CROSS-REFERENCES TO RELATED APPLICATIONS
- STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/519,253, filed Nov. 13, 2003, the entire content of which is herein incorporated by reference.
- BACKGROUND OF THE INVENTION
The present invention relates to a plastic container and, more particularly, to a plastic container including a hinge assembly with a substantially straight plastic hinge pin suitable for automated assembly.
Attempts have been made to automate the assembly of plastic containers including lids and the like, but problems have arisen that prevent cost-efficient automation. For example, hinge pins are typically formed of aluminum or other metal material for its strength characteristics to prevent the hinge from being broken into. In order to secure such pins in place, a bend is typically formed at an end thereof after insertion. It is considerably expensive if not impossible to automate the process of bending the hinge pins after installation into the hinge. Using a straight hinge pin could solve the problem, but then it becomes difficult to prevent the pin from working its way out with extended use or possibly being removed in an attempt to break into the container.
- BRIEF SUMMARY OF THE INVENTION
Plastic hinge pins have been proposed, but it becomes difficult to secure the pin in the hinge. Moreover, plastic hinge pins may be subject to tampering, thereby making it easier to break into a container. In some cases the lids are attached using a C-clip connection by snapping the lid onto a molded pin on the container. This type of connection does not provide an adequate security level since the lid can be removed easily, even if a wire tie is used. Also, the lid can become separated from the container during transport or use.
It is therefore an object of the invention to provide a container including a hinge assembly using a plastic hinge pin that is suitable for automation while overcoming the drawbacks associated with prior attempts. The proposed design uses both a strong and secure snap fit for the hinge pin, which provides an initial engagement between the lid and the container body and a relatively short plastic hinge pin that secures the lid to the container. The initial attachment of the lid to the container can be automated using a clamping device, and the installation of the substantially straight hinge pin can also be automated using a nail gun type or magazine type assembly device or the like. Both the clamping device and the pin insertion device can be incorporated into one assembly machine.
In an exemplary embodiment of the invention, a container includes a container body including side walls, and at least one lid pivotably attached to a corresponding at least one of the side walls via a hinge assembly. The hinge assembly includes a hinge pin having a head and a shaft, wherein the hinge pin is formed of a plastic material, and wherein the hinge pin head has a maximum diameter substantially matching a maximum diameter of the shaft. The container body, the at least one lid, and the hinge assembly are preferably formed of a plastic material, for example, of molded plastic materials. In one arrangement, the hinge pin is constructed to be tamper-evident. For example, the hinge pin may be formed of a plastic material that is differently colored from the plastic material of the hinge assembly.
The at least one side wall may include a first hinge pin receiving channel, wherein the at least one lid may include a second hinge pin receiving channel. The first and second hinge pin receiving channels are aligned to receive the hinge pin when the lid is attached to the side wall. In this context, the at least one side wall may include a pair of spaced first hinge pin receiving channels, with the second hinge pin receiving channel being fit between the first hinge pin receiving channels when the lid is attached to the side wall.
In a preferred arrangement, the hinge assembly receives the hinge pin in a snap fit. In this context, the hinge pin shaft may have a reduced diameter adjacent the hinge pin head. Additionally, the hinge pin head preferably tapers inward toward a head tip.
In another exemplary embodiment of the invention, a container formed entirely of molded plastic materials includes a container body and a lid secured to the container body via a hinge assembly, wherein the hinge assembly includes a hinge pin having a head and a shaft, and wherein the hinge pin head has a maximum diameter substantially matching a maximum diameter of the shaft. The container may be assembled in an automated two-step process, where the steps include (1) using a clamping device for an initial attachment of the lid to the container body, and (2) inserting the hinge pin into the hinge assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
In yet another exemplary embodiment of the invention, a plastic hinge assembly is provided for pivotably attaching a first member to a second member. The hinge assembly includes a first hinge pin receiving channel on the first member, and a second hinge pin receiving channel on the second member. The first and second hinge pin receiving channels are aligned when the first member is attached to the second member. A hinge pin having a head and a shaft is insertable through the aligned first and second hinge pin receiving channels. The hinge pin head has a maximum diameter substantially matching a maximum diameter of the shaft.
These and other aspects and advantages of the present invention will be described in detail with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of an exemplary container of the present invention;
FIG. 2 is an assembly drawing illustrating the hinge assembly of the present invention; and
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2A is a close-up view of the hinge pin shaft and head.
