CA1279627C - Comminuter for solid material - Google Patents
Comminuter for solid materialInfo
- Publication number
- CA1279627C CA1279627C CA000534748A CA534748A CA1279627C CA 1279627 C CA1279627 C CA 1279627C CA 000534748 A CA000534748 A CA 000534748A CA 534748 A CA534748 A CA 534748A CA 1279627 C CA1279627 C CA 1279627C
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- comminuting
- tooth
- chamber
- screening
- rolls
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Abstract
IMPROVED COMMINUTER FOR SOLID MATERIAL
Abstract of the Disclosure An improved comminuting device for pulverizing solid material includes a comminuting chamber and a discharge chamber adjacent the com-minuting chamber. A screening assembly is located at the interface between the comminuting chamber and the discharge chamber and regulates the size of particles permitted to pass from the comminuting chamber into the discharge chamber. The screening assembly is adjustable to selectively vary the maximum size particles permitted to pass into the discharge chamber. Also, the comminuting chamber is defined by a series of rolls having abrading protrusions on their outer surfaces. The protrusions comprise teeth that are removably and replaceably mounted on the rolls for ease of repair and replacement. The teeth are held in slots formed in the rolls and are oriented so that the force of the material being broken down in the comminuter acts against the teeth to keep them within the slots. In one embodiment, the tooth is deformed as it is inserted into the slot and the tendency of the tooth to return to its original shape provides a biasing force against the walls of the slot to maintain the tooth within the slot.
Abstract of the Disclosure An improved comminuting device for pulverizing solid material includes a comminuting chamber and a discharge chamber adjacent the com-minuting chamber. A screening assembly is located at the interface between the comminuting chamber and the discharge chamber and regulates the size of particles permitted to pass from the comminuting chamber into the discharge chamber. The screening assembly is adjustable to selectively vary the maximum size particles permitted to pass into the discharge chamber. Also, the comminuting chamber is defined by a series of rolls having abrading protrusions on their outer surfaces. The protrusions comprise teeth that are removably and replaceably mounted on the rolls for ease of repair and replacement. The teeth are held in slots formed in the rolls and are oriented so that the force of the material being broken down in the comminuter acts against the teeth to keep them within the slots. In one embodiment, the tooth is deformed as it is inserted into the slot and the tendency of the tooth to return to its original shape provides a biasing force against the walls of the slot to maintain the tooth within the slot.
Description
~ '7~ 7 IMPROVED COMMINUTER FOR SOLID MATERIAL
Background of the Invention This lnvention relates to improvements in apparatus for comminuting solids such as wood, bark, junk metal articles, et cetera. More particularly, it5 relates to improvements in the portions of the apparatus that handle the screen-ing, sizing, and sorting of the end product of the comminuter and an improved construction for the comminuter grinding rolls.
In comminuters of the type described in my U.S. Patent No. 4,366,928, in which a series of upright rolls define a comminuting chamber, it 10 is desirable to provide an adjustable particle output size so that the same com-minuter can be used with a minimum of adjustment for grinding and pulverizing various materials. It is an object of the invention herein to provide a screen means, for screening the discharge from the comminuting chamber, that is adjust-able within a predetermined range to vary the output product of the comminuter 15 from very fine particles to relatively large particles.
Also, in comminuters of the rotary roll-type, the tooth-like projec-tions from the comminuting rolls that are used to assist the rolls in grinding material placed in the comminuter tend to wear after a period of time, and in conventional comminuting devices, the entire roll must be replaced in order to 20 provide a roll with fresh teeth to bring the comminuter back to its original effi-ciency. It is an object of this invention to provide a comminuter that has replace-able teeth mounted on the comminuting rolls, so that as teeth wear, they can be individually or collectively replaced without replacement or removal of the entire roll.
Summary of the Invention In an apparatus for comminuting solid materials including a housing defining a comminuting chamber, and an adjacent discharge chamber, the inven-tion provides a screening means located at the interface between the comminuting C ~
- la-chamber and the discharge chamber. The screenlng means ls constructed and arranged to contain orifices to permit passage of partlcles of a predetermined maximum size from the commlnutlng chamber to the dlscharge chamber and to block passage of particles larger than the maximum size. The slze of the orlfices 5 is selectively adJustable.
In accordance with the preferred form of the invention, the com-minuter includes a series of upright rolls arranged to enclose a commlnuting chamber, each of the rolls having replaceable teeth projecting therefrom, the rolls being driven to cause turbulent motion of materials placed within the comminut-10 ing chamber, so that the materials are pulverlzed by the repeated ~ i contact with one another and with the surfaces of the rolls. ~s the productmoves in turbulent motion through the com minuting chamber, particles are moved by the force of gravity to the bottom of the chamber and an adjustable screening device is mounted at the bottom of the chamber. The screening device 5 cooperates with the exterior walls of the com minuter housing to screen the particles according to size. Only those particles of a predetermined maximum size are permitted to exit the comminuting chamber and enter the discharge chamber located below the screening device. A preferred embodiment of the screening device of the present invention includes a series of elongate movable 10 fingers circumferentially arranged in radial orientation about the surface of a disk. The fingers are movably mounted on the disk so as to be individually adjustable to determine the maximum size particle that will be allowed to exit the comminuting chamber. ~ notch is preferably formed in a bottom plate of the comminuting chamber adjacent the screening member to facilitate the exit 15 of fibrous materials that build up in clumps within the comminuting chamber.
The preferred embodiment of the invention also includes a stationary tooth member projecting into the discharge chamber directly below the screening device to contact and sever any elongated pieces of material such as branches and twigs, to break them off and allow them to fall from the comminuting 20 chamber to the discharge chamber without jamming of the screening device.
Preferably, the screening disk includes vanes extending verticaUy from the uppersurface of the disk, the movable fingers being mounted on the lower surface of the screening disk.
