Trash compactor
United States Patent 3903790
A trash compactor having a loose trash receiving container and a plunger mounted to reciprocate into and out of the container to compact the trash therein. The plunger closely fits within the container, and an edge of the plunger is formed as a recessed, rabbit-like, L-shaped step for catching and pushing into the container loose trash which tends to become trapped between the side walls of the plunger and the container. The container is box-like in shape and is supported upon a piston-rod operated by a cylinder mounted upon a fixed beam arranged transversely of the plunger, and aligned notches formed in the plunger walls transversely receive the beam within the plunger when the plunger is spaced from the container.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
53/527, 100/229A, 100/245, 100/295, 141/80
International Classes:
B30B9/30; (IPC1-7): B30B15/30
Field of Search:
100/214,215,295,229A,240,245 53
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Primary Examiner:
Wilhite, Billy J.
Attorney, Agent or Firm:
Cullen, Settle, Sloman & Cantor
Having fully described an operative embodiment of this invention, I now claim

1. In a trash compactor having a trash receiving container into which loose trash is placed for compacting therein, with the container having an open end, and a compressor plunger arranged for reciprocating into and out of the container through said open end, with the plunger having a base face for contacting with and compressing against the trash within the container, and having side walls extending away from the base face, with the plunger being sized to closely fit within and through the container open end with its side walls closely adjacent to the periphery of said container open end, the improvement comprising:

2. A construction as defined in claim 1, and said plunger base face being substantially rectangular in shape, with said walls being approximately perpendicular thereto, and with said stepped edge portion extending along the full length of at least one of the edges of the base face.

3. A construction as defined in claim 1, and means for reciprocating the plunger comprising a fixed elongated beam arranged transversely of the plunger, on the side of the plunger base face opposite to the container;

4. A construction as defined in claim 1, and said container being substantially rectangular in cross-section, with the plunger correspondingly being rectangular and with said stepped edge portion extending along the full length of at least one of the edges of the plunger base face.

5. In a trash compactor having a housing enclosing a trash receiving container with an open end, a plunger for reciprocating into and out of the container through the open end thereof, and an improved means for supporting and moving the plunger, comprising:

6. A construction as defined in claim 5, and said beam being formed of two sections, namely, a long section extending a length greater than the width of the plunger for being received within said notches, and a short section, centered on the long section and shorter than the width of the plunger for fitting entirely within the plunger.

7. A construction as defined in claim 5, and wherein an inverted L-shaped stepped edge is formed along a portion of the plunger wall along the peripheral edge of the base plate, with the base of the L-shape being at a distance from and generally parallel to the plunger base plate;

8. In a trash compactor formed of an enclosed cabinet-like housing, with an upwardly opening container arranged within the housing lower portion, a vertically reciprocal piston arranged above the container for movement downwardly into and upwardly out of the container, with the piston normally spaced a distance above the container to provide a space into which trash may be thrown to fall downwardly into the container, and a trash receiving opening formed in the front of the cabinet at said space, with a closure normally closing said opening, the improvement comprising:

9. A construction as defined in claim 8, and including a plate-like guide overlapping and extending the length of the rear upper edge of the container, and the piston rear wall being likewise stepped inwardly similarly to the piston front wall.


The invention herein relates to an improved trash compressor or compactor of the type exemplified in my prior U.S. Pat. Nos. 3,438,321 issued Apr. 15, 1969 and 3,824,920 issued July 23, 1974. As illustrated in such patents, such type of trash compactors generally comprise a housing within which a trash receiving container is located. A piston or plunger arranged above the container reciprocates into the container periodically for compressing or compacting the loose trash thrown therein through an open portion of the housing. From time to time, the container may be removed from the housing for emptying the compacted trash therefrom. For this purpose, the container may be provided with a bag-like liner for easy removal of the trash from the container.

