Abstract:
The invention relates an oil pan plug assembly comprising an elongated sleeve and a plug member. The elongated sleeve includes first and second ends and defines a longitudinal drain bore therethrough having corresponding first and second end portions, the second end of the sleeve configured to project outwardly from the exterior of the oil pan through an opening in the oil pan disposed about the sleeve, and a securement means for forming a fluid-tight seal through the opening in the oil pan when the sleeve is mounted in the oil pan. The plug member defines a head including an axially projecting skirt with a first and a second end, an adjacent, axially projecting locking sleeve having a first end, a second end, a middle section between the first and second ends having an outer diameter that is less than one or both of the first end and the second end, the locking sleeve surrounding the skirt and being telescoped over the skirt to releasably secure the plug member to the elongated sleeve by slidable lengthwise retraction from the sleeve bore, the plug member further comprising an elongated shank projecting length wise outwardly from one side of said enlarged head and removably telescopingly received in the longitudinal bore second end portion of the elongated sleeve.

Description:
TECHNICAL FIELD 
       [0001]    The field of the invention generally relates to a two piece replacement oil pan plug assembly that permits easy removal and replacement of the plug for changing engine oil. 
       BACKGROUND 
       [0002]    Internal combustion engine oil pans are provided with threaded drain plugs whereby engine oil may be drained from the oil pan. However, repeated removal and insertion of the threaded drain plugs sometimes results in the threads in the oil pan being damaged to the extent that the threaded plug may no longer form a fluid-tight closure for the oil pan drain bore. Accordingly, various forms of replacement plug assemblies previously have been provided. 
         [0003]    Some of these replacement plug assemblies include lengthwise stretchable, and thus radially contractable, resilient plugs, self-threading plugs and plastic plugs, or plug members configured for slidable lengthwise retraction from the sleeve bore. However, these previously known forms of replacement plugs are either difficult to remove when an oil change becomes necessary, require special tools for removal and/or insertion and are themselves limited in effective life span. Accordingly, a need exists for an improved form of replacement oil pan plug which may be repeatedly removed with ease and enjoy an extended expected lifetime of effective operation. 
         [0004]    Various forms of plugs, couplings and other structures including some of the general structural and operational features of the instant invention are disclosed in U.S. Pat. Nos. 2,824,945, 2,935,338, 3,097,867, 3,229,069, 3,422,390, 3,423,110, 3,761,117 and 4,205,758. However, these previously known structures are believed to fail to provide an effective readily removable and repeatedly usable replacement oil pan plug, or describe a structure that can be improved. 
       SUMMARY 
       [0005]    The easy grip, threadless oil pan plug assembly of the instant invention includes a tubular sleeve for sealed securement through the drain opening of an oil pan and a plug member including a head and an elongated shank projecting lengthwise outwardly from one side of the head and removably telescopingly received in the sleeve from the end thereof on the exterior of the associated oil pan. The shank includes a seal structure for establishing a slidable fluid-tight seal between the shank, the sleeve bore and the exterior end portion of the sleeve. The head of the plug member includes an axially projecting skirt and an adjacent locking sleeve telescoped over the head and the skirt to releasably secure the plug member to the elongated sleeve. The locking sleeve is configured to permit the user to easily grip the sleeve and slide it along the plug member in the direction of the shank head to release the plug member from the oil pan. 
         [0006]    One object of this invention is to provide an oil pan plug assembly which may be readily installed with a minimum of tools. Another object of this invention is to provide an easy grip oil pan plug assembly including a plug member that is easily grasped to be easily removed for ready draining of oil from the associated oil pan. 
         [0007]    Another object of this invention, in accordance with the immediately preceding objectives is to provide an oil pan plug assembly including a plug member therefore which may be substantially instantly reinstalled after being removed and is automatically self-locking upon reinstallation. 
         [0008]    Still another object of this invention is to provide an oil pan plug assembly including a removable plug member which may be readily removed and installed without the utilization of tools. 
         [0009]    A final object of this invention is to provide a method of removing and replacing an oil pan plug assembly by mounting the tubular sleeve in an opening in the oil pan followed by mounting the plug member to the tubular sleeve to form a fluid tight seal. 
