Abstract:
The present invention relates to a visual valve indicator comprised of a handle assembly with peripheral sidewalls attached to a linear moving valve stem for opening and closing of the valve and a grommet stratified into one or more color bands attached to and surrounding the base of the valve stem.

Description:
RELATED APPLICATION 
     There are no related applications. 
     FIELD OF THE INVENTION 
     The present invention relates to an apparatus for visually indicating the open and closed position of a valve having a linear moving valve stem. 
     BACKGROUND OF THE INVENTION 
     It is often difficult to determine at a glance whether a valve is open or closed. This problem is of particular concern in consumer goods, such as with valves on propane gas tanks, where harmful gases could escape without notice and potentially cause serious injury. Known types of indicating devises are generally not well suited for use in valve-containing consumer goods because these indicators are typically integrated with the valve assembly and/or contain a number of moving parts which increase the possibility of malfunction and also increase the cost of production. 
     Known inventions include those in which the valve indicator is part of the valve handle assembly. For example, U.S. Pat. No. 3,910,308 describes a valve indicator consisting of a knurled valve handle having windows that expose an on/off color indicator of an interior ring operating by means of a spring and ball bearing mechanism. 
     Other known indicator devices function by attachment to the valve stem or actuator stem. U.S. Pat. No. 5,469,805 discloses a valve position indicator fitted to the drive shaft of a valve actuator. The indicator has a sleeve interposed between an inner cylinder and an outer cylinder and arranged such that rotation of the actuator rotates the inner cylinder and causes the sleeve to slide between the inner and outer cylinders allowing a different color to be visible when the valve is open or closed. 
     Another known mechanism of operation for valve position indicators is by attachment of the indicator to the valve bonnet. U.S. No. Pat. 2,485,942 discloses an indicator comprised of contrasting color vanes, one affixed to the valve bonnet and the other responsive to valve stem movement. When the valve stem is moved, one vane slides over the other to indicate whether the valve is open or closed. 
     Each of the aforementioned inventions illustrates the disadvantages of known mechanisms for valve position indicators. These indicators operate by use of moving parts, which are additional to the valve mechanism itself. Additional moving parts not only increase costs of production, but could also potentially fail, leading possible error on the part of the operator and the need to replace the entire valve assembly. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a valve indicator wherein the open/closed position of the valve is indicated by the visible appearance of one or two color bands below the hand wheel on a linear moving valve stem. Although the present invention will be described with particular reference to propane gas tank valves, it will be appreciated that the invention has broader applications and may be used with other types of valves having a valve stem that moves linearly from the open to closed position and/or in other environments. The invention is comprised of a hand wheel assembly with a hand grip having peripheral sidewalls and a downward depending annular sleeve wherein the hand wheel assembly is attached to a linear moving valve stem which operates to open and close the valve. A grommet stratified into one or more color bands is attached to and rests on the valve bonnet adjacent to the point where the valve stem enters the valve bonnet. As the valve is closed, the length of the valve stem shortens, drawing the annular sleeve of the hand wheel assembly down over the grommet to obscure one or more layers of the grommet&#39;s color bands from vision, indicating that the valve is in the closed position. As the valve is opened, the length of the valve stem becomes longer, moving the annular sleeve of the hand wheel away from the grommet, thus exposing one or more layers of the grommet&#39;s color band, indicating that the valve is in the open position. 
     In a preferred embodiment, the indicating means of the present invention is utilized in a propane gas tank valve. 
     It is an object of the present invention to provide a visual signal on a valve to indicate that a valve is open or closed. 
     It is a further object of the present invention to provide an indicator that is advantageously suited for use in consumer goods containing valves. 
     It is an additional object of the present invention to provide an inexpensive means to provide a visual valve position indication. 
     It is another object of the present invention to provide visual position indicating means on a valve without the addition of moving parts to facilitate manufacturing. 