Such type devices are intended for use primarily in handling large quantities of trash, particularly paper and plastic types of trash as accumulates in cafeterias, schools and other types of institutions. For such uses, it is desirable to provide the maximum compacting of the loose trash thereby requiring a very strong, but economical, compactor construction which is as trouble-free as possible. In such type devices, one form of problem that arises is that at times trash tends to become trapped between the side walls of the plunger or piston and the walls of the container, thereby jamming the piston in its reciprocating movement and requiring manual freeing of the jammed trash. Another type of problem arising in such equipment is that the reaction forces on the plunger or piston during compacting of trash, requires a relatively heavy back-up or support structure which also is bulky and increases the overall size of the compactor. Thus, the invention herein relates to an improved construction which tends to eliminate the foregoing problems as well as provide a more economical compactor construction.


The invention herein relates to a trash compactor formed of a cabinet or housing within which an open top receptacle or container for trash is positioned, with a box-like plunger or piston arranged above the container for periodically reciprocating into the container and compressing the trash therein. The forward and rear walls forming the box-like plunger are formed with rabbited or L-shaped stepped lower edges which push trash, which is caught between the container walls and the plunger walls, downwardly into the container to thereby avoid jamming.

The plunger is supported upon the lower end of a piston rod fitted within a hydraulic or pneumatic cylinder which is mounted upon a transversely arranged beam which spans the cabinet above the plunger. The opposite end walls of the plunger are notched so that the plunger may be elevated to the point where the beam is received within the hollow plunger thereby permitted it to be raised a considerable distance above the open end of the container. The beam is reinforced by a secondary, centrally located reinforcing beam which also fits within the plunger so that the overall height of the cabinet may be reduced.

The box-like shape of the plunger and its stepped edges, along with the beam support, permits the application of considerable force upon the loose trash thrown within the container to thereby permit a substantial degree of compression for increasing the capacity of the compactor.

These and other objects and advantages of this invention will become apparent upon reading the following description, of which the attached drawings form a part.


FIG. 1 is a perspective, elevational view of the compactor with its front panels open so as to view the internal construction.

FIG. 2 is a front elevational view taken as if in the direction of arrows 2--2 of FIG. 1.

FIG. 3 is a side, cross-sectional view taken in the direction of arrows 3--3 of FIG. 2.

FIG. 4 is a perspective view of the plunger and its support beam.

FIG. 5 is an end view of the plunger and support beam per se with the beam received within the plunger.

FIGS. 6 through 9, inclusive, are fragmentary side views, partly in cross-section, showing various steps in the downward movement of the plunger for compacting trash within the container.


As illustrated in FIGS. 1-3, the compactor or compressor 10 is formed of an open front cabinet or housing 11 within which is positioned a trash container or receptacle 12. Such container is preferably substantially rectangular in a cross-section with an open top. Covering the container receiving area of the cabinet is a door panel 14 which preferably is hinged to one side of the cabinet for swinging open into the position shown in FIG. 1. The door panel 14 is provided with a window-like opening 15 communicating with the space above the container. Such opening is preferably closed with a swinging closure 16 having side guides or flanges 17 which fit closely along the inside surfaces of the side walls of the cabinet when the door and closure are both closed. The closure is preferably hinged along a horizontal axis by hinge pins 18 along its lower edge (see FIGS. 3 and 6).

An upper panel 19 closes the remainder of the cabinet opening above the door panel 14. Such upper panel may also be hingedly connected by suitable conventional hinges (not shown) to the side wall of the cabinet.

A box-like, preferably substantially rectangular in shape, plunger or piston 21 is arranged within the cabinet, at a distance above the open end of the container 12. Such plunger or piston may be formed of heavy gauge sheet metal and is provided with a base plate or face 22, which contacts and compresses the trash within the container, and vertically arranged front and rear walls 23 and 24. The lower edges of these walls are indented or stepped to form rabbit-like inverted L-shaped lower edge portion 25. The plunger also includes end walls 26 whose upper edges are provided with aligned notches 27. The plunger is of a size and shape to closely correspond to the opening of the container so that it closely fits within the container, except for the L-shaped lower stepped edges which are spaced inwardly a short distance from the corresponding container walls.

Above the plunger, within the cabinet, a transversely arranged beam spans the space between the side walls of the cabinet with its ends secured to such side walls. Preferably, the beam is U-shaped in cross-section. A second, lower beam 31 which is shorter than the upper beam 30, is centered upon the base of the upper beam 30 and welded thereto for reinforcing the transverse beam 30 against buckling and at the same time permitting lightening its weight and thinning its cross-section while maintaining its ability to sustain the required reaction loads.

