.
2. The threaded fastener as set forth in claim 1, wherein:
each one of said plurality of saw-blade type teeth has a substantially triangular configuration.
3. The threaded fastener as set forth in claim 2, wherein:
valleys are defined between successive ones of said plurality of substantially contiguous substantially triangular-shaped saw-blade type teeth.
4. The threaded fastener as set forth in claim 3, wherein:
each one of said valleys comprises an included angle of 100.
5. The threaded fastener as set forth in claim 1, wherein:
said plurality of substantially contiguous saw-blade type teeth are only formed upon peripheral edge portions of said crest portions of leading ones of said individual thread portions of said substantially continuous single helical thread.
6. The threaded fastener as set forth in claim 5, wherein:
said leading ones of said individual thread portions of said substantially continuous single helical thread comprises approximately the leading one-third to one-half of the number of individual thread portions of said substantially continuous single helical thread formed upon said shank portion of said threaded fastener.
7. The threaded fastener as set forth in claim 1, wherein:
said plurality of substantially contiguous saw-blade type teeth have a predetermined pitch defined between adjacent ones of said plurality of substantially contiguous saw-blade type teeth; and
each one of plurality of substantially contiguous saw-blade type teeth has a predetermined radial depth dimension.
8. The threaded fastener as set forth in claim 7, wherein:
said threaded fastener comprises either one of a number six and a number eight sized threaded fastener;
said predetermined pitch defined between said plurality of substantially contiguous saw-blade type teeth comprises 0.60 mm; and
each one of plurality of substantially contiguous saw-blade type teeth has a predetermined depth dimension of 0.21 mm.
9. The threaded fastener as set forth in claim 7, wherein:
said threaded fastener comprises either one of a number ten and a number twelve sized threaded fastener;
said predetermined pitch defined between said plurality of substantially contiguous saw-blade type teeth comprises 0.70 mm; and
each one of plurality of substantially contiguous saw-blade type teeth has a predetermined depth dimension of 0.25 mm.
10. The threaded fastener as set forth in claim 7, wherein:
said threaded fastener comprises a number fourteen sized threaded fastener;
said predetermined pitch defined between said plurality of substantially contiguous saw-blade type teeth comprises 0.80 mm; and
each one of plurality of substantially contiguous saw-blade type teeth has a predetermined depth dimension of 0.29 mm.
11. The threaded fastener as set forth in claim 1, wherein:
each one of said individual thread portions of said substantially continuous single helical thread comprises an upper flank surface and a lower flank surface; and
an included angle defined between said upper flank and lower flank surfaces is within the range of 30-50.
12. A threaded fastener, comprising:
a shank portion;
a head portion formed upon a first end of said shank portion;
a tip portion formed upon a second opposite end of said shank portion;
a substantially continuous single helical thread formed upon said shank portion, wherein individual thread portions of said substantially continuous single helical thread comprise crest portions; and
a plurality of substantially contiguous serrated teeth formed upon peripheral edge portions of said crest portions of said individual thread portions of said substantially continuous single helical thread.
13. The threaded fastener as set forth in claim 12, wherein:
each one of said plurality of serrated teeth has a substantially triangular configuration.
14. The threaded fastener as set forth in claim 13, wherein:
valleys are defined between successive ones of said plurality of substantially contiguous substantially triangular-shaped serrated teeth.
15. The threaded fastener as set forth in claim 14, wherein:
each one of said valleys comprises an included angle of 100.
16. The threaded fastener as set forth in claim 12, wherein:
said plurality of substantially contiguous serrated teeth are only formed upon peripheral edge portions of said crest portions of leading ones of said individual thread portions of said substantially continuous single helical thread.
17. The threaded fastener as set forth in claim 16, wherein:
said leading ones of said individual thread portions of said substantially continuous single helical thread comprises approximately the leading one-third to one-half of the number of individual thread portions of said substantially continuous single helical thread formed upon said shank portion of said threaded fastener.
18. The threaded fastener as set forth in claim 12, wherein:
said plurality of substantially contiguous serrated teeth have a predetermined pitch defined between adjacent ones of said plurality of substantially contiguous serrated teeth; and
each one of plurality of substantially contiguous serrated teeth has a predetermined radial depth dimension.
19. The threaded fastener as set forth in claim 18, wherein:
said threaded fastener comprises either one of a number six and a number eight sized threaded fastener;
said predetermined pitch defined between said plurality of substantially contiguous serrated teeth comprises 0.60 mm; and
