Abstract In a document feeder with a vacuum belt platen transport system for transporting document sheets over the platen of a copier under a vacuum plenum backing surface closely overlying the platen and into a registration position for imaging the document sheet, with a registration system for stopping the document sheet at the registration position, the platen transport system including a vacuum source for applying a partial vacuum to a document sheet being transported sufficient to provide transport of the document sheet with movement of the belt transport into the registration system, and a system for automatically reducing the level of the partial vacuum in the vacuum plenum sufficiently to allow slippage of a document sheet relative to the belt transport at the registration system, and wherein the registration system comprises document engaging registration fingers movable into and out of the path of a document sheet being transported by the vacuum belt platen transport system, the improvement wherein the system for automatically reducing the level of the partial vacuum in the vacuum plenum comprises a valve system directly actuated by the registration system by mechanical connection to the movable registration fingers to automatically reduce the vacuum level in the vacuum plenum in direct response to the movement of the registration fingers into the path of a document sheet.
In a document feeder with a vacuum belt platen transport system for transporting document sheets over the platen of a copier under a vacuum plenum backing surface closely overlying said platen and into a registration position for imaging the document sheet, with registration means for stopping the document sheet at a said registration position, said platen transport system including a vacuum source for applying a partial vacuum to a document sheet being transported sufficient to provide transport of the document sheet with movement of said belt transport into said registration means, and means for automatically reducing the level of said partial vacuum in said vacuum plenum sufficiently to allow slippage of a document sheet relative to said belt transport at said registration means, and wherein said registration means comprises document engaging registration fingers movable into and out of the path of a document sheet being transported by said vacuum belt platen transport system, the improvement wherein said means for automatically reducing the level of said partial vacuum in said vacuum plenum comprises valve means directly actuated by said registration means by mechanical connection to said movable registration fingers to automatically reduce the vacuum level in said vacuum plenum in direct response to said movement of said registration fingers into the path of a document sheet.
Claim 2
Dependent Claim
215 words
In a document feeder with a vacuum belt platen transport system for transporting document sheets over the platen of a copier under a vacuum plenum backing surface closely overlying said platen and into a registration position for imaging the document sheet, with registration means for stopping the document sheet at a said registration position, said platen transport system including a vacuum source for applying a partial vacuum to a document sheet being transported sufficient to provide transport of the document sheet with movement of said belt transport into said registration means, and means for automatically reducing the level of said partial vacuum in said vacuum plenum sufficiently to allow slippage of a document sheet relative to said belt transport at said registration means, and wherein said registration means comprises document engaging registration fingers movable into and out of the path of a document sheet being transported by said vacuum belt platen transport system, the improvement wherein said means for automatically reducing the level of said partial vacuum in said vacuum plenum comprises valve means directly actuated by said registration means by mechanical connection to said movable registration fingers to automatically reduce the vacuum level in said vacuum plenum in direct response to said movement of said registration fingers into the path of a document sheet.
Claim 3
Dependent Claim
111 words
The document feeder of claim 1, wherein said vacuum belt platen transport system comprises plural unapertured spaced apart moving belts between which said partial vacuum is applied, and where said partial vacuum level is automatically so reduced to less than approximately 8 millimeters of water by said valve means after partial said transporting of the document sheet over said platen of said copier but prior to the transporting of a document sheet into said registration means, and wherein said belts continue to move after the document sheet is stopped at said registration position by said registration means with slippage between said belts and the document sheet and without document sheet damage.
Claim 4
Dependent Claim
70 words
The document feeder of claim 1, wherein said valve means comprises a vent aperture in said vacuum plenum to vent it to the atmosphere and a vent door connected to said registration fingers for movement therewith and adapted to close said vent aperture whenever said registration fingers are moved out of said document path and to open said vent aperture whenever said registration fingers are moved into said document path.
Claim 5
Dependent Claim
175 words
The document feeder of claim 1, wherein said vacuum belt platen transport system comprises plural unapertured spaced apart moving belts between which said partial vacuum is applied, and wherein said partial vacuum level is automatically so reduced to less than approximately 8 millimeters of water by said valve means after partial said transporting of the document sheet over said platen of said copier but prior to the transporting of a document sheet into said registration means, and wherein said belts continue to move after the document sheet is stopped at said registration position by said registration means with slippage between said belts and the document sheet and without document sheet-damage; and wherein said valve means comprises a vent aperture in said vacuum plenum to vent it to the atmosphere and a vent door connected to said registration fingers for movement therewith and adapted to close said vent aperture whenever said registration fingers are moved out of said document path and to open said vent aperture whenever said registration fingers are moved into said document path.