US2785865A

US2785865A - Hammer mill construction

Info

Publication number: US2785865A
Application number: US349027A
Authority: US
Inventors: William E Berling
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-04-15
Filing date: 1953-04-15
Publication date: 1957-03-19
Anticipated expiration: 1974-03-19

Description

March 19, 1957 w. E. BERLING 2,785,865

HAMMER MILL CONSTRUCTION Filed April 15, 1953 2 Sheets-Sheet l #421 MHZ. .5554 mm flrrok/vars.

March 19, 1957 w. E. BERLING HAMMER MILL CONSTRUCTION 2 Sheets-Sheet 2 INVENTOR. Mum/1 E firm/A e flrraz/vzns,

Filed April 15, 1953 HAB/TMER MILL CONSTRUCTION William E. Berling, Indianapolis, Ind.

Application April 15, 1953, Serial No. 349,627

1 Claim. (Cl. 241-186) This invention relates to a hammer mill, and more particularly to one designed for custom grinding of a wide variety oi materials.

Heretofore it has been necessary in connection with conventional hammer mills to go to considerable trouble and efiort when it is desired to change the degree of fineness of the material being ground. For example, in order to effect the change it has been necessary that a screen mesh be inserted. This is a time consuming undertaking, and as well involves the expense of having screens of different mesh on hand. It is the primary object of this invention to eliminate this loss of time and expense. The object is accomplished through the provision of a hammer mill which can readily and easily be adjusted to vary the degree of fineness of the grind without stopping the mill and without changing the screen. Furthermore, the change can be made by the operator from the operating floor above the mill. It i thus unnecessary for him to climb down into the pit in which the mills are customarily positioned.

it is a further object of the present invention to provide a mill in which both friable and non-friable mateterials can be ground without hammer adjustment or change. This is accomplished through the provision of three separate series of heavy crushing hammers, medium grinding hammers, and thin cutting hammers respectively, the series being characterized by progressively smaller hammers from the inlet towards the outlet end. With this progressive reduction from heavy impact hammers to thin shear hammers, any grindable material or mixture of materials can be efficiently ground regardless of their specific gravity.

It is a still further object of this invention to assure a cool, even grind of the materials, thereby preserving their nutritional values. It has long been known that high temperatures destroy or at least reduce the nutritional values of materials, and the present invention is designed to avoid this occurrence. This is accomplished through the elimination of the screens and the provision of means which direct a moving stream of cool air through the mill. Provision is also made for readily adjusting the air control, thereby making possible a more precise particle size control and classification.

A further advantage stemming from the air control means is the ability to grind heat sensitive materials at higher capacity.

It is a still further object of the present invention to eliminate the gradual reduction in grinding capacity which characterizes conventional mills because of the inevitable Wear of their screens. Materials are ground in the present invention without forcing them through any screen.

it is an even further object of this invention to provide a mill of such construction that it will withstand the rigors of the heaviest grinding without undue strain.

The full nature of the invention will be understood from the accompanying drawings and the following description and claim.

States Patent In the drawings:

Fig. 1 is a side elevation view of the invention with parts thereof shown in section.

Fig. 2 is a vertical section view thereof taken on lines 22 of Fig. 1 in the direction of the arrows, with the feed table shown in side elevation.

Fig. 3 is an enlarged view of relatively adjustable plates which determine the degree of fineness of the grind.

Fig. 4 is a schematic view in a fiat plane of the arrangement of the respective series of hammers.

In the drawings the base or platform upon which the mill is supported is shown at 10. Secured thereto and extending upwardly therefrom are the two spaced bearing supports 11 and 12 which at their upperv ends mount the

bearings

13 and 14. Suitably journalled in the bearings is the driven shaft 15 which as will readily be observed from Fig. l is twice reduced in diameter at each end at 16 and 17 respectively. The shaft is connected to a crown type drive pulley 18 about which may be trained in the conventional manner a belt that is driven by a motor. If desired the shaft may be connected direct to the motor driving shaft. 7 Neither the belt nor the motor is shown since they are of conventional form and do not constitute a part of the invention.

The mill housing or hopper is shown generally at 19, it defining the annular grinding chamber 2%. The material to be ground is fed into the chamber through the inlet opening 21 that is defined by the upwardly inclined portion 22 of the housing. An end plate 23 is secured to the adjacent portion of the housing in any suitable manner such as through the bolts 24.

Extending into the inlet opening is a feed table 25 which is hingedly mounted at 26 upon the annular wall 27 of the housing. This table has 2. depending and slotted angle 28 secured thereto by the bolts 29. A brace 39 is provided for the table, it being pivotally connected to the housing at one end 31 and being slidably supported within the slot at its other end. As a consequence of this construction it is apparent that the table may be arcuately swung about its hinge connection within a range of desired positions as determined by the character of the material placed upon the feed table.

The lower portion of the housing is characterized by the side plates or skirts 32 which are suitably bolted to the adjacent portion of the housing by the bolts 33. Along one inner side of this lower portion there extends an inwardly directed guide plate 34 that is secured at its upper end to the adjacent housing side wall 35. Extending outwardly through an opening 36 formed in the lower portion of the end plate 23 and secured thereto is the vent 37 which at its upper end mounts relatively slidahle plates 38 and Si. Each of these plates is apertured at 4t? and with the manual sliding of plate 39 relative to plate 38 the size of the vent opening may be varied as desired.