         [0010]    In one implementation, there is provided an oil pan plug assembly that includes an elongated sleeve and a plug member. The elongated sleeve includes first and second ends and defines a longitudinal drain bore therethrough having corresponding first and second end portions, the second end of the sleeve configured to project outwardly from the exterior of the oil pan through an opening in the oil pan disposed about the sleeve, and a securement means for forming a fluid-tight seal through the opening in the oil pan when the sleeve is mounted in the oil pan. The plug member defines a head including an axially projecting skirt with a first and a second end, and an adjacent, axially projecting locking sleeve having a first end, a second end, and a middle section between the first and second ends having an outer diameter that is less than one or both of the first end and the second end. The locking sleeve surrounds the skirt and is telescoped over the skirt to releasably secure the plug member to the elongated sleeve by slidable lengthwise retraction from the sleeve bore. The plug member further comprises an elongated shank projecting length wise outwardly from one side of the enlarged head and is removably telescopingly received in the longitudinal bore second end portion of the elongated sleeve. 
         [0011]    Embodiments of the oil pan plug assembly may include one or more of the following features. For example, the oil pan plug assembly may further include a seal means carried by the shank establishing a slidable fluid-tight seal between the shank and the one end portion of the bore, and the head and the exterior of the second end of the sleeve may include coacting means releasably securing the plug member against outward displacement relative to the second end of the sleeve and lengthwise retraction of the shank from the second end portion of the bore. 
         [0012]    The middle section of the locking sleeve may have an outer diameter that is less adjacent the first end than the second end. The middle section of the locking sleeve may have an outer diameter that is less adjacent the second end than the first end. The middle section of the locking sleeve may have an outer diameter that changes over its length such that a minimum of the outer diameter is attained in a middle region of the middle section. The middle section of the locking sleeve may have a constant outer diameter over its length. 
         [0013]    A transition between the first end and the middle section of the locking sleeve may form a gripping surface for sliding the locking sleeve. The middle section of the locking sleeve may have a textured outer surface, a ribbed outer surface or circumferential grooves. 
         [0014]    The locking sleeve may have a rough surface intermediate its opposite ends. One or both of the first end and the second end of the locking sleeve may have a textured, roughened and/or ribbed surface. 
         [0015]    The securement means comprises a retaining nut disposed around the elongated sleeve and the second end of the locking sleeve extends circumferentially over at least a portion of the retaining nut when the plug member is mounted to the elongated sleeve. The second end of the locking sleeve may cover the entirety of the retaining nut. The second end of the locking sleeve may cover a majority of the retaining nut. The second end of the locking sleeve may cover less than half of the retaining nut. 
         [0016]    The securement means may include an enlarged head on the first end of the sleeve and a nut threaded on the second end of the sleeve. The enlarged head may be formed integrally with the sleeve. The securement means may include a resilient axially compressible and radially expandable sealing sleeve disposed on the elongated sleeve between the enlarged head and nut. 
         [0017]    The oil pan plug may be installed in the oil pan of a vehicle. The oil pan plug may be installed in an oil pan. 
         [0018]    In another general aspect, the method includes removing and replacing a replaceable oil pan plug. The method includes providing a replaceable oil pan plug assembly, mounting the elongated sleeve in an opening in the oil pan, and mounting the plug member to the elongated sleeve to form a fluid tight seal. 
         [0019]    Mounting the plug member to the elongated sleeve to form a fluid tight seal includes gripping the middle section of the locking sleeve and sliding the locking sleeve in the direction of the head, sliding the sleeve into the sleeve bore, and releasing the middle section of the locking sleeve to form a fluid tight seal. 
