Mechanical Automatic Rebar Tying Tool

Modern buildings typically use reinforced concrete for construction.

This reinforcement consists in layers of inter-crossed steel bars, tied together with steel wire.

These ties are usually made manually by the construction workers, who need to bend over every time.

As a result of that a lot of workers end up with back pain and become unable to work on these tasks.

The goal was to create an automated solution that would allow the workers to tie the wire without bending their back.

The task was:

• Establish a concept that allows to unwind, tighten and cut the wire in as few steps as possible

• Design a prototype using as much lightweight, yet standard components

• Make it all mechanical; no electrical motors/battery/electronics

Unique solution:

Ergonomics was one of the most important constraints on this product; it needed to be easier to use, more effective and less harmful than the manual method, all at the same time.

So we tried to combine the functions as much as possible; here we had the unwinding, clamping and cutting all on the pedal, and the tying on the wheel.

Smartphone Clamping Ring

The idea with this product was to offer an alternative to the very famous iRing phone ring with more features, making it more useful for video/photo application

The task was:

• Make a split-able, clamp-able ring system

• Keep it all as compact as possible

• Feature a disengage-able nut to switch between a spring loaded and screwed clamping mode

Unique solution:

The disengageable nut was probably the most delicate part of this concept; using an oblong hole, threaded on one side to allow the screw to decouple from the thread when offset on the unthreaded, oversized side.

Epicyclic Valve Rectifier

This project was a part of my product design study assignment and was completed for Eagle France, now EKK, on their truck AC valve product.

The issue concerned an abnormal defect rate on the rectifying process. The valves were plastic injected then rectified by hand, with an operator manually loading the parts onto a plate and sanding it on a sheet of sandpaper.

The defect rate was over 20% and something needed to be done about that.

The task was:

• Create a more repeatable, semi-automated solution

• Reproduce the manual sanding motion

• Keep at least the same cycle time and capacity

Unique solution:

After extensive product analysis and research we chose to go for an epicyclic carrier, offering the most regular sanding action, guaranteeing the best results.

2 support plates drilled with holes to hold the valves radially would then be pressured against the sanding surface with spring loaded pressure plates. The spring load was calculated to reproduce the manual pressure.

The gearing ratio was also calculated based on the manual action, from the individual valve translation speed to the electric motor, passing by the main and planetary axles rotational speed.

On the manufacturing side, the gears, nuts and bearings were chosen from standard catalogs.