Abstract:
A spring-loaded shelf for an existing beverage cooler, which obviates the need for a user to reach more deeply within the confines of the cooler for a beverage as the contents of the cooler become depleted. The spring-loaded shelf has a base, a platform pivotally attached to the base by two scissor-type linkages, and a lifting mechanism for selectively and automatically raising the platform with respect to the base upon the scissor-type linkages, as the weight of the beverages placed upon the platform gradually decreases. Use of the spring-loaded shelf prevents injury to the user while retrieving a beverage from the cooler, and also provides for increased accessibility and visibility of the contents of the cooler.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention generally relates to an accessory for an existing cooler, and in particular relates to a spring-loaded shelf which is selectively positioned within an existing beverage cooler, having a platform which gradually vertically rises as beverages are removed therefrom, thereby obviating the need for a user to reach deeply within the confines of the cooler in order to retrieve a beverage. 
   2. Description of the Related Art 
   Top-loading beverage coolers are used by various business establishments for storing bottled and canned beverages, and for maintaining the beverages at low temperatures. While top-loading coolers are extremely useful for storing beverages until they are needed, they have a notable drawback. In particular, as the contents of the top-loading cooler become depleted, it becomes increasingly necessary for a user to reach deeply within the confines of the cooler to retrieve a beverage therefrom, which may strain the shoulder, arm, and stomach muscles of the user. Moreover, the user may accidentally cut his/her hand upon a broken bottle that may be resting, unseen, at the bottom of the cooler. Accordingly, there is a need for a spring-loaded shelf which is selectively positioned within an existing top-loading beverage cooler, having a platform which gradually vertically rises as beverages are removed therefrom, thereby obviating the need for a user to reach more deeply within the confines of the cooler for a beverage as the contents become depleted, and thereby preventing straining the muscles of the user or otherwise injuring the user. 
   A variety of coolers and cooler accessories have been devised. For example, U.S. Pat. No. 6,269,965 to White appears to show a cooler insert for an existing portable cooler or ice chest, having a platform with apertures for supporting flanged food receptacles by their upper flanges, in order to present the contents of the receptacles for better visibility and accessibility to the public. Moreover, U.S. Pat. No. 5,605,056 to Brown et al appears to show a portable cooler with a suspended grate for ice-free storage areas. 
   In addition, various lifts have been devised for selectively raising an object that has been placed thereupon. For example, U.S. Pat. No. 5,722,513 to Rowan appears to show a scissor lift having a pair of leg assemblies pivotally connected to a base, wherein relative movement between the legs and the base is opposed by spring assemblies that may be selectively connected to the carriage to vary the bias on the legs. What&#39;s more, U.S. Pat. No. 5,771,816 to Zaguroli, Jr. appears to show a lift table having an air actuator bellows for raising and lowering a load platform with a scissors linkage. 
   While these devices may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter. 
   SUMMARY OF THE INVENTION 
   It is an object of the invention to provide a spring-loaded shelf for a top-loading cooler, which obviates the need for a user to reach more deeply within the confines of the cooler as the items contained therein become depleted, and thereby prevents straining the muscles of the user or otherwise injuring the user. Accordingly, the spring-loaded shelf has a base, a platform pivotally attached to the base by two scissor-type linkages, and a lifting mechanism for selectively raising the platform with respect to the base upon the scissor-type linkages as the weight of items upon the platform gradually decreases, and thereby prevents straining the muscles of the user or otherwise injuring the user. 
   Further objects of the invention will become apparent in the detailed description of the invention that follows. 
   The invention is a spring-loaded shelf for an existing beverage cooler, which obviates the need for a user to reach more deeply within the confines of the cooler for a beverage as the contents of the cooler become depleted. The spring-loaded shelf has a base, a platform pivotally attached to the base by two scissor-type linkages, and a lifting mechanism for selectively and automatically raising the platform with respect to the base upon the scissor-type linkages, as the weight of the beverages placed upon the platform gradually decreases. Use of the spring-loaded shelf prevents straining the muscles of the user or otherwise injuring the user while retrieving a beverage from the cooler, and also provides for increased accessibility and visibility of the contents of the cooler. 
   To the accomplishment of the above and related objects the invention may be embodied in the form illustrated in the accompanying drawings. Attention is called to the fact, however, that the drawings are illustrative only. Variations are contemplated as being part of the invention, limited only by the scope of the claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings, like elements are depicted by like reference numerals. The drawings are briefly described as follows. 
