Abstract:
A storage tray system which includes a rack and a plurality of storage trays. The rack includes a plurality of tray runners for supporting the trays in the rack, and which allow sliding movement of the storage trays between open and closed positions. The storage trays can be inclined downwards when in the open position to allow access to their contents.

Description:
RELATED APPLICATION 
     This application claims priority under 35 U.S.C. §119(a)-(d) to Great Britain Patent Application No. 0620866.4, filed Oct. 20, 2006, the entire content of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a storage tray system. 
     2. Description of the Related Art 
     Storage tray systems are widely used in schools, hospitals and other institutions, for example for storing pupils&#39; work, medical supplies and other items. Typically, a storage tray system comprises a set of moulded plastic trays that may be stored in a metal rack or a wooden cabinet and removed when the contents of the tray are required. The trays can also be opened like drawers to allow items to be placed in or removed from the trays. However, a tray cannot be opened too far as this may cause it to fall out of the rack. The system therefore provides only restricted access to the contents of the trays when they are used in “drawer mode”, without being fully withdrawn from the rack. 
     Another disadvantage of the existing system is that the rack is very bulky and therefore uneconomical to transport and store prior to installation. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to mitigate one or more of the above disadvantages. 
     According to the present invention there is provided a storage tray system including a rack and a plurality of storage trays that are constructed and arranged to be placed in or removed from the rack, the rack including a plurality of tray runners for supporting the trays in the rack, the tray runners being constructed and arranged to allow sliding movement of the storage trays between open and closed positions, at least one of the tray runners including a stop element that is constructed and arranged to engage a respective storage tray when in the open position so as to limit movement of the tray. 
     The provision of a stop element limits movement of the tray as it is pulled open, thereby preventing it from accidentally falling out of the rack. The tray may still be removed however when required, by disengaging the stop element (for example by lifting the tray). 
     Preferably, the tray runner is constructed and arranged to permit limited tilting of the storage tray when in an open position, to allow easier access to the contents of the tray. The tray runner may include upper and lower support elements, wherein the upper support element includes a formation such as an opening or a recess that accommodates the rear edge of the tray when tilted. The lower support element may include a portion adjacent its front end that is inclined downwards to permit tilting of the tray. 
     The stop element preferably comprises an upstanding tooth that engages a complementary stop element located beneath the rim of the storage tray. 
     The tray runner is preferably constructed and arranged to be mounted in a second configuration, in which the stop element is ineffective. In this configuration, the tray can be removed from the rack without having to disengage the stop element. 
     Advantageously, the tray runner includes a stop element to restrict movement of the storage trays when in the closed position. 
     Preferably, the rack includes one or more frame elements to which the tray runners are attached. The tray runners may be constructed and arranged to be attached to the frame elements during installation. This allows the rack to be stored and transported in a partially assembled condition, thereby reducing the size of the unit and providing economies during storage and transportation. 
     The tray runners are preferably moulded plastics components, made for example of glass-filled nylon. 
     According to another aspect of the invention there is provided a storage tray system comprising a rack and a plurality of storage trays that are constructed and arranged to be placed in or removed from the rack, wherein the rack includes one or more frame elements and a plurality of tray runners that may be attached to the frame elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a storage tray system including a rack and a plurality of removable trays; 
         FIG. 2  is a perspective view of the rack with the trays removed; 
         FIG. 3  is a perspective view showing part of the rack, including two frame elements and a set of tray runners; 
         FIG. 4  is a perspective view showing part of a tray runner at an enlarged scale; 
         FIG. 5  is a side elevation showing a tray runner assembly; 
         FIG. 6  is a section on line W-W, showing part of the tray runner assembly from above; 
         FIG. 7  is a plan view from above, showing part of the tray runner assembly at a larger scale; 
         FIG. 8  is a section on line X-X, showing part of the runner assembly, and 
         FIG. 9  is a sectional side view showing part of the rack and two trays in open and closed positions. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The storage tray system includes a rack  2  and a plurality of storage trays  4  that are removably mounted in the rack  2 . 
