| 摘要 |
1,085,300. Radar. BOFORS A.B. Dec. 18, 1964 [Dec. 20, 1963], No. 51694/64. Heading H4D. [Also in Division F3] A control lever is mounted for pivotal movement from a neutral position through a solid of revolution thereabout and return spring means acts on the lever in any position of tilt thereof to urge the lever continuously toward the neutral position, the return spring means including a first member having a surface bounded by a plane circular rim, a second member having a plane seating surface for the first member, one of the members being connected to the lever for participation in pivotal movements thereof and the other member being mounted in a stationary member, and a coil spring axially and symmetrically disposed relative to the circular rim by the first member acts on one of the members in a direction normal to the plane seating surface when the lever is in its neutral position to urge the two members into a stable position relative to each other in which position the circular rim abuts along substantially its entire periphery against the plane seating surface while permitting an angular rocking movement of the first member with respect to the seating surface about any peripheral point of the rim. The lever may be utilized in the control in azimuth and elevation of a guided missile, a radar aerial, or a gun; or the position of a marker across the screen of a radar P.P.I. In one embodiment, Fig. 2, the control lever 1, shown deflected from neutral, is pivoted about a shaft 2 journalled in a gimbal 3 itself pivoted about a shaft 4 journalled in a casing 5, the lever thereby having one degree of freedom about shaft 2 and another about shaft 4. The latter rotation is followed via a gear 9, 10 by a potentiometer, and the former via gear 12, 13 by a second signal generator. Lever extension 16 terminates in a ball 17 in a socket 18 at the upper end of a rod 19 mounting a disc 20 abutting against the base 21 of a recess 22 (see also Fig. 3, not shown). A spring 23 maintains disc 20 in contact with base 21. In a modification the dimensions of the device in the longitudinal direction of the lever are reduced, Fig. 4 (not shown), a disc (27) is attached to the upper end of a rod (30) the lower end of which mounts a ball (31) displaceable in a bore (32) in the bottom of the casing of the device. In a further embodiment, Fig. 5 (not shown), further reduction of dimensions is achieved; the control lever (1) is not mounted in a gimbal but its lower end is provided with a hemi-spherical member (33) in a socket (35) the plane surface (34) of which abuts a spring-loaded disc (36). Two signal generators are controlled by semicircular yokes (39, 40) provided with slots (43, 44) through the intersection of which the control lever passes. |
