To provide a gun barrel arm that almost avoids lifting effect of an arm gun barrel, requires no complex guide groove in a gun cradle pipe and no beam of the arm gun barrel, and is slidably pivoted into the gun cradle pipe.
An elastically deformable first slip bush bearing 5 is disposed on a muzzle side of the arm gun barrel, and a slip bush bearing 6 is disposed on the bottom side with a predetermined engaging looseness. A gun barrel bush 7 surrounded by the first slip bush bearing is supported on the inner wall of the gun cradle pipe 3 via four sector support webs 14 uniformly distributed on the periphery. The gun barrel bush has recessed parts 16 outside the sector shape between adjacent support webs, and recessed parts 19 inside the sector shape on the inner wall 17 opposite to the support webs. Therefore, when the arm gun barrel 2 expands, the gun barrel bush elastically deforms so that a region of the gun barrel bush adjacent to the arm gun barrel bends outwardly into the outside recessed parts, and a region of the arm gun barrel that is not adjacent to the inner wall can displace into the recessed parts inside the gun barrel bush.
BOHNSACK ECKEHARD
KNOERICH FRIEDHELM
Jun Tsuruta
Tetsuro Shimada
Masaya Nishiyama