referring to the drawings in detail , and initially to fig1 - 6 thereof , a windproof umbrella 10 according to a first embodiment of the present invention includes a center post 14 having a handle 12 secured to the lower end thereof , handle 12 being adapted to be grasped by a user to carry umbrella 10 in its stored position ( fig4 ) and to hold umbrella 10 in its raised , opened position ( fig2 ). a stationary hub 30 is secured at the upper end of center post 14 approximately three inches from the tip thereof so as to provide an upper extension 32 which can be pointed as is conventional and depending on the style of the umbrella . a plurality of ribs 18 are pivotally connected to hub 30 so as to be equiangularly spaced thereabout and extend outwardly in a radial direction therefrom . in addition , a sleeve 15 is slidably mounted on center post 14 between handle 12 and stationary hub 30 and can be locked in an intermediate position shown in fig3 by a spring biased locking tab 17 , as is conventional . a plurality of reinforcing struts 16 , equal in number to ribs 18 , are provided such that each reinforcing strut 16 is pivotally secured at one end to sleeve 15 and at its opposite end to a respective rib 18 at a position substantially midway therealong . there are preferably eight reinforcing struts 16 and ribs 18 , although this number may vary . a lower canopy 20 is secured in covering relation on ribs 18 , as is also conventional . lower canopy 20 is made from a water - resistant material ( such as nylon cloth ) and is preferably constructed from substantially triangular cloth sectors 22 which are cut and sewn together to conform to the spaces between ribs 18 . in this manner , when canopy 20 is in its untensioned state , it has an octagonal configuration . canopy 20 is provided with a central opening 21 which fits tightly over hub 30 , with canopy 20 preferably being secured to hub 30 . in order to secure canopy 20 to ribs 18 , the free end or tip 28 of each rib 18 is provided with an eyelet 24 for receiving a thread which is sewn to a corner 26 of canopy 20 . in this manner , the peripheral edge of canopy 20 is secured to free ends 28 of ribs 18 . specifically , corners 26 of canopy 20 correspond to the seam lines between sectors 22 . further , the seam between sectors 22 is preferably stitched to each rib 18 at six to eight inch intervals along its length . the above described arrangement is conventional . generally , because of the dimensions of canopy 20 and ribs 18 and in view of the connection of reinforcing struts 16 , ribs 18 and canopy 20 assume a bowed configuration when umbrella 10 is in its fully opened position , as shown in fig1 . as discussed above , quite frequently a wind will catch the umbrella user unaware and exert a force against the inner surface of canopy 20 which will cause canopy 20 to invert from the position shown in fig1 to an upwardly convex or bowed position . thus , in accordance with a first aspect of the present invention , a vent hole 34 is provided in each canopy sector 22 . preferably , each vent hole 34 has a substantially triangular configuration with gently surrounded corners , although the present invention is not so limited . in addition , each substantially triangular vent hole 34 preferably has a circumferential dimension at a base thereof of approximately four inches and a radial dimension of approximately six inches . as such , air entering the underside of canopy 20 will exit through vent openings 34 so as to allow relief for the wind pressure that would normally invert umbrella 10 . in order to prevent rain from entering vent holes 34 , while simultaneously permitting air to exit from the underside of canopy 20 through vent holes 34 , an upper canopy 36 is positioned over lower canopy 20 in covering relation to vent holes 34 . upper canopy 36 is preferably comprised of the same water - resistant material as lower canopy 20 and is made from a corresponding number of sectors 38 as lower canopy 20 . however , each sector 38 has a dimension in the radial direction of umbrella 10 which is less than that of the corresponding sector 22 of lower canopy 20 . further , as will be made apparent from the discussion hereinafter , the seams connecting sectors 38 are preferably sewn only about one third of the radial length of each sector 38 , starting from the center of upper canopy 36 , thus leaving a space 44 between peripheral corners 46 of adjacent sectors 38 . a center opening 40 is provided in upper canopy 36 and a grommet 42 is secured thereat and is swaged to sectors 38 . grommet 42 has a center hole