Patent Application
20080251968
The present invention relates to waste and recycling containers, and more particularly to waste and recycling containers including radio frequency identification (RFID) devices.
With increasing frequency, waste and recycling containers are being equipped with radio frequency identification (RFID) devices. An RFID device enables the container to be uniquely identified or associated with a customer or pick-up address. The RFID device typically is read during emptying of the container by an RFID reader within the equipment for lifting and/or weighing the container. Where charges are based on the weight of the waste (or where rebates, rewards, or other benefits are provided based on the weight of the recyclable materials), the RFID device enables weight information to be accurately associated with a customer or a pick-up address to enable accurate and reliable customer billing.
One way of equipping a plastic waste container with an RFID device is to mold the device into the body (e.g. the sidewall) of the container. One example of this approach, described in U.S. Pat. No. 6,302,461, includes encapsulating an RFID device in a protective shell, and molding the protective shell into the sidewall of a plastic waste container. Unfortunately, attempts at implementing this approach have been unsuccessful and at best inconsistent because of the temperatures and pressures associated with injection molding. Even when the device is encapsulated in a protective shell, the heat and pressure of plastic flowing over the shell can render the device inoperable. The container therefore becomes unusable. As a result, manufacturers continue to search for an apparatus and method for securely and consistently attaching an RFID device to a plastic waste container.
The aforementioned problems are overcome by the present invention wherein an RFID device is protectively enclosed in a case that is designed to be incorporated into a waste/recycling container in structure and processes that reduce potential harm to the RFID device.
In one embodiment, the case is relatively flat and includes relatively large front and rear surfaces. The surfaces define a wedge shape for the case in cross section. The RFID device is protectively enclosed within the case to withstand in-molding as described below. In a second embodiment, the waste container includes the in-molded case. At least a portion of both the front surface and the rear surface are not covered by plastic, so that the case is protected from the pressures and temperatures of the injection molding process.
In another embodiment, the present invention is directed to a method for manufacturing a waste/recycling container with an RFID device, including the steps of: a) placing an RFID device in a case, the case having a front surface and a rear surface that combine to form a wedge shape; b) providing a mold having a mold surface and a pocket defined in the mold surface, the pocket having at least two walls that converge to form a wedge shape corresponding to the wedge shape of the case; c) placing the case in said pocket, such that a substantial portion of the front and rear surfaces of the case engage the converging walls of the pocket and other portions of the case are exposed; d) injecting a thermoplastic onto the mold surface and over the pocket, the thermoplastic contacting only the exposed portions of the case; e) curing the thermoplastic so the case is securely attached to the cured thermoplastic; and f) removing the molded article from the mold.
In another embodiment, the case is also designed to snap-fit to a portion of a waste/recycling container. The case may include first and second longitudinal ends, a first attachment mechanism on the first end, and a second attachment mechanism on the second end. The first mechanism is adapted to interfit with a first attachment portion on a container, and the second mechanism is adapted to interfit with a second attachment portion on a second rib on the container. The case may snap-fit to a container that already has an in-molded case, for instance, when the in-molded case has failed, or the case may snap-fit to a container that does not include a case.
The present invention enables attachment of an RFID device to a waste/recycling container without destroying the functionality of the device during the attachment process. The wedge shape of the case and corresponding wedge shape of the mold pocket enables a secure fit within the mold that prevents the flow of plastic over the front and rear surfaces of the case—protecting the RFID device from the heat and pressure of the molten thermoplastic. The protrusions on the case further enable retrofitting of the case to containers with or without an in-molded case.
These and other objects, advantages, and features of the invention will be fully understood and appreciated by reference to the description of the current embodiment and the drawings.
