in a palletizing machine , cases of goods are received from a production line and are arranged into patterned layers . the palletizing machine stacks the patterned layers one on top of another to form a stacked load that can be easily transported by machine . during arrangement of the cases into the patterned layers , some cases may need to be turned to change their orientation relative to their direction of travel . the cases can be turned simultaneously in groups of two , three , or more cases , to minimize the contact of the palletizing machine with the cases during turning . the turning device which bears against the case during turning may also be provided with a component of movement in the direction of case travel so as to effect the speed of the collision when the cases contact the turning device and effect the net speed between the cases and the turning device during turning .