Bookbinding: process and apparatus – Apparatus – Book working apparatus
Reexamination Certificate
1999-12-20
2001-01-09
Fridie, Jr., Willmon (Department: 3722)
Bookbinding: process and apparatus
Apparatus
Book working apparatus
Reexamination Certificate
active
06171045
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a device for the mechanical pressing of rounded book blocks and, more particularly, a device for the mechanical pressing of book blocks including a molding tool that applies a variable pressing force to the back of a book block.
2. Description of Related Art
In industrial book production, a book block with a rounded back receives the desired back shape corresponding to the cover type in the pressing processing station. The back shape being determined by a deep or flat fold. The pressing is effected by a molding tool, which is reciprocated over the entire width of the back of the book block and comprises a concave active surface, so that by applying pressure and friction, the folded printed sheets are bent over on both sides from the center of the book block back, namely at an angle increasing towards the outside. In this manner, the book block receives its mushroom-like shape and at the same time a back stabilization. In order to effect the pressing procedure, the book block is clamped between pressing strips with a defined overhang of the rounding end.
In European Patent 0,676,303, which is assigned to the present assignee hereof, in addition to a number of embodiments, a device for the mechanical pressing of book blocks of the construction described above is disclosed. By displacing the bearing with the carriage and the molding tool between the fixed lateral guides, the lateral deflection of the bearing is dispensed with. The axis of rotation of the molding tool lies at a defined distance below its point of contact with the back of the book block. The molding tool moves tangentially and overlies the pivoting axis. By means of stop screws in an intermediate support, the displacement is limited and in this manner the sliding movement is introduced into the lateral region in order to fold over the printed sheets. The size of the displacement stroke can be adjusted by varying the distance of the axis of rotation of the molding tool from the book block back and via the stop screws.
SUMMARY OF THE INVENTION
An object of the present invention is to overcome the above described disadvantages of the prior art.
Another object is to optimize the pressing process of rounded book blocks while also increasing the quality thereof.
It is a further object to provide a flexible device which readily adapts to various materials and back shapes of the book block and wherein the structural outlay and time required for setting up are to be reduced.
The foregoing objects and other objects are achieved according to an embodiment of the invention wherein a molding tool is vertically displaceable in a carriage via an operating cylinder which can be actuated by compressed air. The pressing force of the molding tool is adjustable via the compressed air and is controlled in such a manner that, within a central position, the molding tool acts upon the back of the book block with a pressing force which is reduced in relation to the pressing force in the pivoting position. In this respect, the molding tool can be displaced in the carriage by a computer-controlled sequence into a vertical position in which it is lowered onto the back of the book block and into another vertical position in which it is raised from the back of the book block. It has proved particularly expedient that the molding tool can be lowered onto the back of the book block for locating in the central position, and the pressing force can be adjusted by means of the operating cylinder actuated by a particular pressure.
As a result of the use of compressed air cylinders to control the molding tool, the pressing force on the book block back can be optimally adjusted via compressed air as a function of the materials of the book block. Also, the pressing force can be controlled in such a manner that the molding tool when in a central position only acts with a low pressing force upon the book block back, which has a protective effect on the book block, since excessive compression of the printed sheets located in the center is prevented. In the case of extremely delicate materials of the book block, the pressing force in the central position of the molding tool can also be significantly reduced. By compression of compressed air columns, a sharp increase in the force in the normal direction is attained in the lateral end positions, and with the stroke of the molding tool the tensile/thrust components are generated for bending over the printed sheets. This optimization of the pressing process results in an improvement in the quality of the book blocks.
By means of simple linear guidance in connection with a spindle drive, the pressing head with the molding tool can be lowered in a motor driven manner onto the book block back to a defined vertical position and the central position of the book block back in order to effect a location measurement. Using the measurement result of the piston displacement during its stroke in the pneumatic cylinder, the pressing head is automatically adjusted to a corrected vertical position, so that compensation for the different back rounding and fold widths can be carried out. The respective vertical positions in the end position of the molding tool in the central position and pivoting position for the pressing and for the load-free return stoke are reached in a computer-controlled manner. The pressing force can be adjusted during the measurement as a function of the materials of the book block.
Molding tools with differently shaped radii of the active surface are largely dispensed with in the pressing device according to the invention. Finally, the new type of pressing device can be set up in a problem-free manner in minimal time.
REFERENCES:
patent: 1195679 (1916-08-01), Hill
patent: 4747740 (1988-05-01), Rahe
patent: 5658111 (1997-08-01), Rathert
patent: 36 14 168 (1987-10-01), None
patent: 0 676 303 A1 (1995-10-01), None
Nehring Dieter
Schm{umlaut over (u)}cker Christoph
Alix Yale & Ristas, LLP
Fridie Jr. Willmon
Kolbus GmbH & Co. KG
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