Patent Publication Number: US-7222758-B1

Title: Valve stem stability in pressurized dispensing containers

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to a mechanism for preventing the valve stem in a pressurized dispensing container from rotating when the nozzle around the stem is rotated. 
   The problem arises in pressurized dispensing containers where the product dispensed, such as caulk, gets between the nozzle and the valve stem. The product dries or cures and creates a seal or adhesion between the outside of the valve stem and the inside wall of the nozzle. 
   When that occurs, it becomes difficult to rotate the nozzle relative to the valve. Such rotation is useful, either partially so as to provide a new position of the nozzle on the valve stem or to remove the nozzle for cleaning. 
   Accordingly, it is a major object of this invention to provide a structure that will allow rotation of the nozzle without causing the stem to rotate where the nozzle has to be rotated with a force sufficient to break the binding effect of the dispensed product that seeps between the valve stem and nozzle. 
   It is a related purpose of this invention to achieve the main object in an inexpensive fashion with a design which does not modify or compromise the dispensing operation of the container. 
   BRIEF DESCRIPTION 
   In brief, one embodiment of this invention employs two projections which extend upward from the side of the button that is at the base of the valve stem. These two projections engage the side surface of the resilient sealing boot that provides sealing between the valve stem and the container body. These projections are wedges that are held in the resilient boot by virtue of substantial pressure (for example, about 100 pounds per square inch) that is exerted by the pressurized contents on the valve button. This pressure assures continued engagement between these projections or wedges and the resilient boot. 
   When the nozzle is rotated and there is a binding effect due to dispensed product between nozzle and stem, the stem is held against rotation by the engagement of the projections from the valve into the boot. The projections have to be sized to provide the engagement necessary to overcome the force required to break the seal between nozzle and stem from the dispensed product. Thus, the size, and perhaps even the deployment, of the projections, may be a function of the product involved. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view, in partial section, showing the arrangement between the valve stem  12 , boot  18  and the top of the container body which arrangement incorporates the projections  30  taught by this invention. 
       FIG. 2  is a view, in a larger scale than  FIG. 1 , of the zone around the position where the projections  30  and the valve button  20  engage the resilient boot  18 . 
       FIG. 3  is a bottom view of the button  20  and one projection  30 . 
       FIG. 4  is a view along the plane  4 — 4  of  FIG. 2  of the valve stem  12 , valve button  20  and the two projections  30 . In  FIG. 4 , the resilient boot is deleted. 
       FIG. 5  is a perspective view from underneath the button  20  showing the projections  30  engagement with the resilient sealing boot  18 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The FIGs. all disclose a single embodiment. A pressurized dispensing container  10  has a top central opening through which the valve extends. The stem  12  of the valve is a partially threaded  14  stem and engages the threaded inner surface of the nozzle  16 . A resilient boot  18  extends along the lower portion of the surface of the valve  14  stem and is held between the button  20  at the base of the valve stem and a downwardly facing ledge  22  on the valve stem. The nozzle  16  has a handle  24 . When the handle  24  is pressed by the user, the nozzle engaging the valve stem forces the valve to tilt sufficiently so that one or more of the valve stem openings  26  are exposed to the product held under pressure within the interior of the container  10 . The product under pressure will then be forced through one or more of the openings  26  into the central axial passageway (not shown) of the valve stem to exit from an opening (not shown) at the top of the valve stem into the interior of the nozzle  16  so as to be dispensed at the opening at the upper end  28  of the nozzle. 
   Some of this material will seep down into the space between nozzle  16  and valve stem  14 . When this material cures or hardens or sets, it tends to act as an adhesive between nozzle  16  and valve stem  14  making it difficult to rotate the nozzle relative to the valve stem. 
   Where, for example, it is desirable to unscrew the nozzle  16  so as to remove it to clean it out, it may become impractical to separate the nozzle and valve stem because rotation of the nozzle  16  will cause the valve stem  14  to rotate and track with the nozzle. 
   As may best be seen in  FIGS. 2 through 5 , the device of this invention involves two projections  30  which project upward from the side of the valve button  20 . Wedge portions  34  project into the resilient boot  18 . These projections  30  are held into engagement with the resilient boot  18  by the force applied to the button  20  by the pressurized product that is to be dispensed. 
   In one embodiment employing a caulk product, the projections  30  each have a base portion and a symmetrically pointed wedge portion  34  that extends into the sloping side of the sealing boot  18 . 
   When the nozzle  16  is to be rotated, the user turns the nozzle hard enough to break any seal, due to cured product, between nozzle  16  and valve stem  12 ,  14 . The projections  30 , and particularly the wedge portions  34 , holds the valve  12  in position. 
   Although the embodiment of this invention has been described in detail, it should be apparent to those skilled in the art that various modifications can be made without departing from the scope and teachings of this invention. The scope of the invention is set forth in the claims. It is not intended for those claims to be limited by the specific embodiment shown. 
   For example, although two wedges like projections  30  are shown and are preferred, any number of projections can be employed. It should be understood herein that the reference made herein to a set of projections is to a set that contains anywhere from one projection to any number desired. Applicant believes that in most cases two projections would be enough and that at least two projections should be used in order to assure a circumferential balance in the holding between the boot  18  and the valve button  20 . 
   The embodiment disclosed employs two projections  30  which are positioned radially outboard of the valve button  20 . The projections, or at last the wedge portion thereof, could be placed on the upper surface of the button. But that design is less preferred because it runs the risk of lifting the lower surface of the boot sufficiently off of the button to cause some loss of sealing. 
   The embodiment disclosed employs a tilt valve design in which the nozzle is threaded on the stem. The problem to which the invention is addressed can occur in connection with the dispensing of product employing a valve that is actuated in an up-down direction and also to a design in which the nozzle is not threaded on the stem. Accordingly, it should be understood that this invention applies to such designs as well as other pressurized dispensing container designs. 
   It should be noted that the valve has to be an assembled product before being mounted on the container and before product is loaded into the container. During assembly, the valve and boot have to be forced together in a fashion that will cause the projections to engage the boot. During use, the pressure of the product assures continued engagement.