Apparatus for liquid level measurement in a container

Abstract

A liquid level measuring device for measuring the level of liquid in a storage or dispensing tank has an elongated tubular hollow body that carries a threaded coupler adapted for engaging a threaded nipple on top of the tank. A buoyant float is attached to a lower portion of the elongated body. The body slides in relation to the coupler while the coupler remains stationary in relation to the tank. As the liquid is dispensed from the tank, the buoyant float that was positioned on the surface of the liquid in the tank, lowers in relation to the tank, moving the elongated body into the tank. Measuring indicia placed en the exterior surface of the elongated body allows visual observation of the changing level of liquid in the tank.

I claim:  
     
         1 . An apparatus for determining the amount of liquid in a tank, the tank having a top opening surrounded with an exteriorly threaded nipple, the apparatus comprising: 
 an elongated hollow body;    a coupler threadably attachable to the threaded nipple, said coupler having an interior opening extending therethrough for slidably receiving the body therein;    a buoyant member fixedly secured on a lower portion of said body, said buoyant member extending into said tank when said coupler is engaged with said nipple, said body moving in relation to said tank in response to displacement of said buoyant member caused by a change in a level of liquid in the tank.    
     
     
         2 . The apparatus of  claim 1 , wherein a top portion of said body carries a top cap closing an open top end of said hollow body.  
     
     
         3 . The apparatus of  claim 2 , further comprising a means for limiting slidable movement of said body in relation to said coupler, said means comprising an annular collar slidably positioned between said coupler and said top cap, said collar having an interior opening with a diameter smaller than the exterior size of said top cap and an exterior diameter substantially equal to or greater than an exterior diameter of said coupler.  
     
     
         4 . The apparatus of  claim 3 , wherein said annular collar comprises an upper part and a reduced diameter lower part, and wherein a shoulder is formed about the line of connection between the upper part and the lower part, said shoulder resting on a top edge of said coupler when the apparatus is oriented vertically to extend at least in part into said tank.  
     
     
         5 . The apparatus of  claim 3 , wherein said annular collar comprises an upper part and a reduced diameter lower part, and wherein said lower part contacts an upper edge of said buoyant member when the elongated body is positioned in a tank with a high liquid level, said annular collar gradually moving away from said buoyant member as the liquid level in the tank decreases.  
     
     
         6 . The apparatus of  claim 1 , wherein said coupler comprises an internally threaded lower portion and an upper portion unitary connected to the lower portion, said upper portion being provided with a plurality of through openings formed in the annular wall thereof to permit air circulation between the interior of the tank and an exterior thereof.  
     
     
         7 . The apparatus of  claim 1 , wherein said body has a length substantially equal to or greater than the depth of said tank.  
     
     
         8 . The apparatus of  claim 1 , wherein said body is provided with a measuring indicia on an exterior surface thereof to allow visual observation of the level of liquid left in the tank.  
     
     
         9 . An apparatus for determining the amount of viscous fluid in a dispensing tank, the tank having a top opening surrounded with an exteriorly threaded nipple, the apparatus comprising: 
 an elongated hollow body;    a coupler threadably attachable to the threaded nipple, said coupler having an interior opening extending therethrough for slidably receiving the body therein, said coupler comprising an internally threaded lower portion and an upper portion unitary connected to the lower portion, said upper portion being provided with a plurality of through openings formed in the annular wall thereof to permit air circulation between the interior of the tank and an exterior thereof; and    a buoyant member fixedly secured on a lower portion of said body, said buoyant member extending into said tank when said coupler is engaged with said nipple, said body moving in relation to said tank in response to displacement of said buoyant member caused by a change in a level of viscous fluid in the tank.    
     
     
         10 . The apparatus of  claim 9 , wherein a top portion of said body carries a top cap closing an open top end of said hollow body.  
     
     
         11 . The apparatus of  claim 10 , further comprising a means for limiting slidable movement of said body in relation to said coupler, said means comprising an annular collar slidably positioned between said coupler and said top cap, said collar having an interior opening with a diameter smaller than the exterior size of said top cap and an exterior diameter substantially equal to or greater than an exterior diameter of said coupler.  
     
     
         12 . The apparatus of  claim 11 , wherein said annular collar comprises an upper part and a reduced diameter lower part, and wherein said lower part contacts an upper edge of said buoyant member when the elongated body is positioned in a tank with a high level of viscous fluid, said annular collar gradually moving away from said buoyant member as the level of the viscous fluid in the tank decreases.  
     
     
         13 . The apparatus of  claim 9 , wherein said elongated body is provided with a measuring indicia placed on an exterior surface of said elongated body to allow visual observation of a decreasing level of the viscous fluid in said tank caused by dispensing of the viscous fluid from said tank.  
     
     
         14 . The apparatus of  claim 9 , wherein said elongated body has a length at least as great as the vertical dimensions of said tank.  
     
     
         15 . A method of measuring level in a tank having a top opening and a threaded collar surrounding said top opening, the method comprising the following steps: 
 providing an elongated hollow body, a coupler threadably attachable to the threaded collar, said coupler having an interior opening extending therethrough for slidably receiving the body therein, and a buoyant member fixedly secured on a lower portion of said elongated body;    providing measuring indicia on an exterior surface of said elongated body corresponding to units of liquid measure;    attaching said coupler to said collar, while positioning said buoyant member in an interior of said tank such that the buoyant body floats on the surface of liquid in the tank;    visually observing movement of said elongated body into the interior of said tank caused by a decreasing level of liquid in said tank.    
     
     
         16 . The method of  claim 15 , further comprising the steps of providing vent opening in said coupler to permit circulation of gases between the interior of said tank and the exterior thereof.  
     
     
         17 . The method of  claim 15 , wherein a top portion of said body carries a top cap closing an open top end of said hollow body and wherein a stop means for limiting slidable movement of said body in relation to said coupler are carried by said elongated body.  
     
     
         18 . The method of  claim 17 , wherein said stop means comprises an annular collar slidably positioned between said coupler and said top cap, said collar having an interior opening with a diameter smaller than the exterior size of said top cap and an exterior diameter substantially equal to or greater than an exterior diameter of said coupler.