FIG. 11 is a perspective view of an alternative embodi¬ment of a printing drum assembly.
FIG. 12 is a perspective view of an additional alternative embodiment of a printing drum assembly.
DESCRIPTION OF THE PREFERRED
EMBODIMENT
Referring to FIGS. 1, 2A and 2B, a printing drum assem¬bly 10 of a continuous jet printer for clamping and rotating various sized printing plates includes a leading edge assem¬bly 32 and a trailing edge assembly 34 rotatable with respect to leading edge assembly 32. Leading edge assembly 32 includes a series of spaced disks 12a, here five disks 12a are shown, interconnected by a leading edge plate clamp 20 with bolts 21. Trailing edge assembly 34 includes a second series of spaced disks 12b, here four disks 12b are shown, inter-connected by a trailing edge plate clamp 22 with bolts 23.
Disks 12a are fixedly mounted to an axle 14 to rotate with the axle, as described further below. When assembled, disks
12a and 12b are interleaved as shown in FIG. 1, and disks
12b are rotatably mounted to axle 14 such that the trailing edge assembly 34 can be rotated about the axle. This ability to rotate the trailing edge assembly about axle 14 enables the user to adjust the distance between leading edge plate clamp 20 and trailing edge plate clamp 22 to accommodate differ¬ent length printing plates.
Referring to FIG. 3A, a flexible printing plate 24 includes a leading edge 24a and a trailing edge 24b. Printing plate 24 is supported along its entire length on plate support surfaces 40 of disks 12a, 12b with leading edge 24a held securely by leading edge plate clamp 20 and trailing edge 24b held securely by trailing edge plate clamp 22. To mount a different length printing plate to drum assembly 10, trailing edge assembly 34 is simply rotated, arrow 35, with respect to leading edge assembly 32 to place clamps 20, 22 the
4desired distance apart about the circumference of the drum assembly. Once the clamps are at their desired spacing, trailing edge assembly 34 is locked in position, as described further below.
5 Referring also to FIG. 4, for ease in manufacturing, disks
12a and 12b are injection molded from the same mold such that all of the disks have the same shape. Each disk 12a, 12b has a first side 48 and a second side 50. When assembled, disks 12b are flipped with respect to disks 12a, with the first
10 side of a disk 12a facing the first side of a disk 12b and the second side of a disk 12a facing the second side of a disk 12b.
Disks 12a, 12b are generally circular in shape with a
recessed arcuate region 38 that extends along approximately is 40% of the circumference of the disk. An outward step 39 in recessed region 38 provides a mounting surface for one of the respective clamps 20, 22. The recessed area 38 provides clearance for clamps 20, 22 when trailing edge assembly 34 is rotated with respect to leading edge assembly 32.
Referring also to FIG. 5, each disk 12a, 12b includes a central plate 60 and a wall 62 extending from either side of plate 60. Also extending from either side of plate 60 is an axle sleeve 42 and two balancing weight sleeves 44, 46. Each sleeve 42, 44, 46 defines a through hole, 42a, 44a, 46a, respectively. Through hole 42a is aligned with an axis of rotation 54 of drum assembly 10, and is sized slightly larger in diameter than the diameter of axle 14 to receive axle 14.
Leading edge assembly 32 is mounted to axle 14 with two 30 hubs 36, one placed on either end of drum assembly 10.
Each hub 36 is attached, e.g., by bolting, to axle 14 and to
and end disk, disk 12c or 12d, of leading edge assembly 32.
Rotary motion of axle 14 is transferred to disks 12c, 12d by
hubs 36. The rotary motion of disks 12c, 12d is transferred 35 by leading edge plate clamp 20 to the remainder of disks