Keyed respectively at 41 to the shaft 16 is a plurality of longitudinally spaced annular plates 42, each plate being provided with spaced apertures 43 adjacent its periphery. While eight such apertures are shown in the drawings it is, of course, a matter of some choice as to their exact number. The respective apertures are longitudinally aligned and. have journalled therein the hammer support rods 44. These rods may be held in place to prevent longitudinal movement by the cotter pins 45 or other suitable means. Swingably connected to the rods are three separate series of grinding hammers. The first series 46 of these hammers are crushing hammers, and are disposed at the inlet end of the mill as shown in Fig. l and are characterized by being relatively heavy and by having a relatively wide impact edge. The second series 47 of the hammers are so-called grinding hammers. These are lighter and have a narrower edge than the first series. As will be observed in Figs. 1 and 4, the second series is disposed intermediate the ends of the rods. The third series 48 are so-called thin cutting hammers and are still lighter in weight. and have an even narrower edge. :This series is mounted adjacent the exhaust or ontlet end of the grinding chamber. I Y 1 The hammers are preferably-or". reverse type so that upon wear they may be reversed to present their other edge. The hammers of each series are helically or circumferentially spaced so that their respective paths of rotation at least abut the path of-rotation of adjacent hammers. As shown in Fig. 4 this construction and arrangement is such that the material is forced progressively from the heavier to the lighter hammers, or to state it another way, from the inlet to the outlet end of the mill 7 Mounted in the offset portion 59 in the lower half of the mill is the replaceable liner 49 of wear resisting steel that can be. smooth or serrated as desired. It is spaced from inch to inch from the hammer tips, depending on the application and material being processed.

Closing off the outlet end of the chamber 29 is a pair of annular plates 51 and 52, one of which is suitably securedas by welding or the like at 53 to the housing while the other is rotatably mounted therewithin. Each plate is provided with angular notches or openings 53:: as shown on the plate in Fig. 3, the material being drawn therethrough into the suction yoke 54. When it is desired tochange the degree of fineness of the material it is necessary only for an operator to move the lever 55 that is connected to the rotatable plate thereby rotating it relative to the other plate and enlarging or reducing the size of the'openings 56 formed byboth plates.

The suction yoke is formed in such manner as to clear bearing 14 and is in communication with chamber 57 adjacent chamber 20. The end plate 58 along'with the plate 51 defines chamber 57. An opening 59 is formed in the housing wall that also defines chamber 57, so that the last mentioned chamber is in communication with the suction yoke. This yoke also is provided with slidable gates 60 which may be manually adjusted to enlarge or reduce the opening 61 formed in the Walls of the yoke.

In order to provide air flow means throughout the respective chambers a motor 62 is provided which drives suction fan 63 having hub 64 connected to drive shaft 65. In communication with the suction fan houshig 66 is the suction piping 67 which may comprise the desired number of sections in order to exhaust the material into the conventional bags or receptacles. Each section can be coupled as at 63 to its adjacent section.

In operation the material is first disposed upon the feed table and then fed into the mill. it is immediately engaged by the so-called crushing hammers and is progressively urged by the respective series of hammers towards the outlet end of the mill. The grinding operation is of such character that the material is soon in suspension. As a result of the suspension grinding and by reason of the fact that the hammers merely strike the material, the Furthermore, there is a considerable reduction in the heating of the material. Still further, the suspension grinding prevents slugging and power surges.

The progressive movement or advance ofthe material is facilitated as mentioned, by the construction and arrangement of the respective series of hammers. Howgrinding is more uniform in character;

ever, the advance or movement is accelerated by the provision of the suction fan which draws in cool air through the vent 37 and through the inlet opening into which the material is fed. As a result there is a constant flow of cool air through the grinding chamber as well as through chamber 57. As mentioned, this further reduces the heat which would otherwise be generated by the grinding operation. 7

When it is desired to vary the degree of fineness of the material it is necessary only for an operator to move the lever thereby rotating the plate 51 relative to plate 52. The size of the openings formed by both plates may thus be enlarged or reducedto the required degree; Fur-' thermore, it is unnecessary for the operator tolleave the operating floor above the mill, nor is it necessary for the mill to be stopped'or for any screen to be changed.

In order to assure a greater and more uniform flow of air through the chamber, auxiliary air flow vanes or blades 69 are provided. These are each-provided With a radius at one end that is complementary to thatof the adjacent portion of the shaft 15 which the blade abuts. Each blade is also provided with an aperture 70 through which one of the rods 44'extends. The outer extremity 71 of each blade is bent at'an angle so that as the, shaft 15 rotates the bent portion impinges upon the airin the chamber and thereby accelerates its movement and flow towards the outlet. While the number of such auxiliary blades to be employed is a matter of some choice, they.

are always assembled in aligned, pairs for balance purposes (see Fig. 2). As is apparent, the blades are mount-.

ed in fixed position and are not characterized by the swinging movement of the previously described hammers.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention and the scope of the claim are also desired to be protected.

The invention claimed is:

' A hammer mill comprising a base, a housing having an inlet and an outlet supported thereby, a feed table hingedly connected to said housing adjacent said inlet and areaately swingable about said hinge connection within a range of desired inclinations relative to said inlet, said outlet being defined by a pair of plates having aligned openings formed therein, one of said plates being fixed to said housing and the other of said plates being rotatably mounted adjacent said one plate, the other of said plates having an elongated handle projecting beyond said housing to permit ready rotation of said other plate relative to said one plate to vary the area of the openings of said outlet, air flow control means operably associated with said housing for drawing air from said inlet through said openings, a shaft rotatably mounted in said housing, lon gitudinally spaced members rotatable with said shaft, annularly spaced hammer support elements carried by said members, and a plurality of hammers connected to said elements.

References Cited in the file of this patent UNITED STATES PATENTS Sallee Apr. 29, 1941