US3099408A - Hammer mill - Google Patents

Description

July 30, 1963 R. M. WILLIAMS HAMMER MILL 3 Sheets-Sheet 1 Filed Oct. 31. 1960 mus/v m2: P031582 M Mum/v1.5 E)

Zia 7/ July 30, 1963 R. M. WILLIAMS 3,099,408

HAMMER MILL Filed Oct. 31, 1960 5 Sheets-Sheet 2 $454927 M. 11044 mm:

3 ZZZ/L 5 July 30, 1963 R. M. WILLIAMS HAMMER MILL 3 Sheets-Sheet 3 Filed Oct. 51, 1960 Mme/viz? 'luaaPr/v, Maw/vs United States Patent a corporation of Missouri Filed Oct. 31, 1960, Ser. No. 66,076 1 Claim. (Cl. 241-487) The present invention relates generally to hammer mills and more particularly to hammer mills having traveling breaker plates.

Hammer mills having traveling breaker plates have long been known and used and many devices have been employed in conjunction therewith for adjusting the lineness of grind and to compensate for wear of the parts. For the most part, such devices have included means for adjusting the positions of the principal wear members including the hammers and breaker plates and to this end have required relatively complicated and expensive mechanisms with numerous moving parts which themselves are potential sources of trouble and wear. To overcome these and other disadvantages and shortcomings of the known devices, it is proposed by the present invention to provide relatively inexpensive means to compensate for wear in hammer mills and to eliminate much of the costly adjustment means and at the same time improve the operating relationship between the principal wear members of the mill. The present device also increases the adjustability and flexibility of the mill.

It is therefore a principal object of the present invention to improve the operating relationship between the material reducing members in hammer mills and particularly hammer mills having traveling breaker plates.

Another object is to provide inexpensive means tor adjusting hammer mills.

Another object is to increase the flexibility of adjustment of hammer mills having traveling breaker plates.

Another object is to prolong the life of the wear members in hammer mills.

Another object is to improve the drive means for the movable breaker plate assemblies in hammer mills.

Another object is to increase the range of possible adjustment of hammer mills having traveling breaker plates.

Yet another object is to simplify the construction and operation of hammer mills having traveling breaker plates.

Briefly, the present invention comprises a hammer mill having a rotating hammer mechanism positioned therein,

.a movable breaker assembly positioned tangent to the hammer circle defined by the rotating hammer mechanism for cooperation therewith to reduce material passing therebetween, a tapered member positioned adjacent to the hammer circle and to the movable breaker member on one side of the point of tangency therebetween, and means associated with said tapered member for changing the position thereof relative to the hammer circle and relative to the movable breaker assembly.

These and other objects and advantages of the present invention Will become apparent after considering the following description of a preferred embodiment in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevational view of a hammer mill constructed according to the present invention;

FIG. 2 is an enlarged fragmentary cross-sectional elevational view showing the improved portion of the mill of FIG. 1; and

3,099,408 Patented July 30, 1963 FIG. 3 is a view similar to FIG. 1 showing a modified form of the mill.

Referring to the drawings by reference numerals, the number 10 in FIG. 1 refers generally to a hammer mill constructed according to the present invention. The mill It) has a rotating hammer assembly 12 with one or more rotating hammers 14 positioned thereon. The hammers 14 travel in a hammer circle 16 during operation of the mill, and in so doing cooperate with a traveling breaker plate structure 18 to reduce or pulverize objects and particles that fall therebetween. A single mill unit may have a plurality of sets of rotating hammers and a plurality of cooperating breaking plate structures depending upon the capacity of the mill. However, only one set of hammers and one traveling breaker structure are shown in the drawings to illustrate the invention.

The breaker plate structure 18 includes a plurality of individual breaker members 20 hingedly connected together to form a continuous flexible breaker assembly 21. The breaker assembly 21 extends around spaced upper and lower sprockets 22 and 2.4 and is driven by suitable means preferably connected to the lower sprocket 24.

One span of the breaker assembly 21 extends adjacent to the hammer circle -16 and is tangent thereto in the region where maximum material reducing takes place. This span of the assembly 21 moves along a stationary platen 26 which is shown in FIGS. 1 and 2. The platen 26 is provided with rounded end portions 27 to facilitate movement of the breaker assembly 20 thereover. In FIGS. 1 and 2 the platen 26 is shown mounted on a support member 28 which in turn is attached to the frame work of the mill by support members 30.

