Method and device for separating a sheet from a stack of sheets
First Claim
1. A method for separating a sheet from a stack of sheets, comprising the steps of:
- supporting a generally vertically oriented stack of sheets with the lower edges of the sheets therein abutting against the surface of at least two pairs of rotary traction surfaces forming a nip, a first one of each pair of traction surfaces having a coefficient of friction relative to one surface of the sheet to be separated that is greater than the coefficient of friction of the second one of each pair of traction surfaces relative to the other surface of the sheet to be separated,imparting to each such pair of traction surfaces rotary movements so that said first one advances in the direction of feed of the sheet to be separated, whereas the second one advances in the opposite direction thereby causing the stack of sheets to be displaced to bring the lower edge of the outermost sheet which is supported by said first traction surface into said nip and advanced thereby over a predetermined distance therethrough,after a predetermined length of said outermost sheet has passed beyond said nip, engaging the remainder of the sheets in said stack and lifting the same bodily upwardly away from said traction surfaces so that the remaining sheets in the stack are bodily separated from the sheet to be separated,advancing the thus-separated sheet through and away from said pair of traction surfaces, andreturning the remaining sheets of the stack into lower edgewise abutment with said traction surfaces.
1 Assignment
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Accused Products
Abstract
Single sheets are separated from a stack of sheets arranged in a housing having one open end in which at least one pair of separating rollers is disposed with the lower end of the stack resting in the nip thereof. One roller of each pair has a surface with a greater coefficient of friction relative to the sheet surface than that of the other roller and is rotated in a direction relative to the stack opposite to the other roller so that an outermost sheet is caused to slide from the remainder of the stack by frictional engagement of the one roller while the stack remainder is held from the oppositely rotating roller. Separation is greatly facilitated by the provision of hooks which support the lower edge of the remainder of the stack during separation and positively assist withdrawal of the stack remainder.
17 Citations
17 Claims
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1. A method for separating a sheet from a stack of sheets, comprising the steps of:
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supporting a generally vertically oriented stack of sheets with the lower edges of the sheets therein abutting against the surface of at least two pairs of rotary traction surfaces forming a nip, a first one of each pair of traction surfaces having a coefficient of friction relative to one surface of the sheet to be separated that is greater than the coefficient of friction of the second one of each pair of traction surfaces relative to the other surface of the sheet to be separated, imparting to each such pair of traction surfaces rotary movements so that said first one advances in the direction of feed of the sheet to be separated, whereas the second one advances in the opposite direction thereby causing the stack of sheets to be displaced to bring the lower edge of the outermost sheet which is supported by said first traction surface into said nip and advanced thereby over a predetermined distance therethrough, after a predetermined length of said outermost sheet has passed beyond said nip, engaging the remainder of the sheets in said stack and lifting the same bodily upwardly away from said traction surfaces so that the remaining sheets in the stack are bodily separated from the sheet to be separated, advancing the thus-separated sheet through and away from said pair of traction surfaces, and returning the remaining sheets of the stack into lower edgewise abutment with said traction surfaces. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A device for separating a sheet from a stack of film sheets comprising:
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at least two pairs of rotary traction surfaces forming a nip and supporting one edge of said stack, the first one of each pair of traction surfaces having a coefficient of friction relative to one surface of the sheet to be separated which is greater than the coefficient of friction of the second one of each pair of traction surfaces relative to the other surface of the sheet to be separated; means for rotating said each pair of traction surfaces in directions such that the first one of each pair advances in the direction of feed of the sheet to be separated, whereas the second one of each pair of said traction surfaces advances in the opposite direction, thereby causing said stack of sheets to be displaced so that the lower edge of the outermost sheet which is supported by said first traction surface is directed into said nip and advanced thereby a predetermined distance therethrough; and lifting means operable after the predetermined length of said outermost sheet has passed through said nip to engage the remainder of the stack and lift the same bodily so that the remaining sheets constituting said stack are bodily separated from the sheet to be separated and after separation of the latter to return the stack into edgewise abutting contact with said traction surfaces. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification