FR2620972A1 - DRIVE MECHANISM FOR A FOLDER FOR PRINTED PRODUCTS - Google Patents

Abstract

The invention relates to printing machines. In order to avoid the deterioration of the folded copies 6 during the transfer from the knife cylinder 5 to the collet cylinder 7, the collet cylinder is driven in an intermittent or pulsed movement so that at the instant of engagement of the grippers. knives 9 in the grippers 10 the two cylinders have the same speed while the speed of the gripper cylinder 7 decreases after the transfer of the copies 6, after which it is again accelerated. Main application: machines for high speed printing.

Description

The invention relates to a mechanism for training

  Folder element which comprises at least one knife cylinder and a gripper cylinder. Trainings of this type are already known, for example, from DE-A-28 07 387. In this case, the sheet which is

  core on the knife cylinder which usually

  recesses, and that is pushed through

  knives in the clamps of the gripper cylinder ad-

  jacent, is extracted with a speed that corresponds to the speed of the gripper cylinder. If we increase

  gripper cylinder speed, to adapt to the

  constant increase in the working speed of the

  its, which occurs with the improvement of

  nes, it is possible that during the extraction of the

  of the knife cylinder, the front part of the example

  please be whipped, because of the abrupt change of direction of travel, passes

  usually from the horizontal direction to the direc-

  vertically, which leads with a non-existent frequency

  glaring at a loss of angles or deterioration

copy.

  The object of the invention is to avoid deterioration

  the copy at the moment of its transfer from the cylinder.

  dre knife holders to the gripper cylinder, even in

  the case of high production speeds. According to the invention

  This problem is solved by the fact that

  the gripping cylinder operates in synchronism with the knife cylinder but with a pulsed speed and is of such a configuration

  that there is equality of speed between the cylinders at

  transfer of the folded copies and that the speed of

  of the pliers cylinder is then reduced during

  the collection of copies folded on the cylinder

  you knife. According to another characteristic, the diameter

  clamp cylinder is smaller than the one

  the calculation would give for circumferential velocities

  identical values for the two cylinders. According to one

  Another feature of the invention is the cylinder

  tongs is driven by the knife cylinder by

  intermittent training which

  takes a variable pitch screw, in which drive sheaves are mounted on a disc

  divider which drives the cylindrical cogwheel

linder clamp holder.

  The appended drawing, given solely by way of example, will make it clear how the invention can

to be realized.

  The folder 1 shown schematically receives

  a band of printed products 3, which usually reaches him

  through a funnel 2, and

  passes between two perforation rollers 4 and is then

  cut you off, so you get folded copies

  6 which can be routed to a cylinder

  5. The knife cylinder 5 usually has

  In order to receive the folded copies 6,

  8 and folding knives 9. The folded pieces 6 which are supported on the knife cylinder are transmitted one by one by the knives to a cylinder

  gripper holder 7 which is placed against the cylinder holder

  knives 5, cylinder which is equipped with folding pliers

  in which the knives 9 push the exemplary

6.

  Then each folded copy 6 is transmitted

  the gripper cylinder 7, the front part of the example

  please 6 then changing direction of movement. Under this effect, and in particular, at high speeds, there is a "whiplash"

  lead to deterioration of the copies 6.

  From the gripper cylinder 8, the 6 folded copies transversely can be debited directly to the reception by a paddle wheel, or they can be conveyed, via means of

  not shown in detail, usually

  stowed by belt conveyors, to a pair of

3 2620972

  rollers 12, to receive a second longitudinal fold.

  Then the reception can be done through

  non-referenced means indicated schematically and

universally known.

  With the invention, the risk of deterioration resulting from the extraction movement of the folded copies of the knife cylinder 5 is avoided by the fact

  that the speeds of the gripper cylinder 7 and the cylinder

  knives 5 are identical, that is to say relative to

  at the moment of the transfer of the specimens 6 while, then, that is to say during the extraction movement, the speed of the gripper cylinder 7 is reduced, so that the transfer of the specimens 6 from the Knife cylinder 5 is performed with a reduced speed. This greatly reduces the aforementioned risk or may even completely eliminate it. Then, that is to say when the copies 6 have been applied to the gripper cylinder 7, the gripper cylinder 7 can be re-accelerated, so that, during the transfer of the next copy, the two cylinders 5, 7 are at

  new animated identical speeds.

  A particularly advantageous form of

  According to the principles of the invention mentioned above, the driving mechanism is that the driving of the gripper cylinder 7 is ensured.

  by means of an intermittent drive 13.

  Here, the training movement is taken, through

  of a bevel pinion 14 on the drive wheel.

  not shown in the knife cylinder 5 and the movement is transmitted by means of a screw 16

  variable pitch, in which pebbles of

  17, to a divider disc 18 which is engaged by a pinion 19 with the toothed wheel 20 which entrains the

  7. This ensures that each time

  of a copy 6, the cylinders 5, 7 have the same

  speed, and therefore work in a fully syn-

  chrone, and that, then, there is a reduction in the speed of the gripper cylinder, to allow non-aggressive transmission of the copies. Then, in

  because of the variable pitch of the screw 7, the speed of the cylinder

  The gripper holder 7 is again increased so that identical speeds are available for the operation.

  following copy transfer. The diameter of the

  The gripper holder 7 is preferably smaller than that which the calculation would give to obtain speeds.

identical circumferences.

  In this way, it is possible to avoid

  deterioration of the copies which would otherwise be due to

  the increase of the speed of the machine.

  It goes without saying that various modifications

  by the person skilled in the art to the device that has just been described, in particular by substituting the equivalent technical means, without thereby leaving the

framework of the invention.

Claims (3)

  1 - Drive mechanism for a folder which comprises at least one knife cylinder and a   clamp cylinder, characterized in that the mechanism   The driving arm of the folding clamp cylinder (7) operates in synchronism with the knife cylinder (5) but with a pulsed speed, and is constituted in such a way that there is equal speed between   the cylinders (5, 7) at the time of the transfer of the exemplary   res (6), and that the speed of the pin cylinder   these (7) are then reduced during the removal of the folded copies (6) on the knife cylinder (5). 2 - Drive mechanism for a folder   according to claim 1, characterized in that the diameter   clamp cylinder (7) is less than   their that the calculation would give to obtain identical circumferential speeds for the two cylinders (5, 7).   3 - Drive mechanism for a folder, characterized in that the gripper cylinder (7) is   driven by the knife cylinder (5) through   intermittent training (13) which   takes a screw (16) with variable pitch, in which   drive rollers (17) which are themselves   mounted on a plate (18) driving the toothed wheel cy-   the cylinder of the gripper cylinder (20).