US2665851A - Garbage grinder - Google Patents

Description

Jan. 12, 1954 R. W. STREH LOW GARBAGE GRINDER Filed May 29, 1950 ROBERT w. STREHLOW INVENTOR. B Z- ATTORNEY Patented Jan. 12, 1954 UNITED STATES ATENT 2.5+ FFICE GARBAGE GRINDER Application May 29, 1950, Serial No. 164,923

1 Claim. 1

This invention relates to garbage grinders in general and its several features provide an improved apparatus particularly adapted to the grinding of waste matters found in the kitchens of hotels, restaurants and institutions.

It is the general object of this invention to improve the operating characteristics of grinders and to simplify the mechanical maintenance thereof and to eliminate the necessity for frequently cleaning certain portions of the grinder.

It is a further object of this invention to provide in a grinder of the type utilizing rotating teeth a construction that will facilitate feeding the garbage to the teeth automatically without the necessity of continually prodding or poking the garbage into the grinder.

Another object of this invention is to provide an improved end disc construction for garbage grinders of the type having rotatable cutting discs carried by an overhanging motor shaft.

A still further object of this invention is to provide a replaceable cutting tooth insert for grinders oi the aforesaid type and to thereby facilitate the maintenance of sharp cutting teeth.

According to this invention a series of disclike cutting members are assembled on the shaft of a motor, each disc being in a fixedrelationship with respect to the other discs and the disc assembly being rotatable as a unit with the a motor shaft. Each cutter disc has a raised portion forming a backing and support for a removable rectangular blade portion, such blade portion having a plurality of sharpened edges, any of which may be utilized when mounted in operative cutting position.

The entire cutter disc assembly is contained within a housing in such a manner as to direct garbage to the cutting teeth and limit the passage of garbage between the ends of the cutter disc assembly and the walls of the housing. A packing is provided at the point where the motor shaft enters the housing and an annular washer member is provided at the opposite, outer end of the motor shaft, which washer provides an occasional bearing between the end of the motor shaft and the aforesaid housing. This washer has a smaller diameter than the cutting discs so that the exposed portion of the cutter disc assembly is operative in its entirety to grind garbage. This construction provides a further advantage in that small particles attempting to escape between the outward end of the cutter disc assembly and its housing are centrifugally thrown back into the central portion of the 2 housing, as will be explained subsequently in greater detail.

The cutter disc housing conforms substantially to the circumference of the cutter disc through out substantially three quadrants of its circumference. Into two of these quadrants is inserted a perforated grate extending axially of the cutter disc assembly and forming an exit through which comminuted particles may pass. This grate in prior art structures occupied the bottom half of the cutter disc circumference but in this invention it has been displaced approximately 30 in the direction of rotation of the cutter disc assembly so that a pocket portion might be provided in the housing adjacent the leading edge of the grate. This pocket construction traps garbage fed to it from the upper portion of the grinder housing (which forms a feed chute) and because of the pocket, garbage is retained or trapped in a position in which the cutter teeth may obtain purchase upon it and thereby rapidly comminute said garbage without the necessity of external poking or prodding.

The invention is more fully described in connection with the drawings in which- Fig. l is an end view of the grinder and its housing shown partly in section;

Fig. 2 is a side view of the grinder, housing and motor, also shown partly in section; and

Fig. 3 is a detail view of a cutter disc of the type illustrated in Fig. 1 and showing a replaceable tooth insert.

Referring to the drawings and in particular to Figs. 1 and 2, garbage is fed into the machine by means of a feed chute ll shown as the upper portion of the grinder housing which is indicated generally as i 2 and which provides a chamber in which the rotatable material-disintegrating element of the apparatus is disposed.

Various types of feed pans may be mounted above the feed chute H. One suitable type is that disclosed in the co-pending application of my co-worker, Gilbert W. Quast, Serial No. 247,587, filed September 21, 1952, which enables continuous feed and operation of the grinder. However, the grinder may be operated on a batch principle, in which event it is only necessary to provide a removable cover over the chute H to prevent garbage being ground from being thrown out of the feed inlet.

