Abstract:
A spherical rod end assembly includes a seal component in the form of a fastener or a washer, or a combination thereof. The seal component has a flexible, resilient skirt, affixed to a metal body, which skirt overlies and seals the cavity within which the ball of the assembly is seated, to exclude dirt and other foreign matter, and to enhance lubrication. The seal component further includes a circumferential living hinge formed therein to improve seal integrity and increase angularity of the skirt.

Description:
BACKGROUND OF INVENTION  
       [0001]     Spherical rod end assemblies are extensively used for a wide variety of applications, such as in steering linkages for land vehicles, in aircraft surface controls, in automatic door control mechanisms, and in numerous other mechanical, hydraulic and pneumatic systems. Unless effectively sealed, dirt and other foreign matter invariably collects within the ball-seating cavities of such assemblies, causing excessive wear of components and poor performance ineffective lubrication will of course exacerbate such problems.  
         [0002]     Elements made of rubbery materials have in the past been used in assembly with nuts, bolts and washers, to seal thread joints and to prevent loosening of engaged components. Disclosures of that kind are found in the following U.S. patents including: Hultgren et al., U.S. Pat. No. 1,567,649, Wagner U.S. Pat. No. 3,519,279, Onufer U.S. Pat. No. 3,572,414, Brown U.S. Pat. No. 3,585,894, Dahl U.S. Pat. No. 3,803,793, and DeHaitre U.S. Pat. No. 4,019,550. In addition, Blanks, Sr., et al U.S. Pat. No. 2,908,507 appears to show an element overlying the socket of a tie rod body portion and extending about the steering arm pin seated therein (see  FIGS. 2 and 3 ). U.S. Pat. No. 2,828,984, to Ho Chow, employs protective elastic sleeves to seal linkage joints against dust and lubricant loss.  
         [0003]     More recently, U.S. Pat. No. 5,209,596 to Matczak et al. discloses an assembly comprising a spherical rod end having a head portion with an opening of spheric cross section therewithin, a ball pivotably seated within the opening of the head portion, and fastener means. A first component of the fastener means has a shank portion extending through a bore in the ball, and a second component thereof is engaged on the shank portion of the first. One component (be it the Afirst@ or Asecond,@ or a third component) of the fastener means, disposed on each side of the rod end portion, constitutes a seal component and is comprised of a rigid body element and a sealing element, the latter having an inner portion continuously surrounding the peripheral marginal portion of the body element and sealingly affixed to it. A flexible, resilient, composite wall portion extends from about the inner portion of the seal element and is outwardly flared to terminate at a flexible peripheral lip, the lip being in movable sealing engagement with the exterior surface of the head portion to which it is adjacent, surrounding the opening therein. The wall portion of the sealing element is comprised of an outside shell made of a tough, dense, nonporous material, and an integral lining at least substantially covering the interior face of the wall portion and made of a foraminous material.  
         [0004]     Despite the activity in the art indicated by the foregoing, a need remains for simple and inexpensive means by which the ball-seating socket of a spherical rod end assembly can be effectively sealed against the entry of foreign matter. Accordingly, it is desired to provide a spherical rod end assembly in which those needs are satisfied.  
         [0005]     It is further desired to provide simple and inexpensive seal components which may readily be employed in a spherical rod end assembly, and for diverse other applications, including differently configured ball-seating cavities, to afford such protection in a highly convenient and effective manner.  
       SUMMARY OF INVENTION  
       [0006]     The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by the provision of an assembly comprised of a spherical rod end having a head portion with an opening of spheric cross section therewithin, a ball pivotably seated within the opening of the head portion, and fastener means is presented. A first component of the fastener means has a shank portion extending through a bore in the ball, and a second component thereof is engaged on the shank portion of the first. One component (be it the “first” or “second”, or a “third” component) of the fastener means, disposed on each side of the rod end portion, constitutes a seal component and is comprised of a rigid body element and a sealing element, the latter having an annular inner portion continuously surrounding the peripheral marginal portion of the body element and sealingly affixed to it. A flexible, resilient, composite wall portion extends from about the inner portion of the seal element and is outwardly flared to terminate at a flexible peripheral radiused lip, the lip being in movable sealing engagement with the exterior surface of the head portion to which it is adjacent, surrounding the opening therein. Seal integrity and high angularity is improved by a living hinge intermediate the wall portion and annular inner portion attached to the rigid body element. The wall portion of the sealing element is comprised of a shell made of a tough, dense, nonporous material.  