each one of plurality of substantially contiguous serrated teeth has a predetermined depth dimension of 0.21 mm.
20. The threaded fastener as set forth in claim 18, wherein:
said threaded fastener comprises either one of a number ten and a number twelve sized threaded fastener;
said predetermined pitch defined between said plurality of substantially contiguous serrated teeth comprises 0.70 mm; and
each one of plurality of substantially contiguous serrated teeth has a predetermined depth dimension of 0.25 mm.
21. The threaded fastener as set forth in claim 18, wherein:
said threaded fastener comprises a number fourteen sized threaded fastener;
said predetermined pitch defined between said plurality of substantially contiguous serrated teeth comprises 0.80 mm; and
each one of plurality of substantially contiguous serrated teeth has a predetermined depth dimension of 0.29 mm.
22. The threaded fastener as set forth in claim 12, wherein:
each one of said individual thread portions of said substantially continuous single helical thread comprises an upper flank surface and a lower flank surface; and
an included angle defined between said upper flank and lower flank surfaces is within the range of 30-50.
23. A self-tapping threaded fastener for use in connection with any one of a plurality of substrates, comprising:
a shank portion;
a head portion formed upon a first end of said shank portion;
a tip portion formed upon a second opposite end of said shank portion;
a substantially continuous single helical thread formed upon said shank portion, wherein individual thread portions of said substantially continuous single helical thread comprise crest portions; and
a plurality of substantially contiguous saw-blade type teeth formed upon peripheral edge portions of said crest portions of said individual thread portions of said substantially continuous single helical thread for cutting into side wall portions of a substrate whereby insertion torque required in connection with the insertion of said threaded fastener into the substrate will be reduced, insertion speed of said threaded fastener into the substrate will be shortened, and pull-out resistance of said threaded fastener from the substrate will be enhanced.
24. The threaded fastener as set forth in claim 23, wherein:
each one of said plurality of saw-blade type teeth has a substantially triangular configuration.
25. The threaded fastener as set forth in claim 24, wherein:
valleys are defined between successive ones of said plurality of substantially contiguous substantially triangular-shaped saw-blade type teeth.
26. The threaded fastener as set forth in claim 25, wherein:
each one of said valleys comprises an included angle of 100.
27. The threaded fastener as set forth in claim 23, wherein:
said plurality of substantially contiguous saw-blade type teeth are only formed upon peripheral edge portions of said crest portions of leading ones of said individual thread portions of said substantially continuous single helical thread.
28. The threaded fastener as set forth in claim 27, wherein:
said leading ones of said individual thread portions of said substantially continuous single helical thread comprises approximately the leading one-third to one-half of the number of individual thread portions of said substantially continuous single helical thread formed upon said shank portion of said threaded fastener.
29. The threaded fastener as set forth in claim 23, wherein:
said plurality of substantially contiguous saw-blade type teeth have a predetermined pitch defined between adjacent ones of said plurality of substantially contiguous saw-blade type teeth; and
each one of plurality of substantially contiguous saw-blade type teeth has a predetermined radial depth dimension.
30. The threaded fastener as set forth in claim 29, wherein:
said threaded fastener comprises either one of a number six and a number eight sized threaded fastener;
said predetermined pitch defined between said plurality of substantially contiguous saw-blade type teeth comprises 0.60 mm; and
each one of plurality of substantially contiguous saw-blade type teeth has a predetermined depth dimension of 0.21 mm.
31. The threaded fastener as set forth in claim 29, wherein:
said threaded fastener comprises either one of a number ten and a number twelve sized threaded fastener;
said predetermined pitch defined between said plurality of substantially contiguous saw-blade type teeth comprises 0.70 mm; and
each one of plurality of substantially contiguous saw-blade type teeth has a predetermined depth dimension of 0.25 mm.
32. The threaded fastener as set forth in claim 29, wherein:
said threaded fastener comprises a number fourteen sized threaded fastener;
said predetermined pitch defined between said plurality of substantially contiguous saw-blade type teeth comprises 0.80 mm; and
each one of plurality of substantially contiguous saw-blade type teeth has a predetermined depth dimension of 0.29 mm.
33. The threaded fastener as set forth in claim 23, wherein:
each one of said individual thread portions of said substantially continuous single helical thread comprises an upper flank surface and a lower flank surface; and
an included angle defined between said upper flank and lower flank surfaces is within the range of 30-50.
Description
CROSS REFERENCE TO RELATED PATENT APPLICATION

