Tray for storing and transporting workpieces

Abstract

A group of trays is configured for storing and transporting workpieces. Each tray includes a base and a frame. The base includes a plurality of receiving portion for receiving the workpieces. The frame surrounds the base to form a cavity. A plurality of projections are formed at the outer side of the flange. When two trays are stacked whether in a same direction or opposite direction, the lower tray is partially received in the cavity of the upper tray, and the projections of the lower tray resist the frame of the upper tray to stop the lower tray from being further inserted into the cavity of the upper tray.

1 . A group of trays for storing and transporting workpieces, each tray comprising:
 a base including a plurality of receiving portions for receiving the workpieces; and   a flange, the flange surrounding the base to form a cavity, the flange including a top surface; a plurality of projections formed at the outer side of the top surface; when then trays are stacked in a same direction or an opposite direction, the base of the lower tray is received in the cavity of the upper tray, and the projections of the lower tray resist the top surfaces of the upper tray to prevent the lower tray from being further inserted into the cavity of the upper tray.   
     
     
         2 . The group of trays as claimed in  claim 1 , wherein a plurality of blocks are formed at an outer side of the flange of each tray, and when the trays are stacked in opposite directions, the blocks of the lower tray resist the top surfaces of the upper tray. 
     
     
         3 . The group of trays as claimed in  claim 2 , wherein the trays are made of a plastic. 
     
     
         4 . The group of trays as claimed in  claim 3 , wherein the trays are formed by suction molding. 
     
     
         5 . The group of trays as claimed in  claim 4 , wherein the flange of each tray is partially recessed at an inner side to define a plurality of grooves corresponding to the blocks respectively, the grooves communicating with the top surfaces, and the projections of the upper tray prevent the blocks of the upper tray from being further inserted into the corresponding grooves of the lower tray when two trays are stacked in a same direction. 
     
     
         6 . The group of trays as claimed in  claim 5 , wherein the blocks of each tray are positioned at different locations. 
     
     
         7 . The group of trays as claimed in  claim 6 , wherein the grooves comprise side grooves and corner grooves, and accordingly the blocks comprise side blocks and corner blocks. 
     
     
         8 . The group of trays as claimed in  claim 1 , wherein the projections are tapered and a width of the projection decreases with increasing distance from the top surface of the flange. 
     
     
         9 . A group of trays for storing and transporting workpieces, each tray comprising a base and a flange, the flange and the base defining a cavity; the base including a plurality of receiving portions for receiving the workpieces; a plurality of projections and blocks being formed at the outer side of the flange; when the trays are stacked in a same direction or an opposite direction, the base of the upper tray is received in the cavity of the lower tray; when the trays stacked in an opposite direction, the blocks of the upper tray resist the flange of the lower tray to prevent the upper tray from being further inserted into the cavity; when the trays are stacked in a same direction, the projections of the upper tray resist the flange of the lower tray to prevent the blocks of the lower tray from being inserted into the cavity of the lower tray. 
     
     
         10 . The group of trays as claimed in  claim 9 , wherein the trays are made of plastic material. 
     
     
         11 . The group of trays as claimed in  claim 10 , wherein the trays is formed by suction molding. 
     
     
         12 . The group of trays as claimed in  claim 9 , wherein the flange of each tray is partially recessed at an inner side to define a plurality of grooves corresponding to the blocks respectively, the grooves communicate to the top surfaces correspondingly, and the projections of the upper tray stop the blocks of the upper tray from inserting into the corresponding grooves of the lower tray when two trays are stacked in a same direction. 
     
     
         13 . The group of trays as claimed in  claim 12 , wherein the blocks of each tray are positioned in different space. 
     
     
         14 . The group of trays as claimed in  claim 13 , wherein the grooves comprise side grooves and corner grooves, and accordingly the blocks comprise side blocks and corner blocks. 
     
     
         15 . The group of trays as claimed in  claim 9 , wherein the projections are tapered and a width of the projection decreases with increasing distance from the top surface of the flange.