This application claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 12/807,500, filed on Sep. 27, 2010 entitled Mushroom-compaction Asymmetric-Thread Impact-Drivable Screw which is a continuation in part of U.S. patent application Ser. No. 11/725,967, filed on Mar. 20, 2007, which is a continuation in part of both U.S. Provisional Application Ser. No. 60/790,501 filed by Litzinger on Apr. 7, 2006 entitled Asymmetric Thread Impact Drivable Screw and U.S. Provisional Application Ser. No. 60/854,884 filed by Litzinger on Oct. 27, 2006 entitled Mushroom-compaction Asymmetric-Thread Impact-Drivable Screw which are all hereby incorporated by reference in their entirety.
Not Applicable.
Not Applicable.
A portion of the disclosure of this patent document contains material which is subject to intellectual property rights such as but not limited to copyright, trademark, and/or trade dress protection. The owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent files or records but otherwise reserves all rights whatsoever.
1. Field of the Invention
The present invention relates to the field of impact driveable screws. In particular, the present invention relates specifically to an asymmetric thread screw having a ballistic point for use with impact drivers along with a high degree crest angle forming a long surface area slide flank and a short surface area grip flank to reduce fiber cutting during impact insertion of the screwnail. A secondary mushroom compaction thread is also disclosed.
2. Description of the Known Art
As will be appreciated by those skilled in the art, symmetrical thread screws, self drilling screws, and screws with cutting points have been known for an extended period of time. Present construction techniques use screws with a cutting or self tapping head that are rotated into a material to connect different materials together. This is very time consuming because of the extended time period it takes to rotate the screw into the material.
Other techniques use a combination of glue and regular nails in an attempt to achieve a similar holding power to the rotated screws. This creates a permanent attachment that cannot be disassembled. Similarly, the use of regular nails creates a strong bind that is difficult if not impossible to disassemble.
HITACHI has recently attempted impact driving screws with prior art type screw designs using a cutting point and a sharp angled thread on a wide thread pitch. These screws rip and tear the wood fibers during installation. See http://www.hitachipowertools.com for the limited information on their design.
Patents disclosing information relevant to screws include: U.S. Pat. No. 137,414, issued to Burdick on Apr. 1, 1873; U.S. Pat. No. 276,541, issued to Sloan on Apr. 24, 1883; U.S. Pat. No. 327,296, issued to McGinnis on Sep. 29, 1885; U.S. Pat. No. 373,074, issued to Jones on Nov. 15, 1887; U.S. Pat. No. 426,008, issued to Groff on Apr. 22, 1890; U.S. Pat. No. 471,179, issued to Jones on Mar. 22, 1892; U.S. Pat. No. 676,240, issued to Latty on Jun. 11, 1901; U.S. Pat. No. 1,326,910, issued to Butterfield on Jan. 6, 1920; U.S. Pat. No. 1,891,895, issued to Nagel on Dec. 20, 1932; U.S. Pat. No. 1,912,222, issued to Rosenberg on May 30, 1933; U.S. Pat. No. 1,953,592, issued to Deniston on Apr. 3, 1934; U.S. Pat. No. 2,001,869, issued to Deniston on May 21, 1935; U.S. Pat. No. 2,046,837, issued to Phillips on Jul. 7, 1936; U.S. Pat. No. 2,075,411, issued to Mertens on Mar. 30, 1937; U.S. Pat. No. 2,093,610, issued to Kraemer on Sep. 21, 1937; U.S. Pat. No. 2,190,883, issued to Pauze on Feb. 20, 1940; U.S. Pat. No. 2,269,708, issued to Dickson on Jan. 30, 1942; U.S. Pat. No. 2,558,379, issued to Phipard on Jun. 26, 1951; U.S. Pat. No. 2,605,867, issued to Goodwin on Aug. 5, 1952; U.S. Pat. No. 2,967,448, issued to Hallock on Jan. 10, 1961; U.S. Pat. No. 3,010,353, issued to Psaros on Nov. 28, 1961; U.S. Pat. No. 3,019,460, issued to Corckram on Feb. 6, 1962; U.S. Pat. No. 3,056,234, issued to Nelsson et al. on Oct. 2, 1962; U.S. Pat. No. 3,204,516, issued to Wieber on Sep. 7, 1965; U.S. Pat. No. 3,850,073, issued to Hayes on Nov. 26, 1974; U.S. Pat. No. 3,861,527, issued to Perkins on Jan. 21, 1965; U.S. Pat. No. 3,977,142, issued to Dove et al. on Aug. 31, 1976; U.S. Pat. No. 4,572,720, issued to Rockenfeller et al. on Feb. 25, 1986; U.S. Pat. No. 4,718,802, issued to Rockenfeller, et al. on Jan. 12, 1988; U.S. Pat. No. 4,932,820, issued to Schniedermeier on Jun. 12, 1990; U.S. Pat. No. 5,375,957, issued to Golledge on Dec. 27, 1994; and U.S. Pat. No. 5,741,104, issued to Lat et al. on Apr. 21, 1998. Each of these patents is hereby expressly incorporated by reference in its entirety. These prior art references teach that screws should cut the wood fibers with a cutting or pyramid shaped point during insertion. Thus, it may be seen that these prior art patents are very limited in their teaching and utilization, and an improved impact driveable screwnail is needed to overcome these limitations.