Each of the rolls includes a plurality of removable teeth protruding 25 from them. In one embodiment, a plurality of notches is formed in the surface of the roll. Each of the notches has a wedge-shaped tooth member driven into the notch to form an interference fit so as not to come loose during the comminuting operation. In an alternative embodiment, the tooth member is deformed slightly upon being positioned in the notch, the tendency of the tooth 30 member to return to its original shape providing a biasing force that retains the tooth member within the notch.
Brief Description of the Drawings The objects and advantages of the present invention will be better understood by those of ordinary skill in the art and others upon reading the 35 ensuing specification taken in conjunction with the appended drawings wherein:
FIGURE l is an isometric view of one embodiment of a com-minuter with portions cut away to show a screening member made in accordance ~ ~73~i~7 with the principles of the present invention mounted at the bottom of the comminuting ch~mber;
FIGURE 2 is a side elevational view of the screening device and comminuting apparatus of FIGURE 1;
FIGURE 3 is an isometric view of a portion of the screening device of FIGURE 1;
FIGURE 4 is an elevational view in section taken along the line 4--4 of FIGURE 3;
FIGURE 5 is an elevational view in section taken along the line 5--5 of FIGURE 4;
FIGURE 6 is a plan view of the underside of the portion of the screening device shown in FIGURE 3;
FIGURE 7 is a side elevational view of a portion of an alternate embodiment of the comminuting device of FIGURE 1, showing an inflataMe member used as a screening device;
FIGURE 8 is an exploded isometric view of one embodiment of a comminuting roll made in accordance with the principles of the present invention;
FIGURE 9 is an isometric view of the comminuting roll shown in FIGURE 8;
FIGURE 10 is a sectional view along line 10--10 in FIGURE 8;
FIGURE 11 is an isometric view of an alternate embodiment of a comminuting roll made in accordance with the principles of the present invention; and FIGURE 12 is a sectional view along line 12--12 of FIGURE 11.
Detailed Description of the Preferred Embodiment FIGURE 1 illustrates a comminuter made in accordance with the principles of the present invention, and includes a series of elongated, uprightcomminuting rolls 10 that surround and define a cylindrical comminuting cham-ber. The rolls are mounted at a first end on a stationary base plate 12, and theentire assembly is surrounded by a housing 14. Each of the rolls is mounted on abearing assembly 13 for rotational movement about its own axis. A second base plate 15 lies below the first base plate 12 spaced from the first base plate anddefines the bottom of a discharge chamber, which lies directly below the comminuting chamber, to receive particles from the comminuting chamber. An extension of the housing 14 surrounds and encloses the discharge chamber. A
screening disk 16 is positioned at the bottom of the comminuting chamber in the interface between the comminuting chamber and the discharge chamber and is 3~j~7 bearing-mounted for rotation in a horizontal plane on a base post 8. A series ofvanes 20 is arranged radially on the surface of the screenlng plate. In the illus-trated embodiment, the vanes 20 are of essentially triangular shape, with the upper edge of the vane having its apex at the center of the comminuting chamber 5 and converging as it extends toward the outer circumference of the screening disk. A vane plate 24 is vertically arranged across the screening plate essentially on the diameter of the screening plate, and has an essentially rectangular shapewith notches cut out of each end of the vane plate. If desired, magnets 26 and 28, respectively, are mounted in the notches of the vane plate, to attract any metallic l 0 particles and separate them from the remaining particles when the comminuter is used to grind nonmetallic material such as bark and logs and scrap lumber.
A series of adjustable screening fingers 30 are mounted on the screen-ing plate, and extend radially outward from the circumference of the screening plate toward the comminuting rolls 10. As will be described in greater detail l 5 below, each of the screening fingers is individually adjustable in a radial direction, to vary the spacing between the rolls 10 and the outer end of the screening finger so as to control the size of particles passing between the comminuting chamber and the discharge chamber. Each of the comminuting rolls 10 has a series of projections, designated teeth, which protrude from the exterior surface of the roll 20 and assist in the grinding and tearing action of the comminuter on the materials within the comminuting chamber.
The basic operation of the comminuter is described in U.S. Patent No. 4,366,928, issued January 4, 1983, and also in my United States Patent No. 4,477,028 issued October 16, 1984. The basic operation of the comminuter 25 involves rotating the comminuting rolls and feeding large pieces of material such as wood into the comminuting chamber. The rotating rolls cause a turbulent motion of the material within the chamber, and the interaction between the material and the toothed comminuting rolls pulverizes and breaks the material into smaller and smaller pieces, the longer the material is within the comminuting 30 chamber. The size of particles discharged from the comminuting chamber is determined by the size of the opening in the screening assembly between the comminuting chamber and the discharge chamber. In the present embodiment, by varying the position of the screening fingers, the size of the particles exiting the comminuting chamber can be varied, and until the particles reach that size, they35 will continue to move in turbulent motion within the comminuting chamber, being further reduced in size until they pass through the predetermined opening. To assist the particles in their turbulent motion, the ~.~
~.~'7~ 7 screening disk can be rotated by an external source, or, alternatively, the swirling turbulent mot;on of the material impinging on the vane.s of the screening disk can be utili~ed to turn the screening disk without an independent power source. As can be seen in FIGURE 2 in the illustrated embodiment, an action 5 disk 34 is positioned at the base of alternate ones of the comminuting rolls, and is of a diameter slightly larger than the comminuting rolls. The action disks turn in unison with the comminuting rolls, and provide additional assistance to the turbulent motion of the particles and material within the comminuting chamber.
A series of clearing teeth 40 protrude from the comminuting rolls below the lO action disk and also in a position ~elow the screening fin~ers. The clearing teeth perform the function of maintaining the opening between the screening fingers and the comminuting rolls free of conglomerations of particles, so that there is a free exit of particles from the comminuting chamber.
