US2376361A - Hammer mill - Google Patents

Description

May 22, 1945. H. M. JOHNSTON HAMMER MILL Filed April 24, 1943 4 Sheets-Sheet l IN VEN TOR. Hom/DMJoH/YsTo/v INVENTOR.

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HAMMER MILL Filed April 24, 1945 4'Sheets-Sheet 5 INVENTOR. HOWARD M, JOHNSTON Arron/ver May 22, 1945. H. M. JoHNsToN v2,376,361

HAMMER MILL Filed April 24, 1945 4 sheets-sheet 4 INVENTOR. How/:R0 /YJOH/ysron ATTORNEY Patented May 22, 1945 UNITED STATES PATENT ori-ICE HAMMER MILL Howard M. Johnston, Toronto, Ontario, Canada, assignor to Massey-Harris Co. Ltd., Toronto, I Ontario, Canada, a corporation of Canada Appucsnnn April 24, 194s, serial No. 484,353

2 claims., ((1241-51) The present invention relates to a grinding mill of the hammer type and an object of the invention is to provide a mill that will deliver a more uniformly ground product `than other mills of the class.

Another object of the present invention is to provide a mill that will operate on less power per 100 pounds of feed ground than other mills.

Still another objec of my invention is to provide a mill which can be made largely of sheet or bar stock and having a larger capacity than other mills of the same size, weight or cost.

A further object of my invention is to provide a. mill through which the material iiows continuously and on a direct path; thus to avoid a slowing down of the material because of pockets or unnecessary turns.

An important object of the present invention is to provide a mill wherein it is not necessary to operate under a vacuum high enough to pick the ground material from the bottom of the housing for delivering it to a bagging attachment.

An important object of my invention is to provide a mill in which the ground particles may pass through the screen any place within the 360 diameter of thescreen.

A further object of my invention is to give the material maximum opportunity to pass through the screen when it has been ground to the size of the openings in the screen so that it will not be further reduced in size.

A still further object is to provide an auxiliary air inlet in order to give the operator better control over the grinding and discharging of the material.

The above objects are accomplished by means of a screen which entirely surrounds the rotor and by providing an annular chamber around the screen through which booster blades revolve fan like so the ground feed is immediately swept from the screen after it has pa/ssed therethrough and then moved rapidly in direct lines from the annular chamber to the outlet.

An important object of the present invention is to provide a mill which can be made in very small or very large sizes without departing from itsutility which is commensurate with its capacity.

To these and other useful ends, my invention consists'of parts, combinations of parts, or their equivalents, and mode ofI operation, as hereinafter described and claimed and shown in the accompanying drawings in which:

Fig. 1 is a side elevational view of my improved mm with the access ud lifted. y

Fig. 2 is a sectional view taken on line 2-2 of Figure 1.

Fig. 3 is a sectional view taken on line 3-3 of Figure 2.

t the rotor is,` in its entirety, designated by reference character B. Member A comprises side panels Ill and II and an outer wall I2 which terminates as at I3 and I4. Side panels I0 and f II are cut-away on lines I5 and I6.

A lid which in its entirety is designated by reference character C is formed by means of side plates I'I and I8 and a cover I9 which is hinged to member I2 as at 20. When lid C is closed, as illustrated in Figure 3, means (not shown) is provided for locking the lid in its closed position as at I3 Members I8, II, I2, I1, I8 and I9 complete the housing member.

Members I0, II, I1 and I8 are cut-away so as Vto form concentrically positioned openings 25 and 26. Bearings 21 and V28 are rigidly secured to members Ill and II concentrically with openings 25 and 26. A shaft 3| is rotatably mounted in bearings 21 and 28 as illustrated, the shaft at one end protruding through bearing 28 and havingl means secured to this end preferably a suitableV pulley for driving the shaft.

Member B comprises a hub positioned on shaft 3| in a. manner clearly illustrated in Figure 2. I provide a supplemental partition 36 which is circular land terminates at its periphery asat 3B.

I provide a removable screen preferably formed in three parts 39, 4U and 4I and being secured to members I0 and 36 in a manner whereby each screen member may ,be removed when lid C is lifted. These three screens are carried on guide bars 42-42 which are secured to members I0 and 36 providing a rotor chamber 43 and an annular chamber 44. Annular chamber 44 is interconnected with the space formed by members I I, I8 and 36. I mount a fan blade carrying member 45 on hub 35, this E" member having preferably three arms 46 secured thereto which extend to within a short distance of members I 2 and I9 (see Figure 2).' On each arm I mount a booster or fan blade 4'I, the blade extending into chamber 44 about as shown in Figure 2. ,Member 35 comprises a number Iof sections between which arms 48 extend, the' hub thus formed being preferably keyed to the shaft and made taut against members 48 by means of end nuts 49-49.

