Abstract:
A drain valve to be used with numerous drain applications, such as draining fluid from an engine, includes in an exemplary embodiment a valve body, a first and second o-ring and a valve sleeve. The drain valve eliminates the need for a tool, such as a wrench, to drain the fluid from the engine, for example. The drain valve includes a twist-and-pull valve sleeve feature to manipulate the valve; however, the valve sleeve remains on the drain valve and therefore cannot be lost or misplaced. The valve sleeve further includes an easy grip for opening and closing the valve.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This Non-Provisional Application claims benefit to U.S. Provisional Application Ser. No. 60/591,831 filed Jul. 28, 2004. 

   FIELD OF THE INVENTION 
   The present invention relates generally to a valve, and more particularly to a drain valve for a small gas engine. 
   BACKGROUND OF THE INVENTION 
   It is known that drain plugs are installed on small engines typically below the oil sump of the engine and are used as a removable plug to permit the fluid in the sump to be drained and replaced. The known plugs typically include at one end a threaded portion that mates with a threaded opening in the oil sump. At the opposite end, the known plugs include a tool interface, such as a hexagonal shaped head, that may be manipulated through the use of a tool, such as a wrench, to install and remove the plug. 
   The known drain plugs, however, have several drawbacks. For example, the conventional drain plugs must be removed from the oil sump before the oil will drain. A tool must be used to remove the plug. As a loose item, the removed plug may become lost or misplaced. Occasionally, during the replacement of the plug, the mating threads are not properly aligned creating binding of the threads, an improper seal between the plug and the oil sump, or possibly stripping of the threads. Other drawbacks and disadvantages exist with respect to known drain plugs that are overcome by the present invention. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a drain valve that is a simplified assembly over the prior art and that may be used in numerous applications, including small gas engines. The drain valve of the invention includes generally a valve body, a pair of o-rings, and a valve sleeve. The disclosed drain valve eliminates the need for a tool, such as a wrench, to drain the fluid from the engine. The drain valve further includes a twist-and-pull valve sleeve feature to manipulate the valve. The valve sleeve remains on the valve and therefore cannot be lost or misplaced. Moreover, the drain valve provides an easy grip for opening and closing the valve. 
   Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an isometric exploded view of an exemplary drain valve of the present invention. 
       FIG. 2  is an assembled isometric view of the drain valve of  FIG. 1 , with an attached cap. 
       FIG. 3  is a cut-away view of the drain valve of  FIG. 1 , illustrating the drain valve in a closed valve position. 
       FIG. 4  is a cut-away isometric view of the drain valve of  FIG. 2 , illustrating the drain valve in an open valve position. 
       FIG. 5  is a cross-section view of the drain valve of  FIG. 6  taken at line  5 — 5  and illustrating the drain valve in a closed valve position. 
       FIG. 6  is a side view of the drain valve of the invention, illustrating the drain valve in a closed valve position. 
       FIG. 7  is a cross-section view of the drain valve of  FIG. 8  taken at line  7 — 7  and illustrating the drain valve in an open valve position, with an attached cap. 
       FIG. 8  is a side view of the drain valve of the invention, illustrating the drain valve in an open valve position. 
       FIG. 9  is an isometric view of another embodiment of the drain valve of the invention. 
       FIG. 10  is a cross-section view of the drain valve of  FIG. 11  taken at line  10 — 10  and illustrating the drain valve in a closed valve position. 
       FIG. 11  is a side view of the drain valve of the invention, illustrating the drain valve in a closed valve position. 
       FIG. 12  is a cross-section view of the drain valve of  FIG. 13  taken at line  12 — 12  and illustrating the drain valve in an open valve position, with an attached cap. 
       FIG. 13  is a side view of the drain valve of the invention, illustrating the drain valve in an open valve position. 
   

   Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. 
   DETAILED DESCRIPTION OF THE EMBODIMENTS 
   Referring to the figures there are depicted exemplary embodiments of a drain valve of the present invention. Referring to  FIGS. 1–8 , there is illustrated an exemplary drain valve  10  for use with an engine, such as small gasoline engine. One skilled in the art will appreciate that the teachings of the present invention may be used with numerous other drain applications in addition to the exemplary applications described herein. 
