Umbrella rib structure

Abstract

An umbrella rib structure includes a central post, a plurality of main ribs surrounding the central post and pivoted to a top section of the central post, a sleeve fitted the central post for slidable movement, and a plurality of sub ribs. Each of the main ribs includes an orientation portion, which has two parallel erected walls extending therefrom and two elongated slots formed through the two parallel erected walls respectively. Each of the sub ribs connects to the respective one of the main ribs and the sleeve, and includes a T-shaped conjunction, which has a support portion and a transverse bar connected to the support portion and latched with the two elongated slot. Whereby the transverse bar of the T-shaped conjunction of each sub rib can move slidably along the two elongated slots of the respective main rib, so that each sub rib connects with the respective main rib.

1 . An umbrella rib structure comprising: 
 a central post having a handle section, a top section opposite to the handle section, and an intermediate section connected to the handle section and the top section;    a plurality of main ribs surrounding the central post and pivoted to the top section thereof, each of the main ribs including an orientation portion disposed at a middle part thereof, and the orientation portion having two parallel erected walls extending therefrom and towards the central post and two elongated slots formed through the two parallel erected walls respectively;    a sleeve fitted to and slidably moving along the intermediate section of the central post; and    a plurality of sub ribs having a first end connected to the respective one of the main ribs, and a second end opposite to the first end to pivot to the sleeve; wherein each of the sub ribs includes a T-shaped conjunction disposed at the first end, the T-shaped conjunction has a support portion extending therefrom and towards the respective main rib, and a transverse bar having a middle connected to the support portion and latched with the two elongated slots at a simultaneous manner via two free ends thereof;    whereby the transverse bar of the T-shaped conjunction of each sub rib is capable of moving slidably along the two elongated slots of the respective main rib, so that each sub rib connects with the respective main rib.    
     
     
         2 . The umbrella rib structure as claimed in  claim 1 , wherein the orientation portion is integrally with the respective main rib in one-piece formation.  
     
     
         3 . The umbrella rib structure as claimed in  claim 1 , wherein the orientation portion has a radius larger than that of the main rib.  
     
     
         4 . The umbrella rib structure as claimed in  claim 1 , wherein the top section has a secure ring portion, which has an upper annular portion and a lower annular portion, wherein the upper annular portion has a plurality of main recesses corresponding to the main ribs respectively, and the lower annular portion is arranged below the upper annular portion and includes a plurality of main passageways which correspond to the main ribs; wherein each of the main rib has a main through hole strung by a main wire circling the central post between the upper and lower annular portions, and each of the main rib is located in both of a respective main recess of the upper annular portion and a corresponding main passageway of the lower annular portion; wherein the main through hole has a penetrating direction parallel to a penetrating direction of the two elongated slots of the orientation portion.  
     
     
         5 . The umbrella rib structure as claimed in  claim 1 , wherein the sleeve includes a hollow tube containing the intermediate section of the central post, a first annular portion protruded from a top of the hollow tube and having a plurality of sub recesses which correspond to the sub ribs, and a second annular portion lapped over the first annular portion and having a plurality of sub passageways which correspond to the sub ribs; wherein each of the second end of the respective sub rib has a through hole strung by a sub wire circling the central post between the first and the second annular portions, and each of the sub ribs is located in both of a respective sub recess of the first annular portion and a corresponding sub passageway of the second annular portion; wherein the sub through hole has a penetrating direction parallel to an axis direction of the transverse bar.  
     
     
         6 . The umbrella rib structure as claimed in  claim 5 , wherein the sleeve further includes a projection flange formed at a bottom thereof for manually propping the umbrella easily.  
     
     
         7 . The umbrella rib structure as claimed in  claim 5 , wherein the hollow tube of the sleeve has a slot for exposing a first button that is disposed on the intermediate section of the central post and next to the handle section, and the sleeve further includes a resilient shelter connected with the first annular portion and the projection flange and suspended over the slot.  
     
     
         8 . The umbrella rib structure as claimed in  claim 7 , wherein the central post has an upper stop point and a lower stop point; the upper stop point is disposed over a second button that is disposed on the intermediate section of the central post and next to the top section, the upper stop point is used for retaining against the second annular portion while the sleeve slides upwardly along the central post; the lower stop point is disposed beneath a first button for retaining against the projection flange while the sleeve slides downwardly along the central post.  
     
     
         9 . A method for assembling an umbrella rib structure, comprising: 
 providing a central post with a plurality of main ribs surrounding a top section thereof, and a plurality of sub ribs surrounding an intermediate section thereof;    arranging an orientation portion disposed at a middle part of each of the main ribs, wherein the orientation portion has two parallel erected walls extending therefrom and towards the central post and two elongated slots formed through the two parallel erected walls respectively;    forming a T-shaped conjunction disposed at an end of each of the sub ribs, wherein the T-shaped conjunction has a support portion, and a transverse bar connected to the support portion via a middle thereof the transverse bar;    providing the transverse bar of the T-shaped conjunction between and parallel to the two parallel erected walls of the orientation portion, and aligning the transverse bar of the T-shaped conjunction with the two elongated slots of the orientation portion; and    turning the transverse bar about the support portion so as to be vertical to a parallel axle of the two parallel erected walls, so that the transverse bar slides into the two elongated slots via two free ends thereof for latching the orientation portion.    
     
     
         10 . The method as claimed in  claim 9 , further including: 
 providing a secure ring portion on the top section of the central post, wherein the secure ring portion includes an upper annular portion and a lower annular portion, the upper annular portion has a plurality of main recesses, and the lower annular portion is arranged below the upper annular portion and includes a plurality of main passageways which correspond to the main recesses;    insetting the main ribs into the main passageways of the lower annular portion and the main recesses of the upper annular portion in an one-on-one manner; and    penetrating a main wire through a main through hole that is formed on an end of each main rib in advance, in order to ensure the main ribs circle around the central post, wherein the main wire is arranged between the upper and lower annular portions; wherein the main through hole has a penetrating direction parallel to a penetrating direction of the two elongated slots of the orientation portion;    whereby the main ribs connect to the top section of the central post via the secure ring portion.    
     
     
         11 . The method as claimed in  claim 9 , further including: 
 providing a sleeve on the intermediate section of the central post, wherein the sleeve includes a hollow tube containing the intermediate section of the central post, a first annular portion protruded from a top of the hollow tube and having a plurality of sub recesses, and a second annular portion lapped over the first annular portion and having a plurality of sub passageways which correspond to the sub recesses;    insetting the sub ribs into the sub passageways of the second annular portion and the sub recesses of the first annular portion in an one-on-one manner; and    penetrating a sub wire through a sub through hole that is formed on an end of each sub rib in advance, in order to ensure the sub ribs circle around the central post, wherein the sub wire is arranged between the first and second annular portions; wherein the sub through hole has a penetrating direction parallel to an axis direction of the transverse bar;    whereby the sub ribs connect to the sleeve and slide along the intermediate section of the central post via the sleeve.