Patent Publication Number: US-2022220996-A1

Title: Spindle nut retainer system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the U.S. patent Ser. No. 16/736,002, filed Jan. 7, 2020, which is incorporated herein by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to retaining nuts attached to fixed spindles, and more particularly, to spindle axles for vehicles, including towed trailers, such as boat (marine) and recreational vehicle (RV) trailers. In general, trailers use wheels mounted on spindle axles. Such arrangements are shown in U.S. Pat. Nos. 5,054,859 and 5,551,530. The prior art shows a typical arrangement for connecting a nut to a spindle axle and then retaining the nut to the spindle, against various forces acting upon the nut and spindle during use. That system would include a spindle, having an end which is threaded in any conventional pattern on a cylindrical surface thereof, a washer which is removably slid over surface until abutting a stop or raised portion on spindle (or a tapered roller bearing), a castle nut which is formed with a mating threaded pattern on its interior circumference surface so as to be threaded onto cylindrical surface, and a cotter pin which is removably inserted into passageway extending through spindle adjacent its threaded end. Surface is of sufficient longitudinal dimension that castle nut is threaded onto surface with cotter pin extending through spindle at a location between castle nut and the end face of the spindle. Once mounted onto spindle, the arms or prongs of cotter pin are bent apart to retain the cotter pin in place. 
     Other methods of retaining nuts to spindles have been suggested for various applications, including forming the nut and/or spindle with special slots, into which anti-rotational clips are inserted once the nut is mounted at the desired location on the spindle. An example of that system is shown in U.S. Pat. No. 5,573,311. In other vehicular applications, various nut retainers have been applied, such as shown in U.S. Pat. No. 6,896,463, and spindle end flats with mating washers have been employed, such as with commercially available Dexter E-Z Lube® spindle axles. These various arrangements can function well to retain the nut to the spindle during use, but they often are more expensive to manufacture and use, and/or are more cumbersome to reuse on those occasions where the nut is intended to be removed from the spindle and then re-applied to the spindle. An improved spindle nut retainer is needed. 
     SUMMARY OF THE INVENTION 
     These and other objectives of the present invention are achieved by the provision of a spindle nut retaining system having a spindle with a flat portion on its threaded end, a washer with a mating flat portion slidably mounted over the threaded end, a nut removably threadable to the threaded end of the spindle against the washer, and a nut retainer snap-fit over a plurality of the corners of the nut and formed with a plurality of thread tangs for engaging the threaded portion of the spindle and the flat portion of the spindle. The tangs grip the threaded portion to resist rotation once installed. As installed, at least one of the tangs resides at the intersection of the threads and flat on the spindle. The tang at this location serves as a locking tang and further resists rotation. The retainer can be used with the hub as pictured or with a hub that includes brakes. 
     To remove the retainer, the user pries between the spindle nut and annular portion of the retainer to urge the tangs outwardly and over the threads of the spindle. The user has to continue to pry to overcome each thread, until all of the tangs are clear of the outermost thread. Once the retainer is removed from the nut completely, the spindle nut can be removed to service the bearings, replace seals, or remove the hub. 
     Alternatively, the nut retainer can be removed from the nut by flexing or bending the snap-fit tangs away from the nut. If the snap-fit tangs are flexed away, the nut retainer can be immediately reused. If the snap-fit tangs are bent away, they can be rebent into their original position for reuse. Once the snap-fit tangs are flexed or bent away from the nut, the nut retainer can be slid off or threaded off of the spindle, through flexing or bending of the thread tangs. If the thread tangs are so bent for removal, they can be rebent to their original position when reusing the nut retainer. Further, the nut retainer can be formed of frangible material to allow for single use applications where, for example, visible indicium of removal is desirable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of the retainer as part of an assembled axle; 
         FIG. 2  is a side section view  2 - 2  of the assembly as shown in  FIG. 1 ; 
         FIG. 3  is an exploded view of the spindle, nut, washer, and retainer from  FIG. 1 ; 
         FIG. 4  is an isometric view of the retainer in  FIG. 1 ; 
         FIG. 5  is a partial view  5  of the retainer in  FIG. 4 ; 
         FIG. 6  is a partial view of the retainer as installed in  FIG. 1 ; 
         FIG. 7  is a side section view  7 - 7  of the retainer in  FIG. 4 ; 
         FIG. 8  is a side section view  9  of the retainer in  FIG. 2  during the installation process; 
         FIG. 9  is a side section view  9  of the retainer in  FIG. 2  as installed; and 
         FIG. 10  is a partial isometric view  10  of the retainer in  FIG. 7 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A spindle and bearing assembly  10  is shown in  FIG. 1  that is used on trailers, vehicles, and other devices with non-driven wheels. The assembly  10  has a spindle  12  that does not rotate and a hub  14  that rotates on the spindle  12  with bearings  16 ,  18  on its central axis  22 . The bearings  16 ,  18  as shown are commonly tapered roller, but other types are contemplated. For proper bearing life, proper preload of the bearings is critical. This is accomplished by the proper tightening of a single spindle nut  20 . The spindle  12 , bearings  16 ,  18 , and hub  14  are well-known in the art. If the spindle nut  20  is overtightened, premature and catastrophic bearing failure occurs. If the spindle nut  20  is left too loose, uneven tire wear, trailer wandering, and bearing failure can occur. Therefore, it is critical to properly tighten and maintain the position of the spindle nut  20  after assembly. To retain the spindle nut  20 , a retainer  40  is installed over the spindle nut and spindle  12 , shown in  FIGS. 1, 2, and 6 . The retainer  40  engages with the flats  32  and corners  34  of the spindle nut  20 . As shown in  FIG. 5 , the flats  32  on the spindle nut  20  are in common hexagon pattern, with each flat  32  at a 120 degree angle with respect to the adjacent flat  32 . The flats  32  of the spindle nut  20  meet at corners  34 . 