I. Overview
An RFID hard case according to one embodiment of the present invention is shown in
II. Structure
The case 10 is typically injection molded plastic, but may be formed from a variety of materials. In one embodiment, the case 10 includes a first half 14 and a second half 16. The halves 14 and 16 are generally identical and include interior surfaces 18, 20 respectively that each define a cavity 22. In one embodiment, the interior surfaces 18, 20 can be connected together by a conventional method, such as sonic welding or an adhesive, to enclose an RFID device 24.
The assembled case 10 includes a front surface 26, a rear surface 28 opposite the front surface 26, an upper edge 30, a lower edge 32, and first and second longitudinal edges 34, 36. The front 26 and rear 28 surfaces may each include a peripheral portion 29, and a central portion 31. In one embodiment, the peripheral portion 29 extends along the first and second longitudinal edges 34, 36 and the upper edge 30. In one embodiment, the central portion 31 is a portion of the front 26 and rear 28 surfaces that protrudes outwardly from the peripheral portion 29. In the illustrated embodiment, an upper side 33 of the central portion 31 protrudes outwardly a greater distance than a lower side 35, such that the case 10 has a wedge shaped cross-section.
In one embodiment, each longitudinal edge 34, 36 includes a protrusion 38 extending outwardly therefrom. The protrusion 38 may include an upper surface 40 and a lower surface 42, and in one embodiment the upper surface 40 has a rounded shape. As described below, the rounded shape of the upper surface 40 enables the case 10 to be snap-fitted to a portion of the container 12. As shown in
In one embodiment, the RFID device 24 is a conventional RFID label. The RFID label is disposed between the cavities 22 of the two case halves 14, 16. In the illustrated embodiment, shown in
Referring now to
In one embodiment, shown in
III. Mold
In an alternative embodiment, the mold may be configured so that one of the mold halves includes a portion that contacts the front surface 26 of the case 10, and the other mold half includes a portion that contacts the rear surface 28 of the case 10. In this embodiment, the mold halves form a “pocket” that contacts the front 26 and rear 28 surfaces of the case 10 when the mold is closed. In another embodiment, the mold may include one or more slides that can be moved into position to contact the front 26 and/or rear 28 surfaces of the case 10, or other desired portions of the case 10 to prevent plastic from flowing over those portions of the case 10.
IV. Method of Manufacture
In one embodiment, the case 10 is manufactured by injection molding. Each of the halves 14, 16 of the case may be injection molded separately, and then the interior surfaces 18, 20 of the halves may be attached together by a conventional method, such as sonic welding or an adhesive, with the RFID device 24 disposed between them. In one embodiment, the RFID label is sized so that it fits loosely within the case 10. The 10 case may be attached to the waste/recycling container 12 by in-molding, snap-fitting or with fasteners.
In one embodiment, the case 10 is in-molded into the waste/recycling container 12 by placing the case 10 in the pocket 104 in the mold 100, such that the front 26 and rear 28 surfaces of the case 10 engage and contact the walls 108, 110 of the pocket 104. After the case 10 is placed in the pocket 104, a molten thermoplastic is injected over the mold surface 102, such that it flows over the pocket 104 and the exposed portions of the case 10, including the peripheral portion 29. Due to the engagement of the case 10 with the pocket 104, the central portion 31 of the front 26 and rear 28 surfaces of the case 10 does not contact the molten thermoplastic. The upper mold portion 106 may be lowered or otherwise moved into place above the mold surface 102 to form the thermoplastic into the desired shape of the container 12. After the thermoplastic has been formed and cooled (or in some cases during the cooling process), the container 12, including the in-molded case 10, can be removed from the mold 100.
In another embodiment, the case 10 is snap-fitted to the container 12 by snapping each of the protrusions 38 into the holes 76 in the support ribs 74. In yet another embodiment, the case 10 may be attached to a surface of the container 12 with fasteners, such as rivets, that extend through the holes 44, 46 in the case 10 and into the container 12. As described above, a case 10 may be snap-fitted or fastened to a container 12 that includes an in-molded case 10, or to a container that previously did not include a case 10.
The above description is that of the current embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.
