Mills bomb rifle grenade by attaching a metallic rod to its base. This rod-type rifle-grenade had an effective range of about 150 yards. The operating procedure was to insert the Mills bomb rod down the barrel of a standard rifle, put a special blank cartridge in the rifle's chamber, place the rifle stock on the ground, then pull the Mills bomb's safety pin, releasing the safety spoon and immediately fire the rifle. If the soldier did not launch the grenade quickly, the grenade's fuse would time out and explode. The British soon developed a simple cradle attached to the rifle's bayonet lug
Term of patent in the United States patents in the U.S., since the patent term now depends on the priority date, not the issue date. Design patents have a shorter term than utility patents. Design patents filed on or after May 13, 2015 have a term of 15 years from issuance. Design patents filed prior to May 13, 2015 have a term of 14 years from issuance. The original patent term under the 1790 Patent Act was decided individually for each patent, but "not exceeding fourteen years". The 1836 Patent Act (5 Stat. 117, 119, 5) provided (in addition to the fourteen-year term) an extension "for the