Patent Application
20170129517
The present invention relates to blow molded waste carts, also referred to as wheeled trashcans, which are substantially constructed of blow-molded polymeric materials. The present invention related specifically to a molded circumferential compression flange on the upper periphery of the cart body.
Blow molding is used to produce generally hollow plastic parts by melting plastic infeed material, forming a parison (a tubular piece of plastic), placing the parison into a mold and blowing air into the parison to force the plastic out to match the mold. The plastic cools and hardens within the mold and the mold is opened and the part is ejected. The main bodies of waste carts have been made by the blow molding process for many years.
The present invention relates to blow-molded waste carts and more specifically to waste carts with a circumferential compression flange. Specifically, the waste cart includes body with four upstanding side walls and corner sections therebetween, a floor, and a circumferential compression flange around the side walls and corner sections is disclosed. The waste cart may also include an axle and wheels mounted to a side wall and a handle assembly with lid also mounted to a side wall. The circumferential compression flange has a generally consistent width and thickness at each of the side walls and corner sections and the lid rim meets the circumferential compression flange when the lid is closed. A method of forming a blow-molded waste cart body is also disclosed. The process includes melting a polymer material to form a parison, enclosing the parison in a main mold, pressurizing the parison within the mold and moving a secondary mold section onto the main mold squeezing the polymer outward to a gap between the secondary mold and main mold to form the circumferential flange.
A more complete appreciation of the invention and the many embodiments thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
The present invention will now be described with occasional reference to the specific embodiments of the invention. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth as used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that may vary depending on the desired properties sought to be obtained in embodiments of the present invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements.
A blow-molded waste cart is shown in
The blow molding process begins melting the polymer material and forming it into a parison. The parison is a polymer sleeve that is clamped into a mold. The mold includes two halves, which are generally referred to as the pin half and the bushing half. The pin half and bushing half are clamped around the parison. Air is then blown into the mold to force the parison against the mold to form the general shape of the cart. The mold includes a secondary (upper or lower) mold section that slides toward the pin half and bushing half. After the initial molding process, the secondary mold section moves to squeeze the polymer of the parison outward to a gap between the additional mold section and the pin half and bushing half. The polymer is forced out to form the circumferential flange. After the waste cart body is formed and the plastic has cooled somewhat, the secondary mold section is removed, the mold is opened and the waste cart is ejected.
The blow-molded cart 10 of the present invention, including a circumferential compression flange 28 is shown in
A top view of blow-molded cart 10 and circumferential compression flange 28 is shown in
The blow-molded cart and circumferential compression flange is shown a detailed perspective view in
The top view of the blow-molded cart of the present invention is shown in greater detail in
The top view of the blow-molded cart of the present invention is shown in greater detail in
The invention of this application has been described above both generically and with regard to specific embodiments. Although the invention has been set forth in what is believed to be the preferred embodiments, a wide variety of alternatives known to those of skill in the art can be selected within the generic disclosure. The invention is not otherwise limited, except for the recitation of the claims set forth below.
| Number | Date | Country | |
|---|---|---|---|
| 62170542 | Jun 2015 | US |