The present invention is directed to an improved screw nail. In accordance with one exemplary embodiment of the present invention, an asymmetric thread impact drivable screw is provided using an impact head and a conical shaped tip having a ballistic insertion angle formed on the ends of a shank defining an axis. Of particular note is the use of the ballistic tip with the shank defining asymmetrical threads. The ballistic tip and the threads have a unique shape adapted for dividing the wood fibers while minimizing the cutting or breakage of the wood fibers. The thread has an insertion flank protruding from the shank at slide angle to push the fibers aside and allow for penetration of the wood without cutting the fibers. The slide angle has a long surface area leading to a crest that is supported on the back side by a catch flank. The catch flank is protruding from the shank at an impact supporting grip angle that provides the necessary support to the crest during impact insertion while still providing increased gripping strength when compared to bare nail shanks.
In another embodiment, the screws nails are collated into a clip for use with an impact fastener such as a pneumatic or gas operated nail gun.
In yet a further embodiment, the use of mushroom compaction threads are also disclosed.
These and other objects and advantages of the present invention, along with features of novelty appurtenant thereto, will appear or become apparent by reviewing the following detailed description of the invention.
In the following drawings, which form a part of the specification and which are to be construed in conjunction therewith, and in which like reference numerals have been employed throughout wherever possible to indicate like parts in the various views:
As shown in
As shown in
For the preferred embodiment, the impact head 310 is connected with a tapered neck 320 to the shank 340. The tapered neck has a head neck angle HA 322 used for the countersinking of the impact head 310 to the surface of the material that the screwnail is being used to secure.
The opposite end of the shank 340 ends in a conical shaped tip 330 using a ballistic insertion point angle PA 332. The present invention teaches a unique distinction over the prior art teaching of diamond or cutting shaped screw point because a ballistic tip 330 is used to separate fibers with minimal or no cutting of the wood fibers. This allows the present invention to work in a variety of situations, including but not limited to wood to wood, wood to light guage steel, drywall to wood, drywall to steel, foam to wood, foam to steel, subfloor attachment, roof deck attachment, siding attachment, concrete board attachment, fiberboard attachment, fencing applications, deck boards, framework, crating construction, pallet construction, soffit installation, concrete forms and other assemblies.
The shank 340 defines a central axis 342 running from the head end 344 to the tip end 346. The distance form the top of the impact head 310 to the bottom of the tip 330 is shown as the total length TL. The shank 340 defines a shank diameter SD 348 has at least a first threaded section 350 defining a major thread diameter TD 352. Multiple thread sections may be used as shown by the second threaded section 354 where the first section 350 and the second section 354 are separated by a thread gap TG 358. The top of the first thread is shown as the top thread TT measurement in
A key aspect to the present invention is the use of the ballistic point 330 to separate the wood fibers along with the use of asymmetrical threads 360 using a low angle thread pitch 378 which passes the wood fibers with minimal or no tearing of the wood fibers. The asymmetric thread design and the fine thread shown by the pitch depth PD of the present invention keeps the wood fibers spread during insertion of the fastener without the large movements caused by changes between the maximum thread diameter and the root diameter of the thread. Thus, the relative high insertion speed consistency of the external shape of the present invention minimizes the cutting of the wood fibers during installation. The insertion without cutting is provided by a slide insertion flank 362 oriented at a slide angle SA 364 with a long slide surface 366 leading to the crest 368. The slide angle SA is shown in
The preferred embodiments use the following design parameters:
Obvious variations may be made to these examples, including varying the angles outside of these preferred parameters and changing thicknesses or types of coatings. For example, common requests for diameters of screws are 0.099, 0.100, and 0.105 inch diameter screws with varying lengths. Note that any type of coating may be used with this screw design including, galavanized coating, yellow zinc, paint, ceramic, concrete, etc. . . . . Thus, these examples are illustrative only and are not meant to limit the present invention. A further example of this variation is shown in
The mushroom compaction threads 454 use either asymmetric or symmetrical threads 360 with a gripping insertion flank 462 leading to a crest 468 with a corresponding grip catch flank 472. In this manner, both the first and second sides of the threads 454 have a short catch surface 476. This allows for any mushrooming effect from the hole to be caught by the insertion side of the mushroom compaction threads 454 and pulled down into the hole to leave a smooth surface on the board.
