Patent Publication Number: US-6698058-B2

Title: Stand up dustpan

Description:
This application claims the benefit of provisional application No. 60/260,055 filed Jan. 6, 2001. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a dust collecting apparatus generally known as a dustpan, and more particularly to a dustpan that retains its contents while in a self-supporting upright storage position. 
     1. Background of the Invention 
     The use of dustpans to pick up dirt and debris is well known. Many prior art designs exist. These may be one piece or multiple piece constructions, employ metallic or molded materials, and show numerous ornamental variations. The most popular and generally accepted design in widespread use consists of a shallow pan with an open lip at one end, and an elongated handle or grip attached to the opposite end. This handle extends outward from the pan in a direction more or less perpendicular to the lip, thus providing a handy and convenient means for manipulating the dustpan. This design, however, cannot be stored upright without spilling most or all of its contents, and is thus impractical and messy to store unless another receptacle is immediately at hand to receive the dustpan&#39;s contents. Therefore, a dustpan design that could be stored upright without spilling or emptying its contents, but is nevertheless similar to generally accepted designs, would be a useful and novel invention. 
     2. Description of Prior Art 
     U.S. Pat. No. 4,631,774 discloses a dust collecting apparatus that is standable or self-supporting in a storage position. However, this dustpan cannot hold dust or debris in its storage position because the open lip is downward, and thus, any contents will spill out. In addition, the user may not recognize the flat shallow flap that is intended for use as a handle or grip. 
     U.S. Pat. No. 3,170,183 discloses a wastebasket with a lip along one top edge and one or two handle slots in the opposite wall. Though this device holds dirt and debris in its upright storage position, it does not have the elongated handle or grip that readily identifies it to the user as a dustpan. 
     U.S. Pat. No. Des. 351,699 discloses a trash collection container with an extended lip. As in the previous example, this device does not have the elongated handle or grip that readily identifies it to the user as a dustpan. In addition, it appears to have a separate removable top more characteristic of a trash container than a dustpan. 
     U.S. Pat. No. Des. 383,002 discloses a combined brush, dustpan, and waste can wherein the waste can has a flat lip characteristic of a dustpan, and will hold dust and debris in an upright storage position. However, the waste can component again does not have the recognizable elongated handle or grip of most dustpans, nor does the dustpan component. Instead the user must hold onto a flared top edge opposite the lip that is parallel rather than perpendicular to the lip. In addition, dust and debris can spill out of the dustpan component of this device because it does not have a flat and stable base. It must be stored in a nested position within its corresponding wastebasket to hold dust and debris without spilling. 
     Illustrated in PRIOR ART FIG. 1A is the DustBuCan, a molded product made in Brazil by Plasutil and distributed in the U.S. by Kaminstein Imports. It is describe on its product label as a combination dustpan, bucket, and trashcan. Though it can hold dust and debris in its upright storage position, it again does not have the elongated grip or handle that readily identifies it as a dustpan. Instead it has a handle hole in the top edge opposite the lip that is parallel to the lip. 
     Illustrated in PRIOR ART FIG. 1B is a dustpan manufactured by Rubbermaid Inc. of Wooster, Ohio. Though it has a receptacle to hold dust and debris, the end of its handle extends so far beyond the end of its receptacle that it is not self supporting in an upright storage position. Instead it tips over towards its lip, spilling most of its contents. 
     SUMMARY OF THE INVENTION 
     The principle object of my invention is to provide a novel, useful, simple, and recognizable dustpan that stores a generous amount of contents in an upright storage position, thus overcoming the above enumerated deficiencies in known prior art. 
     My invention employs the use of a dustpan shape of the type having a lip at one end and an elongated handle or grip extending outward from the opposite end in a direction more or less perpendicular to the lip. The handle extends away from the perimeter edge of the receptacle in a direction perpendicular to the lip and is unsupported at its far end. However, instead of the shallow pan generally characteristic of prior art of this type, my invention shows an enlarged and elongated dust receptacle extending under the handle or grip to a distance at least as far as the end of the aforementioned handle. This receptacle is tapered for ease of removal from a molding die, and has a more or less flat end wall at nearly a right angle to its bottom wall, such that it stabilizes and holds the dustpan in its upright storage position with the lip upward and the handle downward. A preferred embodiment shows the handle end and the far corners of the receptacle end wall forming a stable tripod base for its upright storage position. Alternatively, the receptacle end wall may extend well beyond the handle, as long as it is flat enough and correctly angled to provide a stable base for upright storage. 
