Device for the control of blowing air, turner bar assembly, and printing machine

#The present invention relates to a device for the control of blowing air, in particular in a web-fed rotary printing machine or in a turner bar of a web-fed rotary printing machine. The device is connected to a compressed-air source and is formed with at least one outflow orifice, and the device has a valve element which is moveable into a first position in which blowing air flows from the compressed-air source at least through a first duct to the outflow orifice and which is moveable into a second position in which blowing air flows from the compressed-air source at least through a second duct to the outflow orifice. A volume flow through the second duct is thereby greater than a volume flow through the first duct.

#The invention relates, furthermore, to a turner bar, in particular for deflecting a printed material web in a web-fed rotary printing machine.

#My earlier U.S. Pat. No. 5,797,531 (see German publication DE 196 37 674 A1) discloses a differential-pressure turning-bar arrangement, by means of which a printed material web, for example a paper web, is deflected from a run-in movement direction to a run-out movement direction, the run-out movement direction being determined by the angle of arrangement of the turner bar to the run-in movement direction and by the looping angle of the material web in relation to the turner bar. In order to prevent the printing ink from being deposited from the freshly printed and, where appropriate, dried material web onto the surface, for example the casing, of the turner bar, the turner bar is connected to a compressed-air supply and is provided with air outlet orifices, out of which blowing air is blown into the region between the turning-bar casing and the material web looping around the turner bar. This results, between the material web and the turning-bar casing, in the formation of an air cushion, on which the material web is moved contactlessly over the turning-bar casing, so that a smudging of printing ink on the looped-around surface region of the turner bar is prevented. The turner bar, has, furthermore, inside it, closing elements, with which the air outlet orifices can be partially closed. The closing elements are provided with a bore, through which blowing air can emerge, even when the air outlet orifice is in the closed state, and are moveable in a guide. When an outlet orifice is covered by a material web, the air stream through the bore is obstructed in the closing element, and, as a result of the dynamic pressure which builds up above the closing element, the latter is moved in the guide into a position in which the closing element releases the air outlet orifice. Blowing air can then flow via a bypass from the compressed-air supply to the air outlet orifice and a sufficiently stable and load-bearing air cushion can form under the material web surrounding the turner bar. However, those air outlet orifices of the turner bar which are not covered by the material web continue to remain closed by the closing element, so that only a reduced air stream which flows through the respective bore in the respective closing element passes outward from them.

#FIG. 1 shows a sectional view of a device according to the invention with a valve element and with a basic body;

#FIG. 2 shows a sectional view of a device according to the invention with an inserted valve element;

#FIG. 3 shows a top view of a device according to the invention;

#Referring now to the figures of the drawing in detail and first, particularly, to FIGS. 1 and 2 thereof, there is shown a device for the control of blowing air 1, which can be used, for example, in a turner bar (also referred to as a turning bar) of a web-fed rotary printing machine. The device 1 comprises a basic body 2, a valve element 4, a ring 6, and a sealing ring 8. The valve element 4 is shown in FIG. 1 next to the basic body 2 for the sake of clarity, but, when the device is in operation, is in the installed or inserted state within the basic body 2, as may be gathered, for example, from FIG. 2. The valve element 4 preferably comprises an annular edge region 10, an intermediate region 12 designed as a bellows, and a substantially disk-shaped diaphragm region 14. At least the intermediate region and the diaphragm region can be produced from an elastomeric material or from an elastomeric mixture, for example rubber or caoutchouc. The edge region 10, which serves for retaining the valve element 4 and can be inserted into a groove 16 of the basic body 2, may likewise be formed from an elastomeric material, but also, for example, from plastic or metal. It is possible, furthermore, to produce the valve element 4 or the edge region, intermediate region and diaphragm region as a single work piece or assemble it from a plurality of individual work pieces. The diaphragm region 14 of the valve element 4 may also be reinforced by a disk 18 and its valve action improved, and it is possible to apply, for example adhesively bond, the disk 18 to the diaphragm region 14, partially embed the disk 18 into the diaphragm region 14 or incorporate the disk 18 completely into the diaphragm region 14. In this case, the disk 18 may be manufactured from various materials, such as, for example, plastic or metal. The edge region 10 of the valve element 4 forms, together with the groove 16 of the basic body 2, an airtight closure.

#FIG. 2 shows the basic body 2 of the device for the control of blowing air, with the valve element 4 inserted. The diaphragm region 14 is in a position in which it is not in touching contact on the diaphragm surface 20 with an annular seat 22, formed in the basic body 2, for the valve element 4.

#The various regions, chambers and ducts of the basic body will be described in more detail below. The basic body 2 has a compressed-air feed duct 24 which, as may also be gathered from FIG. 3, is configured as a hole passing through the basic body 2 or else as a bore. As may be seen from FIG. 4, a plurality of devices 1 according to the invention may be lined up with one another and thus be used for the construction of, for example, a turner bar. It may be gathered again from FIG. 2 that, for this purpose, the basic body 2 comprises a recess 26, which may also be designated as a compressed-air entry, and a projection 28, which may also be designated as a compressed-air exit and which has a groove 30 for receiving the sealing ring 8. The compressed-air entry 26 on one side of the basic body 2 and the compressed-air exit 28 on the other side of the basic body 2 are worked in such a way that, when a plurality of basic bodies 2 are assembled, in each case the compressed-air exit 28 of a preceding basic body can be inserted, for example snapped or plugged, into the compressed-air entry 26 of a following basic body.