US2066615A - Hammer mill - Google Patents

Description

Jan. 5, w37@ c. E. EVERET-n HAMMER MILL Original Filed May 9, 1932 3 Sheets-Sheet l IIJ- Inuenfov @y ,a/.swwvg (1H om@ an. 3% CIE. EVERETT HAMMER MILL Original File May 9, 1932 SSheets-Shee't 2 Inuemov M M M B L S.

B dumme lV n vc. E. EVENE-m 1F11 HAMMER MILL Y OriginlL Filed May 9, 1932 s sheets-'sheet 3 e @Home Patented Jan. 5, 1937 UNITED STATES PATENT oFFlcE HAMMER MILL Charles Edward Everett, Racine, Wis., assig'nor to The Massey-Harris Company, Racine, Wis., a corporation of Maryland s claims. (Cisa- 11)- My invention relates to hammer mills and the particular class of mills of this type adapted to grind grain and roughage of all kinds, such as oats, corn, corn stalks, hay, and the like. This application is a division of my original application, Serial No. 610,260, led May 9, 1932, now PatentNo. 1,960,626.

The particular object of my inventionis to provide a novel feeding mechanism whereby it will cooperate with the grinding unit, under all power conditions, and requirements of service.

Another object is to provide a novel design whereby the various parts may be made sufficiently strong and durable to meet the exacting service required of devices of this kind.

With these objects in View, my invention consists of4 certain features, novel in construction, combination and arrangement of parts, by which said objects are attained, as herein yfully described, and particularly pointed out in the appended claims, and shown in the accompanying drawings in which:

Figure 1 is a side elevation of a hammer mill, constructed in accordance with my invention.

Figure 2 is a side elevation, opposite to that shown in Figure 1, a portion of the housings having been broken away to better disclose the relative position of the'screen, hammers and means forforcing the material into the hammers.

Figure 3 is a top plan View, indicating the relative position and size of the housing, fan and feed table.

. Figure 4 is a central, vertical section of the blower fan, hammer cylinder and housing taken yon line 4 of Figure 1, the usual dust separator l being shown in side elevation in its relative position to the blower.

Figure 5 is a fragmentary, side elevation of the mill, illustrating my novel means for driving the responding parts in the figures of the drawings.

By referring rto the various drawings, my :novel structure as illustrated will be understood as comprising a base or lower housing I', an upper housing or hood 2, having a rearwardly extending trough or feed table 3, forming a unit, which is pivotally mounted on the lower housing as at I.

For the purpose of improving the strength of hood 2, and the appearance of the mill ingeneral, the cover Wall of the hood is made irregular in shape, as clearly indicated in Figures 1 and 2. This shape, it will be observed, provides three flat surfaces having sharp transverse bends therebetween. The front flat surface is vertically postioned above the front wall of the lower housing l, and the rear flat surface is positioned horizontally, a considerable distance above the rear wall of the housing l, providing room for a rough material inlet to the grinding device. The middle flat surface of the cover wall is, as indicated, positioned at an angle of about 45 degrees.

When the mill is in operating condition, the hood 2 is held into position by screw clamp 5, as indicated in Figure 1, but for purposes of inspection, etc., this screw clamp is disengaged and the hood is tipped up as indicated by dotted lines in Figure 1.

The concave screen 6 is supported on brackets l, which are preferably riveted to the side walls of housing l. A stiffening bar 3, is provided and attached to the rear wall of housing l as clearly shown in Figure 8, and a bar 9, for a similar purpose, is attached to the front wall of housing l, as shown in Figure 2.

A recess l0 is provided in the bottom of bar 9, into which the rear edge of screen 6 ts snugly. The front edge of this screen is made flush with the top edge of bar 9, as indicated in Figure 2. These bars, B and' 9, and brackets 'l cooperate to hold the screen into position, particularly so when the hood 2 is in working position, as it will be noted by referring to Figure 2, that the front edge of the hood rests on the screen. However, when the hood is tilted up as indicated by dotted lines in Figure 1, the screen may be easily removed.

