Machine for stacking cup-shaped containers

A machine for stacking cup-shaped containers (25), comprising:

• an oscillating chute (2) and a conveyor (3) feeding the containers in an upright position to a height-adjustable conveyor belt (12), a plurality of photosensors (27) to detect, in connection with a programmable control unit, the orientation of a container on the conveyor belt (12), a stop (18) to halt a container under a stack holder (31) which at its downwards facing end has releasable grippers (35), a vertically displaceable stack disc (20) for lifting said container to the stack holder, and means (39) for returning an incorrectly oriented container to the oscillating chute,
• wherein the stack holder (31), the stop (18) and the stack disc (20) are positioned relative to a point on the height-adjustable conveyor belt (12) at which the orientation of the container (15) is detected by said photosensors (27) immediately prior to stacking,
• said stop (18) being activated to move between a passive position allowing movement of the container (25) past the stop
• and an active position preventing said movement and stopping the container (25) in response to detection by said photosensors (27) that the container 25 is correctly oriented on the conveyor belt (12).