Sod harvesters are configured to stack rolls of sod in layers on a rectangular pallet. A sod harvester can include control circuitry that is configured to operate a stacking head and a stacking conveyor in a manner that produces a first type of layer that includes spaced groups of accumulated rolls and a number of offset rolls positioned between the groups. The stacking head can pick up and stack each offset roll in isolation and may pick up the offset rolls in a center position of the stacking head.

A method of stacking sod rolls can include: (a) moving a head of a sod handling apparatus to a sod pick-up location containing a plurality of sod rolls; (b) picking up a first sod roll with a first sod carrier, picking up a second sod roll with a second sod carrier, and picking up a third sod roll with a third sod carrier; (c) moving the head to a sod drop-off location; (d) depositing the first sod roll from the first sod carrier at the sod drop-off location; (e) after depositing the first sod roll, moving the second sod carrier and the third sod carrier toward the first sod carrier to reduce the spacing between the second and third sod rolls; and (f) depositing the second and third sod rolls at the drop-off location.

A method of stacking sod rolls can include: (a) moving a head of a sod handling apparatus to a sod pick-up location containing a plurality of sod rolls; (b) picking up a first sod roll with a first sod carrier, picking up a second sod roll with a second sod carrier, and picking up a third sod roll with a third sod carrier; (c) moving the head to a sod drop-off location; (d) depositing the first sod roll from the first sod carrier at the sod drop-off location; (e) after depositing the first sod roll, moving the second sod carrier and the third sod carrier toward the first sod carrier to reduce the spacing between the second and third sod rolls; and (f) depositing the second and third sod rolls at the drop-off location.

A stacking head for stacking rolls of sod can include a number of screw assemblies that are employed to secure and remove sod rolls from a stacking conveyor. Each screw assembly can include a center stake and a corkscrew that pierce a roll as the stacking head is forced into the roll. The rate at which the stacking head is moved vertically relative to the roll can be synchronized with the rate at which each screw assembly is rotated. This synchronization ensures that the corkscrew will pass into the roll while the stacking head is simultaneously forced into the roll without damaging the delicate sod.

A stacking head for stacking rolls of sod can include a number of screw assemblies that are employed to secure and remove sod rolls from a stacking conveyor. Each screw assembly can include a center stake and a corkscrew that pierce a roll as the stacking head is forced into the roll. The rate at which the stacking head is moved vertically relative to the roll can be synchronized with the rate at which each screw assembly is rotated. This synchronization ensures that the corkscrew will pass into the roll while the stacking head is simultaneously forced into the roll without damaging the delicate sod.

A roll forming mechanism can include a passive roll-up mechanism that initiates the roll and an active roll-up mechanism that completes the roll. The active roll-up mechanism can include an upper conveyor that is rotated in different directions. The upper conveyor can initially be rotated in a direction opposite that of an inclined conveyor to cause a forming roll to advance along the inclined conveyor. The rotation of the upper conveyor can then be reversed to cause the roll to be completed. Then, the upper conveyor can again be rotated in the direction opposite that of the inclined conveyor to cause the completed roll to be transferred towards the stacking conveyor. The amount by which the upper conveyor is rotated in the reverse direction can be based on a detected length of a tail of the forming roll.

A sod harvester stacking head can include a base that couples to a stacking head supporting mechanism of a sod harvester and a frame that couples to the base via crankshaft assemblies that are configured to allow the frame to rotate through 360 degrees during each stacking operation. Accordingly, a motor that controls the rotation of the crankshaft assemblies can be driven a single time during each stacking operation thereby enhancing the efficiency of the sod harvester. The crankshaft assemblies can also be configured so that the crankshafts are in a vertical orientation while the stacking head travels in a lateral direction such that the load is centered on the rotational axis of the stacking head. A stacking conveyor could similarly be configured with a base and a frame that are coupled via crankshaft assemblies to thereby allow the stacking conveyor to be lifted using 360 degrees of rotation.

A sod harvester stacking head can include a base that couples to a stacking head supporting mechanism of a sod harvester and a frame that couples to the base via crankshaft assemblies that are configured to allow the frame to rotate through 360 degrees during each stacking operation. Accordingly, a motor that controls the rotation of the crankshaft assemblies can be driven a single time during each stacking operation thereby enhancing the efficiency of the sod harvester. The crankshaft assemblies can also be configured so that the crankshafts are in a vertical orientation while the stacking head travels in a lateral direction such that the load is centered on the rotational axis of the stacking head. A stacking conveyor could similarly be configured with a base and a frame that are coupled via crankshaft assemblies to thereby allow the stacking conveyor to be lifted using 360 degrees of rotation.

A method of stacking sod rolls can include the steps of: a) moving a head of a sod handling apparatus into a sod pickup location containing a plurality of sod rolls; b) picking-up a first sod roll with a first sod carrier, picking-up a second sod roll with a second sod carrier, and picking-up a third sod roll with a third sod carrier; c) moving the head to a sod drop-off location; d) releasing the first sod roll from the first sod carrier at the sod drop-off location; e) after releasing the first sod roll, moving the second sod carrier toward the first sod carrier and moving the third sod carrier toward the first sod carrier to reduce the spacing between the second and third rolls of sod; and f) depositing the second sod roll and third sod roll at the drop-off location.

A method of stacking sod rolls can include the steps of: a) moving a head of a sod handling apparatus into a sod pickup location containing a plurality of sod rolls; b) picking-up a first sod roll with a first sod carrier, picking-up a second sod roll with a second sod carrier, and picking-up a third sod roll with a third sod carrier; c) moving the head to a sod drop-off location; d) releasing the first sod roll from the first sod carrier at the sod drop-off location; e) after releasing the first sod roll, moving the second sod carrier toward the first sod carrier and moving the third sod carrier toward the first sod carrier to reduce the spacing between the second and third rolls of sod; and f) depositing the second sod roll and third sod roll at the drop-off location.