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Publication numberUS74489 A
Publication typeGrant
Publication dateFeb 18, 1868
Publication numberUS 74489 A, US 74489A, US-A-74489, US74489 A, US74489A
InventorsA. Bidwell
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Improvement in wood-soeews
US 74489 A
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Description  (OCR text may contain errors)

@ni-ten tetra attent ffice.


Letters .Patent No. 74,489, dated .February I8, 1868.



Be it known that I,'JAsoN.A. BIDWELL, of East Boston, Su'olk county, Stato of Massachusetts, have invented an Improved Wood-Screw; and I do hereby declare the following to be a full, clear, and exact descrip. tion thereof, reference being had to the accompanying drawings, making part of this specification, in which- Figure 1 is a side view of the improved screwt Figure 2 is a diametrical section through the screw.

Figure 3 is an end view. 4 V

Figure 4 is an enlarged sectional view of a portion `of the screw, showingy clearly the form of the thread.

Similar letters of reference indicate corresponding parts in the several gnres.

The object of this invention is to construct a wood-screw which will penetrate wood more readily, and have a firmer hold than wood-screws hitherto made. v

The nature of my invention consists in a. wood-screw having a core, which tapers from the shanl: to the point, and a thread which does not taper, except at the entering-point ofthe screw, said thread being constructed with double convex sides, so as to increase the bearing-surface, and'add g'rcater strength to it, as will be hereinafter described. i V

vTo enable others skilled in the art to understand my invention, I will describe its construction and operation.

In the accompanying drawings,a represents the head of the scre\\,'\vhich may be notched or slotted, as

shown, or it may be perforated; and b represents the cylindrical shank or neck of the screw, which extends from the head to the point, c, where the screw-thread commences. The thread commences at'the.,circunnfer` V ence of the shank b, and gradui'ally increases `in depth, until the full depth ofthe screw isohtained, thereby producing the conical core e, which maybe more or less tapering, as desired. The core g, upon which the full thread d is formed, commences at the termination of the conc-shoulder e, and continues to the entering-pointf, with a gradual taper, as shownin gs. 1 and 2. The'thr'ead d cl is of the same diameter as ,the shank b, from the point c to the point t, when it is gradually reduced, so as to form the ventering-point. It will be seen that the portion d of the thread of my screw abruptly increases in depth upon the conical shoulder e', and then gradually increases in depth from this point to the reduced' entering-cud. Instead of'maliing the surfaces of the thread at, as in some wood-screws hitherto, vI make these surfaces convex or rounding, as shown in figs. 2 and 4, so as to increase their thickness, and consequently increase the strength ofthe thread. The case of the thread also increases in thickness as it approaches the entering-point of the screw, so that it shall not have its strength diminished as it is increased in depth.A V

It will be seen from the above description and :iccompanying drawings, that no part of the core of inv4 improved screw is cylindrical, but that it forms a conical wedge, whichwill enter wood without driving the fibres in advance of it. The fibres of the wood will'be spread out laterally, and compacted between and outside of the thread, while the latter will wind its way down into the wood, andseeue n. firm `h olcl therein.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, 'is- As a new and improved article of manufacture, a wood-screw, having' its core tapering from its shank toits.'

entering-point, and provided with a thread of uniform diameter, as herein described.





Referenced by
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US2746379 *Nov 10, 1952May 22, 1956Covington Mabel VFruit juice extractor
US2787186 *Mar 28, 1952Apr 2, 1957Antonin BrogiottiScrew spike with compression producing thread form
US5100274 *Aug 1, 1991Mar 31, 1992Illinois Tool Works Inc.Roofing fastener and improved screw therefor
US5226766 *May 21, 1992Jul 13, 1993Stuart SurgicalBone screw with improved threads
US5242447 *Feb 6, 1992Sep 7, 1993Howmedica Inc.To penetrate a bone
US5417533 *Jul 13, 1990May 23, 1995National Medical Specialty, Inc.Bone screw with improved threads
US5492442 *Feb 24, 1994Feb 20, 1996National Medical Specialty, Inc.Bone screw with improved threads
US6620163 *Jul 17, 2000Sep 16, 2003Gary K. MichelsonAnterior cervical plating system and bone screw
US6926718Apr 10, 2003Aug 9, 2005Gary K. MichelsonMultilock anterior cervical plating system
US6936050Apr 9, 2003Aug 30, 2005Gary K. MichelsonMultilock anterior cervical plating system
US6936051Apr 10, 2003Aug 30, 2005Gary K. MichelsonMultilock anterior cervical plating system
US6969390Mar 11, 2003Nov 29, 2005Michelson Gary KAnterior cervical plating system and bone screw
US7288095Aug 12, 2004Oct 30, 2007Atlas Spine, Inc.Bone plate with screw lock
US7322984Jan 6, 2005Jan 29, 2008Spinal, LlcSpinal plate with internal screw locks
US7438715May 6, 2005Oct 21, 2008Spinal LlcSpinal implant kit
US7468069Feb 10, 2004Dec 23, 2008Atlas Spine, Inc.Static anterior cervical plate
US7625381Sep 11, 2004Dec 1, 2009Warsaw Orthopedic, Inc.System and method for stabilizing a portion of the spine
US7651497Jul 1, 2004Jan 26, 2010Warsaw Orthopedic, Inc.Segmentable plate with locking element
US7704255Jul 1, 2004Apr 27, 2010Warsaw Orthopedic, Inc.Threadless multi-lock anterior cervical plating system
US7736380Dec 21, 2005Jun 15, 2010Rhausler, Inc.Cervical plate system
US7883528 *Sep 12, 2003Feb 8, 2011Arthrex, Inc.Fully threaded suture anchor with insert-molded suture
US8048075Mar 17, 2004Nov 1, 2011Warsaw Orthopedic, Inc.Orthopedic implant with locking element
US8123788Sep 11, 2004Feb 28, 2012Warsaw Orthopedic, Inc.Plating system having retaining member that permits movement of at least one bone fastener
US8262708Feb 27, 2012Sep 11, 2012Warsaw Orthopedic, Inc.Single-lock plating system
US8480717Sep 11, 2012Jul 9, 2013Warsaw Orthopedic, Inc.Orthopedic implant with locking element
US8641743Jul 9, 2013Feb 4, 2014Warsaw Orthopedic, Inc.Orthopedic implant with locking element
EP1001178A2 *Oct 27, 1999May 17, 2000TOGE-Dübel A. Gerhard KGScrew for gas concrete
International ClassificationF16B25/00
Cooperative ClassificationF16B25/00, F16B25/0015, F16B25/0057, F16B25/0047
European ClassificationF16B25/00G1C, F16B25/00C1, F16B25/00G1A, F16B25/00