Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS2148022 A
Publication typeGrant
Publication dateFeb 21, 1939
Filing dateMar 16, 1937
Priority dateMar 16, 1937
Publication numberUS 2148022 A, US 2148022A, US-A-2148022, US2148022 A, US2148022A
InventorsHaaland Carl E
Original AssigneeHaaland Carl E
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Hammer mill
US 2148022 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

Feb. 21, 1939. c. E. HAALAND HAMMER M ILL Filed March 16, 1937 4 Sheets-Sheet l INVENTOR. Carl E. Haa'l. and


Feb. 21, 1939.

FIG. 2.

Fi l e d M a r G h 1 6 l 9 37 FIG. 7,

. NNNNNNN R. Carl E. Haalanlfl.


Feb. 21, 1939. c HAALAND 2,148,022

HAMMER MILL Filed March 16, 1957 4 Sheets-Sheet INVENTOR.



Earl 111 Haa Feb. 21, 1939. c. E. HAALAND HAMMER MILL 4 SheetsSheet 4 Filed March 16, 1957 FIG. 4.

. INVENTOR. [larl E.-.Haa1 an d.

Patented 1a,. 21,1939 I umrao STATES PATENT ambs This invention relates, to hammer mills, and more particularly to hammer mills adapted to handle material such ashay, straw, dry stalks and similar dry roughage. s I An important object of the invention is toprovide a hammer mill wherein thehammers are neither rigidly secured nor are they flexible, but are of rigid material and-pivoted to operate by centrifugal force. As a result, they have a greater efficiency than do rigidly secured hammers and, at the same timeythey do not become entrangled as do flexible hammers.

Another important object is to provide a hammer mill for material of the character named,

wherein the "dry leaves, such as those-of alfalfa,-

Still another important object is to provide a mill, as described, which will mix such whole leaves with the material after the latter has been reduced by the hammers, so that the feed will 25 irzzolnjuirise a mix of the leaves and hammered mae a 1 Since wear and tear is-an important consideration in the operation and maintenance of hammer mills as described, another'important object 30 is to provide hammers and associated parts which do not touch nor rub against each other during operation of the mill.

Hammer mills are generally subject to considerable vibration and an important object of a 35 the invention is to provide such a mill, where vibrations are reduced. This is due, not only because of a sturdy construction, but because of the specific shape and disposition of the hammers in their association with the adjacent structure of 40 the mill.

Another object is to provide a sturdy mill structure which will not be apt tobe damaged in the event hard materials, such as stones, enter the mill. There are no knives nor cutter bars em- 45 ployed in the construction and, consequently,

alfalfa and the like, which will disintegrate the material without creating dust. Thisis due, in part, to the separate removal, by the mill, of most of the leaves, seeds and the like, before the material reaches the hammers. 5

Other objects and advantages of the invention will be apparent during the course of the following detailed description, taken in connection with the accompanyingdrawings, forming a part of this specification and in which drawings:-

Figure 1 is a vertical longitudinal section of the novel mill,

' Figure 21s one side elevation thereof.

- Figure 3 is an opposite side elevation of the same. 15

Figure 4 is an elevation of the discharge and of the novel mill, parts being broken away in order to better illustrate portions of the interior stru ture.

Figure 5 is a top plan view of the materialreceiving portion of the mill. I

Figure 6 is a fragment of structure associated with the portion shown in Figure 5.

Figure 7 is a developed view of the hammer assembly of the novel mill.

Figure 8 is a side elevation of the hammer assembly, with the hammers at rest.

Figure 9 is a fragmentary section .of a screen forming a portion of the mill assembly.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of the invention and wherein similar reference characters designate corresponding parts throughout the several views, the novel mill is shown as including a housing or frame l0, preferably comprising a plurality of sections, bolted or otherwise secured together. In the example shown, each of the side walls of the housing I0 comprises a forward section H, somewhat triangular in shape, and a rearward section 12, somewhat rectangular in shape, while the forward end wall i3, joining the forward section II, slopes inwardly from its upper end, for a purpose later described. The rearward end wall may comprise several stepped sections l4 and I5. Disposed intermediate the forward end wall l3 and the sections l4 and I5, is a vertical partition, preferably comprising two stepped sections l6 and I1, corresponding somewhat to the sections II and I5, but the section I6 does not extend upwardly as far as the top of the 507 housing within these sections II.

