HK1205547B - Nut lock - Google Patents

Description

Nut locking piece

Technical Field

The present invention relates to a nut locker, and more particularly, to a nut locker including a locking coil.

Background

When high strength and high resistance to loosening are required for nut and bolt assemblies, the nut is generally not locked using a preset torque (prevalightque). A more positive mechanical locking means is preferred. There are a variety of methods used including adhesives, serrated hex flange nuts, jam nuts (jam nuts), cotter pins, locking wires, welding, keyed locking pins or rings, and various added mechanical parts that capture and lock the nut or bolt head in place by attachment to an adjacent structure. In the case of adjacent structures, constraints must be added to both the nut and the bolt head to prevent relative rotation. All of the described locking devices have limitations.

The adhesive requires proper surface preparation and may not be suitable when maintenance requires disassembly.

The serrated hex flange nut is effective for joints where the material has a hardness of less than 40 RC. For nut and bolt assemblies, both the bolt and the nut must use serrated flanges. The serrations can damage the surface of the spray and coating and cause corrosion.

The locknut is a secondary threaded nut, typically thinner, that is tightened against the primary load-bearing nut. The use of a locknut is controversial and is not recommended by the Industrial Fastener Institute because load sharing between two nuts is difficult to control and can lead to loosening or failure of the threads of the locknut.

The particular locknut design sold under the Hard Lock trademark includes a threaded main nut having an eccentric male tapered back side that mates with a threaded locknut having a centering female tapered mating surface. While this design alleges to work effectively, it is relatively complex and requires training in order to be used properly. A significant limitation is that it must be integrally formed with the nut and thus cannot be used with standard nuts.

The cotter pin and locking wire may actively hold the nut, but they do not hold the bolt tension.

The nut and bolt may be welded together or to an adjacent structure. This may be effective, but must be done only by skilled and trained operators and only when a permanent joint is acceptable.

Special fasteners sold under Huck Lockbolt, Truelock Bolt, and Axilok Nuts use a locking ring and keyway to mechanically lock the nut and Bolt. These are complex mechanical systems that cannot be used with standard nuts and bolts.

Other special mechanical locking systems are used, such as the Nordlock tilt washer system and the Stage 8 system. Both of which anchor the bolt head or nut to an adjacent structure and prevent rotation of the anchor member. If relative rotation between the nut and bolt is required, two sets must be used. This adds expense and complexity. Nordlock systems require a limit on the stiffness of the adjacent structure so that serrated washers can be embedded and gripped to prevent rotation. This can damage softer materials as well as the sprayed or coated surface. The Stage 8 system requires various hardware component sets to prevent the bolt head or nut from rotating counterclockwise by anchoring the bolt head or nut to the adjacent structure.

Disclosure of Invention

Nut locks that prevent loosening of the nut, especially under severe operating conditions, are disclosed. The nut lock eliminates the complexity and limitations of these systems and provides the performance required in most demanding applications. The nut lock is used with standard nuts and bolts. In size, it meets the industry standard for locknut size. In use, it is simpler to use than any of the other active locking systems. Only one nut lock is required to prevent rotation of both the nut and bolt relative to each other. The present invention provides a nut lock having improved performance and wider applicability.

As disclosed, the nut lock includes a body, a locking coil, and a cage. The locking coil is positioned within the cage and the cage is secured within the body. The cage includes first and second stops, and the locking coil includes first and second tangs proximate the first and second stops. The tang is positioned to engage the stop as the nut body is rotated so that the coil is loosened when the fastener body is rotated in a first direction and tightened when the fastener body is rotated in a second direction. The locking coil has an inner diameter less than the inner diameter of the body such that only the locking coil engages the threaded member when the nut lock is mounted on the threaded member.

These and other advantages and features of the invention will be more fully understood and appreciated by reference to the description of the current embodiment and the drawings.

Drawings

FIG. 1 is a perspective exploded view of a first embodiment of a nut lock;

FIG. 2 is a top perspective view of a retainer of the nut lock;

FIG. 3 is a bottom view of the locking band and the retainer of the nut lock;

FIG. 4 is a perspective view of the nut lock;

FIG. 5 is a side view of the nut lock mounted on the threaded member adjacent the main nut;

FIG. 6 is a cross-sectional view of the nut lock, main nut, and externally threaded member taken along line V-V of FIG. 5;

FIG. 7 is a perspective exploded view of a second embodiment of the nut lock;

FIG. 8 is a top view of the nut lock of FIG. 7; and

fig. 9 is a top perspective view of the nut lock of fig. 7.

