The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 25, 1983
Filed:
Jun. 12, 1981
Jeffrey Isherwood, Enfield, GB;
Crosfield Electronics Limited, London, GB;
Abstract
A web feeding machine for controlling the feed of a web of material comprises a first pair of rollers which bear against one another to form a first nip, a second pair of rollers which bear against one another to form a second nip downstream from the first nip, means to cause the ratio of the linear speed of the web through the second nip to that through the first nip to be a constant and to have a value greater than one, a variable speed drive for driving the nip rollers, means for monitoring the tension T.sub.1 in the web upstream from the first nip and the tension T.sub.2 between the first and second nips, and control means to control the variable speed drive of the rollers so that the angular velocity .omega. of the rollers satisfies the expression: ##EQU1## where A, B and C are constants. By controlling the angular velocity of the rollers and hence the linear speed of the web in accordance with this expression, a constant flow rate of the web is ensured irrespective of the elasticity of the web or the overall speed of its feed.