Apparatus for measuring tensile stresses in continuously fed webs of material

Claim 3

An apparatus as set forth in claim 1 wherein said duct includes a pair of edges bounding said chambers and a further partition defining two rows of said chambers and wherein said edges and said further partition are disposed at an acute angle against the direction of travel of the web.

Claim 4

An apparatus as set forth in claim 1 wherein said partitions are disposed at an angle to define chambers of triangular cross-sectional shape.

Claim 5

An apparatus as set forth in claim 1 wherein said partitions are disposed at an angle to define chambers of trapezoidal cross-sectional shape.

Claim 6

An apparatus as set forth in claim 4 which further includes a further partition in each chamber extending transversely to the longitudinal axis of said duct.

Claim 7

An apparatus as set forth in claim 1 wherein adjacent chambers on one side of said duct are spaced apart, and the sum of the widths of said chambers on opposite sides of said duct in any cross-section is constant.

Claim 8

An apparatus as set forth in claim 6 wherein each chamber includes a partition disposed transversely or transversely and longitudinally of the longitudinal axis of said duct.

Claim 9

An apparatus as set forth in claim 1 wherein said means is a blower.

Claim 10

In combination, a tank having a liquid medium free of suspended matter therein; an apparatus for measuring tensile stress in a continuously travelling web of material including a duct adjacent the travelling web and extending across the width of the web, said duct being disposed in said tank below the surface of the liquid medium and having a plurality of partitions therein defining a plurality of pocket-like chambers in facing rElation to the web, each said chamber having a bottom and a calibrated choke opening in said bottom communicating with saud duct to receive a supply of liquid medium therefrom to produce a liquid cushion of uniform thickness between the web and said chambers, and a plurality of measuring devices, each said device being connected to a respective chamber to measure the static pressure therein as a measure of the tension in the web lying thereover; and a centrifugal pump connected to said duct and said tank for drawing the liquid medium from said tank and for feeding the drawn liquid medium to said duct under constant pressure.

Claim 11

In combination, a tank having a liquid medium free of suspended matter therein; an apparatus for measuring tensile stress in a continuously travelling web of material including a duct adjacent the travelling web and extending across the width of the web, said duct being disposed in said tank below the surface of the liquid medium and having a plurality of partitions therein defining a plurality of pocket-like chambers in facing rElation to the web, each said chamber having a bottom and a calibrated choke opening in said bottom communicating with saud duct to receive a supply of liquid medium therefrom to produce a liquid cushion of uniform thickness between the web and said chambers, and a plurality of measuring devices, each said device being connected to a respective chamber to measure the static pressure therein as a measure of the tension in the web lying thereover; and a centrifugal pump connected to said duct and said tank for drawing the liquid medium from said tank and for feeding the drawn liquid medium to said duct under constant pressure.