Abstract:
Provided is a Fiberglass Reinforced Plastic umbrella frame comprising ribs each consisting of four segments wherein first rib segment and one strut are connected together by one of U-shaped connecting members and one of Y-shaped pivotal members having a cylindrical seat across both ends of its bifurcation, and any two adjacent rib segments are connected together by the U-shaped connecting member and the Y-shaped pivotal member. There are also provided links each for connecting the pivotal member and the distal connecting member. The umbrella can carry out a smooth folding or extending operation and has a reduced folded size and enhanced structural strength.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of Invention  
         [0002]     The present invention generally relates to FRP (Fiberglass Reinforced Plastics) umbrella frame structure and more particularly to such an umbrella frame having improved ribs each consisting of four segments which are adapted to smoothly fold to minimize storage space of the FRP umbrella.  
         [0003]     2. Description of Related Art  
         [0004]     As well-known in the art, metal umbrella frame has many folded ribs each consisting of four rib segments. For example, U.S. Pat. No. 5,392,799 discloses such umbrella. However, the patent suffered from several disadvantages. For example, a metal pivotal joint between two segments of the rib is secured by metal rivets. This is a tedious and time consuming in manufacturing process. Moreover, quality of the joint is not reliable. It is understood that even one malfunctioned joint, for example caused by rust, can cause jam of an umbrella. Further, the metal umbrella frame tends to break at the rivets due to stress concentration when used after a while.  
         [0005]     Umbrella frame made of FRP (fiberglass reinforced plastics) is rustproof. It is found that ribs of FRP frame are cylindrical in shape for increasing support strength of umbrella. Further, an upper end and an intermediate point of the rib for connecting to a top of shank and a sleeve on the shank are formed with plastic connecting member and pivotal joint respectively. This inevitably increases the size of frame, resulting in difficulties of storage and transportation. Thus, FRP frame is particularly suitable for large golf umbrella with no folding ribs of frame. So far as the present inventor is aware that FRP umbrella frame with four folding ribs has not been commercially available. Hence, a need has arisen for a FRP umbrella frame having improved folding four-segment ribs.  
       SUMMARY OF THE INVENTION  
       [0006]     It is therefore an object of the present invention to provide a FRP umbrella frame comprising a plurality of ribs each including four folded rib segments. The frame is smooth in its folding operation without causing jam.  
         [0007]     It is another object of the present invention to provide a lightweight FRP umbrella frame with folded four-segment ribs. The FRP umbrella is advantageous for being ease of storage and transportation.  
         [0008]     It is a further object of the present invention to provide an enhanced umbrella frame with folding four-segment ribs.  
         [0009]     To achieve the above and other objects, the present invention provides a FRP umbrella including a shank including a plastic top hub having a plurality of slots equally spaced therearound, and a plastic lower sleeve slidably put on the shank and having a plurality of slots equally spaced therearound, and a folding frame comprising: a plurality of plastic upper connecting rods each having an end pivotably connected to the slot of the hub; a plurality of plastic lower connecting rods each having an end pivotably connected to the slot of the sleeve; a plastic Y-shaped first pivotal member having a bifurcation, including a cylindrical seat across both ends of the bifurcation, an opening defined by the bifurcation and the seat thereof, and an intermediate projecting U-shaped element; a plastic Y-shaped second pivotal member having a bifurcation, including a cylindrical seat across both ends of the bifurcation, an opening defined by the bifurcation and the seat thereof, and an intermediate projecting U-shaped element; a plastic Y-shaped third pivotal members having a bifurcation, including a cylindrical seat across both ends of the bifurcation, an opening defined by the bifurcation and the seat thereof, and an intermediate projecting U-shaped element; a plastic Y-shaped fourth pivotal member having a bifurcation, including a cylindrical seat across both ends of the bifurcation, and an opening defined by the bifurcation and the seat thereof; a plastic U-shaped first connecting member including a recess, a tubelike first and second extensions both extended from either end of the recess, respectively and a bore at either end of the extensions in communication