US2045690A - Reducing machine - Google Patents

Description

June 30, 1936. w. 1. ARMSTRONG REDUCING MACHINE Filed March 15, 1932 I lates to a rotor construction for Patented .lune 30, 1936 PATENT Fries BEDUCING MAC Walter J. Arrastre,

to The Jeffrey Man nur e Y i- Of @M9 The present invention relates to ro reducing maoes, and culariy to such ohines as applied to the reduction oi friabie material. More particularly, the invention revolving a new form oi hammer and hammer combination. The invention is particularly applicable to the type of machine broadly covered in U. 8. Patent 10 1,761,083, granted to William K. Liggett, June 3, 1930, wherein the rotor includes centrifugally projectible beaters whose projection is limited by abutment means on the rotor. the beaters being movable inwardly of the rotor to an ineective or l inoperative position upon cessation or counteraction of centrifugal force. In his U. S. application Serial No. 362,951, filed May 14, i929, Nils D. Levin has described a machine in which the Liggett development is carried further to the end that, through the use of comparatively heavy hammers of considerable length, a relatively W speed machine is made practical.

According to the present invention. beaters having relatively great inertia, as ltaught by Levin, are preferably employed, a novel form of beater head being provided whereby the produc-v "tionoi an undesirable amount of unes is avoided. The particular beater or hammer contemplated has a round head which presents a working face convexly curved from its leading to its trailing end. Beaters of this type will strike a blow and sledge or shatter material rather than eut through it as is the tendency of beaters having relatively plane working faces with sharp edges. The machine may be entirely equipped with the round head type of beater for reduction of ma-v terials which break up readily and where no dimculty is encountered in discharging theflni'shed product. On the other hand, the machine may 4u be partly equipped with round head beaters and partly with the' plane f aced type. the particular arrangement depending upon a number of factors, such as the fineness of the product required. `capacity (when time is not an important factor) i5 and the nature of the material whether wet. sticky o r dry. When quantity feed or feed of relatively large material is 'desirablefit may be necessary to use a few plane faced beaters in conjunction the round head beaters.

Where a screening medium, such as the well known screen bars, is present, the matter of discharge therethrough is an important consideration since with some materials the round head hammer will have a tendency to force unfinished material into the finished product. making it such machines in- Columbus, Ohio, gnor iosa, si No. soeces (ci. os--iii necessary to employ a closer spacing of the screen hars. However, the useof a few plane iaced hammers will ordinarily overcome this difllculty, since they will tend to cut through the materialil in the screen section, reducing it sutilciently for passage therethrough without forcing. In explanation of the above, and as will be apparent from the accompanying drawings, the round head beaters engage the material to be reduced with an outward forcing action, whereas the plane faced beaters have a substantially ilat .impact with the material.

The invention also includes a rotor body design intended to accommodate an odd or an even number of axial rows of beaters without destroying the rotor balance.

The invention also includes the other subsidiary improvements which will be mentioned in the following description and which will be pointed out in the claims.

lIn the drawing:

Figure 1 is a trans-axial section through a ma.- chine embodying the improvements of the present invention.

".Figure 2 is a larged, of one of the Figure l, and

Figure 3 is a view similar to that of Figure 1 showing a modified beater arrangement.

The general form of machine shown in Figure 1 is weil known in the art and is specifically described in Reissue Patent No. 17,334, William K. Liggett, June 25, 1929. The machine comprises generally a casing 5 in .which is revolubly mounted a shaft 6 on which are keyed a number of disks as at l spaced axially of theshaft by means of collars as at l. According to thapres: ent invention, the disks are provided outwardly of the collars with a series of apertures 9, twelve of these apertures being shown, and these being spaced at thirty-degree intervals. The apertures 9 of the various disks are in alignment and, as here shown, every third one of the concentric series has a tie-rod Il passed therethrough.

A outwardly of the apertures 9 the disks are provided with another concentrlc series of somewhat larger apertures Il, each disk having twelve of these apertures as here shown with the centers thereof lying on the radii of shaft 8 passing through the centers of theapertures l. It, of course, follows that apertures li are spaced 30 apart.

Pivot rods l2 aremountedfih the apertures il intersected by the radii of shaft I passing through the apertures t which are occupied' by the tieperspective view somewhat ennew beaters as shown in rods I0, and on the rods I2 are mounted beaters generally designated by the reference numeral I3, these beaters each comprising an arm portion I4 and an angularly extending head por'- tion'II at one end of the arm portion. In the i apertures II next succeeding, in the clockwise direction, the apertures II occupied by the rods I2,` are mounted abutment rods I2', which cooperate with the beater arms adjacent the heads to limit the centrifugal projection of the latter. Upon cessation or counteraction of centrifugal force the beaters are movable inwardly of the, rotor body into abutmentwith the collars 8, 'the position of the tie-rods I0 being so chosen that the latter are out of the path of inward movement of the beaters. The selective positioning of the tie-rods is, of course, permitted by theexcess number of apertures 9.

With the disks provided with aperturesat 30 intervals for the reception of the pivot and abutment rods, considerable flexibility of design is permitted so-that various results may be ob-' a number of apertures II, which number is the` common denominator of the integers- 2 and i. More specifically, the invention contemplates the provision of such apertures spaced 30 from each other. Whatever the number of pivot rods involved, the tie-rods may be correspondingly lo'- cated so as not to interfere with the inward movement of the beaters.