Sometimes a long piece of material such as a branch will become 15 lodged within the space between the screening finger and the comminuting roll, causing a jam-up of particles exiting the comminuting chamber and possibly even stopping the motion of the rolls on the screening plate. A branch-clearing tooth 42 protrudes from the outer case of bearing assembly 13 associated with one of the rolls at a lowermost end thereof, and extends into the discharge 20 chamber to break off any elongated pieces sticking down into the discharge chamber, so that they do not cause a jam between the screening disk or screening fingers and the comminuting rolls. Since the tooth 42 is attached to the bearing case 15, it does not rotate with the roll but remains stationary.
Visible in FIGURE 1 is a notch formed in the baseplate 12. The 25 notch 44, designated a woolly notch, is for allowing the passage of fibrous materials such as bark fibers from the comminuting chamber to the discharge chamber. The woolly notch is useful in configuration of the comminuter in which the screening plate is at the level of the baseplate 12 to prevent fibrous materials from clogging the passage between the comminuting chamber and the 30 discharge chamber. Again referring to FIGURE 2, the center spindle, on which the screening plate is mounted, is mounted on a bearing 44, which in turn is mounted in the base 46 of the unit. A pair of hydraulic actuaters 4B and 50, respectively, are mounted between the comminuter housing 14 and the base 15 and are utilized to raise and low~r the comminuter housing to permit access to 35 the internal workings of the comminuter for repair and replacement of the rolls and other parts.
Turning now to FIGURES 3, 4, 5 and 6, the structure of the screen-ing fingers and their mounting to the screening plate is more clearly illustrated.
~7~ 7 ~ach of the elongate screening fingers 30 underlies the screening plate 16 and the long dimension of the screening finger is radially oriented with respect to the screening plate. ,~\ series of bolts 60 is arranged in a circle about the outer perimeter of the screening plate protruding through the top surface of the plate5 and extending froM the bottom of the plate. The screening fingers 30 are located between the bolts arranged circumferentially around the screening disk.
A cable 62 surrounds the outer edge of the bolts and washers 64 are placed between the cable and the screening fingers. The washers 64 are wide enough to overlap adjacent screening fingers and serve to hold the screening fingers IO between the cable ~nd the screening pl~te. Each bolt 60 has a second washer 66 associated with it and the cable is sandwiched between the washers. Each bolt 60 has a nut 67 threadably engaging it to hold the washers and cable in place. Each finger 30 has associated with it a coil spring 68. The cable forms an anchor point for one end of each of the coil springs 68. The other end of each of 15 the springs is hooked onto one of a plurality of eye members 70 extending downwardly from the inward end of each of the screening fingers and places a bias force in the radially outward direction on its associated screening finger.The inward end of each screening finger is formed with a shoulder, which cooperatively engages an associated second bolt 72, which protrudes through 20 holes formed in the screening plate intermediate each of the screening fingers along a circle located radially inward of the location of first bolts 60. The cooperation between the shoulder at the end of the screening finger and the bolt 72 keeps each of the screening fingers from moving radially outward in response to the bias force of its associated spring. A second series of washers 74 25 and nuts 76 are mounted on each of the second series of bolts 72 to keep the screening fingers oriented horizontally and flat against the underside of the screening plate 16. The position of each of the second bolts 72 determines the radial position of its associated screening fingers and therefore determines thespacing between the outer ends of the screening fingers and the rolls 10. The 30 particle size allowed to pass between the comminuting chamber and the discharge chamber is therefore dependent upon the positioning of the screening fingers relative to the rolls which in turn is determined by the position of thesecond bolts 72. Typically, a series of holes 78 will be formed along radial lines in the screening disk so that the position of each individual screening finger can 35 be varied to predetermined positions by placement of the second bolt 72 associated with each of the fingers 30 into the appropriate one of holes 78 as dictated by the desired opening size for particles passing between the comminut-ing chamber and the discharge chamber. While the illustrated embodiment utilizes a spiral expansion spring to bias the screening teeth in the radially outward direction, any suitable spring arrangement can be used to accomplish the same purpose of outwardly biasing the screening teeth.
One advantage to utilizing the screening tooth and spring arrange-5 ment is that since the spring biases the fingers in an outward direction and thenotch and bolt arrangement restrains movement only in the outward direction, there is some yieldability of the fingers in the inward direction. This yieldingability allows the fingers to move in the event that a large piece of metal is in the comminuting chamber and lodges itself in the opening to the discharge 13 chamber. The yieldability of the fingers will allow the metal to dislodge thefinger and widen the opening, allowing it to pass into the discharge chamber without causing a jam of the comminuting rolls or the screening assembly, and minimizing any possibility of serious damage to the equipment.
FIGURE 7 illustrates an alternate screening arrangement to the 15 screening teeth and screening plate illustrated in FIGURES 1-6. FIGURE 7 illustrates a pneumatic annular screening member 79 which is oriented for rotation in a horizontal plane on the bearing spindle at the center of the comminuter. By varying the inflation of the pneumatic annular member, a varying spacing between the annular member and the exterior surface of the 20 comminuting rolls can be obtained, thereby providing a variation in size of the opening between the comminuting chamber above the member and the discharge chamber below the member. In a presently operative embodiment of the invention, the annular screening member is a tire, which is inflated and placed for horizontal rotation within the chamber. It has been found that the use of the 25 pneumatic screening member is especially helpful in comminuting springy material such as cedar and spruce bark. The tire acts as a flexible anvil in relation to the comminuting roll, and while most grinding is done in the main portion of the comminuting chamber, there is a certain amount of finish grindingthat is accomplished between the tire and the comminuting rolls that finally 30 grinds the particles to the size at which they will pass between the comminuting chamber and the discharge chamber.
