Abstract:
A safety gate apparatus ( 10 ) for a platform loading area with a guardrail (G) having an opening includes a frame positioned across the opening. A first gate ( 100 ) pivotally attaches to the frame for movement between a lowered position blocking access to the loading area, and a raised position to provide unobstructed access to the loading area. A second gate ( 200 ) moveably attaches to the frame for movement between a lowered position preventing access through guardrail opening and a raised position allowing access through the opening. Pulleys ( 28 ) attached to the frame are operatively connected between the gates so when the first gate is in its lowered position the second gate is in its raised position, and when the first gate is in its raised position the second gate is in its lowered position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. application Ser. No. 13/151,396, filed Jun. 2, 2011, and derives priority from that application as well as from U.S. Provisional Application 61/352,975, filed Jun. 9, 2010, which are incorporated herein by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
       [0002]    Not Applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    This invention relates to safety gates such as those used on platforms or docks where pallets of material are brought, so to protect a worker handling the pallet and its contents. 
         [0004]    In some manufacturing facilities, materials used in a manufacturing process are stored on a pallet or skid from which the material is dispensed from an upper level of the facility to equipment located on a lower level of the facility. For example, in a blending/mixing operation, an open topped blender mixes various ingredients as part of a manufacturing operation. The blender sits, for example, on the floor of the facility. Materials to be mixed in the blender are dumped or poured into the blender from a level above the top of the blender. These materials are stored or warehoused on a pallet until ready for use. The pallet is then moved onto the platform from which a worker dispenses the material into the blender. 
         [0005]    It will be appreciated that this operation is potentially dangerous and that a safety gate, guard rail, or the like must be in place to protect the worker throughout the unloading process. The process requires that the platform edge be blocked or barricaded when pallets are not being loaded onto or removed from the platform to prevent people from falling off the edge of the platform. The barricade must then be moved out of the way to allow the pallet to be moved onto or off of the platform. Movement of the pallet is typically performed using a fork lift. During lifting of the pallet or skid onto the platform, the worker must still be protected from falling off the edge of the platform. Then, during unloading of the skid, the safety gate or guard needs to afford a worker the ability to easily offload or work with the contents of the pallet, while the worker (and others) is protected from harm. 
         [0006]    Various safety mechanisms are known for enabling the process described above. See, for example, U.S. patents 
         [0000]    
       
         
               
               
               
             
           
               
                   
               
             
             
               
                 7,017,643 
                 6,138,812 
                 5,216,782 
               
               
                 6,837,296 
                 5,709,050 
                 4,938,095 
               
               
                 6,412,220 
                 5,701,701 
                 4,422,264 
               
               
                 6,212,826 
                 5,546,703 
               
               
                   
               
             
          
         
       
     
         [0007]    All of the apparatus described in these patents, as well as other apparatus currently in use have drawbacks. In particular, the apparatus does not allow a worker ready accessibility to the sides of the pallet so the worker can work efficiently to unload its contents. With the present invention, the pallet is fully accessible when the safety structure is in a closed perimeter railing position and fall protection is not compromised when the safety structure is in the isolation railing position and pallets are loaded onto or removed from the platform. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    The present invention is directed to apparatus comprising two gates, an isolation gate and a perimeter gate which, together, protect a worker from falling from a platform from which pallets are loaded or unloaded. The perimeter gate is similar to a perimeter hand railing having horizontal barricade rails or members and a kick plate. The isolation gate is a three-sided structure which isolates and partitions off a pallet loading area where a skid is to be loaded or off-loaded by a fork lift. The two gates are operated in unison using a pulley assembly. This allows the two gates to counterbalance each other so that when the isolation gate is raised the perimeter gate is lowered; and, when the isolation gate is lowered the perimeter gate is raised. 
         [0009]    Let it be assumed that an opening along the perimeter handrailing is present. Through this opening, pallets are loaded onto or off of the platform. The isolation gate has a front rail extending across the width of the opening in the perimeter handrailing where the apparatus is installed and each end of the front rail is connected to a post. A pair of spaced apart, parallel side rails extends along opposite sides of the apparatus and, when the isolation gate is lowered, prevents access to the pallet loading area from its sides. 
         [0010]    A pair of posts is installed on opposite sides of the opening in the perimeter handrailing, at the outer end of the platform. Brackets extend inwardly from each of these posts and the other end of each side rail is rotatably attached to one of the brackets. 
         [0011]    The perimeter gate comprises a frame which is vertically movable installed between the pair of permanently mounted posts. A lower portion of the frame comprises a “kick” plate which, when the perimeter gate is lowered, prevents material on the pallet from inadvertently toppling over the side of the platform. 
         [0012]    A pulley is mounted atop at least one, and preferably, both of this second pair of posts and is attached to a rod spanning the posts. A drive element, such as a cable, rope, chain, or belt has one end secured to the perimeter gate frame, passes around the pulley, and has its other end connected to one of the side rails of the isolation gate for movement of the frame to raise and lower the front rail and side rails. 
         [0013]    Whenever a pallet is not being loaded onto or off of the platform, the perimeter gate is lowered to prevent workers from falling from the platform. When a pallet is to be placed on the platform, a worker pulls on the frame of the isolation gate to lower it into place for protection from the loading area. This action lifts the horizontal barricade rails and kick plate of the perimeter gate up and away from the platform so the pallet can be set in place. When the pallet is in place, the worker raises the three-sided isolation gate which lowers the horizontal barricade rails and kick plate of the perimeter gate back into place, blocking fork lift access to the platform. 
         [0014]    The apparatus is relatively low in cost and easy to install and operate. Importantly, when the isolation gate is raised, no portion of it remains in touch with the platform giving a worker ready access to the pallet and making it easier to unload. 
         [0015]    Other objects and features will be in part apparent and in part pointed out hereinafter. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0016]    The objects of the invention are achieved as set forth in the illustrative embodiments shown in the drawings which form a part of the specification. 
           [0017]      FIG. 1  is a plan view of the safety gate apparatus with an isolation gate in its lowered position and a perimeter gate in its raised position; 
           [0018]      FIG. 2  is a side view of the safety gate apparatus with the isolation gate in its lowered position and the perimeter gate in its raised position; 
           [0019]      FIG. 3  is a plan view of the safety gate apparatus with the isolation gate in its raised position and the perimeter gate in its lowered position; 
           [0020]      FIG. 4  is a side view of the safety gate apparatus with the isolation gate in its raised position and the perimeter gate in its lowered position; 
           [0021]      FIG. 5  is an isometric view of the apparatus with the isolation gate in its lowered position and the perimeter gate in its raised position; 
           [0022]      FIG. 6  is a front elevation view of the apparatus with the isolation gate in its raised position and the perimeter gate in its lowered position; and, 
           [0023]      FIG. 7  is a front elevation view of the apparatus with the perimeter gate in its raised position and the isolation gate is not shown. 
       
