Actuator 76, e.g., an eccentric rod 86, is located in channel 88 underneath top wall 77 of clamping member 72 and extends the length of the clamp. Rod 86 has a short diameter 94 and a long diameter 96. A central key 92 of the rod accepts a handle (not shown) used to rotate the rod within channel 88. When the short diameter 94 is approxi¬mately perpendicular to top wall 77 of the clamp member (as shown in FIG. 7A), rod 86 does not contact clamp member 72 and clamp edge 84 presses against base 74. Rotation of rod 86 such that long diameter 96 is approximately perpen¬dicular to the clamping member (as shown in FIG. 7B) causes rod 86 to engage the clamping member elastically deforming the clamping member from the clamped position shown in FIG. 7A to the open position shown in FIG. 7B in which clamp edge 84 is spaced from base 74. With the clamp in the open position, the printing plate can be slid between the clamp edge and the base. Clamps 20, 22 provide enough clamping force to hold a plate 24 during typical rotation speeds of drum 10 of about 600 rpm, and can hold the plate at speeds of up to about 1800 rpm or more.

 6Referring to FIGS. 10A and 10B, to lock trailing edge assembly 34 to leading edge assembly 32, trailing edge clamp 22 includes a lockdown mechanism 350 located at either end of the clamp. The lockdown mechanisms hold the

5 location of the leading and trailing edge assemblies after adjustment for different plate lengths as earlier discussed. Lockdown mechanism 350 includes a handle 352, a mount¬ing plate 354, a cam shaft 356, and an eccentric cam 358. Base 74 of clamp 22 has a slot 360 in which cam 358 is

10 located. Shaft 356 extends through a hole 362 in base 74 which intersects slot 360 and through a square hole 364 in cam 358. Shaft 356 has a corresponding square surface 366 which causes cam 358 to rotate with shaft 356.

Mounting plate 354 has a first hole 368 through which an

15 end 370 of shaft 356 extends. A second hole 372 in plate 354 accepts a bolt (not shown) which mounts plate 354, and thus shaft 356 and cam 358 to base 74 by threading into a hole 374 in base 74. Plate 354 abuts against a shelf 376 of shaft 356. End 376 of shaft 356 extends through a hole 378 in

20 handle 352. Handle 352 is attached to shaft 356 by a bolt (not shown) which extends through a hole 380 in the handle and is threaded into a hole 382 in the shaft. Actuation of the locking mechanism by rotation of the handle causes the cam to extend below the bottom surface 73 of clamping member

25 72 and engage one of the end disks of the leading edge assembly. If, after plate loading and clamping, the plate is not in tight contact with the drum surface, the lock down mechanisms can be loosened and the clamp positions read¬justed.

30To provide precise registration of each of four printing plates which are engraved to receive a different color during offset printing, clamp 20 is provided with registration pins 100, here four pins 100 are shown. Base 74 defines regis¬tration pin receiving holes 99, and clamping member top

35wall 77 defines pin holes 101. Referring to FIG. 8, leading edge 24a of printing plate 24 defines press registration notches 28A and 28B. The spacing of notches 28A and 28B coincides with the spacing of a pair of the registration pins of clamp 20. The two pins are positioned to extend through

40a respective notch 28A, 28B, and through a respective hole 101 in clamping member 72. The remaining registration pins, whose spacings coincide with press notches of other sized printing plates, remain out of the way in a retracted position below an upper surface 75 of base 74.

Referring also to FIG. 9, to move pins 100 between their retracted and extended positions, pins 100 include a groove 104 that extends along approximately a quarter of the circumference of pin 100. Groove 104 is sloped with a rise 50 to run ratio of approximately one to three. A positioning pin 打印机滚筒英文文献和中文翻译(5):http://www.youerw.com/fanyi/lunwen_61842.html