I provide a secondary wall il which is in the form of a single curve, the front end of which is turned upward abruptly forming an angular approach l2, whereby rough and bulky material is deflected downwardly into the feed-in opening of hood 2. The outer end of extension l2 is made fast to the rear end of the cover wall as shown in Figure 2. The secondary wall contacts and is firmly attached to the dat surfaces at about equally spaced apart points as indicated in Figure 2.

The front end projects downwardly, past the cover wall to thereby contact the inside edge of screen 6, thus to hold the screen snugly against the bar 9. Obviously the secondary wall forms a strong brace for the cover wall and a reinforced smooth inner guide wall for the rough material, providing an ever decreasing space for the material as it travels forward over the grinding cylinder.

The grinding cylinder is preferably of the flexible hammer type and is carried on shaft I3 by means of suitable bearings Iii, which are attached to the side walls of housing I, by means of stiifening bars I5. The hammers I6, are conventional in shape and pivotally supported in groups spaced around the hub plates I'I, (see Figure 4) The cylinder is caused to turn in the direction indicated in Figure 2, by a curvilinear arrow.

The operation of the grinding unit is as follows: The rough material enters between the ends of the hammers and wall Il at the feed-in throat, and is carried forward and gradually forced by wall I I into the rapidly revolving hainmers, which serve to reduce the material until it is of a size which will pass through the interstices of screen Referring now to Figures 2 and 4, it will be noted that there is a large chamber below screen 6. The end walls of the housing converge as shown in Figure 2, and terminate a short distance apart at the bottom, to thereby form a fiat, centrally positioned, transverse trough. An air inlet I8, which registers with one end of this trough, is provided in one of the side walls, and an air and ground product outlet I9, is provided in the other side wall, which registers with the trough.

I provide a deflector plate 2U, which is positioned at an inwardly declining angle, serving to direct the falling material toward outlet I9 and prevent the entering air from rising in the chamber and causing harmful eddy currents directly under the screen and elsewhere. This plate is, at its upper edge, attached to the side wall as indicated in Figure 4, the ends contacting the converging side walls and attached thereto. Thus there are formed three converging surfaces adapted to direct the air and ground product toward outlet port I9.

The blower fan housing 2|, is attached to the lower housing I. This fan is conventional, comprising a hub 22, fan blades 23, and a central inlet port 24. A pipe 25 serves as an air and ground product passage from outlet I9 to port 24.

In order to prevent eddying air currents at the entrance end of pipe 25, it is formed to t outlet I 9, extending for a short distance in a direct line with the trough and then gradually tapering into a circular shape, then bending upward in a long easy curve and back again to port 24 as indicated in Figure 4. Thus there is provided an easy, unobstructed path from the screen 6 to fan inlet port 24.

I supply a gate valve 26 in port 24, thus providing means for adjusting the opening of this port to thereby regulate the quantity of air passing through the mill.

With my improved construction, clogging is impossible because there are no abrupt angles or depressions along the path of the air and therefore no drifting of ground product. A small quantity of material may accumulate on the approach side of valve 26 when partly closed. This however roll and sprockets.

will soon fall into the path of the swiftly moving air and be carried into the fan.

It will be seen that I provide novel means whereby the ground material, in varying conditions of moisture and size, will be successfully moved through the device. The use of the dust collector 28 is optional. It is shown as being connected to the fan by means of pipe 27.

The operation of the mill is as follows: The rough material in passing over the hammer cylinder is pulverized and then forced through the screen. Air enters opening I8, passes under deflector plate 26 which causes the swift moving air current to sweep across the bottom of the chamber and into outlet I9, carrying with it all material having reached the trough. Air also enters the mill at the rough material inlet, passes through the screen, joining the other air current, keeping the converging walls swept clean of ground material and assisting in carrying the ground product into port I9. Regulating the quantity of air passing through the mill is a necessary expedient in order to successfully handle material in varying conditions of moisture, neness or coarseness of grind, speed of grinding, and weight of material.

