PAD PRINTER WITH PAD COUPLER AND PRINTING PAD

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates generally to the printing process and in particular to strategies for mounting of a pad to a pad printer.

BACKGROUND OFTHE INVENTION

[0002] The pad printing process is an indirect intaglio process. Depressions representing the logo of choice are created on a flat surface called "the plate" or pad printing cliche. There are two types of cliche plates-variable depth relief photopolymer plates and fixed depth relief plates. The depressions for logos having multiple colors require multiple plates that are dedicated to each individual color of the image to be printed. A plate for each color in the image is etched, by way of a photoactive polymer and a film positive, by UV light. In the case of variable depth relief photopolymer plates, after an initial exposure period, the logo and plate are completely covered with a screen film and exposed to UV light again ("screening"); this step is not necessary for fixed depth relief plates. Screening is a process that places many small "dots," in the shape of truncated cones, into the surface of the etched image itself. [0003] The pad printing process begins by spreading ink across the surface of the plate with a spatula. Excess ink is then scraped back into an ink reservoir using a "doctor blade" which leaves ink only in the depressions on the plate. As the plate is exposed to air, thinner evaporates from the remaining ink in the depressions causing the ink surface to become tacky. A smooth, resilient, stamp block of silicone rubber (e.g., the pad) is used to lift ink from the

plate and transfer it to the surface to be printed. The stamp block is termed a "pad" and it is this term that has lent its name to the printing process.

[0004] One type of printing system that operates in a fully automatic or near fully automatic mode is a pad printing system. These systems are used to apply high quality print on flat as well as non-flat surfaces. For example, pad printing systems can be used to print logos and the like on cellular telephone covers, game balls such as golf balls and the like. It will be appreciated that such printing can be carried out not only on a spherical surface, but on a surface that is formed with dimples as well. [0005] Conventional pad printing systems use the deformable printing pad, which repeatedly receives ink and transfers an image from the flat cliche plate to a printed surface. The printing pad is typically mounted to the frame of the printer via a base and a pad interface with several screws. Due to repeated use, the deformable material of the printing pad is susceptible to wear and requires occasional replacement. The removal of the printing pad by accessing the screws can be a relatively difficult and time-consuming process. It would therefore be desirable to provide a superior strategy for replacing the printing pad. In addition, the use of both a base and a pad interface requires two parts for mounting the printing pad thereby increasing manufacturing complexity and cost. It would therefore be desirable to provide a more simple strategy for mounting the printing pad.

[0006] Therefore, it would be desirable to provide strategies for mounting the pad to the pad printer that would overcome the aforementioned and other disadvantages.

SUMMARY OF THE INVENTION

[0007] One aspect of the present invention provides a pad printer.

The printer includes a frame. A pad coupler is operably attached to frame. A printing pad is operably attached to the pad coupler. At least one locking mechanism secures the printing pad to the pad coupler.

[0008] Another aspect of the present invention provides a pad printer. The printer includes a frame. A pad coupler is operably attached to frame. A printing pad is operably attached to the pad coupler with at least one pad interface. The pad interface includes at least one surface of the printing pad that corresponds to at least one surface of the pad coupler. The at least one surface of the printing pad interlocks with the at least one surface of the pad coupler.

[0009] Another aspect of the present invention provides a pad printer. The printer includes a frame. A pad coupler is operably attached to frame. A printing pad is operably attached to the pad coupler with at least one magnetic interface. The pad coupler includes a first magnetic member and the printing pad includes a second magnetic member. The first and second magnetic members are magnetically coupled.

