GB1097585A - Improvements in or relating to television cameras - Google Patents

Abstract

1,097,585. Viewing inside of pipes. PYE Ltd. Oct. 20, 1964 [Oct. 30, 1963], No. 42737/63. Heading H4F. A television camera arrangement for viewing the inside of a pipe through which it is moved comprises an electron tube for converting visual images into electrical impulses, and a lens assembly adapted to focus visual images on the tube, the lens assembly being pivotally-connected with the tube so that the central plane of the lens assembly may be maintained substantially normal to the wall of the pipe even at relatively sharp bends in the pipe so that the whole of the inside wall of the pipe may be viewed (explained with reference to Fig. 1, not shown). As shown, a complete inspection assembly for pipe interiors comprises a light source 20 and three pivotally connected sections, i.e. a camera tube 9, lens or lenses 10 and a head amplifier 11. Sections 10 and 11 are linked to the main body of the camera 9 by means of gimbal joints 12 and 13, one pivotal axis of gimbal joint 12 lying in the plane of the pick-up tube face in order to ensure that the distance between lens centre and tube face along the optical axis of the lens remains constant. The light source 20 is attached to the camera by means of a spring steel wire hitch 16 which passes through diametrically opposed lugs 18 on a rotatable washer 19 and is secured by screws 17 to body 9, the wire hitch having two helical portions as shown so that if any binding takes place at the front of the camera the helices unwind, washer 19 rotates and the towing force is applied directly about the centre of body 9 reducing the pivotal length to a minimum and inclining the lens assembly 10 towards the inner wall of the bend. Two conical members arranged base-to-base having reflecting surfaces 22 and 23 are supported by wires 24 which form a protective cage around bulb 21. Reflecting surface 22 reflects light on to the wall of the pipe and prevents light falling directly upon the lens assembly and reflecting surface 23 enables the camera to view perpendicularly a section of the interior wall. The complete assembly is towed through the pipe by means of cable 26 which carries a low voltage supply to the bulb. Cable 15 carries the power to energize the pick-up tube and head amplifier, camera control signals and the video signals from the output of the head amplifier.