Buckle folding unit and method for controlling the register of a buckle folding unit
AssigneeHeidelberger Druckmaschinen AG
InventorHatto Hechler
Life of this patent
Estimating the term…
Abstract
A buckle folding unit with a folding pocket having an adjustable pocket stop, includes a first detector for detecting a first instant as a sheet travels from an inlet to the buckle folding unit until it reaches the pocket stop, a second detector for detecting a second instant as the sheet travels from a formation of a fold as far as an outlet from the folding pocket, and a device for determining a length of the sheet conveyed between the first and the second instants; a method for controlling the register of the buckle folding unit; and a folding machine having at least one buckle folding unit constructed with at least one of the foregoing features.
Claims28
A buckle folding unit to be supplied with sheets running-in one after another, comprising:
- an adjustable folding pocket having a pocket stop and an outlet;
- rollers having parallel center lines and being adapted for conveying a respective sheet into said folding pocket until a leading edge of said sheet abuts said pocket stop and for folding and pulling said sheet out of said outlet;
- a sheet detecting device for generating a first signal at an instant while a respective sheet is running-in and a second signal at an instant while said sheet is being pulled out of said outlet;
- a determining device for determining an actual value of a furnished sheet length of a respective sheet within a time segment lasting from said first signal to said second signal;
- and
- an adjusting device for adjusting said fold pocket in dependence on a difference between said actual value and a predetermined nominal value of furnished sheet length.
The buckle folding unit according to 2, wherein said folding pocket has a pocket mouth with a lower lip, and said sheet detecting device includes a second detector for detecting a deflection of said lower lip when said sheet is becoming folded and for generating said second signal.
A method for controlling the register of a buckle folding unit having an inlet for receiving a sheet and a folding pocket with an outlet, which comprises:
- providing the folding pocket with an adjustable pocket stop;
- detecting a first instant as the sheet travels from the inlet to the buckle folding unit until it reaches the pocket stop;
- detecting a second instant as the sheet travels from a formation of a fold as far as the outlet from the folding pocket;
- determining, in a learning phase, a desired value of a length of a sheet conveyed between the first and the second instant;
- determining, in a production phase, an actual value of the length of the sheet conveyed between the first and the second instant;
- and
- adjusting the actual value to the desired value, during production operation, by adjusting the pocket stop using an adjusting device, in order to compensate for changes in sheet properties or changes of sheet deformation due to changes in production speed.
Dependencies are inferred from the claim text.