US2629136A - Roll member - Google Patents

Description

K. KAISER ROLL MEMBER Feb. 24, 1953 3 Sheets-Sheet 1 Filed Feb. 6, 1946 INVENTORi K/IRL ff/Y/SEP BY K. KAISER ROLL MEMBER Feb. 24, 1953 5 Sheets-Sheet 2 Filed Feb. 6, 1946 INENTOR.

Kfl/PL KA'LSEA Feb. 24, 1953 K KAlsER 2,629,136

' ROLL MEMBER Filed Feb. 6, 1946 3 Sheets-Sheet 5 Patented Feb. 24, 1953 ROLL MEMBER Karl Kaiser, Fresno, Calif., assignor to California Central Fibre Corporation, a corporation of California Application February 6, 1946, Serial No. 645,840

1 Claim.

This invention relates to roll members, and more particularly to roll members adapted for use as brake rolls on decorticating machines and to a method of forming these rolls. This is a continuation-impart of my copending application Ser. No. 394,048, filed May 19, 1941, now Patent No. 2,399,809.

As is well known, decorticating equipment is used to treat various fibers, such as flax, ramie, hemp, jute, crotalaria and other bast fiber producing plants, so as to liberate at least partially the b ast fiber from the other components principally, the woody center portion of the plant stalk, commonly referred to as shive. During the decorticating treatment the material being processed is passed between a series of rotating brake rolls and there subjected to a braking and compressing action with the result that a substantial amount of the shive component is loosened and separated from the outer hast fi-ber.

The roll members of the present invention provide an improved form of brake roll for use on decorticating machines as described above. The brake rolls of my invention are characterized by light weight which permits high speed operation, but are nevertheless adapted for heavy duty use. A further feature of the invention is a method of forming the rolls with integrally cast flutes which require no machining and which consequently retain the tough casting skin so that the rolls have substantially improved wear resistance. The method of constructin the rolls according to the present invention also make it possible to employ a hollow cast shell or body member detachably assembled on a center or mounting shaft so that either the body member or the shaft may be replaced conveniently and economically if either becomes damaged.

My invention is illustrated in the accompanyi'ng drawing, in which:

Fig. 1 is a side elevation of a decorticating machine showing the general arrangement of the brake rolls of the present invention in use;

Fig. 2 is a detail, mainly in section, showing two of the brake rolls and the manner inwhich they are mounted;

Fig. 3 is a transverse section-a1 detail of the pair of brake rolls in Fig. 2, illustrating their disposition in operation;

Fig. 4 is a side elevation of a brake roll constructed in accordance with the present inven' Fig. 6 is a transverse section of the brake roll" shown in Fig.

Fig. 7 is a corresponding transverse section or" the body member of the brake roll;

. Fig. 8 is a longitudinal section of a flask used for casting body members for the brake rolls of the present invention;

Fig. 9 is a corresponding longitudinal section illustrating the method of forming a mold in the flask shown in Fig. 8;

Fig. 10 is a plan view of the strip .plateused in removing the roll pattern from the mold;

Fig. 11 is a longitudinal section of the disposition of the mold during the casting operation; and

Fig. 12 is a detail of the mounting shaft showing the bushings used for assembling the roll body member on the shaft.

Referring first to Fig. l of the drawing, the decorticating apparatus shown is of the portable type adapted for field deoortication to which the brake rolls of the present invention find particular application because of their light weight, although as pointed out more in detail below my improved brake rolls may also be adapted advantageously for use in decorticating equipment generally.

The decorticating apparatus shown in Fig. 1 comprises generally: a feed hopper In for receiving the material, such as flax straw, to be decorticated; straw walkers II for advancing the material from hopper In to a feeding device indicate-d generally at 12, which regulates the amount of material passing through the machine; and a brake roll assembly 13, which receives the material being processed from the feeding device l2 for decortication, Beyond the brake roll assembly l3, the decorticated material is received by a fiber transfer device [4, which leads the material to a conical cleaner I5 and a fiber condenser is for further separation of the shive component. For further details of the arrangement and operation of these elements of the decorticatin apparatus as a whole reference is made to my above identified copending applica-' tion.

The arrangement of the brake roll assembly [3 is illustrated in Figs. 2 and 3. This assembly comprises a series of fluted bottom rolls I1 and a corresponding series of fluted top rolls 18. Thebottom rolls are driven, as described in my copending application, and since they mesh with the top rolls (see Fig. 3) they cause corresponding As previously mentioned, the material being processed is passed through the brake roll assembly |3 to loosen and separate the shive from the bast fiber. The brake rolls are formed with longitudinal flutes in their exterior surface, as shown in Figs. 2 and 3, and as the rolls are disposed so that these flutes mesh, the fiber material being treated is subjected to a bending or braking and compressing action as it passes through the roll assembly l3.