Extending from one side wall, comprising one of the sections II and 12, to the opposite side wall, comprising the other sections ii and i2,

are a pair of converging substantially straight walls It which join each other in a curved wall section 24, this curved section being preferably rather close adjacent the bottom of the housing,

. while the walls I! join the sections II and I2 substantially circular opening 24 in the section II of the rearward end wall, with its axis coincidental with the axis of the opening 23. The are of the opening 24 is substantially that of the curved section 20, as shown in Figure 4. An outwardly extending collar 25 may extend about the opening 24, all for a purpose later set out in detail.

Suitable braces 25 for the side walls of the housing may be provided, preferably comprising L-shaped members having web portions joining the L-shaped members, as shown in Figures 3 and 4.

From the construction thus far described, there are provided two major compartments or chambers within the housing I ll,one, the forward compartment or chamber 21, being open at its top and defined by the forward end wall II, side sections ll, partitions i and I1, sections It, 20 and 22, and the other compartment or chamber 25, being the rearward one and defined by the sections l2, l4, i5, i9 and 20, roof Ill, and partitions l5 and I1. Since the partition I does not extend to the roof It, as described and as shown in Figure 1, there is a forward opening 29 to the compartment 28, as well as the rearward opening 24, heretofore described.

A horizontally disposed partition or platform is provided, to rest, preferably, upon the upper extremity of the partition i8 and extend into the compartment 25 a distance somewhat less than the vertical medial line of this compartment, and to jut into the compartment 21 substantially the distance the stepped partitions l8 and I1 are spaced apart. This platform 30 may be secured to the side sections i2, as by rivets ll. Since the housing walls and partitions may be subjected to the impact of hard material, such as stones, particularly the partition wall It and platform 30 are of heavy material.

Means for conveying roughage or dry fodder into the mill is provided and preferably comprises a substantially horizontally disposed dry fodder trough 35, carried by the housing ll, at one end thereof and disposed to empty into the open upper end of the forward compartment 21. A suitable conveyor may be associated with this trough, such as a chain belt 35, traveling over suitable sprockets 31 fixed to a shaft 38 supported by bearings 38 carried by the housing. 1111s shaft I5 is driven by a pulley 45 in the direction shown by the arrow in Figure 2. The chain belt 35 is provided, at suitable intervals, with transversely extending cleats 4i, which may be formed of angle iron. It will be noted, particularly in Figures 1 and 3, from the location of the shaft 38 and size of the sprockets-l1, that the conveying means just described, conveys the rough material such as dry alfalfa, clovers or other'fodder, to a point just inwardly of the forward wall it, for it'is desirable that subsequent treatment of the roughage take place at once, in order that the leaves will be removed before disintegration of the stalks and stems.

The disintegrating means for the material to be treated is disposed within the compartment 2:

and includes a plurality of hammers 45. These are rigid members, each comprising an integral, substantially rectangular, length of suitable material, carried by pivot pins 45 extending through suitable perforations adjacent the inner ends of the hammers 45 and pivotally coupling the hammers to suitable supports, such as the series of spaced apart discs 41, which are provided with suitable perforations adjacent their peripheries and spaced substantially 90 apart, to accommodate the pivot pins 45? Preferably, there are four such pivot pins 46, each extending through the series of discs 41 and having screw threaded ends, accommodating suitable nuts 44.

The hammers are preferably disposed in a staggered relationship about the disc assembly, as shown particularly in Figures 4 and 7. From this latter figure, it will be seen that (at the extreme right of this figure) there are two hammers 45 pivoted to either face of one disc 41, (the middle disc) by one pivot pin 45, and that there are then four discs intervening between each of these hammers and the next two hammers carried by this pivot pin, and then three discs intervening between each of the last two hammers and the next two hammers. The adjacent six hammers, carried by the next adjacent pivot pin, are staggered with relation to the arrangement of hammers described, and this applies to the other two groups of flxed hammers, each carried by the two other pivot pins. While this arrangement may be varied, that shown has been found, in practice, a very desirable one.

