Seal component and rod end assembly utilizing same

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.

BACKGROUND OF THE INVENTION 
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. 
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. Pat. Nos. Hultgren et al No. 1,567,649, Wagner No. 
3,519,279, Onufer No. 3,572,414, Brown No. 3,585,894, Dahl No. 3,803,793, 
and DeHaitre 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. 
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, and by which the effectiveness of lubrication of the parts 
thereof can readily be improved. Accordingly, it is an object of the 
present invention to provide a spherical rod end assembly in which those 
needs are satisfied. 
A related object of the invention to provide simple and inexpensive seal 
components which may readily be employed in a spherical rod end assembly, 
and for diverse other applications, to afford such protection in a highly 
convenient and effective manner, which components may in addition afford 
greatly improved lubrication for associated parts. 
SUMMARY OF THE INVENTION 
It has now been found that certain of the foregoing and related objects of 
the invention are attained 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. 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 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. 
In preferred embodiments, the wall portion of the sealing element will be 
frustoconical, with a circumferential lip, and it will most desirably form 
an angle of 15.degree. to 30.degree. with the central axis through the 
body of the component. The foraminous material of which the lining is 
fabricated will advantageously have an open cellular, and most desirably 
foamed rubber, structure. 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. 
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 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. 
Other objects of the invention are attained by the provision of a seal 
component, as herein described.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
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. 
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. 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. 
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 
washer components 16 are oriented with their sealing skirts 40 directed 
inwardly, causing the 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. 
As best seen in FIG. 4, the composite skirt element 40 consists of an outer 
lamina or shell 40', and an inner lamina or lining 40" covering the inside 
face of the element 40. The shell 40' is made of a dense, nonporous 
material, and the lining 40' is foraminous; normally, both laminae will be 
fabricated from a rubbery or elastomeric material, with the lining 
preferably being provided by an open-cell, foamed rubber. 
In the illustrated embodiment, the shell 40' is of outwardly tapered cross 
section, typically with an angle of taper of approximately 15.degree.. 
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 15.degree., with the 
interior surface thereof disposed at an angle "b" of 30.degree. 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 same cases. 
Regardless of whether the shell wall is tapered or of uniform thickness, 
and indeed regardless of whether or not a foraminous lining is present 
thereon, it will be advantageous to so form the skirt element that the 
angle "b" will have a value of 15.degree. to 30.degree., and preferably of 
at least 20.degree.. This will promote a highly effective dynamic sealing 
action, while ensuring against inversion of the flexible skirt element. 
As can also be seen, the edge surface 41 on the lip portion will 
advantageously be inwardly bevelled, typically at an angle "c" of 
approximately 5.degree. to 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 edge bevel also helps to ensure that a close fit is maintained with 
contoured surfaces, which frequently surround such socket openings. 
The sealing component will desirably be fabricated by molding the shell 
lamina 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. 
The foraminous liner 40" may be a foamed-in-place layer produced directly 
upon the lamina 40', or it may be an added layer of foam rubber, a fibrous 
material, or the like, bonded to the shell. It should be appreciated that 
the function of the liner is to hold and distribute lubricant (as by 
partial encapsulation or by capillary action), and to wipe the surfaces 
contacted thereby; any material capable of doing so, while affording the 
dynamic action, durability, and other properties required in the skirt 
element, may therefore constitute the foraminous liner. 
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', and a 
foraminous liner 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 bevel 53, to best accommodate 
movement and non-planar contact surfaces. 
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 a foraminous liner 64", and it has an outer 
beveled edge surface 66, for the purposes mentioned. 
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. 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 cooperating to 
affix the components in assembly with one another, and thereby obviating 
the need for any adhesive or other supplementary fastening means. 
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. 
The liner and the shell of the skirt element may either be made of the 
same, or of different, materials, depending of course upon the properties 
that each is to exhibit, and the manner by which it is to be fabricated 
and assembled. The liner may constitute only a relatively thin layer upon 
the surface of the shell, as illustrated, or it may substantially fill the 
volume therewithin. It will generally be important however that the liner 
material not cover the contact face of the associated metal body, since 
that would compromise the level of torque and fastening security that can 
be obtained by use thereof. 
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 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. 
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, 
and by which the effectiveness of lubrication of the parts thereof can 
readily be improved. 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.