Collapsible container invention

Abstract: A collapsible container has four panels that fold down on a base for storage. The base has slide sockets with vertical slots. Front and rear panels pivot on the base with slide hinges received in the slide sockets. The panels are able to slide up and down. A hinge pin has a narrowed waist portion to engage a latch. Left and right panels pivot with snap hinges received in snap sockets on the base. Trunnions, disposed in the snap sockets, are eccentric to increase or decrease the backlash between the snap hinge and the snap socket as the panels pivot. The left and right panels have edge pockets that receive edge fingers on the front and rear panels to hold the container open. The front and rear panels each have an access opening with access doors. Links pivot the access doors on two hinge rods. Locking members wedge the hinge rods in the hinge knuckles. The base has feet with bumper plates having flanges that prevent the container from shifting on an adjacent lower stacked container.

This invention relates to the field of folding containers, and more particularly to a—bulk material container having side and end panels pivotally mounted to a base, and able to fold down upon the base. For shipping or storing the empty container, the panels are folded down flat. To open the container for use, the panels are pivoted upright and locked together at the corners. Open containers filled with bulk material can be stacked one upon another. Folded containers can be stacked for efficient shipping and storage. Mixed open and folded containers can also be stacked.

Collapsible containers are known in the prior art, and have taken a variety of configurations in the past. Some examples of collapsible containers are as follows:

Miller, U.S. Pat. No. 5,094,356; Reiland, U.S. Pat. No. 4,775,068; Friedrich, U.S. Pat. No. 4,062,467; Foy, U.S. Pat. No. 4,923,079; and Hoss, U.S. Pat. No. 4,735,330; each disclose a knock down container with opposite side and end panels hinged to a base.

Miller 356 shows a molded plastic base having a floor with a reinforcing grid beneath it. The floor has numerous large pockets requiring cover plates, so that bulk material or finished products will not drop into the pockets. Furthermore, the pockets require a longer pull to open the mold to eject the finished base.

The side and end panels on these prior-art devices are expected to be able to fold into the closed position quickly and easily. Yet, the hinge joints are all made close fitting, so that as the panels are pivoted downward, they may not nest precisely in the base. It might be necessary to “spring” the panels toward one side or the other to fit them all the way down into the base.

The side panels of the prior-art devices are pivotally attached to the base with a slotted hinge, providing “lost motion,” or vertical sliding motion as well as rotation. This allows the side panel to be raised above the end panel, and then lowered vertically to latch fingers on the side panels into pockets on the end panels. This attaches the panels at the corners. Typically, one or more metal pivot pins or rods are inserted into the side panel hinges and fastened with nuts, washers, or the like fasteners on each end. These fasteners can dislodge, allowing the pin to slide out.

Accordingly, there is a need to provide a molded collapsible container having a base with a reinforcing grid on the bottom and a continuous floor so as to minimize the mold pull distance and eliminate pockets in the floor that would trap bulk material.

There is a further need to provide a collapsible container of the type described and that has hinge joints that are close fitting when the panels are open for precise latching of the corners, and that are loose fitting when the panels are folded for easy nesting of the panels in the base.

There is a yet further need to provide a collapsible container of the type described and that has hinge pins that install quickly and need no fasteners to secure the pins.

There is a still further need to provide a collapsible container of the type described and that can be opened and folded quickly and easily.

There is another need to provide a collapsible container of the type described and that can be manufactured cost-effectively in large quantities of high quality.

In accordance with the present invention, there is provided a collapsible container for use in conveying and storing bulk material and products. A base has a floor, front and rear ends and left and right sides. The base has a wall along the ends and sides, and four corners. The wall projects upward above the floor, which is continuous, with no large openings to trap bulk material and only a few small drain holes.

Front and rear panels each have first, second, top, and bottom edges. The front and rear panels bottom edges are pivotally mounted on the base front and rear ends. The pivotal mounting provides lost motion and allows the panels to be pivoted downward into a folded position on the base, and into an open upright position. Fingers are arrayed along the panel first and second edges. Three slide hinges extend downward from the bottom edges of the panels. Each slide hinge has hooks extending downward and facing alternately inward and outward. The hooks define a transverse passage having a pivot axis. Three slide sockets are provided in each of the base front and rear ends. Each slide socket receives one of the slide hinges. Each slide socket has a pair of opposed, generally vertical slots. A resilient latch extends downward from the bottom edge of the front and rear panels, coextensive with the slide hinge, and between the hooks. A novel hinge pin engages each slide hinge. The hinge pin has a narrowed waist portion to engage the latch. The waist portion retains the hinge pin in the slide hinge. The hinge pin engages the slots to slide upward in the slide socket.

Left and right panels each extend between first, second, top, and bottom edges. The panel bottom edges are pivotally mounted on the base left and right sides. This allows the panels to be pivoted downward into a folded position, and pivoted upward into an open upright position. The panel first and second edges each have an array of pockets. The left and right panel pockets receive the front and rear panel fingers.

Three snap hinges extend downward from the bottom edges of the left and right panels. Three snap sockets are disposed in each of the base left and right sides. Each snap socket receives one of the snap hinges. Each snap socket has a predetermined width. Two novel trunnions project outward from each snap hinge. The trunnions are eccentric to decrease the backlash between the snap hinge and the snap socket with the panels in the open position, to locate the panels precisely. Conversely, the trunnions will increase the backlash with the panels in the closed position, to allow for easy folding of the panels.

Two resilient cantilever members are disposed in each snap socket. The cantilever members will engage and capture the trunnions as the snap hinge is inserted into the snap socket. The cantilever members retain and center the snap hinge in the snap socket.

Front and rear access doors have outer, top, and bottom edges. The outer edges each have an array of plugs. The front and rear panels each have an access opening with an array of receptacles to receive the plugs.