| 摘要 |
807,555. Supports for photographic cameras. VINTEN Ltd., W., and VINTEN, W. P. Nov. 28, 1956 [Dec. 14, 1955], No. 35882/55. Class 97(1) In a tilting mounting especially for a camera, a supporting plate is pivoted on a vertically movable guide and, the guide is constrained by a cam to move by an amount such that the centre of gravity of a camera mounted on the plate can move, on tilting the plate, only in a horizontal plane. As shown in Fig. 1, camera supporting plate 21 is carried on a pair of bars 18 guided for vertical movement by ball bearings 16 mounted between a frame 10 and external plates 15. Frame 10 is rotatable about a vertical axis. On tilting plate 21, the co-operation of the edges of a pair of cam plates 22 with fixed rollers 23 constrains bar 18 to move vertically upwards so that the centre of gravity of a camera for which the apparatus is, designed remains in a fixed horizontal plane. In another form, Fig. 3, the cam plates 30 are fixed and co-operate with rollers 37 carried on bell crank levers 31 pivoted at 32 to bars 18. Pivoted links 34 rotate levers 31 about pivots 32 as plate 21 is tilted. Bars 18 are thus constrained to move vertically upwards as before Levers 31 may be pivoted in either of holes 38 in bar 18 and connected to link 34 by either of holes 39 to adjust the apparatus for cameras having centres of gravity at different heights above plate 21. According to the Provisional Specification, the rollers which co-operate with the cam plates may alternatively be fixed to the supporting plate. Adjustable resistance to movement or locking of plate 21 in a given position may be effected by making pivot 33 screw threaded and providing a wing nut and friction washers. Similarly, in Fig. 1, the rotation of rollers 23 driven by the cam plate may be controlled by braking means and a separate locking plate provided. |
