Patent Publication Number: US-7712725-B2

Title: Drain valve assembly

Description:
Priority in this application is based upon a Provisional Patent Application filed Oct. 26, 2004, identified as U.S. Ser. No. 60/622,465. 

   This invention related to a drain valve assembly for withdrawing fluid from a reservoir and is particularly concerned with draining fluid from a crankcase or the like, particularly in small engines like those found in lawn and garden tractors, small gasoline appliances, and the like. 
   BACKGROUND AND SUMMARY OF THE INVENTION 
   Draining the crankcase of a small engine is frequently done by a home owner and not by a trained mechanic, and that process is often a messy job. Conventionally, this job is done by unscrewing a draincock or plug at the lowest point of the crankcase or fluid reservoir. The unscrewing of the drain plug is frequently associated with a spill of the oil or other liquid. Oftentimes, the drain will begin to leak before the plug is fully opened, and turning it one way or the other will cause the draining to cease or create a steadier uncontrolled flow. Obviously, uncontrolled spills are not only messy, but are adverse to the environment and sometimes dangerous, as the fluid tends to soak into whatever surface it drains to, is often difficult to clear or clean and is some times combustible. 
   In the past, many inventors have sought to deal with these problem by designing special drain valves. Examples of such devices include those structures found in:
         Chen U.S. Pat. No. 6,609,699, OIL DRAIN VALVE;   Wickett U.S. Pat. No. 6,113,072, ACCESS PORT OR DRAIN PLUG WITH VALVE FOR LIQUID CONTAINERS;   Conklin et al U.S. Pat. No. 5,908,086, QUICK DRAIN CRANKCASE DRAIN PLUG;   Shropshire et al U.S. Pat. No. 5,411,115, OIL DRAIN PLUG;   Lombardo U.S. Pat. No. 5,407,117, OIL VALVE DEVICES FOR REMOVING USED OIL FROM DRAIN PANS OF VEHICLES;   Burdick et al U.S. Pat. No. 5,096,158, OIL DRAIN VALVE ASSEMBLY;   Martz U.S. Pat. No. 4,807,847. VALVED OIL PAN PLUG;
 
These designs usually involved critical trigger arrangements for opening and closing the flow of fluid or devices such as balls or cams which could interfere with the smooth flow of fluid (particularly where the fluid contains solids or is pasty) or twisting of the drain plug upon weak parts of the assembly or diverting the flow from a straight gravity flow which interfered with the draining of semi-viscous fluids, like some spent heavy oils. All of these systems are believed to require relatively difficult designs or not suitable or versatile enough for most types of simple drain application or involve risk of leaks or handling of messy parts or dangerous materials to accomplish the fluid draining job.
       

   In the present invention, the drain valve assembly has a stem which may be threaded or otherwise inserted into the housing of an oil pan, preferably at the lowest point thereof, for smooth gravity flow from the fluid reservoir. This stem receives one end of a novel sealing barrel seated therein and extending downwardly therefrom, and arranged over the other end of the barrel is an outside housing. In the stem and housing there is an o-ring which seals the barrel into the stem and outside housing. At the free end of the outside housing, there may be a safety end cap tethered to the housing and free to be moved on to and off the free end of the barrel. Extending from the barrel in the direction of flow are integral tabs which may be pinched together to free the barrel for vertical movement so that the barrel may be pulled downwardly to open a channel through the barrel and allow the fluid to flow from the fluid reservoir, or when opened, to be lifted for closing the channel. With this arrangement, the valve or barrel is opened or closed merely by moving it upwardly or downwardly, without any twisting or switching of a valve relatively to the direction of flow, and further, only the outside of the barrel is manipulated, so that the user does not come into contact with any surface touching the fluid. The barrel may be rotated horizontally so the it is accessible from any degree on its circumference. 
   OBJECTS AND ADVANTAGES OF THE INVENTION 
   It is the object of the present invention to provide a novel drain valve assembly of the character recited. 
   Another object is to provide a novel sealing barrel for a drain valve assembly. 
   Another object is to provide a novel drain valve which can be opened or close by moving a sealing barrel only in the direction of flow. 
   Another object is to provide a novel drain valve which can be opened and closed from the exterior of the valve assembly without contacting parts of the assembly coming in contact with the fluid being drained. 
   Another object is to provide novel opening-closing mechanism for a drain valve assembly which can be manipulated from members formed integrally with a drain valve sealing barrel. 
   Another object is to provide a drain valve assembly which can be fabricated from a few parts. 
   Another object is to provide a drain valve barrel which can be horizontally rotated to any degree position in the circumference of a circle so that its opening tabs may be manipulated irrespective of its orientation in the stem and housing. 
   Another object is to provide a drain valve assembly which is easy and inexpensive to fabricate and simple and efficient to use. 
   These and other objects and advantages of the invention will become more apparent as this description proceeds, taken in conjunction with the appended drawings and claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
       FIG. 1  is a perspective view of a drain valve assembly embodying the invention. 
       FIG. 2  is an isometric view of the drain valve assembly shown in  FIG. 1 , with some of the individual parts of the assembly shown exploded from one another. 
       FIG. 3  is a view showing the sealing barrel of the drain valve assembly arranged against the stem in normally closed position (the safety end cap and tether are not shown). 
       FIG. 4  is a view showing the sealing barrel of the drain valve assembly arranged spaced away from the lower part of the stem in valve open position (the safety end cap and tether are not shown). 
   

