Abstract:
A shopping cart conveyor that inhibits the loading of a non-compliant shopping cart onto the conveyor. In one aspect, the invention provides a conveyor comprising a track operable to guide the shopping cart between a first location and a second location, a gate assembly including a door movable between a closed position inhibiting entry to the track and an open position allowing entry to the track, a lock for securing the door in the closed position, and a sensor (e.g., an ultrasonic sensor, an optical sensor, a radar sensor, an infrared sensor, an RFID reader, a magnetic sensor, and a mechanical sensor) positioned to detect the presence of a shopping cart. In another aspect, the conveyor is configured to move the gate from the closed position to the open position when the sensor detects the presence of a shopping cart. Preferably this is done using a drive mechanism coupled to the gate.

Description:
BACKGROUND  
       [0001]     The present invention relates to conveyor systems, and more specifically to conveyer systems for shopping carts.  
         [0002]     Currently, many large department stores occupy single floor buildings that include many different product departments and thus have a footprint that covers tens of thousands of square feet. In these large department stores, shoppers typically use shopping carts to carry selected merchandise throughout the store while the shopper continues to select merchandise from the various departments within the store. Since a shopper may be selecting a large number of items having substantial weight, shopping carts are essential in the current department store environment.  
         [0003]     Large department stores are commonly located in suburban areas where enough land is available to build a single-story store large enough to-include all of the merchandise to be offered by the retailer. Some large department store chains have been unable to open stores in large, populated urban areas due to the unavailability of large blocks of single-floor retail space. However, in these same urban areas there are often a number of multi-floor vacant buildings that would be large enough to accommodate the floor space required by the department store. Department stores are unable to utilize these multi-floor buildings due to the inability of the department store to transport shopping carts between the various floors of a multi-level store. Although elevators can move shopping carts between he various floors of a multi-floor store, elevators are unable to handle the large number of consumers typically found in one of the large chains of department stores.  
         [0004]     In order to address this problem, shopping cart conveyors have been designed to move shopping carts on an inclined conveyor along side of an escalator. One such shopping cart conveyor is disclosed in U.S. Pat. No. 6,490,979, assign to Pflow Industries of Milwaukee, Wis., which is incorporated herein in its entirety. In the Pflow patent, the shopping cart conveyor moves specially-equipped shopping carts between floor of a building.  
       SUMMARY  
       [0005]     J Shopping cart conveyors typically are designed to accommodate only shopping carts of a certain design. These conveyors usually will not function properly if other shopping carts are used. Accordingly, it would be beneficial if the shopping cart conveyors were designed so that other shopping carts were inhibited from being loaded onto the conveyor.  
         [0006]     The present invention provides such a shopping cart conveyor that inhibits the loading of a non-compliant shopping cart onto the conveyor. In one aspect, the invention provides a conveyor comprising a track operable to guide the shopping cart between a first location and a second location, a gate assembly including a door movable between a closed position inhibiting entry to the track and an open position allowing entry to the track, a lock for securing the door in the closed position, and a sensor (e.g., an ultrasonic sensor, an optical sensor, a radar sensor, an infrared sensor, an RFID reader, a magnetic sensor, and a mechanical sensor) positioned to detect the presence of a shopping cart. In one embodiment, the shopping cart includes an engagement bracket for engagement with the track, and the sensor is configured to detect the engagement bracket. Preferably, the conveyor further includes a controller coupled to the sensor and to the lock, wherein the controller is configured to unlock the lock when the sensor detects the presence of a shopping cart.  
         [0007]     In another aspect, the conveyor is configured to move the gate from the closed position to the open position when the sensor detects the presence of a shopping cart. Preferably this is done using a drive mechanism coupled to the gate. If desired, the movable door can be provided with the above-described lock to secure the gate when it is in the closed position. Alternatively, the drive mechanism can be of a design that substantially prevents movement of the gate when the drive mechanism is not actuated.  
         [0008]     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a perspective view of a shopping cart conveyor system.  
         [0010]      FIG. 2  is an enlarged perspective view of a gate assembly of a shopping cart conveyor system that is a first embodiment of the present invention.  
