FIELD OF THE INVENTION 
       [0001]    The present invention is directed to trays for the display of merchandise, particularly in supermarkets and other large stores. The invention is especially suitable for, but not necessarily limited to, merchandise display trays of the type that are mounted in cantilever fashion, for example as disclosed in U.S. Pat. No. 8,210,367, and which are provided with spring-operated pusher paddles that constantly urge the displayed merchandise forwardly as products are removed by customers from the front of the display. 
       BACKGROUND OF THE INVENTION 
       [0002]    When loading or reloading product display trays of the type referred to above, the spring-loaded pusher paddle must be held in a retracted position while new product items are loaded into the tray. To enable store personnel to have both hands available for loading of product, it is typical to provide a means for mechanically locking the paddle in a fully retracted position while the loading operations are taking place. A variety of arrangements and mechanisms have been proposed for accomplishing this. One such mechanism is reflected in British patent publication 2290077, in which a vertically movable latch element is mounted on the back of a spring-urged pusher paddle. When the paddle is moved to a retracted position, the latch is depressed so that it engages the track and retains the paddle in position while products are loaded into the tray. When the tray is fully loaded, a push against the paddle in a backward direction releases the latch, which returns to an elevated position allowing the paddle to move forwardly to advance the product column. 
         [0003]    European patent EP 0986980 illustrates a basic arrangement in which the base portion of a pusher paddle is provided with a hook engageable with a recess provided in the back portion of the track. When the paddle is retracted for loading of the tray, the entire paddle is tilted backwards to press the hook into the recess and the lock the paddle. The paddle is later released by pressing it backward and tilting it forward to release the hook. 
         [0004]    U.S. Pat. No. 7,931,156 illustrates an arrangement similar to that of the British publication 2 290 077 in that a vertically movable latch element is mounted to the back of the pusher paddle. The latch can be depressed when the paddle is in a retracted position, in order to lock the paddle during reloading operations. When reloading is completed, the paddle is pressed rearwardly (either manually or as a result of being pressed backward after becoming fully loaded with packages) causing release of a latch spring and thus allowing the tray to move forwardly under the action of the paddle spring. 
         [0005]    US patent publication 2012/0211450, owned by the assignee of this application, Trion Industries, Inc., illustrates an arrangement in which a locking element is positioned against the back face of a flexible and tiltable pusher paddle. During normal operations, the paddle is in an upright position, in which the locking element is ineffective. For reloading operations, the paddle is pushed to the back of the tray, and its geometry is such that it tilts forwardly when in its rearward or reload position. In a forwardly tilted position of the paddle, the locking element grips guide rods forming the base of the tray and retains the paddle in a retracted position. When the paddle is tilted back to an upright position, either manually or by the loading of a final product package into a substantially full tray, the lock automatically releases and allows the paddle to move forwardly under the action of its spring. 
         [0006]    US patent publication 2013/0112634 discloses a mechanism in which a U-shaped locking element is inserted through slots in the face of the pusher and has locking elements extending to the rear that automatically engage the tray and lock the pusher when the pusher is moved to a retracted position. Rearward pressure on a portion of the locking element exposed in front of the pusher releases the locking elements and allows the paddle to be pushed forwardly by its spring. This arrangement has the disadvantage of automatically locking the paddle in a retracted position anytime it is moved to the rear of the base. When this happens without the store clerk noticing, the paddle may remain in its locked, retracted position and not function to push the product column to the front as intended. 
         [0007]    All of the above devices function at some level to allow a spring operated pusher paddle to be locked in a retracted position for reloading operations. However, all of them suffer from certain shortcomings, either from an operating standpoint or from extra cost and complication in the manufacture. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides a novel and improved form of product display tray including a product pusher of relatively rigid construction which is biased in a forward direction by a coiled strip spring. The coiled strip spring is arranged in a known manner, with a coiled body portion thereof being positioned behind and bearing forwardly upon the product pusher, and a strip portion thereof extending forwardly in the tray and being anchored at the front of the tray. The new tray includes a novel and improved locking mechanism functioning in combination with the spring-driven pusher to accommodate manual locking of the pusher in a retracted position for reloading of the tray, along with either automatic or manual release of the pusher when reloading has been completed. 
         [0009]    The mechanism of the invention includes a locking element that is pivotally secured at the rear of the front panel of the paddle. The locking element has a portion, which can be referred to as an actuating arm, extending upwardly from the pivot axis directly behind the upright front panel, and a second portion, which can be referred to as a locking leg, extending rearwardly from the pivot axis. In accordance with a feature of the invention, the upwardly extending actuating arm of the locking element is interposed between the coiled body of the strip spring and the back of the pusher paddle. Accordingly, in the device of the present invention, the locking element is constantly urged by the coiled spring body into a position in which the rearwardly extending locking leg is held in an elevated position where it cannot make locking engagement with the base of the tray. 
