Abstract:
A safety device prevents access to the gas valve of a propane tank. The device includes a cup which fits over the valve, and a locking device for preventing the cup from being lifted from the valve. In some embodiments, the device includes a handle which allows the tank to be carried easily while the safety device is installed. In at least one embodiment, there is no handle. The device prevents children, and other unauthorized persons, from operating the valve, and thus prevents the accidental release of flammable gas.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention provides an effective anti-tampering device, intended to fit onto propane tanks which are typically used in domestic applications such as heating and cooking.  
         [0002]     Liquefied propane (LP) is commonly used as fuel for gas grills which are popular for outdoor cooking and barbecuing. LP tanks are also commonly found on mobile or manufactured homes, where they are used to supply flammable gas for use in heating and cooking. LP may also be used in conventional homes located in remote areas which are not served by natural gas utilities.  
         [0003]     Many gas grills use 20-pound propane tanks, which are large enough to store a reasonable supply of fuel, but small enough to be carried by one person. These portable tanks may also be found on recreational vehicles or trailers. It is common to provide a pair of such 20-pound tanks for these vehicles.  
         [0004]     It is very easy to ignite a gas grill. One must simply lift the hood of the grill, open the valve of the LP tank, turn on the gas knobs, and push an igniter button. The simplicity of this process creates a clear hazard, namely that children, in an effort to mimic their parents, may easily ignite a grill at an inappropriate time. If the hood of the grill is in the lowered position, igniting the grill may cause a catastrophic explosion.  
         [0005]     Moreover, if the valve of the LP tank is accidentally left open, the area surrounding the grill could become saturated with propane gas, creating the potential for an explosion if the igniter is pushed, or if the gas comes into contact with a spark, or with a lighted match or cigarette. Similar concerns apply to LP tanks used with mobile or manufactured homes, or recreational vehicles.  
         [0006]     Although there exist federal safety regulations governing the design of LP tanks, there appear to be no regulations requiring a safety device which prevents unauthorized opening of such tanks.  
         [0007]     The present invention provides a safety device which prevents accidental or unintentional release of flammable gas from a propane tank. The device of the present invention, in its preferred embodiment, also provides a convenient means for carrying and transporting a propane tank.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention comprises a safety device which prevents access to the gas valve of a propane tank. In its most basic form, the device includes a cup which is of a size sufficient to fit over the major portion of the valve, and means for locking the cup in place over the valve. The cup therefore prevents access to the valve, and makes it virtually impossible to release flammable gas accidentally.  
         [0009]     In one preferred embodiment, the safety device includes two distinct pieces, namely a cross-member which holds the cup, and a handle portion. The cross-member has one end which engages the collar of the propane tank. The handle portion is threaded through a hole in the cross member, and also engages the collar. The shank of a lock is inserted through openings in a baffle forming part of the cross-member, thereby blocking movement of the handle portion and of the cross-member. The cup is therefore prevented from becoming dislodged from the valve. The handle portion includes a grip which facilitates easy transport of the tank.  
         [0010]     In another embodiment, the handle portion is permanently affixed to the cross-member, and the cross-member has means, at either end, for engagement with the collar of the tank.  
         [0011]     In another embodiment, the handle portion again includes a grip, but the handle portion is permanently affixed, such as by welding, to the cross-member. As before, the cross-member is still engaged, at both ends, with the collar of the tank, so as to lock the cup over the valve, thus preventing access to the valve.  
         [0012]     In still another embodiment, the cup includes holes which allow the prongs of a U-shaped member to pass through. The prongs themselves have holes which can accommodate the shank of a lock, enabling the U-shaped member to be locked to the collar of the tank, or to the cup, or both. The prongs pass beneath the valve, and prevent the cup from being lifted off the valve. This embodiment does not include a handle.  
         [0013]     The invention also includes the methods of securing a valve, as performed by installing the various embodiments described above.  
         [0014]     The invention therefore has the primary object of enhancing the safety of propane tanks and the like, by providing a device for blocking access to the gas valve of such tanks when the tanks are not in use.  
         [0015]     The invention has the further object of preventing children, or other unauthorized persons, from opening the valve of a propane tank.  
         [0016]     The invention has the further object of providing a safety device, as described above, wherein the device includes a handle that permits the propane tank to be easily carried when the tank is locked.  
         [0017]     The invention has the further object of providing a safety device that can be used with existing propane tanks, without modifying such tanks.  
         [0018]     The invention has the further object of providing a method of blocking access to the gas valve of a propane tank when the tank is not in use.  
         [0019]     The reader skilled in the art will recognize other objects and advantages of the present invention, from a reading of the following brief description of the drawings, the detailed description of the invention, and the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1  provides a perspective view of a preferred embodiment of the present invention, showing the invention being used not only to prevent access to the valve of a propane tank, but also as a means of transporting the tank.  