Detailed Description

Before the present embodiments of the invention are described, it is to be noted that the invention is not limited in its application to the details of operation, the construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of implementation in various other embodiments and of being practiced or of being carried out in various alternative ways not explicitly disclosed herein. Also, it is noted that the terminology used herein is for the purpose of description only and should not be regarded as limiting. The use of "including," "comprising," and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Furthermore, enumeration may be used in the description of various embodiments. The use of lists should not be construed as limiting the invention to any particular order or number of components unless expressly stated otherwise. The use of enumeration also should not be taken as excluding from the scope of the invention any additional steps or components that may be combined with or into the enumerated steps or components.

A nut lock constructed in accordance with one embodiment of the present invention is illustrated in fig. 1-6 and generally designated 40. Although shown in fig. 1-6 as a nut lock or locknut, the concepts of the present invention may be incorporated into a variety of nuts and fasteners, as will be appreciated by those skilled in the art.

The nut lock 40 includes a nut body 42 and a locking element, spring, coil or ferrule 44. The nut body 42 includes a hexagonal outer portion 46 configured to be engaged and driven by a conventional driving tool (not shown). The hex portion 46 includes a plurality of corners 48 and a plurality of flats 50 extending therebetween. Alternatively, the nut body 42 may be square, other polygonal, or any other shape. The nut body 42 may also be shaped to be engaged by any conventional driving tool now known or later developed.

The nut body 42 includes a main body portion 54 and a collar 56, the collar 56 extending from the main body portion 54 and defining a counterbore, recess, or pocket. The shoulder 60 separates the main body portion 54 and the collar 56. No portion of the nut body 42 is threaded.

The locking band 44 includes a coil or continuous bend 70 having a circular cross-section extending between a first tang or end portion 72 and a second tang or end portion 74. Although illustrated as having a circular cross-section, other cross-sectional shapes are contemplated, including square, rectangular, oval, triangular, and any other suitable shape.

In this embodiment, the first and second tangs or end portions 72, 74 are straight, but other shapes are also contemplated, including smooth curves and corners. Both tangs 72, 74 extend tangentially outwardly from the curved portion 70. Likewise, the locking band 44 may include a single turn with the first tang 72 overlapping the second tang 74. The locking band 44 may optionally include less than a single turn, or more than one turn, such that adjacent turns substantially contact each other. In the example shown, the locking band 44 has just more than one full turn. In this configuration, the first and second tangs 72, 74 are not stacked one on top of the other, but are radially spaced apart, and the curved portion 70 is stacked or layered in the portion between the first and second tangs 72, 74. As shown in fig. 1, the locking band 44 may be symmetrical to simplify manufacturing.

Referring now to FIGS. 1-3, the nut lock 40 further includes a spring retainer or cage 80. The cage 80 is a generally cup-shaped member having a central opening 82, defining a rim 84 in an upper surface of the cage 80. The cage 80 also includes a circumferential wall or downwardly depending skirt 86 that includes a plurality of slots 88 formed therein. In this embodiment, the cage 80 includes two spaced apart slots 88. In addition, each slot 88 includes two side edges or stops 90.

The cage 80 may be fabricated from flat metal formed in a progressive stamping operation or any other suitable material or forming operation. Although this embodiment includes two slots 88, more or fewer slots 88 are contemplated.

Referring to fig. 3, the locking band 44 is positioned within the retainer 80 and oriented such that the end of the first tang 72 is located in the first slot 88 and the end of the second tang 74 is located in the second slot 88. As can be seen in fig. 3, the angular movement of the first and second tangs 72, 74 is thus constrained by the side edges 90 of the slot 88. For example, the end of the second tang 74 can contact the side edge 90 of the second slot 88 during installation or rotation of the nut lock 40 in a clockwise direction, and the end of the first tang 72 can contact the side edge 90 of the first slot 88 during removal or rotation in a counterclockwise direction. Accordingly, angular movement of the first and second tangs 72, 74 is limited relative to the nut body 42. The curved portion 70 of the locking band 44 is supported on the inner surface of the rim 84.

To retain the cage 80 and the locking band 44 within the nut body 42 and to maintain alignment of the components, the collar 56 of the nut body 42 can be controllably deformed at the cage 80. It is contemplated that manufacturing methods such as swaging, crimping, or pendulum forging may be used. Of course, any other suitable means for flexing the collar 56 over the holder 80 may also be used.

