US2685108A - Mechanism for processing vegetable fibers - Google Patents

Description

Aug- 3, 1954 B. ARMSTRONG 2,685,108

MECHANISM FOR PROCESSING VEGETABLE FIBERS Filed Aug. 22, 1952 2 Sheets-Sheet l gul-Ill.

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ERL/c5 eMsrwo/va Aug. 3, 1954 B. ARMSTRONG MECHANISM FOR PROCESSING VEGETABLE FIBERS 2 Sheets-Sheet 2 Filed Aug. 22, 1952 Patented Aug. 3, 1954 UNTED STATES OFFICE 2,685,108 MECHANISM F01?, PROCESSING VEGETABLE FIBERS Bruce Armstrong,

Saginaw, Mich., `ackson & Church Company,

assigner to Saginaw, Mich.,

6 Claims.

This invention relates to means for processing vegetable bers and particularly toa type thereof involving a pair of rotatable plates having teeth extending into a zone intermediate said plates.

In a method for separating the bers of vegetable materials from each other and for separating the long fibers, otherwise known as bast fibers, from pith or parenchyma, as described in ing said bending moment to said vegetable materials, there is utilized a pair of plates rotating With respect to each other, said plates being slightly spaced apart and each having a plurality of teeth thereon extending into an annular space, or processing zone, defined therebetween. Thus, when the vegetable materials are fed into the center of said annular space and permitted to move outwardly toward the periphery thereof, the teeth extending from one of said plates engage said vegetable materials and bend the same against the teeth of the other of said plates whereby the necessary bending is applied reidly and accurately.

In the provision of plates, and the arrangement of teeth thereon, there has been present in plates designed for related types of machines a number of characteristics which render such plates somewhat ill-suited for carrying' out the method presently under consideration. Accordingly, it was desired to provide plate and tooth design which a high degree of bending of the vegetable material would be obtained, by which a maximum flow of material through the zone occupied by said teeth would be obtained and yet a design according to which a plate could be made rapidly and relatively inexpensively.

Accordingly, a principal object of the invention is the provision of a pair of plates adapted to denne an annular processing zone when co-axially tending toward each other for engaging and benf ing vegetable material fed therebetween.

A further object of the invention is toy provide a device, as aforesaid, wherein the bending can be carried out accurately and efficiently and with a minimum of breakage or cutting of the bers of said vegetable material,

A further object of the invention is to provide a device, as aforesaid, which can be manufactured rapidly and eiiiciently.

A further object of the invention is to provide a device, as aforesaid, which will permit a maximum dow of material through the processing zone.

A further object of the invention is to provide a device, as aforesaid, which will be strong and sturdy and not readily subject to breakage.

A further object of the invention is to provide a device, aforesaid, wherein a tooth can be readily replaced in the event that breakage or damage does occur.

A further object of the invention is to provide Figure 2 represents said two plates.

Figure 3 represents a top view of the upper of said two plates.

Figure 4l is a section taken on the line IV-IV of Figure 2.

Figure 5 shows an alternate tooth structure.

Figure 6 shows a further alternate tooth structure.

Figure 7 is a section taken on the line VII-VII of Figure 6.

Figure 8 shows a further modified taken in central vertical section.

In carrying out the objects and purposes above set forth I have provided a pair of plates adapted for defining a processing Zone when co-axially positioned and suitably spaced apart and provided with a plurality of axially extending teeth, each thereof extending into said zone dened between said two plates. Where, as is usual, one of said plates has an opening in its center for the feeding of material therebetween, the zone into which said teeth extend and in which the vegetable material is processed is an annular zone as indicated in the figures. The teeth are preferably round and extend through said plate from the respectively remote faces of each thereof.