     It is yet another object of the present invention to enhance the safety of a manual valve by providing visual indication of the valve open position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The presently preferred embodiment of the invention is disclosed in the accompanying drawings wherein: 
     FIG. 1 is a cross-sectional elevational view of an upper portion of a valve assembly having the features of the present invention incorporated therein; 
     FIG. 2 is bottom plan view depicting the features of the present invention; 
     FIG. 3 is a perspective view of the valve position indicator in a valve closed position; and 
     FIG. 4 is a perspective view of the valve position indicator in a valve open position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the cross-sectional view in FIG. 1, there is illustrated hand wheel assembly  10  comprised of an exterior hand grip  12  with peripheral sidewalls  14  forming a recessed cavity  16  on the underside of grip  12 . Sidewalls  14  are preferably provided with a surface and shape suitable for secure manual gripping. Disposed within cavity  16  is an integral downward depending annular sleeve  18 . 
     Hand wheel assembly  10  is attached to a valve stem  20  by a fastener  22 . A colored grommet  24  is attached to the upper portion of a valve bonnet  26 . Grommet  24  may be affixed by any number of means, although preferably by an interference fit. A groove  28  may be precisely machined or otherwise formed in valve bonnet  26  corresponding to the limit of travel of stem  20 . 
     In the preferred embodiment, stem  20  is threadedly engaged with a valve actuator  30 . Valve  32  is actuated by rotation of hand wheel assembly  10  attached to stem  20 , causing stem  20  to move linearly in and out of valve bonnet  26 . There may be alternate means of actuating the valve other than by a threaded stem, and the present invention will accommodate any linear moving valve stem having a fixed closed position. 
     An annular sleeve distal end  34  projects at least as far as sidewalls  14 , and preferably slightly beyond sidewalls  14 , in order to enhance the visual contrast between sleeve  18  and the grommet  24 . Distal end  34  may be tapered outwardly to complement a beveled surface  36  of grommet  24 . Furthermore, sleeve  18  must encompass grommet  24  with a close tolerance in both the vertical and horizontal planes in order to achieve accurate indications of position. Grommet  24  must become exposed upon the slightest opening of valve  32  so as to properly indicate position. In a pressurized gas tank, fluid communication occurs upon the slightest opening of the valve seat, and a greater degree of displacement of the valve does not appreciably affect the rate of flow. 
     A bottom plan view of the valve indicator in valve closed position is depicted in FIG.  2 . In the preferred embodiment, exterior handgrip  12  has fluted peripheral sidewalls  14  to provide a suitable gripping surface. Inside the periphery of handgrip  12 , annular sleeve  18  is projects downward to cover colored grommet  24  surrounding valve stem  20 . 
     FIG. 3 depicts the appearance of the valve position indicator when valve  32 , with an inlet  38  and an outlet  40 , is in the closed position. As valve  32  is closed, valve stem  20 , as depicted in FIG. 1, is rotated downward into a valve body  42  to its maximum point of travel. Sleeve  18  is thereby drawn toward valve bonnet  26 . When the valve seat (not shown) closes, grommet  24  is completely concealed within sleeve  18 . The disappearance of colored grommet  24  indicates that valve  32  is in the closed position. 
     FIG. 4 depicts the appearance of the valve position indicator when valve  32  is in the open position. As valve  32  is opened, valve stem  20 , as depicted in FIG. 1, extends as it is rotated away from valve bonnet  26  thereby moving sleeve  18  of hand wheel assembly  10  away from valve bonnet  26  to expose colored grommet  24 . The visual appearance of colored grommet  24  indicates that valve  32  is in the open position. 
     In an alternate embodiment, grommet  24  is stratified into two color bands around valve bonnet  26 . Sleeve  18  covers the first band when in the fully retracted or closed position. 
     As an example, and not by way of limitation, grommet  24  may be constructed of a resilient, elastomeric material that will stretch to conform around the bonnet  26  and retain itself in friction fit. The color bands may also be designated by a bright fluorescent painted ring or rings. 
     As demonstrated by the detailed description of the preferred embodiment, the improved arrangement of the present invention allows the user of the valve to readily determine whether the valve is in the open or closed position. The simplistic construction achieves long-term performance of the indicator at a nominal cost of production. 
     According to the provisions of the patent statutes, we have explained the principle, preferred construction, and mode of operation of the invention, and have illustrated and described what we now consider to represent its best embodiments. However, it should be understood that within the scope of the appended claims and the foregoing description, the invention may be practiced, otherwise than specifically illustrated and described.