[0001] This patent application is related to U.S. patent application Ser. No. ______ filed on Jun. 19, 2001 and entitled FASTENER HAVING MULTIPLE-BOSSED LEAD.

FIELD OF THE INVENTION

[0002] The present invention relates generally to threaded fasteners, and more particularly to a new and improved threaded fastener which has uniquely formed or fabricated saw-tooth or serrated-teeth structure integrally formed upon the peripheral edge regions of the crest portions of the lead threads of the fastener whereby the cutting performance or characteristics of the lead threads is enhanced so as to in turn facilitate and enhance the penetration or insertion rate of the fastener into a substrate, as well as the pull-out resistance of the fastener, and still further, the new and improved fastener is well-adapted for threaded insertion within a plurality of different substrates, such as, for example, wood, metal, composite materials, concrete, or the like.

BACKGROUND OF THE INVENTION

[0003] In connection with the fabrication or manufacture of threaded fasteners, a multiplicity of different fasteners are of course well-known and are accordingly available in the marketplace. More particularly, or furthermore, the multiplicity or different varieties of threaded fasteners have been developed in accordance with various objectives, such as, for example, to enable the fasteners to achieve predeterminedly desired insertion and withdrawal torque characteristics, to enable the fasteners to be used in conjunction with different mounting panels, support surfaces, or substrates comprising different types of materials, to enable the fasteners to exhibit predeterminedly desired pull-out resistance values with respect to such panels, surfaces, or substrates, and the like. Accordingly, the threads of such fasteners are usually provided with supplemental or auxiliary structure which seeks to achieve the aforenoted objectives. For example, as disclosed within U.S. Pat. No. 5,110,245 which issued to Hiroyuki on May 5, 1992, the peripheral edge portions of the threads of the threaded fasteners 1 disclosed therein are provided with slot recesses 6 in order to render the fasteners 1 suitable for enhanced stability within thermoplastic resin substrates. In a similar manner, as disclosed within U.S. Pat. No. 5,044,853 which issued to Dicke on Sep. 3, 1991, the peripheral edge portions of the threaded fastener are provided with parabolic depressions wherein the dispositions of the depressions are effectively skewed such that the insertion torque is less than the withdrawal torque thereby rendering the screwing of the fastener into the particular substrate relatively easier than the unscrewing of the fastener from the substrate. Lastly, as disclosed within U.S. Pat. No. 4,637,767 which issued to Yaotani et al. on Jan. 20, 1987, the threads of the fastener are provided with projections 150 so as to optimize torque levels as well as pull-out resistance values.

[0004] While the aforenoted exemplary threaded fasteners have performed satisfactorily and have accordingly been commercially successful, a need still exists in the art for a new and improved threaded fastener which will have new and improved structure integrally incorporated within the lead thread portions thereof whereby such lead threads can effectively cut into a diverse type of substrates in a relatively faster and smoother manner, such as, for example, wood, metal, composite materials, concrete, or the like. In addition, the lead threads can effectively cause the removal of cut material and the dispersal of the same so as to permit the following or trailing threads to easily traverse the newly formed threads which have been tapped into the substrates by means of the newly structured lead threads, and wherein, as a result of such new and improved screw fastener thread structure, the screw fastener will exhibit enhanced tapping or insertion torque characteristics, enhanced tapping and insertion speed, and improved pull-out resistance properties.

OBJECTS OF THE INVENTION

[0005] Accordingly, it is an object of the present invention to provide a new and improved threaded screw fastener.

[0006] Another object of the present invention is to provide a new and improved threaded screw fastener which effectively overcomes the various disadvantages and drawbacks characteristic of PRIOR ART threaded screw fasteners.

[0007] An additional object of the present invention is to provide a new and improved threaded screw fastener which has new and improved cutting structure integrally incorporated within the peripheral crest regions of the leading threads such that the new and improved threaded screw fastener is uniquely adapted for use in conjunction with a multiplicity of different types of substrates such as, for example, wood, metal, composites, concrete, or the like.

[0008] A further object of the present invention is to provide a new and improved threaded screw fastener which has new and improved cutting structure integrally incorporated within the peripheral crest regions of the leading threads such that the new and improved threaded screw fastener is uniquely adapted for actually cutting, removing, and dispersing material from the particular substrate during the performance of a tapping operation.

