NUT STOPPER FOR LOOSENING PREVENTION

Relationship to Prior Applications:

The present patent application is related, pursuant to the concept of the unity

of an invention, to US provisional patent applications 62/698,026 and 62/743,850 and claims benefit of the filing date of 62/698,026 provisional application.

1. Field of the Invention

This invention relates to fasteners and in particular to devices for nut loosening prevention.

2. Description of the Prior Art

There is a number of types of devices for loosening prevention, most of which are various washers located under the nut; spring-washers, lock-washers, jamming washers etc. Their disadvantage is limited effectiveness in the vast majority of cases, especially when the vibration, that the threaded connection is subjected to, is severe. Furthermore to begin unscrewing the nut it is necessary to first overcome their resistance which may be quite significant. A representative example of such solutions for high vibration environments is described in the US Patent Application 15,549122 where wedge locking washers are described. These washers have teeth that engage the surfaces such us the undersides of the nut and bolt head and the work parts surfaces around the hole through which the bolt passes. To secure one bolted connection 4 such washers are typically needed; 2 under bolt head and 2 under nut which translates into a higher cost and longer time to install. Clearly, the teeth engaging these surfaces can be expected to damage paint or anti-corrosion coating, furthermore these teeth will not work well on very hard surfaces and can be expected to cause unacceptable damage if applied to fragile surfaces. Thus this particular solution has a number of shortcomings and limitations. There are also known washers that are placed on top of the nut which have to be removed before the nut is unscrewed, as is for example described in the

Application PCT/IL2017/051095. However, while the washers therein described are more effective, they cost more than the lock-washers that they are meant to replace. A loosening prevention device made out of wire, which is likely to be cheaper is also described in PCT/IL2017/051095 and comprises at least one wire coil to be put around the bolt, whereas one end of that wire is suitably pointed or sharpened to be able to enter the clearance between the end of nut’s thread and the bolt thread channel’s bottom. The other end of that wire stopper device is intended to either enter a hole or a suitable indentation on the nut’s top surface or to have either a wire loop or semi-loop to be placed onto the nut - in both cases the intent is to assure that there is no relative movement between said wire stopper device and the nut thereby making sure that the elastic force produced by the flexed wire end, affixed to the nut as described above, continues by pivoting the wire stopper around the bolt to gently press said pointed wire end into said opening. The above described wire stopper device thus requires either the changes to the standard nut such as holes or indentations on top surface or needs a wire loop or semi loop. It’s not well suited to be removed by a wrench or socket or any nut runner mechanism and is best suited to be removed by hand. Another example of a nut stopper comprised of wire is presented in JP2001059514 wherein a spring with a handle at its rear and optionally a sharpened tip are presented. The use of a cap put onto said spring to tighten said spring’s grip onto the bolt shank is also described. The handle, as described in said patent can only be used to screw said spring into position; to remove it it needs to be pulled off, for example with pliers, and discarded. Thus the removal is destructive; there is no reuse. Furthermore the recommended combination of said spring with cap is relatively expensive and requires extra effort to install it.

In light of the foregoing we conclude that the prior art needs to be further improved upon.

3. Objects and Advantages.

One object of the present invention is to provide a coiled wire nut stopper with one sharp wire end for insertion into clearance between the end of nut thread and bolt thread channel and having handles for screwing it onto the bolt and off the bolt

Another object is to provide a coiled nut stopper with reversible top and bottom and both ends of its wire sharp for reversibility and fool-proofing it. Another object is to provide said coiled wire nut stopper with handles to enable its easy screwing onto and off the bolt.

Another object is to provide said coiled wire nut stopper with structural features to enable temporary wire stopper diameter expansion for easily putting it on the bolt or removing it without screwing.

Another object is to provide said coiled wire nut stopper with at least the leading handle close enough to leading wire tip to come into contact with nut top surface facing it to exert elastic force on the nut opposing its unscrewing.

4. Brief Description of the Drawings

Fig 1 shows top view of coiled wire nut stopper of first embodiment.

Fig 2 shows a view from the side of coiled wire nut stopper of second embodiment.

