Abstract: Disclosed are a filter cake scraping method which can scrape a filter cake layer deposited on the surface of a filter drum with a scrape blade even if the particles of the cake are fine, and a rotary drum filter using this method. When pressure inside a suspension vessel rises above a predetermined value, a control means quickly reduces the pressure. Accordingly, precoated material or the like, which has been deposited on the filter drum, expands to push a layer of filter cake outward, thus permitting a scrape blade provided beside the filter drum to scrape the expanded cake layer.

Abstract: A lumbar support device for an automotive seat, in which a support arm, on which a lumbar support plate is rockably supported, is retained in a base bracket against movement by way of a biasing member and limiting element, under an unloaded condition. Therefore, the lumbar support plate does not give a pressure to the lumbar part of an occupant on the seat.

Abstract: A lumbar support device for a vehicle seat, in which a lumbar support force is adjusted in a fine, stepless way at a desired degree. Springs are disposed between a slider and a arm having a lumbar support plate so as to give a force to the lumbar support plate. The slider is threadedly engaged with a drive shaft in a manner being movable thereon by operation of a handle fixed to the drive shaft.

Abstract: An apparatus for measuring the content of hydrogen dissolved in a molten metal, comprising an immersion head immersed within a batch of the molten metal to bring an inert gas into contact with the molten metal, an inert gas circulating device connected to the immersion head and having gas passages cooperating with the immersion head to form a closed circulatory path for circulating the inert gas a plurality of times through the path to and from the immersion head. The apparatus further comprises a hydrogen gas content measuring device connected to the gas passage for measuring the hydrogen-content of the inert gas flowing through the gas passage, the measuring device comprising a first measuring cell connected to the gas passage and having therein an electric resistance wire exposed to the circulated inert gas containing the hydrogen picked up from the molten metal, and further comprising a second measuring cell filled with atmosphere whose thermal conductivity is substantially equal to that of the inert gas.