A profiled roller for pressing sheet material evenly against a roller that applies a film of liquid to the material, without collecting or forming a meniscus of the liquid in the absence of material to be moistened, comprises on a core a sleeve composed of many contiguous identical rings each provided with a peripheral series of protuberances that recur n times circumferentially thereof with each ring turned circumferentially relative to a contiguous ring at an angle thereto of less than 360.degree./n. The tops of the protuberances, each having a surface area of less than 0.5 mm.sup.2, define a cylindrical roller outline and are spaced apart by a distance of 1.5 to 4 mm, providing between them open spaces that will not retain the liquid by capillary action. The opposite sides of each ring are formed with complementary profiles disposed circumferentially apart at the said angle so that the rings may be readily assembled in the required angular disposition on the core.
A pressure roller for applying pressure to a sheet-like material passing between the pressure roller and an application roller for applying a layer of liquid to the material, as in the development of diazotype copies, comprises a plurality of relatively short constituent rollers connected to one another by connecting means which permit radial displacement of the adjacent constituent rollers relative to each other and wherein each constituent roller is urged toward the application roller by at least one resilient spring-like element. The pressure roller thus enables contact between it and the application roller with an even pressure, without significant sagging along its length, while allowing uneven areas of the sheet-like material to pass therebetween without affecting the force exerted over the entire nip between the rollers. Improved development of diazotype copies can thus be obtained.
The apparatus comprises a metering roller (7) for the metered supply of liquid developer to an applicator roller (10). A profiled roller (11) is provided for pressing the photosensitive stock against the applicator roller. The profiled roller has a cylindrical core (12). The outer surface of the core is completely covered with a coating (13) of a permanently elastic material. The surface of the coating remote from the core is provided with projecting, mutually staggered, substantially conical or pyramidal nubs (14). The nubs are made of the same permanently elastic material as the coating. A pressing roller (17) rests against the profiled roller and, in the direction of travel designated from I to O of the stock to be developed, precedes the point of contact of the profiled roller against the applicator roller. Stock inserted at I is grasped at the point of contact (19) between the pressing roller and the profiled roller and conveyed on. Because of the soft nubs and the relatively light bearing pressure of the pressing roller, the stock to be developed can be shifted or straightened before it comes in contact with the liquid developer. Adjacent nubs have the tendency to spread apart in the region of the points of contact with either the pressing roller or the applicator roller. An additional tightening of the stock to be developed is thereby produced between these nubs. Especially at the applicator roller, this leads to extremely uniform application of the liquid.
A roller press for surface impregnating leather and similar materials, includes a load-bearing structure (2) which supports an upper impregnating roller (8), a lower drive roller (9), and a pair of conveyor belts (5 and 6) placed one above the other which turn in the same direction and partly touch each other so as to forward feed the leather (P) to be impregnated. The rollers are approximately parallel to each other and spaced apart so as to create a converging/diverging channel (10) between them, having the minimum section (11) approximately equal in height to the thickness of the leather being worked. There is a pressing member (20) arranged immediately upstream of the minimum section (11) which acts flexibly and uniformly over the entire width of the leather so as to keep it in stable contact with the lower drive roller (9) and preventing it from rolling up.
A roll for hot dipping bath includes at its outer peripheral surface at least one spiral groove for the discharge of dross. In this roll, the outer peripheral surface existing between the adjoining groove portions includes a rough surface, capable of applying a molten metal composition to a sheet of metal without transferring a groove mark to the sheet.
An apparatus serves for the metered coating of an inking roller (1) with a fluid coating medium, in particular an inking roller in a printing press which directly or indirectly inks a printing form, whereby the inking roller (1) is in contact with a soft transfer roller (2) or soft printing roller arranged in parallel, and whereby the surfaces of the inking roller (1) and the transfer roller (2) or the printing roller respectively at least have a path speed which is more or less identical. The surface of the inking roller (1) dips directly into the coating medium (3), whereby the thickness of the film of coating medium (3) remaining on the surface of the inking roller (1) is determined by a wiping roller (4) which is arranged parallel to the inking roller (1), is supported on this, has an engraving and, in comparison to the inking roller, a small outside diameter.