     The rack  2  includes front and rear frame elements  6 , 8  and a plurality of runner assemblies  10  that form the sides of the frame and interconnect the frame elements  6 , 8 . Each frame element  6 , 8  comprises a rectangular welded steel frame having two uprights  12 , an upper beam  14  and a lower beam  16 . 
     The tray  4  includes a substantially rectangular base  18  and four upstanding walls  20 . At the upper edge of each wall  20  a down-turned rim  22  is provided, which is connected to the wall by an outwards extending flange  24 . A plurality of strengthening webs  26   a,b  connect the rim  22  to the wall  20  at various points along its length. As shown in  FIG. 9 , the two webs  26   a  that are located on the side of the tray towards its ends extend downwards to the full depth of the rim  22 , whereas the two intermediate webs  26   b  are slightly shorter and end just above the lower edge of the rim  22 . The tray  4  is moulded from a plastics material, for example high impact polystyrene. 
     Each tray runner assembly  10  includes a set of three vertically spaced tray runners  30 , which are interconnected by front, rear and middle vertical support bars  32   a,b,c . The front and rear support bars  32   a,b  include perpendicular strengthening ribs  34   a,b  and are arranged to engage the front and rear support elements  6 , 8  respectively. The tray runner assembly  10  is attached to front and rear support element  6 , 8  by screws  35  that extend through the ends of the runners  30 . 
     Each tray runner  30  includes upper and lower horizontal support elements  36   a,b  and a vertical wall element  38 . At the front end of each runner  30 , the lower support element  36   b  includes a downwardly inclined portion  40 . A stop element  42  in the form of an upstanding tooth is formed on the lower support element  36   b  at the start of the inclined portion  40 . Towards the front end of the runner  30 , the upper support element  36   a  includes a downwards extending stop element  44 . Also towards the front end of the runner  30 , but set a little further back, the upper support element  36   a  includes an upwards extending recessed portion  46 . 
     In use, the rim  22  of the tray  4  is supported on the lower support element  36   b  of a runner  30  on each side of the rack  10 . The tray may be configured in a closed position as shown in  FIG. 1  and  FIG. 9  (upper tray  4 ) or it may be pulled out to an open position as shown in  FIG. 9  (lower tray  4 ′). The rim  22  of the tray slides along the runner  30  to allow easy movement of the tray. 
     When the tray  4  is in the closed position, the stop element  42  engages the web  26   a  at the front end of the tray to limit rearwards movement. When the tray is open, the stop  42  engages the web  26   a  at the rear of the tray to limit forwards movement and prevent the tray from falling out of the rack. The intermediate webs  26   b  are shorter than the front and rear webs  26   a  and therefore pass over the stop element  42  without engaging it. 
     As shown in  FIG. 9 , when the tray  4 ′ is in the open position, it can tilt forwards owing to the inclined portion  40  at the front end of the runner  30 , and the recess  46  in the upper support element  36   a , which accommodates and supports the rear edge of the tray. The tray can also be removed from the rack by lifting it slightly so that the web  26   a  at the rear of the tray passes over the stop element  42 . 
     Alternatively, the runner assembly  10  can be rotated 180° about a horizontal axis and attached to the frame elements  6 , 8  in an inverted condition. Rearwards movement of the tray will then be restricted by the second stop element  44 , which engages the rim  22  at the rear of the tray. Forwards movement of the tray will be unrestricted, allowing the tray to be opened or completely removed from the rack  2  without any restriction. 
     Various modifications of the system are of course possible. For example, the height of the rack  2  may be modified to accommodate more or fewer trays  4 , or it may be adapted to house two or more columns of trays. The rack  2  may be supplied as a modular unit, which can be interconnected vertically and/or horizontally with other racks to support different numbers of trays. Instead of a metal frame, the rack  2  may consist of a wooden cabinet to which the runner assemblies  10  are attached. Each runner assembly  10  may have more or fewer than three tray runners  30 . The runner assemblies  10  may also be designed to be interconnected. The rack  2  may also include support feet or wheels/castors to allow for easy movement.