Turning now to the assembly of the comminuting rolls themselves, two alternate embodiments of comminuting roll assemblies is shown in FIGURES 8-12. Referring to the first embodiment pictured in FIGURES 8, 9, 35 and l0, a series of notches 80 is formed in an outer surface of the comminuting roll 82. A wedge-shaped tooth member 84 fits within each of the notches and is held in place by a keeper segment 86 that is welded in place on the roll 82. Care must be taken, when welding the keeper plate 86 onto the roll 82, to not ~ ~7<~
accidently weld the tooth 8~ to either the keeper plate or the roll, since it i9intended that the tooth be removable for replacement or sharpening. The tooth 84has a wedge shape and is inserted in the slot in an orientation such that upon rotation of the roll, the tooth will engage material in the comminuting chamber 5 and the force of the material on the tooth will be such as to jam the tooth into the slot, instead of pushing the tooth out of the slot. For example, in FIGURE
10, the rotation of the roll would be in a counterclockwise direction so that the tooth 84' shown at the top of the FIGURE would be pushed to the right, thereby maintaining the tooth in the slot. When it is desired to remove the tooth for lO replacement or sharpening, a force is applied such as by a hammer to the narrower end 8~a of the tooth to drive the tooth out of the slot, while the keeper plate remains in place because of its welded attachment to the roll 82.
Similarly, the replacement tooth is placed into the slot from the left and then a force can be applied to the square surface 84b to drive the tooth back into the 15 slot without damaging the sharpened point 84c of the tooth. The weld beads over the keeper plate 86 that attach it to the roll 82 are hard-faced welds that willwithstand the abrasive action incurred during the comminuting operation.
FIGURES 11 and 12 show an alternate embodiment of replaceable teeth made in accordance with the principles of this invention. In this alternate 20 embodiment, a plurality of tooth-holding brackets 90 are welded at various locations to the roll 82'. Replaceable teeth 92 are removably inserted into the brackets 90 by driving them, such as with a hammer, into the bracket. Each of the teeth 92 is T-shaped with a sharp edge 92a at the crossbar portion of the tooth and a squared edge 92b at the end of the shaft of the tooth opposite the 25 crossbar portion. Each of the teeth 92 is bent slightly at a point intermediate the two ends, while the interior walls of the slot in the tooth-holding bracket 90 are parallel. When the tooth 92 is driven into the slot within the bracket 90, the bent tooth is deformed to fit the straight-walled slot within the bracket;
however, the tooth has a tendency to return to its bent position and this internal 30 tendency of the tooth biases the tooth against the interior walls of the slot to form an interference fit retaining the tooth within the slot without the necessity of welding or other fixation means. As with the case of the first embodiment described above, the tooth is oriented so that as the roll rotates, and the tooth encounters material in the comminuting chamber, the force of the material on 35 the tooth acts in a manner that will force the tooth into the slot as opposed to removing the tooth from the slot. As viewed in FIGURE 12, rotation of the roll would be in the counterclockwise direction so that each of the teeth 90 would have the crossbar portion, which is wider t'nan the mouth of the bracket slot, 1.;~7'3~,~7 g forced into abutment with the edges of the tooth-holding bracket 90, tending to retain the tooth within the slot. When it is desired to remove the tooth for sharpening or replacement, force is applied to the square end 92b of the tooth to drive it from the slot.
In summary, therefore, an improved comminuting device for grind-ing and pulverizing solid materials has been described and illustrated. The irnproved comminuting device includes a screening member positioned between the comminuting chamber and the discharge chamber to regulate the size of particles exiting the comminuting chamber. The screening member is adjustable to selectively vary the size of particles permitted to exit the comminuting chamber. Also, the comminuting device has removable teeth mounted in the comminuting rolls to permit replacement and repair of the teeth without removal of the entire roll or replacement of the entire roll from the comminut-ing device. While two embodiments of the replaceable teeth are illustrated, it will be realized by those of ordinary skill in the art that changes can be made to the illustrated embodiments while remaining within the scope of the invention.
Likewise, changes can be made in the illustrated embodiment of the adjustable screening member, for example, the placement of the spring can be varied and the use of a compression rather than expansion spring can be substituted, while remaining within the confines of the invention. Therefore, the invention should not be considered limited by the illustrated and described embodiments and thoseshould be considered as exemplary only. The invention should be defined solely by reference to the appended claims.
Background of the Invention This lnvention relates to improvements in apparatus for comminuting solids such as wood, bark, junk metal articles, et cetera. More particularly, it5 relates to improvements in the portions of the apparatus that handle the screen-ing, sizing, and sorting of the end product of the comminuter and an improved construction for the comminuter grinding rolls.
In comminuters of the type described in my U.S. Patent No. 4,366,928, in which a series of upright rolls define a comminuting chamber, it 10 is desirable to provide an adjustable particle output size so that the same com-minuter can be used with a minimum of adjustment for grinding and pulverizing various materials. It is an object of the invention herein to provide a screen means, for screening the discharge from the comminuting chamber, that is adjust-able within a predetermined range to vary the output product of the comminuter 15 from very fine particles to relatively large particles.
Also, in comminuters of the rotary roll-type, the tooth-like projec-tions from the comminuting rolls that are used to assist the rolls in grinding material placed in the comminuter tend to wear after a period of time, and in conventional comminuting devices, the entire roll must be replaced in order to 20 provide a roll with fresh teeth to bring the comminuter back to its original effi-ciency. It is an object of this invention to provide a comminuter that has replace-able teeth mounted on the comminuting rolls, so that as teeth wear, they can be individually or collectively replaced without replacement or removal of the entire roll.
Summary of the Invention In an apparatus for comminuting solid materials including a housing defining a comminuting chamber, and an adjacent discharge chamber, the inven-tion provides a screening means located at the interface between the comminuting C ~
- la-chamber and the discharge chamber. The screenlng means ls constructed and arranged to contain orifices to permit passage of partlcles of a predetermined maximum size from the commlnutlng chamber to the dlscharge chamber and to block passage of particles larger than the maximum size. The slze of the orlfices 5 is selectively adJustable.
