Altec Engineering builds vision system for inspecting hearing aid components
UK company Altec Engineering has designed and installed a vision system for 100 per cent inspection of components used in hearing aids.
The vision systems were integrated within a machine that sorts rubber grommets before presenting them for sealant application. The line operates at 600 parts per minute.
The process begins with grommets being fed from a vibratory bowl feeder into a track containing 10 separate rows. The grommets then move down the tracks to an escapement where they are released and fed into trays. Each tray contains multiple pockets which should contain a single grommet.
The trays then travel to the first vision inspection station that is used to check that the grommets are in place within the tray and also in the correct orientation, with a slot at the top. This information is stored and subsequently used to control the sealant application.
The sealant station comprises a total of 10 dispensing heads, five on each side of the station. Once the tray containing the grommets has been presented to the sealant applicators, individual applicators only advance to apply sealant if the grommet in that position has previously been deemed as present and in the correct orientation.
A pre-determined quantity of sealant is then applied to each grommet and when this operation is complete the trays then continue to advance through the machine to the second vision inspection station.
This inspection area uses a black light to make a dye within the sealant fluoresce allowing the camera to verify that the sealant has been applied correctly. The trays containing the processed grommets then pass through a heater system before reaching a double venturi system. Here all good parts are removed by one half of the system and any parts identified as reject are removed by the other. Empty trays then continue through the machine and return to the start position.