In mills of the present class, when not supplied with a suitable feeding device, considerable troubleis encountered by, first, choking of the grinding device, second, by permitting passage of air'out of proportion to the quantity of material being ground, third, by insufficient power to handle the quantity of material fed into the mill which results in reduced speed thereby throwing the entire mill out of adjustment. I provide feeding means which cooperate with the mill and available power to thereby eliminate the above outlined troubles.

I provide novel feed rolls in the feed-in throat of the mill, 'novel means for feeding material thereto and novel means for driving the rolls. A smooth lower roll 35 (see Figures 8 and 9), is mounted on shaft ends 36, which are journalled in bearings 3l. These bearings are attached to the side walls of upper housing 2, approximately over the rear wall of housing I. A stop plate (see Figure 8), forms a closure between roll 35 and bar 8 thereby to prevent material from escaping. The feed table, or trough 3, is provided with a suitable bottom plate 39. This plate is positioned preferably even with the top of roll 35 (see Figure 8). The front end of the plate and roll are in juxtaposition for their entire width, thus to prevent passage of small particles therebetween. Obviously, when driving sprockets are positioned on the ends of the lower feed roll as is common practice, a portion must be cut from the conveyor plate in order to make room for the sprocket teeth, therefore more or less material escapes, and further some of it is pressed between the teeth by the chain and accumulates, causing frequent trouble, and further, corn leaves etc., are caught by the teeth and wound around the My improved device prevents these troubles as will hereinafter appear.

I provide a 'conventional endless feed conveyor comprising two chains 4D and spaced apart nights 4I]a therebetween. This conveyor is, as indicated in the various gures, carried at its front end by roll 35 and at its rear end by means of the usual sprockets and carrying shaft, the bearings for which have means to thereby adjust the tautness of the conveyor chains. It will be observed that I provide a ledge or cover 4I for the rear end of the chain. This ledge extends over a length 75 junction with sheave 42, thereby causing the shaft 43 to rotate. after said sheave has attained a predetermined speed, all of which is accomplished by means too well known to need further l description. Spur gear 45 drives a large gear v41 which is securely fastened to shaft `50. This shaft is journalled in suitable bearings as shown in Figure 10.

I fasten two sprockets 5I in suitable positions on shaft 50, whereby to carry and drive thelower chains of the endless conveyory as clearly indi-F cated in Figures Sand 10. The sprockets 5| are positioned comparatively near roll 35 and as close to plate 39 as possible for obviousl reasons. Thusl it will be seen that the conveyor will bedriven by sprockets 5I and that the roll 35 will be friction driven by the conveyor. Obviously, therefore, the roll 35 will be kept free of trash for reasons already outlined, and further because the frictional action of the conveyor on the roll will tend to rev move or prevent collection of trash.

0n the shaft 50, at the end opposite the gear 41, I fasten a sprocket 56 which drives the upper feed roll 52 by means of chain 58. A novel feature of this drive is the arrangement I employ for keeping a constant tautness of this chain, which is clearly shown in Figure 5.

The upper feed roll 52 is made rough on its surface to aid in gripping the material and is supplied with a suitable shaft' and other means whereby it may adjust itself to varying quantities of material, as it passes over the lower feed roll 35. Upon the side walls of the housing 2 and on the outside thereof, I pivotally fasten arms 53 (see Figures 3 and 5), as at 59 having at their free ends suitable bearings 53e for the shaft which carries roll 52. An opening 55 is provided into' which a portion of the bearings 53 extend. This opening is of considerable height and preferably cut into the side walls on a radius with 59 (see Figure 8), thus to permit free vertical movement of the roll 52. On the end of the upper feed roll shaft I securely attach a sprocket 51.

Arm 53 on the drive side of the mill, is provided with an integral depending arm 54. At the pivot point 59, I locate a rotatably mounted sprocket 60. At the end of arm 54, I locate a rotatably mounted )tightener sprocket 5I adjustably held in slot 63 `by bolt 62.