[0009] A last object of the present invention is to provide a new and improved threaded screw fastener which has new and improved cutting structure integrally incorporated within the peripheral crest regions of the leading threads such that the new and improved threaded screw fastener is uniquely adapted for actually cutting, removing, and dispersing material from the particular substrate during the performance of a tapping operation such that torque insertion requirements are diminished, insertion speed is enhanced, and pull-out resistance properties are improved.

SUMMARY OF THE INVENTION

[0010] The foregoing and other objectives are achieved in accordance with the teachings and principles of the present invention through the provision of a new and improved threaded screw fastener which comprises a shank portion, a tip portion, and a head portion. The shank portion has, for example, a single, continuous, helical thread integrally formed thereon, and the leading thread portions each have serrated teeth integrally formed within and along the crest portions thereof. The serrated teeth each have a substantially triangular configuration with valley regions formed between adjacent ones of the serrated teeth having, or defined by, included angles of 100. The serrated teeth thus serve, in effect, as saw-blade type teeth which actually cut threads into the substrate walls, as opposed to in effect simply moving substrate material from the tapped regions, and the thread structure also serves to remove and disperse the cut debris such that the following or trailing thread portions can smoothly and quickly traverse the previously tapped threads. In this manner, the insertion torque level and installation time are substantially reduced, and still further, the fastener exhibits enhanced pull-out resistance values.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Various other objects, features, and attendant advantages of the present invention will be more fully appreciated from the following detailed description when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts throughout the several views, and wherein:

[0012]FIG. 1 is a vertical front elevational view of a new and improved threaded screw fastener constructed in accordance with the principles and teachings of the present invention wherein the lead threads of the screw fastener are provided with the plurality of unique and novel, circumferentially arranged saw-blade type teeth upon the outer peripheral edge regions of the lead thread crest portions; and

[0013]FIG. 2 is an enlarged, partial cross-sectional, bottom perspective view of a lead thread portion of the new and improved threaded screw fastener shown in FIG. 1, wherein the details of the saw-blade type teeth, integrally formed upon the outer peripheral edge regions of the lead thread crest portions of the single continuous helical thread formed upon the threaded screw fastener so as to achieve the advantageous torque, insertion, and pull-out resistance properties characteristic of the present invention, are particularly illustrated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0014] Referring now to the drawings, and more particularly to FIG. 1 thereof, a new and improved threaded screw fastener, constructed in accordance with the principles and teachings of the present invention wherein the lead threads of the screw fastener are provided with the plurality of unique and novel, circumferentially arranged saw-blade type teeth upon the outer peripheral edge regions of the lead thread crest portions so as to achieve reduced insertion torque characteristics rendering the insertion or installation procedure quicker and faster, as well as enhancing pull-out resistance values, is disclosed and is generally indicated by the reference character 10. More particularly, the threaded screw fastener 10 comprises a shank portion 12 of substantially constant diameter D1, and a tapered head portion 14 formed upon the upper end of the shank portion 12, wherein the tapered head portion 14 has an axial depth or thickness H, a diametrical extent HD, and an included taper angle HA of approximately 85-90. A pointed tip portion 16 is formed upon the lower end of the shank portion 12, and a tapered neck portion 18 integrally interconnects the tapered head portion 14 of the fastener 10 to the upper end of the shank portion 12. The tapered neck portion 18 has an axial depth or thickness N and an included taper angle NA of approximately 48-52, and it is noted that the pointed tip portion 16 comprises an end point 20 at which diametrically opposite sides or planes of the pointed tip portion 16 effectively intersect each other at an angle A which is within the range of 20-25. A single continuous helical thread 22 is formed upon the shank and tip portions 12,16 of the fastener 10, and it is noted that the individual threads 24, comprising the overall single continuous helical thread 22 and which are formed upon the constant diameter portion D1 of the shank portion 12 so as to have a pitch P defined therebetween, have an external crest diameter dimension D2. Still further, it is noted that each one of the individual threads 24 comprises an upper flank or surface 26 and a lower flank or surface 28 wherein planes defined within the upper and lower flanks or surfaces 26,28 effectively intersect each other at an angle B which is within the range of 30-50, and preferably has a value of 40.

