Abstract:
An inflatable calendar formed of thin flexible plastic sheet defining when inflated a fourteen-sided polyhedron enclosure comprising opposite top and bottom hexagonal walls and six consecutive trapezoidal upper side walls extending downward from said top wall and six consecutive trapezoidal lower side walls extending upward from said bottom wall, the mutually adjacent edges of all mutually adjacent walls being sealed together, said polyhedron enclosure further comprising a valve for inflating, deflating or maintaining inflated said enclosure, and graphic indicia on said six upper and lower side walls respectively displaying the twelve months of a selected year, where each side wall displays the days of one month.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention is in the field of calendars, and desk accessories and inflatable articles and particularly three-dimensional or sculptural calendars. 
     2. Prior Art 
     Prior art calendars are obviously primarily two-dimensional sheets of paper or plastic. One example of a three-dimensional calendar is a rigid ceramic cup on which the months and days are printed or painted around the circumferential surface. Another three-dimensional calendar is made of unfoldable cardboard which forms generally a six-sided cylinder with indicia for two months printed on each of the six sides. Optionally, six months appear upright on six successive sides when the cylinder is upright; on reversing the cylinder to upside down state, the remaining six months appear upright on successive six sides. A further variation is a fourteen sided unfoldable cardboard polyhedron having the top and bottom ends and twelve side surfaces for the calendar months. These twelve surfaces are inclined from vertical for easier viewing. 
     SUMMARY OF THE INVENTION 
     The new invention provides a calendar in the shape of a fourteen sided polyhedron in a new medium, namely inflatable plastic sheet. It is novel, amusing and attractive. Also it is substantially inexpensive to make, package and ship and is even deflatable and reinflatable if desired. It also functions as a toy or an object to be thrown and caught or bounced. It is highly suitable as a promotional or advertising medium because selected graphics can be easily and inexpensively applied to the exposed surfaces. While the overall shape has been utilized before, this invention is novelty in the selected medium, structure and mode of construction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevation view of the new inflatable calendar. 
     FIG. 2 is a top front perspective view of FIG.  1 . 
     FIG. 3 is a plan view of the component parts of the inflatable calendar of FIG.  1 . 
     FIG. 4 shows schematically heat sealing step  1  in the assembly of the component parts of FIG.  3 . 
     FIG. 5 shows schematically heat sealing step  2  of said assembly. 
     FIG. 6 is a fragmentary sectional view taken along line  6 — 6  of FIG.  4 . 
     FIG. 7 is a fragmentary sectional view taken along line  7 — 7  of FIG.  4 . 
     FIG. 8 is a fragmentary section view showing heat sealing step  3  for joining the third sheet in the assembly. 
     FIG. 9 is a fragmentary plan view of the valve. 
     FIG. 10 is a partial section view taken along lines  10 — 10  in FIG.  9 . 
     FIG. 11 is a section view showing heat sealing step  6  for joining the sixth sheet in the assembly. 
     FIG. 12 is a partial perspective view showing a die, the assembled side sheets formed into a cylinder which is situated in the die, and the top wall components positioned to be heat sealed to the top edges of said sides. 
     FIG. 12A is a partial sectional view of the die and parts to be heat sealed seen in FIG.  12 . 
     FIG. 13 is a schematic partial elevation view showing another embodiment of a die, jig or fixture for the heat sealing operation of FIG.  12 . 
     FIG. 14 is a schematic partial plan view taken along lines  14 — 14  in FIG.  13 . 
     FIG. 15 is similar to FIG. 13 showing the heat sealing of the bottom wall to the assembly. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A. Description of Assembled Calendar 
     FIGS. 1 and 2 show the new inflatable calendar  10  in inflated condition. This calendar as shown is a fourteen sided polyhedron enclosure comprising hexogonical top wall  12 , hexogonical bottom wall  14 , trapezoidal upper walls  15 - 20 , trapezoidal lower walls  21 - 27 , and valve  30 . The top wall and upper trapezoidal walls define an upper canopy with adjacent side edges heat sealed together; the bottom wall and lower trapezoidal walls defining a similar lower canopy, upside down and opposite said upper canopy. For the purpose of explaining this invention the side walls have been described as twelve separate trapezoidal shapes; however, in preferred practice and as illustrated in the drawings herein, each set of adjacent upper and lower trapezoidal walls is formed of a single sheet for simplifying construction and improving appearance. 
     Said hexogonal top wall  12  has six edges a-f as seen in FIG.  2 . The top edge  20 T of top wall  20 , for example, is secured to edge a of top wall  12 . The other edges b-f of top wall  12  are similarly secured to adjacent upper walls. Each two adjacent upper side walls have their respective adjacent edges joined together. The lower side walls are similarly joined. Also, the bottom hexogonal wall  14  is joined similarly as the top hexogonal wall. As noted above, the present drawings show each upper side wall being an extension of and contiguous with an adjacent bottom side wall, thus defining a simple sheet. 
     Each of said side walls is formed of a single layer of plastic sheet, whether formed of upper and lower parts or as a single element. The top and bottom walls differ from said side walls in that each is a laminate of two of said sheets of plastic with a sheet of cardboard between the plastic sheets to result in relatively stiff top and bottom surfaces  12  and  14  of the polyhedron. This will stabilize the calendar to sit erect when placed with said top or bottom wall on a flat surface such as a table top. 