6o t; The chain 58 operatively engages sprockets 56, ,51, 60, and 6I, which are positioned as indicated in Figure 5, whereby when the roll 52 rises or travels away from sprocket 56, sprocket 5I will travel toward sprocket 56, (see dotted lines) to 65 thus maintain a uniform tautness of the chain. Roll 52 is preferably supplied with suitable spring pressure as clearly indicated in Figures 5 and 6. v

As the rough material is loaded on the conveyor in varying quantities, the upper feed roll Vwill move 70 upward to compensate for the varying volume. 'I'he upper feed roll is normally held in the lowest position. When an excessive amount of material reaches the grinding cylinder of the mill the lspeed will be reduced to a point where the centrifugal 75 governor will partially or wholly disengage the drum 44. Thus the power required will be reduced and the-'speed of the mill may increase again to normal. Thus the mill and fan speed will be resumed at a speed which insures successful operation. 5

Thus it will be observed that I have provided a novel feed mechanism and novel means for driving the same, that the inner conveyor roll is smooth and friction driven, that the upper feed roll is yieldingly held on the material and is posilo tively driven by a self adjusting chain.

Having thus show'n and described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A device of the class described, comprising a 15 grinding mill having a feed-in opening, meansfor moving material into said opening comprising a trough having an endless conveyor in the bottom thereof, the front end of which is positioned in said opening, a feed roll positionedin said open- 20 ing and above the front end of said conveyor, means' for carrying and driving said feed roll, comprising a driving sprocket, a driven sprocket on the shaft of said feed roll, a bearing for said shaft' adjacent said driven sprocket having a piv- 25 otally supported arm whereby said feed roll may move over incoming material and an idler sprocket adjacent said pivot, a depending arm attachedto the pivoted end of said rst arm thefree end of which carries an idler sprocket, a chain opera- 30 tively engaging said four sprockets, whereby when said roll and driven sprocket rise said arms cooperating whereby said second idler sprocket moves toward said driving sprocket to thereby maintain the tautness of said chain. 35

, 2. A device of the class described, comprising a grinding mill having a feed-in opening, an upper feed roll suitably positioned in said feed-in opening, means for feeding the material to be ground under said feed` roll, comprising a trough, a' 40 smooth roll, an endless chain type conveyor and a conveyor plate, said smooth roll positioned under said upper feed roll and adapted to carry the front end of said conveyor and be friction driven thereby, said plate adapted to carry the upper 45 half of said conveyor and lhaving its front end and the top of said smooth roll on approximately the same plane and in juxtaposition for the width of said conveyor, said feed roll journaled on the free ends of pivotally mounted arms, one arm having 50 a depending leg and an adjusting idler sprocket 'at the free end thereof, an idler sprocket adjacent said last named arm pivot, a driving sprocket, av driven sprocket attached to said feed roll, said driven sprocket positioned between and above said 55 driving and adjusting sprockets, a driving chain operatively engaging said four sprockets, whereby, when said feed roll rises or falls, said adjusting sprocket will be caused to move toward and away from said driving sprocketto thereby maintain a uniform tautness of said chain.

3. A device of the class described, comprising a grinding mill having a feed-in opening, a roll rotatably positioned near the bottom of said opening, means for feeding the material to be ground into said opening, comprising a trough, an endless chain type conveyor therein and a conveyor plate, said roll having a smooth surface for the Width of said conveyor and adapted to carry the front end thereof and be. friction driven thereby, said plate adapted to carry lthe upper half of said conveyor and having its front end and the top of said roll on approximately the same plane and in juxtaposition `for the entire width of said conveyor, a feed roll positioned in said opening and above said rst roll, having means to yieldingly move over the incoming material, means for driving said feed roll, comprising a driver sprocket, a driven sprocket carried by said feed roll, a stationary idler sprocket and a movably supported idler sprocket positioned below said idler sprocket and being mounted movably to or from said driving sprocket, a single driver chain surrounding and operatively engaging each of said four sprockets, means operatively connecting said feed roll to said movably supported sprocket, whereby when said feed roll rises or falls, said movably supported sprocket will move toward or from said driving sprocket to thereby maintain a uniform tautness of said chain.

CHARLES EDWARD EVERETI.

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