Apparatus for feeding and classifying cut tobacco

Claim 2

In an apparatus for feeding and classifying cut tobacco, a combination comprising a pneumatic duct having an upper portion and a lower portion; distributor means including a source of intermixed lighter and heavier particles and delivery means for feeding particles from said source into said duct in a region below said upper portion thereof; circulating means for conveying through said duct an ascending current of air strong enough to entrain only the lighter particles so that the heavier particles descend by gravity into the lower portion and the lighter particles enter the upper portion of said duct; means for receiving heavier particles from the lower portion of said duct; means for collecting lighter particles which enter the upper portion of said duct and for forming said particles into a moving carpet, comprising chute means having an upper end arranged to receive lighter particles and a lower end, the thus received lighter particles forming in said chute means a column extending upwardly from said lower end, and evacuating means for withdrawing lighter partIcles from the lower end of said chute means; adjustable condensing means for condensing lighter particles in said column; and means for adjusting said condensing means as a function of changes in density of the tobacco particles in the column in the region of the lower end of said chute means.

Claim 3

In an apparatus for feeding and classifying cut tobacco, a combination comprising a pneumatic duct having an upper portion and a lower portion; distributor means including a source of intermixed lighter and heavier tobacco particles and delivery means for feeding particles from said source substantially transversely into said duct in a region below said upper portion thereof; circulating means for conveying through said duct an ascending current of air strong enough to entrain only the lighter particles so that the heavier particles descend by gravity into the lower portion and the lighter particles enter the upper portion of said duct; means for receiving heavier particles from the lower portion of said duct; collecting means for collecting lighter particles which enter the upper portion of said duct to form a supply of lighter particles, including a rotary suction drum overlying the upper portion of said duct to collect the lighter particles supplied by said air current; carpet forming means for withdrawing from said supply in said collecting means lighter particles at a substantially constant rate in the form of a continuous carpet; and stream forming means for converting said carpet into a tobacco stream.

Claim 4

In an apparatus for feeding and classifying cut tobacco, a combination comprising a pneumatic duct having an upper portion and a lower portion; distributor means including a source of intermixed lighter and heavier tobacco particles and delivery means for feeding particles from said source substantially transversely into said duct in a region below said upper portion thereof; circulating means for conveying through said duct an ascending current of air strong enough to entrain only the lighter particles so that the heavier particles descend by gravity into the lower portion and the lighter particles enter the upper portion of said duct; means for receiving heavier particles from the lower portion of said duct; collecting means for collecting lighter particles which enter the upper portion of said duct to form a supply of lighter particles, including a rotary suction drum overlying the upper portion of said duct to collect the lighter particles supplied by said air current; carpet forming means for withdrawing from said supply in said collecting means lighter particles at a substantially constant rate in the form of a continuous carpet; and stream forming means for converting said carpet into a tobacco stream.

Claim 5

A combination as defined in claim 2, wherein said collecting means further comprise a receptacle for accommodating said supply of lighter particles and having an upper portion overlapped by said suction drum, said suction drum having an air permeable rotor arranged to attract and to transport lighter particles from the upper portion of said duct into registry with the upper portion of said receptacle and means for blocking the flow of suction producing air through the periphery of that portion of said rotor which overlaps the upper portion of said receptacle so that the lighter particles which reach said last mentioned upper portion can descend in said receptacle by gravity.

Claim 6

In an apparatus for feeding and classifying cut tobacco, a combination comprising a pneumatic duct having an upper portion and a lower portion; distributor means including a source of intermixed lighter and heavier tobacco particles and delivery means for feeding particles from said source substantially transversely into said duct in a region below said upper portion thereof; circulating means for conveying through said duct an ascending current of air strong enough to entrain only the lighter particles so that the heavier particles descend by gravity into the lower portion and the lighter particles enter the upper portion of said duct; means for receiving heavier particles from the lower portion of said duct; collecting means for collecting lighter particles which enter the upper portion of said duct to form a supply of lighter particles; adjustable condensing means for condensing lighter particles of said supply; means for adjusting said condensing means as a function of changes in density of said supply; carpet forming means for withdrawing from said supply in said collecting means lighter particles at a substantially constant rate in the form of a continuous carpet; and stream forming means for converting said carpet into a tobacco stream.