The discs 41 are spaced apart by suitable spacers 49. These are of slightly more peripheral width than the thickness of the hammers 45 and are of less diameter than the diameter of the discs 41, as may be seen particularly in Figure 8. This arrangement provides for free play of the hammers and permits them, when the mill comes to a stop,'to drop into the grooves provided by the adjacent discs 41 and spacers 49, thus clearing the surfaces of the hammers as well as the walls of the grooves of any foreign material which had accumulated thereon.

The discs 41 and spacers 49 are mounted upon and secured to a shaft 55, by any approved means, such as the key 5|. This shaft extends across the chamber 28, from one housing section l2 to the other housing section I2 and is disposed so that, preferably, the hammers 45 when thrown outwardly by centrifugal force, will just clear the horizontal plane of the platform 30, as may be seen in Figure 1. The shaft 50 extends outwardly of the housing, through suitable perforations therein and is supported by bearings 52 which may be carried exteriorly of the housing.

At one end, the shaft 50 terminates in a pulley 53. which may be operatively connected with a suitable source of power, such as by the main drive belt 54, the pulley 53 rotating counterclockwise as viewed in Figure 2.

The opposite end of the shaft 55 terminates in a second pulley 55, being operatively connected with a portion of the mill to be next described.

Spaced above the hammer-disc-spacer assembly just described, is a combined beater and deaisaoaa flector assembly, preferably comprising a plurality of rigid, straight arms 88, provided with perforations midway thereof so that they may be mounted upon a suitable shaft 51 and secured thereto, as by a key 58, with each adjacent arm 58 normal to the next arm 58. Thus, each two adjacent arms form substantially a Greek cross and each two of such arms, may be spaced apart as by spacers 59 disposed about the shaft 51. The arm and spacer assembly may be prevented from moving longitudinally of the shaft 51, as by suitable nuts 68, cooperating with screw threads upon the shaft 51. The shaft 51 extends across the chamber 28, paralleling the shaft 58, and projects outwardly of the housing section l2, where suitable bearings 8l,- mounted exteriorly of the housing, accommodate it. At one end of the shaft 51, corresponding with the end of the shaft 58 carrying the pulley 55, is disposed a pulley 82, which is operatively connected with the pulley 55, as by a belt 83 disposed, as is well known in the art, so that as the shaft 58 and pulley 55 rotate in one direction, theshaft 51 and pulley 52 will travel in the opposite direction, as shown by the arrows in Figure 3.

Extending across the lower portion of the chamber 28 from one section l2 to the opposite section l2 of the housing, and from the section it to the section 16, at substantially the stepped portions of these sections with their associated sections l5 and I1, is an arcuate screen 55. The are described by this screen and its direction is such that the hammers 45 when extended outwardly by centrifugal force, will clear the upper face of the screen 85. This screen is preferably of somewhat flexible material, having a plurality of spaced apart perforations 68 and suitably carried by the housing, as by a pair of spaced apart, arcuate members 61 secured to the inner faces of the sections 12, as by rivets 68, particularly as shown in Figure 9. The opposite ends of the screen 85 extend into the space between the spac ing pairs of members 61.

So that the pivot pin 48 may be readily removed, in order to replace the hammers 45, a suitable opening 89 is provided in each housing section l2, with the axis of the opening coincident with the longitudinal axes of the pivot pins 46, as one after the other of the pivot pins moves with the rotation of the shaft '58.

Novel means for urging the fodder or roughage from the-conveying means to the disintegrating means is shown, particularly in Figures 1, 5 and 6. This includes a plurality of spaced apart, substantially straight arms or members I5 arranged in substantial parallelism with their forward ends I8 extending towards the conveying means and disposed at the upper end of the compartment 21, and with their rearward extremities 'I'I extending toward the disintegrating means and disposed within the compartment 28 and adjacent the opening 29 therein, through which opening they extend. Each arm may carry a suitable removable bearing 18 at its forward end I6 as well as one or more prongs or hook-shaped teeth I9, which preferably extend outwardly along the longitudinal axis of the arm I5 and may be mounted upon the bearing I8, as is the uppermost prong I9, or mounted upon the lower face of the arm I5, as is the lowermost prong 19.,

Extending along the under side of each arm 15 is a plurality of spaced apart prongs or teeth 88, preferably set at such an angle with the arm I5 that they normally point downwardly and towards the rear end 11 of the arm 15.

