Patent Application
20090232589
Embodiments of the present invention generally relate to dust boots assemblies and apparatus for providing grease relief for a dust boot. More specifically, the present invention relates to dust boot assemblies and apparatus for providing grease relief for dust boots coupled to greasable joints such as ball-and-socket joints.
Many joint assemblies and compatible dust boots exist for coupling to one or more components (e.g., automobile chassis components). An example of one such prior art joint assembly and compatible dust boot for use with an outer tie rod end of an automobile chassis is depicted in
Often, dust boots such as dust boot 108′ are coupled to a joint assembly to prevent dirt, dust, water, mud, moisture, and other contaminants from infiltrating the joint and/or the grease present in the joint since such infiltration typically decreases the service life of the joint. Such dust boots typically include a main body such as dust boot body 150′. In the depicted embodiment, dust boot body 150′ has an ovate shape, however, dust boots having alternate shapes including, but not limited to, conical, dome-shaped, hemi-spherical, spherical, and accordion-shaped are also known.
Many such bodies include first and second apertures such as first and second apertures 126′ and 152′, respectively, to facilitate coupling of dust boot 108′ to a joint, a joint assembly, and/or a component coupled thereto (collectively referred to hereinafter as non-dust boot components) while allowing an extension of the non-dust boot component to pass therethrough. Alternate dust boot bodies include an aperture designed to mate with a flanged portion of the housing to which it will be coupled (e.g., the joint housing, joint assembly housing, or the housing of a component coupled thereto).
Coupling of a dust boot to a non-dust boot component may be performed using a variety of methods. One such method is to perform such coupling via one or more O-rings, clamping rings, and/or combinations thereof, which encircle or are otherwise affixed to the exterior portion of the dust boot in contact with the non-dust boot component such that the dust boot is held to the non-dust boot component. For example, such O-rings, clamping rings (e.g., duplex clamping ring 124′), and/or combinations thereof may surround the exterior portion of a dust boot aperture such as first and second apertures 126′ and 152′. Alternatively, such coupling may be performed via inclusion of metal rings, plastic rings, or the like internal to the portion of the dust boot encircling or otherwise affixed to the non-dust boot component (e.g., internal metal ring 156′ or a plastic ring similar thereto).
In the exemplary prior art embodiment depicted in
In dust boot 108′ depicted in
Some such joint assemblies, including joint assembly 110′, are greasable (i.e., it is possible to add grease to the joint). Greasing the joint lubricates the joint, thereby facilitating smooth movement of same as such joints are typically made of metal and/or plastic components and, therefore, such joints involve metal to metal contact, plastic to plastic contact, and/or metal to plastic contact. For example, if the joint is a ball-and-socket joint, greasing facilitates smooth movement of the ball relative to the socket and it reduces the friction exerted upon the surfaces of the ball and socket by each other. Greasing of the joint also extends the service life of the joint and helps to expel any dirt, moisture, or other contaminants that may have entered the joint. Greasing also beneficially expels grease which has been previously injected into the joint as such grease tends to thin and otherwise spoil over time.
Dust boots having one or more apertures through a wall of the dust boot such as grease relief aperture 168′ also exist. Such apertures are intended to provide an aperture through which excess grease may exit the internal cavity of the dust boot when over-greasing occurs. In the joint assembly 110′ depicted in
Other types of pressure relief boot seals are known for use with joint assemblies such as ball-and-socket type joint assembles. One such boot seal includes a rigid collar member molded into a resilient body member, wherein the rigid collar member has radial and thrust bearing surfaces. The rigid collar member includes axial and radial grooves surrounding the entire periphery of the rigid collar that allow grease present internal to the boot seal to flow to a chamber located between the rigid collar member, a sealing lip, and a component to which the joint assembly is coupled. Upon an accumulation of excess grease internal to this chamber, the sealing lip deflects to allow the grease in the chamber to pass between the sealing lip and the component to which the joint assembly is coupled.
Briefly stated, in one aspect of the present invention, a dust boot assembly including at least one grease relief route for relieving excess grease located internal to the dust boot assembly is provided. This assembly includes: a body, the body including at least one aperture for coupling the body to at least one non-dust boot component, the at least one aperture bounded by a first edge; at least one cavity, at least a portion of the cavity located internal to the body; at least one covering located along at least a portion of the periphery of the first edge; and a grease relief insert shaped for insertion between and mating with at least one of the group consisting of the body, the covering, and combinations thereof and at least one of the non-dust boot component, the grease relief insert including at least a portion of the at least one grease relief route, a first end of the at least a portion of the at least one grease relief route passing through an outwardly facing surface of the grease relief insert, the outwardly facing surface shaped to mate with an inwardly facing surface of the covering, at least a portion of the inwardly facing surface covering the first end prior to an introduction of the excess grease, a second end of the route passing through an inner surface of the grease relief insert, the inner surface of the grease relief insert forming a portion of the boundary of the at least one cavity.