         [0021]      FIGS. 2-4  provide perspective views of the embodiment of  FIG. 1 , illustrating the steps of inserting the device of the invention over the valve of a propane tank, and locking the device onto the tank.  
         [0022]      FIG. 5  provides a perspective view of another embodiment of the invention, wherein the locking device is formed of one piece.  
         [0023]      FIGS. 6 and 7  provide perspective views of another embodiment of the invention, wherein a handle is permanently welded to the main body of the device.  
         [0024]      FIGS. 8 and 9  provide perspective views of another embodiment of the present invention, wherein the safety device does not include a handle.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]      FIGS. 1-4  illustrate a first preferred embodiment of the present invention.  FIG. 1  shows the safety device installed on a propane tank, and shows the tank being carried by the handle forming part of the safety device.  FIGS. 2 and 3  show intermediate steps in the installation of this embodiment of the safety device.  FIG. 4  provides a more detailed perspective view of the safety device as installed on a propane tank.  
         [0026]     The safety device of the present invention is intended for use with propane tank  1  which has collar  3  which surrounds gas valve  5 . The collar is a structure that forms part of the tank, and is not part of the present invention. The collar may be integrally formed with the tank, or it may be welded thereto. A protective cover  7 , usually made of plastic, surrounds the valve, and is removed or partially released from the valve when the tank is in use. The cover  7  also does not form part of the present invention, but is typically supplied with the tank. In the drawings of this disclosure, the cover is shown in the partially released condition.  
         [0027]     In the embodiment of  FIGS. 1-4 , the safety device comprises two distinct pieces. The first piece is a cross-member  9  which is attached to cup  11 . The second is a handle portion  13  which attaches to the cross-member as described below, and as illustrated, for example, in  FIG. 3 .  
         [0028]      FIG. 2  shows the cross-member  9  as it is being inserted over the gas valve  5 . The cross-member includes L-shaped portion  20 , which fits through an opening defined by the collar  3 , so as to engage the collar. The cup  11  has a diameter and height sufficient to enclose a substantial portion, and preferably the major portion, of the valve  5 , when the cross-member is inserted. The cross-member is sized such that the end opposite the L-shaped portion  20  does not extend beyond the collar. Thus, the entire cross-member, except for L-shaped portion  20 , fits within the interior region bounded by the collar, as shown in  FIG. 3 . The cross-member also includes opening  26 , visible in  FIG. 2 .  
         [0029]     In  FIG. 3 , handle portion  13  is being inserted. The handle portion includes grip  22  at one end, and an L-shaped member  24  at the other end. The grip  22  may be made of foam or other equivalent material, to make it more comfortable to carry the tank in the manner illustrated in  FIG. 1 . The L-shaped member  24  of the handle portion  13  is threaded through opening  26  in cross-member  9 , such that the distal end of the L-shaped member protrudes through another opening defined by the collar  3 , opposite to the opening that receives L-shaped portion  20  of the cross-member. The handle portion  13  is threaded through opening  26  until it assumes the position shown in  FIG. 4 .  
         [0030]     The cross-member also includes a pair of baffles  30 , the baffles having holes  32  which are mutually aligned. The holes are spaced sufficiently away from the main body of the cross-member so as to enable the body of the handle to come to rest below the level of the holes, as shown in  FIG. 4 . A shank of lock  40  can therefore be attached through these holes, and will prevent upward movement of the handle. The lock thus prevents the handle portion  13  from being removed, and therefore also prevents the cross-member from being dislodged, because the cross-member is blocked by the handle portion. Thus, the cup  11  is effectively locked in place over the valve, and prevents access to the valve.  
         [0031]      FIG. 1  shows the tank  1  being carried by handle portion  13 , with the device of the present invention fully installed.  
         [0032]      FIG. 5  shows another embodiment of the invention. In this embodiment, the safety device comprises one piece. A propane tank  51  includes collar  53 , as before. The safety device of this embodiment includes a cross-member  55  which is attached to cup  57 . A handle portion  59  is attached to the cross-member. The cross-member includes, at one end, a pair of generally parallel members  61  and  62 , generally perpendicular to the main body of the cross-member. The parallel members  61  and  62  are intended to fit around the collar of the tank. In  FIG. 5 , member  62  is obscured by the collar of the tank, and is therefore shown in dotted outline.  
         [0033]     The cross-member also includes a C-shaped structure  63  at the other end. The C-shaped structure enables the cross-member to engage a corresponding opening in the collar  53 . Preferably, the C-shaped structure  63  includes an upwardly extending flange which causes the C-shaped structure to surround the collar, at least partially, and thereby to latch the C-shaped structure to the collar.  