     The spindle  12  has a threaded end  24  with threads  26 . The threads mate with the spindle nut  20  to retain the hub  14  and bearings  16 ,  18 . A keyed washer  28  is located between the outer bearing  18  and the spindle nut  20 . The keyed washer  28  interfaces with the flat  30  to prevent any rotation of the bearing that could urge the spindle nut  20  to rotate. The flat  30  can also be a keyway, notch, or other feature on the threaded end  24  that interrupts the threads  26 . A thread edge  36  is defined by the corner where the flat  30  meets the threads  26 . The flat  30  is closer to the central axis  22  than the threads  26 . The threads  26  have an outside diameter  27  as defined by the tip (or crest) of the threads, shown in  FIGS. 8 and 9 . 
     The retainer  40  as shown in  FIG. 4  is formed from a single piece of stamped steel or other equivalent material, however it is contemplated that it could be formed from multiple pieces joined together. The retainer  40  is formed from materials that will tolerate some deformation, but then return to its original shape after the deforming force or component is removed. The retainer  40  has an annular portion  42  that is flat and ring-shaped. The annular portion  42  has a side that faces the spindle nut  20  and an opposite side that faces outwardly. The annular portion  42  has an outer edge  44  where retaining fingers  46  are located. The retaining fingers  46  are grouped in pairs  48  and extend perpendicularly from the annular portion  42 . It is contemplated that the retaining fingers may be obliquely angled with respect to the annular portion  42 , as long as they can still interface with the spindle nut  20  to prevent rotational movement between the nut  20  and retainer  40  once installed. As shown, three pairs  48  are located at 120 degree angles around the outer edge  44 . Each finger  46  has a flat portion  50  that extends to a hook portion  52 . The flat portion  50  has an inside surface  54  that is planar and is roughly the same length as the flats  32 . The hook portion  52  curves inwardly towards the center to grasp the inside facing surface of the spindle nut  20 . The flat portion  50  of one finger  46  is parallel to and faces the flat portion  50  on the finger  16  located opposite therefrom. 
     The annular portion  42  surrounds a central opening with an array of tangs  60  that extend inwardly into the center. The tangs  60  are all the same with twenty-four in the embodiment as described, but other quantities of tangs are contemplated. The tangs  60  are equally spaced on the annular portion  42 . As shown in  FIGS. 7 and 10 , each tang  60  has a lead-in portion  62  that extends to a catch wall portion  64 . The lead-in portion  62  is obliquely angled with respect to the annular portion  42  with the lead-in portion extending away from the annular portion in a direction opposite the retaining fingers  46 . The catch wall portion  64  has a terminal end  66  and a thread-facing surface  68 . The thread facing surface  68  is shown as having a radius, but it is contemplated that the thread-facing surface  68  is flat or squared off. Between the thread-facing surface  68  and the terminal end  66  is a curl surface  69 . Side surfaces  70 ,  72  meet the thread-facing surface  68  at corners  74 ,  76 . 
     The thread-facing surfaces  68  all form a spindle-retaining diameter  71  that is smaller than the thread diameter  27  with the tangs  60  in their resting position. This is shown in  FIG. 8 . Each tang  60  is independently moveable between a resting and displaced position, such that displacement of one tang does not impact the position of the adjacent tangs  60 . Displaced tangs  60  are shown in  FIG. 9  and tangs  60  in the resting position are shown in  FIG. 8 . 