[0015] In accordance with the principles and teachings of the present invention, it is further seen from FIG. 1, and as may best be seen from FIG. 2, that the individual leading threads 24 of the threaded screw fastener 10 are providvided with unique and novel structure comprising a series of saw-blade type or serrated teeth 30 which are integrally formed upon the outer peripheral edge regions of the leading thread crest portions 32 of the single continuous helical thread 22 formed upon the threaded screw fastener 10 so as to enable or facilitate achievement of the advantageous insertion, torque, and pull-out resistance properties characteristic of the new and improved threaded screw fastener 10. It is to be initially noted that, in connection with the provision of such unique and novel structure comprising the series of saw-blade type teeth 30 integrally formed upon the outer peripheral edge regions of the leading thread crest portions 32 of the single continuous helical thread 22 formed upon the threaded screw fastener 10, and in view of the additional fact that the threaded screw fastener 10 may have any suitable longitudinal or axial length dimension, such as, for example, between 0.625 inches and 3.50 inches, the saw-blade type teeth 30 are provided upon those individual leading threads 24 which are disposed within approximately the leading one-third or one-half axial extent of the threaded screw fastener 10 as measured from the pointed tip 20 to the head portion 14.

[0016] With reference therefore now being specifically made to FIG. 2, the detailed structure of the unique and novel series of saw-blade type teeth 30, as integrally formed upon the outer peripheral edge regions of the leading thread crest portions 32 of the single continuous helical thread 22 formed upon the threaded screw fastener 10, will now be described. More particularly, it is seen that as a result of the use of suitably specific tooling, not shown, but which may be, for example, a suitable rolling die, the outer peripheral edge regions of the leading thread crest portions 32 of the single continuous helical thread 22 have the contiguous series or set of saw-blade teeth 30 formed therein such that valley regions 34 interposed between adjacent ones of the saw-blade teeth 30 are defined by means of an included angle IA of approximately 100. In addition, it is further noted that the tooth pitch TP, or in other words, the circumferential distance defined between adjacent saw-blade teeth 30, will have predetermined values, as will be noted hereinafter in connection with several fabricated examples of the new and improved threaded screw fastener 10 of the present invention, depending upon the particular diametrical size of the fastener 10, and in a similar manner, each one of the saw-blade teeth 30 will have a predetermined depth dimension TD, that is, the radial distance defined between the radially outermost tip of each tooth 30 to the base of each tooth 30, which will also accordingly vary depending upon the particular diametrical size of the fastener 10. It is lastly noted that each saw-blade tooth 30 can have a predeterminedly dimensioned width W, as measured in the peripheral or circumferential direction, which can be optimally varied so as to in fact achieve different degrees of cutting efficiency depending upon the particular substrate material into which the self-tapping fasteners 10 are being inserted.

[0017] As has been noted above, various conventionally sized threaded screw fasteners can have the unique and novel saw-blade teeth 30, constructed in accordance with the principles and teachings of the present invention, incorporated therein, and accordingly, the following examples of fasteners 10, provided with the saw-blade teeth 30 of the present invention, are set forth wherein the particular structural and size characteristics of the saw-blade teeth 30, and their interoperative cooperation, will become readily apparent:

EXAMPLE 1 A NUMBER 6 SIZED SCREW FASTENER

[0018]

Head Diameter HD 6.40-6.80 mm
Head Thickness H 2.20 mm
Neck Thickness N 1.40 mm
Shank Diameter D1 2.20 mm
Thread Crest Diameter D2 3.30-3.60 mm
Thread Pitch P 1.80 mm
Saw-Blade Teeth Pitch TP 0.60 mm
Saw-Blade Teeth Depth TD 0.21 mm
Saw-Blade Teeth Included Angle IA 100 Degrees

EXAMPLE 2 A NUMBER 8 SIZED SCREW FASTENER

[0019]

Head Diameter HD 7.70-8.10 mm
Head Thickness H 2.50 mm
Neck Thickness N 1.60 mm
Shank Diameter D1 2.40 mm
Thread Crest Diameter D2 3.80-4.10 mm
Thread Pitch P 2.00 mm
Saw-Blade Teeth Pitch TP 0.60 mm
Saw-Blade Teeth Depth TD 0.21 mm
Saw-Blade Teeth Included Angle IA 100 Degrees

EXAMPLE 3 A NUMBER 10 SIZED SCREW FASTENER

[0020]

Head Diameter HD 9.10-9.50 mm
Head Thickness H 2.80 mm
Neck Thickness N 1.80 mm
Shank Diameter D1 3.03 mm
Thread Crest Diameter D2 4.80-5.10 mm
Thread Pitch P 2.60 mm
Saw-Blade Teeth Pitch TP 0.70 mm
Saw-Blade Teeth Depth TD 0.25 mm
Saw-Blade Teeth Included Angle IA 100 Degrees