and fits snugly on upper extension 32 immediately above stationary hub 30 . in order to secure the peripheral edge of upper canopy 36 to umbrella 10 , a strip of elastic material 48 has opposite ends thereof sewn or otherwise attached to corners 46 of adjacent sectors 38 of upper canopy 36 . a fastening means 50 , such as a small metal grommet 52 , as shown best in fig5 is secured to a midpoint each elastic strip 48 . thus , each grommet 52 is slipped over a respective free end of a rib 18 , as shown in fig2 . because of the use of an elastic strip 48 , upper canopy 36 is maintained in a slightly taut condition , whether umbrella 10 is in the opened position of fig2 or the closed position of fig4 . as best shown in fig3 during rainy , windy weather , wind 54 that is caught beneath canopy 20 exits through vent holes 34 and applies pressure to the underside of upper canopy 36 . this force causes canopy 36 to lift away from lower canopy 20 by means of elastic strips 48 which are slightly stretched to provide a relatively large escape path 56 for wind 54 . wind 54 can then pass through spaces 44 to escape umbrella 10 . thus , any excessive wind 54 will not invert umbrella 10 . further , because of the overlap of upper canopy 36 , any rain thereon flows downwardly and outwardly onto the peripheral edges of lower canopy 20 and away from the user . optionally , with the present invention , it will readily be appreciated that upper canopy 36 may be separated from umbrella 10 so that it can be dried independently thereof . thus , any water caught between upper canopy 36 and lower canopy 20 may dry in a shorter period of time . as a further aspect of the present invention , in the event that rain enters the space between upper canopy 36 and lower canopy 20 , such rain would tend to fall through vent holes 34 onto the user . such rain could , for example , possibly enter through grommet 42 . in such case , as shown in fig1 and 6 , a bead 57 or other channel forming member can be provided in surrounding relation to each vent hole 34 . such bead 57 can be made of any suitable water - resistant material and could merely be a raised surface in surrounding relation to each vent hole 34 . in this manner , beads 57 provide a water channel around the outside of the vent holes 34 , and prevent any water from entering vent holes 34 and falling on the user during a particularly heavy rain . specifically , any water that enters the upper part of the space between upper canopy 36 and lower canopy 20 rolls down lower canopy 20 and hits beads 57 . thereafter , the water travels about beads 57 to the peripheral edge of lower canopy 20 . fig6 a shows another embodiment of a channel forming member 57a surrounding a vent hole 34 . referring now to fig7 and 8 , an alternative structure for securing upper canopy 36 to the free ends or tips 28 of ribs 18 will now be described . as shown , a securing device 58 , which is preferably made of a suitable plastic material has a generally oval configuration . a transverse bore 60 extends through the upper end of securing device 58 for receiving an elastic strip 48 therethrough . the opposite end of securing device 58 is pivotally secured to the free end or tip 28 of a respective rib 18 . in this regard , a spherical seat 62 is provided at the lower end of securing device 58 so as to fit snugly over the rounded tip 28 of a rib 18 . a groove 64 which is in communication with spherical seat 62 extends upwardly toward transverse bore 60 , but stops short thereof . in addition , the lower end 66 of securing device 58 is bifurcated , at 68 . in this manner , the lower end 66 of securing device 58 can be biased slightly apart to receive the spherical tip 28 of a rib 18 and upon release of the separating pressure , the spherical tip 28 of such rib 18 is pivotally held captive within spherical seat 62 . in such case , when an excessive wind pressure exits through vent openings 34 , the elasticity of the material of upper canopy 36 , combined with the pivoting nature of securing device 58 at the free end 28 of each rib 18 , provides for the raising of upper canopy 36 , as shown in fig3 to permit wind 54 to exit from vent holes 34 without inverting umbrella 10 . referring now to fig9 a windproof umbrella 110 according to another embodiment of the present invention will now be described , in which elements corresponding to those of umbrella 10 are identified by the same reference numerals , augmented by 100 , and a detailed description thereof will be omitted herein for the sake of brevity . windproof umbrella 110 is identical to windproof