US2811241A - Feeding mechanism and process for fibrous materials - Google Patents

Description

Oct. 29, 1957 5, BOGATY FEEDING MECHANISM AND PROCESS FOR FIBROUS MATERIALS Filed Aug. 26. 1954 FEEDING MECHANISM AND PROCESS FOR FIBROUS MATERIALS Stanislaus Bogaty, Philadelphia, Pa., assignor to Proctor and Schwartz, Inc., Philadelphia, Pa., a corporation of Pennsylvania Application August 26, 1954, Serial No. 452,269 1 Claim. (Cl. 198-229) This invention relates to the feeding of fibrous materials incident to the performance of manufacturing processes and is concerned especially with the art of conveyors and means associated with such conveyors for controlling the feeding of material thereon and its discharge therefrom. It was conceived and developed especially with reference to problems encountered in automatically controlling the feed of leaf tobacco uniformly to a dryer conveyor and will accordingly be described specifically with reference to such problems.

In feeding apparatus designed for this purpose, it has been customary to pass the tobacco upwardly on an in clined forward flight of an endless conveyor in the form of a belt provided with blunt-ended pins which form bucket-like spaces between which the tobacco leaves are carried. As the tobacco moves upwardly, it is subjected to the levelling action of kicker blades which rotate counter to the movement of the tobacco, to kick back tobacco which may have been carried forward beyond the desired depth, and to maintain the depth of the bed of tobacco substantially uniform. After passing around the sprocket or pulley at the end of its forward flight, the successive conveyor portions make their return flight. Most of the tobacco drops off at this point, but some of it sticks on the under side of the conveyor as it starts this return flight. This part is removed from the conveyor and discharged by the action of a rapidly rotating doifer having blades which rotate in paths including arcs between the pins, the movement of the doffer blades being in the same directions as that of the endless-conveyor flight across which they operate to perform the discharging function. The doffer blades thus force the tobacco forwardly and downwardly, where it is deflected by a back panel lying in its path, and dropped on the advancing endless conveyor by which it is fed through the dryer.

While this system operates well to provide a steady flow of tobacco through the dryer, it has been subject to some difficulty in operation, particularly in connection with the discharge of the tobacco from the conveyor. In order to clear the pins, it has been necessary to mount the back panel in a position in which its upper edge is somewhat spaced from the underside of the conveyor. As a consequence, some of the tobacco has been caught on the top edge of the panel and later carried down to the floor by the conveyor. Tobacco accumulating on the back panel in this way also tends to form lumps, and these are deleterious to the product in cases when they later find their way into the finished product.

A principal object of the invention has been to obviate these diificulties, and to provide a combination which operates to discharge the tobacco cleanly, without the objectionable stickage discussed above.

Further objects and advantages of the invention, and the manner in which they have been attained, will be evident from reading of the following specification in the light of the attached drawing, in which, the single figure tates Patent '0 2,811,241 Patented .Oct. 29, 1957 is a longitudinal cross-section through the conveyor housing and mechanism of the invention. 7

The feeding mechanism of the invention may be contained in a housing 10. having an inlet 11 through which the tobacco or other fibrous material is to be received, and an outlet 12 through which it is to be discharged, after being spread out in a uniform layer in the feeding apparatus of the invention; Upon being received through the inlet 11, the material (hereinafter referred to' as tobacco for the sake of convenience) is passed forwardly in a step-by-step movement by an endless conveyor 13 on which it accumulates to a substantial depth. The conveyor 13 is driven by a roller 14 through a ratchet 15 and a pawl 16 which receives its step-by-step movement from a link'17 carried by a crank 18 rotating with a shaft 19 which receives its motion from a sprocket 20 through chains 21. These chains carry between them an endless conveyor 22 which may be a belt provided with girts carrying spaced blunt-ended pins 23 between which the tobacco is carried forwardly and upwardly. The chain drive for this conveyor is obtained through a drive sprocket 24 deriving its power from a prime mover through a variable speed drive unit 25 and intermediate gearing, as illustrated.

The conveyor and driving chains are guided in their succession of upward and forward, horizontal forward, and downward and rearward flights by the sprockets 20 and 24, and by intermediate guide sprockets 26 and 27. The rearward flight of the conveyor 22 includes, in the portion just under and to the left of the drive sprocket 24, a first flight portion 28 extending at only a slight angle to the horizontal, and a second flight portion 29 beyond the guide sprocket 27, extending at a much more substantial angle. The kicker 30, which may take the form well-known in the art and include a number of blades or arms 31, is rotated by a motor 32 and chain or belt 33 in a direction opposed to that of movement of the tobacco upwardly along conveyor 23, and through an are which, at its nearest point of approach to the conveyor flight, determines the thickness of the bed of tobacco impelled forwardly beyond this point, by kicking tobacco in excess of this level rearwardly from this point on the conveyor. Both the kicker and the conveyor features discussed up to this point are fairly conventional and well understood by persons skilled in this art.

Most of the tobacco is discharged downwardly from conveyor 22 to'receiving belt 39 as conveyor 32 starts its downward and rearward flight. However, some tobacco will be entrained or impaled by the conveyor, and this is removed by doifer 34. This doifer 34 is rotated through a sprocketor pulley 35 by the chain or belt 33, and is mounted in a position such that its radiating arms or blades 36 describe arcs which extend between the pins 23 as they move diagonally downward on the portion 28 of the return flight of conveyor 22. This movement of the doffer arms 36 across and through the path of material entrained by the pins on the conveyor as these pins extend downwardly in the return flight knocks the tobacco loose from the pins and the conveyor against the forward end 37 of the housing 10, and the sides and ends of the housing, together with a rear plate or panel 38, constitute a receiving chute by which the tobacco falling from the conveyor together with that removed by the doifer is continuously fed to the receiving end of the endless conveyor 39 by which it may be continuously passed through the dryer, for example.

From the foregoing discussion, it will be evident that the tobacco is spread out in a uniform layer by its discharge on the conveyor 22, and the action of the kicker 30, and that residual tobacco is removed from this conveyor in clean-cut fashion by the arms or blades 36 of the dofler 34, and thence deposited on belt 39 for movement through the dryer with other tobacco which drops normally on belt 39. It will also be evident that the disadvantages of the prior art, in which the dofier operated in the reverse direction to that herevinvolved; and in: which substantial amounts of tobacco stuck to the upper:

edge of the back panel corresponding to .33," have been entirely eliminated, f

-While only a single embodiment ofi'the invention has been described, it'will' be evident to those skilled in' the art that. it is susceptible to various modifications and refinements, and I therefore wishrit to be understood that its interpretation is not to be limited except bythe scope of the following claim. a we I claim:

In a feed mechanism for fibrous material, the combination of an endless conveyor having spaced pins. for entraining the material and carrying it to a delivery point, means including rotary guide and driving members for impelling and directing successive longitudinal portions of said conveyor forwardly and diagonally upwardly through a material-advancing flight in which said pins project upwardly from said portions, and rearwardly and diagonally downwardly through a material-discharging and return flight in which said pins project downwardly from said portions, a material-receiving hopper located below the rotary member about which said conveyor turns in changing from its material-advancing to its return flight, and having a forward Wall located forwardly of the forward end of said rotary member, and a dofier mounted for rotation within said hopper and having arms Y rearwardly in the return flight of said successive portions.

References Cited in the file of this patent UNITED STATES PATENTS 475,246 ,b Morton May 17, 1892 675,703

FOREIGN PATENTS Allen June 4, 1901 Great Britain Feb. 16, 193s

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