12A. When trailing edge assembly 34 is locked to leading

edge assembly 32, rotation of leading edge assembly 32

causes trailing edge assembly 34 to rotate as well.

Leading edge assembly 32 and trailing edge assembly 34

40 are independently balanced about axis of rotation 54 such that rotation of trailing edge assembly 34 relative to leading edge assembly 32 does not cause an imbalance in the drum. Referring to FIGS. 3A and 3B, a balancing weight 45 is secured in sleeve 44 of each disk, e.g., by an interference fit,

45 to balance the respective assemblies. The magnitudes of the weights are selected to account for the disks and the clamp.

A balancing weight 47 having the same or a different magnitude than weight 45 can be secured in sleeve 46 to provide additional control over the magnitude and direction

so of the balancing force. Selection of the balancing weights can be performed by the manufacturer and need not be adjusted by the user.

It can be necessary to provide additional user adjustable balancing to account for the weight added when printing

ss plate 24 is mounted to the drum. It is desirable to make the additional balancing adjustable since the dimensions of the plates which drum assembly 10 is adapted to receive vary. For example, the length of plate 24 typically ranges between about 14.57 inches and 21.625 inches, the width of plate 24

60 typically ranges between about 10.63 inches and 29 inches, and the thickness of plate 24 typically ranges between about 5 mils and 12 mils. For these size ranges, the weight of plate 24 typically ranged between about 0.07 and 0.8 pounds.源1自3优尔8.论~文'网·www.youerw.com

Referring to FIGS. 6A and 6B, to accommodate the

65 varying sizes and weights of the plates which drum assem-bly 10 is adapted to receive, one of disks 12a, preferable one of the five leading edge disks which is centrally located on

the drum, is replaced with a manually adjustable drum assembly 200. Drum assembly 200 includes a central disk 202 with an axle sleeve 204 defining a through hole 206 through which axle 14 is received.

As with disks 12a and 12b, disk 202 is generally circular in shape with a recessed arcuate region 238 that extends along approximately 40% of the circumference of the disk. An outward step 239 in recessed region 238 provides a mounting surface for clamp 20. The recessed area 238 provides clearance for clamp 22 when trailing edge assem¬bly 34 is rotated with respect to leading edge assembly 32. Central disk 202 need not include balancing weight sleeves 44, 46.

Rotatably mounted by a slip fit to either side 210, 212 of disk 202 is a ring 214. Each ring 214 includes an axle sleeve 216 for receiving axle 14. A weight 218 is mounted to each ring 214 near the outer circumference of the ring. Rings 214 can be independently rotated about axis 54 to adjust the positions of weights 218, and thus the magnitude and direction of the balancing force. When the desired position of each of the rings is selected, each ring is secured in place, e.g., by engaging one of a series of detente features 222 located on an inner surface 223 of ring 214 with a spring loaded ball 220 mounted on disk 210 (only one ball 220 is shown in FIG. 6B). The lockdown detente force is selected to prevent undesirable slippage of the ring due to forces such as drum acceleration or deceleration, but also allows easy user adjustment of the ring position. Position scale 225 on the outer diameter surface 227 of each ring 214 are used to locate the positions of rings 214 relative to trailing edge clamp 22. Scale settings are identified with a call out table based on plate dimensions.

Referring to FIGS. 1, 7A and 7B, clamps 20 and 22 each include a base 74, a clamping member 72 and an actuator 76. Base 74 is generally rectangular in shape and defines a clamping member mounting notch 80 and an actuator chan¬nel 88. Clamping member 72 is a c-shaped clamp formed, e.g., from 300 series tempered stainless steel. Clamping member 72 has a bottom wall 73, a side wall 75, a top wall 77. A tab 78 extends from bottom wall 73 into notch 80 to secure clamping member 72 to base 74. Clamping member 72 is prestressed such that a clamp edge 84 presses against a printing plate 24 with a predetermined clamping force necessary to hold the printing plate between clamp edge 84 and base 74. A relieved section 74a in base 74 aids in preventing other portions of the top wall of the clamping member from contacting the base such that the clamping force is concentrated at edge 84. 打印机滚筒英文文献和中文翻译(4):http://www.youerw.com/fanyi/lunwen_61842.html