US2692088A - Dust guard - Google Patents

Description

Oct. 19, 1954 Filed July 24, 1952 A. J. LAYBERGER DUST GUARD 3 Sheets-Sheet l y j a7 41? INVENTOR. flizwamflnyas/wzfi OCt. 19, 1954 LAYBERGER DUST GUARD 1 Filed July 24, 1952 3 Sheets-Sheet 2 [HUME];

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O t. 19, 1954 A. J. LAYBERGER DUST GUARD 3 Sheets-Sheet 3 Filed July 24, 1952 lNV TOR BY 3 ATTQ NEY Patented Oct. 19, 1954 DUST GUARD Arthur J. Layberger, Havcrtown, Pa., assignor to Pennsylvania Crusher Company, Philadelphia, Pa., a. corporation of New York Application July 24, 1952, Serial No. 300,719

6- Claims.

This invention relates to a dust guard for a reversible type hammermill to intercept the dust carried around by the hammers and forced up the feed chute.

This application is a continuation in part of my copending application Serial Number 178,798, filed on August 11, 1950, entitled Dust Guard, now issued as Patent No. 2,609,996.

The object of the invention is to provide a hammermill type crusher with a feed chute having a dust guard mechanism cooperating with the hammers and casing to intercept and divert dust. created by the crushing process and prevent the dust from escaping out through the feed chute into the atmosphere outside the casmg.

Another object of the invention is to provide a dust guard that is easily and readily adjust able. from outside the feed chute.

Another object of the invention is to provide a dust guard that is readily settable at different positions with relation to the rotating hammers.

Another object of the invention is to provide a dust guard that is inexpensive and durable in construction.

Other and further objects of the invention will appear from the following description taken in connection with the accompanying drawings of wh ch:

Fig. l is a top view of the dust uard;

Fig, 2 is a cross-sectional view of the dust guard along lines 2-2 of Fig. 1;

Fig. 3 is a cross-sectional view along lines 33 of F s- 1;

Fig. i is a fragmentary end view of another embodiment of: the invention;

Fig. 5 is a fragmentary side view of the other embodiment of the dust guard;

Fig. 6 illustrates an end view of the Fig. 4; and

Fig. 7 illustrates schematically various positions of the dust guard.

Referring to Figs. 1, 2 and 3 of the drawings there are shown the hammers Ill of a reversible type hammermill crusher mounted on a driven rotor (not shown) and subscribing a hammercircle H on rotation, On each side of the rotating hammers are breaker surfaces I3 and [4 against which the material dropped through the feed chute I2 is hit by the hammers. The material is smashed against the breaker surfaces and shattered into smaller particles. The breaker surfaces are arranged on both sides of the feed chute l2 and are spaced above the hammers I0 to term a. breaker chamber (6. The breaker surfaces are shown schematically since the detail construction and arrangement of these surfaces varies with the type of material to be crushed and the size of crushed material desired, These surfaces are preferably of the same constuction on each side of the feed chute so that the rotor may be turned in either direction With the same resulting action of the material against the breaking surfaces. The broken material is carried by the hammers around and down to screen bars (not shown) where the broken material is further crushed and dropped through the screen bar. However dust formed by the crushing process tends to remain within the rotor and be carried upwards and thrown with the air currents into the breaking chamber and up into the feed chute. This dust and air currents interfere with the incoming material and the dust eventually escapes out of the top of the feed chute into the atmosphere causing an objectionable suspension of fine dust.

To prevent this dust and air currents from entering the breaker chamber I6 and feed chute I2, a plate i1 is positioned in. the breaker chamber it between.- the end of the breaker surface l4 adjacent the chute l2 and the incoming material and extends almost down to the hammer circle I! as illustrated in Fig. 2. As the hammers It! approach the chute on a counterclockwise rotation, the end of the plate or dust guard i'l breaks the momentum of the dust and deflects the dust and air currents back into the hammer circle. The incoming material then drops substantially free from these disturbing air currents and dust from the hammers, l

When the rotor is turned clockwise the plate i1 is raised, swung across the feed chute and lowered into position on the other side of the feed chute. Thus the plate H is utilized as a dust guard for both clockwise rotation and counterclockwise rotation.

The plate I! is mounted within the feed chute l2 and is suspended from the rocker arms 53, I9. The arms are mounted on the rota-table shafts 2 i, 22 and have counterweights 23, 24 to counterbalance the weight of the arms l8, l9 and the plate l'l. The shafts 2|, 22 are journaled in the beams 36, 38 respectively and outer end members 41, 44 respectively. The arms l8, 59 are mounted on the stubs of the shafts 2|, 22 extending through the beams 36, 38 into the chute side of the beams and keyed to the stubs. Drive gears 42, 45 are secured to the respective shafts 2|, 22 and rotate the shafts to adjust the position of the plate I? or switched from side to side. The. gears 42, 45 are connected to the gears 48, U by the chains 41, 49 respectively. The gears 48, 50 are keyed to the shaft and are rotated together by the worm 52 and gear 53. The worm and gear mechanism provides a slow adjustment of the plate i1 and will hold theplate H in any desired position. The worm 52 is mounted on and keyed to the shaft 54 with a crank socket 55. The outer ends of the shafts 23, 2! are journaled in the members 45, 44 with safety collars 43, 43 on the chute side of the members. The collars 43, 43 cooperate with the hubs of the gears 42, 45 to prevent excessive axial play of the shafts and to hold the plate i! in the longitudinal position.

The feed chute is of a rectangular shape with recesses 38, 39 in opposite lateral sides. The arms l8, [9 are positioned within the recesses respectively. Longitudinal walls are formed by the beams 34, 36 and the plates 26, 28 extending below the beams 34, 35 respectively down to the breaker surfaces l3, I4 respectively. The beams 35, 3! are set further apart than the plates 26, 28 to allow space for the ends of the arms I8, l 9.

