摘要:
The invention relates to a device for floatably guiding webs of material by means of a gaseous or liquid medium. The device comprises one or more elongate flow elements having a surface which is arched more particularly convexly to the web of material which are disposed in succession in the direction of travel of the web and transversely thereof, and nozzles so disposed in rows at a distance from such surface that the free jets emerging from the nozzles blow on the surface of the flow member at a shallow approach flow angle and are converted on the surface into wall jets, before they blow on the web of material, more particularly by reversal of flow. More particularly nozzles associated with both longitudinal edges of each flow member and delivering free jets directed towards one another produce on contrast with conventional devices, which operate on the supporting surface or air cushion principle, improved supporting behavior with a strongly progressive characteristic in the proximal zone of the web of material and a relatively steep entry into the zero value of the supporting force.
摘要:
A probe is employed for removing dust from moving webs, paper webs for example. It has at least one electrostatic high-voltage electrode, at least one blower for gas, preferably air, oriented against the direction that the web travels in, and a vacuum channel for suctioning up the dust-laden gas. The pointed or blade-shaped subsidiary electrodes in the high-voltage electrode (10) lie in a plane that does not parallel the web (7). The direction that the row of round and/or slotted nozzles (12) in the blower (11) blow along lies in another plane downstream of the high-voltage electrode (10). The two planes intersect at a line that lies in the plane of the web (7) and extends across it. The round and/or slotted openings (14) into the vacuum channel (13) are on the other hand positioned upstream of the high-voltage electrode (10) in the web-travel direction (8).
摘要:
In an apparatus for contactless guiding of webs of material, in particular metal strips, by means of a gas medium, nozzle boxes are disposed above and below the web of material. The distances of the nozzle boxes from an imaginary, essentially horizontal center plane extending in the direction of transport differs individually or in groups. The positions of the outlet planes of the nozzle boxes are adaptable to the wave form, and each wave trough and each wave crest of the wave form is formed by at least two adjacent nozzle boxes.
摘要:
The invention relates to a plant for drying a material web. Such plant includes a plurality of upper (3) and lower blow boxes arranged substantially mutually parallel and at right angles to the travelling direction of the web. The lower boxes are intended to support the web and are provided in their surfaces facing towards the web with orifices for blowing air in directions substantially parallel to the plane of the web. The air ejection velocity is thereby sufficient to maintain the web in a specified floating position above said boxes. The upper blow boxes (3) are situated on the other side of the material web and have orifices for blowing air substantially perpendicularly to the plane of the web. According to the invention, the distance (H) between the blowing orifices of the upper blow boxes and the web is variable. It is furthermore adjustable so that the relative energy requirement for the upper blow boxes may be brought closely into the region of the value 1. The variable distance (H) may be provided, in accordance with one embodiment of the invention, by the upper blow boxes (3) being at one end ( 6) pivotably mounted in a wall (7) of a compressed air chamber, while their other ends (8) are movable in height for adjusting the distance (H) to the underlying, fixed web-positioning blow box (4).
摘要:
An automatically controlled cutting machine includes a conveyor table having an endless conveyor belt for moving segments of limp sheet material onto the table for cutting. A cutting carriage and blade are mounted for controlled movement over the support surface of the table to cut pattern pieces from the limp sheet material positioned on the surface. A vacuum chamber envelops the endless conveyor belt except for the portion of the belt defining the support surface, and the chamber communicates with the sheet material on the surface to draw a vacuum within the material and hold the material in a compressed state on the surface for cutting.
摘要:
Apparatus is provided for taking a stack of flat articles such as folded newspapers, and delivering them successively to a conveyor in an overlapped or shingled arrangement to move to a processing station for labeling or addressing or for opening them to receive inserts. A rectangular hopper or gate is located over a traveling belt means to hold a stack of such flat articles with its converging angle pointing downstream. Each bottom article is gripped by the belt means, which is vacuumized in the area under the stack, and is pulled under the gate and downstream.When a given article is only partially through the gate, the succeeding article is gripped primarily by its side portions and pulled under the gate in overlapping or shingled relation with the preceding one, each article being arranged with its side edges at a substantial angle to the direction of travel. A shield underlies the rear portion of the stack to prevent gripping the rearmost portions of the articles until they are moving with the speed of the belt to prevent distortion or damage.
摘要:
An improved floatation-type pressure pad is described as having lines of jet nozzles which are so arranged at the opposing ends of the pad that streams or jets of gas, emitting from the nozzles and striking a strip of material passing nearby, tend to stretch the material in a crosswise direction to flatten the strip and eliminate any crosswise distortions in the strip. Ancillary to this, is vertically offsetting pairs of adjacent pads to momentarily form in the strip of material, an inclination or wave in a lengthwise direction to help flatten the strip and eliminate such distortions in the strip.
摘要:
The invention relates to a web guide roller for a web which is required to be moved at a high speed, having cavities arranged on its surface for receiving the air carried with the moving web, whereby a finely branched network of compression chambers is arranged on the surface between plateau-like smoothly ground and polished areas on which the web lies in contact. Further the invention relates to a process for the production of this web guide rollers for use at high speed.
摘要:
Apparatus for producing discrete blanks from a web of foil or the like is provided, in which the foil or the like are given continuous constrained guidance during the phase between separation of the web until transfer to a packet or packing machine. The web is transported into the system between a first pair of pulling rollers then transferred to a conveyor of two spaced belts. The belts are provided with a series of apertures through which a suction is pulled to hold the transported web. The belts diverge slightly and pull the web at a higher speed than the first pair of rollers so that the web is stretched both lengthwise and transversely. Severance from the web is carried out in at least one initial cut, followed by a main cut, during continuous constrained guidance.
摘要:
Apparatus for cutting patterns from successive contiguous segments of an elongated layup of sheet material has a zoned vacuum table which includes an endless bristle mat conveyor, for shifting a layup along the table to position a segment of the layup in the cutting zone of the table and for holding the layup segment in the cutting zone, and a carriage assembly, which moves a cutting mechanism relative to the table and in cutting engagement with the segment to cut patterns from the segment in response to signals from a programmable controller. A rotary encoder mounted on the carriage assembly has a pinion which engages a rack carried by the conveyor to detect movement of the carriage assembly relative to the conveyor when the carriage assembly returns to its starting position after completing its cutting cycle. A responsive circuit connects the encoder to the conveyor drive motor and energizes the drive motor in response to the relative movement detected by the encoder to cause the conveyor to move the layup in the return direction and through a distance equal to the distance traversed by the carriage assembly in returning to its starting position whereby the next successive segment of the layup is accurately positioned in the cutting zone. An error sensing circuit detects the magnitude and direction of an error in positioning the layup and alters the data in the controller to nullify the error. A vacuum device cleans the bristle mat while the conveyor is in motion and also reduces the vacuum holddown force applied to the layup while it is being shifted by the conveyor.