How are collapsible stainless steel cups made?
These cups are shorter in size. They can be expanded like telescope and used it for drinking water or juice. after use, again press it to shorter size.
Each section is a section of a cone. The top dia of each section is slightly more than that of the bottom dia of the section above. The bottom most section has a base. All sections are assembled together first. The bottom section is then welded to the larger dia base. When the topmost section is pulled up, it goes up till the next section catches the bottom dia of the top section. As the pulling continues , one by one all sections come up. Once all are up, a slight pull makes each section to lock with the one above by elastic deformation so that a leak tight joint is got.