Patent Application
20240367292
The present invention relates to a hand tool used for the operation of predominantly hexagonal, nuts, bolts and fasteners, in particular relating to an open end wrench or open box or ring wrench capable of being used to circumvent fastener elongate attachments such as obstructing tubes, pipes etc. attached to the fitting or fastener to be operated.
Pipes or tubes utilise pipe or tube nuts or fasteners to connect the pipework to the various hydraulic, pneumatic or fluid or air machines or controls. The tube nuts utilised are generally made from brass or other “soft” metals which can be easily damaged during dismantling especially when corrosion, sealant or the like causes the pipe-nut to be tighter than expected. When used on tight fasteners normal open ended or crowfoot wrenches tend to round off the corners of the flare nut drive flats often to a stage that they become inoperable.
In particular the three jaw wrench or socket portion is designed to work on overly tight, undersized or worn fasteners, with little chance of slippage through the use of three equidistant individual, or alternately three dual sets of torque application points, incorporated within equidistantly spaced three jaw chuck spaced like “jaws”, each “jaw” gripping every second driven half face of the worked hexagonal fastener head, bolt or nut.
Hex bolts, nuts, screws, and other similar threaded devices hereinafter termed fasteners are used to secure and hold multiple parts together.
A conventional open wrench is a tool used to provide grip and mechanical advantage in applying torque to turn engaged fasteners, it can further be utilized to operate such as to keep the complementary head part of the fastener from turning. One type of wrench is called an open-end wrench, which usually has a parallel U-shaped opening to grip two opposite, parallel faces of a fastener head. As torque is applied to the wrench head the torque is transmitted to the fasteners in the appropriate chosen drive direction. The said open-end wrench head is configured to be essentially a one direction wrench, the opposite working direction requiring the wrench to be flipped over.
As only the leading half of the hexagonal fastener head faces in the operated direction can be actually levered in the chosen drive direction, the fastener can typically only be operated by the two opposite leading halves or hereafter termed driven half faces of its hexagonal drive flats, the first usually largest operating jaw only actually requiring to be half its length in order to operate the said leading half of the correspondingly sized worked hexagonal fastener head driven half face, although the conventional shaped open-end wrench has a full length first operating jaw. In order to operate the fastener opposing driven half face, the conventionally shaped open-end wrench does require a full length second operating jaw, although this jaw is invariably less substantial in structure, the outmost tip of the second jaw face is normally the most vulnerable stress point of the actual wrench operating profile as it is also subject to the maximum lever arm force during operation of the worked corresponding hexagonal fastener head driven half face. Closed sockets, box or ring type wrenches are preferable to open jaw type wrenches because the torque arm force applied to the socket is transmitted to the fastener via a much larger contact area and the closed ring head of the socket or wrench is inherently stronger and therefore can transmit a far greater torque with less harmful distortion of the fastener head and less chance of the socket or wrench head damaging or slipping off the fastener. A typical open-end wrench has a wrench head which consists of two jaws each with parallel, smooth planar surfaces that engage the opposite sides of mainly hexagonal fasteners. In order to transmit without damage to either the fastener head or the operating wrench head the jaw surfaces require to be a snug fit upon the fastener hex flats, further requiring that only properly sized metric or inch wrenches should be used on the correspondingly sized fastener head if any reasonable amount of torque level is used. One of the most common problems in operating hexagonal headed fasteners using typical open wrench heads, whether on nuts or bolts, is the wrench head slipping on the operated fastener head. This can be caused by either a worn fastener, improperly sized wrench usage, corrosion, previous over tightening or previous damage to the operated fastener head or wrench head inner drive profile.
Prior art open-end wrenches suffer in that the jaws of such open-end wrenches tend to spread under load. This enables the fastener to rotate within the open-end wrench head, which damages the corners of the operated hexagonal or other polygonal fastener by rounding off the worked corners of the said fastener. This rotation moves the fastener outwards towards the weaker distal end of the wrench head jaw flats simultaneously abating the possible level of robustness of engagement of the wrench head jaw flats upon the opposing fastener driven flats or points. In operations requiring medium to high torque this can damage one or both the fastener and the wrench head, as the fastener becomes unseated in the jaws of the wrench, this occurrence of the fastener becoming unseated is colloquially referred to as “walking the wrench”.
