US1565842A - Grinder roll - Google Patents

Description

Dec. 15, 1925.

0. ARA M- GRINDER ROLL 5 Filed April 4, 19 22 ff afia? WWQW 4 ATTORNEY ZZZ v AM); dig/45hr WITNESS S' Patented Dec. 15, 1925.

UNITED STATES PATENT OFFICE.

GRINDER ROLL.

Application filed April 4, 1922. Serial No. 549,492.

To all whom it may concern:

Be it known that I, OTTO ARAM, a citizen of the United States, and a resident of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in Grinder Rolls, of Which the following is a specification.

My invention relates to grinder rolls, particularly to rolls of the character employed in removing clinker and ash from mechanically operated furnaces, and it has for an object to provide, in an apparatus of the character designated, a built-up structurewhich shall be capable of assembly in varying lengths to accommodate furnaces of different widths, and in which the torsional stresses imposed upon the grinder roll shall be carried by overlapping castings rigidly secured one to another and carried by a single shaft. Anotherobject of my invention is to provide a grinder roll which shall have a continuous cutting action during rotation thereof, which cuttingaction shall be produced by two spirally arranged series of cutters disposed diametrically opposite to each other and extending the length of the roll. I

It is a still further object of my invention to provide in a grinder roll of this character an interchangeable tooth structure which may be readily replaceable and which shall exert a cutting action in either direction of rotation of the roll.

These, and other objects which are made more manifest in the further description of my invention, may be attained in the a paratus hereinafter described and illustrated in the accompanying drawings, in which Fig. 1 is a view in elevation showing the assembled roll, the teeth being omittedin order to show more clearly the arrangement and mode of fastening of the semi-cylindrical castings; Fig. 2 is a view in section taken on line II-II of Fig. 1; Fig. 3 is a similar sectional View taken on line IIIIII of Fig. 1; Fig. 4 is a longitudinal sectional view of one of the hollow semi-cylindrical castings; Fig. 5 is a View in end elevation of the casting illustrated in Fig. 4; Fig. 6 is an enlarged detailed View in side elevation of one of the interchangeable teeth; and Fig. 7 is an end view of the tooth illustrated in Fig. 7.

High duty furnaces of central power stations are usually of considerable width and the grinder rolls therefor, commonly located at the bottom of the refuse pit, are of a length corresponding to the width of the furnace. The power for rotating grinder rolls is ordinarily applied at one end of the roll, or in extremely wide furnaces where two aligned rolls are employed the'power is applied at the outer end of each roll, a construction which imposes severe torsional stresses upon the shaft supporting the roll. The present invention contemplates the absorption of these torsional stresses by employing sectional, semi-cylindrical hollow castings bolted together lation around an axially disposed shaft to form a light and rigid built-up structure.

The grinder roll described in the present application, when designed for use in connection with a standard underfeed stoker, comprises an assembly of two distinct 1101-. low, semi-cylindrical castings. In order that from these castings rolls of any desired length, as for example, for a 5, 7 or 9 retort stoker, may be readily assembled, it is preferable to construct one of the said castings equal in length to the width of a retort and the other casting twice that length.

The castings are suitably cored for the reception of interchangeable teeth, the tooth openin 's being symmetrically disposed about t e cylindricalsurfaces of the castings in such manner as to produce a double helical series of teeth for any assembly of sectional castin s.

All teeth for the roll are removable and interchangeable and consequently may be cast from a single pattern. Each tooth is designed to abut at its in er square end against a supporting shaft and to engage the cylindrical shell of the roll of castings by means of a shoulder. No other securing means for the teeth is necessary since each tooth is held securely in place by bolting together the castings in their assembled relation.

Referring to the drawings for a more detailed description of my invention, in Fig. l I show at 10 an assembled roll composed of short-hollow, semi-cylindrical castings 11, and long hollow cylindrical castings 12. The longer castings 12 are pre ferably twice the length of the castings ll so that by combination of these castings, rolls of varying lengths to meet the reln overlapping requirements of any installation may be constructed. Each of the castings 11, 12 has closed end portions 13, provided with right triangular notches 14, adapted to engage a square shaft 15 when in an assembled position. Cored holes 16 are provided in the. end portions of the short castings 11 and in the end and intermediate portions of the castings 12, the holes 16 being suitably disposed for the reception of bolts 17 by means of which the castings are held securely to each other and to the square shaft. Each casting is further provided with a plurality of cored radial openings 19 for the reception of the cutting teeth 20, the arrangement of these openings being such that upon a proper assembly of any number of sections, a double series of diametrically opposed teeth 20 may be located therein.

Each tooth 20 consists of a base portion 21 having a beveled end face 22, which engages a side of the square shaft, and a cutting or blade portion 23 which protrudes beyond the periphery of the cylindrical roll. Between these portions, a tapered portion 2a, which engages a cooperating shoulder 25 in the opening 19, serves to hold the. tooth in position against the shaft 14. The outer end of the tooth is preferably slightly concave, as at 27, to provide a cutting edge in either direction of the grinder roll.

The assembly and the operation of my improved grinder roll is evident from the above description. In brief, when it is desired to equip a stoker of any given capacity, the requisite number of long and short semi-cylindrical castings are selected and the teeth 20 slipped into the several apertures 19, in such manner that the beveled faces will engage the sides of the square shaft 15. The castings are then placed about the shaft and bolted to each other so that the sections form a rigid integral cylindrical roll in which the teeth are securely held because of their engagement between the shaft and the shoulders 26 of the openings in the castings. The assembled structure is then ready for installation.