In accordance with the preferred form of the invention, the com-minuter includes a series of upright rolls arranged to enclose a commlnuting chamber, each of the rolls having replaceable teeth projecting therefrom, the rolls being driven to cause turbulent motion of materials placed within the comminut-10 ing chamber, so that the materials are pulverlzed by the repeated ~ i contact with one another and with the surfaces of the rolls. ~s the productmoves in turbulent motion through the com minuting chamber, particles are moved by the force of gravity to the bottom of the chamber and an adjustable screening device is mounted at the bottom of the chamber. The screening device 5 cooperates with the exterior walls of the com minuter housing to screen the particles according to size. Only those particles of a predetermined maximum size are permitted to exit the comminuting chamber and enter the discharge chamber located below the screening device. A preferred embodiment of the screening device of the present invention includes a series of elongate movable 10 fingers circumferentially arranged in radial orientation about the surface of a disk. The fingers are movably mounted on the disk so as to be individually adjustable to determine the maximum size particle that will be allowed to exit the comminuting chamber. ~ notch is preferably formed in a bottom plate of the comminuting chamber adjacent the screening member to facilitate the exit 15 of fibrous materials that build up in clumps within the comminuting chamber.
The preferred embodiment of the invention also includes a stationary tooth member projecting into the discharge chamber directly below the screening device to contact and sever any elongated pieces of material such as branches and twigs, to break them off and allow them to fall from the comminuting 20 chamber to the discharge chamber without jamming of the screening device.
Preferably, the screening disk includes vanes extending verticaUy from the uppersurface of the disk, the movable fingers being mounted on the lower surface of the screening disk.
Each of the rolls includes a plurality of removable teeth protruding 25 from them. In one embodiment, a plurality of notches is formed in the surface of the roll. Each of the notches has a wedge-shaped tooth member driven into the notch to form an interference fit so as not to come loose during the comminuting operation. In an alternative embodiment, the tooth member is deformed slightly upon being positioned in the notch, the tendency of the tooth 30 member to return to its original shape providing a biasing force that retains the tooth member within the notch.
Brief Description of the Drawings The objects and advantages of the present invention will be better understood by those of ordinary skill in the art and others upon reading the 35 ensuing specification taken in conjunction with the appended drawings wherein:
FIGURE l is an isometric view of one embodiment of a com-minuter with portions cut away to show a screening member made in accordance ~ ~73~i~7 with the principles of the present invention mounted at the bottom of the comminuting ch~mber;
FIGURE 2 is a side elevational view of the screening device and comminuting apparatus of FIGURE 1;
FIGURE 3 is an isometric view of a portion of the screening device of FIGURE 1;
FIGURE 4 is an elevational view in section taken along the line 4--4 of FIGURE 3;
FIGURE 5 is an elevational view in section taken along the line 5--5 of FIGURE 4;
FIGURE 6 is a plan view of the underside of the portion of the screening device shown in FIGURE 3;
FIGURE 7 is a side elevational view of a portion of an alternate embodiment of the comminuting device of FIGURE 1, showing an inflataMe member used as a screening device;
FIGURE 8 is an exploded isometric view of one embodiment of a comminuting roll made in accordance with the principles of the present invention;
FIGURE 9 is an isometric view of the comminuting roll shown in FIGURE 8;
FIGURE 10 is a sectional view along line 10--10 in FIGURE 8;
FIGURE 11 is an isometric view of an alternate embodiment of a comminuting roll made in accordance with the principles of the present invention; and FIGURE 12 is a sectional view along line 12--12 of FIGURE 11.
Detailed Description of the Preferred Embodiment FIGURE 1 illustrates a comminuter made in accordance with the principles of the present invention, and includes a series of elongated, uprightcomminuting rolls 10 that surround and define a cylindrical comminuting cham-ber. The rolls are mounted at a first end on a stationary base plate 12, and theentire assembly is surrounded by a housing 14. Each of the rolls is mounted on abearing assembly 13 for rotational movement about its own axis. A second base plate 15 lies below the first base plate 12 spaced from the first base plate anddefines the bottom of a discharge chamber, which lies directly below the comminuting chamber, to receive particles from the comminuting chamber. An extension of the housing 14 surrounds and encloses the discharge chamber. A
screening disk 16 is positioned at the bottom of the comminuting chamber in the interface between the comminuting chamber and the discharge chamber and is 3~j~7 bearing-mounted for rotation in a horizontal plane on a base post 8. A series ofvanes 20 is arranged radially on the surface of the screenlng plate. In the illus-trated embodiment, the vanes 20 are of essentially triangular shape, with the upper edge of the vane having its apex at the center of the comminuting chamber 5 and converging as it extends toward the outer circumference of the screening disk. A vane plate 24 is vertically arranged across the screening plate essentially on the diameter of the screening plate, and has an essentially rectangular shapewith notches cut out of each end of the vane plate. If desired, magnets 26 and 28, respectively, are mounted in the notches of the vane plate, to attract any metallic l 0 particles and separate them from the remaining particles when the comminuter is used to grind nonmetallic material such as bark and logs and scrap lumber.
A series of adjustable screening fingers 30 are mounted on the screen-ing plate, and extend radially outward from the circumference of the screening plate toward the comminuting rolls 10. As will be described in greater detail l 5 below, each of the screening fingers is individually adjustable in a radial direction, to vary the spacing between the rolls 10 and the outer end of the screening finger so as to control the size of particles passing between the comminuting chamber and the discharge chamber. Each of the comminuting rolls 10 has a series of projections, designated teeth, which protrude from the exterior surface of the roll 20 and assist in the grinding and tearing action of the comminuter on the materials within the comminuting chamber.
