Reduction of tape stiction

Claim 2

In a tape system which includes a vacuum chamber, a tape within the chamber, forming a loop a surface of which lies on and tends to adhere to walls of the chamber as the tape is drawn through the chamber, a method for reducing this tendency comprising the step of creating a film of air, at a pressure greater than that within the tape loop, between at least the major portion of tape surface and the walls to which it tends to adhere.

Claim 3

In a tape system which includes a vacuum chamber, a tape within the chamber forming a loop a surface of which lies on and tends to adhere to walls of the chamber as the tape is drawn through the chamber, a method for reducing this tendency comprising the step of creating a wedge-shaped air film which is relatively thicker in the region of the chamber where the loop enters said chamber than in the region thereof further into the chamber and which is at a pressure greater than that within the tape loop, between at least the major portion of tape surface and the walls to which it tends to adhere.

Claim 4

In a tape system which includes a vacuum chamber, a tape within the chamber forming a loop a surface of which lies on and tends to adhere to walls of the chamber as the tape is drawn through the chamber, a method for reducing this tendency comprising the step of creating a wedge-shaped air film which is relatively thicker in the region of the chamber where the loop enters said chamber than in the region thereof further into the chamber and which is at a pressure greater than that within the tape loop, between at least the major portion of tape surface and the walls to which it tends to adhere.

Claim 5

In combination: a vacuum chamber; a driven tape forming a loop within the chamber, a surface of which tape is adjacent to and tends to stick to walls of said chamber as the tape is drawn through the chamber; and means for reducing said sticking tendency comprising means for maintaining the air pressure of the volume defined by the inner surface of said tape loop lower than that between the outer surface of said tape and said walls to thereby form an air film between said tape surface and the walls to which it is adjacent.

Claim 6

In combination: a vacuum chamber; a driven tape forming a loop within the chamber, a surface of which tape is adjacent to and tends to stick to walls of said chamber as the tape is drawn through the chamber; and means for reducing said sticking tendency comprising means for maintaining the air pressure of the volume defined by the inner surface of said tape loop lower than that between the outer surface of said tape and said walls to thereby form an air film between said tape surface and the walls to which it is adjacent.

Claim 7

In the combination as set forth in Claim 3, wherein said last-named means comprises: means including passages between the tape and chamber for permitting air to enter between the tape and walls and means for restricting the flow of air into the volume within said loop; and means for introducing air between the tape and walls comprising the means for creating a vacuum in said chamber, said vacuum causing a reduced air pressure within said loop relative to that in the region between said tape and said walls, thereby causing air to be drawn through said passages and between the tape and walls while it is being withdrawn from said chamber.

Claim 8

In the combination as set forth in claim 3, said last-named means comprising: means for spacing the tape from the walls at the point the tape enters and leaves the chamber; means including passages between the tape and chamber for permitting air to enter said spaces between the tape and walls; and means for introducing air into said spaces comprising the means for creating a vacuum in said chamber, said vacuum causing air to be drawn through said passages and into said spaces while it is being withdrawn from said chamber.

Claim 9

In the combination as set forth in claim 5, said means spacing the tape from the walls providing at least one wedge-shaped space extending in the loop direction, said wedge-shaped space having a smaller opening toward the closed end of the loop than at the region of the loop closer to where it is admitted to the chamber.

Claim 10

In combination: a vacuum chamber comprising a pair of walls separated a nonuniform distance; a tape forming a loop within the chamber with its width dimension extending between the said pair of walls, the said walls being spaced only slightly greater than the tape width dimension; and means including vacuum-producing means for exerting a variable pressure on the tape in proportion to the position of the tape loop within the chamber.

Claim 11

In combination: a vacuum chamber comprising a pair of walls separated a nonuniform distance; a tape forming a loop within the chamber with its width dimension extending between the said pair of walls, the said walls being spaced only slightly greater than the tape width dimension; and means including vacuum-producing means for exerting a variable pressure on the tape in proportion to the position of the tape loop within the chamber.

Claim 12

In combination: an elongated vacuum chamber having an end wall and opposite sidewalls; a driven tape forming a loop within said chamber, havinG a curved portion extending toward said end wall, and relatively straight portions which tend to stick to said sidewalls as said tape is drawn through the chamber; means for creating a region between said sidewalls and said tape at relatively high pressure; means for maintaining the region between the curved portion of the loop and said end wall at relatively low pressure for drawing said tape into said chamber; and means for maintaining the region within said loop at a pressure between said relatively high and low pressures, the pressure differential thereby existing between the region within said loop and the regions between said sidewalls and the tape maintaining the tape spaced from said walls over the major portion of the extent of said relatively straight portions of said tape.

Claim 13

In combination: an elongated vacuum chamber having an end wall and opposite sidewalls; a driven tape forming a loop within said chamber, havinG a curved portion extending toward said end wall, and relatively straight portions which tend to stick to said sidewalls as said tape is drawn through the chamber; means for creating a region between said sidewalls and said tape at relatively high pressure; means for maintaining the region between the curved portion of the loop and said end wall at relatively low pressure for drawing said tape into said chamber; and means for maintaining the region within said loop at a pressure between said relatively high and low pressures, the pressure differential thereby existing between the region within said loop and the regions between said sidewalls and the tape maintaining the tape spaced from said walls over the major portion of the extent of said relatively straight portions of said tape.

Claim 14

An elongated vacuum chamber having an opening at one end, an end wall at the other end, and sidewalls extending from said opening to said end wall; a driven tape extending into said opening forming a loop within said chamber a surface of which is adjacent to and tends to stick to said sidewalls as said tape is driven through the chamber; means for restricting the flow of air into said opening and into the region comprising the interior of said loop; passages in said sidewalls for permitting the flow of air into the region between said sidewalls and said tape; and vacuum means coupled to the other end of said chamber sidewalls creating a relatively low first pressure differential between the region of the chamber adjacent to the end wall and region of the chamber within the loop and a relatively high second pressure differential between the region of the chamber adjacent to said end wall and the regions between said side and said tape, whereby said tape is urged away from contact with said sidewalls.

Claim 15

An elongated vacuum chamber having an opening at one end, an end wall at the other end, and sidewalls extending from said opening to said end wall; a driven tape extending into said opening forming a loop within said chamber a surface of which is adjacent to and tends to stick to said sidewalls as said tape is driven through the chamber; means for restricting the flow of air into said opening and into the region comprising the interior of said loop; passages in said sidewalls for permitting the flow of air into the region between said sidewalls and said tape; and vacuum means coupled to the other end of said chamber sidewalls creating a relatively low first pressure differential between the region of the chamber adjacent to the end wall and region of the chamber within the loop and a relatively high second pressure differential between the region of the chamber adjacent to said end wall and the regions between said side and said tape, whereby said tape is urged away from contact with said sidewalls.