[00010] The foregoing and other features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention, rather than limiting the scope of the invention being defined by the appended claims and equivalents thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[00011] FIG. 1 is a perspective view of a pad printer in accordance with one embodiment of the present invention;

[00012] FIG. 2 is a cross-sectional view of a pad coupler operably attached to a printing pad illustrating a C-clip locking mechanism, in accordance with one embodiment of the present invention;

[00013] FIG.3 is a cross-sectional view of a pad coupler operably attached to a printing pad illustrating a pin locking mechanism, in accordance with one embodiment of the present invention; [00014] FIG.4 is a cross-sectional view of a pad coupler operably attached to a printing pad illustrating a dovetail interface, in accordance with one embodiment of the present invention;

[00015] FIG. 5 is a cross-sectional view of a pad coupler operably attached to a printing pad illustrating a flange interface, in accordance with one embodiment of the present invention;

[00016] FIG.6 is a cross-sectional view of a pad coupler operably attached to a printing pad illustrating a magnetic interface, in accordance with one embodiment of the present invention; and

[00017] FIG. 7 is a cross-sectional view of a pad coupler operably attached to a printing pad illustrating a magnetic interface, in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[00018] FIG. 1 is a perspective view of a pad printer in accordance with one embodiment of the present invention, shown generally by numeral 100.

Printer 100 includes a frame 110. At least one pad assembly 120 is operably attached to the frame 110. A cliche plate 112 is operably attached to the frame 110. Those skilled in the art will recognize that the printer 100 can vary and is not limited to the configurations located in the description and illustrations provided herein.

[00019] In one embodiment, the pad assembly 120 includes a printing pad 122 that reciprocates into contact with the cliche plate 112 and an ink cup 124. Pad assembly 120 further includes a pad coupler 126, which is operably attached to the print pad 122 and the frame 110. Printing pad 122 is a deformable pad onto which ink is transferred, and from which the ink is transferred to an object to be imprinted. A typical printing pad 122 is formed from a resilient, low permeability material such as silicone rubber or the like. Pad assembly 120 includes a motor for powering the reciprocation of the printing pad 122. Cliche plate 112 and ink cup 124 also reciprocate relative to one another (as indicated by arrows A) to supply ink to the cliche plate 112. Ink cup 124 includes a reservoir body 126 with an open lower end and a doctor blade or knife ring around the open end. The doctor blade is maintained in intimate contact with the cliche plate 112 to form a seal for retaining the ink in the ink cup 124. The blade also serves to scrape the cliche plate 112 surface to clean off excess ink as the cliche plate 112 is advanced from a loading position to a transfer position. Substantially, the only ink retained on the cliche plate 112 is that in the engraved or etched regions in the cliche plate 112 surface that define the print pattern. As such, a relatively "clean" image is produced on the printed surface. [00020] In a first embodiment, shown in FIGS.2 and 3, at least one, in this case one, locking mechanism 128 secures the printing pad 122 to the pad

coupler 126. The locking mechanism is defined herein as one or more objects that facilitate removable attachment of the printing pad 122 from the pad coupler 126. The locking mechanism 128 is removably attached (i.e., the locking mechanism 128 can be removed and reattached from the printer 100). [00021] In one embodiment, shown in FIG. 2, the locking mechanism 128 is a locking ring 130. Ring 130 is positioned through an aperture formed in the printing pad 122 and the pad coupler 126. Aperture is shaped to correspond to the shape of the ring 130. Ring 130, for example, can be a C- shaped clip or clip of another shape. Ring 130 provides an inward spring force for holding the printing pad 122 fast to the pad coupler 126.

[00022] In another embodiment, shown in FIG. 3, the locking mechanism 128 is a pin 140. Printing pad 122 includes a flange portion 132, which is positioned in between flange portions 134, 136 of the pad coupler 126. Pin 140 is positioned through an aperture formed in the printing pad 122 and the pad coupler 126. Specifically, pin 140 is positioned through apertures of the printing pad 122 flange portion 132 and the pad coupler 126 flange portions 134, 136. Apertures are shaped to correspond to the shape of the pin 140. Pin 140 can be a smooth member (i.e., lacking grooves) or a screw (i.e., with grooves). [00023] In a second embodiment, shown in FIGS.4 and 5, the printing pad 122 is operably attached to the pad coupler 126 with at least one, in this case two, pad interfaces 150. Pad interfaces 150 includes at least one, in this case two, surfaces 152 of the printing pad 122 that correspond to at least one, in this case two, surfaces 154 of the pad coupler 126. Surfaces 152 of the printing pad 122 interlock with the surfaces of the pad coupler.