Fig 3 shows top view of a coiled wire nut stopper of second embodiment, second version

Fig 4 shows view from the top of a coiled wire nut stopper of third embodiment.

Fig 5 shows a top view of a coiled wire nut stopper of fourth embodiment.

Fig 6 shows a top view of second version of fourth embodiment.

Fig 7 shows top view of nut stopper of fifth embodiment.

Fig 8 shows side view of nut stopper of sixth embodiment.

5. Description of Preferred Embodiments.

The first embodiment of the coiled wire nut stopper of this invention (Fig 1 ) has one pointed or suitably sharpened wire end (1 ) for insertion into clearance between the end of nut thread and bolt thread channel, to jam it thus preventing the nut from loosening and unscrewing due to vibration. The coils (4) of the wire are of a diameter suitable to hug the thread of the bolt (3) with predetermined degree of compressive force and are of diameter smaller by a predetermined amount than the diameter of the thread.

However to enable easy screwing on of the coil facing the nut, it may be optionally made of slightly varying radius along its circumference with the part of said coil closest to the leading pointed or sharpened end being of a radius closer to that of the bolt thread. The rest of the first (or only coil) is of a radius smaller by predetermined amount than the radius of the bolt thread. For this optional implementation if there is more than one wire coil in the stopper; the following coil(s) will also have radiuses smaller than the radius of the bolt’s threaded shank by a predetermined amount. The wire cross-section may be round or of other suitable shapes, such as for example oval, triangular or diamond shape to fit into the thread better.

Optionally the pitch of the coils can be made smaller by a predetermined amount than that of the bolt thread; the result of that is that they are being subjected to not only a radial but a lengthwise extension and thus produce high level of static friction with bolt threads, thereby precluding the stopper’s turning and thus its axial displacement along the bolt. The 2 handles (2) are produced by bending the wire into loops. Preferably one handle (2) is located on the first coil/only coil at a predetermined distance to the sharpened end of the wire, while the second handle is preferably located on the last coil at a predetermined distance to the trailing end of the wire. The second handle (2) is preferably located in a diametrically opposite point to the first and can optionally have the handles of such length, so that the distance between their tips (2a) is the same as the distance between the opposing corner points of the nut a given coiled wire stopper is to be used with, although said distance between tips can be slightly smaller making the socket easier to place on the stopper, whereas said socket would be able to turn it for the instances where the coils compressive force and therefore static friction against the bolt thread are relatively limited. For ease of manufacturing and structural strength of the handles, they can be produced by bending the wire to form broader wire loops with the length of wire after the handle until its end shaped to curve around the bolt to prevent excessive flexing and residual deformation of handles when force is applied to them. Optionally it is possible to implement the nut stopper of first

embodiment making it out of wire of such diameter or size (in case of non-circular wire cross-sections) that a second non-sharp end of the wire could too enter clearance between the end of nut thread and bolt thread channel thereby making the nut stopper of this embodiment more fool-proof.

The second embodiment, (Fig 2) is similar to the first embodiment, except the trailing end of wire on the last coil is also made pointed or sharpened (1 ), while the trailing handle is located relative to trailing end similarly and generally diametrically opposite to the leading handle (2) located after the leading sharp end (1 ) of first coil, thereby making it possible, that either end of the nut stopper could be in contact with and jamming the nut. This embodiment would make the use of nut stopper easier and more foolproof. The second version of this embodiment (Fig 3) will dull wire ends (5), but will instead rely on the relatively smaller wire diameter or size (for non-circular wire cross- sections) for penetrating the clearance between the end of nut thread and bolt thread channel with either of its wire ends.

The third embodiment (Fig 4) can have either one or two sharp wire ends for insertion into clearance between the end of nut thread and bolt thread channel or like in the second embodiment the wire comprising the nut stopper can be thin enough to enter said clearance.

. Flowever the handles (2) are located along the coils at a plurality of points so that their tips form a shape such as a square, hexagon etc, possibly also forming a 3 dimensional shape having significant height as well due to handles location on different coils and thus at different levels, suitable for use of sockets or wrenches.

