Reversible foil blade having multi-activity zones
OwnerJohn D. Eamesinventor
Life of this patent
Estimating the term…
Abstract
A reversible foil blade for a papermaking machine providing for a plurality of activity zones wherein the drainage and sheet activity characteristics of the blade can be independently and separately predetermined, established, and controlled. The shape of the foil blade is designed to provide both leading and trailing edges that each form an angle less than 90° with the horizontal, the paper sheet and conveying forming fabric, thereby providing different drainage and sheet activity characteristics when the blade is reversed and installed in a reverse orientation.
Claims31
A foil blade for paper machines comprising
- a first orientation of the foil blade having a leading edge angle α1 that is less than 90 degrees from the horizontal;
- an entry surface positioned at the angle α1;
- and a tee slot to facilitate the mounting, installation and/or removal of the blade on the paper machine, such that when the foil blade is installed on a paper machine in the first orientation the leading edge angle is the first portion of the foil blade that is traversed by a conveying fabric and by a sheet being formed on the paper machine, thereby providing a predetermined and controlled effect of the blade on drainage and sheet activity.
A foil blade for paper machines comprising
- a first orientation of the foil blade having a leading edge angle α1 that is less than 90 degrees from the horizontal;
- an entry surface positioned at the angle α1;
- and a tee slot to facilitate the mounting, installation and/or removal of the blade on the paper machine, such that when the foil blade is installed on a paper machine in the first orientation the leading edge angle is the first portion of the foil blade that is traversed by a conveying fabric and by a sheet being formed on the paper machine, thereby providing a predetermined and controlled effect of the blade on drainage and sheet activity and wherein reversing of the blade with respect to the machine direction changes the entry angle from affecting activity to function as an exit angle affecting drainage.
A foil blade for paper machines comprising
- a first orientation of the foil blade having a leading edge angle α1 that is less than 90 degrees from the horizontal;
- an entry surface positioned at the angle α1 having a first flat surface F1;
- an angle θ1 of the conveying fabric with the horizontal at fabric entry to the blade and an angle θ3 of the conveying fabric with the horizontal at fabric exit from the blade;
- a second entry surface positioned at the angle α3 having a second flat surface F2;
- wherein a first activity zone is produced according to the formula
- acceleration (a)=(fabric speed)2×(θ1+α2)/F1;
- and a tee slot to facilitate the mounting, installation and/or removal of the blade on the paper machine, such that when the foil blade is installed on a paper machine in the first orientation the leading edge angle is the first portion of the foil blade that is traversed by a conveying fabric and by a sheet being formed on the paper machine, thereby providing a predetermined and controlled effect of the blade on drainage and sheet activity.
A method for using a foil blade for paper machines comprising the steps of:
- providing a foil blade having a leading edge angle α1 that is less than 90 degrees from the horizontal;
- an entry surface positioned at the angle α1;
- and a tee slot to facilitate the mounting, installation and/or removal of the blade on the paper machine;
- installing the foil blade in a first orientation such that when the foil blade is installed on a paper machine in the first orientation the leading edge angle is the first portion of the foil blade that is traversed by a conveying fabric and by a sheet being formed on the paper machine, thereby providing a predetermined and controlled effect of the blade on drainage and sheet activity.
Dependencies are inferred from the claim text.