Dimensions for the preferred embodiment of the mushroom compaction asymmetric thread impact drivable screw 400 are as follows:
The overall crest angle from the mushroom threads is 55°±5° symmetrically divided and the overall length is 2.25 inches. The ballistic angle, crest angle, slide angle and grip angle are as previously described. The material is c-1018 or 1022 steel with a surface hardness of Hv450 minimum and a case depth of 0.05 mm minimum. The bending angle is 12° Min with a torsional strength of 35 kg/cm minimum. Note that the mushrooming threads are comparatively short in length in this application due to the minimal, if any, mushrooming associated with the slide angle type of threads. This allows for use of the impact screw with most nail guns by allowing the penetration and holding power to be developed by the sliding threads with only the slight amount of compression used by the limited mushroom controlling threads. This allows for screw applications with the mushrooming control while still working in the limited capabilities of common impact drivers.
Thus, it may be seen that the present invention provides an advantage over the prior by using a ballistic point in combination with a unique thread design that allows for insertion of the screwnails with minimal or no tearing of the wood fibers.
Reference numerals used throughout the detailed description and the drawings correspond to the following elements:
From the foregoing, it will be seen that this invention is well adapted to obtain all the ends and objects herein set forth, together with other advantages which are inherent to the structure. It will also be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. Many possible embodiments may be made of the invention without departing from the scope thereof. Therefore, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
When interpreting the claims of this application, method claims may be recognized by the explicit use of the word ‘method’ in the preamble of the claims and the use of the ‘ing’ tense of the active word. Method claims should not be interpreted to have particular steps in a particular order unless the claim element specifically referring to a previous element, a previous action, or the result of a previous action. Apparatus claims may be recognized by the use of the word ‘apparatus’ in the preamble of the claim and should not be interpreted to have ‘means plus function language’ unless the word ‘means’ is specifically used in the claim element. The words ‘defining,’ ‘having,’ or ‘including’ should be interpreted as open ended claim language that allows additional elements or structures.
Number | Name | Date | Kind |
---|---|---|---|
71166 | Harvey | Nov 1867 | A |
108986 | Dunn | Nov 1870 | A |
137414 | Burdick | Apr 1873 | A |
221729 | Harvey | Nov 1879 | A |
276541 | Sloan | Apr 1883 | A |
313078 | Jones | Mar 1885 | A |
327296 | McGinnis | Sep 1885 | A |
338956 | Hall | Mar 1886 | A |
355825 | Jones | Jan 1887 | A |
364300 | Rogers | Jun 1887 | A |
364301 | Rogers | Jun 1887 | A |
368687 | Rogers | Aug 1887 | A |
426008 | Groff | Apr 1890 | A |
471179 | Jones | Mar 1892 | A |
676240 | Latty et al. | Jun 1901 | A |
1326910 | Butterfield | Jan 1920 | A |
1891895 | Nagel | Dec 1932 | A |
1912222 | Rosenberg | May 1933 | A |
1953592 | Deniston, Jr. | Apr 1934 | A |
2001869 | Deniston, Jr. | May 1935 | A |
2046837 | Phillips | Jul 1936 | A |
2075411 | Von Mertens | Mar 1937 | A |
2093610 | Kraemer | Sep 1937 | A |
2140014 | Iasillo | Dec 1938 | A |
2174578 | Graham | Oct 1939 | A |
2190883 | Pauze | Feb 1940 | A |
2226006 | Maze | Dec 1940 | A |
2242758 | Ruggieri | May 1941 | A |
2269708 | Dickson | Jan 1942 | A |
2558379 | Phipard | Jun 1951 | A |
2605867 | Goodwin | Aug 1952 | A |
2967448 | Hallock | Jan 1961 | A |
3010353 | Psaros | Nov 1961 | A |
3019460 | Corckran | Feb 1962 | A |
3056234 | Nelsson et al. | Oct 1962 | A |
3204516 | Wieber | Sep 1965 | A |
3827131 | Coltrin | Aug 1974 | A |
3850073 | Hayes | Nov 1974 | A |
3861527 | Perkins | Jan 1975 | A |
3861529 | Coleman | Jan 1975 | A |
3977142 | Dove et al. | Aug 1976 | A |
4572720 | Rockenfeller et al. | Feb 1986 | A |
4718802 | Rockenfeller et al. | Jan 1988 | A |
4932820 | Schniedermeier | Jun 1990 | A |
5375957 | Golledge | Dec 1994 | A |
5741104 | Lat et al. | Apr 1998 | A |
6022177 | Hofer | Feb 2000 | A |
6074149 | Habermehl et al. | Jun 2000 | A |
6666638 | Craven | Dec 2003 | B2 |
6941635 | Craven | Sep 2005 | B2 |
20070258794 | Litzinger | Nov 2007 | A1 |
20120096701 | Schachner | Apr 2012 | A1 |
Number | Date | Country |
---|---|---|
2710240 | Sep 1978 | DE |
20214686 | Feb 2003 | DE |
129404 | Jun 1984 | EP |
WO03014578 | Aug 2002 | WO |
Number | Date | Country | |
---|---|---|---|
20150240855 A1 | Aug 2015 | US |