Abstract:
A web of copying material is transported on-edge through an exposure-station web guidance system provided with a masking system which includes stationary and shiftable transverse-edge framing plates. The projected image of a first longitudinal-edge reference line on the copy table supporting the original is brought into register with a corresponding reference line of the masking system. The projection scale is adjusted to cause the format-breadth of the projected image to be at most slightly smaller than the format breadth of the web, but in no event greater. The projected image of the first transverse edge of the original is brought into register with the edge of the stationary framing plate, and then that of the second transverse edge with that of the shiftable framing plate. This registration is effected by sensing infrared-light images of the dark-light transitions associated with the transverse edges of the original. An exposure is performed. Before transporting the exposed section of web out of the exposure station, a cutting mark is provided by a perforator on the shiftable framing plate, and this cutting mark is thereafter detected by a detector on the stationary framing plate and triggers a severing operation.
Abstract:
An original to be copied is fed onto the copy table of the copying machine. The receipt of the original to be copied triggers the establishment of an electrostatic holding field which holds the original flat on the copy table during the exposure operation. Performance of the exposure operation triggers disestablishment of the electrostatic holding field. The polarity of the electrostatic holding field is successively reversed.
Abstract:
A press for the production of pressed board with injection of steam utilizes press platens to which the steam is fed to the steam-feed channels from opposite sides in a collision flow, the chanels communicating with steam-nozzle bores opening at the pressing surface and such that the cross section of each channel is equal to at least 60% of the total flow cross sections of the boards communicating with that channel. Before the pressing commences, the channels are through-flushed with steam to flush air from the channels and bores and to evacuate air from the pressed mat by a venturi effect.
Abstract:
A cassette housing has an inlet and accommodates in its interior a turntable provided with a tape-engaging hub. The turntable is rotatable about a normally upright axis in one direction to take tape up on the hub, and in the opposite direction to pay tape out from the hub. A pair of guide baffles guides the tape for travel between the inlet and the hub. An articulated band of curved band sections surrounds the hub over a portion of arc and rests freely slidably on the turntable so that when the same is rotated in take-up direction the articulated band contracts about the hub to urge tape on the same against the hub, whereas when the turntable is rotated in the pay-out direction the articulated band expands about the hub to recede outwardly from it so as to permit unobstructed paying-out of the tape.
Abstract:
A press for the production of pressed board with injection of steam utilizes press platens to which the steam is fed to the steam-feed channels from opposite sides in a collision flow, the channels communicating with steam-nozzle bores opening at the pressing surface and such that the cross section of each channel is equal to at least 60% of the total flow cross sections of the boards communicating with that channel. Before the pressing commences, the channels are through-flushed with steam to flush air from the channels and bores and to evacuate air from the pressed mat by a venturi effect.
Abstract:
A process for making a composite wood panel, fiberboard or the like comprises putting a mat to be pressed between the press platens of a press, compressing the mat with heated press platens in a first compression step without feeding in steam until a density of at least 50% of that of the product panel is reached, preferably 70 to 85%, in a second compression step feeding steam with a pressure of between 1 to 3 bar through both press platens and compressing further until from 10 to 40% of the compression occuring in the first compression step (this is taken as 100%) is attained, in a third compression step interrupting the steam feed, the density attained in the second step being maintained, and subsequently compressing with a pressure of steam which is greater than the steam pressure used in the second compression step. Advantageously the steam pressing step is characterized by a flushing event in which the steam issues from the steam pressing orifices of one of the press platens and flows through the mat and also into the steam orifices of the other one of the press platens which temporarily are cut off from the source of the steam. Furthermore during a final compression time interval the mat is exposed to the action of a vacuum source connected to at least one of the press platens to dry the mat.
Abstract:
The apparatus for hot pressing a pressed board mat used in making chipboard panels, fiberboard panels and pressed board panels comprises a continuously operating press with a lower press belt and an upper press belt and a conveyor with at least two endless conveyor belts adjoining each other. The press has a mouth entrance in which the conveyor extends with a delivery nose directed in the feed direction up to a delivery region in the entrance. The delivery nose is movable in the vertical direction, in the transport direction and in a direction opposite to the transport direction and because of that, the delivery region is displaceable in the entrance of the press according to the thickness of the pressed board mat to be pressed.
Abstract:
Apparatus for transporting exposed films or webs of photographic paper along a helical path through a vessel in a developing machine has a set of parallel rings mounted between and rotated by three shafts which are parallel to the axis of the helical path. The planes of the rings make acute angles with the axis of the helical path, and each ring is rotated about its own axis. The leader of a web which is fed into the space within the rings is engaged by the inner surfaces of successive rings and is transported along the helical path. During transport along such path, the web travels around a stationary or rotating twin-walled foraminous pipe which discharges a pressurized fluid whereby the fluid impinges against the emulsion-coated inner side of the web and urges the web against the inner surfaces of the rings so that the pressure of fluid assists the centrifugal force and cohesion between the web and the rings to maintain the web in the helical path. The shafts have circumferential grooves for portions of the rings, and one of the shafts is movable axially to change the inclination of the rings.