Abstract:
Clip ( 10 ) for holding lid flaps ( 110 ) of a carton ( 100 ) in an open position against carton walls ( 101 ) to facilitate packing of carton ( 100 ). Clip ( 10 ) includes a horizontal spine ( 20 ) to which are attached a center post ( 30 ), a long prong ( 40 ) a short prong ( 50 ), and a handle tab ( 25 ). To use clip ( 10 ), clip ( 10 ) is positioned with center post ( 30 ) above a corner ( 107 ) of carton ( 100 ) and lowered to insert center post ( 30 ) in interior dihedral angle ( 108 ) of corner ( 107 ). Long prong ( 40 ) contacts a first lid flap ( 110 ) and rotates flap ( 110 ) into the open position. Short prong ( 50 ) contacts a second flap ( 110 ) shortly afterward and rotates second flap ( 110 ) into an open position.

Description:
FIELD OF THE INVENTION 
     This invention relates to a clip for carton lid flaps, and more specifically relates to a reuseable clip without moving parts for holding the lid flaps of packing cartons in an open position and to a method of using the clip. 
     BACKGROUND OF THE INVENTION 
     Cardboard boxes or cartons are ubiquitous in manufacturing companies, retailers who deliver customers&#39; orders, and print shops. The most familiar cardboard carton is a square or rectangular box stamped from a single piece of corrugated cardboard. The cardboard sheet is slit and scored into a shape that can be folded and glued into a cube or rectangular prism with four walls attached to each other and attached flaps to form the bottom and lid. This type of carton is sometimes called a self-closing carton because there is no separate lid. 
     The cartons are usually stored flat and assembled only when needed for filling. The packing operation in a business often assembles as many cartons as will fit on the floor of the packing area and fills the cartons with goods in assembly-line fashion. Often, styrofoam packing material, such as the nuggets called “popcorn,” is dispensed from a hopper via a movable chute into the cartons to protect the goods. 
     To assemble a new carton, the packer pops the flat walls into a cube or rectangle prism. The lid and bottom flaps are scored for folding, but generally each is initially extended coplanar with the wall to which the flap is attached. The packer folds the bottom flaps inward to cover the bottom of the carton and tapes them in place, or secures any other fastening arrangement, such as tabs and slots. 
     The fresh carton is set on the floor on its bottom and made ready for packing. Leaving the lid flaps in the extended position makes loading the carton inconvenient. “Popcorn” must be dispensed from farther away and more is spilled than when it is dispensed directly into the interior of the carton. The extended flaps are rigid and abrasive. People packing cartons frequently cut or scrape their hands, arms, and even faces when bending over the carton. 
     The lid flaps may be folded down from the extended position, but the springiness of the cardboard of a fresh carton prevents the flaps from staying in the fully open position adjacent the outside face of the carton wall. Folded-down flaps usually end up spread outward from the carton walls. The outspread flaps allow fewer cartons to fit on the floor of the packing area and cause the cartons to be arranged less neatly than desired for efficient, fast packing. Flaps of adjacent boxes interfere; picking up or bumping a carton may overturn nearby cartons. 
     Some packers fasten the lid flaps in the open position in some manner. Clips for holding the flaps open are known, but are not in commercial use. Of clips that have been patented, some are awkward to use; some are too bulky to store; and some pose danger to the user. Others are for specialized use or would disfigure the carton, which is unacceptable to most shippers. 
     Some packers put a piece of adhesive tape on each flap to hold it in the open position. This also tends to disfigure the carton and wastes the packer&#39;s time trying to remove the tape carefully. Other packers create chain loops of intertwined rubber bands that can be slipped around the entire perimeter of the carton to hold the flaps. This is a popular and traditional craft on shipping docks, but not really a means for making packing efficient or speedy. The chains fit only a limited range of size of carton and do not last long. 
     Therefore, there has been a need for an easy to use device for helping a person pack or unpack a cardboard carton more efficiently, safely, and quickly. Such a device must be simple to use, convenient to store, and durable. The device must not cause damage to the carton or goods being packed or unpacked. 
     SUMMARY OF THE INVENTION 
     The invention is a clip for holding the lid flaps of a cardboard carton in an open position for convenient and safe packing of the carton. 
     The clip is generally a linear spine with three tines: a center post, a long prong, and a short prong. In use, the center post is inserted into an interior corner of a carton. The prongs are spaced apart from the center post sufficiently that the prongs fall on the exterior of the carton walls when the center post is within the corner. As the clip is lowered onto the corner of the carton, the prongs each engage a lid flap and lever the flap downward. 
     The long prong is about the same length as the center post, but the short prong is shorter than either. The unequal length of the prongs allows the packer to insert the clip over one flap at a time while holding down the flap with one hand. 
     The preferred embodiment described below is of a universal design that can be used in an approximately right-angled corner of a carton of any size. Generally, two clips per carton would be used; one clip in each diagonally opposite corner. Each clip holds the two flaps adjacent the corner. 