A vertically arranged, hydraulic or pneumatic power cylinder 33 is centered on the transverse beam, passing downwardly through an opening in the upper beam 30 and having its lower end welded or otherwise fastened to the lower beam section 31 and preferably also to the upper beam 30. A piston rod 34 contained within the cylinder 33 and provided with a cylinder piston 35 (see FIG. 3) for pneumatic or hydraulic operation, extends downwardly through a piston rod opening 36 in the lower beam 31 so that its lower end 37 is rigidly connected to the center of the plunger base plate 22. In addition, a stabilizing rod 40, journalled through holes 41 and 42 in the beam sections 30 and 31, has its lower end 43 connected to the plunger base plate 22.

A suitable hydraulic or pneumatic pump and motor system 45 is mounted within the cabinet for providing fluid for the operation of the cylinder 33 and the culinder piston 35. The hydraulic or pneumatic pump and motor system 45 may be of any conventional type and thus, is illustrated only schematically. Likewise, where compressed air is available, it may be directly connected to the cylinder, thus eliminating any need for compressors or motors within the cabinet for that purpose.

The cabinet also contains such manually or automatically operated electrical switches as may be necessary for actuating the plunger for periodic operation, that is for actuating the cylinder 33, as well as suitable safety switches for deactivating the system upon opening of the cabinet panels or the swinging closure 16. Detailed descriptions of these are omitted here since they form no part of the invention herein.

As can be seen in FIG. 7, the lower edge 47 of the closure 16 is sufficiently thickened so that when the closure is arranged vertically or upright, such lower edge overlaps the forward upper edge of the container. Similarly, the rear upper edge of the container is overlapped by the lower edge 48 of a rear inner panel 49 mounted upon the rear wall of the cabinet.


In operation, the container 12 is positioned within the cabinet as illustrated in the drawings. Preferably, a plastic or paper bag liner is positioned within the container. The plunger is elevated to the point where the transverse beam 30 is received within the end wall notches 27 (see FIG. 5) and the beam lower section 31 is entirely contained within the plunger. Thus, a maximum space is provided between the bottom of the plunger and the open upper end of the container.

The users of the compactor, merely manually open the swinging closure 16, depositing trash thereon. The trash slides down between the side guides 17 and falls into the open upper end of the container 12. Periodically, as the loose trash accumulates within the container, the plunger is manually or automatically (e.g., by a timer or a level sensing switch) actuated for lowering and compacting the trash. This may be accomplished by a suitable electrical circuit and hand operated switch which actuates the pneumatic or hydraulic system 45 to cause the piston rod 34 to lower and thereby lower the plunger.

As the plunger lowers, any trash which has accumulated above the height of the container is guided downwardly into the container by the inner surface of the closure 16 and by the rear inner plate 49. Continued lowering of the plunger compacts the trash, which for the most part tends to remain beneath the plunger base plate or face 22. Thus, as shown in FIGS. 6-9, the trash, generally designated as 50, gradually compacts or compresses as the plunger moves downwardly. However, should trash fragments, designated 51 in FIG. 8, tend to catch between the plunger walls and the walls of the container, such fragments or trash portions slip into the stepped lower edges 25 of the front and rear walls of the plunger and then are pushed downwardly by the bases of the inverted L-shape configuration forming such steps. In that way, trash cannot jam tightly between the close fitting portions of the front and rear walls of the plunger and the corresponding walls of the container. By providing a place for these trash fragments and a means for pushing them inwardly into the container, jam-ups are substantially eliminated.

The arrangement wherein the transverse beam is fitted within the plunger when the plunger is elevated, makes it possible to provide the plunger with higher walls for both strength and elimination of jam-ups and at the same time permits a reduction in the overall height of the cabinet. Moreover, the plunger can thereby be shaped to compact a large area which may be rectangular, as illustrated in the drawings, or square, to thereby increase the capacity of the compactor as compared to prior devices.