   In one embodiment, the exemplary drain valve  10  is a simplified assembly over the prior art and generally is a four piece assembly that includes a valve body  12 , a first o-ring  14 , a valve sleeve  16 , and a second o-ring  18 . As illustrated by  FIGS. 1–4 , the valve body  12  is generally cylindrical in shape and defines an interior cylindrical passageway  20  extending the length of the body. The valve body  12  also defines a first end  22  having a plurality of openings or windows  24  and a second opposing threaded end  26  also having an opening  28 . The threaded end  26  is sized to mate with a threaded opening in the engine sump or crankcase, not shown. Positioned on the exterior of the valve body  12  between the first end  22  and the second end  26  is a hexagonal shaped head  27  used to install the threaded end  26  of the valve body  12  to the threaded opening in the engine sump or crankcase. Once the valve body  12  of the drain valve  10  is installed, no tools are required to drain the fluid from the engine sump or crankcase, as described below. The valve body  12  further includes an annular ramp  21  that extends outwardly from the exterior of the valve body  12  and that serves as an inclined surface for the valve sleeve  16  to aid in aligning and properly positioning the valve sleeve  16  onto the valve body  12 . 
   As illustrated in  FIGS. 1 and 3 , the first end  22  of the valve body  12  defines a nose  23  of the valve body and forms the plurality of openings or windows  24 . The openings or windows are separated from each other by a plurality of support ribs  25  that connect the end  22  to the main body portion of the valve body  12 . The shape of the nose  23  and the plurality of support ribs  25  give the first end  22  a truncated conical shape. The number and spacing of openings  24  and ribs  25  may vary. In the illustrated embodiment, four openings or windows  24  are formed by four support ribs  25  spaced equidistant around the central axis of the valve body  12 . Depending on the application, it may be desirable to increase the fluid flow out of the valve. In those circumstances, it may be desirable to reduce the number of support ribs  25  to thereby increase the size of the openings  24  and thus increase the fluid flow rate. Similarly, it may be desirable to decrease the fluid flow rate, in which case, the size of the openings  24  may be reduced by increasing the number and/or size of the support ribs  25 . As discussed in detail below, when the valve sleeve  16  is manipulated to the open valve position, the fluid to be drained from the engine sump or crankcase will flow through the passageway  20  and out the plurality of openings or windows  24 . 
   As depicted in  FIG. 3 , the first o-ring  14  is positioned in a groove  30  and located on one side of the plurality of openings or windows  24 . The o-ring  14  creates a seal between the exterior of the valve body  12  and the interior of the valve sleeve  16 . The second o-ring  18  is positioned in a groove  32  and located on the opposite side of the plurality of openings or windows  24  adjacent to the nose  23 . As illustrated by  FIG. 3 , the second o-ring  18  creates a seal between the exterior of the valve body  12  and the interior of the valve sleeve  16 , when the valve  10  is in the closed valve position. As illustrated by  FIGS. 4 and 7 , when the valve sleeve  16  is manipulated to the open valve position, the second o-ring  18  no longer creates a seal between the valve body  12  and the valve sleeve  16 . In this position, fluid is permitted to exit through the plurality of openings or windows  24 , through the valve sleeve  16 , and out an opening  46  in the valve sleeve  16 . As depicted in the Figures, the second o-ring  18  defines a diameter that is less than the diameter of the first o-ring  14 . A standard rubber o-ring may be used as the first and second o-rings  14 ,  18 . 
   Referring to  FIG. 1 , the valve body  12  includes at least one pin  34 , and preferably two pins, that extend outwardly from the valve body  12 . Each pin  34  is configured to engage with a mating slot  36  formed in the valve sleeve  16 . The illustrated pin and slot configuration provides a valve  10  that requires a twist and pull action to open the valve, thus reducing the risk of accidental opening of the valve. The illustrated configuration also prevents the valve sleeve  16  from sliding off the valve body  12 , as discussed below. Other shaped pin and slot configurations may be used to provide the additional manipulation of the valve sleeve  16  to open and close the valve, and to prevent the valve sleeve  16  from sliding off the valve body  12 . The valve body  12  may be made of zinc die cast, rigid plastic, or other suitable material. 
   Referring to  FIGS. 1–4 , the valve sleeve  16  is configured to fit over the valve body  12 . The valve sleeve  16  defines a generally cylindrical valve sleeve body  40 , an interior cylindrical passageway  42  and a hose connect  44 . The hose connect  44  defines hose connect elements  45  configured on the exterior of the hose connect  44  for connection with a drain hose, or the like, not shown. The hose connect  44  also defines an opening  46  through which fluid to be drained from the engine sump or crankcase may flow. As illustrated, the opening  46  is configured with a diameter that is less than the diameter of the cylindrical passageway  42 . The interior cylindrical passageway  42  is shaped and configured to match the exterior shape and configuration of the valve body  12 . 
