Abstract: A protective cap (11) for a bolt guide of a spot-type disc brake, comprises an elastic (pleated) bellows, one end portion of which is fastened to the periphery of a first cylindrical part, while the other end portion thereof is secured to the periphery of a second cylindrical part. A rigid reinforcing and retaining member (15, 16) is provided on each one of said end portions (12, 13) with both reinforcing and retaining members being arranged with at least part of their radial extension on the same radius. To avoid damage to the cylindrical part and the guide surface thereof, at least one (16) of the reinforcing and retaining members is secured radially outwards at the corresponding end portion of the elastic bellows. Thus, an axially extending annular surface is formed which is free from the material of the elastic bellows and wherein the reinforcing and retaining members (16) together with this annular surface is arranged in press fit in a corresponding bore (20) of the associated cylindrical part.

Abstract: The invention relates to a method and apparatus for the heat treatment of fine-grained material wherein a precalcination zone formed by the kiln exhaust gas duct of a rotary kiln and into which two branch streams of cooling air which have been subjected to opposing rotational flow are introduced. In this way an equalization of the speed profile over the cross-section of the kiln exhaust gas duct and an improvement in the burning up of the fuel is achieved.

Abstract: A sealing cap for mating to cylindrical parts such as the bolt guide of a spot-type disk brake. The cap includes a resilient boot one end portion of which is adapted to be secured circumferentially to a first cylindrical part and the other end portion of which is adapted to be secured circumferentially to a second cylindrical part. At least one of said end portion comprises a rigid insert member. In order that the sealing cap may be easily mounted and secured with no adverse effects, the other end portion may comprise a rigid insert member. Both insert memebers have at least a part of the radial extension thereof are disposed the same radial distance from the axis of the cylindrical parts.

Abstract: A process for producing cement wherein preheated, partially calcined powder-form raw material is finally calcined in a fluidized bed and is discharged to a cooler through which a cooling stream of air passes. A part of the cooling air passes into the fluidized bed from below and another part of the cooling air, together with the partially calcined material, passes into the fluidized bed from the side. The rates of material flow to and from the fluidized bed is regulated to maintain a substantially uniform intersticial ratio between the upper and lower regions of the fluidized bed.