Each arm I! is carried by a crank shaft 8|. It is preferred that the crank shaft have as many throws 82 as there are arms II. In the example shown. particularly in Figure 5. there are four arms I5 and four throws to the crank shaft, ea'ch throw being spaced substantially from the one next to it. This crank shaft 8| is rotatably carried by bearings 83, mounted upon the upper extremities of the walls Ii. One end of the crank shaft 8i terminates in a pulley 84, turning in a clockwise direction, as viewed in Figure 2. This pulley 84 may be turned bya cross belt 85, extending over a pulley 88, of smaller diameter than the pulley 84. 81 extending through suitable bearings 88, preferably mounted on each of the sections I! at the top wall i8. This shaft 81 carries a second or conveyor-means-driving pulley 88, adJacent the pulley 88, which pulley 88 carries a belt extending to and about the pulley 48, which is fixed to the shaft 38 as described. It will be noted in Figure 2,that the diameter of the pulley 48 is considerably greater than that of the pulley 88, with which it is operatively connected.

The shaft 81 may extend over the roof l8 and terminate at its end opposite that upon which the pulley 89 is mounted, in a third pulley 8| about which extends the belt 63, which is also operatively connected with the pulley 55 associated with the hammer disc and spacer assembly, as well as associated with the pulley 52 which forms a portion of the beater and deflector assembly. The disposition of the belt 83 is best shown in Figure 3, and it will be noted therein that while the pulley 55 is rotating clockwise, the pulley 9i and its shaft 81 is also rotating clockwise and that the pulley ST is of considerably greater diameter than either of the pulleys 55 and 62.

Again referring to the arms 15 of the means for urging the fodder from the conveying means to the disintegrating means and particularly shown in Figures 1, 5 and 6, the rearward end ll of each arm 15 is pivotally connected to one end (the lower end) of a pair of upwardly extending links 82, as shownin Figure 6. At their opposite or upper ends the links 92 are pivotally connected to a suitable member, such as a rod or rods 93, extending across the chamber 28 towards the sections l2 but free of these sections. Preferably, at least a pair of links 84 extend from the rod 93 upwardly and towards the opening 28 where they may be pivotally supported by ears 85 or other suitable rigid fittings, through which and the links 94 extend bolts or other means to pivotally connect them with the rigid fittings mentioned. The rod 83 also carries one or more upwardly extending members, each of which may be a short rod 88, having an eye at its lower end encircling the rod 83 and provided with screw threads at its upper end, which end protrudes through a suitable perforation in the roof l8, where the rod 93 terminates in a nut 81 or other enlargement of greater diameter than the perforation mentioned in the roof I 8.

With the arrangement of parts described, it will be noted that there will be a forward and backward movement of the arms I5 as well as an upward and downward motion, so that the forward ends I8 of the arms I5 will describe arcuate paths, substantially as shown in dotted lines in Figure 1. Thus, the arms I5, at their forward ends, will descend upon material discharged from the conveying means and will then drag such material progressively, with a shaking motion.

The pulley 88 is carried by a shaft towards the disintegrating means, the prongs I9 and aiding in this dragging motion. This motion is not merely a jerking one (whereby the material would be jerked, with the stalks of the maother end moves nearest such said means. With this motion the material travels progressively towards the disintegrating means and, in addition, because of the zig-zag, shaking motion described, leaves are caused to be shaken from the stalks and stems of the material and drop downwardly.

In order to provide a surface over which the material may travel from the conveying means until it reaches the horizontal platform 30, a substantially horizontally disposed platform 90 is provided, extending from the end wall I3 to the platform 30 (of which it may be said to form a continuation) and from one side section II to the other side section II. This platform is preferably disposed a short distance below the lower run of the chain belt 25 and below the lowermost path of the arms I5, as shown particularly in Figure 1. This platform 99 is preferably made up of a plurality of spaced apart rods or slats, extending longitudinally of the mill, so that leaves may drop, through the spaces between adjacent rods, into the chamber 21 below the platform.

