Patent Publication Number: US-2012045293-A1

Title: Replaceable thread locking element

Description:
BACKGROUND 
     In the assembly of many different types of devices, threaded fasteners are often torqued to achieve a desired tightness or pre-load. Such torqueing is performed to ensure that the components being fastened together are sufficiently held together to withstand the particular conditions and environment to which they will be exposed when used. In most situations the tightening is sufficient to keep the fasteners torque to the pre-load levels until such time as the device is disassembled for maintenance or repair. In some applications, however, the threaded fasteners are exposed to situations such as thermal cycling or vibration where the threaded joint can loosen and loose the tightening pre-load torque that was initially applied. Such loss of pre-load can cause failure of a joint or loss of fastener. To address such applications, thread locking elements or compounds are used on the threads of the fasteners. The problem with thread locking elements as they exist are known in the world today is that they are permanently applied. As a result, when the assembled devices need to be disassembled, fasteners with the thread locking element must be replaced entirely. Otherwise, if they are re-used, there is a risk that the thread locking element will fail to secure the fastened at the pre-load because they will lose effectiveness after repeated installation and removal. 
     For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for improved thread locking elements. 
     SUMMARY 
     The Embodiments of the present invention provide methods and systems for improved thread locking elements and will be understood by reading and studying the following specification. 
     In one embodiment, a threaded fastener device comprises: a first member having a threaded region; a cutout within the ring shaped member that cuts across the threaded region; and a replaceable thread locking element removeably coupled to the ring shaped member within the cutout, the replaceable thread locking element comprising a displacement member coupled to a nipple via an extending member. The nipple is inserted into and orifice within the cutout, the nipple shaped to apply a force against the first member that holds the displacement member within the cutout. 
    
    
     
       DRAWINGS 
       Embodiments of the present invention can be more easily understood and further advantages and uses thereof more readily apparent, when considered in view of the description of the preferred embodiments and the following figures in which: 
         FIGS. 1-3  are diagrams illustrating a male threaded ring fastener of one embodiment of the present invention; 
         FIG. 4  is a diagram illustrating a replaceable thread locking element of one embodiment of the present invention; 
         FIG. 5  is a diagram providing a cross-sectional view of a replaceable thread locking element inserted within a threaded fastener of one embodiment of the present invention; 
         FIG. 6  is a diagram illustrating a male threaded fastener of one embodiment of the present invention; 
         FIG. 7  is a diagram illustrating a female threaded ring fastener of one embodiment of the present invention; and 
         FIG. 8  is a flow chart illustrating a method of one embodiment of the present invention. 
     
    
    