In order to lessen the occurrence of slippage when using such an open wrench the jaw driving surfaces can be roughened, high friction, ridged or even serrated as in U.S. Pat. Nos. 5,117,714, 5,148,726, 4,778,730, 6,276,240, 6,907,805, 8,667,873 or 9,120,210 and applications US 2019/0134787, US 2019/0015961 all these prior art wrench jaws use multiple ridges or protrusions on the opposing operating jaw surfaces and are incapable of much more “proof torque” (the maximum level of torque at which the open wrench head is rendered inoperable by means of its splaying or indeed breakage) than a conventional quality open wrench operating a good properly sized fastener. There are several prior art designs which have similar results but differing execution, wherein the fastener actual driven half face is usefully levered or driven only on the weaker outer portion of the second jaw or sometimes termed protruding tongue. As only the driven half face of the hexagonal fastener drive flats in for example the operated clockwise drive direction (the wrench head engaging the corresponding fastener head from generally the right hand side), can be utilized to actually operate the worked fastener in the chosen drive direction, any wrench head face abutting the non-driven half face of the hexagonal fastener drive flats when operated in the said clockwise drive direction cannot be utilized to operate the fastener. The simple flipping over of the wrench, allows drive in the opposite counter-clockwise direction. The best of this design of wrenches having only minimal improvement in proof compared to a high quality open-end wrench having jaw surfaces which are a snug fit upon the fastener hex driven half face. U.S. Pat. No. 6,269,715 in particular as best shown in FIG. 12 illustrating a ratcheting open-wrench whereas the fastener head 4 is driven by respective protuberances P2, P7 on the opposite jaw grips and a “supplementary” protuberance P5 urged in localized support upon the leading half of the said hex drive flats 43. Given that even high quality fastener hexagonal heads can normally be 1.5 to 2.5% undersized and the fastener hexagonal head corners are normally radiused contributing a further 2% reduction in the fastener hexagonal head corner to corner size, in best practice any wrench drive profile requires to be just far enough from the fastener hexagonal head corners to prevent detrimental corner contact with the said fastener hexagonal head corners, so that the said corners are not destructively rounded off during the application of any applied robust torque required. Empirical testing of such wrench designs has shown that the wrench head profile first or initial gripping or driving surface requires to be extremely robust in both shape and strength, as this is invariably the weakest point of this type of wrench head profile, The said U.S. Pat. No. 6,269,715 wrench in order to be able to ratchet, as shown in all depictions and has a useful first or initial gripping point of less than 6% of the length of a normal fastener hex drive flats from the fastener hex corners.
It is known that the most efficient operation of the fastener drive by any wrench profile is to apply the operating torque as close as possible to the corners or points of the fastener hexagonal drive profile. However, the closeness to these said corners can be problematic as these same corners are easily rounded off especially if the open-end wrench has jaw surfaces having less than snug fit upon the fastener hex flats.
U.S. Pat. No. 4,688,454A as illustrated and as claimed within all claims is a crowfoot type “wrench” operated by a separate wrench socket, within “a double square drive socket having eight notch shaped points” claim 1, “is an open ended, high torque wrench”, “for use on a nut of selected size to which there is limited access”, “having a jaw formed substantially as an arc,” “having an open-end” and “having two spaced opposing ends of the arc at the open-end, said open-end sized to engage said nut”, in tests using top grade chrome molybdenum instead of the industry standard but inferior chrome vanadium, correctly hardened using the specification given, resulted in proof torque of less than 250 in lbs nothing near the 1,800 in lbs specified.
As illustrated or constructed to any claim this device has useable torque only in a single direction, depicted in a clockwise direction, it is assumed flipping over for torque use in the anti-clockwise direction. Any use in the incorrect torque direction would and will result in so low a “proof torque” as to render the device un-usable.
FIGS. 3, 4, 5, 6, 7 and 8 illustrating a box or ring type socket having approximately 110-120 degrees of its circumference removed. In what can be termed “the first iteration”, as shown in FIGS. 4 and 7, in order to allow direct access for the fastener to be operated, as in the illustrated clock-wise direction only two 102, 98 of the four flat walls 102,104, 96, 98 of the inner drive profile actually act to operate the worked fastener flat sides 108, 110 driven half faces, any lever arm force applied by the remaining two of four flat walls 104, 96 will and would merely urge the fastener out the open end 62. This iteration has no better and arguably less proof torque than a standard quality open-ended wrench or crowfoot, in correct test conditions using the specified dimensions and using top grade chrome molybdenum steel, correctly hardened, failures occurred at approximately 210 in lbs. Claim 1 further states, “said jaw being in tension around the nut as it is rotated to prevent said jaw from slipping on the nut”, this is clearly not the case in this iteration as only the outer jaw 58 is under tension, the inner jaw 60 clearly being under compression.