The feed chute i I is tapered so that it diverges downwardly and it is therefore apparent that any pieces of garbage which are capable of en tering the chute will pass therethrough and be presented to the cutting teeth. An orifice it is provided in one side of the feed chute H and communicates with an external cup l4 into which water may be supplied from a source [5 to facilitate grinding and flushing.

The cutting portion of the grinder is illustrated as comprising a series of co-axial, disc-like members I6 assembled on the overhanging horizontal shaft H of a motor 58. Each of the discs 16 has a raised portion it which forms a backing for a replaceable cutter tooth 2B. The discs are se-. cured together into a unitary cylindrical rotor element by means of bolts 2| passed through the discs and threaded into the disc i6 adjacent to the motor 18. The cutting surfaces of the respective discs are staggered radially of the rotor or cutting assembly so that adjacent cutting surfaces are not axially aligned. A seal 22 is provided at the entrance point of the motor shaft into the housing i2 which prevents the passage of water and particles of garbage into the motor housing.

At the outer end of the motor shaft a washer member 23, concentric with the cutter discs, is carried by the motor shaft and held firmly against the outermost cutting disc it" by means of a nut 24 which, through frictional engagement, holds the cutter disc assembly securely on the motor shaft and assures its rotation therewith. This washer 23 is of a smaller diameter than are the cutting discs 16 and fits into a re end surface of the last cutter disc and the grinder 7 housing are thrown outwardly because of the rapid speed of rotation of the cutter disc and are thereby prevented from entering the recess 2% in the grinder housing end plate. in normal operation the washer 23 does not contact the end plate surfaces defining the recess 25 but if the motor shaft 1? is deflected due to hard grinding, the peripheral surface of the washer forms an occasional bearing with a cylindrical portion 28 of the end plate 2'1 and thereby provides a support for the overhanging motor shaft I1 limiting deflection thereof to the clearance between the washer periphery and the cylindrical portion 23 of the end plate, thus preventing permanent distortion of the shaft.

A better understanding of the advantages of the end washer construction here illustrated is possible in view of the prior art. l-leretofcre it has been the practice to utilize an end disc or washer of substantially the same diameter as the cutting discs and it rotated in a recess similar to the recess 26 here illustrated except that the cylindrical portion 28 was of a diameter slightly larger than the cutting discs. With this construction it was necessary to completely fill the recess 28 with grease in order to discourage the entry of comminuted particles. However, in operation, the grease was centrifuged into the grinding portion of the housing and escaped into the sewer, after which comminuted particles worked into the recess 25 and filled it, creating an objectionable odor and necessitating frequent cleaning.

The improved construction here illustrated overcomes the greater portion of this difiiculty. The space or running clearance 25 between the last cutter disc I5 and the housing end plate 2'! lies wholly in a plane normal to the axis of the shaft ii and communicates radially around its outer periphery with the interior of the grinding chamber. Because of the rapid rotation of 4 the cutter disc l5" particles which enter the space 25 are thrown back into the grinding portion of the housing by centrifugal force. With the prior art construction, the space 25 was an inverted L shape and did not communicate radially with the grinding chamber with the result that particles could not be thrown clear because they struck the horizontal portion of the space and could not escape. The present construction operates for long periods of time without becoming contaminated and grease is not required in the recess 26.

In operation the motor rotates counterclockwise in the direction of the arrow in Fig. 1 and the separate teeth 20 of the cutter discs it comminute garbage passed through the feed chute H. The comminuted particles then pass out through a grate or cage 29 occupying substantially 186 of the rotation of the cutter discs and conforming substantially with the circumference of their circle of rotation. The grate 29 occupies the lower portion of the circle of rotation of the cutter teeth except that it is displaced forward in the direction of rotation approximately 30. This displacement makes possible the creation of a semi-crescent shaped pocket 35 adjacent the cutting discs it which is formed by a curved, downwardl converging side 3! of the feed chute H. This pocket tapers into an apex below the axis of the motor shaft and has an axial length substantially equal to the axial length of the cutter disc assembly.

