Appeal No. 2002-1053 Page 11
Application No. 09/702,981
In order to dampen the system and keep the roll 18 of sheet material 20 from
over running, a friction roller assembly 160 preferably is used to provide a constant
resistance to rotation to the roll 18, or another type of braking device may be used. The
friction roller assembly 160 includes a roller 162 mounted to a swing arm 164 which is
pivotally secured to the arms 102. Spring 166 pulls the roller 162 against the surface of
the roll 18 to provide a continuous and preferably constant drag. Any suitable means
for generating a frictional load on the roller 162 may be used, such as a drum-type
brake, a caliper-type brake, or even a set screw which bears down on a turning shaft.
The key function, as with any damped feed back controlled system, is to allow the
system to respond rapidly without excessive overshooting. In the illustrated
arrangement, the braking force will progressively decrease as the diameter of the roll,
and thus its inertial mass, decreases.
Wood
Wood's invention relates to a tension roll for webs, and although capable of other
uses, is especially adapted for printing presses. The principal objects of Wood's
invention are to provide means whereby if the web runs on one end of the
spring-pressed roll the roll will be kept in alignment, irrespective of the differences in
pressure on the two ends of the roll, this being especially desirable when running a half
or quarter width web on the roll; to provide this means in a simple and convenient form
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