         [0020]    The replaceable oil pan plug assembly includes an elongated sleeve and a plug member. The elongated sleeve includes first and second ends and defines a longitudinal drain bore therethrough having corresponding first and second end portions, the second end of the sleeve configured to project outwardly from the exterior of the oil pan through an opening in the oil pan disposed about the sleeve, and a securement means for forming a fluid-tight seal through the opening in the oil pan when the sleeve is mounted in the oil pan. The plug member defines a head including an axially projecting skirt with a first and a second end, an adjacent, axially projecting locking sleeve having a first end, a second end, a middle section between the first and second ends having an outer diameter that is less than one or both of the first end and the second end, the locking sleeve surrounding the skirt and being telescoped over the skirt to releasably secure the plug member to the elongated sleeve by slidable lengthwise retraction from the sleeve bore, the plug member further comprising an elongated shank projecting length wise outwardly from one side of said enlarged head and removably telescopingly received in the longitudinal bore second end portion of the elongated sleeve. 
         [0021]    Embodiments of the method may include one or more of the following features or those described above. For example, the method may further include removing the plug member from the elongated sleeve by gripping the middle section of the locking sleeve and sliding the locking sleeve in the direction of the head, and sliding the sleeve from the sleeve bore. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a perspective view of the drain plug area of a conventional oil pan with a plug assembly of the present invention. 
           [0023]      FIG. 2  is a vertical sectional view of the oil pan plug assembly illustrated in  FIG. 1  as seen from the inside of the oil pan. 
           [0024]      FIG. 3  is a cross-sectional side view the drain plug area of a conventional oil pan with a plug assembly constructed in accordance with the present invention taken along section lines  3 - 3  of  FIG. 1 . 
           [0025]      FIG. 4  is a cross-sectional side view of the locking sleeve of  FIG. 1 . 
           [0026]      FIG. 5  is a perspective view of the sleeve portion of the oil pan plug assembly with the securing nut therefore removed. 
           [0027]      FIGS. 6-10  are side views of additional embodiments of the locking sleeve for the oil pan plug assembly. Each embodiment includes a textured surface to enhance the ability to grip the locking sleeve. Each embodiment also includes a section that covers a portion of a nut that retains the plug assembly to the oil pan.  FIGS. 6 ,  7 ,  9  and  10  each include a middle section that is of reduced diameter relative to one or both of the end sections of the locking sleeve such that there is an improved ability to grip and hold onto the sleeve when pulling the sleeve back to remove the sleeve from the plug assembly or re-mount the sleeve to the plug assembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    The invention relates to an easily removable and replaceable oil pan plug assembly. As noted above, removable and replaceable oil pan plugs exist. However, the inventors have determined that such oil pan plugs can be improved for ease of handling and to prevent potential problems with their use. In particular, the inventors have modified an oil pan plug assembly generally described in U.S. Pat. No. 4,205,758, the contents of which are incorporated herein in their entirety for purposes of constructing and using the oil pan plug. 
         [0029]    In particular, the disclosure of the &#39;758 Patent is incorporated herein by reference for its disclosure of various securement means for retaining the oil pan plug assembly in an oil pan. For example, the securement means can be made up off one or more nuts, washers and flanges or the like mounted temporarily or permanently on a sleeve mountable within an opening in an oil pan. For example, two pairs of nuts and washers can be used on a threaded sleeve on opposite sides of a wall of an oil pan. By tightening the nuts to reduce the space in between, a seal can be formed that permits oil to pass through the bore of the sleeve but not through the space between the outside surface of the sleeve and the opening in the oil pan. Similarly, one or more nuts can be mounted to the oil pan such that the threaded sleeve can be mounted in a sealed manner within the bore. In another embodiment, the sleeve can have a flange on one end that is positioned within the oil pan and a nut is threaded over the sleeve that is tightened against the oil pan and forms an oil tight seal. The nut can have a long sleeve that extends over the sleeve mounted through the opening in the oil pan. These are but some of the variations possible as known in the art to form an oil tight seal through the opening in the oil pan. 
         [0030]    While the oil pan plug of the &#39;758 Patent can be used in engines, the inventor have worked with this oil pan plug and found a number of improvements that can be made which will provide great advantages to consumers, users, and mechanics. In particular, the inventors have improved a locking sleeve that is used on the oil pan plug to better allow the sleeve to be gripped and/or prevent the oil pan plug assembly from being damaged. The &#39;758 Patent is incorporated herein for the teaching of the oil pan plug assemblies disclosed herein with the exception of the configuration of the locking sleeve which has been improved upon by the inventor. 
