U.S. Patent 7,997,196 for “Portable intaglio printing press.”
Texas Business Patent Of The Day: A Dallas-area man developed a new process for a centuries old technology—printing.
Paul L. Whelan of Plano received U.S. Patent 7,997,196 for “Portable intaglio printing press.”
Whelan filed for the patent on April 10, 2007.
The term intaglio refers to a die used in printing that is incised so as to produce an image in relief. Generally, an intaglio printing die has incisions, depressions and recessed areas that are marked into a plate of copper, brass, iron, zinc, plastic or linoleum.
The basic methods of intaglio printmaking have remained relatively unchanged for centuries. Once an image has been incised onto a plate, ink is spread on the plate and forces it into the recessed areas of the plate.
The surface is wiped clean of ink, leaving only the ink in the recessed areas of the plate. The plate is then placed in a special press and the paper that will receive the intaglio print is registered, face down, on the plate.
It should be mentioned that one characteristic of intaglio prints that make them so desirable is the plate mark received in the paper from the outline of the plate, so care is taken that the paper is registered correctly to the plate. Often the paper is dampened to make it receptive to the ink and more supple so that the paper can more easily be pressed into the incised marks (dampening the paper also enhances the print mark).
One or more felt blankets are placed over the paper in preparation for the press. The press applies direct pressure to the felt, which compresses the felt, and more importantly, the paper into the inked relief of the image on the plate.
Two general designs of printing presses suitable for intaglio printmaking have been used; a screw-type press that compresses the entire surface of the artwork between two flat plates, and a cylinder-type press that applies rotational pressure on the artwork at a point between two larger cylinders and simultaneously feeds the artwork plate, paper and felt in the direction of rotation.
The screw-type press design has been in continuous use since the fifteenth century. It is simple to operate, relatively easy to maintain and has relatively few wear parts to replace. One major drawback in the screw-type design is that because force is simultaneously applied over the entire surface area of the work surface, the working pressure is inversely proportional to the surface area of the workpiece.
The larger the work surface, the lower the amount of pressure that can be generated from the force applied by the screw. As a practical matter, the performance of most screw-type designs drops off considerably over a few hundred square inches of surface area.
Cylinder-type intaglio printing presses do not suffer from this shortcoming because the pressure to the workpiece is applied along a line between two cylindrically shaped rollers. Essentially, the cylinder-type design applies pressure in only one direction along the work surface, rather than across the entire two-dimensional surface area of the work surface as in the screw-type device. Because the surface area between the contact points on the rollers is relatively small, the cylinder-type design enables the operator to focus a significant amount of surface pressure with a comparatively low force applied on the rollers. Therefore, the length of the roller can be increased to accommodate larger artwork without a substantial corresponding decrease in the working pressure common to the screw-type press design.
Whelan’s invention is a lightweight and portable intaglio printing press that enables an operator to manually generate the amount of compressive force that is necessary to emboss quality intaglio prints from artwork.
The present invention is comprised generally of two assemblies: a press bed assembly and a print head assembly. The design of a novel print head assembly serves as a first class lever within a pair of surfaces of a press bed assembly that define runway. The runway structure of the press bed assembly confines the force applied to the print head assembly and translates that force into a pressure directed to the print paper covered and inked artwork. The runway structure is defined by upper and lower surfaces of the press bed assembly that are separated by a predetermined distance and substantially parallel to each other. The print paper and inked artwork are positioned proximate to the lower surface and the print head portion of the print head assembly is situated between the artwork and the upper surface.
The print head assembly comprises one or more lever handles, a compression roller and one or more track roller. The lever handle(s) serves at least two purposes: to provide a torque lever for receiving a manually exerting downward force and translating that force into compression force on the artwork and print paper (in conjunction with the surfaces of the runway structure); and to provide a handle for moving the print head assembly along the runway, thereby making compression passes across the artwork. The track roller and compression roller are secured a predetermined distance from each other and within a housing that forces the compression roller against the workpiece (the print paper and inked artwork) at the lower surface of the runway and simultaneously forces the track roller (or bearings) against the upper surface of the runway. Printmaking proceeds one pass at a time across the lateral extent of the print paper covered artwork. Rather than drawing the workpiece past a pair of rollers using the rotation of the rollers, as is typical of prior art presses, the workpiece is moved perpendicularly with respect to the direction of the print head passes, thereby exposing a fresh area of the workpiece for imprinting.