         [0007]     The wall portion of the sealing element is preferably frustoconical, with a circumferential lip, and an inner surface defining the wall portion will most desirably form an angle of about 45 degrees with the central axis through the body of the component, while an outer surface defining the wall portion will most desirably form an angle of about 38.5 degrees therewith. When the seal component comprises a bolt, its threaded shaft provides the shank portion of the “first” component of the fastener means, and its head provides the rigid body element thereof. When it comprises a nut, the seal component provides the “second” component of the fastener means and the nut constitutes the requisite body element.  
         [0008]     The fastener means may additionally include one or two washers or bushings (both types of components sometimes being referred to herein as “washer members”) disposed on the shank of the “first” component, directly adjacent either or both of the exterior surfaces of the rod end head portion; the washer member(s) will thus provide the seal component(s) of the fastener means, and will constitute the rigid body element thereof. Regardless of the form of the seal component, the body element will normally be fabricated from metal. The sealing element may be molded upon the body, and a groove or an adhesion-promoting substance may advantageously be applied to the marginal portion of the metal body to enhance the strength of the bond; alternatively, tight frictional interengagement may be relied upon to affix the sealing element to the body element.  
         [0009]     Other objects of the invention are attained by the provision of a seal component, as herein described.  
         [0010]     The above discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description and drawings. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0011]     Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:  
         [0012]      FIG. 1  is a perspective view showing a spherical rod end assembly embodying the present invention;  
         [0013]      FIG. 2  is an exploded elevational view of the assembly of  FIG. 1 ;  
         [0014]      FIG. 3  is a plan view of a sealing washer embodying the invention and utilized as a seal component in the assembly of the foregoing Figures, drawn to an enlarged scale;  
         [0015]      FIG. 4A  is a sectional view of the sealing washer of  FIG. 3 , taken along line  4 - 4  thereof;  
         [0016]      FIG. 4B  is an enlarged partial sectional view of the sealing washer of  FIG. 4B ;  
         [0017]      FIG. 5  is a fragmentary sectional view showing the assembly of the invention mounted on a supporting part;  
         [0018]      FIG. 6  is an elevational view of a bolt constituting a seal component embodying the invention; seal component embodying the invention;  
         [0019]      FIG. 7  is a left-end elevational view of the bolt of  FIG. 6 ;  
         [0020]      FIG. 8  is a sectional view of the bolt, taken along line  8 - 8  of  FIG. 6 ;  
         [0021]      FIG. 9  is an elevational view of a nut constituting a seal component embodying the invention;  
         [0022]      FIG. 10  is a left-end elevational view of the nut of  FIG. 9 ;  
         [0023]      FIG. 11  is a sectional view of the nut taken along line  11 — 11  of  FIG. 9 ; and  
         [0024]      FIG. 12  is a sectional view of a bushing constituting a seal component embodying the invention. 
     
    
     DETAILED DESCRIPTION  
       [0025]     Turning first in detail to  FIGS. 1-5  of the appended drawings, therein illustrated is a spherical rod end assembly embodying the present invention, including a spherical rod end, a bolt, a nut and a pair of sealing washers, generally designated respectively by the numerals  10 ,  12 ,  14  and  16 . The rod end  10  consists of a head portion  18  and a threaded shank portion  20 , the head portion  18  having an integral insert  24  ( FIG. 5 ) affixed thereon, providing an opening  26  defined by a spheric wall surface. A truncated ball, generally designated by the numeral  28 , is rotatably and pivotably seated within the opening  26 , and has a diametric bore  30  through which extends the threaded shaft  32  of the bolt  12 .  