with the recess thereof; a plastic U-shaped second connecting member including a recess, a tubelike first and second extensions both extended from either end of the recess, respectively and a bore at either end of the extensions in communication with the recess thereof; a plastic U-shaped third connecting member including a recess, a tubelike first and second extensions both extended from either end of the recess, respectively and a bore at either end of the extensions in communication with the recess thereof; a plastic U-shaped fourth connecting member including a recess, a tubelike first and second extensions both extended from either end of the recess, respectively and a bore at either end of the in communication with the recess thereof; a plurality of FRP struts; a plurality of FRP folding ribs each including a first segments, a second segments, a third segments, and a fourth rib segments; and a plurality of first, second, and third links; wherein the seat of the Y-shaped first pivotal member is fitted in the recess of the U-shaped first connecting member; the seat of the Y-shaped second pivotal member is fitted in the recess of the U-shaped second connecting member; the seat of the Y-shaped third pivotal member is fitted in the recess of the U-shaped third connecting member; the seat of the Y-shaped fourth pivotal member is fitted in the recess of the U-shaped fourth connecting member; each of the struts passes through the tubelike second extension, the recess, and the tubelike first extension of the U-shaped first connecting member to have one end connected to the lower connecting rod and the other end thereof connected to one end of the second pivotal member with the U-shaped first connecting member slidably put thereon; the first rib segment has one end connected to the other end of the upper connecting rod and the other end thereof connected to one end of the Y-shaped first pivotal member; the second rib segment has one end connected to one end of the U-shaped second connecting member by passing through the second extension, the recess and the first extension of the U-shaped second connecting member, and the other end thereof connected to one end of the Y-shaped third pivotal member; the third rib segment has one end connected to one end of the U-shaped third connecting member by passing through the second extension, the recess and the first extension of the U-shaped third connecting member, and the other end thereof connected to one end of the Y-shaped fourth pivotal member; the fourth rib segment has one end connected to one end of the U-shaped fourth connecting member by passing through the second extension, the recess and the first extension of the U-shaped fourth connecting member, and the other end thereof secured to a peripheral edge of a canopy fitted over the frame; each of the first links interconnects a first U-shaped element of the Y-shaped first pivotal member and the U-shaped second connecting member; each of the second links interconnects a second U-shaped element of the Y-shaped second pivotal member and the U-shaped third connecting member; and each of the third links interconnects a third U-shaped element of the Y-shaped third pivotal member and the U-shaped fourth connecting member.  
         [0010]     The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a perspective view of a preferred embodiment of FRP umbrella frame according to the invention in its partially folded position;  
         [0012]      FIG. 2  is an exploded perspective view of the frame for showing its components and its connection to a top hub of a shank and a lower sleeve put on the shank;  
         [0013]      FIG. 3  is a side view of the assembled elements shown in  FIG. 2 , where the frame is partially extended;  
         [0014]      FIG. 4  is a view similar to  FIG. 3 , where the frame is fully extended; and  
         [0015]      FIG. 5  is a view similar to  FIG. 3 , where the frame is fully folded. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     Referring to  FIGS. 1, 2  and  3 , an umbrella frame  10  (e.g., one formed of FRP) in accordance with a preferred embodiment of the invention comprises a shank  11  including a plastic top hub  12  having a plurality of slots  120  equally spaced therearound, and a plastic lower sleeve  13  slidably put on the shank  11  and having a plurality of slots  130  equally spaced therearound. An plastic upper connecting rod  20  has a flat portion  200  at one end fitted in and pivotably connected to one slot  120  and a plastic lower connecting rod  21  has a flat portion  210  at one end fitted in and pivotably connected to one slot  130 . Each of the connecting rods  20  and  21  is formed of plastic material. The other end of each of the connecting rods  20  and  21  is formed with a bore  201  or  211  for snugly receiving one end of a first rib segment  14  or a strut  15 .  
