Control of the filling level of silver reservoirs in the textile industry

Claim 2

In a method for standardizing the cross section or weight per unit length of a sliver produced by a textile machine including the steps of measuring the supply of material at the outlet of the machine, drafting the material at the outlet of the machine, correcting long-term fluctuations in the material at the outlet of the machine by controlling the supply of material at the inlet of the machine in response to the measured supply of material, correcting short-term fluctuations in the material at the outlet of the machine in response to the measured supply of material by altering the draft thereof, and adjusting the difference between the variable rate of the short-term correction operation and the rate of travel of the sliver by supplying said sliver to a sliver reservoir, the improvement comprising the steps of monitoring a minimum filling level and a lower than minimum filling level of the sliver reservoir and, as a result of such monitoring, controlling the long-term fluctuations in response to the lower than minimum filling level and controlling said correction of short-term fluctuations in response to the minimum filling level in such a way that the average filling level of the sliver reservoir is controlled on the basis of the size of said fluctuations in this filling level.

Claim 3

A method as defined in claim 1 wherein said step of correcting short-term fluctuations is temporarily inhibited upon detection of said less than minimum filling level in the sliver reservoir.

Claim 4

In an apparatus for standardizing the cross section or weight per unit length of the sliver produced by a textile machine having a feed roller at the inlet thereof, comprising measuring means for measuring the cross section of the sliver at the output of said textile machine, first regulating means responsive to said measuring means for controlling the speed of the feed roller of said textile machine to control the supply of material received at the inlet end of the textile machine and second regulating means in the form of a drawing arrangement including a rear pair of cylinders connected to said textile machine to be driven therewith, a front pair of cylinders, and drive means responsive to said measuring means for driving said front pair of cylinders at a variable rate to correct short-term fluctuations in the material received at the outlet of said textile machine, a sliver reservoir receiving the sliver obtained from said second regulating means, the improvement comprising first and second detection means for generating respective signals representative of the minimum filling level and a less than minimum filling level of said sliver reservoir, respectively, first control means responsive to said second detection means for influencing said first regulating means to increase the supply of material to the inlet of the machine, and second control means responsive to a signal from said first detection means for influencing said second regulating means in such a way that the filling level of the reservoir is controlled on the basis of the size of the fluctuations of this filling level.

Claim 5

In an apparatus for standardizing the cross section or weight per unit length of the sliver produced by a textile machine having a feed roller at the inlet thereof, comprising measuring means for measuring the cross section of the sliver at the output of said textile machine, first regulating means responsive to said measuring means for controlling the speed of the feed roller of said textile machine to control the supply of material received at the inlet end of the textile machine and second regulating means in the form of a drawing arrangement including a rear pair of cylinders connected to said textile machine to be driven therewith, a front pair of cylinders, and drive means responsive to said measuring means for driving said front pair of cylinders at a variable rate to correct short-term fluctuations in the material received at the outlet of said textile machine, a sliver reservoir receiving the sliver obtained from said second regulating means, the improvement comprising first and second detection means for generating respective signals representative of the minimum filling level and a less than minimum filling level of said sliver reservoir, respectively, first control means responsive to said second detection means for influencing said first regulating means to increase the supply of material to the inlet of the machine, and second control means responsive to a signal from said first detection means for influencing said second regulating means in such a way that the filling level of the reservoir is controlled on the basis of the size of the fluctuations of this filling level.

Claim 6

Apparatus as defined in claim 3 wherein said second detection means includes a first sensor for detecting said less than minimum level in said sliver reservoir and for providing a signal in response thereto, said first control means being responsive to the signal from said first sensor for controlling said first regulating means to increase the quantity of sliver supplied to said sliver reservoir.

Claim 7

Apparatus as defined in claim 4 wherein said first detection means includes a second sensor for detecting said minimum quantity of sliver in said sliver reservoir and for providing a signal in response thereto, said second control means being responsive to the signal from said second sensor for inhibiting said second regulating means to increase the supply of sliver to said sliver reservoir.