Referring to Figure 1, it will be noted that there is a rocking motion of the links 92, indicated by the dashes, as the arms move, urged by the crank shaft 0|, and there is also a possible up-and-down motion of the rearward ends 11 of the arms I5. This up-and-down motion provides for such emergency as when an unusually large amount of material may seek to pass under the rearward ends 11 of the arms. In such a case, upward movement of that end of the arm 15 will cause the short rods 99 to move upwardly, protruding from the roof I8 of the housing, where they will remain until the emergency is passed, whereupon the rods 90 will move downwardly until stopped by the enlargements 91. Thus,

these rods, as they protrude, provide a signal for the operator, who may not be in a position to observe conditions at the forward end of the mill, and he will be advised that material is accumulating under the rearward ends of the arms or that the conveying means is feeding too fast.

The assembly of links 94 and short rods 96 is not the equivalent of a coil spring or other resilient means. Such resilient means does not function properly after being in use for some time, coil springs soon have the spaces between their convolutions filled with material disintegrated by the mill and are inclined to bend and twist. However, the size of the various pulleys is such that there will be a synchronism of the various portions of the mill so that the material will be generally handled in a steady, even way.

Fromthe description of the housing, particu-- larly that of the converging sections I9 and curved section 20 forming the trough 2I, as well as the inclined wall I9, the leaves and similar material dropping between the rods, from the platform 98, will either drop directly into the trough 2I or will slide down the inclined wall I3 and be deposited in the trough 2I. In addition to this, the stalks and stems disintegrated by the hammers l and beater arms 50, will drop through the screen 05 aromas and be deposited in the trough 2|. In order to convey and mix these two materials, a screw conveyor I00 may be provided, extending longitudinally of the trough 2I, with the forward end I M of its shaft extending through the perforation 23 in the wall 22 and being carried by a suitable bearing I02 terminating in, preferably, a bevel gear I09. This bevel gear I09 meshes with a companion bevel gear I 04, both of which may be protected by a suitable housing I05. The gear I04 is operatively connected with a suitable pulley I 06, exterior of the housing I05, from which may extend a belt I01 to a pulley I09 carried by a shaft I 09 extending transversely of the mill exteriorly of the section I5 of the rearward end wall of the housing. This shaft I09 is carried by a suitable bearing H0 and terminates at its other end in a pulley III, operatively connected with the belt 63, as shown particularly in Figure 3, where it will be seen that the pulley III rotates clockwise, as viewed from said figure.

The rearward end II2 of the screw conveyor shaft projects outwardly of the collar 25 and is carried by a suitable bearing H3 and an arm Ill extending therefrom which may be secured to the housing upon the section I5 thereof.

With the arrangement of gears I03 and I04, pulley I06, belt I0'I, pulley I09, shaft I09 and pulley III, which latter is operatively connected with the main drive as described and illustrated, there is a motion imparted to the material in the trough 2I so that it will finally emerge from the collar 25 in a thoroughly mixed condition.

Inwardly of one wall I2, the shaft I09 may carry a third pulley I I5 so that a belt II 6 may extend about this pulley and be operatively connected with a suitable conveyor means for the disintegrated fodder, so that the latter may be conducted from the point of discharge (the collar 25 or opening 24) to a location for sacking, storage or the like. This means may consist of a conventional elevator III, shown in Figure 2.

The material disintegrated by the hammers 45, assisted by the beater arms 56, will be in a fine condition, since the fodder or roughage delivered by the arms I5, is immediately beaten into the path of the hammers 45 by the arms 50, which strike the material and break it up, drive it against the section ll of the housing and then force it over the upper surface of the screen 65. Such material as does not drop immediately through the screen openings 66, is again forced upwardly against the partition I0 and under side of the platform 30, then thrown into the path of the beater arms and again beaten down again into the path of the hammers.

The hammers 45, being rigid in themselves but pivotally carried, and being rectangular, strike the stalks and stems normal to the length of the'same and, being rigid, do not become entangled with the material or with themselves, as is sometimes characteristic of flexible hammers. Being pivotally carried and disposed as set out with relation to the discs and spacers, they are self-cleaning as has been described. In addition to the closure 69 described, for the openings in the sections I2, other openings and closures may be provided in the walls and sections of the housing, so that other portions of the interior mechanism of the mill may be readily reached.

