Abstract: In an automatic play compensation arrangement for a cable-operated parking brake including a brake operating element and a cable extending between the brake operating element and a vehicle brake for actuating the vehicle brake, a support bracket is mounted for movement with the brake operating element and has a spring-loaded clamping lever supported therein through which a cable end extends and by which the cable end is firmly engaged with the support bracket when the brake operating element is actuated, and a spring is provided for tensioning the cable when the brake operating element is in a brake-releasing rest position.

Abstract: A hearth for use in a furnace, which comprises an upper layer of magnesia containing chromic oxide, a lower layer containing graphite and an organic bonding agent, and an intermediate layer of a mixture of the materials forming the upper and lower layers. The hearth is particularly useful in DC arc funaces, in which steel rods embedded in the bottom act as the anode. The hearth has improved service durability.

Abstract: A heating boiler with a combustion chamber between a front wall, a rear wall and a convection part in each one of the side walls, a flue system composed of parallel flues of substantially circular cross-section arranged vertically in different cross-section planes through the boiler with at least two flues in each side wall in one and the same cross sectional plane, forming upwards or downwards passages for flue gases.

Abstract: A varifocal object selectively focusable upon a normal range of object distances and a substantially shorter macro range can be supplemented by a negative component of one or more lenses whose focal length is less than the depth of the macro range and which forms a virtual image of a nearby object on the object plane of the objective when the latter is adjusted to a predetermined closeup position. A correlating linkage between a seat for the supplemental component and a control member designed to establish the closeup position serves to index the control member in that position or to prevent the emplacement of the supplemental component if the objective is in a different position.