I have shown two members 48 positioned as illustrated in Figure 3 through which the shaft extends. In, order to lock members 48 to the hub member, I provide a number of locking pins 50 so the arms and ,hub will be rmly locked by trictional contact between nuts 49 or a suit able key may be provided for locking the members rigidly together and to the shaft.

I provide preferably two wearing plates 55 on each end of members 4l. These plates in the larger machines are made removable and reversible so when the corners become badly worn, they may be turned for wear on the other corner and when both corners at one end are badly worn, then they may be reversed so the other ends of these plates will be serviceable.

I provide an inlet opening 56 in member I0 anda feed-in trough which in its entirety is designated by reference character D. This trough is provided 'with a bottom 51 and side plates 58 and 59, the side plates having the shape shown in Figure 2. A gate valve 80 is provided for regulating the volume of material fed into the machine.

Between members Ill and 80 I mount a screen 6I. Clearly if ilne grain is being lfed into the machine for grinding and member 60 is left open only far enough to permit the right volume to v enter the grinder, there will be no air permitted to enter the grinder. Mills of the class require a certain volume of air which is drawn through the grinding chamber and screen.

In the presenty design, a vacuum is set up by the action of blades 41 and this vacuum will cause air to be drawn through screen 6I and into the rotor chamber through inlet 56. Blades 41 will act to draw the feed particles through the screen as soon as they are small enough to pass through openings S3 in the screen and discharge the ground feed through an opening 54 in housing member I2. Clearly the fan will act centrifugal- 1y to move the material as it leaves the screen directly into outlet 84.

It will be seen that the path from inlet 56 to outlet 64 is short and direct and that there is no place within the rotor chamber or within the annular chamber where the material will be retarded in its direct movement through the machine and that there is no place for the ground material to lodge so that immediately after it passes through the screen, it will be swept into the outlet.

In Figures 1, 2 and 3 or for the smaller sized machines, four suitably shaped legs 10 may be used as a mounting for the device. In Figures 4 and 5 the mounting is somewhat heavier and may be formed as illustrated in these gures having preferably transverse supporting blocks 1I-1 I. In this design, I provide a feed-in trough which in its entirety is designated by reference character E. The trough proper terminates as at 12 and having gate valves 13-13 for regulating the iiow of grain into the machine, the trough having an extension 14 which surrounds an open'- ing in the side wall similar to opening 56 in the other figures. Extension 14 is provided with'a covering 15 and a screened opening 16 which acts similar to screen 8| in the other figures.

In the larger mills, it has been found that it is necessary to control the volume of air entering the mill through screen 15. For this purpose, I provide a gate valve 11 hingedly mounted on member 15 as at 18 and having means 19 whereby the valve may be locked in any desired position for the purpose of regulating the volume of air entering the machine.

In Figure 2 I illustrate a V-belt drive pulley on asvasci It will be seen that 'the material will all beY held in suspension from the time it leaves the screen until it enters the outlet and that the fan blades, sweeping close to and along the outside surface of the screen, will act to urge the material through and away from the screen immediately after it is small enough to pass through the screen to prevent the particles from rebreaking and forming fine dust particlesT Since the screen surrounds theV rotor for 360, the rotorwill operate with minimum power and maximum eiliciency and have very large output capacity.

Obviously a minimum vacuum will be required since the path from the screen to the outlet is direct and the ground material is not permitted to slow down or come to rest on guideways or on the bottom of the housing as in other mills; thus in addition to the power saved in the grinding process, there will also be a great saving of power required to move the material from the screen to the outlet.

By scrutinizing the drawings it will be seen that when the housing lid is lifted, all of the 'operating parts of the mill may be moved in full view of the operator.

Clearly my device will occupy minimum space relative to capacity and can be easily manufactured at low cost.

Having thus shown and described my invention,

I of the housing and being somewhat smaller in diameter than the housing, a screen secured to the periphery of said supplemental partition and to the other wall of the housing forming a rotor rchamber and an annular chamber on the outside of the screen, said annular chamber being interconnected with the narrow space between the first wall and supplemental partition, a shaft concentrically rotatably mounted in the walls of said housing and means for turning the shaft, a rotor mounted on said shaft within said chamber, a fan member secured to said shaft and extending outwardly between said partition and rst housing l wall and a distan-ce past the transverse plane of said screen and having mounted thereon spaced fan blades positioned in said annular chamber and intermediate the screen and the outer wall of the housing, an inlet in said rotor chamber and an outlet in the wall oi the housing, said outlet being positioned and shaped to thereby act as a fan and ground feed outlet.

2. A device as recited in claim 1 including; said inlet having a feed-in trough and a gate valve spaced a distance from'the inlet for regulating the volume of feed entering the device, means forming a closure for they trough between said gate valve and inlet, having an air inlet and a gate valve therefor whereby the air entering the air inlet may be manually controlled.

HOWARD M. JOHNSTON.

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