A real conundrum, Joe, as I have searched every patent between 1945/1980 for IT, NL,ES,DE,US FR & US without success! Lory pistures by Stecol appears to be an earlier design, with two halves screwed together, and a safety wire which appears to be retained by staking-slight depression in top face of Stecol's photos. Lory 9 is of much more sophisticated design, with a safety pin, possibly moulded integrally with the pull tab, and a rubber sleeve sealing the pin aperture, and positevely retained by a lug seated in a recess. The outer skirt -Item 19 in SGDBDR's excellent drawings, must be a soft, resilient elastomer to permit stretching for assembly, and would also absorb impact shock when scattered by discharge from helicopter carried containers. Early efforts to seal these plastic mines by ultrasonic welding proved unsatisfactory through humidity ingress, and metal reinforcement led to splitting through differtial thermal expansion. The use of a safety segment was used in a device patented by Technical Arco Est, Lichenstein, but there were no other similarities.
SGDBDR-do you have the text that goes with your annotated drawings. I am wondering if air leaked from the pressure chamber via clearance along the pressure disc shaft. The construction is so novel & compact that I feel that it must have been patented, but the Italian Patent office is so broke that for long periods copies of the patents have not been circulated to other countries.(It was traditional, in earlier days, when it was important to establish priority, to wrap your patent in a brick, and throw it through a window of the Office at night!) Strangely most of the Italian Plastic mines are to designs by unknown companies registered in Lichtenstein, but by Italian inventors-Brind (Invented the MAUS), AEBI-Invented Valsella Mines & Technical Arco Establishment are some. No Lory! Only somebody in Italy would be able to look for a Lory patent, assuming no foreign patents were taken out.
Martin