In the “second crowfoot type iteration” as illustrated in FIGS. 5 and 8, “said arced shaped jaw using notch-shaped points, each notch-shaped point having two flat walls,” “joined at their outer ends to form a notch-shaped point; said notch-shaped points being engageable with respective points of a properly sized nut”, in order to manufacture a crowfoot socket or wrench to this design with the quoted minimum 1,800 inch/pounds torque (requiring an ½″ socket drive) to an approximate scale according to FIG. 6, a ¾″ (19.1 mm) fastener operated size with an as stated, considerable socket wall thickness of 0.2″ (5.1 mm.) and a maximum specification depth of 0.405 inch (10.3 mm) would require a construction using expensive exotic tool steels as proper physical tests using top grade chrome molybdenum, which is a higher grade than chrome vanadium, correctly hardened, the test samples completely failed to meet their 1,800″lb torque minimum specification whereas the three jaw wrench to the identical specification, hardness and material can easily exceed this minimum specification.
U.S. Pat. No. 7,146,884 denotes a two jaw open end wrench, head 14, according to claim 1, 6, 10 and 14 comprising two adjacent bite surfaces 24, 32 “disposed at an angle (Ft, Fc) greater than or equal to about 15 degrees and less than or equal to about 30 degrees with respect to the body axis” FIGS. 2B, 2C, 2D and in particular 2E, “between them a throat (web)” 18, the three jaw wrench designed to work at a similar angle of 5-10 degrees. Further claimed in claim 2, “wherein the (single) bite edges 29, 31 are of sufficient sharpness to plow into the fastener 36 sides” 46, 48 in order to drive the operated fastener 36 as illustrated in FIGS. 2E and 2F depicting the actual operation. As further described in the detailed description, “Plowing” “refers to the jaw bite edges and surfaces digging into the fastener head so that fastener material builds up in front of the bite surface”, “in order to achieve adequate plowing, the bite surfaces must be adequately sharp”. The operated fastener 36 if tight to operate would be damaged and in most circumstances leaving problematic sharp bur's. Furthermore claim 3 is specific in no engagement with a third torque application point. All the associated patents were allowed to lapse during or after 2010.
Many known, stamped metal plate, multiple function bicycle wrenches or spanners as they are known in the UK made since the 1940's till this present time, have their head portion fastener access 90 degrees to the handle portion. As the head width of these wrenches is unrestricted they perform well, if their depth were similar to normal wrenches they would easily exceed the required ASME 107.6 standard open wrench proof torque specification.
The majority of failures in all types of prior art open-end wrenches occur within the second jaw, as the normally susceptible tongue shaped prior art elongate second or bottom jaw with its leverage point at its extremity can cause the said second jaw to either flex or fail under anything but a perfect fit upon the fastener hex flats. In use on over tight for any reason fasteners, a professional would never presently in choice use an open wrench to slacken a tight fastener if a box or ring wrench or socket could possibly be used.
Aspects of the present invention teach certain benefits in construction and use in which give rise to the exemplary advantages described below.
It is a general object of the three jaw wrench to provide a far more robust flare nut or crowfoot wrench, whilst having a fastener access bigger than any normal fastener corresponding elongate attachment such as a brake pipe, hydraulic pipe, fluid or air pipe, or any further tube, pipe or rod etc. utilized and which avoids some disadvantages of prior art wrenches while affording additional structural and operational advantages, or to provide an alternative to existing products at a lower manufacturing cost.
Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessary obscuring of the disclosure. Accordingly, the description and drawings are to be regarded as illustrative, rather than in a restrictive sense. It is an object of the present invention to provide a low cost tool comprising a single piece three jaw wrench or socket portion with an extremely high torque capability, for example manufactured by industry standard forging, from industry standard steels and capable of several useful functions in one unique extremely robust three jaw wrench head or socket portion design.
