Abstract:
A handheld shaker with a reciprocating agitator, comprising a mixing vessel that operatively contains a guide rod that runs from one end of the vessel to an opposite end of the vessel. The mixing vessel is operatively connected to both such ends. The shaker also uses a hollow agitator frame that operatively reciprocates from the one end of the vessel to the opposite end, and thereby mixes fluid contained within the vessel. A reciprocating agitator is also disclosed.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a shaker for mixing and agitating fluids. More particularly, the present invention relates to a shaker and agitator that mix liquids quickly, uniformly and easily. 
   BACKGROUND OF THE INVENTION 
   Pancake batters, dietary supplements drinks, baby formulas and nutritional shakes often require an agitation or dispersion mechanism for optimal mixing and dispersion of their powdered constituents. Several such mechanisms include an agitator attached to a mixing container. These attached or fixed agitators may have a semi-permanent connection to the container, or they may be manufactured integrally within the container. Several such devices are described in U.S. Pat. Nos. 1,060,419 and 3,136,532. These attached elements often create cracks and crevices, however, which are difficult to clean. Furthermore, these devices often do not allow sufficient movement or reach of the agitator to the entire container area, and thus fail to provide optimal mixing. 
   Hand mixing the above-mentioned mixtures into a smooth, homogeneous suspension often requires a considerable amount of work as well. The powdered composition of these mixtures often clumps, forming aggregations of powder surrounded by thick layers of paste that inhibit liquid from penetrating into the clumps. These clumps may float, sink to the bottom of the container, or remain suspended at some level in the fluid. Because powder may also stick to the sides or bottom of a container and resist mixing by simple shaking, in many cases, an elastic agitator is necessary for complete dispersion of clumps and aggregations on the container walls. For example, U.S. Pat. No. 6,739,032 discloses several elastic agitators. These agitators strike the container walls in random directions with respect to their direction of compressibility, however, and thereby fail on most such contacts to compress. 
   Hence the prior art fails to provide an agitation element and mixture vessel combination that is effective at reaching clumps and aggregation at the top, middle and bottom of a container while utilizing the full agitating capacity of the agitator. 
   SUMMARY OF THE INVENTION 
   Thus, the present invention is directed to a shaker with an agitator that maximizes shaking efficiency by providing both adequate internal container coverage and full utilization of spring agitating capacity. 
   One aspect of the present invention is directed to a handheld shaker with reciprocating agitator, comprising a mixing vessel, operatively containing a guide rod that runs from one end of the vessel to an opposite end of the vessel, and that is operatively connected to both such ends. It also has a hollow agitator frame that operatively reciprocates from the one end of the vessel to the opposite end, and thereby mixes fluid contained within the vessel. 
   In another aspect, the agitator frame has an internal attachment member that operatively attaches the frame to the guide rod and operatively slides along the guide rod. 
   In another aspect, the agitator frame can slide onto, and off of, the rod. 
   In yet another aspect, the agitator frame has an external mixing member, wherein the external mixing member and the internal attachment member are concentric coils. 
   In still another aspect, the concentric coils are made from one continuous piece of material. 
   In yet another aspect, the agitator frame is diamond, circular, spherical, cube, polyhedral, or pyramid-shaped. 
   In still another aspect, the guide rod is substantially solid. 
   In yet another aspect, the agitator frame operatively has a primary axis of elast cty parallel with the guide rod, and along which the frame contracts when it hits one of the vessel ends. 
   In still another aspect, the agitator frame has an external mixing frame comprised of concentric coils, wherein multiple coils can operatively touch the end of the vessel when the frame contracts against the end. 
   In yet another aspect, the agitator frame has a spring that operatively impacts the vessel&#39;s ends only at its ends. 
   Another aspect of the invention is directed to a reciprocating agitator, comprising a hollow agitator frame that operatively reciprocates from one end of a mixing vessel to an opposite end of the mixing vessel, and thereby mixes fluid contained within the vessel. The mixing vessel operatively contains a guide rod that runs from the one end of the vessel to the opposite end of the vessel, and that is operatively connected to both such ends. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith, and in which like reference numerals are used to indicate like parts in the various views: 
       FIG. 1  is a side perspective view of a shaker and agitator according to the present invention; 
       FIG. 2  is a side plan view of the agitator of  FIG. 1  as it slides along the guide rod of  FIG. 1 ; 
       FIG. 3  is a side perspective view of the agitator of  FIG. 1  as it contracts while contacting the bottom of the shaker of  FIG. 1 ; 
       FIG. 4   a  is a top perspective view of a spherical agitator according to the present invention; 
       FIG. 4   b  is a top perspective view of a cubical agitator according to the present invention; 
       FIG. 5  is a side perspective view of another shaker and agitator according to the present invention; and 
       FIG. 6  is a side perspective cross-sectional view of the shaker and agitator in  FIG. 5  along the plane designated by bisecting line X-X. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   As illustrated in the accompanying drawings and discussed in detail below, one aspect of the present invention is directed to a shaker and agitator that allow mixing of liquid and solid constituents quickly and easily when shaken by hand. The shaker and agitator of this aspect maximize the mixing capacity of the agitator by aligning the agitator&#39;s primary axis of elasticity with the direction of the agitator&#39;s movement. As a result, the agitator compresses with every contact against the vessel&#39;s walls, thereby taking full advantage of its elasticity with every vessel sidewall collision. 
   The shaker and agitator of this aspect also completely mix all solid and liquid constituents in every area of the mixing vessel. 
