This invention relates to shipping containers, and more particularly, to a shipping container which is particularly suitable for shipping particulate material, for example, powdered and pelleted materials.
There is a need for satisfactory shipping containers for particulate materials, including plastics and synthetic resins, chemicals, food products such as flour, coffee, and grain, and similar powdered, granular, or pelleted materials. These materials exhibit fluid-like or flowable properties, and they are desirably shipped in a manner which protects the material from contamination.
It is also desirable that the container can be used for shipping materials other than particulate material, for example, bulk products. A container which can be used only with particulate material is generally a one-way container which is returned empty to the original shipper. A container which can be used to ship product in only one direction substantially increases shipping costs compared to a container which can be used to ship product in both directions.
Previous attempts to provide shipping containers are exemplified by U.S. Pat. Nos. 4,875,811, 5,487,485, 5,911,337 and 6,837,391. The '811 patent describes a plastic bag inside of a conventional shipping container. The particulate material is loaded into the bag, and the bag is sealed. However, the bag increases the difficulty in loading and unloading the particulate material, and the bag creates disposal problems.
The '485 and '391 patents describe liners for a shipping container. The liners suffer from some of the same problems as a plastic bag and increase the costs of the shipping container.
The '337 patent describes a rigid aluminum vessel which is inserted into a shipping container. This vessel further increases costs and reduces the ability of the shipping container to be used for other purposes.
The invention provides a shipping container which can be used to ship both particulate material and non-particulate material or bulk material. The container can therefore be used to ship particulate material, e.g., powdered plastic resin, in one direction, e.g., to a manufacturing facility which uses the plastic resin to manufacture molded plastic products. The shipping container can then be used to ship the manufactured products from the manufacturer.
The shipping container has the general shape and appearance of a conventional shipping container. Such containers are commonly 20 or 40 feet long and can be conveniently loaded on a truck, railroad car, or ship for transport. The container includes front and back walls, top and bottom walls, and opposite side walls which form a storage enclosure or compartment. The inside surface of each wall is coated with a material which is inert with respect to the particulate material, for example, an epoxy material such as epoxy paint. The particulate material is thereby protected from contamination.
The back wall of the container is formed by a pair of doors which are hingedly secured to the container. Each door may be releasably locked by a vertically extending locking bar. An inlet opening is provided in one of the doors so that particulate material can be loaded into the container. An outlet opening is provided in at least one of the doors and preferably both doors for unloading the material. Each outlet opening is positioned near the bottom of the container, and a baffle extends upwardly from the bottom wall toward the outlet opening for guiding material to the outlet opening when the front of the container is raised.
A discharge conduit extends from each outlet opening, and a valve or folded discharge tube is positioned in the discharge conduit for opening and closing the conduit. A pair of small doors are hingedly mounted on the larger door for covering the discharge conduit.
The 20 foot container may locate the baffle wall and load/unloading ports either in the hinged doors or in the front of the container. The forward or reverse location of the baffle and ports is optional on 20 foot containers due to the inherent construction of 20 foot containers. Forty foot containers have a goose neck protrusion to “lock” the container in a transport chassis while 20 foot containers do not have the goose neck. The ability to transport a 20 foot container in a forward or reverse mount position permits product delivery options.
The invention will be explained in conjunction with illustrative embodiments shown in the accompanying drawing, in which:
Referring to
The container illustrated in the drawing is intended to be pulled over the road by a tractor cab and is provided with a conventional coupler for attaching the container to the cab. However, the wheels 22 and stand 23 could be omitted, and the container could be transported in other ways, for example, on a railroad car or ship.
The container body 21 is formed by front and back walls 25 and 26, opposite side walls 27 and 28, a top wall 29, and a bottom wall or chassis 30. The top and side walls may be formed from conventional corrugated sheet metal. The interior seams of the walls are advantageously welded to provide relatively smooth surfaces which do not trap granular material. The inside surfaces of the bottom and side walls, and if desired, the top wall, may be coated with an inert material, e.g., a food grade epoxy coating. Such a coating may prevent the interior surfaces from corroding and reacting with the granular material.
The back wall 26 is formed by two doors 32 and 33 which are hingedly connected to the sides of the body. Each door can be releasably locked closed by one or two conventional locking bars 34 which are rotatably mounted on the door and which extend between latches on the top and bottom walls. Each locking bar is rotatable between locking and unlocking positions by a handle 35.