The container illustrated in FIG. 1 is exemplary as many other container configurations may benefit from the subject matter of the present invention. Additionally, the hinge assembly and the manner of securing the lid(s) to the container body is also exemplary. The invention is not necessarily meant to be limited to the container and hinge assembly shown in the drawings.
The container 10 in FIG. 1 includes a main body portion 12 formed by a bottom, side walls and end walls. A pair of complementary shaped lid members 14 are secured via a hinge assembly 16 to an uppermost surface of the side walls as shown. With the exemplary container shown in FIG. 1, in a closed position, the lid members 14 cooperate to close the container 10. Of course, the container 12 may alternatively include a single lid member or even additional lid members.
With continued reference to FIG. 1 and with reference to FIG. 2, the hinge assembly 16 is preferably formed entirely of molded plastic materials including a plastic hinge pin 18. Each lid member 14 includes a series of hinge members including a support portion 20 molded integrally with the lid 14 and a pair of generally cylindrical pegs 22 extending from the support portion 20, the pegs and support portion being constructed generally in a “rolling pin” shape. The support portion 20 may alternatively have a cylindrical, square, rectangular or other shaped cross section depending on a desired appearance for the assembled container.
Corresponding hinge receiving sections 24 of the hinge assembly 16 are formed integral with the container side walls. The hinge receiving sections 24 define a plurality of snap receptacles 26 that receive the cylindrical pegs 22 of the hinge members on the lid 14 in a snap fit.
The lid members 14 also include a hinge pin receiving channel 28 at outside ends of the lid members 14. Each hinge pin receiving channel 28 is disposed adjacent at least one corresponding channel 30 formed on the top portion of the container side walls. In a preferred arrangement shown in FIG. 2, a pair of hinge pin receiving channels 30 are provided on the container side wall in a spaced configuration such that the pin receiving channel 28 on the lid 14 is fit between the pair of corresponding channels 30 on the container body 12.
When the lid hinge members 20, 22 are snapped into engagement with the hinge receiving sections 24 on the container side walls, the hinge pin receiving channel 28 of the lid is aligned with the corresponding channels 30 on the container side walls, thereby defining a hinge pin receiving chamber. The plastic hinge pin 18 is inserted into each hinge pin receiving chamber to secure the lids 14 in place.
To facilitate automation of the assembly process, the hinge pin head 18A has a maximum diameter substantially matching a maximum diameter of the hinge pin shaft 18B (see FIG. 2A) The hinge pin shaft 18B has a reduced diameter adjacent the hinge pin head 18A. With this construction, the hinge assembly 16 receives the hinge pin 18 in a snap fit. That is, the hinge pin receiving channel 30 on the container side wall includes a plastic opening having a width generally corresponding to the reduced diameter section of the hinge pin shaft 18B. The hinge pin head 18A tapers slightly inward toward the head tip as shown in FIG. 2A, and as the hinge pin 18 is pushed into the opening of the hinge pin receiving channel 30, the hinge pin head 18A deflects the plastic opening, and the hinge pin receiving channel 30 receives the hinge pin 18 in a snap engagement surrounding the reduced diameter area of the hinge pin shaft 18B.
When the lidded container is sealed using a wire tie or other tamper-evident seal, the lid 14 cannot be removed from the container without breaking the plastic hinge pin 18 or the lid 14 itself. The design of the hinge assembly 16 makes it very difficult to remove the hinge pin 18, and subsequently the lid 14, in a short time period and without leaving any evidence. Additionally, in one arrangement, the hinge pin 18 can be manufactured in a specific color, different from the color of the container and lid, thereby making it easy to see if the pin 18 has been removed. Moreover, the unique design and size of the hinge pin 18 make it difficult for anyone tampering with the lid attachment to replace a damaged pin, since the pin 18 is not readily available in the marketplace.
As noted, the assembled product is preferably made of 100% plastic material, thereby making it simple and cost-effective to recycle the product. Manufacture and assembly of the container are also facilitated. Assembly can be automated using a two-step process, wherein the initial attachment of the lid 14 to the container body 12 can be automated using a clamping device, and the installation of the substantially straight hinge pin 18 can be automated using a nail gun or magazine type assembly device or the like. Both the clamping device and the pin insertion device can be incorporated into a single assembly machine.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.