| 摘要 |
<p>1,071,482. Television cameras. RANK PRECISION INDUSTRIES Ltd., [trading as RANK ORGANISATION RANK TAYLOR HOBSON DIVISION]. March 20, 1964 [March 28, 1963], No. 12342/63. Heading H4F. [Also in Division G2] A cine or television camera A with a zoom lens B is mounted on a pan and tilt head A, and has a handle C extending rearwardly with a hollow hand-grip D rotatable about its axis, a ring G being rotatable with respect to the grip to control the movable parts B 2 of the zoom lens. Grip D rotates in bearing D 3 in bracket D 4 detachably fixed to the handle C through a short bracket E by means of a clamping chain E 2 . Ring G is spring-urged to a zero position and controls the setting of the tapping J 3 on a potentiometer J which provides a current whose magnitude and direction decides the direction and speed of an electric reversible motor K which moves elements B 2 of the zoom lens through ring B 4' The potentiometer output is fed to an amplifier L with the opposing voltage output of a tacho-generator K 1 mounted on a common shaft K 2 with motor K, and the amplified difference drives motor K, the system thereby constituting a speed-controlling servodevice which quickly brings the motor to rest when contact J 3 is returned to zero by ring G. The potentiometer may or may not be carried in the hand-grip. The spring return means for ring G comprises two springs acting in opposite directions keyed between a barrel H 4 and two sleeves, H 2 and H 3 respectively, which surround and are keyed to spindles H and H 1 , Stops limit the rotation of ring G which is keyed to spindle H 1 , while grip D is keyed to spindle H.</p> |