   The valve sleeve body  40  further includes at least one arcuate-shaped slot  36  that, in operation, mates with the at least one pin  34  and guides the pin  34  along the slot  36 . The slot  36  at its end defines a pair of opposing detents  48  that extend toward each other and into the slot  36 . In use, the detents  48  serve to retain the valve sleeve  16  onto the valve body  12  when the valve sleeve  16  is pulled to the open valve position, thereby preventing the valve sleeve  16  from sliding off the valve body  12 . Located on the exterior of the valve sleeve body  40  are a plurality of gripping elements  50  that serve as a gripping surface for a user to manipulate the valve sleeve  16  from a closed valve position to an open valve position and vice versa. The valve sleeve  16  may be molded from a plastic material, or any other suitable material. 
   Referring to  FIGS. 2 ,  4  and  7 , a cap  60  may be positioned over the hose connect  44  portion of the valve sleeve  16  to cover the opening  46  from ambient conditions and prevent dirt, moisture and other items from entering the opening  46 . The cap  60  may be snap fit over the hose connect  44  or may be attached to the hose connect  44  through other known techniques. The cap  60  may include an attachment ring  62  that is positioned around the hose connect  44  to retain the cap  60  onto the valve sleeve  16  and thereby prevent the cap  60  from being lost or misplaced. 
   With the embodiment described above, when the valve sleeve  16  is twisted and pulled, the valve  10  is moved to an open valve position, as shown in  FIGS. 4 ,  7  and  8 , whereby the fluid from the engine will drain from the engine by flowing through the passageway  20  and openings  24  and out the hose connect opening  46 . Fluid is permitted to flow through the valve because the second o-ring  18  on the valve body  12  is disengaged from the interior of the valve sleeve  16 , thus breaking the seal between the valve body  12  and the valve sleeve  16 . Once in this position, the fluid is no longer hindered from flowing out the hose connect opening  46  of the valve sleeve  16 . As shown in the Figures, the first o-ring  14  on the valve body  12  remains in a sealing contact with the valve sleeve  16  to prevent fluid from exiting back out between the valve body  12  and the valve sleeve  16 , thereby forcing the fluid to exit at the hose connect opening  46 . 
   The valve  10  is closed by reversing the motion. That is, the user first pushes the valve sleeve  16  and then twists the valve sleeve  16  to force the second o-ring  18  to seal against the inside of the valve sleeve  16 , thereby preventing fluid from passing out the opening  46 . 
   Referring to  FIGS. 9–13 , there is depicted another embodiment of the drain valve. In this embodiment, a drain valve  68  includes a plurality of tabs  70  that may be added to the exterior of the valve sleeve  16  to assist the user with the manipulation of the valve sleeve  16  to open and close the valve. The plurality of tabs  70  may be positioned in an equidistant manner around the valve sleeve  16  to serve as additional gripping elements to facilitate the turning of the valve sleeve  16 . The plurality of tabs  70  may define other tab shapes and configurations that enhance the user&#39;s manipulation of the valve sleeve  16 . As with the above described embodiment, when the valve sleeve  16  is twisted and pulled to an open valve position, as illustrated in  FIGS. 12 and 13 , the second o-ring  18  on the valve body  12  is disengaged from the interior of the valve sleeve  16 , thus breaking the seal between the valve body  12  and the valve sleeve  16 . In this position, fluid from the engine will drain from the engine through the passageway  20 , out the plurality of openings  24  and the hose connect opening  46 . Similarly, when the valve sleeve  16  is pushed and twisted to the closed valve position, the second o-ring  18  will seal against the inside of the valve sleeve  16 , thereby preventing fluid to flow out through the hose connect opening  46 . The remaining features of the valve body  12  and valve sleeve  16  are similar to the features of the embodiment described above and illustrated in  FIGS. 1–8  and therefore will not be repeated here. 
   Advantageously, with the embodiments described above and illustrated in the figures, no tool is required to operate the valve sleeve  16  and thereby open the valve  10  to drain the fluid. In addition, because the valve sleeve  16  is retained by the valve body  12 , the valve sleeve cannot be inadvertently lost or misplaced. As illustrated, the valve sleeve may include different types of gripping elements and tabs to facilitate the opening and closing of the valve. Also, with the invention, it is no longer necessary to reinstall the drain valve after the initial installation and thus the problems associated with cross-threading, thread stripping, and resulting leakage are avoided. 
   Variations and modifications of the foregoing are within the scope of the present invention. It should be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art. 
   Various features of the invention are set forth in the following claims.