Projecting'inwardly are central portions 3D, 3! on the beams 36, 34 respectively and having the chute surface preferably flush with the inner surface of the plates 26, 21. The lateral sides of the chutes are formed by the plates 25, 2'1 extending from the end plates of the crusher and flaring outwardly at any angle'to form a sloped bottom 25a, 22a to the recesses 38, 39 respectively. The extended portions or Wings 55, 5'? of the plate I! fit into the recesses 38, 39 and are clear of the material in the chute. Pins 58, 59 are mounted in the edge of the wings and fit in slots 30, 5!. The guides 62, 63, 64, 65 are rigidly mounted on the sloped bottoms 25a, 2711., respectively, and are spaced from the adjacent longitudinal wall a distance slightly larger than the width of the plate IT. The upper edge of the guides is beveled or rounded to provide a gradual narrowing of the space between the guide and the adjacent wall in order to receive the edge of the plate I? and guide it between the guide and the wall. The bottoms 25a, 27a may be flat, then the'corresponding edge of the plate H would be flat and the beveled edges would correspondingly be horizontal. However, it is preferable to have the bottom 25a, 27a at an angle to slide off any entering material catching v in the recess 38, 39.

The plate I1 is a steel'plate having pins 58, '59

mounted in the ends of plate. The pins 58, 59 fit into radial slots 60, 6! in the arms l8, l9 respectively. The slot permits the plate to move substantially vertically in the guides 62, 63 or 64, 65.

In an operating position the arms l8, l9 are at a slight angle above the horizontal'and the pins 58, 59 are positioned at the outer ends of the slots Bil, 6! respectively. The'hammer edge of the plate is spaced slightly above the hammers to prevent the hammer tips from impinging on the edge of the plate. The plate may be shifted from one side of the chute to the other while the ham-- mers are still rotating. It is preferable to move the plate away from the hammer and then reverse the rotation of the rotor. As the plate is lifted, the pins 58, 59 move outwardly in the slots 53, 65, Pig. 2. The plate I? will then tiltslightly and move further upon the beveled edges, Fig. 7a, when the pins 58, 59 will stick to the inner end of'slots 63, El and the arms pick the plate I! off of the guides 62, 64 and carry it over the guides 55a, 51a, Fig.;7b, toengage the beveled edges. Th pla te tilts slightly, Fig. 7c, and as grades 82, 91 it assumes a vertical position and the pins '16, ll move to the outer end of the slots l8, 19, Fig. 7d. The arms 24, 25 lower the plate and as it is lowered the pins 73, T! move to the inner end of the slots 18, 19.

On the longitudinal beams 34, 36 are the center projecting portions 3B, 3! 'on opposite sides of the feed chute and extend from one recess to the other. The projecting portions are preferably flush with the longitudinal side to form a continuous surface along which the plate I! can slide. These projecting portions also prevent material from accumulating behind the plate and falling into the recesses 38, 39.

The beams 34, 35, 36, 31 may extend higher or have rectangular wall sections mounted on the upper flanges of the beams 34, 35, 36, 3? to posi tion the lower edge of the upper portion. of the feed chute above the are subscribed by the arms l8, 19 as the plate I7 is moved from one position to another. Various other feeding structures may be used Without interfering with the dust guard. i

The plate I! can be adjusted to different vertical positions with relation to the hammer circle depending on the circumstances. The plate ll may be held in position by the worm and gear mechanism or any other suitable device. As the hammer circle edge of the plate is worn, the wear 7 tioned by stops 59, 13 mounted on the end or lateral walls of the chute. In Fig. 4 the suspension of one end of the plate is shown by the arms til mounted on a shaft 33 and plate tfi'pivotally mounted at the outer end of the arm. A pin ll supporting the plate is fixedly mounted in the end of the plate 65 and rotatably fits into-the crank arm so as the crank arm is shifted from one position to the other the plate 65 remains vertical. The plate 36 extends into the breaker chamber almost to the hammer circle forming a dust guard. The rotation of the crank arms is limited by the stops 69, it upon which the'crank arm rests and supports the plate in position. The stops are mounted on the end walls of the delivery chute. The stops may be made adjustable by the stops fitting through slots in the Wall and fastened to slide bars l4, 75 respectively by clamps '33, H. The plates may beshifted from one'side to the other by means similar to the mechanism shown in Figs. 1 to 3 or any other suitable mechanism. The stops could be individually loosened and reset at another position.

Various other modifications and changes may be made in the embodiments shown without departhammers comprising a plate positioned along the inside of the chute and extendable adjacent the periphery of the rotating hammers, rotatably mounted crank arms at the ends of said plate pivotally supporting said plate at radially spaced pointson said crank arms to readily shift the plate from one side of the delivery chute to the other side and to suspend the plate in the space,

between the breaker plates and the periphery of the rotating hammers...

2. A dust guard as claimed in claim 1 wherein the sides of the chute at the ends of the plate have recesses and the crank arms are mounted in the recesses clear of the material passing through the feed chute.

3. A dust guard as claimed in claim 2 wherein the plate has portions extending into the recesses.

4. A dust guard as claimed in claim 3 wherein guides are provided in said recesses extending longitudinally to the wall and spaced therefrom to hold the plate along the chute wall.

5. A dust guard as claimed in claim 4 wherein said arms have radial slots and said plate has a pin at each end fitting in said slots so that the 6 plate moves vertically when adjacent the hammercircle.

6. A dust guard as claimed in claim 5 wherein the upper ends of said guides are beveled to permit the extended portions of the plate to tilt the plate when it is moved from one side of the chute.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,514,111 Wilson July 4, 1950 2,609,996 Layberger Sept. 9, 1952

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