The present disclosure relates generally to a torque retaining device. More particularly, the present disclosure relates to a torque retaining device for preventing unitary rotation of a nut and fastener.
This section provides background information related to the present disclosure which is not necessarily prior art.
The joining of parts, particularly during the construction of mechanical assemblies, often requires the use of threaded fasteners and corresponding nuts and washers. In general, fasteners are placed through corresponding pre-drilled holes of at least two parts to form a joint. While the pre-drilled holes can be threaded and attached directly to the fastener, this is generally avoided, as threaded surfaces have a tendency of being stripped. Therefore, the joining of parts is typically achieved via clamping by relative rotation of the fastener and nut. Fasteners offer a low tech and simplified solution over other types of fastening means, such as welding, and also allow later removal. However, certain types of joints can be difficult to assemble with fasteners. Because the fastener rotates with respect to the nut, either the nut or fastener needs to be rotationally held in place while the other is rotated, otherwise unitary rotation prevents tightening. It becomes increasingly difficult to tighten a fastener and nut in smaller spaces as access to both the nut and fastener is not always available or convenient. Likewise, where the two parts that are joined are large, it is not always feasible for one person to simultaneously reach both the nut and fastener.
In attempts to assist fastener use in these situations, certain devices have been developed for fasteners and nuts that are industrially referred to as “flag bolts” and “flag nuts.” Flag bolts and flag nuts include an elongated “flag” which engages a portion of the part during fastening. This engagement prevents rotation of the attached fastener or nut and thus allows the opposite to be tightened without unitary rotation. While these flags do present development within the art, they suffer certain drawbacks. For example, flags are constructed integrally and thus can only be used once, utilize more material, and require increased tooling costs. In addition, the integral flag adds weight which is particularly problematic in the automobile industry where there is a constant effort to reduce weight. Furthermore, the flags are often times made of thin, highly corrosive metal which spreads to more expensive parts via metallic contact. Moreover, the flag has corroded, removing the fastener becomes difficult requiring extra time and tools thus increasing maintenance costs. The above issues create the risk of blossoming into improper assembly and generally slow down the assembly process.
Accordingly, there is a continuing desire to provide a torque retaining device that provides the benefits of the flag without the many shortcomings.
The subject invention provides a torque retaining device for preventing unitary rotation of a nut and a fastener extending through two parts to be connected. The torque retaining device comprises an engagement portion including a wall having an inner side defining a cavity for placement of the fastener head or nut. The inner side of the wall is shaped to rotate with the fastener head or nut. The torque retaining device further includes an elongated portion having at least one sidewall extending radially outwardly from the engagement portion for rotationally catching on one of the parts that the fastener is to be extended through. At least one flexible member extends radially inwardly from the inner side of the wall for holding the fastener head or nut in the cavity of the engagement portion.
In another aspect of the present disclosure, the subject invention further provides a torque retaining system for preventing unitary rotation of a nut and a fastener extending through two parts to be connected. The system comprises a fastener head having an exterior surface that defines an indentation extending radially inwardly. A torque retaining device is also included and comprises an engagement portion and an elongated portion. The elongated portion extends radially outwardly from the engagement portion for rotationally catching on one of the parts that the fastener is to be extended through. The engagement portion includes a wall that has an inner side defining a cavity for engagement with the exterior surface of the fastener head. The inner side of the wall being shaped to rotate with the fastener head. At least one flexible member extends radially inwardly from the inner side of the wall into the indentation of the fastener head for holding the fastener head in the engagement portion.
In yet another aspect of the present disclosure, the subject invention further provides a torque retaining device for preventing unitary rotation of a nut and a fastener extending through two parts to be connected. The torque retaining device has an engagement portion that includes a wall having an inner side defining a cavity for placement of the fastener head or nut. The inner side of the wall is shaped to rotate with the fastener head or nut. At least one flexible member extends radially inwardly from the inner side of the wall for holding the fastener head or nut in the engagement portion. The flexible member includes an arm extending to an angled cam surface for effectuating radial outward flexing of the arm as the cam surface engages the fastener head or nut.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and are not intended to limit the scope of the present disclosure. The inventive concepts associated with the present disclosure will be more readily understood by reference to the following description in combination with the accompanying drawings wherein:
Example embodiments will now be described more fully with reference to the accompanying drawings. In general, the subject embodiments are directed to a torque retaining device that prevents a nut and fastener from simultaneously rotating during the tightening of the fastener during the connection of two parts. However, the example embodiments are only provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
Referring to the Figures, wherein like numerals indicate corresponding parts throughout the views, the torque retaining device is shown to ease workability with fasteners in tight spaces. As it will be appreciated with further reading, the torque retaining device prevents unitary rotation of a nut and fastener without the drawbacks associated with the prior art. More particularly, the torque retaining device includes a holding mechanism that allows removal of the torque retaining device from the fastener or nut once the two parts are tightened enough to prevent unitary rotation.