         [0031]    Referring to  FIGS. 1-3 , an oil pan plug assembly  16  is illustrated that can be removably inserted into an oil pan. The numeral  10  generally designates an oil pan having a conventional drain opening  12  formed therein. An annular reinforcing member  14  is secured to the inner surface of the oil pan  10 . Conventionally, the drain opening and reinforcing member are internally coextensively threaded to receive a conventional threaded oil pan plug. However, referring specifically to  FIG. 3 , the threads in the drain opening  12  and the reinforcing member  14  sometimes become damaged and are no longer capable of retaining a conventional threaded oil pan in tightly closed position sealing the drain opening  12 . In such a situation, a removably insertable oil pan plug can advantageously be used in this situation. Of course, a removably insertable oil pan plug can be used in other situations as well, such as a standard part on a new car, a replacement part to increase the ease of oil changes, etc. 
         [0032]    The basic form of a replacement plug assembly is referred to in general by the reference numeral  16  and includes an elongated sleeve  18  including first and second ends  20  and  22 . The first end  20  of the sleeve  18  is provided with a diametric slot  24  and the sleeve defines a central longitudinal bore  26  opening outwardly of the second end  22  of the sleeve and terminating inwardly of the first end  20  of the sleeve  18 , but opening into the slot  24 . The sleeve  18  includes an enlarged head  28  adjacent the first end thereof and is externally threaded as at  30  from the head  28  to the second end  22  of the sleeve  18 . 
         [0033]    A resilient combined sleeve and washer  32  constructed of any suitable material such as neoprene is threaded onto the exterior of the sleeve  18  and includes a circumferentially extending and axially projecting flange  34 . A retaining nut  36  is provided and includes a diametrically reduced sleeve portion  38  projecting outwardly from one end thereof and the sleeve portion  38  includes a circumferential groove  40 . 
         [0034]    As explained above, the elongated sleeve can be mounted within the oil pan by a number of different methods. For example, the elongated sleeve portion of the oil pan plug assembly can be threadably received into the oil pan. Other methods can be used as are well-known in the art. 
         [0035]    A plug member referred to in general by the reference numeral  42  is also provided and includes a cylindrical shank  44  having a circumferential groove  46  and an O-ring  48  seated in the groove  46 . The groove  46  is formed in the shank  44  centrally intermediate its opposite ends and one end of the shank  44  includes a diametrically enlarged head  50  including an axially projecting cylindrical skirt  52  provided with circumferentially spaced inwardly tapering radial bores  54  in which spherical lock members  56  are seated. 
         [0036]    A locking sleeve  58  is telescoped over the exterior of the head  50  and the skirt  52  and includes a diametrically reduced mid-portion  60  retained on the skirt  52  at one end by a locking ring  62  and spring-biased by spring  64  toward a position with the diametrically reduced portion  60  engaged with the locking ring  62  by a compression spring  64 . The compression spring  64 , when totally compressed, limits shifting of the locking sleeve  58  to the left relative to the head  50  as viewed in  FIG. 3  and the locking ring  62  limits shifting of the locking sleeve  58  to the right as viewed in  FIG. 3 . When the locking sleeve  58  is shifted to its limit of movement to the left as viewed in  FIG. 3  against the collapsed spring  64 , the diametrically reduced portion  60  of the locking sleeve  58  uncovers the outer sides of the spherical members  56  and thus enables the latter to unseat themselves from the groove  40  to thereby enable the plug member  42  to be withdrawn from the sleeve  18 . Of course, an outward pull on the locking sleeve  58  releases the plug member  42  for disengagement from the sleeve  44  and the nut  36  and thereby enables merely an outward pull on the locking sleeve  58  to effect total disengagement of the plug member  42  from the sleeve  18 . 
         [0037]    When it is desired to reinstall the plug member  42 , the sleeve  58  is shifted to its limit position of movement to the left as viewed in  FIG. 3  of the drawings, and the plug member  42  is then inserted into the sleeve  18 . Thereafter, the locking sleeve  58  may be released in order that the diametrically reduced portion  60  may cam the lock members  56  into seated engagement in the groove  40 . 