In another aspect of the present invention, a dust boot assembly including at least one grease relief route for relieving excess grease located internal to the dust boot assembly is also provided. This assembly includes: a body, the body including at least one aperture for coupling the body to at least one non-dust boot component, the at least one aperture bounded by a first edge; at least one cavity, at least a portion of the cavity located internal to the body; a grease relief insert shaped for insertion between and mating with the body, and at least one of the non-dust boot component, the grease relief insert including at least a portion of the at least one grease relief route, a first end of the at least a portion of the at least one grease relief route passing through an outwardly facing surface of the grease relief insert, a second end of the route passing through an inner surface of the grease relief insert, the inner surface of the grease relief insert forming a portion of the boundary of the at least one cavity; and at least one valve located in the first end of the at least a portion of the at least one grease relief route.
In another aspect of the present invention, a method of coupling at least one non-dust boot component to a dust boot assembly, the dust boot assembly including a dust boot, an insert shield, and an insert body, is provided. This method includes the steps of: coupling a first radial shield surface of the insert shield to a first radial component surface of the at least one non-dust boot component; coupling a first radial body surface of the insert body to a second radial shield surface of the insert shield; and positioning an inwardly facing dust boot surface of the dust boot adjacent an outwardly facing shield surface of the insert shield and an outwardly facing body surface of the insert body.
In yet another aspect of the present invention, a method of coupling at least one non-dust boot component to a dust boot assembly, the dust boot assembly including a dust boot and a one-piece grease relief insert, is also provided. This method includes the steps of: coupling a first radial surface of the grease relief insert to a first radial surface of the at least one non-dust boot component; and positioning an inwardly facing dust boot surface of the dust boot adjacent an outwardly facing surface of the grease relief insert.
In still another aspect of the present invention, a method of coupling at least one non-dust boot component to a dust boot assembly, the dust boot assembly including a dust boot and an insert body, is provided. This method includes the steps of: coupling a first radial surface of the insert body to a first radial surface of the at least one non-dust boot component, the coupling forming at least a portion of at least one grease relief route between the insert body and the at least one non-dust boot component; and positioning an inwardly facing dust boot surface of the dust boot adjacent an outwardly facing body surface of the insert body and an outwardly facing component surface of the at least one non-dust boot component.
The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
Certain terminology may be used in the following description for convenience only and is not limiting. The words “lower” and “upper” and “top” and “bottom” designate directions in the drawings to which reference is made. The terminology includes the words above specifically mentioned, derivatives thereof and words of similar import.
Where a term is provided in the singular, the inventors also contemplate aspects of the invention described by the plural of that term. As used in this specification and in the appended claims, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. Thus, for example, a reference to “a method” includes one or more methods, and/or steps of the type described herein and/or which will become apparent to those persons skilled in the art upon reading this disclosure.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods, constructs and materials are now described. All publications mentioned herein are incorporated herein by reference in their entirety. Where there are discrepancies in terms and definitions used in references that are incorporated by reference, the terms used in this application shall have the definitions given herein.
Referring first to
Dust boot 148 is similar to dust boots known in the art such as dust boot 108′ (
Additionally, in the depicted embodiment of the present invention, skirt 146 is a tubular skirt that extends from the edge of second aperture 152′ around its entire periphery and skirt 146 has a thickness approximately equal to the thickness of lip 128′. This thickness is provided to minimize the cost of manufacturing. However, alternate thicknesses may be substituted without departing from the scope of the present invention.
