摘要:
An apparatus for accurately guiding a web of light-sensitive recording media into a cylindrical support shoe of a printer includes a metering roller at the inlet side of a stationary support shoe around which a received media web is wrapped. At least one media guide belt is mounted about a set of pulleys to guide media toward a nip between a pressure roller and the metering roller through which the media is driven into the stationary support shoe. The metering roller is mounted to rotate about a predetermined axis, and the pressure roller has one end held in a frame and is spring loaded into the frame and the metering roller. The other end of the pressure roller is also spring loaded into the metering roller and into an adjustment plate which is pivotal about the axis of the metering roller, whereby the pressure roller can be steered so that the axis of the metering roller and the axis of rotation of the pressure roller are made parallel, and so that the nip between the metering roller and the pressure roller can be adjusted to lie in a plane defined by the axis of the metering roller and the axis of rotation of the pressure roller to cause media to run uniformly and predictably when metering into and out of the cylindrical support shoe.
摘要:
A drawing roller drive for the conveyance of a web in a rotary printing press utilizes a differential gear to accomplish a very exact change in the speed of the drawing roller. A single drive shaft and a single power take-off shaft are aligned coaxially with respect to each other. The differential gear arrangement includes a ball race gear and a downstream tension shaft gear.
摘要:
An apparatus for measuring sliver thickness in a drawing frame includes a sliver guiding device having converging inner wall faces for bringing a plurality of simultaneously introduced slivers together to form a sliver assembly constituted by side-by-side positioned running slivers arranged in a plane. The apparatus further includes a sensor element and a counterelement laterally contacting the sliver assembly from opposite sides. The sensor element has an operative position and a servicing position; in the servicing position the apparatus outlet is free for access from the exterior. The sensor element is urged into a resilient contact with the sliver assembly whereby the sensor element undergoes excursions upon variation of thickness of the sliver assembly. There is further provided a setting arrangement for selectively positioning the sensor element into the operative or servicing position. The sensor element and the counterelement together define a constriction through which the sliver assembly passes. A transducer converts excursions of the sensor element into electric pulses. A withdrawing roller pair supported downstream of the sliver guiding device pulls the sliver assembly through the sliver guiding device.
摘要:
An apparatus for controlling the transportation speed of a sheet, such as a printed sheet or manuscript, includes a sheet transportation system and a speed controller. The transportation system includes a single drive motor and a plurality of rollers driven by the single motor and arranged in such a manner that a sheet to be transported is held by the rollers one after another. The speed controller includes a sensor for detecting the position of the sheet. The number of rollers which hold the sheet is determined. A speed controller provides the motor with a designated speed command calculated on the basis of the numbers of rollers, so that the actual sheet transportation speed is always constant regardless of the numbers of rollers which hold the sheet.
摘要:
A method and an apparatus provided to calculate and control the elongation in a running web (16), e.g. in connection with a preparation of a web in a printing machine. In connection with at least an increase or decrease in the web tension, the length change in a reference length of the web material is measured, and by means of web tension meters the web tension before and after the web tension change (.sigma..sub.1 -.sigma..sub.2) or each one of the web tension alterations is determined. The tension-free length (n.sub.o) of the reference length is also calculated and if it is needed, the elongation of the web is corrected through an increase or a decrease in the web tension depending on said measurements.
摘要:
A system and method for preventing a broken printing web from wrapping about or otherwise fouling the blanket cylinders of printing press units. The system and method includes a web tensioning device located downstream of the printing press units for maintaining tension upon a broken web and pulling the web from the printing press units. The device includes a plurality of web disturbance detectors for detecting a wave, ripple or other disturbance indicative of a web break. A pair of anti-wrap rollers located above and below the web are engaged upon detection of a web break to engage the web between them to exert tension onto the web and pull it from the printing units. The anti-wrap rollers are rotated at a surface speed nominally greater than the surface speed of the printing rolls. The anti-wrap rollers include a plurality of opposed peak and valley portions which enable them to interlock and grip the web along a line of contact.
摘要:
A cassette tape transport has a tape speed control servo for driving either of a pair of tape drive motors at constant speed in response to tape speed pulses from a tape speed sensor. Upon development of a tape slack, as manifested by a decrease in the recurrence rate of the tape speed pulses, the tape speed control servo is overridden, and the pair of drive motors are simultaneously energized for rotating the cassette reels in opposite directions, thereby stretching the tape between the reels until the slack is removed. The tape transport has a microcomputer which may be factory preprogrammed to include a slack takeup routine. The microcomputer starts the slack takeup routine not only upon decrease in the recurrence rate of the tape speed pulses but also when the tape cassette is loaded in the tape transport and when no tape speed pulse is produced for a predetermined length of time.
摘要:
The tension on a tape web is controlled with a lock mechanism in an apparatus wherein a first dancer device, a pair of engaging-disengaging rolls, a second dancer device, and a pair of nip rolls are located in this order from the upstream side to the downstream side in the direction along which the tape web moves. The speed at which the engaging-disengaging rolls rotate is adjusted on the basis of the vertical position of a dancer roll of the first dancer device, and the speed at which the nip rolls rotate is adjusted on the basis of the vertical position of a dancer roll of the second dancer device, whereby the tension on the tape web is adjusted. A method for controlling the tension with a lock mechanism comprises the steps of locking the position of the dancer roll of the first dancer device at a predetermined position when the engaging-disengaging rolls disengage from each other, and releasing the dancer roll of the first dancer device from its locked position when the engaging-disengaging rolls engage with each other.
摘要:
In a device and a method for the regulation of the controlled infeed of web material to a printing machine, a control component of a differential gear placed ahead of a web drive roller is driven by a second continuously adjustable drive by the main drive of the printing machine. Control of the second drive takes place via a servomotor which is connected by a control circuit with a tensioning roller deflectable by the paper web. During control the voltage signal generated by the deflection of the tensioning roller is converted parallel into a voltage signal characterizing the position of the tensioning roller and into a voltage signal weighting the direction of movement. Then these signals are linked into a single output signal and are routed to the servomotor.
摘要:
Modular web processing units may be physically and electrically assembled into clusters to perform various web processes (e.g. the production of paper forms such as invoices, checks, labels, etc.). Each module has a main process driver which is not directly coupled to a web drive mechanism. Rather, the web driver is program controlled so as to effect the desired web process at controlled displacement intervals along the web. Accordingly, a plurality of successive but different form lengths or depths can be accommodated as the web surface is sequentially processed. A system of such modules can be physically wheeled into position as individual units and electrically connected together by suitable umbilical cords to rapidly configure a desired overall web finishing process. Nevertheless, the entire ensemble of modules performs as though it is a unitary special purpose web processing machine with its various process stations interconnected and synchronized by an electronic "drive shaft". One of the modular units automatically becomes the master source of process drive pulses for the others and the entire ensemble may be controlled from the control panel of any one of the modules. Examples of modules for unwinding web from a roll, for folding processed web, for printing and for perforation or cut-off are described.