The basic operation of the comminuter is described in U.S. Patent No. 4,366,928, issued January 4, 1983, and also in my United States Patent No. 4,477,028 issued October 16, 1984. The basic operation of the comminuter 25 involves rotating the comminuting rolls and feeding large pieces of material such as wood into the comminuting chamber. The rotating rolls cause a turbulent motion of the material within the chamber, and the interaction between the material and the toothed comminuting rolls pulverizes and breaks the material into smaller and smaller pieces, the longer the material is within the comminuting 30 chamber. The size of particles discharged from the comminuting chamber is determined by the size of the opening in the screening assembly between the comminuting chamber and the discharge chamber. In the present embodiment, by varying the position of the screening fingers, the size of the particles exiting the comminuting chamber can be varied, and until the particles reach that size, they35 will continue to move in turbulent motion within the comminuting chamber, being further reduced in size until they pass through the predetermined opening. To assist the particles in their turbulent motion, the ~.~
~.~'7~ 7 screening disk can be rotated by an external source, or, alternatively, the swirling turbulent mot;on of the material impinging on the vane.s of the screening disk can be utili~ed to turn the screening disk without an independent power source. As can be seen in FIGURE 2 in the illustrated embodiment, an action 5 disk 34 is positioned at the base of alternate ones of the comminuting rolls, and is of a diameter slightly larger than the comminuting rolls. The action disks turn in unison with the comminuting rolls, and provide additional assistance to the turbulent motion of the particles and material within the comminuting chamber.
A series of clearing teeth 40 protrude from the comminuting rolls below the lO action disk and also in a position ~elow the screening fin~ers. The clearing teeth perform the function of maintaining the opening between the screening fingers and the comminuting rolls free of conglomerations of particles, so that there is a free exit of particles from the comminuting chamber.
Sometimes a long piece of material such as a branch will become 15 lodged within the space between the screening finger and the comminuting roll, causing a jam-up of particles exiting the comminuting chamber and possibly even stopping the motion of the rolls on the screening plate. A branch-clearing tooth 42 protrudes from the outer case of bearing assembly 13 associated with one of the rolls at a lowermost end thereof, and extends into the discharge 20 chamber to break off any elongated pieces sticking down into the discharge chamber, so that they do not cause a jam between the screening disk or screening fingers and the comminuting rolls. Since the tooth 42 is attached to the bearing case 15, it does not rotate with the roll but remains stationary.
Visible in FIGURE 1 is a notch formed in the baseplate 12. The 25 notch 44, designated a woolly notch, is for allowing the passage of fibrous materials such as bark fibers from the comminuting chamber to the discharge chamber. The woolly notch is useful in configuration of the comminuter in which the screening plate is at the level of the baseplate 12 to prevent fibrous materials from clogging the passage between the comminuting chamber and the 30 discharge chamber. Again referring to FIGURE 2, the center spindle, on which the screening plate is mounted, is mounted on a bearing 44, which in turn is mounted in the base 46 of the unit. A pair of hydraulic actuaters 4B and 50, respectively, are mounted between the comminuter housing 14 and the base 15 and are utilized to raise and low~r the comminuter housing to permit access to 35 the internal workings of the comminuter for repair and replacement of the rolls and other parts.
Turning now to FIGURES 3, 4, 5 and 6, the structure of the screen-ing fingers and their mounting to the screening plate is more clearly illustrated.
~7~ 7 ~ach of the elongate screening fingers 30 underlies the screening plate 16 and the long dimension of the screening finger is radially oriented with respect to the screening plate. ,~\ series of bolts 60 is arranged in a circle about the outer perimeter of the screening plate protruding through the top surface of the plate5 and extending froM the bottom of the plate. The screening fingers 30 are located between the bolts arranged circumferentially around the screening disk.
A cable 62 surrounds the outer edge of the bolts and washers 64 are placed between the cable and the screening fingers. The washers 64 are wide enough to overlap adjacent screening fingers and serve to hold the screening fingers IO between the cable ~nd the screening pl~te. Each bolt 60 has a second washer 66 associated with it and the cable is sandwiched between the washers. Each bolt 60 has a nut 67 threadably engaging it to hold the washers and cable in place. Each finger 30 has associated with it a coil spring 68. The cable forms an anchor point for one end of each of the coil springs 68. The other end of each of 15 the springs is hooked onto one of a plurality of eye members 70 extending downwardly from the inward end of each of the screening fingers and places a bias force in the radially outward direction on its associated screening finger.The inward end of each screening finger is formed with a shoulder, which cooperatively engages an associated second bolt 72, which protrudes through 20 holes formed in the screening plate intermediate each of the screening fingers along a circle located radially inward of the location of first bolts 60. The cooperation between the shoulder at the end of the screening finger and the bolt 72 keeps each of the screening fingers from moving radially outward in response to the bias force of its associated spring. A second series of washers 74 25 and nuts 76 are mounted on each of the second series of bolts 72 to keep the screening fingers oriented horizontally and flat against the underside of the screening plate 16. The position of each of the second bolts 72 determines the radial position of its associated screening fingers and therefore determines thespacing between the outer ends of the screening fingers and the rolls 10. The 30 particle size allowed to pass between the comminuting chamber and the discharge chamber is therefore dependent upon the positioning of the screening fingers relative to the rolls which in turn is determined by the position of thesecond bolts 72. Typically, a series of holes 78 will be formed along radial lines in the screening disk so that the position of each individual screening finger can 35 be varied to predetermined positions by placement of the second bolt 72 associated with each of the fingers 30 into the appropriate one of holes 78 as dictated by the desired opening size for particles passing between the comminut-ing chamber and the discharge chamber. While the illustrated embodiment utilizes a spiral expansion spring to bias the screening teeth in the radially outward direction, any suitable spring arrangement can be used to accomplish the same purpose of outwardly biasing the screening teeth.