The tubular configuration of skirt 146 is selected to allow the inwardly facing surface (i.e., those surfaces facing toward body 106′, ball 116′, and first and second socket sections 118′ and 119′, respectively) thereof to mate with the outwardly facing surface (i.e., those surfaces facing away from body 106′, ball 116′, and first and second socket sections 118′ and 119′, respectively) of second radial flange 132 and insert shield 104. Prior to the introduction of excess grease into cavity 122′, this mating allows the inwardly facing surface of skirt 146 to cover the grease relief exit ports 166 (i.e., the outer ends of radial channels 410), which pass through the outwardly facing surface of second radial flange 132, to prevent, or minimize, the infiltration of contaminants into grease relief exit ports 166 and radial channels 410. In turn, prevention or minimization of the presence of contaminants in grease relief exit ports 166 and radial channels 410 prevents or minimizes the presence of contaminants in axial channels 404, boot cavity 122′, and between the surfaces of ball 116′ and first and second socket sections 118′ and 119′, respectively, as such contaminants are completely prohibited, or are at least impeded, from passing into these areas from the exterior environment via grease relief exit ports 166 and radial channels 410. Although skirt 146 is depicted in FIGS. 1 and 3-5B as tubular, other configurations of skirt 146 may be substituted so long as such configurations are capable of mating with at least a portion of the outwardly facing surface of the grease relief insert such that any channels/routes passing through this outwardly facing surface are covered. For example, skirt 146 may include a plurality of spaced flanges or flaps, wherein such flanges or flaps are located to cover the grease relief ports of the grease relief insert with which the skirt, and its associated dust boot, will be used. Furthermore, although skirt 146 is depicted as extending around the entire periphery of the edge of second aperture 152′, skirts extending around less than the entire periphery of this edge are also envisioned without departing from the scope of the present invention. Also, alternate embodiments of skirt 146 are envisioned in which an external coupler (e.g., an O-ring, clamping ring, or the like) may be added around the exterior surface of skirt 146 and/or an internal coupler (e.g., an internal metal or plastic ring mounted) may be included internal to skirt 146. In some such embodiments, the coupler may be located in the area of grease relief ports 166, however, such location is not required to achieve the purposes of the present invention.
If an excess quantity of grease is injected into boot cavity 122′, the force exerted by the oversupply of grease in such cavity forces a portion of the grease into one or more of radial channels 410 via axial channels 404. This force continues to force the excess grease through one or more radial channels 410 until it reaches the respective grease relief ports 166, whereupon the grease is forced against the inwardly facing surface of skirt 146 in contact with such grease relief ports 166. This path of the grease is depicted by arrows 220. The elasticity of skirt 146 allows the skirt to be expanded and/or deflected only to the degree necessary to accommodate relief of the excess grease present in boot cavity 122′, axial channel(s) 404, and radial channel(s) 410 into the environment external to the dust boot assembly, body 106′, and joint assembly 110′ via grease relief exit ports 166. The presence of the grease between the inwardly facing surface of skirt 146 and grease relief ports 166 prevents, or minimizes, the infiltration of contaminants into grease relief exit ports 166 and radial channel(s) 410 while skirt 146 is in its expanded and/or deflected state. Furthermore, as soon as grease is no longer present between these surfaces, the elasticity of skirt 146 will cause it to partially or fully return to its original position in which it covers grease relief exit ports 166, thereby preventing, or minimizing, the infiltration of contaminants into grease relief exit ports 166 and radial channels 410 and, therefore, axial channels 404, boot cavity 122′, and the area located between the surfaces of ball 116′ and first and second socket sections 118′ and 119′, respectively.
The relatively small, almost nonexistent, area between the inwardly facing surface of skirt 146 and the outwardly facing surface of grease relief ports 166 further minimizes, or eliminates, the potential for contaminant infiltration due to the small surface area into which such contaminants must pass.
Additionally, the incorporation of two relatively small grease relief exit ports 166 further minimizes, or eliminates, the potential for contaminant infiltration as such contaminants must penetrate below the inwardly facing surface of skirt 146 in the vicinity of one of grease relief exit ports 166. However, alternate embodiments of the present invention are envisioned having a greater or lesser quantity of grease relief exit ports 166.
Also, since grease is relieved via grease relief exit port 166 of insert body 102 and an inwardly facing surface of skirt 146 of boot 148, the dust boot assembly of the present invention may be used in conjunction with a larger quantity of commercially available non-dust boot components. That is, in this embodiment of the present invention, grease relief is not dependent upon, and does not occur, adjacent a surface of the non-dust boot component. Therefore, the sizes, shapes, and configurations of the non-dust boot component may change without the need for alteration of the grease relief exit ports and covering skirts of the present invention.
Furthermore, although dust boot 148 and skirt 146 are depicted in
Although the grease relief insert of the present invention is discussed herein for use with a dust boot having skirt-type grease relief exit port coverings, other grease relief exit port coverings may be substituted without departing from the scope of the present invention. For example, a portion of the dust boot (e.g., a skirt or a non-skirt portion) located adjacent to the grease relief exit ports (e.g., grease relief exit ports 166) may be reinforced with a coupler including, but not limited to, an elastic O-ring, clamping ring, internal metal or plastic ring, or the like, wherein the elasticity of the ring allows this portion of the dust boot to expand and contract as necessary to accommodate grease relief in the same manner as the non-reinforced skirt (i.e., skirt 146) as discussed in greater detail above. In another example, the covering may be a reinforced or non-reinforced portion of the dust boot (e.g., a skirt or a non-skirt portion) located adjacent to the grease relief exit ports (e.g., grease relief exit ports 166) that includes a uni-directional valve or valve-like device that allows grease expelled from grease relief exit ports to pass through the valve without allowing grease or other contaminants to pass from the exterior of the dust boot to the interior thereof. Or, the covering may be a uni-directional valve located in the outwardly facing surface of the insert body in the grease relief exit port.
