Abstract: An apparatus for sensing the density variation of a sliver, includes a sliver funnel through which the sliver passes and which has an intake portion, a discharge portion and a chamber formed as an enlarged part of the discharge portion. The chamber is, through a lateral opening, in communication with a source of pressurized air and a pressure sensing device. The pressure sensing device receives pneumatic signals as a function of the variation of pressure in the chamber dependent upon the density of the sliver portion momentarily present in the chamber. The sliver funnel is arranged at an output of a carding machine for receiving a web discharged thereby and for combining the web into a sliver passing through the chamber. The pressure sensing device comprises a pressure-responsive precision sensor which includes an arrangement for converting the pneumatic signals into digital signals.

Abstract: A circuit for controlling the speed of a feed roller in a card or the like in which the sliver thickness is detected and a signal produced which is combined with signals representing feed and doff roller speeds, and a signal representing feed motor torque. The resulting signal is compared with a ramp signal to drive the feed motor so as to maintain sliver thickness at a desired value.

Abstract: An apparatus for making a uniform, continuous sliver has a sliver sensor for continuously sensing the throughput quantity of the sliver and generating a continuous main regulating signal x as a function of the throughput quantity and a first regulator connected to the sliver sensor for receiving the signal x and generating a reference signal w.sub.h as a function of the signal x. The apparatus further has a tuft column sensor connected to a tuft shaft of a card for sensing a variable of the tuft column advancing in the tuft shaft. The tuft column sensor has a signal generator for emitting an auxiliary regulating signal x.sub.h as a function of the sensed variable of the tuft column and a desired value setter which receives the signal w.sub.h and varies the signal x.sub.h as a function of the signal w.sub.h. Further, the apparatus has a tuft column altering arrangement including a second, auxiliary regulator which receives the signal x.sub.

Abstract: A method of, and apparatus for, forming a fiber layer of substantially constant weight per unit length, there being provided supply means for supplying a fiber and air mixture onto a moving, fiber-separating, perforated surface. A suction opening is arranged beneath and extends over a certain zone or region of such perforated surface. The suction opening can be moved forward and backward with respect to the direction of transport of the fiber and air mixture by the perforated surface as a function of a measuring value which is representative of the thickness of the fiber layer deposited upon such perforated surface.

Abstract: A method and apparatus for automatically leveling a band of fibers such as sliver, roving and the like by varying the drafting speed of a drafting mechanism responsive to variations in the thickness of the band. Analogue signals are produced by variations in the thickness of the band and are converted to digital signals for being stored in a digital register. After a period of time, corresponding with the time for conveyance of the scanned point in the sliver up to and into the draft zone, the information is read out of the storage register and converted back to an analogue signal. The analogue signal is compared with another signal representing the actual drafting speed for producing a compared signal for controlling the drafting speed.

Abstract: An apparatus for producing a uniform textile fiber sliver which is removed from a sliver supply device, for instance a card, and taken-up by a driven take-up or receiving device, wherein the fiber sliver removed from the sliver supply device is guided through a regulation drafting arrangement having a pair of measuring rolls and a driven pair of drafting rolls. One roll of the measuring roll pair is driven by the sliver supply device, and the other measuring roll is deflected as a function of a change in thickness of the fiber sliver traveling through the measuring rolls. The drive speed of the pair of drafting rolls and the receiving or take-up device is regulated as a function of the deflection of said other measuring roll, and the drive speed of the take-up device additionally is regulated as a function of the length of the fiber band between the pair of drafting rolls and the take-up device.

Abstract: A method and apparatus for controlling the sliver thickness variation in a carding machine. The thickness variation of the sliver delivered from the carding machine is measured and an electrical signal corresponding to the thickness variation of the carded sliver is issued. A difference signal is created by comparing the above-mentioned electric signal, and a control pulse signal in accordance with the difference signal is intermittently created at predetermined time intervals, each of said time intervals being shorter than a time required for a length of the carded sliver which length corresponds to a long term variation of the carded slivers thickness. The supply amount of fiber tufts to the carding machine is intermittently adjusted for reducing the above-mentioned control signal toward zero by said control pulse signal at each of said time intervals.

Abstract: A pneumatic measuring means is placed over the main cylinder to measure pressure variations due to changes in fiber layer thickness. The measured pressures are transmitted to a measuring and control means which compares the measured pressures to a pre-set value and produces a difference signal which is then used to control the card. The difference signal can be imposed on the supply means for the card, the doffing means or the drafting means.

Abstract: A plurality of combing machine slivers having periodically variable densities are combined in such a way that the density variations approximately compensate one another and a complete sliver having little density variation is formed. The relative phase positions of the respective combing machine slivers when assembled together are controlled in response to the periodicity of the complete sliver.

Abstract: The deviations in measuring the density of the fiber strand caused by manufacturing tolerances in the take-off rolls are monitored by integrating the deviations in densities from a preset value over periodic intervals in a control device. The integrator is controlled by periodic impulse signals and is used to adjust the transporting air stream so as to regulate the pressure drop to achieve an even strand.

Abstract: In a deep pile fabric knitting machine which includes carding wheels from which fibers are transferred to rotary doffers and from which the fibers are selectively taken by knitting needles traveling with a rotary cylinder, but with at least some untaken fibers remaining on the doffers, remaining fibers are scavenged from the doffers, substantially uniformly dispersed and returned for recycling in the same carding paths from which the fibers were originally transferred to the doffers. Returned fibers may be applied directly to the perimeters of the carding wheels, or to sliver leading to the carding wheels. Scavenging may be effected by high speed scavenger rolls and return of the fibers effected pneumatically with mechanical dispersion. Loose fibers are blown from the knitting needles and recycled in the same system with the fibers scavenged from the doffers.

Abstract: Apparatus in a card for sensing and controlling the relative speeds of the feed and doffer rolls in accordance with the sliver density as sensed by error detection circuitry responding to the amount of a transduced compression wave in the sonic ultrasonic range which passes through the sliver.

Abstract: Apparatus in a card for sensing and controlling the relative speeds of the feed and doffer rolls in accordance with the sliver density. A mechanical sensing device responds to the cross-section of the sliver to close the contacts of an electrical circuit when the cross-section deviates from an acceptable range. On contact closure, the circuit provides an electrical signal to the drive arrangement of the feed and doffer rolls to vary the roll speeds thereby effecting a correction in sliver cross-section.

Abstract: In order to compensate the combing periods in density fluctuation machine slivers, the density of each of a plurality of slivers is measured to detect the phase positions of the combing periods therein and then the relative positions of the respective slivers are adjusted to place the combing periods in each sliver out of phase with the combing periods in the other slivers before the slivers are combined. The adjustment of the phase position of the slivers is effected by varying the length of the path of the sliver between the combing machine and the point where the slivers are combined.

Abstract: An apparatus for maintaining sliver thickness uniform whereby the web from a carding machine is gathered by a trumpet and passed between a grooved driven roller and a sensor roller riding in the groove so that the movements of the sensor roller vary as a function of sliver density. The sensor roller is mechanically connected to a magnetic core so that movement of the sensor roller varies the coupling between a primary transformer winding and a pair of secondary windings. The voltages induced in the secondary windings are applied, after a delay, to a first differential amplifier whose output in turn is connected to a second differential amplifier which is periodically rendered operative by a pulse generator and to which is also connected a potentiometer for adjusting desired density. The output of the second amplifier is connected to a pair of relay coils, one responsive to positive excursions and the other to negative.