   Referring to  FIG. 1 , shaker  5  includes mixing vessel  1 , screw-on top  7 , snap-lid  9 , guide rod  3 , and spring agitator  11 . Solid and liquid mixture constituents are poured into vessel  1  through an opening in screw-on top  7 . Snap-lid  9  is closed and the user shakes shaker  5  back and forth along the general direction that is parallel to centrally disposed guide rod  3 , which causes spring agitator  11  to slide back and forth along guide rod  3 . 
   Vessel  1  and top  7  can be made from any material suitable for containing and agitating non-toxic liquid mixtures, including various plastics, metals and durable glass materials. 
   Mixture constituents are agitated as they flow through spaces  21  in spring agitator  11 , which further enhances mixing by creating turbulence in the mixture as it passes from side to side—between top end  15  and bottom end  17  of vessel  1 . 
   In one embodiment, spring agitator  11  passes from one horizontal side end to another horizontal side end of a mixing vessel. 
   Referring to  FIG. 2 , spring agitator  11  includes concentric internal  22  and external  25  coils, and weighted slide bar  40 . Internal  22  and external  25  coils are made from one continuous stainless steel piece, at the ends  27  and  29  of which is attached weighted slide bar  40 . 
   Internal coil  22  wraps very closely around guide rod  13  so that it does not provide additional agitation. 
   Internal coil  22  also secures every segment of the entire at rest length L of agitator  11  to rod  13 , which minimizes sideways distortion or movement of the entire length of agitator  11 . As such, coil  22  effectively holds the entirety of external coil  25  extremely firmly against guide rod  13 , and thereby focuses all of the elastic energy of agitator  11  in the direction of its primary axis E of elasticity. 
   In one embodiment, internal coil  22  is replaced by an internal hollow cylinder that runs the length of agitator  11 . Any guide element that trains the movement of agitator  11  almost exclusively along the direction of, or parallel to, guide rod  13 , however, can be used. 
   Weighted slide bar  40  slides along rod  13  and provides additional centralized density, which enhances the momentum and compressibility of agitator  11 . Slide bar weight  40  is made from stainless steel but can be made from any relatively dense material. 
   External coil  25  is diamond-shaped, which allows many of its points  13  individually to impact top end  15  and bottom end  17  of mixing vessel  1 , absorb the impact, and spring back to aid mixing motion in the opposite direction. 
   Referring to  FIG. 3 , each time spring agitator  11  travels along guide rod  13 , it contacts bottom (or top  15 ) end  17  with a certain momentum, almost all of which is imparted along axis E, which forces each of individual rings  45  to collapse upon one another as shown by direction arrows B. The full elastic capacity of agitator  11  is fully, or almost fully, harnessed each time it strikes an inside vessel wall. As a result, the change in relative distance between rings  45 , and the force exerted by rings  45 , changes more frequently. This change of relative positioning between the rings  45  creates additional turbulence, which maximizes mixing efficiency. 
   The total diameter N formed by the largest ring  45  is just shorter than internal diameter M of vessel  1 . Thus, rings  45  reach nearly every part of the internal area defined by vessel  1  so that every constituent, even constituents that may otherwise tend to stick along the sides or internal edges of vessel  1 , is mixed thoroughly. 
   A homogeneous, or otherwise evenly dispersed mixture, quickly and easily results. Any mixture can be made using this aspect, but several mixtures are especially appropriate for its use. These include, but are not limited to, pancake batters, dietary supplements drinks, baby formulas and nutritional shakes. Other drinks where this aspect is especially useful are those which require an agitation or dispersion mechanism for optimal mixing and dispersion of powered constituents. 
   Other embodiments contemplate the use of multiple or variously shaped and sized spring agitators. Referring to  FIG. 4   a , one embodiment uses circular spring agitator  50 , which includes internal  52  and external  54  coils that are made of one continuous piece of material. 
   Referring to  FIG. 4   b , an alternate embodiment uses cubical spring agitator  60 , which includes internal  62  and external  64  coils that are made of one continuous piece of material. 
   Referring to  FIG. 5 , shaker  100  includes mixing vessel  101  screw on lid  112 , guide rod  110 , and mixing element  130 . Mixing element  130  more specifically includes spherically-shaped external coil  134  and internal slide weight  136 , which attaches to, and slides along, guide rod  110 . 
   Referring to  FIG. 6 , shaker  100  also includes inner shell  102  and outer shell  104 . Inner shell  102  comprises cylinder  120 , which allows maximum efficiency in mixing. Outer diameter D of mixing element  130  is just slightly less than inner diameter C of cylinder  120 . Outer shell  104  is ergonomically shaped to assist a user in shaking. 
   In various embodiments, the two shell design can be used to provide different properties to each shell. For example, inner shell  102  is very rigid, while outer shell  104  is softer and has a tacky feel to provide a more comfortable and secure grip, which makes shaking easier. 
   Rod  110  is removably attached to the inside center of lid  112  at notch  113 . The raised area at the bottom of inner shell  102  contains depression  131 , which helps securely seat rod  110  along center axis Y of inner shell  102 . Rod  110  includes retaining flange  114  (or alternately another projection) just above base  116 , which prevents mixing element  130  from falling off rod  110  when lid  112  is removed. Mixing element  130  can be separated from rod  110  by sliding it off of rod  110  after separating rod  110  from lid  112 . 
   Snap spout cover  118  allows the contents of shaker  100  to be emptied without disturbing rod  110  or mixing element  130 . Mixing element  130  is a stainless steel spring. Rod  110  is made from solid stainless steel. 
   In one embodiment, the guide rod is hollow, and it contains both agitator  130  and the liquid that is mixed. 
   Another aspect of the present invention is directed to an agitating element, the details and several embodiments of which are substantially described above. 
   While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objectives of the present invention, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Additionally, feature(s) and/or element(s) from any embodiment may be used singly or in combination with other embodiment(s). Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments that would come within the spirit and scope of the present invention.