The handles themselves can have straight parts at their tips to promote improved hold of sockets or wrenches. The nut stopper of third embodiment can also be made symmetrical with symmetrical locations of the handles along the coils and close to wire ends.

The nut stopper of fourth embodiment, first version will have non-round coils, possibly of complex shape as shown, for example, on Fig 5 which will have parts of them lodged in the thread (6) and other parts (7) whose function is to provide the structure for the socket or a wrench to hold onto. As the total length of wire embedded into the bolt’s thread in each coil is limited thereby limiting the total static friction force available, the number of coils required will need to be predetermined to assure that a sufficient static friction force is produced. Second version of this embodiment (Fig 6) will have a predetermined number of coils forming shapes such as rectangles, squares, hexagons or other shapes suitable for gripping by a wrench or a socket wherein the bolt shank’s end is to be put through an opening in said coils (8) produced by drilling and/or broaching a circular widening in said coil stack of a diameter smaller by a

predetermined amount than the external diameter of the bolt’s threaded shank. For both versions if a sharp leading wire end for jamming is used a smaller predetermined number of coils will be required, as compared to the alternative implementation of nut stopper of this embodiment implemented without the sharp end for jamming.

For the shapes of handles and/or configurations formed by a plurality of them there are great many possible variations, however mutatis mutandis they are all considered to be within the spirit and scope of this invention.

The nut stopper of the fifth embodiment (Fig 7) may have one or two sharp tips (1 ). Alternatively it can be implemented like the second version of second embodiment by using a thinner wire whose ends are able to enter clearance between the end of nut thread and bolt thread channel even if dull. Flowever unlike the first and second embodiments, it has leading (2) and trailing handles (2a) which are located not in the diametrically opposing positions as in those embodiments, but rather closer together, when seen from above, at a predetermined distance from each other on the same side of nut stopper; either the side where the wire ends are or the opposing side. The predetermined distance between said handles must be such that it is possible to pull the handles close together to a predetermined distance between them using fingers or tools, such as for example pliers.

The nut stopper of the sixth embodiment (Fig 3) is not designed to penetrate the clearance between the end of nut thread and bolt thread channel. In its first version it has an end of wire of a diameter or size (for non-circular wire cross-sections) which will prevent it entering said clearance. As this nut stopper will not have the tip jammed in said clearance it has to have sufficient static friction force holding it in place which can be accomplished by making its coil’s predetermined inner diameter relatively smaller by a predetermined amount than the inner diameter of a nut stopper for the same thread size with wire tip(s) designed to penetrate said clearance. Alternatively the radially compressive force and therefore static friction holding the nut stopper in place, can be increased by increasing the wire thickness by a predetermined amount, while keeping the predetermined inner diameter the same or by a predetermined combination of changes in these two parameters. The second version of this embodiment (Fig 8) likewise won’t have the tip(s) designed to penetrate said clearance between the end of nut thread and bolt thread channel. The wire ends (5) are to be located within a predetermined, comparatively shorter distance from the leading handle (9) to assure that the leading handle comes into contact with the nut’s top surface (10) first and prevents significant further advancement of the nut stopper, as any further

advancement will cause the leading handle to be pressed harder against the nut’s top surface causing it to be turned backward while subjecting the wire behind the leading handle to torsion. Thus an elastic force is produced by handle pressing on the nut eccentrically and urging the nut in the direction opposite to unscrewing. The known spring washers urge the nut in the direction of unscrewing and they have been observed to actually promote loosening. In this case the handle will act like a spring washer, but in the right direction to prevent unscrewing. It’s possible to implement this nut stopper with a plurality of handles that can come into contact with the top of the nut. That can be done by having more than one such handle on the leading wire coil, where they can optionally be made upturned, and possibly having upturned towards the top of the nut handle(s) (9a) on the following coil(s). Upturned towards the top of the nut handles when pressed by the nut top (10) will experience greater, predetermined torsion and therefore greater force pressing on the nut. As the wire torsion needs to produce significant force to exert pressure on the nut top the wire has to be of predetermined diameter or size (for non-circular wire cross-sections) to produce that required force for a given nut size.