The first embodiment is a three jaw wrench or socket comprising a triangulated three jaw operating profile and head portion design which provides far superior operating torque and proof torque than any known prior art similar width open-wrench or crow foot wrench or socket, the proof torque attainable being capable of over ten times that currently required by a similar sized heavy duty crowfoot under the ASME B107 standard, the test mandrill normally failing before the test three jaw wrench or socket, the operating profile is characterised in robustly gripping in the drive torque direction of use a correspondingly near sized worked hexagonal fastener by a triangulated grip operating profile, further termed equidistant torque application points, one engaging each second corresponding hexagonal fastener head or nut driven half face in the drive torque direction of lever arm force application, the occurring projected force simultaneously self centring upon the worked fastener driven half faces, any slight variances in fastener drive flat to flats manufacturing tolerances or worn or damaged fastener drive flats being automatically adjusted and compensated for in the same manner as a three legged stool compensates for an uneven floor.
Furthermore, allowing substantial reduction of the overall wrench head width, whilst considerably increasing the strength and torque capability of the head portion structure.
The second embodiment of the three jaw wrench or socket portion, whereas the head portion has a triangular grip operating profile and head portion design which firstly provides far superior operating torque by concentrating the torque applied to the corresponding worked fastener head driven half faces by the use of three separate generally equidistant torque application points, said torque application points comprising drive flats, other known drive profiles, or in best practice equidistant torque application points, whilst minimizing the damage to either the head portion or driven fastener head or nut drive flats or corner points. The three jaw wrench inner operating profile is notionally generally hexagonal in shape characterised by approximately one and a half lengths of the fastener faces or approximately 100 degrees of the said generally hexagonal shape being removed to form a substantial head portion elongate fastener attachment access.
The remaining generally part hexagon inner operating profile has concave arcuate corner profiles, these radii chosen to prevent stress cracks under high torque use. The torque application point leading edges when engaged usefully intersect only in the chosen drive torque direction the corresponding leading halves of the worked fastener drive flats hereafter termed the fastener driven half faces, forming in best practice three robust torque application points within the wrench head inner operating profile. Although smaller radiused torque application point leading edges having lower converging angles can be used, they exhibit much lower levels of torque use before damage to either the torque application point radiused leading edges or fastener driven half faces. The third embodiment of the three jaw wrench or socket portion comprises, wherein in order to construct as robust and compact a head portion as possible, the first and third torque application points within the head portion inner operating profile, when operated, are under tension as they grip and pull around, their corresponding fastener drive flat driven faces whilst the second torque application point is under compression as it pushes its corresponding fastener driven half face, characterized by the said torque application points contact with their corresponding worked fastener driven half face being initially in generally the same point within each said leading fastener drive half flat, constantly equalizing any lever arm force applied by each of the said torque application points upon said driven half faces of the worked fastener.
The fourth embodiment of the three jaw wrench is in order to further construct as robust and compact a wrench head as possible, the three jaw wrench head inner profile second jaw incorporates the second torque application point, the leading edge of which is specifically designed to operate under compression, gripping and pushing the corresponding fastener driven half face being worked, the resultant compressive force reaction being directed into the strong handle portion. Characterized by said second torque application point being incorporated within an extremely short and thick second jaw, the second torque application point, as far as prudent, comprising the point of convergence between the handle portion and the head portion, resulting in a far greater inherent open wrench head torque capability as the normally susceptible tongue shaped prior art elongate second jaw with its greatest drive capability at its extremity is the main cause of the prior art second jaw to either flex or fail.
The fifth embodiment of the three jaw wrench, comprises, a wrench head portion wherein as only the driven half faces of the hexagonal fastener drive flats, in one example in the operated clockwise drive direction (the wrench head engaging the corresponding fastener head from generally the right hand side), can be utilized to actually operate the worked fastener in the chosen drive direction, any wrench head face abutting the non-driven half of the hexagonal fastener drive flats when operated in the said clockwise drive direction cannot in any way be utilized to operate the said fastener. The present invention is characterised whereas its optimum point of engagement between the in best practice torque application point radiused leading edges and the said driven half faces of the fastener drive flats when used on undamaged fasteners is approximately 8-20% of the length of the operated fastener drive flat face from the driven half hex corners. This produces an three jaw wrench profile, or socket portion capable of robustly operating a corresponding hexagonal fastener head a full half size smaller than the said initial fastener head size, for example 12.5 mm instead of 13 mm, likewise a badly worn or damaged 13 mm fastener head size is still capable of being robustly operated at torque levels far above that of a prior art open or crowfoot wrench.
The sixth embodiment of the three jaw wrench or socket portion comprises, a head portion characterised wherein the optimum point of engagement between the torque application point leading edges and the said driven half faces of the fastener drive flats when used on undamaged fasteners is approximately 8-20% of the length of the operated fastener drive flat face from the fastener corner points on the smaller sizes of operated fastener and requires to be no more than 4 mm in from the adjoining fastener hex corner on the largest wrench head sizes, however if the operator requires a wrench head profile predominately for use on worn or very worn or damaged fastener heads the said percentage or indeed length from the adjoining operated fastener hex corner can be increased significantly, in best practice said point of engagement always remains upon the driven half faces of the fastener drive flats.
The seventh embodiment of the three jaw wrench, comprises an open-wrench or socket, inner drive operating profile characterized by the implementation of three generally equidistant torque application points the contact face of which being toothed, serrated or generally roughened. The central point of the inscribed circle of said torque application points being generally equivalent to the worked fastener head inscribed circle radius intersecting the said torque application points from the said central point, said torque application points being further capable of automatically self-centring upon and equally operating on at full force torque upon any undulations still remaining comprising the worked fastener worn or damaged driven half faces out with said inscribed circle.
The eighth embodiment of the three jaw wrench comprises, first, second and third torque application points which can comprise the utilization of many different profiles, the most universally useful being characterized by the torque application points utilizing radiused leading edges which have the greatest overall advantages, the leading edges of which comprise a radius the size of which is chosen according to the wrench commercial requirements, the smaller said leading edge radius, the greater the grip provided for use on worn or damaged fasteners, a larger leading edge radius utilized where new or undamaged fasteners are worked. In order to promote as robust as possible inner operation profile, the rear aspect of the torque application points radiused leading edges, comprises a larger smooth radius or straight profile merging into the wrench head inner drive profile, the rear aspect of the said leading edge radius nearest the corner profiles, in best practice merging into the adjacent concave arcuate corner profiles. The said torque application point radiused leading edges may be singular or in sets according to the market requirements.
The ninth embodiment of the three jaw wrench, or socket portion comprises a three generally equidistant torque application point operating profile, being further capable of adapting to and operating upon at full force torque, both metric and inch and vice versa near sized hexagonal fastener heads or nuts.
The tenth embodiment of the three jaw wrench or socket portion whereas the fastener driven half faces can differ in shape from those illustrated as many differing fastener or workpiece profiles exist, all of which further profiled torque application point types could be incorporated according to the operators requirements or manufacturers needs whilst not deviating from the basis of the present invention.
The eleventh embodiment of the three jaw wrench, comprises a closed box head portion profile similar to a known box or ring wrench or closed socket but implementing the said triangular grip operating profile.
If the wrench requires to be utilized in the opposite direction the wrench is simply flipped over. While one or more preferred embodiments of the invention have been described above, it should have been understood that any and all equivalent realisations of the present invention are included within the scope and spirit thereof. The embodiments depicted are presented by way of example only and are not intended as limitations upon the present invention. Thus, it should be understood by those of ordinary skill in this art, that the present invention is not limited to these embodiments since modifications can be made. Therefore, it is contemplated that any and all such embodiments are included in the present invention as may fall within the scope of appended claims.
Following is a listing of the components used in the best mode preferred embodiment and alternative embodiments. For the ready reference of the reader the reference numerals have been arranged in ascending numerical order.
A full and enabling disclosure of the present invention including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended drawings, in which:
Referring to the drawings as shown in,
The three jaw wrench 1 or closed box head portion 320, socket portion 326 utilizing dual sets of torque application points 325, provides a low cost tool that can be a stand-alone open- or box wrench or crowfoot socket or conventional socket used in conjunction with known square drive hand tools (not shown).
As depicted in
The head and handle portions convergence points 317, 21, close proximity to the second jaw 303 and handle portion 20, further denoted.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types above. Whilst the invention has been illustrated and described as embodiments of a three jaw wrench, accordingly it is not limited to the details shown, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and its operation can be made by those skilled in the art without departing in any way from the spirit of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2110519.2 | Jul 2021 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2022/051914 | 7/21/2022 | WO |