The brake rolls heretofore commonly available have been formed either by machining the rolls from a solid piece of metal or by casting a cylindrical body member on a steel-shaft and .then machining flutes in the cast; body member. Besides the obvious cost disadvantage of the machining operations necessary *withrolls-of these types, such rolls are also relatively heavy, a standard roll weighing about 150 pounds. This excessive weight has two important disadvantages. In the flrstplace, it :renders the total weight of an effective brake roll assembly impractical forportable decorticating equipment; and secondly, it restricts the operating speed of the rolls in decorticating equipmentgenerally due to difficulty in arranging adequate bearing supports.

Moreover, the brake rolls previously used have had the further disadvantage of requiring complete replacement inthe event of damage to any part of the roll. One of the problems encountered in the operation ofdecorticating equipment is that of dealing with tramp metal or stones which may be included in the material being processed and thus fed through the machine. This tramp material often results in breaking of the flutes on the brake rollsso as to render them-ineffective. Also, with the previous rolls formed of a body cast on a steel shaft, the body often works loose from the shaft rendering the whole roll useless. These and other common operating failures make it highly desirable to have abrake roll which may be easily repaired when damaged'and which is adapted for reuse of undamaged parts.

The roll members of the present invention are adapted to overcome the above mentioned difficulties bya construction incorporating a hollow cast outer shell or body which may be assembled on a steel mounting shaft. The roll members are shown in Figs. 4 and 5, as being of the usual operating form in that a body member 2 I, having integral longitudinal flutes 22 on its exterior surface, is associated with a shaft 23 extending through the body member 2| and providing journal portions for mounting the body member. As shown more in detail in Figs. 6 and 7, however, the body member 2| is hollow and is secured on mounting shaft 23 by means of a flange 24 and taper bushing 25, as described more .in detail below.

The body member 2| is shown separately in Fig.1? in its'finished form. The manner in which the body member 2| is formed is illustrated in Figs. ,8 to 11, inclusive. Previous practice has been to cast the brake roll bodies in horizontal molds split along the axis of the roll. With this method, the pressure of the hot metal, which determines the density of the casting, is at a minimum, and also slag is apt to be trapped in the mold at .the upper portion of the cast roll body. Furthermore trouble is experienced with the gases generated during the casting operation-bubbling through themetalas it is poured and forming .blowholes.

According to the present invention these difliculties are avoided by casting the body member 2| in a cylindrical mold which is positioned vertically during the casting operation. Also, the casting operation is carried out so that the flutes 22 are cast integrally with the body member 2| and the machining operations heretofore necessary informingthe flutes'22 areentirely eliminated. The mold for the body member 2| is formed in a cylindrical flask 28 which may consist of steel tubing as shown in Fig. 8. Vent holes 29 are formed in the wall of flask 28 to allow the gases generated durin casting operation to escape freely, apertures 30 are provided toform seats for pins 3| to hold a bottom core cover 32 and a strip plate 33 for the mold in place, and the flask 28 is further fitted as shown with eyelets 34 for use in handling the mold.

The mold is formed by positioning a brake roll pattern 35 in the flask 28 by means of the bottom core cover 32, as shown in Fig. 9, and then filling the intervening space betweenthe roll pattern 35 and flask 28 with molding sand. The roll pattern .35 used for this purpose is formed according to the exterior fluted configurations of the body member 2|, and accordingly conditions the interior surface of the mold. formed in flask 28 with impressions corresponding 'to the flutes 22. In order to preserve the impression for the flutes'22 in the mold formed .in this manner the roll pattern 35 is withdrawn longitudinally through the strip plate 33. This strip plate 33 is formed with an'aperture 36 having the general form of an interior gear providing a sliding fit with the above mentioned fluted configuration of the roll pattern 35. The outside diameter of strip plate 33 is adapted to fit inside flask 28, as shown in Fig. 9, and be positioned by the previously mentioned pins3| which engage eyelets 31 to wedgethe strip plate 33 in place.

After the intervening space between the roll pattern 35 and flask 28 has been filled with molding sand and this sand has been tamped down to the proper level, the strip plate 33 is positioned as just described and the roll pattern 35 is withdrawn through the strip plate so that the mold formed in flask 28 is supported during this step and the impressions in the mold for the flutes 22 are protected against damage as the pattern is withdrawn.

