EP0089080A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Sheet-holding apparatus
Assignee: Agfa Gevaert NV
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Filing: 1983-03-04
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Granted: —
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Expires: 2003-03-04
Abstract
Abstract Apparatus for temporarily holding flexible sheets and conveying them progressively through an image transfer station, e.g. in a xerographic printer comprising a rotatable sheet holder (30) having two segmental peripheral portions (34,35) which have inter-meshing teeth and can be relatively angularly displaced for varying the arcuate length of the sheet supporting surface (39) formed by such portions. For gripping the leading and trailing margins of a sheet (38) and holding it taut against the surface (39) there are leading and trailing clamps (58, 48) which are likewise relatively angularly displaceable so that they can operate at the leading and trailing ends of the arcuate support surface (39) whatever be its adjusted size.
Inventors
- 👤 Leo Norbert Vackier
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 17:34
CPC Classifications
B; B41; B41L; B41L29/00; B41L29/12; B41L29/14; G; G03; G03G; G03G15/00; G03G15/14; G03G15/16; G03G15/163; G03G15/1635; G03G15/165; G03G15/1655
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
179 words
Sheet-holding apparatus comprising a rotatable sheet holder (30) having a cylindrically curved surface (39) for supporting a sheet of flexible material (38) concentric with the axis of rotation of the holder and comprising mechanical fastening devices (58,48) for engaging the leading and trailing margins of the sheet and holding it taut against said curved supporting surface, characterised in that the holder (30) comprises two parts (32,33) having segmental peripheral portions (34,35) of comb-like structure with intermeshing teeth (96,97) which portions together form a said cylindrically curved sheet supporting surface (39) which subtends an angle of less than 360°; the said holder parts (32,33) are relatively angularly displaceable about their common axis of rotation to enable the angle subtended by the said sheet-supporting surface (39) to be adjusted to suit different sheet dimensions; and the leading and trailing fastening devices (58,48) are likewise relatively angularly displaceable to permit them to hold leading and trailing sheet margins in the vicinity of the leading and trailing ends of said supporting surface (39) in any said adjusted setting of said holder parts (32,33).
Claim 2
Dependent Claim
179 words
Sheet-holding apparatus comprising a rotatable sheet holder (30) having a cylindrically curved surface (39) for supporting a sheet of flexible material (38) concentric with the axis of rotation of the holder and comprising mechanical fastening devices (58,48) for engaging the leading and trailing margins of the sheet and holding it taut against said curved supporting surface, characterised in that the holder (30) comprises two parts (32,33) having segmental peripheral portions (34,35) of comb-like structure with intermeshing teeth (96,97) which portions together form a said cylindrically curved sheet supporting surface (39) which subtends an angle of less than 360°; the said holder parts (32,33) are relatively angularly displaceable about their common axis of rotation to enable the angle subtended by the said sheet-supporting surface (39) to be adjusted to suit different sheet dimensions; and the leading and trailing fastening devices (58,48) are likewise relatively angularly displaceable to permit them to hold leading and trailing sheet margins in the vicinity of the leading and trailing ends of said supporting surface (39) in any said adjusted setting of said holder parts (32,33).
Claim 3
Dependent Claim
42 words
Apparatus according to claim 1, wherein there is mechanism (75,76,78,80,41,40) which causes the angular spacing of the leading and trailing fastening devices (58,48) to increase slightly at a stage such as to cause tensioning of a sheet (38) held by such devices.
Claim 4
Dependent Claim
43 words
Apparatus according to claim 2, wherein said mechanism for causing tensioning of a sheet comprises an electromagnet (75) which functions through mechanical coupling means (76,78,80,41,40) to cause partial rotation of one said holder part (32) together with the adjacent sheet fastening device (58).
Claim 5
Dependent Claim
106 words
Apparatus according to any preceding claim, wherein the leading and trailing fastening devices (58,48) are in the form of clamps and the apparatus includes means (70,67,63) which automatically opens and closes the leading clamp (58) at a predetermined region (P-U) along the path followed by the periphery of the holder (30) during its rotation so that such clamp can take hold of a margin of a sheet (38) if this is held ready for pick-up at that region (P-U), and includes means (52,53,57,54) which automatically subsequently opens and closes the trailing clamp (48) to permit it to take hold of the trailing margin of such sheet.
Claim 6
Dependent Claim
110 words
Apparatus according to claim 4, wherein there is means (91,62,61) which controls the movement of the leading clamp (58) so that for a period of time during part of a revolution of the said holder parts (32,38) said leading clamp (58) is angularly spaced from and is held (against rotation with said segmental parts) at said sheet pick-up region (P-U), and means which during said period of time opens and closes said leading clamp (58) for taking hold of a sheet (38) before said leading clamp is caused to accompany the rotation of said holder parts (32,33) and thereby draw said sheet (38) onto the cylindrically curved supporting surface (39).
Claim 7
Dependent Claim
39 words
Apparatus according to claim 4 or 5, wherein each of the leading and trailing fastening devices (58,48) is in the form of a clamp comprising a series of jaws (36-47; 37-109) distributed in spaced relation across the holder (30).
Claim 8
Dependent Claim
18 words
Apparatus according to claim 6, wherein said jaws (36,37) are independently biased by springs (63,54) towards closed position.
Claim 9
Dependent Claim
28 words
Apparatus according to claim 6 or 7, wherein the means (55,67) for closing the jaws operates to close the inner jaws of each series before the outer ones.
Claim 10
Dependent Claim
33 words
Apparatus according to any preceding claim, wherein the size and adjustment range of said sheet holder (30) are such that it is capable of holding sheets ranging in size from A4 to Al.
Claim 11
Dependent Claim
80 words
Printing apparatus comprising sheet-holding apparatus according to any of claims 4 to 8, means (29a) for supporting flexible sheets in a position near the path followed by the periphery of the sheet holder (30) for take-up by the leading clamp (58), and means (15a, 15b) for conveying image-carrying material to the . vicinity of said sheet holder (30) for image-wise transfer of the image to a sheet (38) while it is held by and rotates with said sheet holder (30).
References Cited (Backward Citations)
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