         [0034]     The parallel members  61  and  62  have holes which are mutually aligned, to allow a shank of lock  65  to pass through both holes, as well as through the opening in the collar, as shown in  FIG. 5 . When the lock is so installed, the end of the cross-member which has members  61  and  62  is thereby prevented from separating from the collar. At the same time, the other end of the cross-member remains firmly latched to the collar. Thus, the cross-member cannot move, and the cup  57  blocks access to the valve.  
         [0035]     Like the first embodiment, the safety device according to the embodiment of  FIG. 5  can be easily carried, in the locked position, simply by using the handle  59 . The handle is preferably attached permanently to the cross-member, or is integrally formed therewith.  
         [0036]      FIGS. 6 and 7  show another embodiment of the present invention. This embodiment is similar to that of  FIGS. 1-4 , except that the handle and the cross-member are essentially one piece. As shown in these figures, cross-member  71  is attached to cup  73 . Handle  75 , which includes a grip portion  77  is attached to the cross-member, such as by welding. Alternatively, the handle could be attached to the cross-member by other means, or it could be integrally formed with the cross-member.  
         [0037]     One end of the cross-member comprises a C-shaped structure  77 , suitable for engagement with collar  79  of propane tank  81 , by passing through the opening in the collar. The other end  83  of the cross-member is L-shaped, and includes hole  85 , which accommodates the shank of padlock  87 . Thus, the cross-member includes means for engaging the collar at diametrically opposed locations. The lock is preferably attached such that the shank passes through hole  85 , and also through the opening in the collar, while still enclosing a portion of the collar. In this way, the L-shaped end of the cross-member is locked to the collar, and the cup cannot move. Access to the valve is therefore blocked.  
         [0038]      FIGS. 8 and 9  illustrate yet another embodiment of the present invention. This embodiment does not include a handle, but still prevents access to the valve of the propane tank. The device includes U-shaped member  91  and cup  93 . As before, the cup fits over the valve of the tank. In this embodiment, the cup includes openings, such as opening  95 , which allow the prongs of the U-shaped member to slide through the cup. The U-shaped member includes at least one hole  97 . In the embodiment shown, there are two such holes, located on both prongs of the member. Also, the prongs are of unequal length, and one of the prongs is long enough to extend beyond the periphery of the collar  99  when the U-shaped member is fully inserted into the cup. The hole in the longer prong is located near the end of that prong, while the hole in the shorter prong is spaced away from the end.  
         [0039]     The U-shaped member  91  therefore slides through the cup  93 . The prongs of the U-shaped member slide below the valve. The valve is not visible in  FIGS. 8 and 9 , but is similar in structure to that shown in  FIGS. 2 and 6 . The shank of padlock  101  can then be inserted through the hole in the long prong, as shown in  FIG. 9 . In this arrangement, the U-shaped member is locked in place, and prevents movement of the cup  93 . The cup cannot be lifted off the valve because the prongs of the U-shaped member are positioned under the knob of the valve, and are therefore blocked by the knob. Thus, the U-shaped member cannot be moved upward. Since the cup is constrained by the U-shaped member, the cup also cannot move away from the valve, and access to the valve is again blocked.  
         [0040]     In an alternative arrangement, one could insert the shank of the lock through the hole in the shorter prong, which is located inside the region bounded by the collar. In this case also, affixing the padlock prevents significant movement of the U-shaped member, and prevents removal of the cup. Access to the valve inside the cup is still blocked.  
         [0041]      FIG. 9  shows the reason for the spacing of the holes  97  in the prongs of the U-shaped member. When the U-shaped member is fully inserted, the hole of the longer prong extends just beyond the collar, and the hole of the shorter prong extends just beyond the cup. Affixation of the lock to either of these holes will have the desired effect. It is also possible to affix two separate locks, to both holes, to increase the degree of security.  
         [0042]     An important advantage of all embodiments of the present invention is that they can be used with existing propane tanks, and do not require modification of such tanks. The device of the present invention does not require any drilling of holes in any part of the tank, or any change to the existing valve structure. It simply provides means for covering the valve with a cup, and for preventing the cup from being moved away from the valve.  
         [0043]     The invention can be modified in various ways, as will be apparent to those skilled in the art. For example, different means of attachment of the cup to the cross-member can be used. The cup could be welded to the cross-member, or it could be attached by a screw and nut, as suggested in the embodiment of  FIGS. 6 and 7 . In another alternative, the cup could be allowed to slide, through a limited range, along a slit in the cross-member, thereby allowing the cup to be correctly positioned over the valve in cases where the valve is not perfectly centered on the tank. These and other modifications should be considered within the spirit and scope of the following claims.