     It is a further object of my invention to provide a dustpan that is attractive, inexpensive, stackable, washable, sturdy, and easily injection moldable in a shape without restrictions requiring mechanical side actions in the molding die. Dies without side actions are less expensive to fabricate and maintain, and more readily permit the resulting molded shapes to be nested economically for inventory, shipping and display. 
     Another object of my invention is to provide a novel means of molding a shallow curved lip without requiring a curved parting line in that portion of the molding die. The advantage of a shallow curved lip is that it allows the user to maintain pressure against the floor without having the lip distort upward and allow dirt to be swept underneath. The advantage of die parting lines that are not curved is that they are less expensive to fabricate and maintain. 
    
    
     These and additional objects of my invention will be apparent upon studying the following detailed description and accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a perspective view of prior art; 
     FIG. 1B is a perspective view of prior art; 
     FIG. 1 is a top left front perspective view of my invention; 
     FIG. 2 is a bottom left back perspective view thereof; 
     FIG. 3 is a top view thereof, 
     FIG. 4 is a left side view thereof, the right side view being a mirror image; 
     FIG. 5 is a bottom view thereof; 
     FIG. 6 is a cross-sectional view along the lines  6 — 6  of FIG. 3; 
     FIG. 7 is a front view thereof; and, 
     FIG. 8 is a back view of my invention. 
     FIG. 9 is a perspective view of an alternative embodiment of my invention. 
     REFERENCE NUMERALS USED IN DRAWINGS 
       20  lip 
       21  lip, central portion 
       22  receptacle 
       24  receptacle bottom 
       26  receptacle bottom, portion adjacent to lip 
       28  receptacle bottom, central portion 
       30  receptacle bottom, portion furthest from lip 
       32  receptacle top 
       34  receptacle left side 
       36  receptacle right side 
       38  receptacle flange 
       40  receptacle end wall 
       42  left corner of receptacle end wall 
       43  right corner of receptacle end wall 
       44  handle 
       46  handle end towards lip 
       48  handle far end 
       50  handle top 
       52  handle left side 
       54  handle right side 
       56  die parting line plane 
       58  parabolic intersection line 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring to FIG.  1  through FIG. 8, the dustpan according to my invention generally includes a lip  20 , a receptacle  22 , and a handle  44 . The receptacle has a floor or bottom  24  connecting the lip  20  to a receptacle end wall  40 . The receptacle has a top  32  that arches over the bottom from a left side  34  to a right side  36 . The top  32 , bottom  24 , sides  34 ,  36 , and end wall  40  thus described, form an open-top receptacle. Preferably the top  32  and sides  34 , 36  form a continuous arch over the bottom, and thus, viewed from the front, a generally D-shaped opening is seen. However, this is not the only shape that will provide benefits according to my invention. For example, the curvature of the sides and top can be varied to form a more triangular or more rectangular opening. Furthermore, it is not necessary that the shape be symmetrical. To aid removal from a molding die the receptacle  22  thus formed is preferably tapered or reduced in size towards the receptacle end wall  40  with a draft angle of between three and seven degrees, though embodiments of my invention can employ other draft angles. 
     Viewed from either side, the open top of the receptacle angles acutely back from the lip  20  towards the end wall  40 , preferably at an angle of between thirty-five and fifty degrees, though other acute angles may be used. Alternatively the opening may be curved as viewed from the sides, though molding dies with curved parting lines are more expensive to make and maintain. The handle  44  is positioned more or less perpendicular to the dustpan lip  20 , this being the orientation most commonly seen and recognized for its superior functionality in use. More specifically, the handle end  46  towards the lip attaches centrally to that portion of the receptacle top  32  nearest the lip. The handle far end  48  is unsupported and extends away from the receptacle  22  in a direction more or less perpendicular to the lip  20 . Viewed from the top, the acutely angled sides  34 ,  36  combine with the perpendicularly attached handle  44  to form generally a Y-shape, with the closed end of the receptacle extending underneath the handle. 
