Abstract:
The present invention is directed to a pallet storage system including a cart that rides on rails between an open or access position and a closed or storage position. More particularly, the present invention relates to a storage device that facilitates the picking of individual cases or items from pallets that are stored on the floor under a rack type storage structure. The device of the present invention enables two-deep storage of pallets on the floor and the automatic presentation of a rear pallet to the access aisle for easy picking of items stored on the pallet using a cart that cantilevers from the end of the rails.

Description:
BACKGROUND OF THE INVENTION 
     The present inventions relate generally to storage devices that support pallets and their loads. More particularly, the present inventions relate to storage devices that facilitate the picking of individual cases or items from pallets that are stored on the floor under a rack type storage structure. The devices of the present inventions enable two-deep storage of pallets on the floor and the automatic presentation of the rear pallet to the access aisle for easy picking of items stored on the pallet using a cart that cantilevers from the end of the rails. 
     There are numerous types of storage systems available to store a variety of loads. For example, in the grocery industry, shelf type storage racks in conjunction with pushback racks are widely used. In general, these systems are configured to form shelves that may directly support pallets and their loads or which may include pushback or other storage systems. In a typical grocery warehouse, the storage racks are arranged to form aisles for access by order pickers and machinery such as straddle trucks and lift trucks. The order pickers pick individual items from the pallets on the lower level and the floor, and the machinery is used to store, retrieve and/or transfer the full pallets from the upper levels. 
     Again by reference to a typical rack structure in the grocery sector, the first shelf of the storage rack is typically 48″ from the floor and each of the shelves above the first shelf are spaced approximately every 48″ or at other increments as required for the facility. In addition, such shelves are typically sized to be able to support and store two pallets wide and two pallets deep between each of the rack trusses and the transverse and lateral beams. Generally, such shelves are 96″ deep by 96″ wide. These racks may extend from floor to ceiling and store thousands of pallets. 
     Because of the height of the typical shelves, storage and removal of pallets and their loads on the second and higher shelves are done with straddle and/or fork lift trucks, since the second shelf is typically 8′ off of the floor. That leaves the floor and the first shelf (4′ off the floor) from which individual items may be picked from the pallets by the order pickers. The first shelf is typically provided with a well known two-deep pushback system that presents the rear pallet to the front for easier picking. However, a pushback rack level is not practical for use on the floor because, among other things, it interferes with the straddles of a straddle truck which is used to place and remove the pallets at these locations. Thus, in order to reach items on the rear pallet on the floor, an order picker has to crawl under the first shelf to reach the rear pallet. Clearly, it is difficult and dangerous for an order picker to reach items on the rear pallet on the floor. This potentially dangerous situation may be avoided by eliminating storage of the rear pallets on the floor. Alternatively, a fork lift truck may be used to move the rear pallet to the front as needed. Not using the rear position is a waste of space and reduces storage density. And, using a truck to rearrange the pallets is an inefficient use of resources and takes additional time. 
     Accordingly, there is a need to make the items on a rear pallet of a two-deep set-up readily accessible, while at the same time maintaining maximum storage density. There is also a need to achieve such accessibility at a minimum of expense and without the need for special lift equipment and the like. In addition, there is a need for the convenient presentation of a pallet and its load in single-deep storage settings. 
     SUMMARY OF THE INVENTION 
     The present inventions preserve the advantages of known storage systems and also provide new features and advantages. For example, the present inventions provide a cantilever cart storage system which is capable of moving a load, such as a pallet, from a storage position to an access position adjacent to an access aisle, including at least one pair of spaced, parallel rails that gradually slope downward from the storage position to the access position, the rails having a lower rolling surface, a side rolling surface and an upper rolling surface; a cart having two pairs of wheels on each side of the cart, a rear pair mounted on a rear portion of the cart and a front pair mounted forward of the rear wheels, the wheels capable of rolling engagement with the upper and lower rolling surfaces of the rail so that the cart remains on the rails as the cart moves between the storage and access positions; and, at least one guide roller mounted to a forward portion of the rails to aide in lateral alignment of said cart during movement of said cart. The present inventions may also include a pair of guide rollers mounted on each side of the cart for aiding lateral alignment of the cart during movement and may have rails which are shorter in length than twice the length of a pallet or other load. The invention may also include a cart stop bumper on the rails and the cart may include a deterrent to engage the bumper to limit the forward movement of the cart to the access position. The invention may also include a release to selectively permit the cart to roll to an access position or to lock it in a stored position. 