         [0011]      FIG. 3  is a perspective view of a gate assembly that is a second embodiment of the present invention.  
         [0012]      FIG. 4  is a perspective view of a gate assembly that is a third embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0013]     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.  
         [0014]      FIG. 1  illustrates a conveyor  10  for moving shopping carts between various locations. In the illustrated embodiment, the conveyor  10  is inclined to move the shopping carts between floors or levels of a department store or the like. The illustrated conveyor  10  includes a first track  14  for moving the shopping cart  14  between a lower level and an upper level, and a second track  18  for moving the shopping cart  12  from the upper level to the lower level. The conveyor  10  may include multiple motors, gears, pulleys, engaging members, and the like. Such components and their respective functions are described in detail in U.S. Pat. No.6,490,979. In some embodiments, the conveyor  10  is provided with a gate assembly  24  at entry and exit points of both the first track  14  and the second track  18 .  
         [0015]     The gate assembly  24  illustrated in  FIG. 2  is entry gate and includes a door  28  that is movable between an open position, allowing access to the track, and a closed position, inhibiting access to the track. In the illustrated embodiment, the gate assembly  24  includes two doors  28 . The operation of one of the doors  28  will be described herein. The door  28  is mounted for pivotal movement relative to the frame  32 . The pivotal movement of the door  28  is only given as a single example. The door  28  can include virtually any type of configuration that provides an open position and a closed position. Single or multiple doors  28  may be used with the invention, and in some embodiments the gate assembly  24  includes a completely different configuration for selectively preventing entry of shopping carts, other objects or beings to the tracks  14 ,  18  of the conveyor  10 .  
         [0016]     In the illustrated embodiment, the door  28  is provided with a lock  36 . The lock  36  allows the door  28  to be configurable in either a locked state or an unlocked state. The lock  36  may consist of virtually any type of device capable of holding the door  28  in a fixed position. The lock  36  in  FIG. 2  is a simple solenoid fixed to the frame  32 . The solenoid includes a movable member for selectively engaging and locking the door  28 .  
         [0017]     With continued reference to  FIG. 2 , the gate assembly  24  is provided with a sensor  44  that is positioned to detect the shopping cart  12 . The sensor  44  communicates via a signal, such as an electrical signal or wireless signal, with a controller  48 . The controller  48  in turn communicates with the lock  36 . Upon detection of the presence of a shopping cart, the sensor  44  sends a signal to the controller, and the controller  48  sends an “unlock” signal to the lock  36 , which triggers the lock  36  to switch from the locked state to the unlocked state. In some embodiments, the lock  36  is biased or otherwise held in the locked state. In other embodiments, a “lock” signal is sent from the controller  48  to the lock  36  for re-locking.  
         [0018]     The gate assembly  24  is further provided with a drive mechanism  52  for moving the door  28  between the closed and open positions. In the illustrated embodiment, the drive mechanism  52  is a motor located within the frame  32 . The drive mechanism  52  is configured to receive an “open” signal sent from the controller  48 . The “open” signal can be independent or dependent upon the signal sent to the lock  36 . For example, in some embodiments, the signal sent by the controller for unlocking the lock  36  begins a delay timer function within the controller, which delays the “open” signal. Upon receiving the “open” signal from the controller  48 , the drive mechanism  52  is energized to move the door  28  from the closed position to the open position, allowing entry to the conveyor  10 . In other embodiments, the lock and motor can be incorporated into a single device, such as a motor with a friction clutch or a motor coupled to a locking gear train.  
         [0019]     Once opened, the door  28  is held in the open position (e.g., by the lock  36 , the drive mechanism  52 , or another holding means) for a fixed amount of time in some embodiments. The controller  48  is programmable to set or change the amount of time that the door  28  is held in the open position after receiving the signal from the sensor  44  indicating the presence of the shopping cart  12 . Alternatively, the closing of the door  28  transpires upon a separate “close” signal from the controller  48 . The “close” signal may be generated by an auxiliary sensor indicating the passing of the shopping cart  12  through the door  28 , but may also be generated by the sensor  44 , a timer function in the controller  48 , or any combination thereof.  