6. Sketches and Diagrams.

Provided separately.

7. Operation.

In operation the nut stopper (Fig 1 ) of the first embodiment is screwed onto the threaded part of the bolt shank protruding from the nut. At the end of said screwing the sharp leading end of the wire comprising the nut stopper enters the clearance between the end of nut’s thread and the thread channel thereby jamming the nut; thus assuring that it cannot move backward. The coils of the nut stopper (4) are hugging the bolt and press radially towards its thread thus creating a significant static friction force acting along the full combined length of the coil(s) and thereby preventing backing off by the nut stopper. The handles (2) are used for screwing or unscrewing the nut stopper onto the bolt end. It’s possible to use the socket for screwing in the nut stopper only when its radial compression of the bolt is relatively light. In most cases, pushing on the leading handle makes the wire embed deeper into the thread with a wedge effect creating very strong friction force; because of that it’s better to push or pull the trailing handle towards the leading handle either by fingers or using a rod-type tool such, as for example, a screwdriver of the appropriate size that can be put through the trailing handle to move it in the direction of screwing or unscrewing. Obviously in case of unscrewing what used to be the leading handle during screwing in, becomes the trailing handle for unscrewing. It is desirable to make an added push when completing the screwing in of the nut stopper to assure that its wire tip enters said clearance as much as possible, that can be accomplished by pushing the trailing handle with an extra force at that final stage so that the trailing handle elastically moves a predetermined distance towards the leading handle thus indicating that the proper torque is applied. Alternatively known torque measuring tool could be used. Optionally at the completion of screwing in, the leading handle can also be nudged forward to assure the best possible penetration by said wire tip (1 ) of said clearance.

The operation of the second embodiment’s first version is similar to the operation of first embodiment (Fig 2), except it is reversible, as it has sharp tips (1 ) on its top and bottom it can be screwed in from either of its ends. For the second version (Fig 3), nut stopper of this embodiment made of wire thin enough to enter the clearance between the end of nut’s thread and the bolt’s thread channel even if dull, the same use is possible; as the nut stopper can be screwed in from either of its ends and either of its wire ends will enter said clearance jamming the nut.

The wire stopper of third embodiment (Fig 4) can be implemented with either one or two tips or made of wire thin enough to enter the clearance between the end of nut’s thread and the bolt’s thread channel, even if dull. So accordingly it can be used like the above-described embodiments, but with one significant difference due to the handle tips (2) being a plurality, whereas their tips are forming shapes suitable for use of sockets or wrenches. Thus screwing in or unscrewing of the nut stopper of this embodiment can be done by hand for smaller thread sizes, but generally is done using sockets or wrenches.

The wire stopper of fourth embodiment (Fig 5) can be implemented with either one or two tips or be made of wire thin enough to enter the clearance between the end of nut’s thread and the bolt’s thread channel, even if dull. So accordingly it can be used just like the nut stopper of third embodiment, as its difference is only in the non-circular shape of coils (7) and the way it is manufactured.

The nut stopper of fifth embodiment (Fig 7) can be operated just like the nut stopper of first or second embodiments, being screwed onto the bolt or off the bolt end.

Flowever its design also allows, by pressing the two handles (2 and 2a) closer together, to temporarily expand the inner diameter of the coils which in turn allows the possibility of easy placement of the nut stopper in one movement, followed by fraction of a turn of nut stopper around the bolt, usually accomplished by pushing the rear handle, to get its wire tip (1 ) to enter into the clearance between the end of nut’s thread and the bolt’s thread channel. For removal it first needs to be turned in the opposite direction to release its tip from said clearance and then by pressing the two handles closer together either by fingers or a tool, such as for example pliers, expand its inner diameter and then remove the nut stopper off the bolt in one movement.

For the sixth embodiment the operation of nut stopper of this embodiment (Fig 8) has been adequately described in the Description Section and will not be reiterated here, but is included by way of reference as if fully set forth.