       FIG. 1  is a perspective view of a spring-loaded shelf in a substantially extended position. 
       FIG. 2  is a perspective view of the spring-loaded shelf in a partially retracted position. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  illustrates a spring-loaded shelf  10  for an existing beverage cooler, having a platform which gradually vertically rises as weighted items such as beverage containers are selectively removed therefrom, thereby obviating the need for a user to reach deeply within the confines of the cooler in order to retrieve one of said items as the cooler empties. The spring-loaded shelf  10  generally comprises a base  14 , the platform  12  pivotally attached to the base  14  by two scissor-type linkages  13 , and a lifting mechanism  19  for automatically raising the platform  12  with respect to the base  14  upon the scissor-type linkages  13  as weighted items such as beverages are removed therefrom, thereby preventing straining the muscles of the user or otherwise injuring the user while retrieving one of said items from the cooler. In  FIG. 1 , several beverage containers  50  are positioned upon the platform  12 . The spring-loaded shelf  10  will now be described in detail. 
   The substantially rectangular platform  12  overlays the base  14 . The platform  12  has a first lateral side  12 A, a second lateral side  12 B, a third side  12 F, and a fourth side  12 R. Similarly, the base  14  has a first lateral side  14 A, a second lateral side  14 B, a third side  14 F, and a fourth side  14 R. One of the scissor-type linkages  13  extends between the first lateral side  12 A of the platform  12  and the first lateral side  14 A of the base  14 . The other scissor-type linkage  13  extends between the second lateral side  12 B of the platform  12  and the second lateral side  14 B of the base  14 . Each scissor-type linkage  13  is substantially identical, and comprises a first arm  16  and a second arm  18 . Accordingly, a description of either scissor-type linkage  13  will suffice as a description of the other. 
   The first arm  16  of each linkage  13  has a top  16 T, a bottom  16 B, and a center  16 C. In like fashion, the second arm  18  of each linkage  13  has a top  18 T, a bottom  18 B, and a center  18 C. The center  16 C of the first arm  16  is pivotally attached to the center  18 C of the second arm  18  at a hinged junction  17 . Each hinged junction  17  comprises a hinge pin  22  extending through an opening  20 . The spring-loaded shelf  10  has a fully extended position wherein the platform  12  is maximally separated from the base  12 , and has a fully retracted position wherein the platform  12  is most proximal to the base  12 . Additionally, the spring-loaded shelf  10  has a spectrum of positions intermediate between the fully extended position and the fully retracted position.  FIG. 1  illustrates the spring-loaded shelf  10  in a substantially extended position.  FIG. 2  illustrates the spring-loaded shelf  10 , as in  FIG. 1 , except that several more beverage containers  50  have been positioned upon the platform  12 , thereby causing the spring-loaded shelf  10  to be in one of the partially retracted positions. 
   The lifting mechanism  19  comprises two spring assemblies  26  and two cylindrical tracks  24 . One of the spring assemblies  26  is substantially parallel to and positioned in proximity to the first lateral side  14 A of the base  14 . The other spring assembly  26  is substantially parallel to and positioned in proximity to the second lateral side  14 B of the base  14 . 
   Correspondingly, one of the cylindrical tracks  24  is substantially parallel to and positioned in proximity to the first lateral side  12 A of the platform  12 , and hence overlays one of the two spring assemblies  26 . The other cylindrical track  24  is substantially parallel to and positioned in proximity to the second lateral side  12 B of the platform  12 , and hence overlays the other spring assembly  26 . 
   Each of the two spring assemblies  26  is substantially identical. Moreover, each of the two cylindrical tracks  24  is substantially identical. Accordingly, a description of one of the two spring assemblies  26 , and the cylindrical track  24  which overlays said spring assembly  26 , will suffice as a description of the other spring assembly  26 , and the cylindrical track  24  which overlays said other spring assembly  26 . 
   Each spring assembly  26  comprises a substantially cylindrical spring housing  30  having a first end  30 A and a second end  30 B. The spring housing  30  has a longitudinal slot  34  that extends substantially from the first end  30 A of the spring housing  30  to the second end  30 B of the spring housing  30 . Each of the spring housings  30  contains a coiled spring  32  having a first end  32 A and a second end  32 B. 
   Each cylindrical track  24  comprises a track housing  36  having a first end  36 A and a second end  36 B. The track housings  36  each have a track slot  38  that extends substantially from the first end  36 A of the cylindrical track  24  to the second end  36 B of the cylindrical track  24 . 