     The present invention is a means of holding the lid flaps of cartons in the open position so that the greatest number of cartons will fit on the floor of the packing area in a neat matrix for high speed packing. The clip is reuseable and durable, and can be stored in minimal space on a shelf. The clip is safe and easily used by a single packer. The clip does not impair access to the interior space of the carton, does not disarrange the packed goods when it is removed, and does not damage or disfigure the carton. 
    
    
     The invention will now be described in more particular detail with respect to the accompanying drawings in which like reference numerals refer to like parts throughout. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a rear perspective view of the clip of the present invention. 
     FIG. 2 is a front elevation view of the clip of FIG.  1 . 
     FIG. 3 is a rear elevation view of the clip of FIG.  1 . 
     FIG. 4 is a top plan view of the clip of FIG.  1 . 
     FIG. 5 is a bottom view of the clip of FIG.  1 . 
     FIG. 6 is a left side view of the clip of FIG.  1 . 
     FIG. 7 is a right side view of the clip of FIG.  1 . 
     FIGS. 8 and 9 show the method of use of the clip of FIG. 1, depicting a user applying the clip to a corner of a carton. 
     FIG. 10 is a perspective view of the carton of FIG. 9 with two clips of the present invention holding four flaps of the carton. 
     FIG. 11 is a top view, partly cut away, of a corner of the carton of FIG. 10 with a clip inserted in the corner. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is a rear perspective view of the clip  10  of the present invention. FIG. 2 is a front elevation view of clip  10  of FIG.  1 . FIG. 3 is a rear elevation view of clip  10  of FIG.  1 . FIG. 4 is a top plan view of clip  10  of FIG.  1 . FIG. 5 is a bottom view of clip  10  of FIG.  1 . FIG. 6 is a left side view of clip  10  of FIG.  1 . FIG. 7 is a right side view of clip  10  of FIG.  1 . 
     Clip  10  generally includes a spine  20 , a center post  30 , a long prong  40 , and a short prong  50 . Spine  20 , center post  30 , and prongs  40 , 50  are generally co-planar so that a pile of clips  10  can rest on a shelf without tangling together or sliding around. 
     Spine  20  includes a first end  21 , a second end  22 , and a middle portion  23  between ends  21 , 22 . Proximal end  42  of long prong  40  is attached to first end  21  of spine  20  and extends downward from spine  20 . Proximal end  52  of short prong  50  is attached to second end  22  of spine  20  and extends downward. Center post  30  is attached to middle portion  23  and extends downward. Proximal end  32  of center post  30  is attached to middle portion  23  of spine  20  and extends downward. Center post  30  has a longitudinal axis  36  . Long prong  40  and short prong  50  are spaced apart from center post  30  and are generally parallel to longitudinal axis  36 . 
     Spine  20  also preferably includes a handle, such as tab  25  attached to middle portion  23 . 
     FIGS. 8 and 9 show the method of use of clip  10  of FIG. 1, depicting a user applying clip  10  to a corner  107  of a carton  100 . FIG. 10 is a perspective view of carton  100  of FIG. 9 with two clips  10  on carton  100 . FIG. 11 is a top view, partly cut away, of corner  107  of carton  100  of FIG. 10 with clip  10  inserted in corner  107 . 
     Carton  100  generally includes four walls  101  attached to each other so as to enclose an inside volume  115 . Each wall  101  includes a top edge  104 , a bottom edge  105 , two side edges  106 , an inner face  102 , and an outer face  103 . Each wall  101  is attached to two other walls  101  along their respective adjoining side edges  106 . Two attached walls  101  form a corner  107 . Corner  107  includes an interior dihedral angle  108  formed by the two inner faces  102  of attached walls  101  and an exterior dihedral angle  109  formed by the outer faces  103  of attached walls  101 . 
     Each wall  101  is attached along its top edge  104  to a lid flap  110 . Top edge  104  serves as a hinge for flap  110 , allowing each flap  110  to rotate from a tucked-in position against inner face  102  of its attached wall  101  nearly 360° to the open position against outer face  103  of wall  101 . Flap  110  includes attached edge  112  attached to top edge  104  of wall  101 , and three free edges  111 . 
     In FIG. 8, three of flaps  110  are shown in an intermediate upwardly-extended position. A hand is shown pushing the right front flap  110  toward the open position against its attached wall  101  as clip  10  is lowered into place in corner  107 . 
     To close carton  100 , flaps  110  are rotated inward such that each flap  110  is at 90° to its attached wall  101  and covering inside volume  115 . The floor or bottom  114  of carton  100 , not fully shown, comprises floor flaps in a similar arrangement. 
     The method of using clip  10  begins with using a first hand to push a first lid flap  110 A of carton  100  toward the open position, while gripping clip  10  with a second hand and positioning clip  10  with center post  30  above a corner  107  adjacent first flap  110 A. Clip  10  is lowered toward corner  107 . Center post  30  slides along interior dihedral angle  108  of corner  107  and long prong  40  comes into contact with and pushes against first flap  110 A. 
     After long prong  40  has engaged first flap  110 A, the first hand is free to move over and push the second flap  110 B toward the open position. Clip  10  is lowered further until short prong.  50  contacts the second flap  110 B and begins pushing the second flap  110 B to the open position. Clip  10  may then be lowered until spine  20  is conveniently close to top edges  104  of walls  101  adjacent corner  107 . 