It has been the usual practice in prior art grinders of this type to locate the grate 29 on the lower one-half of the circle of rotation of the cutter discs and to feed garbage to the upper one-half. Ehis practice had the disadvantage of relying entirely upon the weight of the garbags for the force necessary to hold it against the cutting teeth and made it necessary to poke or shove garbage from the top of the chute with a stick or other apparatus in order to hold it against the teeth with suflicient force to enable them to obtain a purchase and commence their grinding action.

The construction here illustrated and described eliminates the greater portion of this poking because garbage is confined within the pocket 38 and held by the downwardly converging pocket side 3'5. As the cutter discs rotate, garbage is forced into the more restricted lower portion of the pocket and because of the compacting which results, garbage is forced against the teeth, enabling them to comminute the matter with greater dispatch.

Flushing water entering through the orifice l3 falls upon the cutter discs it and passes with the comminuted garbage through the grate 29 thereby facilitating the flushing of ccmminuted particles into the lower portion 32 of the grinder housing from which the comminuted particles may be carried away to a sewer, not shown.

Fig. 3 illustrates a replaceable cutter tooth 2B which fits into a slot 33 on the periphery of the cutter disc I6 and is retained by means of a stud 34 passing through the tooth and threaded into the cutter disc. As may be seen, the cutter disc is formed with a raised portion is which provides a backing to retain the cutter tooth. The tooth 2B is further retained by contact with the fiat, side faces of adjacent cutter discs when the separate cutter discs are assembled together as a unit, as previously described. The cutter tooth 20 may be formed of a hard material and is preferably made rectangular so that each of its eight lateral edges may be exposed successively as a cutting edge. In this manner the maintenance of a sharp cutting edge is greatly facilitated and a tooth need not be sharpened until all eight of its edges have become dulled. Further, in order to sharpen the grinding element it is not necessary to dismantle the cutter discs from the motor shaft as has been necessary in the past due to the fact that the raised portion IQ of the cutter disc was itself a cutting edge.

What I claim is:

Apparatus for grinding garbage and the like, comprising a housing having two vertical opposed end walls; a grate extending between said walls to form a grinding chamber; a horizontal rotatable shaft extending through one of said walls and beyond the plane of the second of such walls; a cylindrical rotor element rigidly carried by said shaft within the grinding chamber and provided with peripheral teeth co-operable with said grate to disintegrate the garbage material, said rotor having vertical end faces having running clearance with the inward faces of said housing walls which clearances have radial straight-line communication with the grinding chamber at the periphery of the rotor whereby disintegrated particles of material finding their way into such clearance may be readily expelled therefrom into the chamber by centrifugal force imparted to such particles by the rotor, said second housing end wall having a recess therein concentric with and freely receiving the portion of the shaft extending beyond the plane of such wall, said recess having a diameter materially smaller than that of the rotor element; a washer mounted on the shaft abutting the rotor and disposed within said recess with running clearance between the outer periphery of the washer and the periphery of the recess, said recess providing substantial clearance around the shaft beyond the washer; and means fixedly securing the washer to the shaft for rotation therewith.

ROBERT W. STREHLOW.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,131,229 Giddings Mar. 9, 1915 1,397,828 Williams Nov. 22, 1921 1,434,540 Hiller Nov. 7, 1922 1,476,177 Plaisted Dec. 4, 1923 1,965,033 Dillon July 3, 1934 2,131,689 Marshall Sept. 27, 1938 2,226,330 Symans Dec. 24, 1940 2,373,691 Kessler Apr. 17, 1945 2,440,051 Lind et a1 Apr. 20, 1948 2,509,242 Miller May 30, 1950

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