     In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize features relevant to the present invention. Reference characters denote like elements throughout figures and text. 
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of specific illustrative embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. 
     Embodiments of the present invention provide the ability to effectively re-use threaded fasteners by providing said fasteners with replaceable thread locking elements. As will be described in greater detail below, the replaceable thread locking elements provided by embodiments of the present invention are easily removed from a threaded fastener and replaced with a new thread locking element prior to re-fastening and torqueing. 
       FIG. 1  is a diagram illustrating a threaded ring fastener  100  of one embodiment of the present invention. Threaded ring fastener  100  comprises a ring shaped member  110  having a threaded region  120  about its outer circumference. Ring shaped member  110  further includes a plurality of teeth  130  which define a tool engagement interface  135  that allows a torque wrench or other tool adapted with a corresponding interface to apply torque to threaded ring fastener  100 . One of ordinary skill in the art would appreciate that in various alternate embodiments, the particular shapes used to define the tool engagement interface will vary based on the application where fastener  100  is to be used, and the amount of pre-load torque to be applied on the fastener  100  by the tool. Accordingly, the particular tooth shaped interface  135  illustrated in  FIG. 1  is not intended to limit embodiments of the present invention to only the shape shown. 
     As shown in greater detail in  FIGS. 2 and 3 , ring shaped member  110  includes a cutout  140  that cuts across threaded region  120 . Cutout  140  includes an orifice  145 , which in the particular embodiment shown defines a through hole that penetrates ring shaped member  110 . As shown in  FIG. 3 , in one embodiment, orifice  145  includes recessed chamfers  146  and  147  that assist in installing and securing a replaceable thread locking element  150  within cutout  140 , as described below. 
       FIG. 4  is a diagram illustrating a replaceable thread locking element  150  of one embodiment of the present invention. In one embodiment, replaceable thread locking element  150  is comprised of a synthetic material such as, but not limited to, nylon. In the embodiment shown in  FIG. 4 , replaceable thread locking element  150  includes a displacement member  152  coupled to a nipple  154  via an extending member  156 . To install replaceable thread locking element  150  within ring shaped member  110 , nipple  154  is inserted into orifice  145  as illustrated in the cut-away view provided by  FIG. 5 . In one embodiment, chamfer  146  causes nipple to deform as it is inserted through orifice  145 . Once nipple  154  clears orifice  145 , it resumes its original shape, applying a friction force/pressure against ring shaped member  110  to hold displacement member  152  securely within cutout  140  and approximately flush with threaded region  120  about the circumference of ring shaped member  110 . Chamfer  147  similarly causes nipple to deform to aid in removal of replaceable thread locking element  150  from ring shaped member  110  without unwanted tearing of element  150 . 
     In operation, when threaded ring fastener  100  is installed into a female threaded receiver, the replaceable thread locking element  150 ′s displacement member  152  displaces threads of the threaded region  120  located 180 degrees from the element  150 ′s location, thereby increasing thread pressure against the receiver&#39;s threads in that area of displacement. The additional thread pressure thus functions to maintain the pre-load placed on the assembled threaded faster that was applied during torqueing. As would be appreciated by one of ordinary skill the art upon reading this specification, in alternate embodiments and applications, female threading receiver is not limited to any particular device as long as it comprises threads compatible in size, gage, and shape with the threads of threaded ring fastener  100 . 
     Subsequently, it may become necessary to remove the threaded ring fastener  100  from its threaded receiver (such as for maintenance or repair, for example). Removing the threaded ring fastener  100  may permanently deform displacement member  152  so that it may no longer be effective in again maintaining a pre-load if it were reused. Embodiments of the present invention thus provide the ability to pop out the removable thread locking element  150 , thereby extending re-use of the faster  100  itself. In one embodiment, element  150  is popped out by applying pressure to a back side of nipple  154  exposed through orifice  145 . A new element  150  is then pressed in place providing a new synthetic that restores the ring assembly&#39;s resistance to movement. 
     Alternate embodiments of the present invention include threaded devices beyond the threaded ring fastener described above. For example, one embodiment, illustrated in  FIG. 6 , comprises a male threaded fastener such as a threaded bolt  610  having a replaceable thread locking element  650 . In such an embodiment, bolt  610  would comprise a threaded region  620  about its outer circumference having a cutout  640  that cuts across threaded region  620 . In one embodiment, cutout  640  includes an orifice  645 , through which a nipple  654  of element  650  is inserted to hold a displacement member  652  of element  650  securely within cutout  640  and approximately flush with threaded region  620 , similar to as described above. 
     Further, in another alternate embodiment, a replaceable thread locking element is provided for female threads of a threaded fastener, such as, but not limited to a threaded nut. For example, one embodiment, illustrated in  FIG. 7 , comprises a threaded fastener  700  having a replaceable thread locking element  750 . Threaded fastener  700  comprises a ring shaped member  710  having a threaded region  720  about its inner circumference  722 . In such an embodiment, threaded region  720  includes a cutout  740  that cuts across threaded region  720 . In one embodiment, cutout  740  includes an orifice  745 , through which a nipple  754  of element  750  is inserted to hold a displacement member  752  of element  750  securely within cutout  740  and approximately flush with threaded region  720 , similar to as described above. In operation, when threaded fastener  700  receives a threaded male fastener, the replaceable thread locking element  750 ′s displacement member  752  displaces threads located 180 degrees from the element  750 ′s location, thereby increasing thread pressure in that area of displacement similar to as described above. In each of these alternate embodiments, the thread locking element placed within the cutout of the devices threaded region is replaceable, allowing repeated use of the fastener itself. 
       FIG. 8  is a flow chart illustrating a method of one embodiment of the present invention. The process begins at  810  with removing a first thread locking element from a first member having a threaded region. In alternate embodiments, the first member may comprise any of the threaded fastener members described above, or other threaded fastener. The method proceeds to  820  with inserting a second thread locking element into a cutout region within the threaded region. In one embodiment, the first and second thread locking elements each comprise a displacement member coupled to a nipple, such as replaceable thread locking element  150  described in  FIG. 4 , for example. For such an embodiment, to insert the second thread locking element the nipple is inserted into an orifice within the cutout region until the displacement member is approximately flush with the threaded region. The method then proceeds to  830  with applying a pre-load torque to secure a threaded joint between the first member and a second threaded member. 
     Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiment shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.