Looking at said plates and tooth structures now in more detail there is shown in Figure 1 a pair of plates i and 2 which in this embodiment may tooth design be taken to be positioned in vertically spaced horizontal planes. The upper of said plates is for illustrative purposes assumed to be affixed to the frame 3 of a machine and the lower of said two plates is mounted on the spindle E which is supported by suitable bearings l! and 5, and driven by any conventional means, not shown. it will be understood, of course, that this somewhat arbitrary section of specific operating details is for illustrative purposes only and is not to be construed as limiting. Heat exchange means 'I may be provided if desired.

Referring now to the lower plate 2 in detail there is shown a plurality of substantially round pins on teeth it. As best shown in Figure e, each of these pins has a body portion l l which is press fitted into an opening l2 in said plate. The lower side of said pin has a head i3 formed thereon for engaging a counter-bore in the lower surface of said lower plate and at the upper end of said pin there is provided a substantially cylindrical shank it which is preferably, for reasons appearing hereinafter, formed with a diameter slightly smaller than the diameter of said body portion.

Referring now to Figure 2, it will be observed that, as indicated by the broken line A, said pins ID are arranged in said plate in radially spaced rings, and the circumferential spacing of said pins is such as to arrange said pins, as indicated by the line By in Figure 2, in substantially spiral rows, said rows being defined by arcs struck from centers of which one is indicated by the point C. Point C is positioned intermediate the center of the lower plate 2 and the periphery thereof and is offset circumferentially with respect to all radii of the plate passing through any of the The amount of such offset and the radius of the arc B will be selected so as to approximate the vector-resultant of the radial and tangential velocities of the material to be processed at three or more radii and to provide a smooth curve drawn through these vectors. rlhe teeth or pins are located at the intersection of arc B and a series of concentric circles A chosen, as shown in Figures 2, 3 and 4, to gradually reduce the bending span as the periphery is approached. Thus, a somewhat spiral path is provided from the central Zone of said lower plate to the periphery thereof, as illustrated by the shaded area D in Figure 2. The purpose of this arrangement will appear hereinafter.

Turning now to Figures 3 and 4, for a similar showing of the structure of the upper plate, it

will be seen that similar teeth are similarly arranged in said upper plate. Said teeth are similarly constructed and are similarly affixed. rEhe arrangement of said teeth in circumferential and radially spaced rows is generally similar to that in the lower plate shown in Figure 2, and said teeth are arranged circumferentially with respect to each other in any respective ring to provide a path indicated by the shaded zone E. It will be noted that said shaded zone E curves in the opposite direction from the zone D of the lower plate shown in Figure 2.

As will appear more clearly after a description of the operation of the apparatus, the circumferential offset of any given row, as the row i3 (Figure 2), with respect to the adjacent radialhr inner row, as the row I9, is in such a direction that the paths indicated by the shaded areas D and E, and their several counterparts, curve for each plate in the direction that material is urged by the teeth of the other plate.

The radially 7 As shown by the phantom form,

inner faces of both plates may preferably diverge to provide a throat I1 for the easier reception of chunks or bundles of unseparated fibers.

In the stationary plate the only energy Present is that imparted to the material by the teeth of the rotating plate. Hence, the distance between the teeth, measured on any concentric circle, is greater in the stationary plate than in the rotating plate in order to not unduly retard the progress of the material through the plate. Extra teeth 24, intermediate the teeth located by the intersection of arcs B with only the outermost of the concentric circles A, are provided in the rotating plate. It is intended to control the volumetric capacity of the apparatus by reducing the discharge area and thus impeding too free a discharge of material, without the necessity of reducing the distance between the plates, that is, the gap indicated in Figure 1. This permits securing a high capacity from the apparatus without danger of burning caused by friction between the plates and the material. On some materials having high resistance to heat damage, low coefficients of friction or capacity to break up readily, these intermediate teeth may be omitted.

On the stationary plate, similar intermediate teeth 25 are similarly provided in the two outermost concentric circles because vthe inherently high centrifugal force developed by the high rotative speed of the rotating plate provides sufficient impetus to keep the material moving through without danger of burning. One or both rows may likewise be omitted here on such materials as indicated above.

