Sheet feeding or delivering – Delivering – Rotary conveyor
Reexamination Certificate
2001-04-06
2003-05-06
Mackey, Patrick H. (Department: 3651)
Sheet feeding or delivering
Delivering
Rotary conveyor
C271S314000, C074S567000, C074S570200
Reexamination Certificate
active
06557844
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a device for transferring sheets in a sheet-processing machine, in particular a sheet-fed printing machine, having a cylinder with at least one gripper device for the sheets, and with a control device for opening and closing the gripper device.
In transfer devices of the type referred to herein, which include at least one cylinder having a gripper device by the periphery of which a sheet, for example, a paper sheet, is transferred, the opening and closing of the gripper device holding the sheet at the leading edge thereof is performed based upon the rotary angle position of the cylinder. Provided for this purpose is a control device, which includes at least one control cam completely enclosing a bearing journal of the cylinder and having an outer contour followed by a follower element coupled to the gripper device. In this case, the follower element is supported continuously on the closed curved path of the control cam. The control cam is disposed in a fixed position with respect to the rotating cylinder, for example, fastened to a side wall of the machine, and is formed with a through opening through which the bearing journal extends.
The assembly or mounting of the control cam is normally readily possible before the cylinder is inserted, in that it is pushed onto the bearing journal. The adjustment for setting the gripper opening/closing times is achieved by rotating the control cam with respect to the side wall which is in a fixed position, so that format adjustment of the sheets is possible. It has been shown that the control cam, for example, as a result of failure of the follower element, for example, because of a lack of lubrication or due to a fault in the material, can be damaged, which makes the replacement thereof necessary. One possibility for sliding the control cam down off the bearing journal in the axial direction requires the removal of the side wall, which is possible only with a very great amount of effort. One further possibility is to break the control cam, which again is made more difficult by the poor accessibility thereof. Use has therefore already been made, even during initial assembly or mounting, of divided control cams, which are detachably connected to one another. A disadvantage here is that the fabrication, assembly or mounting and adjustment of the multipartite control cam is very complicated and therefore costly.
The published German Patent Document GM 79 27 115 U1 reveals a transfer device which has a multipartite control cam. As viewed in cross section, the control cam has a U-shaped basic body, which can be pushed over the bearing journals in radial direction with respect to the axis of rotation of the cylinder. In order to implement a closed cam path, the open region of the basic body is then supplemented by a short cam segment, which is pinned and screwed to the basic body. A disadvantage thereof is that the production and assembly/disassembly or mounting/removal of the control cam is very complicated.
In addition, U.S. Pat. No. 4,535,691 discloses a transfer device that is installed in sheet-fed printing machines, which are capable of being operated selectively or optionally in recto or first-form printing and in recto/verso or first-form and perfector printing. For this purpose, the opening range of the gripper device, i.e., the rotary angle position of the cylinder wherein the gripper device is opened, up to the rotary angle position of the cylinder at which it is closed again in order to release the sheet, is constructed so as to be adjustable, while the closing range of the gripper device, in order to accept the sheet from a preceding printing unit, for example, is always the same. For this purpose, a control device is used which has two control cams, a first, fixed-position control cam for performing the complete guidance of the follower element in the recto printing operation, while a second control cam, which can be adjusted in the peripheral direction with respect to the first control cam, is located in a nonfunctioning waiting position during the recto printing operation. In recto/verso of first-form and perfector printing, the second control cam is adjusted in order to shift the opening time of the gripper device. In this case, the first and the second control cams then provide one movement section, respectively. A disadvantage of this construction is that the first control cam used for recto printing must be of closed construction, the assembly and disassembly or mounting and removal of the control cam being made more difficult in the case of a unipartite configuration, and the manufacture of the control cam being costly in the case of a multipartite configuration thereof.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a transfer device of the type mentioned at the introduction hereto wherein, even with the cylinder already assembled or mounted, the at least one control cam can be assembled and disassembled or mounted and removed simply and thus, preferably, can be produced simply and therefore cost-effectively.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a device for transferring sheets in a sheet-processing machine, comprising a cylinder having at least one gripper device for the sheets, and a control device for opening and closing the gripper device, the control device having a first control cam for recto printing and a second control cam for recto/verso printing, at least one follower element for following the first and second control cams, each of the first and second control cams being formed with a through opening for accommodating a bearing element and, respectively, a cutout formed in the periphery of the first and second control cams and extending as far as the through opening for fitting the first and second control cams to and removing them from the bearing element radially, the first and second control cams, respectively, being of unipartite construction and, in peripheral direction, being aligned with one another so as to provide an at least approximately closed contour path for the at least one follower element.
In accordance with another feature of the invention, at least one of the first and second control cams is rotatable with respect to the other thereof for adjusting opening and closing times of the gripper device.
In accordance with a further feature of the invention, the cutout formed in at least one of the first and the second control cams has a width which is at least as large as the outer diameter of the bearing element, and is at maximum only sufficiently large for a wall defining said through opening to be interrupted by the cutout over a peripheral range of less than 180°.
In accordance with an added feature of the invention, the gripper device is actuatable by the follower element, and the cutout in the first control for recto printing is disposed in a peripheral region wherein the gripper device actuatable by the follower element is inactive during recto printing.
In accordance with an additional feature of the invention, the first and second control cams are formed and aligned with one another in a manner that guide paths thereof for the follower element, in recto printing and recto/verso printing, overlap in at least one peripheral region of the first and second control cams.
In accordance with yet another feature of the invention, the transfer device includes an actuating drive for aligning the first and the second control cams with one another in peripheral direction.
In accordance with yet a further feature of the invention, the transfer device includes structure provided for manually performing the alignment of the first and the second control cams with one another in peripheral direction.
In accordance with yet an added feature of the invention, the first control cam is fixed to a frame fixed in position, and the second control cam is adjustable in peripheral direction with respect to the first control cam.
In accordance with ye
Becker Willi
Conzelmann Daniel
Fricke Andreas
Greenberg Laurence A.
Heidelberger Druckmaschinen AG
Mackey Patrick H.
Mayback Gregrory L.
Stemer Werner H.
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