US 3208676 A
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United States Patent 3,203,676 SELF-ALIGNED MULTIPLE HAMMER ASSEMBLY FOR HAMMERMILLS Sanning C. Jensen, Neola, Iowa Filed July 15, 1963, Ser. No. 295,000 Claims. (Cl. 241-195) This invention relates to hammermill hammers and more particularly it is an object of this invention to provide a multiple hammer assembly of a more effective construction.
A particular object is to provide an assembly as described which is held together by a threaded stud rather than by rivets or bolts for reducing damage to the hammermill and also to prevent the material being ground from having in it large pieces of rivets or bolts.
In the prior art, rivets and bolts have been used in such assemblies with the disadvantage that as the heads of rivets become worn away, the remainder of a rivet falls into the hammermill, tearing up the screen and causing extensive damage, even to the extent of passing up into and through blower blades and into vacuum bins and damaging the finished product.
The wearing away of a nut or bolt head causes a bolt to separate from the assembly falling into the feed or other material being processed and causing damage similar to that experienced with rivets.
The gradual wearing away of metal parts does not damage feed being ground materially, but large chunks of metal such as parts of rivets and bolts are harmful to animals when such chunks of iron are found in the feed.
It is, therefore, an object of this invention to provide an assembly as described which is held together by a threaded stud by threading outside ones of the hammers themselves, whereby when any exposed parts of the stud have become worn away, the stud itself will remain firmly in place protected by the hammers themselves, never falling into the feed or damaging the mill.
A particular object is to provide an assembly as described having in it a resilient locking device for maintaining the threaded connection of the stud under tension, the inner hammers floating on the stud sufficiently during assembly as to be alignable with outer hammers inasmuch as stud-receiving holes on the inner hammers are purposiely of larger diameter than the diameter of the stud itse 'f.
In the prior art, shorter and longer hammers have never been grouped together before. It is an object of this invention to provide a means of assembly in which shorter and longer hammers can be grouped together when desired.
Still another object is to provide an assembly the hammers of which will maintain themselves in alignment after they have once become self-aligned through the floating of inner hammers during assembly, since in use, the hamrner pin itself prevents later rotation of the hammers with respect to each other.
A particular object is to provide an assembly which will tend to operate without chattering, rattling, and rocking.
Other and further objects and advantages of the present invention will be apparent from the following detailed description, drawings and claims, the scope of the invention not being limited to the drawings themselves as the drawings are only for the purpose of illustrating a way in which the principles of this invention can be applied.
Other embodiments of the invention utilizing the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.
In the drawings:
FIGURE 1 is a top plan view of a section of a grain hammermill showing a portion of a housing thereof, a portion of the rotor shaft, half portions of two outwardly extending discs, and an end portion of the hammer pin, an assembly of this invention being shown on the hammer pm.
FIGURE 2 is a top plan view of a hammer assembly of this invention, a portion thereof being broken away.
FIGURE 3 is a side elevation of the assembly of FIG- URE 2 as seen from the right hand side thereof.
FIGURE 4 is a detail in side elevation of a spring washer of the assembly.
FIGURE 5 is a top plan view of the washer of FIG- URE 4 shown in its normal position before it is placed under tension in the assembly.
Referring to FIGURE 1, the rotor of a grain hammermill is generally indicated at 10 having a rotor shaft 11, a housing, a portion of which is shown at 12 with a bolt 14 therethrough; the rotor 10 having hammer pin holding members or discs 20 extending radially outward from the rotor shaft 11 for supporting a hammer pin 24 which is disposed through apertures in the outer ends of the discs 20, the hammer pin 24 being held in place by any suitable means such as a nut 30 disposed at one of its ends. Upon the hammer pin 24 and between the discs 20, a multiple hammer assembly 40 of this invention is arranged.
As best seen in FIGURES 1 and 2, the multiple hammer assembly 40 has two outer hammers 50 each of which have inner ends 52 provided with hammer pin receiving apertures 54 therethrough, the outside hammers 50 being formed of flat plate material which has been bent into shape such that center portions 60 of the hammers 50 are disposed normally in parallelism, the inner ends 52 of the hammers being divergently disposed away from each other toward their innermost ends, and the outer ends of the hammers 50 diverging away from each other progressively toward their outer extremities which latter aS seen at 72 are preferably hard-faced.
The hammers 50 are each of substantially rectangular shape, as seen in FIGURE 3, and as seen in FIGURE 2, the inner and outer sides and of each hammer 50 are preferably disposed in parallelism.
The center portions 60 of each hammer are provided with an opening 160 extending transversely therethrough in parallelism with the hammer pin 24, the opening in each of the hammers 50 being threaded, as best seen in FIGURE 2, for receiving a threaded stud 110.
The assembly 40 further has a plurality of inner hammers 120, which as best seen in FIGURE 2, can be of the same general description as the outer hammers 50, except that the inner hammers 120 are provided with central openings 122 which latter are of larger diameter than the largest diameter of the stud so that the hammers tend to float freely on the stud 110 until assembly has been completed, as later described.
