Methods and devices are provided for performing minimally invasive surgical procedures. Both the walls of the closure cap and the walls at the mouth of the plastic envelope are crimped down together, thereby forming a substantially impermeable seal at the launching end of the cartridge. The other end of the shaft is secured on the locking element. Secondary combustion air is provided through the other of the passages which on a high setting enables secondary combustion and on a low setting may mix with the hot gases and cool them resulting in a lower temperature at the cooking vessel. Both of these movements will be recoverable and provide a \u2018functional crumple zone\u2019.