         [0010]    In accordance with another aspect of the invention, the front panel of the pusher paddle has an opening which provides access to the actuating arm of the locking element. When the pusher paddle is in a retracted position, and the operator desires to actuate the locking device to hold the pusher in a retracted position, the operator can manually access the actuating arm through the panel opening. By pressing rearwardly on the accessible portion of the actuating arm, the operator can pivot the locking element into a position in which the locking leg engages the base of the tray and secures the paddle in a retracted position. Releasing the paddle, when desired, involves merely pushing rearwardly on the upright panel, either manually or by loading of a final package onto the tray. As soon as the pusher paddle is moved slightly to the rear, the pressure of the coiled spring body on the actuating arm causes the locking element to immediately pivot in a release direction and free the paddle for forward movement. 
         [0011]    In accordance with yet another aspect of the invention, a product display tray is provided with a unique design of a rigid pusher paddle. The pusher paddle is designed and constructed to be guided and supported by a plurality (typically four) spaced apart and parallel guide rods that extend longitudinally over the length of the tray to accommodate movement of the pusher paddle between front and back limit positions. Typically, the structure of the tray includes front and back transversely disposed base elements that support the front and back ends of the guide rods. Desirably, the configuration of the pusher paddle is such that it can be assembled with or removed from the guide rods without requiring removal of a base element in order to provide access to the ends of the rods. At the same time, and because of the spring forces applied to the rigid pusher paddle, it is important to assure that the pusher paddle remains assembled with the guide rods unless intentionally removed. To this end, the pusher paddle of the invention incorporates improved guide sleeves that slidably engage the rods and at least certain ones of which include special internal detent projections that require snap-on, snap-off assembly and disassembly, assuring that the pusher paddle will remain attached at all times to the guide rods unless intentionally removed. 
         [0012]    The arrangement of the invention is functionally optimal, in that positive action of the operator is required in order to lock the paddle in a retracted position. At the same time, the mechanism of the invention is highly simplified in nature and enables the paddle return spring to serve in the additional capacity of controlling operations of the locking element. 
         [0013]    For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment of the invention, and to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a front orthographic view, from above, showing a product display tray incorporating features of the invention. 
           [0015]      FIG. 2  is a back orthographic view of the tray of  FIG. 1 , with one side panel removed to show further details and showing the pusher paddle in a forward position. 
           [0016]      FIG. 3  is a side elevational view of the tray of  FIG. 1 , with one side panel removed to show further details and showing the pusher paddle in a retracted but unlocked position. 
           [0017]      FIG. 4  is a side elevational view, similar to  FIG. 3 , showing the pusher paddle of the tray in a retracted and locked position. 
           [0018]      FIG. 5  is a back orthographic view, similar to  FIG. 2 , showing the pusher paddle in a retracted and locked position. 
           [0019]      FIG. 6  is a front orthographic view, from above, showing the pusher paddle in a retracted and locked position. 
           [0020]      FIG. 7  is a front elevational view of the pusher paddle incorporated in the tray of  FIG. 1 . 
           [0021]      FIG. 8  is a side elevational view of the pusher paddle of  FIG. 7   
           [0022]      FIG. 9  is a back elevational view of the pusher paddle of  FIG. 7 . 
           [0023]      FIG. 10  is a back orthographic view, from above, of the pusher paddle of  FIG. 7 . 
           [0024]      FIG. 11  is a side elevational view of a locking element incorporated in the tray of  FIG. 1 . 
           [0025]      FIG. 12  is back elevational view of the locking element of  FIG. 11   
           [0026]      FIGS. 13 and 14  are front and back orthographic views respectively of the locking element of  FIG. 11 . 
           [0027]      FIG. 15  is a back elevational view of a modified form of locking element that can be used in the display tray of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    Referring to the drawings, the reference numeral  20  designates generally a product display tray such as used extensively in supermarkets and other stores. The illustrated tray assembly advantageously, but not necessarily, is of a type disclosed in U.S. Pat. No. 8,210,367, the content of which is incorporated herein by reference. In the illustrated tray assembly, the tray base  21 , formed of longitudinally extending, parallel guide rods, is supported in cantilever fashion by laterally spaced apart side wall panels  22 ,  23 . The sidewall panels include notches  24  at the back that engage and are supported by a rectangular mounting bar (not shown). Transversely disposed support rods  25 ,  26  are mounted at front and back end portions of the respective side wall panels  22 ,  23 . These support rods slidably engage front and back base members  27 ,  28  such that the base members are supported by the sidewall panels  22 ,  23  while enabling lateral adjustment of the sidewall panels to accommodate packages of different sizes. 