     FIG. 10 shows a carton  100  with a clip  10  in each of two diagonally-opposite corners  107 . Because each clip  10  holds two adjacent flaps  110 , two clips  10  retain all four lid flaps  110  of carton  100  in the open position. Clip  10  is preferably fabricated from metal rods, thus the weight of two clips  10  aids in preventing carton  100  from being accidentally tipped over during the packing operation. 
     Clip  10  could alternatively be fabricated of plastic, such as a tough injection moldable plastic. The material used must be durable and able to be flexed slightly without fatigue embrittlement, and should be non-marking and with low coefficient of friction. Anodized aluminum or painted or powder-coated steel are suitable metals; ABS or nylon are suitable plastics. 
     If carton  100  is new, with stiff, springy attachments between top edges  104  and flaps  110 , pushing clip  10  downward against flaps  110  is not an efficient way to rotate flaps  110  to the open position and it is preferable to use a hand to start the rotation. The action of the hand pushing a first flap  110  and then a second flap  110  toward the open position is efficient and natural. 
     If carton  100  has been previously used and the attachments of top edges  103  to flaps  110  have become non-springy, clip  10  can be pushed against first and second flaps  110  to rotate flaps  110  from the extended to the open position without aid from a hand pushing on flap  110 . 
     The difference in lengths of long prong  40  and short prong  50  causes only one flap  110  at a time to be engaged by clip  10 . This feature of clip  10  allows the first hand to fold flaps  110  in sequence. 
     If prongs  40 , 50  were of equal length, both the first and the second flaps  110  would need to be pushed downward simultaneously, requiring the use of the packer&#39;s legs to hold flaps  110  in the open position while pushing clip  10  downward with a hand, or use of both hands to hold flaps  110  in the open position while nudging clip  10  downward with the chin, or other awkward postures. 
     Because prongs  40 , 50  must push straight downward against flaps  110  that may be angled outward from the vertical, each of prongs  40 , 50  include slide means  45 , 55  for sliding along a flap  110  without digging into or scratching the cardboard of flap  110 . Slide means  45 , 55  may comprise any of several different means for accomplishing this, such as including a beveled tip (not shown) on prongs  40 , 50 ; including an enlarged rounded knob (not shown) on prongs  40 , 50 ; or the slide means  45  illustrated in the drawings, which is a bent portion  46  of long prong  40  and a bent portion  56  of short prong  50 . 
     Bent portions  46 , 56  accommodate for the angle of flaps  110  away from walls  101  and use a downward force on clip  10  to rotate flaps  110  to the open position. Tip end  47  is the part below bent portion  46  of long prong  40 . Tip end  57  is the part below bent portion  56  of short prong  50 . Tip ends  47 , 57  do not touch flaps  110  during use of clip  10 . Center post  30  does not include slide means because center post  30  slides vertically down vertical interior dihedral angle  108  when clip  10  is inserted into corner  107 . 
     Bent portions  46 , 56  preferably cause tip ends  47 , 57  to point generally normal to the plane of the flap  110  on which prongs  40 , 50 , respectively, push. Tip ends  47 , 57  also point substantially at right angles to each other. 
     Handle tab  25  is generally perpendicular to spine  20 . When clip  10  is inserted into corner  107  in the orientation shown in FIGS. 8 through 10, handle tab  25  projects radially from corner  107 , as seen in FIG.  11 . Bottom  114  of carton  100  may be seen in FIG.  11 . Clip  10  can be inserted into corner  107  easily by gripping spine  20 , center post  30  and prongs  40 , 50  in any means comfortable. To remove clip  10  from corner  107 , it is easier to pull upward on handle tab  25  because most of clip  10  is lying against parts of carton  100 . 
     Clip  10  could be inserted into corner  107  in the mirror image of that depicted in FIGS. 8 through 11. Clip  10  would hold flaps  110  in the open position equally well, but tab handle  25  would be projecting into inside volume  115  of carton  100  and would be slightly less accessible for retrieval. 
     A four-sided carton  100  has been described and illustrated herein, but other types of cartons can be packed using clip  10 . All that is required is that the spacing between center post  30  and prongs  40 , 50  be such that prongs  40 , 50  fall on the outside of carton  100  when center post  30  is inserted into interior dihedral angle  108  and that prongs  40 , 50  push down flaps  110  and hold flaps  110  in an open position. 
     Flaps  110  have been described and illustrated herein as extending along the length of top edge  104  of carton wall  101 . Clip  10  can be used for packing cartons  100  that do not have flaps  110  the entire length of top edge  104 . The distance between center post  30  and a prong  40 , 50  must be at least equal to the sum of the thickness of flap  110 , the thickness of wall  101 , plus the length of top edge  104  adjacent to corner  107  that is not attached to flap  110 . 
     Although particular embodiments of the invention have been illustrated and described, various changes may be made in the form, composition, construction, and arrangement of the parts herein without sacrificing any of its advantages. Therefore, it is to be understood that all matter herein is to be interpreted as illustrative and not in any limiting sense, and it is intended to cover in the appended claims such modifications as come within the true spirit and scope of the invention.