The location of skirt 146 or an alternative grease relief exit port covering (e.g., a reinforcing ring, a valve, etc.) in a position that extends around the periphery of the edge of second aperture 152′ places skirt 146 such that it is least likely to be affected by the movement of boot 148 along with the movement of ball 116′ and ball extension 154′. As can best be seen with reference to
Also depicted in
Referring now to
As best seen in
As depicted in
Also depicted in
Insert body 102 also includes radial channels 410, as depicted in
As best depicted in the assembled view of
Turning next to
The shape and size of insert shield 104 relative to second radial flange 132 allows ring 104 to be positioned adjacent second body end 408 of second radial flange 132. Such positioning allows insert shield 104 to form a cover for the pair of axial and radial channels 404 and 410, respectively. That is, when insert shield 104 is positioned directly below second body end 408, radial channel 410 and the ends of axial channels 404 passing through second body end 408 are not open to the environment located below second body end 408. The covering aspect of insert shield 104 prevents, or minimizes, infiltration of contaminants into grease relief exit ports 166 and axial and radial channels 404 and 410, respectively. In turn, prevention or minimization of contaminants in grease relief exit ports 166 and axial and radial channels 404 and 410, respectively, prevents or minimizes the presence of contaminants in boot cavity 122′ and between the surfaces of ball 116′ and first and second socket sections 118′ and 119′, respectively, as such contaminants do not pass into these areas from the exterior environment via grease relief exit ports 166 and axial and radial channels 404 and 410, respectively.
In the depicted embodiment of the present invention, both insert body 102 and insert shield 104 are formed of Polyacetal. However, insert body 102 and/or insert shield 104 may be manufactured from a polymer other than Polyacetal or another relatively rigid material including, but not limited to, plastic, nylon, Teflon®, and metal.
Furthermore, although the embodiment of the present invention depicted in FIGS. 1 and 3-5B depicts grease relief insert 100 as a combination of two pieces (i.e., insert body 102 and insert shield 104), alternate embodiments of the grease relief inserts of the present invention are envisioned in which such grease relief inserts are a single unit. For example, insert shield 104 could be formed as a single unit with insert body 102 during the manufacturing process. In this embodiment, a single mold may be created for a single unit grease relief insert in which a first portion of the mold forms the shape of the insert shield (e.g., insert shield 102) and it is adjacent a second portion of the same mold that forms the insert shield (e.g., insert shield 104) in the same relative configuration in which the insert body would normally be positioned adjacent the insert shield.
In yet another alternate embodiment of the grease relief insert of the present invention, the insert body is used alone (i.e., without insert shield 104). In such embodiments, the surface of the non-dust boot component to which the dust boot assembly will be coupled includes a surface that resembles and/or performs the same function as the insert shield with which the insert body is typically used. For example, in an embodiment of the present invention in which the portion of the insert body that typically mates with the insert shield includes a flange having a circular inner and outer diameter as well as axial channel(s) and end(s) of radial channel(s) (such as the embodiment of the insert body depicted in FIGS. 1 and 3-5B), the surface of the non-dust boot component to which the insert body will be mounted must include a flat surface in the area that will be adjacent the axial channel(s) and the end(s) of the radial channel(s) to ensure that these channels are closed to the exterior environment and to further ensure that the intended grease relief route is formed. This flat surface could resemble the mating surface of the insert shield that is typically used in conjunction with the insert body or it could simply resemble as much of that surface as is required to perform the required function of the omitted insert shield (i.e., ensuring that the axial and radial channels are closed to the exterior environment and the intended grease relief route is formed). In this embodiment, insert body only includes a portion of the grease relief route and the non-dust boot component to which the insert body will be coupled also includes a portion of the grease relief route. In the exemplary embodiment detailed in this paragraph, insert body 102 includes the radial and axial channels and a portion of the walls of the grease relief route and the non-dust boot component (i.e., body 106′) adds a portion of the walls of the radial and axial channels to the grease relief route.