   The top  16 T of the first arm  16  is slidably mounted to the platform  12  by the cylindrical track  24 , and selectively slides within the track slot  38  thereof, when the platform  12  is selectively raised by the lifting mechanism  19 . The bottom  16 B of the first arm  16  is slidably mounted to the base  14  by the spring assembly  26 . More particularly, the bottom  16 B of the first arm  16  is mechanically linked to the first end  32 A of the coiled spring  32 . 
   The top  18 T of the second arm  18  is also slidably mounted to the platform  12  by the cylindrical track  24 , and selectively slides within the track slot  38  thereof, when the platform  12  is selectively raised by the lifting mechanism  19 . The bottom  18 B of the second arm  18  is mechanically linked to the second end  32 B of the coiled spring  32 . The top  16 T of the first arm  16  is slidably mounted to the platform  12  at a location along the cylindrical track  24  which is at all times more proximal to the second end  36 B of the track housing  36  than is the top  18 T of the second arm  18 . 
   The center  16 C of the first arm  16  is pivotally attached to the center  18 C of the second arm  18  at the hinged junction  17 . 
   The hinged junctions  17 , the spring assemblies  26 , and the cylindrical tracks  24  together allow the spring-loaded shelf  10  to be facilely inter-converted between the extended position and the retracted position as items are selectively placed upon or removed from the platform  12 , as will now be described. 
   The coiled spring  32  has a stretched conformation and an equilibrium un-stretched conformation. When a user places a weighted item such as a beverage container upon the platform  12 , the weight of the item exerts a downward force upon the arms,  16  and  18 . The downward force causes the bottom  16 B of the first arm  16  to slide towards the first end  30 A of the spring housing  30  within the longitudinal slot  34 , and causes the bottom  18 B of the second arm  18  to slide towards the second end  30 B of the spring housing  30 , also within the longitudinal slot  34 . Simultaneously, the top  16 T of the first arm  16  slides towards the second end  24 B of the cylindrical track  24  within the track slot  38 , and the top  18 T of the second arm  18  slides towards the first end  24 A of the cylindrical track  24 , also within the track slot  38 . Simultaneously, the coiled spring  32  is converted to the stretched conformation. 
   As weighted items are selectively removed from the platform  12 , the spring  32  gradually returns to the equilibrium un-stretched conformation and simultaneously biases the arms,  16  and  18 , of the spring-loaded shelf  10  to return to the extended position wherein the platform  12  is maximally vertically displaced from the base  14 , thereby causing any remaining items present upon the platform  12  to vertically rise within the cooler, thereby allowing the user to retrieve one or more of said items without having to reach deep within the cooler, and thereby preventing straining the muscles of or otherwise injuring the user. 
   The platform  12  and the base  14  are preferably constructed from a durable plastic, and are approximately twenty inches in length and nine inches in width. While being deployed and in the fully retracted position, the platform  12  is approximately several inches above the bottom of the cooler. In the fully extended position, the platform  12  is proximal to the top of the cooler. Although, as described, the spring-loaded shelf  10  is used in conjunction with an existing top-loaded beverage cooler, it is equally well suited for use in conjunction with coolers designed for storage of any number of different food items. 
   In use, a user positions the base  14  of the spring-loaded shelf  10  upon the bottom of an existing cooler, and places a plurality of items such as beverage containers upon the platform  12 , thereby causing the platform  12  to vertically lower towards the bottom of the cooler. The extent of the lowering will, of course, depend on the weight of the items placed upon the platform  12 . As the weighted items are selectively removed by the user from the platform  12 , the tension in the spring  32  biases the spring-loaded shelf  10  to the extended position wherein the platform  12  is maximally vertically displaced from the base  14 , thereby causing any remaining items present upon the platform  12  to vertically rise within the cooler, thereby allowing the user to retrieve one or more of said items without having to reach deep within the cooler, and thereby preventing straining the muscles of the user. 
   In conclusion, herein is presented a spring-loaded shelf for an existing beverage cooler, having a platform that gradually vertically rises as beverages are removed therefrom, thereby obviating the need for a user to reach deeply within the confines of the cooler in order to retrieve a beverage. The invention is illustrated by example in the drawing figures, and throughout the written description. It should be understood that numerous variations are possible, while adhering to the inventive concept. Such variations are contemplated as being a part of the present invention.