    
    
       [0024]    Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    The following detailed description illustrates the invention by way of example and not by way of limitation. This description clearly enables one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention. Additionally, 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 drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it will be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
         [0026]    A safety gate apparatus  10  of the present invention comprises a safety gate or guard rail for protecting workers working in a pallet loading area. As shown in the drawings, the pallet P is loaded with materials M which can be any one of a variety of commodities. The pallet P is raised onto a loading area on a floor F of a platform adjacent an edge E of the platform. A worker then typically unloads the material M into the top of processing or blending equipment or stores the material on the platform. The type of work performed once the pallet P is in place does not matter in this discussion. It is only assumed that the worker needs full access to the pallet P once it is properly loaded onto the loading area of the platform. 
         [0027]    Referring to  FIGS. 1 ,  2 , and  5 , when preparing to raise a pallet P onto the platform, an isolation gate  100  of apparatus  10  is in a lowered position to block access by a worker to the front and sides of the pallet in the loading area, while a perimeter gate  200  of the apparatus is in a raised position providing access through an opening of a guardrail G for the pallet P. Referring to  FIGS. 3 ,  4 , and  6 , when a pallet P is positioned in the loading area of the platform floor F, isolation gate  100  is in the raised position to provide access to the pallet P in the loading area by the worker, while perimeter gate  200  is in the lowered position extending across the opening of the guardrail G to prevent the worker from falling over the edge E of the platform. 
         [0028]    Isolation gate  100  first includes a front rail  12  extending about the width of the opening in the guardrail G. When the isolation gate  100  is in the lowered position, rail  12  prevents anyone from accessing the pallet in the loading area from the front of it. 
         [0029]    Next, the isolation gate  100  has two pair of vertically spaced apart side rails  14   a ,  14   b  and  16   a ,  16   b . One pair of side rails  14   a ,  14   b  extends along one side of the pallet P in the loading area and the other pair  16   a ,  16   b  extends along the opposite side of the pallet P in the loading area. These side rails prevent one from accessing the pallet P in the loading area from either side when the isolation gate  100  is in the lowered position. 
         [0030]    Posts  18   a ,  18   b  are positioned at the front end of isolation gate  100 , on opposite sides of the gate  100 . One end of the front rail  12  is attached to vertical post  18   a , with the other end of the front rail  12  attached to vertical post  18   b . The height of posts  18   a  and  18   b  may vary upon the particular installation, but their height is, for this example, 3′6″. 
         [0031]    Next, the outer end of each side rail  14   a ,  14   b  is rotatably attached to post  18   a , while the outer end of each of rail  16   a ,  16   b  is rotatably attached to post  18   b . As particularly shown in  FIG. 4 , each side rail comprises two sections L and S. Section L is the longer of the two sections and S is the shorter of them. Sections L and S are hinged together, as indicated at hinge point  20  so when the isolation gate is in the raised position, the side rails collapse tightly against posts  18   a ,  18   b , in a generally planar orientation resulting in a narrow profile with little platform interference. In this raised position, the isolation gate  100  has no contact with the floor F and is removed from the loading area including the area above the loading area. Therefore, the worker has generally unobstructed access to the front and sides of the pallet P in the loading area. 
         [0032]    A platform guardrail G extends along the edge of the perimeter of the platform floor F. The opening in the guardrail G (see, particularly,  FIG. 3 ) allows a forklift access to the loading area of platform floor F for loading and unloading of pallets P. A pair of permanently mounted posts  22   a ,  22   b  are installed adjacent the ends of the guardrail G opening. The isolation gate  100  and perimeter gate  200  are raised and lowered relative to these stationary posts  22   a ,  22   b . A pair of brackets  24  attach the side rails  14   a ,  14   b ,  16   a ,  16   b  of the isolation gate to the posts  22   a ,  22   b . These brackets act as hinges and allow the side rails to pivot about the hinge point  26 . 