     The side walls include their graphic indicia each showing one of the twelve calendar months. As shown in part in FIGS. 1 and 2, the months January through June appear on six adjacent upper walls, and the months July through December appear upside down on the six adjacent lower walls. For example, March, April and May in FIG. 1 are designated upper sides  15 ,  16  and  17 . Obviously, when this calendar is inverted to place the top wall is down on a table surface, the bottom wall  14  becomes the top and the lower walls are now oriented upright. It is further obvious that mere rotation of the calendar will expose about three of the upper and lower month walls at any time, with the month in the position of the most centered upper wall being the most visible, that wall being designated April in FIG.  1 . 
     The valve  30  is a standard element common to prior art inflatable articles. It may be a simple tube with an insertable plug  30 A, or it may further include an internal flap valve (not shown) that resists deflation unless the valve tube is squeezed radially inward to displace the internal flap from blocking air flow. 
     The mode of assembly of this inflatable calendar is also novel, to achieve an attractive and economical product. The components of the assembly are shown in FIG. 3 with the top wall  12  formed by the laminate or sandwich of outer sheet  12 A, cardboard insert  12 B and inner sheet  12 C. The bottom wall  14  is similar with outer sheet  14 A, cardboard insert  14 B and inner sheet  14 C. 
     As discussed above, while FIGS. 1 and 2 show the inflatable calendar as having six upper and six lower side walls, the preferred assembly forms these twelve side wall elements of six sheets, each comprising one upper and one adjacent lower wall. This simplifies construction, improves appearance, and reduces cost. Accordingly, as seen in FIG. 3, there are six upper-lower combination walls  22 - 27  now called side walls. 
     B. Description of Method Manufacture 
     First two side walls  22 ,  23  are placed in overlying relationship as seen in FIG. 4, and their adjacent edges  22 E,  23 E are heat scaled together from top to bottom along one side as seen in FIG. 6 by heat scaler jaws  28  and  29 . 
     Next, as seen in FIG. 5 sidewall  23  of the joined walls  22  and  23  is placed to overlie wall  24 , and their adjacent edges are heat sealed as seen in FIG.  7 . This is repeated, as seen in FIG. 8 where sidewall  24  of the three joined walls is placed to overlie wall  25 , and they are heat sealed. This is repeated two more times until a six sided cylinder is formed with six seams or junctions where their mutual edges join as indicated in FIG.  11 . In one of these junctions the valve  30  is situated and heat sealed in a manner common in the prior art and as seen in FIGS. 9 and 10, where  30 A is the cap and air sealing insert. 
     Next, as seen in FIGS. 12,  12 A and  13 - 15 , this six-sided cylinder  30  of soft flexible plastic sheet is placed within a rigid cylindrical die  32  which has top hexogonal edge  32 T. The top peripheral edge  34  of the soft plastic cylinder  32  is positioned to extend transversely and overlie die edge  32 T. The top wall as described earlier is a laminate of lower soft plastic sheet  12 C, relatively stiff cardboard  12 B and upper or outer soft plastic sheet  12 A, all defining a hexagon to conform to the top peripheral edge of the six-sided cylinder to which the top wall is to be heat sealed. 
     The cardboard sheet  12 B has dimensions slightly less in diameter than the plastic sheets  12 C and  12 A below and above it. Then as seen in FIG. 12 the upper die  32 A is moved downward until its heat sealing edge  32 B presses and heats together the peripheral edges of sheets  12 C,  12 A and  34 . 
     FIGS. 13,  14  and  15  show schematically a variation of a die, jig or fixture  39  combined with a heat sealer, as compared to that of FIGS. 12 and 12A. In FIG. 13 the soft plastic article  41  from FIG. 11 is positioned withing the walls  40  of the die, and the top end  41 E is heat sealed to the top wall formed by laminate  42  comprising bottom vinyl sheet  42 A, cardboard insert  42 B and top or outer vinyl sheet  42 C (corresponding to sheets  12 C,  12 B and  12 C in FIG.  12 ). The peripheral edges of sheets  42 A and  42 C and the edge  41 E of the calender enclosure  41  are heat sealed together by the heat sealer jaws  43 . 
     The final heat scaling step is shown in FIG. 15 where the bottom wall laminate  50  is constructed and heat sealed to close the enclosure similarly as the top wall was added. In FIG. 15 the parts have the same reference numbers as in FIG. 14, namely die walls  40 , vinyl sheet enclosure walls  41 S, and heat sealer jaws  43 . 
     Instead of having the sealer aperture at the top and bottom of the die, there could be a single heat sealer with the die being flipped to seal the top end and then the bottom end, or the vinyl cylinder could be flipped with the fixture, but these variations would be far less efficient for high speed production. 
     In a further variation the die could be made of two or more parts separable about the central longitudinal axes of the die X—X seen in FIG. 13, which would allow easier removal of the assembled article. 
     Referring to FIGS. 8 and 11, it can be seen that the heat sealed junctions J are external protrusions. Prior to insertion of the sub-assembly of FIG. 11 into the die or fixture for attachment of the hexogonal top and bottom walls, the sub-assembly can be turned inside out so that these junctions extend inward, thus resulting in a smoother outer surface appearance. 
     Prior to any of this assembly the graphic indicia for the twelve calendar months would be imprinted onto the side wall components, and optionally other graphics would be imprinted on the top and/or bottom walls. As earlier described, it is preferable for the month-date graphics to be oriented on the side walls so that the first six months are on the upper walls arranged sequentially and the second six moths on the lower walls oriented sequentially and inverted. Obviously, the month-date graphics could be arranged in any order. 
     The embodiments described above of the inflatable calendar and method of making same are the preferred embodiments; however, variations are possible within the scope and spirit of this invention as defined by the appended claims.