         [0020]     The sensor  44  of  FIG. 2  is arranged in a generally vertical direction for sensing in a generally upward direction. The sensor  44  of  FIG. 2  is positioned near the bottom of the gate assembly  24  just outside the door  28 . In some embodiments, the sensor  44  is protected from physical contact or interference by positioning it partially or wholly in the floor or bottom surface of the gate assembly  24 . The sensor  44  and controller  48  are configured to detect or sense the shopping cart  12 . In some embodiments, each authorized shopping cart  12  to be used with the conveyor  10  is provided with an identifier, which identifies to the sensor  44  that it is an authorized shopping cart. This helps prevent entry of any cargo to the tracks  14 ,  18  other than the shopping cart  12 . In some embodiments, the shopping cart  12  includes an engagement bracket  56  as disclosed in U.S. Pat. No. 6,490,979. The engagement bracket  56  is used to provide a point of engagement to the tracks  14 ,  18 , but may also be employed as the identifier.  
         [0021]     The sensor  44  may be selected from many various types, depending on the identifier. For example, the sensor  44  may be ultrasonic, optical, infrared, mechanical, radar, magnetic or Hall effect, etc. In some embodiments, the sensor  44  is configured as a radio frequency identification (RFID) reader for identifying RFID tags or labels (identifiers) that may be placed on the shopping carts  12 .  
         [0022]      FIG. 3  illustrates a different gate assembly  60  for use with the conveyor  10 . The gate assembly  60  includes a frame  64  and a door  68 , similar to the previous embodiment. A lock  72  permits the door  68  to be configured in either a locked or an unlocked state. In the illustrated embodiment, a sensor  76  is configured to detect the presence of the shopping cart  12  proximate the conveyor  10 .  
         [0023]     The sensor  76  of  FIG. 3  is positioned near the lateral sides of the gate assembly  60 . The sensor  76  is shown with an exemplary shape, which is tall and narrow. As described above with reference to the previous embodiment, the sensor  76  may employ any one of a number of sensory technologies to detect the presence of the shopping cart  12 . In some embodiments, multiple sensory methods are used in combination.  
         [0024]     As with the previous embodiment, a drive mechanism  80  is operable to open the door  68  from the closed position to the open position. A controller  84  receives a signal from the sensor  76  when the shopping cart  12  is detected near the conveyor  10 . In some embodiments, the sensor  76  also sends a signal to the controller  84  when the shopping cart  12  is not detected (indicating absence of the shopping cart  12 ). Upon detection and identification of the presence of the shopping cart  12  by the sensor  76  and the controller  84 , the controller  84  sends a signal to either the lock  72 , the drive mechanism  80  or both.  
         [0025]      FIG. 4  illustrates a gate assembly  88  including a sensor  92 . The sensor  92  may vary in type and field of view as described above. The sensor  92  is positioned atop the gate assembly  88  and is configured to sense whether or not the shopping cart  12  is present. A lock  96 , a controller  100 , and a drive mechanism  104  are provided for operation as described above with reference to the previous embodiments.  
         [0026]     In another embodiment that is not illustrated, the sensor can be positioned at least partially in the center track ( FIG. 1 ) that is adapted to receive the engagement bracket  56 . In this embodiment, it is less likely that the sensor will be activated by something other than an authorized shopping cart (i.e., one having an engagement bracket). In this embodiment, the center track would need to be extended outward from the conveyor so that the engagement bracket can be inserted into the center track and sensed by the sensor before the shopping cart engages the doors.  
         [0027]     In addition, although the above-described and illustrated embodiments disclose use of an electronic sensor, it should be understood that the sensor could be mechanical. For example the sensor could be a lever that is moved by engagement with a shopping cart (e.g., the engagement bracket  56 ), and the lever could be coupled to a locking device to unlock the gate.  
         [0028]     Thus, the invention provides, among other things, a system and method for controlling access to a conveyor for shopping carts. Various features and advantages of the invention are set forth in the following claims.