Abstract: A holding device using a vacuum clamp arrangement has a suction box closed by a suction plate having a holding surface provided with a plurality of suction bores extending from the holding surface into the suction box. Each of the suction bores has an enlarged expanded bore portion inwardly spaced from the holding surface to form a valve chamber which valve chamber is closed by an inner section of the suction bore between the chamber and the suction box and each of the valve chambers loosely receives the shaped valve reed which will close the inner section of the suction bore for each of the suction bore arrangements which is not covered by the sheet placed on the holding surface. This simple structure keeps vacuum losses low and, therefore, enables utilizing a relatively small vacuum pump for the device.

Abstract: A thermic developing station for recording material which is to be developed by means of heat, comprising a rotatable drum and a heating element which is adapted to fit the curvature of the drum surface, the recording material being fed through between the drum and the heating element by the drum and at the entrance of the recording material into the heating zone an unheated member is provided which is also adapted to fit the surface of the drum.

Abstract: In an echo-sounding recorder wherein received echoes are recorded on a common recording surface, starting from a common zero mark, by means of a recording member moving with uniform velocity, the echo-sounding recorder being switchable to different depth-measuring ranges, respective switching members operable independently of one another for setting the recorder to different main measuring ranges and to different offset measuring ranges, and a scale associated with each of the measuring ranges, the improvement therein includes a scale carrier carrying all of the scales in a common plane, the scale carrier being formed of at least two parts respectively displaceable vertically and horizontally relative to one another, a cover plate disposed in front of the scale carrier parallel to the recorder and formed with a row of windows spaced from one another a distance corresponding to the distance between divisions of the respective scales, the scale carrier being mounted for movement relative to the cover plate in t