Pallet positioning station and associated methods

Abstract

A method for operating a pallet positioning station for positioning a pallet to be impacted by a pallet impact station is provided. The pallet positioning station includes a pallet push arm assembly adjacent the pallet impact station. The pallet push arm assembly includes a pallet push arm movable between a retracted position and a pallet positioning position. The method includes moving the pallet push arm to the retracted position to receive the pallet for positioning, and moving the pallet push arm to the pallet positioning position to position the pallet towards the pallet impact station for impact.

That which is claimed is: 
     
         1 . A method for operating a pallet positioning station for positioning a pallet to be impacted by a pallet impact station, the pallet positioning station comprising a pallet push arm assembly adjacent the pallet impact station, the pallet push arm assembly comprising a pallet push arm movable between a retracted position and a pallet positioning position, the method comprising:
 moving the pallet push arm to the retracted position to receive the pallet for positioning; and   moving the pallet push arm to the pallet positioning position to position the pallet towards the pallet impact station for impact.   
     
     
         2 . The method according to  claim 1  wherein the pallet positioning station further comprises a pallet lift assembly comprising a lift grate moveable between a retracted position and an extended position, the method further comprising:
 moving the lift grate to the retracted position to receive the pallet for positioning; and 
 moving the lift grate to the extended position when the pallet is to be positioned for impact by the pallet impact station. 
 
     
     
         3 . The method according to  claim 2  further comprising positioning the pallet towards the pallet impact station for impact until the pallet is aligned with an impact reference plane. 
     
     
         4 . The method according to  claim 2  wherein the pallet positioning station further comprises a frame adjacent the pallet impact station, with the pallet lift assembly being carried by the frame. 
     
     
         5 . The method according to  claim 2  wherein the lift grate comprises a plurality of spaced apart elongated lift elements, with each respective lift element sized to fit between two adjacent rollers of a roller conveyor. 
     
     
         6 . The method according to  claim 2  wherein the pallet lift assembly further comprises a plurality of vertical actuators, the method further comprising activating the plurality of vertical actuators for moving the lift grate between the retracted position and the extended position. 
     
     
         7 . The method according to  claim 6  wherein the pallet lift assembly further comprises at least one horizontal actuator, the method further comprising activating the at least one horizontal actuator for moving the lift grate in a horizontal direction between an impact reference plane and the pallet push arm so that the pallet contacts the pallet push arm before the pallet push arm is moved to the pallet positioning position. 
     
     
         8 . The method according to  claim 7  further comprising activating the plurality of vertical actuators and the at least one horizontal actuator simultaneously. 
     
     
         9 . The method according to  claim 7  wherein the plurality of vertical actuators and the at least one horizontal actuator each comprises a hydraulic actuator. 
     
     
         10 . The method according to  claim 1  wherein the pallet positioning station further comprises a movement sensor configured to generate a signal corresponding to movement of the pallet push arm when in the pallet positioning position, the method further comprising moving the pallet push arm in the pallet positioning position until the generated signal reaches a predetermined value, with the predetermined value corresponding to when an impact side of the pallet is aligned with an impact reference plane. 
     
     
         11 . The method according to  claim 10  wherein the movement sensor comprises a linear variable differential transformer (LVDT). 
     
     
         12 . The method according to  claim 1  further comprising moving the pallet push arm back to the retracted position after an impact side of the pallet is aligned with an impact reference plane. 
     
     
         13 . The method according to  claim 1  wherein the pallet carries a unit load during impact with the pallet impact station, and wherein the pallet impact station comprises a stationary unit load push bar adjacent an impact reference plane, the method further comprising moving the pallet push arm in the pallet positioning position to move the pallet so that the unit load contacts the stationary unit load push bar as an impact side of the pallet continues to move towards an impact reference plane. 
     
     
         14 . A method for operating a pallet positioning station comprising a pallet push arm movable between a retracted position and a pallet positioning position, and a movement sensor configured to generate a signal corresponding to movement of the pallet push arm when in the pallet positioning position, the method comprising:
 moving the pallet push arm to the retracted position to receive the pallet for positioning; and   moving the pallet push arm to the pallet positioning position to position the pallet towards a pallet impact station based on the generated signal reaching a predetermined value.   
     
     
         15 . The method according to  claim 14  further comprising moving the pallet push arm back to the retracted position after an impact side of the pallet is aligned with an impact reference plane. 
     
     
         16 . The method according to  claim 17  wherein the pallet positioning station further comprises a lift grate moveable between a retracted position and an extended position, the method further comprising:
 moving the lift grate to the retracted position to receive the pallet for positioning; and 
 moving the lift grate to the extended position when the pallet is to be positioned for impact by the pallet impact station. 
 
     
     
         17 . The method according to  claim 16  wherein the lift grate comprises a plurality of spaced apart elongated lift elements, with each respective lift element sized to fit between adjacent rollers of a roller conveyor carrying the pallet for impact by the pallet impact station.