As alternate construction, reference is made t0 Figure 5 wherein there is shown a slant type of tooth capable of effecting certain additional functions. By using this tooth, the clearance between teeth may be readily adjusted when plate are moved axially toward or away from the teeth of the other plate. The reduction in diameter of the shank of the tooth with respect to the body part of the tooth, in both this form of tooth and that shown in Figure 4, is to provide a slight clearance between said teeth under all conditions and thereby to permit ordinary manufacturing errors in the positioning of said teeth to be accommodated. As said plates, fitted with teeth of the Figure 5 are moved axially toward and away from each other it will be apparent that the spacing between said teeth may be readily adjusted very accurately and thereby the equipment rendered capable of performing operations of various types, it being borne in mind that for carrying out the method as above indicated and described in detail in my co-pending application Serial No. 297,078, filed July 3, 1952, it is necessary that he teeth effect only bending of the fibers and do not effect any cutting thereof.

Another type of tooth is illustrated in Figures 6 and '7. In this tooth, both the forward and rearward edges are rounded in the same manner as the cylindrical teeth shown in Figure 5,

i but the tooth is sufciently elongated as to provide substantial support at the trailing side of each tooth. This is for the purpose of enabling the tooth to be materially longer than might otherwise be permitted by the round type of tooth or it may permit the tooth to be somewhat thinner than would be possible with a round type of tooth and thereby the teeth may be set relatively close together for imposing bending moments on the fibers of relatively short lengths. lines in Figure 6, the

In operation, it will be assumed that the upper plate is stationary and the bottom plate is With the lower plate rotating and the upper plate stationary, as above indicated, be processed is introduced first enters the throat I7 and is engaged by the relatively widely spaced inner rows of teeth I8 and I9. For illustrative purposes, a particular section of vegetable material may be considered It will be appreciated actual movement of a given section of vegetable fiber will be the resultant of its radial motion and the tangential motion imparted to it by the teeth, as the teeth 2l and 22, of the movable lower plate. In View of the relatively high speed of rotation of said movable plate, as 1750 R. P. M.,

instance, with plates of 28 inches diameter and having a inch opening through the upper plates, a given section of vegetable liber may be expected to travel some 8 feet circumferentially while it is traveling approximately 61/2 inches will travel throughout in a tively greater.

However, the outward progression of the given section of material will not be in a perfectly smooth spiral but rather it will move somewhat stepwise by moving from one circular path to progression of material place through and along the paths of said open areas. These open areas permit a large quantity of material to move through the apparatus and the equipment is thereby provided with capacity quantity of material.

for handling a large Accordingly. a device has been provided capable of accomplishing the objects and purposes above set forth.

While vention have been here selected for illustrative pressly provide otherwise.

I claim:

respectively adjacent next inner row in circumferential oifset relationship, the direction of said offsets for each plate being that direction in which material is urged by the teeth of the other of said respective plates, whereby to define a plurality of spirally arranged channels through said teeth from an inner zone to the outer periphery of each of said respective plates.

2. A device dened in claim l wherein each of said teeth is substantially cylindrical in the portion thereof within the zone between said plates.

3. The device dened in claim l wherein said teeth extend through the respective plates upon which they are fastened from the respectively remote sides thereof.

4. The device defined in claim 1 wherein said teeth taper convergingly from the respectively opposed surfaces of said plates.

5. The device defined in claim 1 wherein said teeth are arranged in a plurality of spaced rows, each of said rows defined by the arc of a circle whose center is (l) located intermediate the center of said plates and the peripheries thereof and (2) circumferentially olfset from all radii of said plates passing through said teeth.

6. The device defined in claim 1 having teeth near the periphery only of a plate and within said spirally arranged channels.

References Cited in the le of this patent FOREIGN PATENTS Number Country Date 509,633 Germany Oct. 10, 1930 654,573 Great Britain June 20, 1951

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