Various changes may be made to the form of invention herein shown and described, without 76 departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. In a roughage disintegrating mill, 9, housing having a perforation extending from its interior to its exterior; roughage conveying means supported bysaid housing; roughage disintegrating means carried by said housing; and means for urging roughage from said conveying means to said disintegrating means, including a plurality of spaced apart arms provided with teeth at their free ends and a plurality of teeth extending longitudinally along the under sides of said arms, a crank shaft having a plurality of throws, spaced apart about said crank shaft, said arms being pivotally mounted upon said throws intermediate the ends of said arms, a plurality of links, one for each arm and each pivoted at one end to its arm adjacent the end of said arm opposite said free end, an arm pivoted at one end to said housing, a pivot pin pivoting the opposite ends of said links to said last named arm, at the end of said last named arm opposite its pivotal connection with said housing, a suspender pivoted at one end to said pivot pin and extending upwardly and outwardly of said housing, being slidable through said perforation in said housing, and an enlargement upon the outwardly protruding end of said suspender, said enlargement being of greater diameter than the diameter of said perforation.

2. In a roughage disintegrating means particularly adapted for disintegrating leaf-bearing dry roughage, a housing; roughage conveying means supported by said housing; means for urging roughage from said conveying means and for removing leaves therefrom, including a plurality of spaced apart, substantially straight arms, ar-

ranged in parallelism, one with another, roughage engaging members at the free ends of said arms, the free ends of said arms being disposed nearer said conveying means, a crank shaft carried by said housing and having at least two throws, with said arms pivotally mounted upon said throws intermediate the ends of said arms, a plurality of links pivotally secured at one end to said arms opposite the free ends thereof, said links being pivotally carried at their other ends by said housing; a horizontally disposed platform provided with a plurality of vertical openings, said platform extending from said conveying means to a position beneath said arms, the relationship of said platform to said arms being such that as roughage is deposited upon said platform by said conveying means, said arms will first descend upon it and engage it with said roughage engaging members and then draw said roughage over said platform away from said conveying means; roughage disintegrating means, operatively carried by said housing in a position to receive said roughage from said arms, and mixing means below said platform and said disintegrating means, disposed to receive said leaves and the disintegrated roughage from said disintegrating means.

3. In apparatus for reducing vegetation of a character including appendage-carrying stems, means for separating the appendages from the stems, means for reducing the stems after the appendages have been separated therefrom, a trough positioned below the separating and reducing means and into which the appendages and the reduced stems may fall, said trough being provided with an outlet at one end portion, a spiral worm positioned longitudinally in the trough, and means for rotating the worm so as to urge the appendages and the reduced stems toward the outlet end portion of the trough and whereby the appendages and the reduced stems will tend to leave the trough in a. homogeneous mixture.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2491661 *Nov 23, 1945Dec 20, 1949Gruendler Crusher & PulverizerTiltable feed means for grinders
US2540021 *Oct 3, 1946Jan 30, 1951Jeffrey Mfg CoReducing machine, including spaced oppositely rotating rotors
US2546679 *Mar 28, 1947Mar 27, 1951Frederick RodgersCylinder and concave mill with material return paddle
US2954176 *Jan 30, 1956Sep 27, 1960Cole Knox DVariable feed mill throat for admitting whole bales of hay
US3490705 *Aug 10, 1967Jan 20, 1970Fibrelite CorpHammermill for grinding fibrous materials
US3510075 *Mar 3, 1967May 5, 1970Sperry Rand CorpHammer mill
US4377259 *Mar 21, 1980Mar 22, 1983Reclamet, Inc.Chip and turnings separator and crusher
US5353959 *Dec 11, 1992Oct 11, 1994Recot, Inc.Apparatus for dispensing powdered or granular seasoning materials
US5554221 *Jun 21, 1994Sep 10, 1996Recot, Inc.Apparatus for dispensing portions of material
US5721000 *Jun 7, 1995Feb 24, 1998Recot, Inc.Method for producing seasoned food products
US5823707 *Nov 15, 1996Oct 20, 1998Offcine Meccaniche Laurini Lodovico & C.S.N.C.Self-propelled remote-controlled stone crusher designed to operate inside trenches
US6955313 *Sep 11, 2001Oct 18, 2005Antonio Palmiro PaoliniHammer mills
U.S. Classification241/101.6, 241/81, 241/187, 241/186.4, 99/637, 241/186.5, 99/494, 241/86, 241/194
International ClassificationB02C13/26, B02C13/00
Cooperative ClassificationB02C13/26
European ClassificationB02C13/26