         [0029]    Desirably, the front and back base members  27 ,  28  extend slightly below the bottom edges of the sidewall panels  22 ,  23 , such that the trays may be directly supported on shelves where desired. Mostly, however, the trays are supported in cantilever fashion. 
         [0030]    In the illustrated form of tray, the tray base  21  is comprised of the front and back base members  27 ,  28  and a plurality of longitudinally extending guide rods  29 - 32  that are supported at their front and back ends by the base members  27 ,  28 . Crossbars (not shown) extend underneath the guide rods adjacent each end and are welded thereto to form a rigid guide rod structure. The crossbars are received in transverse grooves in the base members  27 ,  28 , preferably by a snap-in attachment, such that the base members and guide rods form a rigid, coherent structure. The outermost guide rods  29 ,  32  have upwardly bent portions  29   a,    32   a  at their forward ends which mount a front barrier plate  33 . In an illustrative but non-limiting example, the guide rods  29 - 32  may have a diameter of approximately 3/16 inch. 
         [0031]    A pusher paddle  34 , details of which are shown in  FIGS. 7-10 , is mounted on the guide rods  29 - 32  for forward-backward sliding movement. A coiled strip spring  35  is positioned with a coiled body portion  36  thereof positioned behind the pusher paddle  34 , with an uncoiled strip portion  36   a  thereof extending through an opening  37  ( FIG. 10 ) at the base of the pusher paddle  34  and anchored at its forward end  38  by the front base member  27 . The coiled spring  35 , in a manner well known to those skilled in the art, applies forward pressure to the paddle to keep the displayed merchandise moving to the front portion of the tray as individual items are removed by customers. 
         [0032]    With reference to  FIGS. 7-10 , the paddle  34  is a one-piece molding of a suitable, relatively rigid plastic material, such as polyvinyl chloride. The paddle includes a front panel  39 , which is generally vertically oriented and joins along its bottom edge with a horizontal base panel  40 . A plurality of triangular gussets  41  extend between the back surface of the front panel  39  and the base panel  40  to maintain a rigid right angle relationship between the two panels. At its opposite side edges the paddle base  40  is formed with outwardly opening, horizontally disposed guide sleeves  42 ,  43  of generally U-shaped configuration. At their inner ends, the horizontal guide sleeves  42 ,  43  are of generally semi-cylindrical form, with their respective axes spaced apart a distance equal to the spacing of the outer guide rods  29 ,  32 . Lower portions of the guide sleeve  42 ,  43  are of the same width as the base panel  40 . However, upper portions  44 ,  45  of the guide sleeves extend rearwardly beyond the back edge of the base panel  40  and overlie the guide rods  29 ,  32  over a greater length to provide increased stability to resist backward forces applied during movement of the pusher paddle into a reload position at the back of the tray. By extending the upper portions  44 ,  45 , but not the lower portions of the guide sleeves  42 ,  43  the paddle  34  can be retracted farther back in the tray for reloading, providing greater room for receiving packages for display. This is evident in  FIGS. 4 and 5 , for example, which show the extended upper portions  44 ,  45  overriding the back base member  28 . In an illustrative but non-limiting example, the upper portions  44 ,  45  of the guide sleeves may have a length of about 1.4 inches, while the lower portion may be approximately one-half that length. 
         [0033]    For engagement with the inner rods  30 ,  31  of the base, the paddle  34  is provided with intermediate guide sleeves  46 ,  47  positioned symmetrically on opposite sides of the center line of the paddle  34 . The guide sleeves  46 ,  47  are of a generally downwardly opening, U-shaped form and are angled divergently at an angle of approximately 30° from the vertical. Preferably, the intermediate guide sleeves  46 ,  47  are of a length equal to the width of the base panel  40  (e.g., in the above illustrative example, approximately 0.7 inch). At their upper ends, the guide sleeves  46 ,  47  are of semi-cylindrical form, with their respective axes located at a common level with the axes of the outer guide sleeves  42 ,  43 . 
