The first prototype Zippo was created in December of 1932 by George Blaisdell himself using his skills as a metal worker. It was made with square tubing and the lid and bottom were soldered on to create the case shape, a hinge was attached to the outside of the case to enable one handed operation. A hook shaped cam held the lid firmly in place when closed and prevented closure whilst open. A piston style spring enabled the cam to have two resting places open or closed. A windproof chimney not unlike the lighter that so inspired George made it windproof, whilst a strong abrasive flintwheel above a spring loaded flint tube provided reliable ignition.
This is a 1932 replica pictured next to the modern shape we know today.
On the 17th of May 1934 a patent was applied for to protect against his competitors copying the design, The patent grant