Patent ID: 6763749
Filing Date: 2004-07-20
Classification: B65H,Y10T

Abstract:
Web speed metering apparatus for receiving and engaging a web that is supplied to the metering apparatus at a constant infeed speed and for cyclically varying the output speed of the web leaving the metering apparatus, said web speed metering apparatus comprising:a) a rotatable shaft defining an axis of rotation that is disposed across a path of movement of a moving web of material to be metered; b) a web-engaging surface carried by the shaft and extending axially thereof, the web-engaging surface adapted to receive the web and defining a non-circular cross section, the cross section having a centroid that is offset from the axis of rotation to cause the speed of the web downstream of the metering apparatus to vary as a function of the instantaneous radial spacing of the web from the axis of rotation of the web-engaging surface, wherein the web-engaging surface includes a first matched speed zone within which the output speed of the web as it leaves the web speed metering apparatus is at a speed that is substantially equal to a surface speed of a downstream web-receiving element; a web storage zone within which the output speed of the web as it leaves the web speed metering apparatus is progressively reduced from the matched speed to a predetermined web output speed value; a second matched speed zone within which the output speed of the web as it leaves the web speed metering apparatus is at a speed that is substantially equal to the web infeed speed; and a null zone between the first and second matched speed zones and within which the output speed of the web is less than the matched speed and within which the leading edge of the web advances a predetermined distance along a moving surface of the downstream web-receiving device.