Both the cage 80 and the locking band 44 may be sized to fit the desired nut body 42 and the externally threaded member 45. As can be seen in fig. 6, the outer diameter of the cage 80 may be selected to fit closely within the inner diameter of the collar 56, and the central opening 82 may be sized to match or provide clearance with the externally threaded member 45. The diameter of the locking band 44 may be sized to fit within the retainer 80, but include sufficient spacing to allow the locking band 44 to expand slightly when the nut lock 40 is installed onto the threaded member 45. The diameter of the circular cross-section of the locking band 44 generally corresponds to the pitch of the threaded member 45 so that the locking band 44 fits within the threads of the threaded member 45. In locking bands with non-circular cross-sections, the surface that engages the threads of the threaded member 45 may be sized smaller, substantially the same, or larger than the pitch of the threaded member.

The inner diameter of the locking band 44 is smaller than the inner diameter of the nut body 42. Thus, only the locking band engages the threaded member 45, and the nut body 42 "only becomes troubled" when the locking band rides within the threads of the member 45.

The fastener body 42, locking band 44, and retainer 80 may be made of any suitable material, including metals and composites. In addition, the locking band 44 may be manufactured from a relatively low cost material, such as round steel wire.

To install the nut lock 40 onto the externally threaded member 45, the nut body 42 is rotated in a first or substantially clockwise direction. Rotating the nut body 42 in the clockwise direction urges the end of the second tang 74 into contact with the side edge 90 of the second slot 88. This contact force causes the locking band 44 to expand slightly and reduces or possibly eliminates friction between the locking element 44 and the threaded member 45 so that the locking band 44 does not inhibit the installation of the nut lock 40 onto the threaded member 45.

Conversely, to remove the nut lock 40, the nut body 42 is rotated in a second or substantially counterclockwise direction. Rotating the nut body 42 in the counterclockwise direction urges the end of the first tang 72 into contact with the side edge 90 of the first slot 88. As installed, this contact force causes the locking band 44 to expand slightly and reduces or eliminates friction between the locking element 44 and the threaded member 45, thereby allowing the nut lock 40 to be removed from the threaded member 45.

Referring to fig. 5, an application of the nut lock 40 is shown wherein the nut lock 40 is used in conjunction with a threaded main nut 100 and an externally threaded member 45 (illustrated as a standard bolt). In this application, the main nut 100 is tightened onto the bolt 45, as is conventional. Installation of the nut lock 40 requires that the bolt 45 be of sufficient length to extend above the main nut 100 to install the nut lock 40. The nut lock 40 is tightened onto the bolt 45 and against the main nut 100 to a torque of, for example, about 10% of the main nut torque. Due to the locking band 44, the nut locker 40 is self-locking, thereby actively preventing the main nut 100 from unscrewing relative to the bolt 45, even under severe vibration.

A nut lock constructed in accordance with a second embodiment of the present invention is illustrated in fig. 7-9 and generally designated 140. The nut lock 140 is similar in construction and function to the nut lock 40 previously described. Thus, each element of the nut lock 140 is identified by the same reference numeral as the corresponding element of the nut lock 40, except that the number is increased by 100. For example, the locking band 144 in the nut lock 140 corresponds to the locking band 44 in the nut lock 40. Only the significantly different elements are described below.

The nut lock 140 omits the retainer 80 of the first embodiment and employs a washer 180 instead. The washer 180 is a simple washer and has a surface 184 and a central opening 182 therethrough. Further, the body 142 defines a first recess 176 and a second recess 178 formed on an interior of the nut body 142. Similar to the first embodiment, the washer 180 and locking collar 144 are retained within the nut body 142 by controllably deforming the collar 156 over the washer 180.

The second tang 174 is received and constrained within a second recess 178 in the nut body 142. As shown in fig. 7, the second recess 178 has an end wall 190, the end wall 190 engaging an end of the second tang 174 during rotation of the nut body 142. Alternatively, the second recess 178 may be configured to engage a corner or any other suitable surface of the second tang 174 during rotation of the nut body 142. Thus, rotating the nut body 142 in the clockwise direction urges the end of the second tang 174 into contact with the end wall 190 of the second recess 178, thereby allowing the nut lock 140 to be installed.

The first tang 172 of the locking band 144 extends into the first recess 176. The first tang 172 normally does not angularly rotate relative to the body 42 within the second recess 64. The first recess 176 has an end wall 192 that engages the end of the first tang 172 during disassembly or counterclockwise rotation of the nut body 142. Thus, rotating the nut body 142 in the counter-clockwise direction urges the end of the first tang 172 into contact with the end wall 192 of the first recess 176, thereby allowing the nut lock 140 to be removed.