     Preferably a narrow flange  38  around the receptacle top  32  connects the handle top  50  to the ends of the lip  20 , acting as a stiffening member. Short handle sides  52 ,  54  extend downward from the handle top  50  to the receptacle top  32 , also acting as stiffening members. The size of these stiffening members may vary, depending on the size and wall thickness of my dustpan. Preferably the whole dustpan is injection molded of thermoplastic resin between 0.060 and 0.120 inches thick, but other materials and thickness dimensions can be employed, and uniform thickness is not a requirement. 
     In operation the dustpan is generally similar to most prior art. With one hand the user picks up the dustpan by its handle  44  and lightly presses it to the floor or similar surface to be cleaned of dirt and debris. With the other hand he uses a brush, broom or similar device to sweep dirt and debris over the lip  20  and into the receptacle  22 . However, in storage the dustpan differs from prior art in that it can be stored upright without emptying the receptacle of its contents. The user merely rotates the dustpan lip upward by rotating his wrist accordingly, and stands the dustpan on its receptacle end wall. In its preferred embodiment the receptacle end wall  40  is curved so that its far corners  42 ,  43  and the handle far end  48  form a stable tripod base for the dustpan&#39;s upright storage position. The planar surface defined by the handle end  48  and corners of the receptacle end wall  40  is more or less perpendicular to receptacle bottom  24 , in order that the center of gravity of the dustpan and its contents be positioned within these three tripod points. This keeps the dustpan from tipping over. Alternatively, the receptacle end wall may extend significantly beyond the handle far end, as long as it is angled such that the center of gravity of the dustpan and its contents is more or less centered on the end wall when stored in its upright position. An example of this alternative embodiment of my invention is illustrated in FIG.  9 . 
     In its preferred embodiment the dustpan lip  20  has a slight convex curve so that its center  21  touches the floor first, and slight pressure by the user then brings the rest of the lip against the floor. This helps prevent dust and debris from being swept under the receptacle bottom  24 . The portion  30  of the receptacle bottom furthest from the lip has a slight concave curve so that the corners of the receptacle end wall  42 ,  43  act as feet or supports that ensure that in use the center of the dustpan lip always touches the floor first. 
     To help strengthen and stiffen the relatively flat receptacle bottom  24 , the convex curve of dustpan lip  20  described above continues across a portion of the receptacle bottom adjacent to the lip  26 , and further across a central portion of the receptacle bottom  28 . Geometrically, this central portion of the receptacle bottom  28  is thus the partial section of the surface of a cylinder. Geometrically, the concave curve on the portion of the receptacle bottom furthest from the lip  30  is also a partial section of the surface of a cylinder, in this case curved in the opposite direction. In side view the centerlines of these two cylinders are angled obtusely apart, preferably two to three degrees, so that a parabolic intersection line  58  appears more or less centrally located on the receptacle bottom  24  where the cylindrical surface sections meet. 
     As described above, a curved lip is advantageous in that it helps prevent sweepings from going underneath a dustpan. Since most molded thermoplastic resin parts tend to warp or shrink inward after they are removed from their molding dies, a curved lip is also advantageous on a molded dustpan because, if enough curvature is built into the die, the molded lip can warp inward considerably yet still retain its preferred convex curve. However, the curved die parting lines required to mold curved dustpan lips are more expensive to fabricate and maintain than straight or planar die parting lines. 
     My dustpan teaches a novel way to mold a convex curved lip without requiring a corresponding curved die parting line. Essentially, it is based on the fact that passing a plane through a cylinder at an angle produces an elliptical cross-section. Thus, if a straight or planar die parting line  56  passes at an angle through that portion of the receptacle bottom  24  that has a convex curve, the resulting cross-section can produce the lip curvature required to help prevent sweepings from going underneath a dustpan, yet not require a corresponding curved die parting line. Preferably this requires an acute angle between the die parting line plane  56  and the central portion of the receptacle bottom  28  of between twenty and forty five degrees, combined with a convex receptacle bottom curvature radius of between thirty and sixty inches. Though molding considerations favor these dimensions, embodiments of the invention can employ other dimensions as well. 
     The lip  20  can be part of the injection-molded structure, or it can be a separate resilient attachment around a lip structure. For example, a cut segment of an elastomeric extrusion may be separately fit onto the lip. This resilient lip provides a flexible surface that helps keeps the dustpan flush with a rough or uneven floor, and in use further prevents sweepings from going underneath the dust pan. 
     The present invention has now been described in connection with a number of specific embodiments thereof. However, numerous modifications that are contemplated as falling within the scope of the present invention should now be apparent to those skilled in the art.