Project info

Video coming soon.

Rotary dial part feeder brings precision and repeatability to medical device assembly.

Medical device manufacturing requires high precision and repeatability to ensure part consistency from one batch to the next, which is a necessary requirement for medical implantables such as pacemakers, syringes, and orthopedic components. For one such product a leading medical device manufacturer hired me to develop a vibratory feeder for complex asymetrical parts.  Complexity was not allowed to affect production rates.

It was assumed a pick and place robot (2-axis) would move parts from a single lane vibratory feeder rail to a multiple lane plate feeder.  The challenge was taking parts that are back-to-back in a feeder rail and somehow spacing them on 5/8-inch centers, as is the destination’s plate feeder lane spacing.

The result draws upon multiple technologies that I have used previously. A rotary dial was the chosen part spacing solution because the technique rarely fails to transfer parts from one pocket to the next and can be done at high speed. Innovation is the ability to combine ideas in new and novel ways.

How it works: Product flow goes from linear to rotary and back again to linear. Major components include: one vibratory rail (linear); two rotary dials (one to strip parts from the vibratory rail and another to reverse the direction of flow relative to the timing belt straight section); and as mentioned, one custom timing belt configured with a straight section (linear for 36 pockets). Feeding from the second rotary dial to the timing belt is the cornerstone of the design because pockets of the rotary dial on 5/8 inch radial distance must synchronize with the belt pockets also on 5/8 inch linear distance, at the transfer point, a function of drive ratios and dial pocket spacing. The timing belt has a syncronous drive tooth pitches of 20 mm. The belt’s total length must be equally divisible by 20 mm (drive side) and 5/8-inch (part pocket side). Once the timing belt advances 36 parts, all 36 can be picked from the belt by the robot and placed into the plate feeder.