         [0026]     Each of the sealing washer components  16  consists of a metal washer  36  and a flared, frustoconical composite skirt element, generally designated by the numeral  40 , Skirt element  40  includes a circumferential living hinge  100  therein defining an annular relief as best seen in  FIG. 4B . One washer component  16  is disposed at each end of the ball  28 , under the nut  14  and the head  34  of the bolt  12 , respectively, lying directly upon the flat truncating surface  29  with its hole  38  aligned with the bore  30  thereof.  
         [0027]     As shown in  FIG. 5 , the assembly is mounted between spaced flanges  15  of a fragmentarily illustrated supporting part (e.g., a clevis), the flanges  15  having apertures  17  through which pass the shaft  32  of the bolt  12 . The components of sealing washer  16  are oriented with their sealing skirts  40  directed inwardly, causing a terminal edge  41  of the circumferential lip portions thereof to bear upon the surfaces  19  of the head portion  18  adjacent thereto, surrounding the opening  26 . With the nut  14  tightened upon the bolt  12 , the washer components  16  are urged inwardly, thus bringing the lip portions thereof into intimate sealing engagement with the surfaces  19 .  
         [0028]     As best seen in  FIGS. 4A and 4B , the composite skirt element  40  consists of a shell  40 ′ having a circumferential living hinge  100  configured therein. The shell  40 ′ is made of a dense, nonporous material, fabricated from a rubbery or elastomeric material. Living hinge  100  is defined by an inwardly extending outer arcuate surface  102 .  
         [0029]     In the illustrated embodiment, the shell  40 ′ is of outwardly tapered cross section, typically with an angle of taper of approximately 38.5 degrees. Taken with reference to a vertical axis (i.e., the central axis) through the hole  38  of the washer  36 , the exterior surface of the shell  40 ′ may therefore desirably be disposed at an angle “a” of about 38.5 degrees, with the interior surface thereof disposed at an angle “b” of about 45 degrees to the axis. Such a construction will promote flexibility of the lip portion, while permitting the inner end portion, at which the skirt element joins the peripheral edge  43  of the washer  36 , to be relatively heavy and inflexible; these features will afford durability, coupled with most effective performance in at least certain instances. Nevertheless, it should be appreciated that the shell  40 ′ of the skirt element may be of uniform cross section throughout, as may be optimal in some cases.  
         [0030]     Regardless of whether the shell wall is tapered or of uniform thickness, it will be advantageous to so form the skirt element that the angle “b” will have a value of about 45 degrees able to approach zero degrees or a plane coincident with washer  36 , and preferably of at least about 22.5 degrees. This will promote a highly effective dynamic sealing action while allowing full articulation of shaft  20  ensuring against inversion of the flexible skirt element.  
         [0031]     As can also be seen, the edge surface  41  on the lip portion advantageously includes a radiused tip generally indicated at  90  to provide a point contact with surfaces  19  when edge surface  41  is angularly articulated between about 38.5 degrees to a horizontal coinciding with a plane parallel to that of the washer  36 . This will help to ensure effective sealing upon the adjacent surface of the rod end, despite the distortion and movement that occurs when the ball  28  swivels within the head portion, as is of course its essential function. The radiused tip  90  also helps to ensure that a close fit is maintained with contoured surfaces, which frequently surround such socket openings.  
         [0032]     The sealing component will desirably be fabricated by molding the shell  40 ′ of the skirt element directly upon an edge of the metal body, which will advantageously constitute (as does the washer  36 ), or provide, a circumferential flange portion. To ensure a tight and strong bond with the elastomeric material, the edge  43  of the washer will desirably be roughened, and it may carry an agent to increase adhesion, the choice of which will depend upon the composition of the material used to produce the skirt element itself. Furthermore, washer  36  optionally includes a circumferential groove  45  to increase bonding area available to the skirt element  40 , a best seen in  FIG. 4B . In an exemplary embodiment, vertical edge  43  is configured with a chamfer generally indicated at  49  to increase a bonding area on washer  36 .  
