Patent Application
20080053884
The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:
While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.
The filter element 10 mounts to and partially surrounds a standpipe 30 that extends axially within the housing receptacle 20. The standpipe 30 includes a central cavity 34 that extends the axial length of the standpipe 30 and serves as a clean fluid return passage. As such, the central cavity 34 fluidly communicates with the interior cavity 38 of a filter element 10 when installed on the standpipe 30.
The filter element 10 includes a generally cylindrical ring of filter media 40 that extends between a first end 42 and an opposite second end 44. The filter media 40 forms the interior cavity 38. The filter media 40 may be any standard filter media including preferably pleated filter paper formed from cellulose material. The standpipe 30 extends into the internal cavity 38 of the filter element 10, when the filter element 10 is mounted to the standpipe 30.
The filter element 10 includes closed and open end caps 48, 50 fixed to the first opposite ends 42, 44 of the filter media 40, respectively. In an embodiment, the end caps 48, 50 are formed from molded plastic. However, one or perhaps both of the end caps 48, 50 may be formed from other materials including metal. Additionally, while unitary one piece end caps are illustrated, the end caps may comprise multiple pieces
In the illustrated embodiment, an interior side of the closed end cap 48 includes an inner annular wall 54 and an outer annular wall 56 that extend axially inward toward the filter media 40 and the open end cap 50. The annular walls 54, 56 are coaxial with the longitudinal central axis of the filter media 40 and are radially spaced apart forming a first annular channel 58 therebetween. One end 42 of the filter media 40 is fixed to the closed end cap 48 within the first annular channel 58, which forms a well for holding bonding material 60, which may include plastisol, or other similar potting material or adhesive, that fixes the closed end cap 48 to the filter media 40. The boding material 60 seals the end of the filter media to the end cap 48 to prevent fluid from short circuiting the filter media 40. In an embodiment, the filter media 40 is radially positioned proximate the outer annular wall 56 and is radially spaced apart from the inner annular wall 54, forming a gap between the inner annular wall 54 and the radial inner periphery of the filter media 40. In an embodiment, the gap between the inner periphery of the filter media 40 and the inner annular wall 54 may be greater than 25% of the thickness of the wall of the cylindrical ring of filter media 40.
Furthermore, the closed end cap 48 includes a plurality of mounting prongs 64 on an exterior side of the closed end cap 48 that extend axially away from the open end cap 50 and the filter media 40. The mounting prongs 64 connect to and engage a cooperating filter mount 66 of the housing cap 22 of the filter housing. The filter mount 66 forms a cavity 68 that receives the mounting prongs 64. When received in the cavity 68, the mounting prongs 64 resiliently flex to secure the filter element 10 to the cap 22. The cavity 68 may include an annular groove 70 that receives a rounded head 72 of each mounting prong 64 to further secure the filter element 10 to the cap 22. The mounting prongs 64 are preferably unitarily formed with the rest of the closed end cap 48. The illustrated embodiment includes multiple mounting prongs 64, however, one of ordinary skill will recognize that any number of mounting prongs may be used, including only a single mounting prong.
The open end cap 50 includes an inner annular wall 76 and an outer annular wall 78 that extend axially toward the filter media 40 and the closed end cap 48. The annular walls 76, 78 are coaxial with the longitudinal central axis of the filter media 40 and are radially spaced apart forming a second annular channel 80, which similarly forms a well for holding plastisol 82 for potting the second end 44 of the filter media 40 therein.
The open end cap 50 includes a radially inward extending sealing lip 92 that defines a central aperture. The central aperture receives the standpipe 30 therethrough and is sized to sealingly engage the outer surface 88 of a main pipe 90 of the standpipe 30 to form a radial seal therebetween. The seal between the second end cap 44 and the standpipe 30 prevents dirty fluid, indicated generally as arrows 94, from short circuiting the filter media 40.
The distal end of the standpipe 30 includes a keyed flow valve, indicated generally by reference number 98, that prevents fluid from flowing through the filter housing if the filter element 10 is removed and not replaced. The standpipe 30 includes a pipe stub 100 that extends axially from the end wall 104 of the main pipe 90 and includes at least one inlet hole 102 that passes through the cylindrical sidewall of the pipe stub 100. The pipe stub 100 extends through an aperture in the end wall 104 of the main pipe 90 and includes a radially extending annular flange 106 positioned within the central cavity 34 of the main pipe 90 that abuts with the interior side of the end wall 104 forming a seal therebetween. The seal prevents fluid from short circuiting a valve 98.
