Transverse sheet withdrawal brake
AssigneeMueller Martini Holding AG
InventorsHanspeter Duss, Christian Troxler
Life of this patent
Estimating the term…
Abstract
A method for operating a device that applies a force to a print sheet during a folding operation, wherein the print sheet is in a specified starting position prior to the folding operation. Braking-force triggering pulses are directed toward the print sheet to counter the acceleration of the print sheet in the starting phase of the folding operation and/or to counter fluttering movements that occur during the intake of the print sheet. The pulses exert an intermittent, uniform or oscillating force onto at least a section of the print sheet. The pulses are controlled by a control unit which operates based on control profiles resulting from queried operating parameters and/or based on stored control profiles.
Claims35
A method for operating a device which makes available a braking force acting upon a print sheet during a folding operation, wherein the print sheet is in a specified position before reaching the folding operation, comprising:
- directing braking-force triggering pulses, that are triggered by a transverse sheet brake arranged across a width of the print sheet, toward the print sheet to counter at least one of acceleration of the print sheet that occurs during a starting phase of the folding operation and fluttering movements that form during the intake of the print sheet to the folding operation, wherein the pulses are triggered to act intermittently, uniformly or oscillatingly on at least a section of the print sheet;
- and
- controlling the braking-force triggering pulses by a control unit operated with at least one of changeable control profiles resulting from queried operating parameters and stored control profiles.
A method for operating a device that makes available a braking force acting upon a print sheet during a folding operation, wherein ahead of the folding operation the print sheet is in a specified position, the method comprising:
- generating braking-force triggering pulses by a transverse sheet brake arranged across a width of the print sheet in a feeding direction of the print sheet, the triggering pulses acting directly or indirectly to position the print sheet while the print sheet is subjected to the folding operation, wherein the braking-force triggering pulses are at least one of pneumatic, mechanical and vacuum generated to cause friction to the print sheet, and wherein the braking-force triggering pulses generate intermittent, uniform or oscillating braking forces that act on the print sheet to at least one of counter an acceleration of the print sheet that occurs during a starting phase of the folding operation and counter fluttering movements of the print sheet during the folding operation;
- and
- controlling the braking-force triggering pulses by a control unit during the intake of the print sheet which is operated based on at least one of changeable control profiles resulting from queried operating parameters and stored control profiles.
A method for braking and positioning a print sheet in a feeding direction and for delaying the print sheet during an intake for a folding operation and/or to counter flattering movements that occur during print sheet intake, the method comprising:
- computing an air pressure needed for braking based on a specified production data including at least one of a folding pattern, paper weight, paper width and cut-off length, and sending an information regarding the computed pressure to an automatic pressure controller, taking into consideration the print sheet has different values on the left and right side based on a folding pattern;
- computing the air pressure required for slowing down the print sheet during intake into the folding station and/or to counter the flattering movements based on specified production data including at least one of the folding pattern, paper weight, paper width and cut-off length, and sending an information regarding the computed air pressure to an automatic pressure controller, taking into consideration that the left and right side of the print sheet have different values, depending on the folding pattern for the print sheet;
- filling a pressure reservoir located in front of a pneumatic switching valve in the flow direction with the computed pressure;
- detecting the print sheet entering or fed into a folding region by a light barrier along the back edge of the print sheet, wherein the light barrier simultaneously serves to ensure a synchronizing of a folding sword with a precise clock speed, and the light barrier detects irregularities within the belt transport of the print sheet and compensates for the irregularities with the control unit;
- triggering a signal for activating a pneumatic switching valve based on an activated trigger signal, taking into consideration a dead time and speed compensation;
- following the triggering, releasing abruptly the air stored in the pressure reservoir to cause an air nozzle to release a pulse-type air blast;
- transmitting the released air blast directly onto the print sheet or indirectly to a lever, which transmits a force of the air blast and the corresponding normal force onto the print sheet;
- pressing the print sheet during the feeding operation and/or during the folding process onto a table-type support and generating a braking force for the print sheet as a result of friction;
- exerting simultaneously or with a phase delay an additional braking force onto the back edge of the print sheet, wherein a material stretching results from the braking operation to cause stiffening of the print sheet;
- selecting the stopping instant such that the print sheet is braked securely to 0, or fits uniformly against the sheet end stop, or the folding sword takes over the print sheet or it is delayed during the folding process;
- and
- following release of the air pulses, closing the pneumatic switching valve immediately and filling the air reservoir again by the pressure controller with air to a predetermined pressure level to make air available for the following cycle.
A device for making available a braking force that acts upon a print sheet during a folding operation, wherein the print sheet is in the specified starting position prior to the folding operation, wherein braking-force triggering pulses are used to counter the acceleration of the print sheet that occurs in the starting phase of the folding operation and/or to counter the fluttering movements that form during the intake of the print sheet, the pulses cause intermittent, uniform or oscillating braking forces that act upon at least a section of the print sheet, and a transverse sheet brake to generate at least one braking force triggered by a pulse and which is operable during the folding operation, and a control unit to control pulses which is operated based on changeable control profiles resulting from queried operating parameters and/or by stored control profiles.
A device for making available a braking force that acts upon a print sheet during a folding operation, wherein a print sheet is in a specified starting position prior to a folding operation, comprising:
- a braking force generating means operative to generate braking force triggering pulses applied directly or indirectly to the print sheet to position the print sheet while the print sheet is in an operative connection with the folding operation, wherein the braking force triggering pulses are effective along a feeding direction for the print sheet, the braking force triggering pulses are at least one of pneumatic, mechanical and vacuum generated to cause friction to the print sheet and at least one pulse-triggered braking force is generated by the transverse sheet brake during the folding operation;
- and a control unit to control the pulses, the control unit being operated based on at least one of changeable control profiles resulting from queried operating parameters and by stored control profiles.
Dependencies are inferred from the claim text.