Although two recesses 176, 178 are illustrated, the body 142 may instead define a combination of recesses and/or surfaces to receive each tang 172, 174.

Further, it is contemplated that the nut locks 40 and 140 may be used without the main nut 100 in applications requiring torsional joint friction but not high joint compression. Examples of such applications include battery cables and ground wires attached to threaded terminals to maintain a reliable electrical connection without risk of vibration loosening. Another application may be mechanical devices where two members are bolted together in an articulated relationship. The use of the nut locks 40 and 140 allows the components to be mounted together with a controlled friction that does not vary with relative movement between the components. The nut locks 40 and 140 will not loosen or tighten despite the rotation in the joint, thereby maintaining a preset torsional friction in the hinge.

The nut lock provides a versatile and simple alternative to conventional nut locks, many of which use secondary components or operations such as adhesives, cotter pins, welding, and locking pins or rings. The nut locking member can be used with standard nuts and bolts, is simpler to use than conventional nut locking members, can be reused for many times without losing effectiveness, can be scaled to meet specific requirements, and does not damage bolt threads. In addition, the nut lock does not change the manner in which the main nut and bolt are installed. Thus, the new nut lock provides an improved balance of simplicity and performance.

The above description is that of the current embodiment of the invention. Various changes and modifications may be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents.

This disclosure is provided for the purpose of illustration and should not be construed as an exhaustive description of all embodiments of the invention or as limiting the scope of the claims to the particular elements shown or described in connection with these embodiments. For example, and not by way of limitation, any of the individual elements of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide suitable operation. For example, this includes optional elements that are currently known (as may currently be known to those of skill in the art) and optional elements that may be developed in the future (such as those that may be considered optional by those of skill in the art after development). Further, the disclosed embodiments include a number of features that are described consistently and that can cooperatively provide a number of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the indicated benefits, except to the extent that they are otherwise explicitly set forth in the issued claims.

Directional terms, such as "vertical," "horizontal," "top," "bottom," "upper," "lower," "inner," "inward," "outer," "outward," "clockwise," and "counterclockwise" are used to aid in describing the invention based on the orientation of the embodiments shown in the drawings. The use of directional terms should not be construed to limit the invention to any particular orientation. Any reference to claim elements in the singular (e.g., using the articles "a," "an," "the," or "said") should not be construed as limiting the element to the singular unless explicitly stated in the claim as issued.

Claims (9)

1. A nut lock, comprising:

a non-threaded nut body having a main body portion and a collar extending from the main body portion to define a pocket, the nut body having an outer portion configured to be engaged and driven by a conventional driving tool;

a locking band within the recess of the nut body, the locking band including a coil portion and first and second tangs extending from the coil portion; and

a cage having an edge and a skirt, the cage being located within the pocket of the nut body, the skirt including first and second slots formed therein, the locking collar being located within the cage, the first and second tangs extending into the first and second slots, respectively, the cage being retained within the nut body by a collar.

2. The nut lock according to claim 1, wherein: the first and second tangs extend generally tangentially from the coil portion.

3. The nut lock according to claim 1, wherein: the first tang is configured to contact a side edge of the first slot during removal of the nut lock from the externally threaded member.

4. A nut lock according to claim 3, wherein: the second tang is configured to contact a side edge of the second slot during installation of the nut lock when installed on the externally threaded member.

5. The nut lock according to claim 1, wherein: the upper portion of the collar is deformed to retain the cage within the nut body.

6. The nut lock according to claim 1, wherein: the rim defines a hole having a diameter corresponding to the inner diameter of the locking band.

7. A nut lock, comprising:

a non-threaded nut body having an outer portion configured to be engaged and driven by a conventional driving tool, the nut body defining a pocket;

a cage secured within the pocket of the nut body, the cage including a circumferential wall defining first and second stops; and

a locking coil comprising first and second tangs, the locking coil being positioned within the pocket of the nut body and within the cage, the locking coil having an inner diameter less than the inner diameter of the nut body, the first and second tangs being proximate the first and second stops such that the first tang engages the first stop when the nut lock is rotated in the first direction and the second tang engages the second stop when the nut lock is rotated in the second direction.

8. The nut lock according to claim 7, wherein:

the first and second stops are defined by first and second slots in the circumferential wall; and

the first and second tangs are positioned in the first and second slots.

9. The nut lock according to claim 7, wherein:

the nut body including a shoulder defining a bottom of the pocket and an opposing swaged portion; and

the retainer is secured between the shoulder and the swaged portion.