Patent GB-1351257-A (GB)
Title: Weapons having elements settable in traverse and elevation
IPC: F41G3/14
Filed: 1971-04-19
Abstract: 1351257 Sighting BOFORS AB 19 April 1971 [13 Feb 1970] 21689/71 Heading F3C A weapon 1 has a barrel 2 supported in trunnions 3 and settable in traverse by movement of the trunnions about an axis 7 which is fixed and in elevation by movement about an axis defined by the trunnions 3, sighting means 5 supported by a gimbal frame 5a mounted for movement about a first axis which is parallel to the barrel axis and about a second axis which is at right angles to said first axis, a control member 9 coupled to the gimbal frame 5a by pre-settable mechanical connection means and movable about an axis which is parallel to the axis 7 and at a fixed distance therefrom, mechanical means to move the control member 9 about its axis when the barrel is moved about the axis 7 and by an angle equal and opposite to the angle of movement of the barrel about the axis 7, whereby, for a given fixed position of the axis 7 and with the connection means pre-set to bring the gimbal frame 5a horizontal at one position of the barrel in traverse, the control member 9 maintains the gimbal frame horizontal during subsequent traverse of the barrel notwithstanding possible inclination to the vertical of the axis 7 in said fixed position. The sighting means 5 comprises an eyepiece 10 and an objective 11, has its gimbal frame 5a mounted on a shaft 6 and has a bracket 13 having two arms 8. The connection means may be an end 9a of the control member 9, which has a part spherical surface 17 engaging a recess in a circular member 18. A fastening member (not shown) releasably fastens the end 9a of the control member 9 to the member 18. The control member 9 is moved about its axis by a link arm 19 which is connected to an end 9b of the control member 9 and a link arm 20 which connects the link arm 19 to a lower carriage of the weapon (not shown). In use the member 18 is set in the horizontal position, by means of a spirit level for example, so as to allow for the inclination of the axis 7 relative to the vertical. When the barrel 2 is rotated, the control member 9 is counterrotated by the link arms 19, 20 so that, in effect, the control member 9 remains in position and the sight 5 remains horizontal independent of the traverse of the barrel 2. The eyepiece 11 of the sighting means 5 is actuated by the rotating member 18, via a parallelogram linkage 12, 12a which effects a counter-rotation of the eyepiece. Thus the eyepiece 11 can be retained on a reference point A which is used for setting the angle to traverse of the weapon even when a movement of the barrel causes the sighting means to rotate in its horizontal plane. The bracket 13 is connected to one of the shafts which supports the trunnions 3 and the bracket arms 8 move in relation to the sighting means 5 in dependence of the elevating movement of the barrel 2. The rotational movement of the bracket arms 8 can be used to measure the angle of elevation. An imaginary circle 21, on an upper carriage 4 through which the control member 9 is passed, represents one full turn of the weapon about its axis 7, the circle being formed by means of a perpendicular which is passed through a centre 22 of the end 9a of the control member 9 and of the member 18. A component 23, Fig. 2, shows the angle of traverse and a component 24 shows the inclination in elevation.