         [0038]    The locking sleeve  58  also has an end  61  that is of a length to cover the majority of the nut  46  when the plug member  42  is installed in the oil pan. This covering of the nut  46  is intended to prevent a mechanic from misunderstanding how the oil pan plug assembly  16  is mounted to the oil pan. In some instances it is expected that a mechanic might not recognize that the plug member  42  is intended to be removed without the use of tools and would try to use a wrench to remove the plug assembly  16 . Because the locking sleeve has an end  61  that interacts with the plug member  42  to cover the majority of the nut  46 , the mechanic will not be inclined to use a wrench to remove the plug member. Instead, it is anticipated that a mechanic who is not familiar with the oil pan plug assembly  16  will examine the assembly  16  and recognize that it should be removed by pulling back on the locking sleeve  58  such that the plug member  42  can be removed from the sleeve portion  38  and oil pan. 
         [0039]    The O-ring seal  48  establishes a fluid-tight seal between the shank  44  and the bore  26  and the flange  34  and radial expansion of the combined sleeve and the washer  32  effect a fluid-tight seal between the sleeve  18  and the annular reinforcing member  14 . 
         [0040]    Referring also to  FIG. 4 , which illustrates the locking sleeve  58  in cross-section, the sleeve includes the end  61  which is of a length to cover the majority of the nut  46  when the plug member  42  is installed in the oil pan. The sleeve  58  also includes an end  70  which covers a portion of the head  50  of the plug member, and the narrowed diameter section  60 . The diameter of section  60  is reduced in both the inner diameter and the outer diameter. In this manner, an individual removing the plug member  42  has a region in which to securely grasp the locking sleeve  58  to slide back the sleeve over the plug member and release it from the sleeve  38 . The reduced diameter section  60  advantageously allows the mechanic to remove the sleeve even when the sleeve has oil on its surface. As can be imagined, if the section  60  was of the same outer diameter as the ends  61  and  70 , a mechanic would not have the ability to securely grip the sleeve to slide it back. This inability to securely grip the sleeve would be exacerbated if the surface had oil on it. 
         [0041]      FIG. 4  also illustrates that a surface  74  of the section  60  has a ribbed surface. This surface  74  improve the grip of the mechanic to grasp the sleeve  58 . The ribbed surface  74  can be modified to have any textured surface that enhances a mechanic&#39;s grip on the sleeve. Further,  FIG. 4  illustrates that a portion of the surface  74  is without a ribbed surface. Such a surface can be ribbed or otherwise textured to improve the ability of the mechanic to remove the sleeve. Similarly, surfaces  72  and  76  can be formed with a textured surface to enhance the ability to grip the locking sleeve  58 . The texture can be ribs, grooves, a knurled surface, a roughened surface and the like. 
         [0042]    From  FIG. 5  of the drawings, it may be seen that the flange  34  is collapsible into a substantially cylindrical condition within an annular recess provided therefore and with an outside diameter substantially equal to the outside diameter of the cylindrical head  28 . When it is desired to install the oil pan plug assembly  16 , the assemblage comprising the sleeve  18  and the combined sleeve and washer  32  is inserted into the opening  12  and the annular reinforcing member  14 . Then, when the flange  34  has cleared the inner side of the reinforcing member  14 , the nut  36  is threaded onto the end of the sleeve  18  remote from the head  28  on the exterior of the pan  10 . The nut  36  includes a diametrically reduced portion  66  which is snugly received within the drain opening  12  and the combined sleeve and washer is axially compressed and radially expanded between the head  28  and the nut  36  so as to tightly expand within the reinforcing member  14 . Further, as the nut  36  is tightened, the head  28  is drawn toward the reinforcing member  14  and the flange  34  has its free end flexed outward and expanded over the inner end of the annular reinforcing member  14 . Thus, a reliable fluid tight seal is defined between the sleeve  18  and the reinforcing member  14 . Once the sleeve  18 , combined sleeve and washer  32  and nut  36  have been installed, it is merely necessary to insert the plug member  42  in the manner hereinbefore set forth. 
