Abstract: An illumination measuring device for panoramic picture taking has a first photoelectric illumination intensity receiver which diffusely determines light falling in a first measuring region and illuminating a first panoramic portion, at least one further photoelectric illumination intensity receiver which diffusely determines light falling in a second measuring region and illuminating a further panoramic portion, and an evaluating unit determining a deviation of an illumination intensity determined by the further illumination intensity receiver from an illumination intensity determined by the first illumination intensity receiver.

Abstract: A panoramic camera has a camera housing having a cylinder segment provided with an image window, an objective drum which is rotatable relative to the cylinder segment about a rotary axis, the cylinder segment having segment flanks located laterally near the image window, the segment flanks being provided with light catching grooves extending parallel to the rotary axis of the objective drum and ending at an angular distance from the outer edges of the cylinder segment, covered by a curvature of the drum.

Abstract: An improved method for manufacturing a spark plug electrode having a substrate formed from a first metal and a spark gap surface area formed from a second metal, such as a precious metal. The spark gap surface area is formed by heating the portion of the first metal at which the spark gap surface is to be formed with a plasma arc and applying the second metal as a consumable welding electrode, cooling the first metal and the applied second metal, and, optionally, shaping the second metal to form a desired surface configuration.

Abstract: A pneumatic switch (25) responsive to the vacuum in a closed crankcase (20) of a reciprocating piston engine (15) for indicating when there is less than a predetermined quantity of oil (21) in the crankcase. The switch includes a housing (30) defining a cylinder (35), a closed end (48) and an open end (74). A piston (36) reciprocates and rotates in the cylinder through a path determined by a cam (51) and a follower (52). Crankcase vacuum is applied to a chamber (47) between the piston and the closed housing end to move the piston against a calibrated spring (50). An electric switch (70, 71 and 76) indicates when the piston is in the portion of its path of motion when the engine is operating and there is less than the predetermined quantity of oil in the crankcase.

Abstract: A method for sensing when the quantity of oil in the crankcase of a reciprocating piston engine is inadequate for proper lubrication while the engine is operating. During engine operation, the crankcase gas pressure cycles between positive and negative values as the piston reciprocates. Positive crankcase gas pressures are vented through a check valve. The resulting cyclic vacuum in the crankcase has a peak and average magnitude which is a function of the quantity of oil in the crankcase. For a constant speed and substantially constant load engine, the crankcase vacuum can be used to indicate the approximate quantity of oil in the crankcase. For constant or variable speed and load engines, a drop in the crankcase vacuum below a predetermined level can be used to automatically stop the engine prior to damage by inadequate lubrication.

Abstract: An arrangement for the automatic critical focusing of optical systems in mirror reflex cameras provided with a partially transmitting reflex mirror, an image field lens arranged in the viewfinder ray path as well as a range-finder image plane, which is equivalent to the film plane. The range-finder image plane, which contains image-forming and deflecting optical components, is arranged in the optical axis of the viewfinder system. By these means a reduction of the expenditure of optical components as well as of the required assembly and adjustment expenditure for automatic critical focusing devices is achieved.