     The present inventions also provide a cantilever pallet cart for storing a pallet under a rack storage system in a back position which is capable of moving the pallet to a front position, the pallet and cart having a length and including at least one pair of spaced, parallel rails that slope downward from the back to the front, the rails having an upper surface, a side rolling surface and a lower rolling surface, the rails having a length less than twice the length of said cart; at least one pair of guide rollers mounted near the front of the rails to aid in lateral alignment of the cart during movement of the cart; at least two pairs of wheels mounted on each side of the cart, a back pair mounted near the back of the cart and a front pair mounted forward of the back pair and rearwardly of the center of the length of the cart, the back pair of wheels capable of rolling on the upper rolling surface when the cart is in a front or back position, or anywhere in between; and, at least one pair of guide rollers mounted near the back of the cart and capable of rolling on the side rolling surface of the rails to aide in lateral alignment of the cart during movement of the cart. The rails may also include a cart stop bumper and the cart may include a cart deterrent capable of interacting with the bumper to limit the forward movement of the cart. 
     Accordingly, it is an object of the present invention to provide a pallet (or other load) storage system that is capable of moving the pallet from a rear or storage position to a front or access position for access to the items on a pallet. 
     Another object of the present invention is to provide a cart storage system having a cart which rides on rails, the front of the cart being capable of extending, in a cantilever fashion, beyond the end of the rails. 
     An additional object of the present invention is to provide a pallet storage system that presents stored items for easy access by order pickers from an access aisle. 
     A further object of the present invention is to provide a cart storage system that may be utilized on the floor of a rack storage system to help maximize storage density. 
     INVENTOR&#39;S DEFINITION OF THE TERMS 
     The terms used in the claims of this patent are intended to have their broadest meaning consistent with the requirements of law. Where alternative meanings are possible, the broadest meaning is intended. All words used in the claims are intended to be used in the normal, customary usage of grammar and the English language. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The stated and unstated features and advantages of the present inventions will become apparent from the following descriptions and drawings wherein like reference numerals represent like elements in the various views, and in which: 
         FIG. 1  is a perspective view of a preferred embodiment of a cantilever pallet drawer of the present invention shown in a forward or open position; 
         FIG. 2  is a perspective view of the embodiment of  FIG. 1  shown in a rearward or closed position; 
         FIG. 3  is a perspective view of a left rail of a preferred rail assembly of the present invention; 
         FIG. 4  is a side view of the rail of  FIG. 3 ; 
         FIG. 5  is an exploded perspective view of components of a preferred embodiment of a back guide roller and cart stop bumper of the present invention; 
         FIG. 6  is an exploded perspective view of components of a preferred embodiment of a front guide roller of the present invention; 
         FIG. 7  is a perspective view of a preferred embodiment of a cart assembly of the present invention; 
         FIG. 8  is an exploded perspective view of components of a front cart roller of the present invention; 
         FIG. 9  is an exploded perspective view of a preferred rear cart roller and cart stop of the present invention; and 
         FIG. 10  is a plan view of the rails of a preferred embodiment of the present invention shown in relation to a typical storage rack system under which it may, but is not required to, be utilized. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Set forth below is a description of what is currently believed to be the preferred embodiments or best representative examples of the inventions claimed. Future and present alternatives and modifications to the embodiments and preferred embodiments are contemplated. Any alternatives or modifications which make insubstantial changes in function, purpose, structure or result are intended to be covered by the claims of this patent. 
     The cantilever pallet drawer of the present invention is shown generally as  20  in  FIGS. 1 and 2 , and consists of two basic assemblies. Specifically, a rail assembly  21  is provided, a preferred embodiment of which is shown in more detail in  FIGS. 3-6  and  10 . A cart assembly  22  is also provided, a preferred embodiment of which is shown in more detail in  FIGS. 7-9 . The cantilever pallet drawer  20  of the present invention is principally designed to be used on the floor of a warehouse, which is typically a concrete slab. Cantilever drawer  20  is sized to support a standard pallet and its load and to fit under the first shelf of typical two-deep type storage structures, a preferred embodiment of which is shown in  FIG. 10 . 