After withdrawal of the pattern roll 35, the strip plate 33 may then be removed and the resulting mold may be further conditioned by graphite spraying of the interior surface and baking, and the like. When themoldhas'thus been prepared for the casting operation a center core 38 and a core cover 39, formed with the usual sprue holes as at 43, are arranged in place, with the mold positioned vertically, as illustrated in Fig. 11, and the body member 2| is then cast in the usual manner. The vertical positioning of the mold obtains'the maximum effect of the pressure of thehot' metal and thus increases the density of the casting formed. Also, the vent holes 29 in flask 28 combined with the vertical positioning of the mold allow the gases generated during the casting operation to escape without any tendency to bubble through the castin being formed. Further provisionmay be made in this latter respect by using a center core 38 formed with internal vent channels (not shown).

The resulting hollow .cast .body member 2| is ;removed from the .mold ,and the ,ends .are

.faced and internal bores are machined as at Al.

and 42 in Fig. 7 to receive the previously mentioned flange member 24 and taper bushing 25 used to mount the body member 2| on mounting shaft 23. The flange 24 is fixed on the shaft 23 by welding, or in any other convenient manner, and is formed with a bushing portion 43 extending along shaft 23 and providing a snug fit with the body member 2| at the internal bore 4|. The body member 2| is positioned on shaft 23 over this bushing portion 43 against flange 24 and is fastened in place with bolts 44 extending through flange 24 and engaging body member 2 I. These bolts 44 provide a secure engagement between the body member 2| and mounting shaft 23 so that the torque applied to the roll during operation is effectively transmitted between shaft 23 and body member 2|. At the other end, body member 2| is centered rigidly on shaft 23 through the taper sleeve or bushing 25. This taper bushing 25 is of a conventional split sleeve type and is driven into place on shaft 23 in the bore 42 of body member 2| to provide a friction fit insuring a tight, lasting connection between the body member and shaft, which renders the mounting of body member 2| on shaft 23 rattle-proof and centers the body member rigidly in place on the shaft.

Brake rolls formed in accordance with the present invention weigh only a little more than one-half as much as the standard brake rolls heretofore in use, and it has been found in actual use that they may be satisfactorily operated at considerably higher speeds. Practical limitations as mentioned above have previously limited the speed at which brake rolls might be operated to about 200 to 225 R. P. M. With the brake rolls of the present invention speeds of 300 R. P. M. and higher have proved feasible. This increased speed of the brake rolls produces a snap action on the material being decorticated that is conducive to eificient removal and separation of shive and this high speed operation is substantially superior to the results obtained with the relatively slow speed rotation of the conventional heavy brake rolls formerly used. Also, as previously mentioned the manner of forming the brake rolls with integrally cast flutes which require no machining retains the tough metal skin on the working surfaces of the cast flutes and thereby makes the flutes stronger and more durable and thus better equipped for high speed operation. The tough metal skin on the cast flutes has the properties of chilled cast iron. The flutes accordingly become highly polished during use which reduces friction and further facilitates high speed operation.

A further feature of the brake rolls of this invention is the manner in which the body member and mounting shaft are assembled so that either of them may be replaced easily and conveniently in the event of damage. In replacing either part, it is only necessary to remove the bolts 44 securing body member 2| to flange 24 and then strip the body member from shaft 23. The undamaged part may then be salvaged and assembled with a replacement for the damaged part. When the advantage of this feature is added to the savings effected in manufacturing a hollow cast body member and separate mounting shaft, the comparative advantage over the unitary construction of the brake rolls previously in use is even more substantial.

I claim:

A brake roll for decorticating machines and the like comprising a tubular outer shell forming the body member of said roll, said tubular outer shell being formed of cast iron and having a fluted exterior surface cast directly therein, whereby the flutes on said exterior surface are encased by the tough skin characteristic of said cast metal outer shell, a shaft extending entirely through said tubular outer shell and providing journal portions for mounting said roll, a flange bushing fixed on said shaft adjacent one end and associated fastening means for securing said shell at one end to said flange in assembled relation with said shaft, and a split taper sleeve pressed between said shell and said shaft at the other end thereof for centering said shell on. said shaft at said other end.

KARL KAISER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 131,486 Wheeldon Sept. 1'7, 1872 945,726 De Montlord Jan. 4, 1910 1,132,122 Roberts Mar. 16, 1915 1,382,606 Norton June 21, 1921 1,405,004 Roberts Jan. 31, 1922 1,976,625 Norman Oct. 9, 1934 2,018,675 Hyde Oct. 29, 1935 2,186,695 Harris Jan. 9, 1940 FOREIGN PATENTS Number Country Date 28,823 Germany Sept. 22, 1884 420,859 Great Britain Dec. 10, 19st

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