   DESCRIPTION OF A PREFERRED EMBODIMENT 
   With reference to the accompanying drawings, a typical drain valve assembly embodying the present invention comprises a stem  10 , which may have a threaded end  11  adapted for insertion in the crankcase of an engine (not shown). The other end of the stem  10  remote from the threaded end  11  comprises a sleeve  12 , and this entire stem has an axial passage  13  which permits the flow of fluid therethrough. This sleeve  12  has on opposed exterior sides thereof at least two ribs  14  extending therefrom. One end of a sealing barrel  15  is positioned in the sleeve  12 , and the other end of the sealing barrel  15  extends through an outside housing  16 . This outside housing  16  has an interior diameter sized to overlay the sleeve  12  of the stem  10 , and has apertures  17  which engage the ribs  14  of the sleeve to hold the housing  16  and stem together overlaying the sealing barrel  15 . At the end  18  of the barrel  15  remote from the stem  15  a safety end cap  19  tethered to the housing by a strap  20  is adapted to close a axial aperture  24  in the barrel  15  which is arranged in line to the axial passage  13  in the stem  10 . 
   O-rings  22  and  23  are provided on the sealing barrel  15  to seal the barrel in the stem  10  and housing  16  and to prevent fluid flow or leakage at points other than through the drain valve in the matter hereinafter described. Aperture  24  in the barrel  15  is in flow communication with the passage  13  and the channel  21  when the valve is open as hereafter described. 
   The barrel  15  has at its end adjacent the sleeve  12  of the stem  10  a plug  25  which is adapted to enter the axial passage  13 , which together with shoulder  26  on the barrel, blocks the flow of fluid entering the stem passage when the barrel is in its home position as shown in  FIG. 3 . When it is desired to open the stem passage  13  and its corresponding fluid communication passage, aperture  24 , the tabs  30  are pressed together to move the barrel  15  downwardly and open the flow passages, as shown in  FIG. 4 . Spaced apart on the tabs  30  are a pair of ribs  31  which define a recess  32  for receiving a return  33  at the end of the housing  16 , and when the tabs or pinched together, these ribs and recess clear the return and permit the barrel  15  to move downwardly and open the passage, and when the barrel is returned to closed position the ribs and recess snap engage the tabs  30  and hold the barrel closed. 
   At the remote end of the barrel  15  on its outer circumference there are a series of ring like undulations or barbs  35  which are adapted to engage the interior of the safety end cap  19 . This end cap  19  also has a lever  36  which may be manipulated when the end cap is installed over the barrel axial aperture  24  to open the end of the fluid passage. The stem  10  may also have a multi-sided area  37  at the base of the threaded portion  11  which may receive a wrench to securely tighten the threaded portion into a crankcase or similar fluid reservoir. 
   The barrel  15  is free to horizontally rotate to any degree in the circumference of a circle. This feature makes it possible for a user to open or close the drain valve assembly from any reachable position by merely pinching the tabs together and pulling the barrel to open position or pushing it closed. The feature may also be important to original equipment manufacturers who can install a more versatile drain valve assembly in their equipment without as much concern for other parts which are near the desired drain valve location and which may block its efficient use. 
   From this disclosure, it is apparent that the improved drain valve assembly shown permits fluid to flow merely by pulling the barrel  15  downwardly or to stop the flow of fluid by pushing the barrel upwardly. No twisting of the barrel is required, although the barrel may be turned on its horizontal axis and the barrel is still functional to move upwardly or downwardly as desired. The surfaces upon which the barrel moves are relatively vertically long, so that the barrel is constantly supported and the flow is open, even if the fluid contains “gunk” or other greasy based solids which could interfere with the fluid flow if the direction of flow was interrupted. By use of the structure taught herein, movement of the sealing barrel in the connected stem and housing may also be used to control the volume and flow of fluid through the fluid passage. 
   While a preferred embodiment of the invention has been shown and described in considerable detail, it should be understood that many changes can be made in the structure without departing from the spirit or scope of the invention, and it is not desired that the invention should be limited to the exact construction disclosed.