Apparatus and method for temporarily retaining articles midway a transport system

Abstract

An article retention apparatus includes a roller conveyor unit with a plurality of rollers arranged in a horizontal plane and a plurality of ladder-shaped rack units on which articles rest. The roller conveyor unit and rack units are configured such that the rack units may be moved above and below the plane of the conveyor unit rollers without interference between the conveyor unit rollers and the rack units. By lifting the rack units one by one from below the roller plane to emerge above the roller plane, the article is transferred from the roller conveyor unit to the rack unit. The articles are taken aside of a transport system and temporarily retained by the apparatus. A belt conveyor unit can be used instead of the roller conveyor unit.

1 . An article retention apparatus for use in a transport system, comprising 
 a conveyor unit including a conveying surface for supporting and conveying an article horizontally,    a plurality of rack units each having support means on which the article rests horizontally,    suspension means for suspending the plurality of rack units in a vertically spaced apart relationship while keeping the rack units horizontal, and    drive means for moving up and down the suspension means,    wherein said conveyor unit and said plurality of rack units are configured such that the rack units may be moved above and below the conveying surface of said conveyor unit without interference between the conveying surface of said conveyor unit and the support means of said rack units.    
     
     
         2 . The article retention apparatus of  claim 1  wherein said suspension means includes generally flexible strips and said plurality of rack units are attached to the strips at predetermined intervals.  
     
     
         3 . The article retention apparatus of  claim 1  wherein said conveyor unit comprises a roller conveyor unit having a plurality of rollers arranged in a horizontal plane, the rollers at their top defining the conveying surface.  
     
     
         4 . The article retention apparatus of  claim 1  wherein said conveyor unit comprises at least one belt conveyor unit having an endless belt, the belt presenting a horizontal upper surface defining the conveying surface.  
     
     
         5 . A method for retaining articles midway a transport system using the article retention apparatus of  claim 1 , 
 placing said plurality of rack units on standby in a stack at a position below the conveying surface of the conveyor unit,    feeding an article from the transport system to the conveyor unit so that the article rests on the conveying surface,    lifting upward the suspension means for moving upward the rack unit of the uppermost stage to emerge above the conveying surface, thereby transferring the article from the conveying surface to the support means of the rack unit,    sequentially lifting upward the suspension means each time when a new article is fed and rested on the conveying surface, for moving upward the rack unit of the next lower stage to emerge above the conveying surface, thereby transferring the article from the conveying surface of the conveyor unit to the support means of the rack unit,    permitting the respective rack units to retain the articles at spaced apart positions above the conveying surface,    thereafter, sequentially moving downward the suspension means until each of the rack units descends below the conveying surface of the conveyor unit, thereby transferring the article from the support means of the rack unit back to the conveying surface, and    discharging the article from the conveyor unit to the transport system.