         [0043]    It is also pointed out that the slot  24  is sufficiently narrow that the blade of a conventional screwdriver of a size to be received through the bore  26  may be received in the slot  24 . When the nut  36  is tightened during installation of the sleeve  18 , the aforementioned screwdriver blade may be utilized to hold the sleeve  18  against rotation while the nut  36  is tightened. 
         [0044]    It also should be understood that the locking sleeve  58  illustrated in  FIGS. 1-4  may be modified to achieve the objectives described above. For example, referring to  FIG. 6 , a locking sleeve  80  can be configured such that the reduced diameter section  60  has a reduction in outer diameter over its length from the head section  70  to the section  61  that covers the nut  36 . The surfaces of one or more of the different sections can be smooth or textured to enhance gripability of the locking sleeve. Further, because there will be a ridge formed at the intersection of the head section  70  and the section  60 , there will be enhanced gripability of the locking sleeve. 
         [0045]    Similarly, referring to  FIG. 7 , a locking sleeve  82  can have a reverse configuration from that of the locking sleeve  80  by having the reduced diameter section  60  has a reduction in outer diameter over its length from the section  61  that covers the nut  36  in the direction of the section  70  that covers the head. The surfaces of one or more of the different sections can be smooth or textured to enhance gripability of the locking sleeve. Further, because there will be a ridge formed at the intersection of the head section  70  and the section  60 , there will be enhanced gripability of the locking sleeve. 
         [0046]    Referring to  FIG. 8 , a locking sleeve  84  has a constant outer diameter along its length. The section  60 , rather than being of a reduced diameter relative to the sections  61  and  70 , has a textured surface that permits the user to more easily grasp the sleeve. Advantageously, in this embodiment and the other embodiments of  FIGS. 6-10 , the section  61  covers the nut  36  to ensure that a mechanic does not attempt to remove the oil plug assembly using a wrench. 
         [0047]    Referring to  FIG. 9 , in an embodiment similar to that disclosed in  FIG. 8 , a locking sleeve  86  has a constant outer diameter section  60  that is of a reduced diameter in comparison to one or both of the sections  61  and  70 .  FIG. 9  illustrates the section  60  having a reduced section in comparison to both sections  61  and  70 . One or all of the surfaces can be textured to enhance gripability of the sleeve. Further, because there will be a ridge formed at the intersection of the head section  70  and the section  60 , there will be enhanced gripability of the locking sleeve. 
         [0048]    Referring to  FIG. 10 , a locking sleeve  88  has a reduced outer diameter section  60  that is of a reduced diameter in comparison to one or both of the sections  61  and  70  and also in comparison to its entire length. The narrowest outer diameter is in the mid-section, which allows improved ability to grip the sleeve and slid it along the plug member. One or all of the surfaces can be textured to enhance gripability of the sleeve. Further, because there can be a ridge formed at the intersection of the head section  70  and the section  60 , there will be enhanced gripability of the locking sleeve. 
         [0049]    In another embodiment of this invention, in accordance with the preceding embodiments, circumferentially spaced radial grooves can be formed on the external surface of the locking sleeve at any location along its length, e.g., intermediate its opposite ends for a better grip. In a still another embodiment the radial grooves are replaced by a rough surface for a better grip. 
         [0050]    Still another embodiment of the invention describes a method of removing and replacing an oil pan plug assembly. The method includes the steps of (1) Providing a replaceable oil pan plug as described herein, (2) Mounting the elongated sleeve in an opening in the oil pan; and (3) Mounting the plug member to the elongated sleeve to form a fluid tight seal with a portion of the plug member covering a majority of a nut used to mount the elongated sleeve in the opening in the oil pan. Mounting the plug member comprises placing one or more fingers on the intermediate narrowed outer diameter and/or rough or grooved section of the locking sleeve between two flanges, gripping and pressing the locking sleeve to its limit position of movement towards the head, placing and pressing the thumb on the head portion and thereby securing the plug member into the elongated sleeve by slidable lengthwise compression into the sleeve bore.