One advantage to utilizing the screening tooth and spring arrange-5 ment is that since the spring biases the fingers in an outward direction and thenotch and bolt arrangement restrains movement only in the outward direction, there is some yieldability of the fingers in the inward direction. This yieldingability allows the fingers to move in the event that a large piece of metal is in the comminuting chamber and lodges itself in the opening to the discharge 13 chamber. The yieldability of the fingers will allow the metal to dislodge thefinger and widen the opening, allowing it to pass into the discharge chamber without causing a jam of the comminuting rolls or the screening assembly, and minimizing any possibility of serious damage to the equipment.
FIGURE 7 illustrates an alternate screening arrangement to the 15 screening teeth and screening plate illustrated in FIGURES 1-6. FIGURE 7 illustrates a pneumatic annular screening member 79 which is oriented for rotation in a horizontal plane on the bearing spindle at the center of the comminuter. By varying the inflation of the pneumatic annular member, a varying spacing between the annular member and the exterior surface of the 20 comminuting rolls can be obtained, thereby providing a variation in size of the opening between the comminuting chamber above the member and the discharge chamber below the member. In a presently operative embodiment of the invention, the annular screening member is a tire, which is inflated and placed for horizontal rotation within the chamber. It has been found that the use of the 25 pneumatic screening member is especially helpful in comminuting springy material such as cedar and spruce bark. The tire acts as a flexible anvil in relation to the comminuting roll, and while most grinding is done in the main portion of the comminuting chamber, there is a certain amount of finish grindingthat is accomplished between the tire and the comminuting rolls that finally 30 grinds the particles to the size at which they will pass between the comminuting chamber and the discharge chamber.
Turning now to the assembly of the comminuting rolls themselves, two alternate embodiments of comminuting roll assemblies is shown in FIGURES 8-12. Referring to the first embodiment pictured in FIGURES 8, 9, 35 and l0, a series of notches 80 is formed in an outer surface of the comminuting roll 82. A wedge-shaped tooth member 84 fits within each of the notches and is held in place by a keeper segment 86 that is welded in place on the roll 82. Care must be taken, when welding the keeper plate 86 onto the roll 82, to not ~ ~7<~
accidently weld the tooth 8~ to either the keeper plate or the roll, since it i9intended that the tooth be removable for replacement or sharpening. The tooth 84has a wedge shape and is inserted in the slot in an orientation such that upon rotation of the roll, the tooth will engage material in the comminuting chamber 5 and the force of the material on the tooth will be such as to jam the tooth into the slot, instead of pushing the tooth out of the slot. For example, in FIGURE
10, the rotation of the roll would be in a counterclockwise direction so that the tooth 84' shown at the top of the FIGURE would be pushed to the right, thereby maintaining the tooth in the slot. When it is desired to remove the tooth for lO replacement or sharpening, a force is applied such as by a hammer to the narrower end 8~a of the tooth to drive the tooth out of the slot, while the keeper plate remains in place because of its welded attachment to the roll 82.
Similarly, the replacement tooth is placed into the slot from the left and then a force can be applied to the square surface 84b to drive the tooth back into the 15 slot without damaging the sharpened point 84c of the tooth. The weld beads over the keeper plate 86 that attach it to the roll 82 are hard-faced welds that willwithstand the abrasive action incurred during the comminuting operation.
FIGURES 11 and 12 show an alternate embodiment of replaceable teeth made in accordance with the principles of this invention. In this alternate 20 embodiment, a plurality of tooth-holding brackets 90 are welded at various locations to the roll 82'. Replaceable teeth 92 are removably inserted into the brackets 90 by driving them, such as with a hammer, into the bracket. Each of the teeth 92 is T-shaped with a sharp edge 92a at the crossbar portion of the tooth and a squared edge 92b at the end of the shaft of the tooth opposite the 25 crossbar portion. Each of the teeth 92 is bent slightly at a point intermediate the two ends, while the interior walls of the slot in the tooth-holding bracket 90 are parallel. When the tooth 92 is driven into the slot within the bracket 90, the bent tooth is deformed to fit the straight-walled slot within the bracket;
however, the tooth has a tendency to return to its bent position and this internal 30 tendency of the tooth biases the tooth against the interior walls of the slot to form an interference fit retaining the tooth within the slot without the necessity of welding or other fixation means. As with the case of the first embodiment described above, the tooth is oriented so that as the roll rotates, and the tooth encounters material in the comminuting chamber, the force of the material on 35 the tooth acts in a manner that will force the tooth into the slot as opposed to removing the tooth from the slot. As viewed in FIGURE 12, rotation of the roll would be in the counterclockwise direction so that each of the teeth 90 would have the crossbar portion, which is wider t'nan the mouth of the bracket slot, 1.;~7'3~,~7 g forced into abutment with the edges of the tooth-holding bracket 90, tending to retain the tooth within the slot. When it is desired to remove the tooth for sharpening or replacement, force is applied to the square end 92b of the tooth to drive it from the slot.
In summary, therefore, an improved comminuting device for grind-ing and pulverizing solid materials has been described and illustrated. The irnproved comminuting device includes a screening member positioned between the comminuting chamber and the discharge chamber to regulate the size of particles exiting the comminuting chamber. The screening member is adjustable to selectively vary the size of particles permitted to exit the comminuting chamber. Also, the comminuting device has removable teeth mounted in the comminuting rolls to permit replacement and repair of the teeth without removal of the entire roll or replacement of the entire roll from the comminut-ing device. While two embodiments of the replaceable teeth are illustrated, it will be realized by those of ordinary skill in the art that changes can be made to the illustrated embodiments while remaining within the scope of the invention.
Likewise, changes can be made in the illustrated embodiment of the adjustable screening member, for example, the placement of the spring can be varied and the use of a compression rather than expansion spring can be substituted, while remaining within the confines of the invention. Therefore, the invention should not be considered limited by the illustrated and described embodiments and thoseshould be considered as exemplary only. The invention should be defined solely by reference to the appended claims.
