The field of the invention is air transportation of fluid in cans.
When plastic containers for fluids such as paint cans are shipped by air, they must have a device attached to the lid to prevent the lower atmospheric pressure at high altitude from causing the can to lose its seal on account of the higher pressure of air trapped above the fluid at the top of the inside of the can. That is, these containers are filled in facilities located at altitudes much closer to sea level than the high altitudes in which air cargo travels. When these cans are filled there is a small amount of air trapped between the top of the paint or fluid and lid of the container. For example, at sea level, the atmospheric pressure of the trapped air is approximately 14.7 lbs per square inch, and the air pressure trapped under the lid and the air pressure outside the lid in the environment are roughly equivalent. On the other hand, atmospheric pressure at an altitude of 30,000 feet is approximately 4.4 lbs per square inch so that, when paint is transmitted by air at these higher altitudes, there exists a risk of losing the seal from the much greater pressure of air trapped inside the container. Government regulations and common sense require that containers in this setting be protected from loss of seal by means of a physical device attached to the container. Although rings for mounting on the tops of containers have existed, they have been either ineffective at preventing loss of seal or their configurations have made installation haphazard or unwieldy.
The efficacy and value of the present invention is a function not only of the actual locking means, but also of the utility of applying the ring from the lid and rim of a can.
What is disclosed is an improved locking ring which holds securely and is easier to apply from the container's rim and lid, on account of the unique structures provided. The invention will not only contain the lid and eliminate the potential for the container to burst open but, if the seal between the lid and rim were lost, the invention would also contain the fluid inside the container.
The container to which the locking ring may be applied may be of any shape including, without limitation, a cylinder, a rectangular prism, a substantially rectangular prism (including one which is tapered for nesting when empty), and the locking ring conforms to the shape of the container, as described herein. Herein, the term “ring” can therefore denote any shape which is circular or not circular including, without limitation, rectangular or rectangular with rounded corners.
The invention comprises a plastic locking ring 1 comprising a channel 2 which is pressed down onto a container so that the rim A and lid B of the container are locked in a closed position. The can and rim are not part of the present invention but are shown for illustrative purposes in U.S. Pat. No. 8,985,383 disclosing a can, and said patent is expressly incorporated in its entirety herein for illustrative purposes regarding an example of a container configuration for which the present invention may be used. The present invention may be used on any other container which has a lip created by an outermost portion D of a rim seated on a can sidewall, wherein the rim's outermost portion D has a diameter (for a cylindrical container) or width (for a non-cylindrical container) which is slightly larger than the diameter or width of the sidewall of the container.
In one embodiment, the present invention comprises a channel 2 comprising, on its top side (which is closest to the arrow pointing from element number 1 on
Other embodiments of the invention are optimized for movement by the locking ring during installation and also during the movement of the lid B when the pressure of air trapped inside the container is higher than the atmospheric pressure, as indicated by the arrows pointing upward in
In another embodiment, the channel comprises an inner wall radius 8 which eases installation of the ring. In this embodiment, the inner wall 3 and the ceiling 4 are integral at a first ceiling radius 9. Also, in this embodiment, the ceiling 4 and the outer wall 5 are integral at a second ceiling radius 10. The outer wall 5 is integral to the sealing ridge 6, and the sealing ridge rises in a first slope 14 from a first point 11 to an apex 13, where the sealing ridge 6 descends in a second slope 15 to a second point 12 where the guide 7 is integral to the sealing ridge 6. The shapes and particular structures of the channel are variable, especially to fit the geometry of different containers, as long as there is an outermost portion D of a rim A which has a diameter or width slightly larger than the container's sidewalls.
For a container substantially in the shape of a rectangular prism (including a rectangular prism with rounded corners) and comprising a rim and lid and having a horizontal cross-section (i.e., parallel to the bottom of the container) which is substantially rectangular (including for example a rectangle with rounded corners), in one embodiment the locking ring 1 in one embodiment has a channel similar to that depicted as channel 2 for the cylindrical container and with structures on the bottom side of the channel similar to those shown in
In one embodiment, the invention is a locking ring for a plastic container for fluid, said locking ring having a shape of a horizontal cross-section of the container, said locking ring comprising a U-shaped channel for receiving a rim and a lid of the container, said U-shaped channel comprising an inner wall and an outer wall, said outer wall being integral to a sealing ridge and said sealing ridge being integral to a guide, so that when the sealing ridge and guide are positioned in a pre-installed position adjacent to the rim then the locking ring may be pressed to an installed position in which the sealing ridge contacts a sidewall of the container and an outermost portion of the rim. The locking ring in an installed position, when atmospheric pressure is less than air pressure inside the container and the lid is forced upward to a loaded position, the sealing ridge presses against the outermost portion of the rim and holds the lid in place. In different embodiments, the shape of the horizontal cross-section (i.e., parallel to the bottom or the top) of the container may be circular, rectangular, rectangular with rounded corners, or any other shape, and so the shape of the locking ring will correspond to the shape of the cross-section of the container. Further, in embodiments in which the container is tapered to allow for nesting of the empty containers, the cross-section of the container to which the shape of the locking ring will correspond will be at the top of the container, that is, the portion of the container on which the rim is located, and which is sized to correspond to the dimensions of the locking ring.