June 19, 2017

Automatic Surgineedle Assembly Machine


Machine No. 5212

This is a fully automatic system used to assemble the four parts shown into a Surgineedle. The Surgineedle is one of the tools used by surgeons while doing minimally invasive surgery. The operator loads the Needles into a stepper driven magazine bank that transfers one row of needles at a time into a linear vibratory feeder. The Needles are then picked up and placed into a spring loaded nest on a cam operated rotary index table. The machine uses a cam operated upper tooling plate above the indexing turret to provide the vertical motions for all of the stations. The horizontal pick and place motions are provided by ADAPT standard air driven slides mounted on the upper tool plate.

Once the Needle is loaded and its presence is verified the Stylet is fed from a vibratory feeder bowl into a vibratory inline feeder. The Stylet is picked up and placed into the Needle. The tip of the Stylet extends out from the point of the needle and a photo sensor is used to verify that the Stylet is all the way down into the Needle. At the next station the Spring is fed from a vibratory feeder bowl, escaped and blown down a tube to a staging area. Once in position it is dropped into the Needle when the upper tool plate moves down over the nest. The Spring is probed at the next station to verify that it was loaded successfully.  The Stopcock is fed from a vibratory feeder bowl into a vibratory inline feeder. The Stopcock is loaded by a separate cam operated linear parts placer, driven by the main indexer. This allows the stopcock to be picked up, dipped in a solvent tank and then placed into the Needle. The presence of the Stopcock is then verified and the presence of the solvent is also checked with an ultraviolet sensor that looks for dye in the solvent.

INSPECTION – The system performs two quality control inspections on the finished assembly. First the Stylet is pushed up from below with a load cell to verify that the Stylet is free and checks the spring force. Second the Stopcock is opened and the torque required to open it is monitored with a torque sensor.

CONTROLS – This machine is controlled by an Allen Bradley PLC 5 controller. All machine motions have manual controls and the operator interface is provided by a Compaq 486 PC running ICOM Winview Man Machine Interface software. The operator can manually control the machine and view data stored in the PLC about faults, production quantities, etc. The operator is also advised of fault conditions on the screen as they occur and corrective actions are suggested.

CYCLE RATE – 15 parts per minute.