Claim 7

In an apparatus for feeding and classifying cut tobacco, a combination comprising a pneumatic duct having an upper portion and a lower portion; distributor means including a source of intermixed lighter and heavier tobacco particles and delivery means for feeding particles from said source substantially transversely into said duct in a region below said upper portion thereof; circulating means for conveying through said duct an ascending current of air strong enough to entrain only the lighter particles so that the heavier particles descend by gravity into the lower portion and the lighter particles enter the upper portion of said duct; means for receiving heavier particles from the lower portion of said duct; collecting means for collecting lighter particles which enter the upper portion of said duct to form a supply of lighter particles; adjustable condensing means for condensing lighter particles of said supply; means for adjusting said condensing means as a function of changes in density of said supply; carpet forming means for withdrawing from said supply in said collecting means lighter particles at a substantially constant rate in the form of a continuous carpet; and stream forming means for converting said carpet into a tobacco stream.

Claim 8

A combination as defined in claim 4, wherein said condensing means comprises vibrator means.

Claim 9

In an apparatus for feeding and classifying cut tobacco, a combination comprising a pneumatic duct having an upper portion and a lower portion; distributor means including a source of intermixed lighter and heavier tobacco particles, tobacco admitting inlet means communicating with said duct between said upper and lower portions thereof, and delivery means for feeding particles from said source, through said inlet means and substantially tranSversely into said duct; partition means provided in said duct in the path of particles fed by said delivery means to divide an intermediate portion of said duct into a plurality of channels one of which receives the particles fed by said delivery means; circulating means for conveying through said duct an ascending current of air strong enough to entrain only the lighter particles into the upper portion of said duct so that the heavier particles descend in said channels by gravity to enter the lower portion and the lighter particles enter the upper portion of said duct; means for receiving heavier particles from the lower portion of said duct; collecting means for collecting lighter particles which enter the upper portion of said duct to form a supply of lighter particles; carpet forming means for withdrawing from said supply in said collecting means lighter particles at a substantially constant rate in the form of a continuous carpet; and stream forming means for converting said carpet into a tobacco stream.

Claim 10

In an apparatus for feeding and classifying cut tobacco, a combination comprising a pneumatic duct having an upper portion and a lower portion; distributor means including a source of intermixed lighter and heavier tobacco particles, tobacco admitting inlet means communicating with said duct between said upper and lower portions thereof, and delivery means for feeding particles from said source, through said inlet means and substantially tranSversely into said duct; partition means provided in said duct in the path of particles fed by said delivery means to divide an intermediate portion of said duct into a plurality of channels one of which receives the particles fed by said delivery means; circulating means for conveying through said duct an ascending current of air strong enough to entrain only the lighter particles into the upper portion of said duct so that the heavier particles descend in said channels by gravity to enter the lower portion and the lighter particles enter the upper portion of said duct; means for receiving heavier particles from the lower portion of said duct; collecting means for collecting lighter particles which enter the upper portion of said duct to form a supply of lighter particles; carpet forming means for withdrawing from said supply in said collecting means lighter particles at a substantially constant rate in the form of a continuous carpet; and stream forming means for converting said carpet into a tobacco stream.

Claim 11

A combination as defined in claim 6, wherein said collecting means is arranged to collect lighter particles at a rate which at least equals said constant rate so that the supply of lighter particles is not exhausted in response to formation of said carpet.

Claim 12

A combination as defined in claim 6, wherein said distributor means is adjustable to deliver to said duct tobacco particles at a variable rate and further comprising means for selecting said last mentioned rate as a function of the quantity of lighter particles forming said supply so that the quantity of lighter particles forming said supply remains between predetermined maximum an minimum values.

Claim 13

A combination as defined in claim 6, further comprising detector means for measuring the density of said supply of lighter particles and means for adjusting said distributor means when the density of said supply is outside of a predetermined range.

Claim 14

A combination as defined in claim 6, wherein said distributor means comprises variable-speed drive means for said delivery means so that said delivery means can feed to said duct tobacco particles at a variable rate and wherein said collecting means comprises a chute in which said supply forms a substantially vertical column of lighter particles, and further comprising means for selecting said variable rate as a function of the height of said column, said selecting means comprising upper and lower level indicators operative to produce signals when said column respectively reaches a predetermined upper level and a predetermined lower level, and signal generating and transmitting means for transmitting signals to said drive means to reduce said variable rate in response to a signal from said upper level indicator and to increase said variable rate in response to a signal from said lower level indicator.

Claim 15

A combination as defined in claim 6, wherein said delivery means is adjustable to deliver to said duct tobacco particles at a variable rate, and further comprising adjustable means for selecting said variable rate as a function of the height of said supply, said adjustable means comprising sensing means for sensing the upper level of said supply and means for adjusting said delivery means as a function of the position of said upper level, said sensing means being movable up and down with reference to said supply and further comprising means for detecting the density of said supply and for adjusting said sensing means as a function of such density.