Tray handler and method

Abstract

The present invention is directed to a tray handler for stacking and de-stacking ophthalmic prescription trays. The tray handler includes a plurality of spaced clamp assemblies defining a stack area along a conveyor, a lift plate, and first and second actuators. The lift plate is operably disposed within the stack area. The first actuator is operably associated with the clamp assemblies, which are inwardly and outwardly moveable relative the lift plate upon actuation of the first actuator. The second actuator is operably associated with the lift plate, which is vertically moveable within the stack area upon actuation of the second actuator. A controller is in communication with the first and second actuators and controls actuation thereof. A method of handling ophthalmic prescription trays is also disclosed.

1 - 31 . (canceled) 
     
     
         32 . A tray handler system for stacking and de-stacking ophthalmic prescription trays, the system comprising:
 a conveyor interconnecting a first location and a second location and conveying a plurality of trays therebetween;   a stacker disposed along said conveyor, said stacker having a plurality of clamp assemblies defining a stacking area along said conveyor, a lift plate operably disposed within the stacking area, a first actuator operably associated with said clamp assemblies, said clamp assemblies inwardly and outwardly moveable relative said lift plate upon actuation of said first actuator, and a second actuator operably associated with said lift plate, said lift plate vertically moveable within the stacking area upon actuation of said second actuator;   a de-stacker disposed along said conveyor and spaced from said stacker, said de-stacker having a plurality of clamp assemblies defining a de-stacking area along said conveyor, a lift plate operably disposed with the de-stacking area, a first actuator operably associated with said clamp assemblies, said clamp assemblies inwardly and outwardly moveable relative said lift plate upon actuation of said first actuator, and a second actuator operably associated with said lift plate, said lift plate vertically moveable within the de-stacking area upon actuation of said second actuator;   a controller in communication with said first and second actuators of said stacker and said first and second actuators of said de-stacker for controlling actuation thereof.   
     
     
         33 . The system of  claim 32 , further comprising a processing machine disposed at at least one of said first location and said second location. 
     
     
         34 . The system of  claim 33 , wherein said processing machine is selected from the group consisting of an edging machine, a surfacing machine, a blocking machine, and a coating machine. 
     
     
         35 . The system of  claim 32 , further comprising an indexing station disposed along said conveyor intermediate said stacker and said de-stacker, said indexing station comprising a plurality of spaced tray stops, each of said tray stops upwardly moveable for preventing a stack of trays from proceeding along said conveyor. 
     
     
         36 . The system of  claim 35 , wherein said tray stops are in communication with said controller, said controller causing actuation of said tray stops so that each stack of trays proceeds through said indexing station at a predetermined rate. 
     
     
         37 . A method of handling ophthalmic prescription trays, comprising the steps of:
 conveying a plurality of trays on a conveyor from a first location to a first tray handler;   forming a stack of trays in the first tray handler;   discharging the stack of trays from the first tray handler onto the conveyor;   conveying the discharged stack of trays on the conveyor from the first tray handler to a second tray handler disposed along the conveyor;   de-stacking the stack of trays in the second tray handler;   discharging each de-stacked tray from the second tray handler onto the conveyor; and   conveying each discharged, de-stacked tray from the second tray handler to a second location.   
     
     
         38 . The method of  claim 37 , including the further step of conveying each discharged, de-stacked tray from the second tray handler to a processing machine. 
     
     
         39 . A method of stacking ophthalmic prescription trays, comprising the steps of:
 a) conveying a first tray on a conveyor into a stacking area;   b) raising the first tray upwardly and off the conveyor to a predetermined height;   c) clamping the first tray by closing a plurality of grippers against the first tray, thereby maintaining the first tray at the predetermined height above the conveyor;   d) conveying a second tray into the stacking area;   e) raising the second tray upwardly and off the conveyor until the second tray contacts the first tray;   f) unclamping the first tray by opening the plurality of grippers;   g) raising the second tray to the predetermined height;   h) clamping the second tray by closing the plurality of grippers against the second tray, thereby maintaining the first and second trays in a stack above the conveyor.   
     
     
         40 . The method of  claim 39 , comprising the further steps of:
 repeating steps a) through h) until the stack includes a desired number of trays; and   unclamping a bottom tray in the stack by opening the plurality of grippers;   lowering the stack onto the conveyor; and   discharging the stack from the tray handler to a second location.   
     
     
         41 . A method of de-stacking ophthalmic prescription trays, comprising the steps of:
 a) conveying a stack of trays on a conveyor into a de-stacking area;   b) raising the stack of trays upwardly and off the conveyor to a predetermined height;   c) clamping a second to lowest tray in the stack by closing a plurality of grippers against the second to lowest tray, thereby maintaining the second to lowest tray at the predetermined height while maintaining the stack above the conveyor;   d) lowering the lowest tray in the stack onto the conveyor, thereby de-stacking the lowest tray from the stack.   
     
     
         42 . The method of  claim 41 , comprising the further steps of:
 e) unclamping a next lowest tray in the stack by opening the plurality of grippers;   f) clamping a second to next lowest tray in the stack by closing the plurality of grippers against the second to next lowest tray, thereby maintaining the second to next lowest tray at the predetermined height while maintaining the stack above the conveyor;   g) lowering the next lowest tray in the stack onto the conveyor;   h) discharging the next lowest tray from the de-stacking area.   
     
     
         43 . The method of  claim 42 , comprising the further steps of repeating steps e) through h) until all trays in the stack of trays are discharged from the de-stacking area.