Between the two inner hammers 126 is a spring washer 130 made in accordance with a special concept.
Referring to FIGURE 4, it will be seen that the spring washer 130 has a central hole 148 of a larger diameter than the largest diameter of the stud 11d and that the hole 148 is not threaded.
The washer 130 has indentations forming protrusions 150 disposed in spaced apart positions surrounding the hole 148, the protrusions 150 being preferably four in number and each having a concave side and a convex side, the convex side being raised approximately one thirtysecond of an inch away from the adjacent flat surf-ace of the washer 130 inasmuch as the washer 130 is otherwise in the form of a piece of plate material with parallel sides whereby the protrusions 150 make the flat plate into a spring washer inasmuch as they are adapted to be compressed, as later described, during assembly of a group of hammers on the stud 110, the material 130 being formed of a resilient metal of a thickness suitable for accomplishing the result to be described.
In assembly, the stud 110 is first threaded through one of the outer hammers St) at its threaded opening 100.
The inner hammers 120 and spring washer 130 are placed on the stud 110 in the position shown in FIG- URE 2.
The other outer hammer 70 is then threaded in place by twisting it around and around. It will be found that the spring washer 130 is so dimensioned and designed that although the alignment of the other outer hammer 70 would not normally occur when the hammer assembly is tight Without the spring Washer 130, yet with the spring washer 13th in place, the other outer hammer 7% can be aligned with the first mentioned outer hammer 70 with a tightness of the hammers on the stud 110 effectively maintained by the resiliency of the spring washer 130.
As thus described, a rigid and strong hammer assembly is formed which will operate as a single unit.
With the inner hammer pin-receiving apertures 54 of the hammers 70 and 120 disposed on the hammer pin 24, since the apertures 54 are all in alignment, the hammer pin assembly can be effectively put in use as seen in FIGURE 1.
In operation, the divergent inner ends 52 of the hammer 70 will tend to consume space between the discs 20 for holding the hammer assembly in position without need for adapters of any kind.
It will be further found that the assembly will operate without chattering, rattling, and rocking, and that any two of the hammers 70 and 120 can be conveniently replaced if it should become worn in access of any of the other hammers of the assembly.
Further it will be found that the hammer assembly of this invention in use will fulfill all objectives above set forth.
It will be seen that the protrusions 150 are three or more and preferably four in number, protruding equal distances from the side of the washer so as to exert an even pressure on the inner hammers 120.
From the foregoing description, it is thought to be obvious that a self-aligned multiple hammer assembly for hammer mills constructed in accordance with my invention is particularly well adapted for use, by reason of the convenience and facility with which it may be assembled and operated, and it will also be obvious that my invention can be changed and modified without departing from the principles and spirit thereof, and for this reason, I do not wish to be understood as limiting myself to the. precise arrangement and formation of the several parts herein shown in carrying out my invention in practice, except as claimed.
1. A multiple hammer assembly for hammermills comprising: a threaded stud, a pair of outer hammers having threaded stud receiving openings thre'adedly received on said stud, a spring Washed disposed between said outer hammers, means for holding said spring washer in a described position, said spring Washer being adapted to cause a pressure to be exerted to its sides such as is sufficient to hold said hammers rigidly in place on said stud, said hammers having aligned hammer pin receiving openings therethrough for slidably receiving a hammer pin.
2. The combination of claim 1 in which a plurality of inner hammers are disposed between said outer hammers, said inner hammers having stud receiving openings therethrough which are of larger diameter than the largest diameter of said stud for slidable reception of said stud.
3. The combination of claim 1 in which said means for maintaining said spring washer between said hammers comprises said spring Washer having a stud opening extending therethrough and receiving said stud, said stud opening being of a size for slidably receiving said stud.
4. The combination of claim'l in which said spring washer has a plurality of protrusions extending outwardly therefrom and in which said spring washer has a resiliency and has dimensions which exert a pressure against said hammers for pressing said hammers against said threads with a force suflicient to form said assembly into a rigid unit, said protrusions being at least three in number and protruding equal distances from the same side of said washer, said protrusions having convex and concave sides so as to be manufacturable from fiat plate material.
5. A multiple hammer assembly for hammermills comprising: a threaded stud, a pair of outer hammers having threaded stud receiving openings threadedly received on said stud, a spring washer disposed between said outer hammers, means for holding said spring washer in said described position, said spring washer being adapted to cause a pressure to be exerted to its sides such as is sufficient to hold said hammers rigidly in place on said stud, said hammers having aligned hammer pin receiving openings therethrough for slidably receiving a hammer pin, a plurality of inner hammers disposed between said outer hammers, said inner hammers having stud receiving openings therethrough which are of larger diameter than the largest diameter of said stud for slidable reception of said stud, said inner hammers being of lesser thickness than said outer hammers.
References Cited by the Examiner UNITED STATES PATENTS 1,952,600 3/34 McComb 151-38 1,963,534 6/34 Trotter 15138 2,607,538 8/52 Larson 241-l95 3,128,483 4/64 Moore l X J. SPENCER OVERHOLSER, Primary Examiner.