         [0017]     A plastic U-shaped first connecting member  30  comprises a U-shaped recess  302  in its intermediate portion, a tubelike first extension  300  extended from one end of the recess  302  and having a bore  3000  therethrough, and a tubelike second extension  301  extended from the other end of the recess  302  and having a bore  3010  therethrough. The bores  3000  and  3010  are in communication through the recess  302 . Thus, the strut  15  is adapted to insert through the bore  3000 , the recess  302 , and the bore  3010 . A lower slope  303  is formed between bottom of the second extension  301  and the recess  302 . The umbrella frame  10  further comprises a plurality of FRP radial ribs each consisting of four rib segments namely first rib segment  14 , second rib segment  16 , third rib segment  17 , and fourth rib segment  18 . The first pivotal member  40  made of plastic is a substantially Y-shaped element and comprises a bore  400  at one end for snugly receiving the other end of the first rib segment  14 , a cylindrical seat  401  across both ends of two branch of its bifurcation  408  with the recess  302  fitted thereon, an indentation  407  also across the branches of the bifurcation  408 , a first opening  402  defined by the bifurcation  408 , the indentation  407 , and the seat  401 , a second opening  403  defined by the bifurcation  408  and the indentation  407 , an enlarged cavity  404  formed at bottom of the second opening  403 , a U-shaped element  405  with its both ends  4050  fitted in the cavity  404  and with its intermediate portion projecting from the second opening  403 , and an arc member  406  at either side of the bifurcation  408 . Thread leaving canopy can insert in and out of the arc member  406  for fastening canopy onto the ribs.  
         [0018]     A second pivotal member  41  made of plastic is a substantially Y-shaped element and comprises a bore  410  at one end for snugly receiving the other end of the strut  15 , a cylindrical seat  411  across both ends of two branch of its bifurcation  418 , an indentation  417  also across the branches of the bifurcation  481 , a first opening  412  defined by the bifurcation  418 , the indentation  417 , and the seat  411 , a second opening  413  defined by the bifurcation  418  and the indentation  417 , an enlarged cavity  414  formed at bottom of the second opening  413 , a U-shaped element  415  with its both ends  4150  fitted in the cavity  414  and with its intermediate portion projecting from the second opening  413 , and an arc member  416  at either side of the bifurcation  418 . Thread leaving canopy can insert in and out of the arc member  416  for fastening canopy onto the ribs.  
         [0019]     A plastic U-shaped second connecting member  31  comprises a U-shaped recess  312  in its intermediate portion with the seat  411  fitted therein, a tubelike first extension  310  extended from one end of the recess  312  and having a bore  3100  therethrough, an arc flat element  3101  extended from the first extension  310 , the flat element  3101  having a hole  3102  through its free end, a tubelike second extension  311  extended from the other end of the recess  312  and having a bore  3110  therethrough, the bore  3110  being in communication with the bore  3100  through the recess  312  such that one end of the second rib segment  16  is adapted to insert through the bore  3100 , the recess  312 , and the bore  3110 , and an upper slope  313  formed between top of the second extension  311  and the recess  312 .  
         [0020]     A third pivotal member  42  made of plastic is identical to the substantially Y-shaped first pivotal member  40  and comprises a bore  420  at one end for snugly receiving the other end of the second rib segment  16 , a cylindrical seat  421  across both ends of two branch of its bifurcation  428 , an indentation  427  also across the branches of the bifurcation  428 , a first opening  422  defined by the bifurcation  428 , the indentation  427 , and the seat  421 , a second opening  423  defined by the bifurcation  428  and the indentation  427 , an enlarged cavity  424  formed at bottom of the second opening  423 , a U-shaped element  425  with its both ends  4250  fitted in the cavity  424  and with its intermediate portion projecting from the second opening  423 , and an arc member  426  at either side of the bifurcation  428 . Thread leaving canopy can insert in and out of the arc member  426  for fastening canopy onto the ribs.  
