US2138178A - Sheet delivery device for printing machines - Google Patents

Description

Nov. 29, 1938. K. 'r. LANG 2,138,173

SHEET DELIVERY DEVICE on PRINTING MACHINES Filed May 20, 1936 (7/7 van/on.

Patented Nov. 29, 1938 PATENT OFFICE 2,138,178 SHEET DELIVERY navrcn FOB ranvrnv Karl Theodor Lang, Coswig-Dresden, Germany,

assignor to Dresden-Leipzig" Schnellpressen- Fabrik-A. G.) Ooswim Ge Application May-20, 1936, Serial No. 80,!71 In Germany August 21, 1935 2Claims.

This invention relates to a sheet delivery device for printing machines.

Various devices are known already for conveying the printed sheet from the machine with the 5 least possible damage, but all of them are open to the objection that the sheet, at least on one side, comes into contact with fixed machine parts and has to pass them, with the result that it either receives undesirable impressions or that the fresh print is slurred. 4

The invention completely eliminates these drawbacks by providing a conveying means for the sheet and pneumatically operated counteracting supporting means between which the sheet travels. The supporting means may be suction or blast devices the air currents of which form on both sides of the sheet a cushion on which the sheet is moved without coming into contact with the fixed machine parts. The sheet thus actually iioats between the air layers.

The supporting means advantageously can be formed as a drying device for directing warm air currents or streams of a special gas against the freshly printed surfaces of the sheet. The pneumatically operating supporting device may further be constructed as guiding surfaces extending on both sides of the sheet over the entire length of the path which the sheet has to travel.

A characteristic feature of the device according to the invention is the provision of a turning drum behind the impression cylinder, over which the conveying means passes. The turning drum is formed as a hollow cylinder and fitted on its circumference with blast nozzles. Opposite the turning drum hollow bodies are disposed which are constructed as guiding faces and also provided with blast nozzles on the side facing the conveying meansr Both the guiding faces and the turning drum are connected with a ventilator to direct air currents through the blast nozzles upon the sheet moved by the conveying means, so that the sheet passes on both sides between air cushions. It is further possible to provide on both sides of the sheet other guiding means of different type for the sheet.

One form of the invention is diagrammatically illustrated in the accompanying drawing.

Referring to the drawing, the impression cyl inder l rotates in the direction of the arrow and possesses the grippers 2 which take up the sheet 3.

Directly adjacent to the impression cylinder l a rotatable turning drum 4 is provided which on the upper portion of its circumference is equipped with the blast nozzles 5. On each end of the 7 turning drum 4 a sprocket I is disposed on a directing air currents towards v hollow shaft 6 and carries the conveying chain 8. Over the entire width of the turning drum 4 or the cylinder I the grippers 9 are distributed and arranged on suitable carriers on the chain 8, which grip the front edge of the sheet 3 coming from the cylinder l and during their motion convey the sheet 3 over the turning-drum 4. The conveying device leads in a manner not shown to the sheet delivery station. I

Above the chain 8 and the path of the sheet a guiding member ID is provided which partly surrounds the turning drum 4 and on its side facing the chain 8 possesses-the blast nozzles H which may extend in the direction of motion of the sheet or oppositely thereto. It is also possible to mount them vertically to the conveying direction.

In the lower portion of the turning drum 4 the conveying chain 8 passes out of reach of the drum. The sheets are then rectilinearly conveyed, the guiding member Ill extending along the conveying path. Directly behind the turning drum 4 and above the conveying path a second guiding member l2 provided with the blast nozzles I3 is disposed. The turning drum 4 as well as the guiding members l0 and 12 are connected with the ventilator I! by means of the suction pipes l4, IS, IS. During operation of the ventilator l'l currents of dry air are directed in the manner indicated against the conveyed sheet 3 which is thus carried between the turning drum 4 and the guiding members Ill, l2, without coming into contact with these parts, and which is simultaneously dried. The important feature is that the sheet can be conveyed from' the impression cylinder in various ways and that on both sides of the sheet surface along the conveying path blast devices are provided which direct a blast towards the sheet and thus form an air cushion between the sheet and the guiding members. .Instead of air, gases, such as dry gases, may be directed against the sheet, and the continuous guiding members ill, l2 may be replaced by individual guiding means like hollow tubes, etc.

I claim: 1

1. A sheet delivery device. for printing machines comprising conveying means for the sheets, grippers on said conveying means for catching the sheets, a turning drum carrying said conveying means, guiding members extending outsi e the circumference of said turning drum. blastnozzles on the surfaces of said drum and guiding members facing one another and means nected with said blast nozzles.

- for producing drying air, said meansbeing con- I 2. A sheet delivery device for printing machines, comprising conveying means for the sheets, grippers on said conveying means for catching the sheets, a turning drum carrying said conveying means, guiding members extending outside the circumference of said drum, additional guiding members disposed behind said KARL IHEODOR LANG.

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