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US5202554A Expired / Lapsed US ⏱️ 0.0 years remaining

Methods of and apparatus for separating and detecting sheets

Assignee: De la Rue International Ltd
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Filing: 1991-05-31
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Granted: 1993-04-13
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Expires: 2011-05-31
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Abstract

Abstract The sheets within a stack of sheets are separated by clamping one end of the stack, bending the other end, clamping the other end and then unbending the stack. A radiation beam such as a laser beam is then directed at the stack of separated sheets, the beam reflecting from the edges of the sheets. The reflected signal is sensed by a photodetector which converts the received intensity into an electrical signal which is then fed to a processor, such as a microprocessor, to count the number of sheets.

Inventors

  • 👤 Christopher G. L. Wilton
  • 👤 Colin A. Langstone

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-10 02:19
CPC Classifications
G; G06; G06M; G06M9/00; B; B65; B65H; B65H3/00; B65H3/46; B65H3/60; B65H2701/00; B65H2701/10; B65H2701/19; B65H2701/1912

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 56 words
A method of detecting sheets within a stack, the method comprising causing portions of sheets in a sheet stack to separate between the ends of the stack; causing a radiation beam to impinge on said separated portions of said sheets; and detecting the presence of respective sheets by monitoring the radiation after impingement on said stack.
Claim 2
Independent Claim 56 words
A method of detecting sheets within a stack, the method comprising causing portions of sheets in a sheet stack to separate between the ends of the stack; causing a radiation beam to impinge on said separated portions of said sheets; and detecting the presence of respective sheets by monitoring the radiation after impingement on said stack.
Claim 3
Dependent Claim 59 words
A method according to claim 1, wherein the sheet separation step comprises clamping said sheets at one end of said stack; imparting a bend in the stack so that said edges of said sheets separate; clamping the stack at a position remote from the clamped end; and unbending said stack so that portions of sheets between said clamps separate.
Claim 4
Dependent Claim 23 words
A method according to claim 1, further comprising causing relative scanning movement between said radiation beam and said separated portions of said sheets.
Claim 5
Dependent Claim 60 words
Apparatus for detecting sheets within a stack, comprising means for causing portions of sheets in a sheet stack to separate between the ends of the stack; means for causing a radiation beam to impinge on said separated portions of said sheets; and detection means for detecting the presence of respective sheets by monitoring the radiation after impingement on said stack.
Claim 6
Dependent Claim 60 words
Apparatus for detecting sheets within a stack, comprising means for causing portions of sheets in a sheet stack to separate between the ends of the stack; means for causing a radiation beam to impinge on said separated portions of said sheets; and detection means for detecting the presence of respective sheets by monitoring the radiation after impingement on said stack.
Claim 7
Dependent Claim 81 words
Apparatus according to claim 4, wherein said means for causing portions of said sheets to separate comprises a first clamp for clamping one end of a sheet stack; bending means for imparting a bend to said sheet stack; and a second clamp for clamping said stack at a position remote from said first clamp, said first and second clamps being relatively movable to impart an unbending motion on aid stack so as to separate portions in said stack between said clamps.
Claim 8
Dependent Claim 52 words
Apparatus according to claim 5, wherein said second clamp is moveable between an initial, open position in which the relative position of sheets within said second clamp can vary during a bending motion, and a second, closed position in which said sheets are held in their relative positions said after bending motion.
Claim 9
Dependent Claim 17 words
Apparatus according to claim 5, wherein said bending means can impart a 180° fold to said stack.
Claim 10
Dependent Claim 49 words
Apparatus according to claim 5, wherein said second clamp comprises a cooperating cam and roller between which said sheet stack is inserted, rotation of said cam causing said sheet stack to clamp against said roller and cause portions of said sheets between said first and second clamps to separate.
Claim 11
Dependent Claim 49 words
Apparatus according to claim 5, wherein said second clamp comprises a slotted roller through which said sheet stack can extend, and clamping means for holding said sheet stack in a slot of said slotted roller whereby rotation of said slotted roller causes a bending motion and said unbending motion.
Claim 12
Dependent Claim 20 words
Apparatus according to claim 9, wherein said clamping means comprises one of a cleat, clamping wheels, and a leaf spring.
Claim 13
Dependent Claim 37 words
Apparatus according to claim 5, wherein said bending means further comprises a lifting member positioned between said first and second clamps for imparting said bend in a portion of said stack betweens aid first and second clamps.
Claim 14
Dependent Claim 25 words
Apparatus according to claim 4, wherein said radiation beam and said stack are relatively moveable so that said beam can scan across said sheet edges.
Claim 15
Dependent Claim 28 words
Apparatus according to claim 12, further comprising a radiation beam source, wherein said stack holding means is moveable relative to said beam source to achieve a scanning movement.
Claim 16
Dependent Claim 28 words
Apparatus according to claim 12 said device further comprising beam scanning means for causing said beam to scan across a stack held by said sheet stack holding means.
Claim 17
Dependent Claim 25 words
Apparatus according to claim 4, further comprising a beam spreader for causing said beam to have a dimension corresponding to a thickness of said stack.
Claim 18
Dependent Claim 18 words
Apparatus according to claim 4, wherein said detection means is arranged to detect radiation reflected from said sheets.
Claim 19
Dependent Claim 14 words
Apparatus according to claim 4, further comprising a laser for generating said radiation beam.
Claim 20
Dependent Claim 12 words
Apparatus according to claim 4, wherein said detection means comprises a photodetector.
Claim 21
Dependent Claim 44 words
Apparatus according to claim 4, further including processing means connected to said detection means for monitoring an output signal from said detection means corresponding to said detected radiation to determine the presence of sheet edges and for counting the number of sheet edges detected.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-04-12 1996-10-12 1997-04-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-04-12 2000-10-12 2001-04-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-04-12 2004-10-12 2005-04-13 $7700.00 Window Closed / Lapsed

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