         [0034]    In order to mount the paddle  34  on the guide rods  29 - 32 , the paddle is placed on a mid portion of the guide rods, and both the inner pair of rods  30 ,  31  and the outer pair  29 ,  32  are deflected outwardly a short distance to allow the rods to enter the bottom openings of the inner guide sleeves  46 ,  47  and the side openings of the outer guide sleeves  42 ,  43 . When the guide rods are released from their deflected positions, they can be fully received in the recesses and be seated in the semi-cylindrical closed ends thereof. The four guide sleeves are of the size to closely receive the respective guide rods  29 - 32 , while allowing free sliding movement of the paddle on the rods. In the illustrated and representative tray, the guide rods  29 - 32  may have a diameter of approximately 3/16 of an inch. However, it will be understood that the rod diameter may vary with the length of the tray and the anticipated weight of the products to be supported thereon. In all cases, the guide sleeves will be correspondingly sized to slide freely on the guide rods while effectively guiding the paddle  34  in its movements thereon. 
         [0035]    In accordance with an aspect of the invention, the downwardly opening inner guide sleeves  46 ,  47  are formed with detent projections  48 ,  49  which are positioned a short distance in from the open ends of the guide sleeves and serve to partially constrict portions of the guide sleeves in the manner to require forcible snap-in, snap-out assembly and disassembly of the inner guide rods  30 ,  31  with the pusher  34 . The detent projections, which may extend fully or partially along the length of the recesses  46 ,  47 , may constrict the recesses by, for example, 30%. Preferably, the exposed surfaces of the detent projections are disposed at inclined angles to the sides of the recesses. The arrangement is such the guide rods  30 ,  31  may be partially received in the recesses before encountering the detent projections. The rods must then be forcibly pressed into the recesses in order to deflect the projections and the recess sidewalls enough to allow passage of the guide rods. Likewise, in order to detach the inner guide rods  30 ,  31  from the paddle  34 , the guide rods must be forcibly pressed outward in order to displace and clear the detent projections  48 ,  49 . The described arrangement enables the paddle to resist the tilting action of the spring  35  and also allows the tray and paddle to be roughly handled by store personnel and customers without concern that the paddle will separate from the guide rods. This is accomplished in the present invention without the requirement of using pins, screws or other devices, achieving equivalent functionality without the extra cost and assembly time associated with the use of separate fastening devices. 
         [0036]    Effective retention of the sliding pusher paddle  34  on the guide rods is an important consideration, because considerable spring force is acting on the paddle, and it can become a potentially harmful projectile if it accidentally becomes detached from the guide rods. 
         [0037]    In accordance with another aspect of the invention, a novel and improved arrangement is provided for locking the pusher paddle  34  in a fully retracted position, against the action of the coiled spring  35 , to accommodate reloading of the tray when necessary. The locking arrangement includes a locking lever  50 , shown in  FIGS. 11-14 , which is pivotally mounted at the back of the pusher  34 , closely adjacent to the base panel  40 . The locking lever  50  includes an upwardly extending actuating arm portion  51  and a rearwardly extending locking leg portion  52  formed in part by side plates  53 ,  54 . At their lower front corners, the side plates  53 ,  54  are provided with laterally outwardly extending pivot pins  55 ,  56  which are arranged to be received in pivot openings  57 ,  58  formed in lower forward portions of the innermost pair of gussets  41  ( FIG. 10 ). Locking lever  50  is a molded part, designed so that the side plates  53 ,  54  are joined in the upper portions thereof by a transverse front panel  59 . The lower, forward portions of the side plates  53 ,  54  are free of cross connection and thus can be squeezed inwardly to allow the pivot pins  55 ,  56  to be inserted into the pivot openings  57 ,  58 , providing a pivotal assembly of the locking lever  50  to the pusher paddle  34 . The lateral spacing of the side plates is such that they straddle and confine the spring  35 , as shown in  FIG. 5 . 
         [0038]    Flanges  60 ,  61  extend inwardly a short distance from forward edges  62  of the side plates  53 ,  54  and are engaged by the coiled body  36  of the spring  35  such that the spring at all times applies a forward pressure on the actuating arm  51  of the locking lever  50 , urging it to pivot toward an upright or “release” position. In the normal or release position of the locking lever, the forward edges  62  of the side plates bear against the back surface of the pusher paddle  34  such that the spring acts through the locking lever to urge the paddle in a forward direction. 
         [0039]    As shown in  FIGS. 11 and 13 , the front panel  59  of the locking lever is offset forwardly from the forward edges  62  of the side plates  53 ,  54  and projects into an opening  63  formed in the front panel  39  of the pusher paddle  34 . When the locking lever is in its release position ( FIG. 3 ) the panel  59  is approximately flush with the front surface of the pusher panel  39 , where it is accessible for actuating the lever  50 . When the pusher paddle  34  is moved to a fully retracted position, as in  FIG. 4 , the locking lever continues to be retained in its release position by the action of the spring body  36  on the flanges  60 ,  61 , so that the paddle is not automatically locked in a retracted position. There are occasions when the paddle is retracted by store personnel for reasons other than reloading of the tray. In such instances, it is undesirable for the paddle to automatically lock in a retracted position because the locking action may not be noticed where it was not intended, causing the tray to malfunction by not maintaining a forward presence of the products. 
         [0040]    In the arrangement of the invention, when a store clerk moves the paddle  34  to a retracted position for reloading, he or she must intentionally lock the paddle by pressing the locking lever panel  59  rearwardly to pivot the locking lever rearwardly to the position shown in  FIGS. 4 and 5 . Downwardly projecting, forwardly opening hooks  64 , at the backs of the side plates  53 ,  54  can then be engaged in a slot  65  in a base cover member  66  to secure the paddle  34  in its retracted position. 
         [0041]    Desirably, the pusher paddle  34  is provided with a stop element  67  which projects rearwardly from a position directly above the access opening  63  and is formed with a downwardly projecting flange  68  positioned to engage upper back portions of the actuating panel  59  of the locking lever  50 , when the lever is displaced rearwardly a predetermined distance relative to the paddle  34 . When the flange  68  is engaged by the panel  59 , the hooks  64  are positioned at a proper level to be received in the slot  65  of the base cover. 
         [0042]    When a reloading operation has been completed, the pusher paddle  34  is released by displacing it rearwardly until the hooks  64  disengage from the slot  65 . As soon as the hooks are disengaged, the locking lever  50  is automatically pivoted forwardly by the action of the spring body  36  against the flanges  60 ,  61  of the locking lever. Frequently, but not necessarily, the pusher paddle is displaced rearwardly upon placement of the final package into the tray. Otherwise, the operator manually displaces the paddle to release the lock. 
         [0043]    In a modified form of the locking lever  50 , shown in  FIG. 15 , a single hook portion  164  extends continuously from one side plate to the other such that the rearward ends of the two side plates  53 ,  54  are rigidly connected. The locking lever of  FIG. 15  functions in the same manner as that of the previously described embodiment. 
         [0044]    The mechanisms of the invention are advantageous in requiring intentional operator action to lock the pusher paddle in a retracted position. However, unlike with prior art devices, the desired functions of the locking mechanism do not require a special spring but are accomplished by an advantageous placement of the locking lever so that the force of the coiled strip spring, which is provided to impart forward biasing to the pusher paddle, can be harnessed to also provide rotational bias to the locking lever in a release direction. This is accomplished in the described embodiment by pivotally mounting the locking lever adjacent the bottom of the pusher paddle, with the coiled body of the spring pressing forward on an upwardly extending actuating arm of the lever. The spring acts to provide forward bias to the actuating arm of the locking lever and also acts through the locking lever to provide forward bias to the pusher paddle. Locking of the pusher paddle in a retracted position for reloading of the tray requires both that the pusher paddle be moved to a retracted position and additionally that the actuating arm of the locking lever be manually pressed backward, through the access opening  63  in the pusher paddle. 
         [0045]    The mechanism of the invention also provides improvements in the manner in which the pusher paddle is mounted on its guide rods. In an arrangement including at least four guide rods, the base of the pusher paddle is provided with outwardly opening, horizontally disposed U-shaped guide sleeves for the reception of the outermost guide rods. A pair of inner guide rods is received in downwardly divergently opening U-shaped guide sleeves, each of which is formed with an internal detent projection requiring forcible snap-in and snap-out assembly and disassembly. The guide sleeves are elongated relative to the diameter of the rods, providing stability to resist tilting forces imparted by the coiled spring and or by store personnel moving the paddle. Additionally, at least certain of the guide sleeves, including the outermost sleeves are further elongated in their upper portions, providing additional stability to resist rearward forces, as when moving the pusher paddle to a reload position, at the back of the tray. 
         [0046]    It should be understood, of course, that the specific embodiments of the invention herein illustrated and described are intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.
A product display tray, which is provided with a spring-actuated pusher paddle for urging a column of products forwardly, includes a manually operated locking element pivotally attached to the pusher paddle and normally urged to a "release" position by the action of the pusher spring. When the paddle is fully retracted, the locking element is manually pivoted into a locking position to engage the tray structure and retain the paddle in its retracted position. The pusher paddle includes special features to facilitate its assembly with, and stable retention on, longitudinal guide rods on which the paddle slides. A pair of downwardly and outwardly inclined U-shaped guide sleeves engage innermost support rods of the tray and have detent projections therein requiring forcible snap-in assembly for greater stability during operations. Selected guide sleeves are partially recessed in lower portions to accommodate overriding of base supports and enable greater retraction of the paddle.