The valve includes a valve member 108 that circumscribes the pipe stub 100 and functions to open and close the inlet hole 102. The valve member 108 is configured to move axially relative to the pipe stub 100 between a first position (
To prevent fluid from short circuiting the valve member 108 in the closed position, a pair of seals 110, 112 are axially spaced apart and having the inlet hole 102 interposed axially therebetween. The seals 110, 12 seal the valve member 108 relative to the pipe stub 100. It is preferable to have the seals 110, 112 seated in annular grooves in the outer surface of the pipe stub 100. As illustrated, the seals 110, 112 may be formed from rubber or rubber like o-rings. When the valve 98 is in a closed position (see
A coil spring 120 positioned between the end wall 104 of the main pipe 90 and the valve member 108 biases the valve member 108 toward the closed position. To lock the valve 98 in the closed position, the valve 98 includes a locking member 122 that includes a plurality of resilient locking prongs 124. The locking prongs 124 are interconnected to one another at an annular common ring portion 126. Each locking prong 124 extends radially inward against the pipe stub 100. The locking prongs 124 also extend axially toward the end wall 104 main pipe 90. In the closed position, the distal ends 127, or heads, of the locking prongs 124 engage an annular locking channel 128 formed in the outer surface 130 of the pipe stub 100 preventing axial movement of the valve member 108. Particularly, the locking prongs 124 prevent axially movement in an axial direction toward the main pipe 90. The interaction of the sealing shoulder 114 and the first seal 110 prevent axial movement away from the main pipe 90 when the valve member 108 is in the closed position.
To open the valve 98, the locking prongs 124 are biased such that the distal ends 127 disengage the locking channel 128 allowing the valve member 108 to move axially toward the main pipe 90. The filter element 10 biases the locking prongs 124 and actuates the valve member 108 between the first and second positions as will be more fully explained below.
In the embodiment illustrated in
The keys 136 function to disengage the locking prongs 124 from the locking channel 128 thereby allowing the valve member 108 to actuate axially to change the valve 98 from the closed first position to the open second position. More specifically, when axially sliding the filter element 10 onto the standpipe 30 each key 136 passes axially through a corresponding key receiving slot 148 in the valve member 108. The keys 136 engage corresponding locking prongs 124 and bias the locking prongs 124 out of engagement with the locking channel 128 in the pipe stub 100. Generally, the keys 136 bias the locking prongs 124 radially outward or away from the pipe stub 100. More particularly, as the keys 136 move axially towards the main pipe 90, the keys 136 contact the locking prongs 124, which are canted relative to the axial movement and apply a radial loading on the locking prongs 124. Once the locking prongs 124 disengage the locking channel 128 the valve member 108 is axially actuated towards the main pipe 90. The axial actuation of the valve member opens the valve 98 and fluidly communicating the interior cavity 38 of the filter element 10 with the interior cavity 34 of the standpipe 30 through inlet hole 102, as illustrated by arrows 152 representing clean fluid flow through the valve 98.
During the actuation of the valve member 108, the coil spring 120 is compressed such that when the filter element 10 is removed from the standpipe 30, the coil spring 120 expands and actuates the valve member 108 back to the first position, thereby reclosing the valve 98. Further, with the housing cap 22 threadedly secured to the receptacle 20, the combination axially secures the filter element 10 in a fixed axial position such that the filter element 10 cannot be axially biased away from the main pipe 90 by the coil spring 122, maintaining the valve in an open position.
After the filter element 10 has been installed and positioned over the standpipe 30 and the valve member 108 has been actuated to the second position, and fluid may flow through the filter system. As illustrated in
The first end cap 248 includes a plurality of keys 236 that extend axially inward directly from the disc portion. The keys 236 are generally similar to and function similarly as the keys 136 of the previous embodiment. However, in an embodiment, intermittent segments 271 of the disc portion are interposed between the keys 236. The surface of these disc portion segments 271 are substantially flat and are formed by and generally planar with the inner surface 260 of the first end cap 248 in which the filter media 240 is embedded. Furthermore, the keys 236 extend directly from the interior surface of 260 of the first end cap 248.
Furthermore, in this embodiment, the first end cap 248 includes a cylindrical stub 284, or shaft, that extends axially away from the second end cap 248 for mounting the filter element 210 to a filter housing cap similar to housing cap 22 of
All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