     When cart assembly  22  is in an open position, as shown in  FIG. 1 , it positions the rear pallet and its load adjacent to the access aisle for easy access by an order picker. When drawer  20  is in its closed position, as shown in  FIG. 2 , it stores a pallet and its load in the second deep position for storage and later use. The rear pallet and the cantilever cart assembly  22  are held in the closed position by the front pallet until it is unloaded and removed. Alternatively, an optional lock and release mechanism (not shown) may be provided. Providing an optional lock and/or release mechanism, as will be understood by those of ordinary skill in the art, is particularly useful in settings where there is no front pallet to hold cart assembly  22  in a closed position or otherwise as the needs require. It will be understood by those of ordinary skill in the art that the present inventions may be used in other storage settings, for example one-deep settings, including those without storage bays, and may be made in a variety of sizes depending upon the application. Moreover, it will be understood that its use is not limited to being placed on the floor. 
     In addition, in this patent, preferred embodiments of the present invention  20  are described with reference to certain structural or formed components as preferred. However, it will be understood by those of ordinary skill in the art that cantilever pallet cart  20  and its related cart  22  and rail  21  assemblies may be constructed from a wide variety of materials (such as iron, steel or aluminum) having a variety of cross-sectional or formed shapes (such as plates, channels, angles, tubing, I-beams and S-beams). 
     Details of a preferred embodiment of rail assembly  21  may be seen by reference to  FIGS. 1-6  and its placement in a typical storage setting is shown in  FIG. 10 . Rail assembly  21  includes a right rail  30  and a left rail  31  which is spaced from and parallel to right rail  30 . Each rail  30  and  31  has a lower rolling surface  32 , a side rolling surface  33  and an upper rolling surface  34 . Although only left rail  31  is shown in  FIGS. 3-5 , it will be understood by those of ordinary skill in the art that right rail  30  is substantially the mirror image of left rail  31  which is spaced apart to accommodate cart assembly  21  as hereinafter described (see  FIGS. 3-6  and  10 ). As shown in the Figures, rails  30  and  31  are preferably fabricated from two angles welded together to form a channel. Of course, rails  30  and  31  may be constructed from a channel, or a variety of structures or formed materials, consistent with the present inventions. 
     The front end of each rail  30  and  31  is provided with a front guide roller  35 . Spaced rearwardly of front guide roller  35  is a back guide roller  36  which is provided on rails  30  and  31 . A cart stop bumper  37  is provided on the rails  30  and/or  31 , which may be part of an assembly including back guide roller  36 . It will be understood by those of ordinary skill in the art that guide rollers  35  and  36  and bumper  37  may be provided in a number of forms and locations consistent with the present inventions and as hereinafter described. 
     In a preferred embodiment of the present invention, rails  30  and  31  are shorter than the length of two carts. Preferably, the length of rails  30  and  31  is approximately 1½ times the length of cart assembly  22  (see  FIG. 10 ). In this manner, when cart assembly  22  is in the open or forward position (see  FIG. 1 ), it cantilevers out from the rails for ease of access from the pick aisle. And, when cart assembly  22  is in the closed or back position (see  FIG. 2 ), the rails  30  and  31  do not protrude unnecessarily into the forward space so as not to interfere with the straddles of a straddle truck. A representative example of the rail assembly  21  is shown in plan view in  FIG. 10 , along with representative columns  11 , lateral beams  12  and transverse beams  13  of a typical storage structure. As shown therein, but not as a limitation, the two pairs of rail assemblies  21  are side by side and are shown in relation to the frame of a typical rack storage structure. 
     The rails  30  and  31  of rail assembly  21  may also include feet  38  and a back stop  39 . Feet  38  may be used to secure rail assembly  21  to the floor. In addition, feet  38  may also be used to provide the desired slope to rails  30  and  31  so that cart assembly  22  rolls smoothly forward when the front pallet is removed to permit easy access to the contents of the rear pallet. As best shown in  FIG. 4 , feet  38  decrease in height from back to front so that rails  30  and  31  slope gradually downward from back to front. Back stop  39  may be used to keep cart assembly  22  from being push off of rail assembly  21 , especially when a pallet and its load are pushed back into the rearward position on cart assembly  22 . And, as shown in  FIG. 10 , the rail assembly  21  may include a variety of support braces or other reinforcing members  15 , as will be understood by those of ordinary skill in the art. 