The torque retaining device 20 can include an engagement portion 34 and an elongated portion 36. According to an aspect, the engagement portion 34 is used for connecting to the fastener head 30 for conjoint rotation therewith. The elongated portion 36 includes two sidewalls 38 extending towards one another radially outwardly from the engagement portion 34 to define a point 40. As the nut 28 is threaded onto the fastener 26, rotation of the fastener head 30 is prevented as the engagement portion 34 rotationally mates with one of the parts 22, 24. This rotational mating can be accomplished via friction between elements and/or one of the parts 22, 24 having a protrusion 42 that contacts the sidewall 38. As described above, preventing unitary rotation is particularly useful in instances where the parts 22, 24 are disposed in a confined space that prevents access to the fastener head 30 with a wrench and also in situations wherein it is difficult for one person to reach both the nut 28 and fastener head 30 simultaneously.
Referring specifically to
The connection portion 53 of the inner side 48 is illustrated in the above embodiment as defining a hexagonal-shape to mate with a traditional bolt-like fastener. However, the inner side 48 can define various shapes for mating with various types of fasteners and corresponding nuts. Certain non-limiting examples are shown in
Another embodiment of the engagement portion 34′ is illustrated in
As best shown in
While it is preferable that as the arms 80 and tabs 86 are flexed out of the way, the tabs 86 can completely snap off of the fastener head 30 or nut 28. Moreover, the tabs 86 can also be spaced further or closer to the flange ring 52. In instances where the torque retaining device 20 completely snaps off of the fastener head 30 or nut 28 upon tightening, the engagement portion 34 generally either has only one flexible member 76 or the arm 80 of the flexible member 76 is rigid with low ductility. In the case of a singular flexible member 76, the tab 86 causes unequal force and thus is automatically removed upon being radially flexed outwardly during tightening of the fastener 26 and nut 28. However, it should also be appreciated that each engagement portion 34 could include any number of flexible members 76 and the flexible members 76 could take many different forms so long as they axially retain the fastener head 30 or nut 28 during tightening.
Another embodiment of the elongated portion 36′ is illustrated in
With reference now to
The over-molded torque retain device 20′ is preferably over-molded onto an accompanying modified fastener 100 as best shown in
A method 200 of attaching the over-molded torque retaining device 20′ on the modified fastener head 102 is also provided and can include a mold 136 defining a cavity 138 that outlines the shape of the over-molded torque retaining device 20′. The modified fastener head is placed 202 within the mold such that it is impermeably sealed therein with the bearing portion abutting 204 an interior surface of the mold 136. The injector provides 206 molten material to the cavity through at least one port. While
It is preferable that the molten material be a plastic base and have a relatively low melting temperature compared to the modified fastener 100 which is preferably metal. It also preferable the molten material have some elasticity for increased friction against a part 22, 24. As one example, the molten material can be rubber to allow the over-molded torque retaining device 20′ to be elastically removed without breaking. However, it may also be desirable to use a more rigid material that can be broken off after use. Regardless of the molten material composition, the method preferably continues with placement 208 of molten material radially inwardly into an indentation defined by the modified fastener head. The molten material is then allowed to cool 210 until it forms into the over-molded torque retaining device. The step of forming the over-molded torque retaining device may further include forming 212 an engagement portion and forming 214 an elongated portion. The method may further include providing an indicia on the modified fastener head that relates to one of size, shape, and material. Additional, the method can include a step of providing a mold projection shaped to fit into the depression of the modified fastener head as to form a top ring defining a central aperture for allowing a user to see the indicia.
The disclosure further includes a method of joining parts 22, 24, wherein a fastener body 32 is placed into superimposed bores 31 of two parts 22, 24. The torque retaining device 20 is placed over either the fastener head 30 or the nut 28 either pre or post mating of the thread on fastener body 32 and the nut 28. The tabs 86 of the torque retaining device 20 are pressed against the fastener head 30 or nut 28 until the arms 80 of the engagement portion 34 are flexed enough to allow the fastener head 30 or nut 22 to enter the cavity 50, wherein the tabs 86 snap back into place upon completed entry of the fastener head 30 or nut 28. The fastener head 30 or nut 28 that is not in the engagement portion 34 is rotated and the elongated portion 36 of the torque retaining device 20 is prevented from unitarily rotating by engaging one of the first or second parts 22, 24. As the fastener 26 and nut 28 are tightened together, the fastener head 30 or nut 28 is spaced from the parts 22, 24 by the tabs 86 until the fastener 26 is tightened enough to flex the arms 86 into the opening 78. Next, the torque retaining device 20 may stay on the fastener head 30 or the nut 28, or it may snap out off by operation of the spacing in the opening 78, the tabs 86 breaking during tightening, or the number of tabs 86.
It should be appreciated that the foregoing description of the embodiments has been provided for purposes of illustration. In other words, the subject disclosure it is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in other embodiments, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of disclosure.
This application claims priority to and the benefit of U.S. provisional patent application Ser. No. 62/598,887 filed Dec. 14, 2017, the disclosure of which is incorporated herein by reference in its entirety.
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Number | Date | Country | |
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20190184530 A1 | Jun 2019 | US |
Number | Date | Country | |
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62598887 | Dec 2017 | US |