[00024] In one embodiment, shown in FIG.4, the pad interface 150 includes at least one, in this case two, dovetail interfaces 156. Dovetail interface 156 includes surfaces at acute angles that prevent the printing pad 122 from removal (i.e., in a direction along arrow A). However, the printing pad 122 can be removed when necessary (e.g., requires replacement) by sliding the printing pad 122 in a direction orthogonal to arrow A (i.e., out of the plane of the page of FIG. 4).

[00025] In one embodiment, shown in FIG. 5, the pad interfaces

150 include at least one, in this case two, flange interfaces 156. Flange interface 156 includes surfaces at approximately perpendicular angles that prevent the printing pad 122 from removal (i.e., in a direction along arrow B). However, the printing pad 122 can be removed when necessary (e.g., requires replacement) by sliding the printing pad 122 in a direction orthogonal to arrow B (i.e., out of the plane of the page of FIG. 5). [00026] In a third embodiment, shown in FIGS. 6 and 7, the printing pad 122 is operably attached to the pad coupler 126 with at least one, in this case one, magnetic interface 160. Pad coupler 126 includes a first magnetic member 162 and the printing pad 122 includes a second magnetic member 164. The first and second magnetic members 162, 164 are magnetically coupled. [00027] In one embodiment, as shown in FIG. 6, the first magnetic member 162 of the pad coupler 126 includes a magnet. The second magnetic member 164 of the printing pad 122 includes a metallic portion manufactured substantially from, for example, a ferrous material. Metallic portion is a pin, such as a screw, bar, and the like, positioned within a flange portion 170 of the printing pad 122. Flange portion 170 is positioned in between flange portions 172, 174 of

the pad coupler 126. The first and second magnetic members 162, 164 are positioned within molded apertures within the pad coupler 126 and printing pad 122, respectively. Alternatively, the magnet can be positioned within the printing pad 122 and the metallic portion positioned within the pad coupler 126. Those skilled in the art will recognize that the configuration of the first and second magnetic members 162, 164 may vary from the described embodiment and corresponding illustrations.

[00028] In one embodiment, as shown in FIG.7, the first magnetic member 162 of the pad coupler 126 includes a magnet. The second magnetic member 164 of the printing pad 122 includes a metallic portion. Metallic portion is a foil member positioned adjacent a surface portion 176 of the printing pad 122. The first magnetic member 162 is positioned within molded aperture within the pad coupler 126. Alternatively, the magnet can be positioned within the printing pad 122 and the metallic portion 180 positioned adjacent a surface portion of the pad coupler 126. Those skilled in the art will recognize that the configuration of the first and second magnetic members 162, 164 may vary from the described embodiment and corresponding illustrations.

[00029] One advantage to a printer made in accordance with the present invention relates to the fact that a worn printing pad can be changed without the need for removing multiple screws. Furthermore, the changing process is relatively easy and less time-consuming. Another advantage relates to the fact that the pad coupler of the present invention allows direct mounting of the printing pad to the frame without the need for a base. As such, less part are needed which may reduce manufacturing complexity and cost.

[00030] It is important to note that the figures and description illustrate specific applications and embodiments of the present invention, and is not intended to limit the scope of the present disclosure or claims to that which is presented therein. While the figures and description present strategies for mounting a pad to a pad printer, the present invention is not limited to that format, and is therefore applicable to other formats. Upon reading the specification and reviewing the drawings hereof, it will become immediately obvious to those skilled in the art that myriad other embodiments of the present invention are possible, and that such embodiments are contemplated and fall within the scope of the presently claimed invention.

[00031] While the embodiments of the invention disclosed herein are presently considered to be preferred, various changes and modifications can be made without departing from the spirit and scope of the invention. The scope of the invention is indicated in the appended claims, and all changes that come within the meaning and range of equivalents are intended to be embraced therein.