umbrella 10 of fig1 - 6 , with the exception that each sector 138 has a flap 70 which is adapted to overlap the adjacent sector 138 so as to completely cover space 44 . in this regard , the peripheral end of each flap 70 has a female snap element 72 at its underside which is adapted to engage a respective male snap element 74 of the adjacent sector 138 in order to secure flaps 70 in covering relation to spaces 44 . velcro ( trademark ) or other hook - and - loop fasteners , or other operable fasteners may be used in place of snap elements 72 , 73 . in such case , rather than the wind utilizing the escape path 56 shown in fig3 through spaces 44 , the wind 54 will tend to escape from the peripheral edge of upper canopy 136 when the flaps 70 are secured in their closed condition . referring now to fig1 and 11 , a windproof umbrella 210 according to another embodiment of the present invention will now be described , in which elements corresponding to those described above with respect to umbrella 10 of fig1 - 6 are identified by the same reference numerals , augmented by 200 , and a detailed description thereof will be omitted herein for the sake of brevity . as shown , vent holes 234 have a substantially circular or slightly oval configuration and are positioned radially inwardly with respect to vent holes 34 such that ribs 218 are substantially tangent to vent holes 234 . further , upper canopy 236 includes openings 76 which are elongated in the circumferential direction thereof and are positioned radially outward from vent holes 234 when upper canopy 236 is positioned over lower canopy 220 . openings 76 and canopy 236 work in conjunction with vent holes 234 of lower canopy 220 to permit a maximum venting of trapped wind 254 along path 256 as shown best in fig1 . as with vent holes 34 , vent holes 234 can be made with a bead or channel forming member ( not shown ) similar to bead 57 or 57a in fig6 or 6a . it will be appreciated that any rain that enters openings 76 merely falls on lower canopy 220 at a position radially outward from vent holes 234 and thereby does not enter vent holes 234 . referring now to fig1 , a windproof umbrella 310 according to yet another embodiment of the present invention will now be described , in which elements corresponding to those described above with reference to umbrella 10 of fig1 - 6 are identified by the same reference numerals , augmented by 300 , and a detailed description thereof will be omitted herein for the sake o brevity . as shown , the substantially triangular vertex 78 of each sector 322 is removed to form a central octagonal cutaway portion of canopy 320 . preferably , the cutaway vertices 78 extend approximately one quarter of the distance of canopy 320 in the radial direction along the ribs from hub 330 to the free end 328 thereof . any of the elastically connected upper canopies 36 , 136 or 236 can be used therewith . accordingly , the present invention provides a windproof umbrella that prevents inversion of the umbrella while also preventing rain from falling on the user . having described specific preferred embodiments of the invention with reference to the accompanying drawings , it will be appreciated that the present invention is not limited to those precise embodiments , and that various changes and modifications may be effected therein by one of ordinary skill in the art without departing from the scope or spirit of the invention as defined in the appended claims .
a windproof umbrella includes a post having a lower end to be grasped by a user and an opposite upper end ; a plurality of ribs extending outwardly in a radial direction from the upper end of the post ; a lower canopy secured in covering relation on the ribs , the lower canopy including a plurality of vent holes therethrough ; a channel forming member secured to the lower canopy in surrounding relation to each lower vent hole for further preventing entry of water therethrough ; an upper canopy positioned over the lower canopy in covering relation to all lower vent holes , the upper canopy including at least one upper vent hole therethrough positioned closer to the free ends of the ribs than the at least one lower vent hole , an outer peripheral edge and a plurality of slits extending inwardly in a radial direction from the outer peripheral edge thereof , each slit being arranged generally in line with one rib , the upper canopy having dimensions less than those of the lower canopy ; and elastic fastening straps securing the upper canopy between the upper end of the post and the free ends of the ribs with an elastic tautness .