     As installed on the spindle nut  20  and spindle  12 , more than half of the tangs  60  are moved from their resting position to a displaced position by the threads  26 , shown in  FIG. 1 . At least one of the tangs  60  lands adjacent the thread edge  36  on the flat  30 , where it is in the resting position or only slightly displaced. As shown in  FIG. 6 , this tang  60  becomes a locking tang  61  because one of the corners  74 ,  76  is in biased contact with the flat  30 . On the other side of the flat  30  where it meets the thread edge  36 , another tang may become a second locking tang  63 . The second locking tang  63  has an edge  76 ,  42  in biased contact with the flat  30  and/or thread edge  36 . In the resting position, the corners  74 ,  76  of locking tangs  61 ,  63  prevent rotation of the spindle nut  20 . Simultaneously, the retaining fingers  46  each overlay a flat  32  on the spindle nut  20  to lock the spindle nut  20  to the retainer  40  to prevent any rotation of the nut  20  with respect to the retainer  40 . 
     To install the retainer  40  on the bearing assembly  10 , the bearings  16 ,  18  are assembled to the hub  14  and then slid onto the spindle  12 . The washer  28  is installed and the spindle nut  20  is torqued to specification for proper endplay, run-out, and preload. The retainer  40  is then pushed onto the end of the spindle  12  with the retaining fingers  46  aligned with the corners  34  of the spindle nut  20 . The retaining fingers  46  are displaced as the hook portions  52  slide over the flats  32 . As the installer continues to push the retainer  40  onto the spindle nut  20 , the tangs  60  meet the end of the threads  26 , shown in  FIG. 8 . The lead-in portions  62  center the retainer  40  as the tangs begin to slide over the threads  26 . Because the thread diameter  27  is larger than the spindle-retaining diameter  71 , the tangs  60  are displaced where they meet the threads  26 , shown in  FIG. 9 . In the area over the flat  30 , the tangs  60  may not be displaced at all, depending on how close they are to the thread edge  36 . The thread edge  36  is a transition between the threads  26  and the flat  30 , which is essential to the function of the retainer  40 . Except for the tangs  60  over the flat  30 , the tangs  60  are in biased contact with the threads  26 , requiring increased force to continue pressing the retainer  40  over the threads  26  and spindle nut  20 . Once the annular portion  42  meets the spindle nut  20 , the retainer is fully installed, shown in  FIGS. 1, 2, and 9 . At this same time, the hook portions  52  have moved beyond the flats  32  and are located on the other side of the spindle nut  20 . 
     The retainer  40  prevents rotation of the spindle nut  20  for at least two reasons. First, a majority of the tangs  60  are in biased contact with the threads  26 , providing a gripping force from each contacting tang  60 . Second, and most importantly, the tangs  60  that are adjacent the thread edge  36  will prevent rotation when the corners  74 ,  76  engage the flat  30 . Because the corner  74 ,  76  is a relatively sharp surface (compared to the thread facing surface  68 ), any attempt to rotate the spindle nut  20  and retainer  40  results in one of the locking tangs  61 ,  63  with its corresponding corner  74 ,  76  to dig into the flat  30  and/or thread edge  36 . The features on the retainer  40  prevent accidental removal or deter removal from the spindle nut  20 . As installed, the retaining fingers  46 , particularly the hook portions  52  are hooked around the back side of the nut as shown in  FIG. 9 , requiring displacement of the fingers  46 . Over the threads  26 , the contacting tangs  60  are in biased contact therewith with some being located between crests of the threads  26 , as shown in  FIG. 9 . Tangs  60  that are located in between crests of threads, either partially or fully, add additional retaining benefits, as any attempt to move the retainer  40  away from the spindle nut  20  would require the tangs  60  to be further displaced to overcome the crest. 
     To remove the retainer  40 , the user will typically pry between the retainer  40  and the spindle nut  20 , typically on the annular portion  42 . This causes any tangs  60  located between crests to be further displaced outward to slide the retainer  40  off. This repeats for each thread crest the tang  60  encounters as it is being removed. The curl surface  69  assists in the removal and prevents the individual tang  60  from becoming trapped between crests. The retaining fingers  46  are also displaced as the retainer  40  is removed, albeit to a lesser extent. 
     It is understood that while certain aspects of the disclosed subject matter have been shown and described, the disclosed subject matter is not limited thereto and encompasses various other embodiments and aspects. No specific limitation with respect to the specific embodiments disclosed herein is intended or should be inferred. Modifications may be made to the disclosed subject matter as set forth in the following claims.