         [0033]    Posts  22   a ,  22   b  are generally U-shaped or have a groove or slot with the open portion of the U facing the opening in the guardrail G. A perimeter gate  200  comprises a frame assembly indicated generally  28  in the drawings which is generally rectangular in shape. Vertical sections  30  of the frame  28  are received in slots (not shown) extending along the inside of the posts  22   a ,  22   b . This prohibits lateral movement of the frame and allows the perimeter gate  200  to smoothly be raised or lowered in a generally vertical movement. Pulleys  32  are mounted on the opposite ends of a rod  34  which extends between posts  22   a ,  22   b . A drive element, such as a cable, chain, belt, or rope R passes around each pulley  32 . One end of the rope R is secured to frame  28  and the other end of the rope R is attached to one of the respective top side rails  14   a ,  16   a . This end of the rope R is attached to the rail inwardly of the connection between sections S and L of the rail as shown in  FIG. 2 . 
         [0034]    Perimeter gate frame  28  includes a top horizontal bar  36 , a middle bar  38  and a lower plate  40  which is also referred to as a kick plate. 
         [0035]    When pallets P are not being placed onto or removed from the loading area, the perimeter gate  200  of apparatus  10  moves to the lowered position. As previously discussed, in this lowered position, the perimeter gate  200  extends across the opening of the guardrail G opening to act as a guardrail preventing workers from falling off of the platform. When a pallet P is about to be placed on the loading area, a worker standing to the side of the apparatus pulls downwardly on one of the members of isolation gate  100  such as post  18   a ,  18   b  and moves the isolation gate  100  to the lowered position. This action pulls the one end of the ropes R downward with the other end of the ropes now lifting the top horizontal bar  36 , middle bar  38 , and lower plate  40  of perimeter gate  200  up and away from the loading area to the raised position as shown in  FIGS. 1 ,  2 ,  5 , and  7 . Pallet P can be now set in place in the loading area. Once the pallet P is in place in the loading area, the worker lifts the isolation gate  100  rails out of the way to the raised position, thereby lowering the perimeter gate frame  28  to the lowered position. In this position, the worker has unobstructed access to the front and sides of the pallet for unloading of material M. 
         [0036]    The perimeter gate  200  can be built as a solid frame with the top horizontal bar  36 , middle bar  38 , lower plate  40 , and vertical sections  30  permanently attached together. Alternately, these components can be designed to move relative to each other. For example, vertical sections  30  can be constructed to telescope. As the isolation gate  100  is lowered, the lower plate is raised to join the middle bar. Both the lower plate and middle bar are raised to join the top horizontal bar. Finally, all three pieces of the perimeter gate  200  are fully raised. Telescoping the perimeter gate frame  28  increases the clearance for loading a pallet through posts  22   a  and  22   b . All, some, or none of the vertical sections  30  may telescope based on project cost and clearance requirements. 
         [0037]    As shown in  FIG. 4 , as upper side rail  16   a  (and not shown  14   a ) of isolation gate  100  are lifted upwardly, the side rails hinge about the hinge point  26  on the post brackets  24 . Because the upper and lower side rails on each side of the isolation gate  100  are connected to the posts  18   a ,  18   b , the lower side rails  14   b ,  16   b  are also lifted, as is front rail  12  which is also connected to the posts  18   a ,  18   b . Further, as the side rails are raised, their sections S and L hinge about the respective hinge points  20  so, as shown in  FIG. 4 , posts  18   a ,  18   b  hang generally vertically. This not only makes the raised position of the isolation gate more compact, but also keeps these gate components from interfering with the unloading activity because they are out of the way of the worker. 
         [0038]    Importantly, it is a feature of the apparatus that when the isolation gate  100  is raised, all the components of the isolation gate  100  are fully off the floor F, again, making it easier to work around pallet P. 
         [0039]    When the pallet is to be removed, the worker raises frame  28  of perimeter gate  200  by pulling on isolation gate post  18   a ,  18   b . It is important to note that the worker must stand outside of the loading area to be properly protected. Also, he does not raise frame  28  by directly lifting the perimeter gate frame. Doing so would position the worker unacceptably close to the edge E of the platform in an unprotected position. Standing outside of the pallet loading area and pulling on post  18   a ,  18   b  pulls the ropes R attached to the perimeter gate frame  28  and allows the side rails and front rail of isolation gate  100  to be lowered back into place, blocking access to the pallet loading area. 
         [0040]    In view of the above, it will be seen that the several objects and advantages of the present disclosure have been achieved and other advantageous results have been obtained.