Claims (18)
1. In an apparatus for comminuting solid materials including a housing defining a comminuting chamber find an adjacent discharge chamber, screening means located at the interface of said comminuting chamber and said discharge chamber, said screening means being constructed and arranged to contain orifices to permit passage of particles of a predetermined maximum size from said comminuting chamber to said discharge chamber and to block passage of particles larger than said maximum size, the size of said orifices being selectively adjustable.
2. The apparatus of Claim 1, wherein said comminuting cham-ber is formed by a series of comminuting rolls arranged within said housing, said screening member including a disk horizontally mounted within said housing having a peripheral edge spaced from said comminuting rolls and including a series of screening fingers radially mounted on said disk and extending past said peripheral edge, said fingers mounted for selective linear movement of said screening fingers in a radial direction so as to selectively vary the spacing of a first end of said screening fingers from said rolls.
3. The apparatus of Claim 2, wherein each of said screening members is individually movable in a radial direction independent of the remaining fingers.
4. The apparatus of Claim 3, wherein each of said fingers is biased in an outwardly radial direction.
5. The apparatus of Claim 4, wherein said screening means further includes constraint means mounted on said disk and cooperable with said screening fingers to restrain the movement of said screening fingers in an outwardly radial direction.
6. The apparatus of Claim 5, wherein one of said constraint means is associated with each of said screening fingers and said constraint means are each selectively positionable on said disk at a predetermined number of locations so as to permit adjustment of said fingers in a predetermined number of locations.
7. The apparatus of Claim 1, wherein said comminuting chamber is defined by a series of comminuting rolls rotatably mounted within said housing and said screening means includes an annular pneumatically inflat-able member mounted for horizontal rotation of said member within said housing at the interface of said comminuting chamber and said discharge chamber, an outer peripheral edge of said inflatable annular member being spaced from said comminuting rolls, the degree of inflation of said member determining the spacing between said rolls and said outer peripheral edge.
8. The apparatus of Claim 7, wherein said pneumatically inflatable annular member is a motor vehicle tire.
9. The apparatus of Claim 2, wherein said screening means further includes a plurality of generally radial vanes vertically oriented and affixed to an upper surface of said disk, such that said vanes extend into said comminuting chamber.
10. The apparatus of Claim 9 further including a magnet mounted on at least one of said vanes.
11. In a comminuting apparatus for comminuting solid materials including a comminuting chamber containing a plurality of comminuting rolls having abrasive protrusions thereon for contacting said solid materials to achieve said comminuting action, the improvement wherein said abrasive protrusions are removably mounted on said rolls.
12. The comminuting apparatus of Claim 11, wherein said abrasive protrusions comprise a plurality of teeth removably received within a corresponding plurality of associated slots formed in the outer surface of said roll; and keeper plates affixed to said roll overlying said teeth to maintain said teeth in position within said slots.
13. The apparatus of Claim 12, wherein said teeth are wedge shaped and oriented within said slot so that the force of said solid material insaid comminuting chamber on said tooth is transferred to the walls of said slot and acts to maintain said tooth within said slot.
14. The apparatus of Claim 11 including a plurality of tooth-holding brackets affixed to the outer surface of said roll, each of said brackets including a rectangular slot formed therein;
a plurality of tooth members, said tooth members being insertable into said slots within said tooth-holding bracket; and biasing means associated with each of said tooth members for biasing said tooth member against the sides of said slot to maintain said tooth member within said slot.
a plurality of tooth members, said tooth members being insertable into said slots within said tooth-holding bracket; and biasing means associated with each of said tooth members for biasing said tooth member against the sides of said slot to maintain said tooth member within said slot.
15. The apparatus of Claim 14, wherein each of said tooth members is deformed upon insertion of said tooth member into said slot and the tendency of said tooth member to return to its original shape provides the biasing force that maintains said tooth member within said slot.
16. The apparatus of Claim 15, wherein said tooth member is wider than said slot at a first end and is positioned on said roll such that theimpact of said material within said comminuting chamber on said tooth forces the first end of said tooth into abutment with the edges of said bracket surrounding said slot to maintain said tooth within said bracket.
17. The comminuting apparatus of Claim 1 further including a stationary branch-breaking tooth member extending associated with said housing and extending horizontally into said discharge chamber below said screening means.
18. The comminuting apparatus of Claim 1 further including a baseplate extending horizontally from said housing at the interface of said discharge chamber and said comminuting chamber, said baseplate having an aperture centrally formed therein defined by a first edge, said screening means lying within said aperture, said edge having a notch formed therein to assist inthe passage of fibrous material from said comminuting chamber to said discharge chamber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000534748A CA1279627C (en) | 1987-04-15 | 1987-04-15 | Comminuter for solid material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000534748A CA1279627C (en) | 1987-04-15 | 1987-04-15 | Comminuter for solid material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1279627C true CA1279627C (en) | 1991-01-29 |
Family
ID=4135436
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000534748A Expired - Fee Related CA1279627C (en) | 1987-04-15 | 1987-04-15 | Comminuter for solid material |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1279627C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115430689A (en) * | 2022-07-21 | 2022-12-06 | 北京市首发天人生态景观有限公司 | Multistage broken recovery plant that refines of abandonment branch |
-
1987
- 1987-04-15 CA CA000534748A patent/CA1279627C/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115430689A (en) * | 2022-07-21 | 2022-12-06 | 北京市首发天人生态景观有限公司 | Multistage broken recovery plant that refines of abandonment branch |
| CN115430689B (en) * | 2022-07-21 | 2023-07-14 | 北京市首发天人生态景观有限公司 | Multistage broken recovery plant that refines of abandonment branch |
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| MKLA | Lapsed |