EXAMPLE 4 A NUMBER 12 SIZED SCREW FASTENER

[0021]

Head Diameter HD 10.30-10.80 mm
Head Thickness H 3.10 mm
Neck Thickness N 2.00 mm
Shank Diameter D1 3.30 mm
Thread Crest Diameter D2 5.30-5.60 mm
Thread Pitch P 2.90 mm
Saw-Blade Teeth Pitch TP 0.70 mm
Saw-Blade Teeth Depth TD 0.25 mm
Saw-Blade Teeth Included Angle IA 100 Degrees

EXAMPLE 5 A NUMBER 14 SIZED SCREW FASTENER

[0022]

Head Diameter HD 11.90-12.40 mm
Head Thickness H 3.40 mm
Neck Thickness N 2.20 mm
Shank Diameter D1 3.60 mm
Thread Crest Diameter D2 5.80-6.10 mm
Thread Pitch P 3.10 mm
Saw-Blade Teeth Pitch TP 0.80 mm
Saw-Blade Teeth Depth TD 0.29 mm
Saw-Blade Teeth Included Angle IA 100 Degrees

[0023] In connection with any one of the aforenoted examples of threaded screw fasteners 10 which may be fabricated in accordance with the principles and teachings of the present invention, it is to be emphasized that as a result of the provision of the contiguous series of saw-blade teeth 30 upon the outer peripheral edge regions of the leading thread crest portions 32 of the single continuous helical thread 22, the saw-blade teeth 30 will effectively cut and remove material forming the side wall portions of bores defined within any one of a multiplicity of substrates, as opposed to simply moving or displacing the material forming the side walls of the substrate bores, as is conventionally achieved by PRIOR ART self-tapping threaded fasteners. This cutting and removal action accomplished by means of the new and improved threaded screw fastener 10 of the present invention therefore leads to a faster and smoother insertion of the fastener 10 into a particular substrate, and the fact that material is actually cut and removed from the side wall portions of the substrate bores permits the following or trailing threads to be inserted or installed more easily. Accordingly, the overall required insertion torque levels are substantially reduced, and due to the well-defined cuts within the side walls of the substrate, the pull-out resistance values characteristic of the fasteners 10 are substantially enhanced. It is further noted that the severed and removed substrate material or debris does not present any problems with respect to the operational efficiency of the threaded fasteners 10 in view of the fact that such material or debris will be shifted toward the shank portion 12 of the fastener 10 and will also drop downwardly and collect within the bottom regions of the substrate bores.

[0024] Thus, it may be seen that in accordance with the principles and teachings of the present invention, there has been provided a new and improved threaded screw fastener which has, for example, a single continuous helical thread integrally formed thereon, and wherein there has been provided, upon the outer peripheral edge regions of the leading thread crest portions of such single continuous helical thread, a plurality of contiguous saw-blade teeth which will effectively cut through side wall portions of bores formed within a particular substrate and remove such severed material, as opposed to simply moving or displacing the material forming the side walls of the substrate bores as is conventionally achieved by PRIOR ART self-tapping threaded fasteners. This cutting and removal action accomplished by means of the new and improved threaded screw fastener of the present invention therefore leads to a faster and smoother insertion of the fastener into a particular substrate, and the fact that material is actually cut and removed from the side wall portions of the substrate bores permits the following or trailing threads to be inserted or installed more easily. Accordingly, the overall required insertion torque levels are substantially reduced, and due to the well-defined cuts within the side walls of the substrate, the pull-out resistance values characteristic of the fasteners are substantially enhanced. The fasteners of the present invention are also able to be used in connection with a diversity of substrates comprising different materials, such as, for example, wood, metal, composites, concrete, and the like.

[0025] Obviously, many variations and modifications of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7163366 *Jan 5, 2005Jan 16, 2007Pei-Hua ChenScrew with two types of threads
Classifications
U.S. Classification411/311
International ClassificationF16B25/10
Cooperative ClassificationF16B25/0052, F16B25/0031, F16B25/10, F16B25/0047
European ClassificationF16B25/00C4, F16B25/00G1B, F16B25/00G1A, F16B25/10
Legal Events
DateCodeEventDescription
Jul 31, 2001ASAssignment
Owner name: ILLINOIS TOOL WORKS INC., ILLINOIS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KRAM, GUETHER REINHARD;CHEN, CHIN-TSAI;REEL/FRAME:012310/0047;SIGNING DATES FROM 20010717 TO 20010726