Abstract: A calendar for the production of packing sheets has a heated cylinder of large diameter on which a packing sheet is progressively built-up of layers of rubber-fiber mixture during many revolutions and the cylinder and an unheated counter pressure cylinder of smaller diameter mounted in slidable bearings for rotation and for movement toward and away from the heated cylinder. As the packing sheet is progressively built-up on the heated cylinder, its thickness is continuously measured by feeler rollers pressed lightly against the surface of the packing sheet and associated inductive sensors. In a comparison circuit, the values of thickness-indicating signals received from the sensors are compared with the sum of an initial zero value recorded before rubber-fiber mixture is applied to the circumference of the heated cylinder, and a predetermined desired value. When the value of the thickness indicating signal equals the sum of the zero value and the desired value, the calender is stopped.

Abstract: A packing sheet calender comprises a cooled cylinder of small diameter and a heated cylinder of large diameter. The heated cylinder comprises a cylindrical casing and end walls with integral stub shafts projecting centrally from the end walls. At least one of the stub shafts is hollow. Circumferentially spaced axially extending bores are provided in the casing for the flow of hot water which is supplied by a tube system extending axially of the cylinder and comprising an inner tube and an outer tube surrounding the inner tube. Radial bores in one end wall connect the axially extending bores in the casing with the outer tube. Radial bores in the other end wall connect the axially extending bores in the casing with an annular chamber which is connected with the inner tube. The inner and outer tubes are connected through the hollow stub shaft with a device for supplying hot water to one of the tubes and withdrawing water from the other.

Abstract: A calender, in particular for the production of packing sheets, comprises a heated cylinder of larger diameter and a cooled cylinder of smaller diameter. The larger diameter cylinder is rotatably supported in calender stands by bearings which are in fixed position on the stands. The smaller diameter cylinder is rotatably supported by bearings which are slidable in the calender stands so that the smaller diameter cylinder is movable toward and away from the larger diameter cylinder. The bearings of the smaller diameter cylinders are connected with a support beam which is slidable on the calender stands and is movable toward and away from the larger diameter cylinder by double-acting cylinder and piston units acting between the support beam and the stands. Counter-bending mechanism for the smaller diameter cylinder comprises double-acting hydraulic cylinder and piston units acting between the support beam and bearings on outer ends of projecting shaft position of the smaller diameter cylinder.