         [0033]     Referring again to  FIG. 4B , the configuration of sealing washer  16  will be described in more detail. Living hinge  100  includes an annular relief portion defined by a peripheral edge  104  defining the annular inner portion  103  and a wall portion edge  106  normal to the peripheral edge  104 . The wall portion edge  106  defines one end of the wall portion opposite the radiused lip  90 . The peripheral edge  104  joins with the wall portion edge  106  with a radius of curvature  102  defining the relief portion. The circumferential living hinge  100  defining an annular relief allows skirt element to angulate toward a plane parallel to that of the washer  36  while radiused tip  90  portion provides point contact with surface  19  in any of these angulations to form a seal therewith. In an exemplary embodiment depicted in  FIG. 4B , the radius of curvature  102  and radiused tip  90  include, but are not limited to, a radius of 0.031 inch radius, for example.  
         [0034]     The rod end assembly of the invention may be employed in either a double shear (as illustrated) or a single shear installation; thus, a nut or a bolt, having an integral sealing element, may be suitable for use therein.  FIGS. 6-8  illustrate such a bolt component, generally designated by the numeral  44 . It has a 12-point head  46  at one end, a threaded shaft  48  at the other, and a composite skirt element, generally designated by the numeral  52 , bonded to the rim of the flange  50  extending about its head  46 . The element  52  is comprised of a dense, nonporous shell  52 ′. In a manner similar to that described with respect to the embodiment of  FIGS. 1-5 , the edge surface  54  of the flange  50  on the bolt head may be prepared to promote maximum bond strength; also, the lip portion of the skirt  52  is formed with a radiused tip  53 , to best accommodate movement and non-planar contact surfaces.  
         [0035]     Turning now to  FIGS. 9-11  of the drawings, the illustrated sealing nut component, generally designated by the numeral  56 , consists of a 12-point nut  58  having a circumferential flange  60 , to the edge  62  of which is bonded a composite sealing skirt  64 . Here again, the element  64  consists of a nonporous shell  64 ′, and it has an outer radiused tip surface  66 , for the purposes mentioned.  
         [0036]     Finally,  FIG. 12  illustrates a sealing bushing component, generally designated by the numeral  68 , consisting of a circular metal bushing  70  and an elastomeric sealing skirt  72  having an annular relief  100 ′″. The outer surface of the bushing  70  has a circumferential groove  74  formed into it, and the skirt  72  has an internal bead element  76  surrounding its smaller diameter end. Needless to say, the skirt  72  is dimensioned to tightly embrace the bushing  70 , with the bead element  76  sealingly engaged in the groove  74  and co-operating to affix the components in assembly with one another, and thereby obviating the need for any adhesive or other supplementary fastening means.  
         [0037]     It will be appreciated that the components of which the assembly of the invention is comprised will normally be made of metal (e.g., steel, aluminum, brass, etc.), except of course for the sealing skirt element. As to the latter, any suitable natural rubber or synthetic polymer may be employed; neoprene rubber, polyurethanes, styrene/butadiene rubbers, nitrile elastomers, and silicone resins might be mentioned as typical, but the selection of a suitable material for any given application will be evident to those skilled in the art.  
         [0038]     In addition to providing the requisite flexibility, resiliency and durability under the variety of conditions to which the rod end assembly might be exposed, the material from which the shell of the skirt element is formed will, in certain embodiments, be capable of producing a rubber-tearing bond with the metal element. As indicated above, that may be promoted by the use of an adhesive, a bonding agent, a chemical surface activator, or the like (the choice of which will also be evident to those skilled in the art), as well as by roughening of the surface of the component to which the rubber is to be bonded (e.g., by sand-blasting or the equivalent), or by other means. In an exemplary embodiment, other means includes a groove in at least one surface defining the washer and a chamfer on a peripheral edge defining the washer. In such instances, the shell of the sealing component will normally be integrally formed by molding of the elastomeric material directly to the metal piece, as by a compression, injection or transfer molding technique; bonding of preformed, separate skirt elements may however also be feasible.  
         [0039]     Thus, it can be seen that the present invention provides simple and inexpensive means by which the ball-seating socket of a spherical rod end assembly can be effectively sealed against the entry of foreign matter. The invention also provides simple and inexpensive sealing components that are suitable for use in a spherical rod end assembly, as well as for a wide diversity of other applications, to afford such protection and enhancement in a convenient and highly effective manner.  
         [0040]     While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.