In the embodiment illustrated in
A generally L-shaped baffle wall 42 is secured to the inside of the door 32 at the bottom of the door, and a generally L-shaped baffle wall 43 is secured to the inside of the door 33. Referring to
The baffle 42 is provided with an opening 48 which forms part of the outlet opening 37 in the door 32, and the baffle 43 is provided with an opening 49 which forms part of the outlet opening 38 in the door 33. Two generally triangular side gusset plates 51 and 52 are welded to each baffle on opposite sides of the opening, and a bottom generally triangular gusset plate 53 is welded to each baffle below the opening. The gusset plates assist in guiding and funneling granular material to the openings in the baffles during unloading. Additional guiding and funneling is provided by an upwardly and rearwardly inclined plate 55 which is welded to the bottom wall and which mates with the bottom edges of the baffles when the doors 32 and 33 are closed.
As can be seen in
A housing 66 (
Referring again to
The conduit can be opened and closed by a disc valve 73 within the conduit which is secured to a shaft 74. The shaft is rotatably mounted in the conduit and is rotatable by a handle 75 on the upper end of the shaft. A spring-loaded latch 76 on the handle releasably locks the handle and valve in the open (
The valve compartments in the housings 57 and 66 can be covered by a pair of doors 80 and 81 which are hingedly attached to the sides of each compartment. A latch 82 on one of the doors is engage able with a catch on the other door for latching the doors closed as shown in
A handle 94 is pivotally mounted on the door by a pin 95. The handle is releasably latched by a handle lock 96. When the handle is withdrawn from the handle lock, the locking bar can be rotated by the handle to rotate the lock bar levers 90 and 91 out of engagement with lever stops 92 and 93 to permit the door to be opened. A gasket 97 (
Referring to
Referring to
The inside surface of the cover 104 is advantageously coated with the same epoxy material as the inside surfaces of the container.
In the preferred embodiment the inlet opening 103 is provided near the top of one of the doors 32 and 33. However, the inlet opening could also be provided in the front wall, side walls, or top wall of the container.
Referring to
When the container is filled, the inlet opening 103 is closed, and the container is transported or shipped to its destination.
The container is unloaded by opening the doors of one or both of the outlet openings 37 and 38 and opening the valves for the outlet openings. If desired, a flexible hose 116 (
Unloading the container can be further assisted by gravity by lifting the front end of the container as shown in
After the container is emptied, the container can be used as a conventional shipping container to ship bulk products, for example, molded plastic products which are made at the site to which the granular material is delivered. The container is loaded by opening the rear doors 32 and 33.
Other embodiments of the container are illustrated in
Referring to
The baffle plate 131 extends upwardly and rearwardly from the bottom wall of the trailer. The baffle plate 132 extends rearwardly and laterally inwardly from one of the side walls of the trailer. The baffle plate 133 extends rearwardly from the center of the trailer and toward the baffle plate 132. The baffle plates 134 and 135 extend rearwardly and upwardly from the top edge of the baffle plates 132 and 133, respectively. Each of the baffle plates is advantageously formed from ½ inch steel plate Each outlet opening is defined by a rectangular border 136 which is formed by four 3 inch by 3 inch angle irons 137 (
A plastic sleeve, tube, or conduit 141 is secured within the channel 139 by an industrial size zip strip 142. Referring to
When the trailer is being transported, the tube can be tied closed by a drawstring 145 (
The trailer can also be unloaded by a pneumatic or vacuum discharge method as illustrated in
The currently preferred embodiment of the inventor uses the flexible sleeve 141 for unloading the trailer rather than the valve assemblies 59 and 67 which are illustrated in
A loading port or inlet opening 167 is provided in the front of the container. A hinged cover 168 closes the opening.
The 20 foot container with front design has the same structure as the rear door design except it is affixed to the front of the container. Through the use of a front mounted L-shaped baffle and load/unload portals no stress is placed on the rear hinged doors when the container is tilted for gravity discharge. In addition, standard 20 foot containers are constructed in a manner that permits a reverse mount on a wheeled chassis which permits product delivery options to customers requiring gravity unloading.
A standard 40 foot container has a “front” protrusion or goose neck which acts as a locking device when the container is mounted on a chassis. This protrusion prevents a 40 foot container from being reverse mounted on a chassis. The goose neck is not present on a 20 foot container, so a 20 foot container may be reverse mounted on the chassis for movement and delivery to a customer. The cost to modify a front mounted 20 foot container chassis is less than a 40 foot container with modifications attached to the hinged doors. Not only is a cost saving present in the front “build out” of a 20 foot container, but maintenance cost is also reduced. The front hopper is somewhat larger, which permits a greater depth, allowing a greater product flow and reduced product residue in the container. The product residue for plastic granules may be only 2 or 3 pounds.
The front loading/unloading modification can be used on with 20 foot or 40 foot containers. Also, the unloading port could be in the front of the container and the loading port in the rear of the container.
While in the foregoing specification a detailed description of specific embodiments was set forth for the purpose of illustration, it will be understood that many of the details described herein can be varied considerably by those skilled in the art without departing from the spirit and scope of the invention.