In our exemplary outer tie rod end embodiment of the present invention, elimination of insert shield 104 involves widening the outer circumference of the outwardly facing surface of seat 164′ (
Turning next to
Once joint assembly 110′ has been assembled, ball extension 154′ is passed through bore 162′ of body 106′ until a point at which the outwardly facing surface of second socket section 119′ mates with the inwardly facing surface of the upper end of body 106′. This mating causes the downwardly facing surface of body 106′ to form a seal with the upwardly facing surfaces of bearing 170′. Next, insert shield 104′ is passed over ball extension 154′ until at least an innermost portion of insert shield 104′ rests upon seat 164′ of body 106′. Next, insert body 102′ is passed over ball extension 154′ until second body end 408 is flush with the outwardly facing surface of insert shield 104.
Lip 128′ and skirt 146 of dust boot 148 are then passed over and/or around insert body 102 and insert shield 104. That is, as most easily seen in the assembled cross-sectional view of
In an embodiment of the present invention in which a one-piece grease relief insert is incorporated as detailed above, the same method of assembling the dust boot assembly depicted in
In an embodiment of the present invention in which the grease relief insert is an insert body only, a similar method to the method of assembling the dust boot assembly depicted in
Although the foregoing method of assembling a dust boot assembly and coupling it to a body of a non-dust boot component (e.g., an outer tie rod end) and joint assembly is described with specificity, the same assembly and coupling may be performed via alternate steps without departing from the scope of the present invention. Furthermore, although
In addition to the other methods and apparatus of providing grease relief while preventing the infiltration of contaminants into boot cavity 122′ and between the surfaces of ball 116′ and first and second socket sections 118′ and 119′, respectively, discussed herein, the incorporation of one or more grease relief routes in a separate grease relief insert (e.g., grease relief insert 100) positioned in a portion of dust boot 148 that are designed to experience limited, or no, motion (e.g., second aperture 152′) provides grease relief ports 166 and a sealing cover therefore (i.e., skirt 146) that do not move when ball 116′ and its ball extension 154′ move. Limited, or no, motion occurs for a plurality of reasons including, but not limited to, the flexible and elastic nature of the material of which grease relief insert 100 is made combined with the rigid nature of the adjacent metal non-dust boot components (e.g., body 106′), the conical shape of grease relief insert 100 and body 106′, and the coupling action of duplex clamping ring 124′.
This limited motion is in contrast to other locations of dust boot body 150′ (e.g., first aperture 126′) that are designed to move with the movement of ball 116′ and its ball extension 154′. Additionally, since grease relief insert 100 is a component that is separate and distinct from boot 148, it is less likely to move due to the typical movement of boot 148 during use, particularly the distal ends of boot 148 which move with the movement of ball 116′ and ball extension 154′. Movement of grease relief exit ports 166 and/or the areas surrounding such ports (e.g., skirt 146) is sometimes undesirable as such movement may cause one or more grease relief exit ports 166 to open in the absence of grease pushing therethrough. Such opening potentially allows contaminants to infiltrate grease relief exit ports 166, radial channels 410, axial channels 404, boot cavity 122′, and/or the surfaces between ball 116′ and first and second socket sections 118′ and 119′, respectively. However, it should be noted that movement of grease relief exit ports 166 and/or the areas surrounding such ports (e.g., skirt 146) will not interfere with grease relief via grease relief exit ports 166.
Furthermore, although the dust boot assembly depicted in FIGS. 1 and 3-5B is depicted coupled to a body of an outer tie rod end and a ball-and-socket joint, alternate embodiments of the present invention are envisioned in which dust boot assemblies created in accordance with the present invention are coupled to the bodies of non-dust boot components other than outer tie rod ends and joint assemblies including, but not limited to, stabilizer links, inner tie rod ends, ball joints, and automotive chassis parts having ball-and-socket style joints.
Importantly, the apparatus and methods of the present invention allow currently known, commercially available dust boots to be easily and inexpensively modified to accommodate the apparatus and methods of the present invention. That is, the apparatus and methods of the present invention may be implemented by simply adding a skirt (e.g., skirt 146) to a commercially-known dust boot and placing a grease relief insert 100 under or internal to an aperture of the commercially known dust boot.
Additionally, since the grease relief insert of the present invention is made of a different material than that from which the boot of the present invention is made, the use of an independent grease relief insert simplifies, and decreases the cost of, the manufacturing process for boot as the boot may be simply molded, or otherwise fabricated, as a single unit of one homogenous material. This is typically less expensive than the cost of manufacturing a boot having two varying materials, for example, a boot in which the grease insert relief is molded or otherwise connected to the internal surface of the boot. However, embodiments of the present invention in which insert body and/or insert shield are fabricated integral to a boot are envisioned.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
