Label stacker

#This invention relates to the field of printers and stackers and to methods of printing and stacking labels.

#The following prior art is made of record: U.S. Pat. Nos. 4,418,618; 5,486,259; 5,695,291; 5,785,442; 5,820,277; 5,833,377; 5,961,228; 6,059,468; 6,078,345; 6,142,622; 6,164,203; 6,241,407; 6,336,760; Users Manual, Paxar Model 656/636 Manual Edition 6.3, 8 Aug. 2003; and Ink Jet Care Label Printers From Markem Technology That Delivers High-Quality Care Labels At Savings Of Up to 50% brochure, circa 1999.

#The invention relates to an improved, low cost, apparatus that can print on both sides of a web, cut the web into predetermined length labels and accumulate the labels in a stack.

#FIG. 1 is a front elevational view of a printer in accordance with an embodiment of the invention showing a printable web threaded to be printed on both sides;

#FIG. 2 is a fragmentary front elevational view showing the printer in an arrangement in which only one side of the web is being printed;

#FIG. 3 is a fragmentary front elevational view showing the printer in an arrangement in which the web is being threaded through the printer prior to printing;

#With reference initially to FIG. 1, there is shown a printer generally indicated at 50 for printing on a printable web W and a stacker generally indicated at 51. The web W is initially in the form of a wound supply roll R mounted on an unwind mechanism generally indicated at 52. The web W is drawn through the printer 50 in the direction of arrows shown along the path of the web W. As the web W is paid out of the web roll R, the web roll R rotates clockwise in the direction of arrow A. The unwind mechanism 52 applies a slight tensioning force to the web W by attempting to rotate the roll R counterclockwise, that is, in a direction opposite to the direction of the arrow A. However, the force exerted on the web W to feed the web W through the printer 50 overcomes the force exerted by the unwind mechanism to enable the web W to be fed through the printer 50. By this arrangement the web W is always maintained under the desired tension.

#The printer 50 includes a print head assembly 53 and a cooperable platen in the form of a platen roll 54. The printer 50 also includes another print head assembly 55 and a cooperable platen in the form of a platen roll 56. The print head assembly 53 and the platen roll 54 may be termed the “first” print head assembly and the “first” platen roll, respectively, because they are upstream of the print head assembly 55 and the platen roll 56. Similarly, the print head assembly 55 and the platen roll 56 are downstream of the print head assembly 53 and the platen roll 54 and may be termed the “second” print head assembly and the “second” platen roll. The print head assemblies 53 and 55 are identical and the platen rolls 54 and 56 are identical. The print head assemblies 53 and 55 are secured to the frame plate 70 by screws (not shown).

#A thermal print head 53′ at a side of the print head assembly 53 cooperates with the platen roll 54 to print on the underside of the web W. A thermal print head 55′ at a lower side of the print head assembly 55 cooperates with the platen roll 56 to print on the upper surface of the web W. The platen rolls 54 and 56 are shown in their respective latched positions in FIG. 1.