Of particular importance to the present invention is an adjustable nose bar 32 which is positioned between the hammer circle 16 and the breaker assembly 2.1 at the lower side of the point of tangency therebetween. The nose bar 32 extends across the width of the mill and is supported adjacent to its ends by means located on the mill housing. The nose bar 32 is diamond shaped in cross section and has its more sharply pointed edges 34 and 36 respectively at the upper and lower ends thereof. The upper edge 34 extends to closely adjacent the point of tangency of the hammer circle 16 and the breaker assembly 21, and the lower edge 36 has substantially the same shape as the upper edge 34 and can be substituted therefor when the edge 34 wears. This is accomplished by simply reversing the nose bar 32 in its mountings.

It is particularly important to be able to adjust the position of the nose bar 32 tocompensate for wear of the hammers 14 and breaker members 20 and also to be able by so doing to adjust the fineness to which particles are to be reduced.

In the past, stationary nose bars have been used but in the known mills the nose bars have not been adjustable and have been relatively diflicult to remove and replace. Furthermore, the relatively costly replacement of the nose bar does not always produce the most desirable operating conditions because it doesnt necessarily compensate for Wear of other parts such as wear of the hammers. To overcome these and other disadvantages, most of the known mill constructions made provision for adjusting the location of the whole breaker P ate assembly or the platen over which the traveling breaker plate moves so that the breaker plates can be adjusted closer or further away from the hammer circle. This requires fairly complicated adjustment mechanism and even then is not entirely satisfactory because adjustment of the traveling breakers toward the hammer circle is limited in known mills by the location of the fixed nose bar. Therefore, in known mills it is often impossible to compensate for hammer wear without either replacing the hammers or removing stock from the under side of the nose bar to prevent rubbing when the traveling breaker plates are adjusted closer to the hammers. All of these solutions are relatively complicated, expensive and time consuming and for these and other reasons are not satisfactory.

To overcome these difficulties in mills having traveling breaker plates, the present mill includes provisions for adjusting the position of the nose bar 32 in all directions relative to the hammer circle and also relative to the breaker plates, and furthermore makes provision for extending the useful life of the nose bar 32 by approximately two times simply by reversing its position.

This is accomplished by providing end extensions 38 on both ends of the nose bar 32 which extend through suitable openings 37 in removable cover members 39 attached to the associated opposite walls 46 of the mill housing. When one of the cover members 39 is removed from the mill It} the nose bar 32 can be moved endwardly out through the associated opening 37 and reversed or replaced.

Each of the nose bar extensions 38 have two side surfaces 42 that are oriented substantially parallel to the active surface of the breaker assembly 21, and the two other side surfaces 44 that are oriented substantially perpendicular thereto. The extensions 38 are supported on fixed support members such as the housing supports 46 and 48 (FIG. 1). The supports 46 are parallel to the extension side surfaces 42 and the supports 48 are parallel to the extension side surfaces 44. The extensions 38 also have crosslb ores 50 which receive threaded members for fastening them to the supports 46 (or 43). The supports 46 (or 48) also have elongated bolt holes 52 therethrough which enables the extensions 38 to be made secure thereto in different operating positions by suitable means such as by nuts 54, bolts 56 and lock washers 58.

The position of the nose bar 32 can be adjusted by positioning one or more shims 60 between the lower surfaces 44 of the extensions 38 at both ends of the nose bar 32 and the associated support members 48, and by positioning one or more shims 62 between the lower surfaces 42 and the associated support members 46. The shims 60 and 62 are put in place before the nuts 54 and bolts 56 are tightened. It is also contemplated to provide other adjustment means for changing the position of the nose bar 32 without departing from the scope of the invention. For example, threaded adjustment means with lock nuts could be used. However, shims are relatively inexpensive and easy to use and provide good support for the nose bar.

Another one of the advantages obtained by the present device is that it enables the platen 26 to be of all welded construction thereby further reducing the cost of the mill. It is contemplated, however, to use the present device with mills having adjustable platens such as the modified mill 66 of FIG. 3 thereby providing increased flexibility and adjustability and longer life for the wear parts including the hammers 14, the breaker members 20, and the nose bar 32.

