Material handling gate system

Abstract

A barrier system for use with a material storage area comprises a pair of gates having a first closed position spanning a zone of access to the material storage area and a second open position displaced from the zone of access to the material storage area. A fluid, e.g., air or liquid, control system includes a sensor which activates the control system for movement of the gates between the gate positions, the sensor being activated or deactivated by sensing the presence of a material handling device, e.g., a forklift, approaching or withdrawing from the zone of access. The system is particularly useful for placement on mezzanine levels such that the gates at their closed position precludes workers on the mezzanine from accidentally stepping off the mezzanine while allowing for selectable access to the material storage area by material handlers on the ground floor therebelow. The system is adaptable for manual operation.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:  
     
         1 . For use with a material storage area having a material support surface presenting a zone of access for passage of the material therethrough, a barrier system for the material storage area comprising: 
 at least one gate having a length adapted for spanning a length of the zone of access;    means for mounting said at least one gate in movement between a first closed position adapted for spanning a length of the zone of access and a second open position, said at least one gate first position precluding passage of the material through the zone of access and said second open position displaced from the zone of access to allow passage of the material through the zone of access;    means for automatically moving said at least one gate from said first to said second position upon sensing a desired entry of a material handler through the zone of access and a moving of said at least one gate from said second to said first position upon sensing a withdrawal of the material handler from the zone of access.    
     
     
         2 . The system as claimed in  claim 1  wherein said mounting means comprises: 
 support structure extending from the support surface;  
 means for fastening said at least one gate to said support structure in said movement between said first and second positions.  
 
     
     
         3 . The system as claimed in  claim 2  wherein said at least one gate movement is a pivotal movement between said first and second gate positions about an axis extending through the support structure.  
     
     
         4 . The system as claimed in  claim 1  wherein the material handler is a mast of a forklift fronting the zone of access.  
     
     
         5 . The system as claimed in  claim 1  wherein said moving means includes: 
 a piston rod having a first end and a second end, said second end attached to said at least one gate;  
 means for reciprocating said rod in movement between first and second positions, said rod at said first position urging said at least one gate connected thereto to said first closed position with said rod at said second position urging said at least one gate connected thereto to said second open position.  
 
     
     
         6 . The system as claimed in  claim 5  wherein said reciprocating means comprises: 
 a cylinder including said first piston rod end therein;  
 air delivery means for controlling delivery of air relative to said cylinder, a delivery of said air to said cylinder urging said rod to said first or second positions.  
 
     
     
         7 . The system as claimed in  claim 5  wherein said at least one gate comprises first and second gates spanning the length of the zone of access and said moving means includes: 
 a pair of piston rods each having a first end and second end, said second end of each rod attached to a respective gate;  
 means for reciprocating said rods in movement between first and second positions, said rods at said first position urging said connected gates to said first closed position with said rods at said second position urging said connected gates to said second open position.  
 
     
     
         8 . The system as claimed in  claim 6  wherein said air delivery means comprises: 
 an air source;  
 first and second air flow paths between said source and said cylinder;  
 valve means movable first and second positions for alternating an air flow through said first or second air paths and into said cylinder, said valve at said second position allowing an air flow through said second air path for moving said rod to said second position with said valve at said first position allowing air flow through said first air flow path for moving said rod to said first position;  
 means for controlling said positions of said valve means, said valve control means responsive to the desired entry of a material handler through the zone of access to move said valve means to said second position and a withdrawal of the material handler from the zone of access to move said valve means to said first position.  
 
     
     
         9 . The system as claimed in  claim 8  wherein said valve control means includes at least one sensor, said at least one sensor moving said valve to said second position upon a material handler fronting the zone of access and said first position upon a withdrawal of the material handler from the zone of access.  
     
     
         10 . The system as claimed in  claim 9  wherein said valve means comprises: 
 a solenoid valve responsive to a control signal to allow for flow of said air through said first air path and into said cylinder while allowing exhausting air in said cylinder through said second air flow path, said valve responsive to a lack of said control signal to reverse flow of said fluid through said first and second air flow paths and allow an air flow through said second air flow path into said cylinder and exhaust of air from said cylinder along said first air flow path and wherein said control means for said valve means comprises: 
 sensor means for producing said control signal to said valve, said sensor means responsive to the desired entry of the material handler to the zone of access to produce said control signal and ceasing the control signal upon the withdrawal of the material handler from the zone of access.  
 
 
     
     
         11 . The system as claimed in  claim 1  wherein the material support surface is a raised mezzanine surface displaced from a ground floor surface, the zone of access along a front of the mezzanine, said moving means positioned under the mezzanine deck and sensing the desired entry and withdrawal of the material handler on the ground floor therebelow.  
     
     
         12 . For use with a material storage area having a material support surface presenting a zone of access, the zone of access for insertion and withdrawal of the material therefrom, a barrier system for the material storage area comprising: 
 at least one gate having a length adapted for spanning a length of the zone of access;    means for mounting said gate in movement between a first closed position precluding passage through the zone of access and a second open position for allowing passage through the zone of access;    control means including a sensor for automatically moving said at least one gate to said second open position upon said sensor identifying a presence of a material handling device adjacent the zone of access and to said first position upon said sensor identifying a withdrawal of the material handling device from the zone of access, said at least one gate first position further precluding passage of a material handler beyond the material storage area.    
     
     
         13 . The system as claimed in  claim 12  wherein said at least one gate movement is a pivotal movement between said first and second positions.  
     
     
         14 . The system as claimed in  claim 12  wherein the material support area is a mezzanine surface elevated from a ground floor surface with said sensor below said mezzanine surface, said zone of access being a front of the mezzanine elevated from said ground surface, said sensor of said control means adapted for response to the material handling device on the ground floor below the elevated mezzanine.  
     
     
         15 . The system as claimed in  claim 14  wherein the material handling device is a forklift, said sensor of said control means sensing the presence and absence of a portion of the forklift below the mezzanine front.  
     
     
         16 . The system as claimed in  claim 12  wherein the material storage area comprises a plurality of laterally adjacent material storage areas, each area having said barrier system thereon.  
     
     
         17 . For use with a material storage area on a mezzanine having a raised material support surface relative to a ground floor and presenting an elevated edge, a barrier for precluding passage beyond the mezzanine edge comprising: 
 at least one gate;    means for mounting said at least one gate between a first closed position wherein said at least one gate spans a length of the mezzanine edge and a second open position displacing said at least one gate from the mezzanine edge;    means for moving said at least one gate by a material handler on the ground floor between said first position restricting passage beyond the mezzanine edge and said second open position allowing passage of material from beyond the mezzanine edge and into the material storage area.    
     
     
         18 . The system as claimed in  claim 17  wherein said at least one gate comprises a pair of gates, said pair of gates at said first position combining to span the entire length of the edge.  
     
     
         19 . The system as claimed in  claim 17  wherein said movement of said at least one gate is a pivotal movement between said first and second positions.  
     
     
         20 . The system as claimed in  claim 17  wherein said mounting means includes automatic control means for moving said at least one gate to said open position upon a material handling device being sensed adjacent the zone of access and to said closed position upon sensing a displacement of the device from the zone of access.