Patent ID: 7493845

Claim:
A recoil mechanism for a gun having a frame with a barrel and a slide that is movable rearwardly of the frame and barrel, when the gun is fired, the mechanism comprising: a cylinder having a rear end with an external flange and an internal diaphragm spaced forwardly of the flange and disposed between a rear chamber and a front chamber both defined in the cylinder; a nut; an axle extending in the cylinder, the axle having a rear end fixed to the nut and a collar spaced forwardly of the rear end and being forward of the diaphragm and trapped in the front chamber by the diaphragm; a first spring around the cylinder, the first spring having a front end abutting the slide and a rear end abutting the flange; a second spring extending at least partly in the rear chamber and having a rear end abutting the nut and a front end abutting the diaphragm; and a third spring in the front chamber, the third spring being shorter in length than the front chamber; the front chamber having a front entry end and a set screw closing the front entry end of the front chamber; wherein upon firing of the gun, a force of gases in the barrel acting on the slide to move the slide in the rearward recoil direction, rises to a point that the slide starts to move in the rearward recoil direction, and, after a time lag, the slide engages the cylinder causing the cylinder to also move in the rearward recoil direction; the time lag being selected to allow a maximum expansion of gases from the barrel for propelling a bullet from the barrel while the slide recoils, so that the bullet has improved range; the third spring functioning in the front chamber to become compressed later during the recoil of the slide to absorb a remainder of recoil energy of the slide, for decelerating any further recoil of the slide, with most recoil energy of the slide being absorbed by a progressive compression of the first spring and the second spring.