Also in the present device the traveling breaker plate is preferably driven from a connection to the lower end sprocket 24 (or 68 in the modified mill 66 of FIG. 3). This has the advantage of maintaining the active portion of the breaker plate which is the portion adjacent to the hammer unit flat and tight during operation thereby im proving the pulverizing action. Furthermore, as shown in the modified mill 66 of FIG. 3, driving the breaker plate from a connection at the bottom simplifies the ad justment of the position of the whole breaker plate assembly 79, including a platen 72 which for illustrative purposes is shown adjustable by the means 74. This type of adjustment also makes it unnecessary to make any changes in the drive mechanism. This is seen in the modified construction of FIG. 3 wherein the whole breaker plate assembly 76) including the platen 72 is pivoted about the lower drive sprocket 24 and is adjusted by the means 76. This illustrates one of many possible existing mill constructions on which the present improvements can be adapted to further increase flexibility and to facilitate adjustrnent.

Thus it is apparent that there has been shown and described a hammer mill structure which fulfills all of the objects and advantages sought therefor, said hammer mill having rotating hammers and a traveling breaker assembly which moves along a path tangent to and adjacent to the hammer circle, said hammer mil-l also including an adjustable and reversible nose bar including mounting means therefor, said nose bar being positioned between the hammer circle and the traveling breaker assembly and extending to adjacent the point of tangency therebetween, and said nose bar mounting means including means for adjusting the position of the nose bar relative to the hammer circle and relative to the traveling breaker assembly.

Many changes, alterations, and modifications of the present device will become apparent to those skilled in the art after considering this specification and the accompanying drawings. All such changes, alterations and modifications which do not depart from the spirit and scope of the invention are deemed covered by the invention which is. limited only by the claim which follow.

What is claimed is:

A hammer mill for crushing solid material into particles of a predetermined size comprising a housing, a hammer unit including a rotatable hammer mounted in the housing, said hammer moving along a path defining a hammer circle, a travelling breaker plate structure positioned adjacent to one side of the hammer circle, said structure having a breaker surface adjacent to the hammer circle, and extending substantially tangent to the circle at a point thereon so as to form a pair of substantially V-shaped recesses on opposite sides of the point, a combination breaker and scraper bar having a pair of converging surfaces positioned in one of said V-shaped recesses so that one surface of the bar is parallel to the breaker surface and the other surface of the bar is substantially tangent to said circle, all portions of said bar being rigidly secured together so as to form a rigid unitary structure, said bar surfaces intersecting in a leading edge adjacent to the point of tangency between the breaker surface and the hammer circle, and means mounting end portions of the bar on the housing, said rneans including a first adjusting means connected to said end portions so as to move said bar in a first direction generally perpendicular to said breaker surface whereby one surface of the bar may be moved by said first adjusting means toward said breaker surface to compensate for wear of said breaker plate structure, and a second adjusting means connected to said end portions so as to move said bar in a direction substantially parallel to said breaker surface whereby the other surface of the bar may be moved by said second adjusting means toward said hammer circle to compensate for wear of said hammer and to regulate the size of the particles crushed by the hammer without effecting the adjustment between the bar and breaker surface, said first and second adjusting means comprising first and second sets of shims having widths substantially greater than their thicknesses, substantially perpendicular shim engaging surfaces on each end portion of the nose bar and a complementary pair of perpendicular surfaces formed on said housing adjacent each end portion, one of said surfaces being parallel to said breaker surface, the width dimensions of the first and second sets of shims being substantially perpendicular to one another 'and secured between said shim engaging surfaces on the nose bar and the shim engaging surfaces on the housing, aligned apertures formed in each end portion of the bar, said first shim means and a portion of said housing, 'a bolt extending through said aligned apertures and provided with a threaded adjusting member on one end thereof.

References Cited in the file of this patent UNITED STATES PATENTS Frickey Feb. 10, 1931 Knight Mar. 8, 1949 Bindner July 25, 1950 Fowler Sept. 19, 1950 Patent No.

It is hereby certified that err ent requiring correction and that th corrected below.

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July 30, 1963 Robert M. Williams or appears in the above numbered pate said Letters Patent should read as 12, and in the heading to the and 4, for "Williams Patent read Williams Patent Signed and sealed this 11th day of February 1964.

ISEAL) Attest:

ERNEST W,

SWIDER Attesting Officer EDWIN L REYNOLDS AC Li IHJ' Commissioner of Patents

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