# US 8,783,275 B2 · Compact folding umbrella with hybrid ribs to resist damage due to inversion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,783,275 B2 - Document ID: US8783275B2 - Status: Granted - Kind: B2 - Application number: 13/749,973 - Filed: 2013-01-25 - Published: 2013-09-05 - Granted: 2014-07-22 - Earliest claimed: 2010-03-31 - Applicants: Kahng J. David - Inventors: Kahng J. David - Web page: https://patentgrep.com/patent/US8783275B2 ## CPC - A45B 19/10: with collapsible ribs - A45B 25/22: Devices for increasing the resistance of umbrellas to wind - A45B: WALKING STICKS (walking aids, e.g. sticks, for blind persons A61H3/06); UMBRELLAS; LADIES' OR LIKE FANS (cane or umbrella stands or holders A47G25/12) ## Abstract A folding umbrella and particularly one having multiple folds, includes a support frame incorporating a hybrid rib typically located intermediate a main rib and a rear or outermost rib. The hybrid rib is formed of multiple sections composed of first and second materials which respectively provide the desired structural strength to reduce inversions of the umbrella to an acceptable minimum and provide the hybrid rib with the desired resiliency and flexibility to return the hybrid rib to its original, unstressed shape and thereby prevent permanent damage to the hybrid rib as well as adjoining frame elements of the umbrella. The thicknesses of the multiple sections and the relative sizes of the sections also significantly contribute to the capability of the hybrid rib to achieve the desired objectives of a compact, small, folding umbrella of reduced weight, and the ability to prevent permanent damage to the frame due to inversion. ## Claims ### Claim 1 A frame (10) for a compact, folding umbrella having multiple folds, comprising in combination: a main shaft (12) having a handle (21b) at a lower end; a collar (16) slidably mounted on said main shaft (12); a cap (14) mounted on an upper end of the main shaft (12); a main stretcher (18) having one end pivotally coupled to said cap (14); a support stretcher (20) having one end (20a) pivotally coupled to said collar (16) and another end (20b) pivotally coupled to an intermediate portion of the main stretcher (18); a rear rib (26); a hybrid rib (22) pivotally coupled to another end of said main stretcher 18 and to an inner end of said rear rib (26); said hybrid rib (22) being formed of first, second and third sections (22-1, 22-3, 22-2); a flexible member (28) having one end (28a) coupled to the main stretcher (18) and another end coupled to the rear rib (26) for extending the rear rib (26) when the frame (10) is opened; said first and second end sections (22-1 and 22-3) having outer ends configured to define the ends pivotally coupled to the main stretcher (18) and rear rib (26); said third section (22-2) being positioned between said first and second sections (22-1 and 22-3) and having first and second ends that are respectively joined to an inner end of said first section (22-1) and an inner end of said second section (22-3), to render the hybrid rib (22) straight and linear; the first and second sections (22-1 and 22-3) being U-shaped in cross section and formed of aluminum; the first section (22-1) having an aluminum wall thickness (th) in a range of 0.5 mm to less than 0.8 mm and having a selected length, and the third section (22-2) being formed of fiberglass and having a length less than the length of the first section (22-1) wherein the third section absorbs forces occurring during multiple inversions of the folding umbrella, allowing the folding umbrella to be repeatably restored to an original undamaged condition from an inverted condition by sliding the collar (16) down the main shaft (12) toward the handle (12b); whereby, the hybrid rib (22) protects the combination from permanent damage by absorbing forces experienced due to inversions of the folding umbrella. ### Claim 2 (depends on 1) The frame of claim 1 wherein the thickness (TH) of the third section (22-2) is 50% to 75% of the width (W) of the third section (22-2). ### Claim 3 (depends on 2) The frame of claim 2 wherein the thickness (TH) of the third section (22-2) is 60% to 70% of the width (W) of the third section (22-2). ### Claim 4 (depends on 1) The frame of claim 1 wherein the length of the third section (22-2) relative to the first section (22-1) is in a range of 40% to 85% of the length of the first section (22-1). ### Claim 5 (depends on 4) The frame of claim 4 wherein the length of the third section (22-2) is 40% of the length of the first section (22-1). ### Claim 6 (depends on 1) The frame of claim 1 wherein the third section (22-2) is formed of fiberglass and has a rectangular, cross-sectional shape, a perimeter of the third section (22-2) being defined by a pair of parallel sides (22-w) and a pair of parallel edges (22-e), said edges (22-e) having a thickness (TH) less than a width (W) of the sides of the third section; the third section (22-2) being oriented so that the third section (22-2) experiences greater bending when a force of a given magnitude is applied to one of the sides than a bending of the third section when a force of like magnitude is applied to one of said edges, enabling the rib (22) to resume a unstressed linear state without distortion when said force is removed; the first and second ends of the third section (22-2) extending into the inner ends of the first (22-1) and second (22-3) sections, respectively. ### Claim 7 (depends on 1) The frame of claim 1 wherein the wall thickness (th) is in a range of 0.5 mm to 0.7 mm. ### Claim 8 (depends on 1) The frame of claim 1 wherein the wall thickness (th) is in a range of 0.6 mm to 0.7 mm. ### Claim 9 (depends on 1) The frame of claim 1 wherein the wall thickness is 0.7 mm. ### Claim 10 (depends on 1) The frame of claim 1 wherein the wall thickness is 0.6 mm. ### Claim 11 (depends on 1) The frame of claim 1 wherein the wall thickness is 0.5 mm.