Improved folding mechanism of flat top umbrella

Abstract

 An improved folding mechanism for telescopic umbrella includes additional rib members (2,4) which allow the length of an umbrella to be shortened to a value of approximately one third the radial span of the canopy, thereby enabling it to be conveniently received in a handbag while providing sufficient shading for the user.

Description

[0001] This invention relates to an improved folding mechanism for a flat top umbrella.

[0002] A favorite collapsible flat top umbrella, as shown in Figure 3, comprises a shaft (13) provided with a fixed pivot ring (131) serving for the pivotal joints of the proximal first main ribs (10) and a slidable pivot ring (12) serving for the pivotal joints of the support ribs (11). Hereinafter, the term "main ribs" refers to the ribs which serve to maintain the shape of the canopy of the umbrella, and the term "support ribs" refers to the ribs for supporting the main ribs to maintain the open state of the umbrella. A second main rib (9) is provided with a pivotal joint (92), to which the distal end of lower rib (11) is pivoted, at a distance from its proximal end (91), where the distal end of a bridging rib (93) is pivoted, the proximal end of the bridging rib. (93) being pivoted to the first main rib (10) at a position spaced from its distal end which is pivoted to the lower rib (11) at a distance from its distal end (92). Here the term "bridging rib" refers to a link of which the both ends are respectively pivoted to two ribs which are otherwise disconnected with each other mechanically.

[0003] Such umbrella has a disadvantage that the collapsed structure is unsatisfactorily long, since the collapsed length depends on the length of the second main rib (9). As a result, the umbrella cannot be folded up and shortened to a length short enough to be received in a handbag or the like. If the umbrella is shaved a fraction to meet this requirement, the rib will have to be shortened, thus the canopy may become too small to provide sufficient shielding from rain drops or shading of sunshine.

[0004] Therefore it is the object of this invention to provide a flat-top umbrella whereby the aforesaid disadvantages are obviated.

[0005] According to this invention, the problem of the aforesaid flat-top umbrella is solved by means of pivoting the most proximal upper rib and the lower rib at a distance from their distal ends.

[0006] Numerous other features and advantages will be apparent when read in connection with the accompanying drawing, in which:

Figure 1 is a graphical representation showing the jointing of the rib member in the open state of an example of an umbrella according to this invention;

Figure 2 shows the folded-up state of the umbrella of Figure 1, with the shaft telescopically shortened;

Figure 3 shows a conventional flat-top umbrella;

Figure 4 shows another embodiment according to this invention;

Figure 5 is an enlarged view of the circled area in Figure 4;

Figure 6 shows the folded-up state of the umbrella in Figure 4.

[0007] Referring to Figure 1, the umbrella also comprises a shaft (8), a fixed pivot ring (81) and a slidable pivot ring (7) with a spring loaded check (82). The inner (most proximal) main rib (3) and the support rib (6) pivot each other at a distance from their distal ends.The distal end of first main rib (3) has two pivotal joints (31) (32) respectively pivoting the proximal ends of two parallel (but very close to each other) middle main ribs (2) (4.), of which the distal ends are respectively pivoted to the two pivotal joints (121) (122) of a pivoter (12), to which the proximal end of the outer main rib (1) (the most distal main rib) is fixed. A bridging rib (5) bridges the distal end of support rib (6) and a pivotal joint (25) on the upper middle main rib (2) at a distance from its proximal end (32). Thus the distal sections of inner main rib (3) and the pivoter (12) define a second parallelogram. Thus when the umbrella is folded up (see Fig. 2, the size of the collapsed structure depends on the length of the outer rib (1), which measures only about one third that of the radial span of the canopy (in contrast to the one half measurement of the conventional flat-top umbrella).

[0008] A modified, equally satisfactory embodiment is seen in Figure 4, in which there are also two parallelograms defined by the framework. However, here the upper middle main rib (2A) is longer than the lower middle main rib (4A), extending beyond its pivotal point (25A) with the bridging rib (5A) and reaching an end pivotal point (32A) with main rib (3). The shorter lower middle main rib (4A) only extends to an end pivotal point (31A) with (5A).

Claims

1. A rib structure for an umbrella comprising a plurality of like sets of ribs extending radially from the shaft of the umbrella, each set comprising a plurality of ribs, in which the proximal end of a first rib is pivotally connected to a fixed point near the tip end of the umbrella, the proximal end of a second rib is pivotally connected to a sliding ring slidably retained on the shaft of the umbrella, and the distal end of a third rib extends to the margin of the canopy of the umbrella, the proximal end of said third rib having two pivotal points, the first and third rib being such that they are always substantially parallel to each other, characterised in that said first and second ribs intersect and are pivotally connected together with each other at a distance from their distal ends; that the proximal end of said third rib has two pivotal points very close to each other, to which the distal ends of a fourth rib and a fifth rib are respectively pivotally connected, at least one of the proximal ends of said fourth and fifth ribs being pivotally connected to the distal end of said first rib, said second, fourth and fifth ribs being such that they are always substantially parallel to each other; and there is a sixth rib, of which the proximal end is pivotally connected to the distal end of said second rib and the distal end is pivotally connected with at least one of said fourth and fifth ribs, said first and sixth ribs being such that they are always substantially parallel to each other.

2. The rib structure according to claim 1, characterized in that said the proximal ends of said fourth and fifth ribs are pivotally connected to the distal end of said first rib, and the distal end of said sixth rib is pivotally connected with only one of said fourth and fifth ribs, said fourth and fifth ribs being substantially equal in length.

3. The rib structure according to claim 1, characterised by that the proximal ends said fourth and fifth ribs are respectively pivotally connected to the distal ends of said first and sixth ribs, said fourth rib being longer than said fifth rib and is pivotally connected with said sixth ribs where said fourth and sixth ribs intersect with each other.

Drawing