         [0021]     A plastic U-shaped third connecting member  32  is identical to the plastic U-shaped second connecting member  31  and comprises a U-shaped recess  322  in its intermediate portion with the seat  421  fitted therein, a tubelike first extension  320  extended from one end of the recess  322  and having a bore  3200  therethrough, an arc flat element  3201  extended from the first extension  320 , the flat element  3201  having a hole  3202  through its free end, a tubelike second extension  321  extended from the other end of the recess  322  and having a bore  3210  therethrough, the bore  3210  being in communication with the bore  3200  through the recess  322  such that one end of the third rib segment  17  is adapted to insert through the bore  3210 , the recess  322 , and the bore  3200 , and a lower slope  323  formed between bottom of the second extension  321  and the recess  322 .  
         [0022]     A fourth pivotal member  43  made of plastic is identical to the substantially Y-shaped first pivotal member  40  and comprises a bore  430  at one end for snugly receiving the other end of the third rib segment  17 , a cylindrical seat  431  across both ends of two branch of its bifurcation  438 , a lower indentation  437  also across the branches of the bifurcation  438 , a first opening  432  defined by the bifurcation  438 , the indentation  437 , and the seat  431 , and an arc member  436  at either side of the bifurcation  438 . Thread leaving canopy can insert in and out of the arc member  436  for fastening canopy onto the ribs.  
         [0023]     A plastic U-shaped fourth connecting member  33  is identical to the plastic U-shaped second connecting member  31  and comprises a U-shaped recess  332  in its intermediate portion with the seat  431  fitted therein, a tubelike first extension  330  extended from one end of the recess  332  and having a bore  3300  therethrough, an arc flat element  3301  extended from the first extension  330 , the flat element  3301  having a hole  3302  through its free end, a tubelike second extension  331  extended from the other end of the recess  332  and having a bore  3310  therethrough, the bore  3310  being in communication with the bore  3300  through the recess  332  such that one end of the fourth rib segment  18  is adapted to insert through the bore  3310 , the recess  332 , and the bore  3300 , and a lower slope  333  formed between bottom of the second extension  331  and the recess  332 . The other end (i.e., free end) of the fourth rib segment  18  is secured to canopy in a manner known in the art.  
         [0024]     In assembly, a first link  50  includes a first hook  51  at one end passed the projecting intermediate portion of the U-shaped element  405  and fastened thereat, and a second hook  52  at the other end passed the hole  3102  and fastened thereat. A second link  60  includes a first hook  61  at one end passed the projecting intermediate portion of the U-shaped element  415  and fastened thereat, a second hook  62  at the other end passed the hole  3202  and fastened thereat, and a U-shaped intermediate member  63  engaged an outer surface of the second rib segment  16 . A first sleeve  160  loosely put on the U-shaped intermediate member  63  and the second rib segment  16  such that the first sleeve  160  is adapted to slide on the second rib segment  16  in a folding or extending operation of the umbrella. Similarly, a third link  70  includes a first hook  71  at one end passed the projecting intermediate portion of the U-shaped element  425  and fastened thereat, a second hook  72  at the other end passed the hole  3302  and fastened thereat, and a U-shaped intermediate member  73  engaged an outer surface of the third rib segment  17 . A second sleeve  170  loosely put on the U-shaped intermediate member  73  and the third rib segment  17  such that the second sleeve  170  is adapted to slide on the third rib segment  17  in a folding or extending operation of the umbrella.  
         [0025]     For extending the umbrella, simply push the lower sleeve  13  upward from the position of  FIG. 5  to the position of  FIG. 4  via the position of  FIG. 3 . To the contrary, for folding the umbrella, simply push the lower sleeve  13  downward from the position of  FIG. 4  to the position of  FIG. 5  via the position of  FIG. 3 . Either extending or folding operation is made smooth due to the advantageous characteristics discussed above.  
         [0026]     Moreover, the arc flat element extended from one end of the second connecting member  31 , the second connecting member  32 , or the third connecting member  33  is adapted to decrease size of the folded umbrella. Further, the indentations  407 ,  417 ,  427 , and  437  of the first, second, third, and fourth pivotal members  40 ,  41 ,  42 , and  43  are adapted to facilitate extending or folding operation of the umbrella and cause rib segments to dispose in a more parallel configuration after folding, thereby further decreasing size of the folded umbrella (see  FIG. 5 ).  
         [0027]     While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.