Each beater arm II at its end opposite the head I5 is provided with a boss I6 pierced to receive a pivot rod I2, the boss being of a size to substantially fill the rod space between adjacent disks. The arm Il and head I5 are of less thickness than the boss, although the head, as here shown, may be provided with lateral ribs I1 having a guided ilt between adjacent disks so as to prevent chattering of the beater. The beater head projects substantially rectangula'rly from Vthe arm and is of substantially the same length as the latter. The longitudinal boundary surface of the arm at the head end thereof and .at the side opposite the head is curvilinearly continued throughout the outer poion ofthehead sothat the head presents e. convexly curved working face indicated at i5, Figure 2, the working face merging at the free end of the head with a reentrant inner longitudinal boundary surface I5b which merges with the other longitudinal boundary surface of the arm. As here shown, the surface Iiib is concavely curved substantially on an arc concentric with the pivotal axis of the beater. As shown in Figure 1, the abutment rods i2' are disposed close to the surface '15, the latter being shaped, as described, inv order not to interfere with the rods while still giving the irse end of the beater as much of a rearward overhang as possible. The surfaces I5a and I5 merge. in a substantially taperedpoint Iiic which is directed toward the opposite end of the arm I4. The reducing action takes place principally on that portion of face I5'l adjacent pointI-V,

this area of the face being directed more or less toward the boss I6.

In order that the beater may offer a considerable resistance to inward movement when the rotor is rotating, head I 5 preferably has a considerably greater mass than arm I4, this being secured by forming it with a considerably great- 'As'in thel reissue patent, 4above referred to, a restricted reducing zone is defined in conjunc- .mtion with the rotor by an abutment bar or breaker .plate I d and screen bars I9. The distance between the pivot rods and abutment rods is less than. the4 distance, between the pivot rods and "the bieaker plate I8 and screen bars I9 or other outerreduction'aone defining means, so that in cases. beaterarmbreaks at any point between the pivotand abutment rods, the pivoted portion cannot be projected suillciently to engage any of the outer zone defining means so as to cause damage thereto. 'Ihe distance between the pivotal axlsof any beaterand its abutment means is preferably no greater than the distance from the pivotal axis to the maximum circle described by thef beater when fully projected.

In Figure 3 the casing and rotor body are the same as in Figure 1. 'I he rotor body, however, supports ltwo opposite axially extending series of round head beaters I3 and two opposite axially extendinggfseries'of plane faced beaters 20. Other relative arrangements of the two types of beaters are, of course, possible, but in any event care must be taken to see that the distribution is such that rotor balance ismaintained. The lbeaters 20 have dat substantially'l'square working faces 2i inclined somewhat rearwardly relative' to radial planes of 1the rotor and, as' above described, have rather a cutting action as contrasted to the round head beaters- 1t will be understood tha'tjwhilel have gone into some detail 'in "the description of the invention in order that the same may' be readily understood ,the following claims.

denim: '1 A 'A 1 In' a machine of 'the class described, a rotor body, 'a bester, said beater having an arm portion and `a. head portion projecting angularly from the portion at one endof' thelatter, the arm por- .,tion being pivoted at its other end to the rotor bodyfwith the head portion in trailing relation as regards the direction of rotor rotation, said head portion having a convexly curved working surface extending lgenerally'in the longitudinal direction -of said arm portion and merging at its end toward the pivot'ed end of said arml portion with a reentrant boundary'surface which merges with said arm portion whereby a substantially hook-shaped beater is provided,'said last named surface being d"practiced, Ido notl limit' myself except as in Y l curved substantially on 'an arc having a center 60 leading ends, said point being outside of the rotor periphery ia'riiclfbeing closer to the rotor axis than Ithe medial *portion of said working surface` when the head is fully projected, the head beingymovable i of oentrirugalfror.

j withizi-the'peripnery of the rotor body upon coun- 2. In a machine kof the `claas described, a rotor body comprising a rotary shaft, axially spaced plates iixed to said shaft, and rods extending through apertures in said plates in parallel relation to said shait, a beater between two adjacent ones of said plates comprising anarmportion .and a head portion projecting angularly from the arm portion at one end o! the latter, the other end ci said arm portion having an apertured bossiormed thereon adapted to be strung on one of said rods, said head portion having a convexlycurved work. ing surface extending ygenerally in the longitudi-v nal direction of said arm portion and merging at its end toward the pivoted end of said arm portion with a re-entrant boundary surface which merges with said arm portion wherebya substantially hook-shaped beater is provided, .,SII-idvlast- .named surface being curved on .an arc having a center substantially lat `the pivoting axis of said arm portion, and an abutment on the rotor for cooperation with said arm` portion and disposed adjacent said arcuate surface, the

beater :arm portion engaging said abutment upon rotor rotation and being heid by the latter within the periphery of the rotory body in parallel relation to a diameter of said body with `the head centrifugally projected from the body1 said surfaces forming a point at their leading ends, said point being outside oi the rotor Aperiphery andbeing closer I.to the rotor axis than the medial portion of said workingsuriace when the head is fully projected, the head being movable within `the periphery oi lthe rotor body upon counteraction of centrifugal force, said boss being of greater thick ness than the arm portion and than the head portion proper, the head portion having laterally projecting ribs thereon to provide a transverse dimension substantially equal to the spacing of the two l adjacent plats, said ribs being spaced inwardly from the working face of said head portion so as to be always between said adjacent plates in guided relation thereto.

J. ARMSTRONG.

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