Machine No. 5217
This machine is used to assemble Baseplates for backup tape cassettes. These include the tapes that are typically used in PC tape backup drives from Colorado and Conner (DC 2120, 3 1/2″) as well as 5 1/4″ tapes used for larger backups. The Baseplates are loaded in a rotary magazine offloader in stacks approximately 18″ high. The stack of Baseplates in the magazine that is currently being unloaded is elevated by a motor driven screw so that the top part in the stack can be picked up and placed onto a conveyor that transports it into the machine. When the current magazine becomes empty the elevator goes down and a new magazine is automatically moved into position. The Baseplates are picked up off of the conveyor, using suction cups, and placed on the first nest by a cam operated walking beam.
The Baseplates are progressed through the machine by the walking beam which is cam driven in the horizontal axis and an air cylinder driven pivot stroke that raises and lowers all of the arms on the walking beam. Each station on the machine is the same in concept and major components, with changes in tooling and air cylinder size to suit the pin being installed in the Baseplate. Each station is fed by a vibratory feeder bowl that discharges pins into a tube that lead down to a cross shuttle escapement. The tube is full of pins from the bowl down to the cross shuttle, but the bushing where the tube enters the cross shuttle can be removed without tools to clear out bad pins and debris and has a thumb screw that will stop all of the pins from falling out when the bushing is removed. The cross shuttle is constructed from a precision THK ball spline and can line the Pin-up under the press tooling for transfer within 0.001″. The Pin is shuttled under the press tooling and is pushed up into the tooling mechanically by an air cylinder and is retained by vacuum. Once the shuttle retracts, the pin is rammed into the plate and seated perpendicular to the plate within 0.25 degrees. The presence of each Pin is verified after insertion with photo sensors and plates with missing pins are automatically ejected at the end of the machine. Complete assemblies are discharged onto an air cushion conveyor to travel to the next manufacturing process.
MACHINE CONTROL – This machine is controlled by a Mitsubishi A2S PLC using remote I/O modules located along the machine, 1 for each pair of stations. The operator interface is provided by a Cincinnati Touch Screen panel and all machine functions can be manually controlled. The screen also displays a real-time view of the status of all of the Baseplates in the machine. It can also display production and fault data for each status well as the whole process.
CYCLE RATE – This machine can produce 20 completed Baseplate/Pin assemblies per minute.