- Customer operation assembles multiple types of laser printers on eight (8) separate assembly lines that need to sorted, bagged, and packaged for shipment to distribution center warehouses.
- Printers are transported through the assembly process on Bosch conveyors and pallets.
- Customer wanted completed printers transferred from the Bosch pallet to a less expensive pallet, transported to an overhead pack-off conveyor, and ultimately sorted into one of four lanes prior to the bagger.
- Empty transport pallets need to be returned to the end of the assembly line where printers are transferred off the Bosch pallet.
- Products weigh a maximum of 25 pounds and are transported to packaging on pallets measuring 17" wide x 22" long.
- The main overhead pack-off conveyor must handle 22 parts per minute operating at 60 feet per minute and each vertical conveyor must handle 4 parts per minute (2 full pallets/2 empty pallets).
- Provision needs to made for recycling full pallets to the four-lane sorting point and for the introduction of other products just prior to sortation.
- Empty transport pallets must be returned to the end of the assembly line.
- The conveyors must be quiet and safe with an aesthetically appealing appearance.
- Customer is responsible for moving the assembled printer from the Bosch pallet to the less expensive transport pallet.
- Shuttleworth is then responsible for moving the printer to a Slip-Torque overhead pack-off line, creating a recycle conveyor, and then physically dividing pallets after the recycle conveyor to one of four lanes.
- Harnischfeger is responsible for the bar code scanning and upper level software that determines which of the four lanes the full pallet is sent to and for the actual packaging operation.
- Hewlett-Packard is responsible for determining which pallets get recycled to or new products introduced to the Shuttleworth recycle conveyor.
- Shuttleworth is responsible for returning the empty transport pallet to the end of the assembly line.
- Shuttleworth engineers designed this system as a two-tier overhead system beginning at the end of the assembly lines. The upper tier is the pack-off line bringing full pallets to the packaging operation while the lower tier is an empty pallet return line. The two tiers become side-by- side conveyors in the sorting area.
- H-P operators manually lift each assembled printer from the Bosch pallet to the transport pallet which then is fed into one lane of a Shuttleworth vertical conveyor with a two-lane conveyor bed.
- The vertical conveyor lifts the full pallet to the top tier pack-off line and discharges it onto a Slip-Torque spur. The vertical conveyor then lowers itself to the empty pallet tier and takes on an empty pallet before dropping to the assembly line level, discharging the empty pallet, and starting the cycle over again.
- There is one vertical conveyor for each of eight printer assembly lines.
- Back on the top tier spur, the full pallet travels to a lift-and-rotate (LAR) device to be rotated 90( so it will travel the "easy way" (lengthwise) on the main pack-off line. A lift-and-transfer (LAT) device feeds the pallet onto to the main Slip-Torque pack-off line.
- Because of the product flow rates required, the main pack-off conveyor actually becomes a two-lane conveyor with four vertical conveyors feeding each bed or lane.
- As the full pallets approach the sorting area, they are combined into one lane before being routed onto the Slip-Torque recycle conveyor for bar code scanning by Harnischfeger equipment. Based on this scan, the pallet is sorted into one of four lanes and moved onto the shipping room transport equipment (Interlake).
- Shuttleworth has a return spur that enables the shipping room transport equipment to (1) return a full pallet or introduce new products to the Shuttleworth recycle conveyor for sorting, or (2) bring the empty pallet to the return line.
- With eight assembly lines, this is an area full of HP operators and noise was a critical issue. Appearance was important because Hewlett-Packard prides itself on a "campus-like", worker-friendly environment. Other line- shaft type conveyors are very noisy while the Slip-Torque system is very quiet.
- HP maintenance personnel had input into the decision and were very impressed with the ease of maintenance for Slip-Torque systems compared to alternative systems..
- HP management thought the Slip-Torque system would be easier to expand in the future than alternative conveyor systems.
- The Shuttleworth system was very competitively priced in relation to a monorail system that HP also considered.