For many years, traditional wrenches have been widely used. Traditional wrenches are frequently found inconvenient, inefficient, cumbersome and new wrenches are highly demanded. For instance, wrenches having closed openings with planar engagement surfaces often result in stress being applied to a hexagonal fastener and thus cause deformation of the fastener as well as providing inefficient torquing ability. Prior art wrenches having closed openings with curved engagement surfaces are known. See U.S. Pat. No. 4,930,378 to Colvin. Although the prior art wrenches include six-point and twelve-point versions, problems with stress distribution are not resolved. Furthermore, the twelve-point version is configured using either metric or inch sizing, rather than both as in a duplex system. Ruzicka et al. discloses rotary wrenching tools capable of wrenching fastener heads in various measuring systems (U.S. Pat. No. 5,388,486. to Ruzicka et al.), but does not disclose a duplex system for both metric and inch sizes. Heberlie discloses ornamental designs for a double-ended box wrench showing the contour of the wrench heads. U.S. Pat. No. D303,069. The invention, however, discloses a double-ended one-sided crown. As the DIYers encounter an increasing number of metric fastener and diminishing percentage of inch sizes, they are required to have two sets of wrenches, for both inch and metric sizes, which are cumbersome, weighty and costly in investment.
In various embodiments, one or more of the problems have been reduced or eliminated.
In one embodiment, duplex open end and duplex box wrench are paired. Although the head of the open end is significantly smaller in profile than traditional wrenches, the paired crowns and the tapered internal guide adds tangential strength to the wrench head thereby permitting a slight reduction in the thickness of the wall of the both open and box wrenches. More noticeable is the smaller profile of the open end version, which has jaws that are more blunt than those of conventional wrenches. Although the wrenches are paired, the head is less than twice as thick as traditional wrenches. The tapered internal guide increases the offset quality of both end and box crowns.
In another embodiment, the box crown can be either six or twelve lobes. In one embodiment, the open end has four lobes to contact the fastener and thus distributes the stresses over the four flats of the hex nut. This decreases deformation of the fastener and inefficient torquing ability.
Another advantage of the present invention is compactness. Compactness of the present invention enables the duplex wrench to operate in tighter spaces than most traditional wrenches can do. The present invention also assures optimum contact on and around the hex while the depth of the crowns is minimized. The tapered internal guide prevents the crown from slipping past the hex.
In another embodiment, the lip provides perfect alignment between wrench and hex because of the bottoming out of the hex against the guide.
Another advantage of this single piece rotary wrenching tool with a tapered internal guide is that it provides sufficient space for the shaft of a hex bolt to pass through. The operator can nest a hex nut in the crown of the duplex wrench and carry it to a bolt in a different place to reach or to the underside of an object, making dropped and lost nuts less of a problem. The wide range of hexes that can be accommodated by the duplex set makes these unique tools an appealing, light-weight addition to a handy emergency kit or other tool box. With four sizes on each wrench it is easy to pick the right one for the job. This eliminates the need for the user to gather a bundle of wrenches before beginning a job. The concept of combining double crowns with a tapered internal guide can be applied to other related tools, such as drive socket, crow foot, nut driver, and flare nut and ratchet wrenches.
In another embodiment, two sets of duplex wrenches, both inch and metric, on back to back crowns, provide the DIYers with additional benefits. The pairing of inch and metric sizes dramatically reduces the number of wrenches needed to work on both measuring systems. They are not required to have or carry a toolbox of mixed wrenches. The duplex three pack enables the DIYers to operate on twenty-four metric and inch size hex fasteners. This also minimizes guesswork on choosing the right size wrench. Another advantage of the present invention is that less weight and metal are required in constructing a duplex wrench of the present invention than traditional wrenches.
The above and other objects, features, and advantages of the present invention will become more readily understood and appreciated from a consideration of the following detailed description of the preferred embodiment when taken together with the accompanying drawings, which, however, should not be taken as limitative to the present invention but for elucidation and explanation only.
Embodiments of the invention are illustrated in the figures. However, the embodiments and figures are illustrative rather than limiting; they provide examples of the invention.
It will be appreciated by those skilled in the art that the preceding examples and preferred embodiments are exemplary and not limiting to the scope of the present invention. It is intended that all permutations, enhancements, equivalents, and improvements thereto that are apparent to those skilled in the art upon a reading of the specification and a study of the drawings are included within the true spirit and scope of the present invention.
The present application is a U.S. continuation patent application of, and claims priority under 35 U.S.C. §120 to, U.S. nonprovisional patent application Ser. No. 12/542,095, filed Aug. 17, 2009, and published as US 2009/0301270 A1 on Dec. 10, 2009, which '095 application is a continuation patent application of, and claims priority under 35 U.S.C. §120 to, U.S. nonprovisional patent application Ser. No. 11/796,350, filed Apr. 26, 2007, and published as US 2008/0105093 A1 on May 8, 2008, which '350 application is a nonprovisional of, and claims priority under 35 U.S.C. §119(e) to, U.S. Provisional Patent Application No. 60/797,190 filed May 2, 2006. Each of the patent applications and patent application publications listed hereinabove is hereby incorporated herein by reference in its entirety.
Number | Date | Country | |
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60797190 | May 2006 | US |
Number | Date | Country | |
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Parent | 12542095 | Aug 2009 | US |
Child | 12836960 | US | |
Parent | 11796350 | Apr 2007 | US |
Child | 12542095 | US |