     The details of cart assembly  22  may be seen by reference to  FIGS. 1 ,  2  and  7 - 9 . The frame of cart assembly  22  consists of side members  40 , a rear member  41  and a front member  42 . A horizontal lip or flange  43  on frame members  40 ,  41  and  42  provides a support surface to hold a pallet and its load (not shown). In a preferred embodiment, frame members  40 ,  41  and  42  are made from structural angles, although a wide variety of structural or formed members may be used. The front member  42  has a lower vertical portion to permit easy placement and retrieval of a pallet on cart assembly  22 . 
     Cart assembly  22  also includes a pair of front wheel assemblies  44  and a pair of rear wheel assemblies  45  that are attached to side members  40  on each side of cart assembly  22 . In a preferred embodiment, front wheel assembly  44  includes a pair of wheels  46  and a reinforcing plate  47 , if desired. However, wheels  46  may be attached to front member  40  in a variety of well known ways. Wheels  46  are designed to roll on lower rolling surface  32  of rails  30  and  31 , as hereinafter described. Similarly, a rear wheel assembly  45  is also provided which includes a pair of wheels  48 . A rear guide roller  49  is also provided to aid in lateral orientation of cart assembly  22  by rolling on side rolling surface  33  during cart assembly  22  operation. Wheels  48  are intended to roll on upper rolling surface  34  of rails  30  and  31 . 
     In a preferred embodiment, both sets of wheels  44  and  45  are behind the center of the length of the cart assembly  22 . This permits the use of shorter rails  30  and  31  and enables cart assembly  22  to cantilever out from the rails as shown in  FIG. 1 . When a pallet is placed on lip or flange  43 , its weight forces wheels  46  of front wheel assembly  44  downward onto lower rolling surface  32 . Also, the back of cart assembly  22  pivots upward from front wheel assembly  44  so that wheels  48  of rear wheel assembly  45  contacts upper rolling surface  34 . 
     In a preferred embodiment, wheels  48  and guide roller  49  are connected to side members  40  using an angle  50 . It will be understood by those of ordinary skill in the art that a variety of means may be used to attach the wheels  48  and guide roller  49  to side member  40 . Also associated with rear wheel assembly  45  is a cart deterrent  51 . Cart deterrent  51  is designed to limit the forward movement of cart assembly  22  by engaging cart stop bumper  37 . 
     The operation of cantilever pallet drawer  20  will now be described by reference to  FIGS. 1 and 2 . Cart assembly  22  is in its back or closed position as shown in  FIG. 2 , and is held in this position by a front pallet or an optional lock and release mechanism (not shown). Wheels  48  of rear wheel assembly  45  are engaged with upper rolling surface  34  or rails  30  and  31 . Wheels  46  of front wheel assembly  44  are engaged with lower rolling surface  32 . Rear guide rollers  49  on cart assembly  22  keep it properly aligned within the rails  30  and  31  against side rolling surface  33 . Similarly, back guide roller  36  on rails  30  and  31  keep the front of cart assembly  22  in proper lateral alignment. 
     When the front pallet is removed, cart assembly  22  may roll to its forward position as shown in  FIG. 1 . As the cart assembly  22  rolls forward, wheels  46  ride on lower rolling surface  32 , wheels  48  ride on upper rolling surface  34  and rear guide roller  49  rides on side rolling surface  33 . Cart assembly  22  is stopped in its most forward or open position when cart deterrent  51  is engaged with cart stop bumper  37  as shown in  FIG. 1 . 
     The above description is not intended to limit the meaning of the words used in or the scope of the following claims that define the invention. Rather, it is contemplated that future modifications in structure, function or result will exist that are not substantial changes and that all such insubstantial changes in what is claimed are intended to be covered by the claims. Thus, while preferred embodiments of the present inventions have been illustrated and described, it will be understood that changes and modifications can be made without departing from the claimed invention. In addition, although the term “claimed invention” or “present invention” is sometimes used herein in the singular, it will be understood that there are a plurality of inventions as described and claimed. 
     Various features of the present inventions are set forth in the following claims.