My novel construction of grinder roll possesses many advantages over similar structures commonly employed. The roll hereinbefore described is constructed from four different stock parts, namely, standard long and short semi-cylindrical castings, standard teeth, and a square shaft cut to the proper length, from which standard parts grinder rolls of any desired length may be assembled. There is thus obtained a material economy in the cost of construction and maintenance of the grinder roll due to the reduction in labor required to make the few standard parts needed for all sizes of equipment, the fewer parts necessary to be carried in stock both by the manufacturer and the user of the machine and the readiness with which any part or parts may be replaced when worn or broken. These advantages are obtained without in any way sacrificing the strength or effectiveness of the roll. Rather has it been found in tests conducted under actual operating conditions that the several castings assembled as herein described give the roll the rigidity of an integral structure and relieves the shaft of the torsional stresses normally carried thereby.

\Vhile I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

lVhat I claim is:

1. In the art of constructing grinder rolls for stoker furnaces in which the rolls comprise a cylindrical member provided with projecting teeth, the method of constructing such rolls of varying lengths which consists in preparing a plurality of semicylindrical castings of a unit length, preparing a plurality similar castings of twice the unit length, all said castings having identically disposed openings for the reception of teeth and bolts, preparing a plurality of teeth of a single size and pattern, then assembling the teeth in a number of castings requisite to form when assembled a roll of the length required and securing the semi-cylindrical castings to each other in overlapping relation about a square shaft with the teeth abutting said shaft cut to a requisite length to form the desired toothed cylindrical grinder roll.

2. A grinder roll for a stoker furnace comprising a square shaft, semi-cylindrical castings secured together in overlapping relation to form a cylindrical grinder roll, said castings being provided with openings and teeth extending through said openings, one end of the teeth abutting the sides of the shaft.

3. A grinder roll for a stoker furnace comprising a polygonal shaft, teeth extending outwardly from the shaft, one end of each tooth abutting the shaft and one edge of said end lying substantially along a corner of the shaft, and means for holding the teeth in engagement with the shaft.

4. A grinder roll for a stoker furnace comprising a square shaft, and semi-cylindrical castings secured together to form a cylindrical grinder roll and having notched portions to embrace said shaft, and cutting teeth carried by the castings, and abutting said shaft.

5. A grinder roll for a stoker furnace comprising a square shaft, semi-cylindrical castings secured together to form a cylindrical grinder roll and having notched portions to embrace said shaft, and teeth carried by the castings and so disposed therein in abutting relation to said shaft as to form two diametrically opposite helical series or rows of cutting teeth.

6. A grinder roll for a stoker furnace comprising semi-cylindrical castings secured together to form a cylindrical grinder roll, a square shaft disposed axially of and supporting the assembled roll, said castings having openings for the reception of cut-- ting teeth, cutting teeth projecting through said openings and held rigidly therein by engagement with the shaft and the castings.

A grinder roll for a stoker furnace comprising hollow semi-cylindrical castings secured together to form a cylindrical grinder roll, a square shaft disposed axially of and supporting the assembled roll, said castings having openings for the reception of cutting teeth, interchangeable and removable cutting teeth projecting through said openings, said teeth being held rigidly therein by engagement With the shaft and the castings.

8. A grinder roll for a stoker furnace, comprising a square shaft, semi-cylindrical castings of unit length, a plurality of semicylindrical castings of twice the unit length, said castings being secured together in overlapping relation to form a rigid grinder roll and having notched end portions to embrace said shaft. a

9. A grinder roll for a stoker furnace comprising hollow, semi-cylindrical castings secured together to form a cylindrical grinder roll, a square shaft disposed axially of and supporting the assembled roll, said casting having openings for the reception of cutting teeth, interchangeable and removable cutting'teeth projecting through said openings, the base portion of each of said teeth being beveled to fit against the sides of the square shaft.

10. A grinder roll for a stoker furnace comprising hollow, semi-cylindrical castings secured together to form a cylindrical grinder roll, a square shaft disposed axially of and supporting the assembled roll, said castings having openings for the reception of cutting teeth, interchangeable and removable cutting teeth projecting through said openings, each of said teeth being provided with an intermediate shoulder to engage a cooperating shoulder in the said opening, and a beveled inner face to fit against a side of the square shaft, whereby the teeth are held rigid with respect to the assembled roll.

g 11. A grinder roll for a stoker furnace comprising hollow, semi-cylindrical castings secured together to form a semi-cylindrical grinder roll, a square shaft disposed axially of and embraced by each casting of the assembled roll, said castings having openings for the reception of cutting teeth, cutting teeth projecting through said openings, and said openings being so disposed as to carry two diametrically opposite helical series or rows of cutting teeth, said teeth abutting said shaft.

12. A grinder roll for a stoker furnace comprising a plurality of hollow, semi-cylindrical castings, some of the said castings being twice the length of other castings, said castings having radially cored openings for the reception of cutting teeth, cutting teeth disposed in said openings, and a shaft, the arrangement of the above parts being such that when the semi-cylindrical castings are secured together about the shaft the teeth are held rigid with respect to the as sembled roll by engagement with the shaft and the castings.

13. In a clinker grinder roll for a stoker, the combination with a shaft whose cross section is a polygon of an even number of sides, of a plurality of pairs of teeth, the teeth of each pair engaging opposite sides of the shaft and having their axes parallel and lying in a plane normal to the axis of the shaft.

In testimony whereof, I have hereunto subscribed my name this 29th day of March, 1922.

OTTO ARAM.

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