Strutless type umbrella

Abstract

Umbrella rib assembly is presented for use in strutless umbrella having a pin and slide canopy conducting mechanism. The rib assembly comprises a longitudinal rib body having a pivot member at its end, and a rib lever extending from the rib body, and being characterized in that the pivot member and the rib body together with the rib lever present a single piece of material, and the pivot member is located in a corner formed between the rib body and the rib lever.

Description

FIELD OF THE INVENTION[0001]This invention is generally in the field of umbrellas, and relates to s strutless-type umbrella.BACKGROUND OF THE INVENTION[0002]Up to date most if not all umbrellas in the market make use of struts extending between the umbrella stick and the canopy for supporting the canopy ribs at some mid portion thereof. Strutless umbrellas (i.e. having a canopy without stretchers extending between the umbrella post and the ribs) are known in the patent literature, and are described for example in the following patents:[0003]U.S. Pat. No. 5,711,234 discloses a strutless umbrella which includes a central post, either an inner plunger or tube, a canopy assembly including ribs pivotally mounted on the upper end of the central post. Links connect the ribs to the inner plunger or tube. Movement of one of the ribs moves the plunger or tube which moves the remaining ribs. A latch pin holds the umbrella in the open position.[0004]U.S. Pat. No. 5,638,846 discloses an umbrella...

AI Technical Summary

Benefits of technology

[0010]Reduction in the weight of umbrellas, whether or not they are strutless, will also be welcomed by users. The motivation of umbrella designers to reduce the number and weight of umbrella components is therefore acknowledged. Moreover, this should be done without significantly affecting umbrella's strength, durability, and fitness to comply with intense winds.

[0014]Referring to AT 231634, it is to be noted that the minimum diameter of the folded umbrella is the distance measured between the bent corners of two opposite ribs. This minimal diameter would be about 130% of the crown's diameter. Also, the diameter of the actuation rod together with twice the wall thickness of the grooved plate adds to the lengths of two opposite rib extensions from pivot pin to sphere in defining a minimum possible diameter of the crown. It is further to be noted that the contact area between the plate and the ends of the ribs is pointed, since it is the area between a flat surface of the plate tangential to the sphere. As the acting forces are high, pressure between the surfaces becomes extremely high, which may result in accelerated wearing of both the surface of the plate and the spheres. The diameter of the pivot pin is about only 5% of the lever arm (i.e. the distance from the pivot pin to the sphere). Accordingly, the contact area between the pin and the apertures in which it pivots is very small, and thus the pressure between the contacting surfaces of the pin and the apertures will be high, causing accelerated wearing of the pivot connection.

[0015]The present invention solves the above problems by providing a novel configuration of a rib assembly for strutless umbrella (having a pin and slide canopy conducting mechanism), enabling reduction of the umbrella diameter when in its folded state. This is achieved by providing at least one of the following configurations of the rib assembly comprised of a longitudinal rib body having a pivot member at its end, and a rib lever extending from the rib body: (i) the pivot member is located in a corner formed between the rib body and the rib lever; (ii) the rib lever extends from the rib body in an angle of between 110-160 degrees; (iii) the rib lever has a goggles shaped profile; (iv) the height of the rib body is similar to the max distance between the round surfaces of the rib lever; (v) the max thickness of the rib lever is certainly smaller comparing to the max distance between the rounded surfaces of the rib lever; (vi) the round sliding surfaces of the rib lever are substantially planner in a direction parallel to a pivoting axis of the rib; (vii) the pivot member is formed as a pair of lateral protrusions protruding from the pivot point to form a pivoting axis from the same piece of material of the rib; (viii) the distance between the pivot member and the free end of the rib lever does not exceed about 200% of the max distance between the round surfaces of the rib lever; (ix) the free end of the rib lever has a coin shape tapering towards the free end; (x) the free end of the rib lever has a coin shape truncated at the free end; (xi) the pivot member has a diameter greater than about 20% of the rib lever's length.

[0023]Preferably, the free ends of the rib levers are located between upper and lower restricting members forming a slide in which rounded upper and lower surface of the rib levers can slide when the rib assemblies are forced to pivot upon a linear movement of the slide in line with the longitudinal axis of the umbrella. The upper and lower restricting members are secured to each other and to the upper edge of a rod passing through the stick, by means of a screw. Preferably, a distance between the round surfaces of the rib lever is greater than a distance between slides which serve mirroring ribs. The rib assemblies preferably have gradually reduced thickness towards their distal ends resulting in flexibility of the ends of the rib assemblies useful for obtaining mushroom shaped canopy.

Problems solved by technology

One problem that should be addressed when designing a strutless umbrella is the dimensions of the umbrella in its folded state, which should preferably not significantly exceed those of the conventional umbrellas (with struts).

It appears that it is not simple to comply with this requirement.

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